COVID-19 in Russia: Clinical and Immunological Features of the First-Wave Patients.

The coronavirus disease outbreak in 2019 (COVID-19) has now achieved the level of a global pandemic and affected more than 100 million people on all five continents and caused over 2 million deaths. Russia is, needless to say, among the countries affected by SARS-CoV-2, and its health authorities have mobilized significant efforts and resources to fight the disease. The paper presents the result of a functional analysis of 155 patients in the Moscow Region who were examined at the Central Clinical Hospital of the Russian Academy of Sciences during the first wave of the pandemic (February-July, 2020). The inclusion criteria were a positive PCR test and typical, computed tomographic findings of viral pneumonia in the form of ground-glass opacities. A clinical correlation analysis was performed in four groups of patients: (1) those who were not on mechanical ventilation, (2) those who were on mechanical ventilation, and (3) those who subsequently recovered or (4) died. The correlation analysis also considered confounding comorbidities (diabetes, metabolic syndrome, hypertension, etc.). The immunological status of the patients was examined (levels of immunoglobulins of the M, A, G classes and their subclasses, as well as the total immunoglobulin level) using an original SARS-CoV-2 antibody ELISA kit. The ELISA kit was developed using linear S-protein RBD-SD1 and NTD fragments, as well as the N-protein, as antigens. These antigens were produced in the prokaryotic E. coli system. Recombinant RBD produced in the eukaryotic CHO system (RBD CHO) was used as an antigen representing conformational RBD epitopes. The immunoglobulin A level was found to be the earliest serological criterion for the development of a SARS-CoV-2 infection and it yielded the best sensitivity and diagnostic significance of ELISA compared to that of class M immunoglobulin. We demonstrated that the seroconversion rate of "early" N-protein-specific IgM and IgA antibodies is comparable to that of antibodies specific to RBD conformational epitopes. At the same time, seroconversion of SARS-CoV-2 N-protein-specific class G immunoglobulins was significantly faster compared to that of other specific antibodies. Our findings suggest that the strong immunogenicity of the RBD fragment is for the most part associated with its conformational epitopes, while the linear RBD and NTD epitopes have the least immunogenicity. An analysis of the occurrence rate of SARS-CoV-2-specific immunoglobulins of different classes revealed that RBD- and N-specific antibodies should be evaluated in parallel to improve the sensitivity of ELISA. An analysis of the immunoglobulin subclass distribution in sera of seropositive patients revealed uniform induction of N-protein-specific IgG subclasses G1-G4 and IgA subclasses A1-A2 in groups of patients with varying severity of COVID-19. In the case of the S-protein, G1, G3, and A1 were the main subclasses of antibodies involved in the immune response.

Comparative Culturing of 3T3 Swiss J2 Mouse Embryo Fibroblasts on Modified Chitosan Matrices.

Comparative culturing of mouse embryo fibroblasts on chitosan matrices and culture plastic was carried out. During the first 2 h of culturing (lag phase), cell adhesion to chitosan and chitosan-gelatin matrices was 20-30% higher than adhesion to culture plastic (control). During the stationary phase, 80% cells adhered to chitosan matrices (vs. 60% in the control). Cell culturing on chitosan matrices was carried out without medium replacement with fresh portions. The cells remained viable within 5 days of culturing. Cell death phase was observed on day 6 of culturing on chitosan matrices: cell adhesion dropped to 50%. Culturing on culture plastic was carried out with daily medium replacement with a fresh portion. Cell death phase (50% decrease in the number of adherent cell) under these condition was observed on day 5. It seems that the observed effect was a result of contact interactions of cell integrins and chitosan ligands, modulation of transmembrane signal, eventually modifying the expression of cell genes. This effect can be required in regenerative medicine for production of primary cell culture.

[INFLUENCE OF TITANIUM COATING ON THE BIOCOMPATIBILITY OF POLYPROPYLENE IMPLANTS].

