65 resultados para Estimador de Horvitz-Thompson


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Individuals with depression process information in an overly negative or biased way (e.g., Henriques & Leitenberg, 2002) and demonstrate significant interpersonal dysfunction (e.g., Zlotnick, Kohn, Keitner, & Della Grotta, 2000). This study examined the relationship between cognitive errors (CEs) and interpersonal interactions in early psychotherapy sessions of 25 female patients with major depression. Transcripts were rated for CEs using the Cognitive Error Rating Scale (Drapeau, Perry, & Dunkley, 2008). Interpersonal patterns were assessed using the Structural Analysis of Social Behavior (Benjamin, 1974). Significant associations were found between CEs and markers of interpersonal functioning in selected contexts. The implications of these findings in bridging the gap between research and practice, enhancing treatment outcome, and improving therapist training are discussed. (PsycINFO Database Record (c) 2012 APA, all rights reserved).

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INTRODUCTION: Published prevalence rates of congenital diaphragmatic hernia (CDH) vary. This study aims to describe the epidemiology of CDH using data from high-quality, population-based registers belonging to the European Surveillance of Congenital Anomalies (EUROCAT). METHODS: Cases of CDH delivered between 1980 and 2009 notified to 31 EUROCAT registers formed the population-based case series. Prevalence over time was estimated using multilevel Poisson regression, and heterogeneity between registers was evaluated from the random component of the intercept. RESULTS: There were 3373 CDH cases reported among 12 155 491 registered births. Of 3131 singleton cases, 353 (10.4%) were associated with a chromosomal anomaly, genetic syndrome or microdeletion, 784 (28.2%) were associated with other major structural anomalies. The male to female ratio of CDH cases overall was 1:0.69. Total prevalence was 2.3 (95% CI 2.2 to 2.4) per 10 000 births and 1.6 (95% CI 1.6 to 1.7) for isolated CDH cases. There was a small but significant increase (relative risk (per year)=1.01, 95% credible interval 1.00-1.01; p=0.030) in the prevalence of total CDH over time but there was no significant increase for isolated cases (ie, CDH cases that did not occur with any other congenital anomaly). There was significant variation in total and isolated CDH prevalence between registers. The proportion of cases that survived to 1 week was 69.3% (1392 cases) for total CDH cases and 72.7% (1107) for isolated cases. CONCLUSIONS: This large population-based study found an increase in total CDH prevalence over time. CDH prevalence also varied significantly according to geographical location. No significant association was found with maternal age.

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Patients with Alzheimer's disease (AD) and schizophrenia display cognitive, behavioural disturbances and morphological abnormalities. Although these latter reflect progressive neurodegeneration in AD, their significance in schizophrenia is still unclear. We explored the patterns of hippocampal and amygdalar atrophy in those patients and their associations with clinical parameters. Structural magnetic resonance imaging was performed in 20 elderly schizophrenia patients, 20 AD and 19 healthy older controls. Hippocampal and amygdalar volumes were obtained by manual segmentation with a standardized protocol and compared among groups. In both schizophrenia and AD patients, left hippocampal and amygdalar volumes were significantly smaller. The hippocampus/amygdala ratio was significantly lower in schizophrenia compared to both AD cases [2.4 bilaterally, 95% C.I. 2.2 to 2.7] and healthy controls bilaterally [2.5, 95% C.I. 2.3 to 2.9 in left and 2.7, 95% C.I. 2.4 to 3.1 in right hemisphere]. In schizophrenia patients, a significant positive correlation was found between age at disease onset and the right hippocampus/amygdala volume ratio (Spearman rho=0.56). Negative symptoms correlated with higher right/left amygdala volume ratio (Spearman's rho=0.43). Our data show that unlike AD, the hippocampus/amygdala ratio is abnormally low and correlates with the age at onset in schizophrenia, being a neurodevelopmental signature of the disease.

