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Biomedical subjects

I M Liampert

Publications and source records attributed to I M Liampert.

At least 19 recordsLinked to original sources
PubMed1991

[Antibodies to the rhamnose determinants of the polysaccharide of streptococci group A in the sera of rheumatism patients and donors].

In the sera of patients with recurrent rheumocarditis, and especially in cases of primary rheumatism, the level of antibodies to group A streptococcal polysaccharide (A-PS) has been found, according to the results of the enzyme immunoassay, to be considerably higher than in the sera of healthy donors. The level of antibodies to rhamnose determinants (RD) of A-PS has been determined by the inhibition of the immunoenzyme reaction with A-PS under the influence of a variant of group A streptococcus and rhamnose disaccharides with the bonds alpha 1-2 and alpha 1-3. In patients with recurrent rheumocarditis the level of antibodies to A-PS has been shown to be considerably higher than in healthy donors having these antibodies. In acute primary rheumatism a high level of antibodies to A-PS has been detected only in a few cases, and at the same time the prevalence of antibodies to the specific RD of A-PS, bound with beta-N-acetylglucosamine, is observed. In the sera of patients with recurrent rheumocarditis and donors having a high content of antibodies to the rhamnose site of A-PS antibodies, seemingly active against at least two RD, have been detected. In acute primary rheumatism an insignificant amount of antibodies to the rhamnose site of A-PS may probably cause the autoimmune process accompanying rheumatism. This suggestion is substantiated by the previously established capacity of these antibodies for inducing the suppression of cytotoxic cell reactions to microbial antigens.

Acute Disease↗
PubMed1991

[The enhancement of the immunogenicity of streptococcal group-A M protein by conjugation with a synthetic polyelectrolyte].

Immunization with the polypeptide fragment of group A streptococcal protein M conjugated with the copolymer of acrylic acid and N-vinylpyrrolidone in complete Freund's adjuvant has been found to lead to a sharp increase in the level of antibodies to the type-specific determinants of protein M, detected in the enzyme immunoassay (EIA). The possibility of the application of such sera to preliminary typing of streptococci in EIA with the use of whole microbial cells as antigens has been shown. The data on high activity of the sera thus obtained in the bactericidal test with streptococci of the homologous type are presented. Recommendations on the use of sera obtained by the above method for highly precise typing of the virulent cultures of group A streptococci in the bactericidal test are given.

Acrylic Resins↗
PubMed1991

[Level of antibodies to different determinants of Streptococcus group A polysaccharide and autoantibodies to basal layer of the skin epithelium in rheumatism].

Direct dependence was established between the presence of autoantibodies reacting with the basal layer of the skin epithelium (BLSE) and the high level of antibodies to the streptococcal group A polysaccharide (APS). By the primary active rheumatic fever (PARF) autoantibodies to the BLSE are revealed. By the recurrent active rheumatic fever (RARF) and in the control sera, autoantibodies reacting with the BLES, apparently, are directed to the rhamnose determinants of APS. These data confirm: different level of antibodies to the GS and to the rhamnose determinants of APS by PARF, RARF and in the control sera; the experiments of the autoantibody inhibition, reacting with the BLSE by the APS or the polysaccharide of streptococci A-variant, containing only the rhamnose determinants.

Adolescent↗
PubMed1991

[Secondary immunopathology in patients with an acute streptococcal infection].

The authors studied the activity of complement, nonspecific adaptive reactions of the body, the presence of antibodies to cross-reacting antigens of Streptococcus, the concentration of circulating immune complexes, some cellular characteristics of the immunogram in patients with different forms of streptococcal infection. The changes revealed allow a conclusion about the presence of autoimmune processes, most pronounced in chronic and recurrent forms of diseases. In the formation of streptococcal infection relapses, of the role is pathology of the complement system in combination with disorders in other components of nonspecific anti-infection resistance.

Acute Disease↗
PubMed1991

[Comparison of the frequency of detection of autoantibodies to epidermal antigens with the level of antibodies to polysaccharide of group A Streptococcus and the number of T-suppressors in glomerulonephritis].

