Promoters for Pd-catalyzed methoxycarbonylation of vinyl acetate

A study on the influence of acidic and non-acidic promoters for Pd(PPh 3)-catalyzed methoxycarbonylation of vinyl acetate was conducted in order to find an efficient protocol for the synthesis of methyl O-acetyl lactate. Besides known promoters also some new catalytic systems were tested. Aluminium triflate is the most active additive

Assessment of indicators of specific humoral immune against COVID-19 in children during the distribution of a new coronavirus infection in the Irkutsk region (2020–2021)

Background. There are many aspects of the development of immunity to the SARSCoV-2 virus, that remain poorly understood, like the influence of age-related characteristics on the intensity of immunity and the course of the disease. Studies of the state of immunity are widely used, mainly in the adults. But questions of the patho- and immunogenesis in children remain unsolved. Determining the nature of seroconversion of antibodies to SARS-CoV-2 in this age group is important information for serological monitoring for targeted immunoprophylaxis of the population and forecasting the epidemic situation in the region.The aim. Evaluation of the dynamics of seroprevalence of specific antibodies to SARS-CoV-2 in children of the Irkutsk region during the pandemic of a new coronavirus infection.Materials and methods. Study was conducted among the child population of the Irkutsk region in the period June 2020 – December 2021 as part of the Rospotrebnadzor project to assess population immunity to SARS-CoV-2 in the population of the Russian Federation. The content of antibodies to SARS-CoV-2 was determined by ELISA using native commercial test systems.Results. Population immunity among the child population of the Irkutsk region was characterized by an upward trend from 7.8 % at stage 1 to 98.4 % at stage 6 of the study. IgG to SARS-CoV-2 remained in 72.8 % and formed in 25.6 % of previously seronegative children. Antibodies were detected in 66.1 % of cases and persisted for up to 10–15 months after COVID-19 infection. The proportion of asymptomatic forms of infection among seropositive volunteers was 69.5 %, which determines the high intensity of the latent epidemic process.Conclusion. The level of seroprevalence was 98.4%. The current results of serological monitoring serve as a scientific basis for adjusting the list and scope of management decisions on the organization of preventive anti-epidemic measures, including vaccination

Change of the composition of splenic lymphocytes at the effect of argentogalactomanann and argento-poly-1-vinyl-1,2,4-triazole on the experimental animals

The article presents the results of the research of effect of metal-containing nanocomposites on the content of splenic Band T-lymphocytes of white mice. Phenotypic analysis of the spleen cells suspension was conducted by flow cytometry on BD FACSCanto ™ П. Stimulating effect of these medications on the immune response formation is showed and is proved by the increase of content of B-lymphocytes and T-helper cells and it indicates cooperative interactions between the cells of immune system. It was experimentally showed that the medications 2-N-HTP-Ag, GM-Ag can be recommended for the further research in order to increase protective properties of an organism

Changes in cellular components of peritoneal fluid of white mice with infection caused by Yersinia pestis with different plasmid profile

The article presents the data on the influence of Yersinia pestis plasmid profile on subpopulation structure of mononuclear cells of peritoneal fluid of mice at the early stages of infectious process. It was showed that change of cellular composition of peritoneal fluid of the experimental animals depended on the plasmid profile of Yersinia pestis strains. The phase character in the changes of quantitative composition of the mast cells of peritoneal fluid of white mice infected with Y. pestis strains with different plasmid spectrum was determined

Changes in immunocompetent guinea pigs immunizing with Francisella Tularensislipopoly-saccharide

Influence of Francisella tularensis lipopolysaccharide preparations on morphological changes in immunocompetent experimental animals was studied by subcutaneous introduction using survey microscopy and morphometric methods. Low expressed activation of B- and T-dependent bands in immunocompetent organs was determined. Proliferation of antigen-presented cells at early stages of investigation indicates the cell immunity activation. Pathomorphological alterations caused by lipopolysaccharide inoculation are homogeneous and benignant

