Publications
| Title | Abstract | Year Filter | PMID(sorted descending) Filter |
|---|
| a cultured cell receptor for the small s protein of hepatitis b virus. | human hepatitis b virus (hbv) has not been passaged in established cell culture systems. to determine whether this inability results from the lack of a receptor, 30 cell lines were examined for their abilities to bind 125i-labeled recombinant hepatitis b virus surface antigen (rhbsag) particles. these particles contained only the small surface (s) protein, which is also found in the envelope of infectious hbv particles. only two cells lines, both derived from african green monkey kidney, were ab ... | 1987 | 3629972 |
| expression of the hepatitis b virus core gene in vitro and in vivo. | the core gene of hepatitis b virus contains two in-phase aug codons which may both be used in the viral life cycle. by in vitro translation of transcripts produced in vitro, we investigated the corresponding core gene products and their counterparts in vivo. depending on the location of the 5' end of the transcripts, two major core gene-derived proteins were obtained. in transcripts with both in-phase augs, only the first one was efficiently used and resulted in synthesis of a 25-kilodalton prot ... | 1987 | 3625840 |
| emerging models in the u.s.a.: swine, woodchucks, and the hairless guinea pig. | swine have been used in biomedical research for many years, but have generally been limited to those locations with personnel familiar with this species and with specially designed facilities and equipment. there is currently a growing trend in the united states for more swine, both miniature and domestic to be used as research models. commercial availability, education through workshops and symposia, and specific research applicability in the areas such as: organ transplantation, cardiovascular ... | 1987 | 3601991 |
| inactivation of influenza b virus by normal guinea-pig serum. | normal guinea-pig serum (gps) lacking detectable antiviral antibody efficiently neutralized the infectivity of influenza b virus grown in chick embryos or mdck cells. the inhibitor was heat-labile and sensitive to trypsin digestion. this beta-like inhibitor required ca2+ and the complement components c1 and c4 for its activity. in contrast, gps did not inactivate influenza a virus. influenza b virus from which the neuraminidase activity of the spikes on the viral envelope had been eliminated by ... | 1987 | 3572357 |
| maintenance of woodchuck hepatitis virus activity in woodchuck hepatocyte primary culture. | primary cultures of non-proliferating hepatocytes isolated by the two-step collagenase perfusion method from woodchuck naturally infected with hepatitis virus (whv) were used to study whv propagation in vitro. hepatocytes carrying whv dna exhibited a very high level of survival and retained their morphological characteristics for 2 to 3 months. over this time, they were found to produce virus-specific proteins and release viral particles with dna polymerase activity into the medium. using southe ... | 1987 | 3572356 |
| microbial oncogenesis. | for more than a century, medical investigators have sought to incriminate microorganisms in the cause of cancer. the first scientific evidence of such a relationship came in 1911, with the first successful induction of a tumor using a cell-free extract. since that time, considerable data have accrued linking retroviruses, herpes viruses, the hepatitis b virus, papovaviruses, and adenoviruses to various malignant neoplasms. there is also increasing evidence that certain bacteria and parasites par ... | 1987 | 3541601 |
| intracellular assembly and packaging of hepatitis b surface antigen particles occur in the endoplasmic reticulum. | hepatitis b surface antigen (hbsag) particles are secreted by chinese hamster ovary cells that are stably transfected with the s gene of hepatitis b virus. the assembly of hbsag into cylindrical and spherical particles occurred intracellularly within the endoplasmic reticulum. hbsag particles accumulated within large dilated areas of the endoplasmic reticulum and remained within these structures for most of the time prior to secretion from the cells. once the particles were formed, the hbsag pol ... | 1986 | 3517385 |
| hepadnavirus infection of peripheral blood lymphocytes in vivo: woodchuck and chimpanzee models of viral hepatitis. | the peripheral blood lymphocytes (pbl) of five hepatitis b virus (hbv)-infected chimpanzees and 17 woodchuck hepatitis virus (whv)-infected woodchucks were examined for the presence of viral dna and rna. hbv dna was detected in the pbl of three of three chronically infected chimpanzees but in neither of two animals with acute hbv infection. whv dna was found in the pbl of 11 of 13 chronically infected woodchucks and in the pbl and bone marrow of 1 of 4 woodchucks with antibody to whv surface ant ... | 1986 | 3485201 |
| hepatocarcinogenicity of the woodchuck hepatitis virus. | during investigations of the evolution of experimental laboratory infections of woodchucks (marmota monax) with the woodchuck hepatitis virus (whv), eight hepatocellular carcinomas (hcc) were observed, six in newborns and two in young adult animals, all within 17-36 months after infection. the absence of an external cocarcinogenic effect in the well-monitored woodchucks indicates the carcinogenicity of whv and suggests the same for the genetically and biologically similar human hepatitis b virus ... | 1987 | 3468514 |
| effects of an extract from phyllanthus niruri on hepatitis b and woodchuck hepatitis viruses: in vitro and in vivo studies. | an aqueous extract of the plant phyllanthus niruri inhibits endogenous dna polymerase of hepatitis b virus and binds to the surface antigen of hepatitis b virus in vitro. the extract also inhibits woodchuck hepatitis virus (whv) dna polymerase and binds to the surface antigen of whv in vitro. the extract, nontoxic to mice, was tested for antiviral activity in woodchucks (marmota monax). in a trial using six long-term whv-carrier woodchucks, five treated animals showed a faster decrease in woodch ... | 1987 | 3467354 |
| common evolutionary origin of hepatitis b virus and retroviruses. | hepatitis b virus (hbv), although classified as a double-stranded dna virus, has been shown recently to replicate by reverse transcription of an rna intermediate. also, the putative viral polymerase has been found to share amino acid homology with reverse transcriptase of retroviruses. using computer-assisted dna and protein sequence analyses, we examined the genomes of 13 hepadnavirus isolates (nine human, two duck, one woodchuck, and one ground squirrel) and found that other conserved regions ... | 1986 | 3458214 |
| main properties of duck hepatitis b virus dna polymerase: comparison with the human and woodchuck hepatitis b virus dna polymerases. | the main properties of the duck hepatitis b virus (dhbv) dna polymerase have been studied and compared with those of the human hepatitis b virus (hbv) and of the woodchuck hepatitis virus (whv) dna polymerases. all 3 enzymes are active under high salt conditions in the presence of high magnesium concentration. dhbv dna polymerase was found less sensitive to ethanol and to operate at higher optimal ph than the hbv and whv dna polymerases. like the other two viral endogenous dna polymerases, the d ... | 1987 | 3446017 |
