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Biomedical subjects

J W Shih

Publications and source records attributed to J W Shih.

At least 91 records · Page 5Linked to original sources
PubMed1989

Association of the virus-like infectious agent originally reported in patients with AIDS with acute fatal disease in previously healthy non-AIDS patients.

We studied 6 patients from 6 different geographic areas who presented with acute flu-like illnesses. The patients developed persistent fevers, lymphadenopathy or diarrhea, pneumonia, and/or heart, liver, or adrenal failure. They died in 1-7 weeks. These patients had no serological evidence of HIV infection and could not be classified as AIDS patients according to CDC criteria. The clinical signs as well as laboratory and pathological studies of these patients suggested an active infectious process, although no etiological agent was found despite extensive infectious disease work-ups during their hospitalization. Post-mortem examinations showed histopathological lesions of fulminant necrosis involving the lymph nodes, spleen, lungs, liver, adrenal glands, heart, and/or brain. No viral inclusion cells, bacteria, fungi, or parasites could be identified in these tissues using special tissue stains. We report that immunohistochemistry using rabbit antiserum raised against VLIA, the virus-like infectious agent previously identified in patients with AIDS and shown to cause fatal systemic infection in primates, revealed VLIA antigens in these necrotizing lesions. In situ hybridization using an 35S labeled VLIA-specific DNA probe also detected VLIA genetic material in the areas of necrosis. Furthermore, virus-like particles closely resembling VLIA were identified ultrastructurally in these histopathological lesions. VLIA was associated with the systemic necrotizing lesions in these previously healthy non-AIDS patients with an acute fatal disease.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Importance of western blot analysis in predicting infectivity of anti-HTLV-III/LAV positive blood.

Stored donor and recipient sera from prospective studies of post-transfusion hepatitis were analysed for the presence of human T-cell lymphotropic virus type-III/lymphadenopathy associated virus (HTLV-III/LAV) antibodies as determined by enzyme-linked immunosorbent assays (ELISA). Of 3961 donor samples given to 461 patients, only 2 (0.05%) contained specific HTLV-III/LAV antibodies as determined by an avidin-biotin-enhanced western blot tech nique. Anti-HTLV-III/LAV was measured before and 3 and 6 months after transfusion in 295 recipients of anti-HTLV-III-negative blood, 7 recipients of ELISA-positive blood which was western blot negative, and 2 recipients of ELISA-positive blood confirmed as specific by western blot. Only the last 2 recipients became infected with HTLV-III/LAV, as assessed by antibody seroconversion (p less than 0.0001). Serocon version occurred early (6 and 8 weeks after transfusion) and was characterised first by antibody to p24 and later by antibody to p41. AIDS has not developed in either patient, but one has a T4/T8 ratio of 0.4 and impaired mitogen responses; the second patient has no evidence of immune dysfunction 4 years after exposure. This study confirms that HTLV-III/LAV infection can be transmitted by blood transfusion and supports the advisability of anti-HTLV-III/LAV testing of all blood donors. It also confirms the validity of western blot testing for HTLV-III/LAV specificity and suggests that ELISA-positive, western-blot-negative blood may not be infectious.

Acquired Immunodeficiency Syndrome↗
PubMed1985

Neutralization of hepatitis B virus infectivity by a murine monoclonal antibody: an experimental study in the chimpanzee.

Two study chimpanzees were inoculated intravenously with approximately 1,000 chimpanzee infectious doses of hepatitis B virus (HBV), one with subtype adr and one with subtype ayw, each previously incubated with 0.1 ml of a murine monoclonal antibody (IgG 1(K) class) directed against a single epitope on hepatitis B surface antigen common to most or all HBV. Two control chimpanzees received identical doses of HBV not incubated with the murine anti-HBs. Neither study chimpanzee developed HBV infection during 12 months of follow-up as judged by normal serum aminotransferase activity, normal liver biopsies, and negative serological tests for HBV-associated antigens and antibodies. In contrast, both control chimpanzees became infected by HBV as evidenced by elevated serum aminotransferase activity, liver biopsy changes characteristic of viral hepatitis, and the appearance of hepatitis B surface antigen (HBsAg) in their sera. Both study chimpanzees were shown to be fully susceptible to infection with these same HBV inocula when challenged 15 months after the initial inoculations at a time when passively administered anti-HBs was no longer detectable. Prior to challenge with HBV, one of the two study chimpanzees received a second injection of the same volume of the murine monoclonal anti-HBs. The survival of this anti-HBs in serum was reduced from six weeks (after the initial injection) to approximately two weeks.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1985

Interaction between various polymerized human albumins and hepatitis B surface antigen.

