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 immunogenicity of three different commercially available, well established Hepatitis B vaccines was determined. Three groups of high risk individuals were administered the vaccine, viz, Albugam (20 micrograms), Engerix-B (20 micrograms) and vaccine produced by Cheil Sugar & Co. (3 micrograms) respectively in a schedule of 3 doses as recommended by the manufacturers. A fourth group was administered a combination of the Albugam (2 doses) and Engerix-B (1 dose) vaccine. The sera collected 2 months after the 3rd dose showed seroconversion rates to be 100 percent and 95.34 percent respectively in the group which received the Albugam and Engerix-B vaccines respectively. The group which received a combination of both, the seropositivity rate was also 100 percent. The Chiel Sugar vaccine gave a seroresponse of only 52.38 percent. Geometric mean titres among the groups which received Albugam vaccine (501.30) were comparable to those receiving the combination of Engerix-B and Albugam (442.28). Those who received all 3 doses of Engerix-B vaccine showed a significantly lower GMT as compared to the above tow groups (GMT--43.14, p < .001, P < .001 respectively). The GMT in the group that received Cheil Sugar Vaccine was 3.81. Seroresponse was found to be inversely proportionate to age.
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PMID:Comparative immunogenicity of different hepatitis B vaccines among certain high risk groups in India. 130 12

Ten monoclonal antibodies were obtained from mice immunized with a yeast recombinant hepatitis B vaccine. They were selected at an early stage for their ability to bind to native surface antigen particles (HBsAg) in human plasma. All antibodies recognized conformational epitopes which were destroyed completely or almost completely by reduction of disulphide bridges. They were divided into five epitope groups by their competition for binding to recombinant S protein, though epitopes within each group are not identical. Recombinant S protein migrated on SDS-PAGE in the absence of reducing agents as a mixture of monomers and dimers/oligomers. Sucrose gradient analysis suggests that all these forms are co-aggregated into HBsAg-like particles. On Western blots, all ten antibodies either bound only to dimers/oligomers or strongly preferred them over monomers. The results suggest that, of the antibodies produced in response to recombinant vaccine in mice, most of those which bind strongly to 'native' HBsAg particles in human plasma recognize surface structures created by interaction between two subunits.
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PMID:Structural relationships between hepatitis B surface antigen in human plasma and dimers from recombinant vaccine: a monoclonal antibody study. 172 65

Immunogenicity of four plasma-derived hepatitis B vaccines (Merck, Sharp and Dohme, Pasteur, Dutch CLB and Korean Cheil-Sugar) was compared in Thai young adults. After primoimmunization, only the Merck and Pasteur vaccines could achieve greater than 90% seroconversion (i.e. anti-HBs greater than or equal to 10 mIU ml-1) whereas both the CLB and Korean vaccines needed a fourth dose to achieve this level of seroconversion. The anti-HBs titres of both heat-inactivated vaccines (CLB and Korean) were also significantly lower than those of the other two vaccines. We propose that the HBsAg content in both heat-inactivated vaccines should be increased and a booster (fourth) dose should be given in order to enhance their immunogenicities.
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PMID:Comparative immunogenicity study of four plasma-derived hepatitis B vaccines in Thai young adults. 252 62

Mice were immunized against duck hepatitis B virus core (DHBc) particles isolated from the liver of asymptomatic carrier ducks of duck hepatitis B virus (DHBV) by ultracentrifugation. Their spleen cells were fused with mouse myeloma (NS-1) cells, and 12 clones of hybridoma cells secreting antibodies against DHBc (anti-DHBc) were isolated. According to the reactivity to core particles and core peptide obtained from DHBc particles treated with SDS-2ME, the 12 antibodies were classified into two groups. Two monoclonal antibodies reacted against both core particles and core peptide (B-type), the other ten monoclonal antibodies reacted against core particles but did not react against core peptide obtained from DHBc particles treated with SDS-2 ME. (A-type). Solid phase enzyme immuno assay (EIA) using these two types of antibodies could detect core antigenisity not only in the liver homogenate but also in the DHBV infected serum. Sucrose gradient analysis and gel filtration analysis revealed this DHBc antigenisity in the serum is not carried by core particles but carried by core peptide, equivalent to HBe antigen in the serum of Hepatitis B virus (HBV) carrier. This EIA may provide sensitive test monitoring both serum DHBe antigen levels and DHBc antigen levels in the liver during DHBV infection.
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PMID:[Preparation of monoclonal antibodies against duck hepatitis B core antigen and analysis of the monoclonal antibodies]. 269 Apr 59

