U(1,1)--Invariant Generation of Charges for Einstein--Maxwell--Dilaton--Axion Theory

The action of the isometry subgroup which preserves the trivial values of the fields is studied for the stationary D=4 Einstein--Maxwell--Dilaton--Axion theory. The technique for generation of charges and the corresponding procedure for construction of new solutions is formulated. A solution describing the double rotating dyon with independent values of all physical charges is presented.Comment: 14 pages, RevTex, no figurie

Soliton solution in dilaton-Maxwell gravity

The inverse scattering problem method application to construction of exact solution for Maxwell dilaton gravity system ia considered. By use of Belinsky and Zakharov L - A pair the solution of the theory is constructed. The rotating Kerr - like configuration with NUT - parameter is obtained.Comment: 8 pages in LaTex; published in Gen. Rel. Grav. pp. 32 (2000) 2219-222

THE ROLE OF PREGNANCY-SPECIFIC GLYCOPROTEIN IN REGULATION OF MOLECULAR GENETIC DIFFERENTIATION MECHANISMS OF IMMUNE MEMORY T CELLS

The role of pregnancy-specific β1-glycoprotein (PSG) in the regulation of molecular genetic factors determining the functional activity of naїve T cells and T cells of immune memory in vitro was studied. Human PSG was isolated with a proprietary immuno-purification method using a biospecific sorbent followed by removing of immunoglobulin contamination with a HiTrapTM Protein G HP column. Physiological concentrations of PSG were used in the experiments. They corresponded to PSG levels in the peripheral blood of pregnant woman: 1, 10 and 100 μg/ml (I, II, III trimester, respectively). The objects of study were monocultures of naїve T cells (CD45RA+) and memory T cells (CD45R0+), obtained by immunomagnetic separation from the peripheral blood of women of reproductive age.It was established that at the level of naїve T cells (CD45RA+) PSG inhibited the expression of CD28 (1, 10, 100 μg/ml) and CD25 (100 μg/ml), without affecting the interleukin-2 (IL-2) production by these cells. At the same time, PSG in all concentrations studied suppressed the expression of CD25 at the immune memory T-cell (CD45R0+) surface but increased the IL-2 production. Expression of U2af1l4, Gfi1, hnRNPLL genes regulating the alternative splicing of the Ptprc gene encoding CD45 was also evaluated. It was found, that PSG reduced the expression of the Gfi1 (1, 10, 100 μg/ml), hnRNPLL (10, 100 μg/ml) genes, but increased the expression of the U2af1l4 gene (1, 10, 100 μg/ml) in the naїve T cells. It was shown that at the immune memory T-cells’ level the effects were similar, with PSG rendering them in all concentrations used. The revealed changes in the mRNA transcription of U2af1l4, Gfi1 and hnRNPLL genes in the studied T cell subsets may lead to the inhibition of CD45 “mature” isoform formation – CD45R0.Thus, PSG reduces the functional activity of naїve T cells and immune memory T cells associated with the expression of costimulation/activation molecules CD25 and CD28 and is involved in the regulation of Ptprc gene alternative splicing, which determines the ratio of CD45 molecule variants. Apparently, using these mechanisms, PSG regulates the functional activity of the memory T cell circulating pool, which is potentially capable of carrying out antigen-specific cytotoxic reactions against fetal antigens in vivo. In general, the data obtained broadens the notion of the PSG role in the regulation of molecular-genetic mechanisms of naїve T cells and immune memory T cells differentiation

Клеточные реакции CD3+ CD4+ CD45RO+ Т-лимфоцитов на дексаметазон в норме и при ревматоидном артрите в системе in vitro

