Long-COVID sequelae are associated with oxidative stress in hemodialysis patients

The pathophysiology of long-COVID sequelae in the general population of SARS-CoV-2-infected patients has been shown to be strongly influenced by oxidative stress. However, the potential role of oxidative stress in the development of long-COVID sequelae in hemodialysis patients (HD) has never been investigated. The present study aimed to evaluate the oxidative status of HD patients 3.5 months after SARS-CoV-2 infection in relation to the presence of long-COVID sequelae and the severity of the acute phase COVID-19. Methods. This cross-sectional cohort study included 63 HD patients with a median age of 55 (43-62.5) years and a dialysis vintage of 42 (25-73) months who had been infected with COVID-19 at least 3 months before recruitment. Patients were divided into two groups according to the occurrence of long-COVID sequelae: Group 1 included 31 (49.2%) HD patients with sequelae, while Group 2 included 32 (50.8%) fully recovered individuals. At 3.5 (3.2-4.6) months after the acute phase of COVID-19, malondialdehyde (MDA) and erythrocyte levels (MDAe), sulfhydryl groups (SH -groups), serum catalase activity, transferrin, and ceruloplasmin were measured. A comparison of the obtained data was performed using the Student's test or the Mann-Whitney test according to the data distribution. A correlation was evaluated with the Spearman test. Results. HD patients with persistent long-COVID sequelae had significantly higher concentrations of MDAs (p = 0.002), MDAe (p = 0.0006), and CTs (p = 0.02), and lower serum levels of SH-groups (p = 0.03) and ceruloplasmin (p = 0.03) compared with Group 2. The concentration of most studied indicators of pro- and antioxidant status did not depend on the severity of the acute phase COVID-19, and only catalase activity was statistically significantly related to the need for hospitalization (r = 0.59;p = 0.001), oxygen support (r = 0.44;p = 0.02), and the percentage of lung injury according to computed tomography (p = 0.03). Although the serum concentration of transferrin did not differ between the studied groups, the individual analysis showed that its value was statistically higher in HD patients with severe COVID-19 even 3.5 months after infection (p < 0.0001). Conclusions. Long-term COVID-19 sequelae in HD patients are associated with oxidative stress. High levels of catalase activity and serum transferrin 3.5 months after COVID-19 may be a consequence of the severe course of the acute phase of the disease. The obtained data suggest that the use of antioxidants may be one of the possible strategies to treat the long-term consequences of COVID in HD patients. © N. Stepanova, L. Korol, L. Snisar, A. Rysyev, T. Ostapenko,V. Marchenko, O. Belousova, O. Popova, N. Malashevska, M. Kolesnyk, 2023. All rights reserved.

NR3C1 rs41423247: genetic predictor of complications in pneumonia caused by SARS-CoV-2

Background/Objectives: Runaway inflammation is a key feature of COVID-19. NR3C1 gene encodes for glucocorticoid receptor which plays an important role in inflammation reaction. The variant rs41423247 cause increased glucocorticoid receptors sensitivity. This study aimed to investigate the impact of variants of NR3C1 gene on the course of COVID-19 pneumonia in patients with necessarily artificial lung ventilation. Method(s): The study group included 20 patients (9 women and 11 men) with diagnosis viral COVID-19 pneumonia on artificial lung ventilation at the intensive care unit. All patients underwent daily standard examinations according clinical protocols. Determination of NR3C1 gene variants was carried out by using PCRRFLP. Result(s): There were found the significant negative correlations between NR3C1 gene variants and level of SpO2 (rS = -0.601, p = 0.008), Glasgow Coma Scale score (rS = -0.523, p = 0.026). Also, it was defined a protective effect of genotype CC at risk of development acute respiratory distress syndrome in this patients (chi2 = 4.38, p = 0.037, OR = 0.05 (CI:0.01-0.66)). Conclusion(s): The investigated variant rs41423247 of the NR3C1 gene may be the genetic predictor of complicated course of COVID-19 pneumonia. .

Development and Characterization of a Vector System Based on the Simian Adenovirus Type 25

Technological versatility and the humoral and cellular immune response induction capacity have conditioned wide spread of adenoviral vectors as vaccine and gene therapy drugs. However, vaccination with Sputnik V made a significant portion of the population immune to the types 5 and 26 (Ad5 and Ad26) recombinant human adenovirus vectors, which are some of the most frequently used bases for candidate vaccines. Today, vaccine designers tend to select alternative adenovirus serotypes as platforms to develop vaccines against new pathogens on. A good example is simian adenovirus type 25 (SAd25), which belongs to subgroup E. It is genetically distant from Ad5 and exhibits extremely low seroprevalence in human beings, which makes it an appealing alternative vaccine vector. The purpose of this work was to design and study a new vaccine platform based on simian adenovirus type 25. We relied on the advanced methods of molecular biology and virology to construct and make recombinant adenoviruses;the phylogenetic analysis in the context of this study was enabled with bioinformatic methods. The resulting recombinant adenoviral vector can effectively replicate itself in the HEK293 cell line (human embryonic kidney cells). This work substantiates the expediency of further investigation into the SAd25 vector as a platform for development of the prevention vaccines against various infectious diseases.Copyright © 2023 Pirogov Russian National Research Medical University. All rights reserved.

