12 resultados para Benthocosm E2

em Consorci de Serveis Universitaris de Catalunya (CSUC), Spain


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En aquesta subtasca es pretén crear eines d'accessibilitat estudiant els productes existents, la seva adaptabilitat i possibilitat de transformació per a crear un nou producte d'accessibilitat universal. Es tracta d'una investigació sobre l'adaptació integració en el mitjà físic i desenvolupament de determinats dispositius destinats a salvar les barreres en els punts d'enllaç entre les diferents escales del Patrimoni que permeti resoldre la cadena de l'accessibilitat al Patrimoni Cultural.

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L'objecte de l'estudi és realitzar una anàlisi de les solucions de millora electroacústica existents comercialment i en desenvolupament la utilització del qual pot estar especialment indicada per a edificis i recintes la utilització dels quals fa que sigui necessària l'actuació sobre l'acústica dels mateixos, però les seves característiques històriques i patrimonials fan que sigui impossible aplicar mètodes d'acondicionament acústic mecànics que implicarien el tractament o modificació de la geometria dels recintes i/o el tractament dels materials que recobrixen les superfícies dels mateixos

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La vulnerabilitat dels vells edificis històrics de maçoneria, a causa del dany desproporcionat fora del plànol de càrrega (causat pel vent, explosions, inundacions o moviments sísmics és un dels greus problemes que enfronten avui dia els enginyers estructurals En l'actualitat s'han desenvolupat diverses tècniques innovadores de rehabilitació d'edificis històrics. L'eficàcia de moltes d'elles ha estat provada tant en laboratoris o sota condicions de càrrega real, tals com moviments sísmics. La qualitat i tipus dels materials de maçoneria i el disseny estructural són criteris fonamentals en l'elecció del mètode de reforç. En aques document es presenten les tècniques més utilitzades en la rehabilitació tradicional i les tècniques modernes i innovadores de rehabilitació utilitzant composites avançats

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BACKGROUND Animal model studies have shown that the colon tumour promoting effect of dietary fat depends not only on the amount but on its fatty acid composition. With respect to this, the effect of n9 fatty acids, present in olive oil, on colon carcinogenesis has been scarcely investigated. AIMS To assess the effect of an n9 fat diet on precancer events, carcinoma development, and changes in mucosal fatty acid composition and prostaglandin (PG)E2 formation in male Sprague-Dawley rats with azoxymethane induced colon cancer. METHODS Rats were divided into three groups to receive isocaloric diets (5% of the energy as fat) rich in n9, n3, or n6 fat, and were administered azoxymethane subcutaneously once a week for 11 weeks at a dose rate of 7.4 mg/kg body weight. Vehicle treated groups received an equal volume of normal saline. Groups of animals were colectomised at weeks 12 and 19 after the first dose of azoxymethane or saline. Mucosal fatty acids were assessed at 12 and 19 weeks. Aberrant crypt foci and the in vivo intracolonic release of PGE2 were assessed at week 12, and tumour formation at week 19. RESULTS Rats on the n6 diet were found to have colonic aberrant crypt foci and adenocarcinomas more often than those consuming either the n9 or n3 diet. There were no differences between the rats on the n9 and n3 diets. On the other hand, administration of both n9 and n3 diets was associated with a decrease in mucosal arachidonate concentrations as compared with the n6 diet. Carcinogen treatment induced an appreciable increase in PGE2 formation in rats fed the n6 diet, but not in those fed the n3 and n9 diets. CONCLUSIONS Dietary olive oil prevented the development of aberrant crypt foci and colon carcinomas in rats, suggesting that olive oil may have chemopreventive activity against colon carcinogenesis. These effects may be partly due to modulation of arachidonic acid metabolism and local PGE2synthesis.

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Background: Mast cells play a critical role in allergic and inflammatory diseases, including exercise-induced bronchoconstriction (EIB) in asthma. The mechanism underlying EIB is probably related to increased airway fluid osmolarity that activates mast cells to the release inflammatory mediators. These mediators then act on bronchial smooth muscle tocause bronchoconstriction. In parallel, protective substances such as prostaglandin E2 (PGE2) are probably also released and could explain the refractory period observed in patients with EIB. Objective: This study aimed to evaluate the protective effect of PGE2 on osmotically activated mast cells, as a model of exercise-induced bronchoconstriction. Methods: We used LAD2, HMC-1, CD34-positive, and human lung mast cell lines. Cells underwent a mannitol challenge, and the effects of PGE2 and prostanoid receptor (EP) antagonists for EP14 were assayed on the activated mast cells. Betahexosaminidase release, protein phosphorylation, and calcium mobilization were assessed. Results: Mannitol both induced mast cell degranulation and activated phosphatidyl inositide 3-kinase and mitogenactivated protein kinase (MAPK) pathways, thereby causing de novo eicosanoid and cytokine synthesis. The addition of PGE2 significantly reduced mannitol-induced degranulation through EP2 and EP4 receptors, as measured by betahexosaminidase release, and consequently calcium influx. Extracellular-signal-regulated kinase 1/2, c-Jun N-terminal kinase,and p38 phosphorylation were diminished when compared with mannitol activation alone. Conclusions: Our data show a protective role for the PGE2 receptors EP2 and EP4 following osmotic changes, through the reduction of human mast cell activity caused by calcium influx impairment and MAP kinase inhibition.