| isolation and characterization of a hepatitis b virus endemic in herons. | a new hepadnavirus (designated heron hepatitis b virus [hhbv]) has been isolated; this virus is endemic in grey herons (ardea cinerea) in germany and closely related to duck hepatitis b virus (dhbv) by morphology of viral particles and size of the genome and of the major viral envelope and core proteins. despite its striking similarities to dhbv, hhbv cannot be transmitted to ducks by infection or by transfection with cloned viral dna. after the viral genome was cloned and sequenced, a comparati ... | 1988 | 3418788 |
| dna-binding activity of hepatitis b e antigen polypeptide lacking the protaminelike sequence of nucleocapsid protein of human hepatitis b virus. | the characteristics of binding of hepatitis b core antigen (hbcag) and hepatitis b e antigen (hbeag) polypeptides to hepatitis b virus (hbv) dna were analyzed. hbcag polypeptide from recombinant hbv core particles and hbeag polypeptide from partially purified serum hbeag were prepared and verified to have molecular weights of 21,500 (p21.5) and of 17,000 (p17) and 18,000 (p18), respectively, by immunoblot analysis. by reaction of these proteins on a nitrocellulose membrane with cloned 32p-hbv dn ... | 1988 | 3404582 |
| presence of antibodies to the polymerase gene product(s) of hepatitis b and woodchuck hepatitis virus in natural and experimental infections. | antibodies against synthetic peptides derived from the polymerase gene of the hepatitis b virus (hbv) were present in 80% of renal dialysis patients infected with hbv and in woodchucks infected with woodchuck hepatitis virus (whv). polymerase antibody (anti-pol) appeared as the earliest marker of both hbv and whv infections in approximately half of the individuals tested, suggesting that these antibodies were generated following early viral replication in the liver during the incubation period a ... | 1988 | 3351482 |
| establishment of a new cell line from a woodchuck hepatocellular carcinoma. | a new cell line derived from a woodchuck hepatitis surface antigen-positive woodchuck hepatocellular carcinoma has been established and named t3-hep-w1. this new cell line was established directly from a primary woodchuck hepatocellular carcinoma. adaptation of the cells to the in vitro culture condition was completed after 3 months, with the doubling time of 24 hr. the morphologic features of the cell by light microscopy were of an epithelial type. the modal chromosome number was 100. ornithine ... | 1988 | 3338696 |
| liver tumors in rodents: extrapolation to man. | man is a poor model for the prediction of agents that are hepatocarcinogenic for laboratory rodents. relatively few agents are known to cause any form of primary liver cancer in man. the most important is hepatitis b virus, for which there is possibly a model in the woodchuck but not one in rats or mice. the only other agents known to cause primary liver cancer in man are certain steroid hormones, vinyl chloride, and thorium dioxide. there are animal models for the first two of these and a reaso ... | 1987 | 3300204 |
| [detection and identification of host cell antigens in the composition of influenza b virus]. | two heterogeneous antigens, forssman antigen and an antigen similar to human group a antigen, were detected by enzyme-immunoassay in cells of normal chick embryo camn and mdck culture (dog kidney). both these antigens were associated with purified influenza b virus preparations reproduced in these cultures since the variants under study actively reacted with antibodies both to forssman antigen and to human a antigen. serological differences between the variants grown in different cell systems we ... | 1987 | 3300030 |
| the vero cell receptor for the hepatitis b virus small s protein is a sialoglycoprotein. | the vero (african green monkey kidney-derived) cell line is capable of binding recombinant hepatitis b surface antigen (rhbsag) particles containing only the small surface (s) protein of hepatitis b virus (hbv). this binding activity appears to be due to a single major population of receptors (m. e. peeples et al., virology 160, 135-142 (1987]. since infectious hbv particles also contain the small s protein, it is possible that the vero cell receptor might also function as an hbv receptor. the i ... | 1988 | 3281375 |
| localization of woodchuck hepatitis virus in the liver. | localization of woodchuck hepatitis virus in liver tissue from 10 infected woodchucks was investigated immunohistochemically and ultrastructurally. woodchuck hepatitis virus surface antigen was detected by immunoperoxidase methods in the cytoplasm of hepatocytes with a fine granular and/or inclusion body appearance. woodchuck hepatitis virus surface antigen positive hepatocytes were often found in the peripheral zone of hepatic lobules. in contrast to human hepatitis b core antigen, woodchuck he ... | 1988 | 3276592 |
| presence of hbe antibody in glomerular deposits in membranous glomerulonephritis is associated with hepatitis b virus infection. | the specificity of igg on the glomerular capillary wall was investigated in 3 patients with hepatitis b virus associated membranous glomerulonephritis. the immune deposits on the capillary walls were stained by immunofluorescent antibody against hbe antigen and igg. the eluted fluid (0.02 m citrate buffer, ph 3.2) from renal biopsy slices contained significant activity of hbe antibody, but not of hbs and hbc antibodies. after elution, the disappearance of igg on the capillary walls was confirmed ... | 1988 | 3239599 |
| analysis of the mechanism of influenza b virus inactivation by guinea pig serum. | normal guinea pig serum lacking detectable antiviral antibody inactivated influenza b virus via the classical complement pathway. this virus inactivation appeared to result from the steric hindrance of ha activity by the association with the virus of serum proteins presumed to be complement components. trypsin digestion of the associated proteins fully restored the ha activity but not infectivity. it was found that the virus underwent minor disruption of the envelope and degradation of m1 protei ... | 1988 | 3214275 |
| influence of aflatoxin b1 intoxication on duck livers with duck hepatitis b virus infection. | in an attempt to determine the effect of aflatoxin b1 (afb) intoxication on livers with duck hepatitis b virus (dhbv) infection, domestic ducks were given 0.1 mg of afb/kg body weight twice a week for a maximum period of 54 weeks employing various experimental designs. the ducks were infected with dhbv by i.v. inoculation of dhbv-positive sera within 24 h posthatch. the livers were examined histologically, immunohistochemically, and ultrastructurally, and the livers and sera were examined by mol ... | 1988 | 3125965 |
| in vitro recombinants of ground squirrel and woodchuck hepatitis viral dnas produce infectious virus in squirrels. | hepatitis b viruses of humans, woodchucks, ground squirrels, and ducks are similar biochemically but differ with respect to host range and pathogenicity. to pursue the genetic basis of these properties in the absence of a cell culture system for virus growth, we exploited the demonstrated infectivity of cloned hepatitis b virus dna in whole animals. we constructed several recombinant molecules in vitro between cloned infectious genomes of woodchuck hepatitis virus (whv) and ground squirrel hepat ... | 1987 | 3041044 |
