990 resultados para likelihood function


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Proteins disabled in Fanconi anemia (FA) are necessary for the maintenance of genome stability during cell proliferation. Upon replication stress signaling by ATR, the FA core complex monoubiquitinates FANCD2 and FANCI in order to activate DNA repair. Here, we identified FANCD2 and FANCI in a proteomic screen of replisome-associated factors bound to nascent DNA in response to replication arrest. We found that FANCD2 can interact directly with minichromosome maintenance (MCM) proteins. ATR signaling promoted the transient association of endogenous FANCD2 with the MCM2-MCM7 replicative helicase independently of FANCD2 monoubiquitination. FANCD2 was necessary for human primary cells to restrain DNA synthesis in the presence of a reduced pool of nucleotides and prevented the accumulation of single-stranded DNA, the induction of p21, and the entry of cells into senescence. These data reveal that FANCD2 is an effector of ATR signaling implicated in a general replisome surveillance mechanism that is necessary for sustaining cell proliferation and attenuating carcinogenesis.

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Memory T cells exert antigen-independent effector functions, but how these responses are regulated is unclear. We discovered an in vivo link between flagellin-induced NLRC4 inflammasome activation in splenic dendritic cells (DCs) and host protective interferon-γ (IFN-γ) secretion by noncognate memory CD8(+) T cells, which could be activated by Salmonella enterica serovar Typhimurium, Yersinia pseudotuberculosis and Pseudomonas aeruginosa. We show that CD8α(+) DCs were particularly efficient at sensing bacterial flagellin through NLRC4 inflammasomes. Although this activation released interleukin 18 (IL-18) and IL-1β, only IL-18 was required for IFN-γ production by memory CD8(+) T cells. Conversely, only the release of IL-1β, but not IL-18, depended on priming signals mediated by Toll-like receptors. These findings provide a comprehensive mechanistic framework for the regulation of noncognate memory T cell responses during bacterial immunity.

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The multiscale finite-volume (MSFV) method has been derived to efficiently solve large problems with spatially varying coefficients. The fine-scale problem is subdivided into local problems that can be solved separately and are coupled by a global problem. This algorithm, in consequence, shares some characteristics with two-level domain decomposition (DD) methods. However, the MSFV algorithm is different in that it incorporates a flux reconstruction step, which delivers a fine-scale mass conservative flux field without the need for iterating. This is achieved by the use of two overlapping coarse grids. The recently introduced correction function allows for a consistent handling of source terms, which makes the MSFV method a flexible algorithm that is applicable to a wide spectrum of problems. It is demonstrated that the MSFV operator, used to compute an approximate pressure solution, can be equivalently constructed by writing the Schur complement with a tangential approximation of a single-cell overlapping grid and incorporation of appropriate coarse-scale mass-balance equations.

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Brain oxidative processes play a major role in age-related cognitive decline, thus consumption of antioxidant-rich foods might help preserve cognition. Our aim was to assess whether consumption of antioxidant-rich foods in the Mediterranean diet relates to cognitive function in the elderly. In asymptomatic subjects at high cardiovascular risk (n = 447; 52% women; age 5580 y) enrolled in the PREDIMED study, a primary prevention dietary-intervention trial, we assessed food intake and cardiovascular risk profile, determined apolipoprotein E genotype, and used neuropsychological tests to evaluate cognitive function.We also measured urinary polyphenols as an objective biomarker of intake. Associations between energy-adjusted food consumption, urinary polyphenols, and cognitive scores were assessed by multiple linear regression models adjusted for potential confounders. Consumption of some foods was independently related to better cognitive function. The specific associations [regression coefficients (95% confidence intervals)] were: total olive oil with immediate verbal memory [0.755 (0.1511.358)]; virgin olive oil and coffee with delayed verbal memory [0.163 (0.0100.316) and 0.294 (0.0550.534), respectively];walnuts with working memory [1.191 (0.0612.322)]; and wine with Mini-Mental State Examination scores [0.252 (0.0060.496)]. Urinary polyphenols were associated with better scores in immediate verbal memory [1.208 (0.2362.180)]. Increased consumption of antioxidant-rich foods in general and of polyphenols in particular is associated with better cognitive performance in elderly subjects at high cardiovascular risk. The results reinforce the notion that Mediterranean diet components might counteract age-related cognitive decline.

