996 resultados para PREDOMINANT
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Perinatal adverse events such as limitation of nutrients or oxygen supply are associated with the occurrence of diseases in adulthood, like cardiovascular diseases and diabetes. We investigated the long-term effects of perinatal hypoxia on the lung circulation, with particular attention to the nitric oxide (NO)/cGMP pathway. Mice were placed under hypoxia in utero 5 days before delivery and for 5 days after birth. Pups were then bred in normoxia until adulthood. Adults born in hypoxia displayed an altered regulation of pulmonary vascular tone with higher right ventricular pressure in normoxia and increased sensitivity to acute hypoxia compared with controls. Perinatal hypoxia dramatically decreased endothelium-dependent relaxation induced by ACh in adult pulmonary arteries (PAs) but did not influence NO-mediated endothelium-independent relaxation. The M(3) muscarinic receptor was implicated in the relaxing action of ACh and M(1) muscarinic receptor (M(1)AChR) in its vasoconstrictive effects. Pirenzepine or telenzepine, two preferential inhibitors of M(1)AChR, abolished the adverse effects of perinatal hypoxia on ACh-induced relaxation. M(1)AChR mRNA expression was increased in lungs and PAs of mice born in hypoxia. The phosphodiesterase 1 (PDE1) inhibitor vinpocetine also reversed the decrease in ACh-induced relaxation following perinatal hypoxia, suggesting that M(1)AChR-mediated alteration of ACh-induced relaxation is due to the activation of calcium-dependent PDE1. Therefore, perinatal hypoxia leads to an altered pulmonary circulation in adulthood with vascular dysfunction characterized by impaired endothelium-dependent relaxation and M(1)AChR plays a predominant role. This raises the possibility that muscarinic receptors could be key determinants in pulmonary vascular diseases in relation to "perinatal imprinting."
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El procés de convergència cap a l'Espai Europeu d' Educació Superior ha fet que les universitats s'hagin plantejat el repte de millorar la docència. Que amb l'EEES es vulgui fomentar un nou model d'ensenyança, ha suscitat opinions divergents, però hagués estat irresponsable no aprofitar el procés de canvi per anar al fons del tema docent. En el context actual, cercar com millorar els processos d'aprenentatge dels i de les estudiants suposa la necessitat de reflexionar col·lectivament sobre què i sobre com s'ha d'ensenyar a la universitat. Per tal d'afavorir un canvi de model que dugui a focalitzar la mirada en el procés d'aprenentatge de l'estudiant, cal debatre sobre els dilemes que sorgeixen quan els requeriments del nou model xoquen amb la cultura tradicionalment predominant entre el professorat universitari. En l'article es comenten alguns d'aquests dilemes.
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The existence of at least three isoforms of Na(+)-K(+)-ATPase in adult brain tissues [alpha 1, kidney type; alpha 2 [or alpha(+)]; alpha 3] suggests that these genes might be regulated in a cell-specific and time-dependent manner during development. We have studied this question in serum-free aggregating cell cultures of mechanically dissociated rat fetal telencephalon. At the protein level, the relative rate of synthesis of the pool of alpha 1-, alpha 2-, and alpha 3-subunits increased approximately twofold over 15 days of culture, leading to a marked increase in the immunochemical pool of alpha-subunits as measured by a panspecific polyclonal antibody. Concomitantly, Na(+)-K(+)-ATPase enzyme-specific activity increased three- (lower forebrain) to sixfold (upper forebrain). The transcripts of all three alpha-isoforms and beta-subunit were detected in vitro in similar proportion to the level observed in vivo. alpha 3-mRNA (3.7 kb) was more abundant than alpha 1 (3.7 kb) or alpha 2 (5.3 and 3.4 kb). Cytosine arabinoside (0.4 microM) and cholera toxin (0.1 microM) were used to selectively eliminate glial cells or neurons, respectively. It was found that alpha 2-mRNA is predominantly transcribed in glial cell cultures, whereas alpha 3- and beta 1-mRNA (2.7, 2.3, and 1.8 kb) are predominant in neuronal cultures.