By the acute glomerulonephritis (GN) of streptococcal etiology, autoantibodies (AA) reacting with the basal layer of skin epithelium (BLSE) are discovered. The presence of this AA's correlate with the high level of antibodies to the streptococcal group A polysaccharide (A-PS). In the control sera such AA's and the high level antibodies to A-PS are discovered very rarely. By the GN of non-streptococcal etiology, AA's to the BLSE apparently of other specificity are obtained in some cases, in spite of the absence of antibodies to A-PS. AA's reacting with the differentiated layers of skin epithelium are discovered in the high percent of cases by GN. The presence of these AA's do not correlate with the levels of antibodies to A-PS. The reduction of the number of T-lymphocyte suppressors is established in the blood by the presence of AA's to the BLSE by GN. This question is a subject of later investigations by the different autoimmune processes. Such data can apparently corroborate the previously expressed hypothesis, that AA's to BLSE, which as a rule react with endocrine thymus epithelium, are the cause of the beginning of immunoregulatory disorders, characteristic of autoimmune processes.

Acute Disease↗
PubMed1991

[Autoantibodies against the basement membrane layer of the skin epithelium as an indicator of the activity of the autoimmune process in children with chronic hepatitis B].

In different forms of chronic hepatitis B, autoantibodies reacting with the epithelium of the basal skin layer (EBSL) and with the epithelium of the cortical and medullary areas of the thymus can be detected by indirect immunofluorescence. The rate of demonstration and the level of these antibodies were established to depend directly on the activity of chronic hepatitis. The data obtained indicate that autoantibodies to EBSL are typical not only for the beginning of the autoimmune process but may also serve as an indicator of the activity of chronic autoimmune disease. The highest titers of the autoantibodies were demonstrated in aggressive hepatitis B associated with liver cirrhosis (in 100% of cases). The data obtained were compared to the liver biopsy findings. Therefore, demonstration of the high titers of autoantibodies can be used without liver biopsy for the diagnosis of liver cirrhosis in hepatitis B.

Adolescent↗
PubMed1990

[The effect of immunization with Streptococcus group A on the development of delayed hypersensitivity to BCG antigens in mice of different strains].

Antibodies to group A streptococcal polysaccharide (A-PS) have been shown to appear within three weeks after the injection of group A streptococcus culture, heat-killed and treated with pepsin (A-STP), in the blood of not only BALB/c mice, but also CBA mice. As revealed in this study, in BALB/c mice antibodies are mainly active against the group-specific antigenic determinant (AD) of A-PS and in CBA mice, against the rhamnose AD of A-PS, common for streptococci of different groups. This study has revealed that the appearance of antibodies to the rhamnose AD of A-PS in the blood of CBA mice inhibits antigen-specific cytotoxicity, appearing with the development of delayed hypersensitivity to BCG antigens. This effect is not linked with the immunization of the animals with high doses of streptococci. Experiments have shown that the in vitro transfer of the inhibition of antigen-specific cytotoxicity to lymph node cells of normal BCG-sensitized animals may be carried out with lymph node cells of CBA mice, immunized with A-STP and having antibodies to the rhamnose AD of A-PS, but not with the serum containing these antibodies. The mechanisms of this effect are discussed.

Animals↗
PubMed1990

[The suppression of delayed hypersensitivity to BCG antigens in BALB/c mice during the production of antibodies to the rhamnose determinants of Streptococcus group A polysaccharide].

