Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The clinical importance of the hepatitis B antigen (HBsAg) is based mainly on the differentiation between different courses of inflammatory liver diseases and/or nonvirus induced diseases of the liver. Epidemiologic studies have shown that beside a parenteral inoculation there is a possibility of a non-parenteral inoculation. Furthermore, there is evidence that the sporadic hepatitis is more commonly hepatitis B. Epidemiologic investigations revealed that clinically healthy HBsAg carriers, the "carrier" status in immunodeficiency syndromes and the natural circulation of the hepatitis B virus are of major interest. The demonstration of HBsAg enables us to characterize some diseases which show associations to hepatitis B virus, but where the pathogenic role of HBsAg/Ab immunocomplexes is questionable. Furthermore, it was possible by the detection of HBsAg to establish newer therapeutic and preventive interventions of virus B hepatitis.
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PMID:[Clinical importance of hepatitis B antigen (author's transl)]. 12 47

The relationship between the presence of hepatitis B surface antigen (HBsAg) and antibodies to human thyroglobulin (HTgAb) has been studied in 110 subjects with Down's syndrome (DS) from 4 months to 50 years of age and in 122 controls carefully matched for sex, age and socio-environmental conditions. The overall percentage of HBsAg carriers was 22.7 in DS and 6.6 in controls and that of HTgAb-positive subjects was 41.8 in DS and 19.7 in controls. In DS the frequency of HTgAb-positive subjects was very high, even in the youngest age groups in which the percentage of HBsAg carriers was relatively low; the latter thereafter showed a marked increase with age. A positive association between the presence of HBsAg and HTgAb was found only in the oldest age group of DS subjects. It is thus concluded that in DS the high frequency of HTgAb cannot be attributed to chronic hepatitis B virus infection. On the contrary, the presence of HTgAb might well represent an early "marker" of immunodeficiency and increased susceptibility to infection with hepatitis B virus.
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PMID:Immunodeficiency in Down's syndrome: relationship between presence of human thyroglobulin antibodies and HBsAg carrier status. 14 56

The high frequency of hepatitis B antigen (HBsAg) in hepatocellular carcinoma (HCC) patients has led to the hypothesis that immunoresponsiveness to hepatitis B virus (HBV) may be deficient in some patients, and that the immune response deficiency may have a genetic basis. Radioelectrocomplexing (REC), a radioimmunoassay in gel based on the principle of counterimmunoelectrophoresis (CIE), has been used to identify four HBV immune status subgroups: 1) HBsAg +ve/HBsAb +ve; 2) HBsAg +ve/HBsAb -ve; 3) HBsAb -ve/HBsAb +ve; 4) HBsAg -ve/HBsAb -ve/HBsAb -ve. These subgroups comprise 2, 6, 70, and 22 percent, respectively, among blood donors, and 32, 19, 23, and 26 percent, respectively, among HCC patients. Although the HBV exposure rates in the two groups were similar, the immune complexemic rates and HBs antigenemic rates were significantly higher in HBB patients than in the blood donors. It is proposed that the failure of termination of HBV infection revealed by these high rates reflects an immunodeficiency state characterized by an inability to produce high-avidity HBsAb. The immunodeficiency might have a primary genetic basis, or it might be secondary to the immunodepressive effects of concurrent viral or parasitic infections.
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PMID:Immunodeficiency to hepatitis B virus infection and genetic susceptibility to development of hepatocellular carcinoma. 17 28

The 'e antigen' (eAg) is specifically associated with hepatitis B virus infections and appears to be a marker for the infectivity and a prognostic indicator of the chronicity of liver disease. Therefore we examined by immunodiffusion the presence of eAg in the seum of HBsAg-positive patients on maintenance dialysis. The dialysis patients had a significantly higher incidence of positive eAg compared with a group of unselected HBsAg-positive patients without renal failure. In most of the dialysis patients the microscopic findings in the liver revealed only 'minimal changes'. Three eAg-positive patients received a renal transplant. Afterwards they displayed an appreciably increased eAg-yield on immunodiffusion and histology revealed chronic persistent hepatitis. It is assumed therefore that the immunodeficiency of patients undergoing chronic haemodialysis is possibly a supporting factor in the synthesis of eAg, and will perhaps induce a more subscute and prolonged course of hepatitis. The synthesis of eAg after renal transplantation may be enhanced by the additional immunosuppressive therapy.
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PMID:E antigen in the serum of HBs antigen-positive patients on maintenance dialysis and after transplantation. 36 77

