The thymus is the central organ of the immunogenesis, the functioning of which determines the protective reactions of the organism. Various stressors can influence the immune organs. One of these factors is exposure to low temperatures. The aim of this research was studying the effect of experimental cold stress on the morphological and functional state of rat thymus using morphometric analysis. The cold exposure was done by placing the rats in individual cages in a refrigeration chamber at a temperature of -10 ± 20 °C for 1 hour at the same time of day for 7, 14, 21, and 30 days. Histological examination of thymus preparations stained with hematoxylin and eosin; on the 7th day after exposure to cold, the area of the cortical substance is significantly reduced compared with the control group, while the area of the medulla tends to increase. Analysis of the cell composition showed an increase in the number of epithelia-reticular cells in the subcapsular zone and a slight decrease in the number of lymphocytes. On the 14th day of exposure, the areas of cortical and medulla and the cortical-cerebral index do not differ from the indicators of intact control. Morphometric counting of cellular elements showed an increase in the number of lymphocytes, epithelia-reticulocytes, and macrophages. After 21 days of the experiment, data on the relative areas of cortical and medulla shows a significant decrease in the rate compared with all the first groups. The counting of cellular elements during this period showed marked changes observed in all morphological and functional zones of the thymus. In the subcapsular zone, there is a sharp decrease in the number of dividing lymphocytes. The number of epithelia-reticular cells is increased relative to the norm. There is frequent detection of apoptotic bodies and fat cells. In the medulla, there is an increase in the number of epithelia-reticulocytes compared with the 7th and 14th day. On the 30th day after exposure, the areas of cortical, medulla, and cortical-cerebral index remained at the same level as on the 21st day. There is a significant decrease in epithelia-reticular cells in the subcapsular zone, a significant decrease in the cortical substance and the cortico-medullary zone compared with all groups, and a significant increase in their number in the medulla. Hassall’s bodies are characterized by pronounced degenerative changes in epithelia-reticulocytes with cellular debris. In the subcapsular zone, a reduced number of cells with mitosis figures is maintained. It was established that as a result of cold stress on days 7, 21 and 30, there is a redistribution of volume and cellular composition, various structural and functional zones, indicating a decrease in the functional activity of the thymus, an increase in the death of lymphocytes by apoptosis, a decrease in mitotic activity, and accumulation of macrophages. Morphological and functional data of the 14th day of the experiment indicate the development of compensatory-adaptive changes in the thymus on the cold effect, manifested in the form of activation of cell division in the cortical substance and the cortical-medullary zone.

Тенденции развития науки и образования РАЗДЕЛ XX. МЕДИЦИНА Маркова И.А., Уарова М.Ю., Аржакова Л.И. Изучение возрастных особенностей антропометрических и физиометрических показателей подростков раннего и позднего пубертантного возраста, проживающих в Республике Саха(Якутия) ФГАОУ ВО «СВФУ имени М.К. Аммосова» (Россия, Якутск

The aim of this study was to assess the anthropometric and physiometric indicators with an analysis of the body composition of young Yakuts of early and late puberty, living in the Republic of Sakha (Yakutia) (RS(Y)). Materials and Methods: A total of 184 indigenous youths aged from 14 to 17 years, permanently residing in RS(Y), were examined. The study used generally accepted methods: anthropometry, dynamometry, spirometry, caliperometry, and body composition assessment by bioelectrical impedance analysis. Results: Among Yakut youth living in RS(Y), an increase in musculoskeletal mass and a decrease in fat mass was observed in groups aged 14 to 17. In the period from 14 to 17 years, Yakut youth show significantly increased indicators of dynamometry, deadlift and vital lung capacity. The data above are accompanied by a decrease in the indicators of the content of fat mass and an increase in lean body mass, musculoskeletal mass and body cell mass. There is growth not only in skeletal muscles and skeleton, but also in the mass of internal organs. The data obtained will be used to develop an interval classification of body composition parameters for males of different ages in order to develop standards of physical development specifically for people living in RS(Y).

The Republic of Sakha (Yakutia) belongs to the regions with significant iodine deficiency in nature and is characterized by a high prevalence of thyroid pathology among children and adults. Due to the fact that the diagnosis of thyroid pathology is associated primarily with ultrasound examination, the deepening of information about the regional features of the absolute and relative indices of the anatomical norm of the thyroid gland is a rather urgent scientific task. The aim of the study was to study the normal ultrasound anatomy of the thyroid gland in young men and women of indigenous nationality living in the Republic of Sakha (Yakutia). The authors carried out an ultrasound examination of 110 students (including 66 girls and 44 boys) of the indigenous nationality, aged 17 to 21 years. Sexual dimorphism of the thyroid gland volumes of the indigenous population of the Sakha Republic (Yakutia) was established. The minimum, maximum and average values of the thyroid gland volume in boys are higher than in girls. The shape of the lobes of the thyroid gland in girls and boys of the indigenous population in most cases is close to a regular ellipsoid. The most common form of a regular ellipsoid is in 53.8% of cases in girls and 46,4% of cases in boys. The shape of an ellipsoid flattened in the frontal plane was visualized to a greater extent in boys (35,4%) and in 29,6% of girls, an ellipsoid flattened in the sagittal plane was determined to a lesser extent, in 3,8% and 4,1% cases, respectively. Thus, the quantitative characteristics of the thyroid gland obtained as a result of the study made it possible to reveal the features of the vital anatomy of this organ, variable in its anatomy, in the indigenous population of the Republic of Sakha (Yakutia), depending of the sex. The obtained results have territorial referential significance.

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