ACTIVITY
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[1] Characterization of glycoproteins of viruses causing hemorrhagic fever with renal syndrome...

[DOC3743] Viruses causing hemorrhagic fever with renal syndrome (HFRS) encode two glycoproteins, G1 and G2. For determination of the biological functions of these glycoproteins, we isolated 15 hybridomas secreting monoclonal antibodies directed against the glycoproteins of the B-1 and Hantaan viruses (HV). From results of neutralizing and hemagglutination inhibition (HI) tests, and studies on the antigenic reactivities of the antibodies with other HV-related viruses by immunofluorescence, we classified these hybridoma clones into two groups producing antibodies to the G1 proteins of the B-1 virus, six groups producing antibodies to G2 proteins of the B-1 virus, and four groups producing antibodies to the G2 protein of HV. Of the antibodies to G2 produced by 12 clones, groups A and B had high HI activity with HV-related virus cross-reactivity and moderate neutralizing activity, group C had moderate HI activity with virus specificity but low neutralizing activity, group G had high neutralizing activity and low HI activity, and five other groups had little or no HI or neutralizing activity. Group A reacting with G1 protein had low level of both neutralizing and HI activity, while group B had no HI activity. One clone of monoclonal antibody had high neutralizing activity and no HI activity, but it did not react with either polypeptide by immunoprecipitation followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis or by the immunoblotting method. These data suggest that both glycoproteins are the targets of neutralizing antibodies. Furthermore, the results indicate that the antigenic determinants with hemagglutination activity are mainly on the G2 protein, and that the domains related to neutralizing activity and to HI activity are separate.

[2] Lipolytic activity of ricin from Ricinus sanguineus and Ricinus communis on neutral lipids...

[DOC15965] The present study was carried out with a view of determining ricin lipolytic activity on neutral lipids in emulsion and in a membrane-like model. Using 2,3-dimercapto-1-propanol tributyrate (BAL-TC(4)) as substrate, the lipolytic activity of ricin was found to be proportional to ricin and substrate concentrations, with an apparent K(m) (K(m,app)) of 2.4 mM, a k(cat) of 200 min(-1) and a specific activity of 1.0 unit/mg of protein. This work was extended to p-nitrophenyl (pNP) fatty acid esters containing two to twelve carbon atoms. Maximum lipolytic activity was registered on pNP decanoate (pNPC(10)), with a K(m,app) of 3.5 mM, a k(cat) of 173 min(-1) and a specific activity of 3.5 units/mg of protein. Ricin lipolytic activity is pH and galactose dependent, with a maximum at pH 7.0 in the presence of 0.2 M galactose. Using the monolayer technique with dicaprin as substrate, ricin showed a lipolytic activity proportional to the ricin concentration at 20 mN/m, which is dependent on the surface pressure of the lipid monolayer and is detectable up to 30 mN/m, a surface pressure that is of the same order of magnitude as that of natural cell membranes. The methods based on pNPC(10) and BAL-TC(4) hydrolysis are simple and reproducible; thus they can be used for routine studies of ricin lipolytic activity. Ricin from Ricinus communis and R. sanguineus were treated with diethyl p-nitrophenylphosphate, an irreversible serine esterase inhibitor, and their lipolytic activities on BAL-TC(4) and pNPC(10), and cytotoxic activity, were concurrently recorded. A reduction in lipolytic activity was accompanied by a decrease in cytotoxicity on Caco2 cells. These data support the idea that the lipolytic activity associated with ricin is relevant to a lipase whose activity is pH and galactose dependent, sensitive to diethyl p-nitrophenylphosphate, and that a lipolytic step may be involved in the process of cell poisoning by ricin. Both colorimetric tests used in this study are sensitive enough to be helpful in the detection of possible lipolytic activities associated with other cytotoxins or lectins.

[3] Cutaneous protease activity in the mouse ear vesicant model.

[DOC15715] Tissue homogenates from mouse ear skin exposed to sulfur mustard (HD, which is a military designation and probably originated from a World War I slang term 'Hun Stuff') were assayed for serine and cysteine protease activities. Enzyme activity was measured using synthetic chromogenic thioester and fluorogenic 7-amino-4-methylcoumarin (AMC) substrates. The tissue samples were obtained from animals (n = 6) at 3, 6, 12 and 24 h post-exposure from the right ear (HD exposed), whereas control samples were obtained from the left ear (treated only with dichloromethane vehicle). The samples of naive control (left and right ear) were obtained from animals that received no HD treatment (n = 3). Elastase activity was assayed with t-butyloxycarbonyl-Ala-Ala-Ala-thiobenzylester, tryptase activity with benzyloxycarbonyl-Arg-AMC and benzyloxycarbonyl-Arg-thiobenzylester, chymase activity with succinylAla-Ala-Pro-Phe-thiobenzylester and succinyl-Ala-Ala-Pro-Phe-AMC, cathepsin B activity with benzyloxycarbonyl-Arg-Arg-AMC, cathepsin H activity with Arg-AMC and calpain activity with succinyl-Leu-Tyr-AMC. The HD-exposed skin homogenates obtained at 12 and 24 h post-exposure had higher elastase activity (670% and 1900% increase) than control samples. For tryptase and calpain activities, only HD-exposed skin homogenates at 24h post-exposure showed higher activities (220% and 170% increase) when compared to the control. No differences from control were observed for HD-exposed skin obtained at 3 and 6 h post-exposure for elastase, tryptase and calpain activities. Generally, both unexposed and HD-exposed skin had distinct cathepsin B and cathepsin H enzyme activities and small chymase activity. Enzymatic assays were also performed for other serine, cysteine and metalloproteases. These data document that proteases are involved in HD skin injury and continued assessment of proteolytic activity should be useful for identifying effective antiproteases with therapeutic use in reducing or eliminating tissue injury caused by HD cutaneous exposure.
Related to Topic 47: ACTIVITY,COMPOUNDS,POTENT,INHIBITORS,ACTIVE,DERIVATIVES (0.359)

[1] Structure-activity relationship of a series of phenylureas linked to 4-phenylimidazole. No...

[DOC10254] In our continuing search to find systemically bioavailable ACAT (acyl-CoA:cholesterol O-acyltransferase) inhibitors with more potent antiatherosclerotic effect than N-[2-(dimethylamino)-6-[3-(5-methyl-4-phenyl-1H-imidazol-1-yl)propoxy] phenyl]-N'-pentylurea (3), a series of phenylureas linked to 4-phenylimidazole were synthesized and evaluated for in vitro inhibitory activity toward both aortic and intestinal ACATs, and for in vivo hypocholesterolemic activity. The structure-activity relationships (SARs) were studied by strategic modification of five regions in the molecule of 3, i.e., by introducing functional groups or exchanging carbon atoms for heteroatoms. The SAR studies allowed us to select optimum substituents in the five regions, as follows. (1) Dimethylamino was convertible into nitro, methyl, ethyl, propyl, isopropyl, and chloro. On the basis of preliminary pharmacokinetic studies, the methyl group in the ortho-position of the phenylurea was selected. (2) Butyl, pentyl, isopentyl, and neopentyl were better substituents in the urea moiety. (3) Propoxy was the optimal moiety in the bridging portion. (4) Proton, methyl, ethyl, isopropyl, hydroxymethyl, and chloro were better substituents at the 5-position of the imidazole moiety. (5) An unsubstituted phenyl ring was selected as the phenyl group of phenylimidazole. The subsequent comparison studies of compounds containing various combinations of the optimum substituents in each region resulted in the selection of two compounds (67, 68) for further pharmacological and toxicological testing. These compounds were orally bioavailable, and possessed potent in vitro aortic ACAT inhibitory activity (IC50 = 0.16 and 0.012 microM, respectively) and in vivo cholesterol lowering effect (46% and 52% at 1 mg/kg po, respectively). In particular, 68 was 10-fold more potent in the in vitro aortic ACAT assay and 5-fold more potent with respect to hypocholesterolemic activity in vivo than 3.

[2] Biological activity of 4-hydroxyisophthalic acid derivatives. II. Anilides with antimicrob...

[DOC7346] A series of 1,3 -bis-anilides of 4-hydroxyisophthalic acid was prepared and tested for antibacterial and antifungal activity. The prepared compounds (I-XVIII), of general structure (A), (Formula: see text) where Xn = H (I); 2-F (II); 3-F (III); 4-F (IV); 2-Cl (V); 3-Cl (VI); 4-Cl (VII); 2-Br (VIII); 3-Br (IX); 4-Br (X); 2-J (XI); 3-J (XII); 4-J (XIII); 2,5-Cl2 (XIV); 2,4-Br2 (XV); 2,3,4-Cl3 (XVI), 2,4,5-Cl3 (XVII); 2,4,6-Cl3 (XVIII), were investigated for the purpose of determining the effect of halogen-substitution on the aniline rings of (A). All of these compounds were prepared in satisfactory hield by reaction of 4-hydroxyisophthalic acid with the appropriate aromatic amine at 175 degrees for 3 hours. The 1,3-bis-anilides prepared in this investigation were screened for antimicrobial activity by a disk-diffusion assay (Kirby-Bauer modified). The organisms used were laboratory cultures of S. aureus, B. subtilis, B. anthracis, M. paratuberculosis 607, E. coli Bb, S. typhi, S. typhimurium, S. paratyphi B, Pr. vulgaris, Kl. pneumoniae, Ps. aeruginosa, C. albicans, and A. niger. The results of this investigation indicated that most of the 1,3-bis-(halogen-anilides) of 4-hydroxyisophthalic acid had little or no antifungal activity "in vitro", while showed significant activity against Gram+ and Gram- bacteria. Some fluoro-derivatives showed inhibitory activity especially toward S. aureus and M. paratuberculosis. Iodo-derivatives showed broad-spectrum "in vitro" antimicrobial activity, and had some antifungal activity.

[3] Synthesis and structure-activity relationships of novel 7-substituted 1,4-dihydro-4-oxo-1-...

[DOC22229] We have previously reported that a series of 7-substituted 6-fluoro-1,4-dihydro-4-oxo-1-(2-thiazolyl)-1,8-naphthyridine-3-carboxylic acids possess moderate cytotoxic activity. In a further attempt to find clinically useful antitumor agents, we investigated the structure-activity relationships (SARs) of a new series of compounds obtained by changing the C-6 position of the fluorine atom in addition to the C-5 and C-7 positions and evaluating their cytotoxic activity against several murine and human tumor cell lines. Our results showed that the 6-unsubstituted 1,8-naphthyridine structure had the most potent cytotoxic activity against murine P388 leukemia twice that of the 6-fluoro analogue. In addition, introduction of an amino group at the C-5 position did not have any substantial effect on the cytotoxic activity, while both the 5-chloro and 5-trifluoromethyl groups decreased the cytotoxic activity by 5- to 10-fold. Moreover, aminopyrrolidine derivatives at the C-7 position showed more potent cytotoxic activity than other amines or carbon derivatives. Among the 7-(3-aminopyrrolidinyl) derivatives, the trans-3-methoxy-4-methylaminopyrrolidinyl derivative (27l) was determined to have potent cytotoxic activity in both in vitro and in vivo assays and high water solubility. Finally, the (S,S)-isomer (AG-7352, 3) of 27l, with a cytotoxic activity against human tumor cell lines more potent than that of etoposide, was selected for further development.
Related to Topic 23: EFFECT,DEPENDENT,INHIBITION,ACTIVITY,INDUCED,INHIBITED (0.143)

[1] Effects of sodium and potassium channel blockers on hyperinflation-induced slowly adapting...

[DOC14812] The excitatory responses of slowly adapting pulmonary stretch receptor (SAR) activity to hyperinflation (inflation volume = 3 tidal volumes) for approximately 10 respiratory cycles were examined before and after administration of flecainide, a Na+ channel blocker, and 4-aminoprydine (4-AP), a K+ channel blocker. The experiments were performed in anesthetized, artificially ventilated rats after unilateral vagotomy. During hyperinflation the SARs increased their activity during inflation and decreased their discharge during deflation. The magnitude of increased SAR activity during inflation became more prominent as compared to that of decreased receptor activity during deflation. Flecainide treatment (6 mg/kg) that was sufficient to block veratridine (50 microg/kg)-induced SAR stimulation did not significantly alter the excitatory response of SAR activity to hyperinflation. Subsequent administration of 3 mg/kg flecainide (a total dose, 9 mg/kg) resulted in a greater inhibition of hyperinflation-induced SAR stimulation. Although administration of 4-AP (2 mg/kg) usually stimulated SAR activity, particularly in the deflation phase, in the control ventilation, 4-AP treatment had no significant effect on hyperinflation-induced SAR stimulation. These results suggest that the excitatory effect of hyperinflation on SAR activity may not be involved in the activation of either flecainide-sensitive Na+ channels or 4-AP-sensitive K+ channels.

[2] [Activity of erythrocyte membrane Na,K-ATPase in rats with experimental botulism]

[DOC6916] The effect of type C botulinum toxin on Na, K, Mg-ATPase activities of erythrocyte membranes of white rats was studied in experiments in vivo and in vitro. The activity of Na, K, Mg-ATPase was found to be markedly inhibited in the preclinical period of poisoning, 2 hours after intraperitoneal injection of the toxin. In this case Mg-ATPase activity noticeably increased. In the presence of the development of a grave paralytic syndrome one day after intraperitoneal injection of the toxin, the activity of Na, K-ATPase of the erythrocyte membrane remained decreased as was the case in the preclinical period of poisoning, whereas the activity of Mg-ATPase returned to normal. The experiments in vitro with preincubation of erythrocyte membranes with botulinum toxin in the concentrations corresponding to the mean calculated ones in the experiments in vivo demonstrated inhibition of Na, K-ATPase. The magnitude of Mg-ATPase activity remained virtually unchanged in all the modifications of the experiments with boiled and native botulinum toxin. The in-vivo experiments with intraperitoneal injection of glutathione and unithiol to the pretreated animals attested to normalization of Na, K-ATPase in the preclinical period of poisoning, with this normalization being brought about by unithiol. In the in-vitro experiments with addition of unithiol or glutathione into the incubation medium, each of the donators of sulphhydryl groups prevented Na, K-ATPase inhibition with botulinum toxin.

[3] Inhibitory mechanism of slowly adapting pulmonary stretch receptors after release from hyp...

[DOC14702] In anesthetized, artificially ventilated rabbits with vagus nerve section, release from 10 consecutive hyperinflations (inflation volume = 3 tidal volume) caused an inhibition of the slowly adapting pulmonary stretch receptor (SAR) activity for 16-22 sec. Intravenous administration of tetraethylammonium (TEA, 10 and 20 mg/kg), a K+ channel blocker, did not significantly alter either basal SAR discharge or tracheal pressure (PT). Although TEA treatment at 10.0 mg/kg had no significant effect on the magnitude and duration of inhibited SAR activity seen after release from hyperinflation, the increasing dose of this K+ channel blocker up to 20 mg/kg inhibited these effects of the receptor activity but this inhibition was small. The Na+ -K+ ATPase inhibitor ouabain (5 and 10 microg/kg) that had no significant effect on SAR activity and P(T) in the control abolished or attenuated the inhibitory action of SARs in a dose-dependent manner. Furthermore, the changes in dynamic lung compliance (Cdyn) and P(T) in response to post-hyperinflation were not significantly influenced by pretreatment with either TEA or ouabain. These results suggest that the inhibitory action of receptors seen during post-hyperinflation corresponded with the induction of slow afterhyperpolarization (sAHP), and that the mechanism of generating the sAHP of SARs is mainly mediated by the activation of Na+ -K+ pump activity.
Related to Topic 5: SOMAN,SARIN,ACHE,ACTIVITY,ACETYLCHOLINESTERASE,POISONING (0.127)

[1] Protective effect of equine butyrylcholinesterase in inhalation intoxication of rats with ...

[DOC22998] The effect of pretreatment with equine butyrylcholinesterase (EqBuChE) on cholinesterase inhibition in the blood and brain of rats following inhalation intoxication with low concentrations (1.25 microg/L for 60 min) of sarin were studied. Animals pretreated with different doses of equine butyrylcholinesterase showed significant increases in plasma butyrylcholinesterase activity. However, erythrocyte acetylcholinesterase activity was unchanged. The decrease in acetylcholinesterase and butyrylcholinesterase activity after inhalation intoxication was dependent on the dose of equine butyrylcholinesterase used for pretreatment and was always greater for erythrocyte acetylcholinesterase. Acetylcholinesterase activity in different brain regions was unchanged following pretreatment with equine butyrylcholinesterase. After inhalation exposure to sarin, acetylcholinesterase activity was diminished markedly in the pontomedullar area (51.5% of normal activity) and frontal cortex (72.0% of normal activity), and slightly in basal ganglia (91.4% of normal activity). Plasma levels of sarin were determined using fluoride-induced reactivation of inhibited enzyme. As expected, the amounts of sarin in plasma were almost identical in rats pretreated with EqBuChE as well as in untreated rats. In pretreated animals, the plasma amount of sarin did not depend on the dose of equine butyrylcholinesterase used for pretreatment. Our results demonstrate that equine butyrylcholinesterase pretreatment can be considered as an effective prophylaxis against nerve agents (at least with sarin) and seems to be an alternative or superior to prophylaxis provided by reversible cholinesterase inhibitors.

[2] Role of aliesterase in organophosphate poisoning.

[DOC7545] Various doses of CBDP (2-(2- methylphenoxy )-4H-1,3,2- benzodioxaphosphorin -2-oxide), a metabolite of tri-o-cresyl phosphate, increased dramatically the acute toxicity of soman ( pinacolyl methylphosphonofluoridate ) in mice. CBDP (5 mg/kg; iv) reduced the soman LD50 value from 136 micrograms/kg in control to 6.95 micrograms/kg. The potentiation of soman toxicity following CBDP pretreatment appeared to be due primarily to inhibition of plasma aliesterase activity. Inhibition of liver aliesterase was not of primary importance in the potentiation of soman toxicity following CBDP pretreatment. In addition pretreatment with ISO-OMPA ( tetraisopropyl pyrophosphoramide ), a selective inhibitor of pseudocholinesterase, had no effect on the acute toxicity of soman. Similarly pretreatment of mice with pyridostigmine, a quaternary carbamate anticholinesterase which does not inhibit aliesterase , resulted in marked inhibition of diaphragm, plasma, and brain acetylcholinesterase had no effect on the acute toxicity of soman. Plasma aliesterase may be a depot for soman poisoning. The acute toxicity of soman by the ip, sc, and iv routes of administration was reduced following pretreatment of mice with phenobarbital (100 mg/kg) for 4 days. The reduced toxicity of soman following phenobarbital pretreatment was due to induction of liver aliesterase activity which subsequently resulted in an increase in plasma aliesterase activity. Thus more soman was probably bound to plasma aliesterase activity resulting in a reduction in acute toxicity of soman. Conversely pretreatment of mice with pentobarbital (70 mg/kg; ip) increased the toxicity of soman. This was probably the result of inhibition of plasma aliesterase by pentobarbital pretreatment combined with the central respiratory depression following pentobarbital administration. Following pentobarbital pretreatment soman inhibition of brain acetylcholinesterase was increased suggesting that plasma aliesterase inhibition alters the distribution of free soman in vivo. In summary, in mice plasma aliesterase appears to be an extremely important detoxification route for soman in vivo.

[3] Evaluation of several oximes as reactivators of unaged soman-inhibited whole blood acetylc...

[DOC3491] The antidotal benefit of oximes against organophosphorus (OP) anticholinesterase intoxication is thought to be due to reactivation of the OP-inhibited acetylcholinesterase (AChE). This study was conducted to determine whether the antidotal efficacy against soman by the oximes 2-hydroxyiminomethyl-3-methyl-1-[2-(3-methyl-3-nitrobutyl oxymethyl)]-imidazolium Cl (ICD 467) and 1,1'-methylenebis[4-(hydroxyiminomethyl) pyridinium] di-Cl (MMB-4) resulted, in part, from reactivation of the inhibited AChE. These oximes were tested in parallel with pralidoxime Cl (2-PAM) and 1-(2-hydroxyiminomethyl-1-pyridinio-3-(4-carbamoyl-1-pyridinio+ ++)-2-oxapropane di-Cl (HI-6). Rabbits were atropinized (8 mg/kg, i.m.) and intoxicated with soman (13 micrograms/kg, i.v.; 1.2 x LD50) 5 min later. Three minutes after soman, animals were treated with oxime (50, 100 or 150 mumol/kg, i.m.). Whole blood was collected from a catheter in the central artery of the ear just before soman, at 2 min after soman and at 2, 5, 10, 15, 30, and 60 min after oxime or vehicle for determination of AChE activity. Shortly thereafter, animals were anesthetized and exsanguinated with immediate flushing using heparinized saline. AChE activity was also determined on the cortex, medulla-pons and diaphragm to assess central and peripheral reactivation. Treatment with HI-6 or MMB-4 (50 mumol/kg, i.m.) resulted in significant (P less than 0.05) reactivation of soman-inhibited whole blood AChE and diaphragm cholinesterase (ChE), but not brain AChE. In contrast, 2-PAM was completely ineffective in reactivating soman-inhibited AChE. HI-6 was significantly better than MMB-4 in reactivating blood AChE; they were essentially equal against soman-inhibited diaphragm ChE. Three animals exposed to soman and treated with ICD 467 died within 15 min. When animals not exposed to soman were treated with ICD 467 (25 mumol/kg, i.m.), whole blood AChE activity was depressed by 60% within 5-10 min after treatment. Furthermore, ICD 467 failed to reactivate significantly unaged soman-inhibited erythrocyte AChE, in vitro. These observations indicate that ICD 467 would be contraindicated as a therapy for anti-ChE intoxication and that the efficacy of HI-6 or MMB-4 can be explained, in part, by reactivation of soman-inhibited AChE.
Related to Topic 24: RICIN,CHAIN,PROTEIN,SYNTHESIS,ACTIVITY,RIBOSOMES (0.096)

[1] Correlation between the activities of five ribosome-inactivating proteins in depurination ...

[DOC9448] The rRNA depurination activities of five ribosome-inactivating proteins (RIPs) were compared in vitro using yeast and tobacco leaf ribosomes as substrates. All of the RIPs (pokeweed antiviral protein (PAP), dianthin 32, tritin, barley RIP and ricin A-chain) were active on yeast ribosomes. PAP and dianthin 32 were highly active and ricin A-chain weakly active on tobacco ribosomes, whereas tritin and barley RIP were inactive. PAP and dianthin 32 were highly effective in inhibiting the formation of local lesions caused by tobacco mosaic virus (TMV) on tobacco leaves, whereas tritin, barley RIP and ricin A-chain were ineffective. The apparent anomaly between the in vitro rRNA depurination activity, but lack of antiviral activity of ricin A-chain was further investigated by assaying for rRNA depurination in situ following the topical application of the RIP to leaves. No activity was detected, a finding consistent with the apparent lack of antiviral activity of this RIP. Thus, it is concluded that there is a positive correlation between RIP-catalysed depurination of tobacco ribosomes and antiviral activity which gives strong support to the hypothesis that the antiviral activity of RIPs works through ribosome inactivation.

[2] Non-specific deadenylation and deguanylation of naked RNA catalyzed by ricin under acidic ...

[DOC15662] Ricin A-chain catalyzes the hydrolysis of the N-glycosidic bond of a conserved adenosine residue at position 4324 in the sarcin/ricin domain of 28S RNA of rat ribosome. The GAGA tetraloop closed by C-G pairs is required for recognition of the cleavage site on 28S ribosomal RNA by ricin A-chain. In this study, ricin A-chain (reduced ricin) exhibits specific depurination on a synthetic oligoribonucleotide (named SRD RNA) mimic of the sarcin/ricin domain of rat 28S ribosomal RNA under neutral and weak acidic conditions. Furthermore, the activity of intact ricin is also similar to that of ricin A-chain. However, under more acidic conditions, both enzymes lose their site specificity. The alteration in specificity of depurination is not dependent on the GAGA tetraloop of SRD RNA. A higher concentration of KCl inhibits the non-specific N-glycosidase activity much more than the specific activity of ricin A-chain. In addition, characterization of depurination sites by RNA sequencing reveals that under acidic conditions ricin A-chain can release not only adenines, but also guanines from SRD RNA or 5S ribosomal RNA. This is the first report of the non-specific deadenylation and deguanylation activity of ricin A-chain to the naked RNA under acidic conditions.

[3] Shiga toxin, Shiga-like toxin II variant, and ricin are all single-site RNA N-glycosidases...

[DOC4180] Ricin, Shiga toxin, and Shiga-like toxin II (SLT-II, Vero toxin 2) exhibit an RNA N-glycosidase activity which specifically removes a single base near the 3' end of 28 S rRNA in isolated rat liver ribosomes and deproteinized 28 S rRNA (Endo Y., Mitsui, K., Motizuki, M., & Tsurugi, K. (1987) J. Biol. Chem. 262, 5908-5912; Endo Y. & Tsurugi, K. (1987) J. Biol. Chem. 262, 8128-8130, Endo, Y., Tsurugi, K., Yutsudo, T., Takeda, Y., Ogasawara, K. & Igarashi, K. (1988) Eur. J. Biochem. 171, 45-50). These workers identified the single base removed, A-4324, by examining a 28 S rRNA degradation product which was generated by contaminating ribonucleases associated with the ribosomes. To determine whether this N-glycosidase activity applies in living cells, we microinjected ricin into Xenopus oocytes. We also microinjected Shiga toxin and a variant of Shiga-like toxin II (SLT-IIv). All three toxins specifically removed A-3732, located 378 nucleotides from the 3' end of 28 S rRNA. This base is analogous to the site observed in rat 28 S rRNA for ricin, Shiga toxin, and SLT-II. Purified, glycosylated, ricin A chain contains this RNA N-glycosidase activity in oocytes. We also demonstrated that the nonglycosylated A subunit of recombinant ricin exhibits this RNA N-glycosidase activity when injected into Xenopus oocytes. Ricin, Shiga toxin, and SLT-IIv also caused a rapid decline in oocyte protein synthesis for nonsecretory proteins.
Related to Topic 27: SOMAN,BRAIN,INDUCED,RATS,MIN,ACTIVITY (0.063)

[1] Pharmacological modulation of soman-induced seizures.

[DOC10277] Anticholinergics, benzodiazepines and N-methyl-D-aspartate (NMDA) antagonists have been shown to modulate the expression of nerve agent-induced seizures. This study examined whether the anticonvulsant actions of these drugs varied depending on the duration of prior seizure activity. Rats implanted with electrodes to record electroencephalographic (EEG) activity were pretreated with the oxime HI-6 (125 mg/kg, IP) to prolong survival, and then challenged with a convulsant dose of the nerve agent soman (180 micrograms/kg, SC); treatment compounds (scopolamine, diazepam, MK-801, atropine, benactyzine, and trihexyphenidyl) were delivered IV at specific times after seizure onset. Both diazepam and MK-801 displayed a similar profile of activity: At both short or long times after seizure initiation the anticonvulsant efficacy of each drug remained the same. Diazepam, and especially MK-801, enhanced the lethal actions of soman by potentiating the respiratory depressant effects of the agent; scopolamine given prior to diazepam or MK-801 protected against the respiratory depression. Scopolamine and atropine showed a dose- and time-dependent effectiveness; the longer the seizure progressed the higher the dose of drug required to terminate the seizure, with eventual loss of anticonvulsant activity if the seizure had progressed for 40 min. In contrast, benactyzine and trihexyphenidyl showed a third profile of activity: There was a smaller increase in drug dosage required for anticonvulsant activity as seizure duration increased, and both drugs could terminate seizures that had progressed for 40 min. The early anticonvulsant action of anticholinergics is interpreted as a specific effect that blocks the primary cholinergic excitatory drive that initiates, and first maintains, nerve agent seizures. If allowed to progress, the seizure activity itself recruits excitatory neurotransmitter systems (i.e., NMDA) that eventually maintain the seizure independent of the initial cholinergic drive. This is indicated by the eventual ineffectiveness of scopolamine and atropine as the duration of the seizure progresses. Diazepam and MK-801 appear to act to moderate nerve agent seizures by enhancing inhibitory activity (diazepam) or dampening the secondarily activated noncholinergic excitatory system (MK-801). Benactyzine and trihexyphenidyl represent compounds that possibly have both anticholinergic and NMDA antagonistic properties.

[2] Effects of anticholinergic-antiparkinsonian drugs on striatal neurotransmitter levels of r...

[DOC9527] Antimuscarinic drugs possessing antiparkinson activity that were effective in preventing convulsions induced by the organophosphorus cholinesterase (ChE) inhibitor soman were studied for their effects on spinal cord ChE activity and striatal levels of acetylcholine (ACh) and catecholamines in soman-intoxicated rats. Either biperiden (BPR) or trihexyphenidyl (THP) was administered to rats at an anticonvulsant dose (0.125 mg/kg, IM) in the presence or absence of soman (100 micrograms/kg, SC). The time course (up to 2 h) for ChE activity and levels of ACh and catecholamines were measured after soman, BPR, THP, soman and BPR, or soman and THP treatment. Soman rapidly inhibited ChE activity (65-75%; 15-120 min) and increased ACh levels (35%; at 30 min). It did not affect norepinephrine or dopamine (DA), but elevated at later time points (60-120 min) levels of the DA metabolites, 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA), thus indicating increased DA turnover. BPR and THP alone reduced striatal ACh level from control, but did not affect any other neurochemical parameters studied. THP and BPR each reversed the effects of soman on DOPAC and HVA levels, but neither affected ChE activity nor ACh level induced by soman. Thus, our findings suggest that the anticonvulsant effects of BPR and THP in soman poisoning may be attributed to their earlier reported muscarinic receptor blocking properties.

[3] Differential Neuroprotective Effects of the NMDA Receptor-Associated Glycine Site Partial ...

[DOC23378] The status epilepticus (SE) induced in rats by lithium-pilocarpine (Li-pilo) shares many common features with soman-induced SE including a glutamatergic phase that is inhibited by NMDA antagonists. The present study determined whether 1-aminocyclopropanecarboxylic acid (ACPC) or d-cycloserine (DCS), both partial agonists of the strychnine-insensitive glycine site on the NMDA receptor ionophore complex, exerted anticonvulsant or neuroprotectant activity in Li-pilo SE. ACPC or DCS were administered either immediately following pilocarpine (exposure treatment) or 5min after the onset of SE as determined by ECoG activity. SE was allowed to proceed for 3h before termination with propofol. The rats were sacrificed 24h following pilocarpine administration. Neither drug had an effect on the latency to seizure onset or the duration of seizure activity. ACPC administered 5min after SE onset produced significant neuroprotection in cortical regions, amygdala and CA1 of the hippocampus. In contrast, when administered as exposure treatment ACPC enhanced the neural damage in the thalamus and CA3 of the hippocampus suggesting the neuropathology in those regions is mediated by a different subset of NMDA receptors. DCS had no neuroprotectant activity in Li-pilo SE but exacerbated neuronal damage in the thalamus. Neither drug affected the cholinergic convulsions but both had differential effects on neural damage. This suggests that the SE-induced seizure activity and subsequent neuronal damage involve independent mechanisms.
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[1] [Analysis on the trend of severe acute respiratory syndrome epidemic in Inner Mongolian Au...

[DOC19916] OBJECTIVE: To analyse the severe acute respiratory syndrome (SARS) epidemics in Inner Mongolian Autonomous Region and to provide scientific basis for prevention and control strategies against it. METHODS: Data from legal communicable diseases surveillance reporting system was analyzed epidemiologically. RESULTS: The first SARS case was reported in Inner Mongolian Autonomous Region on March 27, 2003. Up to May 20, there were 446 cumulative SARS cases in the whole region (with 287 confirmed cases and 159 suspected cases) and 61 cumulative recovered cases had been discharged from the hospitals (56 confirmed cases and 5 suspected cases). Another 131 cases were excluded the original diagnoses of SARS including 10 confirmed cases and 121 suspected cases. 25 confirmed cases died with a mortality rate of 8.7%. Cumulatively, the number of reported cases were distributed in 30 counties in 9 prefectures. Statistical analysis on time sequence of the occurrence of cases showed that majority (67.7% of the total) of the cases concentrated in between April 13 and April 29. The number of cases had started to decrease since April 24 with an average of 5.3 cases per day between May 3 and May 8 and an average of 0.3 cases per day between May 9 and today. CONCLUSIONS: SARS epidemics in our region could be divided into three phases. The first phase fell in between March 18 and April 15 with the first case being imported, the number of cases rose sharply, covering 14 counties in 6 prefectures, having a feature of family clustering. The second phase was from April 16 to April 28, with the appearance of secondary infection, having sharp rise of the cases and spreading to 24 counties in 10 prefectures. One of the major features was that hospitals had become the important sources of secondary infection. Finally, the third phase was between April 29 and May 20, with small wave crests of cases, spreading to 38 counties in 10 prefectures with a high proportion of cases with no history of direct contact with diagnosed SARS patients. Thus, no obvious transmission chain was noticed at this phase.

[2] [Diseases of Compulsory Notification (DCN) in Navarra. 2002]

[DOC19526] Since 1998, the Epidemiological Survelliance System of Navarra has included the notification of 34 transmissible infectious diseases, to which are added epidemic outbreaks of any aetiology and cause. Reporting to the system is carried out on a weekly basis by every doctor who suspects, or diagnoses, any of these processes. In our autonomous community, Diseases of Compulsory Notification (DCN) are reported using standardised forms on a weekly basis to the Section of Infectious Diseases and Control of Outbreaks of the Public Health Institute. Notification is made by the doctors and/or paediatricians of Primary Care and by certain services of Specialised Care. Subsequently, the information is sent to the National Epidemiology Centre where data from the Autonomous Communities is centralised and diffused. The year 2002 marks the fifth year of the new Epidemiological Vigilance System. In these five years there have been 74,814 notifications of disease, 17,184 in the year 2002, which provides a balance of notification of 74.07% for this year. In 2002, under the heading of respiratory transmitted diseases, 24,870 cases of Inluenza were reported, Epidemic Index (EI: 0.80). 58% of total annual cases were reported in the first nine weeks of the year, with a maximum in week 4 when 3,277 cases were reported. 16 cases of Meningococcal Disease were reported to the system (EI: 1.07). All the cases were confirmed microbiologically and all appeared in a sporadic way. With respect to the causative serogroup, on 12 occasions Neisseria meningitidis serogroup B was isolated and in the 4 remaining cases serogroup C was isolated. One case was notified in infants of less than 2 years of age (Rate: 10.52 cases per 100,000), another case in children between 2 and 5 years (5.52 cases per 100,000), 5 cases in the age group of 6 to 19 years (Rate: 5.86 cases per 100,000) and the remaining nine cases in the age group of persons aged 20 years or over (2.2 per 100,000). 70 cases of Legionellosis were declared in 2002 (EI: 4.67), all but one under the clinical form of pneumonia. Twenty-two of the cases were presented in the context of two outbreaks with a community origin, which affected 17 and 5 persons respectively. Similarly, there was a notable increase in the declaration of cases of bacillary dysentery, with 6 cases (EI: 2.00), brucellosis, with 10 cases (EI: 1.67) and chickenpox, with 4,346 notified cases (EI: 1.61).

[3] Epidemiological characteristics of an outbreak of severe acute respiratory syndrome in Don...

[DOC21968] OBJECTIVE: To describe epidemiologic features of an outbreak of severe acute respiratory syndrome (SARS) in Dongcheng District, Beijing occurred in a period between March and May 2003. METHODS: Data of SARS cases notified from Dongcheng District Center for Disease Control and Prevention(CDC)and supplemented by other channels were collected. Clinicians and officials of local hospitals were interviewed in groups and medical records of fatal cases of SARS were reviewed to verify the diagnosis. Stored serum specimens of the patients were detected for IgG antibody against SARS Co-V by enzyme-linked immunosorbent assay (ELISA). All the data were input into dataset files by Microsoft Excel-2000 software and analyzed with SPSS version 10.0 software. RESULTS: Outbreak of SARS in Dongcheng District started on March 14, 2003 with a peak in mid- and late April, and dropped in early May. A total of 572 reported cases were collected during this period in Dongcheng District, Beijing, and 99 of them were excluded from SARS, because of diagnosis of common cold, regular pneumonia, measles and rubella, etc. Actually, 473 SARS cases, which included 390 (82.5%) probable cases and 83 (17.5%) suspect cases, were analyzed. About 90% of the probable cases were positive for IgG antibody. Attack rate of SARS in permanent residents of Dongcheng District was 28.3 per 100 000. Forty-one of them died, with a case-fatality rate of 8.7%. Persons were all susceptible to infection of SARS Co-V, with the highest proportion at ages of 20-50 years, which accounted for 68.7% of the total cases. Average age of the patients at their onset was 40.7 years. No gender difference in SARS cases was found. Number of SARS cases in health-care workers (HCWs) accounted for 18.0% and that in retired workers accounted for 15.4% of the total cases. cases occurred in all 10 sub-districts of Dongcheng, with the highest in Beixinqiao and Andingmen Sub-districts. Totally, 230 of the 572 notified cases (40.2%) were hospitalized at local hospitals under the jurisdiction of Dongcheng District. Eighteen of 85 cases of SARS occurred in HCWs of local hospitals, accounting for 4.5% of the total number of HCWs working at wards caring for SARS patients or fever clinics. There were 34.7% of SARS cases without any histories of contact before the onset of the disease. Familial aggregation phenomena were observed in 41.8% of the cases and 18.1% of households. And 7.4% (attack rate) of those exposed to SARS cases suffered from the illness during the periods of quarantine. CONCLUSIONS: SARS appeared to be infectious in origin and caused outbreak in Dongcheng District, Beijing introduced by an imported case traveling from Hong Kong in a period between March and May 2003. People are all susceptible to infection of SARS Co-V, which mainly threatens the young adults and the middle-aged, as well as HCWs and the retired workers. The main mode of transmission is direct exposure to SARS patients in a near distance at hospitals or families via droplets spread. Prevention and control of SARS should be focused on early isolation of patients and quarantine for close contacts. Current available measures to prevent and control SARS are proved to be effective.
Related to Topic 25: CASES,REPORTED,CASE,OCCURRED,OUTBREAK,CONFIRMED (0.879)

[1] [Analysis on the trend of severe acute respiratory syndrome epidemic in Inner Mongolian Au...

[DOC19916] OBJECTIVE: To analyse the severe acute respiratory syndrome (SARS) epidemics in Inner Mongolian Autonomous Region and to provide scientific basis for prevention and control strategies against it. METHODS: Data from legal communicable diseases surveillance reporting system was analyzed epidemiologically. RESULTS: The first SARS case was reported in Inner Mongolian Autonomous Region on March 27, 2003. Up to May 20, there were 446 cumulative SARS cases in the whole region (with 287 confirmed cases and 159 suspected cases) and 61 cumulative recovered cases had been discharged from the hospitals (56 confirmed cases and 5 suspected cases). Another 131 cases were excluded the original diagnoses of SARS including 10 confirmed cases and 121 suspected cases. 25 confirmed cases died with a mortality rate of 8.7%. Cumulatively, the number of reported cases were distributed in 30 counties in 9 prefectures. Statistical analysis on time sequence of the occurrence of cases showed that majority (67.7% of the total) of the cases concentrated in between April 13 and April 29. The number of cases had started to decrease since April 24 with an average of 5.3 cases per day between May 3 and May 8 and an average of 0.3 cases per day between May 9 and today. CONCLUSIONS: SARS epidemics in our region could be divided into three phases. The first phase fell in between March 18 and April 15 with the first case being imported, the number of cases rose sharply, covering 14 counties in 6 prefectures, having a feature of family clustering. The second phase was from April 16 to April 28, with the appearance of secondary infection, having sharp rise of the cases and spreading to 24 counties in 10 prefectures. One of the major features was that hospitals had become the important sources of secondary infection. Finally, the third phase was between April 29 and May 20, with small wave crests of cases, spreading to 38 counties in 10 prefectures with a high proportion of cases with no history of direct contact with diagnosed SARS patients. Thus, no obvious transmission chain was noticed at this phase.

[2] [Surveillance report on Diseases of Compulsory Declaration (DCD) in Navarra. 2001]

[DOC19965] The Epidemiologic Surveillance System of Navarra includes the notification of 34 communicable diseases, to which are added epidemic outbreaks of any aetiology and cause. Every doctor who suspects, or diagnoses, any of the processes carries out reporting to the system on a weekly basis. In 2001, under the heading of diseases of respiratory transmission, 7,779 cases of Flu were reported (EI: 0.20), with the particular circumstance that the winter epidemic peak did not occur; 48% of total annual cases were reported in the first 12 weeks of the year, with a maximum in week 4 when only 449 cases were reported. 10 cases of Meningococcal Disease were reported to the system (EI: 0.59), a figure that is considered to be an historical minimum. Nine cases were confirmed microbiologically and all appeared in a sporadic way. With respect to the causative serogroup, on 6 occasions Neisseria meningitidis serogroup B was isolated and in the 3 remaining cases serogroup C was isolated. By age groups, 3 cases were declared in infants of less than 2 years of age (Rate: 34.6 cases per 100,000), 2 cases in children between 2 and 5 years (11.0 cases per 100,000), 4 cases in the age group of 6 to 10 years (Rate: 4.7 per 100,000) and the remaining case in the age group of persons aged 20 years or over (0.24 per 100,000). 42 cases of Legionellosis were declared in 2001, all under the clinical form of pneumonia. Twenty-five of them were presented in a context of outbreak; three community outbreaks and one with a nosocomial origin, which affected 19 persons. Similarly, there was a notable increase in the declaration of cases of Hepatitis A, with 33 cases (EI: 2.06), brucellosis, with 9 cases (EI: 0.81) and above all parotiditis, with 267 notified cases (EI: 8.34).

[3] Epidemiological characteristics of an outbreak of severe acute respiratory syndrome in Don...

[DOC21968] OBJECTIVE: To describe epidemiologic features of an outbreak of severe acute respiratory syndrome (SARS) in Dongcheng District, Beijing occurred in a period between March and May 2003. METHODS: Data of SARS cases notified from Dongcheng District Center for Disease Control and Prevention(CDC)and supplemented by other channels were collected. Clinicians and officials of local hospitals were interviewed in groups and medical records of fatal cases of SARS were reviewed to verify the diagnosis. Stored serum specimens of the patients were detected for IgG antibody against SARS Co-V by enzyme-linked immunosorbent assay (ELISA). All the data were input into dataset files by Microsoft Excel-2000 software and analyzed with SPSS version 10.0 software. RESULTS: Outbreak of SARS in Dongcheng District started on March 14, 2003 with a peak in mid- and late April, and dropped in early May. A total of 572 reported cases were collected during this period in Dongcheng District, Beijing, and 99 of them were excluded from SARS, because of diagnosis of common cold, regular pneumonia, measles and rubella, etc. Actually, 473 SARS cases, which included 390 (82.5%) probable cases and 83 (17.5%) suspect cases, were analyzed. About 90% of the probable cases were positive for IgG antibody. Attack rate of SARS in permanent residents of Dongcheng District was 28.3 per 100 000. Forty-one of them died, with a case-fatality rate of 8.7%. Persons were all susceptible to infection of SARS Co-V, with the highest proportion at ages of 20-50 years, which accounted for 68.7% of the total cases. Average age of the patients at their onset was 40.7 years. No gender difference in SARS cases was found. Number of SARS cases in health-care workers (HCWs) accounted for 18.0% and that in retired workers accounted for 15.4% of the total cases. cases occurred in all 10 sub-districts of Dongcheng, with the highest in Beixinqiao and Andingmen Sub-districts. Totally, 230 of the 572 notified cases (40.2%) were hospitalized at local hospitals under the jurisdiction of Dongcheng District. Eighteen of 85 cases of SARS occurred in HCWs of local hospitals, accounting for 4.5% of the total number of HCWs working at wards caring for SARS patients or fever clinics. There were 34.7% of SARS cases without any histories of contact before the onset of the disease. Familial aggregation phenomena were observed in 41.8% of the cases and 18.1% of households. And 7.4% (attack rate) of those exposed to SARS cases suffered from the illness during the periods of quarantine. CONCLUSIONS: SARS appeared to be infectious in origin and caused outbreak in Dongcheng District, Beijing introduced by an imported case traveling from Hong Kong in a period between March and May 2003. People are all susceptible to infection of SARS Co-V, which mainly threatens the young adults and the middle-aged, as well as HCWs and the retired workers. The main mode of transmission is direct exposure to SARS patients in a near distance at hospitals or families via droplets spread. Prevention and control of SARS should be focused on early isolation of patients and quarantine for close contacts. Current available measures to prevent and control SARS are proved to be effective.
Related to Topic 8: CLINICAL,DIAGNOSIS,SYMPTOMS,DISEASE,SIGNS,CASES (0.081)

[1] Clinical manifestations in the West Nile virus outbreak.

[DOC12765] During the summer of 1996 an unusual clustering of meningoencephalitis cases was recorded in the Capital City, Bucharest, and in some areas from South-East Romania. After an initial suspicion of an enteroviral etiology was discarded, the West Nile etiology was confirmed by specific antibodies demonstration through hemagglutination-inhibition and ELISA tests. This study included 251 patients with the diagnoses of West Nile acute encephalitis (166 cases), acute meningitis (57 cases) and acute febrile disease (33 cases). The patients' age ranged from 1 to 89 years (mean 51.1 years). The most frequent clinical manifestations were: fever (95.7% of cases), cephalalgia (92.6%), stiffness of the neck (89.1%), vomiting (62.5%), marked asthenia (46.5%), myalgia (28.9%). In addition, patients with encephalitis exhibited: alteration of consciousness (89.2% of cases), tremor of extremities (40.4%), ataxia (44%), paralysis (15.1%). The fatality rate was 15.1% in acute encephalitis, 1.8% in acute meningitis and 0% in the acute febrile disease.

[2] Neurological features of West Nile virus infection during the 2000 outbreak in a regional ...

[DOC17561] During the summer of 2000, 35 patients with West Nile Virus Fever were admitted to our hospital. Of these, the 26 (21 adults, mean age 56 (19-86) and 5 children (aged 9-15)) presented have neurological involvement, 33% with meningitis, 52% with meningoencephalitis, 10% with encephalitis and 5% with acute polyneuropathy. Presenting clinical features were fever in 95% of cases, headache in 90%, nausea/vomiting in 52%, confusion in 48%, somnolence in 38%, neck stiffness in 33%, a skin rash in 19%, diarrhea in 14%, cervical pain in 14%, seizure in 9%, photophobia in 9% and limb weakness in 4%. Leucopenia was not found. Two patients diagnosed with meningoencephalitis died. Three patients had signs of an acute polyneuropathy, this being the only complaint of one patient. The EEG was abnormal in all cases of meningitis or meningoencephalitis, except in three cases. Outbreaks of West Nile Virus Fever are emerging as a worldwide disease with high rates of neurological involvement and death. It should be considered in cases presenting with aseptic meningoencephalitis, meningitis and acute polyneuropathy, especially during the summer months and in areas along bird migration pathways.

[3] Syndromic variability of Wilson's disease in children. Clinical study of 44 cases.

[DOC12379] BACKGROUND: In children with Wilson's disease, no clinical or laboratory data are specific for diagnosis as in adult age. AIM: Clinical aspects and parameters of copper metabolism in a large series of pediatric cases are evaluated to establish certain criteria for diagnosis and for correct treatment, even in difficult cases. METHODS: In 44 children with Wilson's disease, clinical aspects, histological features, laboratory parameters and data of copper metabolism have been studied. Forty patients, treated with penicillamine, were followed up (median 77 months). RESULTS: The 44 cases were classified as: asymptomatic forms (nine cases, six of them siblings of affected subjects), chronic hepatitis (23 cases), hepatocerebral manifestations (four cases), decompensated cirrhosis (six cases), fulminant hepatic failure with hemolytic anemia (two cases). Ceruloplasmin levels were abnormal in 37 out of 43 tested cases, but normal in six (14%) who showed high basal and after penicillamine load urine copper excretion and increased hepatic copper content. Urine copper concentration was pathological in 35 out of 42 tested cases (83%), but normal in seven patients under six years. Hepatic copper levels were very high in all the 20 tested patients. Under treatment, 27 children had favourable outcome. One patient showed no evolution of disease, seven patients worsened because of non-compliance to the therapy (one underwent successful liver transplantation) or severe side effects. Five patients with failure died. CONCLUSIONS: Wilson's disease in children may present with a broad clinical spectrum, but the liver involvement is by far the most prevalent. The early diagnosis, based on clinical suspicion and results of copper metabolism investigation (including hepatic copper content evaluation in difficult cases) and appropriate treatment can prevent the progression of the disease.
CELL
Most likely documents

[1] Response of normal human keratinocytes to sulfur mustard (HD): cytokine release using a no...

[DOC13012] Cytokines play a major role in both acute and chronic inflammatory processes, including those produced by sulfur mustard (HD). This study describes responses of normal human epidermal keratinocyte (NHEK) cells to 2,2'-dichlorodiethyl sulfide, sulfur mustard (HD), defined by interleukin-1 beta (IL-1beta), interleukin-6 (IL-6), interleukin-8 (IL-8), and tumor necrosis factor-alpha (TNF-alpha) release. A new method for detaching cell to cell adhesion between keratinocytes has been applied. This method permits the characterization of endogenous fluid from cellular content that could be applied for the development of therapeutic intervention. NHEK (typical average cell density 4.4 x 10(6) cells/mL) were exposed to HD (100 and 300 microM) in keratinocyte growth medium (KGM) for 24 h at 37 C in humidified air. Commercially available enzyme-linked immunosorbent assay (ELISA) kits were used to measure the cytokine release in NHEK during exposure to 100 and 300 microM of HD. Exposure to 100 microM HD increased release of cytokines. IL-1beta (exposed: 1.41 x 10(-5) pg/ cell+/-1.60 x 10(-6) pg/cell: control 7.10 x 10(-6) pg/ cell+/-1.20 x 10(-6) pg/cell), TNF-alpha (exposed: 1.06 x 10(5) pg/cell+/-7.3 x 10(-7)pg/cell; control: 4.04 x 10(-6)+/-2.80 x 10(-7) pg/cell) and IL-8 (exposed: 3.71 x 10(-5) pg/ cell+/- 3.26 x 10(-6) pg/cell; control: 2.99 x 10(-6) pg/cell+/-8.80 x 10(-7) pg/cell) were significantly enhanced when NHEK cells were detached from culture flasks by non-enzymatic procedures. cell suspensions of NHEK released low amounts of IL-6 when exposed to 100 microM for 24 h (exposed: 1.47 x 10(-6)+/-1.60 x 10(-7) pg/cell; control: 1.28 x 10(-6)+/-8.40 x 10(-8) pg/cell). However, cell suspensions of NHEK increased levels of IL-6 after exposure to 300 microM HD (4.67 x 10(-5) pg/cell+/-3.90 x 10(-6) pg/cell; control: 3.99 x 10(-6) pg/cell+/-5.50 x 10(-7) pg/cell). The amount of IL-8 and TNF-alpha present in cell suspensions increased up to 59-fold and fourfold, respectively, above control levels when NHEK cells were exposed to 300 microM HD. Exposure of NHEK to 300 microM HD had a highly variable effect on the release of IL-1beta, where sometimes the secretion of IL-1beta increased above baseline level and other times decreased in cell suspensions. Supernatants were collected from cell culture flasks 24 h after exposure of 100 and 300 microM and significantly increased levels of IL-6 were observed. IL-6 was released in a concentration-dependent manner, 3.6-fold up to 8.4-fold, respectively, in supernatant. These pro-inflammatory mediators IL-1beta, IL-8, TNF-alpha and IL-6 may play an important role in HD injury. The present findings suggest that cytokine changes detected could be used as potential biomarkers of cutaneous vesicant injury.

[2] [Occupational lung cancer. A comparison between humans and experimental animals]

[DOC4525] Many epidemiological and experimental studies have suggested that the respiratory tract is one of the most sensitive organs to environmental carcinogens. Nevertheless there is little evidence to determine the relationship between a specific environmental carcinogen and a cell type of lung cancer, because the cell types of lung cancer and their relative frequencies are highly complex compared with those of other organs and tissues. In the present paper, occupational lung-cancer characteristics, which are the clearest in the relation between cause and effect in human lung cancers, were reviewed in comparison with the results of animal experiments concerned with occupational lung carcinogens. Through accumulation of histopathological examinations of the lung cancer cases, the following relationships between cause and cell type were conjectured: chromium and squamous cell carcinoma; asbestos and adenocarcinoma; nickel and squamous cell carcinoma; beryllium and small cell carcinoma; bis (chloromethyl) ether and small cell carcinoma; mustard gas and squamous cell or small cell carcinoma; vinyl chloride and large cell or adenocarcinoma; radionuclides and small cell carcinoma. The relation pertaining to arsenic, benzotrichloride and tar could not be conjectured because of insufficient cases and information in the histological diagnosis. On the other hand, the carcinogenicity of these substances in occupational exposure has been confirmed by animal experiments administered intratracheally or by inhalation studies under relatively higher concentration. As a result of recent refinements of inhalation study, all-day and life-span exposure to extremely low concentrations, such as microgram/m3 orders, of certain substances has been possible. The characteristics of lung tumors occurring in these animals are rather different from those of human. For example, in mouse, almost all of the malignant lung tumors developed by carcinogens are adenocarcinomas and it is rare to find the squamous cell carcinoma. Moreover, small cell carcinoma and large cell carcinoma have not known to occur in the lungs of rats and mice. Therefore, future research should focus elucidating the specific relationship between cause and cell type of human lung cancer by means of animal experiments on lung cancer that give attention to the specificities of each experimental animal and the origin of the resultant lung tumor.

[3] Characterization of porcine stable kidney cell line adapted to hyperthermic temperature.

[DOC21035] The optimum temperature for the growth of porcine stable (PS) kidney cell line is 37 degrees C. We have adapted the cell line to grow at 40 degrees C. The original cell line grown at 37 degrees C has been denoted as PS-37, and the adapted new strain has been denoted as PS-40. Both the cell lines were screened for mycoplasma by Hoechst staining and tritiated uridine-uracil uptake and were found to be negative. Comparative characterization of PS-40 and its progenitor PS-37 cell line was done by using various parameters. The antigenic studies indicated that the new cell strain was not cross-contaminated with any other cell lines. It was observed that PS-40 cells were more fibroblastic with clean cytoplasm and appeared healthy. The growth of PS-40 cells was faster than the original cell line. The karyological study showed heteroploid chromosome number in PS-40 cells. The modal chromosome number of PS-40 cells was 58, whereas that of PS-37 cell line was 38. The lactic dehydrogenase isoenzyme pattern showed a cathodal shift of bands. The PS-40 cell strain could be cryopreserved and revived. The viability of PS-37 as well as PS-40 cell lines is in the range of 90-95%, and the growth characteristics of thawed cells showed six- to eightfold multiplications within 5 d. The virus susceptibility study revealed that the cytopathic effect was more profound and observed 1 d earlier in PS-40 cell line. Increased yields of Japanese encephalitis, Sindbis, and Semliki forest viruses were obtained by 1.8, 1.75, and 1.5 log plaque-forming units/ml, respectively. The yield of West Nile virus was, however, comparable to that in PS-37 cell line. Both the cell lines were refractory to Dengue viruses.
Related to Topic 9: CELLS,CELL,CULTURES,LINES,APOPTOSIS,LINE (0.598)

[1] Transformation and immortalization of Leydig cells from the Sprague-Dawley rat by an early...

[DOC8442] Two transformed cell lines of rat Leydig cells were established by transfection of primary cells with the transforming region of simian virus (SV40) DNA. Normal adult Leydig cells are non-proliferating cells and cease to grow after the first trypsinization for cell culturing. The cell lines, NWL2 and NWL15, continued to proliferate and subsequently needed subculturing every 2 weeks (split ratio 1:2). No crisis was observed after 35 passages for 18 months. Nile red staining showed the presence of lipid droplets in both normal and transformed cells, although the transformed cells had 2-3-fold higher amounts than the normal cells. The integration of T-antigen DNA has taken place in at least 2 and 1 sites in NWL2 and NWL15, respectively. Both cell lines expressed T-antigen mRNA. The cell lines expressed luteinizing hormone receptor (LH-R) (a Leydig cell-specific gene), insulin-like growth factor-I, insulin-like growth factor-I receptor (IGF-I-R) and insulin-like growth factor binding protein-2 (IGFBP-2) genes. The amounts of transcripts of LH-R were lower in the transformed cells as compared to the normal cells. The IGF-I-R mRNA levels were comparable to those of the normal Leydig cells. NWL2 and NWL15 cells also expressed IGF-I mRNA although to a lesser extent than the normal Leydig cells. IGFBP-2 mRNA levels were much higher in both the transformed cell lines than in the normal Leydig cells. The transformed cells were evaluated for the expression of P450scc, which catalyzes the conversion of cholesterol to pregnenolone.(ABSTRACT TRUNCATED AT 250 WORDS)

[2] Major DNA fragmentation is a late event in apoptosis.

[DOC11572] Apoptosis, the terminal morphological and biochemical events of programmed cell death, is characterized by specific changes in cell surface and nuclear morphology. In addition, DNA fragmentation in an internucleosomal pattern is detectable in mass cultures of apoptotic cells. However, DNA fragmentation and nuclear morphological changes may not necessarily be associated events. In this study, we examined OVCAR-3 and KB human carcinoma cells using time-lapse video phase-contrast microscopy to characterize the surface and nuclear morphological features of apoptosis in response to treatment with either taxol or ricin. The surface morphological features of apoptosis were the same in both cell types and with both drugs. Using an in situ nick-translation histochemical assay, these single cells were also examined for DNA strand breaks during apoptosis. Surface morphological changes demonstrated discrete stages of cell rounding, surface blebbing, followed by cessation of movement and the extension of thin surface microspikes, followed much later by surface blistering and cell lysis. Nuclear features examined by DAPI cytochemistry demonstrated apoptotic nuclear condensation very early in this sequence, usually at the time of initial surface blebbing. The nick-translation assay, however, demonstrated DNA strand breaks at a much later time, only after the formation of separated apoptotic bodies or after final cell lysis. This study points out the differences between surface and nuclear morphological changes in apoptosis, and the large temporal separation between nuclear morphological changes and major DNA fragmentation detectable by this in situ technique. This result suggests caution in using in situ nick-translation as a direct correlate of internucleosomal DNA fragmentation in apoptosis.

[3] Characterization of porcine stable kidney cell line adapted to hyperthermic temperature.

[DOC21035] The optimum temperature for the growth of porcine stable (PS) kidney cell line is 37 degrees C. We have adapted the cell line to grow at 40 degrees C. The original cell line grown at 37 degrees C has been denoted as PS-37, and the adapted new strain has been denoted as PS-40. Both the cell lines were screened for mycoplasma by Hoechst staining and tritiated uridine-uracil uptake and were found to be negative. Comparative characterization of PS-40 and its progenitor PS-37 cell line was done by using various parameters. The antigenic studies indicated that the new cell strain was not cross-contaminated with any other cell lines. It was observed that PS-40 cells were more fibroblastic with clean cytoplasm and appeared healthy. The growth of PS-40 cells was faster than the original cell line. The karyological study showed heteroploid chromosome number in PS-40 cells. The modal chromosome number of PS-40 cells was 58, whereas that of PS-37 cell line was 38. The lactic dehydrogenase isoenzyme pattern showed a cathodal shift of bands. The PS-40 cell strain could be cryopreserved and revived. The viability of PS-37 as well as PS-40 cell lines is in the range of 90-95%, and the growth characteristics of thawed cells showed six- to eightfold multiplications within 5 d. The virus susceptibility study revealed that the cytopathic effect was more profound and observed 1 d earlier in PS-40 cell line. Increased yields of Japanese encephalitis, Sindbis, and Semliki forest viruses were obtained by 1.8, 1.75, and 1.5 log plaque-forming units/ml, respectively. The yield of West Nile virus was, however, comparable to that in PS-37 cell line. Both the cell lines were refractory to Dengue viruses.
Related to Topic 57: CD,CELLS,CELL,MARROW,BONE,ANTI (0.126)

[1] Effects of specific anti-B and/or anti-plasma cell immunotherapy on antibody production in...

