Medicine and Biotechnology

Introduction. Despite the advancement of modern transfection methods, such as the use of polyethylenimine- and Lipofectamine-based reagents, their high cost limits their application in large-scale research and biotechnological processes. The classical calcium chloride–mediated transfection method remains a cost-effective alternative; however, its principal drawback is its relatively low efficiency compared to commercial counterparts. The aim of this study is to optimize the plasmid DNA-to-calcium chloride ratio in order to enhance the efficacy of calcium phosphate transfection.
Materials and methods. The efficacy of transfection was evaluated based on the fluorescence intensity of the green fluorescent protein, the nucleotide sequence of which is encoded within the plasmid employed – pCRISPaint-2A-TurboGFP-PEST. For plasmid amplification, competent Escherichia Coli cells were prepared, followed by transformation, plasmid propagation, and subsequent isolation for use in transfection experiments. A series of experiments were conducted to optimize the calcium phosphate transfection protocol for HEK 293T cells. The study examined the effects of varying both the quantity of DNA and the total reaction volume on transfection efficiency. The reference protocol utilized 40 μg of DNA in a total reaction volume of 1 ml.
Results. A consistent correlation was established: transfection efficiency was dependent upon both the quantity of introduced DNA and the volume of the reaction mixture. Optimal efficacy was achieved utilizing double- and quadruple-dose DNA concentrations relative to the reference protocol, conversely, reduction of DNA quantity resulted in a marked decrease in the number of transfected cells. A further observation was a precipitous decline in transfection efficiency upon reduction of the reaction mixture volume while maintaining a constant DNA amount.
Discussion and conclusion. It was determined that the critical factor for enhancing the efficiency of calcium-phosphate transfection is not the absolute quantity of DNA, but rather the balance between its concentration and the total volume of the reaction mixture. An optimal component ratio for 2–3∙105 cells/ml of HEK 293T cells was established at 80 μg of DNA per 1 ml of reaction mixture. This specific ratio ensures the formation of nanoscale precipitate particles suitable for efficient endocytosis. Any deviation from this balance – whether a reduction in DNA quantity or a critical increase in its concentration due to a decrease in volume – resulted in a marked decline in transfection efficiency. Consequently, the proposed modification of the protocol represents a cost-effective alternative to expensive commercial reagents (PEI 40K APExBIO, transfection efficiency 60–80%, cost from 22,000 RUB; Lipofectamine 3000, transfection efficiency >70%, cost from 28,000 RUB), as it enables comparable efficacy while maintaining the accessibility of the method for routine investigations.

Introduction. Beta-blockers are commonly prescribed after myocardial infarction; however, their benefit in patients without heart failure and with preserved left ventricular ejection fraction in the modern era of reperfusion therapy remains unclear. The aim of the study is to evaluate the effect of beta-blockers on clinical outcomes in patients without heart failure.
Materials and methods. The authors conducted a systematic review and meta-analysis of randomized controlled trials evaluating beta-blocker therapy after discharge in patients with myocardial infarction without clinical manifestations of heart failure. Searches in PubMed, Scopus, Web of Science, and Cochrane CENTRAL were performed in February 2026. The primary outcome was major adverse cardiovascular and cerebrovascular events. Secondary outcomes included mortality, recurrent myocardial infarction, heart failure, revascularization, and stroke. Hazard ratios with 95% confidence intervals were pooled using a random-effects model.
Results. Four randomized controlled trials including 19,826 patients were analyzed. Beta-blocker therapy was not associated with a significant reduction in the incidence of major adverse cardiovascular and cerebrovascular events (hazard ratio 0.98, 95% confidence interval: 0.91–1.06, p = 0.64) or any of the secondary outcomes: all-cause mortality (hazard ratio 0.98, 95% confidence interval: 0.85–1.13, p = 0.78), recurrent myocardial infarction (hazard ratio 0.88, 95% confidence interval: 0.72–1.07, p = 0.20), heart failure (hazard ratio 0.82, 95% confidence interval: 0.63–1.07, p = 0.14), revascularization (hazard ratio 1.01, 95% confidence interval: 0.87–1.17, p = 0.86), or stroke (hazard ratio 1.24, 95% confidence interval: 0.97–1.59, p = 0.09).

Discussion and conclusion. In patients with acute myocardial infarction without heart failure and with preserved left ventricular function, routine beta-blocker therapy after discharge was not associated with a reduction in the incidence of major adverse cardiovascular and cerebrovascular events or their individual components in the context of contemporary reperfusion therapy. Further large-scale studies are required to develop individualized therapeutic approaches.

Introduction. The prone position is widely used in modern medicine, ranging from surgical procedures to the management of patients with acute respiratory distress syndrome. The COVID-19 pandemic highlighted its clinical significance, demonstrating improvements in oxygenation and hemodynamics in patients. It is known that the prone position affects the electrical activity of the heart, causing changes in the axis and morphology of the QRS complex, as well as in repolarization parameters. These features
may mimic ischemic changes on the electrocardiogram. Contemporary studies also indicate a possible prolongation of the QT interval and its prognostic significance. The aim of the study is to assess the effect of body position (prone position) on heart rate and repolarization parameters according to electrocardiographic data in young healthy men.

