| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| [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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| 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 |
| evaluation of tuberculin testing and measles prophylaxis procedures used in rhesus macaque quarantine/conditioning protocols. | twenty-three of 103 adult rhesus macaques (macaca mulatta) entering nih holding facilities with no history of measles vaccination or infection, no titer to rubeola virus, a minimum of four negative results of intrapalpebral tuberculosis tests, and negative for herpesvirus simiae and type d retroviruses were selected to evaluate the adequacy of commonly used quarantine/conditioning protocol procedures. one month after sensitization by subcutaneous inoculation with 100 mg of killed mycobacterium t ... | 1995 | 7603012 |
| susceptibility to duck hepatitis b virus infection is associated with the presence of cell surface receptor sites that efficiently bind viral particles. | to test the hypothesis that susceptibility of hepatocytes to duck hepatitis b virus (dhbv) infection requires cell surface receptors that bind the virus in a specific manner, we developed an assay for the binding of dhbv particles to monolayers of intact cells, using radiolabeled immunoglobulin g specific for dhbv envelope protein. both noninfectious dhbv surface antigen particles and infectious virions bound to a susceptible fraction (approximately 60%) of pekin duck hepatocytes. in contrast, b ... | 1995 | 7609048 |
| synergistic hepatocarcinogenic effect of hepadnaviral infection and dietary aflatoxin b1 in woodchucks. | interactive hepadnaviral and chemical hepatocarcinogenesis was studied in woodchucks inoculated as newborns with woodchuck hepatitis virus (whv), which is closely related to the human hepatitis b virus. when the woodchucks reached 12 months of age, aflatoxin b1 (afb1) was administered in the diet at dose levels of 40 micrograms/kg body weight/day for 4 months and subsequently 20 micrograms/kg body weight/day (5 days/week) for lifetime. whv dna was demonstrated by southern blot hybridization in t ... | 1995 | 7614467 |
| efficient production of anti-(hepatitis b virus) antibodies and their neutralizing activity in chimpanzees. | for industrial production of human monoclonal antibodies (hmab) against hepatitis b virus surface antigen (hbsag), we scaled-up a short-term perfusion culture in serum-free medium, which was chosen as the most suitable culture method, to a 50-1 fermentor equipped with a rotating shear filter. using hydrophobic chromatography as the initial step of hmab purification, the mab hbw4, hbw6 and w471 were isolated in good quality from the respective culture broths in yields of approximately 75%. each o ... | 1995 | 7632396 |
| identification of woodchuck class i mhc antigens using monoclonal antibodies. | two class i major histocompatibility complex (mhc) proteins with molecular masses of 43- and 39-kda were identified in the cell surface membranes of normal woodchucks using a newly developed antiwoodchuck class i monoclonal antibody (mab) b1b.b9 and immunoblotting. b1b.b9 was generated by immunizing mice with viable woodchuck peripheral blood mononuclear cells and was selected for anti-class i mhc reactivity using a cellular enzyme-linked immunoassay, indirect immunofluorescence on tissue sectio ... | 1995 | 7652741 |
| differential gene expression in experimental hepatocellular carcinoma induced by woodchuck hepatitis b virus. | hepatitis b virus infection is closely linked to hepatocellular carcinoma (hcc), the pathological mechanism of hepatocarcinogenesis by this virus is not well understood. in order to gain further insight into the molecular mechanism of hcc, we constructed and screened a subtracted c-dna library which was specific to hcc cells of a woodchuck infected with woodchuck hepatitis b virus. among eight clones that were isolated based on their differential expressions, we determined nucleotide sequences o ... | 1995 | 7656224 |
