Prion diseases (PD) represent a group of rare yet fatal neurodegenerative disorders caused by the conformational transformation of the cellular prion protein into its pathological isoform. Despite their low incidence, these diseases remain a significant medical and social challenge due to the lack of effective treatments and the risk of iatrogenic transmission.

Purpose of the review was to identify key unresolved issues in PD research, including molecular mechanisms of pathogenesis, opportunities for early diagnosis, and promising therapeutic approaches, as well as to outline the most critical directions for future studies.

A systematic literature search was conducted in PubMed, Google Scholar, eLibrary, and CyberLeninka databases for the period 2016–2025. Fifty-one relevant publications were selected, comprising original studies, reviews, and clinical cases. The analysis was performed in accordance with CINAR guidelines and SANRA criteria.

Modern diagnostic techniques (RT-QuIC, DWI-MRI) have significantly improved the detection of PD, though their widespread implementation is hindered by high costs and the need for specialized expertise. The most promising therapeutic strategies include monoclonal antibodies (PRN100), antisense oligonucleotides, and CRISPR/Cas9 technology. Epidemiological data confirm a decline in variant Creutzfeldt – Jakob disease (vCJD) cases due to enhanced biosafety measures, though risks associated with prolonged incubation periods persist.

To enhance the diagnosis and treatment of PD, it is essential to establish a national registry, expand laboratory networks, train specialists, and strengthen biosafety protocols. Future research should focus on combined therapeutic strategies and in-depth exploration of the molecular mechanisms underlying these disorders.

Background. Tau protein is considered one of the indicators of risk or progression of neurodegenerative processes. Brain-derived neurotrophic factor (BDNF), on the contrary, is one of the modulators of neuronal survival and differentiation, which prevents their damage. Obstructive sleep apnea (OSA) is an independent risk factor for neurodegenerative diseases such as Alzheimer’s disease and Parkinson’s disease due to chronic hypoxia, sleep fragmentation, systemic inflammation, and oxidative stress. At the moment, not much work has been done on the relationship between the content of tau protein and BDNF in the blood of patients with OSA, but the available data also presents contradictory results that do not fully disclose this relationship.

Objective. To evaluate the content of tau protein and brain-derived neurotrophic factor in patients with severe OSA.

Materials and methods. We performed a cross-sectional comparative study in 23 patients (16 men; 7 women), with an average age of 41 [37;43] years with a severe form of OSA. The diagnosis was confirmed by standard polysomnography. The control group consisted of 17 people (10 men; 7 women), of the “copy – pair” type, with an average age of 37 [21;44.5] years. The levels of tau protein and BDNF were determined by enzyme immunoassay. The data is presented as the median, upper and lower percentiles. Intergroup comparisons were performed using the Mann – Whitney U-test.

Results. The polysomnography (PSG) results obtained by us demonstrate the characteristic breathing pattern and features of the macrostructure of sleep in patients with OSA. The assessment of the content of tau protein and BDNF in blood plasma demonstrates a statistically significant increase in the content of tau protein and BDNF in patients with CCA compared with the indicators of the control group.

Conclusion. The results obtained suggest the presence of an adaptive profile in the processes of neuroplasticity against the background of the incipient processes of neurodegeneration in patients with OSA.

Menstrual disorders (MD) in adolescents are the predictor of reproductive problems in older age; nevertheless, the data on the prevalence of MD in adolescent girls are controversial.

The aim. To estimate the prevalence of menstrual disorders in the urban subpopulation of 14-17-year-old adolescent girls taking into account their gynecological age.

Methods. A cross-sectional study (2020-2023) was conducted with the participation of 417 adolescent girls - students of 1-2 years of pedagogical college, students of 9-11 grades of Lyceum No. 3, and School No. 14 in Irkutsk. The study used a questionnaire survey method and general clinical examination. The incidence of menstrual irregularity was assessed. Statistical analysis methods included descriptive statistics and statistical hypothesis testing.

Results. Four hundred seventeen adolescent girls aged 16.18 ± 0.7 years were examined. Menstrual dysfunction (MD) was detected in 56.35 % (235/417) of girls, and more than one type of dysfunction was observed. The most common disorder was oligomenorrhea, which occurred both in isolation and in combination with other dysfunctions, and was present in 31.17 % (130/417) of the girls; 23.3 % of the girls (97/417) suffered from abnormal uterine bleeding (AUB), and 20.62 % (86/417) suffered from dysmenorrhea. In the structure of menstrual function disorders, isolated oligomenorrhea was detected in 29.79 % (70/235), oligomenorrhea in combination with AUB was detected in 15.74 % (37/235), AUB alone in 15.32 % (36/235), amenorrhea in 2.55 % (6/235) of adolescents, isolated dysmenorrhea occurred in 20.85 % of cases (49/235), and in combination with other types of MD - in 15.74 % (37/235) of the surveyed.