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BACKGROUND: Single-center reports have identified retrograde ascending aortic dissection (rAAD) as a potentially lethal complication of thoracic endovascular aortic repair (TEVAR). METHODS AND RESULTS: Between 1995 and 2008, 28 centers participating in the European Registry on Endovascular Aortic Repair Complications reported a total of 63 rAAD cases (incidence, 1.33%; 95% CI, 0.75 to 2.40). Eighty-one percent of patients underwent TEVAR for acute (n=26, 54%) or chronic type B dissection (n=13, 27%). Stent grafts with proximal bare springs were used in majority of patients (83%). Only 7 (15%) patients had intraoperative rAAD, with the remaining occurring during the index hospitalization (n=10, 21%) and during follow-up (n=31, 64%). Presenting symptoms included acute chest pain (n=16, 33%), syncope (n=12, 25%), and sudden death (n=9, 19%) whereas one fourth of patients were asymptomatic (n=12, 25%). Most patients underwent emergency (n=25) or elective (n=5) surgical repair. Outcome was fatal in 20 of 48 patients (42%). Causes of rAAD included the stent graft itself (60%), manipulation of guide wires/sheaths (15%), and progression of underlying aortic disease (15%). CONCLUSIONS: The incidence of rAAD was low (1.33%) in the present analysis with high mortality (42%). Patients undergoing TEVAR for type B dissection appeared to be most prone for the occurrence of rAAD. This complication occurred not only during the index hospitalization but after discharge up to 1050 days after TEVAR. Importantly, the majority of rAAD cases were associated with the use of proximal bare spring stent grafts with direct evidence of stent graft-induced injury at surgery or necropsy in half of the patients.

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BACKGROUND: Hirschsprung's disease is a congenital gut motility disorder, characterised by the absence of the enteric ganglion cells along the distal gut. The aim of this study was to describe the epidemiology of Hirschsprung's disease, including additional congenital anomalies, total prevalence, trends, and association with maternal age. METHODS: Cases of Hirschsprung's disease delivered during 1980 to 2009 notified to 31 European Surveillance of Congenital Anomaly registers formed the population-based case-series. Prevalence rates and 95% confidence intervals were calculated as the number of cases per 10,000 births. Multilevel Poisson regression was performed to investigate trends in prevalence, geographical variation and the association with maternal age. RESULTS: There were 1,322 cases of Hirschsprung's disease among 12,146,210 births. The total prevalence was 1.09 (95% confidence interval, 1.03-1.15) per 10,000 births and there was a small but significant increase in prevalence over time (relative risk = 1.01; 95% credible interval, 1.00-1.02; p = 0.004). There was evidence of geographical heterogeneity in prevalence (p < 0.001). Excluding 146 (11.0%) cases with chromosomal anomalies or genetic syndromes, there were 1,176 cases (prevalence = 0.97; 95% confidence interval, 0.91-1.03 per 10,000 births), of which 137 (11.6%) had major structural anomalies. There was no evidence of a significant increased risk of Hirschsprung's disease in cases born to women aged ≥35 years compared with those aged 25 to 29 (relative risk = 1.09; 95% credible interval, 0.91-1.31; p = 0.355). CONCLUSION: This large population-based study found evidence of a small increasing trend in Hirschsprung's disease and differences in prevalence by geographic location. There was also no evidence of an association with maternal age. Birth Defects Research (Part A), 100:695-702, 2014. © 2014 Wiley Periodicals, Inc.

