750 research outputs found

    Splenic CD8(+) T cells secrete TGF-beta 1 to exert suppression in mice with anterior chamber-associated immune deviation

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    Background CD8(+) regulatory T cells (Treg) have been considered to be involved in a model of ocular-induced tolerance, known as anterior chamber-associated immune deviation (ACAID). The mechanisms of suppression by CD8(+) T cells in ACAID remain only poorly understood. TGF-beta 1 is considered as an inhibitory cytokine for immunosuppression in some models. The production of TGF-beta 1 by CD8(+) T cells in ACAID, and whether CD8+ T cells exert suppression through TGF-beta 1, is unknown. Methods The suppressive effect of CD8(+) T cells in ACAID mice was determined by a local adoptive transfer (LAT) assay. The production of TGF-beta 1 by CD8(+) T cells was measured by enzyme-linked immunosorbent assay (ELISA). Anti-TGF-beta 1 antibodies were used in the LAT assay to test if they could block the inhibitory effect of CD8(+) T cells. Results CD8(+) T cells from ACAID mice were shown to block the delayed-type hypersensitivity (DTH) response in an antigen-specific manner in a LAT assay. These CD8+ T cells secreted TGF-beta 1, and their suppression could partially be blocked by anti-TGF-beta 1 antibodies. Conclusions Our study confirms that CD8+ T cells from ACAID mice possess inhibitory properties. This population exerts part of its suppressive function via the production of TGF-beta 1

    Degradación de algunos compuestos volátiles de aceites de onagra bajo un proceso UV/TiO2

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    Off-flavor is one of the limiting factors in the quality and commercial acceptability of evening primrose oil (EPO). The results of this study demonstrated that ultraviolet light irradiated with titanium dioxide (UV/TiO2) was able to effectively reduce odorous aldehyde concentrations, which would produce undesired flavors. Specifically, reductions in the E-2-Decenal, 1-octen-3-ol and hexanoic acid in EPO reached 50, 75.2 and 61.4% after a UV/TiO2 process of 5 min, respectively. The odor active values (OAV) and hierarchical cluster analysis (HCA) showed that the result of the 5 min group was similar to that of the original oil. In addition, the physicochemical characteristics of EPO after processing did not change significantly. The result of the aroma profile analysis was consistent with the OAV and HCA results. Therefore, it has been concluded that 5 min UV/TiO2 treatment could degrade some volatile compounds and provide a potential deodorization method for industry.El mal sabor es uno de los factores limitantes de la calidad y aceptabilidad comercial del aceite de onagra (EPO). Los resultados de este estudio demostraron que la luz ultravioleta irradiada con dióxido de titanio (UV/TiO2) fue capaz de reducir eficazmente las concentraciones de aldehídos volátiles, que darían olores no deseados. En concreto, la reducción del E-2-Decenal, 1-octen-3-ol y el ácido hexanoico en EPO alcanzó el 50%, 75,2% y 61,4% respectivamente tras un proceso UV/TiO2 de 5 min. Los valores de olor activo (OAV) y el análisis de conglomerados jerárquicos (HCA) mostraron que el resultado del grupo de 5 min fue similar al del aceite original. Además, las características fisicoquímicas del EPO después del procesamiento no cambiaron significativamente. El resultado del análisis del perfil de aroma fue consistente con nuestro resultado de OAV y HCA. Por lo tanto, se ha llegado a la conclusión de que el tratamiento con UV/TiO2 durante 5 min podría degradar algunos compuestos volátiles y proporcionar un método de desodorización potencial para la industria

    Retinal S-antigen Th1 cell epitope mapping in patients with Behcet's disease

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    Background - Retinal S-antigen (S-Ag) is a most characterized autoantigen of autoimmune uveitis. The recognized immunodominant epitope of human S-Ag in patients with uveitis has not been identified. In this study, we selected certain patients with active uveitis to map the Th1 cell epitope spectrum of human S-Ag in Behcet's disease(BD). Methods - Blood samples were taken from eight active BD patients who showed an immune response to 40 mixed overlapping peptides spanning the entire sequence of human S-Ag. Peripheral blood mononuclear cells were isolated and stimulated with single S-Ag peptide at 5 mu g/ml or 20 mu g/ml. Single-cell immune responses were measured by IFN-gamma ELIspot assay. Results - BD patients heterogeneously responded to the S-Ag peptides at two concentrations. In general, the responses to 5 mu g/ml peptides were slightly stronger than those to 20 mu g/ml peptides, while the maximum SFC frequency to single peptide at the two concentrations was similar. Several peptides including P31, P35 and P40 induced a prominent response, with the frequency of S-Ag specific cells being about 0.007%. Significant reactivity pattern shift was noted in patients with different disease courses. Conclusions - Certain active BD patients have S-Ag specific Th1 cells with a low frequency. The S-Ag epitope specificity between patients is highly heterogeneous, and varies with the uveitis cours

