[Prevention and treatment of venous thromboembolic complications in orthopedic patients]. / Kompleksnaya profilaktika i lechenie venoznykh tromboembolicheskikh oslozhnenii u patsientov ortopedicheskogo profilya.

OBJECTIVE: To analyze the comprehensive program for prevention of thromboembolic complications in orthopedic patients. MATERIAL AND METHODS: We have analyzed thromboembolic complications in orthopedic patients after surgeries on large joints over the past 5 years (2018-2022). CONCLUSION: A comprehensive approach to prevention and treatment of thromboembolic complications including ultrasound, early surgical prevention of pulmonary embolism can significantly improve postoperative outcomes after joint replacement surgery. Vacuum aspiration retrograde thrombectomy is effective, feasible and safe for acute ilio-femoral venous thrombosis reducing hospital-stay (p=0.0124) and restoring vein patency. Widespread thromboembolic complications, especially for pulmonary embolism in 2022, are likely due to a new coronavirus infection and require careful screening of patients with risk factors with appropriate preventive antithrombotic therapy.

Dynamics of Metabolic and Oxidative Parameters of Erythrocytes during Treatment of Chronic Heart Failure with Molecular Hydrogen.

We studied the effect of molecular hydrogen (H2) on the content of 2,3-diphosphoglyceric acid (2,3-DPG), ATP, malondialdehyde, and catalase activity in erythrocytes in chronic heart failure. Inhalation of 2% molecular hydrogen H2 was carried out for 40 min repeatedly (5 days) or once. Inhalation of H2 caused an increase in ATP concentration in both research groups, but was more pronounced after repeated inhalation. The content of 2,3-DPG increased after repeated exposure to H2. The increase in metabolic activity under the effect of H2 was accompanied by a decrease in malondialdehyde concentration and an increase in catalase activity. Thus, the application of H2 in chronic heart failure reduced oxidative stress and improved metabolism of erythrocytes, which contributes to improvement of microcirculation. This allows us to recommend H2 for protection against ischemic and reperfusion damage to the myocardium.

Nitrogen Oxide-Added Extracorporeal Membrane Oxygenation for Treating Critical Acute Heart Failure after Cardiac Surgery.

The aim of the study was to test the use of gaseous nitric oxide added to the extracorporeal membrane oxygenation (ECMO) system for treating critical acute heart failure after cardiac surgery. MATERIALS AND METHODS: Venoarterial ECMO with addition of nitric oxide into the extracorporeal circuit was used for treating a 52-year-old patient after two-step cardiac surgery for acute dissection of the thoracic aorta and aortic valve insufficiency. After the Bentall-de Bono procedure, a technical error was revealed: that was a non-functioning anastomosis to the right coronary artery, which caused massive ischemic myocardial injury. An emergency myocardial revascularization was performed with the help of the cardiopulmonary bypass converted into ECMO; the patient's condition improved and he was transferred to the ICU. RESULTS: Considering the sharp decrease in heart contractility and the extremely high level of myocardial damage markers, it was decided to supply nitric oxide (40 ppm) to the ECMO circuit. A positive effect was noted within 8 h from the start of the procedure: the concentration of creatine phosphokinase-MB decreased almost 4 times and the concentration of troponin I decreased twofold. The most pronounced changes were observed by the end of day 1: a significant decrease in the concentration of myocardial damage markers, a decrease in the VIS indicator by 7.5 times; an improvement in the contractile function. Further on, the patient's condition gradually stabilized: the manifestations of acute heart failure and multiple organ failure stopped, and then ECMO was discontinued after 82 h of work. The patient was decannulated and he continued to show stable hemodynamic parameters. He was discharged from the clinic on day 18 after surgery. CONCLUSION: For the first time, venoarterial ECMO with supply of gaseous nitric oxide into the extracorporeal circuit was used to support blood circulation after cardiac surgery. This made it possible to ensure the survival of the patient with critical ischemia-reperfusion injury developed after the surgery.

Application of Molecular Hydrogen in Heart Surgery under Cardiopulmonary Bypass.

The aim of this work was to study the effect of molecular hydrogen on oxidative processes in cardiac surgery patients with acquired valve heart disease applied during surgery under cardiopulmonary bypass (CPB). Materials and Methods: The study involved 20 patients (16 men and 4 women) with acquired heart valve disease who were operated on under CPB. Two groups of patients were formed. In group 1 (n=11), anesthesia included inhalations of molecular hydrogen, which was supplied to the breathing circuit of the ventilator at a concentration of 1.5-2.0% immediately after tracheal intubation and throughout the operation. In group 2 (n=9), inhalation of molecular hydrogen was not performed. Blood sampling was taken at 4 stages: immediately after anesthesia induction, before CPB and after its termination, and also one day after the operation. The intensity of the processes of lipid peroxidation was evaluated by the level of diene (DC) and triene (TC) conjugates, Schiff bases (SB). Results: In the patients of group 1, the arterial blood samples showed a decrease in the level of TC and SB, as compared to the first stage of the study, before the initiation of CPB and one day after the operation. An increase in the level of DC and TC was detected after the termination of CPB (p<0.05). In the venous blood samples, an increase in the level of DC was noted before the initiation of CPB, which was restored by the third stage of the study (p<0.05). At the same time, after the termination of CPB, a tendency towards a decrease in TC and SB was observed, which persisted one day after the operation.In the patients of group 2, an increase in the concentration of SB in the arterial blood samples was recorded during the study as compared to the first stage. The level of TC and SB in the venous blood samples increased one day after the operation. Conclusion: Intraoperative inhalation of molecular hydrogen leads to a decrease in the oxidative stress manifestation, it being most pronounced one day after the operation. This suggests that molecular hydrogen can be used in cardiac surgery as an effective and safe antioxidant.

