Introduction: The relevance of the research of the article is conditioned upon the problem of the development of molecular genetic diagnostics to determine the effectiveness of treatment for acute lymphoblastic leukemia in children. The purpose of the article is to identify the polymorphism parameters of the P53 Arg72Pro and XRCC1 Arg399Gln genes in acute lymphoblastic leukemia with criteria for determining the survival rates of sick children. Materials and methods: Methods for the study of the identified problem are the study of the medical histories of children with acute leukemia, which allowed selection of the necessary contingent of patients for further genetic study of their frozen blood, where the genomic part of deoxyribonucleic acid was isolated from the frozen blood in a standard way using molecular biological research when performing a polymerase chain reaction. Results: The article presents the results of a study that shows that in children with acute lymphoblastic leukemia, the frequency of genotypes of the XRCC1 Arg399Gln gene is variable. The most common genotypes are Arg/Gln and Arg/Arg, approximately 48% each. The Gln/Gln genotype is less common. Relapse-free survival of children with the Arg/Gln and Gln/Gln genotypes was the highest, slightly lower rates were noted with the Arg/Arg genotype. Conclusion: It was identified that the frequency of genotypes of the XRCC1 Arg399Gln gene can be a predictor of prognosis in acute lymphocytic leukemia in children, which can be considered when choosing treatment tactics, and this has practical significance for the field of medicine.

Background:The relevance of the study lies in the fact that although the role of polymorphism of some genes that are responsible for cell apoptosis and deoxyribonucleic acid repair in the development of acute leukemia has already been established, its relationship with the gender of patients has not been studied enough. This study was aimed at studying the relationship between the Arg399Gln polymorphism in the XRCC1 deoxyribonucleic acid repair gene and the Arg72Pro polymorphism in the TP53 tumor suppressor gene encoding the p53 protein with the gender of children with acute leukemia. Material and methods: The study included 100 newly diagnosed pediatric patients of Kyrgyz nationality (69 boys and 31 girls), among which there were 77 patients with acute lymphoblastic leukemia, 22 patients with acute myeloblastic leukemia and 1 patient with a biphenotypic variant. Determination of polymorphisms was carried out by PCR-RFLP analysis or polymerase chain reaction followed by an analysis of restriction fragment length polymorphism. The interrelation of the results obtained with the patients' gender was assessed using statistical methods. Results:The study showed that there were no gender differences for all three genotypes of the Arg72Pro polymorphic marker of the tumor suppressor p53 (ТР53). Three Arg399Gln genotypes of the XRCC1 gene also did not depend on gender. However, with a separate analysis of each polymorphism, there was a tendency for a greater proportion of the Arg/Gln genotype in the group of boys compared to girls. The Gln/Gln polymorphism relationship requires further study due to insufficient data for analysis. Conclusion: The study has expanded the understanding of genetic changes and their relationship with gender, which have diagnostic, prognostic and therapeutic implications in acute leukemia. The conducted research of the relationship between individual phenotypes of acute lymphoblastic leukemia with risky polymorphisms in some genes contributes to the study of AL.

