902 resultados para Gene do receptor beta-adrenégico 1
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El objetivo de este estudio fue identificar las tendencias en la investigación de la depresión infantil mediante un análisis bibliométrico de artículos publicados entre enero de 2010 y enero de 2015, en las bases de datos EBSCO, Scopus y Scielo. Se incluyeron 146 artículos, escritos en inglés, español y portugués. En el trabajo se identifican los autores más productivos y las tendencias de los autores con respecto al sexo, profesión y producción; así como los países, instituciones y revistas que más publicaron sobre dicho trastorno. La edad y la ansiedad son las variables que con más frecuencia se asocian al tema; de igual forma, se identificó el Children Depression Inventory (CDI) como el instrumento más común para medir la depresión infantil. En este periodo de tiempo destacan los artículos centrados en investigaciones sobre poblaciones con diferentes estados de salud, diseños correlacionales, de corte transversal y escritos por múltiples autores. Al analizar los resultados obtenidos se observa un creciente interés y preocupación de los investigadores por conocer la frecuencia de los trastornos del estado de ánimo y más específicamente de la depresión en niños, y la asociación e influencia que esta puede tener para su desarrollo.
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La llegada masiva de migrantes irregulares provenientes del África sub-sahariana ha sido un fenómeno que ha afectado en términos económicos, sociales, políticos y culturales, a los países que conforman la Unión Europea. Es así como los países más afectados por este tipo de migración (España, Grecia e Italia) han pedido a los demás miembros de la Unión adoptar una política conjunta y armonizada con el fin de solucionar la problemática migratoria irregular. No obstante, la cooperación, como acción unilateral, ha resultado ser el mecanismo más efectivo, en especial el caso español, para contener y externalizar los controles del movimiento migratorio irregular subsahariano en países como Mauritania, como resultado de un proceso de securitización de la migración irregular al interior de España a comienzos del siglo XX.
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Resistant strains of Plasmodium falciparum and the unavailability of useful antimalarial vaccines reinforce the need to develop new efficacious antimalarials. This study details a pharmacophore model that has been used to identify a potent, soluble, orally bioavailable antimalarial bisquinoline, metaquine (N,N'-bis(7-chloroquinolin-4-yl)benzene-1,3-diamine) (dihydrochloride), which is active against Plasmodium berghei in vivo (oral ID50 of 25 mu mol/kg) and multidrug-resistant Plasmodium falciparum K1 in vitro (0.17 mu M). Metaquine shows strong affinity for the putative antimalarial receptor, heme at pH 7.4 in aqueous DMSO. Both crystallographic analyses and quantum mechanical calculations (HF/6-31+G*) reveal important regions of protonation and bonding thought to persist at parasitic vacuolar pH concordant with our receptor model. Formation of drug-heme adduct in solution was confirmed using high-resolution positive ion electrospray mass spectrometry. Metaquine showed strong binding with the receptor in a 1: 1 ratio (log K = 5.7 +/- 0.1) that was predicted by molecular mechanics calculations. This study illustrates a rational multidisciplinary approach for the development of new 4-aminoquinoline antimalarials, with efficacy superior to chloroquine, based on the use of a pharmacophore model.
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The ability of human postprandial triacylglycerol-rich lipoproteins (TRLs), isolated after meals enriched in saturated fatty acids (SFAs), n-6 PUFAs, and MUFAs, to inhibit the uptake of I-125-labeled LDL by the LDL receptor was investigated in HepG2 cells. Addition of TRLs resulted in a dose-dependent inhibition of heparin-releasable binding, cell-associated radioactivity, and degradation products of I-125-labeled LDL (P < 0.001). SFA-rich Svedberg flotation rate (S-f) 60-400 resulted in significantly greater inhibition of cell-associated radioactivity than PUFA-rich particles (P = 0.016) and total uptake of I-125-labeled LDL compared with PUFA- and MUFA-rich particles (P = 0.02). Normalization of the apolipoprotein (apo)E but not apoC-III content of the TRLs removed the effect of meal fatty acid composition, and addition of an anti-apoE antibody reversed the inhibitory effect of TRLs on the total uptake of I-125-labeled LDL. Real time RT-PCR showed that the SFA-rich Sf 60-400 increased the expression of genes involved in hepatic lipid synthesis (P < 0.05) and decreased the expression of the LDL receptor-related protein 1 compared with MUFAs (P = 0.008). In conclusion, these findings suggest an alternative or additional mechanism whereby acute fat ingestion can influence LDL clearance via competitive apoE-dependent effects of TRL on the LDL receptor.-Jackson, K. G., V. Maitin, D. S. Leake, P. Yaqoob, and C. M. Williams. Saturated fat-induced changes in Sf 60 400 particle composition reduces uptake of LDL by HepG2 cells.
