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Query: UMLS:C0019163 (hepatitis B)
 38,309 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Three glycoproteins of intact hepatitis B surface antigen (HBsAg) with mol. wt. of 32 000, 30 000 and 28 000 respectively were identified by reaction with 125I-concanavalin A (Con A) after separation by sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE). The antigen was effectively disrupted with Triton X-100 to produce a structure with a sedimentation coefficient of 3.9S. Affinity chromatography of disrupted HBsAg using concanavalin A-Sepharose 4B (Con A-Sepharose) resulted in two fractions. The first contained material which did not bind to the lectin and consisted of a single polypeptide of mol. wt. 64 000. Further studies revealed this component to be serologically identical to serum albumin and to lack any affinity for antibody to HBsAg. A comparison of the tryptic peptide map of this polypeptide with that of purified serum albumin demonstrated identical amino-acid sequences. The second fraction contained material which bound to Con A and contained two polypeptides with mol. wt. of 28000 and 23000 respectively. HBsAg reactivity was associated with this fraction. This procedure allows the prepartion of HBsAg sub-units in milligram quantities for further immunological studies.
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PMID:Analysis of hepatitis B surface antigen components solubilized with Triton X-100. 9 17

A receptor for polymerized human serum albumin was demonstrated on Dane particles as well as on 20-nm hepatitis B surface antigen particles, isolated from asymptomatic carriers of hepatitis B virus who were positive for HBeAg. In contrast, such receptor was not born by 20-nm hepatitis B surface antigen particles obtained from carriers positive for antibody to HBeAg. Hepatitis B surface antigen particles with the receptor were heavier than those without, and when treated with pronase, they became lighter and lost the receptor. The receptor is responsible for the agglutination of erythrocytes coated with polymerized human serum albumin by the serum of patients with Type B hepatitis and asymptomatic carriers, which have been attributed to autoantibodies directed to denatured albumin molecules. When albumin fractions of chimpanzees were polymerized with glutaraldehyde, they also bound with the receptor on hepatitis B surface antigen. Polymerized albumin fractions of all the other experimental animals without susceptibility to hepatitis B virus, however, failed to bind with the receptor. These results seem to suggest a possible role of the receptor on Dane particles (presently accepted hepatitis B virions) for polymerized albumin molecules in infecting hepatocytes both in humans and chimpanzees.
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PMID:A receptor for polymerized human and chimpanzee albumins on hepatitis B virus particles co-occurring with HBeAg. 10 74

A solid-phase radioimmunoassay has been used successfully for detecting hepatitis B e antigen in fractionated hepatitis B virus-containing serum. Ammonium sulphate precipitation followed by gel filtration through a column of Sepharose CL-6B resulted in two fractions of antigen-containing material with molecular weights of 220,000 and 130,000. The smaller of these two fractions was found to possess an average isoelectric point of 4.9 and consisted of two major polypeptide species with estimated molecular weights of 66,000 and 17,000 respectively. Affinity chromatography on Blue Sepharose showed that e antigen was not retained under conditions which bound serum albumin. These results are discussed in relation to the immunopathogenesis of hepatitis B.
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PMID:The separation and analysis of hepatitis B e antigen. 12 Apr 15

The National Institute of Health Guidelines for Recombinant DNA Research recommends 2% aqueous Wescodyne, an iodophore that is used in many hospitals and laboratories as a disinfectant, as a decontaminant for biological safety cabinets and 5% for a spill outside a cabinet. A contact time of 10 to 15 minutes was given for the 2% solution and 20 minutes was considered adequate for the 5% concentration. The results indicate: 1. Aqueous Wescodyne (5%) is ineffective when used for 80 minutes against poliovirus in a test mixture containing 8.5% bovine serum albumin (a mixture equivalent in protein concentration to the higher range in serum). 2. Wescodyne (10%) employed under the same conditions for 40 minutes is also ineffective. 3. Wescodyne (10% v/v) in 50% ethanol (w/w) was effective and this mixture, originally recommended for hand washing, should be considered for use in biohazard situations, particularly for decontamination of work surfaces and biological safety cabinets. These results are of significance for if a virucide cannot inactivate poliovirus one would be concerned about using the virucide against hepatitis B or SV40 viruses.
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PMID:Wescodyne: lack of activity against poliovirus in the presence of organic matter. 21 87

A new technique using HBsAg-coated Chang cells as target cells was developed in order to measure cell-mediated immune reactions to HBsAg. The specificity of cytotoxic reactions was tested in experiments using Chang cells conjugated with human serum albumin. Antibody-dependent cell-mediated cytotoxicity (ADCC) specific for the HBsAg-coated target cells was demonstrated up to dilutions of anti-HBsAg serum of 10,000 : 1, when lymphocytes from the peripheral blood of normal individuals were added to the target cells. Spontaneous cell-mediated cytotoxicity (CMC) to HBsAg-coated target cells was demonstrated for lymphocytes from patients with hepatitis B and from patients with chronic active hepatitis (CAH), but not for lymphocytes from healthy controls. The CMC of hepatitis B lymphocytes to HBsAg-coated target cells was inhibited in the presence of antiserum to HBsAg. In experiments using purified lymphocyte populations evidence is presented that the CMC is T-cell dependent. HLA-restriction of the CMC was not observed. The described cytotoxicity test system has the advantage that target cells conjugated with defined antigens are used and that relevant control target cells are available.
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PMID:Antibody-dependent cell-mediated cytotoxicity (ADCC) and cell-mediated cytotoxicity (CMC) to HBsAg-coated target cells in patients with hepatitis B and chronic hepatitis (CAH). 37 82

