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Biomedical subjects

J W Shih

Publications and source records attributed to J W Shih.

13 recordsLinked to original sources
PubMed1979

Incidence and significance of antibodies to delta antigen in hepatitis B virus infection.

A microtitre solid-phase blocking radioimmunoassay (RIA) for antibody to the hepatitis B virus (HBV)-associated delta antigen was specific and detected anti-delta antibody at dilutions of serum of up to 10(6). Analysis of sera from HBsAg-negative subjects and different categories of HBsAg carriers from different regions confirmed the association of anti-delta antibody with HBV infection. Anti-delta antibody was detected in persistently high titres in 19.1% and 2.6% of sera from patients with chronic hepatitis and symptomatic chronic carriers, respectively, and was not detected in the sera of HBsAg-negative controls. Anti-delta antibody appeared transiently and in low titres (less than 1:500) in 4.8% of sera from patients with acute type B hepatitis. The presence and persistence of anti-delta antibody seem to be associated with chronic HBV infection and the development of progressive liver damage.

Acute Disease↗
PubMed1979

Demonstration and partial characterization of 22-nm HBsAg and Dane particles of subtype HBsAg/ady.

The present paper describes the demonstration of d, y, w, and r HBsAg determinants in one serum. It was shown that there are two populations of HBsAg particles: HBsAg/ad and HBsAg/ady. All complete Dane particles were of subtype HBsAg/ady. Further characterization of HBsAg/ady particles did not reveal morphologic differences when they were compared with HBsAg/ad and HBsAg/ay particles. An HBsAg/ady phenotype may be the result of a double infection with hepatitis B viruses or exchanges of DNA sequences that determine HBsAg/ay and HBsAg/ad to form a new genotype.

Adult↗
PubMed1978

Radioimmunoassay for the detection of the antibody against hepatitis-B-core antigen (anti-HBc).

In this paper we describe a new sensitive solid phase radioimmunoassay for the detection of anti-HBc. This test was shown to be more sensitive than the widely used immune adherence hemagglutination test (IAHA) and at least as sensitive as the radioimmunoassay using the blocking principle. The new test system appears to be very useful to screen larger groups of individuals (e.g. blood donors) for the presence of anti-HBc.

Antibodies↗
PubMed1978

Antigenicity of the major polypeptides of hepatitis B surface antigen (HBsAg).

The major polypeptides (P-1, P-2, and P-6) of HBsAg were isolated from purified preparations of 22-nm HBsAg particles, iodinated, and analyzed by double-antibody radioimmunoprecipitation assays for the presence of hepatitis B virus (HBV)-specific antigens. Each polypeptide fraction contained both group (a) and subtype (d) specific determinants in common by virtue of their immunoreaction with antiserum to native HBsAg and antisera to the other structural polypeptides. The antigenic and structural similarities of the HBsAg polypeptides establish that they are not each unique gene products of the HBV genome.

Antigens↗
PubMed1977

Expression of hepatitis B virus-specific markers in asymptomatic hepatitis B surface antigen carriers.

A study was undertaken to assess the state of hepatitis B virus infection in a group of asymptomatic hepatitis B surface antigen (HBsAg) carriers. This study confirmed that the presence of hepatitis B e antigen (HBeAg) in serum was closely associated with serum HBsAg-specific deoxyribonucleic acid polymerase activity, hepatitis B core antigen (HBcAg) in serum and liver cell nuclei, and a histological picture of chronic hepatitis. No HBsAg-specific deoxyribonucleic acid polymerase activity or HBcAg was detected in highly concentrated anti-HBe-positive sera. In addition, liver biopsy specimens from carriers with anti-HBe were negative for HbcAg by immunofluorescence, and the liver histology was either normal or revealed only fatty changes. These data indicate that the anti-HBe-positive sera contained either no Dane particles or, if present, at least a 500-fold-lower concentration of Dane particles than that found in HBeAg-positive sera.

Carrier State↗
PubMed1977

Proteins of hepatitis B surface antigen.

