56 research outputs found
Tendencies and Factors of Regulation of Development i n Latvian Banking System
The aim of the paper is to study the influencing factors and to identify the ways of improving the effectiveness of regulation in theLatvian Bank system (LBS). Basing on the systemic comparative and logical analysis data of the efficiency of regulation in differentstages of LBS development article demonstrates that its key factor is the level of business ethics and professionalism of majorshareholders and top management of the banks, but the main directions of improving its efficiency is an increase of the role of contentapproach to control in comparison with the formal approach.Keywords: banking system, factors, features, regulation, tendencies.DOI: http://dx.doi.org/10.15181/rfds.v11i3.61
The feasibility of HIV vaccine efficacy trials among Russian injection drug users
IDU exposure remains a primary driver of the Russian HIV epidemic, and recent incidence data provide little evidence that this epidemic is slowing. While there are multiple important challenges that need to be further explored before starting vaccine trials, most importantly access to evidence-based drug treatment services for trial participants, the current context of high HIV incidence and low genetic diversity of HIV strains, suggests the need for intensified prevention strategies and supports the feasibility of mounting efficacy trials of HIV vaccines among IDUs in the Russian Federation
Two Independent HIV Epidemics in Saint Petersburg, Russia Revealed by Molecular Epidemiology
The HIV epidemic in Russia, one of the world's fastest growing, has been concentrated mostly among people who inject drugs (PWID). We sought to explore the epidemiology of the epidemic in St. Petersburg by sampling from the highest risk groups of PWID and men who have sex with men (MSM) and use viral sequencing data to better understand the nature of the city's epidemic. Serological testing confirmed an HIV prevalence among PWID in excess of 40%. All but 1 of 110 PWID whose blood samples were tested for genetic diversity were infected by subtype A virus, specifically by the AFSU strain. The remaining person was infected with a CRF-06cpx recombinant. Analysis of pairwise genetic distance among all PWID studied revealed an average of 3.1% sequence divergence, suggesting clonal introduction of the AFSU strain and/or constraints on sequence divergence. The HIV prevalence was less than 10% among MSM. All 17 sequences from HIV-infected MSM were found to be a clade B virus with a much higher average sequence diversity of 15.7%. These findings suggest two independent epidemics with little overlap between the two highest at-risk populations, which will require different HIV prevention approaches
A Bayesian Approach to Analyse Genetic Variation within RNA Viral Populations
The development of modern and affordable sequencing technologies has allowed the
study of viral populations to an unprecedented depth. This is of particular
interest for the study of within-host RNA viral populations, where variation due
to error-prone polymerases can lead to immune escape, antiviral resistance and
adaptation to new host species. Methods to sequence RNA virus genomes include
reverse transcription (RT) and polymerase chain reaction (PCR). RT-PCR is a
molecular biology technique widely used to amplify DNA from an RNA template. The
method itself relies on the in vitro synthesis of copy DNA from
RNA followed by multiple cycles of DNA amplification. However, this method
introduces artefactual errors that can act as confounding factors when the
sequence data are analysed. Although there are a growing number of published
studies exploring the intra- and inter-host evolutionary dynamics of RNA
viruses, the complexity of the methods used to generate sequences makes it
difficult to produce probabilistic statements about the likely sources of
observed sequence variants. This complexity is further compounded as both the
depth of sequencing and the length of the genome segment of interest increase.
Here we develop a Bayesian method to characterise and differentiate between
likely structures for the background viral population. This approach can then be
used to identify nucleotide sites that show evidence of change in the
within-host viral population structure, either over time or relative to a
reference sequence (e.g. an inoculum or another source of infection), or both,
without having to build complex evolutionary models. Identification of these
sites can help to inform the design of more focussed experiments using molecular
biology tools, such as site-directed mutagenesis, to assess the function of
specific amino acids. We illustrate the method by applying to datasets from
experimental transmission of equine influenza, and a pre-clinical vaccine trial
for HIV-1
Genotypic and phenotypic characteristics of <i>Mycobacterium tuberculosis</i> drug resistance in TB children
Background. Russian Federation is included in the list of 30 countries with the highest burden of tuberculosis, including MDR tuberculosis. The most important part of this problem is the primary MDR/XDR TB in children.The aim: a comparative analysis of the phenotypic and genotypic profile of drug resistance to anti-tuberculosis drugs (ATP) according to whole genome sequencing of M. tuberculosis strains from children.Materials and methods. Whole genome sequencing (WGS) results of 61 M. tuberculosis isolates from children with tuberculosis in 2006–2020 in the Russian Federation were analyzed for anti-TB drug resistance mutations, according to the WHO catalog and were compared with the results of phenotypic drug sensitivity.Results. The M. tuberculosis belonged to two genetic groups: Beijing genotype – 82 % (50/61) dominant Central Asian Russian (31/50) and B0/W148 (16/50) subtypes, and non-Beijing (Ural, S, LAM) – 18 % (11/61). Three isolates belonged to Asian Ancestral subtype (3/50). Of the 61 isolates, only 14.7 % (9/61) were sensitive to antiTB drugs, 49.2 % (30/61) were MDR and 14.7 % (9/61) were pre-XDR. Comparison of the resistance profile (MDR/pre-XDR) with genotype revealed an upward shift for Beijing isolates, in particular Beijing B0/W148 (15/16) subline compared to other Beijing (19/34) (Chi-square with Yates correction = 5.535; p < 0.05) and nonBeijing (5/12) (Chi-square with Yates correction = 6.741; p < 0.05) subtypes. Discrepancies between genotypic and phenotypic drug resistance profiles were found in 11.5 % (7/61) of cases.Conclusions. Based on the analysis of WGS data, the genotypic characteristics of M. tuberculosis and the most complete set of drug resistance mutations were obtained, indicating a significant prevalence in MDR and pre-XDR TB of cases caused by epidemic subtypes of Beijing (B0/W148 and Central Asian Russian). The molecular mechanisms of adaptation of M. tuberculosis to the treatment of anti-TB drugs are not unique for the child population but reflect the general processes of the spread of MDR/XDR in Russia
CAPRISA 004 tenofovir microbicide trial: no impact of tenofovir gel on the HIV transmission bottleneck.
