93 ± 0.32 and t2 = 26.21 ± 0.28. The experimental results show that the simulation system could track the state and the movement of otolith in real-time, which is of great significance for understanding the diagnostic mechanisms of BPPV evaluations and improving the diagnostic method.A method for detecting HBV DNA in peripheral blood at low viral load using real-time PCR was developed and its significance in identifying HBsAg-negative viral hepatitis B was evaluated. When developing the method, blood plasma samples and liver tissue biopsy material were used from 128 patients living in St. Petersburg, in various regions of the Russian Federation, as well as in the Central Asia countries. We also used blood plasma samples from 96 pregnant women and 37 hemodialysis center patients living in Northwestern Federal District, 199 foreign citizens undergoing medical examination to obtain work permits at the Directorate for Migration in the Northwestern Federal District, 397 conditionally healthy people living in the Socialist Republic of Vietnam. HBV was detected by nested PCR. Analytical sensitivity was tested using the stepwise dilution method. According to the method developed by us, at the first stage, the HBV DNA is amplified using at the first stage oligonucleotides flanking the genome regio and rare in the Russian Federation, circulating in other world regions. The method can be used to detect HBV in risk groups, in the population, as well as in screening blood donors in order to ensure the blood transfusions safety.The aim was to determine how often the PCR method is used in different laboratories in Russia. In 2018, we conducted a questionnaire survey in diagnostic laboratories of medical organizations and the Centers of Hygiene and Epidemiology that performed PCR studies to identify microorganisms of the genus Bordetella in all 85 Russian regions. We found that in 2013 the PCR was used in 33 (38.8%) regions, but in 2017 the number of regions increased to 64 (75.3%). During 2013-2017 the study has not been applied in 21 regions. The number of PCR tests performed in the laboratories of medical organizations was significantly different. There has been an increase in the number of tests for the diagnosis of pertussis among people with clinical signs of infection and among contact persons in foci of infection. Compared to the Centers of Hygiene and Epidemiology, in medical organizations the rate of introduction of the PCR was higher. Between 2013 and 2017 the proportion of samples containing DNA B.pertussis decreased, but the proportion of samples containing DNA of other representatives of the genus Bordetella increased. Moreover, in the case of isolation DNA Bordetella spp. clinicians diagnose «Whooping cough, other unspecified organism», since there is no information on the species of the pathogen. Thus, in order to improve the diagnosis of pertussis, it is necessary to optimize PCR tests by including target genes that allow to identify of currently relevant DNAs of different representatives of the genus Bordetella.The microbiome of oral cavity in healthy people and patients with periodontitis was analyzed to determine their adhesive properties and the ability to form biofilms. The study involved 2 groups healthy, 18 people, and an experimental group, 20 patients with chronic generalized periodontitis moderate severity of the disease. The average age of the studied people was 35-45 years. Material – dental plaque, scraping from the mucous membrane of the back of the tongue, the contents of the periodontal groove and periodontal pocket, as well as oral fluid. The main method of diagnostic was bacteriological. The average adhesion index (AAI) was used to determine adhesion level of microorganisms to epithelial cells of oral cavity’s mucous membrane. The microbiota’s ability to form biofilm was tested on glass and plastic surface. The microbiota of oral cavity of patients with periodontitis was characterized by decrease in the frequency of bacteria of the genera Streptococcus, Peptostreptococcus, Peptococcus, and an increase in Staphylococcus aureus, Veillonella spp., Bacillus spp. The microbiota of the oral cavity of patients with generalized periodontitis has a greater ability to adhere to the cells of the mucous membrane than in healthy people, while their ability to form biofilms and exhibit pathogenic properties is enhanced. The biofilm formation of microorganisms in healthy and sick people differs both on glass and on plastic surfaces.1235 strains of Staphylococci isolated in a multidisciplinary children’s clinic were analyzed. The species and antibiotic resistance of Golden and coagulase-negative Staphylococci were studied. The most frequently identified species were S. aureus-36.06%, S. epidermidis-23.05%, S. haemolyticus-19.7%, S. hominis-14.03%. Phenotype methicillinsensitive strains had 48.9% of the allocated staphylococci, while metitillinrezistentnykh S. aureus was identified in 25.6%, and coagulase-negative staphylococci methicillinresistant- 63.2 per cent. The frequency of associated resistance to aminoglycosides, fluoroquinolones, macrolides and tetracyclines have metitillinresictant strains 92,7%, 78,3%, 83,4% and 52,05% respectively, resistant Staphylococcus and coagulase-negative staphylococci were similar. The minimum number of resistant strains was found in relation to daptomycin, no strains resistant to vancomycin and linezolid were found. Antibiotic resistance of staphylococci in children’s hospitals is determined by the presence of the mecA gene or sensitivity to cefoxitin and does not depend on the type of strain.Platelet function testing is widely used to diagnose disorders of the cellular link of hemostasis. The study of platelet aggregation activity is relevant for the prevention of thromboembolic complications in atrial fibrillation and monitoring the effectiveness and safety of therapy. In this study, a comparative analysis of spontaneous and stimulated platelet aggregation in groups of patients with two types of atrial fibrillation was performed – paroxysmal and