Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| transactivation of cellular gene expression by hepatitis b viral proteins: a possible molecular mechanism of hepatocarcinogenesis. | epidemiologic data indicate the crucial role of chronic hepatitis b virus (hbv) infection in hepatocellular carcinoma (hcc) development. on the molecular level, hbv sequences are frequently integrated in hepatocellular dna. however, in contrast to the woodchuck model, in which specific hbv-dna integration is detectable in most cases, insertional (in-) activation of cellular genes seems to be a rare event in man. the recent discovery of transactivating functions exerted by hbx and truncated hbs(u ... | 1995 | 7602073 |
| recombinant duck interferon: a new reagent for studying the mode of interferon action against hepatitis b virus. | although interferon is widely used to treat chronic hepatitis b virus infections, its mode of action against hepadnaviruses is largely unknown. this deficit is due mainly to the lack of suitable model systems. the duck system could not be used because purified duck interferon was not available in sufficient quantities. we have now cloned a dna fragment that contains an intronless gene for duck interferon. the primary translation product consists of 191 amino acids, the n-terminal 30 residues of ... | 1995 | 7571434 |
| complete nucleotide sequence of the herpesvirus simiae glycoprotein g gene and its expression as an immunogenic fusion protein in bacteria. | the nucleotide sequence of a 2384 bp portion within the unique short (us) region of the herpesvirus simiae (simian herpes b virus; shbv) genome is presented. a partial and a complete open reading frame (orf) were found within this nucleotide sequence. the partial orf encodes the c terminus (147 amino acids) of a protein kinase which is highly conserved in the herpes simplex virus type 1 (hsv-1) and type 2 (hsv-2) and simian agent 8 (sa8) us regions. the complete orf is located 3' to the partial ... | 1995 | 7561753 |
| inhibition of woodchuck hepatitis virus replication by adenine arabinoside monophosphate coupled to lactosaminated poly-l-lysine and administered by intramuscular route. | we prepared a hepatotropic conjugate, suitable for intramuscular (im) injection, of lactosaminated poly-l-lysine with adenine arabinoside monophosphate (ara-amp), a drug active against hepatitis b virus (hbv). we studied its organ distribution in mice and its antiviral activity in woodchucks that are carriers of woodchuck hepatitis virus (whv). in mice, after im administration of a conjugate tritiated in the drug moiety (5.2 micrograms/g equal to 2 micrograms/g of ara-amp) radioactivity in liver ... | 1995 | 7557853 |
| in vitro activation of woodchuck lymphocytes measured by radiopurine incorporation and interleukin-2 production: implications for modeling immunity and therapy in hepatitis b virus infection. | cellular immune responses to hepatitis b virus (hbv) play an important role in the resolution of acute infection. they also influence the course of chronic infection and disease but are inadequate to completely clear the infection. woodchuck hepatitis virus (whv) infection of the woodchuck can provide a model to study these processes. lymphocyte responses of woodchucks were assessed by in vitro proliferation and/or interleukin (il)-2 assays using mitogen (concanavalin a [cona]), cytokine (il-2), ... | 1995 | 7544755 |
| detection of an rnase h activity associated with hepadnaviruses. | replication of the hepadnavirus dna genome is accomplished via reverse transcription of an intermediate, pregenomic rna molecule. this process is likely to be carried out by a virally encoded, multifunctional polymerase which possesses dna- and rna-dependent dna polymerase and rnase h activities. however, the nature of the product(s) of the polymerase gene predicted to mediate these functions is unclear. biochemical studies of the polymerase protein(s) have been limited by its apparent low abund ... | 1995 | 7543585 |
| cytosolic activation of aromatic and heterocyclic amines. inhibition by dicoumarol and enhancement in viral hepatitis b. | the aromatic amines 2-aminofluorene (2af), 2-acetylaminofluorene, and 2-aminoanthracene, and the heterocyclic amines 2-amino-3-methylimidazo[4,5-f]quinoline (iq), 2-amino-3,4-dimethylimidazo[4,5-f]quinoline, and 3-amino-1-methyl-sh-pyrido[4,3-b]indole (trp-p-2) were activated by rat liver cytosolic fractions to form mutagenic metabolites in salmonella typhimurium strains ta98, ta98nr, and ta98/1,8-dnp6. in the case of the trp-p-2, the cytosolic activation was even more potent than the microsomal ... | 1994 | 7534225 |
| improved immunogenicity in mice of a mammalian cell-derived recombinant hepatitis b vaccine containing pre-s1 and pre-s2 antigens as compared with conventional yeast-derived vaccines. | the widely used hepatitis b virus (hbv) vaccines consist of the small hepatitis b surface (shbs) protein produced in transfected yeast cells. the frequency of non-responders, especially among immunocompromised patients, has increased the demand for a more immunogenic vaccine. we evaluated the immunogenicity of recombinant hbs 20 nm particles secreted by transfected chinese hamster ovary (cho) cells, bio-hep-b (biotechnology general ltd, israel), and compared it with yeast-derived vaccines. the c ... | 1994 | 7533967 |