A variety of albumin polymers were prepared and tested for binding with hepatitis B surface antigen (HBsAg): synthetic polymers cross-linked by either glutaraldehyde or carbodiimide; heat-aggregated polymers made by heating albumin solutions at 60 degrees C for 10 h with or without albumin stabilizer; and polymers isolated from fresh or long-stored commercial therapeutic albumin solutions. A sensitive solid-phase, competitive-inhibition radioimmunoassay, which can detect as little as 10 ng of glutaraldehyde-cross-linked human albumin polymer (PHALB-G), was developed and used to measure binding. The binding of PHALB-G with HBsAg was 150- to 1,000-fold greater than that of any other albumin polymer. Glutaraldehyde-cross-linked bovine albumin polymer showed no binding. Albumin monomer and dimer fractions produced by glutaraldehyde treatment exhibited some binding, albeit much weaker than PHALB-G. As measured by a direct-binding assay with solid-phase PHALB-G, the attachment of HBsAg particles from sera positive for antibody to the e antigen was less efficient than that from sera positive for e antigen, even when all sera were tested at equal HBsAg concentrations. In protein blot experiments with radiolabeled albumin preparations, PHALB-G bound almost exclusively to HBsAg polypeptide P31 and showed no binding with the major polypeptides P23 and P26. None of the other radiolabeled albumin polymers was reactive. These results indicate that the interaction between PHALB-G and HBsAg is not due to polymerization of albumin per se, but rather is unique and site specific.

Binding, Competitive↗
PubMed1984

Delta hepatitis agent: structural and antigenic properties of the delta-associated particle.

Delta agent (delta) was serially passaged to a second and third hepatitis B surface antigen (HBsAg) carrier chimpanzee, using as inoculum the peak delta antigen (delta Ag) serum of an animal previously infected with human serum. The characteristics of serially transmitted delta Ag were similar to those described in first-passage animals. It was consistently detected before the development of anti-delta, in association with a 35- to 37-nm subpopulation of HBsAg particles and a unique low-molecular-weight (5.5 X 10(5)) RNA. RNase susceptibility of the delta-associated RNA and release of delta Ag activity upon treatment of delta-associated particles with detergent revealed that this particle is organized into a virion-like form with the RNA and delta Ag as internal components within a coat of HBsAg. Surface determinants of the delta-associated particle other than HBsAg were not detected by radioimmunoprecipitation experiments, using sera of humans and chimpanzees convalescent from delta hepatitis. The HBsAg-associated particle is the "candidate agent" of delta hepatitis.

Animals↗
PubMed1983

Chemically synthesized peptides of hepatitis B surface antigen duplicate the d/y specificities and induce subtype-specific antibodies in chimpanzees.

Synthetic peptides, predicted from the nucleotide sequence of the S gene of hepatitis B virus were analyzed in terms of the established specificities of the hepatitis B surface antigen. The analysis indicated that the group-specific alpha antigen is composed of at least three nonoverlapping sequences and that a relatively hydrophilic region of the surface antigen protein, spanning amino acid residues 110-137, specifies the major d and y subtype system. The d/y subtype appears to depend on changes in one or more variable amino acids at positions 127, 131, and 134 of the hepatitis B surface antigen protein. Peptide 49 (consisting of amino acid sequences of the y subtype for the region 110-137), coupled to a carrier protein and mixed with an adjuvant, stimulated a brisk anti-y response in chimpanzees, the relevant model of human response to hepatitis B virus immunization and infection. Experimental challenge with homologous hepatitis B virus resulted in a pattern of partial protection. The results offer promise for the application of chemically synthesized peptides as vaccines in the prophylaxis of hepatitis B virus disease.

Amino Acid Sequence↗
PubMed1982

Natural and experimental infection of woodchucks with woodchuck hepatitis virus, as measured by new, specific assays for woodchuck surface antigen and antibody.

