FREQUENCY AND FORMS OF INNATE MALFORMATIONS

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LOCALIZATION OF PULMONARY THROMBOEMBOLISM - AN IMPORTANT PROGNOSTIC FACTOR

The prognosis of pulmonary thromboembolism is a serious challenge for the clinicians. A total of 967 patients with pulmonary thromboembolism, 511 males and 456 females at a mean age of 60,1 ±13,7 years were analyzed. A special protocol consisting of 52 parameters was used to define their prognostic value. A non-invasive diagnostic algorithm based on symptoms, ECG, pulmonary roentgenography, perfusion scintigraphy, spiral scan, pulmoangiography, or on autopsy was applied. A prognostic index was elaborated by means of multifactorial analysis of the parameters of prognostic significance concerning the risk of lethal outcome. The localization of the pulmonary thromboembolism as determined by using spiral C T can effectively be used for patients' risk stratification

Fast-activating reserve power sources: is lead dead indeed?

The purpose of this research is to improve the performance and reduce the activation time of reserve power sources based on lead-acid systems at lower temperatures, down to –50 °C. Physico-chemical factors affecting the activation speed of reserve power sources based on Pb–HClO4–PbO2 and Zn–HClO4–PbO2 systems are investigated using chronopotentiometry, scanning electron microscopy, and standard contact porosimetry. Two approaches to the improvement of the low-temperature performance of power sources are used. The first one is based on the substitution of lead as anodic material with zinc. This allows the increase in discharge voltage and simultaneous decrease in activation time, but brings about the instability of discharge characteristics and, finally, deteriorates the reliability of power sources. The second approach is based on the use of PbO2 cathode material with enhanced nanoporosity. The chronopotentiometric method in galvanostatic mode is applied to the quality estimation of cathodes. The criterion of applicability of cathodes for reserve power sources consists in the low discharge overvoltage (0.1–0.2 V). Efficient performance of reserve power sources possessing the stable discharge voltage (1.5–1.8 V per cell) and the unprecedentedly short activation time (under 30 ms) even at lower temperatures (down to –50 °C) is achieved. The results are verified by fabrication and testing of pilot batches of miniaturized reserve power sources having microcells’ volume of 0.02 ml. The second approach to the improvement of power sources is transferred into the industrial production

Phylodynamic characteristics of the LMP-1 gene of the Epstein–Barr virus isolated in the Nizhny Novgorod region

Introduction. Epstein–Barr virus (EBV) is one of the most common herpesviruses and has a pronounced genetic polymorphism. The study of the phylodynamic characteristics of the virus is an important aspect of the study of evolutionary changes in the LMP-1 gene and their consequences. The aim of the work was a philodynamic analysis of EBV isolates from Nizhny Novgorod region based on the C-terminal fragment of the LMP-1 gene. Materials and methods. The study included 158 EBV isolates obtained from blood leukocytes and saliva of children aged 1–17 years with a diagnosis of infectious mononucleosis caused by EBV (n = 68) and apparently healthy children of comparable sex and age (n = 29). LMP-1 genovariants were obtained using the Sanger sequencing method. Comparative analysis of amino acid sequences was performed using the MEGA X program. Philodynamic analysis of the obtained nucleotide sequences and isolates deposited in GenBank was carried out using the BEAST v. 1.10.4 software package. Recombination analysis was performed using the Simplot program. Results. 158 nucleotide sequences of the C-terminal fragment of the LMP-1 gene from Nizhny Novgorod region EBV isolates were obtained and deposited in the GenBank database. The circulation time of the nearest common ancestor for the modified B95-8 genovariants with G212S + E328Q + S366T and NC mutations with the D250N substitution has been established dating back to 1994 and 1923. The rate of evolution of these genovariants was the highest and amounted to 1.298 × 10–4 and 7.868 × 10–4 nucleotide substitutions/site/year. Recombinations were detected in the Nizhny Novgorod region sequences Med-, B95-8, China 1 with mutations G212S, G212S, E214Q, respectively. Conclusion. For the first time, a phylodynamic characterization of Nizhny Novgorod region isolates and LMP-1 EBV genovariants isolated in various regions of the world is given. The data obtained expand the existing understanding of the circulation of EBV LMP-1 genovariants in the territory of the European part of Russia