Alterations of the genital mucosal barrier may influence the number of viruses transmitted from a human immunodeficiency virus–infected source host to the newly infected individual. We used heteroduplex tracking assay and single-genome sequencing to investigate the effect of a tenofovir-based microbicide gel on the transmission bottleneck in women who seroconverted during the CAPRISA 004 microbicide trial. Seventy-seven percent (17 of 22; 95% confidence interval [CI], 56%–90%) of women in the tenofovir gel arm were infected with a single virus compared with 92% (13 of 14; 95% CI, 67%–>99%) in the placebo arm (P = .37). Tenofovir gel had no discernable impact on the transmission bottleneck
Understanding complex dynamics of behavioral, neurochemical and transcriptomic changes induced by prolonged chronic unpredictable stress in zebrafish
Stress-related neuropsychiatric disorders are widespread, debilitating and often treatment-resistant illnesses that represent an urgent unmet biomedical problem. Animal models of these disorders are widely used to study stress pathogenesis. A more recent and historically less utilized model organism, the zebrafish (Danio rerio), is a valuable tool in stress neuroscience research. Utilizing the 5-week chronic unpredictable stress (CUS) model, here we examined brain transcriptomic profiles and complex dynamic behavioral stress responses, as well as neurochemical alterations in adult zebrafish and their correction by chronic antidepressant, fluoxetine, treatment. Overall, CUS induced complex neurochemical and behavioral alterations in zebrafish, including stable anxiety-like behaviors and serotonin metabolism deficits. Chronic fluoxetine (0.1 mg/L for 11 days) rescued most of the observed behavioral and neurochemical responses. Finally, whole-genome brain transcriptomic analyses revealed altered expression of various CNS genes (partially rescued by chronic fluoxetine), including inflammation-, ubiquitin- and arrestin-related genes. Collectively, this supports zebrafish as a valuable translational tool to study stress-related pathogenesis, whose anxiety and serotonergic deficits parallel rodent and clinical studies, and genomic analyses implicate neuroinflammation, structural neuronal remodeling and arrestin/ubiquitin pathways in both stress pathogenesis and its potential therapy. © 2020, The Author(s).The research was supported by the Russian Science Foundation (RSF) Grant 19‐15‐00053. KAD is supported by the President of Russia Graduate Fellowship, the Special Rector’s Productivity Fellowship for SPSU PhD Students, and the Russian Foundation for Basic Research (RFBR) grant 18‐34‐00996. ADP was supported by St. Petersburg University (project ID 51555422). The research team was supported by St. Petersburg State University state budgetary funds (project ID 51130521). AVK is the Chair of the International Zebrafish Neuroscience Research Consortium (ZNRC) and President of the International Stress and Behavior Society (ISBS, www.stress-and-behavior.com) that coordinated this collaborative multi-laboratory project. The consortium provided a collaborative idea exchange platform for this study. It is not considered as an affiliation, and did not fund the study. AVK is supported by the Southwest University Zebrafish Platform Construction Fund. TGA’s research is supported by the budgetary funding for basic research from the Scientific Research Institute of Physiology and Basic Medicine (AAAA-A16-116021010228-0, Novosibirsk, Russia). This study utilized equipment of the Core Facilities Centre “Centre for Molecular and Cell Technologies” of St. Petersburg State University. The funders had no role in the design, analyses, and interpretation of the submitted study, or decision to publish
Clinical significance of HIV-1 coreceptor usage
The identification of phenotypically distinct HIV-1 variants with different prevalence during the progression of the disease has been one of the earliest discoveries in HIV-1 biology, but its relevance to AIDS pathogenesis remains only partially understood. The physiological basis for the phenotypic variability of HIV-1 was elucidated with the discovery of distinct coreceptors employed by the virus to infect susceptible cells. The role of the viral phenotype in the variable clinical course and treatment outcome of HIV-1 infection has been extensively investigated over the past two decades. In this review, we summarize the major findings on the clinical significance of the HIV-1 coreceptor usage
- …