979 resultados para Lateral Inverse Proximity Effect


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RESUMO - Objetivos: Caracterizar a adesão à terapêutica nos doentes do CHLN, na área do VIH/SIDA, Esclerose, Artrite Reumatóide, Psoríase e Paramiloidose e avaliar a hipótese de ser possível prever o risco de um doente se tornar, num doente sem adesão. Metodologia: Estudo retrospetivo, observacional e longitudinal, realizado entre Janeiro de 2010 a 31 de Dezembro de 2013, a 4.761 doentes, em que a adesão à terapêutica foi calculada com base nos registos informáticos das dispensas de medicação, efectuados pelos Serviços Farmacêuticos, com recurso à Compliance Rate (CR) e utilizada como variável dependente. A estatística descritiva foi utilizada para caracterizar os doentes e os seus levantamentos e a regressão logística para avaliar o efeito das variáveis (idade, sexo, distrito de residência, período de observação, número de interrupções superiores a trinta dias e tempo até à primeira interrupção) sobre a adesão à terapêutica. Resultados e Conclusões: A percentagem de doentes com adesão foi de 64%, no entanto no HIV/Sida e na Artrite Reumatóide e Psoríase esta percentagem foi significativamente mais baixa, 42% dos doentes interromperam a terapêutica por períodos superiores a 30 dias, ocorrendo essa interrupção maioritariamente entre o primeiro e segundo ano de terapêutica. O modelo de regressão logística permitiu verificar que só com as variáveis sociodemográficas não é possível prever o risco de um doente se tornar num doente sem adesão, sendo para tal necessário adicionar ao modelo a variável número de interrupções superiores a 30 dias que foi identificada como importante factor preditivo da não adesão (OR=15,9, p=0,000).

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Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disorder characterized by progressive degeneration of upper and lower motor neurons. It is mostly sporadic, but about 2% of cases are associated with mutations in the gene encoding the enzyme superoxide dismutase 1 (SOD1). A major constraint to the comprehension of the pathogenesis of ALS has been long represented by the conviction that this disorder selectively affects motor neurons in a cell-autonomous manner. However, the failure to identify the events underlying the neurodegenerative process and the increased knowledge of the complex cellular interactions necessary for the correct functioning of the CNS has recently focused the attention on the contribution to neurodegeneration of glial cells, including astrocytes. Astrocytes can hurt motor neurons directly by secreting neurotoxic factors, but they can also play a deleterious role indirectly by losing functions that are supportive for neurons. Recently, we reported that a subpopulation of astrocytes degenerates in the spinal cord of hSOD1G93A transgenic mouse model of ALS. Mechanistic studies in cultured astrocytes revealed that such effect is mediated by the excitatory amino acid glutamate.On the bsis of these observations, we next used the established cell culture model as a tool to screen the glioprotective effect of innovative drugs, namely cell-permeable therapeutics. These consist of peptidic effector moieties coupled to the selective intracellular peptide transporter TAT protein. We initially validated the usefulness of these molecules demonstrating that a control fluorescent peptide enters astrocytes in culture and is retained within the cells up to 24-48 h, according to the timing of our cytotoxicity experiments. We then tested the impact of specific intracellular peptides with antiapoptotic properties on glutamate-treated hSOD1G93A- expressing astrocytes and we identified one molecule that protects the cells from death. Chronic treatment of ALS mice with this peptide had a positive impact on the outcome of the disease.

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BACKGROUND & AIMS: Recently, genetic variations in MICA (lead single nucleotide polymorphism [SNP] rs2596542) were identified by a genome-wide association study (GWAS) to be associated with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC) in Japanese patients. In the present study, we sought to determine whether this SNP is predictive of HCC development in the Caucasian population as well. METHODS: An extended region around rs2596542 was genotyped in 1924 HCV-infected patients from the Swiss Hepatitis C Cohort Study (SCCS). Pair-wise correlation between key SNPs was calculated both in the Japanese and European populations (HapMap3: CEU and JPT). RESULTS: To our surprise, the minor allele A of rs2596542 in proximity of MICA appeared to have a protective impact on HCC development in Caucasians, which represents an inverse association as compared to the one observed in the Japanese population. Detailed fine-mapping analyses revealed a new SNP in HCP5 (rs2244546) upstream of MICA as strong predictor of HCV-related HCC in the SCCS (univariable p=0.027; multivariable p=0.0002, odds ratio=3.96, 95% confidence interval=1.90-8.27). This newly identified SNP had a similarly directed effect on HCC in both Caucasian and Japanese populations, suggesting that rs2244546 may better tag a putative true variant than the originally identified SNPs. CONCLUSIONS: Our data confirms the MICA/HCP5 region as susceptibility locus for HCV-related HCC and identifies rs2244546 in HCP5 as a novel tagging SNP. In addition, our data exemplify the need for conducting meta-analyses of cohorts of different ethnicities in order to fine map GWAS signals.