Assessment of Toxic and Immunoadjuvant Properties of Nanocomposites

Introduction. The current direction in medicine is the creation of immunobiological preparations to increase the effectiveness of specific immunotherapy and immunoprophylaxis, containing immunomodulators in their composition. These natural or synthetic substances can have a regulating effect on the immune system. At present, water-soluble organic-inorganic polymeric materials with nanoparticles of various chemical substances with bactericidal and immunomodulating properties can serve as such promising compounds.The aimof the work is to study the acute toxicity of polymer nanocomposites based on 1-vinil-1,2,4-triazole copolymer with N-vinylpyrrolidone with silver, gold and selenium nanoparticles and their effect on the functional state of immune system cells in vitro.Materials and methods.The study of acute toxicity was performed on outbred white mice. The activity of superoxide dismutase and glucose-6-phosphate dehydrogenase were studied in guinea pig peritoneal macrophages. The study of spontaneous and nanocomposite-induced production of pro- (interferon gamma and tumor necrosis factor alpha) and anti-inflammatory (interleukin-4) cytokines by blood cells was carried out using clinical material obtained from volunteers using the ELISA method. Results. It has been established that nanocomposites with silver and gold nanoparticles do not cause the death of white mice, their temperature increase and body weight decrease. The average lethal dose for a nanocomposite with selenium nanoparticles was determined as 1 gram per 1 kilogram of animal mass. It was shown that the tested nanocomposites have a stimulating effect on the production of cytokines by human blood cells in vitro. It was established that a nanocomposite with selenium nanoparticles increases the activity of superoxide dismutase and glucose-6-phosphate dehydrogenase. A comparative analysis of their actions with the actions of commercial preparations of biological origin, with immunomodulatory properties.Conclusion. The data obtained allow us to substantiate the need for further research on the effects of nanocomposites based on 1-vinyl-1,2,4-triazole copolymer with N-vinylpyrrolidone with silver, gold and selenium nanoparticles on the macroorganism in both in vitro and in vivo conditions

ACTION OF 1-VINYL-1,2,4-TRIAZOLE COPOLYMER WITH N-VINYLPIROLIDONE AND METAL-CONTAINING NANOCOMPOSITES ON FUNCTIONAL STATE OF PHAGOCYTIC CELLS

The creation of immuno-biological drugs to increase the effectiveness of specific immunotherapy and immunoprophylaxis is a current trend in medicine to date. Therefore, the search and development of new safe and effective artificial bioorganic complexes (immunomodulators) capable of stimulating individual responses of immune system to reduce infectious morbidity is an important area of research. At the moment, such promising preparations can be considered water-soluble polymeric materials and organo-inorganic polymer nanocomposites with nanoparticles of various metals which possess immunomodulating and bactericidal properties. The study results of the effects of 1-vinyl-1,2,4-triazole copolymer with N-vinylpyrrolidone and nanocomposites based on it with gold and silver nanoparticles on acute toxicity and functional state of immunophagocytic cells of experimental animals, as well as the production of IFN-γ, TNF-α and IL-4 by human blood lymphocytes are represented in this article. It was established that the tested preparations do not cause increase in body temperature, decrease in mass and death of animals. It was shown that they also have the multidirectional action on cytokine production by human blood cells in vitro, the ability to increase activity of оxidative stress-related enzymes and antioxidant protection of phagocytes. The data obtained by us allow to explain the need for further investigation of the actions of nanocomposites and copolymer in vitro and in vivo

Characteristics of an antioxidant activity of Yersinia pestis with different plasmid spectrum

Experimental data concerning complex study of antioxidant activity of Y. pestis with different plasmid spectrum (wild-type Yersinia pestis subsp. pestis, Yersinia pestis subsp. altaica and their isogenic variants) are represented in the article. Superoxide dismutase activity of the tested Y. pestis strains was from 6.0 to 9.0 x 109 microbe cells. Significant differences between the Y. pestis strains with different plasmid composition were not detected by this parameter. Our results, consistent with the data of other authors, tell that superoxide dismutase activity is a thermo-inducible feature and does not depend on a plasmid spectrum. High peroxide destroying activity was also detected in all tested Y. pestis strains. The differences between the strains regarding their common peroxide destroying activity were found. This parameter of the plague microbe strains lacking pYP plasmid was at least 3 times lower than common peroxide destroying activity in strains with this plasmid in the genome. In our opinion these revealed differences were caused by characteristics of plasmid spectrum. The common peroxide destroying activity's degree of Y. pestis strains can be associated with the presence of pYP plasmid in the genome. The isogenic variants of Y. pestis strains lacking one of the plasmids had smaller pathogenic activity. This fact points to the need for further study of these strains

