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

The close association between hepatitis B antigen (HBAg) and the infectious agent of hepatitis B is clear. Many investigations have shown HBAg to be a useful tool for epidemiological studies of hepatitis B. The relation between HBAg and the postulated hepatitis B virus (HBV) is as yet not clear. In light of recent results a possible candidate could be the so-called Dane particle, which has HBAg reactivity on the surface, but possesses an antigenically distinct core. The core has been shown to have associated DNA polymerase activity. The particles which carry HBAg reactivity have surfaces which are antigenically complex. One common specificity a and 2 pairs of mutually exclusive determinants have been recognized namely d and y and w and r but further possible specificities are under investigation. Four different phenotypes have been described, adw, adr, ayw and ayr. Present evidence indicates that adw, adr and ayw are the phenotypic expression of 3 different transmissible strains of HBV. Studies on the epidemiology of these subtypes have shown 3 different geographic patterns. In the USA and Northern Europe both Dw (adw) and YW (ayw) are common, but in the Eastern Mediterranean and Middle East Yw is practically the only type found. In the Far East DR (adr) is the dominating subtype. Investigations have been done to determine whether there are any clinical differences in hepatitis caused by the different tubtypes. No certain differences have been shown.
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PMID:Some epidemiological and clinical aspects of hepatitis B antigen and its subtypes. 5 89

The e determinant of hepatitis B surface antigen (HBS Ag) was found in 23 of 42 patients with chronic hepatitis B virus (HBV) infection. Presence of e antigen was associated with increases in DNA polymerase activity and in the number of circulating Dane particles. In the group with detectable e antigen, the average DNA polymerase activity was 367+/-78 counts per minute (cpm; mean+/-standard error [SE]), and the average number of Dane particles counted in electron micrographs was 4.4% of the total HBS Ag. In contrast, e antigen-negative patients had an average DNA polymerase activity of 40+/-6.9 cpm (P less than 0.1) and an average Dane particle count equal to 0.6% of the HBS Ag. The e antigen was detected in 68% of patients who were HBS Ag carriers or had persistent viral hepatitis and 40% of those with chronic active type B hepatitis. Thus, the presence of e antigen correlated with both the chronicity and presence of infectious HBV. However, it did not correlate with the type or severity of liver disease after HBV infection, since e antigen was present in both chronic benign and chronic aggressive hepatitis B infections.
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PMID:Correlation of e antigen, DNA polymerase activity, and Dane particles in chronic benign and chronic active type B hepatitis infections. 6 88

Twelve infants, born to mothers with hepatitis B virus infection, were inoculated within 7 days of birth with immune serum globulin containing antibody to hepatitis B surface antigen (HBsAg) titers of 1:32 to 1:64 as measured by passive hemagglutination. Six of nine infants (66.7%) born to HBsAg-positive carrier mothers became HBsAg-positive within 3 mo of age. In addition, two of three treated infants born to mothers with acute hepatitis B during the delivery period also developed HBsAg. The hepatitis e antigen was detected in four of five carrier mothers and in two mothers with acute hepatitis, whose infants subsequently became HBsAg positive. In addition, hepatitis B-specific DNA polymerase activity was detected in the seven HBsAg-positive mothers who transmitted the virus to their infants. All eight infants have remained persistently HBsAg positive. Thus, the immune serum globulin containing low-titer antibody to HBsAg is not protective when given to infants born to HBsAg carrier mothers or to mothers with acute hepatitis B during the delivery period.
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PMID:Failure of immune serum globulin to prevent hepatitis B virus infection in infants born to HBsAg-positive mothers. 8 62

The in vitro reaction results of virus-associated DNA polymerases for the demonstration of plasma-suspended particles of avian leukemia virus (AMV) and of hepatitis type B virus (HBV) were compared. AMV particles could be identified by the transcription of the templates poly mC(dG)12-18, poly rAT10, and poly d(AT) using standardized reaction mixtures. With comparable test conditions, no DNA polymerase activity was found in human plasma containing HBV. These findings and the results of a systematic study of factors influencing the polymerization assays are discussed.
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PMID:Problems with particle-associated DNA polymerase assays in the diagnosis of plasma-suspended viruses. 9 14

Hepatitis B virus-like particles (including DANE particles) with DNA polymerase activity but negative for HBs Ag have been identified in NON-A, NON-B hepatitis sera positive for HC Ag. Although specifically associated with the particles, HC Ag is not a surface antigen of the hepatitis C virus identified here for the first time. The relationship of this agent with HBV seems obvious, and deserves further study.
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PMID:[Identification of a virus similar to hepatitis B virus in non-A non-B hepatitis]. 12 Jul 82

