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Biomedical subjects

A R Shikhman

Publications and source records attributed to A R Shikhman.

36 records · Page 2Linked to original sources
PubMed1990

[The level of IgM, IgG and IgA antibodies and total antibodies to the low-molecular, cell-wall protein of Streptococcus group A without type specificity in the serum of patients with a streptococcal infection].

The levels of IgM, IgG and IgA antibodies, as well as total antibodies, to group A streptococcal low-molecular cell-wall protein without type specificity were studied in the sera of patients with primary erysipelas, rheumatism in the active and inactive phases, seronegative rheumatoid arthritis, as well as in the sera of healthy donors. The average level of antibodies to low-molecular protein in the sera of all groups of patients was significantly higher than the sera of healthy donors. The analysis of the distribution of antibodies in accordance with their isotypes revealed the specific features of response, characteristic of each group of patients. For rheumatism patients, the positive correlation between response to low-molecular protein and response to group-specific polysaccharide A was established. This correlation was most pronounced in patients with rheumatism in the inactive phase.

Antibodies, Bacterial↗
PubMed1990

[The physicochemical and biochemical characteristics of the cell walls in M+ and M- variants of Streptococcus group A type 29].

The amino acid composition of cell walls and surface proteins, isolated from virulent (M+) and avirulent (M-) streptococcal strains (group A, type 29) has been determined by the method of E. H. Beachey et al. The kinetics of the lysis and proteolysis of streptococcal cell walls with muramidase and protease obtained from Actinomyces levoris and streptolysin has been studied. The constants describing the progress rates of these processes has been determined; their values in case of both lysis and proteolysis are higher in virulent strains than in avirulent ones.

Amino Acids↗
PubMed1989

[Use of immunoenzyme analysis for determining the persistence and biodegradation of antigens in the cell wall of group A streptococci in patients with rheumatism].

A sandwich ELISA system was used for the study of the identification of antigenic group A polysaccharide determinants by antibodies in a suspension of streptococcus cells with varying degrees of lysis. Antibodies were able to identify less than 0.01% of antigenic A polysaccharides determinants in intact streptococcal cells. It is concluded that A polysaccharide is a marker of the destroyed group A streptococcus cells. The circulation of group A polysaccharide was examined in the sera of patients with rheumatism and acute streptococcal tonsillitis. Group A polysaccharide was detectable more frequently in rheumatic patients, as compared to those with tonsillitis, and circulated for long periods of time in the vascular network. Avidity and titres of antibodies to group A polysaccharide were determined in rheumatic patients with different degrees of antigenemia. In cases of marked antigenemia, correlation was disrupted between the titre and avidity of antibodies to group A polysaccharides.

Epitopes↗
PubMed1989

[Epidemiologic aspects of the laboratory diagnosis of streptococcal infections].

Current status and prospects of laboratory diagnosis of streptococcal infections are analyzed. Available investigation schedules and methods for the detection and identification of Streptococcus pyogenes are assessed in epidemiologic terms. The importance of early laboratory diagnosis of first instances of disease is emphasized. Laboratory tests for streptococcal infection are an important element of prompt epidemiologic evaluation. They are to provide a preventive action rather than state fully-developed epidemics of scarlet fever or angina, as practiced currently. Approaches to the determination of the group and type of the causative agents are assessed critically. Additional investigation methods are presented and described.

Humans↗
PubMed1989

[Clinical and laboratory diagnosis of streptococcal infection].

The problems related to the clinical and laboratory diagnosis of streptococcal infection at all levels of health service are analysed. The principles of microbiological streptococcal identification with the aid of express-systems and standard culture techniques are outlined. Particular emphasis is placed upon immunoassay of streptococci using a broad spectrum of extracellular products and antigens of the cell wall of group A streptococcus, and upon methodological approaches to solving certain clinical and diagnostic problems.

Antibodies, Bacterial↗
PubMed1989

[The secretory and systemic humoral immune response to polysaccharide A in patients with rheumatism].