Materials and methods. A cross-sectional study was conducted at the Research Laboratory “Problems of Hypoxia” of Pitirim Sorokin Syktyvkar State University. The study included 18 young men without chronic or acute diseases. Electrocardiogram recordings were obtained in standard lead II in the supine position and in the prone position using the Poly-Spectrum hardware–software complex. The heart rate, QT interval, corrected QT interval (QTc), Tp–e interval, and the Tp–e/QT and Tp–e/QTc ratios were analyzed.
Results. A statistically significant increase in heart rate was observed in the prone position, averaging 21.5% (12.8%; 31.0%). The QT interval duration in the prone position significantly decreased compared with the supine position, whereas QTc significantly increased. QT dispersion, Tp-e, as well as the Tp-e/QT and Tp-e/QTc ratios did not demonstrate significant changes.
Discussion and conclusion. The prone position affects the electrophysiological parameters of the heart, leading to an increase in heart rate and the QTc interval while not significantly altering indices of repolarization dispersion, which may be relevant for the interpretation of the electrocardiogram in clinical practice.

Introduction. Intestinal microbiocenosis plays a key role in maintaining the body’s homeostasis, but its composition can be disrupted by various factors, including medications. Currently, the effect of antibiotics on intestinal microbiocenosis is well studied, data on the effects of non-antibiotic, hypoglycemic and lipid-lowering drugs remain fragmentary. The aim of the study – to conduct a retrospective review of modern studies on the effect of non-antibiotic hypoglycemic and hypolipidemic pharmacological agents on the qualitative and quantitative composition of intestinal microbiocenosis in patients with cardiometabolic disorders.

Materials and methods. A search was performed for scientific publications in the accessible scientific electronic databases PubMed, Researchgate, Scopus and Web of Science for the period from 2010 to 2025 for keywords related to the microbiome, drugs and dysbiosis. The review includes only human studies to ensure the clinical relevance of the results.

Results. It has been established that non-antibiotic drugs, including hypoglycemic agents (metformin, SGLT2 inhibitors – dapagliflozin, empagliflozin; DPP-4 inhibitors – linagliptin, vildagliptin) and lipid-lowering agents (statins – atorvastatin, rosuvastatin; fenofibrate, ezetimibe), cause specific and reproducible changes in the taxonomic profile of the intestinal microbiota in patients with metabolic disorders. The most significant effects include: an increase in Akkermansia muciniphila when taking metformin and fenofibrate; the growth of Faecalibacterium prausnitzii and Bifidobacterium longum under the action of SGLT2 and DPP-4 inhibitors; a decrease in the α-diversity of the microbiota when using statins; and minimal but statistically significant changes when taking ezetimibe.

Discussion and conclusion. The data obtained indicate that modern hypoglycemic and hypolipidemic drugs have microbiome-modulating potential. Some of these changes (e.g. the growth of A. muciniphila and F. prausnitzii) may partially explain the therapeutic effects of the drugs, including improving tissue sensitivity to insulin, reduced inflammation, and endothelial protection. At the same time, statins are associated with moderate dysbiosis, which requires consideration during long-term therapy. The results highlight the need to integrate microbiome profiling into a personalized approach to the treatment of patients with type 2 diabetes mellitus, dyslipidemia, and metabolic syndrome. Further prospective studies are required to assess the clinical significance of the identified microbiotic shifts and develop strategies for their correction.

Introduction. Colon cancer is characterized by significant heterogeneity due to differences in the embryonic development of the primary intestinal tube, blood supply, lymphatic drainage, and the molecular biological profile of tumors. Right-sided colon cancer is associated with unfavorable prognostic factors for patient survival, while left-sided colon cancer has a more sluggish course. Understanding clinical and demographic factors is key to personalizing therapy. The aim of this study was to conduct a retrospective analysis of data from the regional cancer registry of the Republic of Mordovia to assess the impact of tumor location, stage, gender, and age on overall survival in patients with colon cancer.
Materials and methods. A retrospective, non-randomized, single-center cohort study was conducted using the cancer registry of the Republican Oncology Dispensary of the Republic of Mordovia for the period from 2015 to 2019. Medical history data from 395 patients with colon cancer were analyzed, divided into two groups: those with right-sided (n = 158) and those with left-sided (n = 237) cancer. The primary endpoint of the study was 3- and 5-year overall survival. Statistical analysis was performed using
the Pearson χ² test and significance criterion (p < 0.05).
Results. Overall 3- and 5-year survival rates for colon cancer, regardless of patient gender, age, location, and stage, were 67.2 and 58.9%, respectively, in the Republic of Mordovia. Left-sided tumors were associated with a more favorable prognosis. For stage II 5-year survival for left-sided colon cancer in the Republic of Mordovia was 83.4%, compared to 74.5% for right-sided colon cancer; for stage III, the rates were 62.8% and 52.1%, respectively. The greatest differences were observed in men with stage II disease: 5-year survival was 86.7% for left-sided cancer versus 72% for right-sided cancer. Women with stage III left-sided colon cancer demonstrate a better long-term prognosis (64%). An inverse relationship was found between the age of patients and life expectancy: patients who reached a 5-year follow-up period were younger (59.1 years for left-sided and 61.9 years for right-sided colon cancer, respectively).
Discussion and conclusion. Left-sided colon cancer is a favorable prognostic factor, regardless of gender, age, or stage. Patients with right-sided colon cancer represent a high-risk group for progression and require a more differentiated approach using modern treatment regimens. The data obtained support the need to optimize the regional oncology program based on the side of the colon affected.