PubMed Health⌕ Search

Biomedical subjects

K J Porzig

Publications and source records attributed to K J Porzig.

5 recordsLinked to original sources
PubMed1979

Cellular regulation of mammalian sarcoma virus expression: a gene regulation model for oncogenesis.

Investigations aimed at defining cellular functions required for expression of transformation by mammalian sarcoma viruses have led to the isolation of a class of revertants that contain biologically active feline sarcoma virus, yet possess in vitro and in vivo properties of normal cells. The block to expression of the transformed state in these cellular revertants was spontaneously reversible at low frequency. Moreover, infection with certain helper viruses reversed the block at very high efficiency. Helper virus complementation was shown not to be a direct effect of helper virus functions expressed in the initially infected revertant cell. Rather, the helper virus acted indirectly by rescuing sarcoma virus and allowing it to infect and transform another cell within the revertant population. Using biochemical and immunologic techniques, it was possible to demonstrate a specific and very marked reduction in transcriptional and translational products of the sarcoma viral genome in the revertant cells. Findings that the reversal of this block was associated with reacquisition of the transformed phenotype, together with other evidence, suggest that reversion results from cellular transcriptional regulation of the integrated sarcoma virus genome. Reversion in this virus transformation system provides a model for oncogenesis resulting from derepression of cellular genes that possess malignant potential.

Animals↗
PubMed1979

Nature and distribution of feline sarcoma virus nucleotide sequences.

The genomes of three independent isolates of feline sarcoma virus (FeSV) were compared by molecular hybridization techniques. Using complementary DNAs prepared from two strains, SM- and ST-FeSV, common complementary DNA'S were selected by sequential hybridization to FeSV and feline leukemia virus RNAs. These DNAs were shown to be highly related among the three independent sarcoma virus isolates. FeSV-specific complementary DNAs were prepared by selection for hybridization by the homologous FeSV RNA and against hybridization by fline leukemia virus RNA. Sarcoma virus-specific sequences of SM-FeSV were shown to differ from those of either ST- or GA-FeSV strains, whereas ST-FeSV-specific DNA shared extensive sequence homology with GA-FeSV. By molecular hybridization, each set of FeSV-specific sequences was demonstrated to be present in normal cat cellular DNA in approximately one copy per haploid genome and was conserved throughout Felidae. In contrast, FeSV-common sequences were present in multiple DNA copies and were found only in Mediterranean cats. The present results are consistent with the concept that each FeSV strain has arisen by a mechanism involving recombination between feline leukemia virus and cat cellular DNA sequences, the latter represented within the cat genome in a manner analogous to that of a cellular gene.

Animals↗
PubMed1978

Treatment of advanced Hodgkin's disease with B-CAVE following MOPP failure.

Between March 1973, and December 1976, 22 patients who developed disease progression during or after MOPP therapy were treated with a new combination, B-CAVe (Bleomycin 5 mg/m2 iv days 1, 28, 35; CCNU 100 mg/m2 po day 1; adriamycin 60 mg/m2 iv day 1; and vinblastine 5 mg/m2 iv day 1). Objective responses were achieved in 17 of 22 patients (77%) and 11 of 22 responses were complete (50%). The actuarial survival for all patients is 16.4 months. For complete responders the median is 24 months with 2 complete responders dead without evidence of Hodgkin's Disease. Median relapse free survival for complete responders has not been reached at 35+ months while that for partial responders is 14 months. Significant adriamycin cardiotoxicity was encountered in two patients. There were no life threatening bacterial infections during B-CAVe. Two patients died of Pneumocystis carinii several months after cessation of therapy. B-CAVe is effective in the therapy of advanced Hodgkin's disease after MOPP failure, and this regimen is comparable to other previously reported MOPP salvage combinations.

Adolescent↗