Perinatal hypoxia impairs cardiovascular development by inducing mitochondrial dysfunction, a metabolic shift toward anaerobic glycolysis, and oxidative stress. Identification of effective plant-derived antihypoxic agents remains a relevant objective of experimental pharmacology.
Aim: to investigate the effect of prenatal administration of Calendula officinalis extract on mRNA expression of antioxidant enzyme genes in cardiac tissue of rat pups subjected to acute normobaric hypoxia.
Materials and methods. The study was performed on Wistar rats. Pregnant females (n=20) received intragastric administration of either distilled water (group 1) or aqueous Calendula officinalis extract at a dose of 200 mg/kg (group 2) from the first day of gestation until delivery. On postnatal day 2, pups were exposed to acute normobaric hypoxia (8% O₂, 37°C, 2 h). mRNA expression of Sod1, Cat, GPX1, and GSR in cardiac tissue was assessed by real-time PCR immediately after hypoxia and on days 1, 7, and 14 of observation (n=40 pups per group).
Results. Immediately following hypoxia, both groups exhibited a marked upregulation of Sod1, Cat, and GSR alongside a significant decrease in GPX1; both effects were more pronounced in females. Expression levels gradually returned to baseline over subsequent time points. In group 2, the amplitude of gene expression fluctuations was significantly attenuated, and by day 14 mRNA levels of all four genes were comparable to those of intact animals.
Conclusion. Prenatal administration of Calendula officinalis extract modulates the myocardial antioxidant response to acute hypoxia, accelerating the restoration of the antioxidant enzyme transcriptional profile — an effect indicative of pronounced biological activity of the compounds present in the extract.

Degenerative spine diseases (DSD) are a leading cause of chronic low back pain and disability. Existing conservative and surgical methods often fail to address the root cause of pain and are associated with risks.
This study aimed to evaluate the clinical efficacy and safety of a minimally invasive method of laser autoplasty of the nucleus pulposus in patients with chronic pain syndrome.
Materials and methods. A prospective single-center study was conducted with 20 patients. Inclusion criteria: chronic non-radicular pain or radiculopathy in the irritation phase due to disc degeneration of stages I-III according to a classification (Pfirrmann). Under X-ray control, laser exposure (diode laser, 1061 nm) was
applied to three zones of the nucleus pulposus. Outcomes were assessed before surgery, after, and at 3- and 12-months using VAS, ODI, DN4, PainDetect, SF-36, HADS scales, and MRI of spine.
Results. A significant reduction in low back pain intensity (VAS: from 4.8±1.2 to 1.25±1.11 at 12 months, p<0.001) and improvement in functional status (ODI: from 15.15±4.87 to 5.88±4.28, p=0.0056) were observed. The proportion of patients with neuropathic pain decreased from 30% to 10%. Quality of life (SF-36) scores significantly improved, and levels of anxiety and depression (HADS) decreased. No complications were recorded.
Conclusion. Laser autoplasty of the nucleus pulposus is a highly effective and safe method for treating chronic pain syndrome in patients with stages I-III DSD, providing significant and sustained clinical improvement despite the lack of confirmed long-term structural disc restoration. The method can be considered a promising alternative to more invasive interventions.

Background. Core decompression is the standard joint-preserving procedure for early-stage osteonecrosis of the femoral head; however, a proportion of patients experience treatment failure and subsequently require total hip arthroplasty. Identifying preoperative predictors of decompression failure remains an important clinical challenge. Bone marrow edema and synovitis, detectable on MRI, are potentially informative markers, but their prognostic value has not been systematically evaluated.
Objective. To assess the value of MRI-detected bone marrow edema and synovitis as predictors of core decompression failure in early-stage osteonecrosis of the femoral head.
Materials and Methods. One hundred patients with ARCO stage II osteonecrosis of the femoral head who underwent joint-preserving surgical treatment (core decompression) were enrolled in a prospective study. Preoperative MRI of the hip joint was performed in all patients, with assessment of synovitis and bone marrow edema of the proximal femur. Treatment efficacy was defined by the need for subsequent total hip arthroplasty.
Results. In the absence of MRI signs of synovitis and bone marrow edema, core decompression failed in only 5.9% of patients. The rate of subsequent total hip arthroplasty was 21.1% in patients with isolated synovitis, 20.0% in those with isolated bone marrow edema, and 54.5% in patients presenting with both findings simultaneously.
Conclusion. MRI signs of synovitis and bone marrow edema — particularly in combination — are significant predictors of core decompression failure in ARCO stage II osteonecrosis of the femoral head. Their preoperative identification should be incorporated into surgical planning and patient counseling regarding the likelihood of future total hip arthroplasty. Contrast-enhanced MRI is recommended to accurately assess the extent of synovial inflammation.