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We previously showed that exposure of 3D organotypic rat brain cell cultures to 1mM 2-methylcitrate (2-MCA) or 3-hydroxyglutarate (3- OHGA) every 12h over three days (DIV11-DIV14) results in ammonium accumulation and cell death. The aim of this study was to define the time course (every 24h) of the observed effects. Ammonium in culture medium already increased at DIV12 staying stable on the following days under 3-OHGA exposure, while it increased consecutively up to much higher levels under 2-MCA exposure. Lactate increase and glucose decrease were observed from DIV13 and DIV14, respectively. We conclude that ammonium accumulation precedes alterations of energy metabolism. As observed by immunohistochemistry glial cells were the predominant dying cells. Immunoblotting and immunohistochemistry with cell death specific markers (caspase-3, alpha-fodrin, LC3) showed that 2-MCA exposure significantly increased apoptosis on DIV14, but did not alter autophagy or necrosis. In contrast, 3-OHGA exposure substantially increased necrosis already from DIV13, while no change was observed for apoptosis and autophagy. In conclusion, ammonium accumulation, secondary disturbance of energy metabolism and glial cell death are involved in the neuropathogenesis ofmethylmalonic aciduria and glutaric aciduria type I. Interestingly, brain cells are dying by necrosis under 3-OHGA exposure and by apoptosis under 2-MCA exposure.
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Abstract: Plants cannot run away to escape attacking herbivores, but they defend themselves by producing anti-digestive proteins and toxic compounds (for example glucosinolates). The first goal of this thesis was to study changes in gene expression after insect attack using microarrays. The responses of Arabidopsis thaliana to feeding by the specialist Pieris rapae and the generalist Spodoptera liffora is were compared. We found that the transcript profiles after feeding by the two chewing insects were remarkably similar, although the generalist induced a slightly stronger response. The second goal was to evaluate the implication of the four signals jasmonic acid (JA), salicylic acid (SA), ethylene (ET), and abscisic acid (ABA) in the control of insect-regulated gene expression. Using signaling mutants, we observed that JA was the predominant signal and that ABA modulated defense gene expression. In contrast, SA and ET appeared to control slightly gene expression, but only after feeding by S. litforalis. The third goal was to establish whether plant responses are really effective against insects. In accordance with the transcript profile, both insects were affected by the JA-dependent defenses, as they performed better on the JA-insensitive mutant. S. littoralis also performed better on ABA-deficient mutants, providing evidence for the role of ABA in defense against insects. When testing indole or aliphatic glucosinolate deficient mutants, we found that they were also more susceptible to insect feeding, providing some of the first genetic evidence for the defensive role of glucosinolates in planta. Finally, a glutathione-deficient mutant, pad2-1, was also more susceptible to insect feeding and we could attribute this phenotype to a lowered accumulation of the major indole glucosinolate. In this thesis, we provide a comprehensive list of insect-regulated genes, including many transcription factors that constitute interesting candidate genes for the further study of insect-induced expression changes. Understanding how the plant responses to insects are regulated will provide tools for a better management of insect pest in the field. Résumé: Les plantes ne peuvent s'échapper pour fuir les insectes qui les attaquent, mais elles se défendent en produisant des protéines anti-digestives et des composés toxiques (par exemple des glucosinolates). Le premier but de cette thèse était d'étudier les changements de l'expression génétique lors d'attaque par des insectes en utilisant des puces à ADN. Nous avons comparé la réponse d'Arabidopsis thaliana à deux espèces d'insectes