Inhibition assay of 125I-C1q binding to IgG-p-azobenzamidoethyl Sepharose 6B (IgG-Sepharose) by immune complexes was developed for the detection of circulating soluble immune complexes in the liver disease and was compared with polyclonal rheumatoid factor (pRF) binding inhibition assay and with C1q binding assay. The C1q inhibition assay was proved to be very sensitive, reproducible and rapid. Sucrose density gradient ultracentrifugal analysis showed that the assay could detect aggregates of human IgG (AHGG) larger than 19s. C1q inhibition activity (C1qIA) correlated with severity of the liver disease, defined by histological criteria. The highest C1qIA was observed in sera of patients with primary biliary cirrhosis, followed by liver cirrhosis, fulminant hepatitis, chronic aggressive hepatitis (2B), lupoid hepatitis and hepatocellular carcinoma in the order. There were correlations of C1qIA with serum gamma-globulin levels, sero-positivity for rheumatoid factor and hepatitis B surface antigen, and significant correlations existed also among pRFIA, C1qIA and C1qBA. Ultracentrifugal analysis of sera from patients with the liver disease showed that ClqIA demonstrated two sizes of immune complexes, 7s and larger than 19s, while complexes larger than 8s were seen in pRFIA.
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PMID:Studies on circulating soluble immune complexes of the liver disease. 6. Comparative studies of 125I-pRF inhibition assay, 125I-Clq inhibition assay and 125I-Clq binding assay. 697 71

Deletion mutations were introduced into the hepatitis B virus (HBV) capsid (core) gene to determine the effect on capsid formation, pregenome encapsidation, reverse transcription, and second-strand DNA synthesis. Carboxy-truncated HBV core proteins were expressed in insect cells using recombinant baculoviruses and were tested for capsid forming ability. Sucrose gradient sedimentation analysis revealed that core proteins missing 39 carboxy terminal amino acids produced capsids while removal of an additional 9 amino acids prevented capsid formation. Truncated core proteins co-expressed in the human hepatoma cell line Huh7 were assayed for their ability to complement in trans an HBV genomic plasmid containing a defective core gene. Mutants lacking 7 and 12 carboxy terminal residues complemented the defective core gene of the HBV plasmid as assayed by synthesis of HBV DNA via reverse transcription of the encapsidated RNA pregenome, although the mutant lacking 12 residues was partially defective in completing second-strand DNA synthesis. Capsids formed using a core deletion mutant missing 20 carboxy terminal residues contained HBV RNA but contained little if any HBV DNA. However, the largest encapsidated RNA species was only 1.7 kb, about half the size of the 3.5-kb RNA found in wild-type HBV capsids. Hybridization analysis revealed that the shorter RNA lacked sequences corresponding to the 3' half of the pregenomic RNA. Implications of these findings on HBV packaging are discussed.
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PMID:Carboxy-terminal truncations of the HBV core protein affect capsid formation and the apparent size of encapsidated HBV RNA. 768 72

Hepatitis B (HB) is an occupational hazard among health care workers. The only hope of control is by the use of vaccines. We evaluated the efficacy of HB vaccine, given intradermally to 304 hospital staff members. Two plasma-derived vaccines were used (Merck, Sharpe & Dohme (MSD), USA; Cheil Sugar & Co., South Korea). Both vaccines gave comparable, satisfactory results, the MSD vaccine inducing anti-HBs in 83% of those vaccinated and Cheil Sugar vaccine inducing anti-HBs in 86%. More than 50% developed anti-HBs titres in excess of 1000 mIU ml-1. The vaccines were well tolerated and there were no serious side effects. A good immune response was found when the vaccine was comparatively fresh but there was tapering of response when the vaccine neared the expiry date. The 0.1 ml dose by the intradermal route is safe, cost-effective and suitable for immunization of health care workers in developing countries such as India.
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PMID:Immunization of hospital personnel with low-dose intradermal hepatitis B vaccine. 785 4