| phenotypic mixing between different hepadnavirus nucleocapsid proteins reveals c protein dimerization to be cis preferential. | hepadnaviruses encode a single core (c) protein which assembles into a nucleocapsid containing the polymerase (p) protein and pregenomic rna during viral replication in hepatocytes. we examined the ability of heterologous hepadnavirus c proteins to cross-oligomerize. using a two-hybrid assay in hepg2 cells, we observed cross-oligomerization among the core proteins from hepatitis b virus (hbv), woodchuck hepatitis virus, and ground squirrel hepatitis virus. when expressed in xenopus oocytes, in w ... | 1994 | 7518533 |
| thf gamma 2 stimulates cytokine release by peripheral blood mononuclear cells of patients with chronic hepatitis b virus infection. | a recent study indicated that thymic hormones have antiviral effects in human hepatitis b virus infection and woodchuck hepatitis virus infection. these hormones are known to exert immunomodulatory effects on lymphocyte maturation and function; because these are abnormal in patients with chronic hepatitis b virus infection, we have examined the effects of a thymic hormone (thf gamma 2) on peripheral blood mononuclear cells from patients with chronic hepatitis b virus infection. thf gamma 2 (50 o ... | 1994 | 7516950 |
| replication of influenza b virus in chicken embryos is suppressed by exogenous aprotinin. | chicken embryo proteinases, one of which is a blood clotting factor xa-like proteinase, are known to effectively cleave the haemagglutinin (ha) of influenza b viruses to permit their replication in chicken embryonated eggs. here we show that injection of the serine proteinase inhibitor, aprotinin, into the allantoic cavity of eggs infected with influenza b/hong kong/73 and b/lee/40 viruses suppresses the viral ha cleavage and reduces the virus proteolytic activation and replication. effective in ... | 1994 | 7515225 |
| distinguishing between acute and symptomatic chronic hepatitis b virus infection. | differentiating between an acute hepatitis b (ah-b) infection and an acute exacerbation of a chronic hepatitis b (ch-b) infection can present a problem for the clinician. the only current serological method of distinguishing between acute and symptomatic chronic hepatitis b virus (hbv) infection is the immunoglobulin m antibody to hepatitis b core antigen (anti-hbc) assay, which can be problematic. therefore, in an attempt to better distinguish between acute and chronic hbv infection, sera from ... | 1994 | 7511551 |
| duck hepatitis b virus infection of muscovy duck hepatocytes and nature of virus resistance in vivo. | to test the hypothesis that in vivo resistance to hepadnavirus infection was due to resistance of host hepatocytes, we isolated hepatocytes from muscovy ducklings and chickens, birds that have been shown to be resistant to duck hepatitis b virus (dhbv) infection, and attempted to infect them in vitro with virus from congenitally infected pekin ducks. chicken hepatocytes were resistant to infection, but we were able to infect approximately 1% of muscovy duck hepatocytes in culture. infection requ ... | 1994 | 7511172 |
| duck hepatitis b virus integrations in lmh chicken hepatoma cells: identification and characterization of new episomally derived integrations. | while the cytoplasmic phase of the hepadnavirus replication cycle is well understood, very little is known about the nuclear phase. in contrast to retroviruses, proviral integration is not required for hepadnavirus replication; however, some of the viral dnas in the nucleus are diverted into an integration pathway. under certain conditions these integrations function as carcinogenic agents. in order to study the integration process, we have utilized lmh-d2 cells, which replicate wild-type duck h ... | 1995 | 7494330 |
| 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 |
| membranous glomerulopathy associated with hepatitis b core antigen immune complexes in children. | direct immunofluorescence, immunoelectron microscopy, and special immunohistochemical procedures including guinea pig complement fixation, differential elution, and in situ antigen binding were employed in an immunomorphologic analysis of kidney biopsy specimens from 98 children with clinically diagnosed nephrotic syndrome and/or glomerulonephritis (gn). glomerular deposits of hepatitis b virus (hbv) antigens, immunoglobulins, and complement were detected in specimens from 24 children, all serop ... | 1980 | 7350816 |
| induction of cell-mediated immunity to hbsag polypeptides. | adult male guinea pigs were immunized with hepatitis b virus polypeptides prepared by triton x-100 solubilization of purified 22-nm hepatitis b surface antigen (hbsag) particles. a virus-specific subunit containing both the 28,000 molecular weight glycoprotein and the 23,000 molecular weight protein stimulated both cell-mediated and humoral immunity. a whole-blood-cell transformation assay additionally showed that the 64,000 molecular weight component of hbsag, previously shown to contain host-s ... | 1981 | 7333794 |
