[Health of foreign students - representatives of diasporas as a social problem].

The article is devoted to the analysis of modern approaches to the problem of the health of foreign students who are educational migrants and need medical care, taking into account their current social status and status in the territory of the Russian Federation. The undermining of health, significant psycho-emotional tension and, in general, worries about maintaining health can affect the learning process, therefore it is necessary to determine in whose area of responsibility the health of educational migrants is: whether they themselves are obliged to monitor their condition and organize medical care, whether the university should participate in the organization of medical commissions and examinations, or diasporas, whose members are often foreign students, may have these powers.

[The population health and attitude to it in conditions of instability].

The article considers issues of attitude of modern man to one's own health, both physical and mental in conditions of instability. The results of sociological studies implemented in 2021-2022 among the population of the Kursk Oblast are presented. The results reflect personal characteristics and attitudes to health, in particular in conditions of complex epidemiological situation and changes in population behavior in area of health saving in conditions of complicated geopolitical situation.

[Oxidative stress in the pathogenesis of stroke and its correction]. / Okislitel'nyi stress v patogeneze tserebral'nogo insul'ta i ego korrektsiya.

We reviewed the role of oxidative stress (OS) in the pathogenesis of ischemic (IS) and hemorrhagic stroke (HS). OS plays a major role in programmed cell death, increased permeability of the blood-brain barrier, astroglial and microglial activation, and local inflammatory response. We also reviewed the current state of neuro- and cytoprotection studies and their translation in clinical practice. With respect to experimental and clinical data the efficacy of long term administration of multimodal cytoprotective drug with antioxidant effect - ethylmethylhydroxypyridine succinate (Mexidol) is discussed during the acute and early recovery period after stroke.

[Results of clinical studies of the efficacy and safety of the use of ethylmethylhydroxypyridine succinate in patients with chronic cerebral ischemia]. / Rezul'taty klinicheskikh issledovanii effektivnosti i bezopasnosti primeneniya preparatov etilmetilgidroksipiridina suktsinata u patsientov s khronicheskoi ishemiei golovnogo mozga.

Chronic cerebral ischemia (CCI) is a common syndrome that, in the absence of adequate therapy, is characterized by a progressive course, an increase in cognitive, emotional, motor and other disorders, eventually leading to persistent disability of the patient. In the treatment of patients with CCI, the use of drugs with a multimodal neuroprotective effect is indicated. The results of the analysis of a series of clinical trials of the drugs Mexidol and Mexidol FORTE in patients with CCI are presented. The effects in relation to cognitive, emotional, asthenic, vegetative and other manifestations of CCI are considered. It is concluded that it is advisable to consistently use the drugs Mexidol and Mexidol FORTE in such patients.

The healthy life-style in the system of value orientations of student youth.

The article is devoted to the issue of studying attitude of students to their own health, to healthy lifestyle, to regional health care system. The results of sociological survey carried out in February-April 2021 are presented. The factors and conditions contributing to preservation and strengthening of youth health were identified. The conclusions and recommendations concerning formation of value orientations for healthy lifestyle of students were formulated.

[The characteristics of healthy life-style of rural senior high-school students: social technological approach].

The article considers one of the most actual issues of social policy of the Russian state - the rising generation health. The maintenance of health of rural senior high-school students is considered in chronotopic dimension of key factors and main parameters of healthy life-style during the most dynamic period of their growing up. The rural lifestyle has its own specifics, that are reflected in organization and implementation of healthy life-style at individual and institutional levels and acquires characteristic features at its implementation in gender context. The article presents the results of an attempt to analyze, on the basis of empirical study data, dynamics of changes of attitude to healthy life-style of rural senior high-school students in 7-11 grades of rural schools and to assess impact of main factors and changes of key parameters. The obtained data are oriented to development of health-preserving social technologies at individual and institutional levels in municipalities.

[THE ROLE OF THE FAMILY IN SHAPING ATTITUDES TO YOUTH HEALTH IN THE CONTEXT OF THE PANDEMIC].

The family plays an important role both in the life of each individual and in society as a whole. In conditions of instability, risks, and increased epidemiological burden, the level of intra-family trust has increased, including in matters of health care. The article analyzes the sociological studies conducted during the first and second waves of the pandemic, on the basis of which it is determined that the family forms an attitude to health, which can be manifested from the standpoint of rational and irrational health-oriented behavior.

