Introduction. Magnesium deficiency is a pressing public health problem. To prevent it, the use of biologically active supplements containing magnesium complexes is recommended.

Objective is to study the chemical composition of dietary supplements, evaluate the magnesium content taking into account the solubility at different pH values and the lipophilicity of magnesium compounds to predict their bioavailability.

Materials and methods. Five types of magnesium dietary supplements were studied. Bioavailability was assessed by potentiometry and trilometry when dissolved in water and dilute hydrochloric acid, and the lipophilicity was additionally assessed.

Results. The samples showed significantly better solubility of magnesium in an acidic environment than in water. The Mg content in one tablet or capsule was less than indicated on the package, with the exception of sample 5. The study of the lipophilic properties of complex compounds and salts of Mg by distribution in butanol showed that from 5 % to 58 % of lipophilic compounds are formed in an acidic environment. The content of amorphous silicon dioxide in sample 4 as an anti-caking agent increases the pH of the aqueous solution to 9.9, which has practical relevance for prescribing these dietary supplements to patients with various pH-dependent pathologies.

Conclusion. Laboratory-obtained parameters (solubility, pH level and lipophilicity) allow us to predict the potential bioavailability of magnesium salts from dietary supplements when taken orally by patients.

Introduction. Currently, one of the leading priorities in ensuring public health is the provision of timely and qualified dental care. Teledentistry enables the expansion of consultation, monitoring, examination, and treatment adjustment capabilities, which in turn improves the accessibility and quality of dental services, particularly in situations where personal interaction between the physician and patient is limited.

The aim of this study is to analyze the dynamics of indicators characterizing the availability and demand of the population of the Russia for dental (including surgical) care during 2010–2022, and to substantiate the organizational prerequisites for the application of telemedicine technologies (teledentistry) to enhance the accessibility of preventive care and consultations.

Materials and methods. The study was conducted through the analysis of data from the Federal State Statistics Service concerning changes in the population’s need for dental care in Russia between 2010 and 2022.

Results and discussion. During 2010–2022, the number of dental organizations decreased, while the number of dentists and maxillofacial surgeries increased. The share of the population covered by preventive examinations declined, particularly after 2020, indicating insufficient accessibility and organization of dental care, especially in rural areas.

Conclusions. Russia’s healthcare system has established a personnel reserve of dentists that can be utilized for remote consultations. The implementation of teledentistry can address the issue of territorial accessibility for rural areas and time costs for urban residents, as well as increase preventive care coverage, thereby reducing the burden on surgical dental services.

Relevance. Elderly patients have a change in immune status. Manifestations of senescent immunodeficiency are present in the oral cavity, aggravate the main dental diseases. Local immunity plays a key role in the effective treatment and prevention of inflammatory diseases in the oral cavity.

Materials and methods. A new immunomodulatory mouthwash has been developed based on the “Immunokol LP”. It is created from bovine colostrum products. A clinical study of the effectiveness of a new mouthwash for inflammatory periodontal diseases in elderly patients included determining hygienic and periodontal indices before and after a course of its use. The laboratory study included an analysis of oral fluid parameters (general parameters, inflammatory reaction, local immunity, mineral metabolism).

Results. Clinical evaluation of the effectiveness of the new mouthwash showed an improvement in the hygienic condition of the oral cavity of patients, a decrease in the severity of residual inflammation in the periodontal tissues after a course of its use. Laboratory testing of oral fluid showed a mild anti-inflammatory and immunomodulatory effect of the mouthwash, an increase in calcium concentration, calcium-to-phosphorus ratio.

Conclusion. The new immunomodulatory mouthwash helps to reduce inflammation in the oral tissues and maintain remission of inflammatory periodontal diseases in elderly patients.

Introduction. Oxidative stress is a key factor in external endometriosis. The search for peripheral blood markers is promising due to the lack of non-invasive diagnostics. Existing data are contradictory and require correlation with local changes in lesions.

Aim is to assess the levels of lipid peroxidation (LPO) products and total antioxidant capacity (TAC) in serum, ectopic and eutopic endometrium in patients with endometriosis and to evaluate their potential as diagnostic markers.

