Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| a virus similar to human hepatitis b virus associated with hepatitis and hepatoma in woodchucks. | particles with properties similar to those associated with human hepatitis b were found in serum from woodchucks with chronic hepatitis and hepatocellular carcinoma. it is suggested that woodchuck hepatitis virus is a second member of a novel class of viruses represented by the human hepatitis b virus. | 1978 | 212758 |
| serological relationship of woodchuck hepatitis virus to human hepatitis b virus. | two antigenic systems of the woodchuck hepatitis virus have been identified. the relationship between viral antigens of the woodchuck hepatitis virus and the human hepatitis b virus was determined by using immunoprecipitation, hemagglutination, and immune electron microscopy techniques. antigens found on the cores of the two viruses were cross-reactive. lack of cross-reactivity between the surface antigens of the two viruses in immunodiffusion experiments suggested that the major antigenic deter ... | 1979 | 94359 |
| isolation, characterization, and comparison of recombinant dnas derived from genomes of human hepatitis b virus and woodchuck hepatitis virus. | the human hepatitis b virus (hbv) and the woodchuck hepatitis virus (whv) are closely related by several criteria and belong to the same class of dna viruses. the dna genomes from these viruses are difficult to obtain in quantities required for biochemical analysis. we have, therefore, cloned these two dnas in the vector lambda gtwes and subcloned into the kanamycin resistance plasmid pa01. comparison of the recombinant dnas with authentic viral dnas by specific hybridization, size, and restrict ... | 1980 | 6246507 |
| trisodium phosphonoformate inhibits woodchuck hepatitis virus associated dna polymerase. | recently a new virus has been described which infects woodchucks, marmota monax. this virus, named woodchuck hepatitis virus (whv) is closely related to human hepatitis virus (hbv). the virions have the same principal antigenic system involving surface and core determinants and a serological relationship has been found. whv has also a dna polymerase associated with the core. it has previously been reported that trisodium phosphonoformate (pfa) but not phosphonoacetic acid (paa) inhibits dna poly ... | 1980 | 6449828 |
| a virus in beechey ground squirrels that is related to hepatitis b virus of humans. | a virus given the name ground squirrel hepatitis virus (or gshv), with many of the unique characteristics of human hepatitis b virus (hbv), has been found in beechey ground squirrels in northern california. common features include virus morphology, viral dna size and structure, a virion dna polymerase that repairs a single-stranded region in the viral dna, crossreacting viral antigens, and persistent infection with viral antigen continuously in the blood. although similar, gshv and hbv are not i ... | 1980 | 6930677 |
| genetic variation among hepatitis b and related viruses. | hepatitis b virus (hbv) of man has several characteristics that distinguish it from viruses of other groups. these include its ultrastructure, viral dna size and structure, a virion dna polymerase which repairs a single-stranded region in the viral dna, liver tropism, character of persistent infection, and association with hepatitis and hepatocellular carcinoma. recently three other viruses have been found in other animal species that appear to share these characteristics although the viruses ar ... | 1980 | 7013620 |
| virus of pekin ducks with structural and biological relatedness to human hepatitis b virus. | a virus found in the sera of pekin ducks appears to be a new member of the human hepatitis b-like family of viruses. this virus had a diameter of 40 nm and an appearance in the electron microscope similar to that of human hepatitis b virus. the dna genome of the virus was circular and partially single stranded, and an endogenous dna polymerase associated with the virus was capable of converting the genome to a double-stranded circle with a size of ca. 3,000 base pairs. an analysis for viral dna ... | 1980 | 7463557 |
| woodchuck hepatitis virus in natural woodchuck populations. | woodchuck hepatitis virus (whv) was discovered in serum samples from captive woodchucks (marmota monax) at the penrose research laboratory in december, 1977. whv belongs to the same class of viruses as hepatitis b virus (hbv), the cause of serum hepatitis in man. both appear to be associated with chronic hepatitis and hepatocellular carcinoma in their respective hosts. woodchucks were trapped and blood samples collected to determine the prevalence of whv in natural woodchuck populations. sera fr ... | 1981 | 7241716 |
| viruses similar to hepatitis b virus (icrons). | in 1971, on the basis of the unusual clinical and epidemiologic characteristics of hepatitis b virus, we postulated the existence of a class of viruses that we termed icrons. an increased understanding of the molecular biology of hepatitis b virus resulted in the discovery, by summers and his colleagues, of the woodchuck hepatitis virus. this virus is common in the north american woodchuck (marmota monax) and is associated with primary cancer of the liver in this animal. subsequently similar vir ... | 1981 | 7333575 |
| localization and nucleotide sequence of the gene coding for the woodchuck hepatitis virus surface antigen: comparison with the gene coding for the human hepatitis b virus surface antigen. | nucleotide sequence analysis was performed with the maxam--gilbert method on a cloned woodchuck hepatitis virus dna (eco whv dna). the structural gene coding for the envelope protein of the virus was localized on the viral genome in the partially single-stranded region between map positions 91.2 and 71. this gene is composed of 669 nucleotides and can code for a polypeptide of 25,645 daltons. the dna sequence and the deduced amino acid sequence were compared with those of the corresponding gene ... | 1981 | 6946471 |
| woodchuck hepatitis and hepatocellular carcinoma: correlation of histologic with virologic observations. | the livers of 33 captive woodchucks were examined histologically in 30 biopsy and 10 autopsy specimens and the findings were correlated with serum determinations for woodchuck hepatitis virus (whv), surface antigen (whsag) and antibody (anti-whs), and whv dna and dna polymerase. the liver appeared normal in all 3 serum-negative animals, 7 of 16 with indeterminate whv status, and 1 of 4 with anti-whs, but not in 10 animals with whsag, whv dna, and dna polymerase. mild hepatic inflammation was fou ... | 1981 | 6269981 |
| antigenic and structural relationships of the surface antigens of hepatitis b virus, ground squirrel hepatitis virus, and woodchuck hepatitis virus. | the surface antigens of human hepatitis b (hbsag), ground squirrel hepatitis (gshsag), and woodchuck hepatitis (whsag) viruses were compared serologically, and their major polypeptides were analyzed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and tryptic peptide mapping. results showed that both gshsag and whsag are antigenically cross-reactive, that their major pairs of polypeptides have identical mobilities on sodium dodecyl sulfate gels, and that the major polypeptides of gsh ... | 1981 | 6168776 |
