1,304 research outputs found

    Interferon-γ induces immunoproteasomes and the presentation of MHC I-associated peptides on human salivary gland cells.

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    A prominent histopathological feature of Sjögren's syndrome, an autoimmune disease, is the presence of lymphocytic infiltrates in the salivary and lachrymal glands. Such infiltrates are comprised of activated lymphocytes and macrophages, and known to produce multiple cytokines including interferon-gamma (IFN-γ). In this study, we have demonstrated that IFN-γ strongly induces the expression of immunoproteasome beta subunits (β1i, β2i and β5i) and immunoproteasome activity but conversely inhibits the expression of proteasome beta subunits (β1, β2 and β5) in human salivary gland (HSG) cells. Mass spectrometric analysis has revealed potential MHC I-associated peptides on the HSG cells, including a tryptic peptide derived from salivary amylase, due to IFN-γ stimulation. These results suggest that IFN-γ induces immunoproteasomes in HSG cells, leading to enhanced presentation of MHC I-associated peptides on cell surface. These peptide-presenting salivary gland cells may be recognized and targeted by auto-reactive T lymphocytes. We have also found that lactacystin, a proteasome inhibitor, inhibits the expression of β1 subunit in HSG cells and blocks the IFN-γ-induced expression of β1i and immunoproteasome activity. However, the expression of β2i and β5i in HSG cells is not affected by lactacystin. These results may add new insight into the mechanism regarding how lactacystin blocks the action of proteasomes or immunoproteasomes

    Use and improvement of microbial redox enzymes for environmental purposes

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    Industrial development may result in the increase of environmental risks. The enzymatic transformation of polluting compounds to less toxic or even innocuous products is an alternative to their complete removal. In this regard, a number of different redox enzymes are able to transform a wide variety of toxic pollutants, such as polynuclear aromatic hydrocarbons, phenols, azo dyes, heavy metals, etc. Here, novel information on chromate reductases, enzymes that carry out the reduction of highly toxic Cr(VI) to the less toxic insoluble Cr(III), is discussed. In addition, the properties and application of bacterial and eukaryotic proteins (lignin-modifying enzymes, peroxidases and cytochromes) useful in environmental enzymology is also discussed

    Diez para Dios. El diezmo y su arrendamiento en el Valle de Toluca, 1650 1700

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    Durante el periodo novohispano, el arrendamiento y la cobranza del diezmo eclesiástico estuvieron ligados íntimamente a la actividad productiva de la tierra, sobre todo a la agricultura y ganadería. El Valle de Toluca fue un bastión importante en el arrendamiento del diezmo, de acuerdo con los protocolos de la Notaría N° 1 de Toluca. En la transacción económica Iglesiaparticulares podemos encontrar hacendados de renombre y/o personas que se prestaban como fiadores para la actividad que redituó ganancias a la Iglesia católica. Para la argumentación de este artículo se consultaron fuentes primarias de archivo, siendo el principal el Archivo General de Notarías del Estado de México, en su sección histórica.Durante el periodo novohispano, el arrendamiento y la cobranza del diezmo eclesiástico estuvieron ligados íntimamente a la actividad productiva de la tierra, sobre todo a la agricultura y ganadería. El Valle de Toluca fue un bastión importante en el arrendamiento del diezmo, de acuerdo con los protocolos de la Notaría N° 1 de Toluca. En la transacción económica Iglesiaparticulares podemos encontrar hacendados de renombre y/o personas que se prestaban como fiadores para la actividad que redituó ganancias a la Iglesia católica. Para la argumentación de este artículo se consultaron fuentes primarias de archivo, siendo el principal el Archivo General de Notarías del Estado de México, en su sección histórica

    Evolving wormhole geometries within nonlinear electrodynamics

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    In this work, we explore the possibility of evolving (2+1) and (3+1)-dimensional wormhole spacetimes, conformally related to the respective static geometries, within the context of nonlinear electrodynamics. For the (3+1)-dimensional spacetime, it is found that the Einstein field equation imposes a contracting wormhole solution and the obedience of the weak energy condition. Nevertheless, in the presence of an electric field, the latter presents a singularity at the throat, however, for a pure magnetic field the solution is regular. For the (2+1)-dimensional case, it is also found that the physical fields are singular at the throat. Thus, taking into account the principle of finiteness, which states that a satisfactory theory should avoid physical quantities becoming infinite, one may rule out evolving (3+1)-dimensional wormhole solutions, in the presence of an electric field, and the (2+1)-dimensional case coupled to nonlinear electrodynamics.Comment: 17 pages, 1 figure; to appear in Classical and Quantum Gravity. V2: minor corrections, including a referenc

    EVALUATION OF TOTAL POLYPHENOLS AND ANTIOXIDANT CAPACITY IN MUSHROOM EXTRACTS PLEUROTUS OSTREATUS AND LENTINULA EDODES

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    Objective: This research was aimed at assessing the concentration of total polyphenols in ethanolic and methanolic extracts of Pleurotus ostreatus and Lentinula edodes mushrooms and antioxidant activity. Methods: Polyphenols were determined by the Folin Ciocalteu method, using lyophilized mushroom samples for the preparation of extracts and antioxidant activity by the TBARS method. Results: Extracts prepared from mushrooms showed appreciable values ​​of polyphenols, and for the ethanolic extract of Pleurotus ostreatus and Lentinula edodes values ​​of 102.78 and 81.83 mg of gallic acid/100 g of the sample respectively, comparable to those obtained in some fruits For methanolic extracts, values ​​of 100.45 and 78.92 mg of gallic acid/100 g of sample were obtained. Polyphenol concentration values ​​for the Pleurotus were higher in the two types of extracts and lower for the Lentinula edodes. Conclusion: When evaluating the antioxidant activity, high antioxidant activity was found for the two types of mushroom, Pleurotus ostreatus and Lentinula edodes, presenting peroxidase inhibition values ​​of 88.04 and 89.49% respectively
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