6615 research outputs found
Sort by
In vitro interaction of influenza virus a(H1N1)pdm09 with monocytic macrophages: Individual responses of TLR7 and RIG1 receptor genes
No full textIn vitro differentiation of donor blood monocytes to macrophages (Mph) following GM-CSF treatment was accompanied by a significant increase in the levels of gene transcription signaling receptors TLR7 or RIG1. The levels of intracellular viral RNA (M1 gene) in Mph remained high upon infection by influenza virus A H1N1pdm (Moscow 2009) for 24-96 hours. The innate immunity reactions caused by influenza virus show individual features: they are decreased in Mph from donor 1 which had initially high level of endosomal TLR7 gene activity, and it increased by influenza virus in MPh from donor 2 who had a very low level of TLR7 gene expression. The influenza H1N1pdm virus weakly stimulated expression of gene RIG1 and production of inflammatory cytokines in Mf in donor 1. The differences may be connected with individual sensitivity of the donors to influenza infection
The use of loop-mediated isothermal DNA amplification for the detection and identification of the anthrax pathogen
No full textThe results of detection and identification of Bacillus anthracis strains in loop-mediated isothermal DNA amplification (LAMP) reaction performed under optimized conditions with original primers and thermostable DNA polymerase are presented. Reproducible LAMP-based detection of chromosomal and plasmid DNA targets specific for B. anthracis strains has been demonstrated. No cross reactions with DNA from bacterial strains of other species of the B. cereus group were detected. The development of tests for anthrax-pathogen detection based on the optimized reaction of loop isothermal DNA amplification is planned. These tests will be convenient for clinical studies and field diagnostics due to the absence of requirements for sophisticated equipment. © 2017, Allerton Press, Inc
The organization of hospital care during the epidemic of influenza and sars for the 2016 season in Veliky Novgorod
No full textAnalyzed organization of preventive measures and patient care in Velikiy Novgorod in connection with the exceeding of the epidemic threshold for influenza and acute respiratory viral infections in 2016. The epidemic rise of influenza and other acute respiratory viral infections exceeded epidemiological and economic thresholds among the cumulative population on the territory of the Novgorod region started from the 3rd week 2016 (18.01.2016-24.01.2016) and continued for 4 weeks (until mid February). The peak of the epidemic was passed on the 4th calendar week of 2016, when the weekly prevalence rate was 135,7 per 10 thousand population (8447), the epidemic threshold was exceeded in 2 times. In terms of conversion to the infectious diseases hospital, a multidisciplinary clinic No. 2 "Central city clinical hospital" carried out specialized medical assistance 301 the patient with acute respiratory diseases and influenza, 67 of which were confirmed influenza caused by the H1N1 virus, of which 28 patients would, if hospitalized in serious and critical condition and needed to be held-Institute the intensive care manual
Allelic variants of NRF2 and TLR9 genes in critical illness
No full textAim of the study. To elucidate the association of allelic variants of single nucleotide polymorphism in NRF2 (rs6726395, 177238501A>G) and TLR9 (rs352162, 52218953T>C) genes, each gene separately and in their com bination, with peculiarities of the course of critical conditions during lung infection. Materials and methods. DNA from 86 post-operative patients and oncologic patients was genotyped in an allele specific fashion using tetra-primer polymerase chain reaction followed by gel electrophoresis analysis of products. Results. It has been found that septic shock patients with NRF2 177238501A>G GG genotype had increased mortality and higher APACHE II score and developed non-responsive edema more frequently. Patients with NRF2 177238501A>G GG/TLR9 52218953T>C CC genotype combination developed septic shock and nosocomial pneumonia more rarely. Conclusion. The homozygous NRF2 177238501A>G (GG) allele combination is unfavorable for the course and outcome of critical conditions only in combination with TLR9 52218953T>C СT or TLR9 52218953T>C TT alleles in septic shock patients. At the same time, the combination of TLR9 52218953T>C СС alleles in the same patients with ‘unfavorable’ NRF2 177238501A>G GG protects against development of septic shock and nosoco mial pneumonia. © 2016, V.A. Negovsky Research Institute of General Reanimatology. All Rights reserved
A computational approach to investigate patterns of acute respiratory illness dynamics in the regions with distinct seasonal climate transitions