Comparative analysis of the proliferative activity of inflammatory cells and distribution of collagen types I and III was carried out around the net materials of polypropylene and titanium coating polypropylene using im- munohistochemical method and polarization microscopy. Experimental modeling of implanted mesh material were made in the soft tissues of the lumbar region of rats. On the 7th postoperative day, quantitative analysis of proliferating cells delected using antibodies to the Ki-67 protein showed, a significant decrease (p < 0.001) in the number of proliferating cells around the network elements of the polypropylene (29.1 ± 5.7 %), when com- pared to similar figures of infiltrates in titanium coating polypropylene (33.6 ± 3.1 %). Similar patterns were found on the 30th day of the experiment--15.9 ± 4.3 and 26.9 ± 3.6%--respectively (p < 0.001). Different types of collagen fibers in the granulomas around various types of implanted mesh material were detected on sections stained with Sirius red at polarizing light. On the 7th day after surgery, the ratio of collagen fibers ty- pe I and III in granulomas around the mesh material made of polypropylene was 1.085 ± 0.022 and this rati around materials of titanium coated polypropylene was higher--1.107 ± 0.013 (p = 0.017). On the 30th posto- perative day in the interface area ratio I/III collagen significantly increased and amounted to 1.174 ± 0.036 and 1.246 ± 0.102, respectively (p = 0.045). Assessing the impact of the use of titanium as a coating on the po- lypropylene, it can be argued that it promotes the formation of collagen I type and a more mature connective tis- sue around the mesh of the implants.

[Intraperitoneal and retromuscular abdominal wall repair using ultra-light and titanium-containing polypropylene mesh (experimental research)]. / Intraperitoneal'naya i retromuskulyarnaya plastika bryushnoi stenki ul'tralegkimi polipropilenovymi i titansoderzhashchimi endoprotezami (eksperimental'noe issledovanie).

AIM: To study experimental possibility of light, ultra-light and titanium-containing endoprostheses implantation for postoperative hernias correction. MATERIAL AND METHODS: Abdominal wall repair was simulated in 72 rabbits. In the first group polypropylene mesh with fibers diameter of 90 microns and surface density of 36 g/m2 was used. In the second group we applied polypropylene mesh with fibers diameter of 65 microns and thin layer of titanium. Their surface density was 16 g/m2. Intraperitoneal onlay mesh (IPOM) and sublay retromuscular (SRM) techniques were used in group 1 and 2 respectively. Animals were taken out from the experiment in 30 and 60 days. Adhesive process in implantation area was evaluated using the method of Egiev V.N. and Lyadov V.K. RESULTS: The most pronounced adhesive process was observed in IPOM series. Type of endoprosthesis and terms of postoperative period did not significant effect adhesive process. SRM method was associated with significantly less pronounced adhesions. Analysis of all data showed that severity of adhesive process was significantly higher in IPOM series compared with SRM technique. CONCLUSION: Our study showed that severity of abdominal adhesive process associated with repair using ultra-light mesh is completely determined by surgical technique and did not depend on type of endoprosthesis and terms of postoperative period. Described implants should be used for retromuscular implantation rather intraperitoneal position.

[Application of heated oxygen-helium mixture for combined treatment of community-acquired pneumonia].

Community-acquired pneumonia (CAP) is the commonest infectious disease characterized by the high lethality rate. The aim of this work was to estimate the efficacy of introducing inhalation of heated oxygen-helium mixture (thermoheliox) into standard therapy of CAP. The study included 50 patients with moderately severe CAP 25 patients of group 1 were given standard therapy plus thermoheliox, those of group 2 were treated by standard method. Group 1 showed faster disappearance of symptoms and physical signs including inflammatory changes (chemiluminescence of whole blood) and cardiac rhythm variability as well as more complete recovery of pneumonia upon X-ray examination. It is concluded that thermoheliox is an effective agent for pathogenetic therapy of community-acquired pneumonia.

[Fungal spores: dormancy, germination, chemical composition, and role in biotechnology (review)].

This review is focused on one of the stages of ontogenesis distinctive by its particular tolerance to the action of unfavorable factors and ability to retain the genomic material for a long period of time, i.e., fungal spores. The major part is devoted to the characterization of the specific stage typical for spores, which is called dormancy. Data are presented characterizing the carbohydrate and lipid composition of spores, with special attention being paid to the role of carbohydrate protectors, in particular, trehalose and mannite, as well as to the role of rafts in the process of sporogenesis. The role of special compounds called autoinhibitors and autostimulators in the process of exit from dormancy is discussed. The final section deals with the role of spore seeding material in biotechnological processes. Data on the correlation between the chemical composition of spores, their ability to remain dormant, and the germination process are considered. Special biotechnological approaches are presented for the first; they allow for the preservation of the germinating ability of spores, intensification of sporogenesis, changes in the ratio of final fermentation products, and an increase in their yield.

[The optimal treatment algorithm of radial nerve injuries].

The results of rehabilitation of 52 patients with radial nerve injuries were comparatively analyzed: the traditional rehabilitation complex (massage, training, etc.) was compared with the method of functional biomanagement. The technical characteristics of the designed functional cast were thoroughly described. The study demonstrated that reinnervation and functional recovery of the denervated muscles without segmental influence were significantly slower.

[Early motor rehabilitation with the help of a software/hardware complex "Vertical" in acute period of stroke].