avec des habitudes alimentaires différentes : le spécialiste Pieris rapae et le généraliste Spodoptera littoralis. Nous avons trouvé que les profils de transcription après l'attaque par les deux insectes sont remarquablement similaires, bien que le généraliste induise une réponse légèrement plus forte. Le deuxième but était de déterminer l'implication de quatre signaux dans le contrôle de la réponse :l'acide jasmonique (JA), l'acide salicylique (SA), l'éthylène (ET), et l'acide abscissique (ABA). En utilisant de mutants de signalisation, nous avons montré que l'acide jasmonique était le signal prédominant et que l'acide abscissique modulait l'expression génétique. D'autre part, l'acide salicylique et l'éthylène contrôlent à un degré moindre l'expression génétique, mais seulement après l'attaque par S. littoralís. Le troisième but était d'établir si les réponses des plantes sont efficaces contre les insectes. En accord avec le profil de transcription, les deux espèces d'insectes se sont mieux développées sur un mutant insensible au JA, indiquant que les défenses contrôlées par ce signal sont cruciales pour la plante. De plus, les larves de S. littorales se sont mieux développées sur des mutants déficients en ABA, ce qui fournit une preuve du rôle de l'acide abscissique dans la défense contre les insectes. En testant des mutants déficients en glucosinolates de type indole ou aliphatique, nous avons trouvé qu'ils étaient plus sensibles aux insectes, démontrant ainsi le rôle défensif des glucosinolates in planta. Finalement, le mutant déficient en glutathion pad2-1 était aussi plus sensible à l'attaque des insectes, et nous avons pu attribuer ce phénotype à une plus faible augmentation d'un indole glucosinolate dans ce mutant. Dans cette thèse, nous avons mis en évidence un nombre important de gènes contrôlés par les insectes, comprenant de nombreux facteurs de transcription qui constituent des candidats intéressants pour`étudier plus en détail les changements d'expression génétique induits par les insectes. Une meilleure compréhension de la réponse des plantes contre l'attaque des insectes devrait nous permettre de développer de nouvelles stratégies pour mieux gérer les ravageurs des cultures.
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Here we report the discovery of and phenotypic characterization of a retinal disorder of unknown origin in adults using clinical, electrophysiological and psychophysical techniques, and to seek the presence of circulating retinal autoantibodies in the sera of these patients. Sixteen patients were identified with progressive bilateral visual loss over a period of months. Ten of the patients were male, and the average age was 55.3 years (range from 43 to 76 years). Known causes such as carcinoma-associated retinopathy, acute zonal occult outer retinopathy and hereditary cone dystrophy appeared unlikely. Investigations included electrophysiology, fundus autofluorescence imaging and psychophysical tests. The sera of these patients were analyzed with indirect immunocytochemistry and Western immunoblot analysis on murine (BALB/c) retinal tissue for the presence of retinal autoantibodies. Bilateral visual loss and photophobia progressed over a period of months to years (average 28.7 months, range 3-67) and subsequently stabilized. No abnormality was observed by biomicroscopy, angiography or autofluorescence imaging. Electrophysiology indicated predominant cone-system dysfunction, either macular or generalized, and post-phototransduction involvement in 9 patients (56%). Photopic and scotopic visual fields and dark adaptation kinetics showed both cone and rod system involvement in all cases. Heterogeneous immunohistochemical staining patterns were seen with the sera of these patients as compared with controls. A majority of the affected patients (9/15) stained with an antinuclear pattern. The retinal autoantibodies from the sera of most patients reacted with the retinal proteins of molecular weight between 34 and 40 kDa. The aetiology of this distinctive retinal disorder therefore appears to be mediated through an autoimmune mechanism.
