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

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 hepatitis virus (GSHV) and assayed the recombinants for infectivity after intrahepatic injection in ground squirrels, which support growth of GSHV but not WHV. Two of the recombinants molecules initiated productive infection; in one recombinant genome, 76% of the coding region for the major surface glycoprotein of GSHV and for the overlapping portion of the presumptive gene for DNA polymerase was replaced by WHV DNA; in the other, 29% of the same coding domain was replaced by WHV DNA. These findings demonstrate the feasibility of generating viable recombinants of hepatitis B viruses from different animal species and suggest that the major host range determinants are not encoded within the surface antigen gene of these viruses.
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PMID:In vitro recombinants of ground squirrel and woodchuck hepatitis viral DNAs produce infectious virus in squirrels. 304 Oct 44

Recombinant human interleukin 2 was administered to 10 patients with chronic type B hepatitis as a part of a pilot study to evaluate its antiviral activity. Patients received 1 to 3 x 10(5) units per day of interleukin 2 for 21 to 28 days, and all completed the treatment schedule. During therapy, serum values of DNA polymerase decreased in 6 and became negative in four patients. However, when therapy was discontinued, DNA polymerase levels increased to pretreatment levels in most cases. Serum HBeAg levels did not change during treatment. Serum aminotransferase levels transiently increased in 6 of the 10 patients during therapy; but once therapy was stopped, levels fell markedly. Side effects of interleukin 2 therapy included fever, chills, anorexia and fatigue. After 1 year of follow-up, three treated patients had lost HBeAg and had marked improvement in aminotransferase levels. These serologic and biochemical improvements occurred 1.5 to 11 months after therapy was stopped. Whether a 3- to 4-week course of interleukin 2 therapy leads to an increased rate of seroconversion from HBeAg to antibody in chronic type B hepatitis deserves further evaluation in prospectively randomized, controlled trials.
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PMID:Pilot study of recombinant human interleukin 2 for chronic type B hepatitis. 313 Dec 27

An anti-D-immunoglobulin preparation implicated in a hepatitis non-A,non-B transmission was analyzed for the presence of a DNA, which was originally isolated, cloned and sequenced from feces of a patient with posttransfusion HNANB. The investigation was performed by a DNA polymerase chain reaction using synthetic oligoprimers. Commercially available immunoglobulin preparations served as controls. The demonstration of identical DNA sequences in the infectious material speaks in favour of this up to now unknown circular and partially double-stranded DNA to be a virus genome involved in hepatitis non-A,non-B.
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PMID:[Hepatitis non-A, non-B-associated DNA--demonstration of DNA in proven infectious anti-D-immunoglobulin]. 313 78

Peripheral blood lymphocytes (PBLs) isolated from woodchucks chronically infected with the woodchuck hepatitis virus (WHV) carry low levels of nonreplicating WHV DNA. When PBLs from chronic carrier woodchucks were activated in culture with the generalized mitogen lipopolysaccharide (LPS), WHV DNA replication was initiated in cells obtained from one of three animals examined. Intracellular WHV core particles, containing WHV DNA replication intermediates, RNA/DNA hybrid molecules, and an active endogenous DNA polymerase, appeared 3 days after the start of LPS stimulation. After 5 to 7 days of LPS stimulation, WHV DNA-containing particles, which displayed the properties of intact, mature virions, were released into the culture medium. These studies provide evidence for reactivation of a latent WHV infection of circulating lymphoid cells and indicate that the presence of nonreplicating hepadnaviral DNA in lymphoid cells represents a potentially active infection following cellular activation.
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PMID:Mitogen-induced replication of woodchuck hepatitis virus in cultured peripheral blood lymphocytes. 326 87

A controlled trial of lymphoblastoid interferon versus no therapy in patients positive for HBsAg, HBeAg and DNA polymerase activity with separate randomisation for sexual preference and histology is underway. Thirty two patients have been followed for a minimum period of 6 months of whom 15 have been randomised to receive interferon thrice weekly for 6 months after a 5-day induction phase. Five treated patients developed an hepatitis-like illness during the 3rd month of therapy concurrent with an abrupt and complete loss of DNA polymerase activity from serum. In 3 this was permanent and anti-HBe subsequently developed; 2 of these have also lost HBsAg. In the other 2 patients inhibition of viral replication was transient. In 5 further treated patients DNA polymerase activity was completely inhibited throughout treatment only to return as soon as interferon was withdrawn. In this group serum aminotransferase became normal during treatment. In the remaining 5 treated patients, inhibition of DNA polymerase activity was never complete and serum aminotransferases were unaffected. All the control patients remain seropositive for HBsAg, HBeAg and DNA polymerase activity. The low seroconversion rate in treated patients and the absence of seroconversion in the control group are probably a reflection of the exclusion of patients with marked elevation of serum aminotransferases. The occurrence of an hepatitis-like illness in the 3rd month of therapy in a third of the patients and the loss of HBsAg in 2 of 3 who eventually seroconverted are likely to be a consequence of therapy rather than spontaneous events.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:A controlled trial of 6 months thrice weekly lymphoblastoid interferon versus no therapy in chronic hepatitis B virus infection. A preliminary analysis of the first 32 patients. 329 6

