[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.

Risk Factors and Mechanisms of Cardiovascular Diseases in Posttraumatic Stress Disorder Model in Wistar Rats as Dependent on Stress Resistance and Age.

The article focuses on the pathogenetic mechanisms of posttraumatic stress disorder (PTSD), which is associated with psychological stress because of the coronavirus pandemic. The molecular mechanisms responsible for disease susceptibility in some individuals and stress resistance in others are amongst crucial research interests of experimental and clinical medicine. Priority data were obtained to indicate that distortions of synthesis and metabolism and, most significantly, a switch between two energy transport forms, glucose and lipids, underlie myocardial dysfunction in young and old stress-sensitive Wistar rats in a PTSD model. Histochemistry and polarization microscopy showed energy deficit in cardiomyocytes and signs of ischemic and hypoxic areas emerging in the myocardium as a result of an accumulation of NADH and NADPH, which initiate excessive production of reactive oxygen species.

Hierarchical tensile structures with ultralow mechanical dissipation.

Structural hierarchy is found in myriad biological systems and has improved man-made structures ranging from the Eiffel tower to optical cavities. In mechanical resonators whose rigidity is provided by static tension, structural hierarchy can reduce the dissipation of the fundamental mode to ultralow levels due to an unconventional form of soft clamping. Here, we apply hierarchical design to silicon nitride nanomechanical resonators and realize binary tree-shaped resonators with room temperature quality factors as high as 7.8 × 108 at 107 kHz frequency (1.1 × 109 at T = 6 K). The resonators' thermal-noise-limited force sensitivities reach 740 zN/Hz1/2 at room temperature and 90 zN/Hz1/2 at 6 K, surpassing state-of-the-art cantilevers currently used for force microscopy. Moreover, we demonstrate hierarchically structured, ultralow dissipation membranes suitable for interferometric position measurements in Fabry-Pérot cavities. Hierarchical nanomechanical resonators open new avenues in force sensing, signal transduction and quantum optomechanics, where low dissipation is paramount and operation with the fundamental mode is often advantageous.

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.

Fractal-like Mechanical Resonators with a Soft-Clamped Fundamental Mode.

Self-similar structures occur naturally and have been employed to engineer exotic physical properties. We show that acoustic modes of a fractal-like system of tensioned strings can display increased mechanical quality factors due to the enhancement of dissipation dilution. We describe a realistic resonator design in which the quality factor of the fundamental mode is enhanced by as much as 2 orders of magnitude compared to a simple string with the same size and tension. Our findings can open new avenues in force sensing, cavity quantum optomechanics, and experiments with suspended test masses.

[Surgical treatment of rupture of the anterior wall of the left ventricle in the apical region with the formation of a false aneurysm in the acute stage of myocardial infarction].

One of the most dangerous complications of acute myocardial infarction (MI) is external or internal left ventricular rupture. Despite multiple studies on early diagnostics and algorithms for routing of patients with complicated MI, mortality in this patient group remains extremely high. Presently available publications on the tactics of managing patients with cardiac rupture are very scarce, and expectancies of surgical treatment are questionable. The provided clinical example demonstrates effectiveness of early open-heart surgical intervention, which supports the requirement for aggressive tactics for patients with cardiac rupture.

[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.

Elastic strain engineering for ultralow mechanical dissipation.

Extreme stresses can be produced in nanoscale structures; this feature has been used to realize enhanced materials properties, such as the high mobility of silicon in modern transistors. We show how nanoscale stress can be used to realize exceptionally low mechanical dissipation when combined with "soft-clamping"-a form of phononic engineering. Specifically, using a nonuniform phononic crystal pattern, we colocalize the strain and flexural motion of a free-standing silicon nitride nanobeam. Ringdown measurements at room temperature reveal string-like vibrational modes with quality (Q) factors as high as 800 million and Q × frequency exceeding 1015 hertz. These results illustrate a promising route for engineering ultracoherent nanomechanical devices.

Age-Related Parameters of the Spinal Inhibition of Skeletal Muscles in the Regulation of Voluntary Movements in Males.