The aim of the study was to analyze the influence of glucocorticoid (GC) dexamethasone (Dex) on changes in CD4+ T-cells expressing the surface molecule of activation (CD25, CD71, HLA-DR and CD95) and their ability to produce proinflammatory mediators in cultures of TCR-stimulated CD3+CD45RO+ T-lymphocytes obtained from healthy donors and patients with rheumatoid arthritis in vitro.Materials and methods. The study included 50 patients and 20 healthy donors. T-cell cultures (CD3+ CD45RO+) were obtained from mononuclear leukocytes of immunomagnetic separation (MACS® technology). As an activator of T-lymphocytes, antibiotic particles with biotinylated antibodies against CD2+, CD3+, CD28+, which simulate the process of costimulation of T cells by antigen-presenting cells, were used. The following concentrations of dexamethasone (2, 8, 16, 32, 64 mg) were used in the experiment. The change in the immunophenotype of T-lymphocytes was analyzed by flow cytofluoometry. The secretion of CD3+CD45RO+ T-cells of proinflammatory cytokines IL-2, IFNγ, TNFα, IL-17 and IL-21 was evaluated by enzyme-linked immunosorbent assay.Results. The general suppressor effect of Dex on CD3+CD45RO+ T-cell cultures mediated by a decrease in the number of CD4 + T cells expressing activation molecules (CD25) and proliferation (CD71), as well as inhibition of the production of inflammatory mediators: IFNγ, IL-2 and TNFα. It is shown that against the background of TCR activation Dex increases the number of CD4+CD95+HLA-DR+ cells in CD3+CD45RO+ cultures obtained from RA patients and does not change their content in the control. The correlations between the number of proinflammatory factors (IL-17, IL-21 and TNFα) in CD4+CD45RO+CD95+HLA-DR+ T cells in supernatants of cell cultures in RA patients indicate the presence of a pro-inflammatory potential of this population of T cells. We assume that the resistance of CD4+CD45RO+CD95+HLA-DR+ T cells in RA patients to the suppressor effect of GC generally leads to the preservation and enhancement of the functionality of autoreactive cells in the pathogenesis of RA. Целью исследования явился анализ влияния глюкокортикоида (ГК) дексаметазона (Dex) на изменение числа CD4+ Т-клеток, экспрессирующих поверхностные молекулы активации (CD25, CD71, HLA-DR и CD95), и их способности продуцировать провоспалительные медиаторы в культурах TCRстимулированных Т-лимфоцитов CD3+CD45RO+, полученных у здоровых доноров и больных ревматоидным артритом (РА), в системе in vitro. В исследование включены 50 больных и 20 условно здоровых доноров.Материал и методы. Культуры T-клеток (CD3+CD45RO+) получали из мононуклеарных лейкоцитов методом иммуномагнитной сепарации (технология MACS®). В качестве активатора Т-лимфоцитов использовали антибиотиновые частицы с биотинилированными антителами против CD2+, CD3+, CD28+ человека, имитирующие процесс костимуляции Т-клеток антиген-презентирующими клетками. В эксперименте использованы следующие концентрации дексаметазона – 2; 8; 16; 32; 64 мг. Методом проточной цитофлуориметрии проанализировано изменение иммунофенотипа Т-лимфоцитов; иммуноферментным анализом оценена секреция Т-клетками CD3+CD45RO+ провоспалительных цитокинов: IL-2, IFNγ, TNFα, IL-17 и IL-21.Результаты. Подтвержден общий супрессорный эффект Dex на культуры Т-клеток CD3+CD45RO+, опосредованный снижением числа Т-клеток CD4+, экспрессирующих молекулы активации (CD25) и пролиферации (CD71), а также угнетением продукции медиаторов воспаления: IL-2, IFNγ и TNFα. Показано, что на фоне TCR-активации Dex повышает число клеток CD4+CD95+HLA-DR+ в культурах СD3+CD45RO+, полученных от больных РА, и не изменяет их содержание в контроле. Корреляции между числом Т-клеток CD4+CD45RO+ CD95+HLA-DR+ с уровнем провоспалительных факторов (IL-17, IL-21 и TNFα) в супернатантах клеточных культур у больных РА свидетельствуют о наличии провоспалительного потенциала этой популяции Т-клеток. Предполагается, что резистентность Т-клеток CD4+CD45RO+CD95+HLA-DR+ больных РА к супрессорному действию ГК в целом приводит к сохранению и усилению функциональных возможностей аутореактивных клеток в патогенезе РА.