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Although cardiac stem cells have been isolated based on stem cell surface markers, no single marker is stem cell-specific. Clonogenicity is a defining functional property of stemness. We therefore analyzed cardiac cell clones derived from human hearts.Methods: Clonogenic cells were derived from adult human atrial samples. Cells were either cultured in the absence of an initial marker selection or, in separate experiments, they were initially selected for c-kit (CD117), CD31 or CD164 by magnetic immunobeads, or for high aldehyde dehydrogenase activity (ALDH) by FACS. High ALDH activity has been linked to stem/progenitor cells in several tissues. Surface marker analysis was performed by flow cytometry. Cultured cells were also exposed to different factors that modulate cell differentiation, including Dikkopf-1, Noggin, and Wnt-5.Results: Clonogenic cells mainly showed fibroblast-like morphology, ability to grow for more than 30 passages in vitro, and a heterogeneous marker profile even in clones derived from the same cardiac sample. The predominant phenotype was positive for CD13, CD29, CD31, CD44, CD54, CD105 and CD146, but negative for CD10, CD11b, CD14, CD15, CD34, CD38, CD45, CD56, CD106, CD117, CD123, CD133, CD135 and CD271, primarily consistent with endothelial/vascular progenitor cells. However, a minority of clones showed a different profile characterized by expression of CD90, CD106 and CD318, but not CD31 and CD146, consistent with mesenchymal stem/progenitor cells. When initial cell selection was performed, both phenotypes were observed, similarly to unselected cells, irrespective of the selection marker used. Of note, CD117+ sorted cell clones were CD117-negative in culture. Regardless of the immunophenotype, several clones were able to form spheric cell aggregates (cardiospheres), a distinct stem cell property. Dikkopf-1 induced marked CD15 and CD106 upregulation, consistent with stromal differentiation; this effect was prevented by Noggin.Conclusions: The adult human heart contains clonogenic stem/progenitor cells that can be expanded for many passages and form cardiospheres. The surface marker profile of these cells is heterogeneous, consistent with a majority of clones being comprised of endothelial or vascular progenitor cells and a minority of clones consisting of mesenchymal stem/progenitor cells. Dikkopf-1 and Noggin showed opposing effects on stromal differentiation of human cardiac cell clones.
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B-cell-activating factor of the TNF family (BAFF)/BLyS contributes to B-cell homeostasis and function in the periphery. BAFF is expressed as a membrane-bound protein or released by proteolytic cleavage, but the functional importance of this processing event is poorly understood. Mice expressing BAFF with a mutated furin consensus cleavage site, i.e. furin-mutant BAFF (fmBAFF), were not different from BAFF-deficient mice with regard to their B-cell populations and responses to immunization. It is however noteworthy that an alternative processing event releases some soluble BAFF in fmBAFF mice. Mild overexpression (∼ 5-fold) of fmBAFF alone generated intermediate levels of B cells without improving humoral responses to immunization. Processed BAFF was however important for B-cell homeostasis, as peripheral B-cell populations and antibody responses were readily restored by administration of soluble BAFF trimers in BAFF-deficient mice. However, the rescue of CD23 expression in B cells of BAFF-deficient mice required both soluble BAFF trimers and fmBAFF, or a polymeric form of soluble BAFF (BAFF 60-mer). These results point to a predominant role of processed BAFF for B-cell homeostasis and function, and indicate possible accessory roles for membrane-bound BAFF.
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The identification of genetic causes for Mendelian disorders has been based on the collection of multi-incident families, linkage analysis, and sequencing of genes in candidate intervals. This study describes the application of next-generation sequencing technologies to a Swiss kindred presenting with autosomal-dominant, late-onset Parkinson disease (PD). The family has tremor-predominant dopa-responsive parkinsonism with a mean onset of 50.6 ± 7.3 years. Exome analysis suggests that an aspartic-acid-to-asparagine mutation within vacuolar protein sorting 35 (VPS35 c.1858G>A; p.Asp620Asn) is the genetic determinant of disease. VPS35 is a central component of the retromer cargo-recognition complex, is critical for endosome-trans-golgi trafficking and membrane-protein recycling, and is evolutionarily highly conserved. VPS35 c.1858G>A was found in all affected members of the Swiss kindred and in three more families and one patient with sporadic PD, but it was not observed in 3,309 controls. Further sequencing of familial affected probands revealed only one other missense variant, VPS35 c.946C>T; (p.Pro316Ser), in a pedigree with one unaffected and two affected carriers, and thus the pathogenicity of this mutation remains uncertain. Retromer-mediated sorting and transport is best characterized for acid hydrolase receptors. However, the complex has many types of cargo and is involved in a diverse array of biologic pathways from developmental Wnt signaling to lysosome biogenesis. Our study implicates disruption of VPS35 and retromer-mediated trans-membrane protein sorting, rescue, and recycling in the neurodegenerative process leading to PD.