[DOC15823] Anti-Galalpha1-3Gal antibodies (antialphaGal Ab) are a major barrier to clinical xenotransplantation as they are believed to initiate both hyperacute and acute humoral rejection. Extracorporeal immunoadsorption (EIA) with alphaGal oligosaccharide columns temporarily depletes antialphaGal Ab, but their return is ultimately associated with graft destruction. We therefore assessed the ability of two immunotoxins (IT) and two monoclonal antibodies (mAb) to deplete B and/or plasma cells both in vitro and in vivo in baboons, and to observe the rate of return of antialphaGal Ab following EIA. The effects of the mouse anti-human IT anti-CD22-ricin A (proportional to CD22-IT, directed against a B cell determinant) and anti-CD38-ricin A (proportional to CD38-IT, B and plasma cell determinant) and the mouse anti-human anti-CD38 mAb (proportional to CD38 mAb) and mouse/human chimeric anti-human anti-CD20 mAb (proportional to CD20 mAb, Rituximab, B cell determinant) on B and plasma cell depletion and antialphaGal Ab production were assessed both in vitro and in vivo in baboons (n = 9) that had previously undergone splenectomy. For comparison, two baboons received nonmyeloablative whole body irradiation (WBI) (300 cGy), and one received myeloablative WBI (900 cGy). Depletion of B cells was monitored by flow cytometry of blood, bone marrow (BM) and lymph nodes (LN), staining with anti-CD20 and/or anti-CD22 mAbs, and by histology of LN. EIA was carried out after the therapy and antialphaGal Ab levels were measured daily. In vitro proportional to CD22-IT inhibited protein synthesis in the human Daudi B cell line more effectively than proportional to CD38-IT. Upon differentiation of B cells into plasma cells, however, less inhibition of protein synthesis after proportional to CD22-IT treatment was observed. Depleting CD20-positive cells in vitro from a baboon spleen cell population already depleted of granulocytes, monocytes, and T cells led to a relative enrichment of CD20-negative cells, that is plasma cells, and consequently resulted in a significant increase in antialphaGal Ab production by the remaining cells, whereas depleting CD38-positive cells resulted in a significant decrease in antialphaGal Ab production. In vivo, WBI (300 or 900 cGy) resulted in 100% B cell depletion in blood and BM, > 80% depletion in LN, with substantial recovery of B cells after 21 days and only transient reduction in antialphaGal Ab after EIA. Proportional to CD22-IT depleted B cells by > 97% in blood and BM, and by 60% in LN, but a rebound of B cells was observed after 14 and 62 days in LN and blood, respectively. At 7 days, serum antialphaGal IgG and IgM Ab levels were reduced by a maximum of 40-45% followed by a rebound to levels up to 12-fold that of baseline antialphaGal Ab by day 83 in one baboon. The results obtained with proportional to CD38-IT were inconclusive. This may have been, in part, due to inadequate conjugation of the toxin. cell coating was 100% with proportional to CD38 mAb, but no changes in antialphaGal Ab production were observed. Proportional to CD20 mAb resulted in 100% depletion of B cells in blood and BM, and 80% in LN, with recovery of B cells starting at day 42. Adding 150cGy WBI at this time led to 100% depletion of B cells in the BM and LN. Although B cell depletion in blood and BM persisted for > 3 months, the reduction of serum antialphaGal IgG or IgM Ab levels was not sustained beyond 2 days. Proportional to CD20 mAb + WBI totally and efficiently depleted CD20- and CD22-positive B cells in blood, BM, and LN for > 3 months in vivo, but there was no sustained clinically significant reduction in serum antialphaGal Ab. The majority of antibody secretors are CD38-positive cells, but targeting these cells in vitro or in vivo with proportional to CD38-IT was not very effective. These observations suggest that CD20-and CD22-positive B cells are not the major source of antialphaGal Ab production. Future efforts will be directed towards suppression of plasma cell function.

[2] Experimental cardiac allograft survival across major histocompatibility complex barriers i...

[DOC4987] We have developed a rhesus monkey model consisting of myeloablative total-body irradiation and T lymphocyte-depleted autologous bone marrow transplantation followed by MHC-mismatched heterotopic cardiac allograft implantation that has provided an opportunity to study the role of marrow T cells in cardiac allograft rejection. In order to assess quantitatively the effects of low numbers of residual marrow T cells following depletion, methods to deplete rhesus marrow extensively and to detect residual T cells following depletion at levels below the sensitivity of standard assays have been developed. A rhesus marrow limiting dilution assay has been developed that quantifies less than 1 T cell in 10(5) marrow cells and is superior to traditional detection methods by at least 3 logs. In a direct comparison of four T cell depletion methods, effective depletion has been achieved with complement-mediated cytotoxicity (C'MC), erythrocyte rosetting, and counterflow centrifugal elutriation (CCE), the latter with a simplified single-flow rate protocol. Median marrow T cell depletions of 2.1, 1.1, and 3.1 logs, and total nucleated cell losses of 40%, 61%, and 42% respectively, have been observed. A reported use of ricin A-chain-like toxins for the enhancement of C'MC was of low efficacy with rhesus peripheral blood T cell targets. CCE followed by C'MC has resulted in a median 4.8 logs depletion with residual marrow T cell contents less than 0.001%. Thus, C'MC, E-rosetting, and particularly CCE are effective methods of T cell depletion--and, when used in combination, extensively eliminate marrow T cells. A rhesus marrow limiting dilution assay detects residual T cells at these low levels. These techniques provide a basis for the quantitative study of the role of T cells in organ graft rejection following T lymphocyte-depleted autologous marrow transplantation.

[3] T-cell depletion with ricin A-chain T101 in allogeneic bone marrow transplantation to prev...

[DOC5383] Bone marrow cells from 10 marrow transplant donors were treated with an immunotoxin, which couples A-chain of ricin with a monoclonal anti-T-cell antibody T101 to prevent graft-versus-host disease by the elimination of mature T-cells. Marrow cells treated with the anti human T-cell immunotoxin (IT101) were cultured for erythropoietic colonies, granulocytic colonies, and multilineage hematopoietic colonies (CFU-GEMMT) containing myeloid cells and T-cells, and optimal conditions were defined for the elimination of T-cells present in the harvested donor marrow prior to marrow transplantation. Marrow samples purged with IT101 were examined for residual T-cells by fluorescence activated cell sorting, using anti-T-cell antibodies, [3H]-thymidine incorporation after PHA stimulation, and an assay for clonogenic T-cells. The number of T-cell colonies observed in the treated marrows was less than 5% of the number in comparable unpurged donor marrows. Treatment with IT101 did not alter the plating efficiency of hematopoietic colonies compared to untreated donor marrow cells. These data suggest that multilineage progenitors responsible for the reconstitution of the recipient hematopoietic system are not affected by marrow IT101 purging. The clinical data on 10 patients indicate that the depletion of T-cells in the donor marrow with IT101 is effective in decreasing the severity of acute graft-versus-host disease in allogeneic marrow transplantation and warrants continued investigation.
Related to Topic 1: RICIN,CHAIN,CELLS,IMMUNOTOXIN,ANTI,ANTIBODY (0.113)

[1] Complete suppression of in vivo growth of human leukemia cells by specific immunotoxins: n...

[DOC5631] In this study, immunotoxins containing monoclonal anti-human T-cell leukemia antibodies are shown to be capable of completely suppressing the tumor growth of human T-cell leukemia cells in vivo without any overt undesirable toxicity. These immunotoxins were prepared by conjugating ricin A chain (RA) with our monoclonal antibodies, SN1 and SN2, directed specifically to the human T-cell leukemia cell surface antigens TALLA and GP37, respectively. We have shown that these monoclonal antibodies are highly specific for human T-cell leukemia cells and do not react with various normal cells including normal T and B cells, thymocytes, and bone marrow cells. Ascitic and solid human T-cell leukemia cell tumors were generated in nude mice. The ascitic tumor was generated by transplanting Ichikawa cells (a human T-cell leukemia cell line) i.p. into nude mice, whereas the solid tumor was generated by transplanting s.c. MOLT-4 cells (a human T-cell leukemia cell line) and x-irradiated human fibrosarcoma cells into x-irradiated nude mice. To investigate the efficacy of specific immunotoxins in suppressing the in vivo growth of the ascitic tumor, we divided 40 nude mice that were injected with Ichikawa cells into four groups. Each group of 10 mice was injected with one of the following mixtures: 40 micrograms of purified control mouse IgG [IgG1(kappa)] (group 1), 40 micrograms of control RA conjugate (group 2), 20 micrograms of purified SN1 antibody [IgG1(kappa)] and 20 micrograms of purified SN2 antibody [IgG1(kappa)] (group 3), or 20 micrograms of SN1-RA and 20 micrograms of SN2-RA (group 4). Mice in groups 1 and 2 formed large ascitic tumors, and died 5.8-7.0 weeks after the transplantation. Group 3 mice also formed large ascitic tumors and died 6.4-7.8 weeks after the transplantation. However, none of the mice in group 4 that were treated with SN1-RA and SN2-RA showed any signs of a tumor or undesirable toxic effects for the 20 weeks that they were followed after the transplantation; these mice were indistinguishable from healthy control nude mice that were not injected with Ichikawa cells. Treatment with SN1-RA plus SN2-RA completely suppressed solid tumor growth in 4 of 10 nude mice carrying solid tumors and partially suppressed the tumor growth in the remaining 6 nude mice. These results strongly suggest that SN1-RA and SN2-RA may be useful for clinical treatment.

[2] Evaluation of four CD22 antibodies as ricin A chain-containing immunotoxins for the in viv...

[DOC5361] Ricin A chain-containing immunotoxins (IT-As) specific for the human B-cell antigen, CD22, were prepared from 4 monoclonal antibodies (MAbs) or their Fab' fragments: RFB4, HD6, UV22-I and UV22-2. The ITs were tested for their ability to kill cells from the Burkitt lymphoma line, Daudi, the pre-B-cell leukemia line, NALM-6, and the myeloma cell line, ARH-77. Daudi expresses high levels of CD22, whereas NALM-6 and ARH-77 express low levels of CD22. The IgG-RFB4-A was highly toxic to all 3 cell lines; it killed 50% of the Daudi cells at a concentration of 1.2 x 10(-12) M and 50% of NALM-6 and ARH-77 cells at concentrations of 1.5 to 2.1 x 10(-11) M. IgG-RFB4-A was 10-30 times more toxic to Daudi cells than were the IgG-As constructed from the other 3 CD22 MAbs and 10 times more toxic than ricin itself. IT-As constructed from the Fab' fragments of the 4 CD22 antibodies were 2 to 5 times less toxic to Daudi cells than their IgG-A counterparts. Fab'-RFB4-A was twice as toxic to Daudi cells as ricin, whereas the other Fab'-As were about 7 times less toxic than ricin. Scatchard analyses of the binding of the radio-iodinated antibodies to Daudi cells showed that the intact RFB4 antibody bound 3-10 times more strongly than the other antibodies, whereas the Fab'-RFB4 bound 1.2 to 3.5 times more strongly than the Fab' fragments prepared from the other antibodies. Thus, the potent cytotoxic activity of the RFB4-As appears to derive, in part, from their superior binding affinity. Prior studies have shown that UV22-I and HD6 cross-react with certain normal human tissues lacking cells of B-cell lineage, whereas UV22-2 and RFB4 are B-cell-specific. This fact, together with its superior potency as an IT-A, suggests that RFB4 is the antibody of choice for preparing Fab'-As or IgG-As for in vivo therapy of human B-cell leukemias and lymphomas.

[3] Potentiation of antitumor immunotoxins by liposomal monensin.

[DOC10119] BACKGROUND: The cytotoxicity of specific ricin A-chain immunotoxins is greatly enhanced in vitro by the carboxylic ionophore monensin. However, the highly lipophilic nature of monensin, which is reflected in its poor solubility and short half-life, has restricted its use in in vivo animal studies. PURPOSE: The purpose of this study was to assess the ability of monensin incorporated in unilamellar vesicles (liposomes) to potentiate antitumor immunotoxins in vitro and in vivo. METHODS: Monensin was incorporated into liposomes and used in combination with specific immunotoxins against human tumor cell lines in vitro and in vivo. Inhibition of [3H]leucine incorporation was used to evaluate the cytotoxic action of immunotoxin with or without monensin in vitro on the following human tumor cell lines: H-MESO-1 malignant mesothelioma, LS174T colorectal carcinoma, and U373, U87, and MG-1 glioblastomas. For the in vivo studies of immunotoxins and liposomal monensin, BALB/c nu/nu mice were inoculated intraperitoneally with H-MESO-1 cells. RESULTS: Liposomal monensin potentiated the cytotoxic action of cell-specific anti-human transferrin receptor immunotoxin on H-MESO-1 target cells at a molar concentration of monensin that was 160-fold lower than the concentration of monensin in buffer that produced the same effect (0.3 nM versus 0.05 microM). Moreover, immunotoxin plus 0.1 microM liposomal monensin was fivefold more toxic for H-MESO-1 cells and 1000-fold and 2200-fold more toxic for human glioblastoma U373 and U87 cells, respectively, than immunotoxin plus 0.1 microM free monensin in buffer. Liposomal monensin produced similar effects when it was combined with different specific immunotoxins and other target cell lines (i.e., LS174T, U87, and CEM). Immunotoxin specificity was preserved with liposomal monensin, as shown by the absence of effect with non-cell-binding immunotoxins or on antigen-negative cell lines. In mice, liposomal monensin in combination with specific immunotoxin substantially prolonged survival, and three (21%) of 14 mice bearing H-MESO-1 xenografts treated with the liposomes showed no evidence of tumor at day 160 after treatment. Treatment with control immunotoxin plus liposomal monensin was ineffective. CONCLUSION: These findings suggest that encapsulation of monensin into liposomes increased the capacity of monensin to enhance the potency of cell-specific immunotoxin in vitro and in vivo.
Related to Topic 15: CELLS,RICIN,MEMBRANE,CELL,TRANSPORT,PROTEIN (0.076)

[1] Inhibition of coated pit formation in Hep2 cells blocks the cytotoxicity of diphtheria tox...

[DOC4597] It has been recently shown (Larkin, J. M., M. S. Brown, J. L. Goldstein, and R. G. W. Anderson, 1983, cell, 33:273-285) that after a hypotonic shock followed by incubation in a K+-free medium, human fibroblasts arrest their coated pit formation and therefore arrest receptor-mediated endocytosis of low density lipoprotein. We have used this technique to study the endocytosis of transferrin, diphtheria toxin, and ricin toxin by three cell lines (Vero, Wi38/SV40, and Hep2 cells). Only Hep2 cells totally arrested internalization of [125I]transferrin, a ligand transported by coated pits and coated vesicles, after intracellular K+ depletion. Immunofluorescence studies using anti-clathrin antibodies showed that clathrin associated with the plasma membrane disappeared in Hep2 cells when the level of intracellular K+ was low. In the absence of functional coated pits, diphtheria toxin was unable to intoxicate Hep2 cells but the activity of ricin toxin was unaffected by this treatment. By measuring the rate of internalization of [125I]ricin toxin by Hep2 cells, with and without functional coated pits, we have shown that this labeled ligand was transported in both cases inside the cells. Hep2 cells with active coated pits internalized twice as much [125I]ricin toxin as Hep2 cells without coated pits. Entry of ricin toxin inside the cells was a slow process (8% of the bound toxin per 10 min at 37 degrees C) when compared to transferrin internalization (50% of the bound transferrin per 10 min at 37 degrees C). Using the indirect immunofluorescence technique on permeabilized cells, we have shown that Hep2 cells depleted in intracellular K+ accumulated ricin toxin in compartments that were predominantly localized around the cell nucleus. Our study indicates that in addition to the pathway of coated pits and coated vesicles used by diphtheria toxin and transferrin, another system of endocytosis for receptor-bound molecules takes place at the level of the cell membrane and is used by ricin toxin to enter the cytosol.

[2] Endocytosis, intracellular transport, and cytotoxic action of Shiga toxin and ricin.

[DOC11020] Protein toxins such as ricin and Shiga toxin with intracellular targets have to be endocytosed and translocated to the cytosol to inhibit the protein synthesis and thereby kill the cell. Ricin is internalized by both clathrin-dependent and -independent endocytic mechanisms, whereas Shiga toxin seems to be taken up exclusively from clathrin-coated pits. After endocytosis, internalized membrane and content are delivered to endosomes, where sorting for further routing in the cell takes place. Toxins that remain membrane bound at low endosomal pH can be recycled to the cell surface or transcytosed in polarized epithelia. A large proportion of internalized toxin is transported to lysosomes for degradation. Most importantly, a fraction of the internalized ricin and Shiga toxin molecules is delivered to the trans-Golgi network (TGN). Shiga toxin can, in some very sensitive cells, be transported retrogradely through the Golgi cisterns all the way back to the endoplasmic reticulum (ER), and it is possible that also ricin is transported retrogradely to the ER. In this review, a cell biological overview of these intracellular transport steps is presented, and evidence is provided that the delivery to the TGN and the subsequent retrograde transport to the ER are required for optimal intoxication. Moreover, it is argued that knowledge of this transport is important for targeted drug delivery such as the application of immunotoxins in cancer therapy.

[3] Ricin transport in brefeldin A-treated cells: correlation between Golgi structure and toxi...

[DOC2891] Whereas brefeldin A (BFA) protected a number of cell lines against the protein toxin ricin, two of the cell lines tested were not protected but rather sensitized to ricin by BFA. EM studies revealed that upon addition of BFA the Golgi stacks in cells which were protected against the toxin rapidly transformed into a characteristic tubulo-vesicular reticulum connected to the endoplasmic reticulum, and subcellular fractionation experiments showed that galactosyl transferase disappeared from the Golgi fractions where it was normally located. EM and subcellular fractionation also indicated that in contrast to the Golgi stacks, the trans-Golgi network (TGN) remained intact and that internalized ricin was still localized in the TGN both when BFA was added before and after the toxin. Thus, BFA does not prevent fusion of ricin-containing vesicles with the TGN, and unlike resident proteins in Golgi stacks, ricin is not transported back to ER upon treatment of cells with BFA. Two kidney epithelial cell lines, MDCK and PtK2, were not protected against ricin by BFA, and EM studies of MDCK cells revealed that BFA did not alter the morphology of the Golgi complex in these cells. Also, subcellular fractionation revealed that, in contrast to the other cell types tested, the localization of galactosyl transferase in the gradients was not affected by BFA treatment. The data show that there is a correlation between BFA-induced disassembly of the Golgi stacks and protection against ricin, and they demonstrate that the structural organization of the Golgi apparatus is affected by BFA to different extents in various cell lines.
Related to Topic 62: RESPONSE,IMMUNE,RESPONSES,SPECIFIC,ANTIGEN,CELL (0.060)

[1] Effect of high ligand concentration on West Nile virus-specific T cell proliferation.

[DOC2718] In this paper the phenomenon of suppression of proliferation in vitro of 14 day primed, West Nile Virus (WNV)-specific, murine CD4+ T cells by large numbers of antigen-presenting macrophages and B cells has been investigated. Suppression was apparently not mediated by prostaglandins, as the use of indomethacin in cultures at four times the usual concentration did not reverse suppression. Experiments were designed to evaluate the contribution of major histocompatibility complex (MHC) Class II and nominal WNV antigens in causing suppression of T cell proliferation. Listeria- or thioglycollate-induced macrophages from CBA/H (H-2k) mice, when treated with heat-killed Listeria in vitro for 1 h to maintain or increase, respectively, MHC Class II levels before the addition of alloreactive Iak-specific T cells caused inverse dose-responses; the highest T cell proliferation occurred at a stimulator to responder (S : R) ratio of 0.25 and profound suppression at a S : R ratio of 1 or 2. In contrast, untreated thioglycollate-induced macrophages, which express low MHC Class II levels, gave a direct dose-response with increasing T cell proliferation as antigen-presenting cell (APC) numbers increased. Addition of anti-Ia antibodies (or their Fab fragments) to cultures caused a significant reversal of suppression of anti-WNV T cells imposed by high numbers of Listeria-induced macrophages or 14 day WNV-primed B cell APC. Suppression was also reversed by reducing the concentration of WNV antigen. These observations support the notion that the suppression of T cell proliferation observed at high S : R ratios was due to high concentrations of ligand (WNV-derived peptide complexed with Class II MHC) on APC.

[2] Selective abrogation of antigen-specific human B cell responses by antigen-ricin conjugate...

[DOC7862] The feasibility of selectively eliminating human antigen-specific B cell responses by treating cells in vitro with antigen covalently linked to a cell toxin was examined. Tetanus toxoid (TT) was conjugated to the toxin ricin via a thioether linkage. Peripheral blood mononuclear cells from recently immunized subjects were preincubated for 2 h with TT-ricin in the presence of lactose. Antigen was then removed, and the cells from recently immunized subjects were preincubated for 2 h with TT-ricin in the presence of lactose. Antigen was then removed, and the cells were stimulated with pokeweed mitogen to induce antibody production. TT-specific antibody production was completely abrogated by preincubation with TT-ricin but not by TT alone or a mixture of TT and ricin. In contrast, polyclonal immunoglobulin production was not diminished by TT-ricin. This selective abrogation was also seen when B cells alone were preincubated with TT-ricin and a source of T cell help was later provided. T cell blastogenic responses to TT remained intact after TT-ricin exposure. Thus, antigen-toxin conjugates are capable of selectively eliminating specific antibody-producing B cell clones, while leaving intact the remainder of the B cell repertoire.

[3] Cell-mediated immunity against Francisella tularensis after natural infection.

[DOC7887] 31 subjects with tularemia recently or up to 11 years earlier were studied for cell-mediated immunity against Francisella tularensis using formalin-killed bacteria as antigen in the lymphocyte blast transformation test. Lymphocytes from all the subjects responded to F. tularensis antigen both in separated mononuclear cell and whole blood cultures, whereas lymphocytes from 12 controls responded not at all or only weakly to hig antigen concentrations and only in separated mononuclear cell cultures. The strength of the response remained on the same level as in the cases of recent infection up to 11 years. There was no correlation between the lymphocyte responses and the serum antibodies agglutinating F.l tularensis antigen. Purified protein derivative of tuberculin equally stimulated the cells from the tularemia and control subjects. The lymphocyte stimulation methods can bae used to diagnose infections caused by F. tularensis and to measure cell-mediated immunity and resistance against such infections.
CELLS
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[1] Separation of VX-2 rabbit carcinoma-derived cells capable of releasing collagenase.

[DOC6931] Primary and secondary cultures of VX-2 carcinoma produced high levels of collagenase activity in both active and latent forms in serum-free media. These cultures appeared morphologically heterogeneous in phase-contrast microscopy and revealed the presence of mainly three distinct forms: epithelial-like cells (E cells), fibroblast-like cells (F cells), and large rounded-flat cells which may represent a subclass of the F cells. Cell separation techniques such as brief dispase treatment, Percoll gradient centrifugation, thimerosal treatment, and rabbit serum were used to obtain predominantly one form or the other. The E cells never formed a monolayer but rather grew as limited size clusters of intimately associated cells with large nuclei and often appeared multinucleated. These cells were difficult to maintain in culture or serially passed more than a few times. The F cells, rare in early cultures but having the highest growth potential, appeared in various morphological forms ranging from spindle- to stellate-shaped cells. The cells in their third passage were capable of producing palpable tumors, similar in light and electron microscopic studies to the original tumor from which they were derived, when injected intramuscularly into recipient rabbits and produced specific collagenase activity in active and latent forms in serum-free media. Ultrastructural studies suggested that the E cells were of epithelial origin whereas the F cells were similar to stromal fibroblasts. Cytogenetic studies demonstrated that almost all of the E cells showed both numerical and structural chromosomal changes in a modal number of 54 chromosomes. On the other hand, the major cell population of the F cells resembled normal rabbit fibroblasts; both contained a normal diploid (2n = 44). However, few cells (4-6%) in the F-cell population were hyperdiploid with a modal chromosome number of 54. These cells may represent inadvertent contaminating E cells and account for the apparent limited turmorigenicity observed in early F-cell cultures. The data suggested that the E cells were of tumor origin whereas the majority of the F-cell population appeared to be of host origin. Furthermore, it is suggested that the E cells stimulate tumor-associated stromal cells to produce elevated levels of collagenolytic activity and contribute to collagen degradation during tumor invasion.

[2] Cell death in the avian sclerotome.

[DOC12021] In this study the occurrence of apoptotic cells in chick embryo trunk somites, between 2.5 and 4 days of development, has been examined using an in situ nick-end-labeling method (TUNEL) to identify nuclei in which DNA is undergoing fragmentation. At 2.5 days of development, apoptotic cells were found in the sclerotome with a distribution that depended on the rostrocaudal level in the trunk. At the most rostral levels (somites 1-18), dying cells were present primarily in the rostral half of the ventral sclerotome; at midlevels (somites 19-26), they were present throughout the ventral sclerotome; and at caudal levels (somites 27-32), no dying cells were present. By 4 days of development, the number of dying cells in the sclerotome was sharply reduced, and those present were primarily distributed to the caudal side of the intrasclerotomal fissure. Double labeling of cells for both TUNEL and the HNK-1 epitope, at 2.5 days, indicated that the majority of the dying cells were not neural crest cells. Further, dying cells in the rostral somite half were present largely in regions of the sclerotome that labeled poorly for HNK-1. It was confirmed that apoptotic neural crest cells retain the HNK-1 epitope and therefore would have been observed if present. Neural crest cells only appeared to be apoptotic in relatively small numbers and only at the ventral border of the sclerotome. Examination of DiI-labeled neural crest cells confirmed that the dying cells in the body of the somite were not primarily neural crest cells. Two hypotheses regarding the TUNEL-positive cells in the sclerotome were experimentally tested. First, that they originate from the somitocoel compartment of the somite, because their distribution patterns at 4 days were similar to those of somitocoel cells. To test this, somitocoel cells were labeled with carboxyfluorescein and grafted into host embryos in ovo. Results showed that these cells did not become apoptotic and that the dying cells were therefore not derived from the somitocoel. Second, the hypothesis was tested that the distribution patterns of the dying cells in the sclerotome are determined by factors outside the somite itself. Somites and segmental plates were transplanted into hosts in ovo with reversed orientation, after which the patterns of dying cells were examined using nile blue sulfate staining. The results indicated that the patterns were unchanged after a further 2 days incubation, suggesting that the patterns of cell death in the sclerotome are not determined solely from within the somite. The distribution of the cell death-associated gene products, bcl-2, bax, and interleukin-1 beta converting enzyme, indicates that although these proteins are segmentally distributed in the dermomyotome and in the rostrodorsal quadrant of the sclerotome, their patterns are not directly correlated with the distribution of dying cells.

[3] Effects of specific anti-B and/or anti-plasma cell immunotherapy on antibody production in...

[DOC15823] Anti-Galalpha1-3Gal antibodies (antialphaGal Ab) are a major barrier to clinical xenotransplantation as they are believed to initiate both hyperacute and acute humoral rejection. Extracorporeal immunoadsorption (EIA) with alphaGal oligosaccharide columns temporarily depletes antialphaGal Ab, but their return is ultimately associated with graft destruction. We therefore assessed the ability of two immunotoxins (IT) and two monoclonal antibodies (mAb) to deplete B and/or plasma cells both in vitro and in vivo in baboons, and to observe the rate of return of antialphaGal Ab following EIA. The effects of the mouse anti-human IT anti-CD22-ricin A (proportional to CD22-IT, directed against a B cell determinant) and anti-CD38-ricin A (proportional to CD38-IT, B and plasma cell determinant) and the mouse anti-human anti-CD38 mAb (proportional to CD38 mAb) and mouse/human chimeric anti-human anti-CD20 mAb (proportional to CD20 mAb, Rituximab, B cell determinant) on B and plasma cell depletion and antialphaGal Ab production were assessed both in vitro and in vivo in baboons (n = 9) that had previously undergone splenectomy. For comparison, two baboons received nonmyeloablative whole body irradiation (WBI) (300 cGy), and one received myeloablative WBI (900 cGy). Depletion of B cells was monitored by flow cytometry of blood, bone marrow (BM) and lymph nodes (LN), staining with anti-CD20 and/or anti-CD22 mAbs, and by histology of LN. EIA was carried out after the therapy and antialphaGal Ab levels were measured daily. In vitro proportional to CD22-IT inhibited protein synthesis in the human Daudi B cell line more effectively than proportional to CD38-IT. Upon differentiation of B cells into plasma cells, however, less inhibition of protein synthesis after proportional to CD22-IT treatment was observed. Depleting CD20-positive cells in vitro from a baboon spleen cell population already depleted of granulocytes, monocytes, and T cells led to a relative enrichment of CD20-negative cells, that is plasma cells, and consequently resulted in a significant increase in antialphaGal Ab production by the remaining cells, whereas depleting CD38-positive cells resulted in a significant decrease in antialphaGal Ab production. In vivo, WBI (300 or 900 cGy) resulted in 100% B cell depletion in blood and BM, > 80% depletion in LN, with substantial recovery of B cells after 21 days and only transient reduction in antialphaGal Ab after EIA. Proportional to CD22-IT depleted B cells by > 97% in blood and BM, and by 60% in LN, but a rebound of B cells was observed after 14 and 62 days in LN and blood, respectively. At 7 days, serum antialphaGal IgG and IgM Ab levels were reduced by a maximum of 40-45% followed by a rebound to levels up to 12-fold that of baseline antialphaGal Ab by day 83 in one baboon. The results obtained with proportional to CD38-IT were inconclusive. This may have been, in part, due to inadequate conjugation of the toxin. Cell coating was 100% with proportional to CD38 mAb, but no changes in antialphaGal Ab production were observed. Proportional to CD20 mAb resulted in 100% depletion of B cells in blood and BM, and 80% in LN, with recovery of B cells starting at day 42. Adding 150cGy WBI at this time led to 100% depletion of B cells in the BM and LN. Although B cell depletion in blood and BM persisted for > 3 months, the reduction of serum antialphaGal IgG or IgM Ab levels was not sustained beyond 2 days. Proportional to CD20 mAb + WBI totally and efficiently depleted CD20- and CD22-positive B cells in blood, BM, and LN for > 3 months in vivo, but there was no sustained clinically significant reduction in serum antialphaGal Ab. The majority of antibody secretors are CD38-positive cells, but targeting these cells in vitro or in vivo with proportional to CD38-IT was not very effective. These observations suggest that CD20-and CD22-positive B cells are not the major source of antialphaGal Ab production. Future efforts will be directed towards suppression of plasma cell function.
Related to Topic 9: CELLS,CELL,CULTURES,LINES,APOPTOSIS,LINE (0.605)

[1] Fas antigen-mediated apoptosis of ovarian surface epithelial cells.

[DOC11867] The Fas antigen is a cell surface receptor that, when engaged by Fas ligand or specific agonistic antibodies, triggers apoptosis. The effect of an agonistic monoclonal antibody to mouse Fas antigen (Fas mAb, clone J02) on the viability of cells from dispersed mouse corpora lutea (CL cultures) was tested. Cultures were prepared by enzymatic digestion of CL from day 4-7 pseudopregnant mice. Cultures were pretreated with 0, 1, 10, 100, or 1000 U/ml murine interferon-gamma (IFN) at 72 h of culture. IFN has been shown to increase Fas antigen expression in a number of cell types. At 96 h (time zero), cultures were treated with Fas mAb or IgG. By 4 h after Fas mAb treatment, discrete homogeneous patches of cells within the cultures showed characteristic signs of apoptosis, including blebbing of cell membranes, detachment, and disappearance from the culture. CL cultures contain luteal, stromal, and endothelial cells; fibroblasts; and surface epithelial cells (OSE). cells dying in response to Fas mAb were identified as OSE. Affected cells had the cobblestone appearance and distinct nuclei typical of epithelial cells. Unlike luteal cells, OSE did not stain with the lipophilic dye, Nile red. The cells did not stain with acetylated low density lipoprotein conjugated to the fluorescent marker octadecyl indocarbocyanine, a marker for endothelial cells and monocytes. cells in patches stained positively for cytokeratin, a marker for epithelial cells. Fas-mediated cytotoxicity was quantified by counting the number of cells present in discrete patches of OSE 0 and 8 h after Fas mAb treatment. Fas mAb treatment had no effect in cultures pretreated with 0 or 1 U/ml IFN, but induced significant death of OSE in cultures pretreated with 10, 100, and 1000 U/ml IFN (37 +/- 11%, 54 +/- 18%, and 60 +/- 11%, respectively). There was no apparent effect of Fas mAb on other cell types within the CL cultures. To confirm that cells dying in response to Fas mAb were OSE, experiments were also performed on enriched cultures of OSE prepared by enzymatic digestion of the outer surface of the ovary. In enriched OSE cultures pretreated with 200 U/ml IFN, there was 44% killing in response to Fas mAb, whereas in cells not pretreated with IFN, there was no effect. In situ fluorescent end labeling of DNA in CL cultures indicated that treatment with IFN and Fas mAb induced DNA fragmentation in OSE typical of apoptosis. Immunocytochemistry of CL cultures indicated that Fas antigen was expressed in OSE pretreated with IFN. Quantitative reverse transcriptase-PCR showed that IFN pretreatment increased Fas antigen messenger RNA levels 2.3-fold in enriched cultures of OSE. In summary, OSE in CL cultures and enriched cultures of OSE undergo apoptosis in response to Fas mAb when pretreated with IFN. In vivo, OSE undergo programmed cell death before ovulation and rapidly proliferate to repair the surface of the ovulatory follicle after ovulation. Most ovarian cancers are derived from the OSE. The results have implications for both normal ovarian function and oncogenesis in the ovary.

[2] Transformation and immortalization of Leydig cells from the Sprague-Dawley rat by an early...

[DOC8442] Two transformed cell lines of rat Leydig cells were established by transfection of primary cells with the transforming region of simian virus (SV40) DNA. Normal adult Leydig cells are non-proliferating cells and cease to grow after the first trypsinization for cell culturing. The cell lines, NWL2 and NWL15, continued to proliferate and subsequently needed subculturing every 2 weeks (split ratio 1:2). No crisis was observed after 35 passages for 18 months. Nile red staining showed the presence of lipid droplets in both normal and transformed cells, although the transformed cells had 2-3-fold higher amounts than the normal cells. The integration of T-antigen DNA has taken place in at least 2 and 1 sites in NWL2 and NWL15, respectively. Both cell lines expressed T-antigen mRNA. The cell lines expressed luteinizing hormone receptor (LH-R) (a Leydig cell-specific gene), insulin-like growth factor-I, insulin-like growth factor-I receptor (IGF-I-R) and insulin-like growth factor binding protein-2 (IGFBP-2) genes. The amounts of transcripts of LH-R were lower in the transformed cells as compared to the normal cells. The IGF-I-R mRNA levels were comparable to those of the normal Leydig cells. NWL2 and NWL15 cells also expressed IGF-I mRNA although to a lesser extent than the normal Leydig cells. IGFBP-2 mRNA levels were much higher in both the transformed cell lines than in the normal Leydig cells. The transformed cells were evaluated for the expression of P450scc, which catalyzes the conversion of cholesterol to pregnenolone.(ABSTRACT TRUNCATED AT 250 WORDS)

[3] Separation of VX-2 rabbit carcinoma-derived cells capable of releasing collagenase.

[DOC6931] Primary and secondary cultures of VX-2 carcinoma produced high levels of collagenase activity in both active and latent forms in serum-free media. These cultures appeared morphologically heterogeneous in phase-contrast microscopy and revealed the presence of mainly three distinct forms: epithelial-like cells (E cells), fibroblast-like cells (F cells), and large rounded-flat cells which may represent a subclass of the F cells. Cell separation techniques such as brief dispase treatment, Percoll gradient centrifugation, thimerosal treatment, and rabbit serum were used to obtain predominantly one form or the other. The E cells never formed a monolayer but rather grew as limited size clusters of intimately associated cells with large nuclei and often appeared multinucleated. These cells were difficult to maintain in culture or serially passed more than a few times. The F cells, rare in early cultures but having the highest growth potential, appeared in various morphological forms ranging from spindle- to stellate-shaped cells. The cells in their third passage were capable of producing palpable tumors, similar in light and electron microscopic studies to the original tumor from which they were derived, when injected intramuscularly into recipient rabbits and produced specific collagenase activity in active and latent forms in serum-free media. Ultrastructural studies suggested that the E cells were of epithelial origin whereas the F cells were similar to stromal fibroblasts. Cytogenetic studies demonstrated that almost all of the E cells showed both numerical and structural chromosomal changes in a modal number of 54 chromosomes. On the other hand, the major cell population of the F cells resembled normal rabbit fibroblasts; both contained a normal diploid (2n = 44). However, few cells (4-6%) in the F-cell population were hyperdiploid with a modal chromosome number of 54. These cells may represent inadvertent contaminating E cells and account for the apparent limited turmorigenicity observed in early F-cell cultures. The data suggested that the E cells were of tumor origin whereas the majority of the F-cell population appeared to be of host origin. Furthermore, it is suggested that the E cells stimulate tumor-associated stromal cells to produce elevated levels of collagenolytic activity and contribute to collagen degradation during tumor invasion.
Related to Topic 57: CD,CELLS,CELL,MARROW,BONE,ANTI (0.158)

[1] Effects of specific anti-B and/or anti-plasma cell immunotherapy on antibody production in...

[DOC15823] Anti-Galalpha1-3Gal antibodies (antialphaGal Ab) are a major barrier to clinical xenotransplantation as they are believed to initiate both hyperacute and acute humoral rejection. Extracorporeal immunoadsorption (EIA) with alphaGal oligosaccharide columns temporarily depletes antialphaGal Ab, but their return is ultimately associated with graft destruction. We therefore assessed the ability of two immunotoxins (IT) and two monoclonal antibodies (mAb) to deplete B and/or plasma cells both in vitro and in vivo in baboons, and to observe the rate of return of antialphaGal Ab following EIA. The effects of the mouse anti-human IT anti-CD22-ricin A (proportional to CD22-IT, directed against a B cell determinant) and anti-CD38-ricin A (proportional to CD38-IT, B and plasma cell determinant) and the mouse anti-human anti-CD38 mAb (proportional to CD38 mAb) and mouse/human chimeric anti-human anti-CD20 mAb (proportional to CD20 mAb, Rituximab, B cell determinant) on B and plasma cell depletion and antialphaGal Ab production were assessed both in vitro and in vivo in baboons (n = 9) that had previously undergone splenectomy. For comparison, two baboons received nonmyeloablative whole body irradiation (WBI) (300 cGy), and one received myeloablative WBI (900 cGy). Depletion of B cells was monitored by flow cytometry of blood, bone marrow (BM) and lymph nodes (LN), staining with anti-CD20 and/or anti-CD22 mAbs, and by histology of LN. EIA was carried out after the therapy and antialphaGal Ab levels were measured daily. In vitro proportional to CD22-IT inhibited protein synthesis in the human Daudi B cell line more effectively than proportional to CD38-IT. Upon differentiation of B cells into plasma cells, however, less inhibition of protein synthesis after proportional to CD22-IT treatment was observed. Depleting CD20-positive cells in vitro from a baboon spleen cell population already depleted of granulocytes, monocytes, and T cells led to a relative enrichment of CD20-negative cells, that is plasma cells, and consequently resulted in a significant increase in antialphaGal Ab production by the remaining cells, whereas depleting CD38-positive cells resulted in a significant decrease in antialphaGal Ab production. In vivo, WBI (300 or 900 cGy) resulted in 100% B cell depletion in blood and BM, > 80% depletion in LN, with substantial recovery of B cells after 21 days and only transient reduction in antialphaGal Ab after EIA. Proportional to CD22-IT depleted B cells by > 97% in blood and BM, and by 60% in LN, but a rebound of B cells was observed after 14 and 62 days in LN and blood, respectively. At 7 days, serum antialphaGal IgG and IgM Ab levels were reduced by a maximum of 40-45% followed by a rebound to levels up to 12-fold that of baseline antialphaGal Ab by day 83 in one baboon. The results obtained with proportional to CD38-IT were inconclusive. This may have been, in part, due to inadequate conjugation of the toxin. Cell coating was 100% with proportional to CD38 mAb, but no changes in antialphaGal Ab production were observed. Proportional to CD20 mAb resulted in 100% depletion of B cells in blood and BM, and 80% in LN, with recovery of B cells starting at day 42. Adding 150cGy WBI at this time led to 100% depletion of B cells in the BM and LN. Although B cell depletion in blood and BM persisted for > 3 months, the reduction of serum antialphaGal IgG or IgM Ab levels was not sustained beyond 2 days. Proportional to CD20 mAb + WBI totally and efficiently depleted CD20- and CD22-positive B cells in blood, BM, and LN for > 3 months in vivo, but there was no sustained clinically significant reduction in serum antialphaGal Ab. The majority of antibody secretors are CD38-positive cells, but targeting these cells in vitro or in vivo with proportional to CD38-IT was not very effective. These observations suggest that CD20-and CD22-positive B cells are not the major source of antialphaGal Ab production. Future efforts will be directed towards suppression of plasma cell function.

[2] Effects of anti-CD33 blocked ricin immunotoxin on the capacity of CD34+ human marrow cells...

[DOC1781] Human marrow cells that express the CD34 antigen but lack CD33 are able to initiate sustained, multilineage in vitro hematopoiesis in long-term Dexter cultures and are believed to include the primitive stem cells responsible for effecting long-term hematopoietic reconstitution in vivo following marrow transplantation. In studies described in this report we investigated the effects of a novel anti-CD33 immunotoxin on the clonogenic potential of normal human CD34+ marrow cells and on the ability of these cells to initiate hematopoiesis in two-stage Dexter cultures (long-term marrow cultures, LTMC). This immunotoxin (anti-CD33-bR), shown previously to kill both clonogenic myelogenous leukemia cells and normal mature myeloid progenitor cells (granulocyte-macrophage colony-forming units, CFU-GM), consists of an anti-CD33 monoclonal antibody conjugated to purified ricin that has been modified by blocking the carbohydrate binding domains of the ricin B-chain to eliminate nonspecific binding. For our studies, normal CD34+ human marrow cells were isolated from the light-density (less than 1.070 g/ml) cells of aspirated marrow by positive selection with immunomagnetic beads linked to the monoclonal antibody K6.1. These cell isolates were highly enriched with both multipotential and lineage-restricted clonogenic, hematopoietic progenitors (mixed lineage colony-forming units, CFU-Mix; CFU-GM; and erythroid burst-forming units, BFU-E) which constituted greater than or equal to 20% of the cells. Recovery of clonogenic progenitors from these CD34+ cell preparations, following treatment with anti-CD33-bR (10 nM), was reduced by greater than or equal to 85% for CFU-GM and 20%-40% for CFU-Mix and BFU-E. However, the capacity of these cells to initiate hematopoietic LTMC was preserved. Indeed, the production of high proliferative potential (HPP) CFU-GM, BFU-E, and CFU-Mix in cultures seeded with 10(5) anti-CD33-bR-treated CD34+ marrow cells was substantially greater than that observed in LTMC seeded with equivalent numbers of untreated CD34+ cells. Moreover, concentrations of long-term culture initiating cells in CD34+ cell isolates, quantified by a limiting dilution technique, were found to be increased following anti-CD33-bR treatment. These findings support the potential usefulness of anti-CD33-bR for in vitro marrow purging or in vivo treatment to eliminate CD33+ leukemic clones, while sparing normal CD34+/CD33- stem cells that support normal hematopoiesis and hematopoietic reconstitution in vivo.

[3] T-cell depletion with ricin A-chain T101 in allogeneic bone marrow transplantation to prev...

[DOC5383] Bone marrow cells from 10 marrow transplant donors were treated with an immunotoxin, which couples A-chain of ricin with a monoclonal anti-T-cell antibody T101 to prevent graft-versus-host disease by the elimination of mature T-cells. Marrow cells treated with the anti human T-cell immunotoxin (IT101) were cultured for erythropoietic colonies, granulocytic colonies, and multilineage hematopoietic colonies (CFU-GEMMT) containing myeloid cells and T-cells, and optimal conditions were defined for the elimination of T-cells present in the harvested donor marrow prior to marrow transplantation. Marrow samples purged with IT101 were examined for residual T-cells by fluorescence activated cell sorting, using anti-T-cell antibodies, [3H]-thymidine incorporation after PHA stimulation, and an assay for clonogenic T-cells. The number of T-cell colonies observed in the treated marrows was less than 5% of the number in comparable unpurged donor marrows. Treatment with IT101 did not alter the plating efficiency of hematopoietic colonies compared to untreated donor marrow cells. These data suggest that multilineage progenitors responsible for the reconstitution of the recipient hematopoietic system are not affected by marrow IT101 purging. The clinical data on 10 patients indicate that the depletion of T-cells in the donor marrow with IT101 is effective in decreasing the severity of acute graft-versus-host disease in allogeneic marrow transplantation and warrants continued investigation.
Related to Topic 15: CELLS,RICIN,MEMBRANE,CELL,TRANSPORT,PROTEIN (0.120)

[1] Inhibition of coated pit formation in Hep2 cells blocks the cytotoxicity of diphtheria tox...

[DOC4597] It has been recently shown (Larkin, J. M., M. S. Brown, J. L. Goldstein, and R. G. W. Anderson, 1983, Cell, 33:273-285) that after a hypotonic shock followed by incubation in a K+-free medium, human fibroblasts arrest their coated pit formation and therefore arrest receptor-mediated endocytosis of low density lipoprotein. We have used this technique to study the endocytosis of transferrin, diphtheria toxin, and ricin toxin by three cell lines (Vero, Wi38/SV40, and Hep2 cells). Only Hep2 cells totally arrested internalization of [125I]transferrin, a ligand transported by coated pits and coated vesicles, after intracellular K+ depletion. Immunofluorescence studies using anti-clathrin antibodies showed that clathrin associated with the plasma membrane disappeared in Hep2 cells when the level of intracellular K+ was low. In the absence of functional coated pits, diphtheria toxin was unable to intoxicate Hep2 cells but the activity of ricin toxin was unaffected by this treatment. By measuring the rate of internalization of [125I]ricin toxin by Hep2 cells, with and without functional coated pits, we have shown that this labeled ligand was transported in both cases inside the cells. Hep2 cells with active coated pits internalized twice as much [125I]ricin toxin as Hep2 cells without coated pits. Entry of ricin toxin inside the cells was a slow process (8% of the bound toxin per 10 min at 37 degrees C) when compared to transferrin internalization (50% of the bound transferrin per 10 min at 37 degrees C). Using the indirect immunofluorescence technique on permeabilized cells, we have shown that Hep2 cells depleted in intracellular K+ accumulated ricin toxin in compartments that were predominantly localized around the cell nucleus. Our study indicates that in addition to the pathway of coated pits and coated vesicles used by diphtheria toxin and transferrin, another system of endocytosis for receptor-bound molecules takes place at the level of the cell membrane and is used by ricin toxin to enter the cytosol.

[2] Cerulenin inhibits the cytotoxicity of ricin, modeccin, Pseudomonas toxin, and diphtheria ...

[DOC10265] We have found that cerulenin, an antibiotic that inhibits de novo fatty acid and cholesterol biosynthesis and fatty acylation of proteins, strongly inhibited the cytotoxicity of ricin, modeccin, Pseudomonas toxin, and diphtheria toxin in a brefeldin A (BFA)-resistant mutant of Vero cells (BER-40). The protective effect of cerulenin against ricin was also observed in two other BFA-resistant cell lines, Madin-Darby canine kidney, and PtK1 cells. In contrast to BER-40 cells, no significant effect of cerulenin was observed in Vero cells. Cerulenin did not affect the binding of ricin to the cell-surface receptors, but reduced significantly the internalization of ricin in BER-40 cells; no effect of cerulenin on the binding or internalization of ricin was observed in Vero, PtK1, and Madin-Darby canine kidney cells. Endocytic uptake of fluid-phase markers such as horseradish peroxidase and lucifer yellow was inhibited by cerulenin in BER-40 cells, but the endocytosis of transferrin via the coated pit/coated vesicle pathway was slightly increased. Cerulenin inhibited the degradation and excretion of ricin in BER-40 cells, and this effect of cerulenin was not observed in Vero cells. Furthermore, cerulenin inhibited the bulk protein secretion in a dose-dependent manner, with BER-40 cells being more susceptible than Vero cells. These results suggest that in addition to its effect on endocytosis, cerulenin interferes with the intracellular trafficking or processing of toxin molecules, and the vesicle transport system in BER-40 cells appears to be cerulenin-sensitive. Since addition of fatty acids and cholesterol did not reverse the effects of cerulenin, the protective effect of cerulenin against protein toxins is not due to an inhibition of de novo fatty acids and cholesterol biosynthesis.

[3] Ricin toxicity and intracellular routing in tumoral HT-29 cells. II. Differential ricin to...

[DOC8597] We previously showed that ricin, a toxin commonly used in the construction of immunotoxins, was more toxic to undifferentiated than to differentiated HT-29 tumoral cells. This results from differences in the intracellular routings of the toxin. As these studies concerned the entry through the apical pole of differentiated polarized HT-29 cells, we investigated and compared the intracellular routing of ricin from the apical and basolateral membranes of differentiated HT-29 cells and the toxicity of ricin depending on the pole of administration. For this purpose, we developed the culture of polarized HT-29 cells on porous membrane filters and demonstrated that differentiated HT-29 cells can establish a leakproof monolayer. Ricin is 2.5-fold less toxic when it is added at the basolateral than at the apical pole of the cells, which may result from different observations: (1) less ricin is bound at the basolateral membrane than at the apical one, leading to a lesser internalization of the toxin; (2) ricin sorting in the apical and basolateral endocytic compartments of HT-29 cells differs: apically internalized ricin is targeted intracellularly while basolaterally internalized ricin uses mainly the transcytotic pathway; using NH4Cl and monensin, we observed that ricin follows the same pathway from both sides of the cells, namely the endosomal system, to reach the Golgi apparatus from which toxin intoxication occurs; (3) kinetics studies showed that a delay exists before an efficient intoxication by the basolateral pole is observed. The use of monensin at low concentration in order to perturb only the Golgi functions indicated that this delay could account for a different presentation of the toxin toward the membrane of the apical and basolateral endocytic compartments. Together, our results showed that, in differentiated HT-29 cells, if the pathways carrying ricin from the apical and basolateral membranes to the Golgi apparatus appear identical, ricin exerts differentially its toxicity depending upon the surface of administration, i.e., the apical or the basolateral surface of the cells.
Related to Topic 1: RICIN,CHAIN,CELLS,IMMUNOTOXIN,ANTI,ANTIBODY (0.097)

[1] An epidermal growth factor-ricin A chain (EGF-RTA)-resistant mutant and an epidermal growt...

[DOC3884] H2Oe12 is a mutant HeLa cell line selected for resistance to the toxicity of a chimeric protein conjugate composed of epidermal growth factor (EGF) and the toxic A chain of ricin (RTA). ET-28 is a mutant KB cell line selected for resistance to the toxicity of a chimeric protein conjugate composed of EGF and Pseudomonas exotoxin (PE). In this report we describe the presence or absence, in these mutants, of cross-resistance to the two toxic conjugates and the effects of ammonium chloride, leupeptin, and adenovirus cotreatments on toxin efficacies. ET-28 cells, the EGF-PE-resistant cells, are resistant to both EGF-PE and EGF-RTA. In contrast, H2Oe12 cells, the EGF-RTA-resistant cells, are as sensitive to EGF-PE toxicity as are their parent HeLa cells. Ammonium chloride cotreatment substantially reduces the resistance of H2Oe12 cells to EGF-RTA but has little or no effect on the resistance of ET-28 cells to either EGF-RTA or EGF-PE. Leupeptin has no effect on the toxicity of either chimeric conjugate on any of the four cell lines, effect on the toxicity of either chimeric conjugate on any of the four cell lines, despite its demonstrated ability to inhibit cellular degradation of EGF. In contrast, adenovirus cotreatment enhances the toxicity of EGF-RTA and EGF-PE on all cells tested, and completely nullifies the relative resistance of H2Oe12 and ET-28 cells to these toxic conjugates. H2Oe12 and ET-28 cells appear to be altered in distinct, possibly endosomal, functions.

[2] Toxicity of ligand and antibody-directed ricin A-chain conjugates recognizing the epiderma...

[DOC5638] Approximately equal amounts of 125I-mAb 225 (a monoclonal antibody recognizing the human epidermal growth factor receptor) and 125I-labeled epidermal growth factor (125I-EGF) were bound by HeLa cells. However, these two EGF receptor binding moieties had different fates after binding. Sixty percent of cell-associated 125I-EGF was internalized. The majority of internalized 125I was released from the cell within 2 hr. In contrast, whereas only 30% of bound 125I-mAb 225 was internalized by HeLa cells, the internalized radioactivity remained cell-associated. EGF and mAb 225 were used to construct ricin A-chain (RTA) conjugates. The two chimeric molecules, EGF-RTA and mAb 225-RTA, were equally toxic to human HeLa cells. EGF-RTA was also toxic to murine 3T3 cells. In contrast, mAb 225-RTA was not toxic to 3T3 cells, consistent with the human EGF-receptor specificity of mAb 225. Neither conjugate was cytotoxic to EGF receptor-deficient 3T3-NR6 cells. Rapidity and potency of protein synthesis inhibition of HeLa cells were equivalent for the two chimeric conjugates, as was the degree to which colony-forming ability was reduced. However, ammonium chloride enhanced the toxicity of EGF-RTA but not mAb 225-RTA, suggesting that the two toxic chimeric toxins--like the unconjugated receptor-binding moieties--are processed differently by HeLa cells.

[3] Complete suppression of in vivo growth of human leukemia cells by specific immunotoxins: n...

[DOC5631] In this study, immunotoxins containing monoclonal anti-human T-cell leukemia antibodies are shown to be capable of completely suppressing the tumor growth of human T-cell leukemia cells in vivo without any overt undesirable toxicity. These immunotoxins were prepared by conjugating ricin A chain (RA) with our monoclonal antibodies, SN1 and SN2, directed specifically to the human T-cell leukemia cell surface antigens TALLA and GP37, respectively. We have shown that these monoclonal antibodies are highly specific for human T-cell leukemia cells and do not react with various normal cells including normal T and B cells, thymocytes, and bone marrow cells. Ascitic and solid human T-cell leukemia cell tumors were generated in nude mice. The ascitic tumor was generated by transplanting Ichikawa cells (a human T-cell leukemia cell line) i.p. into nude mice, whereas the solid tumor was generated by transplanting s.c. MOLT-4 cells (a human T-cell leukemia cell line) and x-irradiated human fibrosarcoma cells into x-irradiated nude mice. To investigate the efficacy of specific immunotoxins in suppressing the in vivo growth of the ascitic tumor, we divided 40 nude mice that were injected with Ichikawa cells into four groups. Each group of 10 mice was injected with one of the following mixtures: 40 micrograms of purified control mouse IgG [IgG1(kappa)] (group 1), 40 micrograms of control RA conjugate (group 2), 20 micrograms of purified SN1 antibody [IgG1(kappa)] and 20 micrograms of purified SN2 antibody [IgG1(kappa)] (group 3), or 20 micrograms of SN1-RA and 20 micrograms of SN2-RA (group 4). Mice in groups 1 and 2 formed large ascitic tumors, and died 5.8-7.0 weeks after the transplantation. Group 3 mice also formed large ascitic tumors and died 6.4-7.8 weeks after the transplantation. However, none of the mice in group 4 that were treated with SN1-RA and SN2-RA showed any signs of a tumor or undesirable toxic effects for the 20 weeks that they were followed after the transplantation; these mice were indistinguishable from healthy control nude mice that were not injected with Ichikawa cells. Treatment with SN1-RA plus SN2-RA completely suppressed solid tumor growth in 4 of 10 nude mice carrying solid tumors and partially suppressed the tumor growth in the remaining 6 nude mice. These results strongly suggest that SN1-RA and SN2-RA may be useful for clinical treatment.
CLINICAL
Most likely documents

[1] Presumptive specific clinical diagnosis of genital ulcer disease (GUD) in a primary health...

[DOC10844] During a 12-month period in 1990-1991 in Kenya, 1076 of 22,274 patients (4.8% of all patients over 12 years of age) presented at the Langata Health Center in Nairobi with symptoms of a sexually transmitted disease (STD). Researchers analyzed data on 980 of these patients whose records had complete data to assess the use of presumptive specific clinical diagnosis in the management of STDs in a primary health clinic. 17.1% (168) had genital ulcer disease (GUD). Men were more likely to have a GUD than women (24.7% vs. 10.4%). Haemophilus ducreyi, the etiologic agent of chancroid, was isolated in the cultures of 40% of the patients with a presumptive specific clinical diagnosis of chancroid compared with 17% of those with a presumptive specific clinical diagnosis of syphilis, herpes, or lymphogranuloma venereum (LGV) (p = 0.02). The clinical diagnoses of these two GUDs had only a weak correlation with microbiological and serological diagnoses (p = 0.13). 24% of patients with a presumptive specific clinical diagnosis of syphilis, 31% of those with a presumptive specific clinical diagnosis of chancroid, 6% of those with a specific clinical diagnosis of genital herpes or LGV, and 4.7% of those who had no GUD disease tested positive for syphilis (p 0.001, GUD vs. no GUD). Among patients with syndromic diagnosis of GUD, the presumptive specific clinical diagnosis of chancroid had a high sensitivity (91%), low specificity (24%), and low positive predictive value (40%). Among patients with syndromic diagnosis of syphilis, the presumptive specific clinical diagnosis of syphilis had a low sensitivity (25%), higher specificity (87%), and low positive predictive value (24%). 13% of patients with positive cultures for H. ducreyi did not receive a recommended or effective drug for chancroid. 82% of patients who tested positive for syphilis did not receive a recommended drug for syphilis. Based on these findings, the researchers conclude that syndromic treatment of GUD with use of antimicrobial combinations active against both chancroid and syphilis is a better course of treatment than use of single drugs based on presumptive specific clinical diagnoses for this population.

[2] Central nervous system infections in the compromised host: a diagnostic approach.

