Mitochondrial dysfunction at atherosclerosis and myocardial infarction: molecular and cytochemical cell-markers

We studied capabilities of confocal laser scanning microscopy in the analysis of lipid droplets volume and of quantity of functional mitochondria and reactive oxygen species production in liver cells for early diagnosis of cytochemical disturbances at dyslipoproteinemia (16 days of experiment). The results showed the increase of lipid droplets volume in hepatocytes, decrease of functional mitochondria and increase of reactive oxygen species production. We evaluated the potential of real-time PCR method in the analysis of mitochondrial DNA of blood plasma at early stages of dyslipoproteinemia and in experimental infarction. On the background of registered blood lipid metabolism disorders and structural and functional changes in liver cells, we determined the tendency to three-time increase in concentration of circulating cell-free mtDNA on the 16th day of dyslipoproteinemia as compared to the control data. We used a model of myocardial infarction to show statistically significant increase in the level of circulating cell-free blood mtDNA from 48 hours after adrenaline injection and we found that this level maintained up to 144 hours after adrenaline injection. Obtained data can serve as a basis for creation of technologies for diagnostic monitoring of atherosclerosis and myocardial infarction severity

Acute myocardial ischemia: changes of free circulating mtDNA level in blood after occlusion of the upper one-third left descending branch of the coronary artery

The aim of the present study is to analyze the dynamics of free circulating mtDNA level in blood after occlusion of the upper one-third left descending branch of the coronary artery. We showed that the concentration of free circulating mtDNA of blood tends to decrease 24 hours after ligation; it increased and reached values close to control samples 48 and 72 hours after ligation. These data define the need in further investigation of the dynamics of this parameter during later periods of myocardial infarction modeling that will contribute to objective evaluation of its significance for acute myocardial damage diagnostics and prognosis

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Comparative Analysis of Molecular-Genetic Properties in Non-Toxigenic Vibrio cholerae O1 Strains Biovar El Tor, Isolated in Russia and on Cholera Endemic Territories

Objective of the study was to perform a comparative analysis of molecular-genetic properties in non-toxigenic Vibrio cholerae O1 strains biovar El Tor, isolated in the Republic of Kalmykia and on cholera endemic territories and to reveal their phylogenetic relations to toxigenic isolates.Materials and methods. We have carried out bio-information analysis of whole genome sequences of 60 cholera vibrio strains from endemic as regards cholera regions and from Kalmykia. The presence of pathogenicity and endemicity islands in their genomes has been determined. Specifed have been the sequence-types of the examined strains and whole genome SNP-analysis conducted.Results and discussion. Non-toxigenic El Tor vibrios circulating in Kalmykia are clustered into two major genotypes: ctxA–tcpA+VPI-2+VSP– and ctxA–tcpA–VPI-2Δ+VSP–, where VPI-2 Δ+ signifes the presence of deletions of varying length in the genome of this pathogenicity island. Only the latter one is found in regions endemic for cholera. In addition, ctxA– tcpA+VPI-2+VSP+ populations circulate in cholera endemic foci, not found in Kalmykia. 17 sequence-types were identifed among the studied strains (by seven housekeeping gene loci). Phylogenetic analysis performed using SNP-typing demonstrated the absence of close genetic relation between the ctxA–tcpA+VPI-2+VSP– vibrios from Kalmykia and both toxigenic and non-toxigenic vibrios with different composition of pathogenicity and pandemicity islands in the genome. At the same time, genetic proximity of ctxA–tcpA–VPI-2Δ+VSP– cholera vibrios from endemic cholera foci with those isolated in Kalmykia was detected, which may indicate the possibility of their recurrent importation into the territory of Russia. Non-toxigenic V. cholerae strains found in the territory of Kalmykia are characterized by a high genetic diversity. Circulation of the strains with unique sequence-types suggests their potential for long-term persistence on this territory. At the same time, phylogenetic closeness and identity of certain strains with strains from endemic territories can be an evidence of repeated importation

The early events of atherosclerosis development and the level of free circulating mitochondrial dna in blood in the experimental dyslipidemia