Background. Premature ventricular contractions (PVCs) are not mentioned in the list of risk factors of stroke. Methods. In our investigation, we included 440 patients with PVCs more than 700 per 24 hours. In control group, there were 88 patients with PVCs less than 700 per 24 hours. Within instrumental methods we performed echocardiography (transthoracic or transesophageal), Doppler ultrasound of brachiocephalic arteries, 24-hours electrocardiography (ECG) monitoring, digital sphygmography of common carotid arteries (SG); computer tomography or magnetic resonance imaging of the brain. Laboratory tests were used to identify lipids level, hemoglobin A1c. The patients of the main group were divided into two subgroups up to the characteristics of the revealed PVCs. The 1st subgroup comprised 120 patients with PVCs whose ventricular systole occurred in the phase before the peak of transmitral blood flow in the cardiac cycle, regardless of the location of ectopic foci. In 320 patients with PVCs of the 2nd subgroup the systole of ventricular contraction occurred in the phase after the peak of transmitral blood flow in the cardiac cycle. We observed the patients during 1 year from the onset of the investigation and analyzed the appearance of stroke or transient ischemic attack (TIA). Results. In most instrumental and laboratory parameters subgroups 1, 2 and control group were identical. The most important differences were in hemodynamic and kinetic parameters in accordance to the quantity of PVCs per 24 hours (700 and more in the main subgroups 1,2) and the moment of the ventricular contraction appearance of the PVCs (before or after the transmitral blood flow peak in cardiac cycle). We revealed the following tendency: the earlier PVCs appeared in cardiac cycle the more an increase in hemodynamic and kinetic parameters was observed. All patients were on the common standard therapy. Despite of that, during 1 year from the beginning of the investigation we remarked the statistically significant different appearance of the stroke and TIA within the groups which was more frequent in the 1 subgroup. Conclusion. PVCs are an additional risk factor of stroke. The most dangerous type is when the ventricular contraction (PVC) appears before the transmitral blood flow peak in cardiac cycle. Increased hemodynamical parameters during the spread of the 1st post-extrasystolic wave cause an additional mechanical trauma of arterial intima and can be the key moment in atherosclerotic plaques non-stability with further defragmentation, embolism and onset of stroke. In patients with PVCs more than 700 per 24 hours the promising research can be using novel oral anticoagulants to prevent the cardiovascular events in the dosages as it is indicated in atrial fibrillation.

Aim of investigation is to study the features of the mechanism of restenosis on implanted intravascular stent, using the original device for modeling of intra-arterial circulation. Materials and methods. We use an original device for modeling intra-arterial circulation (document of invention RU 202780). It is a simulation of arterial vessel, made of glass tube rotameter. Its free ends are connected with two silicone tubes, with other ends - to the pump, powered by a 12 Volt battery. We injected the fluid (an aqueous solution of glycerin) into the closed system, diluted corresponding to the viscosity of human blood. A fitting is located at the inlet end of the tube, through which we can introduce a dye (ink), a silk thread or intravascular pressure probe inside the tube. Results. As a prototype of intravascular endoprosthesis, we used a metal device 71 mm length, made in the form of a grid with beams directed in a spiral. We installed a conductor with a 5 cm long silk thread inside the endoprosthesis. The pump works simulating the regular heart rhythm or premature ventricular contractions. We observed an intense pressure effect of the first post-extrasystolic wave on the rotameter tube, with the formation of reflected, standing waves (the pressure increased by 160% compared with the regular heart rhythm). Conclusion. With the spread of the first post-extrasystolic wave, a “hydraulic shock” occurs in the arterial vessel. Its mechanical effect can be the starting point for the onset and progression of restenosis in an implanted intravascular stent.

Prototype models of intra-arterial circulation is one of the priority aims of experimental cardiology, as well as for the study of atherosclerosis. Purpose: To study the features of intra-arterial hemodynamics in the area of​​atheroma of the artery in physical modeling. Materials and methods: We used an original "Device for modeling intra-arterial circulation". The main parts of the model: glass rotameter tube in the form of a truncated cylinder, inlet and outlet ends of which are fixed with elastic plastic tubes connected to an electric water pump immersed in a container with glycerol solution. Inside the rotameter, using a fitting from the inlet, it is possible to install a pressure sensor that transfers data to the oscilloscope; indicators - a silk thread or dye - ink. The variable pump mode allowed us to simulate a regular heart rhythm, extrasystole (ES) and atrial fibrillation (AF). Results: In the first post-extrasystolic wave, a turbulent fluid flow formed after the plaque, standing waves and waves reflected from the walls of the rotameter were observed; the sensor registered an increase in pressure 1,6 times more compared with a regular heart rate wave. The marginal plaque zones along and against the fluid flow, especially the areas bordering the intact part of the arterial vessel, underwent the main mechanical impact. The same patterns were observed in AF with a maximum duration of a pause between pulse waves of ≥1,5 s. Conclusions: Heart arrhythmias play an important role in the intra-arterial hemodynamics changes and are the part of the pathophysiological changes in the arteries in atherosclerosis. The main danger is not the ES itself, but by the first post-extrasystolic contraction or the first pulse wave after a long pause between ventricular contractions in AF.