577 research outputs found

    Toxic effects of four sulphonylureas herbicides on soil microbial biomass

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    The effect of four triazinyl-sulfonylurea herbicides (cinosulfuron, prosulfuron, thifensulfuron methyl, triasulfuron) on soil microbial biomass, soil respiration, metabolic activity, metabolic quotient, and some enzymatic activities (acid and alkaline phosphatase, β-glucosidase, arylsulphatase, and fluorescein diacetate hydrolysis) were monitored under controlled conditions over 30 days. The herbicides were applied at the normal field dose (FD) and at ten-fold (10 FD) the field dose, in order to mimic a long term toxic effect. The measured soil microbial parameters showed that the FD had slight effects on soil microflora, while at 10 FD the tested herbicides exerted a stronger detrimental effect on soil microbial biomass and its biochemical activities

    Cytosolic 5'-Nucleotidase II Interacts with the Leucin Rich Repeat of NLR Family Member Ipaf

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    IMP/GMP preferring cytosolic 5'-nucleotidase II (cN-II) is a bifunctional enzyme whose activities and expression play crucial roles in nucleotide pool maintenance, nucleotide-dependent pathways and programmed cell death. Alignment of primary amino acid sequences of cN-II from human and other organisms show a strong conservation throughout the entire vertebrata taxon suggesting a fundamental role in eukaryotic cells. With the aim to investigate the potential role of this homology in protein-protein interactions, a two hybrid system screening of cN-II interactors was performed in S. cerevisiae. Among the X positive hits, the Leucin Rich Repeat (LRR) domain of Ipaf was found to interact with cN-II. Recombinant Ipaf isoform B (lacking the Nucleotide Binding Domain) was used in an in vitro affinity chromatography assay confirming the interaction obtained in the screening. Moreover, co-immunoprecipitation with proteins from wild type Human Embryonic Kidney 293 T cells demonstrated that endogenous cN-II co-immunoprecipitated both with wild type Ipaf and its LRR domain after transfection with corresponding expression vectors, but not with Ipaf lacking the LRR domain. These results suggest that the interaction takes place through the LRR domain of Ipaf. In addition, a proximity ligation assay was performed in A549 lung carcinoma cells and in MDA-MB-231 breast cancer cells and showed a positive cytosolic signal, confirming that this interaction occurs in human cells. This is the first report of a protein-protein interaction involving cN-II, suggesting either novel functions or an additional level of regulation of this complex enzym

    Un modèle d'endommagement pour des plaques en béton armé sous séisme

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    Afin d'effectuer des calculs sismiques sur des bâtiments industriels, nous proposons un modèle macroscopique d'endommagement pour le béton armé dédié à des éléments plaques, formulé dans le cadre standard généralisé. Les armatures assurant une pente post-élastique toujours positive, on évite les problèmes de localisation dus au comportement adoucissant du béton. L'utilisation d'éléments de structure permet d'autre part de gagner en temps de calcul. On présente des comparaisons avec des expérimentations

    Aplicacion del silicato tricalcico como una alternativa biocompatible.

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    El seleccionar un adecuado material para la obturación apical es un acto fundamental para la resolución de un caso con una lesión periapical persistente; los principales factores que deberá tener este material es su biocompatibilidad y el crear un sellado hermético para evitar filtración; deberá poseer capacidad para inducir osteogénesis y reparación, no desarrollar toxicidad, ser radiopaco y bacteriostático. El Biodentine es un material recientemente introducido al mercado (2011), principalmente compuesto de silicato tricálcico. Es usado para tratamientos de reparación en corona y raíz, reparando perforaciones, resorciones, empleado para apexificaciones y como material de retroobturación; también puede ser utilizado como un sustituto de dentina en caries demasiado extensas.

