The article is devoted to the study of the hygienic state of the oral cavity and the assessment of periodontal tissues of younger schoolchildren against the background of a complex of preventive measures and dental education, which was carried out at the individual and group level in the conditions of a school dental office and health lessons in classes. The study covered 112 schoolchildren. The dynamics of the hygiene index according to Fedorov-Volodkina and the PMA index depend on the shape of the cutting of the working field of the toothbrush, which allows us to offer active use of the “eXceed™” brushes, which have crissCross™ bristles. The high efficiency of hygienic education of schoolchildren based on the comprehensive conduct of dental health lessons and the use of oral hygiene items was established. At the same time, health lessons must be held two times a week for 30 minutes, only 8 lessons per cycle with additional health lessons for teachers and parents once a month for six months. The use of an integrated approach in the controlled hygienic education of schoolchildren through regular dental lessons for schoolchildren, teachers, parents contributes to the development of sustainable manual skills in oral care and makes it possible to recommend the opening of a dental office to the school administration.

Obesity in children is an urgent problem due to its “epidemic” growth throughout the world, involvement of various organs and systems in the pathological process, progressive course and poor prognosis. In many countries of the world, as well as in Russia, there has been an increase in the number of children with overweight and obesity. The article presents a review of literature data on the epidemiology of obesity in children and adolescents in the world, in Russia and Yakutia. The relationship of obesity with ethnic (racial) affiliation was shown, namely, the frequency of overweight and obesity, as well as associated metabolic complications, is higher in children of Africans, Hispanics and Asians, compared with a group of white children. A high prevalence of obesity in children was noted in the countries of East and South Asia, North Africa, and India, China and the United States are considered the leaders of countries in obesity. In Russia, there has been an increase in obesity in the Northwestern, Volga, Urals, and Central Federal Districts. According to the gender composition, the predominance of obesity in boys was noted both in Russia and around the world. By age, there was a trend towards earlier obesity in children of preschool and primary school age. According to the prevalence of urban-rural obesity, no clear trend is shown. In China, a predominantly urban population is noted, while in the United States it is rural. In Russia, a higher prevalence of obesity among the child population is noted in urban areas. When distributing the examined children with obesity into urban and rural in Yakutia, and according to the data of various Russian authors, a predominance of urban children was noted. There has been an increase in obesity in children and adolescents in the context of the COVID-19 pandemic, both in Russia and around the world. Also, a more severe course of the disease has been proven in patients who are overweight and obese.

The authors conducted a study of the prevalence and features of the course of endemic goiter in the Republic of Sakha (Yakutia). According to the classification, the area is considered endemic for goiter if a goiter-altered gland is observed in more than 10 % of the population. There are light, medium and severe goiter endemias. It was revealed that, on average, the prevalence of endemic goiter in the republic is 28 %, which corresponds to the average severity of endemia, but the level of endemia is heterogeneous: there are areas of Yakutia with a severe degree. The peculiarities of endemic goiter in the Republic of Sakha (Yakutia) should also include the predominance of euthyroid forms (92.8 %) and a high (up to 57.3 %) proportion of thyroid nodules in areas with severe endemia. An important feature is the significant frequency of histologically confirmed thyroid malignancies: 8.2 % of the number of operated. In addition to the lack of iodine and a number of other trace elements in the environment, the body as a whole and, in particular, the thyroid is affected by a number of specific features of Yakutia: extreme temperature and light conditions, pronounced seasonality of climate, anomalies of geomagnetic fields. The predominance of nodular formations of the thyroid gland in endemic areas, especially polynodose (up to 86.9 %), is one of the prerequisites for the more frequent development of cervical-thoracic goiter. Cervical-thoracic goiter requires surgical intervention due to manifestations of compression of the mediastinal organs or the threat of their development. Unlike cervical goiter, with cervical-thoracic goiter, there is a problem of differential diagnosis with other intra-thoracic formations.