Conclusion. The results of the study indicate a significant frequency of menstrual disorders in a non-selective (non-hospital) sample of 14-17-year-old female adolescent students. The data obtained dictate the need for active detection and correction of menstrual cycle disorders, a prognostically significant marker of the state of the reproductive system in adolescent girls.

Preeclampsia is a multisystem complication of pregnancy and is one of the leading causes of maternal morbidity and mortality worldwide. Cerebral complications, including Posterior reversible encephalopathy syndrome (PRES), eclampsia and stroke, are life-threatening conditions for the mother that require in-depth study. While diagnostic criteria for preeclampsia appear after 20 weeks of pregnancy, the initial pathogenetic mechanisms are formed much earlier. Clinical studies have obvious limitations in determining the role of trigger factors in the development and progression of preeclampsia. The proposed preclinical animal models make it possible to reproduce individual links in the pathogenesis of preeclampsia, accompanied by the development of characteristic clinical symptoms. The purpose of this review is to analyze publications describing experimental models of the cerebral complications development in preeclampsia. A systematic analysis of modern literature was carried out using the information databases PubMed, Scopus, MEDLINE, Cochrane Library and eLibrary for the period from January 2005 to March 2025. The search strategy included combinations of keywords: “preeclampsia”, “pathogenesis”, “experimental models”, “cerebral edema”, “posterior reversible encephalopathy syndrome”. The initial search gave 1236 results. After removing duplicates and screening according to inclusion criteria (originality, relevance to the topic, accessibility), 50 publications were selected for detailed analysis. This review compares various preclinical models of preeclampsia in terms of their clinical relevance and ability to reproduce PRES. The pathogenetic mechanisms of cerebral disorders in the most widely studied experimental models based on angiogenic imbalance, placental ischemia, and inhibition of endothelial nitric oxide synthase are described. The advantages and disadvantages of each method of modeling hypertensive disorders during pregnancy are presented, taking into account PRES-relevance. PRES models are described separately, including some hypertensive models and combined models. Although preeclampsia is a pathology unique to humans, experimental animal models play a key role in investigating the pathophysiology of this pregnancy complication and remain an important tool for developing new diagnostic and therapeutic methods.

Background. Up to 40 % of patients with suspected monogenic disorders remain undiagnosed when using targeted gene panels or exome sequencing, particularly in cases of compound heterozygosity where one pathogenic variant goes undetected.

The aim. To investigate the molecular and clinical features of compound heterozygous conditions in children with suspected inherited diseases and to evaluate the diagnostic utility of whole genome sequencing (WGS).

Materials and methods. A prospective observational study was conducted between 2023 and 2025. The study included 7 pediatric patients (under 18 years old) with suspected genetic disorders in whom previous genetic testing identified only a single pathogenic variant. All patients underwent WGS followed by bioinformatic analysis and variant interpretation according to ACMG-AMP (2015) guidelines. No medical interventions were performed. The primary endpoint was the identification and phenotypic correlation of compound heterozygous mutations.

Results. Compound heterozygous mutations were identified in all patients, totaling 14 variants across 7 genes (PAH, GALT, DNAH5, CHRNA3, SLC26A2, LAMA2, IDUA). Fifty percent of the variants had not been previously reported. Five patients had variants of uncertain significance (VUS) that followed by syndromic clinical presentations. WGS enabled confirmation of the diagnosis, refinement of the genotypic profile, adjustment of clinical management strategies, and improved diagnostic precision. No adverse events related to diagnostic procedures were observed.

Conclusion. Whole genome sequencing demonstrated high diagnostic value in identifying compound heterozygous mutations, especially in cases where standard methods failed to detect the second variant. The detection of previously unreported mutations and clinically correlated VUS highlights the necessity of integrating WGS into routine pediatric genetic diagnostics.

The article is presented in the format of a lecture material. The lecture examines, from a modern perspective, the etiology, pathogenesis, risk factors, clinical manifestations, diagnosis, and treatment of overactive bladder syndrome (OAB). The continuously growing body of research indicates that OAB is an extremely complex, chronic, and age-progressive clinical syndrome that shares similar symptoms with other urological conditions. It is characterized by urgency, with or without urgency urinary incontinence, increased urinary frequency (more than eight times per day), and nocturia, in the absence of infections or other apparent bladder pathologies that could explain these manifestations. OAB significantly worsens patients’ quality of life by negatively affecting their emotional well-being, social interactions, sexual health, and other aspects of daily living. Despite the fact that this problem is one of the most common in urological practice, it should be recognized that there are difficulties in objectively assessing symptoms, and the treatment of GMP in both men and women remains a difficult problem. Current clinical care standards for OAB aim to ensure a high quality of life for patients and outline three main therapeutic approaches: conservative (non-pharmacological) treatment, pharmacotherapy, and invasive methods. These approaches require the involvement of specialists from multiple medical disciplines. To establish a diagnosis, the urologist must exclude all other potential causes that could explain the patient’s symptoms. When diagnosing OAB, it is essential to consider not only the inability to achieve sustained remission of symptoms but also the presence of significant side effects, which may lead patients to discontinue medication even when remission is achieved. Since symptoms tend to reappear in most patients, treatment is administered either through repeated courses or on a continuous basis.