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Background: Several lines of evidence suggest that the dietary isoflavone genistein (Gen) has beneficial effects with regard to cardiovascular disease and in particular on aspects related to blood pressure and angiogenesis. The biological action of Gen may be, at Least in part, attributed to its ability to affect cell signalling and response. However, so far, most of the molecular mechanisms underlying the activity of Gen in the endothelium are unknown. Methods and results: To examine the transcriptional response to 2.5 mu M Gen on primary human endothelial cells (HUVEC), we applied cDNA array technology both under baseline condition and after treatment with the pro-atherogenic stimulus, copper-oxidized LDL. The alteration of the expression patterns of individual transcripts was substantiated using either RT-PCR or Northern blotting. Gen significantly affected the expression of genes encoding for proteins centrally involved in the vascular tone such as endothelin-converting enzyme-1, endothetin-2, estrogen related receptor a and atria[ natriuretic peptide receptor A precursor. Furthermore, Gen countered the effect of oxLDL on mRNA levels encoding for vascular endothelial growth factor receptor 165, types 1 and 2. Conclusions: Our data indicate that physiologically achievable levels of Gen change the expression of mRNA encoding for proteins involved in the control of blood pressure under baseline conditions and reduce the angiogenic response to oxLDL in the endothelium. (c) 2005 Elsevier B.V. All rights reserved.
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As part of an on-going project to characterize compounds from immature conifer cones with antibacterial or modulatory activity against multidrug-resistant (MDR) strains of Staphylococcus aureus, eight compounds were isolated from the cones of Chatnaecyparis lawsoniana. The active compounds were mainly diterpenes, with minimum inhibitory concentrations ranging from 4 to 128 mu g/ml against MDR effluxing S. aureus strains and two epidemic methicillin-resistant (EMRSA) clinical isolates. The compounds extracted were the diterpenes ferruginol, pisiferol and its epimer 5-epipisiferol, formosanoxide, trans-communic acid and torulosal, the sesquiterpene oplopanonyl acetate and the germacrane 4 beta-hydroxygermacra-1(10)-5-diene. Some of these compounds also exhibited modulatory activity in potentiating antibiotic activity against effluxing strains and ferruginol, used at a sub-inhibitory concentration, resulted in an 80-fold potentiation of oxacillin activity against strain EMRSA-15. An efflux inhibition assay using an S. aureus strain possessing the MDR NorA efflux pump resulted in 40% inhibition of ethidium bromide efflux at 10 mu M ferruginol (2.86 mu g/ml). We report the H-1 and C-13 NMR data for the cis A/B ring junction epimer of pisiferol which we have named 5-epipisiferol. We also unambiguously assign all H-1 and C-13 NMR resonances for trans-communic acid. (c) 2006 Elsevier Ltd. All rights reserved.
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Although neurokinin 1 receptor antagonists prevent ethanol (EtOH)-induced gastric lesions, the mechanisms by which EtOH releases substance P (SP) and SP damages the mucosa are unknown. We hypothesized that EtOH activates transient receptor potential vanilloid 1 (TRPV1) on sensory nerves to release SP, which stimulates epithelial neurokinin 1 receptors to generate damaging reactive oxygen species (ROS). SP release was assayed in the mouse stomach, ROS were detected using dichlorofluorescein diacetate, and neurokinin 1 receptors were localized by immunofluorescence. EtOH-induced SP release was prevented by TRPV1 antagonism. High dose EtOH caused lesions, and TRPV1 or neurokinin 1 receptor antagonism and neurokinin 1 receptor deletion inhibited lesion formation. Coadministration of low, innocuous doses of EtOH and SP caused lesions by a TRPV1-independent but neurokinin 1 receptor-dependent process. EtOH, capsaicin, and SP stimulated generation of ROS by superficial gastric epithelial cells expressing neurokinin 1 receptors by a neurokinin 1 receptor-dependent mechanism. ROS scavengers prevented lesions induced by a high EtOH dose or a low EtOH dose plus SP. Gastric lesions are caused by an initial detrimental effect of EtOH, which is damaging only if associated with TRPV1 activation, SP release from sensory nerves, stimulation of neurokinin 1 receptors on epithelial cells, and ROS generation.
