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Biomedical subjects

M Mára

Publications and source records attributed to M Mára.

At least 55 records · Page 3Linked to original sources
PubMed1986

Enhancement of immunostimulating and immunotherapeutic effect of BCG vaccines using listerial endotoxin-like substances.

On the basis of experience with the immunomodulating effect of the endotoxin-like component of Listeria monocytogenes, designated factor Ei, the time parameters concerning the onset and duration of hypersensitivity induced by listeriae, mycobacteria and their components were compared. Their differences, just like different mechanism of their effect, following their simultaneous and repeated administration, furnish means of significantly enhancing the anti-tuberculosis and anti-tumor effect of strong BCG vaccines in animal experiments. This enhancement of effect makes it possible to lower the number of BCG doses otherwise required to produce the same or similar results.

Animals↗
PubMed1985

Changes in the migratory activity of polymorphonuclear leukocytes after administration of Freund's adjuvant.

Spontaneous and chemotactic activity of polymorphonuclear leukocytes, obtained from the peritoneal cavity, was studied after administration of complete and incomplete Freund's adjuvant to rabbits at intervals of 18-26 d after adjuvant injection. Whereas injection of both complete and incomplete adjuvant increased spontaneous migration of rabbit polymorphonuclear leukocytes, the migration directed by the chemotactic signal, induced in fresh serum by E. coli endotoxin, was decreased. The chemotaxigenic activity of two factors, isolated from cell walls of Listeria monocytogenes was also tested: factor Ei (its most potent component is lipopolysaccharide) and a purified phenol extract of lipopeptidopolysaccharide nature.

Adjuvants, Immunologic↗
PubMed1985

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↗
PubMed1984

Fatty acid composition of a Propionibacterium acnes vaccine and its relationship to immunostimulatory activity.

The distribution of lipids of Propionibacterium acnes (Corynebacterium parvum) vaccine strain in chloroform-methanol, ethanol and light petroleum extracts was determined. Firmly bound lipids released by hydrolysis were also investigated. The petroleum extract differs from other lipidic fractions in its fatty acid composition. The presence of linolic, tuberculostearic and 10-ketostearic acids and branched fatty alcohols was observed in addition to previously described fatty acids of P. acnes. Changes in fatty acid composition during growth of the vaccine strain were determined and extremes were found at 95 h of cultivation. These extremes coincided with a maximum in the immunostimulatory efficiency as measured by the spleen enlargement test. The biological activity of static and stirred cultures of the vaccine strain was in correlation with their fatty acid composition.

Animals↗
PubMed1981

Resistance to Mycobacterium tuberculosis H37Rv infection induced by Listeria and mycobacterial lipids.

The avirulent strain Listeria monocytogenes (Welshimer) induced upon a single injection 4 weeks prior to challenge with Mycobacterium tuberculosis H37Rv resistance in guinea-pigs, which was manifested by a significant decrease of spleen weight and Feldman's index in immunized animals. The degree of resistance was dependent on the immunizing dose and time of administration. Repeated high doses of Listeria yielded only a low or no effect. Further increase of resistance was obtained using the BCG lipids; however, stimulation of resistance with listeria lipids was not successful and, finally, Freund's incomplete adjuvant was significantly effective in the Feldman index only. The BCG lipids, extracted with ethanol, which contained nitrogen and water-soluble substances, induced a significant resistance against M. tuberculosis infection. The chloroform-methanol BCG lipids were also effective, however, significantly less than the ethanol-extracted material. The listeria factor Ei itself or together with Freund's incomplete adjuvant possessed only low effectiveness against mycobacterial infection. However, if injected together with ethanol-extracted BCG lipids, it produced a significant degree of resistance which was higher than that induced by lipids only. The degree of resistance was comparable with the effect of living BCG strain which served as a source of isolated lipids.

Animals↗
PubMed1980

Phenol-extracted lipopeptidopoly-saccharide (LPPS) complex from Listeria monocytogenes.

Endotoxin phenol extraction method with subsequent ultracentrifugation and/or chromatographic analysis on Sepharose 2 B column were used to obtain biologically active isolate that turned out to contain polysaccharide, peptide and lipid fractions. The raw phenol extract formed 15% and the LPPS complex, obtained from it by ultracentrifugation, 0.17% of bacterial biomass. The LPPS complex contained 11 amino acids representing about 11% of its dry weight. Similarly as in factor Ei and in analogous extracts isolated by other authors the prevailing amino acids were glutamic acid, aspartic acid and lysine. The LPPS complex contained 1.26% of hexosamine, further hexoses, methyl pentoses and ribose. KDO was not detected. Further this complex consisted of 3% of freely-bound and 5% of firmly-bound lipids, beta-hydroxymyrist acid was not detectable. The composition of fatty acids in the firmly-bound lipid fraction of the LPPS complex differed quantitatively from that both in factor Ei and bacterial cell bodies. The tightness of lipid bonds during purification and the biological role of the Listeria lipids are discussed. On the basis of detected chemical and biological properties, both compatible and incompatible with peptidoglycan, a specific character of endotoxin-like isolates from L. monocytogenes is assumed.

Amino Acids↗
PubMed1978

Contribution to the taxonomy of haemolytic corynebacteria.

In an attempt to assess the taxonomic relationships among human (Corynebacterium haemolyticum), animal (Corynebacterium pyogenes bovis) haemolytic corynebacteria, typical corynebacteria (Corynebacterium diphteriae mitis, C. ovis, C. ulcerans) and group A and G streptococci, a number of biochemical parameters were established: the DNA content of G + C, the presence of the cytochrome system, composition of fatty acids in free lipids and production of carboxylic acids as end products of fermentation. It was found that according to the above criteria, streptococci differed significantly from the corynebacteria studied. In addition, it was possible to differentiate a subgroup of typically aerobic haemolytic corynebacteria (different from both human and animal corynebacteria), possessing a complete cytochrome system, producing propionic acid and having a different composition of fatty acids.

Carboxylic Acids↗