The article presents a historical insight with a review of the most important scientific results obtained at the Research Institute of Medical Problems of the North, to clarify the peculiarities of the general mechanisms of human organs and systems in their ontogenesis during life-span in the extreme environmental conditions of the Far North. The prevalence, risk factors and features of the clinical course of diseases of the cardiovascular system, gastrointestinal tract, and ENT pathology in various ethnic groups were studied. The pathogenetic mechanisms of immunoreactivity disorders were established. Differentiated approaches to the diagnosis and treatment of various forms and clinical and pathogenetic variants of allergies were developed. The specific relationships between indicators of carbohydrate and lipid metabolism and hormonal regulation were convincingly proven, which made it possible to solve practical problems of diagnosis, treatment and rehabilitation of patients in the northern regions.

The specific damaging effects on almost all functional systems of the child and adult body in the Far North conditions, namely, the newcomer population, with changes in the functional state of vital organs and systems, regulation, immunological reactivity, metabolism and adaptive capabilities were shown to occur.

Specific changes of many functional human systems in high northern latitudes, revealed as a result of long-term complex research, indicate not only the need for the discipline and scientific direction of “Northern Medicine” to be recognized, but also the importance of further detailed fundamental and applied research on studying the physiological data of body organs and systems in the environmental conditions of the North, risk factors and features of developing the pathology affected by disruption of adaptive processes, as well as other complex adaptive body responses during life-span in the conditions of the Far North.

Eosinophilic sialodochitis (or eosinophilic sialoadenitis, synonyms sialodochitis fibrinosa, Kussmaul’s disease) is a rare disease and is clinically manifested by recurrent swelling of the parotid and/or submandibular salivary glands, often accompanied by pain or itching over the affected glands, and the secretion of mucous plugs from the gland ducts due to obstruction of the excretory ducts. The pathogenesis of the disease is based on a local and systemic atopic reaction associated with activation of eosinophils, their primarily infiltration of the large salivary gland ducts, which leads to sialodochitis, accompanied by eosinophilia, increased synthesis of IgE and often related with concomitant allergic diseases, such as bronchial asthma, vasomotor rhinitis. We have not found any descriptions of this rare disorder in the Russian literature. In this article, we present two cases of eosinophilic sialodochitis, also focusштп on clinical and laboratory manifestations, pathogenesis, and differential diagnosis of diseases with similar manifestations, analyzing the literature and approaches to the treatment of this allergic condition. On the example of one patient with a long and severe course of eosinophilic sialodochitis in combination with a poorly controlled bronchial asthma with inefficacy of the standard treatment, prescription of a biological agent from the group of IL-5 inhibitors – benralizumab, we succeeded in achievement of a significant improvement in the both diseases courses.

This article presents the results of studying the course of tuberculosis infection in children and adolescents who have suffered COVID-19 according to a study of ELISA with the presence of Ig G in the blood. The follow-up included 54 patients aged 2 to 16 years with local forms of tuberculosis who were treated in the inpatient conditions of the children’s department of the E.N. Andreev Scientific and Practical Center of Phthisiology from 2020 to 2022. The patients were divided into two groups: the first group – children who had suffered from COVID-19 according to the results of IgG in the blood – 17 patients; the second group – those who had not had COVID-19 with negative results in IgG blood – 37 patients. A comparative medical and social analysis revealed that children who had had COVID-19 had both social and medical risk factors, as well as a burdened epidemiological history, contact with adult patients with acute progressive and destructive forms of pulmonary tuberculosis. Methods of detecting the tuberculosis process in the first group, 88 % of children were detected by contact, 6 % by treatment, 6 % by immunodiagnostics; in the second group, 51 % by contact, 8 % by treatment and 41 % by immunodiagnostics of the patients. In the study of the tuberculosis process in children of the first group, the infiltration phase was recorded in 80 % patients in the reverse development phase: resorption – 10 % and in the calcification phase – 10 %. In the second group, the infiltration phase was in 50 % of children, the resorption phase was in 14 %, and the calcification phase was in 36 % of patients. It should be noted that the effect of a previously transmitted new coronavirus infection on the course and outcomes of the tuberculosis process was not revealed, no correction of chemotherapy was required, and there was no need to increase the duration of treatment.