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Lipin 1 is a coregulator of DNA-bound transcription factors and a phosphatidic acid (PA) phosphatase (PAP) enzyme that catalyzes a critical step in the synthesis of glycerophospholipids. Lipin 1 is highly expressed in adipocytes, and constitutive loss of lipin 1 blocks adipocyte differentiation; however, the effects of Lpin1 deficiency in differentiated adipocytes are unknown. Here we report that adipocyte-specific Lpin1 gene recombination unexpectedly resulted in expression of a truncated lipin 1 protein lacking PAP activity but retaining transcriptional regulatory function. Loss of lipin 1-mediated PAP activity in adipocytes led to reduced glyceride synthesis and increased PA content. Characterization of the deficient mice also revealed that lipin 1 normally modulates cAMP-dependent signaling through protein kinase A to control lipolysis by metabolizing PA, which is an allosteric activator of phosphodiesterase 4 and the molecular target of rapamycin. Consistent with these findings, lipin 1 expression was significantly related to adipose tissue lipolytic rates and protein kinase A signaling in adipose tissue of obese human subjects. Taken together, our findings identify lipin 1 as a reciprocal regulator of triglyceride synthesis and hydrolysis in adipocytes, and suggest that regulation of lipolysis by lipin 1 is mediated by PA-dependent modulation of phosphodiesterase 4.

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The possible immunomodulatory role of polymorphonuclear leukocytes (PMN) in CD4+ T lymphocyte differentiation in mice was examined by studying the effect of transient depletion of PMN during the early phase after Leishmania major delivery. A single injection of the PMN-depleting NIMP-R14 mAb 6 h before infection with L. major prevented the early burst of IL-4 mRNA transcription otherwise occurring in the draining lymph node of susceptible BALB/c mice. Since this early burst of IL-4 mRNA transcripts had previously been shown to instruct Th2 differentiation in mice from this strain, we examined the effect of PMN depletion on Th subset differentiation at later time points after infection. The transient depletion of PMN in BALB/c mice was sufficient to inhibit Th2 cell development otherwise occurring after L. major infection. Decreased Th2 responses were paralleled with partial resolution of the footpad lesions induced by L. major. Furthermore, draining lymph node-derived CD4+ T cells from PMN-depleted mice remained responsive to IL-12 after L. major infection, unlike those of infected BALB/c mice receiving control Ab. PMN depletion had no effect when the NIMP-R14 mAb was injected 24 h postinfection. The protective effect of PMN depletion was shown to be IL-12 dependent, as concomitant neutralization of IL-12 reversed the protective effect of PMN depletion. These results suggest a role for an early wave of PMN in the development of the Th2 response characteristic of mice susceptible to infection with L. major.

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Chronic kidney disease (CKD), impairment of kidney function, is a serious public health problem, and the assessment of genetic factors influencing kidney function has substantial clinical relevance. Here, we report a meta-analysis of genome-wide association studies for kidney function-related traits, including 71,149 east Asian individuals from 18 studies in 11 population-, hospital- or family-based cohorts, conducted as part of the Asian Genetic Epidemiology Network (AGEN). Our meta-analysis identified 17 loci newly associated with kidney function-related traits, including the concentrations of blood urea nitrogen, uric acid and serum creatinine and estimated glomerular filtration rate based on serum creatinine levels (eGFRcrea) (P < 5.0 × 10(-8)). We further examined these loci with in silico replication in individuals of European ancestry from the KidneyGen, CKDGen and GUGC consortia, including a combined total of ∼110,347 individuals. We identify pleiotropic associations among these loci with kidney function-related traits and risk of CKD. These findings provide new insights into the genetics of kidney function.