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PURPOSE: To determine the characteristics specific to boys with disordered eating behaviors (DEB) and the general context in which these DEB occur. METHOD: Data were drawn from the SMASH02 database, a survey carried out among post-mandatory school students in Switzerland aged 16-20 years in 2002. Only males (N=3890) were included, and were classified into into one of four groups based on their level of concern about weight/food and on their eating behaviors, as follows: group 1: one concern without behavior (N=862); group 2: more than one concern without behavior (N=361); group 3: at least one behavior (N=798); and a control group (N=1869), according to previously validated items. Groups were compared for personal, family, school, experience of violence, and health-compromising behaviors variables on the bivariate level. All significant variables were included in a multinomial logistic regression using Stata 9 software. RESULTS: About one-half of the boys reported either a concern or unhealthy eating behavior. Compared with the control group, boys from the three groups were more likely to be students and to report a history of sexual abuse, delinquency, depression, and feeling fat. In addition, boys from group 3 were more likely to report a history of dieting, early puberty, peer teasing, having experienced violence, frequent inebriation, and being overweight. CONCLUSION: DEB concern adolescent males more frequently than thought and seem to be integrated in a general dysfunctional context, in which violence is predominant. Adolescent males also need to be screened for DEB. Moreover, prevention programs should target the increasing social and media pressure regarding boys ideal body shape and raise public consciousness about this phenomenon.
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En aquest article es pretén donar resposta a una pregunta relacionada amb els usos lingüístics dels escolars: es pot afirmar, com han fet força comentaristes, que a Catalunya el català "ha guanyat l'escola però ha perdut el pati?". Per fer-ho, es parteix de la distinció entre dos tipus d'usos lingüístics: els institucionals (l'anàlisi dels quals permetrà determinar fins a quin punt el català "ha guanyat l'escola") i els interpersonals (mitjançant els quals es podrà conèixer si el català "ha perdut el pati"). A partir de dades procedents d'estudis macrosociolingüístics i de recerques etnogràfiques, l'autor arriba a la conclusió que, si per "guanyar l'escola" s'entén convertir el català en la llengua vehicular predominant (però no única) de la majoria d'escoles de Catalunya, l'afirmació és bàsicament adequada en relació amb l'educació primària, i força menys correcta per a la secundària. En canvi, la segona part de l'enunciat no és encertada i indueix a error de diagnòstic: ni el català ha desaparegut dels patis, ni se'n pot atribuir la reculada a un canvi sobtat i recent, ni es pot restringir aquesta reculada a l'escola. En resum, "s'ha avançat molt a l'escola, però no gaire al pati".
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This study analyses the fundamental components shaping the violence legitimation discourse of ETA (Euskadi Ta Askasuna). With this aim, a category system has been built, which organizes the psychosocial processes identified in previous studies related to violence legitimation. Based on the proposed category system, a content analysis was conducted on 21 statements of ETA, released between 1998 and 2011. An intraobserver and inter-observer reliability analysis reveals high level stability and replicability of the categorization. The results show, firstly, that outgroup components have a predominant presence over ingroup components. Secondly, in the components hierarchy, we observe that elements referring to identity come in first place, followed in similar frequencies by those related to violence representation and the definition of the situation.