The level of sIgA saliva antibodies and Ig(M + G + A) serum antibodies to group polysaccharide A of streptococcus was studied in healthy donors and patients with streptococcal angina and rheumatic fever. It was shown that an elevated level of secretory and serum antibodies to polysaccharide A was registered in patients with angina and rheumatic fever reliably more frequently than in healthy donors. Independence of local and systemic humoral immune response to polysaccharide A was established.

Humans↗
PubMed1986

[Immunochemical analysis in research on antibodies to Streptococcus group A ribosomes].

The use of the competitive enzyme immunoassay (EIA) has made it possible to demonstrate that antiserum to the ribosomes of group A streptococcus, type 29 M, contains antibodies to homologous protein M and does not contain antibodies to group A polysaccharide, lipoteichoic acid and peptidoglycan. Ribosomal antiserum has been found to bind with the surface of heterologous type M streptococci in EIA, while forming no precipitation lines with heterologous proteins M in the double immunodiffusion test, which indicates that the binding of ribosomal antibodies with the surface of group A streptococcal cells is not type-specific. Antibodies to the ribosomes of group A streptococcus recognize some of the antigenic determinants of E. coli ribosomes.

Animals↗
PubMed1986

[Determination of antibodies against ribosomes and various cell wall components and detection of circulating antigens of group A Streptococcus in patients with erysipelas].

The level of antibodies to the ribosomes, polysaccharide A and peptidoglycan of group A streptococcus in the blood of patients with primary, secondary, and often relapsing erysipelas was studied by means of the enzyme immunoassay with the use of the sandwich techniques. For control, the sera of healthy donors were used. In the sera obtained from all groups of erysipelas patients a significant rise in the levels of antibodies to ribosomes and peptidoglycan in comparison with the controls was revealed. An increase in the level of antibodies to polysaccharide A was revealed only in patients with frequently relapsing and secondary erysipelas. Depending on the clinical form and the duration of the disease, polysaccharide A was detected in 32-51.9% of erysipelas patients and protein-ribosomal antigen was detected in 28.6-51.9% of such patients.

Antigens, Bacterial↗
PubMed1985

[Cell wall antigenic determinants in ribosomal preparations of Streptococcus group A].

As revealed by double immunodiffusion and the competitive immunoenzyme assay, the immunization of animals with ribosomes isolated from group A streptococci leads to the formation of antibodies to M-protein and does not lead to the formation of antibodies to A-polysaccharide and lipoteichoic acid, which is seemingly caused by the presence of M-protein in ribosomes. Antiribosomal serum has permitted the detection of more antigenic determinants in M-protein than commercial antiserum to homologous M-protein. The immunoenzyme assay for the quantitative determination of ribosomes has been developed.

Animals↗
PubMed1985

[Use of immunoenzyme analysis for evaluating the specificity of the antibody recognition of the antigenic determinants of Streptococcus group A].

Investigations carried out with the use of a CELIA system have revealed that antibodies in the sera of patients with primary erysipelas and antibodies in rabbit antiserum to the ribosomes of group A streptococcus specifically bind with adsorbed streptococcal ribosomes, recognizing the antigenic determinants of streptococcal ribosomes, which differ from those of individual Gram-negative prokaryotes (Escherichia coli, Shigella sonnei, Shigella flexneri, Salmonella minnesota). The modified CELIA system used in this investigation has made it possible to find out that antibodies in the sera of patients with primary erysipelas and antibodies in rabbit ribosomal antiserum bind with different antigenic determinants of the ribosomes of group A streptococcus.

Animals↗
PubMed1981

[Inhibiting effect of phenformin (phenethyl biguanide) on the growth of Ehrlich carcinoma].

Phenformin was shown to inhibit the rate of the Ehrlich carcinoma cell growth both in solid and ascitic forms of the tumor. The effect of phenformin on the tumor was eliminated by a diet containing high level of fats. The supernatant from the 18-hour culture of splenic cells, obtained from carcinoma-bearing mice treated by phenformin, inhibited phagocytosis of normal macrophages to a less extent compared with tumor-bearing mice which were not given phenformin. A peritoneal exudate from these mice was less effective in suppressing normal macrophages adhesiveness compared with untreated tumor-bearing mice.

Animals↗