Background. The polyamines putrescine and cadaverine serve as raw materials for the synthesis of polyamides; their production by microbial synthesis is a current issue of biotechnology, the development of which requires a search for effective producers and aminoacyl decarboxylases. In addition, polyamines are considered as factors of bacterial adaptation to the biotopes of the host and are associated with pathogenicity.

The aim. Evaluating the ability of natural strains of Escherichia coli isolated from different sources to produce polyamines.

Materials and methods. The objects of the study were the following strains of E. coli: isolated from the urine of patients with urinary tract infection (UPEC); isolated from the organs of broiler chickens with signs of colisepticemia (APEC); commensal, isolated from the feces of healthy farm animals (FEC) and healthy people (HFEC). Bacteria were cultured under basal (LB broth, 120 rpm, 37°C) and inducing conditions (M9 medium supplemented with 0.4 % glucose and 10 g/l ornithine/arginine/lysine, 0 rpm, 37°C). Quantitative analysis of polyamines was performed by thin-layer chromatography with preliminary derivatization with dansyl chloride.

Results. The activity of the polyamine-synthesizing system of 121 strains of E. coli was studied. The strains that were capable of producing 3.5 mM putrescine from ornithine and 5 mM putrescine from arginine, as well as more than 5.5 mM cadaverine from lysine, which significantly exceeded the production of polyamines by the E. coli K12 strain (0.3,0.03, and 3 mM, respectively) were found. The mean value of putrescine production from ornithine of the APEC and UPEC strains was more than 2-fold higher as compared with HFEC and FEC strains. Under non-inducing conditions, the ability to produce cadaverine in strains isolated from humans (UPEC, HFEC) was 2-3 times lower compared to strains isolated from animals (APEC, FEC).

Conclusion. A dependence of the ability of E. coli to produce polyamines on the source of isolation has been revealed.

Background. The Ekhirit-Bulagatsky district of the Irkutsk region is the only area in the world where the simultaneous circulation of all known tick-borne encephalitis virus (TBEV) subtypes, with the exception of the Himalayan subtype, has been documented. The unique ecology of this region justifies its selection as a model for studying the influence of environmental factors on the formation of a heterogeneous viral population, and the genetic variability of TBEV circulating in this area merits a more detailed description.

The aim. To characterize the genetic diversity of tick-borne encephalitis virus circulating in the Ekhirit-Bulagatsky district of the Irkutsk region.

Materials and Methods. Thirty-nine TBEV strains from the collection of the Scientific Centre for Family Health and Human Reproduction Problems isolated from various sources in the Ekhirit-Bulagatsky district were analyzed. A combination of molecular genetic methods (MHNA, Sanger sequencing, and NGS) was used for strain genotyping.

Results. Based on genome coding sequence analysis, the circulation of four TBEV subtypes (Siberian, Far Eastern, European, and Baikalian) in the Ekhirit-Bulagatsky district was confirmed, and strain 178-79 with an original genetic structure was identified. The differences in TBEV genotypic composition depending on the landscape type and the source of isolation were demonstrated. An assumption was made about the important role of taiga ticks in the selection of the Siberian subtype of the virus. It was hypothesized that the long-term co-circulation of several TBEV subtypes in one area creates the preconditions for the emergence of strains with a “mosaic” genetic structure. A comparative analysis of the genomes of strains from the Ekhirit-Bulagatsky district and other districts of the Irkutsk region was conducted. The unique amino acid substitutions in the structural and non-structural virus proteins, characteristic of strains from the studied district, were identified.

Conclusion. The Ekhirit-Bulagatsky district has been proven to be unique in terms of TBEV genetic variability, characterized by a wide range of circulating subtypes and the presence of unique genotypic amino acid substitutions within each identified subtype.

Background. Vitamin D deficiency and insufficiency are highly prevalent worldwide, affecting a significant proportion of the general population. This issue is of particular concern in Eastern Siberia due to its geographical location and climate.

Objective. To assess vitamin D status among the population of the Irkutsk region with consideration of seasonal, sex-based, and age-related differences, in order to identify high-risk groups for hypovitaminosis D.

Materials and methods. A retrospective, non-controlled, selective study was conducted to assess the prevalence of vitamin D deficiency among 939 patients: 148 children in clinic of the Scientific Center for Family Health and Human Reproduction Problems, and 791 adults recruited at the Center for Innovative Medicine in 2023-2024. Vitamin D concentrations were determined using ELISA 25-OH vitamin D test systems (Euroimmun AG, Germany).

Results. Age-specific differences in serum 25-hydroxyvitamin D [25(OH)D] concentrations were observed. Among children, the highest levels were observed in preschoolers and younger school-age children (32.8 ± 17.5 ng/mL). A decline in vitamin D levels was noted during adolescence: in the 12-14-year age group, the mean was 27.3 ± 13.9 ng/mL; in older adolescents (15-17 years), the lowest levels were detected - 21.1 ± 11.7 ng/mL. Among adults, 25(OH)D levels demonstrated an increasing trend with age. In young adults (18-44 years), the mean concentration was 31.5 ± 17.2 ng/mL; in middle-aged adults (45-59 years) - 33.7 ± 18.8 ng/mL; and in older adults (> 60 years), the highest mean value was recorded at 41.2 ± 23.6 ng/mL.