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BACKGROUND: The contribution of nephrolithiasis-related end-stage renal disease (ESRD) to patients requiring renal replacement therapy has never been specifically evaluated. METHODS: Of the entire cohort of 1,391 consecutive patients who started maintenance dialysis therapy at our nephrology department between January 1989 and December 2000, a total of 45 patients (21 men) had renal stone disease as the cause of ESRD and constitute the study material. Type and cause of renal stone disease was determined in the 45 patients, as well as the change in prevalence of nephrolithiasis-related ESRD with time during this 12-year period. RESULTS: The overall proportion of nephrolithiasis-related ESRD was 3.2%. Infection (struvite) stones accounted for 42.2%; calcium stones, 26.7%; uric acid nephrolithiasis, 17.8%; and hereditary diseases (including primary hyperoxaluria type 1 and cystinuria), 13.3% of cases. Women were predominant among patients with infection and calcium stones, whereas men were predominant among patients with uric acid or hereditary stone disease. The proportion of patients with nephrolithiasis-related ESRD decreased from 4.7% in the triennial period 1989 to 1991 to 2.2% in the most recent period, 1998 to 2000 ( P = 0.07). This tendency to a decreasing prevalence mainly was caused by a rarefaction of infection and calcium stones with time, whereas frequencies of uric acid and hereditary stone disease remained essentially unchanged. CONCLUSION: Severe forms of nephrolithiasis remain an underestimated cause of potentially avoidable ESRD and need for renal replacement therapy. These findings highlight the crucial importance of accurate stone analysis and metabolic evaluation to provide early diagnosis and proper therapy for conditions that may lead to ESRD through recurrent stone formation and/or parenchymal crystal infiltration.
A fully validated method for the determination of arsenic species in rice and infant cereal products
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A full validation of inorganic arsenic (iAs), methylarsonic acid (MA), and dimethyl arsinic acid (DMA) in several types of rice and rice-based infant cereals is reported. The analytical method was developed and validated in two laboratories. The extraction of the As species was performed using nitric acid 0.2 % and hydrogen peroxide 1 %, and the coupled system liquid chromatography-inductively coupled plasma-mass spectrometry (LCICP-MS) was used for speciation measurements. Detection limit (DL), quantification limit, linearity, precision, trueness, accuracy, selectivity, as well as expanded uncertainty for iAs, MA, and DMA were established. The certified reference materials (CRMs) (NMIJ 7503a, NCS ZC73008, NIST SRM 1568a) were used to check the accuracy. The method was shown to be satisfactory in two proficiency tests (PTs). The broad applicability of the method is shown from the results of analysis of 29 samples including several types of rice, rice products, and infant cereal products. Total As ranged from 40.1 to 323.7 μg As kg1. From the speciation results, iAs was predominant, and DMA was detected in some samples while MA was not detected in any sample.
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An oceanic assemblage of alkaline basalts, radiolarites and polymictic breccias forms the tectonic substratum of the Santa Elena Nappe, which is constituted by extensive outcrops of ultramafic and mafic rocks of the Santa Elena Peninsula (NW Costa Rica). The undulating basal contact of this nappe defines several half-windows along the south shores of the Santa Elena Peninsula. Lithologically it is constituted by vesicular pillowed and massive alkaline basaltic flows, alkaline sills, ribbon-bedded and knobby radiolarites, muddy tuffaceous and detrital turbidites, debris flows and polymictic breccias and megabreccias. Sediments and basalt flows show predominant subvertical dips and occur in packages separated by roughly bed-parallel thrust planes. Individual packages reveal a coherent internal stratigraphy that records younging to the east in all packages and shows rapid coarsening upwards of the detrital facies. Alkaline basalt flows, pillow breccias and sills within radiolarite successions are genetically related to a mid-Cretaceous submarine seamount. Detrital sedimentary facies range form distal turbidites to proximal debris flows and culminate in megabreccias related to collapse and mass wasting in an accretionary prism. According to radiolarian dating, bedded radiolarites and soft-sediment- deformed clasts in the megabreccias formed in a short, late Aptian to Cenomanian time interval. Middle Jurassic to Lower Cretaceous radiolarian ages are found in clasts and blocks reworked from an older oceanic basement. We conclude that the oceanic assemblage beneath the Santa Elena Nappe does not represent a continuous stratigraphic succession. It is a pile of individual thrust sheets constituting an accretionary sequence, where intrusion and extrusion of alkaline basalts, sedimentation of radiolarites, turbidites and trench fill chaotic sediments occurred during the Aptian-Cenomanian. These thrust sheets formed shortly before the off-scraping and accretion of the complex. Here we define the Santa Rosa Accretionary Complex and propose a new hypothesis not considered in former interpretations. This hypothesis would be the basis for further research.