Belarusian State Medical University

About: Belarusian State Medical University is a education organization based out in Minsk, Belarus. It is known for research contribution in the topics: Population & Medicine. The organization has 536 authors who have published 513 publications receiving 4635 citations.

Quasi-Real Time Bio - Tissues Monitoring using Dynamic Laser Speckle Photography

Abstract: Joint development of a laser monitor for the real-time bio-tissue analysis is presented. The monitor is based on the digital dynamic laser speckle photography and deals with soft and hard bio-tissues. In soft tissues, the dynamic bio-speckles are formed in a scattered from a tissue laser light. An optically transparent model of hard bio-tissue was prepared and preliminary analysis of a stress field in the stressed model was performed using the dependence of the refractive index of transparent solids upon the state of stress and the double exposure speckle photography data. The refractive index of the stressed material was evaluated and the state of stress was reconstructed using the stress-optical law.

Investigation of the stressed-strained state of cermet dentures using digital laser speckle-photographic analysis

Abstract: It has been shown that the method of digital dynamic speckle photography is an efficient method of quantitative and qualitative diagnostics in orthopedic stomatology for optimization of the constructions of cermet dentures by evaluating their stressed-strained state. Determination of the stressed-strained state of cermet dentures by the method of digital laser speckle photography at the stages of their manufacture makes it possible to most reliably investigate the quality of manufactured constructions, which diminishes the number of complications and improves the efficiency of treatment in orthopedic stomatology,

Translation-Associated Mutational U-Pressure in the First ORF of SARS-CoV-2 and Other Coronaviruses

Abstract: Within 4 months of the ongoing COVID-19 pandemic caused by SARS-CoV-2, more than 250 nucleotide mutations have been detected in ORF1ab of the virus isolated from infected persons from different parts of the globe. These observations open up an obvious question about the rate and direction of mutational pressure for further vaccine and therapeutics designing. In this study, we did a comparative analysis of ORF1a and ORF1b by using the first isolate (Wuhan strain) as the parent sequence. We observed that most of the nucleotide mutations are C to U transitions. The rate of synonymous C to U transitions is significantly higher than the rate of non-synonymous ones, indicating negative selection on amino acid substitutions. Further, trends in nucleotide usage bias have been investigated in 49 coronaviruses species. A strong bias in nucleotide usage in fourfold degenerate sites toward uracil residues is seen in ORF1ab of all the studied coronaviruses: both in the ORF1a and in the ORF1b translated thanks to the programmed ribosomal frameshifting that has an efficiency of 14 - 45% in different species. A more substantial mutational U-pressure is observed in ORF1a than in ORF1b perhaps because ORF1a is translated more frequently than ORF1b. Mutational U-pressure is there even in ORFs that are not translated from genomic RNA plus strands, but the bias is weaker than in ORF1ab. Unlike other nucleotide mutations, mutational U-pressure caused by cytosine deamination, mostly occurring during the RNA plus strand replication and also translation, cannot be corrected by the proof-reading machinery of coronaviruses. The knowledge generated on the mutational U-pressure that becomes stronger during translation of viral RNA plus strands has implications for vaccine and nucleoside analog development for treating COVID-19 and other coronavirus infections.

High level association of mutation in KatG315 with MDR and XDR clinical isolates of Mycobacterium tuberculosis in Belarus.

Abstract: The mutation in KatG315 is found in the majority of isoniazid resistant strains worldwide, especially in areas with a high incidence of tuberculosis. A total of 138 isoniazid (INH)-resistant strains of Mycobacterium tuberculosis consisting of 108 MDR (multidrug resistant) and 30 XDR (extensively drug resistant) isolated from patients in different regions of Belarus from 2007 to 2008 were screened by a PCR restriction fragment length polymorphism (RFLP) assay and sequencing. As a result, 97.8% prevalence of the KatG315 mutation was detected in all isolates from patients either actually or previously treated with tuberculosis. This mutation was not found in any of 9 INH-susceptible isolates and 2 standard strains of H37Rv and Academia included in the study. All isolates that contained the mutation in KatG315 were classified as MDR and XDR by a culture-based susceptibility testing method. Among the 30 XDR isolates, 15 (50%), 12 (40%), and 3 (10%) were classified into principal genetic groups (PGG) 1, 2, and 3, respectively. It is concluded that INH-resistant MTB were associated with the mutated KatG315 phenotype. The simplicity of the assay, with 100% specificity, permits its implementation in routine practice at clinical microbiology laboratories for first and fast screening of cultures. This method has potential application for rapid diagnosis of INH resistance due to KatG315 mutation.