Solid-phase radioimmunoassays for woodchuck hepatitis virus (WHV) surface antigen (WHsAg) and antibody to it (anti-WHs) were developed. The test for WHsAg could detect as little as 10 ng/ml. In both tests it was necessary to employ radiolabeled WHsAg instead of anti-WHs as the probe because the latter appeared to be labile to the conditions of labeling. The tests were used to characterize naturally acquired and experimental WHV infections of woodchucks. Forty-three of 72 wild-caught woodchucks had serological evidence of WHV infections; 16 of these resulted in chronic infection, and the remainder were self-limiting. All chronically infected animals were positive for WHsAg and DNA polymerase activity. During 3 years of observation, 11 of the 16 WHsAg-positive animals and 3 of the 27 anti-WHs-positive animals, but none of the 21 uninfected animals developed hepatocellular carcinoma. Seroconversion, possibly resulting from infection with WHV, was documented in a chimpanzee inoculated with WHV. An immune adherence hemagglutination test for WHsAg was also developed by using anti-WHs of chimpanzee origin as a reagent, but the test was not useful for detecting anti-WHs of woodchuck origin because of the lability of the latter.

Animals↗
PubMed1982

Surface antigenic determinants of mammalian "hepadnaviruses" defined by group- and class-specific monoclonal antibodies.

The hepatitis B-like viruses (human hepatitis B virus, woodchuck hepatitis virus, ground squirrel hepatitis virus, and duck hepatitis B virus) are hepatotropic DNA viruses which have been referred to collectively as "hepadnaviruses." Using a murine monoclonal antibody (101-2) to the surface antigen of woodchuck hepatitis virus, we have shown that the surface antigens of mammalian hepadnaviruses (HBsAg, WHsAg, and GSHsAg) are antigenically related via a common determinant (HV/101). Furthermore, analysis with other monoclonal antibodies to WHsAg revealed that WHsAg and GHsAg are antigenically distinct, although the antigens had more determinants in common with each other than with HBsAg. The hepadnavirus group-specific antibody (101-2) reacted with HBsAg subtypic variants in a group-specific rather than subtype-specific manner. In conjunction with observations with an HBsAg-specific, group-reactive monoclonal antibody (BX259), the present data suggest that there are at least two group-reactive epitopes of HBsAg: one which is virus specific (HBV/259) and one which is common to two other mammalian hepadnaviruses (HV/101).

Animals↗
PubMed1981

Monoclonal antibodies to respiratory syncytial virus: detection of virus neutralization and other antigen-antibody systems using infected human and murine cells.

Monoclonal antibodies to human respiratory syncytial (RS) virus-specific antigens can be obtained without preliminary recourse to large-scale culture and purification of the virion. Lytically infected human and persistently infected murine cultured cells expressing RS virus-specific cell surface and cytoplasmic antigens were substituted as priming immunogens and as substrates in solid-phase antibody radioimmunoassays. Seven hybridoma clones secreting murine IgG of either the gamma 1 or the gamma 2a subclass bearing kappa light chains were isolated. Two of the antibodies were specific for cell surface viral antigens, but only one was able to neutralize RS virus infectivity. The five remaining antibodies did not neutralize virus infectivity and were specific for viral antigens associated with large cytoplasmic inclusions as judged by indirect immunofluorescence (IF) analysis on fixed infected cells. Similar IF analysis using live cells revealed that those antigens, associated with the cytoplasmic inclusions in both the human and murine infected cells, were not expressed on the cell surface of the live infected human cells, but were expressed on the cell surface of the live infected murine cells. Monoclonal antibodies generated via the present system will prove useful in the immunological analysis of viral components which are specific pathogenic functions, such as infectivity, and those which may be abnormally exposed at the surface of persistently infected cells.

Animals↗
PubMed1981

Expression of the hepatitis B virus surface antigen gene in cell culture by using a simian virus 40 vector.

We have constructed a simian virus 40 recombinant carrying a fragment of DNA from hepatitis B virus. Cultured monkey kidney cells infected with this recombinant produce hepatitis B surface antigen. The antigen is excreted into the culture medium as 22-nm particles with the same physical properties, antigenic composition, and constituent polypeptides as those found in the sera of patients with type B hepatitis.

Animals↗
PubMed1980

Production of monoclonal antibodies against hepatitis B surface antigen (HBsAg) by somatic cell hybrids.