| surface antigenic determinants of mammalian "hepadnaviruses" defined by group- and class-specific monoclonal antibodies. | the hepatitis b-like viruses (human hepatitis b virus, woodchuck hepatitis virus, ground squirrel hepatitis virus, and duck hepatitis b virus) are hepatotropic dna viruses which have been referred to collectively as "hepadnaviruses." using a murine monoclonal antibody (101-2) to the surface antigen of woodchuck hepatitis virus, we have shown that the surface antigens of mammalian hepadnaviruses (hbsag, whsag, and gshsag) are antigenically related via a common determinant (hv/101). furthermore, a ... | 1982 | 6177867 |
| chronic hepatitis and hepatocellular carcinoma associated with woodchuck hepatitis virus. | 1982 | 6282133 | |
| cloning and structural analysis of integrated woodchuck hepatitis virus sequences from hepatocellular carcinomas of woodchucks. | woodchuck hepatitis virus (whv), like the related hepatitis b virus, induces in its natural host hepatocellular carcinomas that contain integrated viral sequences. as a first step in determining whether and how the integrated sequences contribute to formation of the tumors in which they are found, we have cloned two such integrations of whv and have determined their structure by restriction mapping and heteroduplex electron microscopy. the identity of the cloned sequences was confirmed by compar ... | 1982 | 6288257 |
| novel forms of woodchuck hepatitis virus dna isolated from chronically infected woodchuck liver nuclei. | we cloned several unique forms of woodchuck hepatitis virus, a dna virus closely related to hepatitis b virus, from a chronically infected woodchuck liver. each of the three clones contained more than two genome equivalents of viral sequences with extensive rearrangements and no detectable cellular sequences. from the frequency by which they were isolated from a library of recombinant clones, we estimate that they are present in approximately one copy per cell. of a total of 11 sites at which re ... | 1982 | 6294334 |
| natural and experimental infection of woodchucks with woodchuck hepatitis virus, as measured by new, specific assays for woodchuck surface antigen and antibody. | solid-phase radioimmunoassays for woodchuck hepatitis virus (whv) surface antigen (whsag) and antibody to it (anti-whs) were developed. the test for whsag could detect as little as 10 ng/ml. in both tests it was necessary to employ radiolabeled whsag instead of anti-whs as the probe because the latter appeared to be labile to the conditions of labeling. the tests were used to characterize naturally acquired and experimental whv infections of woodchucks. forty-three of 72 wild-caught woodchucks h ... | 1982 | 7076821 |
| nucleotide sequence of a cloned woodchuck hepatitis virus genome: comparison with the hepatitis b virus sequence. | the complete nucleotide sequence of a woodchuck hepatitis virus genome cloned in escherichia coli was determined by the method of maxam and gilbert. this sequence was found to be 3,308 nucleotides long. potential atg initiator triplets and nonsense codons were identified and used to locate regions with a substantial coding capacity. a striking similarity was observed between the organization of human hepatitis b virus and woodchuck hepatitis virus. nucleotide sequences of these open regions in t ... | 1982 | 7086958 |
| presence and state of woodchuck hepatitis virus dna in liver and serum of woodchucks: further analogies with human hepatitis b virus. | 1982 | 7112938 | |
| no in vivo effect of trisodium phosphonoformate on woodchuck hepatitis virus production. | the efficient in vitro inhibition of hepatitis b virus dna polymerase by trisodium phosphonoformate (pfa, inn: foscarnet sodium) and its low toxicity suggested that pfa could be used as a therapeutic agent for hepatitis b infection. pfa was also found to inhibit woodchuck hepatitis virus (whv) dna polymerase in vitro. as a model to test pfa's eventual effect, chronically whv infected woodchucks were treated with pfa. the animals were treated twice daily in a dosage which gave a minimum serum lev ... | 1982 | 6220563 |
| use of the cross-reactivity with hepatitis b virus antigens and antibodies for the demonstration of a woodchuck hepatitis virus 'e' antigen-antibody system. | woodchucks hepatitis virus (whv)-associated antigens and antibodies were studied using current sensitive radio- or enzyme immunoassays (ria, eia). a significant cross-reactivity was observed between hepatitis b surface antigen (hbsag) and woodchuck hepatitis surface antigen (whsag) using ria or eia (abbott laboratories, north chicago, ill., u.s.a.) although not with two other commercial eia tested (organon technika, oss, the netherlands; behringwerke ag, marburg, f.r.g.). a weak but significant ... | 1983 | 6619256 |
| the nature of polypeptides larger in size than the major surface antigen components of hepatitis b and like viruses in ground squirrels, woodchucks, and ducks. | the relationships of various polypeptides associated with hepatitis b surface antigen (hbsag), ground squirrel hepatitis surface antigen (gshsag), woodchuck hepatitis surface antigen (whsag), and duck hepatitis b surface antigen (dhbsag) were studied by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) and tryptic peptide mapping. analysis of independent antigen isolates by sds-page resulted in bands consistently observed at 24,000, 28,000, 32,000, 43,000, and 50,000 da with h ... | 1983 | 6636542 |
| antigenic cross-reactions between woodchuck hepatitis virus and human hepatitis b virus shown by immune electron microscopy. | using immune electron microscopy (iem), low-level cross-reactions could be demonstrated between the surface antigens of hepatitis b and woodchuck hepatitis. however, immune complex formation was greatly enhanced by pre-exposure of the antigens to 0.5% deoxycholate. cross-reaction between the core antigens and e antigens of both viruses was also confirmed by iem as well as radioimmunoassay. it appears that the woodchuck sera used in this study may well contain an anti-immunoglobulin akin to rheum ... | 1983 | 6834011 |
| nonoverlapping antigenic sites of woodchuck hepatitis virus surface antigen and their cross-reactivity with ground squirrel hepatitis virus and hepatitis b virus surface antigens. | five nonoverlapping antigenic sites (sites i through v) of woodchuck hepatitis virus surface antigen were identified with competitive binding assays involving monoclonal antibodies. site i contributed to cross-reactions among surface antigens of hepatitis b-like viruses infecting woodchucks, ground squirrels, and humans. at least three distinct sites (sites i, ii, and iii) are responsible for cross-reactions between woodchuck and ground squirrel hepatitis virus surface antigens. sites iv and v o ... | 1983 | 6864882 |
| transmission of duck hepatitis b virus from chinese carrier ducks to japanese ducklings: a study of viral dna in serum and tissue. | human hepatitis b-like viruses have been found in several animal species, including chinese ducks. sera from chinese carrier ducks which were positive for duck hepatitis b virus (dhbv) were inoculated in 33 japanese one-day-old ducklings. the same sera were inoculated in four 3-week-old ducklings, and three 3-month-old ducks. ten uninoculated ducklings served as controls. hepatitis b e-antigen positive human sera and dna polymerase-positive woodchuck sera were also inoculated into ducklings. dhb ... | 1984 | 6745848 |
| comparison of properties of woodchuck hepatitis virus and human hepatitis b virus endogenous dna polymerases. | the principal properties of the dna polymerases of woodchuck hepatitis virus and human hepatitis b virus were compared. the enzymes of both viruses exhibited optimal activities in the same range of ph, ionic strength, and mgcl2 concentration. like human hepatitis b virus dna polymerase, the woodchuck hepatitis virus dna polymerase was strongly inhibited by phosphonoformic acid but not by phosphonoacetic acid and aphidicolin. similar inhibition patterns for both enzymes were observed with arabino ... | 1984 | 6231885 |
