Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Preparations of hepatitis B virus (HBV) core antigen (HBcAg) synthesised in Escherichia coli have been shown previously to confer partial immunity against infection by the virus [Murray, Bruce, Hinnen, Wingfield, van Eerd, de Reus, and Schellekens: EMBO Journal 3:645-650, 1984]. In a further experiment reported here, immunisation of chimpanzees with a similar preparation of HBcAg that had been treated with sodium dodecyl sulphate in order to expose e antigen epitopes was found to protect one animal completely and another quite substantially upon challenge with the virus. The results are used to support the argument for trials in humans of a vaccine against HBV based upon or containing HBcAg and its e antigen derivative, and in discussion of a more general role for internal antigens in generating immunity against viral infection.
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PMID:Protective immunisation against hepatitis B with an internal antigen of the virus. 244 9

Recent studies suggest that hepatitis B virus (HBV), despite being a DNA virus, replicates via an RNA intermediate (R. H. Miller, P. L. Marion, and S. W. Robinson, Virology 139:64-72, 1984; J. Summers and W. S. Mason, Cell 29:403-415, 1982). The HBV life cycle is therefore a permuted version of the RNA retroviral life cycle. Sequence homology between retroviral reverse transcriptase and the putative HBV polymerase gene product suggests the presence of an HBV reverse transcriptase (H. Toh, H. Hajashida, and T. Miyata, Nature (London) 305:827-829, 1983). As yet, there has been no direct evidence that reverse transcriptase activity is present in the viral particle. We used activity gel analysis to detect the in situ catalytic activities of DNA polymerases after sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Our studies demonstrated that HBV-like particles secreted by a differentiated human hepatoma cell line transfected with genomic HBV DNA contain two major polymerase activities which migrate as approximately 90- and approximately 70-kilodalton (kDa) proteins. This demonstrated, for the first time, that HBV-like particles contain a novel DNA polymerase-reverse transcriptase activity. Furthermore, we propose that the 70-kDa reverse transcriptase may be produced by proteolytic self-cleavage of the 90-kDa precursor protein.
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PMID:Two proteins with reverse transcriptase activities associated with hepatitis B virus-like particles. 244 93

The cloning and expression of the hepatitis B middle-protein surface antigen gene in the yeast Saccharomyces cerevisiae is described. A generalized expression vector carrying the yeast glyceraldehyde-3-phosphate dehydrogenase gene promoter was used. Expressed material, in the form of supramolecular particles, was purified and characterized. Severe proteolysis within the pre-S(2) region was observed for material expressed in a wild-type yeast host. This proteolysis was substantially reduced by utilization of a protease-deficient host. Immunoblotting of sodium dodecyl sulfate-polyacrylamide gels with several antibodies of differing specificity was performed to characterize the various protein species present. All species were analyzed by N-terminal sequencing after electroelution from gels. Carbohydrate staining of gels and glycosidase treatments of the purified antigen material indicated that full-length antigen was present in both glycosylated and unglycosylated forms. Glycosylation appeared to be of both asparagine-linked and threonine/serine-linked types. Site-directed mutagenesis was used to convert two arginine residues in the pre-S(2) region of the antigen to glutamine residues. The changes abolished reactivity with one polyclonal and two monoclonal antibodies specific for epitopes within the pre-S(2) region.
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PMID:Characterization of purified hepatitis B surface antigen containing pre-S(2) epitopes expressed in Saccharomyces cerevisiae. 245 90

A three-year study has been conducted for prevention of infectious hepatitis with supplementation of table salt fortified with 15 ppm anhydrous sodium selenite to the general population of 20,847 persons in a township M.Z. at Qidong County, Jiangsu Province, China. The results showed that the incidence of virus hepatitis infection in the test township was significantly lower than that of controls provided with normal table salt. The incidence rate of infectious hepatitis in the treated township M.Z. was 1.20 and 4.52 per 1,000, whereas the average incidence in the 6 surrounding control townships was 2.96 and 10.48 per 1,000 in 1986 and 1987, respectively. The incidence of hepatitis B surface antigen (HBsAg+) was 13.2% vs 19.23% for males and 10.42% vs 12.24% for females in the supplemented vs nonsupplemented neighboring township, respectively. Epidemiological studies have demonstrated that a low grain Se content is associated with a high regional incidence of hepatitis B virus infections.
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PMID:Chemoprevention trial of human hepatitis with selenium supplementation in China. 248 94

