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Biomedical subjects

A A Demina

Publications and source records attributed to A A Demina.

At least 19 recordsLinked to original sources
PubMed1992

[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. These data substantiate the necessity of using more effective remedies for the control of this infection and, in particular, specific immunization with vaccines against group B meningococci; profound study of the properties of the circulating meningococcal strains is to be carried out.

Adolescent↗
PubMed1992

[The type subtyping of meningococci by means of whole-cell immunoenzyme analysis].

In this work the method of the whole-cell enzyme immunoassay, used for the serotype-subtyping of meningococci by means of specific monoclonal antibodies, is described. High specificity of the method, the simplicity of the assay procedure and evaluation of its results, as well as the availability of this method for practical use, have been demonstrated. The results of this investigation confirm the importance of the evaluation of type-subtype appurtenance of reference and laboratory strains used in experiments. Study of 72 meningococcal strains obtained from patients has revealed their polyclonal character in respect of their type-subtype signs.

Antibodies, Monoclonal↗
PubMed1991

[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. Antibody level was found to increase simultaneously with respect to several meningococcal polysaccharides: A, B in 18.5% and A, B, C in 3.3% of cases. In the clinical interpretation of data obtained in the PHA test and EIA not only the patient's age, the form and duration of meningococcal infection, but also serotherapy should be taken into consideration, as the latter may distort the serological results.

Aging↗
PubMed1990

[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. Diagnostic characteristics--specificity and sensitivity--for group B erythrocyte diagnosticum were, respectively, 90.2% and 63.5%. The study revealed that antibodies to several group-specific meningococcal polysaccharides in blood sera can be simultaneously determined in the passive hemagglutination test with a set of erythrocyte diagnostica, which should be taken into consideration in the clinical interpretation of serological results.

Adult↗
PubMed1990

[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. influenzae, type b, in 23.8% of the patients. In meningitis of pneumococcal etiology high risk groups included mainly adults, especially those over 50 years, and children under 3 years of age. In meningitis of H. influenzae etiology high risk groups included mainly young children under 2 years of age. Meningitis of pneumococcal etiology was characterized by considerable death rate (on the average, 20%), while in meningitis of H. influenzae etiology death rate was 3 times lower. Pneumococci of serotypes 1, 3, 6, and 19 were found to be of the highest etiological importance for adults and pneumococci of serotypes 19, 6, 12, and 1, for children. In recent years greater etiological role of serotype 42 in adults was noted. The study of the spread of meningitides of different etiology is a high-priority task for this country.

Age Factors↗
PubMed1989

[The epidemiological characteristics of meningococcal infection in the USSR].

The epidemiological analysis of morbidity in meningococcal infection in the USSR in the period of 1969-1987 showed that the second rise of the morbidity level occurred in 1984 and was followed by its decrease in most of the regions of the USSR. This study also revealed that the characteristic feature of the second rise of morbidity in meningococcal infection was a considerable involvement of young children (aged up to 3 years), as well as the increased etiological role of group B meningococci in cases of meningococcal infection and the circulation of these microorganisms among the population. Besides, the preservation of the etiological importance of group A meningococci in many regions of the USSR, especially among adults, was noted. In this connection, the use of Soviet group A meningococcal polysaccharide vaccine on epidemiological indications was considered to be epidemiologically substantiated.

Age Factors↗
PubMed1989

[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. The comparison of the results of investigations carried out in 1976 and 1987 has revealed the essential role of the lipopolysaccharide antigen in the formation of the postinfection immunity of the population to meningococcal infection, irrespective of the group of the infective agent.

Adolescent↗
PubMed1987

[Meningococcal serogroup B infection].

The results obtained in the examination of patients with meningococcal infection during the period of 1980-1985 are analyzed. The increasing role of serogroup B meningococci in the etiology of the generalized forms of infection, especially in children aged under 3 years and in adults over 50 years, is shown. As noted in this investigation, the disease induced by group B meningococci runs a more severe course. Morbidity caused by this serogroup of meningococci does not result in epidemics in our country. The distribution of patients among different age groups and specific features of the clinical course of the disease in connection with the serogroup of the causative agent make it possible to regard the risk groups as groups with decreased reactivity, which raises doubts concerning the possibility of forming effective postvaccinal immunity against group B meningococci in such persons.

Adolescent↗
PubMed1987

[Microanalytical methods: latex agglutination and immunoenzyme analysis in the diagnosis of meningococcal infection].

Modified polystyrene latexes with high adsorption capacity, comparable to that of latexes produced by Difco Laboratories (USA), have been developed in the USSR. Diagnostic latex preparations for the detection of meningococci of serogroups A, C, Y and Haemophilus influenza, type b, prepared on the basis of these new latexes, have shown high specificity and sensitivity in experimental and clinical tests. The latex preparations for the detection of serogroup B meningococci requires further improvement. The use of latex preparations, together with other laboratory methods, in the diagnosis of meningococcal infection has promoted the etiological confirmation of the disease in 84% of cases; this method has proved to be 1.5 times more effective than the bacteriological one and not less sensitive than the enzyme immunoassay, while being more specific.

Adsorption↗
PubMed1986

[Epidemiological characteristics of meningococcal infection in Cuba].