Objective. To evaluate long-term outcomes of surgical treatment in patients with locally advanced renal cell carcinoma and to identify clinicopathological factors associated with overall and recurrence-free survival.
Materials and Methods. A retrospective cohort study enrolled 97 patients with stage T3a-cN0M0G1–3 renal cell carcinoma who underwent surgery at the Samara Regional Clinical Oncology Dispensary between 2016 and 2017. Clinical, morphological, and metabolic parameters were analyzed. Survival was estimated using the Kaplan–Meier method with log-rank testing for between-group comparisons.
Results. Five-year overall survival was 78% and recurrence-free survival was 86%. Statistically significant adverse prognostic factors for both endpoints included: tumor size greater than 7 cm, poor differentiation (G3), tumor thrombus (particularly with inferior vena cava extension), grade III obesity, diabetes mellitus, and anemia. Patient age and side of lesion had no significant effect on prognosis; grade I–II obesity did not worsen survival outcomes.
Conclusion. Risk stratification in locally advanced renal cell carcinoma should incorporate not only tumor morphology (size, grade, thrombus extension) but also the patient's metabolic profile (grade III obesity, diabetes, anemia). The identified factors may serve as a basis for individualized postoperative surveillance planning.

Introduction. Over the past decade, there has been an increase in the number of multiple primary malignant tumors. The incidence of multiple primary cancers in the world ranges from 2% to 17%, with a synchronous cancer incidence of approximately 6%. Among patients with multiple primary cancers, the majority have two tumors. The most common gynecological diseases associated with breast cancer are ovarian cancer, endometrial cancer and cervical cancer.
Aim: to study the clinical and morphological characteristics of patients with multiple primary breast and endometrial cancer.
Material and methods. A retrospective analysis of patients with multiple primary cancers registered at the Moscow S.P. Botkin multidisciplinary research and clinical center was conducted.
Results. 35,0% of patients were diagnosed with SMPC, with a median time interval of 2,0 months between tumors detection (Q1-Q3 1,0–1,3), 65,0% had MMPC with a median time between tumor detection of 90,0 months (Q1-Q3 37,5–179,5). The age of patients with SMPC at the time of diagnosis of the first tumor was 38-78 years, with an average of 61,7±11,4 years, and the age of patients with MMPC at the time of diagnosis of the first tumor was 33-83 years, with an average of 57,9±11,1 years (p > 0,05). IA stage of breast cancer and endometrial cancer prevailed – 46,3% and 53,8% of cases, respectively; as well as breast ductal carcinoma – 87,5%, luminal B HER2 negative – 37,5% of cases and endometrial cancer – 85,0% of cases.
Conclusions. In patients with multiple primary breast and endometrial cancer, tumors are predominantly detected at stage I, with a less aggressive histological type and the most favorable molecular type of breast cancer. In most cases, surgery is the treatment of choice. Radiation therapy for breast cancer increased the risk of developing endometrial cancer by 2,6 times.

Relevance. Treatment of chylothorax in patients depends largely on the underlying cause. In some cases, it is associated with disruption of the intact lymphatic duct (due to trauma or surgery), while in others, it is due to venous and lymphatic hypertension (in cases of congenital heart disease, lymphatic duct malformations, heart disease, and cancer). The main goal of conservative treatment is to reduce the flow of chyle through the thoracic duct to ensure spontaneous resorption, reduce systemic lymph production through diet (dry food, fasting, somatostatin/octreotide, midodrine, and sirolimus, parenteral nutrition), replenish nutrient losses, drain the pleural cavity, and use pleurodesis (talc, bleomycin, tetracycline, povidone, hypertonic glucose solution). This treatment is aimed at eliminating the underlying cause of chylothorax. If conservative therapy is ineffective and the chylothorax persists at 1000 ml or more, surgical treatment is performed (video-assisted thoracoscopy, clipping, or ligation of the thoracic duct).
Goal: to develop a step-by-step plan for the comprehensive treatment of patients with chylothorax of various etiologies.
Material and Methods. The study included 21 patients with chylothorax of various etiologies (emergency admissions (17) and transfers (4) from other hospitals) admitted to the thoracic department.
Results. Treatment of chylothorax depends on the underlying cause, individual manifestations, and the intensity of chyle production. In some cases of non-traumatic chylothorax, pulmonary bypass grafting and biopsy were used to identify the cause. Conservative treatment was based on pleural drainage and included a low-fat diet, transfusion therapy, somatostatin/octreotide, and sirolimus. The primary goal was to reduce chyle production by decreasing fat absorption and preventing malnutrition. Nutritional interventions included total parenteral nutrition or enteral diets. In cases of ineffective non-traumatic chemotherapy and postoperative traumatic chemotherapy, VTS + CLP were performed (pleurodesis and pleurectomy were performed if necessary, regardless of the etiology, as it is not always possible to completely relieve chylorrhea). Reducing chyle leakage ensures spontaneous resorption, and in cases of venous and lymphatic hypertension due to heart failure or oncologic pathology, additional specific treatment is required.
Conclusion. The treatment strategy for chemotherapy is determined based on the etiopathogenesis and intensity of lymph leakage, using a step-by-step treatment plan, from the least invasive to the most invasive methods. Malignant neoplasms, chronic chylous effusion complicated by pulmonary embolism, and cardiac disease, despite the complex treatment aimed at reducing chylothorax volume, including VTS and CLP, require additional specific therapy. Traumatic chemotherapy (postoperative). In most cases, along with conservative management, chylothorax requires vascular thoracic surgery and duct clipping, and in some cases, pleurodesis is also needed. Conversely, with typical mechanical trauma and normal lymphatic duct pressure, conservative management is sufficient.