The data obtained for the first time in our studies indicate that the production of antibodies to group A streptococcal polysaccharide (A-PS), one of the cross-reacting streptococcal antigens, may suppress delayed hypersensitivity (DH) to microbial antigens. The existence of sharply pronounced correlation between the suppression of DH and the presence of antibodies to the rhamnose area of A-PS in the blood of BALB/c mice immunized with the pepsin-treated culture of group A streptococci has been shown. The suppression of DH is absent in the immunized animals of the same group whose blood contains antibodies to the determinant, specific for A-PS. As revealed in this study, the effect of the suppression of antigen-specific cytotoxicity linked with DH to BCG antigens can be reproduced by mixing lymph node cells taken from these two groups of the animals. The data thus obtained are possibly linked with the activation of nonspecific T suppressors in the production of antibodies to the rhamnose determinants of A-PS in the animals immunized with streptococci. The mechanism of the newly discovered phenomenon is discussed.

Animals↗
PubMed1990

[Suppression of cytotoxic cellular reactions by the production of antibodies to rhamnose determinants of streptococcal group A polysaccharide cross-reacting with antigens of the skin epithelium].

By the BALB/c mice after different periods of immunization with the streptococci group A, treated with pepsin, antibodies belonging to autoantibodies to the determinants (DT) of polysaccharide (A-PS), cross-reactive (CR) with the epithelial skin cells, were investigated. In one of the mice groups, in the autologous system, on the target cells--macrophages of lymph nodes, the suppression of cytotoxic (CT) reactions was obtained. The CR are bound with the delayed type hypersensitivity appearing after the sensibilization with BCG. The suppression effect correlate (z-0.95) with the presence in the sera antibodies to the rhamnose DT'S of A-PS, which cross-react with the cells of basal and superbasal layers of skin epithelium. Antibodies to the group specific of the A-PS, cross-react only with the basal skin layer and not produce the suppression of CT reactions. It is possible that they also prevent the suppression of CT reactions, bound with the CR antibodies to the rhamnose DT-S of A-PS. The obtained data corroborate the earlier supposition that the autoantibodies to the CR DT'S of A-PS reacting with the skin epithelial cells as a rule common the thymus epithelial cells. It is possible that different IRD'S can prevent or stimulate the development of autoimmune processes by the infections with the streptococci group A.

Animals↗
PubMed1990

[Group A streptococcal polysaccharide--stimulator of nonspecific cytotoxic reaction in autologous system of spleen cells].

p4 was shown the ability of group A streptococcal polysaccharide (A-PS) to stimulate nonspecific cytotoxic effect of spleen cells on autologous adherent cells (macrophages). The stimulating effect can be observed in vivo under the treatment of spleen cells with A-PS and any antigen (BSA, PPD, M-protein of group A streptococci). In the presence of antigen A-PS can induce nonspecific cytotoxic effect of normal spleen cells (mice CBA, BaLB/c) and of the mice with DHT and therefore these two immunologic phenomena do not depend on each other. Because A-PS has cross-reactive (CR) determinant with thymus epithelial antigen (factor), it can be assumed that via the CR determinant A-PS links with T-cells receptor for this thymus factor and thus realized the stimulating effect as it's functional analogue.

Animals↗
PubMed1979

[Immunoglobulin receptors of group A Streptococcus].

It was shown in the gel precipitation tests that absorption of human and rabbit IgG or Fc-fragments obtained from human IgG group A streptococcal cultures results in inhibition of the reactions of these preparations with immunoglobulin sera. The reactions of F(ab')2-fragments with the corresponding sera are not inhibited during their absorption by the same cultures. The results obtained support the presence in a number of group A streptococcal cultures of immunoglobulin receptors (Ig-receptors) capable of reacting with Fc-parts of human and rabbit IgG. Pepsin treatment destroys Ig-receptors. These receptors could not be found by the method used in hydrochloric acid extracts prepared from streptococci containing the receptors. The method can be applied for determination of Ig-receptors in streptococcal cultures.

Animals↗
PubMed1979

[Immunological cross reactions between polysaccharides of Streptococci groups A and L].

Antibodies on sepharose immunosorbents containing A-polysaccharide-sepharose or synthetic beta-N-acetylglucosamine, were isolated from the sera of rabbits immunized with streptococci, group A, by means of affinity chromatography. Antibodies obtained from some sera with both immunosorbents reacted with streptococcus, group A and L polysaccharides. Partial identity of these polysaccharides was revealed by the immunodiffusion test. Absorption of antibodies with polysaccharides, group A and L, showed their different specificities. These antibodies could apparently be directed against the end parts of molecules of streptococcus, group A polysaccharide.