No full textIn the current work we present a set of computational algorithms aimed to analyze the acute respiratory infection (ARI) incidence data in the regions with distinct seasonal climate transitions. Their capabilities include: (a) collecting incidence data, fixing the under-reporting; (b) distinguishing phases of seasonal ARI dynamics (lower ARI level, higher ARI level, level transitions, epidemic outbreak); (c) finding the connections between the ARI dynamics (epidemic and interepidemic) and the weather factors. The algorithms are tested on the data for Saint Petersburg, Moscow and Novosibirsk and compared with the results for Ile-de-France region (Paris and its suburbs). The results are used to clarify the underlying mechanisms of ARI dynamics in temperate regions. © The Authors. Published by Elsevier B.V
Alu RNA regulates the cellular pool of active ribosomes by targeted delivery of SRP9/14 to 40S subunits
No full textThe human genome contains about 1.5 million Alu elements, which are transcribed into Alu RNAs by RNA polymerase III. Their expression is upregulated following stress and viral infection, and they associate with the SRP9/14 protein dimer in the cytoplasm forming Alu RNPs. Using cell-free translation, we have previously shown that Alu RNPs inhibit polysome formation. Here, we describe the mechanism of Alu RNP-mediated inhibition of translation initiation and demonstrate its effect on translation of cellular and viral RNAs. Both cap-dependent and IRES-mediated initiation is inhibited. Inhibition involves direct binding of SRP9/14 to 40S ribosomal subunits and requires Alu RNA as an assembly factor but its continuous association with 40S subunits is not required for inhibition. Binding of SRP9/14 to 40S prevents 48S complex formation by interfering with the recruitment of mRNA to 40S subunits. In cells, overexpression of Alu RNA decreases translation of reporter mRNAs and this effect is alleviated with a mutation that reduces its affinity for SRP9/14. Alu RNPs also inhibit the translation of cellular mRNAs resuming translation after stress and of viral mRNAs suggesting a role of Alu RNPs in adapting the translational output in response to stress and viral infection. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research
What we know but do not understand about nidovirus helicases
No full textHelicases are versatile NTP-dependent motor proteins of monophyletic origin that are found in all kingdoms of life. Their functions range from nucleic acid duplex unwinding to protein displacement and double-strand translocation. This explains their participation in virtually every metabolic process that involves nucleic acids, including DNA replication, recombination and repair, transcription, translation, as well as RNA processing. Helicases are encoded by all plant and animal viruses with a positive-sense RNA genome that is larger than 7. kb, indicating a link to genome size evolution in this virus class. Viral helicases belong to three out of the six currently recognized superfamilies, SF1, SF2, and SF3. Despite being omnipresent, highly conserved and essential, only a few viral helicases, mostly from SF2, have been studied extensively. In general, their specific roles in the viral replication cycle remain poorly understood at present. The SF1 helicase protein of viruses classified in the order Nidovirales is encoded in replicase open reading frame 1b (ORF1b), which is translated to give rise to a large polyprotein following a ribosomal frameshift from the upstream ORF1a. Proteolytic processing of the replicase polyprotein yields a dozen or so mature proteins, one of which includes a helicase. Its hallmark is the presence of an N-terminal multi-nuclear zinc-binding domain, the nidoviral genetic marker and one of the most conserved domains across members of the order. This review summarizes biochemical, structural, and genetic data, including drug development studies, obtained using helicases originating from several mammalian nidoviruses, along with the results of the genomics characterization of a much larger number of (putative) helicases of vertebrate and invertebrate nidoviruses. In the context of our knowledge of related helicases of cellular and viral origin, it discusses the implications of these results for the protein's emerging critical function(s) in nidovirus evolution, genome replication and expression, virion biogenesis, and possibly also post-transcriptional processing of viral RNAs. Using our accumulated knowledge and highlighting gaps in our data, concepts and approaches, it concludes with a perspective on future research aimed at elucidating the role of helicases in the nidovirus replication cycle. © 2014 Elsevier B.V
Safety and immunogenicity in man of a cell culture derived trivalent live attenuated seasonal influenza vaccine: A Phase I dose escalating study in healthy volunteers