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Urotensin-II controls ion/water homeostasis in fish and vascular tone in rodents. We hypothesised that common genetic variants in urotensin-II pathway genes are associated with human blood pressure or renal function. We performed family-based analysis of association between blood pressure, glomerular filtration and genes of the urotensin-II pathway (urotensin-II, urotensin-II related peptide, urotensin-II receptor) saturated with 28 tagging single nucleotide polymorphisms in 2024 individuals from 520 families; followed by an independent replication in 420 families and 7545 unrelated subjects. The expression studies of the urotensin-II pathway were carried out in 97 human kidneys. Phylogenetic evolutionary analysis was conducted in 17 vertebrate species. One single nucleotide polymorphism (rs531485 in urotensin-II gene) was associated with adjusted estimated glomerular filtration rate in the discovery cohort (p = 0.0005). It showed no association with estimated glomerular filtration rate in the combined replication resource of 8724 subjects from 6 populations. Expression of urotensin-II and its receptor showed strong linear correlation (r = 0.86, p<0.0001). There was no difference in renal expression of urotensin-II system between hypertensive and normotensive subjects. Evolutionary analysis revealed accumulation of mutations in urotensin-II since the divergence of primates and weaker conservation of urotensin-II receptor in primates than in lower vertebrates. Our data suggest that urotensin-II system genes are unlikely to play a major role in genetic control of human blood pressure or renal function. The signatures of evolutionary forces acting on urotensin-II system indicate that it may have evolved towards loss of function since the divergence of primates.

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Neuropeptide-Y (NPY) is a 36-amino acid peptide known to inhibit glucose-stimulated insulin secretion in various animal models in vitro and in vivo. NPY is thought to be one of the mediators of sympathetic action in the pancreas through nerve endings surrounding the islets, and it has recently been shown to be synthesized within the islets of Langerhans. To elucidate the potential role of NPY in the endocrine pancreas, we studied the expression and regulation of NPY secretion in a rat insulinoma cell line (INS-1). NPY mRNA and peptide are highly expressed and secreted by INS-1 cells. NPY levels were determined by a sensitive and specific two-site amplified enzyme-linked immunosorbent assay. Incubation of INS-1 cells with various glucose concentrations did not modify NPY secretion; however, stimulation of adenylate cyclase by forskolin induced a dose- and time-dependent increase in NPY release in the medium. The glucagon-like peptide-I-(7-36) amide (GLP-1), a known gluco-incretin in humans, induced at low concentration (10(-9) M) a similar expression of NPY mRNA and peptide secretion in INS-1 cells. On the other hand, the inhibition of cAMP accumulation by the alpha 2-adrenergic agonist clonidine decreased NPY secretion. In conclusion, 1) high levels of gene expression and secretion of NPY are found in a rat insulinoma cell line (INS-1). 2) Accumulation of cAMP induced by forskolin or a gluco-incretin (GLP-1) induces a further increase in NPY gene expression and release. 3) NPY secretion is not modulated by low or high glucose concentrations in the medium. 4) Induction of NPY, a known inhibitor of insulin secretion, may represent a novel counterregulatory mechanism of insulin secretion, limiting the stimulatory effect of GLP-1 on insulin secretion.

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Islet-Brain 1, also known as JNK-interacting protein-1 (IB1/JIP-1) is a scaffold protein mainly involved in the regulation of the pro-apoptotic signalling cascade mediated by c-Jun-N-terminal kinase (JNK). IB1/JIP-1 organizes JNK and upstream kinases in a complex that facilitates JNK activation. However, overexpression of IB1/JIP-1 in neurons in vitro has been reported to result in inhibition of JNK activation and protection against cellular stress and apoptosis. The occurrence and the functional significance of stress-induced modulations of IB1/JIP-1 levels in vivo are not known. We investigated the regulation of IB1/JIP-1 in mouse hippocampus after systemic administration of kainic acid (KA), in wild-type mice as well as in mice hemizygous for the gene MAPK8IP1, encoding for IB1/JIP-1. We show here that IB1/JIP-1 is upregulated transiently in the hippocampus of normal mice, reaching a peak 8 h after seizure induction. Heterozygous mutant mice underexpressing IB1/JIP-1 showed a higher vulnerability to the epileptogenic properties of KA, whereas hippocampal IB1/JIP-1 levels remained unchanged after seizure induction. Subsequently, an increasing activation of JNK in the 8 h following seizure induction was observed in IB1/JIP-1 haploinsufficient mice, which also underwent more severe excitotoxic lesions in hippocampal CA3, as assessed histologically 3 days after KA administration. Taken together, these data indicate that IB1/JIP-1 in hippocampus participates in the regulation of the neuronal response to excitotoxic stress in a level-dependent fashion.