The purpose of our study was the investigation of effectiveness of restoration of lost motor functions in acute period of stroke with the help of software/hardware complex "Vertical". This complex includes a functional bed-trainer for leg movements with phase-dependent functional electrical myostimulation (FES). Fifty-five subjects (mean age 64 +/-1.5 years) were assigned randomly to two groups receiving standard rehabilitation (a control group--27 subjects) and standard rehabilitation combined with the treatment by the "Vertical" complex (FES group--28 subjects). The treatment course was started on average 9 +/- 4 days after stroke and consisted of 30 min sessions 5 days per week during 2 weeks. Outcome was assessed by a battery of scales, everyday movement abilities and biomechanical parameters before and after treatment. No significant differences were found in baseline measurements. After the treatment, there was a positive dynamics in both groups with significant improvement in scores in the FES group. Most of patients of this group (67%) had hemiparesis of mild degree compared to the control group (7%, p < 0.05) to the end of treatment. Also 89% of subjects in the FES group were able to walk without assistance after treatment as compared to the control group (p < 0.05). There was a significant improvement in ankle flexors and extensors force of the paretic leg as well as in ankle joint movements of voluntary "walking" in the supine position in the FES group (p < 0.05).

[Antitumor effect of low-intensity extremely high-frequency electromagnetic radiation on a model of solid Ehrlich carcinoma].

The influence of different exposure regimes of low-intensity extremely high-frequency electromagnetic radiation on the growth rate of solid Ehrlich carcinoma in mice has been studied. It was shown that, at an optimum repetition factor of exposure (20 min daily for five consecutive days after the tumor inoculation), there is a clearly pronounced frequency dependence of the antitumor effect. The analysis of experimental data indicates that the mechanisms of antitumor effects of the radiation may be related to the modification of the immune status of the organism. The results obtained show that extremely high-frequency electromagnetic radiation at a proper selection of exposure regimes can result in distinct and stable antitumor effects.

[Postoperative rehabilitation in patients with sequels of tuberculous and nonspecific gonitis after total endoprosthetic repair of the knee joint].

To evaluate the effectiveness of rehabilitative measures, comprehensive studies have been conducted in 37 patients with sequels of tuberculous and nonspecific gonitis, who underwent primary total endoprosthetic repair of the knee joint with an Osteonics-7000 cement fixation prosthesis (USA) in 1996 to 2002. After discharge from hospital, 18 patients received a complete course of rehabilitation, 19 patients refused it for different reasons. The results were assessed just after completion of the course of rehabilitation (3 months after surgery), following 1 year and on the last examination (on the average 45.2 months later). Statistically significant advantages in the function of the knee joint and in the force of its extensors were observed in the group of patients undergoing a complete course of postoperative rehabilitation just after completion of the course and a year after surgery. The last examination revealed a great difference between the patients who had undergone a complete course of rehabilitation and those who had refused it.

[Functional activity of thrombocytes in patients with post-tuberculosis spinal osteochondrosis complicated by pain syndrome]. / Funktsional'naia aktivnost' trombotsitov u bol'nykh posttuberkuleznym osteokhondrozom pozvonochnika, oslozhnennym bolevym sindromom.

It was found that in patients with attenuated tuberculous spondylitis and post-tuberculous vertebral osteochondrosis there was a sharp increase in platelet aggregability and a decrease in their disaggregability at the peak of the pain syndrome. With the therapy followed by relief of the pain syndrome, a rise in the platelet aggregability was significantly less noticeable, without significant changes in their disaggregability.

[Manual therapy in complex treatment of patients with secondary osteochondrosis after sustained tuberculosis spondylitis]. / Manual'naia terapiia v kompleksnom lechenii bol'nykh so vtorichnym osteokhondrozom posle perenesennogo tuberkuleznogo spondilita.

The treatment results relating to 57 patients with neurological signs of osteochondrosis secondary to sustained tuberculous spondylitis with the pain syndrome prevailing in the clinical picture were studied. The majority of the patients (50) had limited affections of 1 or 2-3 adjoining vertebrae and 7 patients had extended processes (4-6 adjoining vertebrae). The treatment procedure was based on manual therapy: hand strength applied to the vertebral column, joints and muscles for eliminating pain and other neurological signs of the disease. The treatment should be complex and differential in regard to the clinical signs, the disease process and stage, the degree of functional disorders and of the pain syndrome. The manual therapy was the most efficient in patients with osteochondrosis secondary to sustained tuberculous spondylitis or the muscular tonic syndrome and moderate deformations of the vertebral column, as well as in those operated on for the main disease at the early stages.