| [spontaneous and experimental infection of alpine marmots (marmota marmota) by the north american woodchuck hepatitis virus (marmota monax). initial results]. | summer's discovery in 1978 of a dna virus, very close to human hepatitis b virus in a woodchuck population in the u.s.a. (pennsylvania) was a confirmation of the first description made by snyder at penrose research laboratory (philadelphia). it was the first animal model of human b hepatitis infection. the comparative study of morphological, ecological and ethological characteristics of the marmot (marmota marmota) and the woodchuck (marmota monax) enables an easy distinction between these two s ... | 1984 | 6532649 |
| inhibition of human and woodchuck hepatitis virus dna polymerase by the triphosphates of acyclovir, 1-(2'-deoxy-2'-fluoro-beta-d-arabinofuranosyl)-5-iodocytosine and e-5-(2-bromovinyl)-2'-deoxyuridine. | the triphosphates of acyclovir (acv), 1-(2'-deoxy-2'-fluoro-beta-d-arabinofuranosyl)-5-iodocytosine (fiac) and e-5-(2-bromovinyl)-2'-deoxyuridine (bvdu) have been examined for their inhibitory effects on the endogenous dna polymerase reactions of human hepatitis b virus (hbv) and woodchuck hepatitis virus (whv). all three triphosphates (acvtp, fiactp and bvdutp) inhibited the hbv and whv dna polymerases by competing with the corresponding natural substrates. fiactp was the most potent inhibitor ... | 1984 | 6541455 |
| transmission of the hepatitis b virus-associated delta agent to the eastern woodchuck. | delta agent of human origin was inoculated into four woodchucks chronically infected with woodchuck hepatitis virus (whv). the animals developed delta infections with serologic patterns similar to those previously observed in human and chimpanzee infections. delta antigen was detected transiently in serum and liver and was followed by seroconversion to anti-delta antibody. analogous to the chimpanzee model of delta infection, serum and hepatocyte markers of whv were suppressed in the woodchuck d ... | 1984 | 6585793 |
| predicted secondary structure similarity in the absence of primary amino acid sequence homology: hepatitis b virus open reading frames. | proteins that are related evolutionarily may have diverged at the level of primary amino acid sequence while maintaining similar secondary structures. computer analysis has been used to compare the open reading frames of the hepatitis b virus to those of the woodchuck hepatitis virus at the level of amino acid sequence, and to predict the relative hydrophilic character and the secondary structure of putative polypeptides. similarity is seen at the levels of relative hydrophilicity and secondary ... | 1984 | 6585835 |
| immunopathologic aspects of woodchuck hepatitis. | the natural history of infection with woodchuck hepatitis virus (whv) has been studied in a colony of 38 marmota monax. besides serologic assessment for whv markers, light-microscopic findings of 61 liver biopsies were correlated with the results of immunofluorescence analysis for nucleocapsid (whcag) and surface (whsag) antigens. twenty-four chronic whsag carriers all featured signs of continuous viral replication. two major immunomorphologic patterns were observed in their livers: 1) portal he ... | 1984 | 6324594 |
| cloning and structural analysis of integrated woodchuck hepatitis virus sequences from a chronically infected liver. | we have isolated and determined the structure of a recombinant clone in lambda phage charon 30 which contains woodchuck hepatitis virus sequences integrated in woodchuck genomic dna sequences. this clone, in contrast to previously reported clones (ogston et al., cell 29:385-394, 1982), was isolated from a chronically infected liver which never developed hepatocellular carcinoma. southern blot analysis of viral sequences in the clone in conjunction with electron microscope heteroduplex analysis s ... | 1984 | 6328013 |
| woodchuck hepatitis virus: experimental infection and natural occurrence. | sera from 588 woodchucks were assayed for woodchuck hepatitis virus (whv) markers using hepatitis b virus (hbv) reagents which have cross-reactivity with whv markers. twenty per cent of these woodchucks, trapped in delaware, maryland and pennsylvania, had whsag; 50% of these had dna polymerase. there are areas of high and low endemicity within these states. female woodchucks may have a higher incidence of whv markers than do males. woodchuck hepatitis surface antigen (whsag) and anti-whc often o ... | 1984 | 6383996 |
| core antigen and antibody in woodchucks after infection with woodchuck hepatitis virus. | the woodchuck hepatitis virus is a naturally occurring hepatitis b-like virus that infects the eastern woodchuck. direct immunofluorescence staining for woodchuck hepatitis virus core antigen in liver biopsies demonstrated the presence of this antigen in 14 of 17 chronically infected woodchucks, and in 8 of 10 woodchucks undergoing acute infections. fluorescent localization of woodchuck hepatitis virus core antigen was typically cytoplasmic, and this was confirmed further by electron microscopy. ... | 1984 | 6384556 |
| antigenic analysis of woodchuck hepatitis virus surface antigen with site-specific radioimmunoassays. | monoclonal antibodies to five nonoverlapping antigenic domains of woodchuck hepatitis virus surface antigen (whsag) were used to develop site-specific radioimmunoassays. the assays were based on the solid-phase sandwich principle in which different combinations of individual domain-specific antibodies were used as immunoadsorbents and radioiodinated probes. over 85% of the combinations tested were able to detect serum whsag, including those using the same antibody as immunoadsorbent and probe. t ... | 1984 | 6199511 |
| primary hepatoma in a woodchuck (marmota monax) without serologic evidence of woodchuck hepatitis virus infection. | 1984 | 6097011 | |
| nucleotide sequence of a cloned woodchuck hepatitis virus genome: evolutional relationship between hepadnaviruses. | we have determined the complete nucleotide sequence of a cloned dna of woodchuck hepatitis virus (whv), the most oncogenic virus among hepadnaviruses. the genome, designated whv2, is 3,320 base pairs long and contains four major open reading frames (orfs) coded on the same strand of nucleotide sequence as in the human hepatitis b virus (hbv) genome. comparison of the nucleotide sequence and amino acid sequences deduced from it among the genomes of various hepadnaviruses demonstrates that each pr ... | 1985 | 3855246 |
| establishment of a cell line from a woodchuck hepatocellular carcinoma. | a new cell line derived from a woodchuck hepatocellular carcinoma serially transplanted in athymic nude mice has been established and named wh257ge10. the original tumor in the nude mouse system produces woodchuck hepatitis surface antigen and albumin. in addition, woodchuck hepatitis virus dna is integrated into cellular dna. adaptation of the cells to the in vitro culture condition was completed after 15 months with the doubling time of 40 hr. the morphologic features of the cell by light micr ... | 1985 | 3905560 |
| woodchuck hepatitis virus infection: serologic and histopathologic course and outcome. | five out of seven american woodchucks inoculated with woodchuck hepatitis virus developed antigenemia after 2 to 13 weeks followed by an antibody response. one animal became a carrier, and another animal exhibited a primary antibody response. clinical disease was not obvious and aminotransferase elevation could not be demonstrated. liver biopsy showed mononuclear portal infiltration and little parenchymal cell necrosis. | 1985 | 3987680 |
