Translation arrest of potato virus X RNA in Krebs-2 cell-free system: RNase H cleavage promoted by complementary oligodeoxynucleotides

AbstractTranslation arrest of genomic potato virus X (PVX) RNA promoted by complementary oligodeoxynucleotides in Krebs-2 cell-free system is described. 14–15 mer oligodeoxynucleotides complementary to the 5′-proximal cistron of PVX RNA were shown to induce specific truncation of the major non-structural polypeptide coded by PVX RNA. Evidence is presented that effective translational arrest of PVX RNA in the presence of complementary oligonucleotides restults from the site-specific cleavage of RNA by endogenous RNase H intrinsic to the Krebs-2 extract. No similar translational arrest was found in the rabbit reticulocyte lysate cell-free system

Features of case management with neuromuscular disease during COVID-19. Clinical impression

The new COVID-19 coronavirus infection, which has become a pandemic, is a very dangerous disease, the clinical picture of which can vary from mild to extremely severe forms of the course. Currently, there are no complete data on the pathogenetic mechanism of SARS-CoV-2, but there are extensive data on the probable risk factors for the development of extremely severe forms of COVID-19. The study of such factors becomes most suitable in terms of preventing their development and influence on the course of the disease in individuals with compromised immune systems and patients with impaired neuromuscular transmission. The article describes two clinical cases of extremely severe COVID-19 in patients with impaired neuromuscular transmission. Based on the analysis of the course of diseases, the conclusions are made about the possible aggravation and mutual activation of the immunopathological process with the launch of the cascade mechanism of the cytokine storm. An assumption has been made about the influence of human leukocyte antigen (HLA) on the severity of COVID-19, which is confirmed by a positive dynamics against the background of administration of IVIG, glucocorticosteroids (GCS), virusinactivated plasma and extracorporeal detoxification methods

Characterization of Alternanthera mosaic virus and its Coat Protein

A new isolate of Alternanthera mosaic virus (AltMV-MU) was purified from Portulaca grandiflora plants. It has been shown that the AltMV-MU coat protein (CP) can be efficiently reassembled in vitro under different conditions into helical RNA-free virus-like particles (VLPs) antigenically related to native virus. The AltMV-MU and VLPs were examined by atomic force and transmission electron microscopies. The encapsidated AltMV-MU RNA is nontranslatable in vitro. However, it can be translationally activated by CP phosphorylation or by binding to the TGB1protein from the virus-coded movement triple gene block

The state of specific immunity of population of the Republic of Tajikistan to measles, rubella, poliomyelitis viruses

Relevance. To achieve the goals of measles and rubella elimination and poliomyelitis eradication programs, immunization coverage of at least 95% of the target population is required. Objective data on the state of specific herd immunity are provided only by the results of serosurveys. In the Republic of Tajikistan, such monitoring is not carried out regularly. Therefore, the purpose of the study was to assess the actual state of the specific herd immunity to measles, rubella, and poliomyelitis viruses. Materials and methods. The blood sera of 563 children and adults collected in 7 cities and 13 districts of Tajikistan in 2020 were investigated. The level of antibodies (ABs) to measles and rubella viruses was determined using enzyme immunoassay. Test systems VectoKor-IgG (VECTOR-BEST, Russia) and Ecolab, Russia were used to determine ABs to measles and rubella virus, respectively. Neutralizing antibodies (nABs) to the 3 types of poliovirus (PV) were determined in 359 sera using a neutralization reaction with Sabin strains of types 1, 2, 3. Results. The conducted serosurvey showed the level of the specific herd immunity to rubella to be 87.9% in total population, including 86.2% in children, 93.1% in adolescents, and 93.5% and adults, that is sufficient to prevent transmission of the rubella virus. The proportion of individuals seropositive to measles was 54.5%, which is not enough to prevent sustained secondary transmission of infection and the resumption of circulation of the endemic strain of measles virus. The children under 15 years of age should be considered a population at risk of the infection, since children accounted for 38% among seronegative individuals. In general, less than 95% of the examined patients had nABs to PV: 94.4% to PV1, 86.1% to PV2, 83.6% to PV3; 3.3% did not have antibodies to all three types of PV. The level of herd immunity varied in the examined groups depending on the vaccination schedule and the composition of the poliovirus vaccines used: nABs to PV2 had 59.6% of children born during the period when vaccines containing PV2 were not used, and 85.7% of children born after the introduction of trivalent IPV. Deficiency in immunity to PV2 was the cause of a polio outbreak in 2021 caused by circulating vaccine-derived PV type 2. Conclusion. A high level of humoral immunity to the rubella virus was determined. Shortcomings of routine immunization against measles and polio associated with insufficient coverage and lack of IPV have been identified. Conducting regular serological monitoring in the Republic of Tajikistan is advisable to obtain objective information about the level of herd immunity, identify vulnerable groups of the population, and plan additional immunization activities