A radioimmunoassay for albumin-binding sites associated with hepatitis B surface antigen (HBsAg) is described. Polystyrene beads coated with glutaraldehyde-polymerized human serum albumin were incubated with diluted specimens of HBsAg-positive sera which contained either e-antigen (HBeAg) or anti-HBe or were negative for both HBeAg and anti-HBe as determined by rheophoresis. The quantity of HBsAg attached to the beads, determined by measuring the amount of 125I-labeled anti-HBs adsorbed during a subsequent incubation step, was related to the presence of HBeAg in the specimens.
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PMID:Radioimmunoassay for albumin-binding sites associated with HBsAg: correlation of results with the presence of e-antigen in serum. 42 44

HBsAg binds to a solid-phase adsorbent consisting of polymerized human serum albumin (HSA) on glass particles. Both AD and AY antigenic subtypes of hepatitis B surface antigen (HBsAg) display this interaction. In either case, the binding to polymerized HSA is reduced in the presence of human serum, suggesting significant attachment of serum components at the locations on HBsAg particles where polymerized HSA binds. The temperature dependence of the interaction goes through a maximum above room temperature, in contrast to the increasing reaction with temperature of the HBsAg--anti-HBs antibody system. The interaction between HBsAg and polymerized HSA is discussed in relation to previous findings of HSA polymers and anti-polymerized albumin antibodies in hepatic patients. A mechanism for production of an autoimmune, antialbumin antibody condition, in association with hepatitis B virus infection is proposed.
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PMID:Interaction of hepatitis B surface antigen with polymerized human serum albumin. 53 42

The 22 nm spherical form of hepatitis B surface antigen was purified from the serum or plasma of chronic carriers of the antigen. Antigens of subtypes ayw and adr were individually prepared by isopycnic banding in cesium chloride followed by rate zonal separation in sucrose. Each preparation was stabilized with human serum albumin, and aliquots were inactivated with 1:2000 formalin at 37 C for 96 hours. The potency and immunogenicity of each preparation were determined: both antigenicity and immunogenicity were retained by the preparations following purification and inactivation. Seronegative chimpanzees were vaccinated with the antigen preparations. None of the vaccinated chimpanzees developed evidence of infection with hepatitis B virus during the follow-up period. Twenty-four weeks after vaccination vaccinated and control chimpanzees were inoculated with live hepatitis B virus. Control chimpanzees developed hepatitis associated with HBs Ag seven and nine weeks following challenge. In contrast, none of the chimpanzees vaccinated with HBs Ag developed HBs Ag or hepatitis. Thus, hepatitis B vaccine appeared to be safe and efficacious when tested in chimpanzees.
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PMID:Hepatitis B subunit vaccine: a preliminary report of safety and efficacy tests in chimpanzees. 82 32

Serial measurements of complement components were performed in fifty-nine patients with acute, uncomplicated hepatitis and twelve with alcoholic cirrhosis. Thirty-one of the former group had detectable hepatitis B antigen. Abnormal complement profiles were observed in nine patients with hepatitis B and seven with antigen-negative hepatitis. Low levels of C4, C3 and factor B were common in the subjects with cirrhosis and confined to those cases with severe reduction in serum albumin and/or prothrombin index. By contrast, the complement changes in the patients with hepatitis occurred without significant alteration in these parameters; certain subjects also had reduction in C1q and C5 and a significant number had C3d detectable in fresh plasma. The pattern of abnormality suggests predominant involvement of the classical pathway and it is concluded that this results, at least in part, from an immune process evident only in the early clinical phase of hepatitis. Such gross changes in complement are likely to reflect immune-complex activity and it is proposed that these complexes may be important in the clearance of virus material. The data supports a previous suggestion that recovery from acute hepatitis is primarily dependent on host immune competence rather than viral cytotoxicity or generation of immune complexes.
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PMID:Acute hepatitis: significance of changes in complement components. 89 Oct 25

Commercially available lots of plasma derivatives prepared between 1957 and 1975 were tested for hepatitis B surface antigen (HBsAg) by radioimmunoassay. In all, 69 per cent of lots of plasma protein fraction, 40 per cent of factor IX concentrate, 20 per cent of normal serum albumin, 13 per cent of antihemophilic factor, 3 per cent of fibrinogen, and 0.7 per cent of immune serum globulin lots tested were HBsAg-positive. There was great variation in the prevalence of HBsAg-positive lots of each product among the different manufacturers, reflecting not only differences in methods of processing plasma, but also differences in donor populations. Those manufacturers relying upon volunteer donor plasma or placental source material demonstrated lower rates of HBsAg-positive lots of final products than those relying upon commercial donor plasma. There was a marked decrease in the prevalence of positive lots during the period 1971 to 1973, coincident with the onset of routine plasma donor screening for HBsAg. However, current requirements for plasma screening have not resulted in totally HBsAg-free plasma products. Use of more sensitive and more reliable tests for HBsAg will probably reduce contamination of plasma pools with HBsAg to undetectable levels. Despite HBsAg-status, however, the "high-risk" plasma products (fibrinogen, antihemophilic factor, factor IX concentrate) must still be considered capable of transmitting hepatitis and used only with the strictest indications.
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PMID:The prevalence of hepatitis B surface antigen in commercially prepared plasma products. 93 29


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