991 resultados para Local Interactions


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In America, there are two species of Trypanosoma that can infect humans: Trypanosoma cruzi, which is responsible for Chagas disease and Trypanosoma rangeli, which is not pathogenic. We have developed a model of vaccination in mice with T. rangeli epimastigotes that protects against T. cruzi infection. The goal of this work was to study the pattern of specific immunoglobulins in the peritoneum (the site of infection) and in the sera of mice immunized with T. rangeli before and after challenge with T. cruzi. Additionally, we studied the effects triggered by antigen-antibodies binding and the levels of key cytokines involved in the humoral response, such as IL-4, IL-5 and IL-6. The immunization triggered the production of antibodies reactive with T. cruzi in peritoneal fluid (PF) and in serum, mainly IgG1 and, to a lesser magnitude, IgG2. Only immunized mice developed specific IgG3 antibodies in their peritoneal cavities. Antibodies were able to bind to the surface of the parasites and agglutinate them. Among the cytokines studied, IL-6 was elevated in PF during early infection, with higher levels in non-immunized-infected mice. The results indicate that T. rangeli vaccination against T. cruzi infection triggers a high production of specific IgG isotypes in PF and sera before infection and modulates the levels of IL-6 in PF in the early periods of infection.

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La réflexion de ce chapitre explicite, à partir d'observations et d'entretiens conduits auprès des différentes salles de prière, associations ou communautés religieuses musulmanes du canton de Vaud, deux niveaux du paradoxe suivant: être invisibles pour éviter la stigmatisation sociale et être visibles pour se faire entendre et reconnaître à leur juste valeur. L'invisibilité concerne plus spécialement l'échelon local, l'impact et les interactions que peuvent avoir les associations avec leur environnement proche. La visibilité se caractérise par la volonté de l'UVAM de faire sortir les musulmans de l'ombre. Elle touche le niveau supra-local : les objectifs et stratégies communs que la grande majorité des groupes se sont choisis à travers une représentation cantonale fédérative. Le dispositif que l'UVAM met en place vise à poser concrètement la question de la gestion publique de l'islam sur le plan vaudois.

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Peroxisome proliferator-activated receptor (PPARs) are members of the nuclear receptor superfamily. For transcriptional activation of their target genes, PPARs heterodimerize with the retinoid-X receptor (RXR). The convergence of the PPAR and RXR signaling pathways has been shown to have an important function in lipid metabolism. The promoter of the gene encoding the acyl-coenzyme-A oxidase (ACO), the rate-limiting enzyme in peroxisomal beta-oxidation of fatty acids, is a target site of PPAR action. In this study, we examined the role and the contribution of both cis-and trans-acting factors in the transcriptional regulation of this gene using transient transfections in insect cells. We identified several functional cis-acting elements present in the promoter of the ACO gene and established that PPAR-dependent as well as PPAR-independent mechanisms can activate the ACO promoter in these cells. We show that the PPAR/RXR heterodimer exerts its effect through two response elements within the ACO promoter, in synergy with the transcription factor Sp1 via five Sp1-binding sites. Furthermore, this functional interaction also occurs when Sp1 is co-expressed with PPAR or RXR alone, indicating that activation can occur independently of PPAR/RXR heterodimers.

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Amoebae are unicellular protozoan present worldwide in several environments mainly feeding on bacteria. Some of them, the amoebae-resistant bacteria (ARBs), have evolved mechanisms to survive and replicate inside amoebal species. These mainly include legionella, mycobacteria and Chlamydia-related bacteria. Amoebae can provide a replicative niche, can act as reservoir for bacteria whereas the cystic form can protect the internalized bacteria. Moreover, the amoebae represent a Trojan horse for ARBs to infect animals. The long interaction between amoebae and bacteria has likely selected for bacterial virulence traits leading to the adaptation towards an intracellular lifestyle, and some ARBs have acquired the ability to infect mammals. This review intends to highlight the important uses of amoebae in several fields in microbiology by describing the main tools developed using amoebal cells. First, amoebae such as Acanthamoeba are used to isolate and discover new intracellular bacterial species by two main techniques: the amoebal co-culture and the amoebal enrichment. In the second part, taking Waddlia chondrophila as example, we summarize some important recent applications of amoebae to discover new bacterial virulence factors, in particular thanks to the amoebal plaque assay. Finally, the genetically tractable Dictyostelium discoideum is used as a model organism to study host-pathogen interactions, in particular with the development of several approaches to manipulate its genome that allowed the creation of a wide range of mutated strains largely shared within the Dictyostelium community.

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GTPases of the Rab1 subclass are essential for membrane traffic between the endoplasmic reticulum (ER) and Golgi complex in animals, fungi and plants. Rab1-related proteins in higher plants are unusual because sequence comparisons divide them into two putative subclasses, Rab-D1 and Rab-D2, that are conserved in monocots and dicots. We tested the hypothesis that the Rab-D1 and Rab-D2 proteins of Arabidopsis represent functionally distinct groups. RAB-D1 and RAB-D2a each targeted fluorescent proteins to the same punctate structures associated with the Golgi stacks and trans-Golgi-network. Dominant-inhibitory N121I mutants of each protein inhibited traffic of diverse cargo proteins at the ER but they appeared to act via distinct biochemical pathways as biosynthetic traffic in cells expressing either of the N121I mutants could be restored by coexpressing the wild-type form of the same subclass but not the other subclass. The same interaction was observed in transgenic seedlings expressing RAB-D1 [N121I]. Insertional mutants confirmed that the three Arabidopsis Rab-D2 genes were extensively redundant and collectively performed an essential function that could not be provided by RAB-D1, which was non-essential. However, plants lacking RAB-D1, RAB-D2b and RAB-D2c were short and bushy with low fertility, indicating that the Rab-D1 and Rab-D2 subclasses have overlapping functions.