Molecular genetic markers associated with course of severe COVID-19 pneumonia. Different pathways study

Introduction: It is known that the development of COVID-19 in the human body consists of complex system of biological mechanisms underlying the complex interplay between infectious agents and the human host. This raised the question about hosts' genetic variants as predictors of clinical phenotype. The aim of our study was to analyze the effect of the NOS3 gene (VNTR intron 4 a/b), NR3C1 gene (C647G, rs41423247) and the SFTPB gene (C1580T, rs11130866) variants on the course of severe COVID-19 pneumonia in patients. Material(s) and Method(s): The study group included 20 patients (13 men and 7 women) with diagnosis "viral COVID19 pneumonia" treated at the intensive care unit. Investigation of the NOS3, NR3C1 and SFTPB genes variants was carried out by a molecular method using PCR-RFLP and allele-specific PCR, respectively. Result(s): The correlation analysis showed a significant association of the NOS3 gene variants and level of SpO2 (rS=-0.488, p=0.029;SpO2=93.1+/-2.4% for b/b and SpO2=82.0+/-1.1% for a/a genotypes). Also a significant positive correlation was between NR3C1 gene variants and duration of nasal intermittent positive pressure ventilation (nIPP) therapy (rS=0.454, p=0.044;for 647CC - 1.5+/-1.0 days and for 674GG - 3.9+/-2.5 days), presence of fever (need for antipyretics) (rS=0.525, p=0.017;647C vs 647G alleles - chi2=5.8, p=0.016). No significant correlations were found for the variants of SFTPB gene. The obtained results support a hypothesis about the combined influence of different pathways genes variants (NOS3 and NR3C1) on severity of COVID-19. However, in order to draw definite conclusions, further multifaceted research in this area are need.

Clinical case of severe coronavirus infection in a 6-month-old child

Nowadays, the creation of treatment protocols for young children with COVID-19 is especially relevant, as some issues of pathogenesis and genetic determinism of severe lung damage are still unclear. COVID-19-induced respiratory distress syndrome is a predictable severe complication that requires early diagnosis and proper treatment. Given the pathogenetic mechanism of lung damage in COVID-19, surfactant replacement therapy may be useful in the treatment of this cohort of patients. Clinical case. A clinical case of severe coronavirus infection caused by SARS-CoV-2 in a 6-month-old child is presented. The course of the disease was accompanied by severe damage to the lung parenchyma with the development of acute respiratory distress. The examination of the patient confirmed the genetic determinism of severe COVID-19, polymorphic risk alleles of the genes GSTM1, GSTP1, SFTP-B. The child's treatment included not only long-term mechanical ventilation, but also surfactant replacement therapy. The child recovered and was discharged without signs of respiratory failure. Conclusions. This clinical case demonstrates the association of genetic polymorphism with severe virus-induced lung damage. Because severe respiratory failure in COVID-19 is likely to be due to the development of acute respiratory distress syndrome, administration of exogenous surfactant should be considered as a possible treatment option. The research was carried out in accordance with the principles of the Helsinki declaration. The informed consent of the patient was obtained for conducting the studies. © 2021 Group of Companies Med Expert, LLC. All Rights Reserved.

Priority areas to ensure sustainable development of educational exports of Russian universities in the context of digital transformation (regional aspect)

The article considers digital technologies used to attract foreign students to regional universities. Forced distance learning during the pandemic COVID-19 revealed the weaknesses in the educational process when the need for intensive use of the existing digital technologies increased. This served as the basis for the active transformations of the priority areas in developing the digital environment in universities and the active use of online technologies to preserve the sustainable development of educational exports. With distant learning, the global competition for foreign students between universities only intensified making it necessary to create a high-quality digital environment. Russian universities used to compete with universities in other countries. But nowadays students can choose a university without leaving their homes. The main factors for their choice are the quality of education and reliability of the virtual infrastructure [1]. For the sustainable development of educational services exports, regional universities need to engage all the available digital tools to attract foreign applicants. They must position themselves as modern, internationally recognized educational institutions providing high quality education. © The Authors, published by EDP Sciences, 2020.

Preclinical Studies of Immunogenity, Protectivity, and Safety of the Combined Vector Vaccine for Prevention of the Middle East Respiratory Syndrome.