Efficiency of Human Plague Vaccination in Tuvinian Natural Plague Focus

Background. Plague is an especially dangerous natural focal infectious disease belonging to a group of quarantine infections. There are eleven natural plague foci in Russian Federation. In Republic Tyva plague endemic territories include Ovyur, Mongun-Taigin and Tes-Hem areas where Y. pestis strains are intermittently isolated from Citellus undulates. Population living at the territory of the natural foci get immunoprophylaxis against plague at complication of epizootic and epidemic conditions.This paper presents the results of monitoring indicators of the immune status of people vaccinated with the plague vaccine living in the territory of the Tuva natural focus.Materials and methods. The study involved 76 volunteers who had not previously been vaccinated. The study included the determination of production IFN-γ, IL-4, TNF-α by blood cells, titers of specific IgG antibodies to the capsule F1 antigen of the Yersinia pestis, and concentrations of immunoglobulins in serum blood, as well as immunophenotyping of blood lymphocytes.Results. In the course of a comprehensive immunological study, features of the development of cellular and humoral reactions in people living in the territory of the Tuva natural plague focus were established in the first months after vaccination. Changes in the concentration dynamics of the main classes of immunoglobulins were accompanied by an increase in the level of specific IgGs to the F1 within 6 months after immunization. In the same period, a significant increase in the production of cytokines, as well as significant changes in terms of the subpopulation composition of the vaccinated blood.Conclusion. It is necessary to note the importance of studying of the human immune status in 1–3 months after plague vaccination as this period coincides with potentially dangerous season from epidemiological point of view. Nevertheless, much important role for improvement of tactics of the specific prevention measures plays the data received after the revaccination

Structural rearrangement of organs of white mice vaccinated with Yersinia pestis EV in combination with organoselenium compound 974zh

Introduction. An urgent direction is the search for means that increase the effectiveness of the Y. pestis EV NIIEG vaccine and reduce the side pathological manifestations caused by it. Organoselenium compounds have immunotropic properties and increase the antioxidant potential of the body, as well as have an antidystrophic effect and an antiallergic effect. Materials of the study of the immunomodulating effect of the experimental selenium-containing compound 2,6-dipyridinium-9-selenabicyclo[3.3.1]nonane dibromide (974zh) on the macroorganism of laboratory animals are presented.The aim. To evaluate the effect of the organoselenium compound 974zh on the structural rearrangement of the organs of experimental animals in the dynamics of the vaccine process caused by Y. pestis EV.Methods. The study was carried out on 70 certified outbred white mice. Histological material (thymus, lymph nodes, spleen, adrenal glands, liver) was embedded in paraffin, semi-thin sections were stained with hematoxylin and eosin, thionin, and by the Brachet method. The severity of pathological changes in the liver and adrenal glands, proliferation of plasma cells and structural changes in immunocompetent organs (thymus, lymph nodes and spleen) were assessed. Microphotography and quantitative analysis were performed using MoticImagesPlus 2.0. Statistical processing was carried out using the computer program Statistica.Results. It has been established that the combined administration of 974zh and Y. pestis EV leads to morphological and functional restructuring of immunocompetent organs, enhances the proliferation of plasma cells in the spleen and lymph nodes, and eliminates negative changes in the liver and adrenal glands. Conclusion. Thus, the 974zh preparation enhances the immunogenic effect of the Y. pestis EV vaccine strain, increasing the T- and B-dependent zones of the spleen and lymph nodes, increasing the proliferation of plasma cells, and also significantly reduces pathological changes in the liver and adrenal glands