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COVID-19 is a disease first reported in 2019 that claimed the lives of more than 6.5 million people worldwide, paralyzed transport links and locked the borders of many states for a long time. In 2023, 3 years have passed since, yet not all countries have fully recovered and lifted the restrictions, which, of course, highlights that COVID-19 has had a huge impact on all aspects of modern life. The pandemic has given a strong impetus to the development of science and the study of COVID-19 and infectious diseases in general around the world, many articles on COVID-19 have been published in the past 3 years. Particularly interesting was the fact that while some people were asymptomatic, had mild COVID-19, other patients required mechanical ventilation and even medically induced coma. In this regard, the study of the genetic factors contributing to the severe course of the disease, comorbidities and the individual response to drugs has become especially relevant. In our work, we consider the main genes and entire loci of chromosomes involved in the pathogenesis of COVID-19. Genes such as IFNAR2, TMPRSS2, ACE2, TYK2, DPP9, HLA, OAS3, ABO, 3p21.31 locus and 12q24.13 locus have been considered; in addition, the association of severe COVID-19 with diseases such as type 2 diabetes, cardiovascular disease and obesity was discussed.

Biomedical research often requires the use of precise equipment for micromanipulation, particularly in cellular biology. However, relatively inexpensive devices for cellular manipulation with electrophysiological methods or local chemical application with micrometer accuracy are rarely available in the equipment market. In this study, we present a method to develop a micromanipulator device based on stepper motors that is controlled by a microcontroller via a gamepad. This micro-motion system can be easily produced in any laboratory for various scientific experiments that require the movement of the electrode or pipette with a precision of several micrometers.

Various studies have led to our present knowledge of α1-adrenoreceptors and their role in the regulation of cardiovascular physiology. Our study aimed to study the effect of the α1-adrenergic receptor agonist methoxamine on the frequency of spontaneous activity and electrical activity parameters of the atrial myocardium with a preserved sinus node and an imposed rhythm in newborn rats. In working cardiomyocytes of newborn rats with a preserved sinus node, methoxamine caused an increase in the frequency of spontaneous activity. α1-adrenergic receptor agonist methoxamine increased the duration of the repolarization phase of the action potential in both the imposed and the own rhythm.

This research evaluates particularities of surface structural organization of surgical samples of intracapsular distracted formations in treating post-traumatic fibrous ankylosis of proximal interphalangeal joints by means of scanning electron microscopy. The research is carried out on small-fragment samples of intracapsular formations collected in the course of treatment from 8 patients of the Microsurgical Department. Morphological evaluation of the surface of two types of samples was performed: that of proximal interphalangeal joint capsules, and of the regenerate itself. Structural analysis of the surgical samples allowed to identify considerable differences both in form and size of single structure-forming elements, and in their organizational types. It was established that the regenerate has a more compact structure. In the course of microanalysis of elemental composition, it was ascertained that mass percentage of calcium and phosphorus in the examined regenerate samples is 4.4 and 2.2 times respectively higher compared to the capsule samples. These results could be used in further research into approaches to the evaluation of connective tissue regeneration after surgeries, as well as in making recommendations for operative or physiotherapeutic patient treatment in cases of joint capsule distraction. 

The aim of the study was the IR spectroscopic and chromatographic analysis of products formed during the ozonation of fish oil. Fish oil samples were ozonized using an ozone therapy apparatus with an ozone destructor "Medozons - O3" (Nizhny Novgorod, Russia). The study of the chemical composition of fish oil ozonolysis products was performed on a Shimadzu IR Prestige 21 (Japan) infrared Fourier spectrophotometer in the region of wave numbers 4000 - 400 cm–1 in the form of liquid films in KBr, NaCl, or ZnSe windows. Chromatographic study of the composition of fatty acids was carried out on an Agilent 7890B gas chromatograph with a mass-selective detector 5977A. Qualitative and quantitative determination of propionic acid was carried out on the gas chromatographic complex "Chromosome GC – 1000". Chromatographic data processing was performed on the hardware and software complex "Chromatek-Analyst". The dynamics of IR spectra and quantitative composition of fatty acids (chromatographically) of the studied samples before and after ozonation were evaluated. The concentration of reactive oxygen species was controlled by iodometric titration according to the interstate standard GOST ISO 3900 – 2013. The acid number and saponification number of reaction products were determined by chemical methods. It was found that during the processing of fish oil, the reaction with ozone mainly proceeds locally along the ω–3 double bonds, leading to the formation of hydroperoxyesters and hydroperxy acids, as well as propionic acid. It is shown that the number of fragments of ω-6, ω-7 and ω-9 fatty acids practically does not change.

