A study of the antiviral activity of antioxidants against viral infections is believed to be essential for creating complex antiviral agents. Dihydroquercetin is considered as the most active antioxidant extracted from Larix gmelinii. In this work, we present results of experiments of the antiviral properties of dihydroquercetin against a member of the family Picarnaviridae--Coxsackievirus B4 in vitro. We have estimated that dihydroquercetin reduces viral titers at 100 µg/ml concentration as compared with control of virus. We have shown using the plaque assay that CPE of virusis reduced in the presence of dihydroquercetin at 100 µg/ml. Study of the phase of viral lifecycle, in which dihydroquercetin acted, demonstrated that the highest efficacy of the antiviral therapy was reached at early stages of virus reproduction (1-3 hours post infection). These results show that dihydroquercetin has antiviralproperty against Coxsackievirus B4. This drug and other antioxidants can be tested as inhibitors of viral replication.

Transmission electron microscopy (TEM) and small-angle neutron scattering (SANS) studies showed that model peptides QNALVCGLRQ (G33) and QNALVCGLRG (G31) corresponding to region 551–560 of the GP protein of the Sudan Ebola virus are prone to oligomerization in solution. Both peptides can form amyloid-like fibrills. The G33 peptide forms fibrils within one day of incubation, whereas the fibrillogenesis of the G31 peptide is observed only after incubation for several months. The possible role of the observed processes in the pathogenesis and the possibility of applying a combination of the TEM and SANS techniques to search for new compounds that are able to influence the protein oligomerization are discussed.

AIM:To estimate the r, virological and clinical characteristics of chronic viral hepatitis (CVH) with double B/C infection.MATERIALS AND METHODS:We examined 282 patients with CVH. Genomes of hepatitis B virus (HBV) and hepatitis C virus (HCV) were studied by PCR in blood and liver (AmpliSens HBV and Amplisens HCV Russia), nuclear proteins (HBcorAg HBV and NS3 HCV) were determined by immunohistochemical method (Novocastra, UK), HBVgenome was sequenced by the Sanger method using ABI prism BigDye Terminator v3.1 kits and ABIPRISM 3100 analyzer (AppliedBiosystems, USA). Indices of histological activity (HAI), fibrosis, and portal vein (PV) congestion index (CI) were calculated by formula CI=SBB/LB V where S is P V cross section area in cm2 and LB V - linear blood flow velocity in cm/s (Vivid Pro- 7 apparatus, USA).RESULTS:CVH with double B/C infection was diagnosed in 85 (30.1%) patients including 44.7% with viral genomes and proteins in the live; 42.4% with HCVviremia, and 12.9% with HBJV/HCVviremia. Maximum CVH activity was documented in patients with latent HBV/HCVviremia (ALT 157.2±59.2 U/, HAI 11.6±1.3,fibrosis 2.8±0.7, C1 0.059±0.005); it was minimal inpatients.without viremia (Alt 76.25±63.0 U/I, HAI 6.7+-0.6,fibrosis 1.7±0.5, CI 0.042±0.001;p <0.05). Patients with latent HBV infection had precore/ore and pres/s mutations in HBVgenome and cytoplasmic localization ofHBcorAg.CONCLUSION:Double B/C infection was diagnosed in 30.1% of the patients with CVH dominated by HCV Patients with latent HBVhadprecore/ore and pres/s mutations. The highest intensity of hepatic cellular inflamation,fibrosis, and PV congestion was associated with HBV/HCV viremia and the lowest with intrahepatic localization of both viruses.

Sepsis is a generalized infection accompanied by response of the body that manifests in a clinical and laboratory syndrome, namely, in the systemic inflammatory response syndrome (SIRS) from the organism to the infection. Although sepsis is a widespread and life-threatening disease, the assortment of drugs for its treatment is mostly limited by antibiotics. Therefore, the search for new cellular targets for drug therapy of sepsis is an urgent task of modern medicine and pharmacology. One of the most promising targets is the adenosine A(2A) receptor (A(2A)AR). The activation of this receptor, which is mediated by extracellular adenosine, manifests in almost all types of immune cells (lymphocytes, monocytes, macrophages, and dendritic cells) and results in reducing the severity of inflammation and reperfusion injury in various tissues. The activation of adenosine A(2A) receptor inhibits the proliferation of T cells and production of proinflammatory cytokines, which contributes to the activation of the synthesis of anti-inflammatory cytokines, thereby suppressing the systemic response. For this reason, various selective A(2A)AR agonists and antagonists may be considered to be drug candidates for sepsis pharmacotherapy. Nevertheless, they remain only efficient ligands and objects of pre-clinical and clinical trials. This review examines the molecular mechanisms of inflammatory response in sepsis and the structure and functions of A(2A)AR and its role in the pathogenesis of sepsis, as well as examples of using agonists and antagonists of this receptor for the treatment of SIRS and sepsis.