Treatment of any form of chronic Epstein-Barr virus infection (EBVI) is a major challenge for modern medicine. At the present stage, no generally accepted principles of etiotropic treatment of chronic active Epstein-Barr virus infection have been developed, since drugs with antiviral activity do not allow elimination of the pathogen from the body, and the basis of treatment is symptomatic and pathogenetic therapy, but there is no pathogenetically justified scheme of treatment of patients with activation of EBVI. On this basis, we conducted a study to investigate the efficacy of antiviral drug combination in patients with reactivation of chronic Epstein-Barr virus infection. We were to study effectiveness of a combination of antiviral drugs in patients with reactivation of chronic Epstein-Barr viral infection. In order to assess the functional activity of immunocompetent cells at various stages of disease, the antiviral therapy was evaluated in terms of the rate of lymphocyte-platelet adhesion (LPA). In patients with reactivation of CHEBVI, a convincing tendency towards fast relief of then tire symptom complex was revealed when differential antiviral drugs were included in the basic therapy: Panavir® and meglumine acridone acetate (Cycloferon®). In the patients of the main group, the duration of manifestations of tonsillitis syndrome, enlargement and pain of peripheral lymph nodes, hepatomegaly, and the duration of the febrile period were significantly shorter. It was established that in patients receiving panavir+cycloferon, the number of outletforming lymphocytes increased to 10,42 % [9,32; 10,76], which is 1.2 times more compared to the group taking acyclovir 8,30 % [7,05; 9,08]. The use of panavir and cycloferon for EBVI was accompanied not only by a therapeutic effect but also the normalization of LPA indices which reflected stabilization of the pathological process and, accordingly, indicated a greater effectiveness of the therapy carried out with this antiviral drug.

The article presents the results of a retrospective analysis of hemotransfusion complications according to the acts of official investigations of the commissions of the Ministry of Health that arose during the transfusion of blood components in hospitals of the Republic of Sakha (Yakutia) in the period 1991–2023. The structure, causes and outcomes of hemotransfusion complications are presented. The most common mistakes leading to the development of posttransfusion complications, up to a fatal outcome, were identified. It was found that in the vast majority of the cases, violations during hemotransfusion were observed in district hospitals (70.3 %). Hemotransfusion complications in 12 cases (44.4 %) were associated with of ABO-incompatible transfusion; in 7 (25.9 %) cases – with transfusion of media infected with infection transmitted by hemotransmissive route; in 4 (14.8 %) cases – with transfusion of Rh-factor-incompatible; and in 4 (14.8 %) cases – with transfusion of hemolysed erythrocyte-containing blood components. It was shown that the most common complications of transfusion occurred in surgical (37.1 %) and obstetric departments (29.6 %). In 22.2 % of the cases, complications were detected in therapeutic departments; in 11.1 % – in departments of anesthesiology, intensive care and intensive care. Complications developed more often with transfusion of erythrocyte suspension and were observed in 21 (77.7 %) patients. The occurrence of posttransfusion complications was timely detected in 17 (85 %) patients who received emergency medical care, which led to a successful outcome. In 3 cases, a fatal outcome was recorded, which accounted for 11.1 % of the total number of complications. The causes of hemotransfusion complications are more often non-compliance with the rules for determining the blood group and Rh-factor, as well as non-compliance with the rules for conducting blood compatibility tests of the donor and recipient provided for in the instructions on hemotransfusion; therefore, it was concluded that it is necessary to increase the knowledge and training of medical personnel on transfusion therapy.

