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Biomedical subjects

N I Briko

Publications and source records attributed to N I Briko.

At least 37 records · Page 2Linked to original sources
PubMed1993

[Angina morbidity in an organized collective with a periodic turnover of its personnel].

The article studies the average angina morbidity in the military unit during 9 years which resulted in 48.4% (scarlet fever--0.34%). Laboratory diagnostics is needed to make the estimation of streptococcal infection which has an acute respiratory infectious character during its clinical course. Among the whole number of patients 89.2% have come through this illness for one time, 9% twice, and 4.8%--three times. The dynamics of the angina morbidity had a periodical cycle of 2-3 years which was independent from the morbidity cycle of local civilian population. The authors show a statistic dependency between average morbidity index and the quantity of servicemen in one dormitory, its square and volume per one man. Application of "time before illness" index for 24 months made it possible to disclose the phase character in the development of streptococcal infection among personnel of the same call-up period. The general tendency towards reduction of the morbidity index was accompanied with regular upgrades of the infection after each spring or autumn renovation of personnel.

Adolescent↗
PubMed1992

[Antistreptococcal antibodies in the blood serum of glomerulonephritis patients].

To study humoral antistreptococcal immunity, 29 patients with acute glomerulonephritis (AGN), 211 patients with chronic glomerulonephritis (CGN) and 30 healthy donors were examined. According to EIA, blood sera of the indicated groups demonstrated antibodies (AB) to structural components of Streptococcus--A-polysaccharide (A-ps) and hyaluronic acid (HA) and to its extracellular products--streptokinase (SK) and streptolysin-O (ASLO). It has been shown that in the blood of AGN patients, the levels of AB to A-ps, SK and ASLO were high. The highest level of AB and SK was detected in 55% of the patients with the disease standing of up to half a year. In patients of all the clinical groups of CGN, the levels of AB to A-ps, SK and HA were elevated. The degree of the rise of the levels of all AB depended on the disease activity. Of prognostic importance in the chronicity of AGN and progression of CGN are high titers of AB and SK. The etiological role of streptococcus in glomerulonephritis and its importance in CGN exacerbation and prognosis are under discussion.

Adolescent↗
PubMed1991

[A study of the variability of group A type M29 streptococcus on exposure to biologically active substances].

Biologically active substances spermidine and the compounds contained in the low-molecular fraction of cattle blood serum change the phenotype of type 29 group A Streptococcus. Amino acid analysis and enzymatic destruction of cell walls have demonstrated changes of the streptococcal biological characteristics and cell wall structural organization. These changes may result from loss of supervariable component of the M-protein when compounds from cattle blood serum low-molecular fraction are added to culture medium and by unbalanced growth of Streptococcus after spermidine addition to growth medium.

Animals↗
PubMed1991

[Immunological study of lysates from the cell wall of group A Streptococcus].

The chemical composition and presence of immunogenic components in the lysates of the cell walls of group A Streptococcus, type M29, were studied. The lysates were prepared with the use of muramidase. Fc-Receptors were detected in the lysates. Within the first 30 minutes of cell wall lysis by muramidase, 4 times higher amounts of the protein reacting with fibrinogen excreted than in the subsequent 4 hours. The lysates contained immunogenic proteins. Fraction III isolated by chromatography of the 30-minute lysate on DEAE-trisacryl formed a single precipitation band with lysate antiserum. The lysate Fraction IV forming three precipitation bands contained a protein not specific of the type. The protein was identical to the protein antigen from Triton X-100 extracts of group A Streptococcus, types M1, M12 and M29. The group-specific polysaccharide was detected in the lysate Fraction I and Fraction II of the 4-hour lysate.

Bacterial Proteins↗
PubMed1991

[The pharyngeal beta-hemolytic streptococcal carrier state among blood donors].