Modified Mitral Valve Repair with Its Insufficiency of Ischemic Genesis.

The aim of the study was to assess the effectiveness of modified mitral valve repair in comparison with traditional methods of correcting ischemic mitral regurgitation. Materials and Methods: The results of surgical treatment of 80 patients with coronary artery disease complicated by ischemic mitral regurgitation were analyzed. The mean age of the patients was 58.95±8.36 years; the ratio of men and women was 67:13. Heart failure of FC II (according to the NYHA classification) was detected in 6 patients (7.50%), FC III - in 69 (86.25%) patients, FC IV - in 5 (6.25%) patients.Echocardiographic examination was used to determine the significance and genesis of mitral regurgitation in the preoperative period. 57 patients (71.25%) were detected with grade II mitral regurgitation, 23 (28.75%) had grade III.Annuloplasty was chosen as the operation for the correction of the valve apparatus. The patients of group 1 (n=23) underwent reconstructive surgery on the mitral valve using an autopericardial strip according to the technique, which we have developed, in combination with coronary artery bypass grafting (CABG), the patients of group 2 (n=26) underwent plastic surgery using a support ring in combination with CABG, patients of group 3 (n=31) had myocardial revascularization without correction of the valve apparatus. Results: The patients of group 2 underwent restrictive mitral annuloplasty performed with rigid support rings, group 1 - with an autopericardial strip as a soft support ring, the patients of group 3 underwent CABG alone.One patient from group 2 died in the early postoperative period due to acute perioperative myocardial infarction.The most common complications were pleurisy, acute cardiovascular failure, acute respiratory failure, and cardiac arrhythmias. The smallest number of complications was noted in the group 3, where patients underwent CABG alone. After surgery, all the patients showed a decrease in mitral regurgitation, which was most pronounced in the groups with annuloplasty.When analyzing the immediate results of the operations, it was revealed that the patients of groups 1 and 2, who underwent combined interventions, had a higher percentage of complications, and the length of their stay in the ICU increased. However, these groups showed a significant improvement in mitral valve functioning. Plasty of the mitral valve with an autopericardial strip according to the technique, which we have developed, demonstrated a good hemodynamic effect, the absence of significant regurgitation in the postoperative period.

[Threatened paradoxical embolism, massive occlusion of pulmonary artery: risk stratification, treatment policy]. / Ugrozhaiushchaia paradoksal'naia émboliia, massivnaia okkliuziia legochnoi arterii: stratifikatsiia riska, taktika lecheniia.

Described in the article is a clinical case report regarding a male patient presenting with pulmonary thromboembolism, with a floating thrombus in the common femoral vein, in the right atrium, prolapsing into the right ventricle and propagating through a patent foramen ovale to the left atrium, thus being a threat of paradoxical embolism. The echocardiography findings demonstrated the following: mean pressure in the pulmonary artery amounting to 56 mm Hg, dilatation of the right atrium and right ventricle. The patient was subjected to simultaneous thrombectomy from the common femoral artery, from the right, left atria and pulmonary artery in conditions of cardioplegia, as well as ligation of the superficial femoral artery. The postoperative period proved uneventful. The patient was discharged on postoperative day 15, with pressure in the pulmonary artery amounting to 38 mm Hg. Besides, analysed herein are the contemporary literature data, clinical guidelines, and opinions of experts concerning treatment policy in this complex pathology.

Identification of structural elements involved in the interaction of simian virus 40 small tumor antigen with protein phosphatase 2A.

SV40 small tumor antigen (small-t) was used as a model to identify structural elements involved in the interactions between regulatory proteins and protein phosphatase 2A (PP2A). Using mutant proteins and synthetic peptides, we identified a small domain within small-t that is a major site for interaction with the dimeric form of PP2A. A series of small-t truncation mutants identified a region surrounding the first of two conserved cysteine clusters that was critical for interaction with PP2A. These mutants also identified additional regions of small-t that contribute to high affinity interaction. Deletion of residues 110-119, which encompass the first cysteine cluster, resulted in a protein that failed to bind to PP2A. Synthetic peptides that contained residues 105-122 of small-t blocked binding of small-t to PP2A. These peptides also inhibited the phosphatase activity of PP2A in a manner analogous to full-length small-t. The active small-t peptides adopt a beta-strand structure that was essential for high affinity interaction with the PP2A dimer. Based on circular dichroism measurements, the same cysteine cluster-containing peptides that bind to PP2A also interact with zinc. Interaction with zinc required the conserved cysteines but was not required for interaction with PP2A.

Effect of Zajdela ascites hepatoma on the activity and synthesis of liver histidase of tumor-bearing rats.

The synthesis of histidase occurs only in free polyribosomes. The relative content of histidase synthesizing polyribosomes in rat liver, in Zajdela ascites hepatoma cells and in the liver of tumor-bearing rats is equal to 1.35%, 0.11% and 0.57%, respectively (of the total amount of free polyribosomes). It was found that hepatoma cell sap has an inhibitory effect on the synthesis of proteins in the cell-free system reconstructed from polyribosomes and cell sap of control rats.