Expression analysis of apoptotic and survival genes in blood leukocytes of children with various forms of HHV-6 infection

Despite that human herpes virus type 6 (HHV-6) is extremely spread worldwide, molecular mechanisms of behind HHV-6 infection pathogenesis remain largely unexplored. No molecular markers were found linked to unfavorable course of HHV-6 infection which could allow to ease up selecting proper therapy and preventing development of complications. The aim of the study was to analyze expression of apoptosis and survival-related genes in blood leukocytes from 7–17-year-old children upon various forms of HHV-6 infection. The analysis was carried out by using DNA microarrays developed by us allowing to assess changes in expression level both of individual mRNAs and total gene set (-Σ). It was shown that during the acute phase of HHV-6 infection mRNA level was shifted toward pro-apoptotic factors. In the convalescence phase, most altered mRNA levels returned to normal. We have identified a set of mRNAs and genes whose expression level was significantly changed in acute disease phase. According to available data, these factors play an important role in regulation of studied signaling pathways. In order to search for HHV-6-associated factors, which markedly affect disease pattern of severe herpesvirus mixed infection, we analyzed significant changes of mRNA and genes expression levels in patients with severe HHV-6+EBV+CMV mixed infection and EBV+CMV mixed infection of moderate severity compared with healthy donors. The levels of 5 mRNAs (FAF1-NM_007051, DAPK2-NM_014326, CASP8AP2-NM_001137667, CASP8-NM_033356, BTK-NM_001287345) and 3 genes (FAS-Σ, Puma/BBC3-Σ, ITCH-Σ) were significantly increased in severe mixed infection comorbid with HHV-6 (EBV+CMV+HHV-6) but without HHV-6 (EBV+CMV) compared with healthy donors. Most of detected factors belong to Fas-mediated apoptosis pathway, and may be considered as candidate prognostic development factors of severe herpes virus infection involving HHV-6. This study profoundly extends existing understanding on molecular pathogenesis of HHV-6 infection involving apoptosis and pro-survival signaling pathways. Marked changes of mRNA and gene levels most likely contributed to the pathogenesis of HHV-6 as well as severe HHV-6+EBV+CMV mixed infection

Methodological basics for differential detection of EBV1/EBV2 and HHV6A/HHV6B

Among a whole variety of EBV- and HHV6-linked diseases only infectious mononucleosis is subject to official statistical reporting in Russia that substantially complicates objective assessment of etiological structure, incidence rate, characteristics of developing epidemic process. Currently, the data on the genetic EBV heterogeneity, even at the level of the main types (EBV1 and EBV2), as well as HHV6A and HHV6B, prevalence and clinical importance are mainly limited to foreign research publications. Few publications assessing this issue are available in Russian scientific papers. At the same time, examining circulation of virus genetic types (variants) and use of such data in implementing epidemiological surveillance after some other infections have been commonly practiced. One of the key issues is the level of developed laboratory support for molecular genetic monitoring. The goal of the study was to improve methodological basics for differential detection of HHV6A/B and the major EBV types. There were used samples of peripheral blood leukocytes collected from children aged 1–15 years with acute (n = 50) and asymptomatic infectious mononucleosis (n = 29). The detection and quantification of EBV and HHV6 DNA was performed by using real-time PCR. For differential determination of EBV1/EBV2 and HHV6A/HHV6B, an optimized one-round PCR with electrophoretic agarose gel detection amplification products was used. The data from our own study showed that frequency of detected EBV and HHV6 DNA in acute infectious mononucleosis patients comprised 74 and 72% compared to control group reaching 35 and 74%, respectively. It was found that among the examined children of Nizhny Novgorod Region, EBV1 and HHV6B prevailed in the viral population that agrees with existing insights about their geographical distribution in the adjacent territories. EBV2 was found in a single sample only in the control group. HHV6A was not detected in any of the groups. The methodological approach optimized in this study allows to separately detect HHV6A/HHV6B and the main EBV types according to a unified laboratory protocol, whereas combining it with additional stage of DNA enrichment increases the diagnostic sensitivity of PCR analysis, minimizes proportion of discordant and false negative results. Such an integrated approach can be applied for diagnostic, epidemiological and research purposes