Animals↗
PubMed1979

[Immunodiffusion methods of studying the F-fraction antigens obtained from group A streptococci].

F fractions, obtained by the extraction of cultures of group A streptococci with distilled water at different pH, were studied by immunodifusion methods and subjected to chemical analysis. F fractions were shown to contain polyglcerophosphate, antigen E4 and in some cases group polysaccharide. Besides, F fractions were found to contain an antigen insensitive to trypsin and identical to one of the antigens of the thermostable fraction, as well as an antigen sensitive to the action of proteolytic enzymes and common to various types of group A streptococci. The antigen sensitive to the action of proteolytic enzymes were identical to one of the antigens showing no type specificity and contained in HC1 extracts prepared from group A streptococci. In grouping and typing group A streptococci the present of some F fraction antigens unrelated either to polysaccharide or to M substance should be taken into consideration. The antigens of F fraction have no protective properties.

Animals↗
PubMed1977

[Permeability of cutaneous macrophage lysosomal membrane in delayed hypersensitivity to streptococcal antigens].

The acid phosphatase (APh) was studied in the skin macrophage lysosomes of animals with delayed-type hypersensitivity (DTH) to the antigens of group A streptococci or tuberculoproteins. The histochemical procedure for the APh determination was employed in the skin sections without any preliminary tissue fixation. Intradermal injection of specific antigens in DTH proved to lead to the increase of the lysosomal membrane permeability in the skin macrophages. These data support the supposition that the lysosome enzymes of macrophages can act as factors causing tissue destruction in DTH.

Acid Phosphatase↗
PubMed1977

[Reactions of antibodies to streptococcus group A antigens with fibroblasts of human heart interstitial connective tissue].

The indirect immunofluorescence method was applied to the study of the serum of rabbits immunized with fractions containing nontype-specific antigens of streptococcus, group A, belonging to the cell wall proteins. Antibodies reacting with fibroblasts of the interstitial connective tissue of the human heart were revealed in the sera. On the basis of the experimental results of absorption a supposition was put forward on the presence of a cross-reacting antigen common with the fibroblast antigen in some hydrochloric extracts obtained from streptococci, groups A and C.

Animals↗
PubMed1977

[Relationship between the virulence of a culture and the presence of common (non-type-specific) antigens in strains of group A streptococcus of different types].

In studying common (nontypespecific) antigens sensitivity to trypsin there was shown their wide distribution among the cultures of streptococcus, group A, belonging to different types and containing M-proteins. The antigen No. 1, identical to one of the antigens of the thermostable fraction was found in the cultures, irrespective of the degree of their virulence. The antigen No. 2 was characteristic of only virulent cultures obtained after the increase of the virulence and forming matt-form colonies. Both of the antigens were referred to the category of R-antigens. The presence of the nonspecific antigens in the hydrochloric extracts should be taken into consideration in typing streptococci of group A and determination of M-antigens.

Antigens, Bacterial↗
PubMed1976

[Cytotoxic action of immune lymphocytes on "adherent" cells (macrophages) of autologous system lymph nodes during delayed hypersensitivity].

A study was made in the autologous system of the cytotoxic action of immune lymphocytes on the "adherent" cells (macrophages) of the lymph nodes of guinea pigs in delayed hypersensitivity (DH) to the streptococcus antigens and tuberculoproteins. Death of a considerable number of the "adherent" cells in cultivation of a suspension of cells of the lymph nodes of animals sensitized with the culture of streptococcus or BCG in the presence of specific antigen (thermo-stable streptococcus fraction or tuberculin, respectively) alone. Detection of death of the "adherent" cells in the autologous system can be used as one of specific and sensitive tests in studying the DH.

Animals↗