[IMPACT OF LIFE DIFFICULTIES ON HEALTH OF TEACHERS OF HIGHER SCHOOL].

The rapidly changing conditions of a modern unstable society change all spheres of human activity, including education. The increasing complexity of the educational process leads to an increase in the burden on higher education teachers. The implementation of pedagogical activities is accompanied by a number of difficulties, some of which are largely experienced by teachers, difficult to solve and become life difficulties. Life difficulties related to professional activity affect the state of health and worsen it. The work attempts to identify the relationship between the life difficulties of university teachers and the presence of chronic diseases.

[SOCIAL-MEDICAL RISK FACTORS OF IMPLEMENTATION OF MATRIMONIAL BEHAVIOR].

The article analyzes the features of the implementation of matrimonial behavior (on the example of Kursk region). Some results of the study of the impact of adverse social and medical factors on the institution of family and marriage are presented. The aim of the study was to study the specifics of the matrimonial behavior of the population in conditions of social and medical problems. The methodology of the study was based on the theoretical analysis of the concepts of divorce. A sociological survey was conducted by questionnaire survey of the inhabitants of the Kursk region. The study, based on the analysis of the causes of family breakdown, determined that the institution of family and marriage under the influence of social and medical risks of divorce is becoming even more unstable.

Irregularly timed electrical pulses reduce adaptation of retinal ganglion cells.

OBJECTIVE: Retinal prostheses aim to provide visual percepts to blind people affected by diseases caused by photoreceptor degeneration. One of the main challenges presented by current devices is neural adaptation in the retina, which is believed to be the cause of fading-an effect where artificially produced percepts disappear over a short period of time, despite continuous stimulation of the retina. We aim to understand the neural adaptation generated in retinal ganglion cells (RGCs) during electrical stimulation. APPROACH: Current visual prostheses use electrical pulses with fixed frequencies and amplitudes modulated over hundreds of milliseconds to stimulate the retina. However, in nature, neuronal spiking occurs with stochastic timing, hence the information received naturally from other neurons by RGCs is irregularly timed. We used a single epiretinal electrode to stimulate and compare rat RGC responses to stimulus trains of biphasic pulses delivered at regular and random inter-pulse intervals (IPI), the latter taken from an exponential distribution. MAIN RESULTS: Our observations suggest that stimulation with random IPIs result in lower adaptation rates than stimulation with constant IPIs at frequencies of 50 Hz and 200 Hz. We also found a high proportion of lower amplitude action potentials, or spikelets. The spikelets were more prominent at high stimulation frequencies (50 Hz and 200 Hz) and were less susceptible to adaptation, but it was not clear if they propagated along the axon. SIGNIFICANCE: Using random IPI stimulation in retinal prostheses reduces the decay of RGCs and this could potentially reduce fading of electrically induced visual perception.

Retinal ganglion cells: mechanisms underlying depolarization block and differential responses to high frequency electrical stimulation of ON and OFF cells.

OBJECTIVE: ON and OFF retinal ganglion cells (RGCs) are known to have non-monotonic responses to increasing amplitudes of high frequency (2 kHz) biphasic electrical stimulation. That is, an increase in stimulation amplitude causes an increase in the cell's spike rate up to a peak value above which further increases in stimulation amplitude cause the cell to decrease its activity. The peak response for ON and OFF cells occurs at different stimulation amplitudes, which allows differential stimulation of these functional cell types. In this study, we investigate the mechanisms underlying the non-monotonic responses of ON and OFF brisk-transient RGCs and the mechanisms underlying their differential responses. APPROACH: Using in vitro patch-clamp recordings from rat RGCs, together with simulations of single and multiple compartment Hodgkin-Huxley models, we show that the non-monotonic response to increasing amplitudes of stimulation is due to depolarization block, a change in the membrane potential that prevents the cell from generating action potentials. MAIN RESULTS: We show that the onset for depolarization block depends on the amplitude and frequency of stimulation and reveal the biophysical mechanisms that lead to depolarization block during high frequency stimulation. Our results indicate that differences in transmembrane potassium conductance lead to shifts of the stimulus currents that generate peak spike rates, suggesting that the differential responses of ON and OFF cells may be due to differences in the expression of this current type. We also show that the length of the axon's high sodium channel band (SOCB) affects non-monotonic responses and the stimulation amplitude that leads to the peak spike rate, suggesting that the length of the SOCB is shorter in ON cells. SIGNIFICANCE: This may have important implications for stimulation strategies in visual prostheses.

