[Venous gangrene of small intestine following coronavirus infection (SARS-COVID-19)]. / Venoznaya gangrena tonkoi kishki na fone koronavirusnoi infektsii (SARS-COVID-19).

The pandemic of a new coronavirus infection has made certain adjustments to modern emergency medicine. Systemic endothelial dysfunction following COVID-19 largely determines hemostatic disorders. Numerous studies revealed that intense platelet adhesion followed by platelet aggregates in COVID-19 patients and functional disorders of fibrinolysis system are combined with activation and severe endothelial dysfunction. The last one inevitably leads to thrombosis and adverse vascular events. There are a lot of studies devoted to deep vein thrombosis and fatal massive pulmonary embolism under COVID-19 infection. However, there are no descriptions of mesenteric thrombosis followed by intestinal wall necrosis. Our experience is based on the treatment and follow-up of 14 patients with venous gangrene of small intestine under COVID-19-induced severe endothelial dysfunction. We present a 40-year-old man with coronavirus infection complicated by ileum gangrene and subsequent favorable outcome.

[Methylation of Regulatory Regions of DNA Repair Genes in Carotid Atherosclerosis].

The status of DNA methylation in the human genome changes during the pathogenesis of common diseases and acts as a predictor of life expectancy. Therefore, it is of interest to investigate the methylation level of regulatory regions of genes responsible for general biological processes that are potentially significant for the development of age-associated diseases. Among them there are genes encoding proteins of DNA repair system, which are characterized by pleiotropic effects. Here, results of the targeted methylation analysis of two regions of the human genome (the promoter of the MLH1 gene and the enhancer near the ATM gene) in different tissues of patients with carotid atherosclerosis are present. Analysis of the methylation profiles of studied genes in various tissues of the same individuals demonstrated marked differences between leukocytes and tissues of the vascular wall. Differences in methylation levels between normal and atherosclerotic tissues of the carotid arteries were revealed only for two studied CpG sites (chr11:108089866 and chr11:108090020, GRCh37/hg19 assembly) in the ATM gene. Based on this, we can assume the involvement of ATM in the development of atherosclerosis. "Overload" of the studied regions with transcription factor binding sites (according to ReMapp2022 data) indicate that the tissue-specific nature of methylation of the regulatory regions of the MLH1 and ATM may be associated with expression levels of these genes in a particular tissue. It has been shown that inter-individual differences in the methylation levels of CpG sites are associated with sufficiently distant nucleotide substitutions.

[Identification of Functionally Significant Polymorphic Variants in miRNA Genes in Carotid Atherosclerosis].

miRNAs are vital molecules of gene expression. They are involved in the pathogenesis of various common diseases, including atherosclerosis, its risk factors, and its complications. A detailed characterization of the spectrum of functionally significant polymorphisms of miRNA genes in patients with advanced carotid atherosclerosis is an important research task. We analyzed miRNA expression and exome sequencing data of carotid atherosclerotic plaques of male patients (n = 8, 66-71 years of age, 67-90% degree of carotid artery stenosis). For further study and analysis of the association between the rs2910164 polymorphism of the MIR146A gene and advanced carotid atherosclerosis, we recruited 112 patients and 72 relatively healthy Slavic residents of Western Siberia. A total of 321 and 97 single nucleotide variants (SNVs) were detected in the nucleotide sequences of pre- and mature miRNAs in carotid atherosclerotic plaques. These variants were located in 206 and 76 miRNA genes, respectively. Integration of the data of exome sequencing and miRNA expression revealed 24 SNVs of 18 miRNA genes that were processed to mature form in carotid atherosclerotic plaques. SNVs with the greatest potential functional significance for miRNA expression predicted in silico were rs2910164:C>G (MIR146A), rs2682818:A>C (MIR618), rs3746444:A>G (MIR499A), rs776722712:C>T (MIR186), rs199822597:G>A (MIR363). The expression of miR-618 was lower in carotid atherosclerotic plaques of patients with the AC rs2682818 genotype of the MIR618 gene compared with the CC genotype (log2FC = 4.8; p = 0.012). We also found an association of rs2910164:C (MIR146A) with the risk of advanced carotid atherosclerosis (OR = 2.35; 95% CI: 1.43-3.85; p = 0.001). Integrative analysis of polymorphisms in miRNA genes and miRNA expression is informative for identifying functionally significant polymorphisms in miRNA genes. The rs2682818:A>C (MIR618) is a candidate for regulating miRNA expression in carotid atherosclerotic plaques. The rs2910164:C (MIR146A) is associated with the risk of advanced carotid atherosclerosis.