The results of the epidemiological analysis of the morbidity rate in meningococcal infection for 1976-1984 are presented. The maximum rise of morbidity rate, equal to 14.4 per 100000 of population, was observed in 1983. Primarily, the rise of morbidity rate in 1979 was induced by meningococci of two serogroups: C (44.6%) and B (36.4%). The vaccinal prophylaxis of the population, carried out in 1979 with the use of polysaccharide vaccine A + C, did not affect morbidity caused by group B meningococci. The isolation rate of these organisms reached 98.7% from patients and 81.0% from carriers. The characteristic feature of the epidemic process of meningococcal infection in Cuba was a considerable increase in the number of patients under 1 year of age and the absence of seasonal fluctuations in morbidity rate.

Adolescent↗
PubMed1986

[Epidemiological surveillance of meningococcal infection and the prediction of the development of an epidemic process].

The signs necessary for the prognostication of the development of the epidemic process have been formulated on the basis of the epidemiological analysis of materials obtained in the process of trials of the system for the surveillance of meningococcal infection with the use of previously established characteristics. The data on the prevalence of meningococcal infection among different age groups and on the seasonal distribution of the infection as well as on the serogroups of meningococci isolated from patients, have been shown to be of importance for prognostication.

Adolescent↗
PubMed1986

Surveillance of meningococcal infections and other forms of purulent meningitis: a 4-year study in the USSR.

The laboratory examination, by microscopic or bacteriological methods and by counterimmunoelectrophoresis, of CSF and blood from 2653 patients with purulent bacterial meningitis, including those with clinically diagnosed meningococcal infection, was carried out between June 1980 and June 1984. The results showed three main etiological agents: meningococci (79.9%), pneumococci (10.8%) and Haemophilus influenzae type b (5.25%). Out of 488 Neisseria meningitidis strains isolated from the CSF or blood, 58.2% belonged to serogroup A, 17.2% to serogroup B, and 14% to serogroup C; infection due to the B serogroup reached nearly 59% among children in 1984. Serotypes were determined in 131 out of 151 strains of Streptococcus pneumoniae and the most frequent were types 1, 19 and 3; type 34, which was isolated from 4 patients, is not a component of the pneumococcal vaccine. The age groups at high risk were children under 5 years old (for meningococcal infection), adults and babies in the first year (pneumococcal meningitis), and children under 3 years, especially between 6 months and 2 years old (H.influenzae type b infection).

Adolescent↗
PubMed1985

[Increased specificity of immunoenzyme analysis for diagnosing meningococcal infection].

The ELISA test system for the detection of polysaccharide antigens of meningococci, groups A and C, on the basis of the neutralization of specific antibodies has been developed. The specificity of this reaction is determined by the chemically pure preparations of group A and C meningococcal polysaccharides. The sensitivity of this test system based on the neutralization of antibodies is not inferior to that of ELISA with the use of double antiserum.

Animals↗
PubMed1985

[Etiological diagnosis of suppurative bacterial meningitis today].

As the result of laboratory examination of 2165 patients with virulent bacterial meningitides, including cases of meningococcal infection, the etiological diagnosis was confirmed in 1407 patients (65.0%), the number of cases confirmed by the laboratory examination being significantly greater among adults than among children: 67.5 +/- 1.37% and 63.1 +/- 1.53%, respectively, (t = 2.1). Meningococcal infection was confirmed in 1111 (70.6%) out of 1572 patients under examination. Of the patients with purulent meningitides, pneumococcal etiology was determined in 27.4%, type b of Haemophilus influenzae in 13.5%, other infective agents in 10.0%. The comparison of the results obtained in the examination, carried out by different methods, of 946 children and 770 adults with meningococcal infection revealed a considerable difference in the number of positive results yielded by the bacteriological method and countercurrent immunoelectrophoresis (CIE). Among adults meningococci were isolated twice as frequently (41.1 +/- 2.5% - 19.4 +/- 1.6%), and the results yielded by CIE were predominantly positive (55.1 +/- 2.5% and 40.1 +/- 2.5%). CIE and the immunoenzyme assay were shown to have advantages in the diagnosis of the disease. Under the conditions of intensive antibiotic therapy the methods based on the detection of specific antigens in body fluids can greatly assist in diagnosis.

Adolescent↗
PubMed1985

[Specific latex preparations in the etiological diagnosis of suppurative bacterial meningitis].

The results of the evaluation of the diagnostic latex preparations Bactigen, manufactured by Wampole Laboratories (USA) and intended for the detection of meningococcal antigens, serogropus A, B, C, Y, pneumococcal polyantigens and type b Haemophilus influenzae antigens in the spinal fluid and blood of patients with meningococcal infection and purulent bacterial meningitides, are presented. The pathological material was studied by traditional methods and by the latex agglutination (LAG) test. 522 LAG tests were made, including 414 tests for meningococcal infection, 60 tests for pneumococcal infection and 48 tests for type b H. influenzae. The results of this study revealed that the latex preparations were highly specific with respect to type b H. influenzae antigens and meningococcal antigens (false positive reactions constituted 0.96%). The simplicity of the test and the rapid techniques making it possible to obtain results within 30-40 minutes indicate good prospects of using the LAG test in laboratory practice.

Antigens, Bacterial↗