The aim of research: the studying of blood lipid spectrum, C-reactive protein concentration, and free circulating mitochondrial DNA changes in the course of aorta atherosclerosis development in early steps of high-cholesterol diet in experiment. Material and methods. Dyslipidemia was induced by high-cholesterol diet in rabbits “Chinchilla”. The C-reactive protein level and lipid spectrum was analyzed with Beckman synhron 4 multianalyzer (Beckman coulter, USA). The mitochondrial DNA level was registered by real-time PCR. The ultra structure of aorta surface was studied by scanning electron microscopy. Results. It was shown that in the blood of experimental animals is formed the Beckman imbalance of atherogenic and antiatherogenic cholesterol fractions (on 2 days of dyslipidemia) and iselevated the C-reactive protein level (on the 8 days). Concurrently, on the 16 days of study, we registered the leucocyte adhesion on the aorta surface in the areas of connections with arteria, which could be focuses of atherosclerotic plaque development. The level of free circulating mitochondrial DNA showed the tendency to 3-fold elevation in comparing with control. However, this data predetermined the prospects of blood plasma mitochondrial DNA level studying on the more late stages of dyslipidemia. Conclusion. In the whole, the detected complex of biochemical disturbances of blood and ultrastructural changes of aorta surface in the course of early steps of high-cholesterol diet maybe prospective model of early events of atherosclerosis for pre-clinical translational research in the development of new technologies for diagnostics, prophylaxis, and treatment of lipid metabolism disturbances and atherosclerosis

The level of blood plasma mitochondrial DNA upon acute myocardium damage in experiment

The aim of the present investigation is to study the level of plasma mtDNA as a potential marker of cardiomyocyte damage in 2 and 4 h after subcutaneous injection of adrenaline and during the formed morphological alterations of the myocardium (3 days). Methods. Real time PCR. Male Wistar rats were used as the experimental animals. Results. It was shown that during the increase in the activity of cytolysis biomarkers, at the first hours after adrenaline injection, no reliable increase is observed in the level of free circulating blood mtDNA. A tendency of 2.5-fold increase in this parameter was established at the third day after adrenaline injection during the development of acute inflammatory process in the myocardium. On the whole, further researches are needed on the dynamics of mtDNA level upon acute damage of the myocardium in experimental and clinical investigations for unbiased estimation of the prospects of using the parameter in laboratory diagnostics

Molecular-Genetic Monitoring of SARS-CoV-2 Genovariants in the Territory of the Volga Federal District of the Russian Federation. Communication 1

Emergence of various genovariants of the SARS-CoV-2 virus, which are characterized by a higher ability to spread and a more severe clinical manifestations compared to the initial variants, require molecular-genetic monitoring of strains circulating in the Russian Federation.The aim of the work was to identify the VOC SARS-CoV-2 genovariants in the territory of the Republics of Bashkortostan, Tatarstan, Udmurtia, and Samara, Penza, Saratov, Ulyanovsk, and Orenburg Regions.Materials and methods. The identification of genovariants and the determination of the type of mutations was carried out by the Sanger fragment sequencing method.Results and discussion. The study examined 298 samples of clinical material obtained from the Centers for Hygiene and Epidemiology in the Republics of Bashkortostan, Tatarstan, Udmurtia, Samara, Penza, Saratov, Ulyanovsk, and Orenburg Regions. In 17 % of cases, the variability of the SARS-CoV-2 virus was observed for one or more markers: in three samples, a new coronavirus of the B. 1.1.7 line (“British”) was detected; in a number of cases, only one mutation was detected in the virus found in samples – deletion Y144 or substitution D138Y, E484K, N501Y, and very rarely two mutations – deletion Y144 and substitution E484K. The presence of the L141-G142-V143 deletion localized in the recurrent deletion region RDR2 of the S-gene was shown in 10 % of the cases. The data obtained indicate the heterogeneity in macroorganism of the population of the new coronavirus with the deletion L141-G142-V143, which leads to a change in the antigenic structure of the virus, which probably allows the virus to evade the immune response