We studied the age-related features of spinal inhibition in the regulation of voluntary movements in males. It was found that presynaptic, nonreciprocal and reciprocal inhibition of the flexor of toes during voluntary movements was less intense as compared with relative muscle rest in all studied age groups. This results from the age-related features of supraspinalactivatory and inhibitory effects on la and Ib spinal interneurons, which change the mechanism of spinal inhibition of voluntary movements during the development of the organism. In boys aged 9-12 years, the presynaptic inhibition of Iaafferents is lowest, while the nonreciprocal and reciprocal inhibition of (αmotoneurons of the flexor of toes is highest among all studied age groups. In boys aged 14-15 years, the presynaptic inhibition of Iαafferents is higher, while the nonreciprocal and reciprocal inhibition of cxmotoneurons of the flexor of toes is lowest among the age groups. By the age of 17-18 years, the mechanism of nonreciprocal inhibition of αmotoneurons of the flexor of toes during voluntary movements is similar to that at the age of 14-15 years. The final level of presynaptic inhibition of Iαafferents and reciprocal inhibition of αmotoneurons. is reached at the age of 17-18 years.

[Anesthesia during diagnostic endoscopic interventions in the outpatient setting].

The review of the literature is devoted to the urgent problem of today--anesthetic maintenance of diagnostic endoscopic studies. The authors of the review have attempted to systematize the results of numerous publications to provide a deeper insight into the existing problems and perspectives in this field of anesthesiology, which can facilitate an anesthesiologist in his/her decision on anesthesia to be performed in diagnostic endoscopy.

[Epidemiology of postoperative cognitive disorders].

The literature review concisely considers a relatively new problem of postoperative cognitive disorders occurring in surgical patients. The paper considers the present views of the etiology of postoperative cognitive disorders and their contributing and aggravating factors. Particular emphasis is laid on a factor, such as a surface anesthetic level and sudden intraoperative consciousness recovery, as well as on the prevention of this complication through the monitoring of anesthesia depth.

[Possible causes and prevention ways of short-term postoperative mental disorders after regional and general anesthesia].

The authors have studied the incidence and possible causes of short-term postoperative mental disorders (STPMD) (in different types of intraoperative protection) that are determined as a nonspecific central nervous system (CNS) lesion characterized by concomitant disorders of consciousness, recognition, memory, emotions, and psychomotor functions, as well as sleep-wakening cycles. Intraanesthetic awakening has been established to play a leading role in the development of STPMD. Under general anesthesia, the incidence of the latter is not higher than that under regional anesthesia, although the causes of STP-MD are likely to be different in either case. And, finally, CNS function monitoring is seemingly considered to be a compulsory component of intraoperative control of a patient's condition during general anesthesia. In addition, it may prevent intraanesthetic awakening episodes and the development of postoperative cognitive disorders in many respects.

PR48, a novel regulatory subunit of protein phosphatase 2A, interacts with Cdc6 and modulates DNA replication in human cells.

Initiation of DNA replication in eukaryotes is dependent on the activity of protein phosphatase 2A (PP2A), but specific phosphoprotein substrates pertinent to this requirement have not been identified. A novel regulatory subunit of PP2A, termed PR48, was identified by a yeast two-hybrid screen of a human placental cDNA library, using human Cdc6, an essential component of prereplicative complexes, as bait. PR48 binds specifically to an amino-terminal segment of Cdc6 and forms functional holoenzyme complexes with A and C subunits of PP2A. PR48 localizes to the nucleus of mammalian cells, and its forced overexpression perturbs cell cycle progression, causing a G(1) arrest. These results suggest that dephosphorylation of Cdc6 by PP2A, mediated by a specific interaction with PR48, is a regulatory event controlling initiation of DNA replication in mammalian cells.

[The use of computer technology and digital photography in the work of a forensic medical expertise bureau]. / Primenenie vychislitel'noi tekhniki i tsifrovoi fotografii v rabote biuro sudebno-meditsinskoi ékspertizy.

UNISCAN scanner with PC was used at department of medical criminology and at the histological department of the Novosibirsk Regional Bureau of Forensic Medical Expert Evaluations. The quality of images obtained by computers and digital photography is not inferior to that of traditional photographs.

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.