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D S Yohn

Publications and source records attributed to D S Yohn.

At least 55 records · Page 3Linked to original sources
PubMed1970

Simplified procedure for preparation of specific antibodies to gamma globulins.

Antibodies were prepared to rhesus monkey, rabbit, dog, and hamster gamma globulins which had been purified by agar-block electrophoresis. Immunoelectrophoretic analysis demonstrated that these antisera were specific for gamma globulin components in whole serum. The use of these antisera as secondary serological reagents was examined.

Animals↗
PubMed1970

Growth kinetics of Yaba tumor poxvirus after in vitro adaptation to cercopithecus kidney cells.

Yaba tumor poxvirus has been adapted to continuous in vitro cultivation in monolayers of cercopithecus kidney cells. At 35 C, the minimum replicative cycle, after synchronous infection of CV-1 cells with multiplicity of infection of 135 focusforming units per cell, was 35 hr; however, maximum virus yields were not obtained until 75 hr postinfection (PI). Cytoplasmic incorporation of (3)H-thymidine [viral deoxyribonucleic acid (DNA) synthesis] was detected 3 hr PI and was preceded by synthesis of nonstructural associated antigens (YS). Synthesis of YS antigens was not inhibited by the DNA inhibitor, arabinofuranosyl cytosine (ARA-C). Synthesis of at least two virion structural antigens, although not detected by immunofluorescence until 2 hr after the onset of DNA synthesis, occurred in the presence of ARA-C, indicating potential translation of these structural antigens from parental DNA. The first progeny DNA was completed by 20 hr PI but was not detected in infectious form until 35 hr PI. The maximum rate of progeny DNA completion occurred between 20 and 30 hr PI. DNA synthesis continued 45 to 50 hr PI. The adapted virus retained its oncogenicity and, like the wild type, replicated better at 35 C than at 37 C. A synthetic step associated with viral DNA synthesis appears to be temperature-sensitive.

Animals↗
PubMed1970

Immunodiffusion analysis of Yaba poxvirus structural and associated antigens.

Yaba poxvirus virions were extracted and purified from Rhesus monkey tumors. A saline-soluble virion fraction (Y-xp), obtained by mechanical fractionation of purified virions with an X-press, contained seven components in acrylamide gel electrophoresis; five of these components were reactive in immunodiffusion with whole virion and Y-xp antisera produced in rabbits and monkeys. The saline-insoluble residue remaining after X-press treatment was hydrolyzed with sodium dodecyl sulfate, urea, and 2-mercaptoethanol (SUM). This fraction, Y-sum, contained five components, four of which were demonstrable by immunodiffusion. There was no evidence of antigenic relationships between Y-xp and Y-sum antigens in immunodiffusion. In acrylamide gel electrophoresis, one Y-xp and one Y-sum component had similar mobilities. Y-xp but not Y-sum antisera contained viral-neutralizing antibodies. Virus-free saline extracts of Yaba tumor prepared with Genetron (YS) were essentially devoid of virion structural antigens. They failed to induce precipitating antibodies for virion antigens, were nonreactive in immunodiffusion with virion antisera, and gave low complement-fixation titers with virion antisera. Yaba virion antigens were recovered from the Genetron tumor sediment by SUM and alkaline hydrolysis. Antisera prepared to YS extracts gave a maximum of 17 precipitin lines in immunodiffusion with YS extracts; none was identified as a virion structural antigen. Saline extracts of tumor prepared without Genetron contained immunogenic amounts of 5 virion antigens and 12 to 14 associated antigens. Animals immunized with infected cell culture extracts (virus-free) formed antibodies to six to seven virion antigens. The implications of using extracts of Yaba poxvirus-infected tissues in complement-fixation tests to measure virion antibodies were discussed.

Animals↗
PubMed1969

Some physiochemical properties of Yaba poxvirus deoxyribonucleic acid.

Yaba tumor poxvirus deoxyribonucleic acid (DNA) has a density of 1.6905 in CsCl and its T(m) value in 0.015 m citrate in saline is 82.3. The guanine plus cytosine content estimated from these properties was taken to be 32.5 +/- 0.5%, a value 2 to 3% less than for DNA from other poxviruses reported to date.

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