[Specific features of the HIV infection epidemic in Moscow].

Retrospective analysis of the epidemic of HIV infection in Moscow allowed to mark out two periods: the first--from 1987 to 1993 and the second one--from 1994 to 2000. The characteristic feature of the first period of the epidemic was the sexual transmission of the agent mainly among homosexuals; the most affected group were persons aged 20-39 years and the number of AIDS patient decreased with a simultaneous growth in lethality. During the second stage of the HIV infection epidemic changes in the prevailing transmission routes of the agent occurred: injection drug addicts took the leading role.

[An analysis of the epidemic cycle of meningococcal infection in Russia (1969-1993)].

In this work the specific features of the epidemiological rise of morbidity in meningococcal infection in Russia for the period of 25 years are analyzed. Some factors influencing the intensity of the disease, such as etiology, specific features arising from the age of patients, social and territorial factors, are analyzed. Two waves of epidemic have been established in a single epidemic cycle.

[The evolution of meningococcal infection in Mongolia].

On the basis of the generalization and analysis of the results of bacteriological and immunological investigations the epidemic process of meningococcal infection (MI) in Mongolia was found to undergo definite changes during the last 20 years. Group A meningococci prevailing in the etiology of MI were replaced by strains belonging to group B affecting mainly young children (aged up to 3 years). MI morbidity rate caused by group B meningococci was found to be higher in Mongolia than in other countries of the world.

[The effect of vaccination on local immunity indices; the determination of antimeningococcal antibodies in saliva].

Local immunity characteristics were studied in 130 young males; of these, 80 had been immunized with group A meningococcal vaccine. In nonstimulated saliva, collected prior to vaccination, then on days 7, 14 and 30 after vaccination, the levels of IgA antibodies to group A meningococcal group-specific polysaccharide (PS-A) were determined in the enzyme immunoassay, and secretory IgA and IgA, IgG, IgM were determined by Mancini's method. The study revealed that after the parenteral administration of group A meningococcal vaccine an increase in the concentrations of SIgA and IgA antibodies to PS-A occurred.

[The determination of antimeningococcal antibodies in the saliva of healthy people].

The determination of antibodies to the group-specific polysaccharide of group A meningococci (PS-A) in the saliva of 162 healthy persons at different seasons of the year revealed that antimeningococcal antibodies could be detected in all examines. The range of concentrations of antibodies to PS-A varied between 0.1 and 33.

[The characteristics of the serological diagnosis of meningococcal infection in children in the 1st years of life].

The results of clinico-immunological examination of 181 children, aged 1 month to 6 years, with generalized forms of meningococcal infection are presented. In children under observation antimeningococcal antibodies to group-specific meningococci of the main groups A, B and C were determined over the course of the disease by passive hemagglutination (PHA) test and enzyme immunoassay (EIA). The level and frequency of seroconversion were found to depend on the patient's age and the severity of the clinical course of meningococcal infection.

[The diagnostic value of a meningococcal-B erythrocyte diagnostic agent based on the group-specific polysaccharide].

In this work the diagnostic value of group B meningococcal erythrocyte diagnosticum was determined. 585 blood serum samples taken from adult donors were studied: 220 samples from practically healthy persons and 365 samples from 144 patients with meningococcal infection and purulent bacterial meningitis of nonmeningococcal etiology. Group B meningococcal erythrocyte diagnosticum was found to possess serological activity and to reveal the growth of specific antibodies in the sera of patients with meningococcal infection, serologically confirmed by the isolation of group B meningococcal culture, in 100% of cases on weeks 2-3 of the disease.

[New approach to the diagnosis of meningococcal infection: latex-erythrocyte agglutination].

A principal possibility and advantages of the diagnosis of meningococcal infection by means of agglutination of sensibilized latex particles with erythrocytes have been demonstrated. Polysterene carboxylated latex has been sensibilized by rabbit JgG to meningococcus of serogroup A. Dynamics of absorption of meningococcal polysaccharide on erythrocytes in vivo has been studied in mice.

[The characteristics of suppurative meningitis morbidity caused by Streptococcus pneumoniae and Haemophilus influenza type B].

Of the 1,018 patients with purulent bacterial meningitis, hospitalized at the 2nd Clinical Infectious Hospital in Moscow during the period of 1980-1987, the diagnosis was confirmed in 54.7%; of these, meningitis of pneumococcal etiology was established in 44.8% and meningitis caused by H.

[Immunological factors in the evolution of the epidemic process in meningococcal infection].

The results obtained in 1987 in the study of the immunostructure of the population of Yaroslavl with respect to meningococcal polysaccharides, groups, A, B, C, and lipopolysaccharide are presented in comparison with earlier results obtained in 1976. The regulating role of the immunological factor in the evolution of the epidemic process of meningococcal infection has been confirmed. The level of antibodies to meningococcal polysaccharides, groups A and B, has been found to reflect the intensity of the circulation of the infective agent among the population.

[Antibodies to meningococcal lipopolysaccharide in different forms of meningococcal infection].

The results of the determination of antibodies to lipopolysaccharide (LPS) in 270 patients with different forms of meningococcal infection and in 816 healthy persons by means of the passive hemagglutination test are presented. The role of antibodies to LPS in the formation of humoral immunity to meningococci in sick children and adults is shown. Different forms of meningococcal infection have been found to have their specific features of the accumulation of antibodies to LPS.

[A modified method of latex agglutination in capillaries for the detection of meningococcal antigens].