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El GB virus C (GBV-C) o virus de l'hepatitis G (HGV) es un virus format per una única cadena de RNA que pertany a la familia Flaviviridae. En els últims anys, s'han publicat nombrosos treballs en els quals s'associa la coinfecció del GBV-C i del virus de la immunodeficiència humana (VIH) amb una menor progressió de l'esmentada malaltia així com amb una major supervivència dels pacients una vegada que la SIDA s'ha desenvolupat. El mecanisme pel qual el virus GBV-C/HGV exerceix un “efecte protector” en els pacients amb VIH encara no està descrit. L’estudi de la interacció entre els virus GBVC/HGV i VIH podria donar lloc al desenvolupament de nous agents terapèutics per al tractament de la SIDA.Treballs recents mostren com la capacitat inhibitòria del virus del GBV-C/HGV és deguda a la seva glicoproteina estructural E2. S’ha vist que aquesta proteina seria capaç d’inhibir la primera fase de replicació de VIH, així com la unió i la fusió amb les membranes cel•lulars. Sobre la base d’aquests estudis, l’objectiu d’aquest treball ha estat seleccionar inhibidors del pèptid de fusió del VIH utilitzant pèptids sintètics de la proteina E2 del GBV-C/HGV. El treball realitzat ha consistit en estudiar, utilitzant assajos biofísics de leakage i de lipid mixing, la capacitat dels pèptids de la proteina estructural del virus del GBV-C/HGV per inhibir la interacció i el procés de desestabilització de membranes induïdes pel pèptid de fusió de la glicoproteina de l’embolcall, GP41, del VIH. Aquests assajos, com es descriu en treballs anteriors, han resultat útils per a la selecció i la identificació de compostos amb activitat específica anti-GP41. Es pot afirmar que efectivament els pèptids seleccionats de la proteina E2 del virus del GBV-C/HGV inhibeixen l’activitat del pèptid de fusió del VIH probablement com a consequència d’un canvi conformacional en aquest darrer.

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Comparison of donor-acceptor electronic couplings calculated within two-state and three-state models suggests that the two-state treatment can provide unreliable estimates of Vda because of neglecting the multistate effects. We show that in most cases accurate values of the electronic coupling in a π stack, where donor and acceptor are separated by a bridging unit, can be obtained as Ṽ da = (E2 - E1) μ12 Rda + (2 E3 - E1 - E2) 2 μ13 μ23 Rda2, where E1, E2, and E3 are adiabatic energies of the ground, charge-transfer, and bridge states, respectively, μij is the transition dipole moments between the states i and j, and Rda is the distance between the planes of donor and acceptor. In this expression based on the generalized Mulliken-Hush approach, the first term corresponds to the coupling derived within a two-state model, whereas the second term is the superexchange correction accounting for the bridge effect. The formula is extended to bridges consisting of several subunits. The influence of the donor-acceptor energy mismatch on the excess charge distribution, adiabatic dipole and transition moments, and electronic couplings is examined. A diagnostic is developed to determine whether the two-state approach can be applied. Based on numerical results, we showed that the superexchange correction considerably improves estimates of the donor-acceptor coupling derived within a two-state approach. In most cases when the two-state scheme fails, the formula gives reliable results which are in good agreement (within 5%) with the data of the three-state generalized Mulliken-Hush model