Large incisional hernias are a serious problem in modern surgery. Performing separation retromuscular prosthetic hernioplasty for complex ventral hernias is associated with significant injury and high risks of complications. Studying the biomechanics of the anterior abdominal wall may improve the results of surgical treatment of patients with large postoperative ventral hernias.
Objective: to develop and substantiate, using mathematical modeling, an algorithm for performing biomechanical reconstructive hernioplasty for large incisional hernias.
Materials and methods. The theoretical basis of the biomechanical reconstruction was a geometric model of the anterior abdominal wall, formed after transformations, taking into account the restoration of the true size of the abdominal cavity. To create a physically stable line of approximation of a hernial defect, the laws of classical mechanics describing the relationship between body stress and its deformation are used. The presented physico-mathematical model makes it possible to determine the optimal stretching distances for both sides of the muscular-aponeurotic sides of the anterior abdominal wall, at which the forces of elastic deformation will balance each other. To substantiate the presented concept, a prospective single-center study was conducted involving 74 patients with large postoperative ventral hernias. The first group included 33 patients for whom the biomechanical reconstruction model was applied, and the second group consisted of 41 patients for whom this algorithm was not applied.
Results. Both groups had no statistically significant differences at the preoperative stage, and the parametric characteristics of hernias were comparable (p>0.05). Biomechanical reconstruction of the anterior abdominal wall made it possible to reduce the number of bilateral (p<0.001) and increase the number of unilateral posterior separation procedures (p=0.014) in the first group, compared with the second. There was also a reduction in the time of surgery (p=0.021), the length of hospitalization (p=0.037) and the number of complications (p=0.682) in the first group, compared with the second.
Conclusion. The use of biomechanical reconstructive hernioplasty makes it possible to take into account the anatomical and physiological features of the anterior abdominal wall, which is reflected in the creation of a stable suturing line of the hernial defect.

Introduction. Tuberculosis of the musculoskeletal system occupies the fourth place in the incidence structure among extrapulmonary lesions caused by M. tuberculosis, accounting for about 10% among all localizations. In some cases, tuberculosis of the musculoskeletal system is combined with tuberculosis of the lungs.
The aim: to evaluate the effectiveness of simultaneous surgical treatment in patients with tuberculosis of multiple localization: tuberculosis of the respiratory system and thoracic spine, using titanium implants in combination with bone autoplasty and a high-energy laser.
Materials and methods. The analysis of the results of simultaneous surgical treatment of the lungs and thoracic spine performed in 54 patients with tuberculosis of multiple localizations: tuberculosis of the lungs and thoracic spine in the period from 2017 to 2024. All patients were divided into 2 groups: group 1, recruited from 2021 to 2024, consisted of 24 patients who underwent intraoperative irradiation of the bed of the affected vertebrae with a high–energy laser, group 2, recruited from 2017 to 2020, consisted of 30 patients who underwent surgery without the use of a high–energy laser. The groups were comparable to each other (p>0.05).
Results. The median duration of surgery in group 1 was 277.5 (62.5; 359.5 minutes) minutes, in group 2 – 272.5 (61.25; 436) minutes (p>0.05). The median volume of blood loss in group 1 was 550 (33.6; 1165) ml, in group 2 – 387.5 (50; 2443.25) ml (p>0.05). The median stay in the intensive care unit (ICU) in group 1 was 4 (3; 7) days; in group 2 4.5 (3; 7.85) days (p>0.05). The analysis of early postoperative complications revealed that in group 1, complications were significantly less common – 12.6% of cases than in group 2 – in 40% of cases (p<0.05).
Conclusion. These results were achieved primarily by reducing the frequency of intrapleural hemorrhagic complications (bleeding, prolonged exudative pleurisy), the source of which in the control group was the spongy bone tissue of the removed parts of the thoracic vertebrae.