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Oculopharyngeal muscular dystrophy (OPMD) is an adult-onset disorder characterized by ptosis, dysphagia and proximal limb weakness. Autosomal-dominant OPMD is caused by a short (GCG)8–13 expansions within the first exon of the poly(A)-binding protein nuclear 1 gene (PABPN1), leading to an expanded polyalanine tract in the mutated protein. Expanded PABPN1 forms insoluble aggregates in the nuclei of skeletal muscle fibres. In order to gain insight into the different physiological processes affected in OPMD muscles, we have used a transgenic mouse model of OPMD (A17.1) and performed transcriptomic studies combined with a detailed phenotypic characterization of this model at three time points. The transcriptomic analysis revealed a massive gene deregulation in the A17.1 mice, among which we identified a significant deregulation of pathways associated with muscle atrophy. Using a mathematical model for progression, we have identified that one-third of the progressive genes were also associated with muscle atrophy. Functional and histological analysis of the skeletal muscle of this mouse model confirmed a severe and progressive muscular atrophy associated with a reduction in muscle strength. Moreover, muscle atrophy in the A17.1 mice was restricted to fast glycolytic fibres, containing a large number of intranuclear inclusions (INIs). The soleus muscle and, in particular, oxidative fibres were spared, even though they contained INIs albeit to a lesser degree. These results demonstrate a fibre-type specificity of muscle atrophy in this OPMD model. This study improves our understanding of the biological pathways modified in OPMD to identify potential biomarkers and new therapeutic targets.
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The purolindolines are small cysteine-rich proteins which are present in the grain of wheat. They have a major impact on the utilisation of the grain as they are the major determinants of grain texture, which affects both milling and baking properties. Bread and durum wheats were transformed with constructs comprising the promoter regions of the Puroindoline a (Pina) and Puroindoline b (Pinb) genes fused to the uidA (GUS) reporter gene. Nine lines showing 3:1 segregation for the transgene and comprising all transgene/species combinations were selected for detailed analysis of transgene expression during grain development. This showed that transgene expression occurred only in the starchy endosperm cells and was not observed in any other seed or vegetative tissues. The location of the puroindoline proteins in these cells was confirmed by tissue printing of developing grain, using a highly specific monoclonal antibody for detection and an antibody to the aleurone-localised 8S globulin as a control. This provides clear evidence that puroindolines are only synthesised and accumulated in the starchy endosperm cells of the wheat grain.
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Pro-inflammatory cytokines may be important in the pathophysiological responses of the heart. We investigated the activation of the three mitogen-activated protein kinase (MAPK) subfamilies ¿c-Jun N-terminal kinases (JNKs), p38-MAPKs and extracellularly-responsive kinases (ERKs) by interleukin-1 beta (IL-1 beta) or tumour necrosis factor alpha (TNF alpha) in primary cultures of myocytes isolated from neonatal rat ventricles. Both cytokines stimulated a rapid (maximal within 10 min) increase in JNK activity. Although activation of JNKs by IL-1 beta was transient returning to control values within 1 h, the response to TNF alpha was sustained. IL-1 beta and TNF alpha also stimulated p38-MAPK phosphorylation, but the response to IL-1 beta was consistently greater than TNF alpha. Both cytokines activated ERKs, but to a lesser degree than that induced by phorbol esters. The transcription factors, c-Jun and ATF2, are phosphorylated by the MAPKs and are implicated in the upregulation of c-Jun. IL-1 beta and TNF alpha stimulated the phosphorylation of c-Jun and ATF2. However, IL-1 beta induced a greater increase in c-Jun protein. Inhibitors of protein kinase C (PKC) (Ro318220, GF109203X) and the ERK cascade (PD98059) attenuated the increase in c-Jun induced by IL-1 beta, but LY294002 (an inhibitor of phosphatidylinositol 3' kinase) and SB203580 (an inhibitor of p38-MAPK, which also inhibits certain JNK isoforms) had no effect. These data illustrate that some of the pathological effects of IL-1 beta and TNF alpha may be mediated through the MAPK cascades, and that the ERK cascade, rather than JNKs or p38-MAPKs, are implicated in the upregulation of c-Jun by IL-1 beta.
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By means of numerical simulations, we investigate magnetized stellar winds of pre-main-sequence stars. In particular, we analyze under which circumstances these stars will present elongated magnetic features (e.g., helmet streamers, slingshot prominences, etc). We focus on weak-lined T Tauri stars, as the presence of the tenuous accretion disk is not expected to have strong influence on the structure of the stellar wind. We show that the plasma-beta parameter (the ratio of thermal to magnetic energy densities) is a decisive factor in defining the magnetic configuration of the stellar wind. Using initial parameters within the observed range for these stars, we show that the coronal magnetic field configuration can vary between a dipole-like configuration and a configuration with strong collimated polar lines and closed streamers at the equator (multicomponent configuration for the magnetic field). We show that elongated magnetic features will only be present if the plasma-beta parameter at the coronal base is beta(0) << 1. Using our self-consistent three-dimensional magnetohydrodynamics model, we estimate for these stellar winds the timescale of planet migration due to drag forces exerted by the stellar wind on a hot-Jupiter. In contrast to the findings of Lovelace et al., who estimated such timescales using the Weber and Davis model, our model suggests that the stellar wind of these multicomponent coronae are not expected to have significant influence on hot-Jupiters migration. Further simulations are necessary to investigate this result under more intense surface magnetic field strengths (similar to 2-3 kG) and higher coronal base densities, as well as in a tilted stellar magnetosphere.