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UEV proteins are enzymatically inactive variants of the E2 ubiquitin-conjugating enzymes that regulate noncanonical elongation of ubiquitin chains. In Saccharomyces cerevisiae, UEV is part of the RAD6-mediated error-free DNA repair pathway. In mammalian cells, UEV proteins can modulate c-FOS transcription and the G2-M transition of the cell cycle. Here we show that the UEV genes from phylogenetically distant organisms present a remarkable conservation in their exon–intron structure. We also show that the human UEV1 gene is fused with the previously unknown gene Kua. In Caenorhabditis elegans and Drosophila melanogaster, Kua and UEV are in separated loci, and are expressed as independent transcripts and proteins. In humans, Kua and UEV1 are adjacent genes, expressed either as separate transcripts encoding independent Kua and UEV1 proteins, or as a hybrid Kua–UEV transcript, encoding a two-domain protein. Kua proteins represent a novel class of conserved proteins with juxtamembrane histidine-rich motifs. Experiments with epitope-tagged proteins show that UEV1A is a nuclear protein, whereas both Kua and Kua–UEV localize to cytoplasmic structures, indicating that the Kua domain determines the cytoplasmic localization of Kua–UEV. Therefore, the addition of a Kua domain to UEV in the fused Kua–UEV protein confers new biological properties to this regulator of variant polyubiquitination.[Kua cDNAs isolated by RT-PCR and described in this paper have been deposited in the GenBank data library under accession nos. AF1155120 (H. sapiens) and AF152361 (D. melanogaster). Genomic clones containing UEV genes: S. cerevisiae, YGL087c (accession no. Z72609); S. pombe, c338 (accession no. AL023781); P. falciparum, MAL3P2 (accession no. AL034558); A. thaliana, F26F24 (accession no. AC005292); C. elegans, F39B2 (accession no. Z92834); D. melanogaster, AC014908; and H. sapiens, 1185N5 (accession no. AL034423). Accession numbers for Kua cDNAs in GenBank dbEST: M. musculus, AA7853; T. cruzi, AI612534. Other Kua-containing sequences: A. thaliana genomic clones F10M23 (accession no. AL035440), F19K23 (accession no. AC000375), and T20K9 (accession no. AC004786).

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Mastoparan, a basic tetradecapeptide isolated from wasp venom, is a novel mitogen for Swiss 3T3 cells. This peptide induced DNA synthesis in synergy with insulin in a concentration-dependent manner; half-maximum and maximum responses were achieved at 14 and 17 microM, respectively. Mastoparan also stimulated DNA synthesis in the presence of other growth promoting factors including bombesin, insulin-like growth factor-1, and platelet-derived growth factor. The synergistic mitogenic stimulation by mastoparan can be dissociated from activation of phospholipase C. Mastoparan did not stimulate phosphoinositide breakdown, Ca2+ mobilization or protein kinase C-mediated phosphorylation of a major cellular substrate or transmodulation of the epidermal growth factor receptor. In contrast, mastoparan stimulated arachidonic acid release, prostaglandin E2 production, and enhanced cAMP accumulation in the presence of forskolin. These responses were inhibited by prior treatment with pertussis toxin. Hence, mastoparan stimulates arachidonic acid release via a pertussis toxin-sensitive G protein in Swiss 3T3 cells. Arachidonic acid, like mastoparan, stimulated DNA synthesis in the presence of insulin. The ability of mastoparan to stimulate mitogenesis was reduced by pertussis toxin treatment. These results demonstrate, for the first time, that mastoparan stimulates reinitiation of DNA synthesis in Swiss 3T3 cells and indicate that this peptide may be a useful probe to elucidate signal transduction mechanisms in mitogenesis.

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En este trabajo se expone y se sintetiza la teoría del rasgo de personalidad denominado "búsqueda de sensaciones", se proporciona información cronológica de la investigación empírica realizada desde los años 60 hasta nuestros días. Se incide en los correlatos biológicos de este rasgo en particular Potenciales Evocados (PE), Monoaminoxidades Plaquetear (MAO), Reflejo Orienativo (RO) y hormonas sexuales como la Testosterona (T) y Estradiol (E2). Se sugiere que se avance en la investigación psicobiológica del rasgo en cuestión, esfuerzo que por otro lado está generando un importante soporte empírico a la teoría.

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It has been previously described that p21 functions not only as a CDK inhibitor but also as a transcriptional co-repressor in some systems. To investigate the roles of p21 in transcriptional control, we studied the gene expression changes in two human cell systems. Using a human leukemia cell line (K562) with inducible p21 expression and human primary keratinocytes with adenoviral-mediated p21 expression, we carried out microarray-based gene expression profiling. We found that p21 rapidly and strongly repressed the mRNA levels of a number of genes involved in cell cycle and mitosis. One of the most strongly down-regulated genes was CCNE2 (cyclin E2 gene). Mutational analysis in K562 cells showed that the N-terminal region of p21 is required for repression of gene expression of CCNE2 and other genes. Chromatin immunoprecipitation assays indicated that p21 was bound to human CCNE2 and other p21-repressed genes gene in the vicinity of the transcription start site. Moreover, p21 repressed human CCNE2 promoter-luciferase constructs in K562 cells. Bioinformatic analysis revealed that the CDE motif is present in most of the promoters of the p21-regulated genes. Altogether, the results suggest that p21 exerts a repressive effect on a relevant number of genes controlling S phase and mitosis. Thus, p21 activity as inhibitor of cell cycle progression would be mediated not only by the inhibition of CDKs but also by the transcriptional down-regulation of key genes.