    Tubulin binding cofactor C (TBCC) suppresses tumor growth and enhances chemosensitivity in human breast cancer cells

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    <p>Abstract</p> <p>Background</p> <p>Microtubules are considered major therapeutic targets in patients with breast cancer. In spite of their essential role in biological functions including cell motility, cell division and intracellular transport, microtubules have not yet been considered as critical actors influencing tumor cell aggressivity. To evaluate the impact of microtubule mass and dynamics on the phenotype and sensitivity of breast cancer cells, we have targeted tubulin binding cofactor C (TBCC), a crucial protein for the proper folding of α and β tubulins into polymerization-competent tubulin heterodimers.</p> <p>Methods</p> <p>We developed variants of human breast cancer cells with increased content of TBCC. Analysis of proliferation, cell cycle distribution and mitotic durations were assayed to investigate the influence of TBCC on the cell phenotype. <it>In vivo </it>growth of tumors was monitored in mice xenografted with breast cancer cells. The microtubule dynamics and the different fractions of tubulins were studied by time-lapse microscopy and lysate fractionation, respectively. <it>In vitro </it>sensitivity to antimicrotubule agents was studied by flow cytometry. <it>In vivo </it>chemosensitivity was assayed by treatment of mice implanted with tumor cells.</p> <p>Results</p> <p>TBCC overexpression influenced tubulin fraction distribution, with higher content of nonpolymerizable tubulins and lower content of polymerizable dimers and microtubules. Microtubule dynamicity was reduced in cells overexpressing TBCC. Cell cycle distribution was altered in cells containing larger amounts of TBCC with higher percentage of cells in G2-M phase and lower percentage in S-phase, along with slower passage into mitosis. While increased content of TBCC had little effect on cell proliferation <it>in vitro</it>, we observed a significant delay in tumor growth with respect to controls when TBCC overexpressing cells were implanted as xenografts <it>in vivo</it>. TBCC overexpressing variants displayed enhanced sensitivity to antimicrotubule agents both <it>in vitro </it>and in xenografts.</p> <p>Conclusion</p> <p>These results underline the essential role of fine tuned regulation of tubulin content in tumor cells and the major impact of dysregulation of tubulin dimer content on tumor cell phenotype and response to chemotherapy. A better understanding of how the microtubule cytoskeleton is dysregulated in cancer cells would greatly contribute to a better understanding of tumor cell biology and characterisation of resistant phenotypes.</p

    Polymorphisms in xenobiotic transporters ABCB1, ABCG2, ABCC2, ABCC1, ABCC3 and multiple myeloma risk : a case--control study in the context of the International Q1 Multiple Myeloma rESEarch consortium

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    Multiple myeloma (MM) is a hematological neoplasm that arises from a single clone of malignant plasma cells in the bone marrow. In Europe, 4.6/100 000 males and 3.2/100 000 females every year develop MM, with a median age at diagnosis around 60 years.Polish Ministry of Science and Higher Education (Lodz, Poland) - NN40217833Fondo de Investigaciones Sanitarias (Madrid, Spain) - PI081051Consejería de Salud de la Junta de Andalucia (Sevilla, Spain) - P08-CVI-411

    Efficient ortho-formylation in vitamin E series, application to the semi-synthesis of natural 5- and 7-formyl-δ-tocotrienols revealing an unprecedented 5-bromo-7-formyl exchange

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    Semi-synthesis of 5- and 7-formyltocopherols and tocotrienols has been developed by ortho-formylation of C-5 or C-7-unsubstituted vitamin E derivatives (14 examples) up to 90% yield, through heating in the presence of respectively 10-10-15 equivalents of MgCl2-Et3N-(CH2O)n. Formylation of 5-bromo-δ-tocotrienol revealed an unprecedented 5-bromo/7-formyl exchange and yielded 7-bromo-5-formyl-δ-tocotrienol as major product. The minor 5-bromo-7-formyl-δ-tocotrienol led in three steps to 7-formyl-δ-tocotrienol previously isolated from the stem bark of Garcinia virgata
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