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Biomedical subjects

A G Coulepis

Publications and source records attributed to A G Coulepis.

11 recordsLinked to original sources
PubMed1987

Cellular changes associated with persistent hepatitis A infection in vitro.

The rate of division, morphology and ultrastructure of BSC-1 cells, persistently infected with hepatitis A virus (HAV), were compared with uninfected cells for 60 days after splitting of the cells. Both control and infected cells showed a biphasic growth pattern marked firstly by increasing cell density and high mitotic rate (exponential phase) and then high constant cell density and little mitosis (stationary phase). Immunoperoxidase studies showed that hepatitis A antigen (HAAg) appeared as cytoplasmic granules approximately one third of the way through the exponential phase in infected cells. The percentage of cells with HAAg rose until the early stationary phase when virtually all cells contained antigen. Radioimmunoassay demonstrated an increase in HAAg per cell in the stationary phase. Radioimmunofocus assay and immune electron microscopy confirmed the presence of HAV in infected cells in the stationary phase. Thin sectioning electron microscopy showed cytoplasmic annulate lamellae in infected cells of both phases but not in control cells.

Animals↗
PubMed1987

Hepatitis A.

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Age Factors↗
PubMed1986

Molecular cloning of cDNA from hepatitis A virus strain HM-175 after multiple passages in vivo and in vitro.

Hepatitis A virus (HAV) strain HM-175 was passaged six times in marmosets, 59 times in cell culture and purified from infected cell culture supernatant fluid. The viral RNA was extracted, copied into cDNA and the cDNA:RNA hybrids were cloned into the PstI site of plasmid pBR322. The cDNA clones were authenticated by hybridization to RNA extracted from HAV-infected cells and clones representing the 3' end of the genome were identified using a previously authenticated cDNA clone. The clones represented all but 29 bases of the HAV genome. They were compared to HAV strain HM-175 cDNA cloned from viral RNA after three passages in marmosets on the basis of restriction endonuclease mapping and DNA sequencing. No differences were found in either the presence or absence of restriction endonuclease sites using 33 different restriction enzymes. Sequencing of cDNA representing bases 29 to 1002 of the HAV genome revealed eight base changes all of which were within the 5' noncoding region.

Animals↗
PubMed1986

Indirect immunofluorescence assay for the detection of hepatitis A virus-specific serum immunoglobulins.

Hepatitis A virus-specific BSC-1 cells were used for the detection of serum immunoglobulins to hepatitis A virus by indirect immunofluorescence. Of 150 serum samples tested, specific immunoglobulin M was detected only in patients with serologically confirmed acute hepatitis A, while specific immunoglobulin G was detected in patients with acute or past clinical hepatitis A as well as many patients with no known history of hepatitis.

Antibodies, Viral↗
PubMed1986

Taxonomic classification of human hepatitis B virus.

Sufficient data have accumulated to permit the ICTV Study Group on the Nomenclature of Hepatitis Viruses to recognize human hepatitis B virus as a member of a unique group of viruses and to classify it, together with a number of related animal viruses, into a new family called the Hepadnaviridae. Over the past decade, the International Committee on Taxonomy of Viruses (ICTV) has been active in the development of a classification system for viruses. The majority of viruses infecting vertebrate hosts have been classified into families and genera on the recommendations of the Vertebrate Virus Subcommittee (VVSC). In June 1980, the VVSC authorized the formation of an ad hoc Study Group on the Nomenclature of Hepatitis Viruses under the Chairmanship of Dr. Ian D. Gust. This paper represents the first report of the Study Group on the Taxonomic Classification of Human Hepatitis B Virus.

Animals↗
PubMed1985

Detection of hepatitis A virus and antibody by solid-phase radioimmunoassay and enzyme-linked immunosorbent assay with monoclonal antibodies.

Monoclonal antibodies (K3-2F2 and K3-4C8) raised against hepatitis A virus were used to develop a solid-phase radioimmunoassay and enzyme-linked immunosorbent assay for the detection of hepatitis A virus and antibody. Assays with this pair of monoclonal antibodies were compared in parallel with similarly constructed solid-phase radioimmunoassays and enzyme-linked immunosorbent assays in which human polyclonal serum was used. The monoclonal antibody assay proved to be more sensitive for the detection of hepatitis A virus from fecal specimens as well as for anti-hepatitis A virus immunoglobulin G (IgG) and IgM in sera.

Antibodies, Monoclonal↗
PubMed1985

Restrictive events in the replication of hepatitis A virus in vitro.

Hepatitis A virus was purified from the feces of 2 patients with unrelated, naturally acquired infections and was inoculated into FRhK-4 cells. Analysis of protein synthesis by double-label coelectrophoresis and subtraction allowed the resolution of virus-specific proteins synthesized during infection. In FRhK-4 cells the two strains of virus studied produced markedly different profiles of virus-specified proteins, with an accumulation of high-molecular-weight proteins for strain HM790 relative to strain HM175, suggesting a level of restriction in the processing of the viral polyprotein.

Antigens, Surface↗
PubMed1979

Solid-phase enzyme-linked immunosorbent assay for detection of hepatitis A-specific immunoglobulin M.

A solid-phase enzyme linked immunosorbent assay was developed for the detection of immunoglobulin M antibody to hepatitis A virus. The system was capable of detecting hepatitis A-specific immunoglobulin M in a single dilution of serum and appears to be a reliable and rapid means of establishing a diagnosis of hepatitis A infection. Specific immunoglobulin M was only detected in patients with serologically confirmed hepatitis A and not in patients with other forms of hepatitis, chronic liver disease, or autoimmune disease. In patients with hepatitis A, specific immunoglobulin M was usually detectable for 6 weeks after the onset of dark urine, and the longest period for which it was present in any patient was 115 days. This enzyme-linked immunosorbent assay is rapid, simple to perform, and does not require complicated equipment. Provided adequate supplies of purified reagents can be obtained, this enzyme-linked immunosorbent assay procedure is likely to simplify hepatitis A serology, because the same antibody-coated plates can be utilized to detect hepatitis A virus, anti-hepatitis A virus, and hepatitis A-specific immunoglobulin M.

Antibodies, Viral↗
PubMed1978

The polypeptides of hepatitis A virus.

Hepatitis A virus was purified from fecal specimens obtained from 3 patients with naturally acquired hepatitis A, by a process of differential centrifugation, chloroform extraction, column chromatography, and isopycnic ultracentrifugation. Analysis of purified virus by discontinuous SDS-PAGE revealed three major polypeptides with molecular weights of 34,000, 25,500, and 23,000 daltons. These polypeptides appear to be specific for hepatitis A virus and have similar molecular weights to three of the four major polypeptides reported for members of the genus Enterovirus within the family Picornaviridae.

Feces↗
PubMed1978

Purification of hepatitis A virus from human feces.

Hepatitis A virus was purified fecal specimens obtained from 2 patients with naturally acquired hepatitis A. The purification procedure involved differential centrifugation, organic solvent extraction, agarose gel filtration, ion-exchange chromatography, and isopycnic ultracentrifugation in cesium chloride. Using immune electron microscopy and discontinuous SDS-PAGE, this procedure was found to be effective in removing extraneous material from hepatitis A virus. There was significant recovery of virus as judged by immune electron microscopy and solid-phase radioimmunoassay. Using this protocol, it has been possible to obtain virus preparations of sufficient purity and high enough titer to enable biochemical studies to proceed.

Antigen-Antibody Reactions↗