| transcription of woodchuck hepatitis virus in the chronically infected liver. | the transcription of woodchuck hepatitis virus (whv) genome was studied in the liver of chronically infected woodchucks by northern blot, nuclease mapping and primer extension analysis. two major transcripts, 2.1 and 3.7 kb in length, and several minor transcripts were found in samples which supported active whv replication. the 2.1-kb rna represents the major transcript of the s gene, encoding the viral surface antigen (whsag) as demonstrated by blot-hybridization experiments. two transcription ... | 1985 | 4029122 |
| radioimmunoassay and characterization of woodchuck hepatitis virus core antigen and antibody. | solid-phase radioimmunoassays for woodchuck hepatitis virus core antigen (whcag) and antibody (anti-whc) were developed. whcag in woodchuck liver homogenates was characterized by ultracentrifugation in cscl gradients; both heavy (1.35 g/cm3) and light (1.31 g/cm3) cores were obtained from the liver of an animal during acute whv infection, which is consistent with observations in hepatitis b virus infection in man. endpoint titers of anti-whc were higher in chronic whv carriers than in animals re ... | 1985 | 4036315 |
| chronic hepatitis and hepatocellular carcinoma associated with persistent woodchuck hepatitis virus infection. | the livers of 16 woodchucks with naturally acquired chronic infection with woodchuck hepatitis virus were examined both grossly and histologically in 14 biopsy specimens and seven necropsy specimens. fifteen woodchucks had lesions characteristic of chronic hepatitis; ten of these had chronic active hepatitis, four had chronic persistent hepatitis, and one had cirrhosis with nodular regeneration. in one woodchuck there was massive hepatic necrosis attributed to infection with an unclassified prot ... | 1985 | 2994274 |
| scintigraphic diagnosis of primary hepatocellular carcinoma in the woodchuck (marmota monax). | hepatic imaging with 99mtc-sulfur colloid was used to diagnose primary hepatocellular carcinoma (phc) in woodchucks infected with woodchuck hepatitis virus (whv). based on imaging results, 6 of 12 whv-infected woodchucks had space-occupying hepatic lesions, and all 6 had phc. of the remaining woodchucks, 2 did not have phc, 2 had discrete tumors (less than 1 cm diameter), 1 had miliary small tumors, and 1 had tumors located near the great vessels. hepatic imaging was a valuable technique for dia ... | 1986 | 3008602 |
| stable integration of woodchuck hepatitis virus dna in transplanted tumors and established tissue culture cells derived from a woodchuck primary hepatocellular carcinoma. | the fate of integrated woodchuck hepatitis viral (whv) dna was systematically investigated in dna samples from primary hepatocellular carcinoma (hcc) of woodchucks, solid tumors transplanted in athymic mice derived from a primary hcc of woodchuck, and an established cell line of tissue culture originating from the transplanted tumor. in four of five woodchuck primary hccs, whv dna integration was demonstrated in addition to various amounts of extrachromosomal replicative intermediate whv dna. th ... | 1986 | 3011252 |
| hepatocellular carcinoma in ground squirrels persistently infected with ground squirrel hepatitis virus. | although persistent infection with hepatitis b virus and woodchuck hepatitis virus has been associated with development of hepatocellular carcinoma in the host, little has been known of such an association with ground squirrel hepatitis virus (gshv), which is closely related to the woodchuck virus. colonies of gshv-infected and -uninfected beechey ground squirrels were observed for tumors for a period of 5 years. tumors developed in seven squirrels after a minimum of 2.4 years of observation per ... | 1986 | 3012572 |
| rearrangement and enhanced expression of c-myc in hepatocellular carcinoma of hepatitis virus infected woodchucks. | hepatocellularcarcinoma (hcc) that occur in woodchucks chronically infected with woodchuck hepatitis virus (whv) were screened for activation of cellular oncogenes. enhanced expression and allelic alterations of the c-myc oncogene were found in three hcc out of nine. variations in the size of the c-myc transcripts, ranging from 2.0 kilobases (kb) to 5.6 kb, as well as in the level of c-myc gene expression, 5-50-fold higher than in adjacent liver tissues, were observed among the three hcc. rearra ... | 1986 | 3024010 |
| a newly identified hepatitis b type virus in tree squirrels. | virus-associated particles have been isolated from the livers of three common gray tree squirrels (sciurus carolinensis pennsylvanicus) that have histological evidence of hepatitis. two of these livers were also positive by orcein staining, suggesting the presence of surface antigen in the cytoplasm of hepatocytes. fractionation of these particles by cscl density equilibrium gradient centrifugation and assay of the fractions for surface antigen, core antigen, and dna polymerase activities demons ... | 1986 | 3457384 |
| hepadnavirus infection of peripheral blood lymphocytes in vivo: woodchuck and chimpanzee models of viral hepatitis. | the peripheral blood lymphocytes (pbl) of five hepatitis b virus (hbv)-infected chimpanzees and 17 woodchuck hepatitis virus (whv)-infected woodchucks were examined for the presence of viral dna and rna. hbv dna was detected in the pbl of three of three chronically infected chimpanzees but in neither of two animals with acute hbv infection. whv dna was found in the pbl of 11 of 13 chronically infected woodchucks and in the pbl and bone marrow of 1 of 4 woodchucks with antibody to whv surface ant ... | 1986 | 3485201 |
| nucleotide sequence of the woodchuck hepatitis virus surface antigen mrnas and the variability of three overlapping viral genes. | a cdna library was constructed from the liver of a woodchuck chronically infected with woodchuck hepatitis virus (whv). a clone, pws23, encompassing the entire surface and x genes of whv was isolated. comparison of the complete nucleotide (nt) sequence of pws23 with those of genomic dnas from two different whv isolates showed that it contained a nearly full-length copy of the major mrna encoding the viral surface antigen (s mrna). it was colinear with the whv genome over 1858 nt and terminated 2 ... | 1986 | 3582979 |
| experimental infection of the woodchuck (marmota monax monax) with woodchuck hepatitis virus. | six woodchucks, 10 1/2 months of age, injected intramuscularly with 0.02 ml of woodchuck hepatitis virus (whv)-positive serum and two woodchucks of similar age and origin injected with phosphate buffered saline were studied by serial blood samples and liver biopsy sections over an 18 week period. serum samples were assayed for whv surface antigen (whsag), its corresponding antibody (anti-whs) and antibody to whv core antigen (anti-whc). whv core antigen (whcag) was detected in liver biopsy secti ... | 1986 | 3724063 |
| protection of chimpanzees from type b hepatitis by immunization with woodchuck hepatitis virus surface antigen. | two chimpanzees immunized with woodchuck hepatitis virus (whv) surface antigen (whsag) developed antibodies cross-reactive with hepatitis b virus (hbv) surface antigen (hbsag). after challenge with hbv, one animal was completely protected and the other experienced a subclinical infection, without evidence of liver disease. three woodchucks immunized with hbsag developed antibodies to hbsag which did not cross-react with whsag. after challenge with whv, all three woodchucks developed typical acut ... | 1986 | 3783820 |
