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)

The construction of the first stable human cell lines that express and secrete authentic hepatitis B virus surface antigen (HBsAg), using a BK virus (BKV) episomal plasmid vector, is described. The amount of HBsAg produced by BKV vectors (up to 600 ng/10(7) cells) was comparable to other eukaryotic vector systems. The level of HBsAg expression remained the same regardless of the orientation of the HBsAg gene, substitution of the HBsAg gene promoter with the mouse metallothionein I gene promoter or the tissue origin of the human cell lines used to establish stable cellular transformants. Northern blot analysis also indicated synthesis of normal HBsAg transcripts. Surprisingly, however, the vectors were maintained at far lower than expected copy number (one to five copies/cell). Reasons for this are discussed.
J Gen Virol 1988 Feb
PMID:Expression of hepatitis B surface antigen in human cells by a recombinant BK virus DNA vector. 282 19

The complete nucleotide sequence of a strain of hepatitis B virus, originally isolated from a naturally infected chimpanzee, has been determined. Interesting features of the sequence include the presence of an in-phase stop codon in the 'pre-core' region of the core antigen open reading frame. The sequence shows approximately 10% nucleotide divergence from all of the other hepatitis B virus sequences previously published and the possibility that this divergence is the result of passage through chimpanzees is discussed.
J Gen Virol 1988 Jun
PMID:The complete nucleotide sequence of the genome of a hepatitis B virus isolated from a naturally infected chimpanzee. 283 76

A DNA virus with the characteristics of a herpesvirus has been isolated from woodchuck hepatocytes cultured in vitro. We refer to this virus as herpesvirus of marmots (HVM). Electron microscopy of thin sections of HVM-infected cells showed nucleocapsids with a hexagonal outline and a diameter of 80 nm. Enveloped virions were seen in cytoplasmic vacuoles and outside the cell. Negatively stained virus particles purified from cell supernatants were enveloped with the characteristic appearance of herpesviruses. The DNA was double-stranded with a molecular size of approximately 140 kb and a G + C content of 73%. The virus replicated with a lytic effect in kidney cells of owl monkeys and African green monkeys, baby hamster kidney cells, feline kidney cells and WCH-17, a cell line derived from a woodchuck hepatoma. An indirect immunofluorescence assay has shown the presence of antibody to HVM in seven out of 37 animals tested. An important reason for studying HVM lies in its possible role in infection or the disease produced by woodchuck hepatitis virus, an animal model for human hepatitis B virus.
J Gen Virol 1988 Jul
PMID:Characterization of a herpesvirus isolated from woodchuck hepatocytes. 283 96

The large BglII fragment (2.8 kilobases) of hepatitis B virus DNA including the transcription unit for the hepatitis B surface antigen (HBsAg) was inserted into a bovine papillomavirus vector containing the neomycin resistance gene. The recombinant DNA was transfected into mouse C127 cells. A stable transformed cell line (MS128) secreting a large amount of 22 nm HBsAg particles containing pre-S2 protein was established. The secreted HBsAg particles had the receptor for polymerized human serum albumin. Immunoprecipitation and Western blot analyses showed that HBsAg particles consisted of two major proteins of 22K and 26K encoded by the S gene and a minor protein of 35K encoded by the pre-S2 and S genes. Southern blot analysis revealed that the transfected plasmid was integrated into the host chromosomal DNA and that most of the plasmid sequences were present. These results suggest that the stable expression of the HBsAg in MS128 cells is related to the integrated state of the recombinant DNA.
J Gen Virol 1988 Aug
PMID:Stable expression of the hepatitis B virus surface antigen containing pre-S2 protein in mouse cells using a bovine papillomavirus vector. 284 7

The immunogenicity and efficacy of different commercially available vaccines against hepatitis B virus (HBV) has been demonstrated in a number of controlled vaccination trials throughout the world. However, the significance of pre-S proteins in hepatitis B vaccines is still controversially discussed. Therefore, a radioimmunoassay (RIA) was developed to detect pre-S proteins in HBsAg-carriers as well as in different hepatitis B vaccines. This study confirmed the high amount of pre-S proteins as well as poly-albumin receptors in purified Dane particles and sera of patients with acute hepatitis B. The currently available plasma derived vaccine H-B-Vax and the recombinant hepatitis B vaccines Gen H-B-Vax and Engerix B yielded negative results in pre-S- and poly-albumin-receptor-RIAs. The plasma derived vaccine Hevac B Pasteur included pre-S encoded proteins. Future vaccination trials in man have to evaluate the role of pre-S antigens and antibodies in the pathogenesis and the protection of hepatitis B infection including recombinant pre-S vaccines which are under development.
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PMID:[Detection of pre-S gene products in HBsAg carriers and in hepatitis B vaccines]. 285 93