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Màster tesi què pretén determinar quins atributs han de ser considerats per a mesurar la qualitat del servei en establiments rurals amb autenticitat local. Proposa un nou instrument de medició, que l’autor ha anomenat RURALSERV. Se segueix el model SERVQUAL, però amb un format de mesura basat exclusivament en la percepció del visitant

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Projecte de construcció d'un edifici social per a activitats socials, de relació, culturals i esbarjo al municipi de Vilaür (Alt Empordà)

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Certain receptors on natural killer (NK) cells, which are specific for MHC class I (MHC-I) molecules, do not only interact with ligand expressed on opposing cell membranes (in trans) but also interact with those on the same cell membrane (in cis). Cis interactions have been demonstrated for only a small number of cell surface receptors. However, this has not been tested systematically, raising the possibility that additional receptors may be able to bind ligand expressed in cis. Here we describe a number of approaches to evaluate trans and cis binding of the Ly49A NK cell receptor to its H-2D(d) ligand. These procedures should facilitate the investigation of cis/trans interactions of other receptor-ligand pairs and simplify the analysis of NK cell receptor variants.

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Risk factor surveillance is a complementary tool of morbidity and mortality surveillance that improves the likelihood that public health interventions are implemented in a timely fashion. The aim of this study was to identify population predictors of malaria outbreaks in endemic municipalities of Colombia with the goal of developing an early warning system for malaria outbreaks. We conducted a multiple-group, exploratory, ecological study at the municipal level. Each of the 290 municipalities with endemic malaria that we studied was classified according to the presence or absence of outbreaks. The measurement of variables was based on historic registries and logistic regression was performed to analyse the data. Altitude above sea level [odds ratio (OR) 3.65, 95% confidence interval (CI) 1.34-9.98], variability in rainfall (OR 1.85, 95% CI 1.40-2.44) and the proportion of inhabitants over 45 years of age (OR 0.17, 95% CI 0.08-0.38) were factors associated with malaria outbreaks in Colombian municipalities. The results suggest that environmental and demographic factors could have a significant ability to predict malaria outbreaks on the municipal level in Colombia. To advance the development of an early warning system, it will be necessary to adjust and standardise the collection of required data and to evaluate the accuracy of the forecast models.

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Degut a la gran demanda tecnològica, actualment hi ha un gran interès en desenvolupar medis magnètics amb entitats ferromagnètiques de dimensions nanomètriques. Aquesta demanda promou la investigació i el desenvolupament de nous materials i processos de fabricació que permetin controlar d’una manera més precisa les propietats magnètiques i estructurals. Entre els mètodes de litografia convencionals (per exemple deposició física a través de màscares, deposició química en fase vapor i electrodeposició), recentment s’ha demostrat que la irradiació amb ions a través de màscares pre‐litografiades, sembla ser un bon mètode per a la fabricació d’estructures ferromagnètiques de l’ordre dels nanòmetres. Aquesta tècnica pot ser aplicada per aprofitar la transició paramagnètica‐ferromagnètica que presenten alguns materials al ser desordenats estructuralment (per exemple FeAl, FePt3, Ni3Sn2). En el treball que es presenta a continuació s’utilitza l’aliatge Fe60Al40 per a fabricar estructures ferromagnètiques embegudes en una matriu paramagnètica mitjançant irradiació amb ions d’argó a través d’una membrana de polimetil metacrilat (PMMA) prèviament litografiada amb feixos d’electrons (EBL). La fabricació d’aquest sistema té com a objectiu d’estudiar l’evolució de la morfologia i el gruix de PMMA (a partir de SEM i AFM) i del comportament magnètic de les estructures fabricades (MFM i MOKE), quan és irradiat consecutivament a diferents energies. Per a completar l’estudi s’han utilitzat simulacions per a determinar les condicions d’irradiació (TRIM), com per a una millor comprensió dels resultats (simulacions micromagnètiques). El contingut de la memòria inclou una breu introducció històrica i conceptual sobre el magnetisme. A continuació s’exposen les tècniques necessàries per a la fabricació, preparació i caracterització de la mostra. Finalment es presenta una discussió dels resultats obtinguts i les conclusions.

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Boletín semanal para profesionales sanitarios de la Secretaría General de Salud Pública, Inclusión y Calidad de Vida de la Consejería de Salud y Bienestar Social

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Boletín semanal para profesionales sanitarios de la Secretaría General de Salud Pública y Participación Social de la Consejería de Salud

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Resumen del encuentro de expertos europeos sobre la evalución de la implatación de la evalución de impacto en salud. Jornada celebrada en Sevilla en febrero de 2008

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Boletín semanal para profesionales sanitarios de la Secretaría General de Salud Pública y Participación Social de la Consejería de Salud