| 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 |
| 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 |
| a vaccine prepared from the 22 nm particles of surface hepatitis b antigen (hbsag). | a method for obtaining a subunit inactivated vaccine preparation from the 22-nm particles of hbsag is proposed. for inactivation of the residual infectious hepatitis b virus (hbv) the preparations were successively treated with 1% sodium dodecyl sulfate (sds) and nucleases. in addition, thermal denaturation and ultraviolet irradiation of hbv dna were used. as a control the biologic activity of a reference virus (sv40) was tested after the same treatment. the effectiveness of dna inactivation was ... | 1980 | 7229622 |
| breeding of macaca fascicularis for poliovaccine production. | in our institute cynomolgus monkeys (m. fascicularis) are mainly used for production and control of poliovaccine. in 1974 a small individual breeding colony was started. last year the colony was enlarged with 10 harem groups. based on colony reproduction data, group breeding seems more successful than individual breeding. owing to developments in the production of poliovaccine, a state of total self supply is within reach. however attention must be paid to factors reducing breeding results, comp ... | 1981 | 7227650 |
| immunization of chimpanzees with hepatitis b virus-derived polypeptides. | previous studies established that the purified polypeptides derived from the 22-nm particles associated with hepatitis b surface antigen (hbsag) produce both humoral and cellular immunity against hbsag in guinea pigs. therefore, the two major polypeptides with molecular weights of 22,000 and 25,000 (p22 and p25, respectively) were isolated, adsorbed to an alum adjuvant, and used to immunize four nonimmune chimpanzees. a vigorous anti-hbs response was observed in all four animals after one inocul ... | 1981 | 7216495 |
| antibody to hepatitis b virus surface and core antigens in gambia pouched rats (cricetomys gambianus). | sera from 108 cricetomys gambianus (gambia pouched rat) were investigated for hbv and hav serum markers. 42.6% of them evidenced anti-hbs and 12.0% anti-hbc. hbs ag was never detected. the most probable hypothesis is that these animals were infected with a new virus related to hbv. | 1982 | 7184516 |
| biological characterization of acute infection with ground squirrel hepatitis virus. | ground squirrel hepatitis virus (gshv) is a small dna virus, structurally and antigenically related to the human hepatitis b virus, which occurs naturally among certain wild populations of ground squirrels (p. l. marion et al., proc. natl. acad. sci. u.s.a. 77:2941-2945, 1980). serum from naturally infected animals was used to transmit gshv in the laboratory by parenteral inoculation of susceptible squirrels. sixty percent of recipient animals developed viral surface antigenemia after a latent p ... | 1982 | 7143570 |
| presence and state of woodchuck hepatitis virus dna in liver and serum of woodchucks: further analogies with human hepatitis b virus. | 1982 | 7112938 | |
| 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 |
| specificity of hepatitis b virus affinity for human hepatic tissue. | using radiolabeled purified hepatitis b surface antigen and human liver slices, the affinity of hepatitis b virus to its host organ was evaluated. saturable adsorption of the 125i-hbs ag complex to liver was demonstrated over both time and complex concentration which could be blocked by excess unlabeled antigen. the specific binding was not found using human pancreas, lung, or kidney tissue. correspondingly, no specific binding could be found for murine liver but it could be demonstrated with wo ... | 1982 | 7069406 |
| detection of influenza a virus by radioimmunoassay and enzyme-immunoassay from nasopharyngeal specimens. | four-layer (indirect) radioimmunoassay (ria) and enzyme-immunoassay (eia) techniques were developed for the detection of influenza a and b virus in the sonicated nasopharyngeal specimens from patients hospitalized for acute respiratory infection. polystyrene beads (ria) or polystyrene microtiter plates (eia) were used as the solid-phase, guinea pig antivirus immunoglobulins as the catching antibodies, rabbit antivirus immunoglobulins as the secondary antibodies, and 125i-labeled sheep antirabbit ... | 1981 | 7026733 |
| humoral and cellular immunity to hepatitis b virus-derived antigens: comparative activity of freund complete adjuvant alum, and liposomes. | complete freud adjuvant, aluminum gel, and liposomes were compared for their ability to enhance the immunogenicity of an intact 22-nm hbsag particle vaccine and an hbsag-derived polypeptide vaccine in guinea pigs. both humoral and cell-mediated immune responses were evaluated. the greatest immune response was obtained with complete freund adjuvant, regardless of the antigen preparation. aluminum gel appeared to be a better adjuvant for 22-nm hbsag particles, but the liposomes rendered polypeptid ... | 1980 | 7014445 |