Anisotropic acousto-optic interaction in a KRS-5 crystal.

We investigated the acoustic and acousto-optic parameters of cubic crystal KRS-5, which can be used in acousto-optic devices operating with optical radiation from visible to far infrared regions. The results of acoustic and acousto-optic property calculations are presented. Also, we present a possibility of obtaining optical birefringence in cubic material when external static pressure is applied to the KRS-5 crystal. We discuss in detail the results of anisotropic Bragg diffraction observation in cubic crystal in the presence of external static pressure.

[Lesions of the cortical part of the auditory analyzer in explosive injury]. / Narusheniya korkovogo otdela slukhovogo analizatora pri vzryvnoi travme.

A survey of 48 victims aged 19-36 years with explosive trauma and combined damage to the auditory system was conducted to assess the level of damage to nerve structures by analyzing the bioelectric activity of the cerebral cortex. All patients underwent electroencephalography (EEG). It is established that akubarotrauma of explosive genesis almost always leads to lesions of the function of the cortical part of the auditory analyzer. Desynchronized activity on the EEG after acubarotrauma is a favorable prognostic sign, indicating only functional disorders of the cortical part of the auditory analyzer. On the contrary, EEG changes of an organic type of cortical or stem nature are an unfavorable prognostic factor, usually accompanied by sensorineural hearing loss with prolonged and incomplete hearing recovery. Promising drugs for the treatment of otoneurological disorders are antihypoxants, in particular, derivatives of triazine indole, which affect the molecular mechanisms of hypoxia development.

Zero Gravity is a Factor that Induces Negative Changes in Myelinated Fibers of the Spinal Tracts.

The development of hypogravitational motor syndrome is an essential negative consequence of weightlessness for humans; an important role in the pathogenesis of this syndrome is played by changes in axons of the spinal tracts. Myelinated fibers and transcriptome of the spinal cord were studied in mice exposed to hypogravity during a 30-day flight on a biosatellite. Morphometric analysis of myelinated fibers of the spinal tracts showed a decrease in the thickness of the myelin sheath. Analysis of spinal cord transcriptome revealed a decrease in the expression of genes involved in the myelination of nerve fibers. These results suggest that the processes of nerve fiber myelination are involved in the development of the hypogravitational motor syndrome under weightless conditions; the 7-day readaptation period was found to be insufficient for reversion of the negative changes in the myelinated fibers of the spinal cord.

Possible Mechanisms of Axonal Transport Disturbances in Mouse Spinal Motoneurons Induced by Hypogravity.

The data obtained by transcriptome analysis of lumbar spinal cord segments, sciatic nerve, and the respiratory diaphragm of the mice performed after a space flight on board Bion-M1 biosatellite were processed by bioinformatic methods aimed at elucidation of the regularities in hypogravity-induced transcriptome changes in various compartments of motor neurons. The study revealed abnormalities of axonal transport in spinal motor neurons provoked by weightlessness. These data agree with the results of electron microscopy examination of the spinal cord in experimental animals. In space group mice sacrificed on the landing day, the content of perinuclear ribosomes in lumbar motoneurons surpassed that in control mice or in the recovery group examined 1 week after the flight. The data corroborate our hypothesis on contribution of axonal transport disturbances into pathogenesis of hypogravity motor syndrome. They can be employed as a launching pad for further study of hypogravity-triggered motor disorder mechanisms in order to elaborate the preventive therapy against the development of hypogravity motor syndrome in space flights.

[Functionality of mammary-coronary bypass grafts according to the data of intraoperative flowmetry]. / Funktsional'nost' mammarokoronarnykh shuntov po dannym intraoperatsionnoi floumetrii.