Cellular reactions of CD3+ CD4+ CD45RO+ T-lymphocytes on dexamethason in in normal patients and in patients with with rheumatoid arthritis in vitro

The aim of the study was to analyze the influence of glucocorticoid (GC) dexamethasone (Dex) on changes in CD4+ T-cells expressing the surface molecule of activation (CD25, CD71, HLA-DR and CD95) and their ability to produce proinflammatory mediators in cultures of TCR-stimulated CD3+CD45RO+ T-lymphocytes obtained from healthy donors and patients with rheumatoid arthritis in vitro.Materials and methods. The study included 50 patients and 20 healthy donors. T-cell cultures (CD3+ CD45RO+) were obtained from mononuclear leukocytes of immunomagnetic separation (MACS® technology). As an activator of T-lymphocytes, antibiotic particles with biotinylated antibodies against CD2+, CD3+, CD28+, which simulate the process of costimulation of T cells by antigen-presenting cells, were used. The following concentrations of dexamethasone (2, 8, 16, 32, 64 mg) were used in the experiment. The change in the immunophenotype of T-lymphocytes was analyzed by flow cytofluoometry. The secretion of CD3+CD45RO+ T-cells of proinflammatory cytokines IL-2, IFNγ, TNFα, IL-17 and IL-21 was evaluated by enzyme-linked immunosorbent assay.Results. The general suppressor effect of Dex on CD3+CD45RO+ T-cell cultures mediated by a decrease in the number of CD4 + T cells expressing activation molecules (CD25) and proliferation (CD71), as well as inhibition of the production of inflammatory mediators: IFNγ, IL-2 and TNFα. It is shown that against the background of TCR activation Dex increases the number of CD4+CD95+HLA-DR+ cells in CD3+CD45RO+ cultures obtained from RA patients and does not change their content in the control. The correlations between the number of proinflammatory factors (IL-17, IL-21 and TNFα) in CD4+CD45RO+CD95+HLA-DR+ T cells in supernatants of cell cultures in RA patients indicate the presence of a pro-inflammatory potential of this population of T cells. We assume that the resistance of CD4+CD45RO+CD95+HLA-DR+ T cells in RA patients to the suppressor effect of GC generally leads to the preservation and enhancement of the functionality of autoreactive cells in the pathogenesis of RA

Modelling CH₄ emissions from arctic wetlands: effects of hydrological parameterization

International audienceThis study compares the CH4 fluxes from two arctic wetland sites of different annual temperatures during 2004 to 2006. The PEATLAND-VU model was used to simulate the emissions. The CH4 module of PEATLAND-VU is based on the Walter-Heimann model. The first site is located in northeast Siberia, Indigirka lowlands, Kytalyk reserve (70° N, 147° E) in a continuous permafrost region with mean annual temperatures of ?14.3°C. The other site is Stordalen mire in the eastern part of Lake Torneträsk (68° N, 19° E), ten kilometres east of Abisko, northern Sweden. It is located in a discontinuous permafrost region. Stordalen has a sub arctic climate with a mean annual temperature of ?0.7°C. Model input consisted of observed temperature, precipitation and snow cover data. In all cases, modelled CH4 emissions show a direct correlation between variations in water table and soil temperature variations. The differences in CH4 emissions between the two sites are caused by different climate, hydrology, soil physical properties, vegetation type and NPP. For Kytalyk the simulated CH4 fluxes show similar trends during the growing season, having average values for 2004 to 2006 between 1.29?2.09 mg CH4 m?2 h?1. At Stordalen the simulated fluxes show a slightly lower average value for the same years (3.52 mg CH4 m?2 h?1) than the observed 4.7 mg CH4 m?2 h?1. The effect of the longer growing season at Stordalen is simulated correctly. Our study shows that modelling of arctic CH4 fluxes is improved by adding a relatively simple hydrological model that simulates the water table position from generic weather data. We conclude that CH4 fluxes at these sites are less sensitive to temperature variation than to water table variations. Furthermore, parameter uncertainty at site level in wetland CH4 process models is an important factor in large scale modelling of CH4 fluxes