For a long time, the strains Bifidobacterium bifidum 1, Bifidobacterium bifidum 791, and Bifidobacterium longum 379 have been successfully used as probiotic producers; the conclusions about the possibility of their use, their role and functions in the human body were made empirically based on indirect signs. At present, high-tech equipment and modern research methods allow to conduct a complete study of the properties and characterization of strains; it is regulated by modern regulatory documents. In our work we applied the classical bacteriological method, MALDI TOF mass spectrometry method, NGS whole genome sequencing. The analysis of 27 clones of the strains revealed that they have typical morphological properties and stable biochemical profiles; the lists of ionized protein masses (so-called "strain markers") were determined. The whole genomes of strains deposited by us in GenBank in 2015-2017 were analyzed for the first time; we found that they do not contain pathogenicity genes, integrated plasmids, determinants of transmissible antibiotic resistance, and belong to phylogenetic clusters formed by probiotic-producing strains. It was shown that B. bifidum 1 and B. bifidum 791 have a pronounced ability to consume glycans of intestinal mucus, while B. longum 379 can efficiently consume plant glycans. The genomes of B. bifidum 791 and B. longum 379 strains contain genes for the synthesis of the most important neurometabolites of tryptophan and folic acid; the genome of B. bifidum 791 strain contains genes for the synthesis of lasso peptide and flavucin, class I lantibiotics with a wide spectrum of antimicrobial and antiviral activity.

Cataract remains the leading cause of reversible blindness worldwide. Inflammatory postoperative complications remain a significant challenge associated with cataract phacoemulsification. These include corneal melting, also known as aseptic keratomalacia, a sight-threatening inflammatory condition that precedes corneal perforation. Case description: a 70-year-old patient underwent cataract phacoemulsification and subsequently developed indomethacin induced corneal erosion. Despite 2 months of conservative treatment, the erosion progressed to a corneal ulcer. To prevent corneal perforation, a prophylactic conjunctival flap was performed. Dry eye disease and Sjogren's syndrome were diagnosed postoperatively. Follow-up was 5 years. Conclusions: the presented case demonstrates for the first time the role of indomethacin as a trigger of corneal melting after cataract phacoemulsification. Corneal melting, potentially leading to corneal perforation, may occur after successful surgery not only in patients with diagnosed dry eye disease and systemic collagenosis but also in asymptomatic patients. Torpid progression, resistance to conventional therapy and a high risk of corneal perforation require a specialist to select appropriate therapeutic and surgical treatment methods as soon as possible. Treatment begins with withdrawal of NSAIDs, local and systemic steroid therapy, intensive corneal lubrication and objective monitoring using anterior segment optical coherence tomography.

In-depth studies of the etiology and consequences of brain damage induced by chronic prenatal hypoxia are now urgently needed to improve the therapeutic strategies and reinforcing the adaptive capacity of nerve cells to oxygen deficiency. Here, we analyzed the characteristics of spontaneous calcium activity of primary hippocampal cultures obtained from mouse embryos exposed to chronic prenatal hypoxia in a late period of development in vitro (DIV 15 - DIV 21) and the adaptive capabilities of neuron-glial networks to the acute hypoxic injury. Chronic hypoxic stress caused several delays in the functional development of primary hippocampal cultures. On DIV 15, the cultures exhibited the spontaneous calcium activity with a decreased number of active cells and duration of Ca²⁺ oscillations. The reduced values of network characteristics (DIV 15) in the presence of partial destruction of the functional architecture of neuron-glial networks with a reduced force of correlated connections between cells during entire observation period were also shown. Chronic hypoxic stress altered the functional culture's response to acute oxygen deficiency. On day 7 after acute hypoxia modelling, against the background of significant decrease in the number of functionally active cells, the frequency and duration of Ca²⁺ oscillations did not differ from the intact values. Nevertheless, significant decrease in the network characteristics accompanied by substantial rearrangements in the functional architecture of neuron-glial networks indicate the death of significant part of the network elements and increase the risk of aggravation the synaptic transmission impairments leading to loss of network functionality in more distant post-hypoxic period.