Malignant glioma is the most frequently occurring primary brain tumor. Despite significant progress in the diagnostics and treatment of neoplastic diseases the prognosis for patients with III-IV grade gliomas, remains extremely unfavorable. Rapidly developing area in oncology is the employment of therapeutic viruses with natural or genetically engineered oncolytic activity. In the present study we demonstrated the oncolytic potential of a recombinant influenza A virus vector with impaired interferon antagonism function of NS1 protein in treatment of malignant glioma. Recombinant influenza A virus (HA-DS-GFP) expressing green fluorescent protein from the NS1 open reading frame was used as a model vector. HA-DS-GFP virus has shown infectivity towards glioma cells both in vitro, and in vivo (experimental glioma model in rats). Intratumoral inoculation of HA-DS-GFP resulted in a substantial inhibition or complete regression of tumor growth. Our data demonstrate that recombinant influenza vectors have promising potential in therapy of malignant gliomas.

The changeability of viruses largely depends on adaptation to the conditions of reproduction and mechanisms of the antiviral protection of host cells. Within populations, adaptation is associated with HLA specifics of identifying viral antigens. A population’s genetic profile and the diversity of HLA haplotypes affect not only the morbidity rate but also the destiny of entire ethnic groups, their size, and premature mortality indicators. Therefore, the solution to the problem of protecting a population against mass viral infections is impossible without taking into account the HLA interethnic polymorphism, which specifies sensitivity to infections and response to mass vaccination. Recent achievements in human genetics allow the system of preventive medicine to upgrade to the level of genetic personalization. In a multinational country like Russia, this approach should become the basis for the preventive trend in practical medicine.

Influenza A virus (IAV) is a segmented negative-sense RNA virus that causes seasonal epidemics and periodic pandemics in humans. Two regions (nucleotide positions 82–148 and 497–564) in the positive-sense RNA of the NS segment fold into a multi-branch loop or hairpin structures.

Introduction. Biological properties of virus, such as susceptibility to antivirals, the clinical course of chronic hepatitis B (CHB), the probability of developing cirrhosis and hepatocellular carcinoma are determined by genotype and mutations in the genome of the hepatitis B virus (HBV).The aim of the study was evaluating of HBV genetic variants in patients with CHB from St. Petersburg hospitals.Material and methods. A total of 1414 CHB patients with positive polymerase chain reaction HBV genome in blood and/or liver tissue were observed. Genotype was determined in 298 patients, sequencing of the polymerase gene fragment was performed in 80 patients.Results. Viral DNA was detected in 323 (55.8%) patients with CHB. Genotype D was determined in 238 (80,1%), genotype A – in 49 (16,5%), C genotype – in 2 (0,7%) and mixed A+D – in 8 (2,7%) patients. Substitutions in YMDD-motif of the polymerase protein (M204I/V) as well as other primary and secondary resistance mutations to nucleotide analogues (lamivudine, telbivudine, entecavir) were found in four patients. Mutations in the reverse transcriptase (rt) region of polymerase gene were shown to affect the structure of surface protein. The substitution rtA181T in three patients resulted in formation of stop codon (sW172*) and premature termination of surface protein synthesis. The absence of HBeAg and the degree of fibrosis increase in 7 patients may be the result of mutations identified in core gene (G1896A, A1762T, G1764A).Conclusion. Study of the geographical distribution of HBV genotypes and identification of amino acid substitutions leading to decrease in serum markers concentration and emergence of resistance antivirals mutations is of great practical importance for predicting severity of the disease and effectiveness of antiviral therapy.

The system of genetic control of innate immune responses to influenza infection and gene function allows for the development of systemic treatment of influenza with a focus on the phenotype of mutations based on individual genetic susceptibility to severe disease and/or the development of complications.

Ebola virus disease (EVD), formerly known as Ebola haemorrhagic fever is severe acute infectious diseases accompanied by the development of severe systemic inflammatory response followed by the addition of disseminated intravascular coagulation and multiple organ failure. Since 1976 in Africa regularly observed disease outbreaks among humans caused by different types of Ebola virus. Modern epidemic in West Africa began in Guinea in February 2014 and is still going on, coming out of the country and distributed in Liberia, Sierra Leone and Nigeria. According to the World Health Organization (WHO) on December 14, 2014 recorded 18,603 cases of them confirmed EVD 11807, fatal 6915. From July 2014 to currently registered sporadic cases EVD among health care workers caring for patients, as well as among tourists returning from countries affected by the epidemic is already outside of West Africa. Due to the limited use of specific antiviral therapy with special attention to the management ofpatients with EVD should be paid to the intensive and timely pathogenetic therapy. Today, the only way to reduce morbidity and mortality among people from EVD is awareness on the risk factors of infection and the use ofpersonal protective measures.