| 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 |
| 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 |
| 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 |
| 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 |
| antibody to hepatitis b surface antigen in nonprimate animal species. | the hepatitis b virus infects only humans and higher apes. viruses similar to the human hepatitis b virus (hepadna viruses) have been discovered in several nonprimate species including woodchucks, ground squirrels, and domesticated ducks. to search for other models of hepatitis b virus infection, we screened serum specimens from 64 exotic animals (24 species), 56 domesticated animals (6 species), and 52 laboratory animals (3 species). samples were tested for deoxyribonucleic acid polymerase by e ... | 1983 | 6840476 |
| 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 |
| detection of interspecies idiotypic cross-reactions associated with antibodies to hepatitis b surface antigen. | a common idiotype was defined by a rabbit anti-idiotypic antiserum generated against human antibodies to hepatitis b surface antigen (anti-hbs). this idiotype was detected in anti-hbs from eight different individuals who had been previously infected with hepatitis b virus and is referred to as the chbs idiotype. the chbs idiotype was also identified in sera from rabbits, mice, guinea pigs, swine, goats and chimpanzees that had been immunized with hepatitis b surface antigen (hbsag). expression o ... | 1983 | 6832213 |
| virologic control of monkeys used for the production of poliomyelitis virus vaccine. | wild-caught or captive-bred cynomolgus monkeys (macaca fascicularis) used at the national institute of public health for the production of inactivated poliomyelitis virus vaccine are extensively controlled for the presence of antiviral antibodies in their sera. with relatively simple methods of segregation and hygienic measures it seems possible to keep the animals free of infections with certain viruses including herpesvirus simiae and foamy viruses, which is of obvious importance for public he ... | 1981 | 6785124 |
| 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 |
| combined interferon-alpha 2, rimantadine hydrochloride, and ribavirin inhibition of influenza virus replication in vitro. | recombinant dna-produced human interferon-alpha 2 inhibited the replication of influenza a and b viruses in primary rhesus monkey kidney cells (rmk). human interferon-alpha 2 interacted additively or synergistically with rimantadine hydrochloride or ribavirin in reducing the yield of clinical isolates of either h3n2 or h1n1 subtype influenza a viruses. the combination of human interferon-alpha 2 and ribavirin also inhibited the replication of an influenza b virus to a greater extent than either ... | 1984 | 6703684 |
| nucleotide sequence of a cloned duck hepatitis b virus genome: comparison with woodchuck and human hepatitis b virus sequences. | the nucleotide sequence of an ecori duck hepatitis b virus (dhbv) clone was elucidated by using the maxam and gilbert method. this sequence, which is 3,021 nucleotides long, was compared with the two previously analyzed hepatitis b-like viruses (human and woodchuck). from this comparison, it was shown that dhbv is derived from an ancestor common to the two others but has a slightly different genomic organization. there was no intergenic region between genes 5 and 8, which were fused into a singl ... | 1984 | 6699938 |
| hepatitis b virus encodes an rna polymerase iii transcript. | we demonstrated that cloned hepatitis b virus (hbv) dna directs the synthesis of a 700-base rna (hbv 700) by rna polymerase iii in a cell-free transcription system. hbv 700 is the only transcript known to originate from the viral short strand and has been mapped to the region between roughly 1,635 and 954 base pairs on the viral map, between the surface and core antigen coding sequences but overlapping and opposing the putative dna polymerase and b protein genes. the in vitro initiation sites fo ... | 1983 | 6646123 |
| 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 |
| 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 |
| transplantation of woodchuck hepatocellular carcinoma in nude mice. | woodchuck hepatocellular carcinoma has been successfully transplanted into nude (athymic) mice. the morphology of heterotransplanted tumor is similar to that of naturally occurring hepatocellular carcinoma before transplantation. the growth rate of transplanted tumor was very slow compared with those of other transplanted tumors. during the first month, only two tumors appeared. however, definitive tumor growth was noted in 6 of 20 nude mice about 3 months later. seventeen of 20 nude mice exhibi ... | 1983 | 6618433 |
| 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 |