[DOC15763] The diagnostic approach to the compromised host with CNS infection depends on an analysis of the patient's clinical manifestations of CNS disease, the acuteness or subacuteness of the clinical presentation, and an analysis of the type of immune defect compromising the patient's host defenses. Most patients with CNS infections may be grouped into those with meningeal signs, or those with mass lesions. Other common manifestations of CNS infection include encephalopathy, seizures, or a stroke-like presentation. Most pathogens have a predictable clinical presentation that differs from that of the normal host. CNS Aspergillus infections present either as mass lesions (e.g., brain abscess), or as cerebral infarcts, but rarely as meningitis. Cryptococcus neoformans, in contrast, usually presents as a meningitis but not as a cerebral mass lesion even when cryptococcal elements are present. Aspergillus and Cryptococcus CNS infections are manifestations of impaired host defenses, and rarely occur in immunocompetent hosts. In contrast, the clinical presentation of Nocardia infections in the CNS is the same in normal and compromised hosts, although more frequent in compromised hosts. The acuteness of the clinical presentation coupled with the CNS symptomatology further adds to limit differential diagnostic possibilities. Excluding stroke-like presentations, CNS mass lesions tend to present subacutely or chronically. Meningitis and encephalitis tend to present more acutely, which is of some assistance in limiting differential diagnostic possibilities. The analysis of the type of immune defect predicts the range of possible pathogens likely to be responsible for the patient's CNS signs and symptoms. Patients with diseases and disorders that decrease B-lymphocyte function are particularly susceptible to meningitis caused by encapsulated bacterial pathogens. The presentation of bacterial meningitis is essentially the same in normal and compromised hosts with impaired B-lymphocyte immunity. Compromised hosts with impaired T-lymphocyte or macrophage function are prone to develop CNS infections caused by intracellular pathogens. The most common intracellular pathogens are the fungi, particularly Aspergillus, other bacteria (e.g., Nocardia), viruses (i.e., HSV, JC, CMV, HHV-6), and parasites (e.g., T. gondii). The clinical syndromic approach is most accurate when combining the rapidity of clinical presentation and the expression of CNS infection with the defect in host defenses. The presence of extra-CNS sites of involvement also may be helpful in the diagnosis. A patient with impaired cellular immunity with mass lesions in the lungs and brain that have appeared subacutely or chronically should suggest Nocardia or Aspergillus rather than cryptococcosis or toxoplasmosis. Patients with T-lymphocyte defects presenting with meningitis generally have meningitis caused by Listeria or Cryptococcus rather than toxoplasmosis or CMV infection. The disorders that impair host defenses, and the therapeutic modalities used to treat these disorders, may have CNS manifestations that mimic infections of the CNS clinically. Clinicians must be ever vigilant to rule out the mimics of CNS infections caused by noninfectious etiologies. Although the syndromic approach is useful in limiting diagnostic possibilities, a specific diagnosis still is essential in compromised hosts in order to describe effective therapy. Bacterial meningitis, cryptococcal meningitis, and tuberculosis easily are diagnosed accurately from stain, culture, or serology of the CSF. In contrast, patients with CNS mass lesions usually require a tissue biopsy to arrive at a specific etiologic diagnosis. In a compromised host with impaired cellular immunity in which the differential diagnosis of a CNS mass lesion is between TB, lymphoma, and toxoplasmosis, a trial of empiric therapy is warranted. Antitoxoplasmosis therapy may be initiated empirically and usually results in clinical improvement after 2 to 3 weeks of therapy. The nonresponse to antitoxoplasmosis therapy in such a patient would warrant an empiric trial of antituberculous therapy. Lack of response to anti-Toxoplasma and antituberculous therapy should suggest a noninfectious etiology (e.g., CNS lymphoma). Fortunately, most infections in compromised hosts are similar in their clinical presentation to those in the normal host, particularly in the case of meningitis. The compromised host is different than the normal host in the distribution of pathogens, which is determined by the nature of the host defense defect. In compromised hosts, differential diagnostic possibilities are more extensive and the likelihood of noninfectious explanations for CNS symptomatology is greater. (ABSTRACT TRUNCATED)

[3] [Idiopathic partial epilepsy with occipital paroxysms]

[DOC13929] BACKGROUND: The syndrome of idiopathic partial epilepsy with occipital paroxysms in the electroencephalogram (EEG) shows a considerable clinical and prognostic heterogeneity. The semiology of seizures varies considerably among patients and its hallmark, occipital paroxysms blocked by eye opening, may appear in other idiopathic or symptomatic epilepsies of childhood and even in nonepileptic disorders, notably basilar artery migraine. To address these unresolved issues in children with this rare form of epilepsy, the present paper utilized a longitudinal approach and investigated the significance of electrophysiologic and clinical characteristics necessary for the diagnostic and prognostic evaluation during a long-term follow-up. PATIENTS AND METHODS: Over a 9-year period all patients, aged 1-15 years, who showed occipital paroxysms in EEG recordings were included in this study. In addition, clinical correlates were available for all these patients. Neurological, psychiatric and other clinical examinations were done in all patients. Whenever indicated, the neuroimaging of the brain (computerized tomography and/or magnetic resonance) was performed to establish the symptomatic aetiology. The epileptic syndromes were determined according to criteria of the International classification. A detailed EEG analysis of all patients, performed during a 3-12 year follow-up period, included hyperventilation, photic stimulation and a thorough testing of visual reactivity with exclusion of central vision. The incidence of EEG characteristics in patients with various epileptic syndromes was compared and its significance for the differential diagnosis was tested by nonparametric statistical methods. The clinical semiology of epilepsy and/or other associated disorders and EEG findings were compared among the patients with idiopathic partial epilepsy and occipital paroxysms. RESULTS: Occipital epileptiform paroxysms were recorded in EEGs of 76 children with various clinical diagnoses but only 58 patients had seizures. The incidence of epilepsy (39 patients or 51%) was slightly higher than that of various non-epileptic disorders (37 patients or 49%). Two types of these paroxysms were analyzed: reactive (appearing at exclusion of central vision and disappearing on eye opening) or unreactive (persisting in the above situations). The difference in incidence of seizures (in a total of 58 patients) depending on the types of paroxysms was not statistically significant. EEG characteristics in 25 patients with both reactive paroxysms and seizures were compared in relation to the aetiology of epileptic syndromes. Comparing EEG in various types of epilepsy with reactive paroxysms, the statistical analysis (using Fischer's exact test) established that slowed background activity was significantly more frequent in symptomatic partial epilepsy than in idiopathic syndromes. On the other hand, EEG normalization during the follow-up period was a rule in benign epilepsy with centro-temporal paroxysms and in childhood absence epilepsy, and it was significantly more frequent in idiopathic partial epilepsy with occipital paroxysms than in symptomatic partial epilepsy. However, EEG findings per se cound not differentiate idiopathic partial epilepsy with occipital paroxysms from other epileptic syndromes. Neither seizures semiology could distinguish between different forms of occipital lobe epilepsy. Therefore, a correct syndromic and aetiologic classification for each patient with occipital spike-wave paroxysms required the combined and thorough assessment integrating clinical examination, clinical neurophysiological analyses, and neuroimaging studies during the follow-up. Using all above methods during the follow-up of 11 patients with idiopathic partial epilepsy with occipital paroxysms (IPEOP) it was found that this syndrome had often a very favorable prognosis if characterized by rare, nocturnal seizures beginning in preschool age. (ABSTRACT TRUNCATED)
Related to Topic 8: CLINICAL,DIAGNOSIS,SYMPTOMS,DISEASE,SIGNS,CASES (0.567)

[1] Central nervous system infections in the compromised host: a diagnostic approach.

[DOC15763] The diagnostic approach to the compromised host with CNS infection depends on an analysis of the patient's clinical manifestations of CNS disease, the acuteness or subacuteness of the clinical presentation, and an analysis of the type of immune defect compromising the patient's host defenses. Most patients with CNS infections may be grouped into those with meningeal signs, or those with mass lesions. Other common manifestations of CNS infection include encephalopathy, seizures, or a stroke-like presentation. Most pathogens have a predictable clinical presentation that differs from that of the normal host. CNS Aspergillus infections present either as mass lesions (e.g., brain abscess), or as cerebral infarcts, but rarely as meningitis. Cryptococcus neoformans, in contrast, usually presents as a meningitis but not as a cerebral mass lesion even when cryptococcal elements are present. Aspergillus and Cryptococcus CNS infections are manifestations of impaired host defenses, and rarely occur in immunocompetent hosts. In contrast, the clinical presentation of Nocardia infections in the CNS is the same in normal and compromised hosts, although more frequent in compromised hosts. The acuteness of the clinical presentation coupled with the CNS symptomatology further adds to limit differential diagnostic possibilities. Excluding stroke-like presentations, CNS mass lesions tend to present subacutely or chronically. Meningitis and encephalitis tend to present more acutely, which is of some assistance in limiting differential diagnostic possibilities. The analysis of the type of immune defect predicts the range of possible pathogens likely to be responsible for the patient's CNS signs and symptoms. Patients with diseases and disorders that decrease B-lymphocyte function are particularly susceptible to meningitis caused by encapsulated bacterial pathogens. The presentation of bacterial meningitis is essentially the same in normal and compromised hosts with impaired B-lymphocyte immunity. Compromised hosts with impaired T-lymphocyte or macrophage function are prone to develop CNS infections caused by intracellular pathogens. The most common intracellular pathogens are the fungi, particularly Aspergillus, other bacteria (e.g., Nocardia), viruses (i.e., HSV, JC, CMV, HHV-6), and parasites (e.g., T. gondii). The clinical syndromic approach is most accurate when combining the rapidity of clinical presentation and the expression of CNS infection with the defect in host defenses. The presence of extra-CNS sites of involvement also may be helpful in the diagnosis. A patient with impaired cellular immunity with mass lesions in the lungs and brain that have appeared subacutely or chronically should suggest Nocardia or Aspergillus rather than cryptococcosis or toxoplasmosis. Patients with T-lymphocyte defects presenting with meningitis generally have meningitis caused by Listeria or Cryptococcus rather than toxoplasmosis or CMV infection. The disorders that impair host defenses, and the therapeutic modalities used to treat these disorders, may have CNS manifestations that mimic infections of the CNS clinically. Clinicians must be ever vigilant to rule out the mimics of CNS infections caused by noninfectious etiologies. Although the syndromic approach is useful in limiting diagnostic possibilities, a specific diagnosis still is essential in compromised hosts in order to describe effective therapy. Bacterial meningitis, cryptococcal meningitis, and tuberculosis easily are diagnosed accurately from stain, culture, or serology of the CSF. In contrast, patients with CNS mass lesions usually require a tissue biopsy to arrive at a specific etiologic diagnosis. In a compromised host with impaired cellular immunity in which the differential diagnosis of a CNS mass lesion is between TB, lymphoma, and toxoplasmosis, a trial of empiric therapy is warranted. Antitoxoplasmosis therapy may be initiated empirically and usually results in clinical improvement after 2 to 3 weeks of therapy. The nonresponse to antitoxoplasmosis therapy in such a patient would warrant an empiric trial of antituberculous therapy. Lack of response to anti-Toxoplasma and antituberculous therapy should suggest a noninfectious etiology (e.g., CNS lymphoma). Fortunately, most infections in compromised hosts are similar in their clinical presentation to those in the normal host, particularly in the case of meningitis. The compromised host is different than the normal host in the distribution of pathogens, which is determined by the nature of the host defense defect. In compromised hosts, differential diagnostic possibilities are more extensive and the likelihood of noninfectious explanations for CNS symptomatology is greater. (ABSTRACT TRUNCATED)

[2] [Thrombotic thrombocytopenic purpura and hemorrhagic fever with renal syndrome: possible d...

[DOC21966] Thrombotic thrombocytopenic purpura (TTP) and hemolytic uremic syndrome (HUS) are classical diseases characterized by thrombocytopenia and microangiopathic hemolytic anemia. Microangiopathic hemolytic anemia is also a part of clinical picture in patients with hemorrhagic fever with renal syndrome (HFRS). Some overlap in other elements of clinical picture between TTP and HFRS is possible, which could pose difficulties in differential diagnosis. Early treatment of patients with TTP is essential and significantly improves the outcome, whereas the treatment of HFRS is mainly supportive. In the last ten years, we treated 13 patients with TTP and 17 patients with HFRS. Two patients with HFRS were initially treated as TTP because it was not possible to exclude TTP on the basis of clinical picture. Further clinical course and serologic tests excluded TTP and suggested HFRS. CONCLUSION: Sometimes it is difficult to distinguish HFRS from TTP because thrombocytopenia and microangiopathic hemolytic anemia are present in both diseases and overlaps in other parts of clinical picture are possible. The serious consequences of delay in the efficacious treatment of patients with TTP could also influence the physicians' decisions.

[3] The protean manifestations of hemorrhagic fever with renal syndrome. A retrospective revie...

[DOC2939] Twenty-six cases of hemorrhagic fever with renal syndrome from 1981 to 1986 were retrospectively reviewed to determine the scope of clinical presentation and the unique complications of the illness. The diagnosis was confirmed by detection of Hantaan virus antibody in 25 cases and by characteristic autopsy findings in 1 case. The illness could be classified into three distinct clinical subgroups. Fever was universally present. Two patients presented with intractable shock and diffuse hemorrhage and died within 6 days from multi-organ system failure, mimicking the clinical picture of overwhelming sepsis. Eighteen patients presented with acute renal failure with an illness lasting a mean of 21 days (range, 10 to 36 days). Resolution of thrombocytopenia heralded recovery of renal function. At discharge, the serum creatinine level was normal in 13 patients; 5 patients had evidence of minimal renal dysfunction. Acute pulmonary edema requiring hemodialysis and retroperitoneal hemorrhage were the major complications in this subgroup. Six patients had an undifferentiated febrile illness with normal renal function. Fever, thrombocytopenia, abnormal urinalysis, hypertransaminasemia, and a benign clinical course characterized the third clinical pattern. The recent availability of serodiagnostic methods to detect Hantavirus group antibody facilitates the diagnosis of hemorrhagic fever with renal syndrome. Application of this test in the described clinical settings will identify unsuspected cases, broaden the knowledge of the geographic distribution of Hantavirus infection, and increase physician awareness of its protean manifestations.
Related to Topic 6: PATIENTS,PATIENT,CLINICAL,HOSPITAL,DISEASE,SEVERE (0.179)

[1] Severe acute respiratory syndrome: relationship between radiologic and clinical parameters...

[DOC20673] PURPOSE: To quantify severity of severe acute respiratory syndrome (SARS) on chest radiographs and to determine its relationship with clinical parameters. MATERIALS AND METHODS: Forty patients (mean age, 42.90 years +/- 14.01 [SD]; median age, 41.5 years; age range, 25-82 years) with clinically diagnosed SARS were evaluated. Heart rate, oxygen saturation, temperature, and alanine aminotransferase (ALT) and aspartate aminotransferase (AST) levels were recorded daily. Severity of lung changes on chest radiographs was scored according to percentage of involved lung. Radiographic scores at days of admission, treatment, and maximal radiographic score were extracted for statistical analysis with clinical parameters. Time to maximal radiographic score from admission and days between onset and beginning of treatment were determined. Correlations between radiographic and clinical parameters were evaluated with Spearman rank correlation. Sex differences with respect to clinical and radiographic parameters were evaluated with Mann-Whitney test. RESULTS: Median chest radiographic scores peaked 5 days after beginning of treatment before they declined. Maximal and treatment radiographic scores were inversely related to oxygen saturation (r = -0.67, P <.001; r = -0.35, P =.03). Admission radiographic score was correlated with admission AST level (r = 0.53, P =.003); treatment radiographic score, with treatment ALT and AST levels (r = 0.43, P =.007; r = 0.42, P =.019); and time to maximal radiographic score, with AST level at maximal radiographic score (r = -0.45, P =.006), admission radiographic score (r = -0.55, P <.001), treatment radiographic score (r = -0.58, P <.001), and admission ALT and AST levels (r = -0.44, P =.007; r = -0.58, P =.001). Treatment delay was associated with AST level at maximal radiographic score (r = 0.53, P =.001), treatment radiographic score (r = 0.60, P <.001), and time to maximal radiographic score (r = -0.36, P =.02). No sex differences occurred with respect to radiographic and clinical parameters (P >.05). CONCLUSION: Severity of lung abnormalities quantified on chest radiographs correlates with clinical and laboratory parameters.

[2] [Clinical features and management of recurrence of severe acute respiratory syndrome]

[DOC20993] OBJECTIVE: To investigate the clinical features of recurrence of severe acute respiratory syndrome (SARS) and therapeutic response. METHODS: Recurrence was analyzed retrospectively in SARS patients referred to our hospital from April to May this year to understand the clinical features, the recurrent related factors, the response of treatment and the outcomes. RESULTS: One hundred and twenty three patients with SARS were referred to the First Hospital of Peking University from 8, April to 14, May this year and of whom 51 were the critical. Twenty-five patients experienced recurrence, account for 20.3% of total patients (25/123) and 31.4% of critical patients. The clinical features included recurrent fever, worsened breathlessness, exacerbation in radiological lesions and elevated LDH, etc.. These patients were treated with glucocorticoids. Eleven of them were mechanical ventilated. Twenty-one patients recovered. Pulmonary fibrosis were left in 2 patients and another 2 patients died. CONCLUSION: The recurrence of symptoms in SARS patients is one of the common clinical feature of critical patients with SARS. Mechanism of recurrence in SARS patient is unknown. Management with glucocorticoids and noninvasive ventilation can control the progression in these patients effectively.

[3] Severe acute respiratory syndrome: radiographic review of 40 probable cases in Toronto, Ca...

[DOC19935] PURPOSE: To review radiographic findings of patients with probable severe acute respiratory syndrome (SARS) who were seen at a University of Toronto (Ontario, Canada) teaching hospital. MATERIALS AND METHODS: Findings were reviewed for 40 patients who fulfilled the World Health Organization criteria for probable SARS. A template was designed for the analysis of each serial radiograph to observe patterns and distribution of disease, interval changes, and complications. The majority of radiographs were anteroposterior views. A clinical database of these patients was also collected for clinical-radiologic comparison. RESULTS: The mean age of the patients (18 male, 22 female) was 42.7 years. Patients had a normal chest radiograph and focal, multifocal, and/or bilateral consolidation. The pattern of consolidation tended to be peripheral and poorly marginated and involved middle and lower lung zones. The serial sequence fell into two major subgroups, which correlated closely with clinical outcome. Consolidation in one group cleared within a matter of days, while the second group went on to develop rapid and extensive bilateral pneumonia, with a prolonged hospital stay. Subsegmental atelectasis and pleural complications were rarely observed. CONCLUSION: SARS pneumonia can manifest as focal peripheral consolidation that clears relatively quickly and does not cause secondary complications or that progresses to bilateral consolidation and a more protracted clinical course.
Related to Topic 33: TREATMENT,TREATED,EFFECTIVE,THERAPY,EFFECTS,DRUG (0.062)

[1] The management of epilepsy in the 1990s. Acquisitions, uncertainties and priorities for fu...

[DOC8616] The pharmacological treatment of epilepsy has made considerable progress during the last decade, due to improved knowledge of the clinical pharmacology of individual drugs, acquisition of new information on the factors affecting response and need for drug treatment, and development of promising new agents. Once a clinical diagnosis of epilepsy has been made (which generally requires the occurrence of more than one seizure), treatment should be started with a single drug selected on the basis of seizure type and tolerability profile. Although there are important regional differences in prescribing patterns and individual circumstances may dictate alternative choices, carbamazepine is generally regarded as the preferred treatment for partial seizures (with or without secondary generalisation) while valproic acid (sodium valproate) is usually the first choice in most forms of generalised epilepsies. To achieve therapeutic success, the daily dosage must be tailored to meet individual needs, and there is suggestive evidence that in some patients the dosage prescribed initially may be unnecessarily large. Plasma antiepileptic drug concentrations may aid in the individualization of dosage, but should not be regarded as a substitute for careful monitoring of clinical response. Although overall about 70% of patients can be completely controlled, response rate is influenced by a number of factors, the most important of which are seizure type and syndromic form. The importance of a correct syndromic classification for rational drug selection has been poorly assessed and represents a major area for future research. Patients who do not respond to the highest tolerated dose of the initially prescribed drug may be switched to monotherapy with an alternative agent or may be given add-on treatment with a second drug. Appropriate prospective trials are required to assess the merits of either strategy. If add-on therapy is selected and the patient becomes seizure free, it may be possible to discontinue the drug prescribed initially and reinstitute monotherapy. Only a minority of patients are likely to require multiple drug therapy, and it remains to be established whether specific drug combinations are more effective than others. Until further information becomes available, the new agents should be reserved for patients failing to respond to the conventional treatments of first choice. Patients whose seizures cannot be controlled by available drugs should be reassessed, and polytherapy should be maintained only when there is clear evidence that benefits outweigh possible adverse effects. In many patients who have been seizure free for at least 2 years it may be possible to gradually discontinue all medications.(ABSTRACT TRUNCATED AT 400 WORDS)

[2] Increased survival of patients treated with a vaccinia melanoma oncolysate vaccine: second...

[DOC11756] OBJECTIVE: The efficacy of vaccinia melanoma oncolysate (VMO) vaccine to increase overall survival and disease-free survival of patients with surgically resected International Union Against Cancer (UICC) stage II melanoma was studied in a phase III, randomized, multi-institutional trial. SUMMARY BACKGROUND DATA: Phase I and II trials with VMO showed minimal toxicity and clinical efficacy in patients with melanoma. In a recently completed phase III VMO trial, the first interim analysis performed in April 1994 showed an increasing trend in the survival of patients treated with VMO. The second interim analysis was performed in April 1995. METHODS: Patients with surgically resected stage II (UICC) melanoma were treated with VMO (N = 104) or placebo vaccinia vaccine virus (V) (N = 113) once a week for 13 weeks and then once every 2 weeks for a total of 12 months. Patients' clinical data were collected as of May 1995 and analyzed for survival. RESULTS: In this second interim analysis, the mean follow-up time is 42.28 months. No survival difference was observed between VMO and V treatments. However, in a retrospective subset analysis, a subset of males between the ages of 44 and 57 years and having one to five positive nodes (at 2-, 3-, and 5-year intervals, 13.6%, 15.9%, and 20.3% difference insurvival in favor of VMO [N = 20] when compared to V [N = 18] [p = 0.037]) and another subset of patients with clinical stage I (at 3- and 5-year intervals, 30% and 7% difference in survival in favor of VMO [N = 20] when compared to V [N = 23], [p = 0.05]) showed significant survival advantage with VMO. CONCLUSIONS: Although VMO vaccine therapy in surgical adjuvant setting did not produce a significant survival benefit to all patients with melanoma, patients from the above two subsets had significant survival benefit.

[3] Gateways to Clinical Trials.

[DOC18429] Gateways to clinical Trials is a guide to the most recent clinical trials in current literature and congresses. The data in the following tables has been retrieved from the clinical Studies knowledge area of Prous Science Integrity, the drug discovery and development portal, http://integrity.prous.com. This issue focuses on the following selection of drugs: Adalimumab, aeroDose insulin inhaler, agomelatine, alendronic acid sodium salt, aliskiren fumarate, alteplase, amlodipine, aspirin, atazanavir; Bacillus Calmette-Guérin, basiliximab, BQ-788, bupropion hydrochloride; Cabergoline, caffeine citrate, carbamazepine, carvedilol, celecoxib, cyclosporine, clopidogrel hydrogensulfate, colestyramine; Dexamethasone, diclofenac sodium, digoxin, dipyridamole, docetaxel, dutasteride; Eletriptan, enfuvirtidie, eplerenone, ergotamine tartrate, esomeprazole magnesium, estramustine phosphate sodium; Finasteride, fluticasone propionate, fosinopril sodium; Ganciclovir, GBE-761-ONC, glatiramer acetate, gliclazide, granulocyte-CSF; Heparin sodium, human isophane insulin (pyr), Hydrochlorothiazide; Ibuprofen, inhaled insulin, interferon alfa, interferon beta-1a; Laminvudine, lansoprazole, lisinopril, lonafarnib, losartan potassium, lumiracoxib; MAb G250, meloxicam methotrexate, methylprednisolone aceponate, mitomycin, mycophenolate mofetil; Naproxen sodium, natalizumab, nelfinavir mesilate, nemifitide ditriflutate, nimesulide; Omalizumab, omapatrilat, omeprazole, oxybutynin chloride; Pantoprazole sodium, paracetamol, paroxetine, pentoxifylline, pergolide mesylate, permixon, phVEGF-A165, pramipexole hydrochloride, prasterone, prednisone, probucol, propiverine hydrochloride; Rabeprazole sodium, resiniferatoxin, risedronate sodium, risperidone, rofecoxib rosiglitazone maleate, ruboxistaurin mesilate hydrate; Selegiline transdermal system, sertraline, sildenafil citrate, streptokinase; Tadalafil, tamsulosin hydrochloride, technosphere/Insulin, tegaserod maleate, tenofovir disoproxil fumarate, testosterone heptanoate, testosterone undecanoate, tipifarnib, tolterodine tartrate, topiramate, troglitazone; Ursodeoxycholic acid; Valdecoxib, valsartan, vardenafil, venlafaxine hydrochloride, VX-745.
Related to Topic 13: RESEARCH,DEVELOPMENT,RECENT,REVIEW,CURRENT,KNOWLEDGE (0.050)

[1] Laboratory diagnosis of Bartonella infections.

[DOC18609] Bartonella species are pathogens of emerging and reemerging significance, causing a wide array of clinical syndromes. In North America and Europe, they are increasingly recognized as a cause of culture negative endocarditis, neuroretinitis, and disease among homeless, HIV-infected, and other immunosuppressed individuals. In South America, bartonellosis continues to plague those in endemic regions and poses a significant threat to travelers in these areas. As the clinician is increasingly faced with these illnesses, which may be difficult to diagnose, laboratory techniques to confirm or refute the diagnosis are becoming increasingly important. Culture methods have improved over the past decade demonstrating increased sensitivity, but still require prolonged periods before isolation of the organism. Specimen handling, media selection, and growth conditions all may affect results and must be optimized in order to provide the highest likelihood of recovering the organism. Pure culture of the bacteria not only provides morphologic information, but also provides material for further diagnostic testing. Work with liquid media, which may provide a more rapid means of cultivation has shown some promise and should continue to be pursued. Improved blood culture techniques were a primary factor in the discovery of Bartonella endocarditis and continued improvements will likely demonstrate further clinical insights. Serologic testing for B henselae infections has become the cornerstone of clinical diagnosis, replacing the skin test that was poorly standardized and posed a potential risk to the patient. Immunofluorescence assays have been well characterized and validated in clinical trials, however they are not universally available. Vero cell cocultivated antigens appear to provide higher sensitivity and specificity when compared with agar-derived antigens. IFA assays are inherently difficult to perform, requiring significant expertise to provide reproducible results. On the contrary, enzyme immunoassays offer ease of use and a high level of reproducibility, however ideal antigens for use in the diagnosis of Bartonella infections have not been clearly identified. Continued work to define antigenic targets of the human response to infection and incorporation of these into a widely available EIA will provide a cost-effective tool for the clinician and epidemiologist alike. Due to the close phylogenetic relationship of B henselae and B quintana, differentiation between these species by serologic means may prove difficult. Molecular techniques including PCR offer high sensitivity and specificity, rapid availability of information, and the ability to differentiate Bartonella organisms at the highest level. Results of studies to date are promising and as methods are refined it will be important to conduct clinical studies to define the role of these assays. In disseminated Bartonella infections such as bacillary angiomatosis, peliosis, endocarditis, and urban trench fever, PCR currently offers the ability to establish the diagnosis when other tests may be unrevealing. For CSD, this technique should be used as a confirmatory technique when the diagnosis is unclear by other means. PCR analysis of blood specimens offers a minimally invasive approach to diagnosis, but clinical data are scarce and further studies are needed. As DNA microarrays move into the clinical arena, specific hybridization probes may allow improved identification and differentiation of Bartonellae at the molecular level.

[2] Practical applications of viral fitness in clinical practice.

[DOC19827] PURPOSE OF REVIEW: To review recent clinical data regarding viral fitness and its potential utility in clinical practice. Therapeutic failure of antiretroviral regimens is often due to the development of drug resistance. The viral loads achieved by these drug-resistant variants frequently remain suppressed below pretreatment levels. Furthermore, many patients with virologic failure continue to maintain stable CD4 counts and remain clinically well. One possible explanation for these observations is that the resistant virus that emerges during failure of highly active antiretroviral therapy is less fit than its wild-type counterpart as a result of the requirement to maintain resistance mutations that allow it to replicate in the presence of antiretroviral drugs. Since there are many patients with limited treatment options due to extensive resistance or drug toxicities, or both, there is intense interest in exploring the possibility that viral fitness can be exploited for clinical benefit. This review describes the assays that are used to measure fitness and replication capacity, and investigations of their utility in clinical practice. RECENT FINDINGS: A number of methods have been developed to measure viral fitness. Replication kinetic and competitive culture assays are accurate, but labour and time intensive. The availability of a rapid, single-cycle recombinant assay that measures viral replication capacity presents the possibility that assessments of viral fitness could be incorporated into clinical management. The replication capacity assay appears to correlate with more standard measures of viral fitness, and recently accumulated data in both wild-type and drug resistant viral populations suggest that replication capacity describes an intrinsic characteristic of HIV-1. A number of investigations of the clinical utility of fitness and replication capacity assays have established correlations between these measurements and virologic and immunologic outcomes. SUMMARY: Much progress has been made in the past year in our understanding of viral fitness and replication capacity. Assays that measure these viral characteristics have the potential to expand the range of clinical strategies employed against HIV-1. Further investigations are needed to firmly establish the clinical utility of these assays.

[3] Advances in antiretroviral therapy and viral load monitoring.

[DOC11187] OBJECTIVE: To highlight recent developments in the field of antiretroviral therapy and viral load monitoring. METHODS: Review of studies detailing the efficacy of the antiretroviral agents and combinations furthest along in clinical development and the application of plasma HIV RNA quantification as a disease marker. RESULTS: Developments in the field of antiretroviral therapy have led to substantial advances in the approach to management of HIV-infected persons. These include the end of the zidovudine (ZDV) monotherapy era; the demonstration of a survival benefit conferred by antiretroviral therapy in patients with CD4 counts of 200-500x10(6)/l; the further development of newer nucleoside analog combinations (e.g., ZDV-lamivudine, stavudine-didanosine, stavudine-lamivudine, ZDV-1592U89) and the non-nucleoside reverse transcriptase inhibitor class of compounds; and, perhaps most importantly, the advent of the protease inhibitor era. Trials of ritonavir and saquinavir have proven that clinical benefit can be conferred by protease inhibitors, and three-drug combination regimens, such as indinavir-ZDV-lamivudine, have shown the potential for degrees of viral suppression not previously seen. Newer protease inhibitors, such as nelfinavir and VX-478/GW141W94, hold promise for further advances. The concurrent development of assays to quantitatively measure plasma HIV RNA has provided laboratory tools to improve our understanding of disease pathogenesis, to assess the in vivo potency of treatment regimens and to characterize the risk of disease progression. CONCLUSIONS: Recent progress in HIV disease pathogenesis, antiretroviral therapy and viral load monitoring indicates the interdependence of these factors. The current optimism in the field is warranted but complex challenges must be met if the fulfilment of this hope is to be realized by the world community.
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Most likely documents

[1] [Grading the severity of disease in patients with Puumala or Dobrava virus infections from...

[DOC21953] AIM: The aim of our study was to evaluate the proposed Croatian scale for grading the disease severity in patients with hemorrhagic fever with renal syndrome (HFRS). The aim was also to determine whether the infection with Dobrava virus (DOBV) in Croatia was associated with a more severe illness than the infection with Puumala virus (PUUV). PATIENTS AND METHODS: To evaluate the scale, case records of 62 HFRS patients hospitalized at the University Hospital for Infectious diseases in Zagreb from 1995 till 2000 were reviewed. ELISA IgM and IgG tests were used for the detection of specific IgM and IgG antibodies to PUUV or DOBV. DISCUSSION: HFRS caused by hantaviruses is a zoonotic disease spread worldwide, posing a major public health problem of global dimensions. Recent epidemiologic studies show that almost all parts of Croatia are endemic regions for two hantaviruses, Puumala and Dobrava. The disease severity ranges from subclinical infection to severe illness with fatal outcome. Clinical picture is predominated by fever, myalgia, vomiting, hemorrhagic manifestation, visual impairment and kidney affection. There is still a lack of knowledge concerning all the parameters involved in the disease severity. Besides the type of virus and genetic material, host genes are also associated with the variable clinical course. HLA alleles B8, DR3, and DQ2 are strongly associated with severe outcome of PUUV infection, white HLA B27 allele is associated with a mild course. Whether similar genetic factors also operate in DOBV infection remains to be determined. Recently, a Croatian scale for grading the disease severity was proposed. The disease severity is graded by a scoring system (points attributed to specific clinical symptoms and laboratory findings) as 1--mild, 2--moderate, 3--severe, and 4--very severe. We found 60% of HFRS patients to be infected with PUUV and 40% with DOBV. In our study, 65% of patients infected with PUUV had mild, and 24% moderate disease. Severe and very severe disease was recorded in 11% of PUUV infected patients. In contrast, only 44% of patients infected with DOBV had mild disease, whereas 40% of patients showed a moderate clinical picture. Severe and very severe clinical picture was recorded in 16% of patients with DOBV infection. Statistical analysis showed a significant number of pa (p < 0.01) with PUUV infection to have mild disease, whereas a significant number of HFRS patients infected with DOBV had moderate (p < 0.01) and severe or very severe (p < 0.01) disease. CONCLUSION: Our results clearly indicate that in Croatia DOBV infection is associated with a more severe disease than PUUV infection. However, we confirmed previous findings that even PUUV infection could lead to a severe disease. Our initial experience in the evaluation of the proposed grading scale for disease severity demonstrated the proposed Croatian scale to be a useful tool in grading disease severity in patients infected with PUUV or DOBV. Moreover, the proposed scale may also prove highly useful for the prognostic purpose.

[2] Emerging and reemerging infections. Progress and challenges in the subspecialty of infecti...

[DOC11711] Emerging and reemerging infections are attracting greater attention from the public health and medical communities. Pathologists and other physicians are increasingly aware of the importance of the subspecialty of infectious disease pathology as a tool for diagnosis, surveillance, and research of emerging infections. In this communication, we describe the role that infectious disease pathologists have played during the last 2 years in broadening our understanding of selected emerging infections, including such examples as new variant Creutzfeldt-Jakob disease and bovine spongiform encephalopathy, leptospirosis, microsporidiosis, Ebola hemorrhagic fever, and cyclosporiasis. The significance of providing pathology services, especially the autopsy, to patients with potentially hazardous communicable diseases is discussed with the supposition that it is unethical to exclude or withhold health care from a patient based on his or her underlying disease or on risk factors for acquiring a disease. The increasing occurrence of infectious diseases imported into the United States and other nations, including human immunodeficiency virus-1 group O, dengue fever, tuberculosis, malaria, diphtheria and cholera in immigrants and travelers, and Ebola virus in nonhuman primates, emphasizes the necessity for pathologists of having competence with infectious disease pathology. It is critical that new generations of pathologists not only be trained in the subspecialty of infectious disease pathology, but that they also be willing participants in the diagnosis and investigation of infectious diseases. The lack of training programs for infectious disease pathologists, as well as the deficiency in infectious disease pathology support for ongoing and future epidemiologic investigations and research, has led to the broadening of pathology services and initiation of a dedicated section of Infectious disease Pathology at one of the nation's premier public health institutions, the Centers for disease Control and Prevention in Atlanta, Ga. Together with preexisting groups of medical and veterinary infectious disease pathologists at universities, the Armed Forces Institute of Pathology, the US Army Medical Research Institute of Infectious diseases, and the National Institutes of Health, this new program will significantly strengthen the capability of the United States to respond to future challenges of emerging and reemerging infections, both in this country and abroad.

[3] Intravenous ribavirin treatment for severe adenovirus disease in immunocompromised childre...

[DOC17449] BACKGROUND: Adenovirus is an important cause of morbidity and mortality in the immunocompromised host. The incidence of severe adenovirus disease in pediatrics is increasing in association with growing numbers of immunocompromised children, where case fatality rates as high as 50% to 80% have been reported. There are no approved antiviral agents with proven efficacy for the treatment of severe adenovirus disease, nor are there any prospective randomized, controlled trials of potentially useful anti-adenovirus therapies. Apparent clinical success in the treatment of severe adenovirus disease is limited to a few case reports and small series. Experience is greatest with intravenous ribavirin and cidofovir. Ribavirin, a guanosine analogue, has broad antiviral activity against both RNA and DNA viruses, including documented activity against adenovirus in vitro. Ribavirin is licensed in aerosol form for the treatment of respiratory syncytial virus infection, and orally in combination with interferon to treat hepatitis C. Intravenous ribavirin is the treatment of choice for infection with hemorrhagic fever viruses. The most common adverse effect of intravenous ribavirin is reversible mild anemia. The use of cidofovir in severe adenovirus infection has been limited by adverse effects, the most significant of which is nephrotoxicity. OBJECTIVE: We report our experience with intravenous ribavirin therapy for severe adenovirus disease in a series of immunocompromised children and review the literature. DESIGN/METHODS: We retrospectively reviewed the medical records of 5 children treated with intravenous ribavirin for documented severe adenovirus disease. Two patients developed adenovirus hemorrhagic cystitis after cardiac and bone marrow transplants, respectively. The bone marrow transplant patient also received intravenous cidofovir for progressive disseminated disease. An additional 3 children developed adenovirus pneumonia; 2 were neonates, 1 of whom had partial DiGeorge syndrome. The remaining infant had recently undergone a cardiac transplant. Intravenous ribavirin was administered on a compassionate-use protocol. RESULTS: Complete clinical recovery followed later by viral clearance was observed in 2 children: the cardiac transplant recipient with adenovirus hemorrhagic cystitis and the immunocompetent neonate with adenovirus pneumonia. The remaining 3 children died of adenovirus disease. Intravenous ribavirin therapy was well tolerated. Use of cidofovir in 1 child was associated with progressive renal failure and neutropenia. DISCUSSION: Our series of patients is representative of the spectrum of immunocompromised children at greatest risk for severe adenovirus disease, namely solid-organ and bone marrow transplant recipients, neonates, and children with immunodeficiency. Although intravenous ribavirin was not effective for all children with severe adenovirus disease in this series or in the literature, therapy is unlikely to be of benefit if begun late in the course of the infection. Early identification, eg by polymerase chain reaction of those patients at risk of disseminated adenovirus disease may permit earlier antiviral treatment and better evaluation of therapeutic response. CONCLUSIONS: Two of 5 children with severe adenovirus disease treated with intravenous ribavirin recovered. The availability of newer rapid diagnostic techniques, such as polymerase chain reaction, may make earlier, more effective treatment of adenovirus infection possible. Given the seriousness and increasing prevalence of adenovirus disease in certain hosts, especially children, a large, multicenter clinical trial of potentially useful anti-adenoviral therapies, such as intravenous ribavirin, is clearly required to demonstrate the most effective and least toxic therapy.
Related to Topic 49: DISEASES,DISEASE,INFECTIOUS,INFECTIONS,TUBERCULOSIS,HEPATITIS (0.286)

[1] Emerging and reemerging infections. Progress and challenges in the subspecialty of infecti...

[DOC11711] Emerging and reemerging infections are attracting greater attention from the public health and medical communities. Pathologists and other physicians are increasingly aware of the importance of the subspecialty of infectious disease pathology as a tool for diagnosis, surveillance, and research of emerging infections. In this communication, we describe the role that infectious disease pathologists have played during the last 2 years in broadening our understanding of selected emerging infections, including such examples as new variant Creutzfeldt-Jakob disease and bovine spongiform encephalopathy, leptospirosis, microsporidiosis, Ebola hemorrhagic fever, and cyclosporiasis. The significance of providing pathology services, especially the autopsy, to patients with potentially hazardous communicable diseases is discussed with the supposition that it is unethical to exclude or withhold health care from a patient based on his or her underlying disease or on risk factors for acquiring a disease. The increasing occurrence of infectious diseases imported into the United States and other nations, including human immunodeficiency virus-1 group O, dengue fever, tuberculosis, malaria, diphtheria and cholera in immigrants and travelers, and Ebola virus in nonhuman primates, emphasizes the necessity for pathologists of having competence with infectious disease pathology. It is critical that new generations of pathologists not only be trained in the subspecialty of infectious disease pathology, but that they also be willing participants in the diagnosis and investigation of infectious diseases. The lack of training programs for infectious disease pathologists, as well as the deficiency in infectious disease pathology support for ongoing and future epidemiologic investigations and research, has led to the broadening of pathology services and initiation of a dedicated section of Infectious disease Pathology at one of the nation's premier public health institutions, the Centers for disease Control and Prevention in Atlanta, Ga. Together with preexisting groups of medical and veterinary infectious disease pathologists at universities, the Armed Forces Institute of Pathology, the US Army Medical Research Institute of Infectious diseases, and the National Institutes of Health, this new program will significantly strengthen the capability of the United States to respond to future challenges of emerging and reemerging infections, both in this country and abroad.

[2] Ticks and tick-borne diseases in Oklahoma.

[DOC12756] Tick-borne diseases are common in Oklahoma, especially the eastern part of the state where tick prevalence is highest. Three species of hard ticks are present in Oklahoma that are known vectors of human disease--the American dog tick (Rocky Mountain spotted fever; RMSF), the lone star tick (ehrlichiosis) and the black-legged tick (Lyme disease). Oklahoma consistently ranks among the top states in numbers of reported RMSF cases, and Ehrlichiosis may be as prevalent as RMSF. Although Lyme disease is frequently reported in Oklahoma, over-diagnosing of this disease due to false-positive test results is common; positive or equivocal screening tests should be confirmed by Western immunoblot. At present, it is unclear whether the disease seen here is Lyme disease or another Lyme-like disease. If true Lyme disease is present in the state, it is probably rare. Physicians should be aware of the most recent recommendations for diagnosis, therapy and prevention of tick-borne diseases.

[3] Plagues--what's past is present: thoughts on the origin and history of new infectious dise...

[DOC2827] Medical science has made tremendous strides in overcoming infectious diseases in the 20th century. Despite this, several epidemics of previously unrecognized diseases have occurred during the last 15 years. These diseases include Lyme disease, Legionnaires' disease, toxic shock syndrome, and AIDS. Examination of past epidemics, including the plague of Athens, the black death, syphilis, and influenza, suggests that the sudden occurrence of diseases that were previously unrecognized is not unusual. Analysis of the new infectious disease indicates that while all four appeared suddenly, isolated cases of the disease occurred before the actual epidemic. Further, all four new diseases were found to be due to agents or toxins that were not previously recognized. Epidemics due to new infectious diseases may arise by several mechanisms, including mutation of the pathogen to a virulent form and introduction of an infectious agent into a nonimmune population. Environmental and behavioral factors may play an important role, as illustrated by toxic shock syndrome, Legionnaires' disease, and AIDS. On the other hand, epidemic diseases tend to abate over time because of changes in the infecting pathogen and in the host. Hence, epidemics can be seen as cycles; new diseases will arise periodically, occasionally with a devastating outcome. With time the effects of these diseases on the population will ameliorate. The cycle will begin again when a new disease emerges.
Related to Topic 73: HUMAN,DISEASE,ANIMAL,HUMANS,ANIMALS,CAUSED (0.242)

[1] Animals, disease, and man: making connections.

[DOC19372] The intricate causal relationships between disease in man and disease in animals first began to be elucidated in the mid-19th century. Although the connections between animal and human disease are now generally understood, individuals as well as societies remain slow to act on this knowledge. This paper examines the gradual recognition of these disease connections and explores the parallel theme of man's reluctance to appreciate the implications of these connections. It identifies factors that have inhibited the realization of the links between disease in man and animals, and discusses several milestones in the scientific elucidation of these links. Beginning with emerging concerns over the relationship between bovine and human tuberculosis in the 1860s, it follows the discovery of insect vectors, animal reservoirs, and the links between animals, influenza, and man. Despite warnings of the potential significance for human disease of patterns of changes in the relationship with animals and the natural world, scientists have continued to treat human and animal health as largely independent disciplines, while historians too have neglected this important aspect of human disease.

[2] [Surveillance of human brucellosis in France (author's transl)]

[DOC960] Brucellosis is an anthropozoonosis, transmissable between animals and from animals to man. There is no interhuman transmission. Practically all domestic and wild animals are sensitive to various species of Brucella which explains the world-wide occurrence of the disease. Animals transmit the disease to man by direct contact (giving rise most often to professional disease which accounts for approximately 2/3 of the cases in France), and by way of food consumption (milk, cheese). The discovery of host animals may guide the diagnosis of human cases but more often the diagnosis of a human case reveals the existence of a host animal. Among the serological tests which help to follow the course of the human disease, the importance of the card test and of the immunofluorescence reaction are especially emphasized. The incidence of the human disease is difficult to determine: from the number of cases notified, the number of cases actually diagnosed can be estimated (from 3 to 5 times greater in France); however the true number of cases is very difficult to estimate owing to the large number of asymptomatic or atypical cases.

[3] Animals in the influenza world.

[DOC6601] In the history of influenza there are many references, notes and comments about influenza epizootics occurring among various non-human animals, sometimes coinciding with epidemics of influenza in human beings. That the first influenza viruses were recovered from non-human animals is not so surprising, given the current knowledge of the distribution of influenza among animals. Influenza viruses are found in a wide variety of mammalian and avian species. In some species the disease that occurs as a result of the infection mimics the influenza disease of human beings, in other species there are no signs of disease, and in others there is disease specific to a species. It is clear that influenza viruses have a significant impact on the health of several animal species. In recent times it has also become clear that many species of animals are inextricably entwined in the puzzle of influenza viruses and human influenza. Our knowledge in animals has provided both questions and answers about the influenza viruses and their diseases. Certainly our understanding of human influenza has been advanced because of the animals in the influenza world.
Related to Topic 8: CLINICAL,DIAGNOSIS,SYMPTOMS,DISEASE,SIGNS,CASES (0.104)

[1] Adult Still's disease. Evolution of a clinical syndrome and diagnosis, treatment, and foll...

[DOC7512] Adult Still's disease (SD) has evolved into a well-characterized nosologic entity. This categorization allows physicians to place a unifying label on the rare, puzzling patient who presents with a systemic illness characterized by high spiking fever of unknown cause associated with intense arthralgias or arthritis, an evanescent erythematous macular or maculopapular rash, and other less constant features of systemic illness including lymphadenopathy, hepatosplenomegaly, sore throat, leukocytosis, anemia and elevated concentration of hepatic enzymes. The diagnosis of Adult SD is syndromic, based solely on compatible clinical findings; serologic or other diagnostic tests do not aid in diagnosis. The diagnostic problem presented by these patients with such severe systemic illness and the insecurities inherent in diagnosis based solely on clinical features make the availability of the diagnosis, Adult SD, useful in patient care. The cause of Adult SD is unknown. Some have speculated that the disease has features of non-necrotizing immune complex vasculitis. Rubella infection has been reported to be associated with Adult SD, but no clear-cut etiologic relationship has been established. Neither rubella infection nor any other potential antigen has been identified consistently in association with the disease. Management of patients with the disease depends on the correct diagnosis. Diagnosis should include recognition of the syndrome as well as exclude other possible diseases. Control of systemic manifestations may require unusually high doses of aspirin, indomethacin or other non-steroidal anti-inflammatory drugs, prednisone or combinations of these drugs. Some adults appear to require both high-dose prednisone and indomethacin to control disease manifestations. Fortunately, systemic attacks are usually episodic; steroid toxicity can be minimized by use of alternate day doses and attempts to discontinue steroids between episodes. The current series and other reports of long-term follow-up indicate that Adult SD may be more disabling than was originally reported. At least three patterns of recurrences occur: 1) systemic attacks with or without arthritis, 2) pauciarticular disease, and 3) disabling deforming chronic arthritis, which may require surgery and long-term anti-inflammatory, gold, or cytotoxic therapy.

[2] [Clinical picture of hemorrhagic fever with renal syndrome in Croatia]

[DOC21960] Among many viral hemorrhagic fevers, only hemorrhagic fever with renal syndrome (HFRS) occurs in Croatia. HFRS is a natural focus zoonosis with sudden onset, characterized by high fever and other clinical symptoms, renal insufficiency and hemorrhages. In Croatia, HFRS is caused by two types of hantaviruses--Puumala (PUU) and Dobrava (DOB). The basic pathologic and patophysiologic disorder in HFRS is capillary damage (vasculitis). Incubation of HFRS has not been precisely determined, it is most frequently around two weeks. The disease onset is usually abrupt. At the beginning, general symptoms include high fever and myalgias, especially in the lumbar region, and abdominal pain, as well as strong headaches, malaise and nausea, and often vomiting or diarrhea. In half of the patients respiratory symptoms occur. Later on, some patients may experience hypotension, oliguria and other signs of renal failure, and apart from petechial, severe hemorrhages may also occur in other organs. During typical clinical presentation of the disease, some characteristic symptoms are clearly distinguished in particular stages of the disease. Therefore, the course of HFRS is usually divided into five distinct stages (febrile, hypotensive, oliguric, polyuric and convalescent). Such a course of the disease is more commonly present in case of DOB virus than PUU virus infection. The febrile stage with sudden onset usually lasts from 3 to 7 days, when thrombocytopenia and hemoconcentration, as well as albuminuria and hematuria are almost always recorded. The hypotensive stage lasts from one to 2 days on an average and is characterized by lower blood pressure and signs of renal failure. The oliguric stage usually starts at the beginning of the second week of the disease, when extensive hemorrhage may occur and urea and creatinine reach their highest values. The oliguric stage is followed by the polyuric stage which can last for up to two weeks, and is characterized by excretion of a large quantity of urine of low specific gravity (up to 15 liters during 24 hours). The convalescence (convalescent stage) is slower, may last for several weeks or months, but usually resolves without complications. During the infection caused by PUU virus, the course of disease is usually milder with only two stages. The first one is febrile, followed by the second stage with renal symptoms, and rare and mild hemorrhagic manifestations. This type of disease is mostly encountered during epidemics. The mortality in severe cases of the disease (DOB virus) is 5% to 10%, whereas in PUU virus infection it is less than 1%.

[3] Syndromic variability of Wilson's disease in children. Clinical study of 44 cases.

[DOC12379] BACKGROUND: In children with Wilson's disease, no clinical or laboratory data are specific for diagnosis as in adult age. AIM: Clinical aspects and parameters of copper metabolism in a large series of pediatric cases are evaluated to establish certain criteria for diagnosis and for correct treatment, even in difficult cases. METHODS: In 44 children with Wilson's disease, clinical aspects, histological features, laboratory parameters and data of copper metabolism have been studied. Forty patients, treated with penicillamine, were followed up (median 77 months). RESULTS: The 44 cases were classified as: asymptomatic forms (nine cases, six of them siblings of affected subjects), chronic hepatitis (23 cases), hepatocerebral manifestations (four cases), decompensated cirrhosis (six cases), fulminant hepatic failure with hemolytic anemia (two cases). Ceruloplasmin levels were abnormal in 37 out of 43 tested cases, but normal in six (14%) who showed high basal and after penicillamine load urine copper excretion and increased hepatic copper content. Urine copper concentration was pathological in 35 out of 42 tested cases (83%), but normal in seven patients under six years. Hepatic copper levels were very high in all the 20 tested patients. Under treatment, 27 children had favourable outcome. One patient showed no evolution of disease, seven patients worsened because of non-compliance to the therapy (one underwent successful liver transplantation) or severe side effects. Five patients with failure died. CONCLUSIONS: Wilson's disease in children may present with a broad clinical spectrum, but the liver involvement is by far the most prevalent. The early diagnosis, based on clinical suspicion and results of copper metabolism investigation (including hepatic copper content evaluation in difficult cases) and appropriate treatment can prevent the progression of the disease.
Related to Topic 6: PATIENTS,PATIENT,CLINICAL,HOSPITAL,DISEASE,SEVERE (0.067)

[1] High-resolution computed tomography is useful for early diagnosis of severe acute respirat...

[DOC21496] OBJECTIVE: We investigated the usefulness of high-resolution computed tomography (HRCT) in early detection of severe acute respiratory syndrome (SARS)-associated coronavirus pneumonia and analyzed HRCT findings associated with potentially more severe disease. METHODS: All patients with suspected SARS and normal chest radiographs on admission within the study period were subjected to HRCT examination. The clinical, radiologic, and laboratory data of patients who were confirmed to have SARS-associated coronavirus infection by a positive nasopharyngeal aspirate, stool or urine reverse transcription-polymerase chain reaction (RT-PCR) and/or serological testing were prospectively followed up and analyzed. Characteristics of patients admitted to the intensive care unit (ICU) and those that were not were compared. RESULTS: Among 47 suspected SARS patients with normal chest radiographs, 27 had SARS-associated coronavirus infection confirmed by RT-PCR and/or positive serological testing. Twenty-five of the 27 (93%) patients had HRCT changes compatible with atypical pneumonia, and all 25 patients developed SARS with progressive clinical deterioration. Ten (40%) had unifocal diseases, and 15 had multifocal diseases (60%). Ten (40%) patients had the diseases confined to 1 single lung in the first HRCT, and both lungs were involved at initial presentation in 15 (60%) patients. Concerning the overall extent of the disease at initial presentation, 3 (12%) patients had disease process in all lobes, and the disease was confined to 1 single lobe in 10 (40%) patients. The disease process was mainly peripheral in location (96%), and the lower lobes were more commonly involved (68% in the left lower lobe and 64% in the right lower lobe). Small parapneumonic effusions occurred in 1 (4%) patient. None of the patients with unifocal lesions or single-lung involvement were admitted to the ICU (P < 0.05) (in both comparisons). Subsequent follow-up of the 2 (7%) patients with normal HRCT on admission showed that they were having nonpneumonic SARS-associated coronavirus infection only and were eventually denotified from having SARS. CONCLUSIONS: HRCT is useful for early diagnosis of SARS-associated coronavirus pneumonia in patients with normal chest radiographs. HRCT findings in these patients predict potentially severe disease.

[2] Prognostic significance of the radiographic pattern of disease in patients with severe acu...

[DOC21611] OBJECTIVE: This study was performed to evaluate the prognostic significance of the radiographic pattern of disease in probable cases of severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: A retrospective review of 439 radiographs was performed for 51 patients with a final diagnosis of probable SARS. Forty-nine patients were followed up for a mean interval of 23 days (range, 2-63 days). RESULTS: Abnormal findings on a chest radiograph were noted at presentation in 80.4% (41/51) of patients. Four radiographic patterns were seen: normal (group 1) in 19.6% (10/51), focal opacity (group 2) in 39.2% (20/51), multifocal opacities (group 3) in 27.5% (14/51), and diffuse air-space opacification (group 4) in 13.7% (7/51). Radiographic progression of disease occurred in 38.8% (19/49) of the patients in groups 1-4. There were no deaths in groups 1 and 2. In group 3, one (7.7%) of the 13 patients died. Five (71.4%) of the seven patients in group 4 died. Overall, 12.2% (6/49) of the patients died, all of whom had diffuse air-space opacification on the last chest radiograph. In these patients, medical comorbidity was present in 66.7% (4/6), and the exposure history was known in 83.3% (5/6). Death occurred at a mean interval of 18.2 days (range, 9-36 days) from the initial exposure. CONCLUSION: Patients presenting with normal findings or focal air-space opacity on chest radiographs had a good clinical outcome. Patients with multifocal opacities that progressed to diffuse air-space opacification and patients presenting with diffuse air-space opacification had a high fatality rate, but patients in this group were also older and more likely to have comorbid conditions. Patients with SARS present with recognizable patterns of disease that have prognostic significance.

[3] Clinical and laboratory features of severe acute respiratory syndrome vis-a-vis onset of f...

[DOC23428] STUDY OBJECTIVES: Severe acute respiratory syndrome (SARS) is a rapidly progressive disease caused by a novel coronavirus (CoV) infection. However, the disease presentation is nonspecific. The aim of this study was to define clearly the presentation, clinical progression, and laboratory data in a group of patients who had SARS. DESIGN: Retrospective observational study. SETTING: A tertiary care medical center with 51 negative-pressure isolation rooms in Taipei, Taiwan. PATIENTS: Fifty-three patients with SARS seen between April 27 and June 16, 2003. RESULTS: Fever (ie, temperature > 38 degrees C) was the most common symptom (98%) and the earliest. When admitted to the isolation unit of the hospital for observation, most patients reported nonspecific symptoms associated with their fever. Only two patients with preexisting illnesses had cough on the same day the fever began. Eventually, 39 patients (74%) developed cough, beginning at a mean (+/- SD) time of 4.5 +/- 1.9 days after fever onset, and 35 patients (66%) had diarrhea beginning at a mean time of 6.0 +/- 3.3 days after fever onset. Thirty-one patients (59%) had abnormal findings on chest radiographs on hospital admission, and all but 1 patient (98%) eventually developed lung infiltrates that were consistent with pneumonia. The majority of patients (63%) first developed unifocal infiltrates at a mean time of 4.5 +/- 2.1 days after fever onset, while in 37% of patients the initial infiltrates were multifocal, appearing at a mean time of 5.8 +/- 1.3 days after fever onset. Common laboratory findings included lymphopenia (on hospital admission, 70%; during hospitalization, 95%), thrombocytopenia (on hospital admission, 28%; during hospitalization, 40%), elevated lactate dehydrogenase (on hospital admission, 58%; during hospitalization, 88%), creatine kinase (on hospital admission, 18%; during hospitalization, 32%), and aspartate aminotransferase or alanine aminotransferase levels (on hospital admission, 27%; during hospitalization, 62%). Throat or nasopharyngeal swab for SARS-CoV by reverse transcriptase polymerase chain reaction (PCR) and real-time PCR was positive in 40 of the 47 patients (85%) in whom the test was performed. CONCLUSIONS: None of the presenting symptoms or laboratory findings are pathognomonic for SARS. Even though cough developed in a majority of patients, it did not occur until later in the disease course, suggesting that a cough preceding or concurrent with the onset of fever is less likely to indicate SARS. While PCR for SARS-CoV appears to be the best early diagnostic test currently available, it is clear that better methods are needed to differentiate between SARS and non-SARS illness on initial presentation.
Related to Topic 35: CONTACT,INFECTION,TRANSMISSION,WORKERS,RISK,CONTROL (0.056)

[1] US policy for disease control among imported nonhuman primates.

[DOC12980] In 1990, in response to the occurrence of Ebola virus (subsequently identified as subtype Reston) infection among cynomolgus monkeys imported from the Philippines, the United States implemented strict disease control measures for handling nonhuman primates during transit and quarantine and initiated importer facility compliance inspections. disease control measures emphasized protection of workers from exposure, use of containment facilities and procedures, measures to prevent spread of infection among animals, and laboratory testing of animals that die or become ill during quarantine. From 1991-1995, no outbreaks of filovirus infection occurred, and only one other disease outbreak (caused by Mycobacterium species) was recognized. In April 1996, Ebola virus (subtype Reston) infection was identified in another group of cynomolgus monkeys imported from the Philippines. The disease control measures implemented since the first Ebola virus (subtype Reston) outbreak appeared to work well. Currently, the 27 registered importer facilities import approximately 8500 nonhuman primates annually, and mortality rates are <1.0%. Importer facilities receive regular inspections, and compliance with disease control measures and disease reporting is excellent.

[2] Identification and containment of an outbreak of SARS in a community hospital.

[DOC19571] BACKGROUND: Severe acute respiratory syndrome (SARS) is continuing to spread around the world. All hospitals must be prepared to care for patients with SARS. Thus, it is important to understand the transmission of this disease in hospitals and to evaluate methods for its containment in health care institutions. We describe how we cared for the first 2 patients with SARS admitted to our 419-bed community hospital in Richmond Hill, Ont., and the response to a SARS outbreak within our institution. METHODS: We collected clinical and epidemiological data about patients and health care workers at our institution who during a 13-day period had a potential unprotected exposure to 2 patients whose signs and symptoms were subsequently identified as meeting the case definition for probable SARS. The index case at our hospital was a patient who was transferred to our intensive care unit (ICU) from a referral hospital on Mar. 16, 2003, where he had been in close proximity to the son of the individual with the first reported case of SARS in Toronto. After 13 days in the ICU, a diagnosis of probable SARS was reached for our index case. Immediately upon diagnosis of our index case, respiratory isolation and barrier precautions were instituted throughout our hospital and maintained for a period of 10 days, which is the estimated maximum incubation period reported for this disease. Aggressive surveillance measures among hospital staff, patients and visitors were also maintained during this time. RESULTS: During the surveillance period, 15 individuals (10 hospital staff, 3 patients and 2 visitors) were identified as meeting the case definition for probable or suspected SARS, in addition to our index case. All but 1 individual had had direct contact with a symptomatic patient with SARS during the period of unprotected exposure. No additional cases were identified after infection control precautions had been implemented for 8 days. No cases of secondary transmission were identified in the 21 days following the implementation of these precautions at our institution. INTERPRETATION: SARS can easily be spread by direct personal contact in the hospital setting. We found that the implementation of aggressive infection control measures is effective in preventing further transmission of this disease.

[3] Monkeypox in the United States: an occupational health look at the first cases.