No full textLive attenuated influenza vaccine (LAIV) offers the promise of inducing a variety of immune responses thereby conferring protection to circulating field strains. LAIVs are based on cold adapted and temperature sensitive phenotypes of master donor viruses (MDVs) containing the surface glycoprotein genes of seasonal influenza strains. Two types of MDV lineages have been described, the Ann Arbor lineages and the A/Leningrad/17 and B/USSR/60 lineages. Here the safety and immunogenicity of a Madin Darby Canine Kidney - cell culture based, intranasal LAIV derived from A/Leningrad/17 and B/USSR, was evaluated in healthy influenza non-naive volunteers 18-50 years of age. In a double-blind, randomized, placebo-controlled design, single escalating doses of 1×105, 1×106, or 1×107 tissue culture infectious dose 50% (TCID50) of vaccine containing each of the three influenza virus re-assortants recommended by the World Health Organization for the 2008-2009 season were administered intranasally. A statistically significant geometric mean increase in hemagglutination inhibition titer was reached for influenza strain A/H3N2 after immunization with all doses of LAIV. For the A/H1N1 and B strains, the GMI in HI titer did not increase for any of the doses. Virus neutralization antibody titers showed a similar response pattern. A dose-response effect could not be demonstrated for any of the strains, neither for the HI antibody nor for the VN antibody responses. No influenza like symptoms, no nasal congestions, no rhinorrhea, or other influenza related upper respiratory tract symptoms were observed. In addition, no difference in the incidence or nature of adverse events was found between vaccine and placebo treated subjects. Overall, the results indicated that the LAIV for nasal administration is immunogenic (i.e. able to provoke an immune response) and safe both from the perspective of the attenuated virus and the MDCK cell line from which it was derived, and it warrants further development. © 2014 Elsevier Ltd
Docking and molecular dynamics simulations in potential drugs discovery: An application to influenza virus M2 protein
No full textMolecular docking is a common method for searching new potential drugs. Improvement of the results of docking can be achieved by different ways-one of them is molecular dynamics simulations of protein-ligand complexes. As a model for our research we chose M2 membrane protein from influenza virus. M2 protein is a high selective tetrameric pH-gated proton channel. It was previously shown that Omeprazole Family Compounds (OFC) block the “proton pump”, though we hypothesized further that they could interfere with the mechanism of fusion of the virus envelope and endosomal membrane, thereby hindering the M2 proton pump mechanism of influenza viruses. We carried out a Molecular Dynamics (MD) simulation in order to predict constant of binding for OFC. We simulated M2 Protein (PDB code 3C9J) in complex with its ligands: Amantadine, rimantadine as positive controls and omeprazole as putative ligand. We made use of molecular docking as well as the thermodynamic integration method to estimate binding free energies of the ligands. We demonstrate that the thermodynamic integration method predicts free energies of ligand binding better than molecular docking while embedding of M2 protein in a membrane further improves the calculated free energy values. Free energy calculations imply omeprazole as a potent anti-viral drug. © 2014 The Marine E. Bozdaganyan, Philipp S. Orekhov, Nicola L. Bragazzi, Eugeniya Pechkova, Roberto Gasparini and Claudio Nicolini
Microevolution of cholera agent in the modern period
No full textAim: To carry out comparative molecular genetic analysis of highly pathogenic atypical Vibrio cholerae strains biovar El Tor, isolated in the territory of RF, in order to determine micro-evolutionary alterations of cholera agent in the modern period. Materials and methods: 38 clinical strains have been examined by means of polymerase chain reaction, sequencing and MLVA-analysis. The selected strains were isolated at different periods of time during cholera epidemic complications and differed between each other in virulence. Results: It is demonstrated that new variants have emerged in the course of short-term microevolution. Their genome structure and function differ from those of all previously known strains. The genome alterations have been caused by point mutations in ctxB u tcpA genes associated with virulence and located in CTXφ prophage and pathogenicity island VPI-1 respectively, as well as by the extended deletion in pandemicity island VSP-II. Presented is the dynamics of genome structure and function alterations in modern strains. Conclusion: The discovered genomic alterations in the new variants of the agent evolved in the process of microevolution are indicative of their epidemic potential enhancement and probability of virulence potentiation. © 2014, Izdatel'stvo Meditsina. All rights reserved