Improvement of surgical treatment for ischaemic heart disease is one of the main trends in modern medicine. After the operation of coronary bypass grafting, further functioning of blood flow in the grafts largely depends upon its domination over the native blood flow in the target coronary arteries. Therefore, intraoperative diagnosis of functional competence of coronary bypass grafts by means of flowmetry is currently of special importance. The purpose of this study was flowmetric quantitative assessment of the curves of blood flow through the coronary bypass grafts, depending on the degree of stenosis of the target coronary arteries. A total of 135 patients were examined during our study. We evaluated the curves of blood flow through the bypass grafts from the left internal thoracic artery to the anterior descending artery. The bypass grafts were divided into three groups: the 1st group (n=47) with moderate stenosis of the coronary arteries (from 50 to 75%); the 2nd group (n=42) with a more pronounced lesion of the target vessel (from 75 to 99%), and the 3rd group (n = 46) with occluded coronary arteries (100%). It was revealed that the flow rate (Q, ml/min) in group one was lower (17±3.1) than in group two (33±5.3) and group three (45±3.4). Also, differences were revealed in the resistance index of the grafts: it turned out to be higher in group one (5.2±1.1) and group two (4.5±0.9) as compared with group three (1.8±0.5). However, there was no between-group difference in diastolic filling of the grafts, which amounted to 58±13, 61±10 and 64±9% for groups one, two and three, respectively. By the shape of the curve, we assessed the reverse systolic peak whose presence prevailed in the grafts of group one (15 of 47; 31.9%) and group two (11 of 42; 26.2%) as compared with that in the grafts of group three (5 of 46; 10.8%). The obtained findings confirm higher frequency of the presence of competitive blood flow in the grafts used on non-occluded coronary arteries.

Morphological Study of Myelinated Fibers of the Sciatic Nerve in Mice after Space Flight and Readaptation to the Conditions of Earth Gravity.

We revealed a decrease in the thickness of the myelin sheath and myelin delamination in the tibial nerve of C57BL/6N mice after a 30-day flight aboard the biosatellite Bion-M1. The processes of myelin degeneration continued for seven days after return of the animals to Earth and adaptation to the conditions of natural gravity. Our data add to hypothesis on the role of neurogenic component in pathogenesis of hypogravity motor syndrome.

[Single-centre experience with implantation of the 'E-vita open plus' hybrid stent graft]. / Odnotsentrovyi opyt implantatsii gibridnogo stent-grafta 'E-vita open plus'.

Hybrid technologies appear to have been gaining ground in surgery of the thoracic aorta. The present study was aimed at assessing the immediate clinical outcomes of surgical treatment of diseases of the thoracic aorta by means of the 'E-vita open plus' hybrid stent graft. The 'E-vita open plus' hybrid stent graft was implanted to 18 patients. All operations were carried out in the conditions of moderate hypothermia. The brain was protected by unilateral cerebral perfusion through the brachiocephalic trunk. The duration of artificial circulation averagely amounted to 265.1 [214; 281] min., with the mean aortic cross-clamping time equalling 150.8 [121; 177] min., and circulatory arrest lasting 55 [47.5; 62.5] min. In one (5.5%) case resternotomy was performed for haemorrhage. Five (27.8%) patients required haemodialysis to perform for postoperative renal insufficiency. A further five (27.8%) patients were found to have transient impairment of cerebral circulation. One (5.5%) patient was diagnosed as having haemorrhage into the area of the 'old ischaemic focus', one (5.5%) patient developed transient spinal ischaemia spontaneously disappearing within the first 24 hours. There were no cases of cardiac complications. A conclusion was drawn that hybrid operations according to the 'frozen elephant trunk' technique yield satisfactory immediate clinical results of treatment in patients with thoracic aortic aneurysms and dissection.

[Significance of the level of implantation of the 'E-vita open plus' hybrid stent graft into the descending aorta in the development of spinal ischaemic complications]. / Znachenie urovnia implantatsii gibridnogo stent-grafta 'E-vita open plus' v niskhodiashchuiu aortu v razvitii spinal'nykh ishemicheskikh oslozhnenii.