[DOC22554] Between May 15 and June 20, 2003, 71 suspected cases of monkeypox were investigated and 37 individuals in the United States developed laboratory confirmed monkeypox. These were the first cases of human monkeypox ever documented in the United States or in the Western Hemisphere. The disease was transmitted from small animals imported from Africa to other animals, including prairie dogs sold as pets throughout the U.S. Midwest. Direct contact with the infected animals was the method of infection, and although human to human transmission was thought to have occurred, this was not confirmed by follow up testing. Because of the link with contact with a prairie dog, initial evaluation of the disease was focused toward diseases commonly associated with this animal (e.g., tularemia, plague). Laboratory findings at the Marshfield Clinic in Marshfield, Wisconsin pointed to the presence of an orthopox. The CDC confirmed monkeypox was the infecting orthopox agent. Occupational health nurses from the Marshfield Clinic had direct involvement in the identification and follow up of employees who had direct contact with the diagnosed patients. Programs, such as a respiratory protection program initiated and carried out by Clinic occupational health nurses, were used to prevent employee exposure for Clinic staff. One Clinic employee was thought to potentially have monkeypox because of her direct contact with one of the patients. Four Clinic employees were vaccinated with vaccinia vaccine as a result of their contact with patients or lab specimens. Quarantine of the potentially infected employee and her boyfriend uncovered issues that must be addressed if other infectious diseases requiring quarantine or isolation of individuals emerge or re-emerge. These include a system to compensate individuals in quarantine or isolation who do not have any other source of income. The issue of whether workers' compensation should cover an employee who is quarantined or isolated for a potential work related exposure to an infectious disease if no disease is actually diagnosed also needs to be explored. A better system of getting state or CDC laboratory results back to the local level, including the occupational health area of the generating facility, must be developed. This will be very important if diseases such as severe acute respiratory syndrome (SARS) or smallpox should re-emerge in the United States. Occupational health nurses are an integral part of any infectious disease process occurring in the United States. The identification of monkeypox in the United States shows that any planning to detect, prevent, and treat diseases with the potential to affect the employee population must include occupational health nurse involvement.
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Most likely documents

[1] [Is permanent renal function damage possible after hemorrhagic fever with renal syndrome?]

[DOC21955] AIM: To investigate the possibility of permanent renal function impairment and other organ lesions following hemorrhagic fever with renal syndrome (HFRS). METHODS: Data on 30/37 patients infected with HFRS, treated at the Department of Infectious Diseases, Split University Hospital, in 1995 were retrospectively analyzed. The data were collected three to six years following the appearance of HFRS. In 1998, 30/37 patients presented for control checkup, when their history data were collected, along with physical examination, hematology and biochemistry tests, and urinalysis. Creatinine clearance and sodium, potassium, chlorine, phosphorus, beta 2-microglobulin and N-acetyl-beta-D glucosaminase in 24-h urine were determined. In native urine, erythrocyturia was observed, with 10 erythrocytes per field were considered pathologic result. During the 1998-2001 period, renal scintigraphy by means of technetium labeled diethylene triaminopentacetic acid (99mTC DTPA) was performed in 13/30 patients. RESULTS: Of subjective discomforts, 29/30 (96.7%) patients reported lumbar pain. Elevated blood pressure was found in 9/30 (30.0%), erythrocyturia in 4/30 (13.3%) and hepatic lesion in 4/30 (13.3%) patients. Decreased creatinine clearance values (< 1.2 ml/s) were found in 4 and increased values (> 2.35 ml/s) in 10 patients. Increased sodium in 24-h urine was recorded in 10/23 and increased beta 2-microglobulin in 6/23 (26%) patients. Proteinuria exceeding 150 mg/day was detected in 11/23 (47.8%) patients. Scintigraphy of the kidneys demonstrated reduced glomerular filtration (< 100 ml/min/1.72 m2) in 3/13 patients. Prolonged mean times (> 5 minutes) of radiopharmaceutical passage through the renal parenchymae were found in 7/13 (53.8%) patients. DISCUSSION: Studies performed in 30 patients three years after they had recovered from HFRS revealed changes suggesting a mild to moderate impairment of the renal function. Hypertension found in 9/30 patients was a significant finding, considering the fact that all subjects were soldiers, thus having undergone through examinations to prove them completely healthy prior to joining army. Hypertension results were consistent with those reported from the USA. Although erythrocyturia points to urinary tract damage, its glomerular or postglomerular origin was not examined. Decreased creatinine clearance found in 4/23 patients suggested functional renal impairment. Increased natriuresis found in 10/23 patients implied tubular damage, i.e. reduced ability of tubular cells for sodium reabsorption from primary urine. Non-selective albuminuria detected in 11/23 patients indicated permanent lesion of the glomerular basal membrane. Increased beta 2-microglobulin found in 6/23 patients indicated that the lysosomal enzyme level was elevated only in the acute stage of the disease, but may have been an indicator of permanent lesion. No description of post-HFRS scintigraphic lesion of the kidneys was found in the literature. A decreased value of glomerular filtration, found in three patients, and especially the prolonged mean time of glomerular micropharmaceutical passage in 7/13 (53.8%) patients may have suggested glomerular damage. However, the possible reason may have also been a reduced passage of glomerular filtrate through the damaged lower parts of the nephrons. Transaminase increase during the acute stage of HFRS suggested the possible liver infection, maybe even hantavirus replication in hepatocytes. Even though biopsy confirmed the histologic picture of chronic hepatitis in one patient, the question remains whether it could have been caused by hantavirus. CONCLUSION: Studies performed in 30 patients with a history of HFRS revealed renal function impairment, along with hypertension and damage to the liver parenchyma in some patients. The results obtained showed that the HFRS infection in Croatia may have entailed chronic sequels. To confirm this hypothesis, additional studies including a control group of hantavirus negative persons are needed.

[2] Survey of desert bighorn sheep in California for exposure to selected infectious diseases.

[DOC6173] From February 1983 to June 1985, 188 desert bighorn sheep (Ovis canadensis nelsoni, = 161 and Oc cremnobates, = 27) from 18 herds in 17 mountain ranges and one captive herd were caught, marked, and had blood, fecal, and nasal mucus samples collected. Nasal swab specimens were cultured bacteriologically and virologically specifically for parainfluenza-3 (PI-3) virus. Bacterial flora differed from herd to herd. Pathogenic pneumophilic bacteria (eg, Pasteurella sp) seldom were found. Parainfluenza-3 virus was isolated from 6 bighorn sheep in 3 herds. Fecal specimens were examined for parasite ova and low numbers of lungworm (Protostrongylus sp) larvae were found in feces from 2 herds. Sera were evaluated for antibodies against respiratory syncytial virus, ovine progressive pneumonia, infectious bovine rhinotracheitis, PI-3, bovine viral diarrhea, brucellosis, leptospirosis, contagious ecthyma, bluetongue, and epizootic hemorrhagic disease. Blood clots were cultured virologically for bluetongue and epizootic hemorrhagic disease. Serologic evidence of bluetongue and/or epizootic hemorrhagic disease was found in 9 herds, and bluetongue virus (serotypes 10,11,13 and 17) was isolated from 3 herds. Antibody titers against PI-3 and respiratory syncytial virus were found in 9 and 13 herds, respectively. Evidence of bovine viral diarrhea infection was found in 6 herds, whereas infectious bovine rhinotracheitis was found in only 1 herd. Antibody titers against contagious ecthyma were found in 9 of 18 herds in California, and active lesions were seen occasionally. Evidence of ovine progressive pneumonia, leptospirosis, or brucellosis was not found.

[3] Methionine regeneration and aminotransferases in Bacillus subtilis, Bacillus cereus, and B...

[DOC19184] The conversion of ketomethiobutyrate to methionine has been previously examined in a number of organisms, wherein the aminotransferases responsible for the reaction have been found to be members of the Ia subfamily (L. C. Berger, J. Wilson, P. Wood, and B. J. Berger, J. Bacteriol. 183:4421-4434, 2001). The genome of Bacillus subtilis has been found to contain no subfamily Ia aminotransferase sequences. Instead, the analogous enzymes in B. subtilis were found to be members of the If subfamily. These putative aspartate aminotransferases, the yugH, ywfG, ykrV, aspB, and patA gene products, have been cloned, expressed, and characterized for methionine regeneration activity. Only YkrV was able to convert ketomethiobutyrate to methionine, and it catalyzed the reaction only when glutamine was used as amino donor. In contrast, subcellular homogenates of B. subtilis and Bacillus cereus utilized leucine, isoleucine, valine, alanine, phenylalanine, and tyrosine as effective amino donors. The two putative branched-chain aminotransferase genes in B. subtilis, ybgE and ywaA, were also cloned, expressed, and characterized. Both gene products effectively transaminated branched-chain amino acids and ketoglutarate, but only YbgE converted ketomethiobutyrate to methionine. The amino donor preference for methionine regeneration by YbgE was found to be leucine, isoleucine, valine, phenylalanine, and tyrosine. The B. subtilis ybgE gene is a member of the family III of aminotransferases and falls in a subfamily designated here IIIa. Examination of B. cereus and Bacillus anthracis genome data found that there were no subfamily IIIa homologues in these organisms. In both B. cereus and B. anthracis, two putative branched-chain aminotransferases and two putative D-amino acid aminotransferases were discovered as members of subfamily IIIb. These four sequences were cloned from B. cereus, expressed, and characterized. Only the gene product from the sequence designated Bc-BCAT2 was found to convert ketomethiobutyrate to methionine, with an amino donor preference of leucine, isoleucine, valine, phenylalanine, and tyrosine. The B. anthracis homologue of Bc-BCAT2 was also cloned, expressed, and characterized and was found to be identical in activity. The aminooxy compound canaline was found to be an uncompetitive inhibitor of B. subtilis YbgE and also inhibited growth of B. subtilis and B. cereus in culture.
Related to Topic 80: HIGH,LOW,LEVEL,FOUND,OBSERVED,HIGHER (0.226)

[1] Behavioral performance, brain histology, and EEG sequela after immediate combined atropine...

[DOC2034] It is known that rats poisoned with near-lethal doses of pinacolyl methylphosphonofluoridate (soman) develop brain lesions, particularly when convulsions are induced. When rats were intoxicated with a LD50 of soman and treated immediately thereafter with a combination of low doses of atropine and diazepam (LOW AS/DZ treatment), large decrements in performance of an earlier acquired shuttle-box task were found 6 days after intoxication. In contrast, no such decrements were found in soman-intoxicated animals treated similarly with a combination of high doses of these drugs (HIGH AS/DZ treatment). Surprisingly, surviving LOW AS/DZ animals acquired the same task again at a speed that was almost as fast as before intoxication. Similarly treated animals were examined light-microscopically 24 h after intoxication; in LOW-AS/DZ-treated animals, neuropathology was only observed in animals that had exhibited convulsions, whereas in HIGH AS/DZ animals neither convulsions nor brain damage were observed. Power spectra, obtained from electroencephalograms (EEGs) 6 days after intoxication, revealed significant differences between both treatment groups, particularly in the delta-, theta-, and beta-frequencies. After the HIGH AS/DZ treatment, a significant increase in delta activity was found compared to control values, suggestive of neuropathology. It is concluded that, in contrast with the LOW AS/DZ combination, HIGH AS/DZ prevents active avoidance deficits, convulsions, and light-microscopically detectable neuropathology after soman intoxication. However, the results of EEG measurements suggest that some aberrations may still remain even after the HIGH AS/DZ treatment.

[2] [Stratum of the population of the Bashkir ASSR with natural immunity to hemorrhagic fever ...

[DOC6685] Natural immunity to hemorrhagic fever with the renal syndrome (HFRS) in the human population of the Bashkir ASSR having the highest incidence of this infection was first studied using radioimmunoassay. The antigen was a suspension of lungs of rodents from natural foci containing high antigen titres. When 1726 human sera from 8 districts and 2 towns were examined, antibodies to HFRS were found in 20.1%, with variations from 6.9% to 41.5% in different territories. No relationship between the percentage of immune subjects and average incidence values for 17 years was found. In the immune population, men accounted for 21.3%, women for 19.3%. Among subjects under 40, the immune stratum was lower (17.5%) than among older subjects (26.2%). The percentage of immunity was found to depend on the occupation of the population. No significant difference in immunity could be found in persons with different blood groups. Antibody in HFRS convalescent was shown to persist in high titres for up to 20 years after the onset of the disease.

[3] [Epidemiology of human and animal brucellosis in western Africa. The results of six studie...

[DOC313] Brucellosis has a two-fold importance in public health: the transmission of the disease to man by contact with animals or ingestion of raw milk is of direct importance; of indirect importance is the loss of animal protein. The authors have carried out ten epidemiological investigations in different bio-climatic zones of West Africa. More than 120 villages were evaluated. In each village, 100 persons were chosen at random and all or part of the animal population was also studied. Three tests were used for man: the melitin intradermal reaction, the sero-agglutination test of Wright and the complement fixation test. Three tests were used for the animals, the "ring-test" and the same serologic tests used for humans. The results indicated that brucellosis in animals exists in all regions but with varying rates. The bovine species seems to be the most contaminated. The enzooty becomes more widespread towards the South. Human brucellosis was not found to be of great importance in the regions mainly populated by farmers. Shepherds and their families in these zones, however, were found to have been infected. The highest percentage of infected humans was found in the sahelian zone (in Dori 30% of the intradermal reactions and 10% of serologies were positive for humans) in spite of a rather low infection rate among animals (6%-8% ring-tests positive among cattle). The majority of the population are shepherds and close cohabitation with animals is common. A basic dietary constituent is milk, which is often consumed raw (variable according to ethnic group), and provides the principal source of animal protein. Adults were found to have a significantly higher intradermal reaction rate in most of the regions studied. The positivity rate was higher in men than in women. In non-pastoral areas the shepherds and their families had a singificantly higher positivity rate than the general population. Ethnic differences were found. Also considered in this paper are intradermal reaction sizes, the relation between intradermal and serologic results, the modes of human transmission of the disease, and the relationship between human and animal forms of brucellosis.
Related to Topic 74: STUDIES,EVIDENCE,STUDY,PRESENT,FOUND,DATA (0.157)

[1] [Is permanent renal function damage possible after hemorrhagic fever with renal syndrome?]

[DOC21955] AIM: To investigate the possibility of permanent renal function impairment and other organ lesions following hemorrhagic fever with renal syndrome (HFRS). METHODS: Data on 30/37 patients infected with HFRS, treated at the Department of Infectious Diseases, Split University Hospital, in 1995 were retrospectively analyzed. The data were collected three to six years following the appearance of HFRS. In 1998, 30/37 patients presented for control checkup, when their history data were collected, along with physical examination, hematology and biochemistry tests, and urinalysis. Creatinine clearance and sodium, potassium, chlorine, phosphorus, beta 2-microglobulin and N-acetyl-beta-D glucosaminase in 24-h urine were determined. In native urine, erythrocyturia was observed, with 10 erythrocytes per field were considered pathologic result. During the 1998-2001 period, renal scintigraphy by means of technetium labeled diethylene triaminopentacetic acid (99mTC DTPA) was performed in 13/30 patients. RESULTS: Of subjective discomforts, 29/30 (96.7%) patients reported lumbar pain. Elevated blood pressure was found in 9/30 (30.0%), erythrocyturia in 4/30 (13.3%) and hepatic lesion in 4/30 (13.3%) patients. Decreased creatinine clearance values (< 1.2 ml/s) were found in 4 and increased values (> 2.35 ml/s) in 10 patients. Increased sodium in 24-h urine was recorded in 10/23 and increased beta 2-microglobulin in 6/23 (26%) patients. Proteinuria exceeding 150 mg/day was detected in 11/23 (47.8%) patients. Scintigraphy of the kidneys demonstrated reduced glomerular filtration (< 100 ml/min/1.72 m2) in 3/13 patients. Prolonged mean times (> 5 minutes) of radiopharmaceutical passage through the renal parenchymae were found in 7/13 (53.8%) patients. DISCUSSION: Studies performed in 30 patients three years after they had recovered from HFRS revealed changes suggesting a mild to moderate impairment of the renal function. Hypertension found in 9/30 patients was a significant finding, considering the fact that all subjects were soldiers, thus having undergone through examinations to prove them completely healthy prior to joining army. Hypertension results were consistent with those reported from the USA. Although erythrocyturia points to urinary tract damage, its glomerular or postglomerular origin was not examined. Decreased creatinine clearance found in 4/23 patients suggested functional renal impairment. Increased natriuresis found in 10/23 patients implied tubular damage, i.e. reduced ability of tubular cells for sodium reabsorption from primary urine. Non-selective albuminuria detected in 11/23 patients indicated permanent lesion of the glomerular basal membrane. Increased beta 2-microglobulin found in 6/23 patients indicated that the lysosomal enzyme level was elevated only in the acute stage of the disease, but may have been an indicator of permanent lesion. No description of post-HFRS scintigraphic lesion of the kidneys was found in the literature. A decreased value of glomerular filtration, found in three patients, and especially the prolonged mean time of glomerular micropharmaceutical passage in 7/13 (53.8%) patients may have suggested glomerular damage. However, the possible reason may have also been a reduced passage of glomerular filtrate through the damaged lower parts of the nephrons. Transaminase increase during the acute stage of HFRS suggested the possible liver infection, maybe even hantavirus replication in hepatocytes. Even though biopsy confirmed the histologic picture of chronic hepatitis in one patient, the question remains whether it could have been caused by hantavirus. CONCLUSION: Studies performed in 30 patients with a history of HFRS revealed renal function impairment, along with hypertension and damage to the liver parenchyma in some patients. The results obtained showed that the HFRS infection in Croatia may have entailed chronic sequels. To confirm this hypothesis, additional studies including a control group of hantavirus negative persons are needed.

[2] Targeted scan of fifteen regions for nonsyndromic cleft lip and palate in Filipino familie...

[DOC21678] Cleft lip with or without cleft palate (CL/P) is a congenital anomaly with variable birth prevalence based on geographic origins, with the highest rates commonly found in Asian populations. About 70% of cases are nonsyndromic (NS), in which the affected individual has no other abnormalities. NS CL/P is a complex disorder with genetic and environmental effects and no specific genetic loci yet confirmed. Fifteen candidate regions were examined for linkage to NS CL/P. Regions were chosen based on previous suggestive linkage and/or association in human families, or suggestive animal model data. Polymorphic markers in these regions were genotyped for analysis on 36 Filipino families comprised of 126 affected and 218 unaffected individuals. An additional 70 families with 149 affecteds were used for replication of suggestive results. Parametric (LOD score) and nonparametric (SIMIBD) linkage analyses were performed as well as transmission disequilibrium test (TDT) analysis. Five markers yielded suggestive results from the 36 families. The parametric LOD scores for the MSX1-CA and D4S1629 were >1.0 and the SIMIBD P values for D6S1029 and RFC1 are suggestive (<0.06), while the SIMIBD P value of 0.01 for TGFA was significant. Since the Msx1 mouse knockout has cleft palate and MSX1 mutations have been found in rare cases of syndromic CL/P, this locus is especially plausible for linkage. Previous studies have also found linkage of NS CL/P to 4q31 and 6p23. These regions contain several candidate genes, including AP2 at 6p23 and FGF2, BMPR1B, and MADH1 at 4q31. TGFA has both linkage and linkage disequilibrium data supporting it as a candidate gene for NS CL/P. While no region was definitively confirmed for linkage to NS CL/P, the data do support further investigation using larger sample sizes and candidate gene studies at 2p13.2, 4p16.2, 4q31, 6p23, and 16q22-24.

[3] The mammalian safety of Bacillus thuringiensis-based insecticides.

[DOC15050] The United States Environmental Protection Agency between the years 1961 and 1995 registered 177 products containing viable Bacillus thuringiensis (Bt). Numerous laboratory studies have demonstrated that Bt and Bt products are noninfectious and are toxic to mammals only at a dose > or =10(8) colony forming units (cfu) per mouse (a human equivalent based on the weight of >10(11) cfu). In contrast, as few as three vegetative cells of Bacillus anthracis can kill mice (a human equivalent of >10(3) cfu). There are only two literature reports of Bt infection in man between the year 1997 and the present, and all infected individuals had experienced either extensive burns or a blast injury, which predisposed them to infection. Two epidemiology studies conducted during large-scale aerial Bt serovar kurstaki spray campaigns reported no increased incidence of illness. Some recent papers have expressed concern about the production of Bacillus cereus enterotoxins by Bt isolates. Laboratory studies found no evidence of illness in rats and sheep fed Bt products, nor have epidemiology studies found increased incidence of diarrhea during Bt aerial spray campaigns. Increases in human antibody levels following exposure to Bt products have been reported but there was no increased incidence in asthma or other illness. Based on laboratory studies and field experience, Bt insecticides have an excellent safety record.
Related to Topic 95: TYPE,II,TYPES,PRESENT,III,PRESENCE (0.091)

[1] Cryoglobulins and infectious diseases.

[DOC5078] The relationship between infectious diseases due to various pathogenetic factors and cryoglobulin production mechanisms has been investigated. Cryoglobulins have been evidenced in infections caused by very heterogeneous pathogens, i.e. leptospirosis, psittacosis, Mediterranean tick typhus, brucellosis, gram-negative bacterial septicemias, in which they had never been previously reported. In type A hepatitis a high cryoglobulin prevalence (91%) has been confirmed during the acute phase, with a rapid decrease both in prevalence and concentration in the subsequent stages of the disease. Cryoglobulins were all of type III and were mainly represented by IgM; anti-HAV-IgM antibodies have been evidenced in all but one cryoprecipitates. In non-A, non-B hepatitis a lower cryoglobulin prevalence (44.7%) was shown during the acute phase and the same fast decrease has been noted in the subsequent stages. Cryoglobulins were all of type III and in some cases polyclonal IgG was the only Ig class present in cryoprecipitates. The cryoglobulin prevalence in the acute phase of HBsAg-positive hepatitis amounted to 73.4%; all the cryoprecipitates were of type III. No correlation between the presence of cryoglobulins and HBeAg positivity or between cryoglobulins and delta agent infections was found. In all the cases studied the presence of cryoglobulins was related to the persistence of liver damage. Cryoglobulins were not found in HBsAg chronic carriers, while they have been evidenced, by a preliminary study, in 41.6% of HTLV-III antibody-positive subjects complaining of a persistent generalized lymphadenopathy without clinical or laboratory signs of liver impairment. No HTLV-III antibodies were found by ELISA method in the type III cryoprecipitates.

[2] Ribotyping of Burkholderia pseudomallei from clinical and soil isolates in Thailand.

[DOC16322] Burkholderia pseudomallei is a soil saprophyte that causes melioidosis in humans and animals. Restriction fragment length polymorphism of the ribosomal DNA regions (ribotyping) were analyzed in 577 isolates comprising 371 clinical and 206 soil isolates collected throughout Thailand in 1997. A total of 77 distinct ribotype patterns consisting of 2-9 bands with sizes ranging from 2.8 to >23 kb were found. Twelve major ribotypes were identified of which types 3, 8 and 23 were commonly found (278/577, 48.2%) in both clinical (217/371, 58.5%) and environmental isolates (61/206, 29.6%). Three unique environmental types were found whereas a unique clinical type was not observed. Even though ribotypes show high heterogeneity in the rDNA region, the unique environmental patterns were clearly different from the clinical patterns as clearly seen by UPGMA dendrogram. Moreover, the three major types (types 3, 8 and 23) were discovered in nearly half of B. pseudomallei isolates. Subtyping of these major ribotypes in correlation with clinical profiles may help researchers to identify the virulence factor of the organism.

[3] Examination of changes in connective tissue macromolecular components of large white pig s...

[DOC21636] The aim of this study was to provide information about the degradative processes that occur in major connective tissue components in skin following exposure of large white pigs to Lewisite vapour. Of particular interest were alterations in glycoproteins, which are known to mediate dermo-epidermal attachment (laminin and type IV collagen) and the main collagen found in the dermis (type III collagen). The immunostaining of transfer blots from skin extracts run on sodium dodecyl sulphate polyacrylamide gel electrophoresis gels revealed no evidence of cross-linking of laminin or of type III or IV collagen. However, there was evidence of a very considerable degradation of laminin and, to a lesser extent, of type IV collagen. Type III collagen did not appear to be degraded in skin exposed to Lewisite. These degradative processes appeared to be more severe than found in previous studies in Yucatan mini-pigs percutaneously exposed to sulphur mustard, in which only laminin was found to undergo partial cleavage rather than wholesale degradation.The results suggest that damage to macromolecular components in the sub-epidermal basement membrane in skin which mediate dermo-epidermal separation processes may be a common feature in the mechanism of action of vesicating agents such as Lewisite and sulphur mustard. It is of interest that the damage to laminin in this study appeared to be more severe than that previously found for sulphur mustard. This suggests that skin can suffer substantial damage yet, in the case of Lewisite exposure, recover relatively quickly. However, Lewisite is not an alkylating agent. Sulphur mustard, in contrast, generates characteristically slow healing lesions, most probably because of its ability to alkylate cell types that normally would be involved in skin regenerative processes.
Related to Topic 78: MUTATIONS,MUTATION,GENE,LOSS,FOUND,IDENTIFIED (0.081)

[1] Frequencies of gap- and tight-junction mutations in Turkish families with autosomal-recess...

[DOC19659] Mutations in genes encoding gap- and tight-junction proteins have been shown to cause distinct forms of hearing loss. We have now determined the GJB2[connexin 26 (Cx26)] mutation spectrum in 60 index patients from mostly large Turkish families with autosomal-recessive inherited non-syndromic sensorineural hearing loss (NSSHL). GJB2 mutations were found in 31.7% of the families, and the GJB2-35delG mutation accounted for 73.6% of all GJB2 mutations. The carrier frequency of GJB2-35delG in the normal Turkish population was found to be 1.17% (five in 429). In addition to the described W24X, 233delC, 120delE and R127H mutations, we also identified a novel mutation, Q80R, in the GJB2 gene. Interestingly, the Q80R allele was inherited on the same haplotype as V27I and E114G polymorphisms. As little is known about the mutation frequencies of most other recently identified gap- and tight-junction genes as a cause for hearing loss, we further screened our patients for mutations in GJB3 (Cx31), GJA1 (Cx43), DeltaGJB6-D13S1830 (Cx30) and the gene encoding the tight-junction protein, claudin 14 (CLDN14). Several novel polymorphisms, but no disease-associated mutations, were identified in the CLND14 and GJA1 genes, and we were unable to detect the DeltaGJB6-D13S1830 deletion. A novel putative mutation, P223T, was found in the GJB3 gene in heterozygous form in a family with two affected children. Our data shows that the frequency of GJB2 mutations in Turkish patients with autosomal-recessive NSSHL and the carrier rate of the GJB2-35delG mutation in the Turkish population, is much lower than described for other Mediterranean countries. Furthermore, mutations in other gap- and tight-junction proteins are not a frequent cause of hearing loss in Turkey.

[2] The prevalence of connexin 26 ( GJB2) mutations in the Chinese population.

[DOC18248] Mutations in GJB2, encoding gap junction beta 2 protein (connexin 26), are responsible for the commonest form of non-syndromic recessive deafness in many populations. It has been reported recently that the most common 35delG mutation in GJB2 is exceptionally low in Japanese and Korean populations, but another deletion, 235delC, is relatively frequent. Since the Chinese constitute approximately one fifth of the global population, the frequency of GJB2 mutations in the population has important implications for understanding worldwide causes of genetic deafness. To determine whether GJB2 mutations are an important cause of deafness in Chinese, we conducted mutation screening for GJB2 in 118 deaf Chinese probands, including 60 from simplex and 58 from multiplex families with non-syndromic deafness, and 150 normal hearing Chinese controls. Four mutations, including 235delC, 299-300delAT, V37I, and 35delG, were found in the patients. Thirty-nine percent of the probands had a GJB2mutation. Of the 118 probands, 19 carried two definitely pathogenic mutations: three among the 58 multiplex cases (5.2%) and 16 among the 60 simplex cases (26.7%). Twenty-seven probands (22.9%) were found to carry only single GJB2 mutations. None of them had mutations in exon 1 of GJB2 and or the 342-kb deletion of GJB6. The 235delC mutation was the most prevalent mutation (20.3% of alleles), accounting for 81% of the pathologic alleles in multiplex cases and 67% in simplex cases. Analysis of the affected haplotypes in the patients with the homozygous 235delC mutation yielded evidence for a single origin of the mutation. The carrier frequency of the 235delC mutation in control subjects with normal hearing was 1.3%. The 35delG mutation was only noted as a heterozygous change in two simplex cases (1.2% of alleles). These results indicated that mutations in GJB2 are a major cause of inherited and sporadic congenital deafness in the Chinese population. The 235delC mutation, rather than 35delG, is the most common mutation found in the Chinese deaf population. Our data support the view that specific combinations of GJB2 mutation exist in different populations.

[3] Comprehensive screening of the USH2A gene in Usher syndrome type II and non-syndromic rece...

[DOC23528] A screen of the entire coding region of the USH2A gene in 129 unrelated patients with Usher syndrome type II (USH2) and in 146 unrelated patients with non-syndromic autosomal recessive retinitis pigmentosa (ARRP) uncovered 54 different sequence variations, including 18 likely pathogenic mutations (13 frameshift, three nonsense, and two missense), 12 changes of uncertain pathogenicity (11 missense changes and one in-frame deletion), and 24 non-pathogenic rare variants or polymorphisms. Of the 18 likely pathogenic mutations, nine were novel. Among the USH2 patients, 50 (39%) had one or two likely pathogenic mutations. The most common mutant allele in USH2 patients was E767fs, which was found in 29 patients, including one homozygote. Among the ARRP patients, we found 17 (12%) with one or two likely pathogenic mutations. The most common mutant allele in ARRP patients was C759F and it was found in 10 patients. The C759F allele was also found in two USH2 patients; in neither of them was a change in the other allele found. The second most common mutant allele in both patient groups was L1447fs (found in 6/50 USH2 patients and 6/17 ARRP patients). Of the 50+17=67 patients with identified USH2A mutations, only one mutation in one allele was found in 41+12=53 (79%); the reason for the high proportion of patients with only one identified mutation is obscure. Our results indicate that USH2A mutations are found in about 7% of all cases of RP in North America, a frequency similar to the RPGR gene (8%) and the rhodopsin gene (10%).
Related to Topic 69: POSITIVE,BLOOD,SAMPLES,CULTURE,NEGATIVE,SPECIMENS (0.071)

[1] Comparison of BACTEC 9240 Peds Plus medium and isolator 1.5 microbial tube for detection o...

[DOC11484] The sensitivity and time to detection of Brucella melitensis by the BACTEC 9240 and the Isolator blood culture systems were compared in a prospective volume-controlled study. Blood sample aliquots, obtained from children with suspected brucellosis, were inoculated into a BACTEC 9240 Peds Plus bottle and into an Isolator 1.5 Microbial Tube. Overall, 122 pairs of blood samples for culture were obtained, and 28 (23%) were positive by at least one method. The BACTEC 9240 system detected all 28 positive cultures (sensitivity, 100%), and the Isolator system detected 22 positive cultures (sensitivity, 79%) (P = 0.023). Among those 22 cultures positive by both methods, 21 (95%) and 15 (68%) were found to be positive within 3 days by the BACTEC and the Isolator systems, respectively; 8 (36%) were found to be positive at least 1 day earlier by the BACTEC instrument, and the remaining 14 were found to be positive by the two systems on the same day (P = 0.045). The BACTEC 9240 blood culture system is more sensitive than the Isolator system for the detection of B. melitensis and is superior in terms of time to detection of the organism.

[2] Survey of desert bighorn sheep in California for exposure to selected infectious diseases.

[DOC6173] From February 1983 to June 1985, 188 desert bighorn sheep (Ovis canadensis nelsoni, = 161 and Oc cremnobates, = 27) from 18 herds in 17 mountain ranges and one captive herd were caught, marked, and had blood, fecal, and nasal mucus samples collected. Nasal swab specimens were cultured bacteriologically and virologically specifically for parainfluenza-3 (PI-3) virus. Bacterial flora differed from herd to herd. Pathogenic pneumophilic bacteria (eg, Pasteurella sp) seldom were found. Parainfluenza-3 virus was isolated from 6 bighorn sheep in 3 herds. Fecal specimens were examined for parasite ova and low numbers of lungworm (Protostrongylus sp) larvae were found in feces from 2 herds. Sera were evaluated for antibodies against respiratory syncytial virus, ovine progressive pneumonia, infectious bovine rhinotracheitis, PI-3, bovine viral diarrhea, brucellosis, leptospirosis, contagious ecthyma, bluetongue, and epizootic hemorrhagic disease. Blood clots were cultured virologically for bluetongue and epizootic hemorrhagic disease. Serologic evidence of bluetongue and/or epizootic hemorrhagic disease was found in 9 herds, and bluetongue virus (serotypes 10,11,13 and 17) was isolated from 3 herds. Antibody titers against PI-3 and respiratory syncytial virus were found in 9 and 13 herds, respectively. Evidence of bovine viral diarrhea infection was found in 6 herds, whereas infectious bovine rhinotracheitis was found in only 1 herd. Antibody titers against contagious ecthyma were found in 9 of 18 herds in California, and active lesions were seen occasionally. Evidence of ovine progressive pneumonia, leptospirosis, or brucellosis was not found.

[3] [Isolation and identification of SARS-coronavirus in nasal and throat swabs collected from...

[DOC21200] OBJECTIVE: To isolate and identify SARS-coronavirus in nasal and throat swabs collected from clinically diagnosed severe acute respiratory syndrome (SARS) patients. METHODS: Nasal and throat swab specimens were inoculated onto well of 24-well plate containing confluent monolayers of Vero and MRC-5 cells. Isolates were identified with serology, electron microscopy and genome sequence. RESULTS: One hundred and fifty-eight nasal and throat swabs specimens from 79 SARS patients in Peking Union Medical College Hospital between April and May, 2003 were cultured for SARS-coronavirus. Cytopathic effect (CPE) was found in three nasal swab specimens inoculated in Vero cells. Acute and convalescent phase serum specimens collected from SARS patients were found with seroconversions and/or a fourfold or greater rises in indirect fluorescence antibodies (IgG and IgM) titers when the 3 isolates (infected Vero cells) were used as antigen. Coronavirus was observed in the culture supernatant by negative-stain electron microscopy. Genome sequence confirmed the isolates were SARS-coronavirus. CONCLUSIONS: The 3 isolates from nasal and throat swabs samples collected from 79 clinically diagnosed SARS patients were SARS coronavirus.
HUMAN
Most likely documents

[1] Extreme dark cytotoxicity of Nile Blue A in normal human fibroblasts.

[DOC16379] Early reports using mouse models indicated that Nile Blue A (NBA) is taken up more efficiently by tumor cells than normal tissue and retards tumor growth. NBA also shows both dark toxicity and phototoxicity of human tumor cells in vitro. However, studies on the dark toxicity of NBA and the effects of NBA-mediated photodynamic treatment in normal human cells are lacking. In the current study we have examined the cytotoxicity of NBA in normal human fibroblasts, spontaneously immortalized Li-Fraumeni Syndrome (LFS) cells and three different human tumor cell lines. The normal human fibroblasts showed extreme sensitivity to NBA compared with LFS cells and the human tumor cell lines. Treatment with 0.1 microgram/mL of NBA for 1 h reduced the colony formation of normal human fibroblasts by greater than 95%, but had no significant effect on the colony formation of LFS cells. No significant numbers of apoptotic cells were detected in either normal human fibroblasts or LFS cells following this drug concentration. Thus, unlike photodynamic therapy with some other photosensitizers, the dark toxicity of NBA was not caused by apoptosis. Although the drug uptake was higher in normal human fibroblasts compared with LFS cells, the difference in sensitivity between normal human fibroblasts and LFS cells could not be accounted for by the difference in drug uptake alone. In addition, we could not detect any significant photocytotoxic effect of NBA in either normal human fibroblasts or LFS cells for a drug concentration of 0.05 microgram/mL at light exposures of up to 6.7 J/cm2. These data indicate an extreme sensitivity of normal human fibroblasts to NBA and an inability to produce a significant photocytotoxic effect on human cells using NBA concentrations that have relatively low toxicity for normal human fibroblasts.

[2] Cloning and cytotoxicity of a human pancreatic RNase immunofusion.

[DOC11619] BACKGROUND: Immunotoxins based on plant and bacterial proteins are usually very immunogenic. human ribonucleases could provide an alternative basis for the construction of less immunogenic reagents. Two members of the human RNase family, angiogenin and eosinophil-derived neurotoxin (EDN), have been fused to a single chain antibody against the transferrin receptor, which is known to be internalised by endocytosis. The fusion proteins proved to be very efficient inhibitors of protein synthesis using various cell lines. It is not yet known whether the side effects of angiogenin and EDN will compromise their potential use as immunotoxins. OBJECTIVES: The goal of this work was to construct a human immunotoxin with no harmful side effects. Bovine pancreatic ribonuclease has been shown to be as potent as ricin at abolishing protein synthesis on injection into oocytes. We therefore decided to clone its human analogue, which is fairly ubiquitous and per se non-toxic. An immunofusion of human pancreatic RNase with a single chain antibody against the transferrin receptor was tested for its ability to inhibit protein synthesis in three different human tumor cell lines. STUDY DESIGN: DNA coding for the human pancreatic RNase was cloned partially from a human fetal brain cDNA library and then completed by PCR using a human placental cDNA library as a template. The RNase gene was then fused with a DNA coding for an single chain antibody against the transferrin receptor (CD71). After expressing the fusion protein in E. coli, the gene product was isolated from inclusion bodies and tested for cytotoxicity. RESULTS: This fusion protein inhibited the protein synthesis of three human tumor cell lines derived from a melanoma, a renal carcinoma and a breast carcinoma, with IC50s of 8, 5 and 10 nM, respectively. These values were comparable with those using a similar fusion protein constructed with eosinophil derived neurotoxin (EDN) as the toxic moiety (IC50s of 8, 1.2 and 3 nM, respectively). The slightly lower activities of the human pancreatic RNase-scFv (pancRNase-scFv) with two of the cell lines suggests that fewer molecules are reaching the cytoplasmic compartment, since it was twice as active as EDN-scFv in inhibiting the protein synthesis of a rabbit reticulocyte lysate. CONCLUSION: These results demonstrate that the human pancreatic RNase, which is expected to have a very low immunogenic potential in humans with no inherent toxicity, may be a potent cytotoxin for tumor cells after antibody targeting.

[3] Efficacy of an anti-CD5-ricin A chain immunoconjugate in an improved human peripheral bloo...

[DOC8771] Severe combined immunodeficient mice reconstituted with human peripheral blood lymphocytes (hu-PBL-SCID mice) were used to evaluate in vivo efficacy of a mouse IgG1 monoclonal antibody (mAb)-ricin toxin A chain immunoconjugate (H65-RTA) directed against the CD5 cell surface antigen present on human T-cells. Initial studies demonstrated that plasma levels of human soluble interleukin-2 receptor (sIL-2R) are predictive of human T-cell engraftment in spleens and blood of SCID mice transplanted with human PBL. Therefore, chimeric mice with detectable plasma levels of human sIL-2R were used in subsequent studies. Systemic injection of such mice with H65-RTA resulted in a significant depletion of human T-cells from spleens, blood and bone marrow, and a decrease in plasma levels of human sIL-2R as compared to vehicle-treated control animals. The effect of H65-RTA was dose-dependent, treatment schedule-dependent, and mAb-specific, as an isotype-, linker- and toxin-matched immunoconjugate of irrelevant binding specificity was not efficacious. Moreover, human T-cells remained depleted from SCID tissues for at least 10 days after cessation of H65-RTA treatment, indicating that the cells were killed by the immunoconjugate. Unconjugated H65 mAb and an H65-derived F(ab')2-RTA conjugate, but not unconjugated F(ab')2, were also efficacious, suggesting that the Fc portion of the mAb and the toxin moiety may both play a role in the mechanism of human T-cell depletion by H65-RTA in this model. Results indicate that the hu-PBL-SCID mouse model can be used to compare in vivo efficacy of immunosuppressive agents specifically directed against human T-cells.
Related to Topic 73: HUMAN,DISEASE,ANIMAL,HUMANS,ANIMALS,CAUSED (0.702)

[1] Animals, disease, and man: making connections.

[DOC19372] The intricate causal relationships between disease in man and disease in animals first began to be elucidated in the mid-19th century. Although the connections between animal and human disease are now generally understood, individuals as well as societies remain slow to act on this knowledge. This paper examines the gradual recognition of these disease connections and explores the parallel theme of man's reluctance to appreciate the implications of these connections. It identifies factors that have inhibited the realization of the links between disease in man and animals, and discusses several milestones in the scientific elucidation of these links. Beginning with emerging concerns over the relationship between bovine and human tuberculosis in the 1860s, it follows the discovery of insect vectors, animal reservoirs, and the links between animals, influenza, and man. Despite warnings of the potential significance for human disease of patterns of changes in the relationship with animals and the natural world, scientists have continued to treat human and animal health as largely independent disciplines, while historians too have neglected this important aspect of human disease.

[2] Potential of zoonotic transmission of non-primate foamy viruses to humans.

[DOC21123] The zoonotic introduction of an animal pathogen into the human population and the subsequent extension or alteration of its host range leading to the successful maintenance of the corresponding pathogen by human-to-human transmission pose a serious risk for world-wide health care. Such a scenario occurred for instance by the introduction of simian immunodeficiency viruses into the human population resulting in the human immunodeficiency viruses (HIV) and the subsequent AIDS pandemic or the proposed recent host range switch of the SARS coronavirus from a presently unknown animal species to humans. The occurrence of zoonotic transmissions of animal viruses to humans is a permanent threat to human health and is even increased by changes in the human lifestyle. In this review, the potential of the zoonotic transmission of bovine, feline and equine foamy retroviruses will be discussed in the light of well-documented cases of zoonotic transmissions of different simian foamy viruses to humans.

[3] Avian influenza and human health.

[DOC17340] Natural infections with influenza A viruses have been reported in a variety of animal species including humans, pigs, horses, sea mammals, mustelids and birds. Occasionally devastating pandemics occur in humans. Although viruses of relatively few HA and NA subtype combinations have been isolated from mammalian species, all 15 HA subtypes and all 9 NA subtypes, in most combinations, have been isolated from birds.In the 20th century the sudden emergence of antigenically different strains transmissible in humans, termed antigenic shift, has occurred on four occasions, 1918 (H1N1), 1957 (H2N2), 1968 (H3N2) and 1977 (H1N1), each time resulting in a pandemic. Genetic analysis of the isolates demonstrated that 'new' strains most certainly emerged after reassortment of genes of viruses of avian and human origin in a permissive host. The leading theory is that the pig represents the 'mixing vessel' where this genetic reassortment may occur.In 1996, an H7N7 influenza virus of avian origin was isolated from a woman with a self-limiting conjunctivitis. During 1997 in Hong Kong, an H5N1 avian influenza virus was recognised as the cause of death of 6 of 18 infected patients. Genetic analysis revealed these human isolates of H5N1 subtype to be indistinguishable from a highly pathogenic avian influenza virus that was endemic in the local poultry population. More recently, in March 1999, two independent isolations of influenza virus subtype H9N2 were made from girls aged one to four who recovered from flu-like illnesses in Hong Kong. Subsequently, five isolations of H9N2 virus from humans on mainland China in August 1998 were reported. H9N2 viruses were known to be widespread in poultry in China and other Asian countries.In all these cases there was no evidence of human to human spread except with the H5N1 infections where there was evidence of very limited spread. This is in keeping with the finding that all these viruses possessed all eight genes of avian origin. It may well be that infection of humans with avian influenza viruses occurs much more frequently than originally assumed, but due to their limited effect go unrecognised.For the human population as a whole the main danger of direct infection with avian influenza viruses appears to be if people infected with an 'avian' virus are infected simultaneously with a 'human' influenza virus. In such circumstances reassortment could occur with the potential emergence of a virus fully capable of spread in the human population, but with antigenic characteristics for which the human population was immunologically naive. Presumably this represents a very rare coincidence, but one which could result in a true influenza pandemic.
Related to Topic 1: RICIN,CHAIN,CELLS,IMMUNOTOXIN,ANTI,ANTIBODY (0.109)

[1] Potent cytotoxicity of an antihuman transferrin receptor-ricin A-chain immunotoxin on huma...

[DOC3404] The cytotoxic effects of an antihuman transferrin receptor monoclonal antibody-ricin A-chain conjugate (anti-TfR-A) immunotoxin on glioma cells were assessed in vitro. Five human glioma cell lines were studied; three were derived from surgical explants (MG-1, MG-2, MG-3) and two were well characterized established glioma cells (U-87 MG, U-373 MG). The C6 rat glioma line served as a nonhuman control. One of six lines (U-373) expressed glial fibrillary acidic protein, as assessed by immunohistochemistry. All five human lines expressed human transferrin receptor, as assessed by flow cytometry; no human transferrin receptor was demonstrable on rat C6 cells. Potent inhibition of protein synthesis was found after an 18-h incubation with anti-TfR-A. Fifty % inhibitory concentration (IC50) values for human glioma cells ranged from 1.9 X 10(-9) to 1.8 X 10(-8) M. In contrast, no significant inhibition of leucine incorporation was observed when anti-TfR-A was tested on rat cells (IC50 greater than 10(-7) M) or when a control immunotoxin directed against carcinoembryonic antigen was substituted for anti-TfR-A on human glioma cells (IC50 greater than 10(-7) M). Coincubation with the carboxylic ionophore monensin (10(-7) M) decreased the IC50 of anti-TfR-A against human glioma lines from 16- to 842-fold (range, 7.0 X 10(-12) to 1.5 X 10(-10) M). In contrast, an IC50 of greater than 10(-7) M was obtained when C6 cells were incubated with anti-TfR-A and monensin. Anti-TfR-A immunotoxins potentiated by monensin are extremely potent in vitro cytotoxins for human glioma cells.

[2] Sensitivity of human glioma cells to cytotoxic heteroconjugates.

[DOC5184] Several anti-human glioma cytotoxic conjugates were studied in vitro. Monoclonal antibodies (MAbs) to the GE2 glioma-associated antigen (anti-GE 2) and MAbs to HLA-DR antigens (D1/12) or human diferric transferrin (Tfn) were linked to the potent cytotoxin ricin (anti-GE 2-ricin) or to its A subunit (anti-GE 2-RTA, D1/12-RTA, Tfn-RTA). Anti-GE 2-RTA had low cytotoxic activity in both the absence and the presence of lysosomotropic substances inhibiting intracellular degradation. Anti-GE 2-ricin was about 1,000 times more toxic than RTA alone, but showed only 14-fold target specificity. D1/12-RTA was about 20 times more toxic than RTA and its cytotoxic effect increased about 6- to 7-fold when cell-surface HLA-DR antigen expression was enhanced by IFN-gamma treatment. human diferric Tfn linked to RTA demonstrated the highest cytotoxic activity, being about 5,000 times more toxic than RTA alone for glioma cells and about 6,000 times more toxic for Jurkat cells in the presence of the carboxylic ionofore monensin. Ricin toxin was only about 5 times more toxic for Jurkat and glioma cells than Tfn-RTA-monensin. Tfn-RTA was over 100,000 times more potent than the chemotherapeutic agent BCNU in reducing glioma cell survival in vitro. Addition of 80% human pooled cerebrospinal fluid (CSF) reduced Tfn-RTA toxicity about 10-fold. Kinetics of Tfn-RTA cytotoxicity at non-saturating concentrations indicated that over 80% of target cells could be killed within 8-10 hr in the absence and within 10-12 hr in the presence of human pooled CSF.

[3] Complete suppression of in vivo growth of human leukemia cells by specific immunotoxins: n...

[DOC5631] In this study, immunotoxins containing monoclonal anti-human T-cell leukemia antibodies are shown to be capable of completely suppressing the tumor growth of human T-cell leukemia cells in vivo without any overt undesirable toxicity. These immunotoxins were prepared by conjugating ricin A chain (RA) with our monoclonal antibodies, SN1 and SN2, directed specifically to the human T-cell leukemia cell surface antigens TALLA and GP37, respectively. We have shown that these monoclonal antibodies are highly specific for human T-cell leukemia cells and do not react with various normal cells including normal T and B cells, thymocytes, and bone marrow cells. Ascitic and solid human T-cell leukemia cell tumors were generated in nude mice. The ascitic tumor was generated by transplanting Ichikawa cells (a human T-cell leukemia cell line) i.p. into nude mice, whereas the solid tumor was generated by transplanting s.c. MOLT-4 cells (a human T-cell leukemia cell line) and x-irradiated human fibrosarcoma cells into x-irradiated nude mice. To investigate the efficacy of specific immunotoxins in suppressing the in vivo growth of the ascitic tumor, we divided 40 nude mice that were injected with Ichikawa cells into four groups. Each group of 10 mice was injected with one of the following mixtures: 40 micrograms of purified control mouse IgG [IgG1(kappa)] (group 1), 40 micrograms of control RA conjugate (group 2), 20 micrograms of purified SN1 antibody [IgG1(kappa)] and 20 micrograms of purified SN2 antibody [IgG1(kappa)] (group 3), or 20 micrograms of SN1-RA and 20 micrograms of SN2-RA (group 4). Mice in groups 1 and 2 formed large ascitic tumors, and died 5.8-7.0 weeks after the transplantation. Group 3 mice also formed large ascitic tumors and died 6.4-7.8 weeks after the transplantation. However, none of the mice in group 4 that were treated with SN1-RA and SN2-RA showed any signs of a tumor or undesirable toxic effects for the 20 weeks that they were followed after the transplantation; these mice were indistinguishable from healthy control nude mice that were not injected with Ichikawa cells. Treatment with SN1-RA plus SN2-RA completely suppressed solid tumor growth in 4 of 10 nude mice carrying solid tumors and partially suppressed the tumor growth in the remaining 6 nude mice. These results strongly suggest that SN1-RA and SN2-RA may be useful for clinical treatment.
Related to Topic 9: CELLS,CELL,CULTURES,LINES,APOPTOSIS,LINE (0.065)

[1] Extreme dark cytotoxicity of Nile Blue A in normal human fibroblasts.

[DOC16379] Early reports using mouse models indicated that Nile Blue A (NBA) is taken up more efficiently by tumor cells than normal tissue and retards tumor growth. NBA also shows both dark toxicity and phototoxicity of human tumor cells in vitro. However, studies on the dark toxicity of NBA and the effects of NBA-mediated photodynamic treatment in normal human cells are lacking. In the current study we have examined the cytotoxicity of NBA in normal human fibroblasts, spontaneously immortalized Li-Fraumeni Syndrome (LFS) cells and three different human tumor cell lines. The normal human fibroblasts showed extreme sensitivity to NBA compared with LFS cells and the human tumor cell lines. Treatment with 0.1 microgram/mL of NBA for 1 h reduced the colony formation of normal human fibroblasts by greater than 95%, but had no significant effect on the colony formation of LFS cells. No significant numbers of apoptotic cells were detected in either normal human fibroblasts or LFS cells following this drug concentration. Thus, unlike photodynamic therapy with some other photosensitizers, the dark toxicity of NBA was not caused by apoptosis. Although the drug uptake was higher in normal human fibroblasts compared with LFS cells, the difference in sensitivity between normal human fibroblasts and LFS cells could not be accounted for by the difference in drug uptake alone. In addition, we could not detect any significant photocytotoxic effect of NBA in either normal human fibroblasts or LFS cells for a drug concentration of 0.05 microgram/mL at light exposures of up to 6.7 J/cm2. These data indicate an extreme sensitivity of normal human fibroblasts to NBA and an inability to produce a significant photocytotoxic effect on human cells using NBA concentrations that have relatively low toxicity for normal human fibroblasts.

[2] Immunotoxins containing Pseudomonas exotoxin that target LeY damage human endothelial cell...

[DOC12735] Vascular leak syndrome (VLS) was originally found to be a major dose-limiting toxicity in humans with cancer treated with several immunotoxins (ITs) containing ricin A chain or blocked ricin. Recently, VLS has also been observed in patients treated with an IT containing the murine monoclonal antibody (MAb) B3 coupled to LysPE38, a recombinant truncated form of Pseudomonas exotoxin (PE) A. Antibody B3 (IgG1k) recognizes LewisY and related carbohydrate epitopes present on many human solid tumors, and B3-LysPE38 showed excellent antitumor activity in nude mice bearing tumors that express the B3 antigen. In the clinical trial, the development of VLS has prevented the administration of the amount of IT necessary to achieve blood levels required for good therapeutic responses. We have now investigated the effects of several PE-based ITs on different human endothelial cell lines to elucidate the mechanism of VLS induced by ITs containing PE. To assess the cytotoxic effect of IT on endothelial cells, various ITs were incubated with cells for 2 or 20 h, and the incorporation of [3H]leucine into protein was measured. The endothelial cells studied were human umbilical vein endothelial cells, human lung-derived microvascular endothelial cells (HUVECs), human adult dermal microvascular endothelial cells, human pulmonary artery endothelial cells, and human aortic endothelial cells. We found that both B3-LysPE38 (LMB-1), a chemical conjugate of MAb B3 with PE38, as well as B3(Fv)-PE38 (LMB-7), a recombinant single chain immunotoxin, inhibited protein synthesis, with 50% inhibitory concentrations between 600 and 1000 ng/ml for 20-h incubation in HUVECs, human lung-derived microvascular endothelial cells, and human adult dermal microvascular endothelial cells but not on human pulmonary artery endothelial cells. The cytotoxic effect was specific since PE38 itself or PE coupled to several other antibodies did not inhibit protein synthesis in these cells even at 10,000 ng/ml. Further evidence that the cytotoxicity of B3-containing ITs is due to specific B3 binding to endothelial cells comes from the fact that the cytotoxicity can be blocked by excess free MAb B3. HUVECs undergo overt morphological changes after treatment with B3-LysPE38 or B3(Fv)PE38. Gaps between the cells are formed after a 20-h exposure but not after 2 h. These studies suggest that VLS in patients is due to capillary damage caused by prolonged exposure to high concentrations of LMB-1.

[3] The effect of human bcl-2 and bcl-X genes on dengue virus-induced apoptosis in cultured ce...

[DOC15277] Infection of dengue viruses (DENs) can cause human dengue fever, hemorrhagic fever, or shock syndrome. Although DEN-induced apoptosis has been implicated in pathogenesis of the DEN-related diseases, the underlying mechanism remains largely unexplored. In this study, we investigated the effect of ectopic expression of human bcl-2 and bcl-X genes on DEN-induced apoptosis in cultured cells. We employed a human isolate of DEN serotype 2 (DEN-2), PL046, which not only caused cell-cycle arrest in the G1 phase but also induced apoptosis in infected baby hamster kidney (BHK-21) cells, murine neuroblastoma N18 cells, and human neuronal NT-2 cells. Our results reveal that overexpression of bcl-2 in fibroblast-like BHK-21 cells, although not inhibiting virus yields, delayed the process of DEN-induced apoptosis, thereby permitting surviving cells to become persistently infected. In contrast, stable bcl-2 expression in neuronal N18 cells failed to block DEN-induced apoptosis. On the other hand, Bcl-X(L), expressed predominantly in the nervous system, appeared to delay DEN's killing effect in neuronal N18 cells but not in fibroblast-like BHK-21 cells. In addition, inducible expression bcl-X(s), despite its proapoptotic property in other reported system, was found to merely accelerate cell death in DEN-infected N18 but not in infected BHK-21 cells. Thus, through studying the effect of human bcl-2-related genes, our results suggest that DEN infection may trigger target cells to undergo morphologically similar but biochemically distinct apoptotic pathways in a cell-specific manner.
INFECTION
Most likely documents

[1] Minimal requirements for murine resistance to infection with Francisella tularensis LVS.

[DOC10768] Intraperitoneal or intravenous infection of mice with Francisella tularensis LVS is lethal, with an intraperitoneal 50% lethal dose (LD50) approaching a single bacterium. Intradermal (i.d.) LVS infection has a much higher LD50, about 10(6) bacteria in BALB/cByJ mice, and survival of i.d. infection leads to solid generation of immunity against lethal challenge. To define the minimal requirements for both initial and long-term survival of i.d. infection, we characterized the nature of i.d. LVS infection in lymphocyte-deficient BALB/cByJ.scid (scid) mice. scid mice infected i.d. with strain LVS survived for about 20 days and then died from overwhelming disseminated infection. However, scid mice treated with monoclonal antibodies to gamma interferon, tumor necrosis factor alpha, or neutrophils-granulocytes all died within 1 week of infection, indicating that these were essential for early control of infection. Studies using GKO (gamma interferon knockout) mice emphasized that gamma interferon is absolutely required for initial survival of i.d. LVS infection. scid mice could be reconstituted for long-term survival of i.d. LVS infection and clearance of bacteria by intravenous transfer of splenic lymphocytes or purified B220-/T+ lymphocytes but not nu/nu lymphocytes. T cells are therefore required for long-term clearance and survival of i.d. LVS infection; efforts to determine whether CD4+ T cells, CD8+ T cells, or both are involved are ongoing.

[2] Can therapy even be denied for Helicobacter pylori infection?

[DOC11936] Helicobacter pylori infection is a transmissible bacterial infection of the gastric mucosal surface that causes progressive damage with eventual destruction of the stomach. In the United States, the presence of H. pylori infection in patients carries a lifetime risk of developing peptic ulcer of at least 16% and a 1%-3% risk of developing gastric cancer. An infected individual is also a risk to the community because the infection can be transmitted. A review of the data shows that H. pylori is the only treatable infectious disease with such a high rate of morbidity and mortality that is not the subject of an all-out program to eradicate it from the population. The risk of a serious outcome of untreated asymptomatic H. pylori infection is great, or greater, than with asymptomatic syphilis or tuberculosis. H. pylori infection is a serious public health problem, and thus the presence of H. pylori infection justifies treatment. The question is not whom to treat, but whom to test. The gastroenterology community appears to have been unduly influenced by the fact that H. pylori infection is widespread and often asymptomatic, as well as by the costs and complications of current treatment. H. pylori infection is a serious, worldwide infectious disease with tremendous and unacceptable morbidity and mortality. Although there are no emotional reasons to treat H. pylori infection, there are logical and persuasive scientific reasons to treat. If the tools are available, screening the population for the presence of H. pylori infection with the goal of preventing all H. pylori-related diseases is recommended. Our goal should be to totally eliminate H. pylori from the face of the earth, just as we eliminated smallpox.

[3] Brucellosis as a world problem.

[DOC1524] Brucellosis is one of the most widespread and economically the most ravaging of zoonoses. The occurrence of the acute, often incapacitating infection in man caused by Brucella melitensis usually coincides with occurrence of the infection in sheep and goats. Well-known foci of this infection have been identified in the Mediterranean basin, Central Asia and Latin America. Recent investigations in parts of Africa and India have shown that the infection is much more widespread than was previously suspected and that more foci remain to be discovered by the application of laboratory methods in epidemiological investigations. Bovine infection has a wider distribution and is more important than infection of sheep and goats as far as economic losses are concerned. Although the infection has been reduced by control measures to a low level of incidence in some countries of Europe and North America, its incidence in other parts of the world has actually increased because of emphasis on increased animal production and aggregation under poor hygienic conditions. This is particularly the case with dairy production units which have developed around rapidly growing urban centres in many developing countries. Although human infection with B. abortus may be mild, it can cause troublesome and intractable illness. The economic ravages of bovine brucellosis are tremendous and the losses in Latin America and the USA alone have been estimated by their respective governments to be 700 million dollars annually. The world figure must be truly staggering. Swine brucellosis is largely a problem of the Americas although a few foci have recently been discovered in other parts of the world, notably in Europe and Southern Asia. In the Americas, swine infection is second only to bovine brucellosis in its economic importance. A large number of human cases of B. suis infection are detected every year in the endemic areas. Other forms of brucellosis, e.g. B. canis in dogs and B. suis, biotype 4 in reindeer, have a limited distribution and are responsible for only sporadic human infections. B. ovis of sheep is more widespread but is generally confined to sheep. Annexes 1 and 2 show the reported incidence of brucellosis in man and animals. However, the officially reported data are generally incomplete and the actual incidence must in most cases be much higher than is shown in these tables. FAO and WHO have been assisting countries in which brucellosis is endemic by organizing control measures, providing training and reference materials, and by focusing coordinated research on problems which arise in these programmes. Some of the highlights of this work are outlined in the following paragraphs.
Related to Topic 36: MICE,INFECTION,MOUSE,SPLEEN,STRAIN,BALB (0.193)

[1] T-cell-independent resistance to infection and generation of immunity to Francisella tular...