| epitopes recognized by antibodies to denatured core protein of hepatitis b virus. | particulate and denatured core protein as well as e-antigen (hbe) of hepatitis b virus (hbv) differ in part immunologically but this has not been studied in sufficient detail. therefore, in this study the b-cell immune response to native and denatured hbv core protein which both can exhibit hbe-specific epitopes was examined using a panel of mouse mabs and rabbit polyclonal antibodies to native and denatured core protein and polyclonal anti-hbe/anti-hbc antibodies from sera of infected patients. ... | 1993 | 7679466 |
| pharmacokinetics, oral bioavailability, and metabolism in mice and cynomolgus monkeys of (2'r,5's-)-cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl] cytosine, an agent active against human immunodeficiency virus and human hepatitis b virus. | (2'r,5's-)-cis-5-fluoro-1-[2-(hydroxymethyl)-1,3-oxathiolan-5-yl] cytosine (524w91) is a nucleoside analog with potent anti-human immunodeficiency virus and anti-human hepatitis b virus activities in vitro. the pharmacokinetics and bioavailability of 524w91 after oral dosing were studied in mice dosed with 10, 100, and 600 mg of 524w91 per kg of body weight by the oral and intravenous routes. cynomolgus monkeys were dosed with 10 and 80 mg of 524w91 per kg. in both species, the clearance of 524w ... | 1994 | 7695253 |
| herpesvirus papio 2, an sa8-like alpha-herpesvirus of baboons. | several sa8 isolates obtained from baboons were compared to the prototype sa8 herpesvirus of african green monkeys. sds-page and restriction enzyme analyses revealed definite differences between green monkey and baboon isolates. dna and amino acid sequences of the gb, gd and gj glycoprotein genes exhibited substantial differences in variable regions. for the gb and gd, the amount of amino acid substitutions between sa8 and the baboon viruses was comparable to levels observed between analogous ge ... | 1995 | 7733825 |
| detection of hepatitis b and woodchuck hepatitis viral dna in plasma and mononuclear cells from heparinized blood by the polymerase chain reaction. | amplification by the polymerase chain reaction (pcr) of hepatitis b virus (hbv) dna extracted from parallel samples of serum and heparinized plasma gave contradictory results, indicating that heparin inhibits virus detection. similarly, analysis of pcr products of woodchuck hepatitis virus (whv) dna showed that heparinization of blood abolished whv dna amplification, while anticoagulation with sodium edta or acid citrate dextrose did not. amplification of recombinant whv and hbv dna in the prese ... | 1995 | 7738148 |
| risk of venereal b virus (cercopithecine herpesvirus 1) transmission in rhesus monkeys using molecular epidemiology. | the importance of venereal modes of b virus (cercopithecine herpesvirus 1) transmission was evaluated in 49 rhesus monkeys tested at necropsy. antibodies to b virus were demonstrated in 19 monkeys, but no active viral shedding was detected in mucosal swabs collected at death. the polymerase chain reaction demonstrated presence of the icp 18.5 (ul28) gene of b virus in neuronal tissues of 15 monkeys presumed to be latently infected, including 12.8% of trigeminal and 22.9% of lumbosacral ganglia p ... | 1995 | 7751688 |
| saccharomyces cerevisiae can release hepatitis b virus surface antigen (hbsag) particles into the medium by its secretory apparatus. | we constructed a plasmid that directs the synthesis and secretion of hepatitis b virus (hbv) surface antigen (hbsag) particles by saccharomyces cerevisiae. this plasmid contains a proteinase-resistant hbsag m (m-p31c) gene fused at its 5'-terminus with a chicken-lysozyme signal peptide (c-sig) gene, which is placed under the yeast gld (glyceraldehyde-3-phosphate dehydrogenase gene) promoter. the products encoded by the "c-sig+m-p31c" (lm-p31c) gene were synthesized and assembled themselves into ... | 1993 | 7764388 |
| spectrum of liver disease and duck hepatitis b virus infection in a large series of chinese ducks with hepatocellular carcinoma. | the striking difference in the geographical distribution of liver cancer in ducks raised the question of whether duck hepatitis b virus (dhbv), like mammalian hepadnaviruses, could be an oncogenic agent. hepatocellular carcinomas (hccs) have been found only in domestic ducks in qidong, china, where hepatitis b virus infection and aflatoxin b1 (afb1) are both risk factors and where a high frequency of human hccs has been reported. to date, the study of liver pathology occurring in chinese ducks h ... | 1995 | 7768491 |