During the period between January 1975 and August 1976, 203 liver biopsies were received at the Singapore General Hospital from patients with a variety of liver diseases. A histological diagnosis of chronic hepatitis was made in 29 patients: 13 cases of Chronic Aggressive Hepatitis (C.A.H.). 10 cases Chronic Persistent Hepatitis (C.P.H.) and 6 of Chronic Lobular Hepatitis (C.L.H.). C.P.H. and C.L.H. were found mainly in the third and fourth decades. C.A.H. was more common in the fifth to seventh decades and occurred principally in females. Hepatitis B antigenaemia was detected in 48.3% of these cases using the immunoelectroosmophoresis (EOP) technique and showed an even scatter in all histological sub-types. Using the reverse passive haemagglutination (rPHA) method for detection by HBs antigen and the radioelectrocomplexing (REC) method for anti-HBs, an immune sub-group (HBs Ag+/anti-HBs+) was identified in greater proportions in C.A.H. and C.P.H. compared to normal controls. This was interpreted to mean that these patients suffered from a primary immunodeficiency characterized by failure of production of high avidity anti-HBs with resulting failure to clear HBsAg leading to perpetuation of liver damage due to circulating immune complexes. It is also suggested that patients with C.P.H. belonging to this immune sub-group may progress to C.A.H. with its more ominous prognosis.
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PMID:Hepatitis B surface antigen and antibody status in biopsy proven chronic hepatitis in Singapore. 52 86

To determine the interrelationship between hepatitis B viral markers (HBV), the human Immunodeficiency virus (HIV), and hepatocellular carcinoma (HCC) in HCC patients, a total of 282 subjects were included in the study. Out of 282 subjects, 182 were HCC patients as determined by raised alpha-feto-protein (AFP) of greater than 1,000 ng/ml. The other 100 control patients presented with other conditions and had detectable AFP of less than 1,000 ng/ml in their sera. On presentation, 10 ml of venous blood was drawn from each enrolled subject and taken to the laboratory. HBV markers were detected using commercial reagents; HIV antibodies were detected by the commercial ELISA tests and were confirmed by Western blot. AFP was detected using an RIA technique. Of 282 examined subjects 182 (64.5%) had detectable AFP of greater than 1,000 ng/ml. 113 (40.1%) and 103 (36.5%) had HBsAg and Anti-HBc respectively. However, HBeAg was found in 21 of 113 (18.6%) of the HBsAg positive only. Anti-HIV antibodies were present in 15 (5.3%) of the 282 tested individuals. Only 1 (1.0%) of the control group had detectable anti-HIV antibodies in the serum. Eleven percent and 4.0% of the same control group had HBsAg and anti-HBc in their sera respectively. The study shows a significant correlation between HCC and HBV-markers (P less than 0.0001). Similarly, a significant correlation between anti-HIV antibodies and HBV-markers, (P less than 0.0001) was found.
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PMID:The interrelationship between HBV-markers and HIV antibodies in patients with hepatocellular carcinoma. 127 8

Reverse transcriptase (RT) was first discovered as an essential catalyst in the biological cycle of retroviruses. However, in the past years evidence has accumulated showing that RTs are involved in a surprisingly large number of RNA-mediated transpositional events that include both viral and nonviral genetic entities. Although it is probable that some RT-bearing genetic elements like the different types of AIDS viruses and the mammalian LINE family have arisen in recent geological times, the possibility that reverse transcription first took place in the early Archean is supported by (1) the hypothesis that RNA preceded DNA as cellular genetic material; (2) the existence of homologous regions of the subunit tau of the E. coli DNA polymerase III with the simian immunodeficiency virus RT, the hepatitis B virus RT, and the beta' subunit of the E. coli RNA polymerase (McHenry et al. 1988); (3) the presence of several conserved motifs, including a 14-amino-acid segment that consists of an Asp-Asp pair flanked by hydrophobic amino acids, which are found in all RTs and in most cellular and viral RNA polymerases. However, whether extant RTs descend from the primitive polymerase involved in the RNA-to-DNA transition remains unproven. Substrate specificity of the AMV and HIV-1 RTs can be modified in the presence of Mn2+, a cation which allows them to add ribonucleotides to an oligo (dG) primer in a template-dependent reaction. This change in specificity is comparable to that observed under similar conditions in other nucleic acid polymerases. This experimentally induced change in RT substrate specificity may explain previous observations on the misincorporation of ribonucleotides by the Maloney murine sarcoma virus RT in the minus and plus DNA of this retrovirus (Chen and Temin 1980). Our results also suggest that HIV-infected macrophages and T-cell cells may contain mixed polynucleotides containing both ribo- and deoxyribonucleotides. The evolutionary significance of these changes in substrate specificities of nucleic acid polymerases is also discussed.
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PMID:On the early emergence of reverse transcription: theoretical basis and experimental evidence. 128 61