| [hbv and hepatocellular carcinoma]. | significant research evidence has demonstrated an association between persistent infection with hepatitis b virus (hbv) and the generation of hepatocellular carcinoma (hcc). these findings are based on epidemiologic studies, molecular studies and studies of hbv like viruses. epidemiologically, the geographic correlation between hbv infection and hcc, serum hbsag in patients with hcc, familial clustering of hcc, prospective studies, and pathological studies are discussed. molecular studies of hbv ... | 1987 | 3030195 |
| integration of hepatitis b virus: analysis of unoccupied sites. | hepatitis b virus (hbv) sequences integrated in the plc/prf/5 cell line (alexander cells), which was derived from a human primary liver carcinoma, were previously extensively studied. here we describe the analysis of the unoccupied sites of two linearly integrated forms of hbv dna, al-14 and al-26, that were characterized previously. no major cellular dna rearrangements were seen at the integration sites except for small deletions of host sequences: 2 kilobases of dna in al-14 and 17 base pairs ... | 1987 | 3029413 |
| a recombinant chinese hamster ovary cell line containing a 300-fold amplified tetramer of the hepatitis b genome together with a double selection marker expresses high levels of viral protein. | a new series of double-selection plasmids containing recombinant genes expressing the neomycin phosphotransferase (neo) of transposon tn5 and mouse dihydrofolate reductase (dhfr) in mammalian cells is described. activity of the recombinant dhfr gene varied more than 50-fold, depending on the location of the simian virus 40 72 base-pair repeat or enhancer, which is part of the promoter of the neo unit. a neo-dhfr module with the enhancer located at the 3' end of the dhfr gene was inserted into a ... | 1986 | 3023626 |
| hepatocellular carcinoma in ground squirrels persistently infected with ground squirrel hepatitis virus. | although persistent infection with hepatitis b virus and woodchuck hepatitis virus has been associated with development of hepatocellular carcinoma in the host, little has been known of such an association with ground squirrel hepatitis virus (gshv), which is closely related to the woodchuck virus. colonies of gshv-infected and -uninfected beechey ground squirrels were observed for tumors for a period of 5 years. tumors developed in seven squirrels after a minimum of 2.4 years of observation per ... | 1986 | 3012572 |
| herpes simplex virus complement fixing antibody and herpes b virus serum neutralizing antibody in sera of wild and laboratory-bred cynomolgus monkeys. | the result of the complement fixation (cf) test for the antibody to herpes simplex virus (hsv) in sera of the cynomolgus monkeys was compared with that of the neutralization test (ns) for the antibody to herpes b virus (hbv) in the same sera. fifty-seven (74%) of 77 wild-originated monkeys were positive for hsv-cf, while 65 (84%) of the 77 animals were positive for hbv-sn. all of the 57 cf positive cases were also positive for hbv-sn. on the other hand, 30 (75%) of 40 laboratory-bred monkeys had ... | 1986 | 3011466 |
| evidence for the presence of duck hepatitis b virus in wild migrating ducks. | a virus closely related to duck hepatitis b virus (dhbv) was isolated from serum and liver samples of wild migratory ducks (mallards) caught in two separate wildlife reserve parks in france. in the first one (dombes region) 12% of wild mallards were positive for dhbv, and in the second (river somme) 3% of mallards were found positive. the dhbv isolated from the serum of wild mallards was also associated with an endogenous dna polymerase activity capable in vitro of completing a partially double- ... | 1986 | 3005480 |
| [experimental infection of human hepatitis b virus (hbv) in adult tree shrews]. | 1987 | 2962750 | |
| the florey lecture, 1986. vaccine prevention of virus-induced human cancers. | carcinogenic viruses have been discovered in numerous animal species over the last 80 years but their role in human cancer has only recently become an important issue. with eb virus involved with endemic burkitt's lymphoma and undifferentiated nasopharyngeal carcinoma, hepatitis b virus with primary liver cancer, papilloma viruses with carcinoma of the cervix, and t-cell leukaemia virus with adult t leukaemia, 20-25% of all human cancer appears to have a virus component in its causation. by anal ... | 1987 | 2884667 |
| influence of env and long terminal repeat sequences on the tissue tropism of avian leukosis viruses. | adsorption and penetration of retroviruses into eucaryotic cells is mediated by retroviral envelope glycoproteins interacting with host receptors. recombinant avian leukosis viruses (alvs) differing only in envelope determinants that interact with host receptors for subgroup a or e alvs have been found to have unexpectedly distinctive patterns of tissue-specific replication. recombinants of both subgroups were highly expressed in bursal lymphocytes as well as in cultured chicken embryo fibroblas ... | 1988 | 2846895 |
| viral versus chemical hepatocarcinogenesis. | almost all experimental studies on hepatocarcinogenesis have been performed on models induced by chemicals. the human hepatocellular carcinoma (hcc), a highly malignant tumor, particularly frequent in the far east and in africa, is overwhelmingly associated with hepatitis b virus (hbv) infections and only very rarely is it caused by chemicals. this raises the question as to what degree observations on the preferentially studied chemical carcinogenesis apply to human hcc. this question is timely, ... | 1988 | 2842391 |
| characterization of a herpesvirus isolated from woodchuck hepatocytes. | a dna virus with the characteristics of a herpesvirus has been isolated from woodchuck hepatocytes cultured in vitro. we refer to this virus as herpesvirus of marmots (hvm). electron microscopy of thin sections of hvm-infected cells showed nucleocapsids with a hexagonal outline and a diameter of 80 nm. enveloped virions were seen in cytoplasmic vacuoles and outside the cell. negatively stained virus particles purified from cell supernatants were enveloped with the characteristic appearance of he ... | 1988 | 2839596 |
| relation between hepatocellular carcinoma and persistent hepatitis b infection. | epidemiologic studies indicate a close association between hepatocellular carcinoma (hcc) and chronic hepatitis b virus (hbv) infection. hcc, a most frequent malignancy, is far more common in the far east and africa than in the west and may be the first to be greatly eliminated because of prevention of hbv infection by vaccination. the conceptual integration of epidemiologic observations, morphologic studies of the human precursor stages and investigations of animal infections by hepadna viruses ... | 1988 | 2839217 |
| use of peptides for immunization against foot-and-mouth disease. | a peptide corresponding to the major immunogenic site of the protein vp1 of foot-and-mouth disease virus (fmdv) will elicit a protective neutralizing antibody response in guinea-pigs, cattle and pigs. the response is much greater when the peptide is presented as a linear dimer or tetramer and pigs receiving as little as 40 micrograms peptide have been protected against challenge infection. an even greater response is obtained when the peptide is presented as part of the core protein of hepatitis ... | 1988 | 2838987 |