Materials and methods. The study included 58 women (control — 10 patients; mild and severe endometriosis — 12 and 36 patients, respectively). Spectrophotometric analysis of tissue homogenates and serum measured lipid peroxidation products: diene conjugates (DC), ketodienes and conjugated trienes (KD&CT), Schiff bases (SB), and TAC. Statistical analysis used Shapiro-Wilk, Levene, Fisher, Kruskal-Wallis, and post hoc Dunnett-Steel-Critchlow-Fligner tests.

Results. In endometrial homogenates, levels of DC, KD&CT and SB were significantly lower than in control. Conversely, serum DC and TAC levels were statistically higher in endometriosis patients. Tissue TAC was decreased, while serum TAC showed a tendency to increase. In homogenates, DC (heptane phase) and KD&CT (isopropanol phase) levels were lower in mild versus severe disease.

Conclusion. In endometriosis, local oxidative stress in tissues is characterized by decreased TAC, indicating antioxidant depletion, while systemic circulation shows elevated DC. The reduced lipid peroxidation in ectopic versus eutopic endometrium may result from the absence of abdominal microbiota and local adaptive mechanisms. These differences in redox status may be used for the diagnosis of the disease.

Introduction. Male fertility disorders, particularly idiopathic male infertility (IMI), remain a pressing medical and social issue. The pathogenesis of IMI is often associated with oxidative stress, which highlights the relevance of antioxidant vitamins. However, comprehensive studies of their serum concentrations in regional populations, such as the Yugra, are lacking.

Objective is to compare serum concentrations of vitamins A, E, C, D and semen parameters in men with IMI and fertile men residing in Yugra, and to assess the relationship between vitamin levels and semen parameters in the total sample of examined individuals.

Materials and methods. A prospective case-control study was conducted. The main group consisted of 70 patients with IMI, the comparison group — 50 fertile men with normozoospermia. All participants underwent semen analysis (WHO 2021 criteria) and determination of serum concentrations of vitamins A and E by high-performance liquid chromatography (HPLC), vitamin C by HPLC with ultraviolet detection, and 25-hydroxyvitamin D by chemiluminescent immunoassay. Statistical analysis was performed using MedCalc.

Results. Patients with IMI showed a significant decrease in serum levels of vitamins A, E, and C and deterioration in all semen parameters compared to controls (p < 0.001). No differences were found for vitamin D. Correlation analysis in the pooled sample (n = 120) revealed significant positive associations of vitamins A, E, and C with the main semen parameters. The most pronounced correlations were found for vitamin C with the proportion of progressively motile sperm (rS = 0.758; p < 0.001) and total motility (rS = 0.699; p < 0.001). Vitamins A and E also significantly correlated with motility, morphology, and sperm concentration (p < 0.001–0.010). No significant correlations were found between vitamin D and semen parameters (p > 0.050).

Introduction. The study of relationship between nasal obstruction syndrome, adenoids, cephalometric indicators is relevant.

Research objective is to identify the relationship between the size of the nasopharynx and adenoids and the size of the facial skull in children aged 4–7 years, in order to select the appropriate instruments and improve the results of surgeries in clinical practice.

Materials and methods. 79 CT scans of children’s heads aged 4–7 years of both sexes were evaluated сraniometric parameters of facial skeleton from piriform aperture to the hoanas.

Results. The height of nasopharynx is related to width of inferior nasal passage in anterior region, excluding mucous membrane of nasal concha, height of vomer, and width of choana; its length — to thickness of nasal septum in anterior region; its width — to total width of choana; height of adenoids — to total width of choana and width of piriform aperture, in boys the height of adenoids is 1.724 mm less than in girls of the same age; their length — to thickness of lower nasal turbinate on the right in posterior region and width of choana.

Conclusion. In children 4–7 years, the size of the nasopharynx can be calculated based on the identified dependencies from the size of the facial skull, which is important for adenotomy to select instruments and improve the quality of operations. It is not advisable to use regression equations to calculate the size of adenoids based on the size of the facial skull n children aged 4 to 7 years.