The human immunodeficiency virus (HIV) proteins gp120 and gp41 are the principal immune target in HIV infection. One of the most important trends in the study of AIDS is linked to the mapping of sites involving in the binding to the cell receptor CD4 and in the induction of virus-neutralizing antibodies (VNA). Recent studies have revealed that gp120 as the major domain contains inducing type-specific BNA (PND) and a binding region with CD4 (CD4-BR). PND is located in the hypervariable loop of gp120 (residues 301-336 for a BRU strain), and CD4-BR is in the conservation area (residues 410-450). By using the synthetic fragments from these areas (BRU and MN strains) and HIV-infected persons' sera, the authors established that the immune response to PND and CD4-BR is somewhat interrelated: there is a synchronized response of HIV antibodies to peptides from the two regions in ELISA (r = 0.82). For analysis of this phenomenon, experiments with cross-linked immunoreactivity of rabbit antisera to peptides from PND and CD4-BR with homologous and heterologous peptides were performed by applying three control peptides from HIV and hepatitis B virus. It has been found that there is a cross reactivity between rabbit anti-PND (MN, BRU) and anti-CD4-BR abs. Peptide homological analysis revealed common structural elements for PND and CD4-BR despite significant differences in their proposed functions. There is a large amount of positively charged aa within both PND and CD4-BR which may be involved in gp120-CD4 interaction. Acetylation of Lys residues resulted in complete loss of peptide reactivity.
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PMID:[Peptides from the principal neutralizing and CD4-binding domain: similar immunoreactive properties and structure pattern]. 128 21

In a group of 37 haemophilics, 9 (24.3%) were seropositive for human immunodeficiency virus (HIV), while 9 (24.3%) and 10 (27%) were positive for hepatitis B virus (HBV) and hepatitis C virus (HCV) respectively. Haemophilics who were HIV seropositive had higher prevalence of HBV and HCV. Seropositivity for HIV was more in patients with severe haemophilia A who required frequent factor VIII replacement. The need for long term surveillance of voluntary blood donors for transfusion associated viruses like HIV, HBV and HCV, is emphasized.
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PMID:Sero-surveillance of transmissible hepatitis B & C viruses in asymptomatic HIV infection in haemophilics. 128 80

Catechin derivatives including (-)-epicatechin gallate (ECG), (-)-epigallocatechin gallate (EGCG), (-)-epigallocatechin (EGC) and green tea extract (GTE) were found to inhibit the activities of cloned human immunodeficiency virus type 1 reverse transcriptase (HIV-1 RT), duck hepatitis B virus replication complexes reverse transcriptase (DHBV RCs RT), herpes simplex virus 1 DNA polymerase (HSV-1 DNAP) and cow thymus DNA polymerase alpha (CT DNAP alpha). EGCG and ECG were shown to be very potent inhibitors of HIV-1 RT. According to the IC50 values for HIV-1 RT, these compounds can be ordered as EGCG 0.0066 mumol/L > ECG 0.084 mumol/L > GTE 0.1 microgram/ml > EGC 7.2 mumol/L. DHBV RCs RT was the least sensitive to these compounds. Kinetic study showed that EGCG exerts a mixed inhibition with respect to external template inducer poly (rA).oligo (dT) 12-18 and a noncompetitive inhibition with respect to substrate dTTP for HIV-1 RT. Bovine serum albumin significantly reduced the inhibitory effects of catechin analogues and GTE on HIV-1 RT. In tissue culture GTE inhibited the cytopathic effect of coxsackie B3 virus, but did not inhibit the cytopathic effects of HSV-1, HSV-2, influenza A or influenza B viruses.
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PMID:[The inhibitory effects of catechin derivatives on the activities of human immunodeficiency virus reverse transcriptase and DNA polymerases]. 128 89


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