Hybridomas secreting anti-HBs were produced by fusion of either adw or ayw HBsAg primed mouse spleen cells with either P3 X63 Ag8 or P3 NSI 1 Ag4 1 mouse myeloma cell lines. Individual anti-HBs secreting clones were isolated by limiting dilution procedures, and six cell lines have been established, namely, BX182, BX259, BX248, CN324, DN283, and DN296. Progenies of each cell line were derived from a single clone obtained from three subclonings of six anti-HBs positive initial fusion colonies. Clones were passaged in tissue culture and as tumors in syngeneic mice for upwards of six months. Anti-HBs of each line showed characteristic reactivity (detection) patterns in radioimmunoassay using different antigen subtype solid phases followed by either 125I-HBsAg or 125I-goat anti-mouse IgG probe. The specificity of the anti-HBs from each clone for the subdeterminants of HBsAg was identified by their reaction with 125I-HBsAg ligands of several subtypes in a radioimmunoprecipitation assay. Four types of reaction were identified and correlated to the conventional serological subtyping definitions; they were anti-HBs/a (BX259 and CN324), anti-HBs/d (BX182), and possibly anti-HBs/w (BX248 and DN296) and anti-HBs/y (DN283). These monoclonal antibodies will be important for the elucidation of the antigenic structure of native HBsAg and will provide valuable reagents for both antigen detection and subtyping.

Animals↗
PubMed1980

delta Agent: association of delta antigen with hepatitis B surface antigen and RNA in serum of delta-infected chimpanzees.

The hepatitis B virus-associated beta antigen was found in the serum of experimentally infected chimpanzee as an internal component of a discrete subpopulation of hepatitis B surface antigen (HBsAg) particles. The 35- to 37-nm particles banded in CsCl at 1.24-1.25 g/cm3 and sedimented with a mobility intermediate between that of the hepatitis B virion and that of the 22-nm form of HBsAg. The particles contained only indistinct internal structure by electron microscopy and were not unique to delta agent infection, similar particles without delta-antigen activity being observed in the preinfection serum of HBsAg carrier chimpanzees. A small RNA (Mr, 5 X 10(5)) was temporally associated with delta antigen in the serum of infected chimpanzees and copurified with the delta-antigen-associated particles. This RNA is smaller than the genomes of known RNA viruses but larger than the viroids of higher plants.

Animals↗
PubMed1980

Relationship of large hepatitis B surface antigen polypeptide to human serum albumin.

A significant proportion (20 to 40%) of highly purified 22-nm hepatitis B surface antigen (HBsAg) particles contain human serum albumin (HSA) as demonstrated by specific precipitation of radioiodinated particles by anti-HSA. Preparations of the isolated major HBsAg polypeptides (P-1, P-2, and P-6) were iodinated and analyzed by radiommunoprecipitation for reactivity with rabbit antisera to human plasma proteins. Only the P-6 fraction (molecular weight, 68,000) was precipitated and only by anti-HSA; specific precipitation was observed with guinea pig antisera to P-6 and native HBsAg and goat or rabbit antisera to HSA. Coprecipitation of P-6 with antiserum to HBsAg and with anti-HSA, compared to precipitation with each antiserum alone, indicated that the HBsAg and HSA determinants were on separate molecules. The P-6 polypeptide may represent a precursor protein of the hepatitis B virion.

Animals↗
PubMed1980

The hepatitis B virus-associated delta antigen: isolation from liver, development of solid-phase radioimmunoassays for delta antigen and anti-delta and partial characterization of delta antigen.

The delta antigen-antibody (delta Ag/anti-delta) system is associated with type B hepatitis in man. The delta Ag was extracted and solubilized by sonication and treatment with 6 M GuHCl from the nuclei of human liver obtained at autopsy of a delta-positive subject. A microtiter solid-phase radioimmunoassay was developed and used for the partial characterization of delta Ag. Equilibrium centrifugation, gel filtration and chemical and enzymatic treatments revealed delta Ag to be a protein of approximately 68,000 m.w. with a buoyant density of 1.28 g/cm3 in CsCl, stable to heat, acid, nucleases, and glycosidases, and inactivated by alkali and proteases. A standard preparation of delta Ag was used to develop a blocking solid-phase radioimmunoassay for anti-delta.

Antibodies, Viral↗
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↗