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Biomedical subjects

J K Clarke

Publications and source records attributed to J K Clarke.

52 records · Page 3Linked to original sources
PubMed1970

Carrier cultures of simian foamy virus.

The production of cultures of HEp-2 and BHK-21 cells persistently infected with a type 1 simian foamy virus is described. After infection, HEp-2 cells showed no structural changes, whereas BHK-21 cells lost their normal spindle shape and showed mitochondrial damage, and some cells contained many lysosomes. Thin sections also showed that a few BHK-21 cells contained virus particles in low concentration, and infectious virus could be isolated from both the cells and the supernatant fluid. No virus was seen in thin sections of HEp-2 cells, although infectious virus in low titer could be recovered intermittently from lysed cells. Both carrier cultures were immune to challenge with homologous virus and antigen could be detected in over 90% of the cells even after growth for 9 weeks in the presence of virus-neutralizing serum. The distribution of antigen in carrier cultures of both cell types is described and compared with that seen in cytocidal infections.

Animals↗
PubMed1970

Morphogenesis of Bittner virus.

The morphogenesis of Bittner virus (mouse mammary tumor virus) was studied in sectioned mammary tumor cells. Internal components of the virus (type A particles) were seen being assembled in virus factories close to the nucleus and were also seen forming at the plasma membrane. The particles in virus factories became enveloped by budding through the membrane of cytoplasmic vacuoles which were derived from dilated endoplasmic reticulum. Complete virus particles were liberated from these vacuoles by cell lysis. Particles budding at the plasma membrane were released into intercellular spaces. Maturation of enveloped virus occurred after release, but mature internal components were rarely seen in the cytoplasm before envelopment. Direct cell-to-cell transfer of virus by pinocytosis of budding particles by an adjacent cell was observed, and unusual forms of budding virus which participated in this process are illustrated and described. There was evidence that some virus particles contained cytoplasmic constituents, including ribosomes. Certain features of the structure of internal components are discussed in relation to a recently proposed model for the internal component of the mouse leukemia virus. Intracisternal virus-like particles were occasionally seen in tumor cells, but there was no evidence that these structures were developmentally related to Bittner virus.

Animals↗
PubMed1969

New bacteriophage of Haemophilus influenzae.

Some properties of a newly isolated Haemophilus influenzae bacteriophage are described. The phage is morphologically distinct from previously described H. influenzae phages.

Bacteriophages↗
PubMedDate not supplied

Detection of four serotypes of avian adenovirus in New Zealand.

Twenty agents with adenovirus morphology were recovered from New Zealand domestic hens by means of chick kidney cell cultures. All the agents gave distinct cytopathic effects (CPE) in cell cultures, with two different types of CPE observed. On the basis of neutralization tests, the twenty agents were assigned to four distinct serological groups. Physicochemical tests on a "prototype" strain from each serological group confirmed that these agents are adenoviruses. The four prototype strains recovered in New Zealand are related to established overseas strains. One strain is serologically related to agents that cause IBH.

Adenoviridae↗