Genome-Wide Mycobacterium tuberculosis Variation (GMTV) Database: A New Tool for Integrating Sequence Variations and Epidemiology

Background Tuberculosis (TB) poses a worldwide threat due to advancing multidrug-resistant strains and deadly co-infections with Human immunodeficiency virus. Today large amounts of Mycobacterium tuberculosis whole genome sequencing data are being assessed broadly and yet there exists no comprehensive online resource that connects M. tuberculosis genome variants with geographic origin, with drug resistance or with clinical outcome. Description Here we describe a broadly inclusive unifying Genome-wide Mycobacterium tuberculosis Variation (GMTV) database, (http://mtb.dobzhanskycenter.org) that catalogues genome variations of M. tuberculosis strains collected across Russia. GMTV contains a broad spectrum of data derived from different sources and related to M. tuberculosis molecular biology, epidemiology, TB clinical outcome, year and place of isolation, drug resistance profiles and displays the variants across the genome using a dedicated genome browser. GMTV database, which includes 1084 genomes and over 69,000 SNP or Indel variants, can be queried about M. tuberculosis genome variation and putative associations with drug resistance, geographical origin, and clinical stages and outcomes. Conclusions Implementation of GMTV tracks the pattern of changes of M. tuberculosis strains in different geographical areas, facilitates disease gene discoveries associated with drug resistance or different clinical sequelae, and automates comparative genomic analyses among M. tuberculosis strains

Atrasentan and renal events in patients with type 2 diabetes and chronic kidney disease (SONAR): a double-blind, randomised, placebo-controlled trial

Background: Short-term treatment for people with type 2 diabetes using a low dose of the selective endothelin A receptor antagonist atrasentan reduces albuminuria without causing significant sodium retention. We report the long-term effects of treatment with atrasentan on major renal outcomes. Methods: We did this double-blind, randomised, placebo-controlled trial at 689 sites in 41 countries. We enrolled adults aged 18–85 years with type 2 diabetes, estimated glomerular filtration rate (eGFR)25–75 mL/min per 1·73 m 2 of body surface area, and a urine albumin-to-creatinine ratio (UACR)of 300–5000 mg/g who had received maximum labelled or tolerated renin–angiotensin system inhibition for at least 4 weeks. Participants were given atrasentan 0·75 mg orally daily during an enrichment period before random group assignment. Those with a UACR decrease of at least 30% with no substantial fluid retention during the enrichment period (responders)were included in the double-blind treatment period. Responders were randomly assigned to receive either atrasentan 0·75 mg orally daily or placebo. All patients and investigators were masked to treatment assignment. The primary endpoint was a composite of doubling of serum creatinine (sustained for ≥30 days)or end-stage kidney disease (eGFR <15 mL/min per 1·73 m 2 sustained for ≥90 days, chronic dialysis for ≥90 days, kidney transplantation, or death from kidney failure)in the intention-to-treat population of all responders. Safety was assessed in all patients who received at least one dose of their assigned study treatment. The study is registered with ClinicalTrials.gov, number NCT01858532. Findings: Between May 17, 2013, and July 13, 2017, 11 087 patients were screened; 5117 entered the enrichment period, and 4711 completed the enrichment period. Of these, 2648 patients were responders and were randomly assigned to the atrasentan group (n=1325)or placebo group (n=1323). Median follow-up was 2·2 years (IQR 1·4–2·9). 79 (6·0%)of 1325 patients in the atrasentan group and 105 (7·9%)of 1323 in the placebo group had a primary composite renal endpoint event (hazard ratio [HR]0·65 [95% CI 0·49–0·88]; p=0·0047). Fluid retention and anaemia adverse events, which have been previously attributed to endothelin receptor antagonists, were more frequent in the atrasentan group than in the placebo group. Hospital admission for heart failure occurred in 47 (3·5%)of 1325 patients in the atrasentan group and 34 (2·6%)of 1323 patients in the placebo group (HR 1·33 [95% CI 0·85–2·07]; p=0·208). 58 (4·4%)patients in the atrasentan group and 52 (3·9%)in the placebo group died (HR 1·09 [95% CI 0·75–1·59]; p=0·65). Interpretation: Atrasentan reduced the risk of renal events in patients with diabetes and chronic kidney disease who were selected to optimise efficacy and safety. These data support a potential role for selective endothelin receptor antagonists in protecting renal function in patients with type 2 diabetes at high risk of developing end-stage kidney disease. Funding: AbbVie