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Over the past decade, significant interest has been expressed in relating the spatial statistics of surface-based reflection ground-penetrating radar (GPR) data to those of the imaged subsurface volume. A primary motivation for this work is that changes in the radar wave velocity, which largely control the character of the observed data, are expected to be related to corresponding changes in subsurface water content. Although previous work has indeed indicated that the spatial statistics of GPR images are linked to those of the water content distribution of the probed region, a viable method for quantitatively analyzing the GPR data and solving the corresponding inverse problem has not yet been presented. Here we address this issue by first deriving a relationship between the 2-D autocorrelation of a water content distribution and that of the corresponding GPR reflection image. We then show how a Bayesian inversion strategy based on Markov chain Monte Carlo sampling can be used to estimate the posterior distribution of subsurface correlation model parameters that are consistent with the GPR data. Our results indicate that if the underlying assumptions are valid and we possess adequate prior knowledge regarding the water content distribution, in particular its vertical variability, this methodology allows not only for the reliable recovery of lateral correlation model parameters but also for estimates of parameter uncertainties. In the case where prior knowledge regarding the vertical variability of water content is not available, the results show that the methodology still reliably recovers the aspect ratio of the heterogeneity.

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The effect of exendin-(9-39), a described antagonist of the glucagon-like peptide-1 (GLP-1) receptor, was evaluated on the formation of cAMP- and glucose-stimulated insulin secretion (GSIS) by the conditionally immortalized murine betaTC-Tet cells. These cells have a basal intracellular cAMP level that can be increased by GLP-1 with an EC50 of approximately 1 nM and can be decreased dose dependently by exendin-(9-39). This latter effect was receptor dependent, as a beta-cell line not expressing the GLP-1 receptor was not affected by exendin-(9-39). It was also not due to the endogenous production of GLP-1, because this effect was observed in the absence of detectable preproglucagon messenger RNA levels and radioimmunoassayable GLP-1. Importantly, GSIS was shown to be sensitive to this basal level of cAMP, as perifusion of betaTC-Tet cells in the presence of exendin-(9-39) strongly reduced insulin secretion. This reduction of GSIS, however, was observed only with growth-arrested, not proliferating, betaTC-Tet cells; it was also seen with nontransformed mouse beta-cells perifused in similar conditions. These data therefore demonstrated that 1) exendin-(9-39) is an inverse agonist of the murine GLP-1 receptor; 2) the decreased basal cAMP levels induced by this peptide inhibit the secretory response of betaTC-Tet cells and mouse pancreatic islets to glucose; 3) as this effect was observed only with growth-arrested cells, this indicates that the mechanism by which cAMP leads to potentiation of insulin secretion is different in proliferating and growth-arrested cells; and 4) the presence of the GLP-1 receptor, even in the absence of bound peptide, is important for maintaining elevated intracellular cAMP levels and, therefore, the glucose competence of the beta-cells.

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We have characterized the pharmacological antagonism, i.e., neutral antagonism or inverse agonism, displayed by a number of alpha-blockers at two alpha1-adrenergic receptor (AR) subtypes, alpha(1a)- and alpha(1b)-AR. Constitutively activating mutations were introduced into the alpha(1a)-AR at the position homologous to A293 of the alpha(1b)-AR where activating mutations were previously described. Twenty-four alpha-blockers differing in their chemical structures were initially tested for their effect on the agonist-independent inositol phosphate response mediated by the constitutively active A271E and A293E mutants expressed in COS-7 cells. A selected number of drugs also were tested for their effect on the small, but measurable spontaneous activity of the wild-type alpha(1a)- and alpha(1b)-AR expressed in COS-7 cells. The results of our study demonstrate that a large number of structurally different alpha-blockers display profound negative efficacy at both the alpha(1a)- and alpha(1b)-AR subtypes. For other drugs, the negative efficacy varied at the different constitutively active mutants. The most striking difference concerns a group of N-arylpiperazines, including 8-[2-[4-(5-chloro-2-methoxyphenyl)-1-piperazinyl]ethyl]-8-azaspiro [4, 5] decane-7,9-dione (REC 15/3039), REC 15/2739, and REC 15/3011, which are inverse agonists with profound negative efficacy at the wild-type alpha(1b)-AR, but not at the alpha(1a)-AR.