Spinal ischaemia in patients after reconstruction of the thoracic aorta is referred to the category of the most severe postoperative complications, especially in hybrid interventions. The present study was aimed at assessing the risks for the development of spinal ischaemia in patients after implantation of the 'E-vita open plus' stent graft into the descending portion of the thoracic aorta during hybrid reconstruction. The 'E-vita open plus' hybrid stent graft (Jotec, Germany) was implanted to 18 patients presenting with various pathology of the thoracic aorta (dissection, aneurysms). All operations were carried out in the conditions of moderate hypothermia, circulatory arrest and antegrade perfusion of the brain through the brachiocephalic trunk. It was determined that the distal end of the stent graft was located at the level of Th7-Th12. In 12 (66.7%) cases the 'lower' edge of the stent graft was located at the level of thoracic vertebrae Th8-Th9. Before the operation the number of open pairs of intercostal arteries amounted to 10 [9, 11]. After the operation, the number of the open pairs of the segmental arteries amounted to 3 [1; 4], they were all in the lower thoracic portion; the above-located intercostal arteries were shut by the stent graft. In 17 (94.5%) cases in the early postoperative period there were no signs of spinal ischaemia. Only one (5.5%) patient was clinically diagnosed to have developed transient spinal ischaemia noted to disappear spontaneously within the first 24 hours. A conclusion was made that using the 'E-vita open plus' stent graft in the course of hybrid reconstruction of the thoracic aorta was accompanied by the minimal risk for spinal ischaemic complications. The level of the location of the distal edge of the stent graft is not the determining factor in the risks of spinal complications in of such similar operations.

[Puncture treatment of pseudoaneurysms of femoral arteries with the use of human thrombin]. / Punktsionnoe lechenie lozhnykh anevrizm bedrennykh arterii s ispol'zovaniem chelovecheskogo trombina.

The authors analysed both immediate and remote results of puncture treatment with the use of human thrombin under ultrasound control in patients with iatrogenic false aneurysms of femoral arteries. The study included a total of 32 patients presenting with post-puncture pseudoaneurysms of femoral arteries after previous endovascular manipulations. The clinical diagnosis was verified by means of ultrasound duplex scanning. Puncture treatment was carried out using lyophilisate of human thrombin at a concentration of 500 IU according to the patented technique. The obtained outcomes were assessed at various terms (up to 12 months). The predominant ultrasound characteristics of a false aneurysm were as follows: an arterial defect sized 2.1-3 mm with prevailing localization in the superficial femoral artery (singe-chamber pseudoaneurysm with the volume of its cavity amounting to 31-60 cm3). The average dose of thrombin sufficient for obliteration of the cavity amounted to 320.8±104.6 IU. The puncture treatment proved to be effective in 30 (93.7%) patients. In the remaining 2 (6.3%) cases the outcomes of puncture treatment turned out unsatisfactory, thus requiring an operative intervention. No relapsed were observed in the remote period. A conclusion was drawn that puncture treatment is a highly effective method in relation to false aneurysms of femoral arteries and is neither accompanied by relapses nor followed by allergic, thrombotic, infectious complication at various terms of follow up. Efficacy of treatment with human thrombin does not depend on taking antithrombotic agents by the patients.

[Possibilities of "E-vita open plus" hybrid stent graft in surgery of thoracic aorta]. / Vozmozhnosti gibridnogo stent-grafta «E-vita open plus¼ v khirurgii grudnoi aorty.

BACKGROUND: The variety of pathology of the thoracic aorta supposes different approaches of surgical management, including the use of hybrid technologies. OBJECTIVE: To broaden a possible spectrum of indications for implantation of the "E-vita open plus" hybrid stent graft. RESULTS: Surgical treatment of thoracic aorta with the help of the "E-vita open plus" hybrid stent graft according to the "frozen elephant trunk" technique demonstrated satisfactory results in patients with various pathology: type A and B acute and chronic dissection according to the Stanford classification, as well as rare diseases (post-traumatic false aneurysm, complicated atherosclerosis of the thoracic aorta). CONCLUSION: The technology of "frosted elephant trunk" with implantation of the "E-vita open plus" hybrid stent graft in not limited by cases of acute aortic dissection, aortic aneurysmatic transformation and has wider indications for application. The use of this technology in cases of rare pathology of the thoracic aorta ("shaggy aorta" syndrome, posttraumatic false aneurysm) makes it possible to obtain satisfactory clinical results.

[Reconstructive surgery of aortic arch interruption in adults].