Background. Suture failure after surgery for complicated gastric and duodenal ulcers occurs in 11–15% of patients, with mortality rates reaching 50–70%, necessitating the search for effective treatment methods.
Aim. To compare the effectiveness of various surgical treatment methods for duodenal and gastric fistulas that developed after operations for perforated ulcers, gastroduodenal bleeding, and pyloroduodenal stenosis.
Materials and Methods. The study analyzed treatment outcomes in 97 patients (73 men, 24 women, aged 18-95 years) with gastric and duodenal fistulas that developed after suturing of perforated ulcers and gastric resection using Billroth I and Billroth II methods. Fistulas were classified according to V.I. Belokonev and E.P. Izmailov (2005), peritonitis according to V.N. Chernov and B.M. Belik (2002), and intestinal failure according to V.A. Koryachkin and V.I. Strashnov (2002). The following treatment methods were employed: fistula suturing (n=10), external drainage of the insufficiency zone (n=7), fistula obturation with Foley catheter (n=14), through-and-through drainage of the upper gastrointestinal tract (n=14), drainage of subhepatic abscess (n=20), conservative treatment of type III fistulas (n=27), and fistula closure with vascularized muscle flap (n=5).
Results. Overall mortality was 45.4% (44 of 97 patients). Mortality by fistula type: type I — 62.2% (28 of 45), type II — 30% (6 of 20), type III — 33.3% (9 of 27), type IV — 33.3% (1 of 3), type V — 0% (0 of 2). Mortality by treatment method: fistula suturing — 70% (7 of 10), external drainage — 85.7% (6 of 7), Foley catheter obturation — 50% (7 of 14), through-and-through drainage of upper GI tract — 42.8% (6 of 14), subhepatic abscess drainage — 30% (6 of 20), conservative treatment of type III fistulas — 33.3% (9 of 27), muscle flap closure — 20% (1 of 5).
Conclusion. Postoperative mortality in patients with gastric and duodenal fistulas remains high and depends on fistula type and treatment method. Throughand-through drainage of the upper gastrointestinal tract via duodenal fistula demonstrates the lowest mortality (42.8%) among surgical methods for treating type I-II duodenal fistulas. Drainage of subhepatic abscesses in type II fistulas provides 30% mortality. Conservative treatment of typeIII fistulas is effective with adequate drainage (mortality 33.3%).

Relevance. Chronic obstructive pulmonary disease represents a significant public health problem, particularly in patients with human immunodeficiency virus (HIV), where it is more severe and more common.
Objective. To systematize and summarize literature data on the immunological and microbiological factors underlying the development and progression of chronic obstructive pulmonary disease in this patient population.
Materials and Methods. A systematic review of articles in leading databases from 2000 to 2024, as well as original studies, reviews, and meta-analyses, was conducted.
Results. Chronic systemic inflammation, immune dysfunction, and pulmonary microbiota dysbiosis were found to play a key role in the pathogenesis. Specific factors, such as low CD4 lymphocyte counts and recurrent respiratory infections, accelerate lung tissue damage.
Conclusions. The concurrence of human immunodeficiency virus infection and chronic obstructive pulmonary disease is a complex pathological process that leads to rapid disease progression. Understanding the relevant mechanisms is critical for developing targeted prevention and treatment strategies.

Purpose: to conduct a multifactorial comparative analysis of the effectiveness of different dosing regimes of radioiodine therapy in differentiated thyroid cancer (DTC) to identify dose-dependent patterns of tumor response to the therapy.
Materials and methods. The general population of the retrospective-prospective cohort study included 1615 cases during the follow-up period from 2023 to 2025. A multi-level statistical analysis of metastasis rates, disease progression, and the number of courses of radioiodine therapy at different doses of ¹³¹I was conducted.
Results. The personalized approach demonstrated a statistically significant improvement in the control of differentiated thyroid cancer: in the low-risk group, 0% progression at 3350±480 MBq (p<0.001), in the medium-risk group, 1.3% progression at 4750±800 MBq (p=0.003), and in the high-risk group, 4.4% progression at 8250±1250 MBq (p=0.012).
Conclusion. A comprehensive approach, including careful preparation of patients for radioiodine therapy, revision of histological reports if necessary, and a detailed analysis of diagnostic test results and previous post-therapeutic scans, can significantly improve the effectiveness of treatment. The data obtained from the epidemiological analysis serve as a basis for further research and the possibility of refining the national clinical guidelines for the personalized treatment of differentiated thyroid cancer using radioiodine therapy.