Liver biopsy specimens from 58 American patients with chronic type B hepatitis were investigated for the presence and distribution of the hepatitis B core (HBcAg) and surface (HBsAg) antigens by peroxidase-anti-peroxidase techniques. HBsAg was detected in 43 (77%) and HBcAg in 52 (90%) patients. HBcAg was present in 50 of 51 (98%) patients with hepatitis B e antigen (HBeAg) but in only two of seven (29%) of patients with antibody to HBeAg (anti-HBe). There was no correlation between severity of hepatitis or height of aminotransferase activities and the amount of HBsAg or HBcAg in hepatocytes but there was a positive correlation between amount of HBcAg and height of HBV-DNA and DNA polymerase activity in serum. Follow-up liver biopsies, taken 1 to 3 yr later, were available from 39 patients. HBcAg remained detectable in 25 of 26 patients with persistence of HBeAg but disappeared in 12 patients who had lost HBeAg. In nine patients, HBcAg was cytoplasmic as well as nuclear in distribution. Seven of these patients had an intense lobular hepatitis with marked elevations in aminotransferase activities. These findings indicate that the amount of HBcAg in liver correlates with the amount of serum hepatitis B virus as quantified by serum levels of DNA polymerase and HBV-DNA. The amount of nuclear HBcAg does not correlate with the severity of the liver disease, but the presence of cytoplasmic HBcAg usually reflects an active and severe ongoing hepatitis.
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PMID:Peroxidase-anti-peroxidase detection of hepatitis B surface and core antigen in liver biopsy specimens from patients with chronic type B hepatitis. 332 17

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 DHBV enzyme was strongly inhibited by phosphonoformic acid but not by aphidicolin, sulfhydryl group blockers or phosphonoacetic acid. Inhibition of DHBV DNA polymerase by the triphosphate derivatives of several nucleoside analogs appeared similar to that reported for HBV or WHV endogenous polymerase. FIACTP was the most, and ACVTP the least effective inhibitor; BVdUTP was of intermediary potency; araCTP and araTTP had a greater inhibitory effect on DHBV DNA polymerase than HBV or WHV DNA polymerase. The similarities in the properties of DHBV and HBV DNA polymerase justify the use of the duck hepatitis B polymerase model for screening and evaluation of potentially active drugs against HBV infection.
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PMID:Main properties of duck hepatitis B virus DNA polymerase: comparison with the human and woodchuck hepatitis B virus DNA polymerases. 344 17

Virus-associated particles have been isolated from the livers of three common gray tree squirrels (Sciurus carolinensis pennsylvanicus) that have histological evidence of hepatitis. Two of these livers were also positive by orcein staining, suggesting the presence of surface antigen in the cytoplasm of hepatocytes. Fractionation of these particles by CsCl density equilibrium gradient centrifugation and assay of the fractions for surface antigen, core antigen, and DNA polymerase activities demonstrate the presence of all three at an approximate density peak of 1.27. Electron microscopic examination of purified virus preparations showed spherical particles with a mean diameter of 25 nm. Initial characterization of the DNA polymerase product by gel electrophoresis showed a single DNase I sensitive band, migrating slightly faster than the woodchuck hepatitis virus DNA polymerase product. The presence of apparently cross-reacting antibodies was demonstrated by purified hepatitis B surface and/or core antigens binding to some squirrel sera in solid phase assays. Infected tree squirrels appear to lack detectable antigen in their sera. These results suggest that the tree squirrels studied are chronic carriers of a hepatitis B type virus. The host-virus interaction described herein may be useful in understanding the chronic carrier state associated with hepatitis B in man.
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PMID:A newly identified hepatitis B type virus in tree squirrels. 345 84

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 woodchuck hepatitis virus surface antigen titer compared to one untreated control. In animals recently infected with WHV, the extract was effective when administered i.p. in three out of four animals in reducing and within 3-6 weeks eliminating both the surface antigen titer and DNA polymerase activity in serum. The treatment was discontinued after 10 weeks, and the treated animals have remained free of detectable markers of WHV for more than 45 weeks. In contrast, three untreated controls remained positive for both markers for WHV. One of the controls died after 8 weeks; the other two controls have remained positive for WHV markers for more than 45 weeks. In a third trial with long-term carriers, test animals treated subcutaneously with the extract for 12 weeks did not respond; but on switching the mode of administration to i.p., two out of the five animals showed a significant decrease in woodchuck hepatitis virus surface antigen titer compared to controls.
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PMID:Effects of an extract from Phyllanthus niruri on hepatitis B and woodchuck hepatitis viruses: in vitro and in vivo studies. 346 54

Serum levels of antibody to hepatitis B core antigen and IgM antibody to hepatitis B core antigen were tested in 15 patients who participated in a randomized, placebo-controlled trial of a 28-day course of prednisolone therapy. During treatment, serum levels of antibody to hepatitis B core antigen and IgM antibody to hepatitis B core antigen decreased in all 10 treated patients, but in none of five controls (p less than 0.05). Also during therapy, ALT activity decreased by an average of 50% and serum IgG levels by 30% (both p less than 0.05). Serum levels of hepatitis B virus DNA and DNA polymerase activity did not change significantly. Four to 10 weeks after discontinuation of prednisolone, a rebound of serum ALT and IgM antibody to hepatitis B core antigen levels occurred, which usually resolved within the subsequent months of follow-up evaluation. In three patients, however, there was a prolonged exacerbation of the disease following prednisolone withdrawal; in these three, levels of IgM antibody to hepatitis B core antigen and ALT remained elevated above pretreatment values. The close correlation between changes in serum ALT activity and IgM antibody to hepatitis B core antigen levels suggests that corticosteroids can modulate disease activity in chronic type B hepatitis by suppression of the host-immune response to hepatitis B virus antigens.
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PMID:Effect of corticosteroid therapy on levels of antibody to hepatitis B core antigen in patients with chronic type B hepatitis. 355 25


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