Introduction. A rare observation of balloon cell nevus (BN) in a 5-year-old child in the skin of the perianal region is given.

The purpose of this clinical case report is to present the morphological characteristics of an extremely rare skin pathology (BN) in a 5-year-old child in an unusual location (the perianal area) which determines the patient’s subsequent management.

Description of the clinical case. A rounded yellowish formation up to 0.8 cm was found in the perianal region. A formation with a smooth surface with a brownish tint of the periphery, elastic and displaceable together with the dermatoscope board. Under general anesthesia, a rounded formation of a symmetrical appearance, soft-elastic consistency was excised. Microscopically: nests of melanocytes at the border of the epidermis and dermis with transformation into large light balloon cells (up to 90 % of the tumor). Cell polymorphism, nuclear atypia, mitoses are absent. Immunohistochemically: positive expression of Melan-A, S100, HMB-45 by balloon cells, negative expression of panCK, CD68 and CD10.

Discussion of the clinical case. Morphological and immunohistochemical characteristics of the nevus with isolation of immunohistochemical markers of this tumor are discussed in detail. Literature data on the alleged genesis of BN are presented.

Conclusion. The morphological diagnosis in the above observation is extremely important, since it determines the vector of further studies and the tactics of patient management.

Introduction. Currently, cervical cancer (CC) remains a critical issue in oncogynecology. The search for new molecular biomarkers for predicting the occurrence and early diagnosis of CC is an urgent task. In this context, microRNAs (miRNAs) and circular RNAs (circRNAs) are of particular interest.

Materials and methods. An analytical review of contemporary scientific publications (from the last 10 years) from the databases PubMed, Scopus, eLibrary.ru, and Google Scholar has been conducted, focusing on the role of miRNAs and circRNAs in the pathogenesis, diagnosis, and prognosis of cervical intraepithelial neoplasia (CIN) and CC.

Results. Literature data on characteristic patterns of miRNA dysregulation (hyperexpression of miRNA-20a, miRNA-21; hypoexpression of miRNA-23b, miRNA-135a, miRNA-145) at various stages of cervical carcinogenesis associated with human papillomavirus (HPV)-induced oncogenesis have been summarized. Published information on key axes of “circRNA-miRNA-mRNA” regulatory networks mediating essential oncogenic processes has been systematized. Literature data on the significant diagnostic and prognostic potential of miRNA panels (for example, miRNA-20a, miRNA-21, miRNA-23b) have been presented for both tissue samples and liquid cytology materials.

Discussion. The review results demonstrate the evolution of research from studying individual biomarker molecules to a systemic analysis of integral regulatory complexes. The combination of miRNA, circRNA, and epigenetic markers (DNA methylation) analysis within integrative algorithms appears to be the most promising direction for personalizing screening, diagnosis, and prognostic assessment in CC.

Introduction. Syncope and epilepsy often present with similar symptoms, complicating their differential diagnosis. This can lead to incorrect treatment, inadequate management, and poorer patient outcomes. Thus, accurately distinguishing between these conditions remains a key challenge in modern neurology. The primary goal is to identify reliable criteria that allow for timely and precise diagnosis.

Objective. This review aims to analyze the differential diagnostic features of epilepsy and syncope as documented in recent scientific literature.

Materials and methods. A systematic review was conducted on 71 open-access studies published between 2012 and 2025. About 80.3 % of these were international publications, including clinical guidelines, systematic reviews, and original research, while around 19.7 % were domestic sources. The selected works cover clinical, instrumental, and biochemical aspects of syncope and epilepsy, providing practical insights for clinicians. All sources were critically evaluated based on relevance, scientific novelty, and data credibility.

Results and discussion. The review identifies key clinical, instrumental, and laboratory criteria for differentiating syncope from epilepsy. It highlights the importance of the onset and progression of symptoms, electroencephalography, cardiological assessments, neuroimaging, and biochemical markers in clarifying diagnoses and ruling out other pathologies.

Conclusion. Accurate differentiation requires a comprehensive approach considering medical history, clinical features, biochemical data, and instrumental findings. Integrating these factors enhances diagnostic precision and guides effective treatment strategies.