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RESUME: Contexte : l'objectif de cette étude de cohorte prospective était de déterminer la relation entre la survenue d'infections et la dépendance fonctionnelle chez des résidents d'établissements de long séjour durant une période de 6 mois. Population et méthode : les patients inclus (1324 résidents) étaient âgés de 65 ans et plus (âge moyen 85.7 ans, 76.6% de femmes), étaient des résidents de 39 EMS du canton de Vaud. Au baseline, des données démographiques, médicales, concernant les facteurs de risque et protecteurs des infections ont été récoltées. Au cours du suivi de 6 mois, les infirmières des EMS ont documenté la survenue de symptômes et signes d'infection en utilisant les critères développés spécifiquement par l'APIC pour les établissements de long séjour. Les mesures du status fonctionnel ont été évaluées au baseline, à 3 mois et à 6 mois. Deux outcomes différents ont été utilisés : a) le déclin fonctionnel défini comme le décès ou une diminution des capacités fonctionnelles au suivi, b) le status fonctionnel mesuré par une échelle standardisée. Résultats : à la fin du suivi, la mortalité était de 14.6%, similaire pour les résidents avec et sans infection (16.2% versus 13.1%, P .11). Durant les 2 périodes de suivi de 3 mois, les sujets ayant présenté une ou plusieurs infections avaient des odds de déclin fonctionnel plus élevés, y compris après ajustement pour les caractéristiques démographiques, médicales et fonctionnelles du baseline, ainsi que la survenue de nouvelles maladies (odds ratio ajustés (OR) = 1.6, intervalle de confiance à 95% (IC) = 1.2-2.2, P = .002 et OR = 1.5, 95% IC= 1.1-2.0, P= .008, respectivement). Comparés aux résidents non infectés, les odds de déclin fonctionnel augmentaient significativement et graduellement chez ceux ayant eu une, respectivement 2 infections ou plus. L'analyse prédisant le score fonctionnel (restreinte aux sujets ayant survécu) a donné des résultats similaires. Finalement, une analyse de survie prédisant le temps jusqu'à la première infection a confirmé une augmentation progressive de la probabilité d'infection chez les sujets avec dépendance fonctionnelle modérée, respectivement sévère, comparés aux sujets indépendants à la ligne de base. Conclusion : chez les résidents de long séjour, les infections sont à la fois cause et conséquence de la dépendance fonctionnelle. Des études futures devraient être entreprises pour investiguer si des programmes de prévention des infections peuvent également contribuer à prévenir le déclin fonctionnel, un facteur important pour la qualité de vie de ces résidents. ABSTRACT: Objectives: To determine the relationship between infections and functional impairment in nursing home residents. Design: Prospective cohort study (follow-up period, 6 months). Setting: Thirty-nine nursing homes in western Switzerland. Participants: A total of 1,324 residents aged 65 and older (mean age 85.7; 76.6% female) who agreed to participate, or their proxies, by oral informed consent. Measurements: Functional status measured every 3 months. Two different outcomes were used: (a) functional decline defined as death or decreased function at follow-up and (b) functional status score using a standardized measure. Results: At the end of follow-up, mortality was 14.6%, not different for those with and without infection (16.2% vs 13.1%, P= .11) During both 3-month periods, subjects with infection had higher odds of functional decline, even after adjustment for baseline characteristics and occurrence of a new illness (adjusted odds ratio (AOR) = 1.6, 95% confidence interval (CI) = 1.2-2.2, P = .002, and AOR 1.5, 95% CI 1.1-2.0, P .008, respectively). The odds of decline increased in a stepwise fashion in patients with zero, one, and two or more infections. The analyses predicting functional status score (restricted to subjects who survived) gave similar results. A survival analysis predicting time to first infection confirmed a stepwise greater likelihood of infection in subjects -with moderate and severe impairment at baseline than in subjects with no or mild functional impairment at baseline. Conclusion: Infections appear to be both a cause and a consequence of functional impairment in nursing home residents. Further studies should be undertaken to investigate whether effective infection control programs can also contribute to preventing functional decline, an important component of these residents' quality of life.