| 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 |
| liver disease associated with duck hepatitis b virus infection of domestic ducks. | the liver disease associated with duck hepatitis b viremia was investigated in naturally infected ducks from chi-tung county in china and in both naturally and experimentally infected ducks from the united states. liver and serum specimens of adult chinese ducks were examined for duck hepatitis b virus (dhbv) dna by dot and gel blot hybridization. dhbv was found in serum and (in episomal form only) in livers of 6 of 11 birds exhibiting various degrees of chronic hepatitis. in 1 bird with hepatoc ... | 1984 | 6583686 |
| 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 |
| [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 |
| 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 |
| 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 |
| human hepatitis b vaccine from recombinant yeast. | the worldwide importance of human hepatitis b virus infection and the toll it takes in chronic liver disease, cirrhosis and hepatocarcinoma, make it imperative that a vaccine be developed for worldwide application. human hepatitis b vaccines are presently prepared using hepatitis b surface antigen (hbsag) that is purified from the plasma of human carriers of hepatitis b virus infection. the preparation of hepatitis b vaccine from a human source is restricted by the available supply of infected h ... | 1984 | 6318124 |
| rearrangement of the surface antigen gene of hepatitis b virus integrated in the human hepatoma cell lines. | the rearrangement of integrated hbv dna sequences in three different hepatoma cell lines, huh-1, huh-2, kg-55-t from japanese patients, were studied by blot hybridization using whole hbv genome or a hbsag or hbcag dna as a probe. the characteristic existence of multiple integration sites of hbv dna sequences in each hindiii-restricted hepatoma cell dna was revealed by the hbv genome probe. detection of the isolated hbsag gene in the hindiii fragment indicates that the integration of hbv dna was ... | 1983 | 6310497 |
| transforming capacities of avian erythroblastosis virus mutants deleted in the erba or erbb oncogenes. | mutants of avian erythroblastosis virus (aev) were constructed by deleting large nucleotide segments in each of the viral oncogenes termed v-erba and v-erbb. mutants in erba (erba -b +) retained the ability to transform fibroblasts in vitro, and these cells exhibited most of the transformation characteristics that typify wild-type aev-transformed fibroblasts. in addition, the mutants induced small erythroid colonies upon infection of bone marrow cells in culture. chickens inoculated with erba -b ... | 1983 | 6297784 |
| 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 |
| 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 |
| fatal herpesvirus infection in patas monkeys and a black and white colobus monkey. | fatal herpesvirus infections were diagnosed in 3 patas monkeys and 1 black and white colobus monkey over a 4-week period. herpesvirus was isolated from 1 patas monkey and from the black and white colobus monkey. both isolates had growth characteristics similar to herpesvirus hominis and herpesvirus simiae. the isolate from the colobus monkey antigenically appeared to be h simiae or h simiae-like, whereas the isolate from the patas monkey could not be conclusively identified with the antisera use ... | 1981 | 6276349 |
| susceptibility of monkeys to human hepatitis a virus. | a stump-tailed monkey, newly caught and without antibody to hepatitis b virus (hav), was successfully infected with human hav. the following alterations were observed in the monkey's functions: (1) elevation in activities of serum glutamic pyruvic transaminase, lactate dehydrogenase, and its type 5 isoenzyme (electrophoretically the fastest moving); (2) development of antibody to hav; and (3) shedding of hav antigen in feces. the virus isolated from the monkey, designated the hangzhou a-1a strai ... | 1981 | 6267143 |
| detection of antibodies to herpesvirus simiae and herpesvirus hominis in nonhuman primates. | sera from nonhuman primates, predominantly macaca species, were assayed by a serum neutralization test for antibodies to antigenically related herpesvirus simiae (b virus) and herpesvirus hominis type 1. the data indicate that there would have been approximately 50% error in the diagnosis of herpesvirus simiae infection if these sera had been tested only against herpesvirus hominis antigen. the role of active guinea pig complement in the serum neutralization test was also evaluated and found to ... | 1981 | 6264222 |
| detection of primate herpesvirus antibodies including herpesvirus simiae by enzyme immunoassay. | an enzyme immunoassay (eia) was used for the detection of antibodies to herpesvirus hominis type 1 and 2 (hvh-1 and hvh-2), sa8 and herpesvirus simiae (hvb) in human and nonhuman primate sera. optimal assay conditions were approximately the same for hvh-1, hvh-2, and sa8 but different for hvb. the recognized lethality of hvb required studies to determine whether or not inactivated hvb could be used in the eia outside a biohazard safety cabinet. ten percent buffered formalin destroyed infectivity ... | 1980 | 6249690 |