| [induction of protective immune responses by a chimeric soluble protein from a recombinant bcg vector candidate vaccine to hiv-1]. | we have been isolated hiv strains from blood specimens of hiv infected individuals in japan for these 6 years. the number of specimens tested reached approximately 1,700 that ninety percent of them were from hemophiliacs repeatedly injected blood products from the united states. more than 300 of field hiv were successfully isolated from the samples. the isolation rates has decreased to 30 percent in 1993 from 40 percent in 1992, suggesting that treatment with anti-hiv drugs such as azt and/or dd ... | 1995 | 7783347 |
| carbohydrate-dependent biological activities of glycosylated human interferon-beta on human hepatoblastoma cells in vitro. | to evaluate the relationship between the sugar chain structure and biological activity, fibroblast-derived glycosylated human interferon-beta, chinese hamster ovary cell-derived glycosylated recombinant human interferon-beta and escherichia coli-derived unglycosylated recombinant human interferon-beta were evaluated using human hepatoblastoma cells in vitro. native fibroblast interferon-beta expressed more cell-growth inhibitory action, 2'5'-oligoadenylate synthetase induction, and the inhibitio ... | 1995 | 7783683 |
| pure nucleoside enantiomers of beta-2',3'-dideoxycytidine analogs are selective inhibitors of hepatitis b virus in vitro. | (-)-beta-l-2',3'-dideoxycytidine (beta-l-ddc), (+)-beta-d-2',3'-dideoxycytidine (beta-d-ddc), (-)-beta-l-2',3'-dideoxy-5-fluorocytidine (beta-l-fddc), (-)-beta-l-2',3'-dideoxy-5-fluoro-3'-thiacytidine (beta-l-ftc), and (+)-beta-d-1,3-dioxolane-5-fluorocytidine (beta-d-fdoc) were evaluated for their anti-hepatitis b virus (anti-hbv) activities in hbv-transfected human liver cells (2.2.15). the order of decreasing potency for the compounds at the 90% effect level was beta-d-fdoc > beta-l-ftc > bet ... | 1994 | 7811039 |
| phenotypic mixing of rodent but not avian hepadnavirus surface proteins into human hepatitis b virus particles. | the virus family hepadnaviridae comprises two genera: orthohepadnaviruses isolated from humans (hepatitis b virus [hbv]) and rodents (e.g., woodchuck hepatitis virus [whv]) and avihepadnaviruses isolated from birds (e.g., duck hepatitis b virus [dhbv]). they carry in their envelopes two (dhbv) or three (hbv and whv) coterminal proteins referred to as small (s), middle (m), or large (l) surface protein. these proteins are also secreted from infected cells as subviral particles consisting of surfa ... | 1995 | 7815496 |
| state of the p53 gene in hepatocellular carcinomas of ground squirrels and woodchucks with past and ongoing infection with hepadnaviruses. | infection with hepadnaviruses and exposure to dietary aflatoxin are considered major risk factors in the development of hepatocellular carcinoma (hcc) both in humans and in animals. recently, a broad range of mutations in the p53 tumor suppressor gene has been reported in human hccs, predominantly from hepatitis b virus carriers in areas with either high or low levels of exposure to dietary aflatoxin. to determine whether p53 mutations are common to hccs of hosts infected with related hepadnavir ... | 1994 | 7923176 |
| behavioral management of specific pathogen-free rhesus macaques: group formation, reproduction, and parental competence. | breeding colonies of specific pathogen-free (spf) rhesus macaques were established to eradicate the transmission of herpesvirus simiae and several retroviruses in this species. strategies to attain this goal included the combination of large numbers of monkeys into groups, the establishment of small unimale groups, and a program using animals that were temporarily socially restricted. all methods required the establishment of new social groups from unfamiliar animals. in using these methods, we ... | 1994 | 7933968 |
| rapid isolation of highly productive recombinant chinese hamster ovary cell lines. | an expression system combining a unit for the expression of the gene of interest reinforced by the hepatitis b virus x transactivator and a selectable gene weakened by the insertion of an a+t-rich sequence derived from the 3'-untranslated region of the granulocyte-macrophage colony-stimulating factor mrna is described. this vector allows rapid one-step isolation of highly productive chinese hamster ovary clones. | 1994 | 7959014 |