The Middle East Respiratory Syndrome (MERS) is an acute inflammatory disease of the respiratory system caused by the MERS-CoV coronavirus. The mortality rate for MERS is about 34.5%. Due to its high mortality rate, the lack of therapeutic and prophylactic agents, and the continuing threat of the spread of MERS beyond its current confines, developing a vaccine is a pressing task, because vaccination would help limit the spread of MERS and reduce its death toll. We have developed a combined vector vaccine for the prevention of MERS based on recombinant human adenovirus serotypes 26 and 5. Studies of its immunogenicity have shown that vaccination of animals (mice and primates) induces a robust humoral immune response that lasts for at least six months. Studies of the cellular immune response in mice after vaccination showed the emergence of a specific CD4+ and CD8+ T cell response. A study of the vaccine protectivity conducted in a model of transgenic mice carrying the human DPP4 receptor gene showed that our vaccination protected 100% of the animals from the lethal infection caused by the MERS-CoV virus (MERS-CoV EMC/2012, 100LD50 per mouse). Studies of the safety and tolerability of the developed vaccine in rodents, rabbits, and primates showed a good safety profile and tolerance in animals; they revealed no contraindications for clinical testing.

A heterologous virus-vectored vaccine for prevention of Middle East respiratory syndrome induces long protective immune response against MERS-CoV

Introduction. Middle East respiratory syndrome (MERS) is acute inflammatory disease of respiratory system with a high mortality, caused Ьу coronavirus MERS-CoV At present moment, we still lack specific therapeutic preparations and vaccines against MERS. Vaccine administration can help to limit the spread of the disease and lower the mortality. Duration of vaccine-induced immune response is one of the key characteristics of a vaccine, which is connected with duration of its protective effectiveness. Unfortunately, the data on duration of vaccine-induced immune response against MERS is scarce. The aim of the study was to determine duration of humoral immune response in mice and primates and duration of protective immune response in mice after immunization with the heterologous virus-vectored vaccine against MERS (BVRS-GamVac-Combi), developed earlier Ьу our research group. Material and methods. To study duration of humoral immune response, we used mice of C57BL/6 strain and common marmosets. Animals were immunized with the vaccine BVRS-GamVac-Combi, based on recomЬinant adenoviral vectors rAd26 and rAd5. Antigen-specific-antibody titers were determined with ELISA, virus-neutralizing antibody titers were measured with virus neutralization assay using MERS-CoV (EMC/2012). To study duration of protective immune response, we used a model of lethal infection on transgenic mice, carrying human DPP4 gene of viral receptor. Results. In present research, we showed that vaccination of animals with BVRS-GamVac-Combi induced robust humoral immune response, which persisted at least 18 months after immunization. In addition, our vaccine protected 100 % of animals from lethal infection for at least 7 months after immunization. Concluslon. Strength of vaccine-induced immune response is generally connected with a protective effectiveness of a vaccine. One of the key problems of vaccine design is to find a way to provide as long and robust immune response as possible. Duration of vaccine-induced immune response is one of the key characteristics of a vaccine, which demands quality control during multiple steps of a vaccine development. Введение. Ближневосточный респираторный синдром (БВРС) - это острое воспалительное заболевание дыхательной системы с высокой летальностью, возбудителем которого является коронавирус БВРС-КоВ. В настоящее время в мире не существует специфических профилактических и терапевтических средств против БВРС. Вакцино-профилактика позволит ограничить распространение данного заболевания и снизить летальность. Одной из ключевых характеристик вакцин является длительность индуцируемого иммунного ответа, от которой зависит продолжительность протективного эффекта вакцины. К сожалению, данных по длительности поствакцинального иммунного ответа для вакцин против БВРС сейчас недостаточно. Цель исследования - определение длительности гуморального иммунного ответа у грызунов и приматов и протективного иммунного ответа после иммунизации комбинированной векторной вакциной против БВРС (БВРС-ГамВак-Комби), разработанной нами ранее. Материал и методы. Длительность гуморального иммунитета исследовали на мышах линии C57BL/6 и обыкновенных игрунках. ЖивРтных иммунизировали вакциной БВРС-ГамВак-Комби на основе рекомбинантных векторов rAd26 и rAd5. Титр антиген-специфических антител определяли методом иммуноферментного анализа (ИФА). Титр вирус-нейтрализующих антител определяли с помощью реакции вирус-нейтрализации против вируса БВРС-КоВ (MERS-CoV EMC/2012). Длительность протективного иммунитета исследовали на модели летальной инфекции у трансгенных мышей, несущих ген человека DPP4, кодирующий рецептор к БВРС-КоВ. Результаты. Исследование длительности поствакцинального гуморального иммунного ответа у грызунов и приматов показало, что вакцинация животных БВРС-ГамВак-Комби индуцирует формирование напряженного гуморального иммунного ответа к гликопротеину S БВРС-КоВ, который сохраняется на протяжении не менее 18 мес. Также было показано, что вакцинация позволяет защитить 100 % животных от летальной инфекции, вызванной БВРС-КоВ (MERS-CoV EMC/2012, 100 ЛД50/мышь), через 7 мес после иммунизации. Заключение. Напряженность поствакцинального гуморального иммунного ответа, как правило, связана с протективностью вакцины. Одной из ключевых задачпри дизайне вакцин является обеспечение наиболее длительного напряженного иммунного ответа. Длительность поствакцинального иммунного ответа - одна из ключевых характеристик вакцин, которая требует контроля на различных этапах их разработки.