| 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 |
| 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 |
| potency tests for hepatitis b virus vaccines in laboratory animals. | the production of a vaccine for use in humans using the plasma of persistent hepatitis-b virus antigen carriers is a recent development in preventive medicine. this new approach requires strict regulations as to quality control. one of these aspects is the immunogenicity of the vaccine that can be tested in laboratory animals, in which the anti-hbs formation is considered through average titre determinations or through an ed 50 test for seroconversion. both these determinations performed on mice ... | 1983 | 6228477 |
| 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 |
| [enhancement of the activity of hepatitis b virus vaccine by association with murabutide]. | murabutide (n-acetyl-muramyl-l-alanyl-d-glutamine-alpha-butylester), an mdp analogue, is a potential adjuvant for human immunization. high levels of specific antibodies were obtained in mouse and guinea-pig following administration with murabutide of low dosages of anti-hepatitis b viral vaccine containing the surface antigen (hbs). the effect of murabutide was enhanced without increasing the level of specific ige by association with suboptimal dosages of aluminium hydroxide. | 1982 | 6218866 |
| liver orcein stain and viral dna in duck hepatitis b virus infection in chinese ducks and experimentally infected japanese ducklings. | liver sections were stained with orcein, and duck hepatitis b virus was identified in sera and livers by the hybridization technique in 106 ducks (44 chinese ducks, 15 japanese ducks and 47 japanese ducklings). orcein-positive hepatocytes were found in 18 of 38 (47%) duck hepatitis b virus dna seropositive ducks, and only in 3 of 68 (4%) seronegative ducks. the three ducks were all from a heavily infected flock in southern china. serial analyses of viral dna by southern blot and spot hybridizati ... | 1984 | 6209199 |
| 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 |
| 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 |
| antigenic relationship of a hepatitis b surface antigen-derived polypeptide and human serum albumin. | four major polypeptides with mol. wt. of 22000, 25000, 52000 and 68000 were isolated from solubilized preparations of hepatitis type b surface antigen (hbsag). these four populations, referred to as p22, p25, p52 and p68, respectively, were used to immunize guinea-pigs. guinea-pigs were also inoculated with hbsag and with purified human serum albumin (husa). these antisera were utilized to establish that intact hbsag particles are associated with husa antigenic reactivity. husa antigenic determi ... | 1980 | 6156994 |
| sarcoma growth in 15i5 x 7(2) chickens infected with avian sarcoma viruses of subgroup b or g. | a comparative study was made of sarcoma growth in 15i5 x 7(2) chickens infected in the wing web at 4 weeks of age with strains of subgroup b or g avian sarcoma viruses. infection with sarcoma viruses of either subgroup b or g resulted in the formation of progressive wing web sarcomas at the site of inoculation. the survival times of the subgroup g virus-infected chickens were generally at least twice as great as the survival times of the subgroup b virus-infected chickens, which averaged 6-9 wee ... | 1984 | 6100579 |
| liver carcinogenesis in tropical africa. | the geographical pathology of hepatocellular carcinoma (hcc) was essentially anecdotal until systematic cancer registration was introduced, but it is now clear that sub-saharan africa is a high-incidence area. the disease is multifactorial in etiology, the possible etiological agents including hepatitis b virus and a number of chemical carcinogens, among which the most important appear to be the aflatoxins and n-nitroso compounds. medicinal plants and herbal teas used in the tropics also contain ... | 1984 | 6100283 |
| a transformed vero cell line stably producing the hepatitis b virus surface antigen. | we have constructed plasmids in which transcription of the surface antigen gene of the human hepatitis b virus (hbsag) is under the control of the sv40 early promoter. these plasmids have been used to analyze the expression of the hbsag gene, both in mouse cells and in african green monkey kidney (vero) cells. we have established a vero cell line continuously expressing hbsag that is indistinguishable from authentic 22 nm hbsag particles. post-transcriptional modification of hbsag mrna also appe ... | 1984 | 6098537 |
| synthesis in animal cells of hepatitis b surface antigen particles carrying a receptor for polymerized human serum albumin. | a recombinant plasmid (psvs dhfr) encoding the pre-s region and the s gene of human hepatitis b virus (hbv) and murine dihydrofolate reductase (dhfr) cdna has been used for the transfection of chinese hamster ovary (cho) dhfr- cells. selection of clones resistant to methotrexate has permitted amplification of hbv sequences and an increase in production of hepatitis b surface antigen (hbsag). hbv-specific transcripts have been characterized. the hbsag 22-nm particles contain a receptor for polyme ... | 1984 | 6096851 |