Tissues of human primary hepatocellular carcinoma (PHC) from six patients infected with hepatitis B virus (HBV) were propagated in nude mice, as well as a strain of hepatitis B surface antigen-positive PHC (PLC/PRF/5). Integration of viral DNA into chromosomal DNA of tumour cells was evaluated by the capacity to hybridize with radiolabelled DNA probes, each representing fundamental parts of the HBV genome, that is S and C genes and regions pre-S and X. All PHC cells possessed region X integrated in their chromosomes. However, integration of the S gene, C gene and region pre-S was found in only six of the seven PHCs. Based on these findings, the integration of region X seems to be most closely associated with carcinogenesis in HBV infection.
J Gen Virol 1986 Jul
PMID:Integration of region X of hepatitis B virus genome in human primary hepatocellular carcinomas propagated in nude mice. 287

To assess factors influencing acceptance of hepatitis B vaccine, 547 medical residents and 230 surgical residents were surveyed. The vaccination rate among 315 (58%) medical residents who responded was 46%; for 124 (54%) surgical residents who responded it was 76%. Most medical (93%) and surgical (94%) residents who were vaccinated believed they were at risk of hepatitis B virus infection. Among unvaccinated medical residents, 71% indicated concern about vaccine-related side effects, including potential but unknown reactions (58%) and possible transmission of AIDS (37%) and hepatitis (16%). Unvaccinated surgical residents were also concerned about side effects (64%). Stepwise discriminant function analysis revealed that medical residents were vaccinated if they were concerned about risk of exposure to hepatitis B virus and the chronic complications of infection and if they had received hepatitis B immune globulin and influenza vaccine. Surgical residents were vaccinated if they believed hepatitis B vaccine was efficacious, but were not vaccinated if they believed hepatitis B virus infection was not serious.
J Gen Intern Med
PMID:Acceptance of hepatitis B vaccine by medical and surgical residents. 296 57

In this paper, we show that the pattern of expression of the human hepatitis B surface antigen (HBs Ag) gene, transfected along with a dominant selectable marker into mammalian cells, is complex. In human hepatoma (HepG2) cells, late transient expression occurs and permanent expression takes place at high frequencies in the selected clones. In HeLa and human xeroderma pigmentosum (GM4312A)-derived cells, the late transient expression is barely seen or absent and permanent expression is only seen in a few selected clones. In monkey kidney Vero cells, late transient expression has been described and we show in this report that only 5% of the selected clones are capable of expressing HBs Ag in a permanent manner. In most of the Vero clones, the absence of HBs Ag expression is mainly due to HBs Ag gene rearrangements. We have selected and amplified more than 500 transfected Vero clones and have characterized in detail one clone (GAR1412) which is a permanent high-level HBs Ag expressor.
J Gen Virol 1985 Aug
PMID:Comparative expression of the hepatitis B surface antigen gene in biochemically transformed human, simian and murine cells. 299 37

In this study we examined the role of secondary modifications in the expression of polyalbumin receptors by hepatitis B surface antigen (HBsAg) produced in vitro. Several clones isolated from 3T3 mouse fibroblasts after transfection with the hepatitis B virus genome produced HBsAg with marked variation in the expression of polyalbumin receptors. Treatment of the cells with glycosylation inhibitors (tunicamycin, glucosamine) resulted in loss of the 27 000 mol. wt. HBsAg glycopolypeptide, concomitantly with a marked increase in polyalbumin receptors. These data suggest that glycosylation regulates the activity of polyalbumin receptors associated with native HBsAg.
J Gen Virol 1985 Nov
PMID:Effects of glycosylation inhibitors on the expression of polyalbumin receptors by hepatitis B surface antigen produced in vitro. 299 77

A virus closely related to duck hepatitis B virus (DHBV) was isolated from serum and liver samples of wild migratory ducks (mallards) caught in two separate wildlife reserve parks in France. In the first one (Dombes region) 12% of wild mallards were positive for DHBV, and in the second (River Somme) 3% of mallards were found positive. The DHBV isolated from the serum of wild mallards was also associated with an endogenous DNA polymerase activity capable in vitro of completing a partially double-stranded viral DNA into a fully double-stranded DNA of 3 kb. The various replicative DNA forms reported for DHBV were also detected in the liver of wild viraemic mallards. The DNA restriction enzyme pattern of the wild mallard strain differed from that of American and French strains of DHBV. The wild mallard strain DHBV was experimentally transmitted to mallard and Pekin ducklings and induced a chronic viraemia in both varieties of infected birds. This strain might be the common ancestor of all DHBV strains isolated from domestic ducks world-wide. The discovery of a DHBV-related virus in the natural wild population might be an important clue in the study of the different roles of environmental, host and viral factors in the pathogenesis of DHBV infection, and their possible oncogenic action in ducks.
J Gen Virol 1986 Mar
PMID:Evidence for the presence of duck hepatitis B virus in wild migrating ducks. 300 80


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