Background. Femoral neck fracture is one of the most common fractures in the elderly. The number of femoral neck fractures is increasing due to an increase in the incidence of osteoporosis, impaired vision in the elderly, impaired neuromuscular coordination, sedentary lifestyle, and an increase in life expectancy in general. Traditional methods of fixing such fractures often lead to poor results and a high level of complications. Thus, the incidence of complications in osteosynthesis of the femoral neck is up to 46%. The two-pole bipolar fixation method is a new approach that involves the simultaneous placement of screws in two planes, creating a two-point support for screws in the neck and head of the femur.
Aim. The purpose of this study is to evaluate the effectiveness of the two-support bipolar fixation method in the treatment of patients with femoral neck fracture aged 22-86 years.
Methods. A total of 28 patients with fresh hip fractures (less than two weeks old) underwent closed reposition and internal fixation using the method of two-support fixation. The functional results of the patients were evaluated using the Harris scale, and the radiological results of fusion, shortening of the femoral neck, lateralization of screws and avascular necrosis of the femoral head (AVN) were also evaluated.
Results. The results showed that the technique of double-support bipolar fixation is a safe and effective osteosynthesis for fracture of the femoral neck in both young and elderly patients. Of the 28 subjects under observation, 1 patient refused further follow-up. On average, within 20 months (range 6-24 months), 21 (78%) fractures radiographically healed in an average of 6 months. Non-union occurred in three patients (22%), and three patients (12%) had implant migration. One patient had a peri-implant fracture (2.7%). Two patients had varus collapse, but their fractures successfully healed (7.4%).
Conclusion. The two-support fixation technique has a number of advantages over traditional methods, including increased stability and strength of fixation. It can be considered as an alternative to traditional methods of treating femoral neck fractures with a low incidence of non-union, avascular necrosis and the absence of cases of fixation disorders or varus collapse.

Background. Patients with kidney failure receiving renal replacement therapy (RRT) have a 3–5-fold higher risk of gastrointestinal bleeding than the general population.
Aim. To evaluate treatment outcomes in patients with non-variceal upper gastrointestinal bleeding (NVUGIB) receiving RRT.
Materials and methods. We retrospectively analyzed 106 patients with NVUGIB receiving hemodialysis-based RRT who were treated in 2019–2025 at Samara City Clinical Hospital No. 1 (N.I. Pirogov) and Togliatti City Clinical Hospital No. 5. Two clinical groups were defined: Group I—acute kidney injury (AKI; n=33) and Group II—end-stage kidney disease (ESKD) on maintenance hemodialysis (n=73). Categorical variables were compared using the χ² test; Fisher’s exact test was used for 2×2 tables with small expected cell counts. Continuous variables were compared using the Mann–Whitney U test. A two-sided p value <0.05 was considered statistically significant.
Results. In Group I (AKI), 13 patients (39.4%) required endoscopic and/or surgical treatment, whereas 20 (60.6%) were managed conservatively; in-hospital mortality was 21.2% (7/33). In Group II (ESKD), 26 patients (35.6%) underwent endoscopic and/or surgical intervention and 47 (64.4%) received conservative therapy; in-hospital mortality was 15.1% (11/73). Mortality did not differ significantly between the AKI and ESKD groups (χ²=0.61; p=0.40). When patients were regrouped by definitive treatment strategy, mortality was 58.8% (10/17) after surgery, 9.1% (2/22) after endoscopic hemostasis, and 9.0% (6/67) with conservative management (χ²=25.1; df=2; p<0.001). In pairwise comparisons, surgery was associated with higher mortality than endoscopic hemostasis (Fisher’s exact test, p=0.001; OR=14.29, 95% CI 2.49–81.82; RR=6.47, 95% CI 1.63–25.72).
Conclusion. Management of NVUGIB in patients receiving RRT should follow a structured pathway, prioritizing early endoscopy after hemodynamic stabilization, individualized anticoagulation management, and multidisciplinary decision-making. Endoscopic hemostasis was associated with low in-hospital mortality, whereas surgical intervention was linked to markedly worse outcomes and should be reserved for life-threatening situations when endoscopic control fails or is not feasible. Conservative therapy should be viewed as a temporary or selective option rather than an equivalent alternative to endoscopic treatment.