| nucleotide sequence of an infectious molecularly cloned genome of ground squirrel hepatitis virus. | we have determined the complete nucleotide sequence of an infectious cloned genome of ground squirrel hepatitis virus (gshv), a nonpathogenic member of the hepadnavirus group. the genome is 3,311 base pairs long and contains the major open reading frames described for the related human and woodchuck hepatitis b viruses (hbv and whv, respectively). these reading frames include genes for the major structural proteins (the surface and core antigens), unassigned open reading frames (a and b), the lo ... | 1984 | 6086950 |
| [cold hemagglutinins and anti-chicken antibodies during infections with influenza a and b virus]. | 1966 | 5973735 | |
| humoral and cell-mediated immune responses to two hepatitis b virus antigens in guinea pigs. | 1974 | 4413724 | |
| distribution area and natural hosts of latent viruses of monkeys. occurrence of simian vacuolating virus (sv40) and herpesvirus simiae in cynomolgus monkeys in indonesia. | 1966 | 4381988 | |
| herpesvirus simiae infection in macaca radiata. | 1973 | 4347671 | |
| virtual absence of infection with herpesvirus simiae in colony-reared rhesus monkeys (macaca mulatta), with a literature review on antibody prevalence in natural and laboratory rhesus populations. | 1972 | 4334438 | |
| diagnosis and handling of b virus in a rhesus monkey (macaca mulatta). | 1968 | 4300606 | |
| experimental infection of animals with influenzavirus types a and b. | the knowledge that domestic cats were susceptible to infection with freshly isolated a/hong kong/68 influenzavirus led to studies on the susceptibility of some other animal species to this virus, as well as to studies on the ability of egg-passaged hong kong virus and an asian virus to infect cats. the ability of a recent isolate of influenzavirus b to infect these animals was also studied. macaca radiata monkeys could be infected with fresh isolates of a/hong kong virus by intranasal instillati ... | 1972 | 4196340 |
| adsorption of mycoplasma pneumoniae to neuraminic acid receptors of various cells and possible role in virulence. | monkey, rat, and chicken tracheal epithelial cells, as well as monkey, rat, guinea pig, and chicken erythrocytes, adsorbed firmly to colonies of mycoplasma pneumoniae and m. gallisepticum. colonies of m. pulmonis also adsorbed erythrocytes but with less avidity than m. pneumoniae or m. gallisepticum; unlike the latter organisms, m. pulmonis did not adsorb tracheal epithelial cells. colonies of m. orale type 1 and m. orale type 3 adsorbed only chicken red cells. other mycoplasma species tested, i ... | 1968 | 4183967 |
| characterization and separation of viral dna polymerase in mouse milk. | two dna polymerase with properties of viral rna-directed dna polymerase can be found in riii mouse milk. one enzyme is the polymerase of type-c viruses; this enzyme prefers manganese to magnesium with poly(ra).oligo(dt) as synthetic template, is inhibited by specific sera, and has an apparent molecular weight of 70,000. milk from balb/c and nih swiss mice contain a vast predominance of this type-c enzyme. the other dna polymerase from riii mouse milk prefers magnesium to manganese, is not inhibi ... | 1973 | 4124683 |
| alterations in the hemagglutinin associated with adaptation of influenza b virus to growth in eggs. | in 1943 burnet reported on changes in the hemagglutinating properties of human influenza virus which occurred during adaptation of the virus to growth in chicken eggs. only recently has direct evidence been presented that these changes affect the antigenic properties of the virus. schild et al. (g. c. schild, j. s. oxford, j. c. dejong, and r. g. webster (1983), nature (london) 303, 706-709) demonstrated that egg adaptation of influenza b virus selects variants which are antigenically distinct f ... | 1985 | 4060580 |
| [circulation of the influenza virus on poultry-raising farms]. | the results of examinations for immunity to influenza in chickens and the personnel handling them at the permanently observed farm are presented. antibodies mainly to the same antigenic variants of human influenza viruses were found in chicken and human blood sera. alongside with antihemagglutinins to influenza a (h3n2) virus strains, chicken in 1983-1984 were found to have antibodies to influenza b virus epidemically important in those years. thus, in poultry farms human influenza viruses are i ... | 1985 | 4049842 |
| subacute nonsuppurative hepatitis associated with hepatitis b virus infection in two cynomolgus monkeys. | subacute, nonsuppurative hepatitis was diagnosed in a cynomolgus monkey (macaca fascicularis) based on histopathologic examination of a liver biopsy specimen. clinical signs of illness included anorexia, lethargy and hepatomegaly. abnormal laboratory findings included elevations of serum liver enzymes, bilirubin and a monocytosis. circulating antibody (anti-hbs) against hepatitis b surface antigen (hbsag) was present in serum and antigens reactive with anti-hbsag antiserum were found in the live ... | 1985 | 4046551 |