AIM: To evaluate surgical results in adults with aortic arch interruption. MATERIAL AND METHODS: Seven patients with aortic arch interruption were operated. Two of them (28.6%) underwent aortic arch repair using allograft, 4 (57.21%) - distal arch and proximal descending aortic replacement, 1 (14.3%) - supra-coronary ascending aortic, aortic arch and proximal descending aortic replacement. All operations were performed under moderate hypothermia (25 °Ð¡), circulatory arrest with unilateral cerabral perfusion 8-10 ml/kg/min via innominate artery and pressure 69.6±14.7 mm Hg in arterial. RESULTS: Cardiopulmonary bypass (CPB) time was 242±36.1 min, aortic cross-clamping - 110.7±40.4 min, circulatory arrest - 58.6±17.9 min. There were no cases of renal insufficiency, vascular lesion of brain and spinal cord, cardiac events. Resternotomy for bleeding was performed in 1 (14.3%) case. Sufficient descending aortic lumen was achieved in 100% according to CT postoperatively. Peak descending aortic pressure gradient after repair with allograft was 29±1.4 mm Hg, after aortic replaement - 10±4.2 mm Hg. Postoperative and in-hospital 30-day mortality was absent. CONCLUSION: Reconstructive surgery for aortic arch interruption in adults is effective approach with good clinical and hemodynamic results.

[Antegrade unilateral perfusion of the brain through the brachiocephalic trunk in operations on the aortic arch].

Presented herein is a technique of unilateral antegrade perfusion of the brain in operations on the aortic arch. The method makes it possible to perform both systemic artificial circulation and adequate physiological perfusion of the brain, promoting minimization of the number of neurological complications.

Formation of Boron-Carbon Nanosheets and Bilayers in Boron-Doped Diamond: Origin of Metallicity and Superconductivity.

The insufficient data on a structure of the boron-doped diamond (BDD) has frustrated efforts to fully understand the fascinating electronic properties of this material and how they evolve with doping. We have employed X-ray diffraction and Raman scattering for detailed study of the large-sized BDD single crystals. We demonstrate a formation of boron-carbon (B-C) nanosheets and bilayers in BDD with increasing boron concentration. An incorporation of two boron atoms in the diamond unit cell plays a key role for the B-C nanosheets and bilayer formation. Evidence for these B-C bilayers which are parallel to {111} planes is provided by the observation of high-order, super-lattice reflections in X-ray diffraction and Laue patterns. B-C nanosheets and bilayers minimize the strain energy and affect the electronic structure of BDD. A new shallow acceptor level associated with B-C nanosheets at ~37 meV and the spin-orbit splitting of the valence band of ~6 meV are observed in electronic Raman scattering. We identified that the superconducting transitions occur in the (111) BDD surfaces only. We believe that the origin of Mott and superconducting transitions is associated with the two-dimensional (2D) misfit layer structure of BDD. A model for the BDD crystal structure, based on X-ray and Raman data, is proposed and confirmed by density functional theoretical calculation.

[Cold-plasma sternotomy and postoperative sternal consolidation].

MATERIAL AND METHODS: It is presented the results of cold-plasma sternotome application in 16 patients. Efficiency of this technique, its effect on sternal reparation as well as on the incidence of early and remote (4-5 months) postoperative wound complications were analyzed. Control group included 19 patients who underwent conventional sternotomy using high-temperature electrocoagulation and medical wax for hemostasis. Risk factors for sternal infection were comparable in both groups. Physical examination and computed tomography were performed in all patients to access incidence of complications and degree of bone tissueconsolidation respectively in postoperative period. RESULTS: It is shown that cold-plasma sternotomy leads to early inflammation resolution in oversplitting area and to reduction of wound complications incidence.

All-diamond optical assemblies for a beam-multiplexing X-ray monochromator at the Linac Coherent Light Source.

A double-crystal diamond (111) monochromator recently implemented at the Linac Coherent Light Source (LCLS) enables splitting of the primary X-ray beam into a pink (transmitted) and a monochromatic (reflected) branch. The first monochromator crystal, with a thickness of ∼100 µm, provides sufficient X-ray transmittance to enable simultaneous operation of two beamlines. This article reports the design, fabrication and X-ray characterization of the first and second (300 µm-thick) crystals utilized in the monochromator and the optical assemblies holding these crystals. Each crystal plate has a region of about 5 × 2 mm with low defect concentration, sufficient for use in X-ray optics at the LCLS. The optical assemblies holding the crystals were designed to provide mounting on a rigid substrate and to minimize mounting-induced crystal strain. The induced strain was evaluated using double-crystal X-ray topography and was found to be small over the 5 × 2 mm working regions of the crystals.