Background. Estimating the age of subdural hematomas is a critical task in forensic neuropathology. Capsular hemosiderosis is widely used as a morphological time marker; however, the potential confounding effect of prior neurosurgical intervention on this parameter has not been systematically investigated, which may compromise expert accuracy.
Objective. To assess the effect of surgical treatment on the quantitative pathomorphology of subdural hematoma capsules and to develop a regression model for hematoma age determination.
Materials and Methods. A retrospective, blinded morphometric study was performed on capsules of 65 fatal traumatic supratentorial subdural hematomas with known intervals from injury to death ranging from 3 to 90 days. In 43 cases, patients had undergone neurosurgical intervention (decompressive craniectomy); 22 cases were unoperated. Parameters assessed included maximum capsule thickness, relative volume of hemosiderosis, and cellular infiltration intensity.
Results. Neurosurgical treatment significantly reduced the rate of increase in intracapsular hemosiderosis relative volume, with the effect proportional to the duration of the postoperative period. No significant influence of surgery on capsule thickness or cellular infiltration was detected. A regression equation for hematoma age estimation, incorporating maximum capsule thickness and hemosiderosis volume, was developed and implemented as Calculator SDH Age 3.0.
Conclusion. Prior surgical treatment must be considered when estimating subdural hematoma age based on capsular hemosiderosis. The derived regression model and Calculator SDH Age 3.0 are recommended for forensic practice in dating unoperated encapsulated subdural hematomas.

Background. Burnout among higher education faculty represents a significant occupational health concern with direct implications for teaching quality and institutional performance. The convergence of increased administrative burden, digital transformation, and the COVID-19 pandemic has intensified emotional exhaustion across academic settings worldwide.
Objective. To systematize the psychological, social, and organizational determinants of professional burnout among university faculty and to substantiate evidence-based principles for its prevention.
Main Content. Key risk factors examined include chronic work overload, role ambiguity, limited professional autonomy, insufficient institutional support, and interpersonal workplace conflict. Burnout manifestations are analyzed comparatively across technical, humanities, and medical universities. The rationale for multimodal diagnostic approaches — combining standardized instruments (MBI, OLBI) with clinical assessment methods — is discussed. Digital transformation is identified as an independent contributor to emotional exhaustion. Organizational and psychological prevention strategies are proposed, tailored to the characteristics of different academic environments.
Conclusion. Effective burnout prevention in higher education requires the integration of validated diagnostic tools, targeted institutional interventions, and sustained psychological support adapted to the specific profile of each educational organization.

Background. Disseminated pulmonary lesions pose one of the most challenging diagnostic problems in pulmonology and phthisiology. Mycobacterial infection — both tuberculous and non-tuberculous — frequently mimics other interstitial lung diseases, leading to significant diagnostic delays and epidemiological risk, particularly when healthcare workers serving vulnerable populations are affected.
Objective. To present a case illustrating the diagnostic challenges of timely etiological verification of combined mycobacterial infection in a healthcare worker with pulmonary dissemination of undetermined etiology.  
Case Report. A 55-year-old female nurse working with pediatric patients was followed as an outpatient for one year with pulmonary infiltrates of unknown origin, despite multiple specialist consultations. Upon admission to a specialized institution and exhaustion of non-invasive diagnostic options, video-assisted thoracoscopic surgery (VATS) with lung resection was performed for diagnostic and therapeutic purposes. Histopathological examination of the resected specimen revealed features consistent with tuberculosis; subsequent mycobacterial culture additionally confirmed non-tuberculous mycobacterial infection. A comprehensive multidisciplinary approach enabled rapid diagnosis and initiation of targeted therapy.
Conclusion. This case underscores the importance of early referral of patients with undiagnosed pulmonary dissemination to specialized phthisiopulmonology centers equipped with the full range of invasive diagnostic modalities, including VATS biopsy and extended mycobacterial identification.