| failure to detect polyalbumin-binding sites on the woodchuck hepatitis virus surface antigen: implications for the pathogenesis of hepatitis b virus in humans. | binding sites for polymerized albumin on hepatitis b virus components were reported in human hepatitis b virus chronic carriers predominantly with active viral replication (hb e antigen positive). the presence of comparable albumin-binding sites in the woodchuck hepatitis virus (whv) model was examined on whv components obtained from woodchucks with active viral replication (dna polymerase positive). binding sites for polymerized woodchuck serum albumin were not detected on the intact whv virion ... | 1986 | 3783821 |
| identification and localization of pre-s-encoded polypeptides from woodchuck and ground squirrel hepatitis viruses. | a segment from the pre-s region of the woodchuck hepatitis virus (whv) was inserted into an open reading frame vector allowing for the expression in escherichia coli of viral determinants as part of a fusion protein. the bacterially synthesized fusion molecule contained eight amino acids from beta-galactosidase (beta-gal) at the n terminus, followed by 89 pre-s-encoded amino acids and 219 amino acids of chloramphenicol acetyltransferase (cat) at the c terminus (beta-gal:pre-s:cat). this tribrid ... | 1986 | 3941437 |
| main properties of duck hepatitis b virus dna polymerase: comparison with the human and woodchuck hepatitis b virus dna polymerases. | the main properties of the duck hepatitis b virus (dhbv) dna polymerase have been studied and compared with those of the human hepatitis b virus (hbv) and of the woodchuck hepatitis virus (whv) dna polymerases. all 3 enzymes are active under high salt conditions in the presence of high magnesium concentration. dhbv dna polymerase was found less sensitive to ethanol and to operate at higher optimal ph than the hbv and whv dna polymerases. like the other two viral endogenous dna polymerases, the d ... | 1987 | 3446017 |
| hepadnaviruses and retroviruses share genome homology and features of replication. | the hepadnavirus family includes hepatitis b virus (hbv), woodchuck hepatitis virus (whv), ground squirrel hepatitis virus (gshv) and duck hepatitis b virus (dhbv). these viruses share unique ultrastructural, molecular and biological features. hbv has great medical importance in many parts of the world. more important numerically than acute hepatitis b in high prevalence geographic regions is the liver disease associated with chronic infection. there appear to be more than 200 million chronicall ... | 1987 | 3804216 |
| molecular aspects of persistent woodchuck hepatitis virus and hepatitis b virus infection and hepatocellular carcinoma. | it seems evident that the development of fully malignant hcc is a multistage process with many variables. one possible mechanism by which many of these variables may interact is as follows. during chronic active hepatitis, viral dna integration occurs randomly and at a low frequency in hepatocytes. integration may be stimulated by the increased rate of hepatocyte cell division resulting from liver necrosis and regeneration during chronic disease. the presence of viral integrations in the cellula ... | 1987 | 3804217 |
| genetic variation between woodchuck populations with high and low prevalence rates of woodchuck hepatitis virus infection. | woodchuck hepatitis virus (whv) infection is known to be endemic in areas of the mid-atlantic states but is apparently absent from populations in new york and much of new england. blood samples of 40 woodchucks (marmota monax) from new york and from delaware were examined by starch gel electrophoresis, and 18 monomorphic and six polymorphic protein-coding genetic systems were identified. mendelian inheritance of variants of the six polymorphic systems was confirmed in 52 laboratory offspring of ... | 1987 | 3586195 |
| serum bile acid determination for assessment of hepatic injury in the woodchuck. | a direct spectrophotometric assay for determination of the serum bile acid concentration in the woodchuck (marmota monax) has been validated. the assay relies on the conversion of 3-hydroxy bile acids to 3-oxo bile acids by 3 alpha-hydroxysteroid dehydrogenase with concomitant reduction of nad+ to nadh. reduction of nad+ is coupled via a diaphorase catalyst to the formation of a diformazan dye from nitrotetrazolium blue and the diformazan product is measured spectrophotometrically at 540 nm. int ... | 1987 | 3599895 |
| emerging models in the u.s.a.: swine, woodchucks, and the hairless guinea pig. | swine have been used in biomedical research for many years, but have generally been limited to those locations with personnel familiar with this species and with specially designed facilities and equipment. there is currently a growing trend in the united states for more swine, both miniature and domestic to be used as research models. commercial availability, education through workshops and symposia, and specific research applicability in the areas such as: organ transplantation, cardiovascular ... | 1987 | 3601991 |
| metabolism of mutagens and carcinogens in woodchuck liver and its relationship with hepatitis virus infection. | thirty-six wild-caught woodchucks (marmota monax) were characterized according to sex, weight, trapping locality, liver pathology, and serum or hepatic markers of woodchuck hepatitis virus. liver subcellular fractions were assayed for microsomal cytochromes p-450, aryl hydrocarbon hydroxylase, glutathione, cytosolic enzymes involved in its metabolism (glutathione s-transferase, glutathione peroxidase, and glutathione reductase), in the hexose monophosphate shunt (glucose 6-phosphate dehydrogenas ... | 1987 | 3607750 |
| expression of the hepatitis b virus core gene in vitro and in vivo. | the core gene of hepatitis b virus contains two in-phase aug codons which may both be used in the viral life cycle. by in vitro translation of transcripts produced in vitro, we investigated the corresponding core gene products and their counterparts in vivo. depending on the location of the 5' end of the transcripts, two major core gene-derived proteins were obtained. in transcripts with both in-phase augs, only the first one was efficiently used and resulted in synthesis of a 25-kilodalton prot ... | 1987 | 3625840 |
| maintenance of woodchuck hepatitis virus activity in woodchuck hepatocyte primary culture. | primary cultures of non-proliferating hepatocytes isolated by the two-step collagenase perfusion method from woodchuck naturally infected with hepatitis virus (whv) were used to study whv propagation in vitro. hepatocytes carrying whv dna exhibited a very high level of survival and retained their morphological characteristics for 2 to 3 months. over this time, they were found to produce virus-specific proteins and release viral particles with dna polymerase activity into the medium. using southe ... | 1987 | 3572356 |
| lymphoid cells in the spleens of woodchuck hepatitis virus-infected woodchucks are a site of active viral replication. | lymphoid cells were purified from the spleens of 15 woodchucks and examined for the presence of woodchuck hepatitis virus (whv). lymphoid cells from the spleens of eight of eight chronically infected animals contained high levels of whv rna and dna. a 100-fold lower level of whv dna was found in the spleen from one of five animals that had recovered from acute whv infections 2 years before this analysis. no whv nucleic acids were observed in either of two uninfected animals. whv dna patterns in ... | 1987 | 3573141 |