[DOC10132] The intraperitoneal 50% lethal dose (LD50) for Francisella tularensis LVS in both normal control heterozygote BALB/c nu/+ mice and BALB/c nu/nu mice was 2 x 10(0). Both nu/+ and nu/nu mice given 10(7) LVS bacteria or more intradermally (i.d.) died, with a mean time to death of about 7 to 8 days. On the other hand, nu/+ mice given 10(6) LVS bacteria or less survived for more than 60 days and cleared systemic bacteria, while nu/nu mice given 10(6) LVS bacteria or less survived for more than 10 days but died between days 25 and 30. Thus, the short-term (i.e., < 10-day) i.d. LD50 of both nu/nu and nu/+ mice was 3 x 10(6), but the long-term (i.e., > 10-day) i.d. LD50 of nu/nu mice was less than 7 x 10(0). The short-term survival of i.d. infection was dependent on tumor necrosis factor and gamma interferon: treatment of nu/nu mice with anti-tumor necrosis factor or anti-gamma interferon at the time of i.d. infection resulted in death from infection 7 to 8 days later, whereas control infected nu/nu mice survived for 26 days. nu/nu mice infected with LVS i.d. generated LVS-specific serum antibodies, which were predominantly immunoglobulin M: titers peaked 7 days after i.d. infection but declined sharply by day 21, after which mice died. Surprisingly, nu/nu mice given 10(3) LVS bacteria i.d. became resistant to a lethal challenge (5,000 LD50s) of LVS intraperitoneally within 2 days after i.d. infection; nu/nu mice similarly infected with LVS i.d. and challenged with Salmonella typhimurium (10 LD50s) were not protected. nu/nu mice given nu/+ spleen cells intravenously as a source of mature T cells survived i.d. infection for more than 60 days and cleared bacteria. Taken together, these studies demonstrate that i.d. infection of nu/nu mice with LVS rapidly generates T-cell-independent, short-term, specific protective immunity against lethal challenge, but T lymphocytes are essential for long-term survival.

[2] Minimal requirements for murine resistance to infection with Francisella tularensis LVS.

[DOC10768] Intraperitoneal or intravenous infection of mice with Francisella tularensis LVS is lethal, with an intraperitoneal 50% lethal dose (LD50) approaching a single bacterium. Intradermal (i.d.) LVS infection has a much higher LD50, about 10(6) bacteria in BALB/cByJ mice, and survival of i.d. infection leads to solid generation of immunity against lethal challenge. To define the minimal requirements for both initial and long-term survival of i.d. infection, we characterized the nature of i.d. LVS infection in lymphocyte-deficient BALB/cByJ.scid (scid) mice. scid mice infected i.d. with strain LVS survived for about 20 days and then died from overwhelming disseminated infection. However, scid mice treated with monoclonal antibodies to gamma interferon, tumor necrosis factor alpha, or neutrophils-granulocytes all died within 1 week of infection, indicating that these were essential for early control of infection. Studies using GKO (gamma interferon knockout) mice emphasized that gamma interferon is absolutely required for initial survival of i.d. LVS infection. scid mice could be reconstituted for long-term survival of i.d. LVS infection and clearance of bacteria by intravenous transfer of splenic lymphocytes or purified B220-/T+ lymphocytes but not nu/nu lymphocytes. T cells are therefore required for long-term clearance and survival of i.d. LVS infection; efforts to determine whether CD4+ T cells, CD8+ T cells, or both are involved are ongoing.

[3] Loss of either CD4+ or CD8+ T cells does not affect the magnitude of protective immunity t...

[DOC11144] Normal mice readily survive a sublethal intradermal (i.d.) infection with Francisella tularensis live vaccine strain (LVS), a model intracellular bacterium, and are strongly protected against subsequent lethal challenge. However, athymic nu/nu mice, which lack mature alphabeta TCR+ T lymphocytes, succumb to i.d. infection within 30 days. Here we characterize the alphabeta T cell subpopulations necessary for both resolution of i.d. infection and generation of optimal protective immunity to LVS. BALB/cByJ mice treated with anti-CD4 or anti-CD8 Abs before i.d. infection survived and cleared bacteria, and anti-CD4- or anti-CD8-treated immune mice survived a very strong i.p. challenge of 10,000 LD50s. Among mutant mice with targeted gene disruptions (knockouts), CD4-, beta2-microglobulin-deficient (which are also CD8-), and gammadelta TCR- mice all resolved a large sublethal i.d. infection. All CD4- and beta2-microglobulin-deficient mice readily survived subsequent lethal i.p. challenge of 10,000 LD50s, even in the absence of specific IgG Abs, as did most (86%) gammadelta TCR- mice. In contrast, alphabeta TCR- mice or alphabeta + gammadelta TCR- mice died about 35 days after i.d. infection. Depletion of gammadelta+ T cells from alphabeta TCR- mice had no effect on mean time to death from i.d. LVS infection. Therefore alphabeta TCR+ cells are required for protection, but either CD4+ or CD8+ T cells are individually sufficient to resolve a large sublethal i.d. LVS infection and to protect against a maximal secondary lethal challenge. These results emphasize the remarkable plasticity of the alphabeta T cell response in protective immunity to intracellular bacteria.
Related to Topic 35: CONTACT,INFECTION,TRANSMISSION,WORKERS,RISK,CONTROL (0.111)

[1] [An investigation on nosocomial infection with severe acute respiratory syndrome in health...

[DOC22258] OBJECTIVE: To analysis the risk factors influencing nosocomial infection of severe acute respiratory syndrome (SARS) in health-care workers and to evaluate effectiveness of its control and preventive measures in 13 key hospitals caring for SARS patients. METHODS: Number of SARS patients, clinical conditions of them, its attack rate in health-care workers, and characteristics of hospitals, including their environment, isolating measures, etc. were investigated at the 13 hospital in Guangzhou to analyze the risk factors influencing nosocomial infection of SARS and its attack rates in health-care workers before and after implementation of preventive measures and to evaluate their effectiveness. RESULTS: Totally, 841 patients with SARS were treated at the 13 hospitals in Guangzhou and 285 health-care workers caring for them infected nosocomially. Attack rate in health-care workers was higher at general hospitals, hospital accepting more cases in critical conditions and hospitals with poor precautious measures, and lower in hospitals with isolated wards or areas, or department of infection, specially caring for SARS patients, and those with effective intervention measures to prevent secondary infection. CONCLUSION: Nosocomial infection of SARS in health-care workers was affected by clinical condition of SARS patients, characteristics and environment of hospitals and their personal protective measures adopted.

[2] Occupationally acquired infections in health care workers. Part II.

[DOC11179] BACKGROUND: Health care workers are at occupational risk for a vast array of infections that cause substantial illness and occasional deaths. Despite this, few studies have examined the incidence, prevalence, or exposure-associated rates of infection or have considered infection-specific interventions recommended to maintain worker safety. OBJECTIVE: To characterize the type and frequency of infections, the recommended interventions, and the costs of protecting health care workers. Part II of this two-part review focuses on infections caused by bloodborne organisms, organisms spread through the oral-fecal route, and organisms spread through direct contact. It also reviews established interventions for controlling transmission. DATA SOURCES: A MEDLINE search and examination of infectious disease and infection control journals. DATA SELECTION: All English-language articles and meeting abstracts published from January 1983 to February 1996 related to occupationally acquired infections among health care workers were reviewed. Outbreak- and non-outbreak-associated incidence and prevalence rates were derived, as were costs to prevent, control, and treat infections in health care workers. DATA SYNTHESIS: Occupational transmission to health care workers was identified for numerous diseases, including infections caused by bloodborne organisms (human immunodeficiency virus, hepatitis B virus, hepatitis C virus, Ebola virus), organisms spread through the oral-fecal route (salmonella, hepatitis A virus), and organisms spread through direct contact (herpes simplex virus, Sarcoptes scabiei). Most outbreak-associated attack rates range from 15% to 40%. Occupational transmission is usually associated with violation of one or more of three basic principles of infection control: handwashing, vaccination of health care workers, and prompt placement of infectious patients into appropriate isolation. CONCLUSIONS: The risk for occupationally acquired infections is an unavoidable part of daily patient care. Occupationally acquired infections cause substantial illness and occasional death among health care workers. Further studies are needed to enhance compliance with established infection control approaches. As health care is being reformed, the risk for and costs of occupationally acquired infection must be considered.

[3] SARS transmission among hospital workers in Hong Kong.

[DOC22082] Despite infection control measures, breakthrough transmission of severe acute respiratory syndrome (SARS) occurred for many hospital workers in Hong Kong. We conducted a case-control study of 72 hospital workers with SARS and 144 matched controls. Inconsistent use of goggles, gowns, gloves, and caps was associated with a higher risk for SARS infection (unadjusted odds ratio 2.42 to 20.54, p < 0.05). The likelihood of SARS infection was strongly associated with the amount of personal protection equipment perceived to be inadequate, having <2 hours of infection control training, and not understanding infection control procedures. No significant differences existed between the case and control groups in the proportion of workers who performed high-risk procedures, reported minor protection equipment problems, or had social contact with SARS-infected persons. Perceived inadequacy of personal protection equipment supply, infection control training <2 hours, and inconsistent use of personal protection equipment when in contact with SARS patients were significant independent risk factors for SARS infection.
Related to Topic 84: ANIMALS,INFECTED,PIGS,GUINEA,INFECTION,MONKEYS (0.105)

[1] Tumor necrosis factor and the pathogenesis of Pichinde virus infection in guinea pigs.

[DOC8781] Pichinde virus (PIC) is a reticuloendothelial arenavirus of the New World tropics. A guinea pig passage-adapted strain of this virus (adPIC) is uniformly lethal for inbred guinea pigs, while the related, prototype strain (PIC3739) has attenuated virulence. The abilities of adPIC and PIC3739 to induce tumor necrosis factor (TNF) in vivo and in cultured macrophages were compared. infection with adPIC, but not PIC3739, was associated with detectable serum TNF that peaked in week 2 of infection. Tumor necrosis factor was found in the spleens of adPIC- and PIC3739-infected animals in week 1 of infection; TNF alpha mRNA levels in spleens and livers of adPIC infected animals increased and remained high throughout infection, whereas PIC3739-infected organs showed down regulation of TNF alpha mRNA late in infection. Peritoneal macrophages explanted from adPIC-infected animals showed enhanced lipopolysaccharide-inducible TNF production. Altered regulation of TNF production may play a role in the pathogenesis of guinea pig arenavirus disease.

[2] Congenital and perinatal infection with Junin virus in guinea pigs.

[DOC6940] Junin virus infection in guinea pigs is known to be similar to human Argentine hemorrhagic fever (AHF). The guinea pig was chosen as a model for transplacental transmission of Junin virus, as both guinea pig and man have a similar placental structure. Pregnant guinea pigs were infected with the pathogenic XJ strain of Junin virus intramuscularly route at different stages of pregnancy. The group infected during the last third of pregnancy produced 16 newborn, but mortality reached 100%: 18% were born with typical AHF hemorrhagic signs, 54% without signs, and the remainder were stillborn. Virus was recovered from organs of newborns, as well as placental tissues. A second group, infected in the second third of pregnancy, died with intrauterine fetuses, all of which showed hemorrhagic signs and virus present. In a last group, infected in the first third of pregnancy, fetuses were free from macroscopic lesions. In order to determine whether lactation may be an alternative infection route in guinea pigs, mother guinea pigs were infected with Junin virus at different times postparturition. The 84% noninfected newborn housed together with their infected mothers died during the suckling period, half with typical AHF signs. Junin virus transmission from mother to fetus was thus proved, and lactation may be considered as an alternative perinatal infection route.

[3] [Isolation of Junin virus from blood and peripheral lymphocytes of infected Calomys muscul...

[DOC4521] Neonatal Calomys musculinus experimental infection with JunĂ­n virus (JV) XJCl3 strain causes either death or a persistent infection in the major part of surviving animals. JV can be isolated from peritoneal macrophages early during infection, and from brain and salivary glands during the chronic state of disease. It was of interest to investigate the appearance of virus in blood of infected animals. For this purpose, we decided to study the development of viremia in inoculated cricetids. A high frequency of viremia was registered during the acute state of disease (figure 1), which became sporadic approximately from 20 days post-infection onwards. Considering the results above mentioned, the characteristic lymphotropism of arenaviruses and the well-known JV replication in human mononuclear cells, cultures of lympho-monocytes obtained from blood of infected C. musculinus were done in order to investigate the eventual detection of infectious virus in the supernatants. JV was isolated, although in low titres, from cultures established with mononuclear cells belonging to animals in the acute state of disease (table 1); in the case of chronically infected cricetids, attempts to isolate JV were negative. These results show that viremia is currently detected in experimentally infected C. musculinus and that circulating mononuclear cells are permissive for JV multiplication, during the acute state of disease.
Related to Topic 42: VIRUS,VIRAL,RNA,INFECTED,INFECTION,REPLICATION (0.095)

[1] Influence of the infection with lipid-containing viruses on the metabolism and pools of ph...

[DOC797] The influence of infection with three different lipid-containing RNA viruses, Newcastle disease virus, fowl plague virus, and Semliki Forest virus on the phosphatidylcholine precursors of chick embryo cells and of baby hamster kidney (BHK) cells has been measured. In chick embryo cells infection with Newcastle disease virus does not influence the energy charge, or the distribution and absolute pool sizes of the precursors or the choline phosphotransferase activity. In chick embryo cells infected with fowl plague virus the CDP-choline pool increases because of an inhibition of the choline phosphotransferase activity. The phosphorylcholine and CTP pools are smaller in infected cells when compared with mock-infected ones, although the energy charge is not influenced by infection. In chick embryo cells as well as in BHK cells the energy charge is diminished by infection with Semliki Forest virus. Therefore the CTP and phosphorylcholine pools are decreased. The CDP-choline pool in chick embryo cells becomes extremely small after infection with Semliki Forest virus because of a significant stimulation of the choline phosphotransferase. In BHK cells infected with Semliki Forest virus the opposite effect is observed. There are also severe effects on the uptake of the labeled precursors by infection. One and the same virus (Semliki Forest virus) has two completely different effects on the phosphatidylcholine precursors when infecting two different cell types. If one and the same cell type (chick embryo cells) is infected with three different lipid-containing RNA viruses also completely different effects on the phosphatidylcholine precursors were observed. Thus, each virus develops its own strategy to influence the lipid metabolism of the host cell, depending also on the choice of the host. This explains the many disturbing contradictory results described in the literature about the influence of lipid-containing viruses on the lipid metabolism of the host.

[2] Strand-specific detection of Hantaan virus RNA sequences by in vitro DNA amplification.

[DOC9147] Hantaan virus often causes a fatal human disease, hemorrhagic fever with renal syndrome (HFRS). An assay for strand-specific detection and quantitation of Hantaan virus RNA was developed based on the polymerase chain reaction (PCR). A protocol for the efficient detection of both genomic RNA and its transcript is presented, in which a reverse transcriptase reaction (RTR) followed by PCR with two common primers was used to distinguish between positive- and negative-stranded RNA. Using this method, the growth characteristics of Hantaan virus, strain 76-118, were studied in Vero E6 cells. Positive-stranded RNA was detected on the next day after infection, and the amount increased remarkably beginning from 3 days after infection. The negative-stranded RNA (genomic), was detected at 2 days after infection which predominated over the transcript RNA. Three days after infection, the amount of viral RNA attained 80% of the maximum amount which was detected by 6 days after infection, while, 4 days after infection the amount of the positive-stranded RNA became over 80% of the maximum amount of 6 days after infection and reached the amount of viral RNA. Both RNAs reached plateaus at 6 days after infection and after that the amounts of synthesized viral RNA and its transcripts were constant.

[3] Inhibition of the intracellular transport of influenza viral RNA by actinomycin D.

[DOC8414] In primary chicken embryo cells infected with fowl plague virus addition of actinomycin D at defined times during the infection cycle has different consequences on viral replication. If actinomycin D is added immediately after infection with a concentration, which inhibits viral RNA synthesis only partially, it interferes with the nucleo-cytoplasmic transport of all viral RNA species (mRNA and vRNA) so far tested. If actinomycin D is present during infection (adsorption, penetration and uncoating) no viral RNA is synthesized, and the nucleocapsid of the infecting virus does not reach the nucleus, as shown by fluorescent antibodies. Therefore the primary effect of actinomycin D on influenza virus replication is on the transport of the incoming vRNPs from the cytoplasm to the cell nucleus, which is the cell compartment where transcription takes place.
Related to Topic 48: DENGUE,FEVER,HEMORRHAGIC,DHF,INFECTION,SHOCK (0.085)

[1] Activation of coagulation and fibrinolysis during dengue virus infection.

[DOC15072] Dengue virus infection can induce mild dengue fever (DF) or severe dengue hemorrhagic fever and dengue shock syndrome (DHF/DSS) in human. The pathogenesis of hemorrhage in dengue virus infection is not fully understood. Since hemostasis depends on the balance between coagulation and fibrinolysis, alternation of some coagulation parameters (platelet count and activated partial thromoboplastin time, APTT) as well as fibrinolytic parameters (tissue plasminogen activator, tPA and plasminogen activator inhibitor-1, PAI-1) were compared in 8 DHF/DSS and 17 DF patients. Patients showed thrombocytopenia, APTT prolongation, and tPA increase in the acute stage of disease, indicating activation of coagulation and fibrinolysis. The activation of coagulation and fibrinolysis in DHF/DSS patients was much more severe than DF patients. In the convalescent stage, a rise of PAI-1 level and platelet count with concomitant decline of tPA level and APTT returned to normal in both DHF/DSS and DF patients. Therefore, the activation of coagulation and fibrinolysis during the acute stage of dengue virus infection is offset by the increase of platelet and PAI-1 during convalescent stage. Taken together, these results suggest that the degree of coagulation and fibrinolysis activation induced by dengue virus infection is associated with the disease severity.

[2] Enhanced severity of secondary dengue-2 infections: death rates in 1981 and 1997 Cuban out...

[DOC17301] OBJECTIVE: To understand the possible effect that length of time has on disease severity with sequential dengue infections. METHODS: Death and hospitalization rates for dengue hemorrhagic fever/dengue shock syndrome (DHF/DSS) per 10,000 secondary dengue-2 infections were compared in the same age group for two dengue-2 (DEN-2) epidemics in Cuba. The first DEN-2 epidemic affected all of Cuba in 1981; the second one, in 1997, impacted only the city of Santiago de Cuba. The sensitizing infection for DHF/DSS for each of the DEN-2 epidemics was dengue-1 (DEN-1) serotype virus, which was transmitted in 1977-1979, that is, 4 years and 20 years before the two DEN-2 epidemics. Using published seroepidemiological data from the cities of Havana and Santiago de Cuba, we estimated the rates at which persons aged 15-39 years old and those 40 years and older were hospitalized or died of DHF/DSS in Havana and in all of Cuba in 1981 and in just Santiago de Cuba in 1997. RESULTS: Among adults 15-39 years old the death rate per 10,000 secondary DEN-2 infections was 38.5 times as high in Santiago de Cuba in 1997 as in Havana in 1981. As a further indication of the increased severity coming with a longer period between the initial DEN-1 infection and the secondary DEN-2 infection, the case fatality rate for that same age group was 4.7 times as high in Santiago in 1997 as it was in Havana in 1981. CONCLUSION: We found a marked increase in severity with the longer of the two intervals (20 years) between an initial DEN-1 infection and a secondary DEN-2 infection. Such a difference may be due to subtle shifts in causative dengue strains or to changes with the passage of time in the circulating population of human dengue antibodies. These observations have important implications for dengue control, pathogenic mechanisms, and vaccine development.

[3] Evaluation of RT-PCR as a tool for diagnosis of secondary dengue virus infection.

[DOC21398] Dengue fever and dengue hemorrhagic fever are serious illnesses in many tropical and subtropical countries. Laboratory tests are essential for the confirmation of dengue virus infection. In the present study, we examined the reliability of reverse transcriptase polymerase chain reaction (RT-PCR) in the laboratory diagnosis of dengue, especially in secondary dengue virus infections. We defined the day when fever subsided as fever day 0. In primary dengue virus infection, the dengue viral genome was detected in all of the 7 samples which were collected on fever day -1 or earlier, in 3 of 4 samples on fever day 0, and in 1 of 2 samples on fever day 1. None of the samples collected on fever day 2 or later were positive by RT-PCR. In secondary dengue virus infection, the dengue viral genome was detected in all of the 28 samples which were collected on fever day -2 or earlier, in 25 of 26 on fever day -1, in 29 of 34 on fever day 0, and in 5 of 10 on fever days 1-2. None of the samples collected on fever day 3 or later were positive. Virus isolation and direct titration were attempted using the plasma samples. When the data of secondary infection cases were analyzed based on fever day, dengue viruses were isolated from all of the 5 samples which were collected on fever day -2 or earlier, in 5 of 13 samples on fever day -1, and in 4 of 22 on fever day 0, but were not isolated from any of the 4 samples collected on fever days 1-2. Viruses were directly detected in 7 of 11 samples on fever day -2 or earlier, in 4 of 13 on fever day -1, and in 1 of 16 on fever day 0. These results indicate that RT-PCR is more sensitive than virus isolation and direct virus titration for determining secondary dengue virus infection. The results also suggest that RT-PCR is a useful diagnostic test for confirmation of dengue virus infection in secondary infection as well as in primary infection, especially when plasma samples are collected before the fever subsides.
PATIENTS
Most likely documents

[1] [Clinical and epidemiologic characteristics of hemorrhagic fever with renal syndrome in pa...

[DOC21952] AIM: The aim of the study was to examine and analyze the main epidemiologic and clinical data of 94 patients with hemorrhagic fever with renal syndrome (HFRS) hospitalized at the University Hospital for Infectious Diseases in Zagreb during the HFRS outbreak in Croatia in 2002. PATIENTS AND METHODS: A total of 110 patients with clinical diagnosis HFRS were treated at the University Hospital for Infectious Diseases in Zagreb. In 110 of HFRS suspected patients, the clinical diagnosis was verified serologically in 94 patients and they were included in the retrospective study. In 93 patients the diagnosis was confirmed by enzyme-linked immunosorbent assay (ELISA), and in one patient by indirect immunofluorescence assay (IFA). Results were analyzed by the use of descriptive statistics. RESULTS: Puumala (PUU) virus infection was verified in 80 (85.1%), Dobrava (DOB) infection in 8 (8.5%) and cross-reactive antibodies to both PUU and DOB viruses in 5 (5.3%) HFRS patients. In one patient who was confirmed by IFA the hantavirus serotype causing HFRS could not be determined. The localities of the presumed HFRS patient exposure to hantaviruses were mostly in the Zagreb area. Most patients were aged 21-50 (83.0%) and male (76.6%). The majority of HFRS cases occurred between May and August (75.5%). A high proportion of HFRS cases were found in the general population from Zagreb and its surroundings (78.7%). The majority of patients were hospitalized in the febrile stage of the disease (70.2%). The main symptoms were: fever (100%), headache (88.3%) and backache (87.2%). Oliguria was recorded in 56.4% and, anuria in 7.5% of patients, however, only three (3.2%) patients required hemodialysis. Six patients developed hemorrhagic manifestations, especially petechiae on the skin and mucosa. One patient in the convalescent stage had subarachnoidal bleeding. Six patients had pathologic electroencephalogram (EEG) findings and two developed epileptic seizures. Lumbar puncture was performed in 12 patients without inflammatory changes in the cerebrospinal fluid. Pathologic ECG findings were recorded in 30/79 (38.0%) patients, primarily including mild and translent disturbances such as sinus tachycardia, sinus bradycardia, nonspecific alteration of the final complex and incomplete right bundle branch block. Conventional chest radiography revealed abnormal findings in 23/84 (27.4%) patients. The abnormalities consisted of interstitial infiltrates and/or pleural effusions and atelectasis. The patients were divided into 4 groups according to the disease severity: mild in 74 (78.7%), moderate in 15 (16.0%), severe in 4 (4.2%), and very severe in one (1.1%) patient. The latter developed multiorgan failure and died. CONCLUSION: The largest outbreak of HFRS to date was recorded in Croatia in 2002. Ninety-four patients with clinical and serologically verified HFRS were treated at the Dr. Fran Mihaljević University Hospital for Infectious Disease, Zagreb. The majority of patients were hospitalized between May and August. Most patients had mild form of the disease primarily caused by PUU virus.

[2] [Is permanent renal function damage possible after hemorrhagic fever with renal syndrome?]

[DOC21955] AIM: To investigate the possibility of permanent renal function impairment and other organ lesions following hemorrhagic fever with renal syndrome (HFRS). METHODS: Data on 30/37 patients infected with HFRS, treated at the Department of Infectious Diseases, Split University Hospital, in 1995 were retrospectively analyzed. The data were collected three to six years following the appearance of HFRS. In 1998, 30/37 patients presented for control checkup, when their history data were collected, along with physical examination, hematology and biochemistry tests, and urinalysis. Creatinine clearance and sodium, potassium, chlorine, phosphorus, beta 2-microglobulin and N-acetyl-beta-D glucosaminase in 24-h urine were determined. In native urine, erythrocyturia was observed, with 10 erythrocytes per field were considered pathologic result. During the 1998-2001 period, renal scintigraphy by means of technetium labeled diethylene triaminopentacetic acid (99mTC DTPA) was performed in 13/30 patients. RESULTS: Of subjective discomforts, 29/30 (96.7%) patients reported lumbar pain. Elevated blood pressure was found in 9/30 (30.0%), erythrocyturia in 4/30 (13.3%) and hepatic lesion in 4/30 (13.3%) patients. Decreased creatinine clearance values (< 1.2 ml/s) were found in 4 and increased values (> 2.35 ml/s) in 10 patients. Increased sodium in 24-h urine was recorded in 10/23 and increased beta 2-microglobulin in 6/23 (26%) patients. Proteinuria exceeding 150 mg/day was detected in 11/23 (47.8%) patients. Scintigraphy of the kidneys demonstrated reduced glomerular filtration (< 100 ml/min/1.72 m2) in 3/13 patients. Prolonged mean times (> 5 minutes) of radiopharmaceutical passage through the renal parenchymae were found in 7/13 (53.8%) patients. DISCUSSION: Studies performed in 30 patients three years after they had recovered from HFRS revealed changes suggesting a mild to moderate impairment of the renal function. Hypertension found in 9/30 patients was a significant finding, considering the fact that all subjects were soldiers, thus having undergone through examinations to prove them completely healthy prior to joining army. Hypertension results were consistent with those reported from the USA. Although erythrocyturia points to urinary tract damage, its glomerular or postglomerular origin was not examined. Decreased creatinine clearance found in 4/23 patients suggested functional renal impairment. Increased natriuresis found in 10/23 patients implied tubular damage, i.e. reduced ability of tubular cells for sodium reabsorption from primary urine. Non-selective albuminuria detected in 11/23 patients indicated permanent lesion of the glomerular basal membrane. Increased beta 2-microglobulin found in 6/23 patients indicated that the lysosomal enzyme level was elevated only in the acute stage of the disease, but may have been an indicator of permanent lesion. No description of post-HFRS scintigraphic lesion of the kidneys was found in the literature. A decreased value of glomerular filtration, found in three patients, and especially the prolonged mean time of glomerular micropharmaceutical passage in 7/13 (53.8%) patients may have suggested glomerular damage. However, the possible reason may have also been a reduced passage of glomerular filtrate through the damaged lower parts of the nephrons. Transaminase increase during the acute stage of HFRS suggested the possible liver infection, maybe even hantavirus replication in hepatocytes. Even though biopsy confirmed the histologic picture of chronic hepatitis in one patient, the question remains whether it could have been caused by hantavirus. CONCLUSION: Studies performed in 30 patients with a history of HFRS revealed renal function impairment, along with hypertension and damage to the liver parenchyma in some patients. The results obtained showed that the HFRS infection in Croatia may have entailed chronic sequels. To confirm this hypothesis, additional studies including a control group of hantavirus negative persons are needed.

[3] [Clinical characteristics and mechanism of liver injury in patients with severe acute resp...

[DOC20372] OBJECTIVES: To summarize the clinical features of liver injury in patients with severe acute respiratory syndrome (SARS), providing information for further mechanism and clinical study. METHODS: The clinical and some laboratory data of 154 patients suffered from SARS were collected and analyzed, who were admitted to the isolation wards of Beijing You-an Hospital from March 11 to June 3, 2003. The serum samples were taken from 46 patients to detect IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, TNF-alpha, endotoxin and hepatitis related viral inclusions. In addition, 11 patients were detected ultrasonically, and 3 patients were described pathological features. Other two groups including 15 healthy care workers and 22 patients with chronic hepatitis in the same period were selected and analyzed as controls. RESULTS: When being admitted to hospital, serum ALT and (or) AST levels were elevated in 37.7% SARS patients. Some of them (43.1%) were mild, and most of them (56.9%) were moderate. Abnormal liver function mainly resulted from ALT elevation (70.7%), then both ALT and AST elevation (22.4%). The aminotransferases in 75.9% SARS patients normalized within two weeks, while they elevated in four patients during the hospitalization. There was a significant difference in ALT/AST elevation rates between severe and mild clinical type (chi2=19.28, P<0.05). Serum total bilirubin values elevated in 8.4% patients. Serum albumin and prealbumin levels decreased in 24.0% and 28.6% patients, respectively. Creatine kinase (CK) and (or) creatine kinase MB (CK-MB) levels elevated in 72.7% patients when they hospitalized. The six kinds of interleukins and TNF-alpha levels during the first week of hospitalization were higher than those in the fourth week and in control groups (t>or=1.67, P<0.05). The levels of some factors, such as IL-1beta, IL-6 and IL-10 in patients with elevated ALT, were higher than those in ALT normal patients (t>or=2.36, P<0.05). In the first week, only 15.2% patients had elevated serum endotoxin level. Ultrasonic examination and pathological observation showed no special features, compared with those in common acute hepatitis patients. CONCLUSIONS: All the results suggest strongly that there may be a systemic inflammatory response syndrome (SIRS) in most SARS patients in early stage, and the liver damage is only its partial signs. It may be beneficial to suppress cytokines storm in SARS patients in early stage, which will stop the progression of SIRS and release hepatic damage and improve the prognosis of SARS patients.
PROTEIN
Most likely documents

[1] Inflammatory mediators and modulators release in organ culture from rabbit skin lesions pr...

[DOC6460] Extravasated serum seems to be the major modulator of the local inflammatory response, because it provides both proinflammatory and antiinflammatory components. This report describes the rates of entry and turnover of extravasated serum protein in dermal inflammatory lesions produced by the military vesicant sulfur mustard (SM). Rabbits, bearing SM skin lesions, were given an intravenous injection of Evans blue dye, so that at the time of sacrifice, 2 hours later, their skin lesions were 2 hours and 1,2,3,6, and 10 days of age. Evans blue labels serum albumin, a representative serum protein. By multiplying the amount of Evans blue contained in the lesions by a factor that converted micrograms of Evans blue into milligrams of serum protein, the authors could estimate the 2-hour rate of entry of serum protein into these lesions. Serum protein in the lesions was both bound and unbound. The unbound protein was extractable from the lesions into the culture fluids, and, electrophoretically, was similar in composition to serum protein. Grossly edematous peak lesions (1 day of age) contained 7.8 mg of unbound serum protein per square centimeter of skin. Healing lesions (6 and 10 days of age) contained about 4.5 mg/sq cm, and normal skin about 1.7 mg/sq cm. Lesions 1 day of age had the highest rate of serum albumin entry, and about 36% of this Evans-blue-labeled protein was unbound, ie, extractable into the culture fluids. Lesions 3 and 6 days of age had a rate of serum albumin entry that was roughly half that of 1-day lesions, and only about 13% of this entering protein was unbound. Normal skin had a very low rate of serum albumin entry, and only 8% of this entering protein was unbound. The turnover rate of the unbound (extractable) serum protein could be estimated from the 2-hour entry rate of the Evans-blue-labeled albumin and the total protein in the culture fluids. In 1-day lesions, about 25% of the serum protein in the culture fluids was protein which had entered during the last 2 hours, so that 100% of this unbound protein should have been replaced once in 8 hours. In contrast, in 3- and 6-day lesions, this unbound serum protein should have been replaced once in about 35 hours, and in normal skin once in 80 hours. Evans-blue-labeled serum albumin continuously entered both the bound and unbound compartments of the SM lesions, even during the healing stages.(ABSTRACT TRUNCATED AT 400 WORDS)

[2] Sequence analysis of the membrane protein V3 of the flavivirus West Nile virus and of its ...

[DOC6151] Flaviviruses contain a large membrane-associated protein V3, having a mol mass of about 50 kDa which is responsible for hemagglutination. We have isolated the V3 protein from the West Nile (WN) flavivirus and determined its amino-terminal amino acid sequence and amino acid sequences of fragments derived from this protein. We have also transcribed parts of the WN virus genome RNA into cDNA and cloned and sequenced this cDNA. The results of these analyses have allowed us to identify the region of the viral genome coding for the V3 protein. In this report we describe the total nucleotide sequence of the genome region coding for the WN virus V3 protein and the amino acid sequence of the V3 protein derived from these analyses. The exact carboxy terminus of the V3 protein has not been determined in these experiments. These analyses have shown that the V3 protein of WN virus does not contain an Asn-X-Ser/Thr sequence which could allow addition of N-linked carbohydrate chains to this protein. In accordance with this finding, analyses of metabolic labeling of the V3 protein using [3H]glucosamine indicate that the WN virus V3 protein is an unglycosylated protein. Together with our earlier analyses these results show that the viral structural proteins are present on the genome RNA in the order 5'-terminus-core protein (V2)-small membrane-associated protein (NV2)-large membrane-associated protein (V3) and describe the nucleotide sequences coding for all WN virus structural proteins identified so far. A hypothesis concerning the processes involved in the synthesis of all viral structural proteins and the probable orientation of these proteins relative to the endoplasmatic reticulum membrane based on the structure of these proteins is discussed.

[3] Small envelope protein E of SARS: cloning, expression, purification, CD determination, and...

[DOC19663] AIM: To obtain the pure sample of SARS small envelope E protein (SARS E protein), study its properties and analyze its possible functions. METHODS: The plasmid of SARS E protein was constructed by the polymerase chain reaction (PCR), and the protein was expressed in the E coli strain. The secondary structure feature of the protein was determined by circular dichroism (CD) technique. The possible functions of this protein were annotated by bioinformatics methods, and its possible three-dimensional model was constructed by molecular modeling. RESULTS: The pure sample of SARS E protein was obtained. The secondary structure feature derived from CD determination is similar to that from the secondary structure prediction. Bioinformatics analysis indicated that the key residues of SARS E protein were much conserved compared to the E proteins of other coronaviruses. In particular, the primary amino acid sequence of SARS E protein is much more similar to that of murine hepatitis virus (MHV) and other mammal coronaviruses. The transmembrane (TM) segment of the SARS E protein is relatively more conserved in the whole protein than other regions. CONCLUSION: The success of expressing the SARS E protein is a good starting point for investigating the structure and functions of this protein and SARS coronavirus itself as well. The SARS E protein may fold in water solution in a similar way as it in membrane-water mixed environment. It is possible that beta-sheet I of the SARS E protein interacts with the membrane surface via hydrogen bonding, this beta-sheet may uncoil to a random structure in water solution.
Related to Topic 30: PROTEIN,PROTEINS,PURIFIED,MOLECULAR,GEL,KDA (0.290)

[1] Biochemical and biological properties of soluble protein preparations from Brucella abortu...

[DOC7178] Soluble salt-extractable protein antigens (CSP) from Brucella abortus may be of potential value as a vaccine and as a diagnostic reagent for the prevention and diagnosis of bovine brucellosis. These protein antigens, excluding protoplasmic proteins, are those present in the matrix of the outer membrane and in the periplasmic space of gram-negative bacteria. Our research deals mainly with the proteins of the periplasmic space and the nonporin proteins of the outer membrane. We have isolated a group of proteins from intact inactivated cells using mild, nondestructive extraction procedures. The proteins thus obtained range in molecular weight from 10 000 to 51 000 daltons as determined under denaturing conditions and from 10 000 to 124 000 daltons under nondenaturing conditions. The isoelectric pH of these proteins range from 3.5 to 10 with numerous bands in the pH 4.5 to 5.5 region, and a few bands in the pH 6 to 10 region. The low pH region also contains those protein bands which can be labeled with the membrane impermeant reagent, diazotized [125I]-iodosulfanilic acid. The soluble protein preparations are antigenic in guinea pigs, rabbits and cattle, and immunogenic in lemmings, guinea pigs and cattle. Cross-reacting protein antigens are present in protein preparations from B. abortus strains 19 and 2308 when tested with heterologous rabbit sera and with sera from vaccinated and experimentally infected cattle. The soluble protein antigens can be rendered more immunogenic by chemical modification of the primary amino groups with acyl anhydrides, especially with dodecanoyl anhydride. Immunization with dodecanoyl--modified proteins resulted in decreased humoral antibody levels (as measured in guinea pigs and cattle) without loss of protective activity, as measured in lemmings. Furthermore, the soluble proteins have proven to be a sensitive, stable and reliable reagent in the enzyme-linked immunosorbent assay (ELISA) for the detection of antibodies to Brucella abortus in serum of vaccinated and experimentally infected cattle. Other soluble protein antigen preparations have also been evaluated and compared with strain 19 proteins for immunogenic properties and for use as an ELISA reagent.

[2] Differences in the protein composition of bovine retinal rod outer segment disk and plasma...

[DOC3790] The plasma membrane and disk membranes of bovine retinal rod outer segments (ROS) have been purified by a novel density-gradient perturbation method for analysis of their protein compositions. Purified ROS were treated with neuraminidase to expose galactose residues on plasma membrane-specific glycoproteins and labeled with ricin-gold-dextran particles. After the ROS were lysed in hypotonic buffer, the plasma membrane was dissociated from the disks by either mild trypsin digestion or prolonged exposure to low ionic strength buffer. The dense ricin-gold-dextran-labeled plasma membrane was separated from disks by sucrose gradient centrifugation. Electron microscopy was used to follow this fractionation procedure. The dense red pellet primarily consisted of inverted plasma membrane vesicles containing gold particles; the membrane fraction of density 1.13 g/cc consisted of unlabeled intact disks and vesicles. Ricin-binding studies indicated that the plasma membrane from trypsin-treated ROS was purified between 10-15-fold. The protein composition of plasma membranes and disks was significantly different as analyzed by SDS gels and Western blots labeled with lectins and monoclonal antibodies. ROS plasma membrane exhibited three major proteins of 36 (rhodopsin), 38, and 52 kD, three ricin-binding glycoproteins of 230, 160, and 110 kD, and numerous minor proteins in the range of 14-270 kD. In disk membranes rhodopsin appeared as the only major protein. A 220-kD concanavalin A-binding glycoprotein and peripherin, a rim-specific protein, were also present along with minor proteins of 43 and 57-63 kD. Radioimmune assays indicated that the ROS plasma membrane contained about half as much rhodopsin as disk membranes.

[3] [A cyclic 3',5'-adenosine monophosphate-binding protein in the causative agent of plague]

[DOC3364] cAMP-binding protein was isolated from the plaque agent and purified to the homogeneous state. Purification process included filtration of the initial preparation through the membrane able to transmit particles with mol. weight to 300,000 Da, chromatography on cellulose "DE-52" and biogel HTP. The protein homogeneity was confirmed by electrophoresis in polyacrylamide gel and precipitation with commercial plague agglutinating serum. The protein with mol. weight of 180,000 Da consisted of two identical subunits (90,000 Da. each) which could dissociate with formation of monomers (mol. weight approximately 18,000 Da), Cu2+, Co2+, Mn2+ ions stimulated activity of cAMP-binding protein of a plague microbe while Fe3+, Ca2+, Zn2+ ions inhibited it by 30-70%. A monospecific rabbit serum to the homogeneous preparation of cAMP-binding protein was obtained. It helped finding the similar protein in the close relative bacterium Yersinia pseudotuberculosis but not in Y. enterocolitica.
Related to Topic 11: PROTEIN,AMINO,ACID,PROTEINS,TERMINAL,PEPTIDE (0.221)

[1] Analyses of the terminal sequences of West Nile virus structural proteins and of the in vi...

[DOC4280] The proteolytic processes involved in the synthesis of the structural proteins of the West Nile (WN) flavivirus were analyzed: The carboxy-terminal sequences of the structural proteins were determined and the proteins translated in vitro in the presence of membranes from a mRNA coding for the structural polyprotein were analyzed. The results obtained indicate that the following proteolytic activities are involved in the synthesis and assembly of WN virus structural proteins: The growing peptide chain which contains the sequences of the structural proteins in the order C-pre-M-E is cleaved at three places by cellular signalase(s). This cleavage generates the primary amino acid sequence of the mature structural proteins pre-M and E (and the amino-terminus of the ensuing nonstructural protein NS 1). The amino-terminal part of the polyprotein containing the amino acid residues 1 to 123 is released as a molecule which migrates slightly slower than the mature viral core protein and which presumably is associated to the RER membranes via its carboxy-terminal sequence. This protein is called the anchored C virus particles the anchored C protein is converted into mature C protein by removal of the carboxy-terminal hydrophobic segment containing the amino acid residues 106 to 123. Presumably a virus-coded protease which can cleave the polyprotein after two basic amino acid residues is responsible for this cleavage. The cell-associated WN virus particles are constructed from the proteins C, pre-M, and E which contain the amino residues 1-105, 124-290, and 291-787 of the polyprotein, respectively. Cleavage of the pre-M protein between amino acid residues 215 and 216, presumably by a cellular enzyme located in the Golgi vesicles, and loss of the amino-terminal fragment of this protein are associated with the release of virus from the cells.

[2] In vitro synthesis of West Nile virus proteins indicates that the amino-terminal segment o...

[DOC2638] A virus-encoded protease that cleaves after multiple basic amino acid residues has been implicated in the processing of the flavivirus polyprotein. Recently, a computer search of amino acid residues which might form the active site of a protease led to the suggestion that the amino-terminal segment of the NS3 protein represents a serine protease. To examine this possibility we constructed an mRNA which encodes a polyprotein with an amino-terminal signal sequence derived from the influenza virus haemagglutinin, followed by a segment of the West Nile flavivirus polyprotein which includes the non-structural (NS) proteins NS2A, NS2B and the amino-terminal part of the NS3 protein. This polyprotein contains two sequences, located at the termini of the NS2B protein, which are cleaved by the viral protease that cleaves after multiple basic residues in the authentic polyprotein. The proteins that are generated by this mRNA during in vitro translation in the presence of rough endoplasmic reticulum membranes indicate that these two proteolytic cleavages occur in vitro. In vitro translation of polyproteins shortened at the carboxy terminus shows that a polyprotein which does not contain the complete set of proposed catalytic residues present in the NS3 protein segment accumulates as a membrane-associated molecule without proteolytic processing. Similarly, substitution of residue histidine 51 of the NS3 polyprotein segment, which is predicted to be part of the protease catalytic centre, with an alanine residue, blocks the processing of the polyprotein in vitro.

[3] The YSIRK-G/S motif of staphylococcal protein A and its role in efficiency of signal pepti...

[DOC19283] Many surface proteins of pathogenic gram-positive bacteria are linked to the cell wall envelope by a mechanism requiring a C-terminal sorting signal with an LPXTG motif. Surface proteins of Streptococcus pneumoniae harbor another motif, YSIRK-G/S, which is positioned within signal peptides. The signal peptides of some, but not all, of the 20 surface proteins of Staphylococcus aureus carry a YSIRK-G/S motif, whereas those of surface proteins of Listeria monocytogenes and Bacillus anthracis do not. To determine whether the YSIRK-G/S motif is required for the secretion or cell wall anchoring of surface proteins, we analyzed variants of staphylococcal protein A, an immunoglobulin binding protein with an LPXTG sorting signal. Deletion of the YSIR sequence or replacement of G or S significantly reduced the rate of signal peptide processing of protein A precursors. In contrast, cell wall anchoring or the functional display of protein A was not affected. The fusion of cell wall sorting signals to reporter proteins bearing N-terminal signal peptides with or without the YSIRK-G/S motif resulted in hybrid proteins that were anchored in a manner similar to that of wild-type protein A. The requirement of the YSIRK-G/S motif for efficient secretion implies the existence of a specialized mode of substrate recognition by the secretion pathway of gram-positive cocci. It seems, however, that this mechanism is not essential for surface protein anchoring to the cell wall envelope.
Related to Topic 24: RICIN,CHAIN,PROTEIN,SYNTHESIS,ACTIVITY,RIBOSOMES (0.145)

[1] Comparison of RNases and toxins upon injection into Xenopus oocytes.

[DOC2850] Several toxins abolish cellular protein synthesis by attacking specific sites in 28 S RNA. One of these toxins, alpha-sarcin, is an RNase that also cleaves nonspecifically on the 3' side of purines in deproteinized RNA. Several other RNases were injected into Xenopus oocytes, examined for their ability to abolish protein synthesis, and compared with alpha-sarcin and ricin. Surprisingly, pancreatic RNase A or B abolished oocyte protein synthesis at concentrations (approximately 0.03 nM) comparable to, or lower than, the amount of alpha-sarcin (approximately 2 nM) or ricin (approximately 0.07 nM) required to abolish protein synthesis. RNases S and T1 only inhibited oocyte protein synthesis when used at concentrations approximately 10 x higher than RNase A whereas RNases C, T2, U2, and nuclease P1 required concentrations approximately 100 times higher than RNase A to abolish protein synthesis. There was a direct correlation between the degradation of oocyte RNA and the inhibition of protein synthesis. The RNase inhibitors RNasin and Inhibit-Ace injected into the oocyte both prevented RNase A from hydrolyzing oocyte rRNA and abolishing protein synthesis. Enzymatically inactive oxidized RNase A did not inhibit protein synthesis when injected into the oocyte. None of the RNases or alpha-sarcin abolished protein synthesis when added to oocyte extracellular medium. Angiogenin is a human plasma protein that induces blood vessel formation in chick embryos, has 35% amino acid identity with RNase A, and cleaves 18 S and 28 S RNA in rabbit reticulocyte lysates (St. Clair, D. K., Rybak, S. M., Riordan, J. F. & Vallee, B. L. (1988) Biochemistry 27, 7263-7268, and references therein). Recombinant angiogenin injected into oocytes abolished protein synthesis, and this toxic effect was inhibited by RNasin but was not inhibited by Inhibit-Ace. Unlike RNase A and the other nucleases that hydrolyzed cellular rRNA, no cleavage of 18 or 28 S RNA by recombinant angiogenin was seen at concentrations 100 x greater than necessary to abolish protein synthesis. Recombinant angiogenin must selectively attack specific RNA(s) or another target in the cell.

[2] Microinjected oligonucleotides complementary to the alpha-sarcin loop of 28 S RNA abolish ...

[DOC3553] The integrity of the alpha-sarcin loop in 28 S ribosomal RNA is critical during protein synthesis. The toxins alpha-sarcin, ricin, Shiga toxin, and Shiga-like toxin inhibit protein synthesis in oocytes by attacking specific nucleotides within this loop (Ackerman, E.J., Saxena, S. K., and Ulbrich, N. (1988) J. Biol. Chem. 263, 17076-17083; Saxena, S.K., O'Brien, A.D., and Ackerman, E.J. (1989) J. Biol. Chem. 264, 596-601). We injected Xenopus oocytes with deoxyoligonucleotides complementary to the 17-nucleotide alpha-sarcin loop of Xenopus 28 S rRNA. Only injected oligonucleotides fully covering the alpha-sarcin loop or slightly beyond inhibited oocyte protein synthesis. Shorter alpha-sarcin domain deoxyoligonucleotides complementary to the alpha-sarcin and ricin sites but not spanning the entire loop were less effective inhibitors of protein synthesis. The alpha-sarcin domain oligonucleotides covering the entire loop were more effective inhibitors of protein synthesis than injected cycloheximide at equivalent concentrations. Control oligonucleotides complementary to nine other regions of Xenopus 28 S rRNA as well as universal M13 DNA sequencing primers had no effect on oocyte protein synthesis. Oligonucleotides complementary to the highly conserved alpha-sarcin domain therefore represent an alternative to catalytic toxins for causing cell death and may prove effective in immunotherapy.

[3] Active center cleft residues of pokeweed antiviral protein mediate its high-affinity bindi...

[DOC15839] Pokeweed antiviral protein (PAP) is a ribosome-inactivating protein (RIP) which catalytically cleaves a specific adenine base from the highly conserved alpha-sarcin/ricin loop (SRL) of the large ribosomal RNA and thereby inhibits the protein synthesis. The ribosomal protein L3, a highly conserved protein located at the peptidyltransferase center of the ribosomes, is involved in binding of PAP to ribosomes and subsequent depurination of the SRL. We have recently discovered that recombinant PAP mutants with alanine substitution of the active center cleft residues (69)NN(70) (FLP-4) and (90)FND(92) (FLP-7) that are not directly involved in the catalytic depurination at the active site exhibit >150-fold reduced ribosome inhibitory activity [(2000) J. Biol. Chem. 275, 3382--3390]. We hypothesized that the partially exposed half of the active site cleft could be the potential docking site for the L3 molecule. Our modeling studies presented herein indicated that PAP residues 90--96, 69--70, and 118--120 potentially interact with L3. Therefore, mutations of these residues were predicted to result in destabilization of interactions with rRNA and lead to a lower binding affinity with L3. In the present structure-function relationship study, coimmunoprecipitation assays with an in vitro synthesized yeast ribosomal protein L3 suggested that these mutant PAP proteins poorly interact with L3. The binding affinities of the mutant PAP proteins for ribosomes and recombinant L3 protein were calculated from rate constants and analysis of binding using surface plasmon resonance biosensor technology. Here, we show that, compared to wild-type PAP, FLP-4/(69)AA(70) and FLP-7/(90)AAA(92) exhibit significantly impaired affinity for ribosomes and L3 protein, which may account for their inability to efficiently inactivate ribosomes. By comparison, recombinant PAP mutants with alanine substitutions of residues (28)KD(29) and (111)SR(112) that are distant from the active center cleft showed normal binding affinity to ribosomes and L3 protein. The single amino acid mutants of PAP with alanine substitution of the active center cleft residues N69 (FLP-20), F90 (FLP-21), N91 (FLP-22), or D92 (FLP-23) also showed reduced ribosome binding as well as reduced L3 binding, further confirming the importance of the active center cleft for the PAP--ribosome and PAP--L3 interactions. The experimental findings presented in this report provide unprecedented evidence that the active center cleft of PAP is important for its in vitro binding to ribosomes via the L3 protein.
Related to Topic 3: GENE,SEQUENCE,GENES,PROTEIN,EXPRESSION,SEQUENCES (0.135)

[1] SarS, a SarA homolog repressible by agr, is an activator of protein A synthesis in Staphyl...

[DOC15269] The expression of protein A (spa) is repressed by global regulatory loci sarA and agr. Although SarA may directly bind to the spa promoter to downregulate spa expression, the mechanism by which agr represses spa expression is not clearly understood. In searching for SarA homologs in the partially released genome, we found a SarA homolog, encoding a 250-amino-acid protein designated SarS, upstream of the spa gene. The expression of sarS was almost undetectable in parental strain RN6390 but was highly expressed in agr and sarA mutants, strains normally expressing high level of protein A. Interestingly, protein A expression was decreased in a sarS mutant as detected in an immunoblot but returned to near-parental levels in a complemented sarS mutant. Transcriptional fusion studies with a 158- and a 491-bp spa promoter fragment linked to the xylE reporter gene disclosed that the transcription of the spa promoter was also downregulated in the sarS mutant compared with the parental strain. Interestingly, the enhancement in spa expression in an agr mutant returned to a near-parental level in the agr sarS double mutant but not in the sarA sarS double mutant. Correlating with this divergent finding is the observation that enhanced sarS expression in an agr mutant was repressed by the sarA locus supplied in trans but not in a sarA mutant expressing RNAIII from a plasmid. Gel shift studies also revealed the specific binding of SarS to the 158-bp spa promoter. Taken together, these data indicated that the agr locus probably mediates spa repression by suppressing the transcription of sarS, an activator of spa expression. However, the pathway by which the sarA locus downregulates spa expression is sarS independent.

[2] Molecular cloning and nucleotide sequence analysis of the gene encoding the immunoreactive...

[DOC2104] A recombinant 60 kDa Brucella abortus protein expressed in Escherichia coli was recognized in immunoblots by sera from mice experimentally infected with B. abortus and a dog experimentally infected with B. canis. Sera from humans and dogs with naturally acquired brucellosis also recognized this protein, which was designated BA60K. The gene encoding BA60K was localized within an 18 kb B. abortus genomic fragment and its direction of transcription determined by subcloning and maxicell analysis of selected restriction fragments. The nucleotide sequence of 1800 bases encompassing the predicted gene location was determined, revealing an open reading frame encoding a protein of 546 amino acids (predicted relative molecular mass of 57515). Solid phase micro-sequencing of BA60K eluted from two-dimensional polyacrylamide gels confirmed the predicted amino acid sequence. Comparison of the predicted amino acid sequence of BA60K with a protein sequence database revealed that BA60K shares 67.9% identity with the GroEL protein of E. coli, a member of the Hsp60 family of chaperonins. The immunodominant Hsp60 homologs from Legionella pneumophila, Chlamydia trachomatis and Mycobacterium tuberculosis were also found to share greater than 59% amino acid sequence identity with the BA60K protein. The identification of BA60K as a member of the Hsp60 family of chaperonins supports its role in stimulating a prominent host immune response during the course of Brucella infections. It also indicates that BA60K is an important candidate for studies aimed at identifying the antigens responsible for eliciting the protective immune response to brucellosis.

[3] Gene homology between orf virus and smallpox variola virus.

[DOC11189] About 47% identity was observed between the deduced amino acid sequences of a protein encoded by a gene of the parapoxvirus orf virus (OV) strain NZ2 and a 6 kDa protein of unknown function reported to be produced by an open reading frame expressed early after infection by the orthopoxvirus Western Reserve vaccinia virus (VAC); the open reading frame is absent from VAC strain Copenhagen. Examination of sequences reported for variola virus (VAR) strains Bangladesh, India, Congo- 1970, Somalia- 1977 and Garcia- 1966 revealed each encoded a correlate 58 amino acid protein. The open reading frame was not reported in the original analyses of these sequences because a lower limit of 60 amino acids was used to identify potential encoded proteins. Inspection of partial reading frames reported for cowpox virus (CWV) and ectromelia virus (EMV) suggested that these viruses might also code for a correlate of the VAC WR protein. DNA sequencing of cloned fragments of CWV and EMV confirmed that both these orthopoxviruses encode closely related, full length variants of the VAC and VAR open reading frames. The OV homologue is coded in the OV strain NZ2 BamHI-E fragment E2L open reading frame, which we reported is transcribed early postinfection; moreover, analysis of an NZ2 variant showed E2L was absent, indicating that E2L, like the VAC cognate, is nonessential for virus replication in cell culture. The parapoxvirus and orthopoxvirus correlates have about 20% amino acid sequence resemblance to African swine fever virus DNA binding protein p10, suggesting an ancestral relation of genes.
Related to Topic 15: CELLS,RICIN,MEMBRANE,CELL,TRANSPORT,PROTEIN (0.077)

[1] Brefeldin A protects ricin-induced cytotoxicity in human cancer KB cell line, but not in i...

[DOC9904] Brefeldin A (BFA), an isoprenoid fungal metabolite, dramatically disrupts intracellular protein transport and protein secretion. BFA protects cells from the cytotoxicity of a plant toxin, ricin or pseudomonas toxin, but not that of diphtheria toxin (Yoshida et al., 1991. Expt. Cell Res., 192: 389-395.). In this study, we examined whether BFA could differentially change the cytotoxicity of ricin between BFA-sensitive cells and BFA-resistant cells. As a BFA-resistant cell line, we used a resistant cell line, KB/BF2-2, derived from BFA-sensitive human cancer KB cells. BFA treatment caused the disappearance of typical Golgi cisternae and the concomitant appearance of dilated vesicles in the cytoplasm in KB cells. By contrast, KB/BF2-2 cells had already altered Golgi structures with poor development of cisternae and also many vesicles in the absence of BFA, and BFA treatment did not further induce the morphological changes. Although a plasma membrane-specific marker protein, alpha-adaptin, was localized similarly in KB/BF2-2 as KB, Golgi specific markers such as beta-cop and gamma-adaptin were distributed in the cytoplasmic small vesicles as well as Golgi compartments in KB/BF2-2 cells in the absence of BFA, and the mutant cells showed no apparent changes in the distribution even when exposed to BFA. Ricin inhibited protein synthesis in KB and KB/BF2-2 to similar levels while pretreatment of KB cells with BFA at 0.1 microgram/ml almost completely reversed the inhibitory effect of ricin. By contrast, the pre-exposure of KB/BF2-2 cells to 1.0 microgram/ml BFA only partially rescued the ricin-induced inhibition of protein synthesis. Exposure to BFA at 30 min before ricin addition or at 0 min with ricin rescued the protein synthesis inhibition, but no rescue occurred when BFA was added 30 min after ricin addition. BFA could not rescue the protein synthesis inhibition by another toxin, diphtheria toxin. Our results suggest that BFA-resistant mutation causes a specific change in the endocytic membrane traffic of ricin in human cells, and also that cytotoxicity of diphtheria toxin does not share a common pathway of the intracellular transport with that of ricin.

[2] Isolation and characterization of a brefeldin A-resistant mutant of monkey kidney Vero cel...

[DOC1936] Brefeldin A (BFA) is a fungal antibiotic which disrupts protein transport between the endoplasmic reticulum and the Golgi. A BFA-resistant mutant of monkey kidney Vero cells, BER-40, which exhibited about a 90-fold increase in the LD50 of BFA (5.2 ng/ml for Vero cells versus 460 ng/ml for BER-40 cells), has been isolated. The increased resistance of BER-40 cells toward BFA was also manifested in a greatly reduced inhibition of protein secretion by BFA in the mutant and a lack of protection by BFA of the mutant cells from ricin cytotoxicity. Somatic cell hybridization between the Vero and BER-40 cells showed that the BFA-resistance in BER-40 behaved as a codominant trait. The structure of the Golgi region, as examined by immunofluorescence microscopy with antibodies against Golgi markers (the 110-kDa protein and mannosidase II) or with fluorescent lipid NBD-ceramide, was unchanged in the mutant cells as compared to that in the wild-type cells. Treatment of Vero cells with BFA (1 micrograms/ml) or with 2-deoxyglucose plus sodium azide resulted in a rapid release of the 110-kDa protein, mannosidase II, and NBD-ceramide from the Golgi membrane to a more diffuse distribution in the cytosol. In contrast, these three Golgi markers remained to be Golgi-associated following treatment of BER-40 cells with BFA or with 2-deoxyglucose plus sodium azide. Immunoblotting of cell extracts from Vero and BER-40 cells with monoclonal antibody against the 110-kDa protein did not reveal any significant difference in the level of this Golgi marker in the mutant cells. These data suggest that the BFA-resistance mutation in BER-40 has rendered the cyclic pathway of the 110-kDa protein assembly to the Golgi membrane resistant to both BFA and 2-deoxyglucose plus sodium azide.

[3] Temporal separation of protein toxin translocation from processing events.

[DOC5898] Intoxication of Vero cells by ricin, modeccin, diphtheria toxin (DT), and Pseudomonas exotoxin A requires: 1) binding to cell surface receptors; 2) transport to the cytoplasm; and 3) enzymatic inactivation of a component of the protein synthetic machinery. The kinetic profiles of all four toxins consist of a lag followed by the apparent first-order decrease in protein synthesis. Autoradiographic analysis of DT-intoxicated cell populations has demonstrated that two subpopulations of cells exist during the period of decreasing protein synthesis: one population synthesizing at control levels and the other synthesizing little or no protein (Hudson, T. H., and Neville, D. M., Jr. (1985) J. Biol. Chem. 260, 2675-2680). The present study correlates the autoradiographic data with the rates of protein synthesis decline in cells intoxicated with modeccin, ricin, Pseudomonas exotoxin A, as well DT. In all cases, the first time point which exhibits a decrease in protein synthetic activity also exhibits two subpopulations of cells, one synthesizing protein at control rates and the other synthesizing little or no protein. As the intoxication progresses, cells leave the control population by the rapid cessation of all protein synthesis. These experiments demonstrate that transport of all four toxins to the cytosol is the rate-limiting step during the pseudo first-order decline in protein synthesis. Furthermore, the final step in the transport process (translocation) must result in the release to the cytoplasm of a quantity of toxin sufficient to rapidly inactivate all protein synthesis in that cell. The probability of a translocation event occurring in any cell of the population is established during the lag and remains constant throughout the first-order decrease in protein synthesis. The requirement for acidification during the intoxication by DT, Pseudomonas exotoxin A, or modeccin is restricted to the lag period. Acidification is therefore necessary to establish the probability of translocation, but it is not directly involved in the actual translocation of these toxins. The pseudo first-order passage of DT intoxications through antitoxin and NH4Cl- or monensin-sensitive stages are shown to have the same cellular basis as the pseudo first-order decrease in protein synthesis. A kinetic model is presented which defines the DT intoxication process from one of its earliest events (endocytosis) to its penultimate event (translocation of toxin to the cytosol).(ABSTRACT TRUNCATED AT 400 WORDS)
RESULTS
Most likely documents

[1] Proficiency testing of selected antigen and antibody tests for use in dogs and cats.