| evolution of hepatocellular carcinoma associated with chronic hepatitis b virus infection in alaskan eskimos. | hepatocellular carcinoma (hcc) associated with chronic hepatitis b virus (hbv) infection in yupik eskimos in southwestern alaska, detected in early stages as a result of screening, appears to be more frequently associated with variants of chronic portal inflammation in the noninvolved liver than with fully developed cirrhosis, otherwise common in hbv-associated hcc from other geographic areas. of 38 patients diagnosed with hcc since 1969, adequate tissue was available from both the tumor and non ... | 1988 | 2833872 |
| integrated structures of duck hepatitis b virus dna in hepatocellular carcinoma. | the structure of integrated viral dna in a hepatocellular carcinoma of a duck from chi-tung county in china was analyzed. three different clones of integrated viral dna, lambda dhs 6-1, lambda dhs 6-2, and lambda dhe 6-2, were obtained from the neoplastic portion of the liver by molecular cloning. one of the three clones, lambda dhs 6-1, showed inverted repetition of integrated viral dna with chromosomal flanking sequences. another clone, lambda dhs 6-2, showed a head-to-head configuration of th ... | 1988 | 2828681 |
| production of hepatitis b virus surface antigen particles by the human hepatoma cell line hugk-14 in a serum-free medium. | the human hepatoma cell line, hugk-14, containing integrated hepatitis b virus (hbv) dnas, produced a large number of 23 nm spherical particles of hbv surface antigen (hbsag) in a serum-free medium. these particles closely resembled the hbsag particles found in the sera of hbv carriers and elicited a high antibody response in guinea pigs. the hugk-14 cells in a serum-free medium would provide a new, economic source of hbv vaccine. | 1987 | 2828295 |
| transcriptional activation of homologous and heterologous genes by the hepatitis b virus x gene product in cells permissive for viral replication. | the potential of the hepadnavirus x gene product to activate gene expression in trans was tested through a series of cotransfections of x expression vectors with a variety of potential targets for transactivation. the x gene products from human hepatitis b virus (hbv), woodchuck hepatitis virus, and ground squirrel hepatitis virus are all equally active in augmenting the expression of a wide array of target promoters in both permissive and nonpermissive cells. using the hbv genome itself as the ... | 1989 | 2788226 |
| host-independent evolution and a genetic classification of the hepadnavirus family based on nucleotide sequences. | an analysis of molecular phylogeny was undertaken to examine whether the evolution of the hepadnavirus family is host-dependent. using the nucleotide sequences of 18 strains, we constructed phylogenetic trees. the trees obtained show that all 12 strains of hepatitis b virus can be classified into four subgroups that are not compatible with conventional subtypes. we estimated the rate of synonymous (silent) substitution for hepatitis b virus to be 4.57 x 10(-5) per site per year. applying this ra ... | 1989 | 2780562 |
| production of hepatitis b virus surface antigen containing pre-s1 and pre-s2 domains by chinese hamster ovary cells. | we have established transformed chinese hamster ovary cells, which secrete hepatitis b virus surface antigen containing both pre-s1 and pre-s2 domains into culture medium, by using the autologous s gene promoter. | 1989 | 2764727 |
| [breeding and care for wild woodchucks (marmota monax) by indoor and outdoor housing]. | woodchuck (marmota monax) is a very useful animal for studying human diseases such as endocrine, metabolic or cardiovascular diseases. it is regarded especially as the most excellent animal model for human hepatic cell cancer since woodchuck hepatitis virus has various biological characters similar to those of human hepatitis b virus. we have investigated in domestic this wild animals as laboratory experimental animals and succeeded in breeding and rearing in our outdoor facilities. | 1989 | 2744103 |
| enhanced metabolic activation of chemical hepatocarcinogens in woodchucks infected with hepatitis b virus. | the metabolism of chemical carcinogens was investigated in liver preparations from 28 captive woodchucks (marmota monax). of these, 23 were naturally infected with the woodchuck hepatitis virus (whv), and eight also had primary hepatocellular carcinoma (phc). twenty-nine parameters were investigated in liver subcellular fractions, including cross-reactivity with hbsag, and biochemical parameters, such as gamma-glutamyl transpeptidase, cytochrome p-450 and microsomal monooxygenases (aryl hydrocar ... | 1989 | 2720903 |
| enhancement of humoral immune responses against viral vaccines by a non-pyrogenic 6-o-acylmuramyldipeptide and synthetic low toxicity analogues of lipid a. | 6-o-acyl derivatives of n-acetylmuramyl-l-alanyl-d-isoglutamine (mdp) and synthetic, low toxicity lipid-a analogues were examined for their ability to enhance the potency of current viral vaccines. 6-o-(2-tetradecylhexadecanoyl)-mdp (b30-mdp) in non-irritative vehicles such as physiological saline, phosphate-buffered saline (pbs), squalene-pbs emulsion, intralipid or liposomes, significantly stimulated the primary and secondary antibody production of guinea-pigs against influenza split or subuni ... | 1989 | 2718605 |
| hepadnavirus-induced liver cancer in woodchucks. | woodchuck hepatitis virus (whv), a member of the hepadnaviridae, is closely related to hepatitis b virus (hbv) in its virus structure, genetic organization, and mechanism of replication. as with hbv in man, persistent whv infection is common in natural woodchuck populations and is associated with chronic hepatitis and hepatocellular carcinoma (hcc). in 1980, a program was initiated to develop the woodchuck as an experimental model of hepadnavirus infection and disease. the experimental studies h ... | 1989 | 2695243 |
| construction of a plasmid for expression of foreign epitopes as fusion proteins with subunit b of escherichia coli heat-labile enterotoxin. | a novel vector (pfs2.2) for high-level expression of fusion polypeptides with the nontoxic subunit b (lt-b) of escherichia coli heat-labile enterotoxin in escherichia coli and salmonellae is presented. it carries the complete coding sequence of lt-b under lac promoter control and a universal polylinker site for the in-frame insertion of foreign genes at the lt-b gene 3' end. by using this vector, fusion proteins comprising parts of the human or woodchuck hepatitis b virus surface and nucleocapsi ... | 1989 | 2647637 |
| serological survey for viral diseases in the cayo santiago rhesus macaque population. | the free-ranging population of rhesus monkeys (macaca mulatta) on cayo santiago was sero-surveyed for human measles, simian virus 40, b virus (herpes simiae), rhesus cytomegalovirus, human and simian retroviruses and encephalomyocarditis virus to determine the prevalence of these viruses in the colony. the results of this study indicate that the colony is free of sv40, htlviii (hiv-1), stlviii (siv) and srv1; has a low prevalence of measles and emcv; and high prevalence rates for b virus, cmv an ... | 1989 | 2571176 |
| hepatitis b surface antigen binds to human serum albumin cross-linked by transglutaminase. | it has been postulated that polymerized human serum albumin may play a role in the infection of hepatocytes by hepatitis b virus, because both the envelope of hepatitis b virus (hbsag) and hepatocytes exhibit binding activity for human serum albumin after cross-linking by glutaraldehyde. since glutaraldehyde-dependent cross-linking of albumin molecules is not likely to occur in vivo, we considered the possibility that albumin may be polymerized by the action of transglutaminase enzymes present i ... | 1989 | 2565285 |