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The aim of this work was to investigate the effect of the in vitro circadian-like exposure to melatonin [in the presence or absence of insulin (Ins)] on the metabolism and clock gene expression in adipocytes. To simulate the cyclic characteristics of the daily melatonin profile, isolated rat adipocytes were exposed in a circadian-like pattern to melatonin added to the incubating medium for 12 hr (mimicking the night), followed by an equal period without melatonin (mimicking the day) combined or not with Ins. This intermittent incubation was interrupted when four and a half 24-hr cycles were fulfilled. At the end, either during the induced night (melatonin present) or the induced day (melatonin absent), the rates of lipolysis and D-[U-(14)C]-glucose incorporation into lipids were estimated, in addition to the determination of lipogenic [glucose-6-phosphate dehydrogenase and fatty acid synthase (FAS)] and lipolytic (hormone sensitive lipase) enzymes and clock gene (Bmal-1b, Clock, Per-1 and Cry-1) mRNA expression. The leptin release was also measured. During the induced night, the following effects were observed: an increase in the mRNA expression of Clock, Per-1 and FAS; a rise in lipogenic response and leptin secretion; and a decrease in the lipolytic activity. The intermittent exposure of adipocytes to melatonin temporally and rhythmically synchronized their metabolic and hormonal function in a circadian fashion, mimicking what is observed in vivo in animals during the daily light-dark cycle. Therefore, this work helps to clarify the physiological relevance of the circadian pattern of melatonin secretion and its interactions with Ins, contributing to a better understanding of the adipocyte biology.
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Inflammation is a crucial step for the wound healing process. The effect of linoleic and oleic acids on the inflammatory response of the skin during the healing process and on the release of pro-inflammatory cytokines by rat neutrophils in vitro was investigated. A wound in the dorsal surface of adult rats was performed and fatty acids were then topically administered. Both oleic and linoleic acids increased the wound healing tissue mass. The total protein and DNA contents of the wounds were increased by the treatment with linoleic acid. The treatments with oleic and linoleic acids did not affect vascular permeability. However, the number of neutrophils in the wounded area and air pouches was increased and the thickness of the necrotic cell layer edge around the wound was decreased. A dose-dependent increase in vascular endothelial growth factor-alpha (VEGF-alpha) and interleukin-1 beta (IL-1 beta) by neutrophils incubated in the presence of oleic and linoleic acid was observed. Oleic acid was able to stimulate also the production of cytokine-induced neutrophil chemoattractant in inflammation 2 alphalbeta (CINC-2 alpha/beta). This pro-inflammatory effect of oleic and linoleic acids may speed up the wound healing process. Copyright (c) 2007 John Wiley & Sons, Ltd.
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Thyroid hormone (TH) plays a key role on post-natal bone development and metabolism, while its relevance during fetal bone development is uncertain. To Study this, pregnant once were made hypothyroid and fetuses harvested at embryonic days (E) 12.5, 14.5, 16.5 and 18.5. Despite a marked reduction in fetal tissue concentration of both T4 and T3, bone development, as assessed at the distal epiphyseal growth plate of the femur and vertebra, was largely preserved Lip to E16.5. Only at E18.5, the hypothyroid fetuses exhibited a reduction in femoral type I and type X collagen and osteocalcin mRNA levels, in the length and area of the proliferative and hypertrophic zones, in the number of chondrocytes per proliferative column, and in the number of hypertrophic chondrocyres, in addition to a slight delay in endochondral and intramembranous ossification. This Suggests that LIP to E 16.5, thyroid hormone signaling in bone is kept to a minimum. In fact, measuring the expression level of the activating and inactivating iodothyronine deiodinases (D2 and D3) helped understand how this is achieved. D3 mRNA was readily detected as early as E14.5 and its expression decreased markedly (similar to 10-fold) at E18.5, and even more at 14 days after birth (P14). In contrast. D2 mRNA expression increased significantly by E18.5 and markedly (similar to 2.5-fold) by P14. The reciprocal expression levels of D2 and D3 genes during early bone development along with the absence of a hypothyroidism-induced bone phenotype at this time Suggest that coordinated reciprocal deiodinase expression keeps thyroid hormone signaling in bone to very low levels at this early stage of bone development. (c) 2008 Elsevier Inc. All rights reserved.