The effect of therapeutic technologies used in the treatment of burns on the parameters of nitrogen metabolism has not been sufficiently studied. In this regard, the assessment of the level of nitrites and nitrates of blood and tissues in combined thermal trauma (CTT) under the influence of NO is of scientific and practical interest. The aim of the study was to determine the concentration of nitric oxide metabolites in the blood and organs under the influence of NO during CTT. The experiment was carried out on white male rats of the Wistar line. CTT (contact burn on the area of 20% of the body surface and thermal inhalation exposure for 20-30 seconds) was applied under anesthesia. Animals with CTT were treated daily with intraperitoneal injections of a 10% dinitrosyl iron complexes (DNIC) solution or were inhaled with NO (20ppm). The concentration of nitrites and nitrates was determined in the blood plasma and homogenate of the liver, heart, kidneys, and lungs. CTT was accompanied by hyperproduction of NO in blood plasma on the 1st, 7th and 10th days after injury with a maximum growth on the 1st day. The largest decrease in NO_2- and NO_3- levels during CTT was observed in the kidneys > liver > lungs > heart. The use of DNIC in CTT led to an increase in NO_2- and NO_3- in the organs. Inhalations of NO during CTT increased the concentration of NO_2- and NO_3-  in the homogenate of the lungs > kidneys > heart > liver.

Physico-chemical characteristics of optical-induced break-down depend weakly on the protein concentration. This factor distinguishes lysozyme from other aqueous solutions which contain objects with nano-size. The laser radiation of the lysozyme aqueous solution during different time periods shows patterns that are quite similar to the classical patterns. In this particular paper, it has been observed that the catalytic activity of lysozyme is decreasing after the laser radiation. The optical density of the protein solutions is increasing. The fluorescence intensity of the lysozyme solution is determined by the amino-acid residues. It decreases before and after the laser light influence. The position of the maximum of the excitation and emission did not change. The shape of the fluorescence signal on the 3D maps also does not change significantly. This observation suggests the degradation of the amino-acid residues. The viscosity and the pseudo plasticity of the lysozyme aqueous solutions increased. However, there is no massive damage of the polypeptide chain. On the contrary, the optical break-down shows the intensive forming of the lysozyme aggregates.

The high risk of ovarian cancer is primarily associated with mutations in BRCA1 and BRCA2 genes. However, mutations in these explain only a small proportion of cases. Mutations in other genes are also involved in the disease. As a result of previous exome sequencing of DNA samples from breast cancer Germany patients with clinical signs of a hereditary form of the disease without major mutations in the BRCA1, BRCA2, CHEK2 and NBN genes, potentially pathogenic genetic variants in new breast and ovarian cancer candidate genes were selected. Selected as a result of bioinformatics analysis genes are involved in vital cell signaling pathways such as repair, apoptosis, cell cycle regulation, cell proliferation, migration, differentiation, as well as immune response and inflammation. Recently, biological microarray technologies have been widely used to study the general genetic variability throughout the human genome in order to determine genetic associations with the disease and search for genes involved in the pathogenesis of multifactorial pathologies. The use of such approaches can be very useful for identifying risk markers for the development and severity of diseases. Our case-control study is aimed at researching potentially pathogenic variants selected as a result of exome sequencing of DNA samples from Caucasian patients using microarray technology Fluidigm to assess their contribution to ovarian cancer pathogenesis in Bashkortostan. Most of the researched alleles were found with different frequencies among cases and controls; however, our data indicate that the researched potentially pathogenic variants do not contribute to ovarian cancer pathogenesis in Bashkortostan populations.

The article considers the development of biocomposite materials as bacterial cellulose-based hydrogel, chitosan and alginate, plus physiologically active compounds – fusidic acid, resveratrol and dihydroquercetin. It has been found that the use of hydrogel systems derived from microbial polysaccharides and containing bacterial cellulose (BC) / sodium alginate with CaCl₂ /sodium fusidate (SF) and BC/chitosan /sodium fusidate helps to reduce the intensity of lipid peroxidation processes and stabilize phospholipid and fatty acid composition of the skin. It is consistent with the findings of the authors on longer release of sodium fusidate from biocomposite materials of this composition. Therefore, the use of BC and chitosan in combination with sodium fusidate, which exhibits antibacterial properties, and the crosslinking of sodium alginate with calcium chloride solution proves to be the most effective for restoring the skin’s lipid composition and shortening the course of treatment. Most likely, this effect must be explained by the constant release of physiologically active compounds from hydrogel composites and its impact on damaged skin areas.