| hepadnaviruses and hepatocellular carcinoma (hcc). | members of the hepadnavirus family share properties of virion structure, genome structure and replication, epidemiologic behavior, and pathogenic effects. persistent infections with hepatitis b virus (hbv) in man, woodchuck hepatitis virus (whv) in marmota monax, ground squirrel hepatitis virus (gshv) in spermophilus beecheyi, and duck hepatitis b virus (dhbv) in domestic ducks of china are associated with development of hepatocellular carcinoma (hcc). epidemiological evidence implicating hepadn ... | 1989 | 2559799 |
| hepatitis b virus and hepatocellular carcinoma--treatment of hbv carriers with phyllanthus amarus. | extracts of phyllanthus amarus inhibit the dna polymerase of hbv and related viruses. woodchuck carriers of woodchuck hepatitis virus (whv) were treated intraperitoneally with p. amarus extract. three of four animals which had been recently infected lost the virus. animals infected for about 3 months or more had a decrease in virus levels. human carriers of hbv were treated orally for 1 month. about 60% of the carriers lost hbv, which did not return during the observation period. fractions conta ... | 1989 | 2559794 |
| herpesvirus simiae contamination of primary rhesus monkey kidney cell cultures. cdc recommendations to minimize risks to laboratory personnel. | 1989 | 2556236 | |
| interaction of fucoidan from pelvetia fastigiata with surface antigens of hepatitis b and woodchuck hepatitis viruses. | a sulfated polysaccharide isolated from pelvetia fastigiata, a marine algae, was found to inhibit in vitro the reaction of the surface antigen of hepatitis b virus (hbsag) or of woodchuck hepatitis virus (whsag) with antibody to hbsag (anti-hbs). the polysaccharide was composed mainly of 1----2 linked l-fucose-4-sulfate with some (less than 10%) 1----3 linkages. the inhibition of the reaction of hbsag with anti-hbs or of whsag with anti-hbs was found to be directly proportional to the molecular ... | 1989 | 2544915 |
| discrimination between twenty isolates of herpesvirus simiae (b virus) by restriction enzyme analysis of the viral genome. | twenty isolates, obtained from adult breeding monkeys, were all identified as herpesvirus simiae (b virus) by neutralisation with polyclonal b virus antiserum. subsequent analysis of restriction enzyme profiles produced by digestion of dna from the isolates enabled discrimination to be made between them. in particular cynomolgus monkey isolates could be distinguished from those of rhesus animals. one isolate (isolate 9) could not be typed either as b virus or as the antigenically related herpesv ... | 1989 | 2543157 |
| bilateral posterior parietal atrophy in an infant rhesus monkey (macaca mulatta). | a case of severe neurological deficiency syndrome marked by visual impairment, motor disturbances, and bilateral extensive glial scarring of the posterior parietal cortex is described in an infant rhesus monkey. although morphologically resembling perinatal asphyxia, the possibility of a perinatal or postnatal herpesvirus simiae infection is discussed. | 1989 | 2540335 |
| [a study on primary liver cancer in tree shrews induced by human hepatitis b virus and aflatoxin b1]. | among 41 tree shrews exposed to aflatoxin b1(afb1), 17 were experimental infected by human hepatitis b virus (hhbv) and 24 were uninfected. after 158 weeks, 9 cases (52.94%) of primary liver cancer (plc) were found out of the 17 tree shrews infected by hhbv and only 3 cases (12.5%) developed plc in the 24 uninfected animals. significant difference of plc incidence was seen between the hhbv-infected and uninfected groups (p less than 0.05). moreover, 1/9 of the tree shrews that had been infected ... | 1989 | 2505943 |
| characterization of the binding sites for glutaraldehyde-polymerized albumin on purified woodchuck hepatocyte plasma membranes. | highly purified woodchuck hepatocyte plasma membranes demonstrated tight specific binding to glutaraldehyde-polymerized serum albumin immobilized on sepharose macrobeads. this phenomenon was characterized in detail and used for recognition of the plasma membrane constituents involved in binding of the albumin polymer. the hepatocyte membrane-polyalbumin interaction was found to be ligand-specific, saturable, and time-dependent. other characteristics of a specific receptor-ligand interaction were ... | 1989 | 2491821 |
| [the effect of human gamma globulin on tbe production of antibodies to the surface antigen of the hepatitis b virus in an experiment on animals]. | the biological assay for the determination of hbsag in gamma globulin is proposed. the assay is based on the immunizing action of immune complexes and some specific features of secondary immune response. for this purpose, the highly purified preparation of hbsag is injected into guinea pigs. subsequently the animals receive human gamma globulin. an increase in the titer of anti-hbsag antibodies in the animals preimmunized with the antigen is indicative of the presence hbsag in human gamma globul ... | 1989 | 2481912 |
| hepatitis delta antigen. antigenic structure and humoral immune response. | hepatitis delta virus (hdv) is a small rna virus that is dependent on helper functions provided by hepatitis b virus. the hepatitis delta ag (hdag) is the only protein known to be made from the viral genome, from an orf with a coding capacity of 214 amino acids. the immunogenic epitopes of hdag and the immune response to it were mapped by the use of synthetic peptides, antipeptide antibodies, and human mab. antipeptide sera covering approximately 60% of the linear sequence reacted with liver-der ... | 1989 | 2479687 |
| x-region-specific transcript in mammalian hepatitis b virus-infected liver. | in vitro gene expression systems for hepatitis b virus have demonstrated that the virus genome is capable of producing an x-region-specific transcript of approximately 0.7 kilobases (kb). however, this transcript has not been detected in virus-infected cells. we now report the presence of a heterogeneous x-region-specific transcript of approximately 0.65 kb that is found primarily in the nucleus of liver cells infected with the woodchuck hepatitis virus. interestingly, the majority of the transc ... | 1988 | 2459409 |
| structure and replication of the genome of the hepatitis delta virus. | the hepatitis delta virus can be found in the serum and liver of some hepatitis b virus patients. we now report that the rna genome of serum-derived delta virus is single-stranded and circular. livers of infected chimpanzees or woodchucks contained as many as 300,000 copies of genomic strand rna per average cell, and at least some of this rna had a circular conformation. also present in the livers were rna species complementary to the virion rna. the genomic rna was 5-22 times more abundant than ... | 1986 | 2430299 |
| products of the "x" gene in hepatitis b and related viruses. | the x region in hepatitis b virus dna potentially encodes a polypeptide 154 amino acids in length. two synthetic peptides spanning residues 100 to 115 (peptide 99) and 115 to 131 (peptide 100) in a hydrophilic domain within the carboxy terminal third of the proposed gene product were made and used to raise peptide antisera in rabbits. such antisera specifically bound to x reactive determinants in liver-derived core antigen particles from humans (hbcag), ducks (dhbcag), ground squirrels (gshcag) ... | 1986 | 2420692 |
