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Biomedical subjects

M Pospísil

Publications and source records attributed to M Pospísil.

At least 109 records · Page 6Linked to original sources

Carbohydrate-structure-dependent recognition of desialylated serum glycoproteins in the liver and leucocytes. Two complementary systems.

Oligosaccharides with four different types of branching were prepared from purified human transferrin, alpha 2-macroglobulin, caeruloplasmin and alpha 1-acid glycoprotein and labelled with NaBH3 3H. Binding of these oligosaccharides to rat liver plasma membrane, rat leucocytes, pig liver plasma membranes and pig leucocyte plasma membranes was investigated. A striking dependence of binding on oligosaccharide branching was observed. The values of apparent association constants Ka at 4 degrees C vary from 10(6) M-1 (biantennary structure) to 10(9) M-1 (tetra-antennary structure) in the liver, whereas in the leucocytes the Ka values were found to be of reversed order, from 1.8 X 10(9) M-1 for biantennary to 2.2 X 10(6) M-1 for tetra-antennary structures. The binding is completely inhibited by 150 mM-D-galactose, but 150 mM-D-mannose has almost no effect on binding. Leucocyte plasma membranes bind preferentially 125I-asialoglycoproteins with biantennary oligosaccharides, thus completing the specificity pattern of the hepatic recognition system for desialylated glycoproteins. Possible physiological roles of these two complementary recognition systems under normal and pathological conditions are discussed.

Animals↗

Phenol-water extracts of gram-positive Listeria monocytogenes and gram-negative Salmonella typhimurium. Comparison of biological activities.

Using phenol--water extraction, a lipopeptidopolysaccharide complex (LPPS) was isolated from Listeria monocytogenes. Some biological and immunological properties of LPPS were compared with lipopolysaccharide isolated by the same procedure from Salmonella typhimurium. LPPS possesses low pyrogenicity, but the immunological activity is comparable with LPS: slightly lower adjuvant and polyclonal stimulating effect, almost equal mitogenic effect on mouse spleen cells and higher mitogenic effect on human peripheral blood cells. The results are discussed in connection with the chemical structure of both substances.

Adjuvants, Immunologic↗

Production of monoclonal antibodies with haemagglutination-inhibition activity to the Skalica strain from the tick-borne encephalitis complex.

Hybridomas secreting monoclonal antibodies with haemagglutination-inhibition (HI) activity to the Skalica strain of tick-borne encephalitis (TBE) complex were prepared by the fusion of P3-NS1-Ag4-1 myeloma cell line with spleen cells of BALB/c mice immunized with the purified Skalica strain. The highest titres of monoclonal antibodies obtained from the hybridomas S-9, S-15 and S-16 ranged from 512 to 10,240, respectively; the ascitic fluid contained as many as 4.6 mg/ml of monoclonal antibodies. Its analysis by Ouchterlony's double immunodiffusion, agarose electrophoresis, and sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of monoclonal antibodies with mu isotype of the heavy and kappa isotype of the light chain. The specificity of the monoclonal antibodies was proved using 11 different antigens from family Togaviridae in the HI test.

Animals↗