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In order to characterize inverse agonism at alpha1B-adrenoceptors, we have compared the concentration-response relationships of several quinazoline and non-quinazoline alpha1-adrenoceptor antagonists at cloned hamster wild-type (WT) alpha1B-adrenoceptors and a constitutively active mutant (CAM) thereof upon stable expression in Rat-1 fibroblasts. Receptor activation or inhibition thereof was assessed as [3H]inositol phosphate (IP) accumulation. Quinazoline (alfuzosin, doxazosin, prazosin, terazosin) and non-quinazoline alpha1-adrenoceptor antagonists (BE 2254, SB 216,469, tamsulosin) concentration-dependently inhibited phenylephrine-stimulated IP formation at both WT and CAM with Ki values similar to those previously found in radioligand binding studies. At CAM in the absence of phenylephrine, the quinazolines produced concentration-dependent inhibition of basal IP formation; the maximum inhibition was approximately 55%, and the corresponding EC50 values were slightly smaller than the Ki values. In contrast, BE 2254 produced much less inhibition of basal IP formation, SB 216,469 was close to being a neutral antagonist, and tamsulosin even weakly stimulated IP formation. The inhibitory effects of the quinazolines and BE 2254 as well as the stimulatory effect of tamsulosin were equally blocked by SB 216,469 at CAM. At WT in the absence of phenylephrine, tamsulosin did not cause significant stimulation and none of the other compounds caused significant inhibition of basal IP formation. We conclude that alpha1-adrenoceptor antagonsits with a quinazoline structure exhibit greater efficacy as inverse agonists than those without.

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Phototropism allows plants to orient their photosynthetic organs towards the light. In Arabidopsis, phototropins 1 and 2 sense directional blue light such that phot1 triggers phototropism in response to low fluence rates, while both phot1 and phot2 mediate this response under higher light conditions. Phototropism results from asymmetric growth in the hypocotyl elongation zone that depends on an auxin gradient across the embryonic stem. How phototropin activation leads to this growth response is still poorly understood. Members of the phytochrome kinase substrate (PKS) family may act early in this pathway, because PKS1, PKS2 and PKS4 are needed for a normal phototropic response and they associate with phot1 in vivo. Here we show that PKS proteins are needed both for phot1- and phot2-mediated phototropism. The phototropic response is conditioned by the developmental asymmetry of dicotyledonous seedlings, such that there is a faster growth reorientation when cotyledons face away from the light compared with seedlings whose cotyledons face the light. The molecular basis for this developmental effect on phototropism is unknown; here we show that PKS proteins play a role at the interface between development and phototropism. Moreover, we present evidence for a role of PKS genes in hypocotyl gravi-reorientation that is independent of photoreceptors. pks mutants have normal levels of auxin and normal polar auxin transport, however they show altered expression patterns of auxin marker genes. This situation suggests that PKS proteins are involved in auxin signaling and/or lateral auxin redistribution.

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Latitudinal gradient effect on the wing geometry of Auca coctei (Guérin) (Lepidoptera, Nymphalidae). When the environmental conditions change locally, the organisms and populations may also change in response to the selection pressure, so that the development of individuals may become affected in different degrees. There have been only a few studies in which the patterns of wing morphology variation have been looked into along a latitudinal gradient by means of geometric morphometrics. The aim of this work was to assess the morphologic differentiation of wing among butterfly populations of the species Auca coctei. For this purpose, 9 sampling locations were used which are representative of the distribution range of the butterfly and cover a wide latitudinal range in Chile. The wing morphology was studied in a total of 202 specimens of A. coctei (150 males and 52 females), based on digitization of 17 morphologic landmarks. The results show variation of wing shape in both sexes; however, for the centroid size there was significant variation only in females. Females show smaller centroid size at higher latitudes, therefore in this study the Bergmann reverse rule is confirmed for females of A. coctei. Our study extends morphologic projections with latitude, suggesting that wing variation is an environmental response from diverse origins and may influence different characteristics of the life history of a butterfly.