| x antigen/antibody markers in hepadnavirus infections. antibodies to the x gene product(s). | antibodies to the x antigen of hepatitis b virus and woodchuck hepatitis virus were assayed in serial sera from infected individuals and compared with other markers of infection. antibody to the x antigen was found in 11 of 17 (65%) patients and 17 of 40 (42%) woodchucks that were surface-antigen positive. in comparison, this antibody was found in 5 of 14 (36%) patients and in none of 4 woodchucks that were surface-antigen negative. in 5 of 6 patients showing seroconversion from hepatitis b e an ... | 1990 | 2365196 |
| monoclonal antibodies raised to purified woodchuck hepatitis virus core antigen particles demonstrate x antigen reactivity. | woodchuck hepatitis core antigen (whcag) particles purified from the liver of chronically infected animals were used for monoclonal antibody production. most of the putative clones demonstrated anti-whc specificity. however, the supernatants from several putative clones bound x antigen sequences from woodchuck hepatitis virus (whv) and hepatitis b virus (hbv). one monoclonal antibody, designated wc9-85 (an igm), specifically bound hepatitis b x antigen (hbxag) residues spanning positions 115-131 ... | 1990 | 2353460 |
| physiology and function of the vero cell receptor for the hepatitis b virus small s protein. | the african green monkey kidney-derived vero cell line expresses a receptor activity for noninfectious hepatitis b surface antigen (hbsag) particles containing the small s protein. (m.e. peeples, k. komai, r. radek, and m.j. bankowski, 1987, virology 160, 135-142). in this report, the binding characteristics, the physiological requirements, and the functions of this receptor are further characterized. the association rate constant (ka) was determined by measuring binding during a short (10-min) ... | 1990 | 2353459 |
| enhancement of antibody responses to influenza b virus haemagglutinin by use of a new adjuvant formulation. | mice and guinea pigs were immunized with the haemagglutinin (ha) of influenza b-ussr/100 virus, either in syntex adjuvant formulation-1 (saf-1) or in saline. antibody titres were determined by elisa, haemagglutination inhibition and virus neutralization. animals immunized with ha in saf-1 had significantly higher antibody titres than did animals immunized with ha in saline. both 3-week-old and 13 1/2-month-old mice had greater and more uniform antibody responses to ha in saf-1 than to ha in sali ... | 1990 | 2316284 |
| x antigen/antibody markers in hepadnavirus infections. presence and significance of hepadnavirus x gene product(s) in serum. | the finding that x antigen is associated with hepatitis b core antigen particles and that serum hepatitis b e antigen derives from the cleavage of one or more core associated polypeptides raises the question as to whether core associated x antigen could be similarly generated and released into serum. to test this hypothesis, antisera raised to x antigen peptides were used to construct an enzyme-linked solid-phase immunoassay to detect x antigen in sera from patients infected with hepatitis b vir ... | 1990 | 2311861 |
| nci-h292 as an alternative cell line for the isolation and propagation of the human paramyxoviruses. | primary rhesus monkey kidney (mk) cells have long been the cells of choice for isolation and propagation of the human paramyxoviruses (parainfluenza 1, 2, 3, 4a, 4b, and mumps). however, problems with the supply and cost of mk cells and the presence of endogenous viruses, including herpes b virus and sv-5, necessitated a search for an alternative cell line. continuous cell cultures of human origin (l132, a-549, hut-292, hek, g-293, g-401, a-498, a-704, caki-1, rd) and simian origin (llc-mk2, bsc ... | 1990 | 2260924 |
| evidence against a requisite role for defective virus in the establishment of persistent hepadnavirus infections. | the factors involved in the establishment of persistent hepadnavirus infection are poorly understood. recent findings demonstrate that the sequence of the genome of hepatitis b virus (hbv) is variable in infected individuals and that, in some cases, virus mutants predominate. our objectives in the present study were to analyze the variability of woodchuck hepatitis virus (whv) genomes in an infected animal and to determine whether sequence heterogeneity played a critical role in the ability of w ... | 1990 | 2251274 |
| isolation of measles virus in primary rhesus monkey cells from a child with acute interstitial pneumonia who cytologically had giant-cell pneumonia without a rash. | the isolation of measles virus in primary rhesus monkey kidney cells (prmk) in patients with documented giant-cell pneumonia who have presented without a rash is limited. the diagnosis usually is made by cytologic examination of nasal or bronchial secretions in which characteristic multinucleated giant cells with intranuclear and intracytoplasmic inclusion bodies are observed. the diagnosis of giant-cell pneumonia has been associated with measles virus but not exclusively. canine distemper, herp ... | 1990 | 2220674 |
| hepadnaviruses, their infections and hepatocellular carcinoma. | ten years ago hepatitis b virus (hbv) was thought to be a unique virus, not included in any known family of viruses. following the discovery of a number of hbv-like viruses that infect birds and mammals, the existence of a new family known as hepadnaviridae has been confirmed. hepadnaviruses are small hepatotropic viruses that have a characteristic partially double stranded genome, exhibit a narrow host range and replicate by reverse transcription. the family currently comprises six viruses of w ... | 1990 | 2178194 |
| integration of hepatitis virus dna near c-myc in woodchuck hepatocellular carcinoma. | a total of 33 hepatocellular carcinomas, induced in woodchucks by chronic infection with woodchuck hepatitis virus (whv), a virus closely related to the human hepatitis b virus, were analyzed for the state of viral dna, the expression of viral genes and of different cellular proto-oncogenes. low levels of viral replication and presence of integrated viral forms including sequences of the enhancer element, appeared as a general rule in these tumors. enhanced expression of one or more of the nucle ... | 1990 | 2172071 |
| vectors, promoters, and expression of genes in chick embryos. | transgenic chickens were produced by injecting the day-1 egg with 10(5) infectious particles of a replication-competent virus based on the schmidt-ruppin a strain of rous sarcoma virus. the chickens were resistant to transforming subgroup a virus containing the src gene but not the corresponding subgroup b virus. transgenic chickens producing bovine growth hormone (bgh) were generated using a modified virus containing the bryan high titre polymerase gene. the virus was constructed with the bgh g ... | 1990 | 2170640 |
| clonal origin of mammalian hepatitis b virus-related hepatocellular carcinoma. | the clonal origins of 20 multifocal hepatocellular carcinomas (hccs) in four woodchucks were analyzed by the southern blot hybridization technique. the woodchucks were divided into two groups according to the morphological classification of multifocal tumors: 1) three woodchucks had multifocal tumors that were widely separated and similar in size, which suggests a multiclonal origin of the tumors; and 2) one woodchuck had ten small multifocal tumors surrounding two large main tumors, which indic ... | 1990 | 2164561 |