The visceral system can influence consciousness and emotions. In this paper, we investigated whether the processing of short-term emotional stimuli along different phases of the cardiac cycle is selectively regulated. Emotional and neutral faces were presented to the volunteers during cardiac systole, when the release of blood from the heart causes arterial baroreceptors to centrally signal the strength and time of the heartbeat, and in diastole, the period between heartbeats when the baroreceptors are at rest. Participants passively observed the faces appearing in the oddball paradigm in immersive virtual reality (VR). Combining electroencephalography and electrocardiography, cardio synchronous ERP was recorded. The ERP data at the occipital Oz electrode demonstrate the dependence of emotional stimuli in respect to the cardiac cycle. ERP in VR were higher during diastole than systole. More specifically, the cardiac phase influenced late component P300 of the ERP, did not influence early P100 and affected P200 only to angry face. This new evidence that events related to cardiac function can modulate emotional perception in virtual reality might be one more prime example of how body feedback shapes emotions.

The paper focuses on studying the rheological properties of erythrocytes in patients with a new coronavirus infection in the acute period and during early convalescence. A significant decrease in erythrocyte membrane plasticity was found in all patients in the acute period of the disease and every second recovering patients in the early post-COVID period. An increase in the degree and rate of erythrocyte aggregation in a quarter of cases, regardless of the observation period, was accompanied by inhibition of erythrocyte disaggregation mechanisms, which can serve as a pathophysiological basis for the formation of hemorheological disorders both in the micro- and macrovasculature in the first 3 months after recovery.

Along with the wide spread of bacterial antibiotic resistance over the world, the treatment efficiency of infectious disease is greatly affected by the mixed biofilm formation by pathogenic bacteria. Staphylococcus aureus and Pseudomonas aeruginosa, a frequent cause of nosocomial infections, exhibit both synergistic and antagonistic interactions in co-culture, leading to various changes in the metabolic profile of bacteria, which in turn affect their sensitivity to antimicrobials. Here we show that S. aureus cell-free culture liquid exhibits bacteriostatic properties and increases the efficacy of antimicrobials against P. aeruginosa. Thus, the MICs of amikacin, gentamicin, and ciprofloxacin decreased 2-4 fold in the presence of cell-free supernatant of S. aureus 24 h culture. Furthermore, the combination of the latter with antimicrobials increased the efficacy of amikacin up to 64-fold. Thus, the combined use of cell-free culture liquid of S. aureus with broad-spectrum antibiotics can be used to increase the effectiveness of antimicrobial therapy of P. aeruginosa.

Microbial production of testosterone from phytosterol is a promising alternative to the chemical synthesis from androstenedione, which is currently used. It is possible using wild-type or recombinant strains of Mycolicibacterium neoaurum. One of the key steps of biotechnology development is inoculum preparation which determines the volumetric/mass ratios of the bioreactors and affects the biotransformation rate and duration. In the present work, the conditions for the growth of testosterone-producing strain of Mycolicibacterium neoaurum recombinant strain with enhanced 17β-HSD activity were optimized. The effects of medium composition, temperature, and glucose supplements on biomass size and density were estimated. The results are of importance for the development of microbial technology for testosterone production.

In this paper, we present the data on the properties of the probiotic strain Bacillus intestinalis GM2 related to adhesion, auto-, and coaggregation. GM2 exhibits a strong autoaggregation phenotype. The autoaggregation ability of GM2 did not change after trypsin treatment but was reduced under the influence of extracellular culture metabolites. Coaggregation of probiotic strains with pathogens is one of the mechanisms of displacement of pathogens from the intestinal microbiota. It was shown that the GM2 strain exhibits the ability to coaggregate with tested strains of Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, and Bacillus cereus. The studied properties of bacilli can be useful for the creation of new probiotics for poultry farming. 