   The Russian Federation (RF) refers to countries with proven natural iodine deficiency. The relevance of this topic is due to the fact that iodine deficiency diseases (IDD) rank first in prevalence among thyroid diseases, and represent pathological conditions that develop as a result of iodine deficiency in the diet, which can be prevented by normalization of its consumption.

   The purpose of the work is to clarify the relevance of already known information about iodine deficiency states by reviewing modern literary material. About 2 billion people live in conditions of natural iodine deficiency. More than 70 % of the territories of the Russian Federation are geochemical provinces with iodine deficiency, currently there are noticeable disparities between individual regions in the country. Among Russians, there was a decrease in iodine consumption to an average of 50-80 micrograms per day, which is 3 times less than the established norm (150-250 micrograms). With a high prevalence of iodine deficiency, foci of severe iodine deficiency were found in some regions of the North, Siberia and the Far East (in the Republics of Sakha (Yakutia), Tyva, Khakassia, and some districts of Arkhangelsk Oblast). Salt iodization is recommended by WHO and UNICEF as a universal and highly cost-effective method of eliminating IDD on a global scale. In many countries of the world, it has become possible to achieve a significant reduction in the incidence of thyropathies associated with iodine deficiency in the diet by legislatively adopting a decision on mandatory salt iodization, but in the Russian Federation the problem persists.

The study used the SF-36 questionnaire, suitable for use in the general and clinical populations, to compare health status between populations and between diseases. In the world literature, data on the quality of life of the Evenks according to the SF-36 questionnaire were not found. The quality of life of the Evenks associated with the state of health has been studied. To conduct a survey of the adult population of the village of Zhilinda, a sample representative of gender and age was formed in the amount of 150 people, of which 69 were men (46 %) and 81 were women (54 %). The average age of the surveyed women was 43.3 ± 16.6 years, men - 41.1 ± 16.4 years. Gender comparisons were made. The questionnaire contained the following sections: general information, family income, living conditions, employment, nature of work, satisfaction with medical care and a medical examination card, consisting of sections: physical activity, smoking status, consumption of alcoholic beverages, Rose questionnaire, frequency of consumption of certain foods, quality of life questionnaire. To compare the quality of life of the inhabitants of the village of Zhilinda, the base of population values of the transformed indicators of the SF-36 questionnaire from the city of Yakutsk was used. The inhabitants of Zhilinda revealed low levels of physical functioning. The following factors were associated with decreased physical functioning: female gender, increased age, college education, increased body mass index, low income, and presence of joint/spine pain. Social functioning decreased with dissatisfaction with housing, vitality with low income, general health with an increase in the number of cigarettes smoked. Evenki quality of life can be significantly improved by reducing body weight, quitting smoking, treating diseases of the musculoskeletal system, increasing income and improving living conditions.

   In order to search for effective means that increase the body’s resistance to pathogens the analysis of literature data on the composition, antioxidant and antibacterial properties of kumis – a traditional food product in the North. The study was conducted using Information and Search (PubMed) and Library Databases (eLibrary).

   The beneficial properties of kumis are due to the unique composition of mare’s milk, which in terms of the content of protein, milk sugar and mineral salts is closer to that of a woman’s, unlike cow’s. The microbiocenosis of kumis is dominated by lactic acid bacteria and yeast, producing antibiotic substances and vitamins during fermentation. The anti-inflammatory effect of kumis is due to its low molecular weight antioxidants in the composition of kumis, which inhibit the generation of ROS – LPO initiators. Under the action of kumis, there is a decrease in pro-inflammatory interleukins, with a parallel increase in anti-inflammatory cytokines. Considering the fact that one of the most dangerous complications in coronavirus infection is a cytokine storm, data on the effect of kumis on the cytokine status are of particular relevance. The intake of mare’s kumis has a positive effect on the indices of erythrocytes and their morphology, as well as normalizing the leukogram, and has a positive effect on the body’s immune system. The use of one-day Yakut kumis contributes to the correction of secondary immune deficiency states and is a promising product in the prevention of a number of diseases, including viral ones, not excluding the prevention of SARS-CoV-2. Kumis, as a functional food, preserves and improves health and can be recommended for daily consumption in food diets by all age groups.

