Search PubMed⌕ Search

Biomedical subjects

H Koprowski

Publications and source records attributed to H Koprowski.

At least 451 records · Page 25Linked to original sources
PubMed1975

Ultrastructural studies of perivascular cuffing cells in multiple sclerosis brain.

Perivascular cuffs in brains taken at autopsy from 6 patients with multiple sclerosis (MS) were examined by electron microscopy. Light and electron microscopy of brain revealed acute and chronic types of cuffs. The acute type of cuffs, consisting of many lymphocytes and lymphoid cells and a few lipid-laden macrophages, was usually seen in the nondemyelinated white matter or in the margin of the plaques, and infrequently within a plaque. The chronic type consisted mainly of macrophages, plasmacytoid cells, and plasma cells and was always seen within the plaques. In the parenchymal tissue of the white matter, macrophages participated in phagocytosis of myelin and axons, but no peeling or stripping of myelin sheath by inflammatory cells was observed. So-called paramyxovirus-like fuzzy filaments were observed in the nuclei of the mononuclear cells of perivascular cuffs obtained from 5 patients. The filaments were found predominantly in the acute rather than chronic type of cuffs. Specific antigens of measles and 6/94 viruses and intranuclear RNA corresponding to the filaments could not be demonstrated in the perivascular inflammatory cells by the immunofluorescence technique or acridine orange staining.

Autoimmune Diseases↗
PubMed1975

Experimental parainfluenza-type-1-virus-induced encephalopathy in the adult mouse. An ultrastructural study of early lesions.

The adult mouse inoculated intracerebrally with 6/94 strain of parainfluenza type 1 virus developed selective degenerative lesions in cerebral white matter. Ultrastrucrally, the infiltration of mononuclear cells, mostly lymphoid cells, apparently preceded the alterations of white matter parenchyma. The prominent feature of the white matter lesion was a lytic degeneration of both axon and myelin that seemed to be triggered by the mononuclear cell infiltration. Nucleocapsids of paramyxovirus were found only in ependymal cells and the very early stages of the infection. It is suggested that the mechanism of the white matter degeneration might be that of a virus-induced cell-mediated immune response directed at both the axon and myelin.

Animals↗
PubMed1974

Somatic cell hybrids between mouse peritoneal macrophages and SV40-transformed human cells. I. Positive control of the transformed phenotype by the human chromosome 7 carrying the SV40 genome.

Fusion of mouse peritoneal macrophages with SV40-transformed human cells, deficient in hypoxanthine guanine phosphoribosyltransferase, resulted in the formation of transformed somatic cell hybrids which contained, without exception, the human chromosome 7 carrying the SV40 genome. It is postulated that the hybridization of mouse nondividing cells with human cancer cells could permit the identification of the human "oncogenic" chromosome(s) present in human cancer cells, since such chromosome(s) should be retained by the totality of the mouse-human hybrid cells.

Animals↗
PubMed1974

Positive control of transformed phenotype in hybrids between SV40-transformed and normal human cells.

Somatic cell hybrids have been obtained between SV40-transformed Lesch-Nyhan fibroblasts, which are deficient in hypoxanthine-guanine phosphoribosyltransferase (HGPRT) and display glucose-6-phosphate dehydrogenase A (G6PD-A) activity, and late-passage HGPRT-positive W138 human embryo fibroblasts, which display G6PD-B activity. The human-human hybrid clones, which display G6PD-A and G6PD-B and heteropolymers of the two enzyme forms, have the same growth characteristic as the SV40-transformed parental cells and behave as continuous cell lines. The SV40 tumor antigen, the gene for which has been assigned to human chromosome 7, is present in all clones examined.

Antigens, Neoplasm↗
PubMed1974

Concordant segregation of the expression of SV40 T antigen and human chromosome 7 in mouse-human hybrid subclones.

Subcloning of Simian virus 40 (SV40) T antigen-positive mouse-human hybrids, derived from the fusion of mouse cells deficient in thymidine kinase with SV40-transformed Lesch Nyhan fibroblasts, resulted in their segregation into T antigen-positive and negative subclones. Positive correlation between the presence of human chromosome 7 and the expression of SV40 T antigen was established in the subclones examined. These results negate the possibility of a transfer of the SV40 genome to a mouse chromosome.

Animals↗
PubMed1974

Restoration of the conversion of desmosterol to cholesterol in L-cells after hybridization with human fibroblasts.

Hybrids between different human cells (which synthesize cholesterol) and mouse cells (whose end-product of sterol synthesis is desmosterol) were analyzed for the ability to convert desmosterol to cholesterol. Conversion of [(14)C]desmosterol to cholesterol and incorporation of [(14)C]acetate into the end-product sterol were studied in the parental and hybrid cells. Concordant segregation of the conversion of desmosterol to cholesterol and the human chromosome F-20 was observed.

Acetates↗