The suggested microvariant of the latex agglutination test in glass capillaries is not inferior to the traditional latex agglutination on the glass in sensitivity and specificity. The microvariant consists in the following: glass capillaries 0.8 mm in diameter 10 cm long are filled with the pathological material (3/5 of the tube length) and with the diagnostic latex preparation (1/5 of the tube length) so that no air hole is formed between them.

[Evaluation of the reactogenic and immunogenic properties of meningococcal vaccines].

The results of the study of the reactogenic and immunogenic properties of meningococcal polysaccharide A + C vaccine in the controlled epidemiological trial, with regard to variations depending on the initial immunological characteristics of vaccinees in terms of the levels of antibodies to the polysaccharides contained in the vaccine, are presented. The study was made on school children: 303 of them were immunized with the meningococcal vaccine under test, and 229 (controls) with adsorbed diphtheria-tetanus toxoid. This study revealed that the reactogenic properties of the preparation were more pronounced in those children whose blood sera had been found to contain no antibodies to polysaccharides A and C prior to immunization.

[Cross-reacting intraspecies antigens of Neisseria meningitidis. II. The dynamics of antimeningococcal antibodies to cross-reacting antigens in different forms of meningococcal infection].

The presence of antibodies to meningococci has been determined in the sera of 203 patients with meningococcal infection and 234 healthy persons by means of the indirect hemagglutination tests with the use of polyvalent erythrocyte diagnosticum. The tests have shown that antibodies to cross-reacting antigens can be detected both in patients with generalized forms of meningococcal infection and in healthy persons; the level and occurrence of these antibodies depend on the age of the subjects under examination and the form taken by the course of meningococcal infection. The study has revealed that the background level of antibodies to meningococci in healthy persons is mainly formed due to meningococcal carriership.

[Determination of meningococcal antibodies by a radial hemolysis method].

The possibility of using, on principle, the reaction of radial hemolysis for the determination of antibodies to meningococci has been shown. The sensitivity and resolution of this method has been found to depend on the dose of the antigen used for the sensitization of erythrocytes, on the concentration of the erythrocyte suspension introduced into the gel and on the amount of complement. The optimum conditions for the reaction of optimum hemolysis, used for the determination of antibodies to serogroup A Neisseria meningitidis polysaccharide, have been established: the sensitizing dose of the antigen must be 50-100 micrograms/ml, the concentration of sensitized erythrocytes 25%, and the amount of complement 20-40 HU.

[Cross-reacting intraspecific antigens of Neisseria meningitidis. I. The isolation, immunochemical and serological characteristics of the cross-reacting antigens of N. meningitidis serogroup A].

New data on the cross-reacting antigen of N. meningitidis, serogroup A, are presented. A complex of antigens has been isolated by treatment with tryptone X-100, ethanol precipitation and the subsequent treatment with trichloroacetic acid.

[Changes in specific and nonspecific immunity factors in saliva and serum of patients with different clinical variants of meningococcal infection].

Local and humoral immunity factors have been studied in 152 patients with different forms of meningococcal infection. The peculiar pattern of the time course of changes in these factors, depending on the clinical form of the disease, has been revealed. In the generalized form of infection changes in the immunological characteristics of the saliva and blood serum (lysozyme, secretory immunoglobulin, immunoglobulins of the main classes and specific antimeningococcal antibodies) have been shown to be more essential than in the localized form.

[Evaluation of the toxicity of meningococcal antigens by the development of paw edema in white mice].

The comparative evaluation of group A meningococcal antigens of different chemical nature (protein, polysaccharide, lipopolysaccharide and complex fraction) was made by the method of paw edema. The preparations were introduced in a dose of 100 micrograms/0.05 ml.

[Study of Vibrio cholerae fractions. III. The gel chromatographic and immunochemical characteristics of vibrionin].

Three fractions differing by molecular weight (fraction 1--greater than 14 x 10(4)--less than 2 x 10(6) dalton, fraction 11--greater than 7 x 10(4)--less than 14 x 10(4) dalton, fraction III--greater than l0(4) less 35 x 10(3) dalton) were isolated from vibrionin, a preparation of cholera allergen, by gel chromatography on Sephadex G-150. These fractions possessed a different immunochemical activity and were capable of detecting the state of increased sensitivity to cholera vibrio.

[Study of Vibrio cholerae fractions. II. A comparison of the immunochemical and biological properties of preparations of alkaline extracts (vibrionin) and the endotoxin of Vibrio cholerae].

Comparative study of immuno-chemical and biological properties of vibrionin and cholera vibrio endotoxin showed vibrionin to contain up to 73.5% of protein, whereas endotoxin preparations contained only 25% of protein. Use of disc electrophoresis in polyacrylamide gel permitted to determine the relative electrophoretic mobility of the protein component bands of both preparations.

[Cholera vibrio fractions. I. Isolation of alkaline extracts of cholera vibrios and a study of their biological properties].

The authors suggest a well-reproducible method of preparation of a biologically-active fraction of an alkaline extract of cholera vibrio from the strain 569B of Inaba serological type consisting in a preliminary triple removal of endotoxin (O-antigen) of the causative agent from the microbial cell suspension with trichloracetic acid with the subsequent extraction of the microbial mass and neutralization of the extract obtained capable of effective detection of the state of specific sensitization of the organism to cholera vibrio. Preparations of the alkaline extracts (cholera allergen) obtained were standard by chemical composition, they were characterized by a high protein content (up to 77%) and were practically nontoxic. These preparations can be used as a bacterial allergen for the experimental investigations.