Relevance. Cholelithiasis (GI) remains one of the most common diseases in gastroenterology and surgery, and its complications (acute cholecystitis, choledocholithiasis, biliary pancreatitis) continue to pose a serious threat to the lives of patients. A historical analysis of the evolution of views on these complications allows not only to pay tribute to key discoveries, but also to better understand modern therapeutic and diagnostic paradigms, as well as identify promising areas for future research.
The purpose of the study. To conduct a systematic analysis of the historical stages of the study of gallstone disease complications, from the first pathomorphological descriptions to the development of modern minimally invasive technologies.
Materials and methods. An analytical review of historical scientific literary sources, archival medical publications and modern clinical recommendations has been conducted. The methodology included historical and retrospective analysis, systematization and synthesis of data.
Results. Five key stages in the study of GI complications have been identified: 1. The era of pre–scientific observations (Antiquity - XVIII century): the works of Morgagni, which laid the foundations of pathoanatomic understanding. 2. The origin of biliary surgery (19th century): Langenbuch's first cholecystectomy, Courvosier's law. 3. Delving into pathophysiology (the first half of the 20th century): the theory of biliary pancreatitis, description of Mirrizzi syndrome. 4. Technological revolution (the second half of the 20th century): the introduction of ultrasound, ERCP and laparoscopic cholecystectomy. 5. The modern stage (the turn of the XX-XXI centuries): algorithmization (Tokyo recommendations), personalized approach. It is shown how the development of technologies and scientific concepts has consistently reduced the invasiveness of treatment and improved the prognosis of patients.  
Conclusions. The history of studying the complications of cholelithiasis demonstrates impressive progress – from fatalistic acceptance of an inevitable fatal outcome to active prevention and effective treatment. Further research should focus on improving a personalized approach, minimizing the invasiveness of interventions, and improving long-term treatment outcomes.

Background. Abandonment of protocol liver biopsies in most transplant centers allows clinically significant graft pathology — fibrosis, steatosis, chronic hepatitis, ductopenia — to remain undetected for prolonged periods, even in the absence of graft dysfunction or laboratory abnormalities, resulting in unexpected late graft failure.
Objective. To assess the prevalence of bile duct loss, graft steatosis, active hepatitis, and liver fibrosis, and to identify independent clinical and laboratory factors associated with these pathological changes in the long-term posttransplant period.
Materials and Methods. Histological findings from 168 adequate liver biopsy specimens obtained from 178 adult liver transplant recipients were retrospectively analyzed. All biopsies were performed no earlier than 12 months post-transplantation (median follow-up 57.8 [26.3; 94.9] months). Liver function test values were normalized to sex-specific upper limits of normal. Overt graft dysfunction was defined as elevation of ALT, AST, or alkaline phosphatase above 1.5× ULN. Fibrosis was assessed using METAVIR and the liver allograft fibrosis (LAF) scale, evaluating portal, sinusoidal, and centrilobular components separately. Statistical methods included Mann–Whitney U test, chi-square test, Spearman rank correlation, and multivariate logistic regression.
Results. Graft steatosis (>5% of hepatocytes) was detected in 29.2% of cases, steatohepatitis in 14.9%, active hepatitis (METAVIR A2–A3) in 10.1%, advanced fibrosis (METAVIR F3–F4) in 14.9%, and ductopenia in 16.1%. On multivariate analysis, steatosis and steatohepatitis were independently associated with elevated BMI, eGFR <45 ml/min/1.73 m², and fatty liver disease as the original indication for transplantation; steatohepatitis was additionally associated with post-transplant diabetes. Advanced portal fibrosis (LAFp) was independently associated with overt graft dysfunction, time elapsed since transplantation, and low eGFR; sinusoidal fibrosis with low eGFR alone; centrilobular fibrosis with younger donor age and cyclosporine use. Ductopenia was independently associated with autoimmune liver disease as the transplant indication and with biliary strictures.
Conclusion. Late graft disease encompasses at least two distinct pathological patterns — chronic hepatitis and graft steatotic liver disease — differing in risk factors, progression kinetics, and laboratory markers. Reduced eGFR emerges as an unexpectedly robust independent predictor of multiple histological injury patterns in adult recipients. These findings provide a rationale for reintroducing protocol biopsy in the long-term post-transplant follow-up.