    Estimation of Canadian manure and fertilizer nitrogen application rates for crops at the soil polygon level using the CANB v2.0 model

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    Non-Peer ReviewedIn response to national environmental and climate change modeling projects such as agri-environmental indicators, greenhouse gases, carbon sequestration and policy scenarios, fertilizer N and manure nitrogen N application rates were estimated for individual crops at the Soil Landscapes of Canada (SLC) polygon scale (1:1 million). This database provides an estimate of the actual amount of N applied per crop and per hectare, based on provincial fertilization recommendations, manure production levels of each type of livestock and reported amounts of fertilizer sold. The database is being incorporated into ongoing programs related to Kyoto accounting of greenhouse gas emissions, environmental performance and policy formulation at Agriculture and Agri-Food Canada. A standardized Canadian Agricultural Nitrogen Budget (CANB v2.0) model was developed to calculate the agri-environmental indicators Residual Soil Nitrogen (RSN) and Indicator of Risk of Water Contamination by Nitrogen (IROWC-N). CANB is a national-level model that operates on 3500 SLC polygons using generalized soil, landscape, climate, and Census of Agriculture socioeconomic data. It is designed to provide a regional update on the soil N balance for each of the census years of 1981, 1986, 1991, 1996, 2001 and into the future. The database and model have the capability to calculate a number of different components of the nutrient balance, including the inputs of fertilizer N, manure N, biological N and atmospheric N and N the removals of N in the harvested proportion of the crop and via nitrogenous gas emissions. This paper describes the procedures to estimate fertilizer N and manure N inputs for each crop within each polygon. It includes: (i) the compilation of soil-specific N application rates from provincial extension guidelines, (ii) the calculation of total manure N production from animal numbers and excretion rates, (iii) the calculation of available manure N after storage and handling losses, and (iv) the recommended and adjusted nitrogen application rates. Adjustments were made to account for the amount of inorganic N in the manure applied to the various crops. The adjusted nitrogen rate data was also reconciled with the provincial fertilizer sales data

    Uptake and transformation of steroid estrogens as emerging contaminants influence plant development

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    Steroid estrogens are emerging contaminants of concern due to their devastating effects on reproduction and development in animals and humans at very low concentrations. The increasing steroid estrogen in the environment all over the world contrasts very few studies for potential impacts on plant development as a result of estrogen uptake. This study evaluated the uptake, transformation and effects of estradiol (17β-E2) and ethinyl estradiol (EE2) (0.1–1000 μg L−1) on lettuce. Uptake increased in leaves and roots in a dose-dependent manner, and roots were the major organ in which most of the estrogen was deposited. The transformation of estrogens to major metabolite and their further reverse biotransformation in lettuce tissue was identified. At low concentrations (0.1 and 50 μg L−1) estrogens resulted in enhanced photosynthetic pigments, root growth and shoot biomass. Application of higher concentrations of estrogens (10 mg L−1) significantly reduced total root growth and development. This was accompanied by increased levels of hydrogen peroxide (H2O2), and malondialdehyde (MDA), and activities of antioxidant enzymes superoxide dismutase (SOD), peroxidase (POD), catalase (CAT) and ascorbate peroxidase (APX). Taken together, these findings suggest that at low concentrations estrogens may biostimulate growth and primary metabolism of lettuce, while at elevated levels they have adverse effects

    Chiral Baryon Fields in the QCD Sum Rule

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    We study the structure of local baryon fields using the method of QCD sum rule. We only consider the single baryon fields and calculate their operator product expansions. We find that the octet baryon fields belonging to the chiral representations [(3,3*)+(3*,3)] and [(8,1)+(1,8)] and the decuplet baryon fields belonging to the chiral representations [(3,6)+(6,3)] lead to the baryon masses which are consistent with the experimental data of ground baryon masses. We also calculate their decay constants, check our normalizations for baryon fields in PRD81:054002(2010) and find that they are well-defined.Comment: 12 pages, 6 figure, 1 table, accepted by EPJ

    EGAM Induced by Energetic-electrons and Nonlinear Interactions among EGAM, BAEs and Tearing Modes in a Toroidal Plasma

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    In this letter, it is reported that the first experimental results are associated with the GAM induced by energetic electrons (eEGAM) in HL-2A Ohmic plasma. The energetic-electrons are generated by parallel electric fields during magnetic reconnection associated with tearing mode (TM). The eEGAM localizes in the core plasma, i.e. in the vicinity of q=2 surface, and is very different from one excited by the drift-wave turbulence in the edge plasma. The analysis indicated that the eEGAM is provided with the magnetic components, whose intensities depend on the poloidal angles, and its mode numbers are jm/nj=2/0. Further, there exist intense nonlinear interactions among eEGAM, BAEs and strong tearing modes (TMs). These new findings shed light on the underlying physics mechanism for the excitation of the low frequency (LF) Alfv\'enic and acoustic uctuations.Comment: 5 pages,4 figure
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