This study is aimed at identifying TMJ dysfunction and non-surgical treatment of this pathology. Dysfunctions of the dental system in patients with malocclusion remain a pressing problem in modern dentistry, due to the fact that the diagnosis and treatment of these disorders are quite difficult, and the clinical picture is quite diverse and quite complex. According to various studies, symptoms of articular disorders are characterized by high prevalence and are observed in 25 – 70 % of the adult population, which indicates the relevance of the problem of treating TMJ pathologies. The purpose of the study was to increase the effectiveness of treatment of dysfunctions of the dentofacial system in patients with malocclusions; objectives – identification and diagnosis of dysfunctions of the dental system in patients with malocclusions; drawing up a treatment plan using splint therapy and kinesiotherapy; long-term results and assessment of the degree of effectiveness of these treatment methods. 14 days after the therapy, with the use of repositioning and muscle relaxation splints, the majority of the subjects observed a decrease in the tone of the masticatory muscles, pain sensitivity in the masticatory muscles and the area of the temporomandibular joint, clicks, crepitus, and deviation when opening the mouth disappeared. Patients no longer clenched their teeth during the day, did not experience difficulty opening their mouths immediately after waking up, and headaches radiating to the temple and jaw decreased. It is recommended to use splint therapy together with kinesiotherapy as an additional treatment method. After splint therapy, all subjects in the group showed positive dynamics within two weeks, which indicates the need to treat TMJ diseases using these methods.

Depressive disorders are an urgent problem of modern psychiatry and related disciplines and are a growing public health issue. Genetic and non-genetic (demographic, environmental and dietary) factors are associated with the development of depressive disorders in various age groups of the population. The relationship between nutrients and the severity of depressive disorders is of increasing interest to researchers and clinicians. Such nutrients include iodine, which is an important trace element in the development and functioning of the central nervous system. Iodine deficiency is clinically often accompanied by a decrease in mood, a feeling of fatigue, a feeling of depression or anxiety, nervousness and trembling, a decrease in life satisfaction, decreased appetite, emotional lability, difficulty concentrating, cognitive disorders. In this regard, nutritional support is considered as one of the components of disease-modifying therapy for depressive in children and adults. The narrative review presents updated knowledge about the relationship of iodine concentrations in blood serum and urine with the development and severity of depressive disorder in children and adults, based on the analysis and generalization of the results of domestic and international clinical and laboratory studies. It has been shown that low intake of iodine into the human body with food, dietary supplements, oral and transdermal drugs and an age-dependent increase in urinary iodine excretion are sensitive predictors of a high risk of developing depressive disorders. Monitoring and correction of iodine deficiency conditions in patients with severe and recurrent depressive disorders is an urgent problem in real psychiatric practice. It is possible to recommend a study of serum iodine levels and a study of the level of iodine excretion in urine for patients to diagnose iodine-associated depressive disorders and timely resolve the issue of personalized appointment of disease-modifying therapy for deficiency of this nutrient.

Pearson syndrome (PS) is a rare multisystem disease with predominant involvement of the hematopoietic organs, pancreas and liver, developing due to a defect in mitochondrial DNA. Most often, the first clinical manifestations of Pearson syndrome in the form of anemia of varying severity appear in the first year of life. The disease was first described in 1979 by Howard Pearson, who included in this syndrome sideroblastic anemia, vacuolation of hematopoietic progenitor cells in the bone marrow, exocrine pancreatic dysfunction, and early onset of the disease, usually before the age of 1 year. According to the literature, the incidence of Pearson syndrome is 1:5000.

This article presents a clinical case of a boy diagnosed with Pearson syndrome at the age of 6 months. The child had pale skin from birth and a general blood test showed severe anemia. In the myelogram: Moderate increase in proliferation of the erythroid germ with impaired maturation, diserythro and dysmegakaryocytopoiesis, moderate monocytosis, ring-shaped sideroblasts 45 %. In a molecular genetic study: on DNA material isolated from the patient’s blood cells and urinary sediment using the polymerase chain reaction of very long fragments, the patient was analyzed for the presence of mitochondrial DNA deletions in the region where most of the major changes were described (m.6380-m. 16567). DNA isolated from the patient’s blood cells and urine sediment revealed a deletion of about 3000 bp. in a homoplasmic state. The boy also has neurological disorders. Currently, the child is admitted monthly to the oncology department of the pediatric center for replacement therapy with blood components. He has been observed by hematologists together with neurologists. He also receives chelation therapy and methylprednisolone therapy on an ongoing basis. For anticonvulsant purposes: vigabatrin. Symptomatic therapy, according to the recommendations of the federal center: Courses of Riboflavin, Tocopherol (vitamin E), Coenzyme Q, Succinic acid, L-carnitine, Thiamine.