persistent. The effect of β-adrenoblocker therapy on platelet aggregation activity in patients with atrial fibrillation was also studied. Platelet aggregation activity was studied using the method of G. Born in the modification of Z.A. Gabbasov on a two-channel laser analyzer „Biola”. Collagen at a concentration of 2 mg / ml and adrenaline in a concentration range of 2.5-10 μg / ml were used as aggregation-promoting agents. It has been established that spontaneous aggregation potential and collagen-induced platelet aggregation depend on the type of atrial fibrillation, as well as on the presence or absence of β-blockers in therapy. The response of platelets to stimulation with adrenaline depends, first of all, on the type of atrial fibrillation and the concentration of adrenaline in the reaction medium. The most significant changes were noted in the group of patients with a paroxysmal form atrial fibrillation, taking β-blockers in therapy.One of the urgent problems of nursing premature babies is the timely prediction, diagnosis and treatment of anemia, the frequency of which reaches 90%. Of particular importance is the study of reticulocytic blood parameters in deep-premature newborns, since the correct assessment of hemograms is crucial in the management of this category of children. To determine the characteristics of red blood cells and reticulocyte parameters of venous blood hemogram in premature newborns 24-32 weeks of gestation in the dynamics of the neonatal period. 111 newborns were examined at 24-32 weeks of gestation in the early neonatal period (on day 3-7) and at the age of 1 month of life. Along with standard diagnostic procedures, in accordance with current clinical recommendations and standards, 28 parameters of erythrocyte and reticulocyte hemogram parameters were determined for children. Venous blood was examined using an automatic hematological analyzer ADVIA 2120i, Siemens, USA. In deep-premature newborns in the early neonatal period, there is a high activity of erythropoiesis, respectively, the severity of respiratory and metabolic disorders with rejuvenation of reticulocytic subpopulations. Negative values of Delta hemoglobin were found against the background of a decrease in the average amount of hemoglobin in reticulocytes in children 24-27 weeks of gestation, which characterizes the lowest values of iron availability for erythropoiesis in this category of newborns. It is shown that a decrease in reticulocyte counts and normochromia in all examined newborns by the age of one month are accompanied by high levels of immature reticulocyte fraction, while a third of children still have limited iron availability for erythropoiesis.The morphofunctional state of erythrocytes significantly changes by the onset and progression of various diseases, as well as in critical conditions, injuries, accompanied by severe tissue damage. This leads to a violation of microcirculation and has an effect on hemorheology in general. In connection with this, there is a need for the development of adequate methods for assessing the functional activity of erythrocytes. The aim of the work was to study the possibilities of laser interference microscopy in the analysis of the functional state of erythrocytes. The results allowed us to quantify the state of the phase height and phase diameter of erythrocytes. Analysis of the surface nanostructure gave a qualitative assessment of the functional activity of cells. The following patterns were revealed the action of adrenaline causes the appearance of echinocytes with an increase in phase height and decrease phase diameter and the appearance of spicules on the surface of cells. The action of cortisol leads to a decrease in the phase height and the phase diameter with the appearance of numerous loosening of the structure of the cell surface. Moreover, the traditional method of analyzing the distribution of erythrocytes in a population by morphology (discocytes, stomatocytes, and degeneratively altered cell forms) did not reveal statistically significant differences. Thus, the results indicate that the interference microscopy method allows a qualitative assessment of the morphofunctional activity of native cells. This increases the information content of the analysis and leads to the objectification of data on the functional capabilities of erythrocytes.The study was performed in 9 cancer patients with sepsis. A clinical blood test of patients with sepsis was accompanied by a neutrophilic leukemoid reaction, with the appearance in the differential count of white blood cells of young cells (myelocytes, metamyelocytes). According to the literature, it is shown that in severe sepsis, a local infection is accompanied by systemic of neutrophil activation (NF). Moreover, excessive activation and location of NF in the microvasculature, especially its young forms and the formation of extracellular trap networks (NETs), can contribute to pathological manifestations of multiple organ failure and thrombosis.The characterization of the functioning of the blood circulatory system of the organism in terms of its ability to adapt to environmental conditions includes the definition of adaptive potential (AP). The purpose of the study is to supplement the idea of adaptive potential in the aspect of its association with indicators of the hypothalamus-pituitary-gonadal system in healthy men living in the climatic conditions of the Arctic zone of the Russian Federation. The study involved 94 apparently healthy men. Serum hormone levels of the hypothalamus-pituitary-gonadal system were determined by enzyme-linked immunosorbent assay. Percent of men with satisfactory adaptation was 67%. Markers of increased tension in adaptive mechanisms include a decrease in values of testosterone, sex hormone -binding globulin, and testosterone / estradiol ratio. It has been shown that in individuals with a 4-th degree of adaptive potential, the activity of the pituitary-gonadal and the pituitary-adrenal cortex systems participating in the maintenance of the circulatory system is suppressed.