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Background: The combined serum creatinine (SCreat) and cystatin C (CysC) CKD-EPI formula constitutes a new advance for glomerular filtration rate (GFR) estimation in adults. Using inulin clearances (iGFRs), the revised SCreat and the combined Schwartz formulas, this study aims to evaluate the applicability of the combined CKD-EPI formula in children. Method: 201 iGFRs for 201 children were analyzed and divided by chronic kidney disease (CKD) stages (iGFRs ≥90 ml/min/1.73 m(2), 90 > iGFRs > 60, and iGFRs ≤59), and by age groups (<10, 10-15, and >15 years). Medians with 95% confidence intervals of bias, precision, and accuracies within 30% of the iGFRs, for all three formulas, were compared using the Wilcoxon signed-rank test. Results: For the entire cohort and for all CKD and age groups, medians of bias for the CKD-EPI formula were significantly higher (p < 0.001) and precision was significantly lower than the solely SCreat and the combined SCreat and CysC Schwartz formulas. We also found that using the CKD-EPI formula, bias decreased and accuracy increased while the child age group increased, with a better formula performance above 15 years of age. However, the CKD-EPI formula accuracy is 58% compared to 93 and 92% for the SCreat and combined Schwartz formulas in this adolescent group. Conclusions: The performance of the combined CKD-EPI formula improves in adolescence compared with younger ages. Nevertheless, the CKD-EPI formula performs more poorly than the SCreat and the combined Schwartz formula in pediatric population. © 2013 S. Karger AG, Basel.

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The hypothesis that ornaments can honestly signal quality only if their expression is condition-dependent has dominated the study of the evolution and function of colour traits. Much less interest has been devoted to the adaptive function of colour traits for which the expression is not, or is to a low extent, sensitive to body condition and the environment in which individuals live. The aim of the present paper is to review the current theoretical and empirical knowledge of the evolution, maintenance and adaptive function of colour plumage traits for which the expression is mainly under genetic control. The finding that in many bird species the inheritance of colour morphs follows the laws of Mendel indicates that genetic colour polymorphism is frequent. Polymorphism may have evolved or be maintained because each colour morph facilitates the exploitation of alternative ecological niches as suggested by the observation that individuals are not randomly distributed among habitats with respect to coloration. Consistent with the hypothesis that different colour morphs are linked to alternative strategies is the finding that in a majority of species polymorphism is associated with reproductive parameters, and behavioural, life-history and physiological traits. Experimental studies showed that such covariations can have a genetic basis. These observations suggest that colour polymorphism has an adaptive function. Aviary and field experiments demonstrated that colour polymorphism is used as a criterion in mate-choice decisions and dominance interactions confirming the claim that conspecifics assess each other's colour morphs. The factors favouring the evolution and maintenance of genetic variation in coloration are reviewed, but empirical data are virtually lacking to assess their importance. Although current theory predicts that only condition-dependent traits can signal quality, the present review shows that genetically inherited morphs can reveal the same qualities. The study of genetic colour polymorphism will provide important and original insights on the adaptive function of conspicuous traits.

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AIMS: Women and men have different clinical presentations and outcomes in coronary artery disease (CAD). We tested the hypothesis that sex differences may influence coronary atherosclerotic burden and coronary endothelial function before development of obstructive CAD. METHODS AND RESULTS: A total of 142 patients (53 men, 89 women; mean +/- SD age, 49.3 +/- 11.7 years) with early CAD simultaneously underwent intravascular ultrasonography and coronary endothelial function assessment. Atheroma burden in the left main and proximal left anterior descending (LAD) arteries was significantly greater in men than women (median, 23.0% vs. 14.1%, P = 0.002; median, 40.1% vs. 29.3%, P = 0.001, respectively). Atheroma eccentricity in the proximal LAD artery was significantly higher in men than women (median, 0.89 vs. 0.80, P = 0.04). The length of the coronary segments with endothelial dysfunction was significantly longer in men than women (median, 39.2 vs. 11.1 mm, P = 0.002). In contrast, maximal coronary flow reserve was significantly lower in women than men (2.80 vs. 3.30, P < 0.001). Sex was an independent predictor of atheroma burden in the left main and proximal LAD arteries (both P < 0.05) by multivariate analysis. CONCLUSION: Men have greater atheroma burden, more eccentric atheroma, and more diffuse epicardial endothelial dysfunction than women. These results suggest that men have more severe structural and functional abnormalities in epicardial coronary arteries than women, even in patients with early atherosclerosis, which may result in the higher incidence rates of CAD and ST-segment myocardial infarction in men than women.

