Introduction. Extracorporeal membrane oxygenation has found wide application in clinical practice during the COVID-19 pandemic. Oxidative stress, endothelial dysfunction, and systemic inflammatory response syndrome play an important role in the pathogenesis of COVID-19. Our research was designed to study correlations in-between those factors and the impact of extracorporeal membrane oxygenation on them.
Aim. The study of systemic inflammatory response and endothelial function in patients with COVID-19 during extracorporeal membrane oxygenation.
Material and methods. In the course of a prospective study, we examined 100 COVID-19 patients aged 26 to 75 years, median 55 years [47;60], who were treated at the N.V. Sklifosovsky Research Institute for Emergency Medicine, using extracorporeal membrane oxygenation. As a control group (normal), 25 practically healthy people whose median age was 32 years [25;39] were examined. The function of the vascular endothelium was assessed by the content of nitric oxide stable metabolites in the blood serum and the level of angiotensin-converting enzyme. Next, the ratio of nitric oxide metabolite to angiotensin-converting enzyme level was calculated, reflecting the imbalance between endotheliumdependent vasodilation and vasoconstriction. To assess the severity of oxidative stress in blood serum, malondialdehyde was determined as a marker of lipid peroxidation. The state of the antioxidant system was assessed in terms of total antioxidant status of blood serum. The presence of an imbalance in the system of lipid peroxidation and the antioxidant system total antioxidant status was judged by the oxidative stress coefficient, i.e. the ratio of malondialdehyde to the total antioxidant activity.
Results. The analysis showed the presence and progression of endothelial dysfunction, impaired vascular regulation, activation of free radical processes, the presence of an imbalance in the prooxidant/antioxidant system, as well as the progression of the inflammatory process with a decrease in the level of markers of the COVID-19 severity.
Conclusion. Further studies of the correlation between endothelial damage and the severity of the systemic inflammatory response syndrome may be of fundamental importance for explaining the pathophysiological mechanisms of COVID-19 course and developing new treatments for such patients.

Introduction. Natural killers are the "first line" of antitumor and antiviral protection in the early stages after аllogeneic hematopoietic stem cell transplantation. Quantitative characteristics reach normal values already in the first month after the infusion of blood stem cells to the recipient. Self-tolerance of natural killers is achieved due to many receptors on their surface, but killer immunoglobulin-like receptors play a key role. Their role is to recognize "self" cells and block signals aimed at destroying their own cells. Knowledge of the functional activity of natural killers urged to studying the impact of mismatches between the inhibitory receptor gene and the ligand on the development of allogeneic hematopoietic stem cell transplant failure.
The aim of research was to study the probability of the graft failure development in allogeneic hematopoietic stem cell transplantation depending on the recipient's killer immunoglobulin-like receptor genotype.
Material and methods. Genotyping of killer-cell immunoglobulin-like receptors in 66 recipients of blood stem cells by the polymerase chain reaction method was performed in the study. Using an online calculator, receptors were classified as "best", "better" and "neutral" depending on the genotype. The end point of the assessment was the development of graft failure in the presence of different genotypes of immunoglobulin-like receptors in the recipient.
Results. According to the data obtained, the presence of the “best” and "better" killer-cell immunoglobulin-like receptor genotype in the recipient significantly increased the risks of developing various forms of graft failure.
Conclusion. The presence of the KIR2DL3 genotype in a recipient of hematopoietic stem cells significantly (by 3 times) reduces the likelihood of primary graft failure. This result is of great prognostic significance, although at present no ways of influencing it have been developed. The presence of the “best” killer immunoglobulin-like receptors genotype in the recipient increases the likelihood of developing graft failure by more than 3 times compared to the best and neutral genotype (44.4% vs. 13.4%).

Background. Around half of bioprosthetic heart valves become dysfunctional 15 years postimplantation because of structural valve deterioration notable for the degradation and calcification of the prosthetic tissue. Protection of bioprosthetic heart valves from structural valve deterioration requires innovative materials, science approaches including enveloping of the bioprosthetic heart valves into the polymer sheath.
Aim. To develop a polyvinyl alcohol sheath for improving resistance of bioprosthetic heart valves to calcification.
Material and methods. Bovine pericardium fixed with ethylene glycol diglycidyl ether was incubated with distinct concentrations of polyvinyl alcohol (5, 10, 12, or 15%) with the following freezing and thawing to perform cryotropic gelation. Surface and structure of unmodified and polyvinyl alcohol-modified bovine pericardium have been investigated by fluorescence microscopy and scanning electron microscopy, whilst tensile testing was carried out by uniaxial tension test. Haemocompatibility was assessed through the measurements of haemolysis and platelet aggregation/adhesion upon the contact of donor blood with the samples. Resistance to calcification was tested by incubation of the samples in calcium and phosphate supersaturated (10 µmol/L) cell culture medium for 3 and 6 weeks with the following tissue lysis and colorimetric measurement of Ca2+ ions.
Results. Using cryotropic gelation, we obtained a polyvinyl alcohol-coated and filled bovine pericardium matrix. Out of all polyvinyl alcohol concentrations, 12% polyvinyl alcohol solution sealed pores and hollows within the bovine pericardium (what was not achieved using 5% or 10% polyvinyl alcohol solutions) and demonstrated the best processability as compared to 15% polyvinyl alcohol solution. Cryotropic gelation did not deteriorate durability, elasticity, or haemocompatibility of bovine pericardium. After 3 and 6 weeks of the incubation in calcium-supersaturated solution, polyvinyl alcoholmodified bovine pericardium contained 5- and 3-fold reduced amount of calcium compared to unmodified bovine pericardium.
Conclusions. Enveloping of bovine pericardium into polyvinyl alcohol increases its calcification resistance, retains its tensile properties and haemocompatibility, and can be considered as a promising approach for the modification of bovine pericardium during the manufacturing of bioprosthetic heart valves.