[DOC10828] OBJECTIVE: To determine the correlation of seroimmunologic test results between reference and nonreference laboratories. DESIGN: Retrospective data analysis. PROCEDURE: Serum samples obtained from naturally infected dogs and cats were distributed to reference and nonreference laboratories for seroimmunologic testing. Correlation of test results was evaluated by use of nonparametric analysis. RESULTS: Correlation coefficients were high between laboratory groups for samples tested for feline immunodeficiency virus antibodies, FeLV antigen, and toxoplasmosis antibodies in cats. results for feline immunodeficiency virus antibody tests from reference laboratories were more likely to be positive than results from nonreference laboratories. Test results for feline infectious peritonitis antibodies, antinuclear antibodies, and Borrelia antibodies in cats were not significant. Coefficient correlations were significant for results of heart-worm antigen, Brucella antibodies, Toxoplasma antibodies, antinuclear antibodies, and rheumatoid factor in dogs. results for Borrelia antibodies were not correlated between laboratory groups. CLINICAL IMPLICATIONS: results were highly correlated between reference and nonreference laboratories for 8 of 14 seroimmunologic tests. Seroimmunologic tests for use in cats were less correlated as a group than those for use in dogs. Poor correlation of results between laboratories was attributed to variations in control agents, antigens, reagents, technical expertise, and cutoff values and end-point titers used for diagnosis.

[2] A new method for normalized interpretation of antimicrobial resistance from disk test resu...

[DOC18928] OBJECTIVE: To evaluate a calibration method for disk diffusion antibiotic susceptibility tests, using zone diameter values generated in the individual laboratory as the internal calibrator for combinations of antibiotic and bacterial species. METHODS: The high-zone side of zone histogram distributions was first analyzed by moving averages to determine the peak position of the susceptible population. The accumulated percentages of isolates for the high zone diameter values were calculated and converted into probit values. The normal distribution of the ideal population of susceptible strains was then determined by using the least-squares method for probit values against zone diameters, and the ideal population was thereby defined, including mean and standard deviation. Zone diameter values were obtained from laboratories at the Karolinska Hospital (KS) and Växjö Hospital (VX), and from two laboratories (LabA, LabB) in Argentina. The method relies on well standardized disk tests, but is independent of differences in MIC limits and zone breakpoints, and does not require the use of reference strains. Resistance was tentatively set at below 3 SD from the calculated, ideal mean zone diameter of the susceptible population. RESULTS: The method, called normalized interpretation of antimicrobial resistance, was tested on results from the KS and VX clinical microbiology laboratories, using the disk diffusion method for antimicrobial susceptibility tests, and for two bacterial species, Staphylococcus aureus and Escherichia coli. In total, 114 217 test results were included for the clinical isolates, and 3582 test results for control strains. The methodology at KS and VX followed the standard of the Swedish Reference Group for Antibiotics (SRGA). Zone diameter histograms for control strains were first analyzed to validate the procedure, and a comparison of actual means with the calculated means showed a correlation coefficient of r = 0.998. results for clinical isolates at the two laboratories showed an excellent agreement for 54 of 57 combinations of antibiotic and bacterial species between normalized interpretations and the interpretations given by the laboratories. There were difficulties with E. coli and mecillinam, and S. aureus and tetracycline and rifampicin. The method was also tested on results from two laboratories using the NCCLS standard, and preliminary results showed very good agreement with quality-controlled laboratory interpretations. CONCLUSIONS: The normalized resistance interpretation offers a new approach to comparative surveillance studies whereby the inhibition zone diameter results from disk tests in clinical laboratories can be used for calibration of the test.

[3] [Diagnostic value of the rose bengal plate test in the diagnosis of bovine brucellosis]

[DOC5116] The value of rose bengal plate test (RBPT) in diagnosing brucellosis in cattle was determined by statistical comparison of its results with the results of the tests used in Poland, i.e. SAT, CFT, AGT and MET. RBPT was made in 2 variants. In routine, highly specific test, equal parts of antigen and serum--0.03 cm3, were used whereas in the experimental one the sensitivity was increased using half the amount of antigen--0.015 cm3 (RBPT0.015). Two batches of cattle serum were examined. In group I 249 cattle serums from the herds infected with brucellosis were examined. In group 2 there were 1269 cattle serums from the herds free of brucellosis, positive in SAT but negative in CFT. The reactions in SAT were considered as not specific if the reaction in the additional examination in CFT, AGT and MET was negative. On the basis of the results in group I, mainly the sensitivity of RBPT was determined compared with the total evaluation of the results of SAT/CFT. In RBPT0.015 the consistency of the results was 99.4% but in RBPT0.03 only 87.9%. Detectability of reactions, i.e. the percentage of positive results in infected herds was calculated. The results were as follows: AGT--89.6%, RBPT0.015--74.3%, SAT/CFT--66.3%, CFT--65.9%, RBPT0.03--59.8%, SAT--55.4%. In the group 2 mainly specificity of RBPT in relation to CFT, AGT and MET was determined. In RBPT0.03 it achieved 97.1% whereas in RBPT0.015--83.1%. The application of RBPT0.03 in the group 2 eliminated 95.8% of the not specific reactions in SAT and that of RBPT0.015--77.9%, respectively. The author suggests to use RBPT0.03 as a screening method instead of SAT and CFT to diagnose cattle brucellosis in the areas free from the disease. On the other hand, RBPT0.015, as more sensitive test is suggested to be used in the herds suspected of brucellosis to identify quickly infected animals.
Related to Topic 52: RESULTS,STUDY,METHODS,CONCLUSIONS,OBJECTIVE,CONCLUSION (0.405)

[1] Proficiency testing of selected antigen and antibody tests for use in dogs and cats.

[DOC10828] OBJECTIVE: To determine the correlation of seroimmunologic test results between reference and nonreference laboratories. DESIGN: Retrospective data analysis. PROCEDURE: Serum samples obtained from naturally infected dogs and cats were distributed to reference and nonreference laboratories for seroimmunologic testing. Correlation of test results was evaluated by use of nonparametric analysis. RESULTS: Correlation coefficients were high between laboratory groups for samples tested for feline immunodeficiency virus antibodies, FeLV antigen, and toxoplasmosis antibodies in cats. results for feline immunodeficiency virus antibody tests from reference laboratories were more likely to be positive than results from nonreference laboratories. Test results for feline infectious peritonitis antibodies, antinuclear antibodies, and Borrelia antibodies in cats were not significant. Coefficient correlations were significant for results of heart-worm antigen, Brucella antibodies, Toxoplasma antibodies, antinuclear antibodies, and rheumatoid factor in dogs. results for Borrelia antibodies were not correlated between laboratory groups. CLINICAL IMPLICATIONS: results were highly correlated between reference and nonreference laboratories for 8 of 14 seroimmunologic tests. Seroimmunologic tests for use in cats were less correlated as a group than those for use in dogs. Poor correlation of results between laboratories was attributed to variations in control agents, antigens, reagents, technical expertise, and cutoff values and end-point titers used for diagnosis.

[2] [The results of speech rehabilitation in patients with non-syndromic deafness type DFNB1]

[DOC23052] THE AIM of this work was an evaluation of the rehabilitation results in a group of patients with a prelingual deafness DFNB1 type. MATERIAL AND METHOD: 50 patients examined, aged 12-15 years with non syndromic prelingual deafness. All patients were qualified on the basis on molecular and audiometrical examinations (the hearing threshold above 70 dB). In all cases audiologic, logopedic and lingual skill tests were performed. The control group were 50 school age children with environmental prelingual deafness. THE RESULTS of performed lingual test were following: 52% obtained low results, 16% middle results and 32% high results. In control group results were following: 42% low, 20% middle, 38% high level of speech efficiency. CONCLUSIONS: 1/3 of examined patients with nonsyndromic prelingual deafness independent on cause of hearing loss have possibility to obtain high speech efficiency.

[3] Optimum results of the surgical treatment of carotid territory ischemia.

[DOC2987] Continuing controversy over the role of carotid endarterectomy in stroke prevention is based largely on reports in which high perioperative morbidity and mortality rates obviate possible long-term benefit from the procedure. The purpose of this review is to examine optimal results of carotid surgery in order to describe the potential for the procedure in stroke prevention. Optimal surgical results are compared with optimal medical results in the therapy of symptomatic patients and with optimal nonsurgical results in the therapy of asymptomatic patients. Factors common to series with excellent results, such as patient selection and operative technique, are examined, and problems such as recurrent carotid stenosis and coexisting coronary disease, which continue to plague even the best surgical series, are discussed.
Related to Topic 28: TEST,TESTS,SENSITIVITY,DIAGNOSIS,POSITIVE,DIAGNOSTIC (0.096)

[1] Comparison of a new immunochromatographic rapid test with a commercial EIA for the detecti...

[DOC16125] BACKGROUND: Hantaviruses are associated with two human diseases: haemorrhagic fever with renal syndrome (HFRS) and Hantavirus pulmonary syndrome (HPS). Puumala virus (PUUV), which is one of the Hantaviruses, is a causative agent of nephropathia epidemica (NE), a mild form of HFRS. OBJECTIVE: a new 5 min rapid test, POC PUUMALA (Erilab Ltd, Finland), for detecting IgM antibodies to PUUV was evaluated and compared with the commercially available Hantavirus (Puumala) IgM ELISA test (Progen, Germany). Discrepant test results between the two tests were confirmed by a mu-capture reference EIA. STUDY DESIGN: Two hundred and thirty five serum samples, which had earlier been analyzed with the Progen IgM ELISA, were assayed with the POC PUUMALA rapid test. Five persons, without knowing the Progen IgM ELISA test results, interpreted independently the rapid test results. In addition, a panel of 48 serum samples was analyzed in parallel with the rapid test and the Progen IgM ELISA by one technician in daily routine diagnostics in a clinical microbiology laboratory. RESULTS: the agreement between the results of the five interpreters was 95%, and the congruence of the results between individual readers and commercial ELISA test varied from 93 to 96%. Diagnostic efficacy of the rapid test varied between 98 and 99% compared with 96% of the Progen IgM ELISA. The POC PUUMALA rapid test showed higher or similar sensitivity compared with the Progen IgM ELISA, whereas both the tests had similar levels of specificity. CONCLUSIONS: the analytical performance of the POC PUUMALA rapid test was found to be as good or even slightly better than the analytical performance of the Progen IgM ELISA. In addition, the rapid and straightforward procedure makes the POC PUUMALA a feasible tool for the diagnosis of the acute PUUV infection.

[2] Enzyme immunoassays for serological diagnosis of bovine brucellosis: A trial in Latin Amer...

[DOC12545] The results of a field trial conducted in Latin America with two indirect enzyme-linked immunosorbent assays (ELISAs) and two competitive ELISAs (CELISAs) for the detection of bovine antibody to Brucella abortus are reported. One of the CELISA formats performed most accurately. The percentage of positive reactions in the CELISA relative to the selected positive rose bengal agglutination test (RBT) and complement fixation test (CFT) results was 97.47%, the percentage of negatives relative to the selected negative RBT and CFT results for unexposed cattle was 98.32%, and the percentage of negatives in cattle vaccinated with B. abortus 19 was 96.51%. The same assay format under Canadian conditions had an actual sensitivity of 100%, a specificity of 99.90% in nonvaccinates, and a specificity of 97.7% in a strain 19-vaccinated population. Overall, the CELISA performed as expected and the results were not dissimilar from the results obtained in the Canadian study. This provided further evidence that this CELISA can in many instances differentiate infected cattle from those that are vaccinated or infected with a cross-reacting organism while still giving very few false-positive or false-negative results.

[3] Proficiency testing of selected antigen and antibody tests for use in dogs and cats.

[DOC10828] OBJECTIVE: To determine the correlation of seroimmunologic test results between reference and nonreference laboratories. DESIGN: Retrospective data analysis. PROCEDURE: Serum samples obtained from naturally infected dogs and cats were distributed to reference and nonreference laboratories for seroimmunologic testing. Correlation of test results was evaluated by use of nonparametric analysis. RESULTS: Correlation coefficients were high between laboratory groups for samples tested for feline immunodeficiency virus antibodies, FeLV antigen, and toxoplasmosis antibodies in cats. results for feline immunodeficiency virus antibody tests from reference laboratories were more likely to be positive than results from nonreference laboratories. Test results for feline infectious peritonitis antibodies, antinuclear antibodies, and Borrelia antibodies in cats were not significant. Coefficient correlations were significant for results of heart-worm antigen, Brucella antibodies, Toxoplasma antibodies, antinuclear antibodies, and rheumatoid factor in dogs. results for Borrelia antibodies were not correlated between laboratory groups. CLINICAL IMPLICATIONS: results were highly correlated between reference and nonreference laboratories for 8 of 14 seroimmunologic tests. Seroimmunologic tests for use in cats were less correlated as a group than those for use in dogs. Poor correlation of results between laboratories was attributed to variations in control agents, antigens, reagents, technical expertise, and cutoff values and end-point titers used for diagnosis.
Related to Topic 74: STUDIES,EVIDENCE,STUDY,PRESENT,FOUND,DATA (0.083)

[1] Genetic analysis of candidate loci in non-syndromic cleft lip families from Antioquia-Colo...

[DOC21826] Non-syndromic cleft lip with or without cleft palate (CL/P) is a genetically complex birth defect, with a prevalence from 1/500 to 1/1,000 live births. Evidence from linkage and linkage disequilibrium studies is contradictory suggesting that heterogeneity between study populations may exist. A recent report of a genome widescan in 92 sib pairs from the United Kingdom revealed suggestive linkage to 10 loci [Prescott et al., 2000]. The purpose of this study is to replicate those results and evaluate additional candidate genes in 49 Colombian and 13 Ohio families. Genotypes were obtained for STRPs at 1p36, 2p13 (TGFA), 4p16 (MSX1), 6p23-25, 6q25-27, 8q23-24, 11p12-q13, 12q13, 14q24 (TGFB3), 16q22-24, 17q12-21 (RARA), and Xcen-q21. Linkage was performed using parametric (dominant and recessive models) and non-parametric (GenehunterNPL and SimIBD) analyses. In addition, heterogeneity was analyzed using GenehunterHLOD, and association determined by the TDT. The Colombian families showed significant SimIBD results for 11p12-q13 (P = 0.034), 12q13 (P = 0.015), 16q22-24 (0.01), and 17q12-21 (0.009), while the Ohio families showed significant SimIBD results for 1p36 (P = 0.02), TGFA (P = 0.005), 6p23 (P = 0.004), 11p12-q13 (P = 0.048) and significant NPL results for TGFA (NPL = 3.01, P = 0.009), 4p16 (MNPL = 2.07, P = 0.03) and 12q13 (SNPL = 3.55, P = 0.007). Significant association results were obtained only for the Colombian families in the regions 1p36 (P = 0.046), 6p23-25 (P = 0.020), and 12q13 (P = 0.046). In addition several families yielded LOD scores ranging from 1.09 to 1.73, for loci at 4p16, 6p23-25, 16q22-24, and 17q13. These results confirm previous reports for these loci. However, the differences between the two populations suggest that population specific locus heterogeneity exists. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299/suppmat/index.html.

[2] [Association of non-syndromic cleft lip and cleft palate with microsatellite markers locat...

[DOC14354] BACKGROUND: Nonsyndromic cleft lip with or without cleft palate (NSCLP) is a common craniofacial developmental defect. Association studies have suggested that a clefting locus is located on chromosome 6p at or near two possible loci, Factor 13A (FI3A) in the region 6p 25-24 and HLA at 6p 21.3. AIM: To test the hypothesis on the possible presence of a major gene on chromosome 6p associated with NSCLP. PATIENTS AND METHODS: We carried out an association study on a sample of unrelated NSCLP patients from multiplex (Mx) and simplex (Sx) families, of their unaffected relatives and in control individuals. DNA was analyzed with three PCR markers close to the putative NSCLP locus, dinucleotide repeats at loci D6S89, D6S109 and D6S105. PCR products were resolved by PAGE and visualized by silver staining. Statistical analysis was performed by means of chi 2 log ratio. RESULTS: Significant differences were observed when comparing the allele frequency distribution of D6S89 in patients with NSCLP and controls and in patients with NSCLP-Mx and controls. No significant differences were observed for patients with NSCLP-Sx. D6S109 and D6S105 showed no significant differences in any of the comparisons. CONCLUSIONS: Our results support the hypothesis that a NSCLP locus maps on 6p23 very close to D6S89. results for D6S109 and D6S105 do not show a clear association. Differences observed between NSCLP-MX and Sx families seem to represent different etiologic entities. The results of the present study, plus those already published for candidate loci, TGFA and MSX1, support the hypothesis that several interacting major genes participate in the etiology of NSCLP.

[3] [Is permanent renal function damage possible after hemorrhagic fever with renal syndrome?]

[DOC21955] AIM: To investigate the possibility of permanent renal function impairment and other organ lesions following hemorrhagic fever with renal syndrome (HFRS). METHODS: Data on 30/37 patients infected with HFRS, treated at the Department of Infectious Diseases, Split University Hospital, in 1995 were retrospectively analyzed. The data were collected three to six years following the appearance of HFRS. In 1998, 30/37 patients presented for control checkup, when their history data were collected, along with physical examination, hematology and biochemistry tests, and urinalysis. Creatinine clearance and sodium, potassium, chlorine, phosphorus, beta 2-microglobulin and N-acetyl-beta-D glucosaminase in 24-h urine were determined. In native urine, erythrocyturia was observed, with 10 erythrocytes per field were considered pathologic result. During the 1998-2001 period, renal scintigraphy by means of technetium labeled diethylene triaminopentacetic acid (99mTC DTPA) was performed in 13/30 patients. RESULTS: Of subjective discomforts, 29/30 (96.7%) patients reported lumbar pain. Elevated blood pressure was found in 9/30 (30.0%), erythrocyturia in 4/30 (13.3%) and hepatic lesion in 4/30 (13.3%) patients. Decreased creatinine clearance values (< 1.2 ml/s) were found in 4 and increased values (> 2.35 ml/s) in 10 patients. Increased sodium in 24-h urine was recorded in 10/23 and increased beta 2-microglobulin in 6/23 (26%) patients. Proteinuria exceeding 150 mg/day was detected in 11/23 (47.8%) patients. Scintigraphy of the kidneys demonstrated reduced glomerular filtration (< 100 ml/min/1.72 m2) in 3/13 patients. Prolonged mean times (> 5 minutes) of radiopharmaceutical passage through the renal parenchymae were found in 7/13 (53.8%) patients. DISCUSSION: Studies performed in 30 patients three years after they had recovered from HFRS revealed changes suggesting a mild to moderate impairment of the renal function. Hypertension found in 9/30 patients was a significant finding, considering the fact that all subjects were soldiers, thus having undergone through examinations to prove them completely healthy prior to joining army. Hypertension results were consistent with those reported from the USA. Although erythrocyturia points to urinary tract damage, its glomerular or postglomerular origin was not examined. Decreased creatinine clearance found in 4/23 patients suggested functional renal impairment. Increased natriuresis found in 10/23 patients implied tubular damage, i.e. reduced ability of tubular cells for sodium reabsorption from primary urine. Non-selective albuminuria detected in 11/23 patients indicated permanent lesion of the glomerular basal membrane. Increased beta 2-microglobulin found in 6/23 patients indicated that the lysosomal enzyme level was elevated only in the acute stage of the disease, but may have been an indicator of permanent lesion. No description of post-HFRS scintigraphic lesion of the kidneys was found in the literature. A decreased value of glomerular filtration, found in three patients, and especially the prolonged mean time of glomerular micropharmaceutical passage in 7/13 (53.8%) patients may have suggested glomerular damage. However, the possible reason may have also been a reduced passage of glomerular filtrate through the damaged lower parts of the nephrons. Transaminase increase during the acute stage of HFRS suggested the possible liver infection, maybe even hantavirus replication in hepatocytes. Even though biopsy confirmed the histologic picture of chronic hepatitis in one patient, the question remains whether it could have been caused by hantavirus. CONCLUSION: Studies performed in 30 patients with a history of HFRS revealed renal function impairment, along with hypertension and damage to the liver parenchyma in some patients. The results obtained showed that the HFRS infection in Croatia may have entailed chronic sequels. To confirm this hypothesis, additional studies including a control group of hantavirus negative persons are needed.
Related to Topic 80: HIGH,LOW,LEVEL,FOUND,OBSERVED,HIGHER (0.057)

[1] The use of supplementary tests in the serological diagnosis of bovine brucellosis.

[DOC1085] Comparative tests were carried out on serum samples using the Rose Bengal test (RBT), the complement fixation test (CFT), the antibovine globulin test (ABGT) by tube, plate and rapid variants, the mercaptoethanol test (MET) and the dithiothreitol test (DTT). Forty cows, from which Br. abortus had been recovered, gave strong reactions in all tests except for 2 cows in the SAT and 3 cows in the DTT Another group of 405 cows had not yielded Br. abortus on limited bacteriological examination. There was good correlation between the results of the CFT, RBT, tube ABGT, rapid ABGT and, to a lesser extent, the MET in cows with a CF titre greater than or equal to 16 or less than 4. In cows with CF titres of 8 the correlation was not as good while cows with a CF titre of 4 gave a wide range of reactions in these supplementary tests. A plate variant of the ABGT gave titres which were generally lower, by about 1 dilution, than those in the tube procedure. The results of the rapid ABGT correlated well with the results of the tube ABGT and the CFT in samples of high and low titre but not as well in samples of intermediate titre. The DTT gave titres which were usually lower than the corresponding MET titre. On the basis of the results obtained, tentative standards for the interpretation of the ABGT (tube) and MET were defined. It was concluded that these tests could be used to elucidate the status of a proportion of the cows which gave inconclusive results in the CFT.

[2] Proficiency testing of selected antigen and antibody tests for use in dogs and cats.

[DOC10828] OBJECTIVE: To determine the correlation of seroimmunologic test results between reference and nonreference laboratories. DESIGN: Retrospective data analysis. PROCEDURE: Serum samples obtained from naturally infected dogs and cats were distributed to reference and nonreference laboratories for seroimmunologic testing. Correlation of test results was evaluated by use of nonparametric analysis. RESULTS: Correlation coefficients were high between laboratory groups for samples tested for feline immunodeficiency virus antibodies, FeLV antigen, and toxoplasmosis antibodies in cats. results for feline immunodeficiency virus antibody tests from reference laboratories were more likely to be positive than results from nonreference laboratories. Test results for feline infectious peritonitis antibodies, antinuclear antibodies, and Borrelia antibodies in cats were not significant. Coefficient correlations were significant for results of heart-worm antigen, Brucella antibodies, Toxoplasma antibodies, antinuclear antibodies, and rheumatoid factor in dogs. results for Borrelia antibodies were not correlated between laboratory groups. CLINICAL IMPLICATIONS: results were highly correlated between reference and nonreference laboratories for 8 of 14 seroimmunologic tests. Seroimmunologic tests for use in cats were less correlated as a group than those for use in dogs. Poor correlation of results between laboratories was attributed to variations in control agents, antigens, reagents, technical expertise, and cutoff values and end-point titers used for diagnosis.

[3] Extra-low acoustic power harmonic images of the liver with perflutren: novel imaging for r...

[DOC20593] OBJECTIVE: The features of images below the extra-low mechanical index level were studied to elucidate a suitable mechanical index level for observing real-time and continuous harmonic images of rabbit livers with VX-2 tumors with the use of perflutren. METHODS: Eight New Zealand White rabbits, 2 with healthy livers and 6 with VX-2 tumors, were examined by harmonic imaging (1.85 and 3.7 MHz) at a frame rate of 17 Hz under various mechanical index levels. RESULTS: Real-time enhanced images of the liver were observed continuously in all rabbits. Vascular images were more clearly visualized at the low mechanical index level (mechanical index, 0.18) than at any other level. However, predominant enhanced images of the whole liver were observed only at the extra-low mechanical index level (mechanical index, 0.06). In VX-2 tumors, tumor vessels were shown more clearly at a low acoustic power level than at an extra-low level. The histologically proved area of viable tumor was enhanced as a stain in the tumor nodule at an extra-low mechanical index level. CONCLUSIONS: Harmonic imaging under extra-low mechanical index levels with perflutren could provide real-time and continuous enhanced images of the liver, which would contribute to improvement of the diagnostic ability of contrast-enhanced sonography in liver diseases.
Related to Topic 23: EFFECT,DEPENDENT,INHIBITION,ACTIVITY,INDUCED,INHIBITED (0.049)

[1] Comparative analyses of the pigment-aggregating and -dispersing actions of MCH on fish chr...

[DOC15678] In melanophores of the peppered catfish and the Nile tilapia, melanin-concentrating hormone (MCH) at low doses (<1 microM) induced pigment aggregation, and the aggregated state was maintained in the presence of MCH. However, at higher MCH concentrations (such as 1 and 10 microM), pigment aggregation was immediately followed by some re-dispersion, even in the continued presence of MCH, which led to an apparent decrease in aggregation. This pigment-dispersing activity at higher concentrations of MCH required extracellular Ca(2+) ions. By contrast, medaka melanophores responded to MCH only by pigment aggregation, even at the highest concentration employed (10 microM). Since it is known that medaka melanophores possess specific receptors for alpha-melanophore-stimulating hormone (alpha-MSH), the possibility that interaction between MSH receptors and MCH at high doses in the presence of Ca(2+) might cause pigment dispersion is ruled out. Cyclic MCH analogs, MCH (1-14) and MCH (5-17), failed to induce pigment dispersion, whereas they induced aggregation of melanin granules. These results suggest that another type of MCH receptor that mediates pigment dispersion is present in catfish and tilapia melanophores, and that intact MCH may be the only molecule that can bind to these receptors. Determinations of cAMP content in melanophores, which were isolated from the skin of three fish species and treated with 10 nM or 10 microM MCH, indicate that MCH receptors mediating aggregation may be coupled with Gi protein, whereas MCH receptors that mediate dispersion may be linked to Gs. The response of erythrophores, xanthophores and leucophores to MCH at various concentrations was also examined, and the results suggest that the distribution patterns of the two types of MCH receptors may differ among fish species and among types of chromatophore in the same fish.

[2] In vitro effects of toxogonin, HI-6 and HLö-7 on the release of [3H]acetylcholine from pe...

[DOC10793] The purpose of this work was to evaluate the possible non-reactivating effects of toxogonin (1,1'[oxybis(methylene)]bis[4-[hydroxyimino) methyl]pyridinium]-dichloride), HI-6 (1-[[[(4-aminocarbonyl)pyridinio] methoxy]methyl]-2-[(hydroxyimino)methyl]pyridinium-dichloride) and HLö-7 (pyridinium, 1-[[[4-(aminocarbonyl)pyridino]methoxy] methyl]-2,4-bis-[(hydroxyimino)methyl]diiodide) on the release of acetylcholine from cholinergic nerves. The oximes have been tested in our rat bronchial smooth muscle model, with respect to the effects of oximes on the K+ (51 mM)-evoked release of [3H]acetylcholine in the presence and absence of soman (1.0 microM). Toxogonin (100 microM) had no effect on the K(+)-evoked release of [3H]acetylcholine in the presence or absence of soman (1.0 microM). Similar results were found for HI-6 (100 microM). In contrast, HLö-7 (100 microM) enhanced the K(+)-evoked release of [3H]acetylcholine in the absence of soman. In the presence of soman HLö-7 did not alter the release of [3H]acetylcholine induced by K+ stimulation. The potentiating effect of HLö-7 on the release of [3H]acetylcholine could be blocked by the L-, N- and P-Ca2+ channel blockers verapamil (0.1 and 1.0 microM), omega-conotoxin GVIA (1.0 microM) and omega-agatoxin IV-A (0.2 microM), respectively. Muscarinic receptor antagonists (atropine (10 microM), pirenzepine (M1) (1.0 microM) and methoctramine (M2) (1.0 microM) had no effects on the HLö-7 (100 microM)-enhanced release of [3H]acetylcholine. Protein kinase inhibitors (H-7 (20 microM), calphostin C (1.0 microM) and KN-62 (10 microM) inhibited the HLö-7 (100 microM)-enhanced K(+)-evoked release of [3H]acetylcholine. The results showed that only HLö-7 had a direct enhancing effect on the release of acetylcholine through activation or opening of Ca2+ channels and a subsequent protein phosphorylation in the nerve terminal.

[3] Cross-talk between the pathways leading to the induction of apoptosis and the secretion of...

[DOC21738] Ricin induced apoptotic nuclear morphological changes in mouse macrophage cell line RAW264.7 cells at concentrations sufficient to cause severe protein synthesis inhibition. Ricin also induced the release of tumor necrosis factor-alpha (TNF-alpha) from this cell line in a dose-dependent manner but the profile was bell-shaped. However, the isolated galactose-specific ricin B-chain had no such effects. These results suggest that the receptor-binding of ricin through the B-chain is not enough, and subsequent attack on the intracellular target, i.e., the 28S ribosomal RNA (rRNA), by the A-chain of internalized ricin is required for the effects of ricin. Z-D-CH2-DCB, a caspase family inhibitor, showed potent inhibition of the release of TNF-alpha from RAW264.7 cells as well as blockage of the induction of apoptosis by ricin. Furthermore, SB202190, a specific P38 mitogen-activated protein (MAP) kinase inhibitor that strongly inhibits the release of TNF-alpha, also showed significant inhibition of ricin-induced apoptosis. These results suggest that there may be cross-talk between the pathways leading to the release of TNF-alpha and apoptosis. Time course analysis revealed that the activation of p38 MAP kinase started prior to the induction of TNF-alpha release and apoptosis. Since the activation of p38 MAP kinase in ricin-treated RAW264.7 cells was not prevented by Z-D-CH2-DCB, the activation of p38 MAP kinase may occur upstream of the caspase cascade. Among the other protein synthesis inhibitors examined, modeccin and anisomycin, which can trigger a ribotoxic stress response similar to ricin, induced the release of TNF-alpha, but emetine and cycloheximide did not. These results suggest that the specific attack on the 28S ribosomal RNA and the resulting ribotoxic stress response may trigger the multiple signal transduction pathways through the activation of p38 MAP kinase, which in turn leads to TNF-alpha release and apoptosis.
RICIN
Most likely documents

[1] Biochemical studies on oral toxicity of ricin. V. The role of lectin activity in the intes...

[DOC1823] In order to investigate a possible role of lectin activity of ricin in its absorption from the small intestine, we prepared two ricin derivatives. BMH-ricin, prepared by crosslinking A and B chains of ricin with 1,6-bismaleimidohexane, was nearly non-toxic but the lectin activity was unaltered. And, NBS-ricin, prepared by the oxidation of tryptophanyl residues of ricin with N-bromosuccinimide, was not only non-toxic but also non-lectinic. After the oral administration of ricin derivatives to rats, their interaction with the digestive tract and absorption into the circulatory systems have been compared with those of ricin, immunochemically and histologically. It was shown by immunostaining that ricin and BMH-ricin could bind to the intestinal mucosa, whereas NBS-ricin could not. No appreciable damage in the small intestine from rats treated with either BMH-ricin or NBS-ricin has been observed, in contrast to ricin treatment where severe impairment of the small intestinal tissues resulted after 5 h. Immunoreactive ricin in the liver has been determined with the ricin enzyme immunoassay (EIA). When compared at 48 h after oral administration, NBS-ricin was not detected, whereas BMH-ricin was found to be 38 micrograms/liver and ricin 100 micrograms/liver. From these results, it was inferred that the lectin activity of ricin plays an important role in the absorption of ricin from the small intestine and that the absorption of ricin protein was enhanced by its high toxicity.

[2] Ricin binding and protein synthesis inhibition in human hematopoietic cell lines.

[DOC5232] Previous studies showed that human blood cells exhibited varying sensitivities to ricin. To investigate the basis for these differences, ricin binding to human hematopoietic cell lines was assessed and correlated with in vitro ricin sensitivities. Resistant mutants were also isolated and characterized. ricin binding to CEM cells was rapid, time-dependent, and blocked by unlabeled ricin, but not albumin; ricin binding approached saturation at 3 mumol/L. Scatchard analyses showed multiple classes of binding sites, with maximum and minimum Kd values estimated at 1.5 x 10(-8) mol/L and 2.5 x 10(-7) mol/L. At 4 degrees C, membrane-bound ricin dissociated slowly from the cell surface in the presence of unlabeled ricin, but greater than 95% of the surface-bound ricin was removed with 0.1 mol/L lactose. At 37 degrees C, ricin dissociated from the cell surface with biphasic kinetics. ricin uptake at 37 degrees C increased linearly for 15 to 30 minutes and plateaued at levels representing 12% to 29% of the amount of ricin bound at 4 degrees C, depending on the cell line. ricin binding at 4 degrees C varied two- to fivefold among hematopoietic cell lines and was reduced approximately tenfold by incubation with lactose. When compared with parent CEM cells, ricin-resistant CEM variants showed a greater than 95% reduction in ricin binding and showed no detectable binding with lactose added. However, these cells were as sensitive as parent CEM cells to an anti-T-cell ricin immunoconjugate. For all cells examined, there was a close correlation (r = +.9) between ricin bound per cell and in vitro ricin sensitivity. Human hematopoietic cells show widely varying ricin binding, indicating major differences in the carbohydrate content or structure of surface glycoproteins and glycolipids. These variations are probably the major determinant of nonspecific toxicity of ricin immunoconjugates.

[3] Assessment of ligand effects in intracellular trafficking of ricin A chain using anti-rici...

[DOC2998] Intracellular ricin and immunotoxin trafficking has been difficult to study as only one to two cytosolic ricin A chain (RTA) molecules are sufficient to cause cell death. Previous studies (R.J. Youle and M. Colombatti, J. Biol. Chem., 262: 4676-4882, 1987) using anti-ricin hybridomas identified the secretory pre-Golgi as a critical site for RTA intoxication. We used ricin and RTA immunotoxins constructed with transferrin (TF) or anti-murine TF receptor antibody (RI7/217) to compare patterns of cytotoxicity and intracellular trafficking in anti-ricin hybridomas. Anti-RTA and anti-ricin B chain (RTB) hybridomas bound similar amounts of ricin and secreted comparable amounts of anti-ricin immunoglobulin. Anti-RTA hybridomas were 50- to 500-fold more resistant to ricin than nonsecretory and anti-RTB hybridomas, defining a ricin-resistant phenotype. All hybridomas expressed similar levels of surface TF receptors. RTA immunotoxins were constructed using human TF or RI7/217 and a disulfide linker. In protein synthesis inhibition assays, ricin-resistant hybridomas were manyfold more resistant to RI7/217-RTA than were ricin-sensitive hybridomas. In contrast, all hybridomas were equally sensitive to TF-RTA. Monensin increased ricin cytotoxicity minimally against all hybridomas, but dramatically increased RI7/217-RTA cytotoxicity in ricin-resistant and ricin-sensitive hybridomas in a way that abrogated the ricin-resistant phenotype. In contrast, monensin increased TF-RTA cytotoxicity equally in all hybridomas. Ammonium chloride had little effect on ricin or RI7/217-RTA cytotoxicity, but increased TF-RTA cytotoxicity against all hybridomas. Taken together, these results suggest that RTA molecules mediating cytotoxicity pass through an anti-RTA antibody-containing pre-Golgi compartment when bound to RTB or RI7/217, but not when bound to TF. Monensin abrogates the ricin-resistant phenotype when RTA is linked to RI7/217, but not RTB. This suggests that monensin alters RI7/217-RTA processing proximal to the pre-Golgi and that passage through the pre-Golgi may not be necessary for translocation of RTA to the cytoplasm. Ammonium chloride alters toxin cytotoxicity only when RTA is linked to TF, suggesting that only TF trafficks RTA through an acid-sensitive compartment prior to cytoplasmic translocation. With the addition of potentiating agents, each toxin studied showed a unique cytotoxicity profile against the anti-ricin hybridomas, demonstrating a dominant role of the cell binding ligand in intracellular toxin trafficking.
Related to Topic 1: RICIN,CHAIN,CELLS,IMMUNOTOXIN,ANTI,ANTIBODY (0.343)

[1] Blocked and non-blocked ricin immunotoxins against the CD4 antigen exhibit higher cytotoxi...

[DOC2999] An immunotoxin consisting of ricin A chain linked to the monoclonal antibody M-T151, recognising the CD4 antigen, was weakly toxic to the human T-lymphoblastoid cell line CEM in tissue culture. The incorporation of [3H]leucine by CEM cells was inhibited by 50% at an M-T151--ricin-A-chain concentration (IC50) of 4.6 nM compared with an IC50 of 1.0 pM for ricin. In contrast, immunotoxins made by linking intact ricin to M-T151 in such a way that the galactose-binding sites of the B chain subunit were either blocked sterically by the antibody component or were left unblocked, were both powerfully cytotoxic with IC50 values of 20-30 pM. The addition of ricin B chain to CEM cells treated with M-T151--ricin-A-chain enhanced cytotoxicity by only eight-fold indicating that isolated B chain potentiated the action of the A chain less effectively than it did as an integral component of an intact ricin immunotoxin. ricin B chain linked to goat anti-(mouse immunoglobulin) also potentiated weakly. Lactose completely inhibited the ability of isolated ricin B chain to potentiate the cytotoxicity of M-T151--ricin-A-chain and partially (3- to 4-fold) inhibited the cytotoxicity of the blocked and non-blocked ricin immunotoxins. Thus, in this system, the galactose-binding sites of the B chain contributed to cell killing regardless of whether isolated B chain was associated with the A chain immunotoxin or was present in blocked or non-blocked form as part of an intact ricin immunotoxin. The findings suggest that the blocked ricin immunotoxin may become unblocked after binding to the target antigen to re-expose the cryptic galactose-binding sites. However, the unblocking cannot be complete because the maximal inhibition of [3H]leucine incorporation by the blocked immunotoxin was only 80% compared with greater than 99% inhibition by the non-blocked immunotoxin.

[2] Novel synthesis and in vitro characterization of disulfide-linked ricin-monoclonal antibod...

[DOC5347] The use of tumor immunotherapy using whole ricin-antibody conjugates is complicated by the nonspecific lectin activity of the ricin B-chain which leads to toxic side effects. A novel method of coupling whole intact ricin to monoclonal antibody (MoAb) is described herein, where the nonspecific binding of the ricin B-chain is blocked. The coupling was done using the bifunctional reagents S-acetylmercaptosuccinic anhydride for antibody and succinimidyl 3-(2-pyridyldithio)propionate for ricin, and this resulted in the loss of B-chain binding activity, while impairing neither the toxic potential of the A-chain nor the activity of the MoAb. The purified immunotoxins could not bind to lactose-Sepharose and were equally cytotoxic in vitro to MoAb-reactive cell lines in the presence or absence of lactose. The coupling method was suitable for six different ricin-antibody conjugates and also using ricin deglycosylated by treatment with periodate. However, the blocking of the ricin B-chain was only effective with whole IgG molecules as F(ab')2-ricin immunotoxins could, like ricin, bind to lactose-Sepharose. ricin-antibody conjugates reduced the [3H]leucine incorporation of appropriate target cells by 50% at a concentration of 6 to 45 ng/ml, whereas nonreactive antibody immunotoxins were not toxic to the target cells at concentrations as high as 10(4) ng/ml. The specific cytotoxicity of these immunotoxins could be inhibited by the addition of unconjugated reactive MoAb; the presence of lactose or a nonreactive MoAb did not significantly affect the observed cytotoxicity. Thus, whole ricin-antibody conjugates produced in this way do not bind nonspecifically to target cells, the most important implication being that such immunotoxins should be more potent that ricin A-chain conjugates and capable of being used in vivo.

[3] Intratumour therapy of solid tumours with ricin-antibody conjugates.

[DOC4432] Immunotoxin conjugates of whole ricin with monoclonal antibody were prepared with the galactose binding site on the ricin B chain blocked. These whole ricin-antibody conjugates were then injected directly into tumours (IT) in mice with established solid tumours. The conjugates were found to be effective, in vivo, in (C57BL/6XBALB/c)F1 mice carrying thymoma grafts and in nude mice bearing human tumour xenografts. Thymomas (Ly-1.1-, 2.1+) completely regressed following IT injection of either ricin-anti-Ly-2.1 or 'modified' (periodate treated to remove carbohydrate) ricin-anti-Ly-2.1 but did not regress when treated with the non-reactive ricin-anti-Ly-1.1. Similarly, established CEM (transferrin receptor+) or HT-29 (17.1/2+) tumours in nude mice completely regressed following IT injection of ricin-anti-transferrin receptor antibody or ricin-17.1/2 antibody conjugates. The tumours disappeared within 48 h, and in 80-100% of these there was no recurrence. Intact ricin-antibody conjugates did not require the presence of lactose to block the binding of native ricin and selective activity was entirely dependent on the reactivity of the monoclonal antibodies (MoAb). Further, the killing of target cells was specific because non-reactive ricin-antibody conjugates did not cause regression of tumours and MoAb alone did not inhibit tumour growth. In addition, there was no systemic toxicity evident in mice treated with reactive conjugates. By contrast, in mice treated with only ricin or with non-reactive ricin-antibody conjugates there was toxicity to liver and spleen due to diffusion from the tumour; thus the MoAb moiety of the immunotoxin serves to target the ricin to the tumour, to hold ricin in the tumour, and little escapes. It was found that ricin-antibody conjugate treatment (IT) with 1-2 micrograms of ricin-antibody conjugate was not harmful to mice, in contrast to ricin alone, which killed all treated tumour bearing mice at a dose of 0.5 micrograms. Thus whole ricin-antibody conjugates can be used successfully in vivo for local therapy, leading to the eradication of solid tumours by direct injection of the tumour.
Related to Topic 24: RICIN,CHAIN,PROTEIN,SYNTHESIS,ACTIVITY,RIBOSOMES (0.290)

[1] Non-specific deadenylation and deguanylation of naked RNA catalyzed by ricin under acidic ...

[DOC15662] ricin A-chain catalyzes the hydrolysis of the N-glycosidic bond of a conserved adenosine residue at position 4324 in the sarcin/ricin domain of 28S RNA of rat ribosome. The GAGA tetraloop closed by C-G pairs is required for recognition of the cleavage site on 28S ribosomal RNA by ricin A-chain. In this study, ricin A-chain (reduced ricin) exhibits specific depurination on a synthetic oligoribonucleotide (named SRD RNA) mimic of the sarcin/ricin domain of rat 28S ribosomal RNA under neutral and weak acidic conditions. Furthermore, the activity of intact ricin is also similar to that of ricin A-chain. However, under more acidic conditions, both enzymes lose their site specificity. The alteration in specificity of depurination is not dependent on the GAGA tetraloop of SRD RNA. A higher concentration of KCl inhibits the non-specific N-glycosidase activity much more than the specific activity of ricin A-chain. In addition, characterization of depurination sites by RNA sequencing reveals that under acidic conditions ricin A-chain can release not only adenines, but also guanines from SRD RNA or 5S ribosomal RNA. This is the first report of the non-specific deadenylation and deguanylation activity of ricin A-chain to the naked RNA under acidic conditions.

[2] Ribosomal RNA identity elements for ricin A-chain recognition and catalysis. Analysis with...

[DOC1795] ricin is a cytotoxic protein that inactivates ribosomes by hydrolyzing the N-glycosidic bond between the base and the ribose of the adenosine at position 4324 in eukaryotic 28 S rRNA. ricin A-chain will also catalyze depurination in naked prokaryotic 16 S rRNA; the adenosine is at position 1014 in a GAGA tetraloop. The rRNA identity elements for recognition by ricin A-chain and for the catalysis of cleavage were examined using synthetic GAGA tetraloop oligoribonucleotides. The RNA designated wild-type, an oligoribonucleotide (19-mer) that approximates the structure of the ricin-sensitive site in 16 S rRNA, and a number of mutants were transcribed in vitro from synthetic DNA templates with phage T7 RNA polymerase. With the wild-type tetraloop oligoribonucleotide the ricin A-chain-catalyzed reaction has a Km of 5.7 microM and a Kcat of 0.01 min-1. The toxin alpha-sarcin, which cleaves the phosphodiester bond on the 3' side of G4325 in 28 S rRNA, does not recognize the tetraloop RNA, although alpha-sarcin does affect a larger synthetic oligoribonucleotide that has a 17-nucleotide loop with a GAGA sequence; thus, there is a clear divergence in the identity elements for the two toxins. Mutants were constructed with all of the possible transitions and transversions of each nucleotide in the GAGA tetraloop; none was recognized by ricin A-chain. Thus, there is an absolute requirement for the integrity of the GAGA sequence in the tetraloop. The helical stem of the tetraloop oligoribonucleotide can be reduced to three base-pairs, indeed, to two base-pairs if the temperature is decreased, without affecting recognition; the nature of these base-pairs does not influence recognition or catalysis by ricin A-chain. If the tetraloop is opened so as to form a GAGA-containing hexaloop, recognition by ricin A-chain is lost. This suggests that during the elongation cycle, a GAGA tetraloop either exists or is formed in the putative 17-member single-stranded region of the ricin domain in 28 S rRNA and this bears on the mechanism of protein synthesis.

[3] Shiga toxin, Shiga-like toxin II variant, and ricin are all single-site RNA N-glycosidases...

[DOC4180] ricin, Shiga toxin, and Shiga-like toxin II (SLT-II, Vero toxin 2) exhibit an RNA N-glycosidase activity which specifically removes a single base near the 3' end of 28 S rRNA in isolated rat liver ribosomes and deproteinized 28 S rRNA (Endo Y., Mitsui, K., Motizuki, M., & Tsurugi, K. (1987) J. Biol. Chem. 262, 5908-5912; Endo Y. & Tsurugi, K. (1987) J. Biol. Chem. 262, 8128-8130, Endo, Y., Tsurugi, K., Yutsudo, T., Takeda, Y., Ogasawara, K. & Igarashi, K. (1988) Eur. J. Biochem. 171, 45-50). These workers identified the single base removed, A-4324, by examining a 28 S rRNA degradation product which was generated by contaminating ribonucleases associated with the ribosomes. To determine whether this N-glycosidase activity applies in living cells, we microinjected ricin into Xenopus oocytes. We also microinjected Shiga toxin and a variant of Shiga-like toxin II (SLT-IIv). All three toxins specifically removed A-3732, located 378 nucleotides from the 3' end of 28 S rRNA. This base is analogous to the site observed in rat 28 S rRNA for ricin, Shiga toxin, and SLT-II. Purified, glycosylated, ricin A chain contains this RNA N-glycosidase activity in oocytes. We also demonstrated that the nonglycosylated A subunit of recombinant ricin exhibits this RNA N-glycosidase activity when injected into Xenopus oocytes. ricin, Shiga toxin, and SLT-IIv also caused a rapid decline in oocyte protein synthesis for nonsecretory proteins.
Related to Topic 18: BINDING,RICIN,LECTIN,GALACTOSE,AGGLUTININ,LECTINS (0.209)

[1] Studies on the galactose-binding site of ricin and the hybrid toxin Man6P-ricin.

[DOC8370] N-acetylimidazole (NAI) was used to O-acetylate the plant seed toxin ricin. O-acetylation of one to two tyrosine residues per molecule of ricin inhibited ricin binding to Sepharose 4B and decreased toxicity by 90% in a protein synthesis inhibition assay in HeLa cells. Lactose, known to block the binding site on the ricin B subunit, protected ricin from NAI modification of binding or toxicity. Thus NAI, under these conditions, can be a lactose site-specific inhibitor. The lactose site-specific modification of the hybrid toxin, Man6P-ricin, performed under the same conditions, exhibited the same 90% inhibition of Man6P receptor-mediated toxicity as the galactose-containing receptor-mediated toxicity of either Man6P-ricin or ricin. Thus the ricin B chain lactose-binding site appears to be essential for the high potency of Man6P-ricin via the new cell type-specific Man6P receptor. Treatment of fibroblasts with neuraminidase exposes galactose residues, thus increasing the sensitivity to ricin eight fold. The Man6P receptor-mediated toxicity of Man6P-ricin is not affected by this treatment, although the galactose-inhibited route is potentiated eight fold. The Man6P-ricin hybrid appears to require the ricin B chain galactose-binding site to enter the cytosol after initially binding to the Man6P receptor. These data provide some insights into the proper design of hybrid toxins. We discuss a number of possible models for hybrid toxin entry.

[2] The galactose-binding sites of the cytotoxic lectin ricin can be chemically blocked in hig...

[DOC2404] A glycopeptide containing a triantennary N-linked oligosaccharide from fetuin was modified by a series of chemical and enzymic reactions to afford a reagent that contained a terminal residue of 6-(N-methylamino)-6-deoxy-D-galactose on one branch of the triantennary structure and terminal galactose residues on the other two branches. Binding assays and gel filtration experiments showed that this modified glycopeptide could bind to the sugar-binding sites of ricin. The ligand was activated at the 6-(N-methylamino)-6-deoxy-D-galactose residue by reaction with cyanuric chloride. The resulting dichlorotriazine derivative of the ligand reacts with ricin, forming a stable covalent linkage. The reaction was confined to the B-chain and was inhibited by lactose. Bovine serum albumin and ovalbumin were not modified by the activated ligand under similar conditions, and we conclude, therefore, that the reaction of the ligand with ricin B-chain was dependent upon specific binding to sugar-binding sites. ricin that had its galactose-binding sites blocked by the covalent reaction with the activated ligand was purified by affinity chromatography. The major species in this fraction was found to contain 2 covalently linked ligands per ricin B-chain, while a minor species contained 3 ligands per B-chain. The cytotoxicity of blocked ricin was at least 1000-fold less than that of native ricin for cultured cells in vitro, even though the activity of the A-chain in a cell-free system was equal to that from native ricin. Modified ricin that contained only 1 covalently linked ligand was also purified. This fraction retained an ability to bind to galactose affinity columns, although with a lower affinity than ricin, and was only 5- to 20-fold less cytotoxic than native ricin.

[3] Crystal structures of the sugar complexes of Streptomyces olivaceoviridis E-86 xylanase: s...

[DOC16713] The family 10 xylanase from Streptomyces olivaceoviridis E-86 contains a (beta/alpha)(8)-barrel as a catalytic domain, a family 13 carbohydrate binding module (CBM) as a xylan binding domain (XBD) and a Gly/Pro-rich linker between them. The crystal structure of this enzyme showed that XBD has three similar subdomains, as indicated by the presence of a triple-repeated sequence, forming a galactose binding lectin fold similar to that found in the ricin toxin B-chain. Comparison with the structure of ricin/lactose complex suggests three potential sugar binding sites in XBD. In order to understand how XBD binds to the xylan chain, we analyzed the sugar-complex structure by the soaking experiment method using the xylooligosaccharides and other sugars. In the catalytic cleft, bound sugars were observed in the xylobiose and xylotriose complex structures. In the XBD, bound sugars were identified in subdomains alpha and gamma in all of the complexes with xylose, xylobiose, xylotriose, glucose, galactose and lactose. XBD binds xylose or xylooligosaccharides at the same sugar binding sites as in the case of the ricin/lactose complex but its binding manner for xylose and xylooligosaccharides is different from the galactose binding mode in ricin, even though XBD binds galactose in the same manner as in the ricin/galactose complex. These different binding modes are utilized efficiently and differently to bind the long substrate to xylanase and ricin-type lectin. XBD can bind any xylose in the xylan backbone, whereas ricin-type lectin recognizes the terminal galactose to sandwich the large sugar chain, even though the two domains have the same family 13 CBM structure. Family 13 CBM has rather loose and broad sugar specificities and is used by some kinds of proteins to bind their target sugars. In such enzyme, XBD binds xylan, and the catalytic domain may assume a flexible position with respect to the XBD/xylan complex, inasmuch as the linker region is unstructured.
Related to Topic 15: CELLS,RICIN,MEMBRANE,CELL,TRANSPORT,PROTEIN (0.158)

[1] Role of lipids in the retrograde pathway of ricin intoxication.

[DOC19885] The plant toxin ricin binds to both glycosphingolipids and glycoproteins with terminal galactose and is transported to the Golgi apparatus in a cholesterol-dependent manner. To explore the question of whether glycosphingolipid binding of ricin or glycosphingolipid synthesis is essential for transport of ricin from the plasma membrane to the Golgi apparatus, retrogradely to the endoplasmic reticulum or for translocation of the toxin to the cytosol, we have investigated the effect of ricin and the intracellular transport of this toxin in a glycosphingolipid-deficient mouse melanoma cell line (GM95), in the same cell line transfected with ceramide glucosyltransferase to restore glycosphingolipid synthesis (GM95-CGlcT-KKVK) and in the parental cell line (MEB4). ricin transport to the Golgi apparatus was monitored by quantifying sulfation of a modified ricin molecule, and toxicity was studied by measuring protein synthesis. The data reveal that ricin is transported retrogradely to the Golgi apparatus and to the endoplasmic reticulum and translocated to the cytosol equally well and apparently at the same rate in cells with and without glycosphingolipids. Importantly cholesterol depletion reduced endosome to Golgi transport of ricin even in cells without glycosphingolipids, demonstrating that cholesterol is required for Golgi transport of ricin bound to glycoproteins. The rate of retrograde transport of ricin was increased strongly by monensin and the lag time for intoxication was reduced both in cells with and in those without glycosphingolipids. In conclusion, neither glycosphingolipid synthesis nor binding of ricin to glycosphingolipids is essential for cholesterol-dependent retrograde transport of ricin. Binding of ricin to glycoproteins is sufficient for all transport steps required for ricin intoxication.

[2] Endosome to Golgi transport of ricin is independent of clathrin and of the Rab9- and Rab11...

[DOC15775] The plant toxin ricin is transported to the Golgi and the endoplasmic reticulum before translocation to the cytosol where it inhibits protein synthesis. The toxin can therefore be used to investigate pathways leading to the Golgi apparatus. Except for the Rab9-mediated transport of mannose 6-phosphate receptors from endosomes to the trans-Golgi network (TGN), transport routes between endosomes and the Golgi apparatus are still poorly characterized. To investigate endosome to Golgi transport, we have used here a modified ricin molecule containing a tyrosine sulfation site and quantified incorporation of radioactive sulfate, a TGN modification. A tetracycline-inducible mutant Rab9S21N HeLa cell line was constructed and characterized to study whether Rab9 was involved in transport of ricin to the TGN and, if not, to further investigate the route used by ricin. Induced expression of Rab9S21N inhibited Golgi transport of mannose 6-phosphate receptors but did not affect the sulfation of ricin, suggesting that ricin is transported to the TGN via a Rab9-independent pathway. Moreover, because Rab11 is present in the endosomal recycling compartment and the TGN, studies of transient transfections with mutant Rab11 were performed. The results indicated that routing of ricin from endosomes to the TGN occurs by a Rab11-independent pathway. Finally, because clathrin has been implicated in early endosome to TGN transport, ricin transport was investigated in cells with inducible expression of antisense to clathrin heavy chain. Importantly, endosome to TGN transport (sulfation of endocytosed ricin) was unchanged when clathrin function was abolished. In conclusion, ricin is transported from endosomes to the Golgi apparatus by a Rab9-, Rab11-, and clathrin-independent pathway.

[3] Endocytosis, intracellular transport and transcytosis of the toxic protein ricin by a pola...

[DOC3585] The toxic plant protein ricin binds to both the apical and basolateral surface domains of MDCK (strain I) cells grown on polycarbonate filters. Endocytosis of 125I-labeled ricin was not only higher from the basolateral than from the apical surface--an observation which can be explained by the higher surface area of the basolateral surface--but it also appeared to be more efficient when measured as a percentage of total cell-associated ricin. Monovalent ricin-horseradish peroxidase (Ri-HRP), which is known to behave like native ricin with respect to intracellular transport, also binds to, and is taken up from, both the apical and the basolateral surfaces. Initially, after 10 to 15 min, molecules taken up from the two surface domains at 37 degrees C are present in two separate (basolateral and apical) early endosomal populations. This can also be obtained by incubating for 60 min at 18 degrees C. However, after 30 to 60 min at 37 degrees C, most internalized ligand is found in apical lysosomes, regardless from which surface endocytosis took place. Experiments with endocytosis of cationized ferritin from the apical pole and HRP or Ri-HRP from the basolateral pole showed that intermixing in apical lysosomes (or prelysosomes) of molecules taken up from the two poles occurs. Bidirectional transcytosis involving coated pits of both 125I-labeled ricin and Ri-HRP was demonstrated and was found to be most efficient (as measured in per cent of endocytosed toxin) from the apical pole. Transcytosis was strongly reduced at 18 degrees C, and no transepithelial transport of ricin could be measured at 4 degrees C. Transcytosed ricin was intact and could intoxicate new cells. Finally, delivery of ricin internalized from both the apical and the basolateral surface to the apically localized trans-Golgi network occurred at 37 degrees C but not at 18 degrees C, and ricin inhibited protein synthesis largely with the same kinetics following uptake from the two poles. Incubation at 18 degrees C strongly inhibited the toxic effect of ricin. These data show that ricin can intoxicate epithelia from both sides and also penetrate tight epithelial barriers in intact form.
SARS
Most likely documents

[1] Newly discovered coronavirus as the primary cause of severe acute respiratory syndrome.

[DOC20137] BACKGROUND: The worldwide outbreak of severe acute respiratory syndrome (SARS) is associated with a newly discovered coronavirus, SARS-associated coronavirus (SARS-CoV). We did clinical and experimental studies to assess the role of this virus in the cause of SARS. METHODS: We tested clinical and postmortem samples from 436 SARS patients in six countries for infection with SARS-CoV, human metapneumovirus, and other respiratory pathogens. We infected four cynomolgus macaques (Macaca fascicularis) with SARS-CoV in an attempt to replicate SARS and did necropsies on day 6 after infection. FINDINGS: SARS-CoV infection was diagnosed in 329 (75%) of 436 patients fitting the case definition of SARS; human metapneumovirus was diagnosed in 41 (12%) of 335, and other respiratory pathogens were diagnosed only sporadically. SARS-CoV was, therefore, the most likely causal agent of SARS. The four SARS-CoV-infected macaques excreted SARS-CoV from nose, mouth, and pharynx from 2 days after infection. Three of four macaques developed diffuse alveolar damage, similar to that in SARS patients, and characterised by epithelial necrosis, serosanguineous exudate, formation of hyaline membranes, type 2 pneumocyte hyperplasia, and the presence of syncytia. SARS-CoV was detected in pneumonic areas by virus isolation and RT-PCR, and was localised to alveolar epithelial cells and syncytia by immunohistochemistry and transmission electron microscopy. INTERPRETATION: Replication in SARS-CoV-infected macaques of pneumonia similar to that in human beings with SARS, combined with the high prevalence of SARS-CoV infection in SARS patients, fulfill the criteria required to prove that SARS-CoV is the primary cause of SARS.

[2] Epidemiological characteristics of an outbreak of severe acute respiratory syndrome in Don...