Conclusion. Seasonal analysis revealed statistically significant differences in 25(OH)D levels between the autumn - winter and spring - summer periods (p = 0.0005).

Population aging is accompanied by an increasing incidence of age-related diseases, including oncological, neurodegenerative, and cardiovascular pathologies. One of the key mechanisms underlying these processes is cellular senescence - an irreversible arrest of cell division while maintaining metabolic activity. With age, such cells accumulate, contribute to chronic inflammation, and disrupt tissue homeostasis. In this context, the development of reliable biomarkers of cellular aging is becoming particularly relevant.

The aim. To provide an overview of current data on cellular senescence: consider its concept and significance in pathophysiology, key molecular mechanisms, various types of senescence biomarkers and methods for their detection, as well as the clinical significance of these biomarkers, difficulties and prospects for their application.

Materials and methods. Search and analysis of domestic and international scientific sources were conducted using databases such as PubMed, eLibrary.ru, Scopus, and Google Scholar, as well as open-access resources available covering the period from 2011 to 2025.

Results and discussion. This study presents a comprehensive classification of cellular aging biomarkers, encompassing genetic, epigenetic, protein, endocrine, and metabolic indicators. Genetic markers include telomere shortening, while epigenetic markers involve alterations in DNA methylation and the formation of specific heterochromatin foci. Protein biomarkers are characterized by increased expression of cell cycle inhibitors and pro-inflammatory molecules secreted by senescent cells. Endocrine markers comprise levels of dehydroepiandrosterone sulfate, cortisol, and insulin-like growth factor 1. Metabolic markers include elevated β-galactosidase activity, lipofuscin accumulation, and increased concentrations of reactive oxygen species. The clinical relevance of these biomarkers lies in their utility for assessing biological age, stratifying the risk of age-related diseases, and monitoring the efficacy of geroprotective and senolytic interventions.

Conclusion. The necessity of a comprehensive approach to the assessment of cellular aging is substantiated, integrating molecular, metabolic, and functional parameters. The review highlights the prospects for developing a standardized panel of biomarkers (an “aging passport”) for implementation in clinical practice and personalized medicine.

Background. Sleep disturbances significantly reduce life quality. Insomnia is one of the most common symptoms of menopause. Various questionnaires, such as the Insomnia Severity Index (ISI), the Pittsburgh Sleep Quality Index (PSQI), and the Epworth Sleepiness Scale (ESS) are considered for subjective quality assessment. Studies often use one or two questionnaires, making it difficult to compare results. Further complications are caused by differences in the number of groups which the sample is divided based on the results. To successfully compare the results of studies using different questionnaires, it is necessary to correlate the questionnaire results and standardize the groupings.

The aim. To compare sleep questionnaires and determine the most appropriate cut-off point for binary distribution for ISI.

Methods. Ninety-six menopausal women participated in the study. Participants taking melatonin, suffering from diabetes or cancer, or chronic diseases on acute stage, were excluded. Participants completed the Pittsburgh Sleep Quality Index (PSQI), the Insomnia Severity Index (ISI), and the Epworth Sleepiness Scale (ESS). Results were assessed and women were grouped according to standard protocols for these questionnaires. A comparison of the ISI questionnaire results (based on the four-group questionnaire modification) with the PSQI and ESS to determine the most appropriate cut-off point for obtaining a binary distribution was performed using Cohen's kappa.

Results. The ISI correlates with the PSQI. The ESS should be considered as an assessment of another aspect of sleep disturbance. The cut-off point at which the ISI and PSQI groups similarity is higher was 10 points.

Conclusion. Defining a specific cut-off point allows to use the ISI questionnaire when binary division is necessary.

Background. Cognitive decline reduces the quality of life and difficult responds to treatment in the elderly patients. Arterial hypertension (AH) is an independent risk factor for cognitive impairment. The target level of blood pressure (BP) in elderly patients for maintaining cognitive function has not yet been determined.

The aim. Assessment of the state of cognitive functions using the P300 event-related potential in women aged 60-74 years living in the European North of Russia, depending on the degree of hypertension control.

Methods. The study involved elderly women with controlled hypertension (n = 63), with uncontrolled hypertension (n = 57), and without hypertension (n = 28) living in Arkhangelsk. The registration of the P300 and N2 components was carried out on the Neuron-Spektr-4/VPM electroencephalograph (Neurosoft, Russia), using the oddball paradigm. Blood pressure was measured with an automatic blood pressure monitor A&D Medical UA-668 (Japan).