It has been postulated that polymerized human serum albumin may play a role in the infection of hepatocytes by hepatitis B virus, because both the envelope of hepatitis B virus (HBsAg) and hepatocytes exhibit binding activity for human serum albumin after cross-linking by glutaraldehyde. Since glutaraldehyde-dependent cross-linking of albumin molecules is not likely to occur in vivo, we considered the possibility that albumin may be polymerized by the action of transglutaminase enzymes present in plasma as activated factor XIII or released into plasma from tissues. Guinea pig liver transglutaminase covalently cross-linked human serum albumin molecules into dimers, trimers and polymers up to hexamers as shown by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. HBsAg particles bound transglutaminase-cross-linked as well as glutaraldehyde-cross-linked human serum albumin as demonstrated by radioimmunoassay and immunoelectron microscopy. The binding was blocked by preincubation of HBsAg with transglutaminase- or glutaraldehyde-cross-linked human serum albumin, anti-HBs or monoclonal anti-pre-S2, but not by polymerized bovine or rat serum albumin or by monomeric human serum albumin. These data indicate that HBsAg particles contain specific binding sites for transglutaminase-cross-linked human serum albumin, but it remains to be determined whether the albumin polymers play a role in the attachment of hepatitis B virus to hepatocytes.
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PMID:Hepatitis B surface antigen binds to human serum albumin cross-linked by transglutaminase. 256 85

Highly purified hepatitis B virus core particles were obtained in large amounts from the cytoplasm of infected human liver cells. This DNA polymerase-negative core preparation had only hepatitis B core antigen-specific antigenicity and showed a surprising stability. Two forms of a single protein of 22,000 molecular weight, P22, were resolved electrophoretically; the slower moving species, P22a, appeared to be a reduced form of the protein, and the faster moving species, P22b, could have represented a conformational isomer containing an intramolecular disulfide bond(s). The immunological properties and DNA-binding activity of the reduced form, P22a, were examined following separation by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and by transfer onto nitrocellulose membranes (Western blotting). We found that the hepatitis B virus C gene protein shared the antigenic site responsible for both hepatitis B core and e antigen reactivity. We also demonstrated that the core protein(s) bound specifically the genomic hepatitis B virus DNA in comparison with a plasmid DNA (pBR322). This last observation was further substantiated by a radioimmunological method. P22a was also found to be phosphorylated in vitro by the endogenous protein kinase activity, copurified with the hepatitis B core antigen particles. These findings suggest that P22 is a multifunctional protein which is incorporated into core particles within the cytoplasm of the host cell before DNA encapsidation. A critical role of this protein in hepatitis B virus assembly is suggested.
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PMID:HBc and HBe antigenicity and DNA-binding activity of major core protein P22 in hepatitis B virus core particles isolated from the cytoplasm of human liver cells. 257 75

In the period between 15/12/1987 and 15/08/1989, ten patients with either fulminating or subfulminating hepatitis have been treated by orthotopic liver transplantation (O.L.T.). Six patients are doing well in the post-operative period with a mean follow-up of 12 months (7-23 months). No evidence of neurological sequelae has been observed and recurrence of HB virus infection was absent from the three cases who survived hepatitis B transplantation. Four out these ten patients died after initial successful O.L.T... One patient succumbed 7 days after O.L.T. from sepsis or early super-acute rejection, the second 21 days after O.L.T. from neuromeningeal listeria, the third 43 days post O.L.T. from acute rejection, while the fourth developed cytomegalovirus pneumonia and died 61 days after O.L.T. Orthotopic liver transplantation has become the treatment of fulminating hepatitis. It is an emergency which is usually accompanied by successive difficulties in decision making: indication criteria, then acceptance or refusal of ABO incompatible grafts (5/10) and of suboptimal donors. Orthotopic liver transplantation for fulminating hepatitis is technically easy to perform, but usually requires the use of extra-corporal veno-venous circulation. Accompanying intensive medical care is essential and usually includes one or multiple plasmaphereses to correct existing coagulopathy without any fluid or sodium overload to the circulation.
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PMID:[Fulminant and subfulminant hepatitis treated by orthotopic transplantation of the liver. Apropos of 10 cases]. 270 Jan 60

