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J Svejcar

Publications and source records attributed to J Svejcar.

150 records · Page 9Linked to original sources

Histochemical and quantitative biochemical changes in mucopolysaccharides of the term placenta of the diabetic rat.

Full-term placentae of rats with streptozotocin-induced diabetes were analysed histochemically and biochemically for changes in mucopolysaccharide content. The experimental diabetes induced severe cystic degeneration in the spongiosa zone of the placenta and this was accompanied by extracellular deposition of hyaluronate and neutral polysaccharides. The labyrinth zone was affected to a lesser extent. Biochemical analysis also revealed quantitative differences in the total contents of mucopolysaccharides (MPS) between the two zones of the placenta in both diabetic and normal placentae. The spongiosa had a higher total mucopolysaccharide content than the labyrinth. Polysaccharides of low molecular weight were always predominant. The amount of hyaluronate exceeded the quantitites of sulphated mucopolysaccharides which were found in relatively small amounts in both placental zones. In diabetic placentae there was a two- to threefold increase, which was more pronounced in the spongiosa. The increase was observed among all types of MPS. A close correlation between the accumulation of MPS in the placenta and the degree of maternal hyperglycaemia was found. The placentae of the three streptozotocin-resistant animals showed neither histological nor biochemical changes. It is suggested that the accumulation of MPS in the diabetic placenta might be a consequence of a shift in carbohydrate metabolism induced by hyperglycaemia or a persistence of the fetal metabolic features as a part of a retarded maturational process of the placenta.

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[Use of the macrophage migration inhibition test in the study of relationships between mycobacterial antigens].

In this study, 3 groups of 15 rabbits each were sensitized with killed Mycobacterium tuberculosis, M. kansasii or M. avium bacteria. The sensitization was performed through the footpad. Eighteen days after sensitization, cellular immunity of the rabbits was tested with total homologous and heterologous antigens by direct and indirect migration inhibition tests using spleen macrophages. The bacteria were sonicated and centrifuged at 100,000 g for 1 h. The supernatant was used as the cytoplasmic antigen. Assayed by indirect migration, the migration index (MI) for homologous antigens was highly specific compared to heterologous antigens (MI of 0,60-0,65 compared to 0,79-0,96). The patterns obtained for rabbits sensitized with M. tuberculosis or M. kansasii when assayed by direct migration in the presence of homologous antigens (MI of 0,58 and 0,61, respectively) were similar. M. avium gave a distinct pattern. The results obtained indicate that crossed activity with heterologous antigens would be due to the presence of common components in the total antigens of the mycobacteria in question. On the other hand, the lower specificity of the direct test would result from the role played by humoral factors and antibodies, which might influence simultaneously migration of the target macrophages.

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