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OBJECTIVE: Genetic studies might provide new insights into the biological mechanisms underlying lipid metabolism and risk of CAD. We therefore conducted a genome-wide association study to identify novel genetic determinants of low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglycerides. METHODS AND RESULTS: We combined genome-wide association data from 8 studies, comprising up to 17 723 participants with information on circulating lipid concentrations. We did independent replication studies in up to 37 774 participants from 8 populations and also in a population of Indian Asian descent. We also assessed the association between single-nucleotide polymorphisms (SNPs) at lipid loci and risk of CAD in up to 9 633 cases and 38 684 controls. We identified 4 novel genetic loci that showed reproducible associations with lipids (probability values, 1.6×10(-8) to 3.1×10(-10)). These include a potentially functional SNP in the SLC39A8 gene for HDL-C, an SNP near the MYLIP/GMPR and PPP1R3B genes for LDL-C, and at the AFF1 gene for triglycerides. SNPs showing strong statistical association with 1 or more lipid traits at the CELSR2, APOB, APOE-C1-C4-C2 cluster, LPL, ZNF259-APOA5-A4-C3-A1 cluster and TRIB1 loci were also associated with CAD risk (probability values, 1.1×10(-3) to 1.2×10(-9)). CONCLUSIONS: We have identified 4 novel loci associated with circulating lipids. We also show that in addition to those that are largely associated with LDL-C, genetic loci mainly associated with circulating triglycerides and HDL-C are also associated with risk of CAD. These findings potentially provide new insights into the biological mechanisms underlying lipid metabolism and CAD risk.

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Comparative analyses of survival senescence by using life tables have identified generalizations including the observation that mammals senesce faster than similar-sized birds. These generalizations have been challenged because of limitations of life-table approaches and the growing appreciation that senescence is more than an increasing probability of death. Without using life tables, we examine senescence rates in annual individual fitness using 20 individual-based data sets of terrestrial vertebrates with contrasting life histories and body size. We find that senescence is widespread in the wild and equally likely to occur in survival and reproduction. Additionally, mammals senesce faster than birds because they have a faster life history for a given body size. By allowing us to disentangle the effects of two major fitness components our methods allow an assessment of the robustness of the prevalent life-table approach. Focusing on one aspect of life history - survival or recruitment - can provide reliable information on overall senescence.

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Obesity is globally prevalent and highly heritable, but its underlying genetic factors remain largely elusive. To identify genetic loci for obesity susceptibility, we examined associations between body mass index and ∼ 2.8 million SNPs in up to 123,865 individuals with targeted follow up of 42 SNPs in up to 125,931 additional individuals. We confirmed 14 known obesity susceptibility loci and identified 18 new loci associated with body mass index (P < 5 × 10⁻⁸), one of which includes a copy number variant near GPRC5B. Some loci (at MC4R, POMC, SH2B1 and BDNF) map near key hypothalamic regulators of energy balance, and one of these loci is near GIPR, an incretin receptor. Furthermore, genes in other newly associated loci may provide new insights into human body weight regulation.

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Zebrafish and Xenopus have become popular model organisms for studying vertebrate development of many organ systems, including the heart. However, it is not clear whether the single ventricular hearts of these species possess any equivalent of the specialized ventricular conduction system found in higher vertebrates. Isolated hearts of adult zebrafish (Danio rerio) and African toads (Xenopus laevis) were stained with voltage-sensitive dye and optically mapped in spontaneous and paced rhythms followed by histological examination focusing on myocardial continuity between the atrium and the ventricle. Spread of the excitation wave through the atria was uniform with average activation times of 20 +/- 2 and 50 +/- 2 ms for zebrafish and Xenopus toads, respectively. After a delay of 47 +/- 8 and 414 +/- 16 ms, the ventricle became activated first in the apical region. Ectopic ventricular activation was propagated significantly more slowly (total ventricular activation times: 24 +/- 3 vs. 14 +/- 2 ms in zebrafish and 74 +/- 14 vs. 35 +/- 9 ms in Xenopus). Although we did not observe any histologically defined tracts of specialized conduction cells within the ventricle, there were trabecular bands with prominent polysialic acid-neural cell adhesion molecule staining forming direct myocardial continuity between the atrioventricular canal and the apex of the ventricle; i.e., the site of the epicardial breakthrough. We thus conclude that these hearts are able to achieve the apex-to-base ventricular activation pattern observed in higher vertebrates in the apparent absence of differentiated conduction fascicles, suggesting that the ventricular trabeculae serve as a functional equivalent of the His-Purkinje system.

