Individual resistance to hypoxia largely determines the severity of inflammatory processes and, probably, can affect the regeneration of the skin wound.The aim was to study reparative and inflammatory changes in the wound in Wistar rats with different resistance to hypoxia.Material and methods. The study was performed on mature male Wistar rats weighing 300–350 g. Before the experiment, the resistance of animals to hypoxia was determined. Rats were classified as highly resistant to hypoxia (HR), in which the time to take a lateral position in the pressure chamber “at a height” of 11,500 m was more than 360 s (n=5), to low-resistant (LR) – less than 40 s (n=5). A full-thickness wound with a diameter of 16 mm was applied to the animals in the interscapular zone of the back. On the 7th day after the infliction of the wound, a histological and morphometric study was performed. The proliferative activity of cells in the granulation tissue of the wound was determined immunohistochemically using the Ki-67 marker. Real-time PCR was used to evaluate the level of expression of the Hif-1α, Nf-κB, and Vegf genes.Results. It was shown that in rats with high resistance to hypoxia, the total number of cells and, among them, the number of inflammatory cells was higher than in rats with low resistance to hypoxia. However, the percentage of inflammatory cells in the compared groups did not differ significantly. Cell proliferative activity, as measured by the number of Ki-67 positive cells, was higher in rats with high resistance to hypoxia. In the granulation tissue of highly resistant to hypoxia rats, the expression of the Vegf gene was statistically significantly higher than in low-resistant animals, while there were no statistically significant differences in the level of expression of the Hif-1α, Nf-κB genes.Conclusion. In rats with high resistance to hypoxia, on the 7th day of healing of a full-thickness skin wound, reparative processes in it are more pronounced. In the horizontal layer of fibroblasts, there are more cells, among them inflammatory ones - histiocytes and macrophages, which is combined with a higher number of proliferating Ki-67 positive cells and the expression level of vascular endothelial growth factor (Vegf).

Dermal fibroblast cell culture is a convenient model for studying various effects on cells, including hypoxia. Fibroblasts, in addition to collagen production, are able to synthesize biogenic amines, hormones, neuropeptides, and neurotransmitters identical to those in the central nervous and endocrine systems, which allows them to be used to study cellular disorders in various diseases. The purpose of the study was to evaluate the functional changes in the culture of dermal fibroblasts under hypoxic conditions using biochemical and molecular biological methods. In cells of fibroblast culture under normoxia (air and 5% CO₂ in an incubator) and hypoxic exposure (a mixture of gases - 95% N₂ and 5% CO₂) at 1 and 3 hours, biochemical methods were used to determine the activity of aspartate aminotransferase (AsAT), alanine aminotransferase (AlAT), gamma-glutamyl transferase (GGT), lactate dehydrogenase (LDH), glucose levels, concentrations of ATP, ADP, AMP, as well as the level of mRNA expression of the hypoxia-induced factor Hif-1a and the nuclear factor Nf-κb by polymerase chain reaction. It was shown that under hypoxic exposure at 1 hour in fibroblast culture, cell viability, glucose levels and activity of LDH, AlAT, AsAT decrease, the amount of ATP decreases, after 3 hours there is a tendency to normalize all indicators. Adaptive mechanisms make it possible to normalize the functioning of cells under hypoxic conditions from 1 to 3 hours. The results obtained in the evaluation of metabolic changes at different times of hypoxic exposure (1 and 3 hours) in the culture of rat fibroblasts indicate a high adaptive capacity of connective tissue cells - fibroblasts at a lack of oxygen. The study of intracellular parameters during hypoxia, the determination of critical points depending on the time of exposure will determine the directions for further study of the mechanisms of cell adaptation, which, perhaps, will complement the tactics of compensatory effects in ischemia of tissues of various genesis. The revealed changes reflect the adaptive response of the fibroblast culture in response to hypoxic exposure.

Introduction. Obtaining primary cultures of fibroblasts is necessary for conducting experimental studies to investigate the basic cell response mechanisms to various stimuli. Despite the widespread use of fibroblast cultures, methods for obtaining them from the skin are not standardized. The aim of the studywas to find the optimal conditions to obtain a fibroblast culture from rat skin using enzymatic tissue disaggregation. Materials and methods. The fibroblast culture was obtained from the dermis of 18 male Wistar rats (N=12, 5–6-week-old, and 60–65 g body weight; N=6, 8–10-week-old rats, and 160–180 g body weight). A series of experiments was carried out to obtain a fibroblast culture with selecting the collagenase type and defining its concentration and exposure time. Results.An optimized protocol to obtain rat dermis fibroblasts is presented. Moreover, the problems of obtaining a culture and practical aspects of its use are discussed. Conclusion. When obtaining a primary culture of rat skin fibroblasts we should consider the following fac-tors: the type of the enzyme, its concentration, and exposure time; the age of the animals; the area of skin graft collection. In young rats, the optimal result was achieved when the cells were isolated from the axillary zone using collagenase type II at a 1 mg/ml concentration during a 90-minute exposure. In adult animals, the enzymatic effect of collagenase type II on the skin graft obtained from the back was optimal at a 5 mg/ml concentration during a 120-minute exposure. Keywords: fibroblast culture, dermis, preparation protocols, rats