DETERMINATION OF SOME IMMUNOLOGICAL FEATURES OF HHV-6-MEDIATED INFECTIOUS MONONUCLEOSIS IN CHILDREN BY THE METHOD OF DISCRIMINATORY ANALYSIS

Human herpesvirus type 6 (HHV-6) is a lymphotropic virus that is an etiological agent of infectious mononucleosis (IM) in children. HHV-6- mediated infectious mononucleosis (HHV-6M) does not have clearly  defined clinical features. Nowadays immunopathogenetic aspects of  this disease have not been fully understood. The purpose of this  work was to study the characteristics of the quantitative composition  of populations of immunocompetent cells of peripheral  blood in children with HHV-6M. The material for the study was  samples of peripheral blood from children with “infectious  mononucleosis” diagnosis and from virtually healthy children.  Depending on the etiologic cause of the disease, children with IM  were divided into three groups: HHV-6M, IM of other etiology and  mixed infection (combination of HHV-6 and Epstein–Barr virus  and/or Cytomegalovirus). Virtually healthy children formed the  fourth group. In blood samples, the absolute content of the following populations of immunocompetent cells was determined by the  method of flow cytometry: the total population of T-lymphocytes, T- helpers, cytotoxic T-lymphocytes, double positive T-lymphocytes  (CD4+CD8+), NK cells and B-lymphocytes. Discriminant analysis  was carried out: based on the obtained data on the population  composition of blood cells we constructed a model of a child’s  attribution to one of the four groups analyzed in pairs. We used the  method of machine learning — the algorithm of gradient boosting  over decision trees. It was determined whether it is possible to  classify patients on the basis of the studied indicators and which  combination of indicators is optimal for classification. As a result of  the study it was possible to classify the following pairs of groups:  healthy children — children with HHV- 6M, healthy children —  children with IM of other etiology, children with HHV-6M — children  with IM of other etiology. When solving the problem of classifying  children from group with mixed infection and from any other group,  it was not possible to find a model of satisfactory quality. In  comparison with virtually healthy children, children with HHV-6M were characterized by an increased content of the total  population of T-lymphocytes and cytotoxic T-cells, as well as by a  reduced content of doub le-positive T-lymphocytes. Compared with  children with IM of other etiology, children with HHV-6M were  characterized by an increased content of cytotoxic T-lymphocytes, T- helpers, B-lymphocytes and a reduced number of double-positive T  cells. Our results indicate that HHV-6-mediated infectious  mononucleosis causes changes in the quantitative composition of  certain populations of immunocompetent cells of peripheral blood,  different from those of other etiology, in children