Results. In women without arterial hypertension and in women with controlled arterial hypertension, there were no differences in the latent time (LT) of N2 and P300 and the magnitude of the amplitude of P300 between the groups. In women with uncontrolled hypertension, there was an elongation of LT N2 in the anterior temporal region on the left and LTP300 in the anterior temporal on the left, central and frontal on the left brain regions, which indicates an increase in the time of primary recognition and signal differentiation, a decrease in the speed of information processing and decision-making.

Conclusion. In elderly women with uncontrolled hypertension with SBP > 140 mmHg and DBP > 90 mmHg, there is a decrease in the rate of recognition and differentiation of the sound stimulus and a decrease in the speed of decision-making. In elderly women with controlled hypertension with SBP < 140 mmHg and DBP < 90 mmHg, the rate of differentiation of the sound stimulus and decision-making were comparable to the group of elderly women without hypertension.

Background. Neuroendocrine tumors are rare malignant neoplasms. Recently, there has been a tendency towards an increase in the incidence of neuroendocrine tumors of the gastrointestinal tract in general and the duodenum in particular.

The aim. To analyze the methods of surgical treatment in patients with neuroendocrine tumors of the duodenum depending on the stage of the disease.

Methods. The object of the study were 35 patients with neuroendocrine tumors of the duodenum who were examined and treated at the Irkutsk Regional Oncology Dispensary from 2010 to 2022. Of these, 17 (48.6 %) were men and 18 (51.4 %) were women aged 33 to 81 years, with an average age of 61.9 years. The materials for the study were the medical records of patients. The study included a study of clinical, laboratory parameters and instrumental diagnostic methods, protocols of surgical interventions, and the results of immunohistochemical analysis.

Results. The study determined that in 80 % of cases the tumors were located in the duodenal bulb, and the size of the formations did not exceed 10 mm - 89.2 % of cases. According to the examination results, stage I of the disease was established in 31 (88.6 %) patients, stage II - in 2 (5.7 %), stage III - in 1 (2.8 %), stage IV - in 1 (2.8 %). Endoscopic intraluminal operations were most often performed, which were performed in 25 (71.4 %) patients at stage I of the disease. Traditional surgeries were performed in 5 (14.3 %) patients with stages I, II and III of the disease. Symptomatic treatment was performed at stage IV.

Conclusion. It was established that neuroendocrine tumors of the duodenum were most often diagnosed at stage I. As a result of the study analysis, it was determined that endoscopic intraluminal interventions at an early stage of the disease allow for successful minimally invasive organ-preserving treatment.

The aim. To examine how identity develops in primary school students and adolescents with different levels of intellectual giftedness and academic success, and what social factors determine the features of this dynamics.

Materials and methods. The results of examining of 293 subjects – school students from 2018 to 2023 were analyzed. The level of intellectual giftedness was determined using the Raven’s Colored and Progressive Matrices methods, the Torrance Creativity Test, and the average score. The level of identity development was determined using the Twenty Statements, Semantic Differential, SEI test, and OKI methods. The Spearman correlation criterion, the Mann–Whitney U-test, the Wilcoxon criterion, the χ² criterion, and the φ criterion were used.

Results. In younger school children with pronounced intelligence, self-esteem increases, while in those with a more moderate level of intelligence, it decreases. There is no such connection in adolescents. In junior schoolchildren with pronounced intellectual giftedness, the share of the Educational component is higher and the share of the Personal component is lower, while in schoolchildren with another level of giftedness, the opposite is true; the differences are also associated with the Activity, Group, and Gender-Role components. It has been established that the identity of intellectually gifted children is more labile. Also, the identity crisis in intellectually gifted adolescents is no less pronounced than in their peers, but affects other aspects.

Conclusion. It has been confirmed that gifted primary school students make their success at school a part of their identity, which is expressed in the growth of the Academic and Group components of their identity. Less gifted students find other reference groups for identification. The identity crisis in intellectually gifted adolescents is quite pronounced. However, the severity of crisis phenomena, on the contrary, can be considered as a positive aspect that leads to a more productive, coordinated identity.

Introduction. Movements influence child development throughout of life. Through movement, needs for play, communication, and learning are realized. Individual differences in movement formation are associated with many factors, including environmental influence. However, how the environment and population setting of a child affect various characteristics of motor function has not been fully studied.

The aim. To identify differences in the development of the kinetic component of voluntary movements in children depending on their habitat and population environment.

Materials and methods. As part of a comprehensive screening neuropsychological study, 2253 children aged 4-10 years were examined, of whom 1362 lived in cities and 891 in rural areas of Eastern Siberia. Well-adapted methods were used to study the kinetic aspect of movements: tests for reciprocal coordination of movements and dynamic praxis. Test performance results were evaluated using a five-point scale.

Results. This study was the first to analyze the developmental features of kinetic organization of movement in populations of urban and rural children during ontogenesis. At age 4, when kinetic organization of voluntary movements is not yet fully formed, no notable differences between urban and rural children were observed. However, after age 5, the urban population acquired a consistent advantage in developing kinetic components of voluntary movements. The onset of school education did not significantly influence the dynamics of this process, indicating heterochrony in the development of the voluntary kinetic component of motor function at the population level.