| characterization of hepatitis b virus core mutants that inhibit viral replication. | we have generated and functionally characterized dominant negative core protein variants of the hepadnaviruses to determine their effects on "wild type" viral replication. plasmids expressing these constructs were introduced into hepatoma cell lines by transient transfection and effects on wild type woodchuck hepatitis virus (whv) and hepatitis b virus (hbv) replication were evaluated by southern blot analysis of purified viral core particles. whv and hbv constructs expressing a truncated core p ... | 1994 | 7975206 |
| analysis of the x gene promoter of woodchuck hepatitis virus. | during the course of woodchuck hepatitis virus (whv) replication three virus-specific mrna transcripts that encode four essential proteins are produced. the transcripts are 3.6, 2.3, and 0.7 kb in size. the 3.6-kb transcript serves as the replicative intermediate as well as the template for translation of the nucleocapsid and polymerase proteins. the 2.3-kb mrna serves as the template for translation of the virus envelope proteins. both the 3.6- and 2.3-kb transcripts are polyadenylated and are ... | 1994 | 7975227 |
| therapy of chronic hepatitis b with a 6-month course of ribavirin. | ribavirin is a nucleoside analogue with broad spectrum antiviral activity that has been shown to inhibit viral replication in the woodchuck model of hepatitis b virus infection. we studied the effect of ribavirin on viral replication in 18 patients with chronic hepatitis b who were positive for hepatitis b e antigen. patients were randomized to receive a 24-week course of oral ribavirin at a dose of either 800, 1000, or 1200 mg/kg per day. all patients completed 24 weeks of treatment and an addi ... | 1994 | 7989704 |
| woodchuck hepatitis virus surface antigen induces nitric oxide synthesis in hepatocytes: possible role in hepatocarcinogenesis. | woodchuck hepatitis virus surface antigen (whsag) stimulated hepatocytes in culture to produce nitric oxide (no.), as evidenced by the accumulation of nitrite in the medium. no. synthesis by hepatocytes was positively correlated with whsag concentration. whsag-induced no. synthesis was inhibited by ng-monomethyl-l-arginine and anti-whsag antibody. to our knowledge, this is the first demonstration of an increase in no. formation by a viral antigen. these data, when considered in the light of the ... | 1994 | 8001249 |
| absence of p53 mutation at codon 249 in duck hepatocellular carcinomas from the high incidence area of qidong (china). | dietary aflatoxin and hepatitis b virus infection may play a role in generating the p53 tumor suppressor gene codon 249 hotspot mutation found in human hepatocellular carcinomas (hccs) from qidong (china) and southern africa. no data are available on the hcc site-specific mutation of the p53 gene in hepadnavirus-infected animals exposed to afb1. we have searched for the presence of p53 gene codon 249 mutations in both duck hepatitis b virus (dhbv) positive and negative hccs of domestic ducks fro ... | 1994 | 8033311 |
| analysis of integrated ground squirrel hepatitis virus and flanking host dna in two hepatocellular carcinomas. | we cloned the integrated ground squirrel hepatitis b virus (gshv) sequences from two hepatomas showing a single viral insertion. the gshv inserts shared structural features with integrated dnas of other hepadnaviruses. insertional activation of a cellular gene appears unlikely: the integrated gshv sequences lacked the known viral enhancers and were not expressed in the tumors, and we found no evidence for the presence of a gene at the integration site. our results, together with those earlier st ... | 1994 | 8035528 |
| woodchuck hepatitis virus surface antigen produced in vitro fails to bind polymerized woodchuck serum albumin. | using a plasmid (psws) similar to one that has been successfully used for large-scale production of hepatitis b virus (hbv) envelope protein particles (psvs) but containing the corresponding woodchuck hepatitis virus (whv) envelope gene sequences, we have stably transformed the rodent dihydrofolate reductase-deficient cell line cho dhfr-. although production of whv envelope particles in cho/psws cell lines was low, it was sufficient to test whether these particles could bind to polymerized serum ... | 1994 | 8046413 |