The production of edible vaccines in transgenic plants and plant cell culture may be improved through a better understanding of antigen processing and assembly. The hepatitis B surface antigen (HBsAg) was chosen for study because it undergoes substantial and complex post-translational modifications, which are necessary for its immunogenicity. This antigen was expressed in soybean (Glycine max L. Merr. cv Williams 82) and tobacco NT1 (Nicotiana tabacum L.) cell suspension cultures, and HBsAg production in batch culture was characterized. The plant-derived antigen consisted predominantly of disulfide cross-linked HBsAg protein (p24(s)) dimers, which were all membrane associated. Similar to yeast, the plant-expressed HBsAg was retained intracellularly. The maximal HBsAg titers were obtained with soybean suspension cultures (20-22 mg/L) with titers in tobacco cultures being approximately 10-fold lower. For soybean cells, electron microscopy and immunolocalization demonstrated that all the HBsAg was localized to the endoplasmic reticulum (ER) and provoked dilation and proliferation of the ER network. Sucrose gradient analysis of crude extracts showed that HBsAg had a complex size distribution uncharacteristic of the antigen's normal structure of uniform 22-nm virus-like particles. The extent of authentic epitope formation was assessed by comparing total p24(s) synthesized to that reactive by polyclonal and monoclonal immunoassays. Depending on culture age, between 40% and 100% of total p24(s) was polyclonal antibody reactive whereas between 6% and 37% was recognized by a commercial monoclonal antibody assay. Possible strategies to increase HBsAg production and improve post-translational processing are discussed.
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PMID:Hepatitis B surface antigen (HBsAg) expression in plant cell culture: Kinetics of antigen accumulation in batch culture and its intracellular form. 1240 27

Hepatitis B virus core antigen (HBcAg) gene (C gene) was expressed in Saccharomyces cerevisiae and the products (rHBcAg or core particles) were purified from a crude lysate of the yeast by three steps: Sephrose CL-4B chromatography, Sucrose step-gradient ultracentrifugation and CsCl-isopycnic ultracentrifugation. It has been observed that HBcAg was synthesized in yeast cells as a particle consisting of polypeptides with a molecular weight of 21.5 kDa (p21.5). Results of ELISA test and density analysis of CsCl-isopycnic ultracentrifugation indicated that the purified products (rHBcAg particles) with HBcAg antigenicity mainly located at the densities of 1.27 and 1.40 g ml(-1), respectively. Observation and analysis of the purified rHBcAg products by TEM indicated that rHBcAg peptides could mainly self-assemble into two size classes of core particles. The larger particles were approximately 30.1 nm and the smaller were approximately 21.5 nm in mean diameter. Further observation and analysis of the same rHBcAg (core) particles by AFM also indicated that rHBcAg (core) particles were similar to the native HBcAg (core) particles from infected human hepatocytes and mainly composed of two size classes of partides core. The larger particles were approximately 31.3 nm and the smaller were approximately 22.5 nm in mean diameter which was similar to the results obtained by TEM. All results from both TEM and AFM suggested that core particles (capsids) produced in S. cerevisiae possessed dimorphism.
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PMID:Purification of the recombinant hepatitis B virus core antigen (rHBcAg) produced in the yeast Saccharomyces cerevisiae and comparative observation of its particles by transmission electron microscopy (TEM) and atomic force microscopy (AFM). 1500 57

The aryl hydrocarbon receptor (AHR) is a ligand activated transcription factor that acts as an environmental sensor by binding to a variety of xenobiotics. AHR activation serves to combat xenotoxic stress by inducing metabolic enzyme expression in the liver. The hepatitis B virus X-associated protein (XAP2) is a component of the cytosolic AHR complex and modulates AHR transcriptional properties in vitro and in cell culture and yeast systems. Expression of XAP2 is low in liver compared with other nonhepatic tissues and the AHR exhibits high ligand-induced transcriptional activity. Because XAP2 has been demonstrated to repress AHR activity, we hypothesized that XAP2 may be limiting in liver and that increasing XAP2 levels would attenuate AHR transcriptional activity. To this end, transgenic mice were generated that exhibit hepatocyte-specific elevation in XAP2 expression. Transgenic XAP2 expression was restricted to liver, and its ability to complex with the AHR was verified. Gene expression experiments were performed by inducing AHR transcriptional activity with beta-naphthoflavone via intraperitoneal injection, and mRNA quantification was done by real-time polymerase chain reaction. Wild-type and transgenic animals showed little difference in constitutive or ligand-induced CYP1A1; CYP1A2; UDP glucuronosyltransferase 1A2; NAD(P)H dehydrogenase, quinone 1; constitutive androstane receptor; or nuclear factor erythroid 2-related factor 2 mRNA expression. Sucrose density fractionation and AHR immunoprecipitation experiments found little or no stoichiometric increase in bound XAP2 to the AHR between genotypes. Gene array studies were performed to identify novel XAP2-regulated targets. Taken together, this work shows that despite the relatively low level of XAP2 in liver, it is not a limiting component in AHR regulation.
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PMID:Endogenous hepatic expression of the hepatitis B virus X-associated protein 2 is adequate for maximal association with aryl hydrocarbon receptor-90-kDa heat shock protein complexes. 1698 12


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