Machine perfusion of donor organs is becoming the standard of preservation in transplantology; however, perfusion parameters — pressure, volumetric flow, and vascular resistance — are still set empirically, without accounting for the hydrodynamic characteristics of the individual organ. Computational fluid dynamics, primarily one-dimensional (1D) and three-dimensional (3D) flow modeling, provides the tools for a physically grounded selection of perfusion regimens.
Aim: to describe the conceptual framework and methodology of 1D modeling of intrahepatic and intrarenal blood flow as applied to machine perfusion of donor liver and kidneys; to present preliminary results of 1D model validation on clinical liver transplantation data; to report the results of 3D CFD modeling of portal vein hemodynamics as a basis for understanding perfusion fluid dynamics; and to propose physically justified perfusion regimens.
Materials and methods. One-dimensional models of hepatic and renal vascular trees were constructed based on the Navier–Stokes equations for tubular structures and Murray's law. Validation of the 1D hepatic arterial tree model was performed in 80 patients who underwent liver transplantation at the N.V. Sklifosovsky Research Institute of Emergency Medicine. To study portal vein hemodynamics, 3D CFD modeling was performed using FlowVision 3.13.01 on two geometric models reconstructed from CT data of real patients; both steady-state and transient simulations were carried out with Doppler-derived pulsatile flow boundary conditions.
Results. The error of the 1D model in calculating pressure at the arterial anastomosis site did not exceed 15%. CFD-guided optimization of reconstruction technique altered surgical strategy in 25% of high-risk patients, yielding a 33.1% increase in wall shear stress and a 64.3% reduction in prothrombotic zones. 3D CFD of the portal vein demonstrated that qualitative differences between Newtonian (Navier–Stokes) and non-Newtonian (Caro) rheological models are negligible, justifying the use of the computationally less demanding Newtonian model; three types of high-risk thrombosis zones were identified — stasis, recirculation, and abrupt flow redirection. With regard to perfusiology: for the liver, the optimal portal flow is 0.25–0.40 ml/min/g at a pressure of 3–6 mmHg; transition to D-HOPE reduces zonal acinar perfusion inhomogeneity from 28–35% to 9–13%; for the kidney — 18–22 mmHg at a flow of 0.8–1.2 ml/min/g.
Conclusion. The combination of 1D modeling (rapid calculation of pressure and flow distribution across the entire organ) and 3D CFD (spatial analysis of local hemodynamic risks) provides the most complete physical basis for machine perfusion parameter selection. The transition from empirical to computationally justified perfusion protocols is feasible on the basis of currently available clinical material.

Introduction. This article describes mistakes that occur during the baseline diagnosis and fabrication stages of splinting. Each error increases the risk of complications leading to retreatment and the choice of new tactics. The analysis of complications that occurred after immobilization of teeth in the immediate and distant periods after treatment will allow us to give practical recommendations for their prevention, and to develop methods for eliminating existing deficiencies and complications.
The aim of the study is to investigate the mistakes and complications occurring in dental splinting.
Materials and methods. Visual assessment and analysis of adhesive splinting structures were performed in 280 patients.
Results. Complications arising from splinting of teeth in acute and chronic injuries have been identified. The analysis of the main causes of complications at the stages of splinting of movable teeth was carried out.
Conclusion. Knowing the causes of errors and complications after splinting teeth allows you to diagnose and choose a treatment method with the optimal location of the splint, and thereby minimize the occurrence of complications.

Background. Growing interest in external compressive stenosis of the internal jugular veins (IJV) stems from its proposed role in the pathogenesis of intracranial hypertension and cerebral venous dysfunction. However, the literature lacks consensus on terminology, diagnostic criteria, stenosis grading systems, and threshold values, hampering inter-study comparability and evidence-based clinical guidance.
Objective. To systematize available data on diagnostic methods, calculated parameters, and grading systems for external compressive IJV stenosis, and to evaluate stenosis thresholds associated with intracranial venous congestion and clinical manifestations of cerebral venous dysfunction.
Materials and Methods. A narrative review of Russian- and English-language literature published between 1965 and 2025 was conducted using Medline/PubMed and the Russian Science Citation Index (RSCI/eLibrary). Search terms included: venous outflow, external stenosis, internal jugular vein, cerebral venous dystonia/dysfunction/congestion/stasis, venous encephalopathy, and intracranial hypertension, as well as their Russian-language equivalents.
Results. A stenosis threshold of 70–80% in one IJV was identified as the critical value for the development of intracranial venous congestion with clinical manifestations of cerebral venous dysfunction and venous encephalopathy. The venous-arterial balance (VAB) calculator was identified as a promising supplementary diagnostic tool: a total VAB below 40% indicates high probability of intracranial venous congestion, while values in the 40–59% range represent a zone of uncertainty, the clinical outcome of which depends on the degree of compensatory remodeling of cervical venous collaterals. The non-invasive combination of duplex ultrasound scanning and non-contrast magnetic resonance venography is recommended as the preferred first-line diagnostic approach.
Conclusion. External compressive IJV stenosis is a clinically significant yet insufficiently standardized entity. Establishing unified diagnostic criteria, stenosis grading systems, and venous balance parameters is essential for achieving inter-study comparability and building an evidence base for surgical correction of impaired cerebral venous drainage.