Differential Expression of Alternative Oxidase Genes in Maize Mitochondrial Mutants

We have examined the expression of three alternative oxidase (aox) genes in two types of maize mitochondrial mutants. Nonchromosomal stripe (NCS) mutants carry mitochondrial DNA deletions that affect subunits of respiratory complexes and show constitutively defective growth. Cytoplasmic male-sterile (CMS) mutants have mitochondrial DNA rearrangements, but they are impaired for mitochondrial function only during anther development. In contrast to normal plants, which have very low levels of AOX, NCS mutants exhibit high expression of aox genes in all nonphotosynthetic tissues tested. The expression pattern is specific for each type of mitochondrial lesion: the NADH dehydrogenase–defective NCS2 mutant has high expression of aox2, whereas the cytochrome oxidase–defective NCS6 mutant predominantly expresses aox3. Similarly, aox2 and aox3 can be induced differentially in normal maize seedlings by specific inhibitors of these two respiratory complexes. Translation-defective NCS4 plants show induction of both aox2 and aox3. AOX2 and AOX3 proteins differ in their ability to be regulated by reversible dimerization. CMS mutants show relatively high levels of aox2 mRNAs in young tassels but none in ear shoots. Significant expression of aox1 is detected only in NCS and CMS tassels. The induction pattern of maize aox genes could serve as a selective marker for diverse mitochondrial defects

Designing Stable Bacillus anthracis Antigens with a View to Recombinant Anthrax Vaccine Development

Anthrax is a disease caused by Bacillus anthracis that affects mammals, including humans. Recombinant B. anthracis protective antigen (rPA) is the most common basis for modern anthrax vaccine candidates. However, this protein is characterised by low stability due to proteolysis and deamidation. Here, for the first time, two modification variants leading to full-size rPA stabilisation have been implemented simultaneously, through deamidation-prone asparagine residues substitution and by inactivation of proteolysis sites. Obtained modified rPA (rPA83m) has been demonstrated to be stable in various temperature conditions. Additionally, rPA1+2 containing PA domains I and II and rPA3+4 containing domains III and IV, including the same modifications, have been shown to be stable as well. These antigens can serve as the basis for a vaccine, since the protective properties of PA can be attributed to individual PA domains. The stability of each of three modified anthrax antigens has been considerably improved in compositions with tobacco mosaic virus-based spherical particles (SPs). rPA1+2/rPA3+4/rPA83m in compositions with SPs have maintained their antigenic specificity even after 40 days of incubation at +37 &deg;C. Considering previously proven adjuvant properties and safety of SPs, their compositions with rPA83m/rPA1+2/rPA3+4 in any combinations might be suitable as a basis for new-generation anthrax vaccines