Background. It is assumed that chronic immune-inflammatory rheumatic disease may be a factor increasing the likelihood of developing hypogonadism syndrome, and vice versa – the presence of uncompensated testosterone deficiency may predispose to a higher risk of developing or a more severe course of immune-inflammatory rheumatic disease. Aim. To study the frequency of hypogonadism in men with systemic sclerosis (SSc) and idiopathic inflammatory myopathy (IIM) and its associations with clinical manifestations of SSc and IIM. Materials and methods. A total of 65 patients were included in the one-stage continuous study, including 39 with SSc and 26 with IIM, who were undergoing inpatient treatment at Nasonova Research Institute of Rheumatology. The patients underwent determination of the level of total testosterone with subsequent division into subgroups with normal (12 nmol/l) and reduced levels. An intergroup comparison was performed using the main indicators used in clinical rheumatology practice to assess the clinical and demographic characteristics of SSc and IIM. A correlation analysis was performed between the level of total testosterone and some clinical and laboratory indicators. Results. The frequency of detected testosterone deficiency in SSc was 23.1%, and in IIM – also 23.1%. Patients with hypogonadism and SSc, compared with the group with normal testosterone levels, were characterized by a higher body mass index – BMI (27.0 [25.8; 29.8] kg/m2 vs 23.5 [22.0; 26.1] kg/m2; p=0.033), were more often obese (77.8% vs 33.3%; p=0.022) and had a higher mean fasting glucose level (5.62 [5.27; 5.69] mmol/l vs 5.03 [4.82; 5.33] mmol/l; p=0.037). In addition, patients with hypogonadism were more often positive for anti-Scl70 (100.0% vs 40.7%; p=0.003) and had a trend towards higher titers of antinuclear factor (p=0.063). Significant inverse correlations were found between total testosterone levels and BMI, as well as antinuclear factor titer. Patients with IIМ and hypogonadism were characterized by a higher frequency of interstitial lung disease (66.7% vs 15.0%; p=0.012). Significant negative correlations were found between total testosterone levels and age, BMI and erythrocyte sedimentation rate. Conclusion. A high frequency of hypogonadism was shown in men with SSc and IIМ. Reduced testosterone levels were accompanied by some metabolic disorders, as well as a high frequency of antibodies and clinical features characteristic of a more unfavorable course of the disease.

Objective: to study the association of muscle, adipose, and bone tissue markers with abnormal body composition phenotypes in women with rheumatoid arthritis (RA). Material and methods. A total of 163 women (median age 61.0 [52.0; 66.0] years) with a confirmed diagnosis of RA were examined. Dualenergy X-ray absorptiometry was performed; based on the results, the following body composition phenotypes were identified: normal (NP), osteoporotic (OP), sarcopenic (SP), and osteosarcopenic (OSP). Serum levels of myostatin, insulin-like growth factor 1 (IGF-1), leptin (LEP), adiponectin (ADPN), resistin (RES), interleukin 6 (IL-6), irisin, and sclerostin (SOST) were measured. Results and discussion. In patients with OP and OSP, LEP, RES, and SOST levels were significantly lower than in women with NP. In those with OSP, ADPN levels were higher than in patients with NP (p=0.031). IGF-1 levels in NP were significantly higher than in OP, SP, and OSP. Logistic regression showed an association of IGF-1 with OP, SP, and OSP (odds ratio, OR 0.96, 95% confidence interval, CI 0.93–0.99; OR 0.94, 95% CI 0.89–0.99; and OR 0.97, 95% CI 0.95–0.99, respectively; p<0.05). ADPN levels were associated with OP and OSP (OR 1.30, 95% CI 1.02–1.66 and OR 1.23, 95% CI 1.02–1.48, respectively; p<0.05); SOST levels associated with OP and OSP (OR 0.90, 95% CI 0.86–0.95 and OR 0.92, 95% CI 0.87–0.96, respectively; p<0.001); and LEP and RES levels with OP (OR 0.72, 95% CI 0.53–0.99 and OR 0.72, 95% CI 0.58–0.89, respectively; p<0.05). Conclusion. Associations were identified between OP and levels of LEP, ADPN, RES, SOST, and IGF-1; between OSP and levels of ADPN, SOST, and IGF-1; and between SP and IGF-1 only. For IGF-1, the positive predictive value was 100% at the identified cut-off points, which allows it to be considered a predictive marker of abnormal body composition phenotypes in patients with RA.

Existing diagnostic markers of sepsis indicate already developed inflammatory complications, whereas predictors enable preoperative identification of high-risk patients for preventive measures. This study aimed to evaluate the prognostic value of preoperative inflammatory biomarkers for postoperative complications in cardiac surgery patients. Preoperatively, we assessed age, body mass index, EuroSCORE II (European System for Cardiac Operative Risk Evaluation II), complete blood count with hematological indices including neutrophil-to-lymphocyte ratio (NLR), serum cytokines, HIF1A (hypoxia-inducible factor 1-alpha), and EPAS1 (endothelial PAS domain protein 1) expression in peripheral blood leukocytes. During surgery, cardiopulmonary bypass time, myocardial ischemia time, and blood loss were recorded. Postoperatively, complications, intensive care unit (ICU) stay, and total hospitalization were documented. No differences were found in non-modifiable risk factors or perioperative parameters between groups, except for longer ICU stay in the complications group. Preoperatively, absolute neutrophil count and NLR were higher in patients without complications, while eosinophil count, HIF1A expression, and HIF1A/EPAS1 ratio were higher in those with it. The HIF1A/EPAS1 ratio demonstrated the best diagnostic characteristics. Thus, preoperative predictors of postoperative inflammatory complications include low neutrophil count and NLR, as well as high HIF1A expression and HIF1A/EPAS1 ratio. These markers may facilitate early risk stratification and preventive strategies before surgery.