| effects of an extract from phyllanthus niruri on hepatitis b and woodchuck hepatitis viruses: in vitro and in vivo studies. | an aqueous extract of the plant phyllanthus niruri inhibits endogenous dna polymerase of hepatitis b virus and binds to the surface antigen of hepatitis b virus in vitro. the extract also inhibits woodchuck hepatitis virus (whv) dna polymerase and binds to the surface antigen of whv in vitro. the extract, nontoxic to mice, was tested for antiviral activity in woodchucks (marmota monax). in a trial using six long-term whv-carrier woodchucks, five treated animals showed a faster decrease in woodch ... | 1987 | 3467354 |
| hepatocarcinogenicity of the woodchuck hepatitis virus. | during investigations of the evolution of experimental laboratory infections of woodchucks (marmota monax) with the woodchuck hepatitis virus (whv), eight hepatocellular carcinomas (hcc) were observed, six in newborns and two in young adult animals, all within 17-36 months after infection. the absence of an external cocarcinogenic effect in the well-monitored woodchucks indicates the carcinogenicity of whv and suggests the same for the genetically and biologically similar human hepatitis b virus ... | 1987 | 3468514 |
| establishment and characterization of a diethylnitrosamine-initiated woodchuck hepatocyte cell line. | woodchucks free from woodchuck hepatitis virus were treated with diethylnitrosamine in vivo for 2 months, and then hepatocytes obtained by enzymatic perfusion were cultured with the hepatopromoter phenobarbital. this in vivo-in vitro procedure gave rise to proliferating epithelial cell foci, from one of which the presently described hepatocyte cell line (wlc-3) was established and characterized. wlc-3 cells possess morphological and biochemical features of differentiated hepatocytes, including g ... | 1987 | 2888713 |
| [hbv and hepatocellular carcinoma]. | significant research evidence has demonstrated an association between persistent infection with hepatitis b virus (hbv) and the generation of hepatocellular carcinoma (hcc). these findings are based on epidemiologic studies, molecular studies and studies of hbv like viruses. epidemiologically, the geographic correlation between hbv infection and hcc, serum hbsag in patients with hcc, familial clustering of hcc, prospective studies, and pathological studies are discussed. molecular studies of hbv ... | 1987 | 3030195 |
| in vitro recombinants of ground squirrel and woodchuck hepatitis viral dnas produce infectious virus in squirrels. | hepatitis b viruses of humans, woodchucks, ground squirrels, and ducks are similar biochemically but differ with respect to host range and pathogenicity. to pursue the genetic basis of these properties in the absence of a cell culture system for virus growth, we exploited the demonstrated infectivity of cloned hepatitis b virus dna in whole animals. we constructed several recombinant molecules in vitro between cloned infectious genomes of woodchuck hepatitis virus (whv) and ground squirrel hepat ... | 1987 | 3041044 |
| activation of c-myc by woodchuck hepatitis virus insertion in hepatocellular carcinoma. | two hepatocellular carcinomas, induced in woodchucks chronically infected with woodchuck hepatitis virus, were characterized for viral integration near c-myc and alterations of c-myc expression. in one tumor, viral integration within the untranslated region of c-myc exon 3 resulted in overexpression of a long c-myc viral cotranscript. in the second tumor, a single insertion of highly rearranged viral sequences 600 bp upstream of c-myc exon 1 was associated with increased levels of normal c-myc m ... | 1988 | 3180223 |
| propagation of woodchuck hepatitis delta virus in primary woodchuck hepatocytes. | monolayer cell cultures of primary woodchuck hepatocytes, prepared by perfusing the liver in situ with collagenase type i, yielded hepatocytes with a viability of greater than 90% which could be held in culture for up to 3 months. cultures of primary woodchuck hepatocytes were infected one day after plating with hepatitis delta virus (hdv) which had been passaged five times in woodchucks and was therefore identified as woodchuck hepatitis delta virus (whdv). replication of whdv was demonstrated ... | 1988 | 3201748 |
| vertical transmission of woodchuck hepatitis virus. | one newborn and 24 fetal woodchuck litters from a woodchuck hepatitis virus (whv) endemic population were examined for serological or hepatic evidence of whv. in 18 of 24 fetal litters, there was detectable whv dna in the livers, either at explant culture or tissue extract. most of those whv dna-positive liver extracts, which were examined by southern blot, showed integration of whv. however, whv dna replicative forms without integration were demonstrated in livers of two litters from late gesta ... | 1988 | 3204365 |
| mitogen-induced replication of woodchuck hepatitis virus in cultured peripheral blood lymphocytes. | peripheral blood lymphocytes (pbls) isolated from woodchucks chronically infected with the woodchuck hepatitis virus (whv) carry low levels of nonreplicating whv dna. when pbls from chronic carrier woodchucks were activated in culture with the generalized mitogen lipopolysaccharide (lps), whv dna replication was initiated in cells obtained from one of three animals examined. intracellular whv core particles, containing whv dna replication intermediates, rna/dna hybrid molecules, and an active en ... | 1988 | 3261887 |
| localization of woodchuck hepatitis virus in the liver. | localization of woodchuck hepatitis virus in liver tissue from 10 infected woodchucks was investigated immunohistochemically and ultrastructurally. woodchuck hepatitis virus surface antigen was detected by immunoperoxidase methods in the cytoplasm of hepatocytes with a fine granular and/or inclusion body appearance. woodchuck hepatitis virus surface antigen positive hepatocytes were often found in the peripheral zone of hepatic lobules. in contrast to human hepatitis b core antigen, woodchuck he ... | 1988 | 3276592 |
| interaction of woodchuck hepatitis virus surface antigen with hepatocyte plasma membrane in woodchuck chronic hepatitis. | the extent of association between woodchuck hepatitis virus surface antigen and host hepatocyte plasma membrane in chronic hepatitis was studied. purified membranes containing the antigen were treated with various agents which perturb plasma membrane constituents to elute woodchuck hepatitis virus surface antigen. the products from disrupted membranes were analyzed by sedimentation in sucrose gradients and tested to identify the antigen reactivity. the results indicated that membrane-bound woodc ... | 1988 | 3286458 |
| sequence comparison of woodchuck hepatitis virus replicative forms shows conservation of the genome. | the complete nucleotide sequence of virion dna from two isolates of woodchuck hepatitis virus (whv 7 and whv 59) was determined along with the sequence of supercoiled dna from one of those isolates (whv 7). the sequences of the two whv isolates were compared with the previously published sequences of two other isolates (whv 1 and whv 8). the range of nucleotide sequence variation of the four isolates (1 to 3.5%) was similar to those of hbvs of the same subtype (1.5 to 2%), but less than those of ... | 1988 | 3336938 |