Nowadays, manned cosmonautics is faced with the task of carrying out a long-term space flight beyond the limits of low Earth orbit. Under the conditions of an orbital space flight, a person is exposed to a number of adverse effects on the body, among which microgravity is especially distinguished. Prolonged exposure to microgravity can lead to severe immune impairment. At present, immunological studies of cosmonauts can be conducted only after they return to Earth at the end of a space flight, as a result of which the use of ground-based models that imitate specific space factors seems to be an advanced direction. A well-studied microgravity model is bed rest, during which volunteers are kept in strict rest in bed. Granulocytes, as representatives of innate immunity, are the first among immune cells to respond to an altered state of the body; therefore, researches of the influence of bed rest on the granulocyte phenotypic characteristics can provide important information for the development of prophylaxis measures to the immune disorders’ development when exposed to microgravity. The work used data obtained from six subjects. The impact of bed rest was determined at the end of the model, after 21 days. The following granulocyte clusters of differentiation (CD) were studied by flow cytometry: CD25, CD64, CD23, CD14, CD16, CD36, CD11b, CD18, CD286. Tendencies to a decrease in the percentage of CD64⁺ subpopulation and an increase in the percentage of CD23⁺, as well as CD25⁺ subpopulation of granulocytes after 21 days of bed rest were revealed.

Radiotherapy is one of the most effective and most commonly used methods of cancer treatment. However, as a result of irradiation, there are side effects that occur as a result of ionizing radiation on healthy tissues. The use of a combined approach with the use of low doses of radiation and antitumor drugs that have a radiosensitizing effect may be one of the ways to reduce side effects and overcome the resistance of malignant cells. This study was undertaken to evaluate the combined effects of radiotherapy and the chemotherapeutic agent Doxorubicin on A431 human epidermoid carcinoma cell line. The cells were incubated with the antitumor antibiotic Doxorubicin and then exposed to high-energy electron ionizing radiation. The cell viability was examined using the MTT assay. The results showed that Doxorubicin acts as a radiosensitizer. Moreover, the combined effect of Doxorubicin and high-energy ionizing radiation of electrons is additive. According to the obtained results, combination therapy used in the treatment of oncological diseases can significantly reduce the radiation dose and minimize the side effects that occur during high doses of irradiation.

Aim of the study: to analyze the results of performing retrograde perfusion of the pulmonary artery during an open thromboembolectomy from the pulmonary artery. Materials and methods: the experience of performing retrograde perfusion of the pulmonary artery in 10 patients operated in our clinic for massive pulmonary embolism is presented. Retrograde perfusion was performed after the stage of embolectomy from the pulmonary artery. For the latter, we used a disposable cardioplegic solution delivery system and 2 cardioplegic pumps of the heart-lung machine: the first for taking blood perfusate from the oxygenator, the second for supplying the combined solution. The blood perfusate and solution were mixed in a 3:1 ratio and injected selectively into the orifices of the pulmonary veins under a pressure of up to 20 mm Hg. (volume perfusion rate 200-250 ml/min) for 4 minutes. Results: despite the initial severity of the patients' condition, as well as the amount of surgical intervention performed, the hospital survival rate was 100%. Along with this, we did not note the development of specific complications, as well as the aggravation of the course of the intraoperative and early postoperative periods. Conclusion: retrograde pulmonary artery perfusion is a very encouraging and promising technique that provides effective and safe removal of small thromboembolism from the peripheral parts of the pulmonary arterial bed, as well as preventing the development of residual pulmonary hypertension as a result of developing intraoperative air embolism.

Viliuisk encephalomyelitis (VE) is a neurodegenerative disorder that afflicts the aboriginal people of Yakutia in Siberia. The disease is characterized by a progressive duration and aseptic inflammatory episodes, with intrathecal synthesis of oligoclonal IgG (OCBs) in some patients. The aim of this study was to evaluate the role of soluble ligands and receptors of the tumour necrosis factor (TNF) superfamily as potential participants in VE pathogenesis. To achieve this goal, we measured the levels of sTNF-α, sFas-L, sTRAIL, sCD40L ligands, and sCD40 receptor by ELISA in the plasma of VE patients compared with healthy individuals of the same population and patients with demyelinating diseases, including multiple sclerosis (MS) and neuromyelitis optica (NMO), as examples of disorders involving immune pathology. In addition, the same markers were analyzed in the CSF of VE patients and patients with demyelinating diseases. The results obtained showed that the increased level of plasma sTNF-α in VE patients was associated with the detection of OCBs (p = 0.01; two-tailed Student’s t-test). The sCD40L level in plasma was significantly increased in VE patients, regardless of the presence of an inflammatory component (p = 0.001; Student's t-test), and their healthy relatives (p = 0.004; Student's t-test). Our results suggested that increased blood sCD40L levels are associated with the chronic form of VE and may participate in the predisposition to the disease. Increased blood sCD40L levels may lead to pathology of the vascular endothelium in the brain and the development of VE pathology.