Conclusion. Different degrees of maturation of prefrontal motor brain systems and varying intensity of development of anterior corpus callosum regions during ontogenesis in different child populations can be assumed. Urban environments stimulate preferential development of the kinetic factor in the structure of voluntary movement compared to other aspects of motor function.

Background. Periodontal inflammation is a pressing health problem due high prevalence in young people and progressive course. Biologically active substances - medium molecular peptides (MMP) are damaging factors and endogenous toxins.

The aim. To analyze the endogenous intoxication level (the content of MMP in the peripheral blood) in young men with mild chronic periodontitis, and to establish the relationship between these indicators and the clinical manifestations of the disease.

Methods. A total of 80 young men (18-23 years old) were examined. Using the diagnostic criteria for chronic periodontitis, groups of men with mild disease (n = 60) and practically healthy men (control group) (n = 20) were formed. The MMP level in blood plasma was determined, spectrophotometrically, at wavelengths λ = 238,254,260 and 280 nm, and the distribution coefficients were calculated (238/260, 238/280, 280/254).

Results. The men with periodontitis have increased values of endogenous intoxication indicators - MMP 260 (p = 0.048) and MMP 280 (p = 0.005), as well as the peptide-nucleotide coefficient (MMP 238/MMP 260) (p = 0.039) relative to the control (r = 0.39; p = 0.035). Correlation analysis showed the presence a statistically significant relationship between the periodontal index (PI) and the level of the MMP 238/MMP 260 coefficient (r = 0.39; p = 0.035).

Conclusion. The data indicate an increase in individual fractions of medium-molecular toxins in young men with chronic periodontitis at the initial stage of the disease. The most sensitive indicator of periodontal tissue damage was the peptide-nucleotide distribution coefficient (MMP 238/MMP 260), which was confirmed by a significant correlation with the periodontal index. The obtained results indicate the need to evaluate and control of these parameters content in young men with periodontitis to facilitate differential diagnosis and justify the feasibility of corrective measures in the early stages of the disease.

Introduction. Indications for reverse shoulder arthroplasties (RSA) have increased since their development by Paul Grammont in 1985. The design of the endoprosthesis has been improved, significantly reducing the incidence of postoperative complications. However, the question of how to treat the subscapularis muscle (SSC muscle) during reverse shoulder arthroplasty remains open.

The aim. To compare the functional and clinical outcomes in patients undergoing reverse shoulder arthroplasty performed via the deltopectoral approach with either complete or partial subscapularis muscle dissection.

Materials and methods. A randomized clinical trial was conducted for evaluating the outcomes of reverse shoulder arthroplasty in 49 patients. The cohort was divided into two groups. In the first group, implantation of the reverse endoprosthesis was performed using the standard deltopectoral approach, whereas in the second group a novel surgical approach with partial subscapularis muscle dissection was employed. Clinical and functional outcomes were assessed postoperatively, and at 3 and 12 months of follow-up, using the American Shoulder and Elbow Surgeons (ASES) score and the Visual Analog Scale (VAS) for pain.

Results. Patients who underwent a surgical approach with partial subscapularis muscle dissection, in the postoperative period, demonstrated better scores on the ASES scale, a greater degree of anterior flexion and less intensity of pain compared to the group of patients after standard deltopectoral approach.

Conclusion. The surgical approach with partial subscapularis muscle dissection improves functional and clinical outcomes after reverse shoulder arthroplasty also it reduces the probability of joint dislocation.

Background. Tuberculosis (TB) remains a priority public health problem, including in the Far North regions with low population density and insufficient transport infrastructure. This necessitates the introduction of digital technologies to increase access to tuberculosis care, improve diagnostics, epidemiological monitoring, and control of the disease, as exemplified by the Republic of Sakha (Yakutia).

The aim. To analyze the dynamics of TB incidence in the socio-economic zones of the Republic of Sakha (Yakutia) at the stages of introducing information technologies into the activities of the anti-tuberculosis service.

Methods. A retrospective epidemiological study was conducted, the incidence of tuberculosis and the main clinical and epidemiological indicators were analyzed in five zones of the Republic of Sakha (Yakutia). Official statistical data were retrospectively analyzed for 3 periods: 1. Traditional workflow practices (2014-2016); 2. Implementation of digital solutions (2017-2019); 3. Widescale use of digital solutions (2020-2024).

Results. By 2024, total incidence had declined by a factor of 2.5 (from 65.0 ⁰/₀₀₀₀ to 26.3 ⁰/₀₀₀₀ per 100 000), most prominently in Arctic zone (from 76.8 ⁰/₀₀₀₀ to 18.7 ⁰/₀₀₀₀ per 100 000) and the Rural zone (from 72.0 ⁰/₀₀₀₀ to 15.0 ⁰/₀₀₀₀ per 100,000), while the smallest decline was in Yakutsk (from 88.8 ⁰/₀₀₀₀ to 42.00 ⁰/₀₀₀₀ per 100,000). Alongside the general decrease in TB incidence, there was a trend toward an increase in the proportion of multidrug-resistant (MDR) cases among newly diagnosed TB patients across the republic, reaching 41.3% primary MDR by 2020-2024, with the highest rates in urbanized and industrialized zones. Additionally, a structural shift in the clinical picture was recorded in Sakha Republic (Yakutia), characterized by a significant rise in the share of destructive forms of pulmonary TB among newly diagnosed TB cases of the respiratory organs.