Perfluorosulfonic Acid Membrane for Lithium–Sulfur Batteries with S/C Cathodes

Polymer electrolyte based on Nafion-117 membranes in the Li+ form with intercalated 1,3-dioxolane-dimethoxyethane solvent mixtures (DOL-DME) has been obtained. The obtained electrolyte Nafion-Li+-DOL-DME has been characterized by DSC analysis, IR- and impedance spectroscopy. The solvent uptake of membrane in the DOL-DME mixture amounts to 1.9. Nafion-Li+-DOL-DME is characterized by an ionic conductivity ~10−7 S cm−1 at room temperature. The comparative study of the electrochemical properties of Li–S batteries with liquid electrolyte (1M Li(CF3SO2)2N in DOL-DME) with polypropylene film (PP) or Nafion-Li+-DOL-DME and S/C composites with mesoporous carbon as cathode materials has shown that the use of membrane can improve cyclability of the cell. The first-cycle discharge capacities of S/C electrodes in the Li–S battery cells with PP and Nafion-Li+-DOL-DME were 730 and 450 mAh g−1, respectively (0.1 mV s−1). However, the discharge capacity of S/C in the cell with PP reduced significantly after 10 cycles. The Li–S battery with the use of membrane exhibits significantly enhanced cyclability. The discharge capacity of S/C in the cell with Nafion-Li+-DOL-DME amounts to 365 mAh g−1 after 10 cycles and to up to 290 mAh g−1 after 40 cycles

ROLE OF CD95 AND DR3 RECEPTORS IN NA VE T-LYMPHOCYTES APOPTOSIS IN CHILDREN WITH INFECTIOUS MONONUCLEOSIS DURING CONVALESCENCE

Infectious mononucleosis is a widespread disease caused by certain members of Herpesviridae family. Acute infectious mononucleosis develops predominantly in children and is accompanied by an increase of the number of circulating naive CD4+ and naive CD8+ T-lymphocytes in the peripheral blood. The normalization of immunological parameters is achieved within 4–6 months after recovery and that is an indicator of a proper functioning of the immune system. CD95 and DR3 death receptors are involved in the initiation of apoptosis of naive T-lymphocytes in healthy people and in patients with infectious mononucleosis. The aim of the study was to evaluate the ability of CD95 and DR3 receptors to initiate apoptosis of naive CD4+ and naive CD8+ T-lymphocytes in children with infectious mononucleosis during convalescence. The material for the study was the samples of the peripheral blood of children who previously had infectious mononucleosis. The blood sampling was carried out again after 4–6 months after the disease. At the time of the study, children did not display clinical and laboratory signs of infectious mononucleosis. Same children who were examined earlier in the period of the development of acute infectious mononucleosis, as well as relatively healthy children were used as the comparison groups. Isolation of naive CD4+ and naive CD8+ T-lymphocytes was performed by negative magnetic immunoseparation. For specific stimulation of CD95 and DR3 receptors monoclonal antibodies were used. The level of apoptosis and expression of death receptors were evaluated by flow cytometry. Freshly isolated cells were analyzed, as well as cells cultured with the addition of appropriate monoclonal antibodies. It was shown that the recovery period was accompanied by increased apoptosis of freshly isolated naive CD4+ and naive CD8+ T-lymphocytes compared with the acute phase of infectious mononucleosis. Thus in both populations of naive T-cells showed an increase of CD95+ cells’ susceptibility to apoptosis. CD95 stimulation in the cell culture did not lead to the change in the level of apoptosis of naive CD4+ and naive CD8+ T-lymphocytes. The freshly isolated naive CD4+ and naive CD8+ T-lymphocytes DR3+ cells were resistant to apoptosis, and in the process of cultivating their sensitivity varied depending on the subpopulation belonging. Thus in the culture of naive CD4+ T-lymphocytes DR3 was not involved in the transfer of pro-apoptotic signal. In the culture of naive CD8+ T-lymphocytes DR3+ cells were possible to increase the apoptosis of DR3-negative cells. At the same time the DR3 activation by monoclonal antibodies in the culture caused the death of DR3+ naive CD8+ T-lymphocytes that naturally associated with decreased proapoptotic activity of these cells and resulted in inhibition of apoptosis of total pool of naive CD8+ T-lymphocytes. Thus, the functional ability of CD95 and DR3 receptors to trigger an apoptosis of naive T-lymphocytes in children during convalescence of infectious mononucleosis varied and depended on their belonging to naive CD4+ or naive CD8+ T-lymphocytes