| 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 |
| neuraminic acid is involved in the binding of influenza c virus to erythrocytes. | neuraminidases of both viral and bacterial origin have been reported to be unable to destroy the cellular receptor for influenza c virus on chicken erythrocytes, in contrast to the receptors for influenza a and b virus. however, under appropriate conditions neuraminidases from both vibrio cholerae and clostridium perfringens were able (i) to make chicken red blood cells resistant against agglutination by influenza c virus and (ii) to reduce the hemagglutination-inhibiting activity of rat serum. ... | 1985 | 3976175 |
| 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 |
| the hbv hbx gene expressed in e. coli is recognised by sera from hepatitis patients. | we have cloned the x gene (hbx) and the hbc antigen (hbc ag) gene of human hepatitis b virus (hbv) in escherichia coli as fusion products with beta-galactosidase. both hbv genes are expressed in e. coli strain csr 603. expression is detected by u.v. irradiation of the bacteria, metabolic labelling and electrophoresis of the labelled extracts on sds-polyacrylamide gels. the hbc ag protein produced in bacteria can be recognised by anti-hbc sera and peptides derived from the protein are also recogn ... | 1985 | 3891326 |
| detection of an igm antiidiotype directed against anti-hbs in hepatitis b patients. | an igm-specific anti-[anti-hbs] antibody was detected by radioimmunoassay using anti-igm-coated beads and 125i-labeled anti-hbs. this antiidiotype was found only in the sera of hepatitis b virus-infected patients, both acute and chronic. however, not all hbsag-positive patients exhibited this reaction, and activity was correlated with the presence of hbeag. approximately 93% of sera that contained antiidiotype activity also contained hbeag. conversely, 70% of the sera positive for hbeag reacted ... | 1985 | 3875543 |
| duck hepatitis b virus dna in liver and serum of chinese ducks: integration of viral dna in a hepatocellular carcinoma. | the presence of duck hepatitis b virus (dhbv) dna in liver and serum and its state (integrated vs. free) were studied in 23 ducks from chi-tung county in china by spot hybridization and southern blot hybridization, respectively. in 16 of 23 (70%), dhbv dna was detected in serum and/or in liver tissue. these infected ducks showed a variety of pathological changes including advanced chronic disease in the liver. in contrast, none of the virus-negative ducks had advanced hepatic changes. one dhbv d ... | 1985 | 3860852 |
| 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 |
| infectious influenza a and b virus variants with long carboxyl terminal deletions in the ns1 polypeptides. | an influenza a virus, a/turkey/oregon/71, was shown by protein gel analysis to code for an ns1 protein approximately half the size of those of other influenza a viruses. sequence analysis of the ns gene of this virus revealed a 10 nucleotide deletion resulting in an ns1 protein of only 124 amino acids. this truncated ns1 polypeptide retained its karyophilic pattern as detected by indirect immunofluorescence analysis of virus infected cells. also, a/turkey/oregon/71 virus grew to high titer in em ... | 1987 | 3811235 |
| regulation of secretion of the hepatitis b virus major surface antigen by the pres-1 protein. | p24, p30, and p39, the three major surface antigens of the envelope of hepatitis b virus, are co-carboxy-terminal proteins with different amino-terminal extensions. we prompted expression of these proteins in chinese hamster ovary (cho) cells by placing the appropriate coding sequence(s) under the control of the simian virus 40 early promoter. p24 and p30 formed 22-nm particles which were efficiently secreted. in contrast, p39 accumulated in a perinuclear structure, presumably the golgi complex, ... | 1987 | 3806798 |
| 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 |
| 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 |
| occurrence and ultrastructural localization of duck hepatitis b virus in the liver of ducks after experimental infection. | a sequential study was performed to investigate the occurrence and localization of duck hepatitis b virus in the liver of domestic ducks utilizing the indirect immunoperoxidase method and electron microscopy. seventeen ducklings were injected intravenously with duck hepatitis b virus-positive serum within 24 hr after hatching and were subsequently sacrificed on the 2nd, 3rd, 4th, 5th, 27th and 44th day after injection. nine ducklings were not injected and were used as a negative control. duck he ... | 1987 | 3804203 |
| 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 |
| 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 |