| a cross sectional survey for b virus antibody in a colony of group housed rhesus macaques. | a systematic sampling technique was used in combination with a highly sensitive and specific elisa to provide unbiased age-specific prevalence estimates of b virus antibody in rhesus monkeys housed in three different outdoor breeding corrals. among 146 sampled monkeys, 97% of animals 2.5 years and older were seropositive, while only 22% of younger animals were seropositive. neither gender nor social dominance ranking were predictive of b virus antibody status. the strong age association was not ... | 1990 | 2162979 |
| reduced duck hepatitis b virus viraemia in ducklings coinfected with the immunodepressive reticuloendotheliosis virus. | coinfection of avian hosts by duck hepatitis b virus (dhbv) and reticuloendotheliosis virus (rev) was studied to assess the effect of immunodepression by rev on the replication of dhbv. one-day-old ducklings, domestic chickens, and turkey poults were inoculated either with dhbv or dhbv and rev and were bled and weighed at regular intervals. dhbv infection as manifested by viraemia and dhbv dna in liver was established only in ducklings. all chickens and turkeys were negative for dhbv dna in seru ... | 1990 | 2160513 |
| seroprevalence of b virus (herpesvirus simiae) antibodies in a naturally formed group of rhesus macaques. | eighty-two percent of a group of rhesus monkeys removed from cayo santiago were seropositive for b virus (herpesvirus simiae) antibodies. similar results were obtained from the cayo santiago macaque population two decades ago and from feral indian rhesus monkeys. thus it is likely that b virus has been enzootic in the cayo santiago population since 1938, when the colony was established with stock imported from india. | 1990 | 2160017 |
| ocular histopathologic findings in a case of human herpes b virus infection. | a 37-year-old male laboratory technician who sustained a cutaneous penetrating wound from a rhesus monkey developed a progressive ascending encephalomyelitis due to culture-proven herpes b virus (herpesvirus simiae) infection. he died 6 weeks after his injury despite acyclovir and ganciclovir treatment that was initiated after central nervous system symptoms developed. histopathological examination of the patient's left eye revealed a multifocal necrotizing retinitis associated with a vitritis, ... | 1990 | 2159276 |
| hepatitis b virus and primary hepatocellular carcinoma: treatment of hbv carriers with phyllanthus amarus. | a viricide capable of eliminating hepatitis b virus (hbv) from chronic carriers should, theoretically, decrease the risk of primary hepatocellular carcinoma. extracts of phyllanthus amarus have been shown to inhibit the dna polymerase of hbv and woodchuck hepatitis virus (whv) in vitro. three of four recently infected whv carriers treated i.p. with p. amarus extract lost whv, animals infected for greater than or equal to 3 months showed a decrease in virus levels. preliminary results in human ca ... | 1990 | 2158192 |
| trans-complementation of the c gene of human and the p gene of woodchuck hepadnaviruses. | a 5 bp insertion was introduced into the bsteii site at nucleotide 2815 in dna of hepatitis b virus (hbv) and a mutant hbv genome was produced, which coded for envelope and core proteins, but not for dna polymerase, due to a frameshift. cultured hepatoma cells (hepg2) were simultaneously transfected with a plasmid harbouring a tandem dimer of the mutant hbv dna and another plasmid harbouring a tandem dimer of dna of woodchuck hepatitis virus or duck hepatitis b virus. the replication of mutant h ... | 1990 | 2157804 |
| anti-influenza virus activity of the compound ly253963. | the compound ly253963 (1,3,4-thiadiazol-2-ylcyanamide) inhibited the in vitro replication of representative influenza a and b viruses in madin-darby canine kidney (mdck) cells at concentrations of 1-3.2 micrograms/ml. the yield of an influenza a (h3n2) virus in primary rhesus monkey kidney (rmk) cells was inhibited at 0.1-0.3 micrograms/ml. however, similar concentrations were inhibitory for the growth of uninfected mcdk or rmk cells. combination drug studies generally found indifferent interact ... | 1990 | 2080866 |
| production of polyclonal antibodies against the s and pres2 regions of woodchuck hepatitis virus: lack of detectable low glycosylated pres2 protein (gp33) in sera from infected animals. | polyclonal antibodies directed against the pres2 and s domains of the woodchuck hepatitis virus (whv) envelope proteins were prepared using synthetic peptides and fusion polypeptides as immunogens. they were tested by immunoblotting and immunoprecipitation of infected woodchuck sera and lysates of a eukaryotic cell line expressing whv envelope proteins. only one anti-peptide serum directed against the pres2 domain was reactive with whv envelope proteins, recognizing the pres2 and pres1 proteins ... | 1991 | 1993879 |
| natural and experimental infection of wild mallard ducks with duck hepatitis b virus. | wild duck populations were investigated over a 4 year period for duck hepatitis b virus (dhbv) infection and liver disease. it appeared that dhbv is endemic in wild migratory mallards from france and the u.s.a., although neither hepatocellular carcinoma nor viral dna integration could be detected in liver samples examined. the follow up of natural infection indicated that wild mallards developed significantly higher serum titres to dhbv dna than pekin ducks. the results of experimental transmiss ... | 1991 | 1993878 |
| polymerase-related polypeptides associated with woodchuck hepatitis core antigen (whcag) particles. | the woodchuck hepatitis virus (whv) polymerase (pol)-encoded polypeptide(s), obtained from purified virus nucleocapsid particles, have been characterized by western blotting. peptide antibodies to amino-terminal (residues 32-45, whv pol-6) and carboxy-terminal (residues 861-879, whv pol-1) sequences were used, in addition to monoclonal antibodies made from purified woodchuck hepatitis core antigen (whcag) particles. one of the monoclonal antibodies, wc pol-11, specifically bound whv pol-1. both ... | 1991 | 1984662 |
| adjuvant formulations and their mode of action. | we have developed an adjuvant formulation (saf) consisting of a synthetic muramyl dipeptide analogue (n-acetylmuramyl-l-threonyl-d-isoglutamine) in a squalane-pluronic polymer emulsion. used with a variety of antigens saf elicits cell-mediated immunity and antibodies of protective isotypes (igg2a in the mouse). saf augments responses to influenza virus haemagglutinin and hepatitis b virus surface antigen. vaccines using saf have protected guinea pigs against genital herpes simplex virus infectio ... | 1990 | 1966859 |
| fatal herpesvirus simiae (b virus) infection in a patas monkey (erythrocebus patas). | 1990 | 1965586 | |
| hepatitis delta virus cdna sequence from an acutely hbv-infected chimpanzee: sequence conservation in experimental animals. | hepatitis delta virus (hdv) rna was isolated from the serum of a chimpanzee acutely infected with hepatitis b virus (hbv) and superinfected with hdv. interference of hdv with hbv resulted in decreased hbv dna levels in the serum. this interference did not change the size of the two hbv specific rnas present in the liver of the chimpanzee. the complete cdna sequence of the hdv rna (5th passage) was determined. comparison of this cdna sequence with our previously published sequence (4th passage), ... | 1991 | 1940877 |