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PURPOSE OF REVIEW: Previous studies have shown that a variety of specific renal functions exhibit circadian oscillations. This review aims to provide an update on the molecular mechanisms underlying circadian rhythms in the kidney, and to discuss how dysregulation of circadian rhythms can interfere with kidney function. RECENT FINDINGS: The molecular mechanism responsible for generating and maintaining circadian rhythms has been unraveled in great detail. This mechanism, known as the circadian clock, drives circadian oscillation in expression levels of a large number of renal mRNA transcripts. Several proteins critically involved in renal homeostatic functions have been shown to exhibit significant circadian oscillation in their expression levels or in their posttranslational modifications. In transgenic mouse models, disruption of circadian clock activity results in dramatic changes in the circadian pattern of urinary sodium and potassium excretion and causes significant changes in arterial blood pressure. A growing amount of evidence suggests that dysregulation of circadian rhythms is associated with the development of hypertension and accelerated progression of chronic kidney disease and cardiovascular disease in humans. Chronotherapy studies have shown that the efficacy of antihypertensive medication is greatly dependent on the circadian time of drug administration. SUMMARY: Recent research points to the major role of circadian rhythms in renal function and in control of blood pressure.

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Two likelihood ratio (LR) approaches are presented to evaluate the strength of evidence of MDMA tablet comparisons. The first one is based on a more 'traditional' comparison of MDMA tablets by using distance measures (e.g., Pearson correlation distance or a Euclidean distance). In this approach, LRs are calculated using the distribution of distances between tablets of the same-batch and that of different-batches. The second approach is based on methods used in some other fields of forensic comparison. Here LRs are calculated based on the distribution of values of MDMA tablet characteristics within a specific batch and from all batches. The data used in this paper must be seen as examples to illustrate both methods. In future research the methods can be applied to other and more complex data. In this paper, the methods and their results are discussed, considering their performance in evidence evaluation and several practical aspects. With respect to evidence in favor of the correct hypothesis, the second method proved to be better than the first one. It is shown that the LRs in same-batch comparisons are generally higher compared to the first method and the LRs in different-batch comparisons are generally lower. On the other hand, for operational purposes (where quick information is needed), the first method may be preferred, because it is less time consuming. With this method a model has to be estimated only once in a while, which means that only a few measurements have to be done, while with the second method more measurements are needed because each time a new model has to be estimated.

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Objectives-Peroxisome proliferator-activated receptor beta/delta (PPAR beta/delta) is a nuclear receptor found in platelets. PPAR beta/delta agonists acutely inhibit platelet function within a few minutes of addition. As platelets are anucleated, the effects of PPAR beta/delta agonists on platelets must be nongenomic. Currently, the particular role of PPAR beta/delta receptors and their intracellular signaling pathways in platelets are not known. Methods and Results-We have used mice lacking PPAR beta/delta (PPAR beta/delta(-/-)) to show the effects of the PPAR beta/delta agonist GW501516 on platelet adhesion and cAMP levels are mediated specifically by PPAR beta/delta, however GW501516 had no PPAR beta/delta-specific effect on platelet aggregation. Studies in human platelets showed that PKC alpha, which can mediate platelet activation, was bound and repressed by PPAR beta/delta after platelets were treated with GW501516. Conclusions-These data provide evidence of a novel mechanism by which PPAR receptors influence platelet activity and thereby thrombotic risk. (Arterioscler Thromb Vasc Biol. 2009; 29: 1871-1873.)