| apparent helper-independent infection of woodchucks by hepatitis delta virus and subsequent rescue with woodchuck hepatitis virus. | hepatitis delta virus (hdv) is a subviral agent of humans which is dependent upon hepatitis b virus as a helper for transmission. hdv can be experimentally transmitted to woodchucks by using woodchuck hepatitis virus (whv) as the helper. we used this model system to study two types of hdv infections: those of animals already chronically infected with whv and those of animals without any evidence of prior exposure to whv. at 5 to 10 days after infection with hdv, liver biopsies of these two group ... | 1994 | 8057418 |
| dot blot hybridization assay for the detection of duck hepatitis b virus dna among healthy indian country ducks. | a dna molecular hybridization technique employing duck hepatitis b virus (dhbv) dna of 3.0 kilobase pairs as a probe was used to screen for the presence of dhbv dna in blood samples, collected from 90 apparently healthy indian country ducks. six out of 90 ducks showed positivity for dhbv dna in serum (5.4%) and only 4 out of 6 dhbv dna positive ducks answered in counter immuno electrophoresis (ciep) using specific antibody against dhbv surface antigen raised in guinea pig. the results indicate t ... | 1994 | 8088900 |
| a hepatitis b virus pre-s-retinoic acid receptor beta chimera transforms erythrocytic progenitor cells in vitro. | in this report, we investigated the transforming properties of retinoic acid receptor beta (rar beta). the v-erba protein, which is the viral oncogenic homologue of the thyroid hormone receptor, was replaced by either the complete rar beta (beta r) or a hepatitis b virus pre-s-rar beta (h beta r) hybrid product in an avian erythroblastosis virus-based vector. in chicken hematopoietic cells, the h beta r protein was able to transform erythroid progenitor cells, whereas no such transformation was ... | 1993 | 8093562 |
| spontaneous development of anti-hepatitis b virus envelope (anti-idiotypic) antibodies in animals immunized with human liver endonexin ii or with the f(ab')2 fragment of anti-human liver endonexin ii immunoglobulin g: evidence for a receptor-ligand-like relationship between small hepatitis b surface antigen and endonexin ii. | in a previous study, we have identified endonexin ii (e-ii) on human liver plasma membranes as a specific, ca(2+)-dependent, small hepatitis b surface antigen (hbsag)-binding protein. in this article, we describe the spontaneous development of anti-hbs antibodies in rabbits immunized with native or recombinant human liver e-ii and in chickens immunized with the f(ab')2 fragment of rabbit anti-human liver e-ii immunoglobulin g. anti-hbs activity was not observed in rabbits immunized with rat live ... | 1994 | 8107214 |
| duck hepatitis b virus (dhbv) infection in indian domestic ducks: a pilot study. | one hundred and two apparently healthy indian domestic ducks from the poultry research station, madras were screened for duck hepatitis b virus (dhbv) infection by; 1. screening for the duck hepatitis b virus surface antigen (dhbsag) in their sera using hepatitis b virus (hbv) reagents, 2. screening for dhbsag using specific duck hepatitis b virus (dhbv) reagents and 3. demonstration of dhbv dna using dhbv dna probe by dot blot hybridisation. while 5 ducks (4.9%) were consistently positive with ... | 1993 | 8109057 |
| characterization and biosynthesis of the woodchuck hepatitis virus e antigen. | the biosynthesis of the secretory core gene product of the woodchuck hepatitis virus (whv) was studied in human cells. we have shown that the whv e antigen was a n-glycosylated (most likely a diglycosylated) protein, with an apparent m(r) of 24k. to demonstrate that the whv precore protein was correctly processed in human cells, we engineered chimeric proteins in which signal peptides or arginine-rich domains of whv and hepatitis b virus (hbv) precore proteins were exchanged. our results showed ... | 1994 | 8113724 |