   The article presents a study on the control and dynamics of heart rate in athletes involved in sled jumping. The relevance of the study lies in the fact that athletes of various levels were controlled. Many researchers study the physiological processes of athletes in various sports, but the reaction of an athlete’s body to jumping over sleds still remains unexplored.

   The purpose of the study: control and dynamics of heart rate in athletes of different qualifications. Materials and methods. The study was carried out using a Polar FT80 heart rate monitor. The study involved athletes of various skill levels from dischargers to the master of sports of the Russian Federation. Results. Indicators of the dynamics of heart rate of athletes of different skill levels have significant differences and features. The average heart rate in athletes of the masters of sports of the Russian Federation and candidates for the master of sports increased sharply until the fortieth jump over the sled, then stabilized. A significant increase in heart rate from the moment the jumps began and at the end of the first 20 sledges was observed in athletes under the numbers of the dischargers. Conclusion. The indicators of heart rate in the process of performing sled jumps in athletes of different sports qualifications were revealed. The heart rate range is determined in the value of 170-190 beats / min, at which it is possible to overcome the largest number of sleds.

In the Republic of Sakha (Yakutia), persistently high incidence rates of CVH remain, as well as mortality rates from complications of liver cirrhosis (LC), as the most common complication. It seems relevant to search for genetic predictors of early development of severe complications in CVH patients in the Yakut population. They can be polymorphic variants of the genes for endothelial dysfunction and oxidative stress NOS3 and CYBA. The collection of representative material was carried out on the basis of the Infectious Diseases Department of the State Budgetary Institution of the Republic of Sakha (Yakutia) of the Yakut Republican Clinical Hospital. In total, 47 DNA samples of patients with chronic viral hepatitis В and liver cirrhosis in its outcome, hospitalized in the Infectious Diseases Department from September 2020 to June 2021, were studied. The control group consisted of patients not infected with viral hepatitis, as well as without pathology of the hemostasis system. The experimental part of the study was carried out by real-time PCR with the melting of hybridization products with a fluorescent label, followed by analysis of the RealBest-Genetics melting curves. As a result of the PCR- RFLP analysis of the rs1799983 polymorphism of the NOS3 gene among patients with chronic viral hepatitis, the T allele frequency was 0.09, and the G allele frequency was 0.91. The frequency of the C allele of the rs2070744 polymorphism of the NOS3 gene was 0.05, the frequency of the T allele was 0.95. The frequency of occurrence of the major allele C of the rs4673 polymorphism of the CYBA gene was 0.78, the minor allele T was 0.22. The relationship between the carriage of polymorphisms of these genes and the disease was not found. However, it was found that carriers of the mutant allele for the rs1799983 polymorphism of the NOS3 gene were 1.81 times more likely to develop liver cirrhosis (95 % CI, odds in the groups 0.176–0.098), carriers of the mutant allele for the rs4673 polymorphism of the CYBA gene were more likely to develop cirrhosis liver cirrhosis is 1.9 times higher (95 % CI, odds in groups 0.211–0.111), in carriers of the mutant allele for the rs2070744 polymorphism of the NOS3 gene, the probability of developing liver cirrhosis is 2.03 times higher (95 % CI, odds in groups 0.181–0.089 ). In carriers of the mutant allele for the rs4673 polymorphism of the CYBA gene, shortening of PT and APTT (17.79±10.26 and 35.13±7.82 sec) is observed, which may indicate a greater tendency of this group to hypercoagulability. In carriers of the mutant allele for the rs2070744 polymorphism of the NOS3 gene, shortening of PT and APTT (11.56±0.99 and 30.12±4.45 sec) is observed, which may also indicate a greater tendency of this group to hypercoagulability.