Resulting directly from the discovery of virus-related antigens, rapid progress has marked the last decade of viral hepatitis research. The hepatitis B virion has been tentatively identified as a DNA virus with an endogenous DNA polymerase, and new serological markers for type B hepatitis have been discovered. Hepatitis A antigen has been identified on a virus-like particle thought to be the hepatitis A virion. Progressively more sophisticated assays for hepatitis antigens and antibodies have been applied to the study of viral hepatitis epidemiology and biochemical-biophysical characterization of the agents. Most recently, knowledge learned from such studies has been exploited to develop a prototype non-infectious but immunogenic hepatitis B vaccine using hepatitis B surface antigen (HBsAg) purified in large quantities from chronic HBsAg carriers. Especially exciting is the prospect, suggested by serological studies of viral hepatitis, that hepatitis viruses besides hepatitis A and B viruses will be identified.
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PMID:Recent advances in the identification of hepatitis viruses. 19 74

Hepatitis B immune globulin (HBIG) and immune serum globulin (ISG) were examined in a randomized, double-blind trial to assess their relative efficacies in preventing type B hepatitis after needle-stick exposure to hepatitis B surface antigen (HBsAG)-positive donors. Clinical hepatitis developed in 1.4% of HBIG and in 5.9% of ISG recipients (P = 0.016), and seroconversion (anti-HBs) occurred in 5.6% and 20.7% of them respectively (P less than 0.001). Mild and transient side-effects were noted in 3.0% of ISG and in 3.2% of HBIG recipients. Available donor sera were examined for DNA polymerase (DNAP) and e antigen and antibody (HBeAg; anti-HBE). Both DNAP and HBeAg showed a highly statistically significant correlation with the infectivity of HBsAg-positive donors. Hepatitis B immune globulin remained significantly superior to ISG in preventing type B hepatitis even when the analysis was confined to these two high-risk subgroups. The efficacy of ISG in preventing type B hepatitis cannot be ascertained because a true placebo group was not included.
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PMID:Type B hepatitis after needle-stick exposure: prevention with hepatitis B immune globulin. Final report of the Veterans Administration Cooperative Study. 34 78

The discovery of Australian antigen (HBsAg) has led to an increasing deal of knowledges about the virus of type B hepatitis (HBV); several markers of HBV have been detected and are becoming disposable for clinical and epidemiological purposes. The HBsAg is carried by 3 types of particulate structures discovered by electron microscopy as small spherical particles having diameter around 22 nm, long filaments and spherical particles having an overall diameter of the 42 nm (Dane-particle) with an electron-dense core. Dane-particle core contains circular double-stranded DNA molecules and an enzyme, the DNA polymerase. At present, Dane-particle is thought to represent the HBV, having properties consistent with those of a complete virus. Four antigen/antibody systems related to viral type B hepatitis have been discovered; they have been designated with the following nomenclature: HBsAg/anti-HBs, HBcAg/anti-HBc, HBeAg/anti-HBe, epilon antigen/anti epilson. The availability of the HBV markers for clinical purposes will permit a better understanding of the sequence of the biological reactions as well as of the clinical and epidemiological features concerning this viral infection: incubation period, acute disease, resolution, chronic carrier state, actively or passively immunized subject, persistent or subsided infectivity, prognosis.
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PMID:[Markers of type B viral hepatitis]. 38 66

Evidence available indicates that the so-called Dane particles are the hepatitis virus. A DNA polymerase is associated with the core of these particles. The probability that this is the viral DNA polymerase offers the possibility of preventing hepatitis B multiplication by selective inhibition of this enzyme. This investigation reports that trisodium phosphonoformate (PFA) at low concentrations but not phosphonoacetate acid (PAA) inhitits Dane particle associated DNA polymerase.
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PMID:Trisodium phosphonoformate inhibits hepatitis B Dane particle DNA polymerase. 43

Serum levels of hepatitis B virus specific DNA polymerase and hepatitis B e antigen were studied serially in 34 patients with hepatitis B virus infection--20 who had the acute illness and recovered, seven who died with fulminant disease, three who died as a result of subacute hepatic necrosis, and four who went on to develop chronic active hepatitis. DNA polymerase activity was present in 16 (80%) and HBeAg in 13 (65%) of the uncomplicated cases at presentation and in all of those patients from whom the initial sample was obtained before the peak in aminotransferase. Both markers disappeared after 30 days from the onset but DNAP remained persistently positive during a follow-up period of four to 10 months in the four patients who progressed to chronic hepatitis. These results indicate that DNAP and HBeAg are transiently present in all cases of acute hepatitis B. Only their persistence after the acute episode could represent a useful prognostic marker of chronically. In this respect, DNAP was more reliable in our patients than HBeAg. In uncomplicated acute hepatitis, the peak in DNAP levels, which defines the time of maximum virus replication in the liver, preceded the peak in aminotransferase levels. Among the 10 patients who developed massive liver damage after hepatitis B infection, DNAP was detected in five of the seven with fluminant hepatitis, with enzyme levels that were comparable with those observed in uncomplicated acute hepatitis and presentation, but not in the cases of subacute hepatic necrosis. These findings are consistent with the hypothesis that in hepatitis B infection, liver damage, whatever the severity, is not directly related to the degree of virus replication.
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PMID:Changes in hepatitis B virus DNA polymerase in relation to the outcome of acute hepatitis type B. 43 51


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