Suicide prevention is a topical issue in modern healthcare. There are northern regions in the Russian Federation where the suicide rate exceeds Russian indicators by 2.8-3 times. The purpose of this study is a comparative analysis of the suicidal index (SI) in the Arctic zone of the Republic of Sakha (Yakutia) and among American Indians – residents of Alaska, to identify the main factor contributing to the widespread suicidal behavior among residents of the Far North. Materials and methods of research. A comparative analysis of the materials of the organizational and methodological department of the State Budgetary Institution of the RS(Ya) “Yakut Neuropsychiatric Dispensary”, as well as data from the territorial body of the Federal State Statistics Service for the Republic of Sakha (Yakutia) on the mortality of the population of the Arctic zone of the RS(Y) from suicide and statistical data on suicides of the Center for Disease Prevention and Control of the USA – CDC (Centers for Disease Control and Prevention) for 2018 and 2021 . It was found that from 2018 to 2021, the SI increased among residents of the Arctic zone of the Republic of Sakha (Yakutia) by 34 %. For American Indians living in Alaska, the SI increased by 23 % over the same period of time. The SI for 2018 for residents of the Arctic zone of the Republic of Yakutia is 2.6 times higher than for residents of the Russian Federation. The suicide index (SI) for 2018 among American Indians – residents of Alaska is 1.6 times higher than that of residents of the United States. The SI for 2021 for residents of the Arctic zone, the RS(Ya) is 4 times higher than for residents of the Russian Federation. The SI for 2021 the American Indian population of Alaska is 2 times higher than that of the residents of the United States. It was established that there are two regions in the world with extremely high suicide rates – Greenland and Chukotka Autonomous District in the Russian Federation. Both regions differ from other parts of the world in that they are located at the highest geographical latitudes. These are territories with the most extreme living conditions. The Arctic zone of the RS(Ya) belongs to the coldest regions of the Russian Federation. Remoteness from the central regions and extreme living and working conditions lead to a shortage of personnel in the Arctic zone of the RS(Ya) of psychiatrists. Consequently, the extremely high suicide rate in the Arctic zone of the RS(Ya) is influenced by the difficulty of accessing necessary psychiatric care and the lack of preventive mental health work.

Determining the variability of the proportions of the human body living in extreme climatic and geographical conditions of the North is relevant for understanding the topography of internal organs, the ratio of body components, and the proportionality of the body surface to body weight. In Yakutia, there are not enough scientific papers on body proportions, which determined the relevance of this work. The aim of the work was to identify the ethnic and gender characteristics of the body proportions of Yakutian students. A total of 314 girls aged 16-20 and 156 boys aged 17-21 of Yakut ethnicity were examined. Somatometric examination was carried out according to the method of V.V. Bunak, with the determination of body length and body weight. The diameter of the shoulders, the diameter of the pelvis, the transverse diameter of the chest and the anterior-posterior diameter of the chest were measured. The following heights were determined on the upper limb: acromial, radial, styloid and finger point. The trochanter, upper tibial height and lower tibial point were measured on the lower limb. An index assessment of physical development was carried out (index of relative width of shoulders, pelvis, index of arm and leg length, pelvic-shoulder index, Brugsch index). Statistical processing was performed using the SPSS application software package for Windows (version 22.0). Parametric and nonparametric methods of statistical analysis were applied. Gender differences in all studied anthropometric parameters among the Yakuts were established. Indicators of body length and weight, arm index, leg index, index of relative shoulder width in the boys were significantly higher than the parameters of the girls. The index of the relative width of the pelvis and the pelvic index were significantly higher in girls. According to the index of relative pelvic width, metriopyelia was significantly more often registered among the girls, and stenopyelia among the boys. The predominant body shape for the girls was a rectangular shape, for the boys – the average body shape. Ethnic characteristics were expressed in lower body length, shoulder diameter and leg length in Yakut girls compared to Russian girls living in Yakutia. In boys, among the compared parameters, the ethnic difference is observed only in the parameter of shoulder diameter, which was significantly smaller in Yakut boys.