Modelling CH₄ emissions from arctic wetlands: effects of hydrological parameterization

International audienceThis study compares the CH4 fluxes from two arctic wetland sites of different annual temperatures during 2004 to 2006. The PEATLAND-VU model was used to simulate the emissions. The CH4 module of PEATLAND-VU is based on the Walter-Heimann model. The first site is located in northeast Siberia, Indigirka lowlands, Kytalyk reserve (70° N, 147° E) in a continuous permafrost region with mean annual temperatures of ?14.3°C. The other site is Stordalen mire in the eastern part of Lake Torneträsk (68° N, 19° E) ten kilometres east of Abisko, northern Sweden. It is located in a discontinuous permafrost region. Stordalen has a sub arctic climate with a mean annual temperature of ?0.7°C. Model input consisted of observed temperature, precipitation and snow cover data. In all cases, modelled CH4 emissions show a direct correlation between variations in water table and soil temperature variations. The differences in CH4 emissions between the two sites are caused by different climate, hydrology, soil physical properties, vegetation type and NPP. For Kytalyk the simulated CH4 fluxes show similar trends during the growing season, having average values for 2004 to 2006 between 1.29?2.09 mg CH4 m?2 hr?1. At Stordalen the simulated fluxes show a slightly lower average value for the same years (3.52 mg CH4 m?2 hr?1) than the observed 4.7 mg CH4 m?2 hr?1. The effect of the longer growing season at Stordalen is simulated correctly. Our study shows that modelling of arctic CH4 fluxes is improved by adding a relatively simple hydrological model that simulates the water table position from generic weather data. Our results support the generalization in literature that CH4 fluxes in northern wetland are regulated more tightly by water table than temperature. Furthermore, parameter uncertainty at site level in wetland CH4 process models is an important factor in large scale modelling of CH4 fluxes

Modelling CH4 emissions from arctic wetlands: effects of hydrological parameterization

This study compares the CH4 fluxes from two arctic wetland sites of different annual temperatures during 2004 to 2006. The PEATLAND-VU model was used to simulate the emissions. The CH4 module of PEATLAND-VU is based on the Walter-Heimann model. The first site is located in northeast Siberia, Indigirka lowlands, Kytalyk reserve (70 degrees N, 147 degrees E) in a continuous permafrost region with mean annual temperatures of -14.3 degrees C. The other site is Stordalen mire in the eastern part of Lake Tornetrask (68 degrees N, 19 degrees E) ten kilometres east of Abisko, northern Sweden. It is located in a discontinuous permafrost region. Stordalen has a sub arctic climate with a mean annual temperature of -0.7 degrees C. Model input consisted of observed temperature, precipitation and snow cover data. In all cases, modelled CH4 emissions show a direct correlation between variations in water table and soil temperature variations. The differences in CH4 emissions between the two sites are caused by different climate, hydrology, soil physical properties, vegetation type and NPP. For Kytalyk the simulated CH4 fluxes show similar trends during the growing season, having average values for 2004 to 2006 between 1.29-2.09 mg CH4 m(-2) hr(-1). At Stordalen the simulated fluxes show a slightly lower average value for the same years (3.52 mg CH4 m(-2) hr(-1)) than the observed 4.7 mg CH4 m(-2) hr(-1). The effect of the longer growing season at Stordalen is simulated correctly. Our study shows that modelling of arctic CH4 fluxes is improved by adding a relatively simple hydrological model that simulates the water table position from generic weather data. Our results support the generalization in literature that CH4 fluxes in northern wetland are regulated more tightly by water table than temperature. Furthermore, parameter uncertainty at site level in wetland CH4 process models is an important factor in large scale modelling of CH4 fluxes