| establishment of a new cell line from a woodchuck hepatocellular carcinoma. | a new cell line derived from a woodchuck hepatitis surface antigen-positive woodchuck hepatocellular carcinoma has been established and named t3-hep-w1. this new cell line was established directly from a primary woodchuck hepatocellular carcinoma. adaptation of the cells to the in vitro culture condition was completed after 3 months, with the doubling time of 24 hr. the morphologic features of the cell by light microscopy were of an epithelial type. the modal chromosome number was 100. ornithine ... | 1988 | 3338696 |
| presence of antibodies to the polymerase gene product(s) of hepatitis b and woodchuck hepatitis virus in natural and experimental infections. | antibodies against synthetic peptides derived from the polymerase gene of the hepatitis b virus (hbv) were present in 80% of renal dialysis patients infected with hbv and in woodchucks infected with woodchuck hepatitis virus (whv). polymerase antibody (anti-pol) appeared as the earliest marker of both hbv and whv infections in approximately half of the individuals tested, suggesting that these antibodies were generated following early viral replication in the liver during the incubation period a ... | 1988 | 3351482 |
| an experimental transmission of woodchuck hepatitis virus to young chinese marmots. | fourteen young chinese marmots (marmota bobak sibirica radde) were randomly allocated to two groups of seven each. they were injected intrahepatically with a standard woodchuck hepatitis virus challenge pool or a negative pool, prepared from sera of woodchucks with and without woodchuck hepatitis virus infection, respectively. marmot no. 2 in the experimental group experienced an episode of seroconversion from woodchuck hepatitis surface antigen to anti-woodchuck hepatitis antibody. woodchuck he ... | 1988 | 3356418 |
| systemic distribution of woodchuck hepatitis virus in the tissues of experimentally infected woodchucks. | to better assess the extent of the tissue tropism of mammalian hepadnaviruses, 10 tissues from each of six woodchucks were examined for the presence and state of woodchuck hepatitis virus (whv) nucleic acids 15 months after experimental whv infection. the tissues examined were peripheral blood lymphocytes, lymph node, spleen, bone marrow, thymus, pancreas, kidney, ovary, testis, and liver. tissue samples from three chronically infected animals and three animals with serologic patterns of recover ... | 1988 | 3388768 |
| the hybrid eia test: a specific and sensitive assay for the detection of woodchuck antibody to hepatitis surface antigen (anti-whs). | 'ausria ii' polystyrene beads (abbott labs, n. chicago) are reacted with woodchuck serum positive for whsag in a dilution predetermined by titration. this modified bead is used in a blocking assay to detect the presence of antibody to the surface antigen of woodchuck hepatitis virus (anti-whs). serum containing woodchuck anti-whs and commercial horseradish peroxidase (hrp) labeled anti-hbs are sequentially added. a drop in optical density at 492 nm of 50% or more due to the blocking of hrp conju ... | 1988 | 3397403 |
| dna-binding activity of hepatitis b e antigen polypeptide lacking the protaminelike sequence of nucleocapsid protein of human hepatitis b virus. | the characteristics of binding of hepatitis b core antigen (hbcag) and hepatitis b e antigen (hbeag) polypeptides to hepatitis b virus (hbv) dna were analyzed. hbcag polypeptide from recombinant hbv core particles and hbeag polypeptide from partially purified serum hbeag were prepared and verified to have molecular weights of 21,500 (p21.5) and of 17,000 (p17) and 18,000 (p18), respectively, by immunoblot analysis. by reaction of these proteins on a nitrocellulose membrane with cloned 32p-hbv dn ... | 1988 | 3404582 |
| enzyme-altered liver cell foci in woodchucks infected with woodchuck hepatitis virus. | the histochemical characteristics of liver cell foci in woodchucks were investigated. the foci appeared to be distributed throughout the liver and were observed only in the woodchuck hepatitis virus (whv)-positive animals, including all 19 woodchucks with hepatocellular carcinoma(hcc), and 7 without hcc. no foci appeared in 11 whv-negative animals. histochemical studies revealed that liver cell foci and carcinoma cells were characterized by positive gamma-glutamyl transpeptidase (ggt) enzymatic ... | 1988 | 2898465 |
| characterization of a herpesvirus isolated from woodchuck hepatocytes. | 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 he ... | 1988 | 2839596 |
| establishment and characterization of a woodchuck hepatocellular carcinoma cell line (wh44ka). | a continuous cell line was established from a hepatocellular carcinoma obtained from a woodchuck that was sero-positive for woodchuck hepatitis virus (whv). the cell line, designated wh44ka, grows as an adhering monolayer with a doubling time of 36 hr in dulbecco's modified eagle's medium supplemented with 10% fetal bovine serum. the cells not only showed epithelial origin on light and electron microscopic examination but also possess biosynthetic markers of the latter, such as albumin and alpha ... | 1988 | 2453497 |
| insulinlike growth factor ii expression and oval cell proliferation associated with hepatocarcinogenesis in woodchuck hepatitis virus carriers. | insulinlike growth factor ii (igf-ii) is a highly mitogenic fetal growth factor suspected of regulating the growth of a wide spectrum of tissues via an autocrine or paracrine mode of action or both. high steady-state levels of igf-ii rna were detected in 45% of hepatocellular carcinomas (hccs) arising from woodchuck livers with persistent woodchuck hepatitis virus (whv) infection. analysis of whv rna in the same hccs revealed that hccs with high levels of igf-ii rna contained low or undetectable ... | 1988 | 2457114 |
| x-region-specific transcript in mammalian hepatitis b virus-infected liver. | in vitro gene expression systems for hepatitis b virus have demonstrated that the virus genome is capable of producing an x-region-specific transcript of approximately 0.7 kilobases (kb). however, this transcript has not been detected in virus-infected cells. we now report the presence of a heterogeneous x-region-specific transcript of approximately 0.65 kb that is found primarily in the nucleus of liver cells infected with the woodchuck hepatitis virus. interestingly, the majority of the transc ... | 1988 | 2459409 |
| hepatocellular carcinoma in woodchuck hepatitis virus-infected woodchucks: presence of viral dna in tumor tissue from chronic carriers and animals serologically recovered from acute infections. | during long-term studies of the natural history of woodchuck hepatitis virus infection, five cases of histologically confirmed, primary hepatocellular carcinoma were observed in a total of 92 woodchucks which had recovered, by analysis of viral serologic markers (whsag-, anti-whc+, anti-whs+), from experimental acute woodchuck hepatitis virus infections 20 to 30 months prior to the detection of hepatocellular carcinoma. no hepatocellular carcinoma was observed in 167 uninfected controls at least ... | 1989 | 2465987 |
| characterization of the incorporation of woodchuck hepatitis virus surface antigen into hepatocyte plasma membrane in woodchuck hepatitis and in the virus-induced hepatocellular carcinoma. | interaction between woodchuck hepatitis virus surface antigen and proteins of hepatocyte plasma membranes were examined in the course of woodchuck hepatitis virus infection. membranes purified from animals with histologically confirmed acute hepatitis, active or persistent chronic hepatitis and the virus-related hepatocellular carcinoma were evaluated for the virus surface antigen contents, treated with agents eluting plasma membrane-bound antigen to test the extent of the antigen-membrane assoc ... | 1989 | 2535620 |