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We report a spectroscopic study about the energy transfer mechanism among silicon nanoparticles (Si-np), both amorphous and crystalline, and Er ions in a silicon dioxide matrix. From infrared spectroscopic analysis, we have determined that the physics of the transfer mechanism does not depend on the Si-np nature, finding a fast (< 200 ns) energy transfer in both cases, while the amorphous nanoclusters reveal a larger transfer efficiency than the nanocrystals. Moreover, the detailed spectroscopic results in the visible range here reported are essential to understand the physics behind the sensitization effect, whose knowledge assumes a crucial role to enhance the transfer rate and possibly employing the material in optical amplifier devices. Joining the experimental data, performed with pulsed and continuous-wave excitation, we develop a model in which the internal intraband recombination within Si-np is competitive with the transfer process via an Auger electron"recycling" effect. Posing a different light on some detrimental mechanism such as Auger processes, our findings clearly recast the role of Si-np in the sensitization scheme, where they are able to excite very efficiently ions in close proximity to their surface. (C) 2010 American Institute of Physics.

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Introduction: Several methods have already been proposed to improve the mobility of reversed prostheses (lateral or inferior displacement, increase of the glenosphere size). However, the effect of these design changes have only been evaluated on the maximal range of motion and were not related to activities of daily living (ADL). Our aim was thus to measure the effect of these design changes and to relate it to 4 typical ADL. Methods: CT data were used to reconstruct a accurate geometric model of the scapula and humerus. The Aequalis reversed prosthesis (Tornier) was used. The mobility of a healthy shoulder was compared to the mobility of 4 different reversed designs: 36 and 42 mm glenospheres diameters, inferior (4 mm) and lateral (3.2 mm) glenospheres displacements. The complete mobility map of the prosthesis was compared to kinematics measurement on healthy subjects for 4 ADL: 1) hand to contra lateral shoulder, 2) hand to mouth, 3) combing hair, 4) hand to back pocket. The results are presented as percentage of the allowed movement of the prosthestic shouder relative to the healthy shoulder, considered as the control group. Results: None of the tested designs allowed to recover a full mobility. The differences of allowed range of motion among each prosthetic designs appeared mainly in two of the 4 movements: hand to back pocket and hand to contra lateral shoulder. For the hand to back pocket, the 36 had the lowest mobility range, particularly for the last third of the movement. The 42 appeared to be a good compromise for all ADL activities. Conclusion: Reverse shoulder prostheses does not allow to recover a full range of motion compared to healthy shoulders, even for ADL. The present study allowed to obtain a complete 3D mobility map for several glenosphere positions and sizes, and to relate it to typical ADL. We mainly observed an improved mobility with inferior displacement and increased glenosphere size. We would suggest to use larger glenosphere, whenever it is possible.

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Each year several prestressed concrete girder bridges in Iowa and other states are struck and damaged by vehicles with loads too high to pass under the bridge. Whether or not intermediate diaphragms play a significant role in reducing the effect of these unusual loading conditions has often been a topic of discussion. A study of the effects of the type and location of intermediate diaphragms in prestressed concrete girder bridges when the bridge girder flanges were subjected to various levels of vertical and horizontal loading was undertaken. The purpose of the research was to determine whether steel diaphragms of any conventional configuration can provide adequate protection to minimize the damage to prestressed concrete girders caused by lateral loads, similar to the protection provided by the reinforced concrete intermediate diaphragms presently being used by the Iowa Department of Transportation. The research program conducted and described in this report included the following: A comprehensive literature search and survey questionnaire were undertaken to define the state-of-the-art in the use of intermediate diaphragms in prestressed concrete girder bridges. A full scale, simple span, restressed concrete girder bridge model, containing three beams was constructed and tested with several types of intermediate diaphragms located at the one-third points of the span or at the mid-span. Analytical studies involving a three-dimensional finite element analysis model were used to provide additional information on the behavior of the experimental bridge. The performance of the bridge with no intermediate diaphragms was quite different than that with intermediate diaphragms in place. All intermediate diaphragms tested had some effect in distributing the loads to the slab and other girders, although some diaphragm types performed better than others. The research conducted has indicated that the replacement of the reinforced concrete intermediate diaphragms currently being used in Iowa with structural steel diaphragms may be possible.