Purified 22-nm forms of hepatitis B surface antigen (Hbsag) representing the three major antigenic subtypes (adw, ayw, and adr) were analyzed for their constituent polypeptides by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. No consistent difference in either the number or relative distributions of the polypeptides was observed for the various subtypes. Seven polypeptides were designated as P-1 through P-7 in order of their decreasing mobilities. By comparison with protein standards, their molecular weights were estimated as 23, 29.5, 36, 41.5, 53.5, 72, and 97 thousand. The P-1 and P-2 components represented the major polypeptides; P-2 and P-5 might by glycoproteins, based on their reaction with periodic acid-Shiff reagent. Each polypeptide contains cysteine residues. HBSAg was radiolabeled with 3H or 14C by reductive methylation or iodinated with 125I by the chloramine-T or lactoperoxidase procedures. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of labeled HBSAg yielded patterns identical to those obtained with protein stain. Comparison of HBSAg labeled by the chloramine-T and lactoperoxide procedures indicated that there was no distinction between internal or external components within the 22-nm structure.

Cysteine↗
PubMed1977

Proteins of hepatitis B surface antigen: amino acid compositions of the major polypeptides.

The major polypeptides isolated from two different preparations of hepatitis B surface antigen/adw were analyzed for their amino acid compositions. The results indicated a high degree of compositional relatedness between the P-1 (23,000, molecular weight) and P-2 (29,500, molecular weight) polypeptides for each of the two preparations. A considerable proportion of the major P-1 and P-2 polypeptides may be composed of a common structure. No amino sugars were detected in the preparations of isolated polypeptides.

Amino Acids↗
PubMed1977

Immunochemistry and polypeptide composition of hepatitis B core antigen (HBc Ag).

Core particles were isolated from a nuclear extract of a hepatitis B-infected liver labeled with 125I by using chloramine-T and further purified by rate zonal sedimentation on sucrose gradients. Iodinated HBcAg was used as a ligand in a sensitive double-antibody radioimmunoprecipitation (RIP) assay for antibody to HBcAg. The specificity of the RIP reaction was evaluated using defined anti-HBc sera and paired sera from six well-documented cases of hepatitis B infection. The polypeptide composition of the iodinated antigen was examined by SDS-polyacrylamide gel electrophoresis of solubilized complexes of 125I-HBcAg and anti-HBc. Two major polypeptides with apparent m.w. of 17,000 and 35,000 daltons were observed and designated as cP-1 and cP-2, respectively.

Antibodies, Viral↗
PubMed1977

The demonstration of subtype (D or Y)-specific determinants on the surface of the presumed hepatitis B virus.

Dane particles isolated from the sera of HBsAg/ad and HBsAg/ay carriers were reacted with monospecific antibodies to the d and y subtype-specific determinants of HBsAg/. Dane particles from HBsAg/ad expressed the d determinant on their surfaces and those from HBsAg/ay sera contained the y specificity. Both complete (DNA-P and HBcAg) and defective (HBcAg alone) Dane particles expressed the subtype-specific determinants.

Epitopes↗
PubMed1976

Characterization of antibodies to the structural polypeptides of HGSAg: evidence for subtype-specific determinants.

Antisera prepared in guinea pigs to the structural polypeptides of HBAAg/adw and HBSAg/ayw were examined by a modified passive hemagglutination assay for antibodies to the subtype-specific d and y determinants. All of the isolated polypeptide fractions stimulated antibodies to both group specific and subtype-specific antigens of the native HBSAg particle from which they were derived. These data indicate that the polypeptides have similarities in their immunochemical structure.

Animals↗
PubMedDate not supplied

Biophysical and biochemical characterization of hepatitis B antigen.

Hepatitis B surface antigens specified by the genome of the hepatitis B virus are shared by various particulate forms which circulate in the sera of chronic HBs Ag carriers. As purified from sera, HBs Ag consists of at least seven polypeptides, two of which appear to be glycoproteins. Most or all of these polypeptides contain both group-specific (a) and subtype-specific (d or y) determinants aspart of their structure. One particulate form, the Dane particle, is present as a minor component in most sera and may actually represent the virus of type B hepatitis.

Animals↗