[DOC21968] OBJECTIVE: To describe epidemiologic features of an outbreak of severe acute respiratory syndrome (SARS) in Dongcheng District, Beijing occurred in a period between March and May 2003. METHODS: Data of SARS cases notified from Dongcheng District Center for Disease Control and Prevention(CDC)and supplemented by other channels were collected. Clinicians and officials of local hospitals were interviewed in groups and medical records of fatal cases of SARS were reviewed to verify the diagnosis. Stored serum specimens of the patients were detected for IgG antibody against SARS Co-V by enzyme-linked immunosorbent assay (ELISA). All the data were input into dataset files by Microsoft Excel-2000 software and analyzed with SPSS version 10.0 software. RESULTS: Outbreak of SARS in Dongcheng District started on March 14, 2003 with a peak in mid- and late April, and dropped in early May. A total of 572 reported cases were collected during this period in Dongcheng District, Beijing, and 99 of them were excluded from SARS, because of diagnosis of common cold, regular pneumonia, measles and rubella, etc. Actually, 473 SARS cases, which included 390 (82.5%) probable cases and 83 (17.5%) suspect cases, were analyzed. About 90% of the probable cases were positive for IgG antibody. Attack rate of SARS in permanent residents of Dongcheng District was 28.3 per 100 000. Forty-one of them died, with a case-fatality rate of 8.7%. Persons were all susceptible to infection of SARS Co-V, with the highest proportion at ages of 20-50 years, which accounted for 68.7% of the total cases. Average age of the patients at their onset was 40.7 years. No gender difference in SARS cases was found. Number of SARS cases in health-care workers (HCWs) accounted for 18.0% and that in retired workers accounted for 15.4% of the total cases. Cases occurred in all 10 sub-districts of Dongcheng, with the highest in Beixinqiao and Andingmen Sub-districts. Totally, 230 of the 572 notified cases (40.2%) were hospitalized at local hospitals under the jurisdiction of Dongcheng District. Eighteen of 85 cases of SARS occurred in HCWs of local hospitals, accounting for 4.5% of the total number of HCWs working at wards caring for SARS patients or fever clinics. There were 34.7% of SARS cases without any histories of contact before the onset of the disease. Familial aggregation phenomena were observed in 41.8% of the cases and 18.1% of households. And 7.4% (attack rate) of those exposed to SARS cases suffered from the illness during the periods of quarantine. CONCLUSIONS: SARS appeared to be infectious in origin and caused outbreak in Dongcheng District, Beijing introduced by an imported case traveling from Hong Kong in a period between March and May 2003. People are all susceptible to infection of SARS Co-V, which mainly threatens the young adults and the middle-aged, as well as HCWs and the retired workers. The main mode of transmission is direct exposure to SARS patients in a near distance at hospitals or families via droplets spread. Prevention and control of SARS should be focused on early isolation of patients and quarantine for close contacts. Current available measures to prevent and control SARS are proved to be effective.

[3] [An outbreak of SARS in Dongcheng District, Beijing during March to June 2003]

[DOC21203] OBJECTIVE: To describe epidemiological characteristics of an outbreak of severe acute respiratory syndrome (SRAS) in Dongcheng District, Beijing during March to June 2003. METHODS: Data of SARS cases notified from Dongcheng District Center for Disease Control and Prevention (CDC) and supplemented by other channels were collected. All data were input into dataset files by Microsoft Excel-2000 software and analyzed with SPSS version 10.0 software. RESULTS: Totally, 572 cases notified were collected during this period in Dongcheng District, Beijing, and 99 of them were excluded from SARS, because of diagnosis of common cold, pneumonia, measles, or rubella, etc. Actually, 473 SARS cases were analyzed. Attack rate of SARS in permanent residents of Dongcheng was 28.3 per 100,000. Forty-one of them died, with a case-fatality ratio of 8.7%. Outbreak of SARS in Dongcheng District started on March 14, with a peak during mid- and late April, and dropped from May 5, 2003. Persons were all susceptible to SARS, with the highest proportion at ages of 20-50 years, which accounted for 68.7% of the total cases. Average age of the patients at their onset was 40.7 years. No gender difference in SARS cases was found. Number of SARS cases in health care workers (HCWs) accounted for 18.0% and that in the retired persons accounted for 15.4% of the total cases. Cases occurred in all 10 sub-districts of Dongcheng. Totally, 230 of the 572 notified cases (40.2%) hospitalized at local hospitals under the jurisdiction of Dongcheng District. Eighteen of 85 cases of SARS occurred in health care workers of local hospitals, accounting for 4.5% of the total number of health care workers working at the wards caring for SARS patients or at fever clinics. There were 34.7% of SARS cases without any contact histories before their onset. Familial aggregation phenomena were observed in 41.8% of the cases and 18.1% of households. And, 7.4% (attack rate) in those exposed to SARS cases suffered the illness during the periods of quarantine. CONCLUSIONS: SARS appeared outbreak in Dongcheng District, Beijing during March to June 2003. People were all susceptible to SARS, which mainly threatened the young adults and the middle-aged, as well as health care workers and the retired workers. Main mode of transmission was exposure to SARS patients in a near distance at hospitals or families. Prevention and control of SARS should be focused on early isolation of patients and quarantine for the contacts. Current available measures to prevent and control SARS proved effective.
SPECIFIC
Most likely documents

[1] Analysis of gp74 expression by transformed rat fibroblasts from experimental pulmonary met...

[DOC4233] Ricin A chain immunotoxin (IT) 45-2D9-RTA mediates regression of spontaneous pulmonary metastases and lung colonies from K-ras transformed rat fibroblasts (TRF cells). However, residual metastases are frequently noted after IT therapy, and therefore, possible mechanisms mediating tumor cell escape were investigated. Individual lung colonies were dissected from lungs of BALB/c mice, and single-cell suspensions of fresh cells from short-term cultures (eight passages) were tested. Immunoperoxidase staining with 45-2D9 monoclonal antibody showed that stable loss of surface antigen by cells cultured from IT-treated mice did not occur after four injections of specific IT. Sensitivity to specific IT in vitro was equal for metastatic tumor cells from mice treated with either two or four doses of specific IT compared to cells from nonspecific IT-treated mice and to parental cells. Clones derived from metastases of IT-treated mice were not resistant to IT. Clones derived from metastases of specific IT-treated mice internalized bound antibody or IT at the same rate as untreated cells. Freshly disaggregated cells from specific IT-treated mice were as sensitive to specific IT as were cells from nonspecific IT-treated or untreated mice. specific IT successfully mediated reduction of lung colonies derived from fresh suspensions of lung colony TRF cells from IT-treated mice. This reduction was equivalent to that seen for cells not previously exposed to specific IT. Immunoperoxidase stains of lung sections with 45-2D9 showed that colonies consisting entirely of unstained TRF cells were present in both specific IT and phosphate buffered saline-treated mice. There was a trend toward a higher percentage of antigen-negative colonies in mice treated with IT, although 9 days following specific IT therapy, greater than 80% of lung colonies expressed gp74 antigen. When TRF cells were grown on agar plugs, which promoted three-dimensional growth, groups of cells showing absence of immunoperoxidase staining with antibody to gp74 were identified during 2 weeks of growth. Thus, stability of antigen-negative variants is favored by three-dimensional growth conditions and the selective pressure of IT administration. Our results also suggest that impaired trafficking of IT to antigen-positive cells may also contribute to escape from IT therapy.

[2] Epitope mosaic on the surface proteins of orthopoxviruses.

[DOC3797] Epitopes on the surface components of orthopoxviruses were analyzed with monoclonal antibodies (MAbs) against monkeypox and vaccinia viruses by enzyme-linked immunosorbent assay (ELISA), Western blotting (WB), radioimmunoprecipitation (RIP), and competitive binding inhibition assay (CBIA). When compared by ELISA, three vaccinia virus strains exhibited a similar reactivity to 99 tested MAbs despite their remote passage history. All five isolates of monkeypox virus closely resembled one another, irrespective of the host species (human, monkey, squirrel) from which they were isolated. Taterapox virus reacted similar to vaccinia virus against 97 of the 99 tested MAbs, and reacted with 2 MAbs which were cross-reactive with monkeypox and mousepox. Mousepox and cowpox viruses reacted with these MAbs in a species-specific manner: MAbs reactive to cowpox virus distinctly differ from those reactive to mousepox virus. Of the 99 tested MAbs, 32 reacted with all the 11 tested orthopoxviruses, indicating that the corresponding epitopes existed in all the viruses. Fifty-four MAbs reacted with two or more virus species and were classified as partially common MAbs. Eight MAbs were apparently type-specific for monkeypox, and five were specific for vaccinia and taterapox viruses. No strain-specific epitope was detected. Sera of monkeypox-infected patients, when analyzed by CBIA, interfered with the binding of monkeypox-specific MAb H12C1 but not of vaccinia-specific MAb G6C6. Sera of monkeypox-infected patients who had been vaccinated competed against both MAbs, demonstrating the original antigenic sin phenomenon. The two MAbs could distinguish between the sera of monkeypox patients and those of vaccinated persons. However, the serum of a smallpox patient was competitive against these apparently vaccinia- or monkeypox-specific MAbs. Three of the eight monkeypox-specific epitopes were recognized by the above CBIA test, which suggests that they also exist in smallpox virus. The mosaic-like combination of common epitopes and the small number of type-specific epitopes manifested the antigenic characteristics of orthopox viruses. The species boundary was obscured due to the partially common epitopes, but the total composition of epitopes was stable enough to maintain the antigenic species-specificity. The mutual relationship of the orthopoxviruses was visualized in a three-dimensional network.

[3] Presumptive specific clinical diagnosis of genital ulcer disease (GUD) in a primary health...

[DOC10844] During a 12-month period in 1990-1991 in Kenya, 1076 of 22,274 patients (4.8% of all patients over 12 years of age) presented at the Langata Health Center in Nairobi with symptoms of a sexually transmitted disease (STD). Researchers analyzed data on 980 of these patients whose records had complete data to assess the use of presumptive specific clinical diagnosis in the management of STDs in a primary health clinic. 17.1% (168) had genital ulcer disease (GUD). Men were more likely to have a GUD than women (24.7% vs. 10.4%). Haemophilus ducreyi, the etiologic agent of chancroid, was isolated in the cultures of 40% of the patients with a presumptive specific clinical diagnosis of chancroid compared with 17% of those with a presumptive specific clinical diagnosis of syphilis, herpes, or lymphogranuloma venereum (LGV) (p = 0.02). The clinical diagnoses of these two GUDs had only a weak correlation with microbiological and serological diagnoses (p = 0.13). 24% of patients with a presumptive specific clinical diagnosis of syphilis, 31% of those with a presumptive specific clinical diagnosis of chancroid, 6% of those with a specific clinical diagnosis of genital herpes or LGV, and 4.7% of those who had no GUD disease tested positive for syphilis (p 0.001, GUD vs. no GUD). Among patients with syndromic diagnosis of GUD, the presumptive specific clinical diagnosis of chancroid had a high sensitivity (91%), low specificity (24%), and low positive predictive value (40%). Among patients with syndromic diagnosis of syphilis, the presumptive specific clinical diagnosis of syphilis had a low sensitivity (25%), higher specificity (87%), and low positive predictive value (24%). 13% of patients with positive cultures for H. ducreyi did not receive a recommended or effective drug for chancroid. 82% of patients who tested positive for syphilis did not receive a recommended drug for syphilis. Based on these findings, the researchers conclude that syndromic treatment of GUD with use of antimicrobial combinations active against both chancroid and syphilis is a better course of treatment than use of single drugs based on presumptive specific clinical diagnoses for this population.
Related to Topic 45: ANTIBODIES,SPECIFIC,CROSS,ANTI,MONOCLONAL,ANTIBODY (0.237)

[1] Epitope mosaic on the surface proteins of orthopoxviruses.

[DOC3797] Epitopes on the surface components of orthopoxviruses were analyzed with monoclonal antibodies (MAbs) against monkeypox and vaccinia viruses by enzyme-linked immunosorbent assay (ELISA), Western blotting (WB), radioimmunoprecipitation (RIP), and competitive binding inhibition assay (CBIA). When compared by ELISA, three vaccinia virus strains exhibited a similar reactivity to 99 tested MAbs despite their remote passage history. All five isolates of monkeypox virus closely resembled one another, irrespective of the host species (human, monkey, squirrel) from which they were isolated. Taterapox virus reacted similar to vaccinia virus against 97 of the 99 tested MAbs, and reacted with 2 MAbs which were cross-reactive with monkeypox and mousepox. Mousepox and cowpox viruses reacted with these MAbs in a species-specific manner: MAbs reactive to cowpox virus distinctly differ from those reactive to mousepox virus. Of the 99 tested MAbs, 32 reacted with all the 11 tested orthopoxviruses, indicating that the corresponding epitopes existed in all the viruses. Fifty-four MAbs reacted with two or more virus species and were classified as partially common MAbs. Eight MAbs were apparently type-specific for monkeypox, and five were specific for vaccinia and taterapox viruses. No strain-specific epitope was detected. Sera of monkeypox-infected patients, when analyzed by CBIA, interfered with the binding of monkeypox-specific MAb H12C1 but not of vaccinia-specific MAb G6C6. Sera of monkeypox-infected patients who had been vaccinated competed against both MAbs, demonstrating the original antigenic sin phenomenon. The two MAbs could distinguish between the sera of monkeypox patients and those of vaccinated persons. However, the serum of a smallpox patient was competitive against these apparently vaccinia- or monkeypox-specific MAbs. Three of the eight monkeypox-specific epitopes were recognized by the above CBIA test, which suggests that they also exist in smallpox virus. The mosaic-like combination of common epitopes and the small number of type-specific epitopes manifested the antigenic characteristics of orthopox viruses. The species boundary was obscured due to the partially common epitopes, but the total composition of epitopes was stable enough to maintain the antigenic species-specificity. The mutual relationship of the orthopoxviruses was visualized in a three-dimensional network.

[2] Characterization of O-polysaccharide specific monoclonal antibodies derived from mice infe...

[DOC8770] Twenty-two monoclonal antibodies (mAbs) specific for smooth lipopolysaccharide (S-LPS) were generated by fusion of spleen cells from mice infected with the rough Brucella melitensis strain B115 with the NSO myeloma. According to reactivity in enzyme-linked immunosorbent assay (ELISA) with O-polysaccharide (O-PS) and absence of reactivity with rough lipopolysaccharide (R-LPS), it was postulated that these mAbs recognized epitopes present on the O-PS. Most of the mAbs reacted equally well in ELISA and immunoblotting with S-LPS types of Brucella A and M dominant strains and were designated as specific for common (C) epitopes. Three mAbs were highly specific for M dominant S-LPS. All these mAbs, in contrast to a mAb specific for the A epitope, showed little or no cross-reactivity with Yersinia enterocolitica O:9 S-LPS. S-LPS of B. melitensis B115 was extracted and analysed by immunoblotting and ELISA with mAbs specific for A, M and C epitopes. Reactivity of the mAbs with this S-LPS was compared to reactivity with S-LPS of A and M dominant smooth Brucella strains. The results suggest that S-LPS of B. melitensis B115 bears mainly C epitopes and a few M epitopes. The very weak reactivity of this S-LPS with the mAb specific for the A epitope and the fact that the mAbs specific for C and M epitopes showed little or no cross-reactivity with Y. enterocolitica O:9 S-LPS suggest that O-PS from this rough strain could be used to distinguish Y. enterocolitica O:9 infection from Brucella infection.(ABSTRACT TRUNCATED AT 250 WORDS)

[3] Monoclonal antibodies to three strains of hantaviruses: Hantaan, R22, and Puumala.

[DOC2789] Thirty hybrid cell lines that produce monoclonal antibodies to three strains of hantaviruses have been generated and characterized. One clone specific to Hantaan 76-118 strain, four clones specific to Rattus strains and one clone specific to Puumala virus have been identified. Most of the monoclones produced antibodies specific to nucleoproteins. Only two monoclones were found to produce glycoprotein specific, neutralizing antibodies. The immunofluorescent (IFA) staining patterns of the monoclonal antibodies show consistent correlation with viral protein specificities as described for other hemorrhagic fever viruses. Cross-reactivity studies with hantaviruses tested demonstrate conserved antigenic sites on nucleoproteins among these hantaviruses tested. Puumala specific monoclones, produced for the first time, reveal both conserved and strain specific sites on the viral nucleoproteins of the Scandinavian virus.
Related to Topic 62: RESPONSE,IMMUNE,RESPONSES,SPECIFIC,ANTIGEN,CELL (0.167)

[1] In vitro T-cell proliferative response to the flavivirus, west Nile.

[DOC2440] West Nile virus (WNV)-specific murine T-cell proliferation in vitro was investigated in terms of conditions that optimize antigen-specific responses and reduce background proliferation. The responder populations consisted of splenocytes from WNV-primed mice enriched for L3T4+ T cells. Ia+ antigen-presenting cells (APC) were derived from splenocytes of WNV-primed or naive mice. Antigen was a lysate prepared from WNV-infected Vero cells at 12 h postinfection. Strong virus-specific proliferative responses were observed when antigen-pulsed APC were cocultured with responders at a 1:1 ratio. Substantial nonspecific proliferation occurred when culture medium supplemented with 5% fetal bovine serum (FBS) was used, whereas with 1% normal mouse serum a higher degree of antigen specificity was evident, although the magnitude of the responses was lower. The best separation between antigen-specific and background proliferation was obtained by using an exogenous source of T-cell growth factors to amplify for 2 days the proliferation of L3T4+ cells triggered by an initial 3 days of culture with antigen-pulsed APC. This investigation has defined optimal conditions for investigating the stimulation of WNV-primed L3T4+ T-cell proliferation in response to the presentation of viral gene products by Ia+ APC. This assay should permit detailed analysis of the efficiency of various APC populations and identification of viral antigens that stimulate the proliferation of Class II MHC-restricted T cells.

[2] Functional analysis of macrophages, B cells and splenic dendritic cells as antigen-present...

[DOC2323] In this paper, the relative efficacy of macrophages, B cells and splenic dendritic cells (SDC) in presenting West Nile virus (WNV) antigens to WNV memory CD4+ T cells is examined. The results indicate that, under appropriate conditions, all these cell types can function as antigen-presenting cells (APC). Listeria-induced peritoneal macrophages induced higher proliferative responses than SDC or B cells derived from naive or 14 day WNV-primed mice. The ability of Listeria-induced macrophage populations to present antigen was specifically inhibited by anti-Class II major histocompatibility complex (MHC) antibodies. On a cell population basis, B cells obtained from mice primed with WNV 14 days previously evoked higher responses than resting B cells. B cells from mice receiving weekly injections of WNV over a period of 4 weeks elicited optimal responses with lower doses of antigen than naive or 14 day WNV-primed B cells. When macrophages were used as APC, addition of specific antibodies to WNV resulted in increased efficiency of presentation, probably due to increased uptake of antigen by opsonization. In contrast, addition of anti-WNV antibodies to hyperimmune B cells reduced their efficacy presumably by reducing uptake of antigen by B cell surface immunoglobulin. When SDC from C57BL/6 mice were used as APC, WNV-specific proliferative responses were directly related to the number of stimulator cells used, and the background proliferation with mock antigen was two- to five-fold lower than specific responses. Higher levels of background proliferation were stimulated by SDC from CBA/H mice so that the antigen-specific responses were always less than two-fold higher than background.

[3] Modified vaccinia virus Ankara for delivery of human tyrosinase as melanoma-associated ant...

[DOC13697] Vaccination with tumor-associated antigens is a promising approach for cancer immunotherapy. Because the majority of these antigens are normal self antigens, they may require suitable delivery systems to promote their immunogenicity. A recombinant vector based on the modified vaccinia virus Ankara (MVA) was used for expression of human tyrosinase, a melanoma-specific differentiation antigen, and evaluated for its efficacy as an antitumor vaccine. Stable recombinant viruses (MVA-hTyr) were constructed that have deleted the selection marker lacZ and efficiently expressed human tyrosinase in primary human cells and cell lines. Tyrosinase-specific human CTLs were activated in vitro by MVA-hTyr-infected, HLA-A*0201-positive human dendritic cells. Importantly, an efficient tyrosinase- and melanoma-specific CTL response was induced in vitro using MVA-hTyr-infected autologous dendritic cells as activators for peripheral blood mononuclear cells derived from HLA-A*0201-positive melanoma patients despite prior vaccination against smallpox. Immunization of HLA-A*0201/Kb transgenic mice with MVA-hTyr induced A*0201-restricted CTLs specific for the human tyrosinase-derived peptide epitope 369-377. These in vivo primed CTLs were of sufficiently high avidity to recognize and lyse human melanoma cells, which present the endogenously processed tyrosinase peptide in the context of A*0201. Tyrosinase-specific CTL responses were significantly augmented by repeated vaccination with MVA-hTyr. These findings demonstrate that HLA-restricted CTLs specific for human tumor-associated antigens can be efficiently generated by immunization with recombinant MVA vaccines. The results are an essential basis for MVA-based vaccination trials in cancer patients.
Related to Topic 38: PCR,REACTION,ASSAY,DETECTION,SPECIFIC,POLYMERASE (0.131)

[1] Development of a real-time reverse transcriptase PCR assay for type A influenza virus and ...

[DOC17838] A real-time reverse transcriptase PCR (RRT-PCR) assay based on the avian influenza virus matrix gene was developed for the rapid detection of type A influenza virus. Additionally, H5 and H7 hemagglutinin subtype-specific probe sets were developed based on North American avian influenza virus sequences. The RRT-PCR assay utilizes a one-step RT-PCR protocol and fluorogenic hydrolysis type probes. The matrix gene RRT-PCR assay has a detection limit of 10 fg or approximately 1,000 copies of target RNA and can detect 0.1 50% egg infective dose of virus. The H5- and H7-specific probe sets each have a detection limit of 100 fg of target RNA or approximately 10(3) to 10(4) gene copies. The sensitivity and specificity of the real-time PCR assay were directly compared with those of the current standard for detection of influenza virus: virus isolation (VI) in embryonated chicken eggs and hemagglutinin subtyping by hemagglutination inhibition (HI) assay. The comparison was performed with 1,550 tracheal and cloacal swabs from various avian species and environmental swabs obtained from live-bird markets in New York and New Jersey. Influenza virus-specific RRT-PCR results correlated with VI results for 89% of the samples. The remaining samples were positive with only one detection method. Overall the sensitivity and specificity of the H7- and H5-specific RRT-PCR were similar to those of VI and HI.

[2] PCR-DIG ELISA with biotinylated primers is unsuitable for use in whole blood samples from ...

[DOC23313] In an attempt to avoid some of the inconveniences associated with conventional PCR, such as electrophoresis in ethidium bromide, we developed and analyzed the yield of a digoxigenin-based enzyme-linked immunosorbent PCR assay (PCR-DIG ELISA) for the detection of specific Brucella target DNA. During the DNA amplification process in healthy subjects and controls (Brucella abortus B-19) non-specific amplification of fragments was formed between genomic DNA and specific biotin-labeled primers. The labeled non-specific fragments bound to streptavidin-coated wells, saturating the solid phase streptavidin by biotin-streptavidin interaction. The formation of these non-specific PCR products was demonstrated by reduction in absorbance with hemin, a Taq polymerase inhibitor, and identified by use of a silver stained method which improves the sensitivity of nucleic acid visualization.

[3] A generic sandwich-type biosensor with nanomolar detection limits.

[DOC23055] A quantitative and highly sensitive, yet simple and rapid, biosensor system was developed for the detection of nucleic acid sequences that can also be adapted to the detection of antigens. A dipstick-type biosensor with liposome amplification, based on a sandwich assay format with optical detection, was combined with a simple coupling reaction that allows the transformation of the generic biosensor components to target specific ones by a mere incubation step. This biosensor platform system was developed and optimized, and its principle was proven using DNA oligonucleotides that provided a nucleic acid biosensor for the specific detection of RNA and DNA sequences. However, the coupling reaction principle chosen can also be used for the immobilization of antibodies or receptor molecules, and therefore for the development of immunosensors and receptor-based biosensors. The generic biosensor consists of liposomes entrapping sulforhodamine B that are coated with streptavidin on the outside, and polyethersulfone membranes with anti-fluorescein antibodies immobilized in the detection zone. In order to transform the generic biosensor into a specific DNA/RNA biosensor, two oligonucleotides that are able to hybridize to the target sequence were labeled with a biotin and a fluorescein molecule, respectively. By simultaneously incubating the liposomes, both oligonucleotides, and the target sequence in a hybridization buffer for 20-30 min at 42 degrees C, a sandwich complex was formed. The mixture was applied to the polyethersulfone membrane. The complex was captured in the detection zone and quantified using a hand-held reflectometer. The system was tested using RNA sequences from B. anthracis, C. parvum and E. coli. Quantitation of concentrations between 10 fmol and 1000 fmol (10-1000 nM) was possible without altering any biosensor assay conditions. In addition, no changes to hybridization conditions were required when using authentic nucleic acid sequence-based amplified RNA sequences, and the generic biosensor compared favorably with those previously developed specifically for the RNA sequences. Therefore, the universal biosensor described is an excellent tool, for use in laboratories or at test sites, for rapidly investigating and quantifying any nucleic acid sequence of interest, as well as potentially any antigen of interest that can be bound by two antibodies simultaneously.
Related to Topic 79: SYSTEM,POTENTIAL,SPECIFIC,ABILITY,TARGET,SYSTEMS (0.110)

[1] Potentiation of antitumor immunotoxins by liposomal monensin.

[DOC10119] BACKGROUND: The cytotoxicity of specific ricin A-chain immunotoxins is greatly enhanced in vitro by the carboxylic ionophore monensin. However, the highly lipophilic nature of monensin, which is reflected in its poor solubility and short half-life, has restricted its use in in vivo animal studies. PURPOSE: The purpose of this study was to assess the ability of monensin incorporated in unilamellar vesicles (liposomes) to potentiate antitumor immunotoxins in vitro and in vivo. METHODS: Monensin was incorporated into liposomes and used in combination with specific immunotoxins against human tumor cell lines in vitro and in vivo. Inhibition of [3H]leucine incorporation was used to evaluate the cytotoxic action of immunotoxin with or without monensin in vitro on the following human tumor cell lines: H-MESO-1 malignant mesothelioma, LS174T colorectal carcinoma, and U373, U87, and MG-1 glioblastomas. For the in vivo studies of immunotoxins and liposomal monensin, BALB/c nu/nu mice were inoculated intraperitoneally with H-MESO-1 cells. RESULTS: Liposomal monensin potentiated the cytotoxic action of cell-specific anti-human transferrin receptor immunotoxin on H-MESO-1 target cells at a molar concentration of monensin that was 160-fold lower than the concentration of monensin in buffer that produced the same effect (0.3 nM versus 0.05 microM). Moreover, immunotoxin plus 0.1 microM liposomal monensin was fivefold more toxic for H-MESO-1 cells and 1000-fold and 2200-fold more toxic for human glioblastoma U373 and U87 cells, respectively, than immunotoxin plus 0.1 microM free monensin in buffer. Liposomal monensin produced similar effects when it was combined with different specific immunotoxins and other target cell lines (i.e., LS174T, U87, and CEM). Immunotoxin specificity was preserved with liposomal monensin, as shown by the absence of effect with non-cell-binding immunotoxins or on antigen-negative cell lines. In mice, liposomal monensin in combination with specific immunotoxin substantially prolonged survival, and three (21%) of 14 mice bearing H-MESO-1 xenografts treated with the liposomes showed no evidence of tumor at day 160 after treatment. Treatment with control immunotoxin plus liposomal monensin was ineffective. CONCLUSION: These findings suggest that encapsulation of monensin into liposomes increased the capacity of monensin to enhance the potency of cell-specific immunotoxin in vitro and in vivo.

[2] Modified vaccinia virus Ankara for delivery of human tyrosinase as melanoma-associated ant...

[DOC13697] Vaccination with tumor-associated antigens is a promising approach for cancer immunotherapy. Because the majority of these antigens are normal self antigens, they may require suitable delivery systems to promote their immunogenicity. A recombinant vector based on the modified vaccinia virus Ankara (MVA) was used for expression of human tyrosinase, a melanoma-specific differentiation antigen, and evaluated for its efficacy as an antitumor vaccine. Stable recombinant viruses (MVA-hTyr) were constructed that have deleted the selection marker lacZ and efficiently expressed human tyrosinase in primary human cells and cell lines. Tyrosinase-specific human CTLs were activated in vitro by MVA-hTyr-infected, HLA-A*0201-positive human dendritic cells. Importantly, an efficient tyrosinase- and melanoma-specific CTL response was induced in vitro using MVA-hTyr-infected autologous dendritic cells as activators for peripheral blood mononuclear cells derived from HLA-A*0201-positive melanoma patients despite prior vaccination against smallpox. Immunization of HLA-A*0201/Kb transgenic mice with MVA-hTyr induced A*0201-restricted CTLs specific for the human tyrosinase-derived peptide epitope 369-377. These in vivo primed CTLs were of sufficiently high avidity to recognize and lyse human melanoma cells, which present the endogenously processed tyrosinase peptide in the context of A*0201. Tyrosinase-specific CTL responses were significantly augmented by repeated vaccination with MVA-hTyr. These findings demonstrate that HLA-restricted CTLs specific for human tumor-associated antigens can be efficiently generated by immunization with recombinant MVA vaccines. The results are an essential basis for MVA-based vaccination trials in cancer patients.

[3] Cell-specific delivery of bacteriophage-encapsidated ricin A chain.

[DOC11194] We have used covalent coupling of deglycosylated ricin A chain (RAC) to the assembly initiation/translational repression RNA stem-loop (TR) of the bacteriophage MS2 to direct encapsulation of the toxin in bacteriophage capsids. Multiple copies of the TR-RAC conjugate can be incorporated into single capsid shells. The resultant particles can then be directed to specific cells by receptor-mediated endocytosis (RME) of complexes formed with anti-MS2 coat protein antibodies or by further covalent modification of the capsids by addition of human transferrin molecules. The results suggest that bacteriophage encapsulation and targeting is an efficient way to deliver toxins in a cell-specific fashion. The system may have widespread application in the field of targeted drug delivery, including antisense reagents.
Related to Topic 4: ANTIBODIES,ANTIBODY,SERA,ELISA,IGG,SERUM (0.101)

[1] Detection of human immunoglobulins G and M antibodies to Rift Valley fever virus by enzyme...

[DOC7338] Rift Valley fever virus (RVFV) is an important human and animal pathogen in Africa and has been responsible for infections in travelers. Because of the aerosol infectivity and risk of dissemination of the virus, a need exists for simple, safe, serological tests for diagnosis. An enzyme-linked immunosorbent assay (ELISA) was developed to detect RVFV-specific immunoglobulins (immunoglobulin G [IgG] and IgM). In the test, a betapropiolactone-inactivated, sucrose-acetone-extracted, suckling mouse liver RVFV antigen was captured by mouse RVFV antibodies adsorbed to polystyrene plates. The test sample (human serum) was then added, and the binding of specific antibodies was indicated by alkaline phosphatase-conjugated swine anti-human IgG or IgM. A mu-capture IgM ELISA was also developed by using polystyrene plates coated with goat anti-human IgM incubated successively with serum sample, RVFV antigen, and indicator antibodies. The ELISA for RVFV-specific IgG proved to be more sensitive than hemagglutination inhibition or complement fixation tests and almost as sensitive as the plaque reduction neutralization test in detecting specific antibodies in human sera after vaccination. The two ELISA IgM tests could detect specific IgM antibodies during the first 6 weeks after RVFV vaccination. Three injections of inactivated vaccine were given on days 0, 6 to 8, and 32 to 34. ELISA IgM values for sera obtained on days 6 to 8 were negative or in the lower range of significance, on days 32 to 34 they were strongly positive, and on days 42 to 52 they were waning. Later sera were negative. The plague reduction neutralization test was negative on days 6 to 8 but rose progressively in later samples. These findings suggest that the three doses of RVFV vaccine induce a prolonged primary antibody response. The ELISA IgM could become an important tool for early diagnosis in acute human infection. A number of African sera, some of which were positive for RVFV by plaque reduction neutralization test, were also tested by ELISA IgG. There was good agreement between both tests.

[2] Class and subclass distribution of Hantavirus-specific serum antibodies at different times...

[DOC9207] Sera from Dutch and Belgium individuals who suffered from nephropathia epidemica (NE), a mild form of haemorrhagic fever with renal syndrome (HFRS), were tested for the distribution of classes and subclasses of Hantavirus (HV)-specific antibodies at different times after the onset of the disease, with class- and subclass-specific Ig capture enzyme-linked immunosorbent assays (ELISAs). In the acute, early convalescent, and convalescent phases, predominantly specific IgA, IgM, and IgG3 antibodies were detected. specific IgG2 antibodies were only detected at low levels in the early convalescent and convalescent phases. In the late convalescent phase specific IgG1 and IgG3 antibodies were found, whereas in the late postconvalescent phase only specific IgG1 antibodies proved to be present. specific IgG4 antibodies were not detected in any of the respective phases. These data show that the simultaneous determination of classes and subclasses of HV specific serum antibodies allows the estimation of the time elapsed after the onset of NE.

[3] Immunoradiometric assay for examination and quantitation of Brucella abortus-specific anti...

[DOC7670] An immunoradiometric assay was designed to quantitate antibodies which bind to Brucella abortus antigens adsorbed to bovine erythrocytes. This allowed examination of antibodies specific for B. abortus antigens detectable in the indirect hemolysis test for bovine brucellosis. Assay parameters were optimized for measuring antigen-specific immunoglobulin G1 (IgG1), IgG2, and IgM antibodies. The immunoradiometric assay allowed examination of binding interactions which occur during the indirect hemolysis test. Affinity-purified antibovine IgG1, IgG2, and IgM were used to detect specific bovine antibodies of these classes (and subclasses). The binding of the anti-immunoglobulins was linear as a function of immunoglobulin concentration. However, the binding of bovine antibodies of the different classes and subclasses to B. abortus antigen was nonlinear. Since B. abortus-specific antibodies of all classes and subclasses were present in the "standard serum" during the immunoradiometric assays, it is possible that the non-linearity was due to competition between antibodies for antigenic sites. IgG2 and IgM antibodies specific for B. abortus antigen(s) appeared to be capable of binding independently to antigen(s). However, the binding efficiencies of IgG1 antibodies changed as the ratio of antigenic sites to antibodies was increased.
STUDY
Most likely documents

[1] Effect of coadministration of nelfinavir, indinavir, and saquinavir on the pharmacokinetic...

[DOC17776] OBJECTIVE: Pharmacokinetic interactions are expected when human immunodeficiency virus (HIV) protease inhibitors are coadministered because many are both substrates for and inhibitors of CYP3A4. The goal of this model-based pharmacokinetic analysis was to describe the differences observed in amprenavir pharmacokinetics among treatment arms in the Adult AIDS Clinical Trial Group (AACTG) study protocol 398 and to propose mechanisms to account for them. METHODS: One hundred seventy-six HIV-positive subjects receiving 1200 mg amprenavir twice daily as part of AACTG protocol 398 were included in the pharmacokinetic study. All patients also received background medications efavirenz, adefovir dipivoxil, and abacavir and, depending on the study arm, placebo or one of the following protease inhibitors: nelfinavir, indinavir, or saquinavir. A population pharmacokinetic model was fitted to a total of 565 amprenavir concentration measurements. The blood samples for concentration measurements were drawn at week 2 (12-hour pharmacokinetic study, approximately 7 samples per study; 46 patients) and at week 24 (6-hour pharmacokinetic study, approximately 5 samples per study; 10 patients). In addition, samples were collected at 1 or more follow-up visits (population pharmacokinetic study, 1 to 3 occasions per patient; 150 patients). Results and Conclusion: Amprenavir intrinsic clearance was significantly reduced relative to placebo by nelfinavir (-41%) and indinavir (-54%) but not by saquinavir. The absolute magnitude of amprenavir intrinsic clearance suggests that CYP3A4 inhibition by nelfinavir and indinavir is balanced by enzymatic induction in the presence of the background drug(s), most likely efavirenz. Amprenavir intrinsic clearance apparently increases by more than 30% between weeks 2 and 24, possibly because of the time course of CYP3A4 induction.

[2] Clinical and serologic study of four smallpox vaccines comparing variations of dose and ro...

[DOC343] The present four-center collaborative study was undertaken in an attempt to define the best vaccine and/or vaccination procedure for use in areas of the world that are free of smallpox. The study was designed to compare the effect of different vaccinial strains, viral concentrations, and routes of administration on the morbidity and antibody response associated with primary vaccination and standard challenge revaccination. Primary vaccinations were performed on 1,585 children; 49.6% of the children were vaccinated by the percutaneous route, and 50.4% received vaccine subcutaneously. The overall age and sex distributions of percutaneous and subcutaneous vaccinees were comparable, but there were marked differences in participants among the four study centers. Vaccines in Kentucky had a greater mean age; the greatest number of Negroid children were enrolled in St. Louis, and more of them were vaccinated by the subcutaneous route; and the dropout rate was much greater in San Diego and Colorado. An analysis of comparative interlaboratory serologic procedures with the use of 20 coded duplicate samples of serum revealed good agreement in the hemagglutination-inhibition test; results of neutralization tests had greater variability of mean titers. On duplicate samples of serum from study participants there was generally good correlation between each of the four study centers and the Center for Disease Control's reference laboratory in titers of hemagglutination-inhibiting antibody. In contrast, 38% of the neutralization titers determined at the four study centers were greater than or equal to 0.67 log10 higher than the respective titers noted at the Center for Disease Control.

[3] Biosecurity practices of beef cow-calf producers.

[DOC14517] OBJECTIVE: To evaluate biosecurity practices of cow-calf producers. DESIGN: Cross-sectional survey. SAMPLE POPULATION: 2,713 cow-calf operations were used in phase 1 of the study, and 1,190 cow-calf operations were used in phase 2. PROCEDURE: Producers were contacted for a personal interview between Dec 30, 1996 and Feb 3, 1997 regarding their management practices. Noninstitutional operations with 1 or more beef cows were eligible to participate in the study. Producers who participated in the first phase of the study and who had > or = 5 beef cows were requested to continue in the study and were contacted by a veterinarian or animal health technician who administered further questionnaires. All contacts for the second phase of the study were made between Mar 3, 1997 and Apr 30, 1997. Additional data on use of various vaccines, testing of imported cattle for brucellosis, Mycobacterium paratuberculosis, bovine viral diarrhea, and tuberculosis as well as potential for feed contamination were collected during the second phase of the study. RESULTS: Producers commonly engaged in management practices that increased risk of introducing disease to their cattle such as importing cattle, failing to quarantine imported cattle, and communal grazing. Producers inconsistently adjusted for the increased risk of their management practices by increasing the types of vaccines given, increasing the quarantine time or proportion of imported animals quarantined, or increasing testing for various diseases in imported animals. CONCLUSIONS AND CLINICAL RELEVANCE: Cow-calf herds are at risk for disease exposure from outside sources when cattle are introduced to the herd, and producers do not always adjust management practices such as vaccination schedules and quarantine procedures appropriately to minimize this risk. Veterinary involvement in education of producers regarding biosecurity risks and development of rational and economical biosecurity plans is needed.
Related to Topic 52: RESULTS,STUDY,METHODS,CONCLUSIONS,OBJECTIVE,CONCLUSION (0.443)

[1] Electronic prescribing: criteria for evaluating handheld prescribing systems and an evalua...

[DOC15485] OBJECTIVE: The objectives of this study were: 1) to establish criteria for evaluating handheld computerized prescribing systems; and 2) to evaluate out-of-box performance and features of a new, Palm Operating System (OS)-based, handheld, wireless wide area network (WWAN) prescribing system. The system consisted of a Palm Vx handheld organizer, a Novatel Minstrel V wireless modem, OmniSky wireless internet access and ePhysician ePad 1.1, the Palm OS electronic prescribing software program. DESIGN: A dermatologist familiar with healthcare information technology conducted an evaluation of the performance and features of a new, handheld, WWAN electronic prescribing system in an office practice during a three-month period in 2000. System performance, defined as transmission success rate, was determined from data collected during the three-month trial. Evaluation criteria consisted of an analysis of features found in electronic prescribing systems. METHODS: All prescriptions written for all patients seen during a three-month period (August - November, 2000) were eligible for inclusion. Prescriptions written for patients who intended to fill them at pharmacies without known facsimile receiving capabilities were excluded from the study. The performance of the system was evaluated using data collected during the study. Criteria for evaluating features of electronic prescribing systems were developed and used to analyze the system employed in this study. RESULTS: During this three-month trial, 200 electronic prescriptions were generated for 132 patients included in the study. Of these prescriptions, 92.5 percent were successfully transmitted to pharmacies. Transmission failures resulted from incorrect facsimile numbers and non-functioning facsimile machines. Criteria established for evaluation of electronic prescribing systems included System (Hardware & Software), Costs, System Features, Printing & Transmission, Formulary & Insurance, Customization, Drug Safety and Security. CONCLUSION: This study is the first effort to establish comprehensive criteria for evaluating handheld prescribing systems and to evaluate the performance and features of a handheld, electronic prescribing system. The results demonstrated that the evaluated system: 1) was simple to install; 2) successfully interfaced with a commonly used practice management system; 3) was user-friendly and easy to operate; 4) offered a robust variety of standard features; and, 5) resulted in a high rate of success for transmitting electronic prescriptions. The criteria established for the evaluation of features of an electronic prescribing system can be used to critically evaluate the performance and features of other handheld and personal computer-based electronic prescribing systems.

[2] Effect of coadministration of nelfinavir, indinavir, and saquinavir on the pharmacokinetic...

[DOC17776] OBJECTIVE: Pharmacokinetic interactions are expected when human immunodeficiency virus (HIV) protease inhibitors are coadministered because many are both substrates for and inhibitors of CYP3A4. The goal of this model-based pharmacokinetic analysis was to describe the differences observed in amprenavir pharmacokinetics among treatment arms in the Adult AIDS Clinical Trial Group (AACTG) study protocol 398 and to propose mechanisms to account for them. METHODS: One hundred seventy-six HIV-positive subjects receiving 1200 mg amprenavir twice daily as part of AACTG protocol 398 were included in the pharmacokinetic study. All patients also received background medications efavirenz, adefovir dipivoxil, and abacavir and, depending on the study arm, placebo or one of the following protease inhibitors: nelfinavir, indinavir, or saquinavir. A population pharmacokinetic model was fitted to a total of 565 amprenavir concentration measurements. The blood samples for concentration measurements were drawn at week 2 (12-hour pharmacokinetic study, approximately 7 samples per study; 46 patients) and at week 24 (6-hour pharmacokinetic study, approximately 5 samples per study; 10 patients). In addition, samples were collected at 1 or more follow-up visits (population pharmacokinetic study, 1 to 3 occasions per patient; 150 patients). Results and Conclusion: Amprenavir intrinsic clearance was significantly reduced relative to placebo by nelfinavir (-41%) and indinavir (-54%) but not by saquinavir. The absolute magnitude of amprenavir intrinsic clearance suggests that CYP3A4 inhibition by nelfinavir and indinavir is balanced by enzymatic induction in the presence of the background drug(s), most likely efavirenz. Amprenavir intrinsic clearance apparently increases by more than 30% between weeks 2 and 24, possibly because of the time course of CYP3A4 induction.

[3] The otologic consequences of the Omagh bomb disaster.

[DOC16820] OBJECTIVES: The goal of the study was to compare the spontaneous healing rate for traumatic perforation of the tympanic membrane sustained in the Omagh bomb disaster with that of previous reports in the literature. DESIGN AND SETTING: A retrospective study was conducted at Tyrone County Hospital, Northern Ireland, 2 years after the incident. PARTICIPANTS: One hundred thirty-eight patients who sustained otologic injuries from the bomb blast were included in the study. RESULTS: Only 47 of the 124 perforations healed spontaneously. The previously reported spontaneous healing rate for traumatic perforations of the tympanic membrane is 80% to 90%; in our study, the healing rate was unexpectedly low at 38%. CONCLUSION: The massive explosion in a narrow street with hundreds of persons in close proximity to the bomb may account for the poor healing rate.
Related to Topic 74: STUDIES,EVIDENCE,STUDY,PRESENT,FOUND,DATA (0.175)

[1] Genetic analysis of candidate loci in non-syndromic cleft lip families from Antioquia-Colo...

[DOC21826] Non-syndromic cleft lip with or without cleft palate (CL/P) is a genetically complex birth defect, with a prevalence from 1/500 to 1/1,000 live births. Evidence from linkage and linkage disequilibrium studies is contradictory suggesting that heterogeneity between study populations may exist. A recent report of a genome widescan in 92 sib pairs from the United Kingdom revealed suggestive linkage to 10 loci [Prescott et al., 2000]. The purpose of this study is to replicate those results and evaluate additional candidate genes in 49 Colombian and 13 Ohio families. Genotypes were obtained for STRPs at 1p36, 2p13 (TGFA), 4p16 (MSX1), 6p23-25, 6q25-27, 8q23-24, 11p12-q13, 12q13, 14q24 (TGFB3), 16q22-24, 17q12-21 (RARA), and Xcen-q21. Linkage was performed using parametric (dominant and recessive models) and non-parametric (GenehunterNPL and SimIBD) analyses. In addition, heterogeneity was analyzed using GenehunterHLOD, and association determined by the TDT. The Colombian families showed significant SimIBD results for 11p12-q13 (P = 0.034), 12q13 (P = 0.015), 16q22-24 (0.01), and 17q12-21 (0.009), while the Ohio families showed significant SimIBD results for 1p36 (P = 0.02), TGFA (P = 0.005), 6p23 (P = 0.004), 11p12-q13 (P = 0.048) and significant NPL results for TGFA (NPL = 3.01, P = 0.009), 4p16 (MNPL = 2.07, P = 0.03) and 12q13 (SNPL = 3.55, P = 0.007). Significant association results were obtained only for the Colombian families in the regions 1p36 (P = 0.046), 6p23-25 (P = 0.020), and 12q13 (P = 0.046). In addition several families yielded LOD scores ranging from 1.09 to 1.73, for loci at 4p16, 6p23-25, 16q22-24, and 17q13. These results confirm previous reports for these loci. However, the differences between the two populations suggest that population specific locus heterogeneity exists. This article contains supplementary material, which may be viewed at the American Journal of Medical Genetics website at http://www.interscience.wiley.com/jpages/0148-7299/suppmat/index.html.

[2] Reactive chemicals and cancer.

[DOC12119] Epidemiologic evidence on the relation between reactive chemicals and cancer is reviewed. These highly reactive chemicals (acrylonitrile; bis[chloromethyl]ether and chloromethyl methyl ether; 1,3-butadiene, ethylene oxide; formaldehyde; mustard gas; sulfuric acid; and vinyl chloride) vary in use and exposure. All are animal carcinogens that also have received considerable epidemiologic attention. Acrylonitrile is a chemical of current economic importance. The epidemiologic evidence is quite weak, but the available studies were very small. Epidemiologic studies clearly demonstrate that bis (chloromethyl) ether and chloromethyl methyl ether cause lung cancer. Continued follow-up of exposed workers is encouraged to provide information on risks for other cancers. Results from epidemiologic studies of butadiene-exposed workers are somewhat inconsistent, but the largest study with the best exposure assessment found the largest relative risk for leukemia. The failure of several larger studies to replicate the early Swedish findings of a very strong association between leukemia and ethylene oxide has not been adequately explained. Epidemiologic studies of formaldehyde provide limited evidence for an association with cancer of the nasopharynx and possibly with nasal cancer. These very rare tumors, however, are difficult to study epidemiologically. Mustard gas is a well-established lung carcinogen, but a recent follow-up of the English cohort suggests that other sites also may be affected. Sulfuric acid appears to cause laryngeal cancer. A suggested relationship with lung cancer in a few studies is of concern because of the widespread opportunity for exposure from ambient air pollution. Vinyl chloride causes angiosarcoma of the liver, but a large, multi-country study provided no clear evidence that other sites are affected.

[3] Exploring individual differences in reactions to mortality salience: does attachment style...

[DOC14622] Five studies examined the contribution of attachment style to mortality salience effects. In study 1, mortality salience led to more severe judgments of transgressions only among anxious-ambivalent and avoidant persons but not among secure persons. In addition, whereas anxious-ambivalent persons showed immediate and delayed increases in severity judgments, avoidant persons showed this response only after a delay period. In study 2, anxious-ambivalent persons showed immediate and delayed increases in death-thought accessibility after death reminders. Avoidant and secure persons showed this effect only after a delay period. study 3 revealed that worldview defense in response to mortality salience reduced death-thought accessibility only among avoidant persons. Studies 4-5 revealed that mortality salience led to an increase in the sense of symbolic immortality as well as in the desire of intimacy only among secure persons, but not among avoidant and anxious-ambivalent persons.
Related to Topic 59: RISK,STUDY,FACTORS,SUBJECTS,RATIO,CI (0.139)

[1] Use of US birth certificate data to estimate the risk of maternal cigarette smoking for or...

[DOC16850] OBJECTIVE: The purpose of this study was to evaluate the relationship between maternal cigarette smoking and the risk of having an offspring with an oral cleft. DESIGN: This was a large population-based, matched case-control study derived from the United States Natality database for 1997. SUBJECTS: The sample consisted of 2029 cases with non-syndromic oral clefts and 4050 non-malformed controls. Controls were matched to cases on mother's and father's race and child's sex, county of birth, and month of birth. This sample was selected from a total of 3,093,821 births in the United States, which represents 80% of all births in this country during 1997. RESULTS: The association between maternal cigarette smoking and oral clefts in the offspring was close to the null (odds ratio 1.16; 95% confidence interval (CI) 1.01 to 1.33; one-sided Fisher exact test p =.0207). The comparison and pooling of results to those of a similar study that used the U.S. Natality database for 1996 resulted in a common Mantel-Haenszel odds ratio of 1.33 (95% CI 1.21 to 1.46). The dose-response analysis was slightly significant for all levels of maternal smoking. CONCLUSION: This large study confirms that smoking during pregnancy is only a minor risk factor for oral clefting in the offspring.

[2] Renal cell carcinoma and occupational exposure to chemicals in Canada.

[DOC17344] This study assesses the effect of occupational exposure to specific chemicals on the risk of renal cell carcinoma in Canada. Mailed questionnaires were used to obtain data on 1279 (691 male and 588 female) newly diagnosed, histologically confirmed renal cell carcinoma cases and 5370 population controls in eight Canadian provinces, between 1994 and 1997. Data were collected on socio-economic status, smoking habit, alcohol use, diet, residential and occupational histories, and years of exposure to any of 17 chemicals. Odds ratios (ORs) and 95% confidence intervals (CIs) were derived using unconditional logistic regression. The study found an increased risk of renal cell carcinoma in males only, which was associated with occupational exposure to benzene; benzidine; coal tar, soot, pitch, creosote or asphalt; herbicides; mineral, cutting or lubricating oil; mustard gas; pesticides; and vinyl chloride. Compared with no exposure to the specific chemical, the adjusted ORs were 1.8 (95% CI = 1.2-2.6), 2.1 (1.3-3.6), 1.4 (1.1-1.8), 1.6 (1.3-2.0), 1.3 (1.1-1.7), 4.6 (1.7-12.5), 1.8 (1.4-2.3) and 2.0 (1.2-3.3), respectively; an elevated risk was also associated with exposure to cadmium salts and isopropyl oil. The risk of renal cell carcinoma increased with duration of exposure to benzene, benzidine, cadmium, herbicides and vinyl chloride. Very few females were exposed to specific chemicals in this study; further research is needed to clarify the association between occupational exposure to chemicals and renal cell carcinoma in females.

[3] Sampling in epidemiological research: a case study of the prevalence of brucellosis in Sau...

[DOC1879] The superficial description in biomedical journals of sampling methods used in epidemiological studies of the prevalence of some diseases can be attributed to shallow knowledge of basic sampling techniques. The population of interest in most community surveys is usually very large and resources and time available limited, so that researchers have little or no choice but to study a sample of the population. One of the basic principles of sampling is the avoidance of bias, guaranteed by taking a random sample. But the term 'random sample' has often been misinterpreted as synonymous with 'haphazard sample', taking a sample without a definite pattern. It is re-emphasised that a random sample is a probability sample that gives every unit in the population a known probability of being selected in the sample. The procedures for taking a random sample for a nationwide study in the Kingdom of Saudi Arabia are not easy because of the structure of the population, and therefore require more complex sampling methods like the stratified cluster sampling. It is also necessary in a stratified sample to calculate estimated persons affected by a condition for each selected subgroup of the population before obtaining the overall prevalence rate. A proper understanding and use of appropriate sampling techniques is most likely to result in the most desired representative sample, and guarantees that some underlying assumptions for inferential statistics will be satisfied.
Related to Topic 70: GROUP,GROUPS,CONTROL,COMPARED,SIGNIFICANT,SIGNIFICANTLY (0.106)

[1] Childhood factors in ulcerative colitis and Crohn's disease. An international cooperative ...

[DOC5904] This international case control study was conducted in 14 centers in 9 countries to investigate factors in childhood which may have a bearing on the etiology or pathogenesis of ulcerative colitis (UC) and Crohn's disease (CD). 197 patients with UC and 302 with CD (499 with inflammatory bowel disease (IBD] whose disease started before age 20 years and whose age at time of study was less than 25 years were investigated, with two age- and sex-matched controls for each patient. All subjects were studied with uniform questionnaires. Eczema was found significantly more frequently in patients with CD (p less than 0.005) and in their fathers (p less than 0.025), mothers (p less than 0.002), and siblings (p less than 0.01) as compared with their respective controls. IBD was significantly more frequent in parents, siblings, cousins, grandparents, and uncles of patients than in their respective controls. The fathers of patients with UC had significantly more major gastrointestinal and cardiovascular diseases at the time of the patient's birth than the fathers of controls. In North America mothers of patients with UC and CD took vitamin, mineral, and iron preparations during pregnancy significantly less frequently than mothers of controls. Patients with CD and UC consumed a lower residue diet than controls. Recurrent respiratory infections were more frequent in patients with UC and CD (p less than 0.001); it is uncertain whether this preceded disease. Hospitalization for respiratory diseases was more frequent in patients than controls, and the use of antibiotics more frequent in patients with CD. Smallpox vaccination was less frequent (p less than 0.05) in patients with CD, and chickenpox infection was less common in patients with UC (p less than 0.01). No significant differences were found between patients and controls in relation to various human and non-human contacts during childhood. Number of siblings, being an only child, and birth order did not differ markedly between patients and controls, and we could not confirm the 'sheltered child' hypothesis in IBD. The parents of controls were slightly better educated and their social class tended to be higher than those of parents of patients. There were significant associations between some of the main factors investigated in this study. No significant differences were found between patients and controls in the frequency of breast feeding, cereal consumption, sugar added to milk in infancy, gastroenteritis in childhood, major stressful life events, and many other factors.(ABSTRACT TRUNCATED AT 400 WORDS)

[2] Inhibition of carcinogenic and clastogenic effects of N-nitrosomorpholine in rats immunize...

[DOC17292] The aim of the present work was to study whether immunization of rats with tularemia live vaccine (TLV) can influence carcinogenic and mutagenic action of N-nitrosomorpholine (NNM). The experiments were performed with male albino random-bred rats. The first group of rats was immunized with TLV 15 days before the start of experiment. These animals and the second group (positive control) were treated with NNM orally, (total dose was about 250 mg/rat). Rats including solvent (negative) control group were killed 12 months after the start of NNM treatment to study the carcinogenic effect. Experiments to study the influence of TLV on mutagenesis were performed with three groups of rats: the first (on 15th day after immunization with TLV) and the second group were injected intraperitoneally with NNM 100 mg/kg b.w. on 2 consecutive days, third group received only distilled water. The results of long-term experiment have shown that tumor incidence (both malignant and benign) in rats of positive control group was 74.2%. Immunized rats had significantly decreased incidence of tumors compared with the previous group--36.1%. Micronuclei level in bone marrow cells of non-immunized rats was statistically significantly higher than that in immunized rats. The inhibition of carcinogenic and clastogenic effects of NNM in rats immunized with TLV are probably due to a decrease in cytochrome P-450 activity. We suggest that immunization of rats with TLV can protect them against the cacinogenic and clastogenic actions of some chemicals.

[3] [Effects of sodium ethamsylate on anticoagulant and anti-aggregation activity of vascular ...

[DOC13457] AIM: To elucidate effects of sodium ethamsylate (SE) on anticoagulant and antiaggregation activity of vascular endothelium in patients suffering from hemorrhagic fever with renal syndrome (HFRS). MATERIALS AND METHODS: A trial of SE enrolled 70 HFRS patients (58 males, 12 females aged under 30 years) compatible by the disease severity. They were divided into two groups. 42 patients of the control group received standard therapy, 28 patients of the study group received adjuvant 12% solution of SE in daily dose 1500-2000 mg in the course of HFRS oliguria period. Hemostatic parameters were measured before and after the cuff test to investigate the condition of vascular wall with calculation of the athrombogenicity index (the ratio of the relevant indices before and after the cuff test). SE effects on vascular endothelium was assessed by a blind method. RESULTS: In oliguria, both groups had baseline antiaggregation indices significantly higher than in the control. After the cuff test, control patients' indices tended to an increase while in the study group there was a marked decrease. The trend in anticoagulant activity of microvascular endothelium did not differ much with the groups. This picture persisted also in polyuria. In convalescence hemostasis was similar in both groups. CONCLUSION: SE enhances antiaggregant activity of vascular endothelium in oliguria period of HFRS without affecting its anticoagulant properties. This is explained by a direct effect of SE on vascular endothelium.
TREATMENT
Most likely documents

[1] Severe acute respiratory syndrome: radiographic evaluation and clinical outcome measures.

[DOC20966] PURPOSE: To evaluate the relationship among chest radiographs, oxygen supplementation requirement, and treatment response in severe acute respiratory syndrome (SARS). MATERIALS AND METHODS: Forty patients (20 women, 20 men; mean age, 42.90 years +/- 14.01 [SD]; median age, 41.5 years; age range, 25-82 years) with SARS were evaluated. Daily chest radiographs were graded according to percentage of lung involvement during 20.15 days +/- 5.56 (median, 20 days; range, 14-38 days). Times between symptoms and treatment and time to reach maximal radiographic score from admission and treatment day were determined. Daily oxygen saturation (Sao2) and oxygen supplementation including mechanically assisted ventilation were recorded. treatment response was defined as good, fair, and poor. Patterns of radiographic opacity at admission and at maximal radiographic score were noted. Differences in radiographic and clinical parameters with respect to oxygen supplementation and treatment response were respectively evaluated with Mann-Whitney and Kruskal-Wallis tests. RESULTS: Larger maximal radiographic scores, lower Sao2 at maximal radiographic change, longer time from treatment to maximal radiographic score (P <.01), and diffuse consolidation at maximal radiographic score were associated with oxygen supplementation. Parameters that influenced treatment response were time from symptom onset to treatment day (P =.003), time from admission to treatment day (P <.001), time to maximal radiographic score from treatment day (P =.001), maximal radiographic score (P =.009), Sao2 at maximal radiographic score (P =.13), and treatment radiographic score (P =.03). Fair responders had shorter time between admission and treatment than did either good (P <.001) or poor responders (P =.002) and shorter time between symptoms and treatment (P <.001) and lower treatment radiographic score (P =.012) than did good responders. Good (82%), poor (36%), and fair (33%) responders developed maximal chest radiographic scores within 4 days of treatment (P =.008). Radiographic patterns at both admission and maximal radiographic score did not influence treatment response. CONCLUSION: There are significant relationships among radiographic parameters, oxygen supplementation, and treatment response, and these relationships appear to be clinically useful in the treatment of SARS.

[2] Model-based evaluation of single-round mass treatment of sexually transmitted diseases for...

[DOC14234] OBJECTIVES: To compare the impact of single-round mass treatment of sexually transmitted diseases (STD), sustained syndromic treatment and their combination on the incidence of HIV in rural Africa. METHODS: We studied the effects of STD interventions by stochastic simulation using the model STDSIM. Parameters were fitted using data from a trial of improved STD treatment services in Mwanza, Tanzania. Effectiveness was assessed by comparing the prevalences of gonorrhoea, chlamydia, syphilis and chancroid, and the incidence of HIV, in the general adult population in simulations with and without intervention. RESULTS: Single-round mass treatment was projected to achieve an immediate, substantial reduction in STD prevalences, which would return to baseline levels over 5-10 years. The effect on syphilis was somewhat larger if participants cured of latent syphilis were not immediately susceptible to re-infection. At 80% coverage, the model projected a reduction in cumulative HIV incidence over 2 years of 36%. A similar impact was achieved if treatment of syphilis was excluded from the intervention or confined to those in the infectious stages. In comparison with sustained syndromic treatment, single-round mass treatment had a greater short-term impact on HIV (36 versus 30% over 2 years), but a smaller long-term impact (24 versus 62% over 10 years). Mass treatment combined with improved treatment services led to a rapid and sustained fall in HIV incidence (57% over 2 years; 70% over 10 years). CONCLUSIONS: In populations in which STD control can reduce HIV incidence, mass treatment may, in the short run, have an impact comparable to sustained syndromic treatment. Mass treatment combined with sustained syndromic treatment may be particularly effective.

