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Biomedical subjects

W C Saxinger

Publications and source records attributed to W C Saxinger.

47 records · Page 3Linked to original sources
PubMed1977

Lack of expression of type C hamster virus after neoplastic transformation of hamster embryo fibroblasts by benzo(a)pyrene.

Syrian hamster embryo fibroblasts transformed in vitro with benzo(a)pyrene were analyzed for the presence of type C viral components, including extra- and intracellular reverse transcriptase activity, intracellular type C hamster virus-related RNA, and cellular hamster virus group-specific antigen. No evidence could be obtained for the presence of any of these components, although they were easily detectable in hamster fibroblasts producing either B-34 virus (a hamster virus pseudotype of Harvey murine sarcoma virus which contains an excess of helper type C hamster virus) or Harvey virus itself. In addition, intracellular viral RNA could not be detected in normal hamster embryo fibroblasts, in hamster fibroblasts transformed with simian virus 40, or in newborn hamster kidney and liver. Thus the detectable expression of the indigenous hamster type C virus is not required to maintain the transformed phenotype of these cells.

Antigens, Viral↗
PubMed1975

Evolutionary nature of human reverse transcriptase and of viral-related DNA synthesized in vitro by human leukemic cells.

The reverse transcriptase and endogenous DNA product synthesized by virus-like particles in the cytoplasm of human leukemic cells have been studied for their genetic relatedness to homologous components obtained from several animal RNA tumor viruses. The human reverse transcriptase activity was inhibited by antibodies prepared against reverse transcriptase from some animal RNA tumor viruses. The DNA molecules synthesized endogenously by the human cytoplasmic particle in the presence of actinomycin D, using the reverse transcriptase enzyme and RNA template residing in the particle, hybridized to 70S RNA purified from certain animal RNA tumor viruses. Both the human reverse transcriptase and DNA product are closely related to homologues from primate type-C viruses, more distantly related to those from murine type-C viruses, and essentially unrelated to similar structures from feline or avian type-C viruses. They are not related to type-B RNA tumor viruses. The results demonstrate that the components from the human leukemic cells are viral (type-C) and primate in nature.

Cytoplasm↗
PubMed1974

Systematics of RNA tumor viruses and virus-like particles of human origin.

[(3)H]DNA copies of avian, feline, murine, and primate RNA tumor virus genomes were synthesized in vitro by an RNA-dependent DNA polymerase reaction. These DNAs were hybridized to 60-70S RNA that had been purified from the viruses. The amount of the [(3)H]DNA hybridized yielded a measure of the genetic relatedness among the DNA preparations synthesized by the viruses. When many combinations of DNA and RNA were analyzed, the pattern of hybridization showed in some cases that the DNA copies of the viral RNA were related to each other in the same way that the natural hosts of the viruses are phylogenetically related. This pattern was observed only among the RNA leukemia viruses. The sarcoma component in sarcoma-leukemia viruses from rats and primates appeared to be unusually closely related. The mouse mammary carcinoma virus and two unclassified viruses (MPMV and Visna) appeared to be genetically distinct.A similar analysis of DNA synthesized by an RNA-dependent DNA polymerase associated with a viral-like particle obtained from the cytoplasm of human leukemic white blood cells demonstrated that this DNA occupied a space in the affinity pattern of leukemia viruses which is expected of a nucleic acid from a primate-type-C RNA tumor virus. This observation strengthens earlier evidence that components of RNA tumor viruses are associated with human leukemia.

Animals↗
PubMed1973

Primate RNA tumor virus-like DNA synthesized endogenously by RNA-dependent DNA polymerase in virus-like particles from fresh human acute leukemic blood cells.

A particle of discrete biochemical composition was purified from fresh, unfrozen peripheral blood leukocytes of human patients with acute myeloblastic leukemia. This particle endogenously synthesized DNA by use of an RNA primer and template. About half of the DNA sequences synthesized in the presence of actinomycin D hybridized to RNA isolated from type-C sarcoma viruses of primates or mice; lower annealing values were obtained with RNA isolated from other sarcoma or leukemia viruses. The results confirm and extend previous results from molecular hybridization experiments related to the existence in human leukemia of components of RNA tumor viruses.

Adult↗
PubMed1972

Nucleic acid hybridization with RNA immobilized on filter paper.

RNA has been immobilized in a manner suitable for use in molecular hybridization experiments with dissolved RNA or DNA by a nonaqueous solid-phase reaction with carbonyldiimidazole and RNA "dry coated" on cellulose or, preferably, on previously activated phosphocellulose filters. Immobilization of RNA does not appear to alter its chemical character or cause it to acquire affinity for unspecific RNA or DNA. The versatility and efficiency of this method make it potentially attractive for use in routine analytical or preparative hybridization experiments, among other applications.

Cellulose↗