| identification of factor-binding sites in the duck hepatitis b virus enhancer and in vivo effects of enhancer mutations. | hepatitis b viruses (hepadnaviruses) can cause chronic, productive infections of hepatocytes. analyses of the enhancers and promoters of these viruses in cell lines have suggested a requirement of these elements for liver-enriched transcription factors. in this study, a minimum of seven factor-binding sites on the duck hepatitis b virus enhancer were detected by dnase i footprinting using duck liver nuclear extracts. among the sites that were tentatively identified were one c/ebp-, one hnf1-, an ... | 1994 | 8139013 |
| the in vitro anti-hepatitis b virus activity of fiau [1-(2'-deoxy-2'-fluoro-1-beta-d-arabinofuranosyl-5-iodo)uracil] is selective, reversible, and determined, at least in part, by the host cell. | a human hepatoblastoma cell line was stably transfected with a head-to-tail dimer of the hepatitis b virus (hbv), subtype adw, genome to generate a cell line which produces hbv. fiau [1-(2'-deoxy-2'-fluoro-1-beta-d-arabinofuranosyl-5-iodo)uracil] inhibited viral replication in these cells with an ic50 of 0.90 microm, as determined by pcr analysis of extracellular dane particle dna, and displayed a 50% cytotoxic concentration (tc50) of 344.3 microm, as determined using the mtt assay. the selectiv ... | 1994 | 8141592 |
| infrequent shedding and transmission of herpesvirus simiae from seropositive macaques. | the epizootiologic properties of herpesvirus simiae (b virus) were studied in singly housed macaques (macaca mulatta and m. fascicularis) in a biomedical vivarium to determine whether commonly encountered environments and procedures such as quarantine, breeding, caesarean section, parturition, and social stress induced virus shedding and transmission. macaques were tested serologically and for infectious virus. oral, conjunctival, and vaginal swab samples were obtained repeatedly. virus excretio ... | 1993 | 8158977 |
| disseminated b virus infection in a cynomolgus monkey. | a cynomolgus monkey (macaca fascicularis) was euthanatized 1 week following dystocia because of severe peritonitis. histologic examination revealed lesions characteristic of herpesvirus infection in lungs, liver, spleen, bone marrow, uterus, and adrenal gland, and on the serosal surface of intestines, pancreas, and reproductive tract. immunohistochemical studies on liver and lungs revealed herpes b-like antigens in the lesions. b virus was isolated from serum. as systemic b-virus infection was n ... | 1993 | 8158978 |
| different in situ expression of insulin-like growth factor type ii in hepatocellular carcinoma. an in situ hybridization and immunohistochemical study. | reexpression of the insulin-like growth factor type ii (igf-ii) gene has recently been described in hepatocellular carcinoma (hcc). in this study, we used a nonisotopic in situ hybridization method to analyze the expression of igf-ii mrna in a series of 28 hccs arising on cirrhotic and noncirrhotic livers. an immunohistochemical method was used to detect igf-ii peptide. hepatitis b virus (hbv) status and the histological differentiation degree were also evaluated. increased expression of igf-ii ... | 1994 | 8162257 |
| molecular events in the pathogenesis of hepadnavirus-associated hepatocellular carcinoma. | chronic hepadnavirus infection is associated with hepatocellular carcinoma (hcc) in natural hosts such as humans, woodchucks, and beechey ground squirrels. several possible oncogenic mechanisms have been identified, including a potential role of the hepadnavirus x (hbx) gene, which transactivates transcription regulated by certain cis-acting sequences, e.g. regulatory sequences of the hepatitis b virus (hbv) and heterologous regulatory sequences of other viruses and cellular genes. the oncogenic ... | 1994 | 8198385 |
| comparative anti-influenza virus activity of 2'-deoxy-2'-fluororibosides in vitro. | the anti-influenza virus activity of 2'-deoxy-2'-fluoroguanosine was determined in cell culture and in explants of human respiratory epithelium by yield reduction assay. the concentration causing at least 1.0 log10 reduction in influenza a (h3n2) virus yield (ec90) at 24 h was 2.5 micrograms/ml in primary rhesus monkey kidney and 12 micrograms/ml in madin-darby canine kidney (mdck) cells, compared to 0.5 micrograms/ml and 0.9 micrograms/ml, respectively, for ribavirin. the estimated therapeutic ... | 1993 | 8215305 |