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Biomedical subjects

W Wittmann

Publications and source records attributed to W Wittmann.

At least 37 records · Page 2Linked to original sources
PubMed1985

Electron microscopic investigation on the fine structure of the virus of enzootic bovine leukosis (BLV).

Systematically electron microscopical control of BLV producing cells and stimulated lymphocytes of leukotic cattle in the last years revealed maturation processes of BLV in a different form from comparable type C viruses. Electron microscopic representation of bridge-like junctions between core and envelope within examined retroviruses were discussed and compared with new model concepts.

Animals↗
PubMed1982

Differences of the in vitro reactivity of lymphocytes from normal and persistently lymphocytotic cows to enzootic bovine leukosis tumour membrane extracts as detected with the macrophage-electrophoretic mobility test.

The response of peripheral blood lymphocytes from normal and persistently lymphocytotic cows to cell membranes and sodium cholate-extracted membrane proteins from normal and tumourous lymph nodes was tested with the macrophage-electrophoretic-mobility test with guinea pig peritoneal macrophages as indicator cells. Lymphocytes from 13 cows with persistent lymphocytosis (PL) showed a positive reaction with cholate extracts from tumour cell membranes. On the other hand, there was a negative reaction with corresponding extracts from normal lymph nodes for 11 animals. 4 of 10 hematologically normal cows also showed a positive reaction against tumour cell membrane extracts. One of these, however, thereafter developed antibodies against BLV glycoprotein gp 51. Using tumour cell membrane preparations as antigen, the 4 cows with PL tested also exhibited a positive reaction, whereas none of 3 hematologically normal cows showed any reactivity. As efforts to detect the main antigenic proteins of BLV (gp 51, p 24) in detergent extracts of tumour cell membranes proved unsuccessful, these findings are thought to provide evidence for the existence of a common non-viral antigen on cell membranes of bovine leukosis tumour cells.

Animals↗
PubMed1981

[Structure of the enzootic cattle leukosis virus. 1. Biophysicochemical characterization of several virus-specific components].

Concentrated virus material partially purified, after having been obtained from permanent cell cultures, was allowed to undergo repeated gradient centrifugation for an analysis of density and sedimentation. Serological tests were conducted, in that context, together with electron microscopy and gel electrophoresis. Isodensities of the virion were 1.17 g/ml in CsCl solution or 1.16 g/ml in saccharose solution. The average densities of the internal bodies, between 45 nm and 80 nm in diameter, were measured by electron microscopy and accounted for something between 1.32 g/ml and 1.34 g/ml in CsCl solution or between 1.22 g/ml and 1.24 g/ml up to 1.28 g/ml in saccharose solution. Four revertase-positive components, 915 S, 704 S, 469 S and 264 S +/- 40 S, were found in flattened cane-sugar gradients. conclusions for non-invasive ultracentrifugation in the virus were drawn from those high S-values. High-titre mixed antigens, virus-specific bands from the density gradients, and washed antigen-antibody precipitates were investigated by the authors by means of slab-gel electrophoresis. Molecular weights of 53 kilodalton (kD) and 24 kD were recorded from the major components. There also were polypeptides weighing 10 kD, 12 kD, 15.6 kD, 42.5 kD, 63 kD, and 70 kD.

Animals↗