Ischemic heart disease holds the leading position in the structure of cardiovascular diseases. Early reperfusion therapy for acute myocardial infarction led to a decrease in mortality and severe complications of coronary artery disease. Despite advances in the treatment of coronary artery disease, dilatation and remodeling of the left ventricle develop in 20% of patients who have had a heart attack, leading to mitral insufficiency and systolic dysfunction of the left ventricle. Aneurysm of the left ventricle is a delayed severe complication of myocardial infarction, which significantly worsens the prognosis. Large aneurysms of the left ventricle cause progressive dilatation of the left ventricle, its volumetric overload with an increase in wall tension in the non-infarction zone, decreased functional characteristics of the left ventricle, thrombosis in the aneurysm cavity, life-threatening arrhythmias, and sudden death. Postinfarction left ventricular remodeling can lead to secondary mitral regurgitation, which is an independent predictor of mortality in the longterm period. Surgical treatment of coronary heart disease and its complications is one of the main problems of modern cardiovascular surgery.

Introduction. Long-term results of renal transplantation from living donors are much better than the results of cadaveric transplantations. Recently, because of the shortage of living donors, some centers have started using kidneys from living donors with asymptomatic stones as a potential solution for the problem. However, the optimal surgical solution for such situations has not yet been developed.
Aim. To evaluate our obtained transplantation results of using the kidneys from living donors with nephrolithiasis and compare them with the literature data.
Material and methods. In the period from 2012-2021, renal transplantations in our clinic were done in three patients from related donors with stones in the kidney. One donor underwent mini-percutaneous lithotripsy one month prior to nephrectomy. The other two underwent simultaneous retrograde lithotripsy and laparoscopic donor nephrectomy. In these cases a holmium or thulium laser was used for the destruction of calculi. All donors underwent laparoscopic retroperitoneal nephrectomy.
Results. All stones were successfully removed. There were no surgical complications in donors during and after procedures. Warm ischemia time did not exceed 3.5 minutes. The general length of hospital stay was 10 days in case of predonation stone removal surgery and 6 and 4 days in the cases of simultaneous procedures, respectively. All grafts were transplanted to related recipients. One of the recipients was treated with hemodialysis before transplantation, the other one with peritoneal dialysis. The third recipient underwent preemptive transplantation (before the start of dialysis). The graft function in all cases was immediate. During the follow-up period (9-57 months), no signs of nephrolithiasis were seen in either donors, or recipients.
Conclusions. Consideration of potential donors with stones in one kidney might increase the number of living donor renal transplantation. Simultaneous RIRS and laparoscopic donor nephrectomy can be considered as an alternative to sequential operations or ex vivo stone extraction. The presented technique is reproducible, safe and was not associated with an increased length of hospital stay.

The patient's anamnesis, the peculiarities of the course of pregnancy, delivery in a kidney and pancreas recipient have been described. The results of the patient's follow-up for nine months after delivery are presented. The authors emphasize that the management of pregnancy in a woman after organ transplantation is possible only with the effective interaction of obstetricians, gynecologists, and transplantologists.

The absolute uterine factor infertility is a non-treatable cause of female infertility. Surrogacy has become the only option that allows this group of patients to achieve genetic, although biological motherhood. According to statistics there are more than 30 thousand women of fertile age in Russia who cannot get pregnant due to the absolute uterine factor infertility. The recently emerged possibility of uterine transplantation has become the only treatment for this kind of female infertility.
Prior to the very first clinical study of human uterine transplantation which was carried out in 2013 in Sweden, scientists had conducted systematic studies in animals (rodents, pigs, cattle and primates). The first clinical trial with the uterine transplantation performed resulted in a live birth in September 2014. Currently, cases of successful uterine transplantation in humans have been reported in Sweden, Brazil, USA and Italy. Experience and practice in animal research played a key role in the success of the first clinical study on uterine transplantation. The application of this method is fundamental in the introduction of the scientifically grounded technology of uterine transplantation in Russia.
Aim. Analysis of the problems of the clinical application of the uterine transplantation based on a literature review.

