Applicability of the single-layer flat-coil-oscillator technology-based vibration and vibro-acoustic sensors in medical and biological study of the cardiovascular system: Advantages and perspectives of the carotid pulse wave registration.

The possibility and feasibility of using the single-layer flat-coil-oscillator (SFCO) technology-based vibration and vibro-acoustic sensors in diagnostic devices and biomedical studies of the cardiovascular system are discussed in this paper. Using an example of recording pulse waves of left carotid artery and their analysis, the information content of the data recorded by these sensors in a number of cases is shown-assessment of age-related changes in the stiffness of the vascular wall, assessment of the dynamics of systolic volume, reflecting myocardial contractility, and rhythm disturbance (extra-systole and arrhythmia). These sensors are shown to be promising in recording heart sounds due to their high sensitivity. The possibility of assessing the dynamics of relaxation of the cardiovascular system after exercise (stress test) is shown. The advantages of using SFCO vibration and vibro-acoustic sensors are high sensitivity, ease of use, and no need to train specialists. These advantages open new perspectives for their implementation in mobile wearable "smart" devices for individual monitoring.

[The role and place of serologic research in the system of epidemiologic surveillance of meningococcal infection]. / Rol' i mesto serologicheskikh issledovanii v sisteme épidemiologicheskogo nadzora za meningokokkovoi infektsiei.

The results of serological surveys, carried out with a view to the detection of capsular meningococcal polysaccharides in the passive hemagglutination (PHA) test and covering 1,289 patients with systemic meningococcal infection, 221 patients with bacteriologically confirmed meningococcal nasopharyngitis, 2,820 persons in organized groups of children and adults with different epidemiological situation (including 650 carriers) and 4,050 residents of 8 cities with different morbidity levels, were analyzed. The patients, the carriers and the members of organized groups underwent multiple surveys. As shown in this study, the confirmation of the meningococcal etiology of the systemic forms of meningococcal infection (meningitis, meningococcemia) in all cases with the exception of children under 1 year of age, as well as the determination of the groups of meningococci, could be achieved in the PHA test twice as frequently, i.e. in 60-70% of cases, as with the use of the bacteriological method. The same regularities were observed in nasopharyngitis. The conclusion was made on the possibility of using the PHA test for more exact determination of the group of meningococci, prevailing at the initial stage of diseases, this determination playing an essential role in the epidemiological surveillance. The data obtained as the result of serological surveys in organized groups may lead to conclusions on the circulation of meningococci and their group composition, thus showing the necessity of profound epidemiological study with ensuring epidemic-control measures. The selective serological study of some hundreds of donor sera is not expedient in big cities, as it provides no data on the circulation of meningococci there.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparative evaluation of different meningococcal group-specific erythrocyte diagnostic kits in passive hemagglutination test]. / Sravnitel'noe izuchenie razlichnykh meningokokkovykh gruppospetsificheskikh éritrotsitarnykh diagnostikumov v reaktsii passivnoi gemaggluitinatsii.

The comparative evaluation of the sensitivity and specificity of serogroup A, C, Y meningococcal antigenic preparations obtained by different methods was carried out by means of the passive hemagglutination test. In case of group 0 (I) human red blood cells sensitized with serogroup A and C vaccinal preparations obtained by Gotschlich's method (designated as A-1 and C-1) were used. In the other case formalin-treated sheep red blood cells sensitized with group-specific polysaccharides obtained by alcohol precipitation from the cultural fluid of group A, C and Y meningococci with subsequent heating (designated as A-2, C-2, Y) were used. Titrations with commercial immune rabbit sera showed that both variants of the antigenic preparations were similar in their specificity and sensitivity. In patients with the symptoms of meningitis the diagnostic titer was 1:40 for preparations A-1, C-1 and 1:80 for preparations A-2, C-2 and Y. The results of the examination of 164 patients (220 serum specimens) demonstrated that these preparations were of equal diagnostic value.

[Serologic studies of patients with meningococcal nasopharyngitis]. / Serologicheskie issledovaniia u bol'nykh meningokokkovymi nazofaringitami.

The results of the serological examination of 156 patients with bacteriologically confirmed meningococcal nasopharyngitis are presented. For control 221 patients with acute respiratory diseases and 345 healthy persons from groups having no registered cases of meningococcal infection were examined. The passive hemagglutination test with serogroup A and C polysaccharides revealed the presence of antibody titers between 1:20 and 1:640 in 67.3% of nasopharyngitis patients and antibody titers not exceeding 1:40 in 11.3-11.6% of persons in the control groups. The time course of antibody formation in nasopharyngitis was similar to that in generalized forms, but response was less pronounced: the maximum response was observed on days 5-10, and the decrease of the antibody level by day 20. In 47 foci of meningococcal infection the etiology of the disease was serologically confirmed on the first day of an epidemiologist's visit to the focus in 62.2% of 162 nasopharyngitis patients and in 36% of patients with acute respiratory diseases.

[Epidemiological evaluation of the serological grouping of meningococci]. / Epidemiologicheskaia otsenka serologicheskogo gruppirovaniia meningokokkov.

Use of the precipitation and hemagglutination inhibition tests to determine the serological group of 114 meningococcus strains which cannot be grouped by agglutination slide permitted to establish the serological group of 56% of the strains, this pointing to the greater diagnostic value of these tests. Nevertheless, 70% of 307 strains isolated from carriers could not be referred to any of the determinable groups (A, C, X, Y, and Z). Strains (417) isolated from the cerebrospinal fluid of patients with meningitis were grouped depending on the epidemic curve: only half of the cultures could be classified in sporadic cases, but from 80 to 100% of the strains were classified at the "peak" of the meningitis incidence rise. This rise was connected with increase of the incidence of cases caused by meningococcus, group A; at the decline these strains were eliminated, and cases due to the rarely encountered serological groups and nongrouping strains occurred. Marking meningococc by serological groups proved to be of no use for detection of epidemiological relations between the infected persons.

[Detection of the etiologic structure of generalized and localized forms of meningococcal infection using the passive hemagglutination test]. / Vyiavlenie étiologicheskoi struktury generalizovannykh i lokalizovannykh form meningokokkovoi infektsii s pomoshch'iu reaktsii passivnoi gemaggliutinatsii.

Preparations of formalin-treated erythrocytes sensitized with meningococcus polysaccharides of serological groups A, C, X, Y, and Z were used for the purpose of examination of patients with meningococcus infection; these preparations were highly specific in the tests of precipitation, hemagglutination and hemagglutination inhibition. Indirect hemagglutination test with the sera of 99 patients suffering from generalized forms of meningococcus infection was conducted with the mentioned preparations in Moscow and Novosibirsk in 1974--1975 when a stable morbidity decline was noted in these towns after an epidemic rise. The diagnostic value of this test was confirmed: it permitted to diagnose meningococcus etiology beginning from the 5th day of the disease and to decipher it from the aspect of individual serological groups. As shown, the incidence of cases caused by serological group A, reaching 87% at the height of the epidemic rise, fell to 49.5% at the stage of decline. Cases caused by group Y which was not encountered formerly were revealed in 16.2% of the patients. Among 127 patients with miningitis of nonmeningococcus etiology meningococcus antibodies to groups A and Y were revealed with the same frequency (in titres of not over 1 : 20--1 : 80), but the leading role of serological group A in the etiology of the manifest forms permitted to draw a conclusion on the presence of a higher invasiveness in the strains of group A.