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Query: UMLS:C0019158 (hepatitis)
 30,205 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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 Southern blot analysis and a recombinant hepatitis B virus DNA plasmid probe, intracellular and extracellular viral DNA was consistently detected. Only extrachromosomal forms of WHV DNA were observed and no integration could be demonstrated in the DNA of the cells. The WHV DNA patterns were repeatedly identical with a characteristic smear starting from 3.3 kb associated with other smaller DNA fragments which presumably represented intermediate replicative forms of viral DNA. Furthermore, dot blot hybridization of the total RNA revealed the presence of WHV-specific transcripts in cells after 3 weeks of culture. All these results are compatible with the maintenance of active WHV replication in vitro although it was somewhat reduced after the first day of culture. This provides a mammalian model for hepadnavirus replication studies in stable primary hepatocyte cultures.
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PMID:Maintenance of woodchuck hepatitis virus activity in woodchuck hepatocyte primary culture. 357 56

Lymphoid cells were purified from the spleens of 15 woodchucks and examined for the presence of woodchuck hepatitis virus (WHV). Lymphoid cells from the spleens of eight of eight chronically infected animals contained high levels of WHV RNA and DNA. A 100-fold lower level of WHV DNA was found in the spleen from one of five animals that had recovered from acute WHV infections 2 years before this analysis. No WHV nucleic acids were observed in either of two uninfected animals. WHV DNA patterns in the lymphoid cells from the spleens of the chronically infected animals, which included the presence of single-stranded DNA and RNA-DNA hybrid molecules, were identical to those observed in WHV-infected liver. WHV DNA in these cells was present in intact, 27-nm core particles which also contained the endogenous DNA polymerase activity. These results indicate that the spleen is a site of active WHV DNA replication and is most likely a major source of WHV-infected cells in the circulating lymphoid cell population.
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PMID:Lymphoid cells in the spleens of woodchuck hepatitis virus-infected woodchucks are a site of active viral replication. 357 41

To understand the relationship among the time of infection, infection patterns, and liver diseases, experimental transmission of duck hepatitis B virus (DHBV) utilizing 165 Japanese white domestic ducklings was performed. Twenty to 25 ducklings were each inoculated with DHBV-positive serum intravenously at day one, 3, 5, 7, 10, and 14 posthatch and were sacrificed during the 1st, 2nd, 3rd, and 4th (and 24th in those inoculated on day one and day 3 posthatch) week after inoculation to obtain sera and the liver. The sera served for the measurement of DHBV DNA by spot hybridization test and DNA polymerase activity, and the liver was subjected to morphological examination including immunostaining for DHBV. The ducklings inoculated with DHBV on 1 day and 3 days posthatch always revealed persistent viremia, whereas those on and after 5 days posthatch showed persistent or transient viremia. The hepatitis activity in the liver was seen in ducklings inoculated with DHBV on and after 3 days posthatch and was very weak consistent with the diagnosis of mild acute hepatitis of humans. The serum transaminase activity was not significantly elevated at the time of occurrence of histological hepatitis activity. Since host immune mechanism establish at 3 to 5 days posthatch in birds, the host immune response seemed to determine whether DHBV infection was persistent or transient and the occurrence of hepatitis activity as seen in human hepatitis B virus (HBV) infection.
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PMID:A sequential study of viral DNA in serum in experimental transmission of duck hepatitis B virus. 358 87

Short-term prednisolone therapy was instituted on 27 patients with chronic active hepatitis (CAH) type B, in an attempt to induce seroconversion from hepatitis B e antigen (HBeAg) to the corresponding antibody (anti-HBe). Patients with CAH received a four-week regimen of prednisolone with daily dosage tapering from 40 to 10 mg (total 700 mg). Within one year after the withdrawal of prednisolone, 19 (70%) lost HBeAg and 11 of them (41% of the total) developed anti-HBe, at rates significantly higher than 3 (12%) and 1 (4%) who spontaneously showed respective serological changes among 26 matched controls during one year (p less than 0.001). Within two years after the withdrawal, 21 (78%) lost HBeAg and 19 (70%) developed anti-HBe, in contrast to 6 (23%) and 2 (8%) of controls who showed respective changes during that period (p less than 0.001). Seroconversion to anti-HBe was invariably accompanied by clinical and biochemical improvements along with loss of DNA polymerase from circulation. Elevation in transaminase levels, reflecting the rebound of steroid withdrawal, always heralded and appeared to be required for the seroconversion, but serious aggravation of hepatitis was not encountered in any of the patients.
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PMID:Short-term prednisolone for inducing seroconversion from hepatitis B e antigen to antibody along with clinical improvement in patients with chronic active hepatitis type B. 362 61

During a prospective study of acute symptomatic viral hepatitis, started in 1978, 664 consecutive adult patients, including 223 drug abusers, fulfilled the diagnostic criteria (anti-HBc IgM positivity) for acute type B hepatitis. In order to evaluate the outcome of the disease, 443 patients were followed for up to 12 months after the onset. 2.4% of the infections became chronic; the rate did not significantly differ between drug addicts and non-drug abusers, suggesting that chronic hepatitis is a rare complication of acute symptomatic hepatitis type B. Ongoing liver damage after clearance of HBsAg from serum was observed in drug abusers only (14% of the cases). Clinical, biochemical and virological features of the acute phase in patients with ongoing infection were compared with those of uncomplicated cases. Anicteric hepatitis and lower transaminase values were significantly (p less than 0.05) associated to a chronic evolution of the disease, as well as a higher prevalence of HBV-DNA, DNA polymerase and HBcAg positivity in serum. Testing HBV-DNA and DNA polymerase early in the course of the infection appeared to be of high predictive value for the subsequent outcome of the illness.
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PMID:Chronic evolution of acute hepatitis type B: prevalence and predictive markers. 371 May 94