Acute inflammation of the peritoneum – peritonitis – often develops after injury to hollow visceral organs, intestinal necrosis, failure of anastomosis, or tumor processes. Subsequent microbial contamination of the abdominal cavity leads to infection, in response to which immune mechanisms are activated. The pathogenesis of inflammatory processes in the abdominal cavity and their features are largely determined by the structure and function of the peritoneum, as well as its close connection with the omentum. An important point in resolving peritonitis is to maintain the balance of cytokines, the activity of immunocytes and complement functioning in the immune lymphoid clusters of the peritoneum and omentum, and their collaborative action during inflammation. The review presents data on the structure and function of the peritoneum and omentum, the role of neutrophil, macrophage, lymphocytic links of the immune system, as well as those of pro- and anti-inflammatory cytokines and complement in the development and cessation of acute inflammation in the abdominal cavity.

On the eve of the anniversaries of two historical events: the 145th anniversary of the experiments in which Eck's fistula was performed and the 55th anniversary of the successful clinical approbation of the selective distal splenorenal anastomosis, a retrospective analysis of the key historical stages in the development of portal hypertension surgery was performed: from the first attempts to describe the anatomy of the hepatic vascular system, explaining its purpose in the body, the development of direct portacaval anastomosis, and the widespread use of selective splenorenal anastomoses, to the Transjugular Intrahepatic Portosystemic Shunt procedure and orthotopic liver transplantation. Meantime, the emphasis has been focused on the most colorful characters of researchers and clinicians who passed this path. The expediency of an integrated approach in solving the problems of portal hypertension with the development of both fundamental and applied clinical and organizational aspects has been substantiated. It is shown that the discoveries born from summarizing the results achieved by numerous researchers have contributed to a better understanding of this field of medicine, have become a solid foundation for what we have today and are a reliable platform for a successful start into the future.

Background. Bibliographic analysis for the period 2017–2022 showed an extremely small number of literary sources (scientific publications) in both foreign and domestic periodicals, which would cover issues related to the consideration, study and/or analysis of any aspects of publication activity in the field of transplantology at the global, national and regional levels or in with respect to specific organizations, journals and authors. In Russian periodicals, the objects of research are often either various countries of the world (in comparative characteristics with Russia), or medical universities of the Russian Federation, or scientific medical organizations of federal designation, while there is a complete absence or a small number of publications devoted to the issues of publication activity of organizations at the level of the city of Moscow.
Aim. Conducting a scientometric study to characterize, analyze and evaluate the publication activity of the Moscow Healthcare Department organizations in the subject area "Transplantation".
Material and methods. The study was carried out for the subject area "Transplantation" using analytical platform SciVal for more than 10 quantitative and shared scientometric indicators (from 2019 to 2021) for 55 organizations from the categories of research institutes, scientific and practical centers and city clinical hospitals subordinated to the Moscow Healthcare Department.
Results and discussion. The main scientometric indicators (in quantitative and fractional ratio) characterizing the publication activity over a three–year period – from 2019 to 2021 – in the subject area "Transplantation" in organizations subordinate to the Moscow Healthcare Department.
Conclusion. It is shown that in the subject area "Transplantation" during the period under review, positive growth and changes in scientometric indicators such as the total number of publications, the number of publications in 1st–2^nd quartiles, the number of publications in national and intraorganizational collaboration are observed for the Moscow Healthcare Department organizations.

The paper presents the analysis of two publications written by two pioneers of heart transplantation in the USSR, A.A. Vishnevsky with co-authors and G.M. Solovyov, which covered the state of the organ transplantation issue in 1971–1973 and gave predictions for its future development. It is shown that the authors of those publications saw and formulated the main trends in the development of the problem in one and the same way. Meanwhile, G.M. Solovyov, being the Director of the specialized Institute of Organ and Tissue Transplantation of the USSR Academy of Medical Sciences saw the issues of organ transplantation more in depth than A.A. Vishnevsky who headed the A.V. Vishnevsky Institute of Surgery of the USSR Academy of Medical Sciences. In particular, this concerned immunological studies. Shortly after its establishment in 1969, the Institute of Organ and Tissue Transplantation arranged a powerful laboratory of immunogenetics on its base. The staff of that laboratory (L.V. Smirnova, Yu.M. Zaretskaya, L.P. Alekseev, V.I. Shkurko, A.M. Sochneva, I.V. Petrova, etc.) conducted world-class immunological studies, which results inspired certain optimism among surgeons. A more complicated situation was with the clinical issues of organ transplantation, with the solution of organizational, moral and ethical issues, where, in addition to doctors, the active participation of legislators, economists, and healthcare organizers was required. This paper presents comparative data on the state of political, economic, and organizational issues of organ transplantation in the Russian Federation between the 2010s and early 2020s. It is shown that the planned in the 2020s tendency of their positive solution and further development inspires certain optimism.