459 blood donors aged 18-50 years were examined in 1987-1988 in Moscow. Among them, carrier state with respect to beta-hemolytic streptococci was detected in 107 donors (23.3%). The number of carriers gradually decreased with the increase of age of the examined donors. Group C streptococci occurred least of all (6.9%). Group A beta-hemolytic streptococci were isolated in 16.7% of the carriers. The isolation rate of streptococci from blood achieved its maximum in autumn and winter months and did not depend on preceding diseases, unhealthy working conditions, the rhesus factor and, with the exception of group A streptococci, the blood group. Among tonsillectomized donors carrier state with respect to beta-hemolytic streptococci occurred 2.2 times less frequently than among donors who had not undergone tonsillectomy. Carrier state with respect to beta-hemolytic streptococci was accompanied by higher levels of salivary sIgA antibodies to polysaccharide A, serum antibodies to polysaccharide A and circulating polysaccharide A. All beta-hemolytic streptococci were sensitive to erythromycin. All groups of streptococci showed the highest percentage of cultures resistant to gentamicin and tetracycline. In 100% of cases group A streptococci were sensitive to benzylpenicillin, methicillin, ampicillin, erythromycin and lincomycin.

Age Factors↗
PubMed1990

[Preparation of immune sera to group A streptococcus lipoteichoic acid].

A method is described for the preparation of sera highly active in reactions with Group A Streptococcus lipoteichoic acid. Ultrasound-destroyed biomass of Streptomyces levoris K-3053 strain is used as the antigen. This strain was isolated in studies of soil Streptomyces; it contains sufficient amounts of nonglycosylated glycerolteichoic acid of the first-third types, that is identical in structure to polyglycerophosphate skeleton of Group A Streptococcus lipoteichoic acid.

Immune Sera↗
PubMed1990

[Heterogeneity of streptococcus group A cell wall protein components].

Cell wall surface proteins of group A streptococcus (M 29) were isolated by mild chemical extraction with 1 M hydroxylamine pH 6.0 (37 degrees C). The proteins were purified by ammonium sulfate fractionation, gel filtration on Sephadex G-150 and ion-exchange chromatography on DEAE-Trisacryl M. Using two independent methods (disc electrophoresis in 7.5% PAAG pH 8.9 and high pressure gel filtration), it was shown that after chromatography on Sephadex G-150 the original protein fraction contains up to 8 protein components, while SDS-PAAG electrophoresis performed according to Laemmli revealed up to 25 protein components in the same fraction. During SDS-PAAG electrophoresis six protein fractions performed after ion-exchange chromatography were resolved into 40 protein components whose molecular masses vary from 13 to 80 kDa. Possible reasons for the heterogeneity of surface proteins of group A streptococcus cell wall are discussed.

Bacterial Proteins↗
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 epidemic process of an acute streptococcal respiratory infection in large organized collectives of children].

The study of the specific features of the development of the epidemic process of scarlet fever, tonsillitis, and acute respiratory diseases (ARD) in two large organized groups of children revealed the presence of some differences which depended on the character of prophylactic measures taken in these groups. Thus, in the absence of prophylaxis with bicillin a pronounced increase in the level of carriership, accompanied by an increase in the infective capacity of carriers, was noted. This resulted in a high level and unfavorable dynamics of morbidity in scarlet fever, tonsillitis, and ARD. On the contrary, the use of prophylaxis with bicillin ensured the stability of the level of carriership, while the infective capacity of carriers was not pronounced. At the same time a rise in ARD morbidity was insignificant, and morbidity in scarlet fever and tonsillitis was reduced to nil.

Acute Disease↗
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↗
PubMed1990

[An explosive outbreak of respiratory streptococcal infection with a droplet transmission mechanism].

The data obtained in the study of an explosive outbreak of acute respiratory diseases, tonsillitis and scarlet fever in one of schools in Moscow have made it possible to exclude the alimentary mechanism of its development and to demonstrate the role of the droplet mechanism of transmission in the appearance of its outbreak. The epidemiological analysis of the outbreak has permitted the formulation of the hypothesis on the conditions of the formation and spread of the epidemic variant of the infective agent; this hypothesis corresponds to the available data in literature on the qualitative changes of the infective agent in the course of the epidemic process. The study has shown that the prophylaxis of the explosive outbreaks of respiratory streptococcal infections must be ensured by the system of epidemiological surveillance with timely intervention into the epidemiological process at its early stages.

Adolescent↗
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

[Hydrophobic quality and the level of surface proteins in the cell wall of cultures of Streptococcus pyogenes isolated from clinically healthy children from an organized collective].

The Str. pyogenes cultures isolated from clinically healthy children were found to have different hydrophobic properties and quantities of surface cell wall proteins, and to exhibit pronounced variability in these signs in time. Most studied cultures lacked a correlation between their hydrophobic properties and the quantity of surface proteins of the cell wall.

Absorption↗
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↗