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Introduction: Primary bone sarcomas around the ankle are rare. Due to the proximity of neurovascular structures and limited soft tissue reserves, limb salvage is often not possible. Case report: A 19 yo male presented with pain and a progressive swelling of his ankle. X-rays revealed cortical erosions and an extensive periosteal reaction (sunburst) of the distal fibula. MRI showed a large mass of the fibula invading adjacent soft tissue. The lesion appeared close to the ankle joint, but with the articular cartilage as a barrier and without joint effusion. Core-needle biopsy revealed a high-grade chondroblastic osteosarcoma. No metastases were detected. After presentation at our multidisciplinary sarcoma board, the patient was subjected to neo-adjuvant chemotherapy (AOST 03-331). Without any sign of intra-articular contamination of the ankle joint, surgical treatment consisted of wide resection of the lateral malleolus including a large skin patch, the distal third of the fibula, the lateral surfaces of the tibia and talus as well as the insertion of the lateral ligament on the calcaneus. The distal parts of the anterior, peroneal, and posterior muscular compartments were resected en bloc with the tumor. The defect was reconstructed with tibio-talar and talo-calcanear fusion, bony allograft and a plate. Soft-tissue coverage was achieved with a free fascio-cutaneous flap from the controlateral thigh. Histological analysis revealed clear margins and 50% of tumor necrosis. The oncologic treatment was completed with adjuvant chemotherapy. Conclusion: Wide resection and reconstruction of the lateral malleolus is technically demanding but possible in selected cases. Despite some important functional loss, limb salvage is superior to an amputation.

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In previous studies we showed that the wild-type histamine H(2) receptor stably expressed in Chinese hamster ovary cells is constitutively active. Because constitutive activity of the H(2) receptor is already found at low expression levels (300 fmol/mg protein) this receptor is a relatively unique member of the G-protein-coupled receptor (GPCR) family and a useful tool for studying GPCR activation. In this study the role of the highly conserved DRY motif in activation of the H(2) receptor was investigated. Mutation of the aspartate 115 residue in this motif resulted in H(2) receptors with high constitutive activity, increased agonist affinity, and increased signaling properties. In addition, the mutant receptors were shown to be highly structurally instable. Mutation of the arginine 116 residue in the DRY motif resulted also in a highly structurally instable receptor; expression of the receptor could only be detected after stabilization with either an agonist or inverse agonist. Moreover, the agonist affinity at the Arg-116 mutant receptors was increased, whereas the signal transduction properties of these receptors were decreased. We conclude that the Arg-116 mutant receptors can adopt an active conformation but have a decreased ability to couple to or activate the G(s)-protein. This study examines the pivotal role of the aspartate and arginine residues of the DRY motif in GPCR function. Disruption of receptor stabilizing constraints by mutation in the DRY motif leads to the formation of active GPCR conformations, but concomitantly to GPCR instability.

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Candidate gene and genome-wide association studies have not identified common variants, which are reliably associated with depression. The recent identification of obesity predisposing genes that are highly expressed in the brain raises the possibility of their genetic contribution to depression. As variation in the intron 1 of the fat mass- and obesity-associated (FTO) gene contributes to polygenic obesity, we assessed the possibility that FTO gene may contribute to depression in a cross-sectional multi-ethnic sample of 6561 depression cases and 21 932 controls selected from the EpiDREAM, INTERHEART, DeCC (depression case-control study) and Cohorte Lausannoise (CoLaus) studies. Major depression was defined according to DSM IV diagnostic criteria. Association analyses were performed under the additive genetic model. A meta-analysis of the four studies showed a significant inverse association between the obesity risk FTO rs9939609 A variant and depression (odds ratio=0.92 (0.89, 0.97), P=3 × 10(-4)) adjusted for age, sex, ethnicity/population structure and body-mass index (BMI) with no significant between-study heterogeneity (I(2)=0%, P=0.63). The FTO rs9939609 A variant was also associated with increased BMI in the four studies (β 0.30 (0.08, 0.51), P=0.0064) adjusted for age, sex and ethnicity/population structure. In conclusion, we provide the first evidence that the FTO rs9939609 A variant may be associated with a lower risk of depression independently of its effect on BMI. This study highlights the potential importance of obesity predisposing genes on depression.