Conclusions. The study demonstrated changes in the epidemic process of TB during the digitalization period: a steady decline in incidence, likely due to improved detection, against a backdrop of increasing MDR cases, which may be associated with advancements in diagnosing complex forms of the disease and a more complicated epidemiological picture for TB.

Background. One of the top priorities in phthisiology at present is the problem of tuberculosis treatment with multiple drug resistance (MDR) and extensive drug resistance (XDR) Mycobacterium tuberculosis (MBT). The unsatisfactory results of etiotropic chemotherapy associated with a large number of factors determine the need for surgical treatment. The effectiveness of surgical treatment and the advantages of using surgical techniques (in combination with chemotherapy) compared to the use of chemotherapy alone, it is currently poorly understood and undoubtedly requires research at various levels.

The aim. Evaluation of the effectiveness and determination of optimal timing and risks of surgical intervention in the framework of complex treatment of tuberculosis with MDR/XDR pathogen using modern chemotherapy regimens.

Materials and methods. The data on the treatment outcomes of 71 patients with MDR/XDR pathogen after surgery who received identical modern chemotherapy regimens (including bedaquiline, linezolid, fluoroquinolones, cycloserine) with a catamnesis of sufficient duration (at least 5 years) were analyzed.

Results. Successful treatment outcome (cure with transfer to the III GDN or de-registration) was registered in 83.1 % (95% CI 72.6-90.2 %). One independent risk factor for an unfavorable outcome was identified - the presence of behavioral characteristics of the patient, indicating his low adherence to treatment (p = 0.014). For relapse, the only independent risk factor was taking less than 90 doses of drugs according to the treatment regimen for drug-resistant tuberculosis, including bedaquiline and linezolid before surgery (p = 0.013).

Conclusion. The high efficiency of complex treatment during surgical intervention against the background of MDR/XDR-tuberculosis chemotherapy regimens with the inclusion of bedaquiline and linezolid has been shown. The priority role of working with patients' commitment to treatment for the prevention of adverse outcomes has been confirmed. The optimal duration of preoperative chemotherapy according to the “new” regimens (3 months or more) has been determined.

Ehlers-Danlos syndrome (EDS) is a rare genetic disorder that affects the synthesis and function of collagen. The vascular type (vEDS) is one of the most severe variants of the disease, associated with high mortality rates due to the development of life-threatening complications. The most frequent manifestations include spontaneous perforations of the intestinal wall and spontaneous ruptures of arteries. This paper presents the disease course of a patient with severe vascular EDS complicated by advanced abdominal manifestations, detailing the staged surgical treatment and the eventual cause of death. At the age of 15, the patient was admitted to the Irkutsk Regional Children's Clinical Hospital with a clinical presentation of complicated appendicitis. The diagnosis of vascular EDS had been established in early childhood based on genetic testing. Intraoperative laparoscopy revealed a spontaneous perforation of the sigmoid colon. Initially, a laparoscopic appendectomy was performed for a gangrenous appendix. However, further revision confirmed the sigmoid perforation. The procedure was converted to a midline laparotomy, the affected intestinal segment was resected, and an end sigmoid colostomy was created. In the postoperative period, the patient developed recurrent spontaneous perforations of the small intestine, requiring multiple laparotomies and primary suturing of the bowel wall defects. During the fourth surgical intervention, a laparostomy was formed, through which a high-output small bowel fistula was noted. During the reconstructive stage, the fistula and laparostomy were successfully closed. After a 3-month recovery period, the sigmoid colostomy was reversed. The immediate postoperative period was uneventful. Three months later, at home and in a state of complete well-being, the patient experienced a sudden clinical deterioration with a sudden drop in blood pressure (hypotension) and died during emergency hospitalization. A postmortem forensic medical examination revealed a spontaneous rupture of the abdominal aorta as the cause of death.

Rationale. Despite the high clinical efficacy of the atypical antipsychotic drug olanzapine, its use is limited by serious metabolic side effects, including hyperphagia, weight gain, obesity, dyslipidemia, and insulin resistance.

The aim. To study the effect of Inula helenium L. extract on the development of metabolic side effects induced by the atypical antipsychotic drug olanzapine using the Drosophila melanogaster model.

Materials and methods. Male and female Drosophila melanogaster were maintained on standard medium supplemented with olanzapine (1 pg/ml) and/or Inula helenium L. extract (50 pg/ml) for 7 days. Food seeking/preference behavior was determined using the geotaxis behavioral test. The body weight of individual flies was determined using an analytical balance.