[3] Highlights in the development of new antiviral agents.

[DOC18200] The potential of a large variety of new compounds and new strategies for the treatment of virtually all major virus infections has been addressed. This includes, for the treatment of HIV infections, virus adsorption inhibitors (cosalane derivatives, cyanovirin-N), co-receptor antagonists (TAK-779, AMD3100), viral fusion inhibitors (pentafuside T-20, betulinic acid derivatives), viral uncoating inhibitors (azodicarbonamide), nucleoside/nucleotide reverse transcriptase inhibitors (NRTIs: emtricitabine, amdoxovir, dOTC, d4TMP prodrugs, tenofovir disoproxil fumarate), non-nucleoside reverse transcriptase inhibitors (NNRTIs: thiocarboxanilide UC-781, capravirine, SJ-3366, DPC 083, TMC 125/R165335), integrase inhibitors (diketo acids), transcription inhibitors (temacrazine, flavopiridol), protease inhibitors (atazanavir, mozenavir, tipranavir); for the treatment of RSV and paramyxovirus infections, viral fusion inhibitors (R170591, VP-14637, NMS03); for the treatment of picornavirus infections, viral uncoating inhibitors (pleconaril); for the treatment of pesti- (hepaci-, flavi-) virus infections, RNA replicase inhibitors (VP-32947); for the treatment of herpesvirus (HSV, VZV, CMV) infections, DNA polymerase inhibitors (A-5021, L- and D-cyclohexenylguanine); for the treatment of VZV infections, bicyclic furopyrimidine analogues; for the treatment of CMV infections, fomivirsen; for the treatment of DNA virus infections at large (papilloma-, polyoma-, herpes-, adeno- and poxvirus infections), cidofovir; for the treatment of influenza, neuraminidase inhibitors (zanamivir, oseltamivir, RWJ-270201); for the treatment of HBV infections, adefovir dipivoxil; for the treatment of HBV and HCV infections, N-glycosylation inhibitors (N-nonyl-deoxynojirimycin); and, finally, IMP dehydrogenase inhibitors and S-adenosylhomocysteine hydrolase inhibitors, for the treatment of various virus infections, including hemorrhagic fever virus infections.
Related to Topic 33: TREATMENT,TREATED,EFFECTIVE,THERAPY,EFFECTS,DRUG (0.659)

[1] Pentoxifylline and severe acute respiratory syndrome (SARS): a drug to be considered.

[DOC19838] The recent outbreak of Severe Acute Respiratory Syndrome (SARS) as a new viral disease is causing a great concern for health authorities and general population. Very little is known about the infectious agent (a coronavirus) and its etiopathogeny, having no specific treatment yet. Proinflammatory cytokines released by stimulated macrophages in the alveoli could have a prominent role in pathogenesis of SARS. Current treatment of SARS with antiviral agents such as ribavirin and corticosteroids have not achieved very satisfactory results. Corticosteroids exert an antiinflammatory effect and are indicated for the treatment of respiratory distress, but, in the other hand, they exert an immunosuppressor effect on humoral and cellular arms of Immune System. Based on previous reports and on our own experience in HIV, we propose here pentoxifylline (PTX), a drug commonly used in vascular indications, as a possible treatment for SARS due to its interesting properties. PTX would feature a possible antiviral activity along with a well-known cytokine-modulating activity not as immunosuppressant as that of the corticoids, down-regulating proinflammatory cytokines but leaving functional the rest of the immune response. Other effects of PTX are discussed, as bronchodilation. CONCLUSIONS: The antiinflammatory, antiviral, immunomodulatory and bronchodilatory effects of PTX, along with its low cost and toxicity, make it a promising drug to be considered for SARS treatment, alone or as an adjuvant therapy in combination with other drugs. The classical antiviral approach as single treatment for viral diseases should be reviewed in this occasion; immunomodulatory therapies could play an important role in SARS therapy.

[2] The management of epilepsy in the 1990s. Acquisitions, uncertainties and priorities for fu...

[DOC8616] The pharmacological treatment of epilepsy has made considerable progress during the last decade, due to improved knowledge of the clinical pharmacology of individual drugs, acquisition of new information on the factors affecting response and need for drug treatment, and development of promising new agents. Once a clinical diagnosis of epilepsy has been made (which generally requires the occurrence of more than one seizure), treatment should be started with a single drug selected on the basis of seizure type and tolerability profile. Although there are important regional differences in prescribing patterns and individual circumstances may dictate alternative choices, carbamazepine is generally regarded as the preferred treatment for partial seizures (with or without secondary generalisation) while valproic acid (sodium valproate) is usually the first choice in most forms of generalised epilepsies. To achieve therapeutic success, the daily dosage must be tailored to meet individual needs, and there is suggestive evidence that in some patients the dosage prescribed initially may be unnecessarily large. Plasma antiepileptic drug concentrations may aid in the individualization of dosage, but should not be regarded as a substitute for careful monitoring of clinical response. Although overall about 70% of patients can be completely controlled, response rate is influenced by a number of factors, the most important of which are seizure type and syndromic form. The importance of a correct syndromic classification for rational drug selection has been poorly assessed and represents a major area for future research. Patients who do not respond to the highest tolerated dose of the initially prescribed drug may be switched to monotherapy with an alternative agent or may be given add-on treatment with a second drug. Appropriate prospective trials are required to assess the merits of either strategy. If add-on therapy is selected and the patient becomes seizure free, it may be possible to discontinue the drug prescribed initially and reinstitute monotherapy. Only a minority of patients are likely to require multiple drug therapy, and it remains to be established whether specific drug combinations are more effective than others. Until further information becomes available, the new agents should be reserved for patients failing to respond to the conventional treatments of first choice. Patients whose seizures cannot be controlled by available drugs should be reassessed, and polytherapy should be maintained only when there is clear evidence that benefits outweigh possible adverse effects. In many patients who have been seizure free for at least 2 years it may be possible to gradually discontinue all medications.(ABSTRACT TRUNCATED AT 400 WORDS)

[3] Dose-response effects of atropine and HI-6 treatment of organophosphorus poisoning in guin...

[DOC8402] HI-6 (1-2-hydroxyiminomethyl-1-pyridino-3-(4-carbamoyl-1-pyridino -2- oxapropane dichloride) has been evaluated as an oxime alternative to pralidoxime, and toxogonin in the treatment of organophosphorus (OP) poisoning. The dose response effects of atropine (ATR) and HI-6 were investigated to more fully explore the interaction of these compounds in the treatment of OP poisoning. ATR, HI-6 and various combinations of the two drugs were evaluated against lethal poisoning by soman (GD) and tabun (GA) in guinea pigs. The effect of adjunctive diazepam treatment on the efficacy of atropine and HI-6 against soman was also investigated. Animals of either sex were challenged s.c. with OP and treated i.m. 1 min later with ATR and/or HI-6. When used, diazepam was injected immediately after ATR+HI6. LD50s of each treatment were calculated from probit models based on 24-hour survival against 5 levels of nerve agent and 6 animals per challenge level. A protective index (PI) was calculated by dividing the nerve agent LD50 in the presence of treatment by the LD50 in the absence of treatment. treatment with HI6 alone had little effect on the toxicity of either OP. treatment with ATR alone was more effective than HI-6 alone and was significantly more effective against soman than against tabun. When used in combination atropine and HI-6 had a strong synergistic effect against both agents. The dose of atropine used with HI-6 was critical in determining the efficacy of HI-6 against either agent. The slopes of the dose-lethality curves were minimally affected by the dose of ATR or HI-6. Adjunctive treatment with diazepam enhanced the efficacy of HI-6 and atropine against soman. It is concluded that 1) ATR has a large effect on the efficacy of HI-6 against OP poisoning, 2) the dose of ATR must be carefully selected in studies investigating the efficacy of HI-6 against OP poisoning, 3) the effective dose of ATR in the guinea pig is approximately 16 mg/kg, and 4) diazepam is a useful adjunct to atropine and HI-6.
Related to Topic 86: TREATMENT,THERAPY,ANTIBIOTIC,ANTIBIOTICS,DOXYCYCLINE,TREATED (0.168)

[1] [Antibiotic treatment of brucellosis]

[DOC9297] Forty years after active drug therapy was defined, the treatment of brucellosis still raises the problem of selecting the correct antibiotic and the duration of treatment. Indeed, requirements may be complex since one must select antibiotics which are active in vitro and which diffuse readily into the tissues and into the cells without developing bacterial resistance. Prescriptions must also be long enough, not only to achieve cure, but also to eliminate the Brucella strain. Antibiotics must be found which meet this last criteria yet do not lead to toxic effects or impair the patient's own immune response. Acute septicemic brucellosis in adult men and non-pregnant women has been effectively treated with the following three regimens: 1) doxycycline 200 mg/d and rifampin 900 mg/d orally for 45 days; 2) doxycycline 200 mg/d orally for 45 days and streptomycin 1 g/d IM for three weeks; 3) TMP-SMZ 320-1600 mg/d and rifampin 900 mg/d orally for 45 days. All regimens require a combination of two antibiotics and a prolonged course for total recovery, although casual relapses may occur. The doxycycline-rifampin combination shows the most favorable efficacy/safety ratio, and either antibiotic alone was used successfully in pregnant women by some investigators. The TMP-SMZ-rifampin combination is recommended in children below 8 years of age. Osteoarticular infections can be treated with doxycycline plus rifampin for 3 to 6 months, and streptomycin during the first 2 or 3 weeks. In nervous system complications, the preferred treatment is TMP-SMZ plus rifampin for 3 to 6 months. Brucellar endocarditis should be treated parenterally with streptomycin or gentamycin combined with TMP-SMZ, rifampin and doxycycline, and often requires valvular replacement. Many other antibiotics have been used with good clinical responses in the treatment of brucellosis, e.g., chloramphenicol, erythromycin, ampicillin, and more recently cephalosporins, thienamycin and fluoroquinolones; however, more cases have to be studied before any of these agents is definitely chosen for the treatment of brucellosis.

[2] Amoxycillin-clavulanic acid treatment of melioidosis.

[DOC2550] Melioidosis is a serious infection with high acute mortality, and a high rate of relapse despite protracted antimicrobial treatment. The current recommended conventional oral treatment regimen is a 4-drug combination of high-dose chloramphenicol, doxycycline and trimethoprim-sulphamethoxazole given for between 6 weeks and 6 months. We have evaluated prospectively the use of amoxycillin-clavulanic acid, to which Pseudomonas pseudomallei is consistently sensitive in vitro, for the oral maintenance treatment of melioidosis. Amoxycillin-clavulanic acid was used either as sole treatment of localized disease, or as maintenance therapy following either parenteral ceftazidime or the conventional 4-drug regime; 20 patients with localized infections and 26 with septicaemic melioidosis received a median of 7.5 (2-12) weeks treatment. After a mean follow-up period of 6 months (range 1-19), 31 patients (67%) remain free of disease. The drug was well tolerated. Three patients had fatal relapses, one other died suddenly at home, and another died from underlying promyelocytic leukaemia. The remaining 10 relapses were treated successfully. Resistance developed in one case. Amoxycillin-clavulanic acid is a safe alternative to the conventional 4-drug antimicrobial combination for the oral treatment of melioidosis. It may be of particular value in children, pregnant women, and in infections with Ps. pseudomallei resistant to the potentially toxic conventional regimen, but the optimum dose and duration of therapy need to be established.

[3] Ofloxacin plus rifampicin versus doxycycline plus rifampicin in the treatment of brucellos...

[DOC23060] BACKGROUND: The combination therapies recommended by the World Health Organization for treatment of brucellosis are doxycycline plus rifampicin or doxycycline plus streptomycin. Although highly successful results have been obtained with these two regimens, relapse rates as high as 14.4%. The most effective and the least toxic chemotherapy for human brucellosis is still undetermined. The aim of the present study was to investigate the efficacy, adverse effects and cost of ofloxacin plus rifampicin therapy, and doxycycline plus rifampicin therapy and evaluate in the treatment of brucellosis. METHODS: The open trial has been carried out prospectively by the two medical centers from December 1999 to December 2001 in Duzce region Turkey. The diagnosis was based on the presence of signs and symptoms compatible with brucellosis including a positive agglutination titre (>/=1/160) and/or a positive culture. Doxycycline and rifampicin group consisted of 14 patients who were given doxycycline 200 mg/day plus rifampicin 600 mg/day during 45 days and this group Ofloxacin plus rifampicin group was consisted of 15 patients who were given ofloxacin 400 mg/day plus rifampicin 600 mg/day during 30 days. RESULTS: Regarding clinical and/or demographic characteristics no significant difference was found between two groups of patients that underwent two different therapeutic regimens. At the end of the therapy, two relapses were seen in both groups (p = 0.695). Although duration of therapy was two weeks shorter in group treated with rifampicin plus ofloxacin, the cure rate was similar in both groups of examinees. Fever dropped more rapidly in the group that treated with rifampicin plus ofloxacin, 74 +/- 30 (ranges 48-216) vs. 106 +/- 26 (ranges 48-262) hours (p = 0.016). CONCLUSIONS: Ofloxacin plus rifampicin therapy has advantages of shorter treatment duration and provided shorter course of fever with treatment than in doxycycline plus rifampicin therapy. However, cost of ofloxacin plus rifampicin treatment is higher than doxycycline plus rifampicin treatment. Because of the similar effects, adverse effects and relapses rates between two regimens, we still advice doxycycline plus rifampicin for the treatment of brucellosis for countries, which have limited resources.
Related to Topic 68: MANAGEMENT,TREATMENT,WOMEN,HIV,STD,SYNDROMIC (0.098)

[1] Population-based interventions for reducing sexually transmitted infections, including HIV...

[DOC15634] BACKGROUND: Sexually transmitted infections (STI) are common in developing countries. The World Health Organisation (WHO) estimates that in 1995, 333 million new cases of syphilis, gonorrhoea, chlamydial infection and trichomoniasis occurred. Human immunodeficiency virus (HIV) infection is also common in developing countries. UNAIDS estimates that over 90% of the 33 million people infected with HIV by December 1999 live in developing countries (UNAIDS 1999). The STI and HIV epidemics are interdependent. Similar behaviours, such as frequent unprotected intercourse with different partners, place people at high risk of both infections, and there is clear evidence that conventional STIs increase the likelihood of HIV transmission. Several studies have demonstrated a strong association between both ulcerative and non-ulcerative STIs, and HIV infection (Cameron 1989, Laga 1993) and there is biological evidence that the presence of an STI increases shedding of HIV and that STI treatment reduces HIV shedding (Cohen 1997, Robinson 1997). Therefore, STI control may have the potential to contribute substantially to HIV prevention. OBJECTIVES: To determine the impact of population-based STI interventions on the frequency of HIV infection, frequency of STIs and quality of STI management. SEARCH STRATEGY: The following electronic databases were searched for relevant randomised trials or reviews: 1) MEDLINE for the years 1966 to current using the search terms sexually transmitted diseases and human immunodeficiency virus infection 2) The Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effectiveness and the Cochrane Clinical Trials Register in the most recent issue of the Cochrane Library 3) The specialist register of trials maintained by the Cochrane Infectious Diseases Group. 4) EMBASE The abstracts of relevant conferences were searched and reference lists of all review articles and primary studies were scanned. Finally, authors of included trials and other experts in the field were contacted as appropriate. SELECTION CRITERIA: Randomised controlled trials in which the unit of randomisation is either a community or a treatment facility. Studies where individuals are randomised were excluded. DATA COLLECTION AND ANALYSIS: Two reviewers independently applied the inclusion criteria to potential studies with any disagreements resolved by discussion. Trials were examined for completeness of reporting. The methodological quality of each trial was assessed by the same two reviewers with details recorded of randomisation method, blinding, use of intention-to-treat analysis and the number of patients lost to follow-up using standard guidelines of the Cochrane Infectious Diseases Group. MAIN RESULTS: Four trials were included. Frequency of HIV infection: In Rakai, after 3 rounds of treatment of all community members for STIs the rate ratio of incident HIV infection was 0.97 (95%CI 0.81 to 1.16), indicating no effect of the intervention. In Mwanza, the incidence of HIV infection in the intervention groups (strengthened syndromic management of STIs in primary care clinics) was 1.2% compared with 1.9% in the control groups (OR=0.58, 95% CI 0.42-0.70), corresponding to a 38% reduction (95%CI 15% to 55%) in HIV incidence in the intervention group. Frequency of STIs: In both Mwanza and Rakai, there was no significant reduction in gonorrhoea, chlamydia, urethritis, or reported STI symptoms among intervention communities. The prevalence ratio of syphilis between intervention and control groups in Rakai was 0.8 (95%CI 0.71-0.89), of trichmoniasis was 0.59 (0.38-0.91), and of bacterial vaginosis was 0.87 (0.74-1.02). In Mwanza, the prevalence of serologically diagnosed syphilis in the intervention community was 5% compared with 7% in the control community at the end of the trial (adjusted relative risk 0.71 (95%CI 0.54-0.93). Quality of treatment: In Lima, following training of pharmacy assistants in STI syndromic management, symptoms were recognised as being due to an STI in 65% of standardised simulated patients (SSPs) visiting intervention and 60% of SSPs visiting control pharmacies (p=0.35). Medication was offered without referral to a doctor in most cases (83% intervention and 78% control, p=0.61). Of those SSPs offered medication, only 1.4% that visited intervention pharmacies and only 0.7% of those that visited control pharmacies (p=0.57) were offered a recommended regimen. Similarly in only 15% and 16% of SSP visits respectively was any recommended drug offered. However, education and counseling were more likely to be given to SSPs visiting intervention pharmacies (40% vs 27%, p=0.01). No SSPs were given partner cards or condoms. In Hlabisa, following the intervention targeting primary care clinic nurses (strengthened STI syndromic management and provision of STI syndrome packets containing recommended drugs, condom, partner cards and patient information leaflets), SSPs were more likely to be given recommended drugs in intervention clinics (83% vs 12%, p <0.005) and more likely to be correctly case managed [given correct drugs, partner cards and condoms] (88% vs 50%, p <0.005). There were no significant difference in the proportions adequately counseled (68% vs 46%, p=0.06), experiencing good staff attitude (84% vs 58%, p=0.07), and being consulted in privacy (92% vs 86%, p=0.4). There was no strong evidence of any impact on treatment seeking behaviour, utilisation of services, or sexual behaviour in any of the four trials. REVIEWERS' CONCLUSIONS: There is limited evidence from randomised controlled trials for STI control as an effective HIV prevention strategy. Improved STI treatment services have been shown to reduce HIV incidence in an environment characterised by an emerging HIV epidemic (low and slowly rising prevalence), where STI treatment services are poor and where STIs are highly prevalent. There is no evidence for substantial benefit from treatment of all community members. There are however other compelling reasons why STI treatment services should be strengthened and the available evidence suggests that when an intervention is accepted it can substantially improve quality of services provided. Further community based randomised controlled trials that test a range of alternative STI control strategies are needed in a variety of different settings. Such trials should aim to measure a range of factors that include health seeking behaviour and quality of treatment as well as HIV, STI and other biological endpoints.

[2] Population-based interventions for reducing sexually transmitted infections, including HIV...

[DOC22474] BACKGROUND: Sexually transmitted infections (STI) are common in developing countries. The World Health Organisation (WHO) estimates that in 1999, 340 million new cases of syphilis, gonorrhoea, chlamydial infection and trichomoniasis occurred. Human immunodeficiency virus (HIV) infection is also common in developing countries. UNAIDS estimates that over 95% of the 40 million people infected with HIV by December 1999 live in developing countries (UNAIDS 2003). The STI and HIV epidemics are interdependent. Similar behaviours, such as frequent unprotected intercourse with different partners, place people at high risk of both infections, and there is clear evidence that conventional STIs increase the likelihood of HIV transmission. Several studies have demonstrated a strong association between both ulcerative and non-ulcerative STIs and HIV infection (Cameron 1989, Laga 1993). There is biological evidence, too, that the presence of an STI increases shedding of HIV, and that STI treatment reduces HIV shedding (Cohen 1997, Robinson 1997). Therefore, STI control may have the potential to contribute substantially to HIV prevention. OBJECTIVES: To determine the impact of population-based STI interventions on the frequency of HIV infection, frequency of STIs and quality of STI management. SEARCH STRATEGY: The following electronic databases were searched for relevant randomised trials or reviews:1) MEDLINE for the years 1966 to 2003 using the search terms "sexually transmitted diseases" and "human immunodeficiency virus infection"2) The Cochrane Database of Systematic Reviews, Database of Abstracts of Reviews of Effectiveness and the Cochrane Clinical Trials Register, in the most recent issue of the Cochrane Library3) The specialist registry of trials maintained by the Cochrane Infectious Diseases Group.4) EMBASE The abstracts of relevant conferences were searched, and reference lists of all review articles and primary studies were scanned. Finally, authors of included trials and other experts in the field were contacted as appropriate. SELECTION CRITERIA: Randomised controlled trials in which the unit of randomisation is either a community or a treatment facility. Studies where individuals are randomised were excluded. DATA COLLECTION AND ANALYSIS: Two reviewers independently applied the inclusion criteria to potential studies, with any disagreements resolved by discussion. Trials were examined for completeness of reporting. The methodological quality of each trial was assessed by the same two reviewers, with details recorded of randomisation method, blinding, use of intention-to-treat analysis and the number of patients lost to follow-up, using standard guidelines of the Cochrane Infectious Diseases Group. MAIN RESULTS: Five trials were included.Frequency of HIV infection: In Rakai, after 3 rounds of treatment of all community members for STIs, the rate ratio of incident HIV infection was 0.97 (95%CI 0.81 to 1.16), indicating no effect of the intervention. In Mwanza, the incidence of HIV infection in the intervention groups (strengthened syndromic management of STIs in primary care clinics) was 1.2% compared with 1.9% in the control groups (OR=0.58, 95% CI 0.42-0.70), corresponding to a 38% reduction (95%CI 15% to 55%) in HIV incidence in the intervention group. In the newest trial by Kamali et al, the rate ratio of behavioral intervention & STI management compared to control on HIV incidence was 1.00 (0.63-1.58, p=.98). These are consistent with Rakai data showing no effect of intervention.Frequency of STIs: In both Mwanza and Rakai, there was no significant reduction in gonorrhoea, chlamydia, urethritis, or reported STI symptoms among intervention communities. The prevalence ratio of syphilis between intervention and control groups in Rakai was 0.8 (95%CI 0.71-0.89), of trichmoniasis was 0.59 (0.38-0.91), and of bacterial vaginosis was 0.87 (0.74-1.02). In Mwanza, the prevalence of serologically diagnosed syphilis in the intervention community was 5% compared with 7% in the control community at the end of the trial (adjusted re7% in the control community at the end of the trial (adjusted relative risk 0.71 (95%CI 0.54-0.93). In Kamali et al, there was a significant decrease in gonorrhoea and active syphilis cases. Rate ratio for gonorrhoea was 0.29(0.12-0.71, p=0.016), active syphilis was 0.53(0.33-0.84,p=0.016). There was a trend towards significance with intervention on the use of condoms with the last casual partner; the rate ratio was 1.27(1.02-1.56,p=0.036).Quality of treatment: In Lima, following training of pharmacy assistants in STI syndromic management, symptoms were recognised as being due to an STI in 65% of standardised simulated patients (SSPs) visiting intervention and 60% of SSPs visiting control pharmacies (p=0.35). Medication was offered without referral to a doctor in most cases (83% intervention and 78% control, p=0.61). Of those SSPs offered medication, only 1.4% that visited intervention pharmacies and only 0.7% of those that visited control pharmacies (p=0.57) were offered a recommended regimen. Similarly in only 15% and 16% of SSP visits respectively was any recommended drug offered. However, education and counseling were more likely to be given to SSPs visiting intervention pharmacies (40% vs 27%, p=0.01). No SSPs were given partner cards or condoms. In Hlabisa, following the intervention targeting primary care clinic nurses (strengthened STI syndromic management and provision of STI syndrome packets containing recommended drugs, condom, partner cards and patient information leaflets), SSPs were more likely to be given recommended drugs in intervention clinics (83% vs 12%, p<0.005) and more likely to be correctly case managed [given correct drugs, partner cards and condoms] (88% vs 50%, p<0.005). There were no significant differences in the proportions adequately counseled (68% vs 46%, p=0.06), experiencing good staff attitude (84% vs 58%, p=0.07), and being consulted in privacy (92% vs 86%, p=0.4). There was no strong evidence of any impact on treatment-seeking behaviour, utilisation of services, or sexual behaviour in any of the four trials. REVIEWERS' CONCLUSIONS: There is limited evidence from randomised controlled trials for STI control as an effective HIV prevention strategy. Improved STI treatment services have been shown to reduce HIV incidence in an environment characterised by an emerging HIV epidemic (low and slowly rising prevalence), where STI treatment services are poor and where STIs are highly prevalent. There is no evidence for substantial benefit from treatment of all community members. The addition of the Kamali trial to the existing evidence supports the data from the Rakai trial of no effect. There are, however, other compelling reasons why STI treatment services should be strengthened, and the available evidence suggests that when an intervention is accepted it can substantially improve quality of services provided. The Kamali trial shows an increase in the use of condoms, a marker for improved risk behaviors. Further community-based randomised controlled trials that test a range of alternative STI control strategies are needed in a variety of different settings. Such trials should aim to measure a range of factors that include health seeking behaviour and quality of treatment, as well as HIV, STI and other biological endpoints.

[3] Risk assessment, symptoms, and signs as predictors of vulvovaginal and cervical infections...

[DOC13000] OBJECTIVE: To identify clinical epidemiological correlates of cervical and vaginal infections and assess alternative algorithms, including two new reproductive tract infection (RTI) algorithms, for syndromic management of these infections. DESIGN, SETTING AND SUBJECTS: We prospectively studied clinical manifestations and risk correlates of cervical and vaginal infections in a randomly sampled group of 779 female patients seeking evaluation for a new problem at a Seattle STD clinic. METHODS: One experienced clinician performed standardised history, physical examination, and microscopy. Reference laboratories performed microbiological tests. Three levels of retrospective evaluation of algorithms included risk assessment and symptom review (RAS) alone; addition of speculum and bimanual examinations; and further addition of microscopy. RESULTS: (1) Chief complaint of abnormal vaginal discharge predicted a significantly lower rate of gonorrhoea (GC) or chlamydial infection (CT) than rates observed with no complaint of vaginal discharge. Only the elicited symptom of yellow vaginal discharge (not the more common symptoms of increased or malodorous vaginal discharge) predicted GC or CT. Chief complaint of abnormal vaginal discharge itself predicted trichomoniasis (TV) and bacterial vaginosis (BV), not cervical infection. Candida albicans was strongly associated with the chief complaint of vulvar pruritus, not with the chief complaint of abnormal vaginal discharge. (2) Applying these algorithms in STD clinics only to women with the chief complaint of abnormal vaginal discharge, rather than to all women, decreases sensitivity for GC or CT, without increasing positive predictive value (PPV). Criteria for inclusion of patients have more effect on the performance of these algorithms than do the levels of evaluation used. (3) A modified World Health Organisation (WHO) algorithm applied only to patients with symptoms of vaginal discharge, involving treatment of RAS positives for cervical infection, followed by treatment of vaginal infections and cervicitis based on examination of RAS negatives and positives, had a sensitivity of 50% and PPV of 33% for cervical infection, and very low sensitivity for BV, TV, and for vulvovaginal candidiasis (VVC). (4) An RTI algorithm derived from these data, and applied to all STD patients, involving RAS and examination of all RAS negatives, provided treatment to all cases of BV and TV associated with symptoms of vaginal discharge; treatment of all VVC associated with symptoms of vulvar pruritus; treatment for GC and GT to all RAS positives (using easily elicited risk factors) and to RAS negatives with signs of cervicitis or PID. This algorithm had a sensitivity of 87% and a PPV of 33% for GC or CT in this population, with its 24% prevalence of GC or CT. The sensitivity for BV, TV, and VVC greatly exceeded that of the modified WHO algorithm. (5) A modified RTI algorithm, involving examination rather than treatment of RAS positive women, no examination of RAS negatives, decreased the sensitivity for cervical infection to 55% but increased the PPV to 51%. CONCLUSIONS: Syndromic management of vaginal discharge offers relief of symptoms, prevention of transmission of trichomonas, and perhaps prevention of complications of BV. The 51% PPV of the modified RTI algorithm probably would warrant treatment and partner notification for GC and CT in settings with similar rates of GC and CT where more specific tests are lacking. However, as the prevalence of GC or CT decreases, the ratio of uninfected to infected who receive treatment with these algorithms would increase greatly, making the algorithms potential victims of their own success.
VIRUS
Most likely documents

[1] Dengue virus-specific, human CD4+ CD8- cytotoxic T-cell clones: multiple patterns of virus...

[DOC2403] Thirteen dengue virus-specific, cytotoxic CD4+ CD8- T-cell clones were established from a donor who was infected with dengue virus type 3. These clones were examined for virus specificity and human leukocyte antigen (HLA) restriction in cytotoxic assays. Six patterns of virus specificities were determined. Two serotype-specific clones recognized only dengue virus type 3. Two dengue virus subcomplex-specific clones recognized dengue virus types 2, 3, and 4, and one subcomplex-specific clone recognized dengue virus types 1, 2, and 3. Four dengue virus serotype-cross-reactive clones recognized dengue virus types 1, 2, 3, and 4. One flavivirus-cross-reactive clone recognized dengue virus types 1, 2, 3, and 4 and West Nile virus (WNV), but did not recognize yellow fever virus (YFV), whereas three flavivirus-cross-reactive clones recognized dengue virus types 1, 2, 3, and 4, WNV, and YFV. HLA restriction in the lysis by these T-cell clones was also heterogeneous. HLA-DP, HLA-DQ, and HLA-DR were used as restriction elements by various T-cell clones. We also examined the recognition of viral nonstructural protein NS3, purified from cells infected with dengue virus type 3 or WNV, by these T-cell clones. One serotype-specific clone, two dengue virus subcomplex-specific clones, and three dengue virus serotype-cross-reactive clones recognized NS3 of dengue virus type 3. One flavivirus-cross-reactive clone recognized NS3 of dengue virus type 3 and WNV. These results indicate that heterogeneous dengue virus-specific CD4+ cytotoxic T cells are stimulated in response to infection with a dengue virus and that a nonstructural protein, NS3, contains multiple dominant T-cell epitopes.

[2] Mosquito-borne viruses in western Europe: a review.

[DOC13500] Several mosquito-borne arboviruses belonging to the genera Alphavirus, Flavivirus, and Bunyavirus have been reported to occur in mosquitoes and to infect humans and other vertebrates in western Europe. These zoonotic viruses circulate in nature either in an Aedes-mammal, Anopheles-mammal, or Culex-bird transmission cycle. Infected humans normally do not contribute to the virus circulation. West Nile virus (Flavivirus) caused an outbreak of fever, malaise, pain in eyes and muscles, and headache and encephalitis in southern France during 1962-1965, and an outbreak of encephalitis with a high case-fatality rate in Romania during 1996. West Nile virus has been isolated from birds, horses, and mosquitoes in Portugal, France, the former Czechoslovakia, and Romania. These data, together with reports of antibodies to West Nile virus in birds, domestic mammals, and humans in several other countries, show virus activity in southern and central Europe. Sindbis virus (Alphavirus) caused outbreaks of fever, rash, and arthralgia in northern Europe during 1981-1982, 1988, and 1995. Two California group viruses (Bunyavirus), Tahyna virus and Inkoo virus, have been identified in western Europe. Tahyna virus causes fever and respiratory symptoms and sometimes also central nervous system involvement. It occurs in most countries of central and southern Europe, and is most common in central Europe. Inkoo virus has not been associated with disease in humans in western Europe although Russian studies indicated that it can cause encephalitis. Inkoo virus occurs in northern Europe, especially in the far north. Batai virus of the Bunyamwera-group (Bunyavirus) occurs in southern, central, and northern Europe, most frequently in central Europe. The antibody prevalence in humans generally is very low, indicating that the potential of this virus as a human pathogen is probably low in Europe. The Lednice virus (Bunyavirus) has been reported only from the former Czechoslovakia and Romania, and apparently is not transmitted to humans. In addition to the six mosquito-borne viruses documented in western Europe, there is serological evidence of infection with a Semliki Forest complex virus (Alphavirus) in central and southern Europe. Although mosquito-borne viruses presently are not considered to be the cause of major health problems in western Europe, the morbidity caused by Sindbis virus, and the morbidity and mortality caused by West Nile virus, merit further studies on the ecology, epidemiology, and medical importance of these viruses. The California group of viruses and a virus of the Semliki Forest complex may be the cause of unrecognized health problems in western Europe. Specific sampling of potential vectors for virus isolation, detailed characterization of virus strains, and the use of fully characterized strains for serological diagnosis will help to elucidate the present and future potential of mosquito-borne viruses as human pathogens in Europe.

[3] Use of immunoglobulin m cross-reactions in differential diagnosis of human flaviviral ence...

[DOC17139] To define the virus specificity of the immunoglobulin M (IgM) antibody-capture enzyme-linked immunosorbent assay (MAC-ELISA) among the medically important members of the Japanese encephalitis (JE) virus serocomplex of flaviviruses, 103 IgM-positive human serum samples from patients with confirmed West Nile (WN) virus, St. Louis encephalitis (SLE) virus, or JE virus infections were assembled and simultaneously tested against all three viral antigens in a standardized MAC-ELISA. Of the serum samples tested, 96 (93%) showed higher positive-to-negative absorbance ratios (P/Ns) with the infecting virus antigen compared to those obtained with the other two virus antigens. Of the seven specimens with higher P/Ns with heterologous virus antigens, six were from patients with SLE virus infections (the serum samples had higher levels of reactivity with WN virus antigen) and one was from a patient with a JE virus infection (this serum sample also had a higher level of reactivity with WN virus antigen). Not surprisingly, similar virus specificity was observed with WN virus-elicited IgM in cerebrospinal fluid. As shown in previous studies, a subset of these specimens was even less reactive in the MAC-ELISA with dengue virus, a member of a different flavivirus serocomplex. The degree of virus cross-reactivity did not appear to be related to days postonset, at least during the first 40 days of infection. Infections with WN virus could be correctly distinguished from infections with SLE virus on the basis of the observed anti-viral IgM cross-reactivities alone 92% of the time. Infections with SLE virus resulted in antibody that was more cross-reactive, so identification of SLE virus as the infecting agent by use of MAC-ELISA cross-reactivity alone was more problematic.
Related to Topic 42: VIRUS,VIRAL,RNA,INFECTED,INFECTION,REPLICATION (0.392)

[1] Influence of the infection with lipid-containing viruses on the metabolism and pools of ph...

[DOC797] The influence of infection with three different lipid-containing RNA viruses, Newcastle disease virus, fowl plague virus, and Semliki Forest virus on the phosphatidylcholine precursors of chick embryo cells and of baby hamster kidney (BHK) cells has been measured. In chick embryo cells infection with Newcastle disease virus does not influence the energy charge, or the distribution and absolute pool sizes of the precursors or the choline phosphotransferase activity. In chick embryo cells infected with fowl plague virus the CDP-choline pool increases because of an inhibition of the choline phosphotransferase activity. The phosphorylcholine and CTP pools are smaller in infected cells when compared with mock-infected ones, although the energy charge is not influenced by infection. In chick embryo cells as well as in BHK cells the energy charge is diminished by infection with Semliki Forest virus. Therefore the CTP and phosphorylcholine pools are decreased. The CDP-choline pool in chick embryo cells becomes extremely small after infection with Semliki Forest virus because of a significant stimulation of the choline phosphotransferase. In BHK cells infected with Semliki Forest virus the opposite effect is observed. There are also severe effects on the uptake of the labeled precursors by infection. One and the same virus (Semliki Forest virus) has two completely different effects on the phosphatidylcholine precursors when infecting two different cell types. If one and the same cell type (chick embryo cells) is infected with three different lipid-containing RNA viruses also completely different effects on the phosphatidylcholine precursors were observed. Thus, each virus develops its own strategy to influence the lipid metabolism of the host cell, depending also on the choice of the host. This explains the many disturbing contradictory results described in the literature about the influence of lipid-containing viruses on the lipid metabolism of the host.

[2] Inhibition of cellular protein synthesis by simultaneous pretreatment of host cells with f...

[DOC299] A method is described for analysis of viral protein synthesis early after infection when minute amounts of viral proteins are effectively concealed by large amounts of produced host-specific proteins. The method is superior to a radioimmune assay, since all virus-induced proteins can be measured independent of their immunological reactivity. Host-specific protein synthesis can be suppressed by infection with fowl plague virus. Addition of actinomycin C 1.25 h postinfection does not prevent this suppression, but it does block effectively the formation of fowl plague virus-specific proteins. Such cells synthesize only small amounts of cellular proteins, as revealed by polyacrylamide electrophoresis. They can be superinfected with several different enveloped viruses, however, without significant diminution of virus yeilds. In pretreated cells the eclipse is shortened for Semliki Forest virus, Sindbis virus, and vesicular stomatitis virus, but prolonged for Newcastle disease virus. The onset of protein synthesis, specific for the superinfecting virus, could be clearly demonstrated within 1 h after superinfection. At this time, in cells superinfected with Semliki Forest virus, great amounts of NSP 75 (nonstructural protein; molecular weight, 75 X 10(3)) and reduced amounts of the core protein C could be deomonstrated. The precursor glycoprotein NSP 68 is followed by a new polypeptide, NSP 65: three proteins with molecular weights exceeding 100 X 10(3) were observed which are missing later in the infectious cycle. Similar results were obtained after superinfection with Sindbis virus. The formation of a new polypeptide with a molecular weight of about 80 X 10(3) was detected. After superinfection with vesicular stomatis virus or Newcastle disease virus the formation of new proteins, characteristic for the early stage of infeciton, was not observed.

[3] 2001 ASPET Otto Krayer Award Lecture. Molecular targets for antiviral agents.

[DOC15278] There are a number of virus-specific processes within the virus replicative cycle or virus-infected cell that have proven to be attractive targets for chemotherapeutic intervention, i.e., virus adsorption and entry into the cells, reverse (RNA --> DNA) transcription, viral DNA polymerization, and cellular enzymatic reactions that are associated with viral DNA and RNA synthesis and viral mRNA maturation (i.e., methylation). A variety of chemotherapeutic agents, both nucleoside (and nucleotide) and non-nucleoside entities, have been identified that specifically interact with these viral targets, that selectively inhibit virus replication, and that are either used or considered for clinical use in the treatment of virus infections in humans. Their indications encompass virtually all major human viral pathogens, including human immunodeficiency virus (HIV), hepatitis B virus (HBV), herpes simplex virus (HSV), varicella-zoster virus (VZV), cytomegalovirus (CMV), human papilloma virus (HPV), orthomyxoviruses (influenza A and B), paramyxoviruses [e.g., respiratory syncytial virus (RSV)] and hemorrhagic fever viruses (such as Ebola virus).
Related to Topic 16: VIRUS,WEST,NILE,WNV,ENCEPHALITIS,WN (0.191)

[1] Growth characteristics of the veterinary vaccine candidate ChimeriVax-West Nile (WN) virus...

[DOC20379] In 1999 West Nile (WN) virus was introduced to North America where this flavivirus has spread rapidly among wildlife (especially birds) transmitted by various species of mosquitoes (Diptera: Culicidae). Increasing numbers of cases and deaths among humans, horses and other domestic animals require development of effective vaccines. 'ChimeriVax-West Nile(vet)' is being developed for use as a veterinary vaccine to protect against WN infection. This chimeric virus contains the pre-membrane (prM) and envelope (E) genes from the wild-type WN NY99 virus (isolated from a flamingo in New York zoo during the 1999 WN epidemic) in the backbone of yellow fever (YF) 17D vaccine virus. Replication kinetics of ChimeriVax-WN(vet) virus were evaluated in mosquito cell culture (Aedes albopictus C6/36), in WN vector mosquitoes [Culex tritaeniorhynchus Giles, Cx. nigripalpus Theobald and Cx. quinquefasciatus Say (Diptera: Culicidae)] and in YF vectors [Aedes aegypti (L) and Ae. albopictus (Skuse)], to determine whether these mosquitoes become infected through feeding on a viraemic vaccine, and their potential infectivity to transmit the virus. Growth of ChimeriVax-WN(vet) virus was found to be restricted in mosquitoes, compared to WN virus in Ae. albopictus C6/36 cells. When inoculated intrathoracically, ChimeriVax-WN(vet) and YF 17D viruses did not replicate in Cx. tritaeniorhynchus or Cx. nigripalpus; replication was very restricted compared to the wild-type WN virus in Cx. quinquefasciatus, Ae. aegypti and Ae. albopictus. When fed on hanging drops with ChimeriVax-WN(vet) virus (7.7 log10 PFU/mL), none of the Culex mosquitoes became infected; one Ae. albopictus and 10% of the Ae. aegypti became infected, but the titre was very low and virus did not disseminate to head tissue. ChimeriVax-WN(vet) virus had a replication profile similar to that of the attenuated vaccine virus YF 17D, which is not transmitted by mosquitoes. These results suggest that the natural mosquito vectors of WN and YF viruses, which may incidentally take a bloodmeal from a vaccinated host, will not become infected with ChimeriVax-WN(vet) virus.

[2] Mosquito-borne viruses in western Europe: a review.

[DOC13500] Several mosquito-borne arboviruses belonging to the genera Alphavirus, Flavivirus, and Bunyavirus have been reported to occur in mosquitoes and to infect humans and other vertebrates in western Europe. These zoonotic viruses circulate in nature either in an Aedes-mammal, Anopheles-mammal, or Culex-bird transmission cycle. Infected humans normally do not contribute to the virus circulation. West Nile virus (Flavivirus) caused an outbreak of fever, malaise, pain in eyes and muscles, and headache and encephalitis in southern France during 1962-1965, and an outbreak of encephalitis with a high case-fatality rate in Romania during 1996. West Nile virus has been isolated from birds, horses, and mosquitoes in Portugal, France, the former Czechoslovakia, and Romania. These data, together with reports of antibodies to West Nile virus in birds, domestic mammals, and humans in several other countries, show virus activity in southern and central Europe. Sindbis virus (Alphavirus) caused outbreaks of fever, rash, and arthralgia in northern Europe during 1981-1982, 1988, and 1995. Two California group viruses (Bunyavirus), Tahyna virus and Inkoo virus, have been identified in western Europe. Tahyna virus causes fever and respiratory symptoms and sometimes also central nervous system involvement. It occurs in most countries of central and southern Europe, and is most common in central Europe. Inkoo virus has not been associated with disease in humans in western Europe although Russian studies indicated that it can cause encephalitis. Inkoo virus occurs in northern Europe, especially in the far north. Batai virus of the Bunyamwera-group (Bunyavirus) occurs in southern, central, and northern Europe, most frequently in central Europe. The antibody prevalence in humans generally is very low, indicating that the potential of this virus as a human pathogen is probably low in Europe. The Lednice virus (Bunyavirus) has been reported only from the former Czechoslovakia and Romania, and apparently is not transmitted to humans. In addition to the six mosquito-borne viruses documented in western Europe, there is serological evidence of infection with a Semliki Forest complex virus (Alphavirus) in central and southern Europe. Although mosquito-borne viruses presently are not considered to be the cause of major health problems in western Europe, the morbidity caused by Sindbis virus, and the morbidity and mortality caused by West Nile virus, merit further studies on the ecology, epidemiology, and medical importance of these viruses. The California group of viruses and a virus of the Semliki Forest complex may be the cause of unrecognized health problems in western Europe. Specific sampling of potential vectors for virus isolation, detailed characterization of virus strains, and the use of fully characterized strains for serological diagnosis will help to elucidate the present and future potential of mosquito-borne viruses as human pathogens in Europe.

[3] Vector competence of North American mosquitoes (Diptera: Culicidae) for West Nile virus.

[DOC15374] We evaluated the potential for several North American mosquito species to transmit the newly introduced West Nile (WN) virus. Mosquitoes collected in the New York City metropolitan area during the recent WN virus outbreak, at the Assateague Island Wildlife Refuge, VA, or from established colonies were allowed to feed on chickens infected with WN virus isolated from a crow that died during the 1999 outbreak. These mosquitoes were tested approximately 2 wk later to determine infection, dissemination, and transmission rates. Aedes albopictus (Skuse), Aedes atropalpus (Coquillett), and Aedes japonicus (Theobald) were highly susceptible to infection, and nearly all individuals with a disseminated infection transmitted virus by bite. Culex pipiens L. and Aedes sollicitans (Walker) were moderately susceptible. In contrast, Aedes vexans (Meigen), Aedes aegypti (L.), and Aedes taeniorhynchus (Wiedemann) were relatively refractory to infection, but individual mosquitoes inoculated with WN virus did transmit virus by bite. Infected female Cx. pipiens transmitted WN virus to one of 1,618 F1 progeny, indicating the potential for vertical transmission of this virus. In addition to laboratory vector competence, host-feeding preferences, relative abundance, and season of activity also determine the role that these species could play in transmitting WN virus.
Related to Topic 81: VIRUS,EBOLA,FEVER,GP,VIRUSES,HEMORRHAGIC (0.178)

[1] Lentiviral vectors pseudotyped with a modified RD114 envelope glycoprotein show increased ...

[DOC17562] Generating lentiviral vectors pseudotyped with different viral glycoproteins (GPs) may modulate the physicochemical properties of the vectors, their interaction with the host immune system, and their host range. We have investigated the capacity of a panel of GPs of both retroviral (amphotropic murine leukemia virus [MLV-A]; gibbon ape leukemia virus [GALV]; RD114, feline endogenous virus) and nonretroviral (fowl plague virus [FPV]; Ebola virus [EboV]; vesicular stomatitis virus [VSV]; lymphocytic choriomeningitis virus [LCMV]) origins to pseudotype lentiviral vectors derived from simian immunodeficiency virus (SIVmac251). SIV vectors were efficiently pseudotyped with the FPV hemagglutinin, VSV-G, LCMV, and MLV-A GPs. In contrast, the GALV and RD114 GPs conferred much lower infectivity to the vectors. Capitalizing on the conservation of some structural features in the transmembrane domains and cytoplasmic tails of the incorporation-competent MLV-A GP and in RD114 and GALV GPs, we generated chimeric GPs encoding the extracellular and transmembrane domains of GALV or RD114 GPs fused to the cytoplasmic tail (designated TR) of MLV-A GP. Importantly, SIV-derived vectors pseudotyped with these GALV/TR and RD114/TR GP chimeras had significantly higher titers than vectors coated with the parental GPs. Additionally, RD114/TR-pseudotyped vectors were efficiently concentrated and were resistant to inactivation induced by the complement of both human and macaque sera, indicating that modified RD114 GP-pseudotyped lentiviral vectors may be of particular interest for in vivo gene transfer applications. Furthermore, as compared to vectors pseudotyped with other retroviral GPs or with VSV-G, RD114/TR-pseudotyped vectors showed augmented transduction of human and macaque primary blood lymphocytes and CD34+ cells.

[2] Budding of PPxY-containing rhabdoviruses is not dependent on host proteins TGS101 and VPS4...

[DOC21865] Viral matrix proteins of several enveloped RNA viruses play important roles in virus assembly and budding and are by themselves able to bud from the cell surface in the form of lipid-enveloped, virus-like particles (VLPs). Three motifs (PT/SAP, PPxY, and YxxL) have been identified as late budding domains (L-domains) responsible for efficient budding. L-domains can functionally interact with cellular proteins involved in vacuolar sorting (VPS4A and TSG101) and endocytic pathways (Nedd4), suggesting involvement of these pathways in virus budding. Ebola virus VP40 has overlapping PTAP and PPEY motifs, which can functionally interact with TSG101 and Nedd4, respectively. As for vesicular stomatitis virus (VSV), a PPPY motif within M protein can interact with Nedd4. In addition, M protein has a PSAP sequence downstream of the PPPY motif, but the function of PSAP in budding is not clear. In this study, we compared L-domain functions between Ebola virus and VSV by constructing a chimeric M protein (M40), in which the PPPY motif of VSV M is replaced by the L domains of VP40. The budding efficiency of M40 was 10-fold higher than that of wild-type (wt) M protein. Overexpression of a dominant negative mutant of VPS4A or depletion of cellular TSG101 reduced the budding of only M40-containing VLPs but not that of wt M VLPs or live VSV. These findings suggest that the PSAP motif of M protein is not critical for budding and that there are fundamental differences between PTAP-containing viruses (Ebola virus and human immunodeficiency virus type 1) and PPPY-containing viruses (VSV and rabies virus) regarding their dependence on specific host factors for efficient budding.

[3] Targeted transduction patterns in the mouse brain by lentivirus vectors pseudotyped with V...

[DOC17155] Lentiviral vectors have proven to be promising tools for transduction of central nervous system (CNS) cells in vivo and in vitro. In this study, CNS transduction patterns of lentiviral vectors pseudotyped with envelope glycoproteins from Ebola virus, murine leukemia virus (MuLV), lymphocytic choriomeningitis virus (LCMV), or the rabies-related Mokola virus were compared to a vector pseudotyped with the vesicular stomatitis virus glycoprotein (VSV-G). Mokola-, LCMV-, and VSV-G-pseudotyped vectors transduced similar populations, including striatum, thalamus, and white matter. Mokola-pseudotyped vectors were the most efficient of the three. MuLV-pseudotyped lentivirus efficiently transduced striatum and hippocampal dentate gyrus. In contrast, no transduction resulted from injection of Ebola-pseudotyped virus in the CNS. The same pattern was observed in vitro with primary cultured oligodendrocytes. LCMV, MuLV, and Ebola pseudotypes were the most stable. These results demonstrate that targeted transduction in the CNS can be achieved using specific envelope glycoproteins to pseudotype lentiviral vectors, and support the use of Mokola-pseudotyped and MuLV-pseudotyped lentiviral vectors as efficient and stable alternatives to VSV-G-pseudotyped vectors for experiments in the mouse CNS.
Related to Topic 44: INFLUENZA,VIRUS,VIRUSES,AVIAN,HA,CHICKENS (0.120)

[1] Characterization of a highly pathogenic H5N1 avian influenza A virus isolated from duck me...

[DOC17232] Since the 1997 H5N1 influenza virus outbreak in humans and poultry in Hong Kong, the emergence of closely related viruses in poultry has raised concerns that additional zoonotic transmissions of influenza viruses from poultry to humans may occur. In May 2001, an avian H5N1 influenza A virus was isolated from duck meat that had been imported to South Korea from China. Phylogenetic analysis of the hemagglutinin (HA) gene of A/Duck/Anyang/AVL-1/01 showed that the virus clustered with the H5 Goose/Guandong/1/96 lineage and 1997 Hong Kong human isolates and possessed an HA cleavage site sequence identical to these isolates. Following intravenous or intranasal inoculation, this virus was highly pathogenic and replicated to high titers in chickens. The pathogenesis of DK/Anyang/AVL-1/01 virus in Pekin ducks was further characterized and compared with a recent H5N1 isolate, A/Chicken/Hong Kong/317.5/01, and an H5N1 1997 chicken isolate, A/Chicken/Hong Kong/220/97. Although no clinical signs of disease were observed in H5N1 virus-inoculated ducks, infectious virus could be detected in lung tissue, cloacal, and oropharyngeal swabs. The DK/Anyang/AVL-1/01 virus was unique among the H5N1 isolates in that infectious virus and viral antigen could also be detected in muscle and brain tissue of ducks. The pathogenesis of DK/Anyang/AVL-1/01 virus was characterized in BALB/c mice and compared with the other H5N1 isolates. All viruses replicated in mice, but in contrast to the highly lethal CK/HK/220/97 virus, DK/Anyang/AVL-1/01 and CK/HK/317.5/01 viruses remained localized to the respiratory tract. DK/Anyang/AVL-1/01 virus caused weight loss and resulted in 22 to 33% mortality, whereas CK/HK/317.5/01-infected mice exhibited no morbidity or mortality. The isolation of a highly pathogenic H5N1 influenza virus from poultry indicates that such viruses are still circulating in China and may present a risk for transmission of the virus to humans.

[2] The pathogenicity of four avian influenza viruses for fowls, turkeys and ducks.

[DOC874] Groups of 10 two-week-old chicks, turkey poults and ducklings were each infected by the intranasal route with one of four avian influenza viruses: a/fowl/Germany/34 (Hav 1N))--Rostock, A/FPV/Dutch/27 (Hav 1 Neq 1)--Dutch, A/fowl/Victoria/75 (Hav 1 Neq 1)--Australian, and A/parrot/Ulster/73 (Hav 1 N1)--Ulster. Eight hours after infection 10 birds of the same age and species were placed in contact with each group and allowed to mix. The clinical signs of disease and onset of sickness and death were recorded. Ulster virus was completely avirulent for all birds. Rostock, Dutch and Australian viruses were virulent for fowls and turkeys causing death in all birds with the exception of 3/10 in contact fowls from the Rostock virus group and 2/10 in contact fowls from the Australian virus group. Only Rostock virus caused sicked sickness or death in ducks, 9/10 intranasally infected and 6/7 in contact birds showed clinical signs and 2/10 intranasally infected and 3/7 in contact ducks died. Intranasal and in contact pathogenicity indices were calculated for each virus in each bird species and indicated quantitatively the differences in virulence of the four virus strains. virus isolation and immune response studies indicated that surviving in contact fowls in the Rostock virus group had never been infected but that surviving Australian virus in contact fowls had recovered from infection. Infection was not established in Ulster virus in contact fowls and Australian virus intranasally infected and in contact ducks. The birds in all other groups showed positive virus isolations and a high incidence of positive immune response. The last virus isolation was made at 22 days after intranasal infection of ducks with Ulster virus.

[3] Pathogenicity and antigenicity of a new influenza A (H5N1) virus isolated from duck meat.

[DOC18970] Avian influenza A viruses are the ancestral origin of all human influenza viruses. The outbreak of highly pathogenic (HP) avian H5N1 in Hong Kong in 1997 highlighted the potential of these viruses to infect and cause severe disease in humans. Since 1999, HP H5N1 viruses were isolated several times from domestic poultry in Asia. In 2001, a HP H5N1 virus, A/Duck/Anyang/AVL-1/2001 (Dk/Anyang), was isolated from imported frozen duck meat in Korea. Because of this novel source of HP H5N1 virus isolation, concerns were raised about the potential for human exposure and infection; we therefore compared the Dk/Anyang virus with HP H5N1 viruses isolated from humans in 1997 in terms of antigenicity and pathogenicity for mammals. At high doses, Dk/Anyang virus caused up to 50% mortality in BALB/c mice, was isolated from the brains and lymphoid organs of mice, and caused lymphopenia. Overall Dk/Anyang virus was substantially less pathogenic for mice than the H5N1 virus isolated from a fatal human case in 1997. Likewise, Dk/Anyang virus was apathogenic for ferrets. Dk/Anyang virus was antigenically distinguishable by hemagglutination-inhibition (HI) assay from human H5N1 viruses isolated in 1997 and avian H5N1 viruses isolated in 2001 in Hong Kong. Nevertheless, prior infection with Dk/Anyang virus protected mice from death after secondary infection with HP human H5N1 viruses. These results indicate that compared with HP human H5N1 viruses, Dk/Anyang virus is substantially less pathogenic for mammalian species. Nevertheless, the novel source of isolation of this avian H5N1 virus must be considered when evaluating the potential risk to public health.
Related to Topic 63: RENAL,HFRS,SYNDROME,FEVER,VIRUS,HEMORRHAGIC (0.061)

[1] Muroid virus nephropathies and muroid viruses of the Hantaan virus group.

[DOC6662] Hemorrhagic fever with renal syndrome (HFRS) came dramatically to the attention of Western medicine in 1951 with the "new" disease becoming a major source of morbidity and mortality in American troops in Korea. Known there as epidemic hemorrhagic fever (EHF) or Korean hemorrhagic fever (KHF), it became apparent that it was the same disease as the endemic (epidemic) hemorrhagic nephroso-nephritis of the Soviet Far East and Songo fever of the Japanese Army in Manchuria. The conjecture that the milder epidemic (endemic) nephropathy of Scandinavia and European Russia was the same or a related disease has now been substantiated with the demonstration of close serological relationship of the Bunyamwera-like virus causing KHF (Hantaan virus) to that of HFRS in Finland, Sweden, European Russia, Greece and Yugoslavia. In the past decade the disease has been recognized as a serious problem in 19 provinces of China and in Japan, where the virus is the Hantaan virus. The severe EHF (or KHF) has its silent reservoir in the wild mouse Apodemus agrarius or in laboratory rats while the less virulent European disease resides in the voles Clethrionomys sp. A mild nonhemorrhagic form of the East Asian nephropathy is carried to man by infected urban rats, Rattus rattus or Rattus norvegicus, in Japan and Korea. All forms are carried to man as a respiratory infection "when a mouse (or rat or vole) coughs". Antibodies to the Hantaan virus have been found in man in India, Iran, Central Africa, Alaska, Bolivia and in wild rodents and urban rats in the USA where human cases of muroid virus nephropathy have not been recognized. Antibody patterns to Hantaan virus and to Scandinavian nephropathia epidemica virus antigens found in human and rodent sera in America and in Sweden, Yugoslavia, and European Russia suggest the possibility of yet a third (or more) virus serotype(s), and also the possible presence of the East Asian type of virus in Europe.

[2] Hemorrhagic fever with renal syndrome caused by the Seoul virus.

[DOC10439] The Seoul virus is an important etiologic agent in hemorrhagic fever with renal syndrome (HFRS), and infections with the Seoul virus are less severe than those with the Hantaan virus. However, the information on HFRS caused by the Seoul virus is limited in Korea. Retrospective clinical analysis was done on 30 patients with Seoul virus infection who had been diagnosed as having HFRS by clinical features and serologic testing by the plaque reduction neutralization test from 1986 to 1991 at the Seoul National University Hospital. They were compared with 69 patients with Hantaan virus infection. The Seoul virus was the etiologic agent in 25% of Korean HFRS and the major cause of HFRS during the summer season although infections occurred throughout the year. The Seoul virus infection had a milder degree of bleeding and renal derangement but had severer liver dysfunction than the Hantaan virus infection. Renal histopathologic findings revealed a milder degree of hemorrhage and vascular changes than cases involving Hantaan virus infection. The precise mechanisms of vascular dysfunction and organ involvement in Seoul virus infection, however, still remain to be explored.

[3] Serological analysis of hemorrhagic fever with renal syndrome (HFRS) patients in Far Easte...

[DOC20159] Hemorrhagic fever with renal syndrome (HFRS) is endemic in East Asia and Europe. The disease is caused by several viruses belonging to the genus Hantavirus, including the Hantaan virus (HTNV), Seoul virus (SEOV), Dobrava Belgrade virus (DOBV), and Puumala virus (PUUV). Recently, HTNV-related viruses, Amur (AMR) and Far East (FE) genotypes were identified as causative agents of HFRS in Far Eastern Russia. To investigate the epidemiology of HFRS and virus transmission, we collected sera from 17 acute and 32 convalescent patients who were clinically diagnosed with HFRS in the Khabarovsk region of Far Eastern Russia, and detected anti-hantavirus antibodies using an ELISA that can differentiate the infected virus serotype using truncated hantavirus nucleocapsid protein antigen. Sixteen of the 17 acute phase patients had antibodies to hantavirus, and all the positive sera had higher optical densities for HTNV-specific antigen than for SEOV-, DOBV-, or PUUV-specific antigens. The partial M segment of the viral genome was amplified from blood clots from three acute patients by PCR. The nucleotide sequences had closer identities to the FE genotype (>96%) than to the prototype HTNV (88 to 89%) or AMR genotype (81 to 83%). A phylogenetic analysis found that the virus sequences from the patients clustered with the FE type, and were distinct from the AMR type. Thirty-one of 32 convalescent patient sera had antibodies to HTNV-specific antigen. These data suggest that our ELISA system can detect HTNV-specific antibodies to the FE type, which may be responsible for most of the HFRS in Khabarovsk.