| characterization of infectious and defective cloned avian hepadnavirus genomes. | the infectivity in vivo, replication competence in vitro, and expression of viral genes of several molecularly cloned duck hepatitis b virus (dhbv) genomes were investigated. in addition, replication competence, core protein expression, and secretion of viral proteins were investigated for a grey heron hepatitis b virus genome. except two, all dhbv isolates tested induced a systemic infection in pekin ducks when injected as cloned viral dna into the liver. after transfection of chicken hepatoma ... | 1991 | 1926780 |
| a percutaneous liver biopsy technique in ducks (anas platyrhynchos) experimentally infected with duck hepatitis b virus. | aylesbury ducks (anas platyrhynchos) chronically infected with the duck hepatitis b virus provide a useful model for studying hepadna-virus infection, replication and the effects of antiviral therapy. in these studies, it is necessary to have an effective method for obtaining repeat liver specimens for histological and molecular analyses. we have therefore developed a percutaneous liver biopsy technique which has a low rate of complications, can be performed at repeated intervals, and provides s ... | 1991 | 1921325 |
| improvement of hepatitis b vaccine by the use of a new adjuvant. | humoral and cellular immune responses of mice and guinea-pigs to hepatitis b virus surface antigen when alum-precipitated or administered with syntex adjuvant formulation (saf) were compared. two doses of hbsag in saf were sufficient to elicit antibody responses, and using saf the dose of antigen could be reduced to one-tenth of that required to elicit antibody responses by alum-adjuvanted hbsag. the use of saf increased and made more consistent the antibody responses in young mice and in strain ... | 1991 | 1872014 |
| [hepatitis b and primary cancer of the liver: recent data on the role of b virus in oncogenesis]. | although epidemiologic studies have clearly demonstrated the importance of the hepatitis b virus in the genesis of hepatocellular carcinoma, the molecular basis for this tumorigenic effect is still under debate. studies of woodchucks infected with a virus closely related to the human hepatitis b virus suggest that integration of the viral dna in the host genome often plays a direct role by activating myc cellular oncogenes through insertional mutagenesis. a similar mechanism involving other cell ... | 1991 | 1850121 |
| genetic analysis of the rous sarcoma virus subgroup d env gene: mammal tropism correlates with temperature sensitivity of gp85. | subgroup d avian sarcoma and leukosis viruses can penetrate a variety of mammalian cells in addition to cells from their natural host, chickens. sequences derived from the gp85-coding domain within the env gene of a mammal-tropic subgroup d virus (schmidt-ruppin d strain of rous sarcoma virus [sr-d rsv]) and a non-mammal-tropic subgroup b virus (rous-associated virus type 2) were recombined to map genetic determinants that allow penetration of mammalian cells. the following conclusions were base ... | 1991 | 1848317 |
| cyclosporin a modulates the course of woodchuck hepatitis virus infection and induces chronicity. | immunosuppression is known to influence the state of chronic hepatitis b virus infection, and is thought to increase the risk of developing chronic infection in newly exposed individuals. cyclosporin a (csa), an immunosuppressive agent that inhibits th cell function, was administered to woodchucks chronically infected with woodchuck hepatitis virus (whv), and resulted in a decreased severity of chronic hepatitis and an increased viremia during the treatment. adult woodchucks inoculated with whv ... | 1991 | 1826706 |
| [hepatitis b virus and hepatocellular carcinoma]. | hepatocellular carcinoma in woodchuck were characterized for woodchuck hepatitis virus integration nea c-myc oncogene. in one tumor, viral integration resulted in overexpression of a c-myc viral cotranscript. in a second tumor, viral insertion, 600 bp upstream of c-myc exon 1, was associated with increased levels of normal c-myc mrna. these results demonstrate that integration of woodchuck hepatitis virus near a proto-oncogene can contribute to the genesis of liver tumors. from a comparison of a ... | 1991 | 1772242 |
| animal models of hepatocellular carcinoma: hepadnavirus-induced liver cancer in woodchucks. | woodchuck hepatitis virus (whv), a member of the hepadnaviridae, is closely related to hepatitis-b virus (hbv) in its virus structure, genetic organization, and mechanism of replication. as with hbv in man, persistent whv infection is common in natural woodchuck populations and is associated with chronic hepatitis and hepatocellular carcinoma (hcc). experimental studies have established that whv causes hcc in woodchucks. chronic whv carriage as an outcome of experimental infection is a function ... | 1991 | 1751825 |
| a novel particulate influenza vaccine induces long-term and broad-based immunity in mice after oral immunization. | the immunogenicity of a novel particulate oral influenza vaccine was examined in terms of antibody response and protection in mice. oral immunization with chicken erythrocytes (crbc) adsorbed with gamma-irradiated influenza a virus induced high levels of immunoglobulin g antibodies and protection in the lung compared with gamma-irradiated virus administered alone or crbc. immunoglobulin a antibodies were the predominant antibodies in nasal washings, and their presence did not correlate with prot ... | 1992 | 1731094 |
| alpha-fetoprotein in the woodchuck model of hepadnavirus infection and disease: normal physiological patterns and responses to woodchuck hepatitis virus infection and hepatocellular carcinoma. | persistent infection of the eastern woodchuck (marmota monax) with the woodchuck hepatitis virus (whv) produces disease sequelae similar to those observed in humans with persistent hepatitis b virus infection, including hepatocellular carcinoma (hcc). to further characterize serological markers of hcc in the woodchuck, serum alpha-fetoprotein (afp) was measured under normal physiological conditions and following infection with whv. serum afp was elevated in association with whv-induced hepatitis ... | 1990 | 1701355 |
| alpha-fetoprotein in the woodchuck model of hepadnavirus infection and disease: immunochemical analysis of woodchuck alpha-fetoprotein and measurement in serum by quantitative monoclonal radioimmunoassay. | woodchuck hepatitis virus infection of the eastern woodchuck represents a useful model for the study of hepatitis b virus infection and disease in humans, including hepatocellular carcinoma. in man, hepatocellular carcinoma is frequently detected and monitored using assays for serum alpha-fetoprotein. to study the relationship between alpha-fetoprotein and woodchuck hepatitis virus-induced hepatocellular carcinoma in the woodchuck model, we produced a monoclonal antibody to woodchuck alpha-fetop ... | 1990 | 1693355 |
| animal transmission of enteric non-a, non-b hepatitis infection to macaca mulatta by faeco-oral route. | m. mulatta monkeys were inoculated faeco-orally by enteric non-a, non-b virus to study the development of clinical, biochemical, histopathological and serological changes in the blood and liver. pooled stool samples positive for putative non-a, non-b viral antigen by micro-elisa and aggregated viral particles by immune electron microscopy, were administered in two m. mulatta monkeys. biochemical, histopathological and serological changes were seen in the blood and liver and excretion of 27 nm vi ... | 1990 | 1693136 |