Comparison of spatial-temporal spread of influenza in the Northern and southern hemispheres according to the WHO and the analysis of the epidemic of influenza in Russia in the 2014 – 2015 season, according to the research Institute of influenza on the incidence of influenza and ARI in 59 cities of Russia.It is shown that in the season 2014 – 2015 in the Northern hemisphere, the intensity of the epidemics was higher in North America and Europe than East Asia and North Africa. In the Southern hemisphere have experienced low influenza activity. In the etiology of epidemics in countries of both hemispheres was dominated by influenza A(H3N2) and influenza B. The proportion of influenza A(H1N1)pdm09 was less in the Southern hemisphere was higher than in Northern countries. The incidence of influenza A(H3N2) in the Northern hemisphere was predominantly linked to the new strain A/Switzerland/9715293/2013 (H3N2), differing from the vaccine. In Europe, the majority of circulating influenza B strains were related to the strain B/Phuket/3073/2013, did not match the vaccine.In Russia the intensity of the influenza epidemic in 2015, was more than the previous epidemic of 2014, the prevalence in the cities, the morbidity especially children 7 – 14 years of age and adult population, the incidence of hospitalization with a diagnosis of «influenza» and the number of deaths.

Ebola hemorrhagic fever (EHF) epidemic currently ongoing in West Africa is not the first among numerous epidemics in the continent. Yet it seems to be the worst EHF epidemic outbreak caused by Ebola virus Zaire since 1976 as regards its extremely large scale and rapid spread in the population. Experiments to study the agent have continued for more than 20 years. The EHF virus has a relatively simple genome with seven genes and additional reading frame resulting from RNA editing. While being of a relatively low genetic capacity, the virus can be ranked as a standard for pathogenicity with the ability to evade the host immune response in uttermost perfection. The EHF virus has similarities with retroviruses, but belongs to (-)RNA viruses of a nonretroviral origin. Genetic elements of the virus, NIRV, were detected in animal and human genomes. EHF virus glycoprotein (GP) is a class I fusion protein and shows more similarities than distinctions in tertiary structure with SIV and HIV gp41 proteins and even influenza virus hemagglutinin. EHF is an unusual infectious disease, and studying the molecular basis of its pathogenesis may contribute to new findings in therapy of severe conditions leading to a fatal outcome.

Аnalogues of nucleos(t)ides (AN) such as lamivudine (LAM), telbivudine (TBV), adefovir (ADP), entecavir (ENT) are widely used for the treatment of chronic hepatitis B (CHB). However, the prolonged treatment using these drugs often leads to the development of drug resistance. The most common substitutions in the reverse transcriptase are methionine for valine (rtM204V), or methionine for isoleucine (rtM204I) at position 204. Early AN-resistant mutations detection is of great importance to determine the treatment strategy of patients with CHB. Currently there are many highly sensitive methods for detection of drug resistance mutations, such as next-generation sequencing, reverse hybridizationbased line probe assay (LiPA), mass spectrometry. However, these methods require expensive equipment and reagents, and they are not widely used in clinical laboratories. The aim of this study was to develop a simple and accurate real-time PCR method for detection of rtM204I/V mutation. This method showed high specificity and sensitivity (1000 copies/ml), it is less laborious and does not require additional equipment, fast and cost effective compared to other methods. HBV mutations of resistance to AN were determined in 5 groups of patients with CHB. Patients of the first group received monotherapy with pegylated interferon (n = 12), the second group — lamivudine (n = 10), the third group — telbivudine (n = 7), the fourth group — entecavir (n = 15). The fifth group consisted of patients who did not receive antiviral therapy (n = 3). The frequency of mutations in HBV polymerase YMDD-motif was determined among 47 patients with CHB: it was 10% for lamivudine treated patients, 20% — for entecavir, 28% — for telbivudine. YIDD/YVDD motifs were identified in two patients and YMDD/YIDD — in one patient. Real-time PCR method for the detection of AN-resistant rtM204I/V mutations in HBV polymerase can be used in routine diagnostics for primary screening of patients not responding to AN treatment. The application of this method can reduce the number of samples for in-depth study of primary and compensatory mutations of resistance to AN by sequencing method. The developed method versus Sanger-sequencing is fast, economical, and provides the detection of minor variants of HBV populations.

Comparative analysis of the three past epidemics with the participation of the pandemic influenza A(H1N1)pdm09 was conducted according to the results of the epidemiological trials of two WHO National influenza centers for the morbidity, hospitalization, and mortality of the influenza in 59 cities of Russia for the period from 2009 to 2013. The first wave of the pandemic of 2009 was the most severe. Compared with this wave, during the next epidemics of 2011 and 2013, the involvement of urban population in the epidemic was reduced, as well as the morbidity in the people 15-64 years old and schoolchildren 7-14 years old. The duration of the epidemic among the adult population, the mortality rate of the total population, and the mortality rates in all age groups were also decreased. Vice versa, the incidence in the children of preschool age and the elderly people and the duration of the epidemic among children (especially preschool children) were increased. The share of patients 65 years and older, children 0-2 years old, and patients with pathology of the cardiovascular systems among the deceased patients increased to 33.6%.