[Oogenesis of Mozambique tilapia. IV. Yolk formation]. / Oogenez mozambikskoi tiliapii. IV. Obrazovanie zheltka.

Yolk globules in developing oocytes of Tilapia mosambique are formed by two processes: 1) biosynthetical activity of oocyte organoides; 2) vitellogenin migration by micropinocytosis and its further transformation. Undoubtedly, yolk globules of endogenic and exogenic origin are fused. The primary yolk globules are spherical, and the secondary ones are lobular. The latter originate by incorporating the former. The fast growth of the late vitellogenic stage oocytes occurs as a result of active migration of primary yolk globules into the central part of the oocyte and as their association with the secondary yolk globules. In vitellogenic oocytes of T. mosambique no yolk vesicles (cortical granules), were found by any existing methods.

[Oogenesis of Mozambique tilapia. II. Synthesis of RNA and development of the nucleoli]. / Oogenez mozambikskoi tiliapii. II. Sintez RNK i razvitie iadryshkovogo apparata.

Using methods of light and electron microscopy and authoradiography, morphology and biosynthetic activity of nucleoli and RNA synthesis in developing oocytes of Tilapia mossambique were studied. In previtellogenic oocytes nucleoli are mostly composed of fibrils, while the granular component is poorly developed. 3H-uridine is poorly incorporated in their peripheral parts. With the start of vitellogenesis, fibrils and granules are seen randomly located throughout the whole volume of the nucleoli, with primary granule concentrations in their peripheral region. 3H-uridine is intensely incorporated in the whole volume of nucleoli, and the labeled RNA migrates to the cytoplasm. In early previtellogenic oocytes chromosomes are strongly labeled with 3H-uridine, and RNA quickly migrates to the cytoplasm.

[Oogenesis of Tilapia mossambica. III. The cytoplasm of previtellogenic oocytes]. / Oogenez mozambikskoi tiliapii. III. Tsitoplazma ootsitov perioda previtellogeneza.

Using methods of light and electron microscopy and of autoradiography, the morphology of cytoplasm in previtellogenic oocytes of tilapia mossambique was studied. Similar to other bony fishes, mitochondria at the early previtellogenic oocytes are mostly located in the perinuclear cytoplasm to be later distributed over the whole volume of growing oocytes. The Golgi complex is poorly developed. In the peripheral regions of the late previtellogenic oocytes, stickform mitochondria, pinocytotic vesicles and microvilli are observed, along with the perioocyte space formation. In the cytoplasm of previtellogenic oocytes polyribosomes appear. No differences in 3H-leucine incorporation intensity was noticed in oocytes of different previtellogenic stages. The characteristic feature of tilapia mossambique previtellogenic oocytes, in comparison with other bony fishes, is the presence of fat droplets in their cytoplasm.

[Oogenesis of Tilapia mossambica. I. Oogonia and meiotic prophase oocytes]. / Oogenez Mozambiksko'i tiliapii. I.Gonii i ootsity ranne'i profazy me'ioza.

Using light and electron microscopy and autoradiography, the morphology and synthesis of DNA, RNA and proteins in oogonia and early meiotic prophase oocytes in Tilaria mossabique were studied. According to dimensions and morphological features observed it is possible to distinguish between two groups of oogonia: large oogonia corresponding to type A spermatogonia of mammals, and small actively dividing oogonia, located in groups and identical to type B spermatogonia. The morphology of oogonia and of the early meiotic prophase oocytes well compares with the pattern described for other species of bony fishes. In the cytoplasm of these cells dense bodies, nuage-material, free ribosomes, large mitochondria with lamellar cristae and Golgi cisterns are available. In the oocyte nuclei at zygotene and pahytene stages 3H-thymidine incorporation was seen mainly into the nucleolus-associated chromatin. Besides, the formation of a heterochromatin cape and the synaptonemal complex was observed. Incorporation of 3H-uridine and 3H-leucine in the nuclei of these cells was very poor.