Results. Olanzapine induced marked hyperphagia and weight gain, especially in males (~90 % increase in body weight). Addition of Inula helenium L. extract together with olanzapine completely prevented olanzapine-induced hyperphagia and weight gain in males; in females, the blocking effect was not observed. Administration of the extract alone had no effect on behavioral and morphometric parameters.

Conclusion. Inula helenium L. extract exhibits protective properties against the metabolic side effects of olanzapine in a gender-specific manner, making it a promising candidate for the development of adjuvant agents in antipsychotic therapy. The obtained results demonstrate for the first time in an invertebrate model the potential of phytoextracts to modulate the metabolic side effects of drugs.

The study of vascularization of fat implants is focused on the assessment of specific external and/or internal factors affecting its stimulation.

The aim. To study the vascular bed density and VEGF-A expression in various fat grafts during lipofilling in rats at mid and late postoperative periods.

Materials and methods. The study was conducted on 65 sexually mature male Wistar rats. VEGF-A expression in recipient tissues and fat grafts was assessed on days 30, 90 and 180 after lipofilling modeling in biological objects: transplantation in the withers area on an area of 1 cm² of solid fat graft (3x4x2 mm), crushed fat grafts (1x2x2 mm) and homogenized fat (0.05 ml).

Results. Transplantation of a solid graft larger than 3x3x3 mm results in necrotic changes due to ischemia and hypoxia; leukocyte infiltration and inflammatory phenomena persist 1 month after transplantation. Maximum VEGF-A expression and higher microvessel density were observed in groups of animals with a solid graft and crushed fat grafts compared to homogenized fat in a Luer-Lock syringe. Vascularization of homogenized fat is less intense compared to fat grafts.

Conclusion. VEGF-A expression in the center of a solid fat graft reaches its maximum on the 30th postoperative day. A decrease in VEGF-A protein expression in a solid graft 6 months after autotransplantation indicates normalization of hemoperfusion of its central sections. In the third month after lipofilling, an active process of neoangiogenesis occurs on the periphery of small fat grafts. Vascularization of homogenized fat occurs with less intensity and does not differ from the physiological vascularization of normal adipose tissue.

Background. In 2019, because of the past large-scale flood in the Irkutsk region, the infrastructure of eight municipal districts was destroyed. In the affected territory - Nizhneudinsky district, observations were made on the natural focus of leptospirosis.

The aim. To assess the impact of the flood on the natural focus of leptospirosis.

Materials and methods. Small mammals (SM) were counted and captured in flood-plain-marsh and forest-shrub stations. In 2012, 2014, 2019, 2021-2023, 493 SM individuals were captured. Biological material from humans and animals was examined using molecular biological and serological methods.

Results. During the flood, the activity of the focus was significantly reduced, and in 2021-2022, an increase in the number (up to 22.0 % of hits per 100 l/s) and infection rate (up to 14.0 ± 5.3 %) of carriers in the focus was detected. In addition, agricultural and domestic animals can become a source of infection; for example, up to 90.0 ± 6.7 % of unvaccinated livestock have antibodies to leptospires. The high seroprevalence of the population (up to 20.0 ± 5.7 %) indicates sporadic contacts with the infection.

Conclusion. The flood of 2019 contributed to a temporary decrease in the activity of the natural focus of leptospirosis, but later, there was a tendency for the epizootic situation to worsen. Therefore, preventive measures are necessary.

Background. Current tuberculosis monitoring methods rely on retrospective analysis and fail to account for the dynamics of the pathogen population's genetic structure. The lack of analytical tools capable of integrating molecular genetic indicators into quantitative risk models prevents a transition toward predictive, risk-based surveillance.

The aim. To develop and justify a methodology for applying the territorial epidemiological risk index within the genomic surveillance system for multidrug-resistant and extensively drug-resistant tuberculosis in regions of the Russian Federation to investigate the dynamics of the epidemic process and forecast adverse trends.

Materials and Methods. The index architecture is based on the consolidation of regional statistics and a complex of genotypic determinants: lineage-specific hazard weights, population frequencies, and drug resistance levels. Monte Carlo simulation (100,000 iterations) was employed to determine statistical thresholds for the epidemic significance of genotypes. Risk level scaling was performed through quartile analysis of the theoretical distribution (10,000 iterations). The tool was validated using data from four constituent entities of the Russian Federation with contrasting pathogen population structures.

Results. Stochastic modeling established a critical expansion threshold of 2.15 (p < 0.001), enabling mathematically sound identification of epidemically significant genotypes. Quartile analysis facilitated an objective classification of territories based on the threat of situational destabilization. A high coefficient of determination (R^2 = 0.874) confirms that the pathogen population structure is a decisive factor in regional epidemiological distress.

Conclusion. The developed index addresses modern epidemiological challenges by enabling the detection of cryptic expansion of aggressive genotypes before they are reflected in standard reporting forms. The tool is applicable within both polymerase chain reaction monitoring programs and whole-genome sequencing systems, serving as a universal platform for state sanitary and epidemiological control.