| chromosomal assignment of woodchuck hepatitis virus (whv) dna integration sites in a woodchuck hepatocellular carcinoma-derived cell line (wh257ge10). | the chromosomal sites of woodchuck hepatitis virus (whv) dna integration were identified in a woodchuck hepatocellular carcinoma-derived cell line (wh257ge10) by the in situ hybridization technique using 3h-labelled whv whole genome (whv 2) as a probe. the g-banded chromosome spreads from wh257ge10 were identified and diagrammed schematically according to their band patterns. whv dna was integrated into 2 sites: 33 region of the long arm of chromosome 6 (6q33) and 31 region of the long arm of ch ... | 1989 | 2539331 |
| interaction of fucoidan from pelvetia fastigiata with surface antigens of hepatitis b and woodchuck hepatitis viruses. | a sulfated polysaccharide isolated from pelvetia fastigiata, a marine algae, was found to inhibit in vitro the reaction of the surface antigen of hepatitis b virus (hbsag) or of woodchuck hepatitis virus (whsag) with antibody to hbsag (anti-hbs). the polysaccharide was composed mainly of 1----2 linked l-fucose-4-sulfate with some (less than 10%) 1----3 linkages. the inhibition of the reaction of hbsag with anti-hbs or of whsag with anti-hbs was found to be directly proportional to the molecular ... | 1989 | 2544915 |
| characterization of woodchuck hepatitis virus dna and rna in the hepatocellular carcinomas of woodchucks. | integration and transcription of woodchuck hepatitis virus dna were studied by southern and northern blot analysis in 26 hepatocellular carcinomas and in adjacent nontumor tissue of woodchucks (marmota monax). all liver tissue chronically infected with woodchuck hepatitis virus contained various amounts of episomal and replicative forms of woodchuck hepatitis virus dna: episomal and replicative forms of woodchuck hepatitis virus dna without integration were found in six tumors, episomal and inte ... | 1989 | 2545590 |
| in vitro infection of woodchuck hepatocytes with woodchuck hepatitis virus and ground squirrel hepatitis virus. | primary cultures of woodchuck hepatocytes were demonstrated to be susceptible to in vitro infection by both woodchuck hepatitis virus and ground squirrel hepatitis virus, as evidenced by the appearance of dna species characteristic of hepadnavirus replication. initiation of infection by woodchuck hepatitis virus was blocked by the presence of suramin, polybrene, or dideoxycytidine. viral ccc dna, the putative template for viral rna transcription, was detected at 2 days postinfection. accumulatio ... | 1989 | 2549713 |
| hepatitis b virus and hepatocellular carcinoma--treatment of hbv carriers with phyllanthus amarus. | extracts of phyllanthus amarus inhibit the dna polymerase of hbv and related viruses. woodchuck carriers of woodchuck hepatitis virus (whv) were treated intraperitoneally with p. amarus extract. three of four animals which had been recently infected lost the virus. animals infected for about 3 months or more had a decrease in virus levels. human carriers of hbv were treated orally for 1 month. about 60% of the carriers lost hbv, which did not return during the observation period. fractions conta ... | 1989 | 2559794 |
| hepadnaviruses and hepatocellular carcinoma (hcc). | members of the hepadnavirus family share properties of virion structure, genome structure and replication, epidemiologic behavior, and pathogenic effects. persistent infections with hepatitis b virus (hbv) in man, woodchuck hepatitis virus (whv) in marmota monax, ground squirrel hepatitis virus (gshv) in spermophilus beecheyi, and duck hepatitis b virus (dhbv) in domestic ducks of china are associated with development of hepatocellular carcinoma (hcc). epidemiological evidence implicating hepadn ... | 1989 | 2559799 |
| construction of a plasmid for expression of foreign epitopes as fusion proteins with subunit b of escherichia coli heat-labile enterotoxin. | a novel vector (pfs2.2) for high-level expression of fusion polypeptides with the nontoxic subunit b (lt-b) of escherichia coli heat-labile enterotoxin in escherichia coli and salmonellae is presented. it carries the complete coding sequence of lt-b under lac promoter control and a universal polylinker site for the in-frame insertion of foreign genes at the lt-b gene 3' end. by using this vector, fusion proteins comprising parts of the human or woodchuck hepatitis b virus surface and nucleocapsi ... | 1989 | 2647637 |
| hepadnavirus-induced liver cancer in woodchucks. | woodchuck hepatitis virus (whv), a member of the hepadnaviridae, is closely related to hepatitis b virus (hbv) in its virus structure, genetic organization, and mechanism of replication. as with hbv in man, persistent whv infection is common in natural woodchuck populations and is associated with chronic hepatitis and hepatocellular carcinoma (hcc). in 1980, a program was initiated to develop the woodchuck as an experimental model of hepadnavirus infection and disease. the experimental studies h ... | 1989 | 2695243 |
| molecular analysis of the function of direct repeats and a polypurine tract for plus-strand dna priming in woodchuck hepatitis virus. | the replication of the hepadnavirus dna genome is initiated by reverse transcription of pregenome rna into minus-strand dna followed by plus-strand dna synthesis. the priming of plus-strand dna requires the transfer of an rna primer from pregenome rna to the primer-binding site on minus-strand dna. annealing of the primer to the primer-binding site is facilitated by short direct repeats, dr1 and dr2. to investigate the mechanism of plus-strand primer formation, we have introduced specific mutati ... | 1989 | 2704069 |
| enhanced metabolic activation of chemical hepatocarcinogens in woodchucks infected with hepatitis b virus. | the metabolism of chemical carcinogens was investigated in liver preparations from 28 captive woodchucks (marmota monax). of these, 23 were naturally infected with the woodchuck hepatitis virus (whv), and eight also had primary hepatocellular carcinoma (phc). twenty-nine parameters were investigated in liver subcellular fractions, including cross-reactivity with hbsag, and biochemical parameters, such as gamma-glutamyl transpeptidase, cytochrome p-450 and microsomal monooxygenases (aryl hydrocar ... | 1989 | 2720903 |
| mutation rate of the hepadnavirus genome. | an essential factor for charting the evolution of hepadnaviruses is an estimation of the mutation rate of the virus genome during replication in the host. in order to determine the mutation rate of the hepadnavirus genome under defined experimental conditions, we transfected 10 neonatal woodchucks with an infectious molecular clone of woodchuck hepatitis virus (whv). by 4 months post-transfection, all 10 animals showed serological evidence for whv infection. subsequently, 1 animal became chronic ... | 1989 | 2728351 |
| [breeding and care for wild woodchucks (marmota monax) by indoor and outdoor housing]. | woodchuck (marmota monax) is a very useful animal for studying human diseases such as endocrine, metabolic or cardiovascular diseases. it is regarded especially as the most excellent animal model for human hepatic cell cancer since woodchuck hepatitis virus has various biological characters similar to those of human hepatitis b virus. we have investigated in domestic this wild animals as laboratory experimental animals and succeeded in breeding and rearing in our outdoor facilities. | 1989 | 2744103 |