Circulating immune complexes composed of HBcAg and anti-HBc have been demonstrated recently in patients with hepatitis B virus replication. After dissociation of immune complexes by chaotropic ions, HBcAg was quantified radioimmunologically. In the present study, we describe 10 patients with hepatitis B virus replication, absent or delayed anti-HBc formation and exposed HBcAg in serum. Four of the 10 patients had acute hepatitis, and six patients had chronic persistent hepatitis. In seven of 10 patients, a secondary immune defect was apparent due to acquired immunodeficiency syndrome, leukemia, histiocytosis X, sarcoidosis or end-stage renal disease. Electron microscopy demonstrated that Dane particles from anti-HBc-negative patients were agglutinated after addition of monoclonal anti-HBc antibodies, whereas Dane particles from anti-HBc-positive sera did not show agglutination. Monoclonal HBsAg-specific antibodies aggregated Dane particles independent of the presence of anti-HBc. Circulating HBcAg was always associated with the Dane particle fraction after density gradient separation. Hepatitis B virus core proteins from patients with and without anti-HBc studied by immunoblotting after sodium dodecyl sulfate-gel electrophoresis showed identical patterns. Hepatocytes from anti-HBc-negative patients were positive for HBcAg but negative for immunoglobulin G by immunofluorescence technique. The data indicate that HBcAg may also be expressed on the surface of Dane particles, where it is commonly masked by anti-HBc.
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PMID:HBcAg expressed on the surface of circulating Dane particles in patients with hepatitis B virus infection without evidence of anti-HBc formation. 274 30

Although primary hepatoma is not very frequent in alcoholics, the incidence of hepatoma in cases of hepatitis B infection combined with heavy alcohol drinking is high. In the present study, the effects of chronic alcohol administration on the development of chemical-induced hepatic cancer in rats were analyzed. In 70% hepatectomized Wistar strain male rats, a single dose (1 mg per 100 gm body weight) of diethylnitrosamine was injected intraperitoneally. Eight weeks after the injection, 20% alcohol-10% sucrose solution (diethylnitrosamine-alcohol group), 0.1% sodium phenobarbital solution (diethylnitrosamine-phenobarbital group), 10% sucrose solution (diethylnitrosamine-sucrose group) or tap water (diethylnitrosamine-alone group) was given as drinking water for 32 weeks. The numbers of visible nodules per liver were significantly greater in the diethylnitrosamine-alcohol and diethylnitrosamine-phenobarbital groups compared to the diethylnitrosamine-alone and diethylnitrosamine-sucrose groups. The numbers of enzyme-altered foci which were positive to gamma-glutamyl transpeptidase staining per square centimeter of liver section were also greater in the diethylnitrosamine-alcohol and diethylnitrosamine-phenobarbital groups than in the diethylnitrosamine-alone and diethylnitrosamine-sucrose groups, although the numbers of nodules and enzyme-altered foci were significantly larger in the diethylnitrosamine-phenobarbital group than in the diethylnitrosamine-alcohol group. The enzyme-altered foci areas calculated by gamma-glutamyl transpeptidase staining were significantly larger in the diethylnitrosamine-alcohol and diethylnitrosamine-phenobarbital groups than in the diethylnitrosamine-alone and diethylnitrosamine-sucrose groups. Histologically, visible nodules observed in diethylnitrosamine-phenobarbital and diethylnitrosamine-alcohol groups showed characteristic features of neoplastic nodules. These results indicate that alcohol has a promoter action on the development of chemically induced hepatic cancer like phenobarbital.
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PMID:Effects of ethanol on experimental hepatocarcinogenesis. 286 66

Blood product sterilization with 0.3% tri(n-butyl)phosphate (TNBP)/0.2% sodium cholate (CA), a combination known to permit high recovery of factor VIII and factor IX, was evaluated for its effect on hepatitis B (HBV), non-A, non-B (NANB), and human T-lymphotropic type III (HTLV-III) viruses. 2 chimpanzees received factor VIII preparations contaminated with 100,000 chimpanzee infectious doses of HBV and treated with TNBP/CA. Neither had evidence of HBV during the 9 month follow-up, but hepatitis B surface antigen (HBsAG) developed 5 and 6 weeks, respectively, after challenge with untreated inoculum. 2 chimpanzees were similarly exposed to NAMB inoculum treated with TNBP/CA. Neither became infected during 26 weeks of follow-up, but both had characteristic NANB-associated ultrastructural changes 3-5 weeks after exposure to untreated inoculum. 2 chimpanzees inoculated with TNBP/CA-treated factor VIII derived from a pool of 13 lots obtained from 5 US manufacturers remained free of any evidence of NANB infection during 32 weeks of follow-up. Subsequently, NANB infection developed in both animals 3-4 weeks after exposure to untreated inoculum. Exposure of HTLV-III diluted into a factor VIII preparation to TNBP/CA inactivated tissue culture infected doses within 20 minutes. These results demonstrate that exposure of labile blood derivatives to TNBP/CA effectively inactivates HBV, NANB, and HTLV-III viruses, although additional experiments with more potent inocula are needed to establish limits of inactivation efficacy against these agents. To provide absolute safety, a process efficacy of = or 5-6 log 10 is preferable.
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PMID:Sterilisation of hepatitis and HTLV-III viruses by exposure to tri(n-butyl)phosphate and sodium cholate. 287 Feb 24


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