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Although experimental studies have suggested that insulin-like growth factor I (IGF-I) and its binding protein IGFBP-3 might have a role in the aetiology of coronary artery disease (CAD), the relevance of circulating IGFs and their binding proteins in the development of CAD in human populations is unclear. We conducted a nested case-control study, with a mean follow-up of six years, within the EPIC-Norfolk cohort to assess the association between circulating levels of IGF-I and IGFBP-3 and risk of CAD in up to 1,013 cases and 2,055 controls matched for age, sex and study enrolment date. After adjustment for cardiovascular risk factors, we found no association between circulating levels of IGF-I or IGFBP-3 and risk of CAD (odds ratio: 0.98 (95% Cl 0.90-1.06) per 1 SD increase in circulating IGF-I; odds ratio: 1.02 (95% Cl 0.94-1.12) for IGFBP-3). We examined associations between tagging single nucleotide polymorphisms (tSNPs) at the IGF1 and IGFBP3 loci and circulating IGF-I and IGFBP-3 levels in up to 1,133 cases and 2,223 controls and identified three tSNPs (rs1520220, rs3730204, rs2132571) that showed independent association with either circulating IGF-I or IGFBP-3 levels. In an assessment of 31 SNPs spanning the IGF1 or IGFBP3 loci, none were associated with risk of CAD in a meta-analysis that included EPIC-Norfolk and eight additional studies comprising up to 9,319 cases and 19,964 controls. Our results indicate that IGF-I and IGFBP-3 are unlikely to be importantly involved in the aetiology of CAD in human populations.

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Smoking is a leading global cause of disease and mortality. We established the Oxford-GlaxoSmithKline study (Ox-GSK) to perform a genome-wide meta-analysis of SNP association with smoking-related behavioral traits. Our final data set included 41,150 individuals drawn from 20 disease, population and control cohorts. Our analysis confirmed an effect on smoking quantity at a locus on 15q25 (P = 9.45 x 10(-19)) that includes CHRNA5, CHRNA3 and CHRNB4, three genes encoding neuronal nicotinic acetylcholine receptor subunits. We used data from the 1000 Genomes project to investigate the region using imputation, which allowed for analysis of virtually all common SNPs in the region and offered a fivefold increase in marker density over HapMap2 (ref. 2) as an imputation reference panel. Our fine-mapping approach identified a SNP showing the highest significance, rs55853698, located within the promoter region of CHRNA5. Conditional analysis also identified a secondary locus (rs6495308) in CHRNA3.

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The transcriptome is the readout of the genome. Identifying common features in it across distant species can reveal fundamental principles. To this end, the ENCODE and modENCODE consortia have generated large amounts of matched RNA-sequencing data for human, worm and fly. Uniform processing and comprehensive annotation of these data allow comparison across metazoan phyla, extending beyond earlier within-phylum transcriptome comparisons and revealing ancient, conserved features. Specifically, we discover co-expression modules shared across animals, many of which are enriched in developmental genes. Moreover, we use expression patterns to align the stages in worm and fly development and find a novel pairing between worm embryo and fly pupae, in addition to the embryo-to-embryo and larvae-to-larvae pairings. Furthermore, we find that the extent of non-canonical, non-coding transcription is similar in each organism, per base pair. Finally, we find in all three organisms that the gene-expression levels, both coding and non-coding, can be quantitatively predicted from chromatin features at the promoter using a 'universal model' based on a single set of organism-independent parameters.