Biomedical subjects

W W Hall

Publications and source records attributed to W W Hall.

At least 109 records · Page 6Linked to original sources

PubMed1977

Biological and biochemical characterization of a latent subacute sclerosing panencephalitis (SSPE) virus infection in tissue culture.

The present investigation describes the biological and biochemical properties of a persistent SSPE virus infection. Persistently infected cells were derived by cocultivation of infected brain cells and uninfected Vero cells, and cultures were maintained by normal subculturing methods. No infectious virus was ever released from these cultures, and all attempts to induce infectious virus release were unsuccessful. Biological assays showed that infected cells contained nucleocapsid and salt-dependent hemagglutinin antigens, whereas the normal hemagglutinin appeared not to be present. Electron microscopic examination demonstrated the presence of both intranuclear and cytoplasmic nucleocapsids together with the release of virus particles (defective?) from the cell membrane. Biochemical analysis demonstrated that approximately 90% of the intracellular genomic RNA was defective or subgenomic although a small quantity of infectious genomes was present. It is proposed that the large quantities of defective genomes in the infected cells are the major factor in the maintenance of this persistent infection.

Animals↗

PubMed1977

The effects of actinomycin D on RNA synthesis in measles virus-infected cells.

The effect of actinomycin D on the production of genomic RNA, messenger RNA and protein in measles virus-infected cells were investigated. It was found that whereas high concentrations of the drug inhibited genome synthesis, the production of messenger RNA was unaffected and in some cases enhanced. These effects were shown, at least in part, to be due to a secondary effect of the drug which caused an inhibition of virus-specific protein synthesis.

Cell Line↗

PubMed1977

Cell generation and type C virus expression in the human embryonic cell strain HEL-12.

The spontaneous expression of a type C virus in a diploid strain of human embryonic lung fibroblast-like cells (HEL-12) was examined during serial culture. Virus antigen expression was determined by indirect immunofluorescenc with antisera to disrupted simian sarcoma virus and the 28000 mol. wt. internal antigen of the endogenous cat virus RD-114. Virus production was examined by reverse transcriptase assays of culture fluids. Virus antigens were not detected for 25 days after frozen, primary HEL-12 cells were reinstated in culture. The cells expressed virus antigens but did not release virus particles between 25 and 80 days. Spontaneous virus release and maximal antigen expression occurred in cells grown for 80 to 120 days. Virus particles were not detected after 120 days although virus antigens persisted until the experiment was terminated. The HEL-12 virus was infectious for cell cultures of human, rhesus monkey, dog and rabbit cells. The proportion of SiSV-like and RD-114-like antigenic components of HEL-12 virus were altered by passage through heterologous cells suggesting heterogeneity of the HEL-12 virus population.

Antigens, Viral↗

PubMed1977

The effect of cycloheximide on the replication of measles virus.

Treatment of measles virus-infected cells with cycloheximide results in a three-fold increase of 3H-uridine incorporation into the 12 to 36S mRNA species and in the inhibition of genomic 50S RNA synthesis. Consistent with these observations was the finding of a build-up of polyribosomes but an absence of nucleocapsids in the infected cells. These results suggest that measles virus RNA replication, but not transcription, is dependent upon active protein synthesis.

Capsid↗

PubMed1976