Binding sites for polymerized albumin on hepatitis B virus components were reported in human hepatitis B virus chronic carriers predominantly with active viral replication (HB e antigen positive). The presence of comparable albumin-binding sites in the woodchuck hepatitis virus (WHV) model was examined on WHV components obtained from woodchucks with active viral replication (DNA polymerase positive). Binding sites for polymerized woodchuck serum albumin were not detected on the intact WHV virion, on 22-nm woodchuck hepatitis surface antigen (WHsAg), or on WHsAg polypeptides. Woodchuck albumin was not detected in purified 22-nm WHsAg, and anti-albumin antibodies were not detected in WHV chronic-carrier woodchucks. Our results in the WHV model argue against a role for viral polyalbumin-binding sites in tissue- and host-specific virus infectivity.
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PMID:Failure to detect polyalbumin-binding sites on the woodchuck hepatitis virus surface antigen: implications for the pathogenesis of hepatitis B virus in humans. 378 21

Risk factors associated with HBsAg carriers were prospectively examined in 1821 women attending the Antenatal Clinic of an inner-city obstetrics hospital. Of the sample, 3.2% were HBsAg carriers and 28.7% of 725 tested for anti-HBs were positive. Birth in a country where the prevalence of HBsAg is high and Aboriginal ancestry were the major associated factors rather than a past history of hepatitis or intravenous drug use. Women from Indochina or the Pacific region, if HBsAg-positive, were more likely than other carriers to have markers of viral replication including HBeAg, hepatitis B virus (HBV) DNA, and DNA polymerase. Evidence of past infection with HBV also varied with country of birth, but 11% of women with no apparent risk factors for prior HBV infection were anti-HBs positive. This study indicates the need for a screening programme for HBsAg in antenatal populations.
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PMID:Risk factors associated with hepatitis B infection in antenatal patients. 386 41

Nine patients with chronic type B hepatitis were entered into a preliminary study of recombinant, human alpha-interferon therapy. Patients received one to four courses of interferon, each consisting of a fixed dose of 18, 36, 50, 68, or 100 million units given three times a week for 2 wk. Side effects including fever, chills, fatigue, myalgias, headache, and neutropenia were common and especially severe with higher doses. Serum hepatitis B virus DNA polymerase activity fell during therapy to 15%-30% of the pretreatment levels irrespective of interferon dose, but rose to the initial level by 10 days after the course ended. During follow-up, 2 patients had a sustained clinical remission in which hepatitis B virus DNA, DNA polymerase, and hepatitis B e antigen disappeared from serum and amino-transferase activities fell to normal. One patient became hepatitis B surface antigen negative. We conclude that higher doses (50 and 68 million units) of interferon have greater side effects than lower doses (18 and 36 million units), without having any greater antiviral efficacy. Further studies should be directed at therapy with lower doses given over longer periods.
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PMID:Pilot study of recombinant human alpha-interferon for chronic type B hepatitis. 394 Feb 41

A segment from the pre-s region of the woodchuck hepatitis virus (WHV) was inserted into an open reading frame vector allowing for the expression in Escherichia coli of viral determinants as part of a fusion protein. The bacterially synthesized fusion molecule contained eight amino acids from beta-galactosidase (beta-gal) at the N terminus, followed by 89 pre-s-encoded amino acids and 219 amino acids of chloramphenicol acetyltransferase (CAT) at the C terminus (beta-gal:pre-s:CAT). This tribrid protein was used to generate antiserum which had a significant titer to the viral portion of the fusion polypeptide. Anti-beta-gal:pre-s:CAT was used in Western blot analysis to identify viral proteins containing pre-s-encoded determinants. Antiserum to the tribrid molecule recognized four WHV polypeptides with molecular masses of 33, 36, 45, and 47 kilodaltons, each of which was also recognized by a monoclonal antibody to WHV surface antigen. Using the same anti-tribrid serum, we also identified analogous polypeptides from ground squirrel hepatitis virus. The antiserum was also used to immunoprecipitate virus particles containing endogenous DNA polymerase activity, indicating that pre-s determinants are found on the surface of mature virions. Based on previous computer studies and the location of pre-s-encoded molecules on the surface of virus particles, a role in hepadnavirus host cell entry is suggested for these polypeptides.
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PMID:Identification and localization of pre-s-encoded polypeptides from woodchuck and ground squirrel hepatitis viruses. 394 37

Three asymptomatic chronic carriers of hepatitis B surface antigen, who had normal serum aminotransferase levels and no detectable hepatitis B e antigen in serum, developed icteric, symptomatic acute hepatitis. Serologic evidence of acute infection with hepatitis A virus, delta hepatitis virus, cytomegalovirus, or Epstein-Barr virus was absent. However, hepatitis B virus DNA and DNA polymerase activity, which were not detectable before the exacerbation, appeared in the serum of all three patients during the acute illness, confirming the diagnosis of spontaneous reactivation of chronic type B hepatitis. Thus, acute exacerbations of chronic type B hepatitis may present as an acute hepatitis superimposed on the chronic carrier state.
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PMID:Reactivation of chronic type B hepatitis presenting as acute viral hepatitis. 399 87


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