996 resultados para Ray analyses


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Background and Aims: Vitamin D is an important modulatorof numerous cellular processes. Some of us recently observedan association of the 1a-hydroxylase promoter polymorphismCYP27B1-1260 rs10877012 with sustained virologic response (SVR)in a relatively small number of German patients with chronichepatitis C. In the present study, we aimed to validate thisassociation in a large and well characterized patient cohort, theSwiss Hepatitis C Cohort Study (SCCS). In addition, we examinedthe effect of vitamin D on the hepatitis C virus (HCV) life cyclein vitro.Methods: CYP27B1-1260 rs10877012 and IL28B rs12979860 singlenucleotide polymorphisms (SNPs) were genotyped in 1049 patientswith chronic hepatitis C from the SCCS, of whom 698 were treatedwith pegylated interferon-a (PEG-IFN-a) and ribavirin. In addition,112 patients with spontaneous clearance of HCV were examined.SNPs were correlated with variables reflecting the natural courseand treatment outcome of chronic hepatitis C. The effect of1,25-(OH)2D3 (calcitriol) on HCV replication and viral particleproduction was investigated in vitro using human hepatoma celllines (Huh-7.5) harbouring subgenomic replicons and cell culturederivedHCV.Results: The CYP27B1-1260 rs10877012 genotype was notassociated with SVR in patients with the good-response IL28Brs1279860 CC genotype. However, in patients with poor-responseIL28B rs1279860 genotype CT and TT, CYP27B1-1260 rs10877012was a significant independent predictor of SVR (15% difference inSVR between rs10877012 genotype AA vs. CC, p = 0.030, OR = 1.495,95% CI = 1.038-2.152). The CYPB27-1260 rs10877012 genotype wasneither associated with spontaneous clearance of HCV, nor withliver fibrosis progression rate, inflammatory activity of chronichepatitis C, or HCV viral load. Physiological doses of 1,25-(OH)2D3did not significantly affect HCVRNA replication or infectiousparticle production in vitro.Conclusions: The results of this large-scale genetic validationstudy reveal a role of vitamin D metabolism in the responseto treatment in chronic hepatitis C, but 1,25-(OH)2D3 does notexhibit a significant direct inhibitory antiviral effect. Thus, theability of vitamin D to modulate immunity against HCV shouldbe investigated.

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A lot of research in cognition and decision making suffers from a lack of formalism. The quantum probability program could help to improve this situation, but we wonder whether it would provide even more added value if its presumed focus on outcome models were complemented by process models that are, ideally, informed by ecological analyses and integrated into cognitive architectures.

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The synthesis of spinel ferrites with composition Zn1-2xNaxFe2+xO4has been performed and the composition range in which single phase samples are obtained has been defined. The characterization of the samples has been carried out from atomic absorption and X-ray fluorescence analyses, X-ray diffraction patterns, Mössbauer spectroscopy and thermomagnetic measurements. It is show that significant loss of Na does exist when the synthesis is performed at high temperatures. When the Na volatilization is avoided spinel oxides with Na content up to 0.25 atoms per unit formula can be obtained. In this case the increase of the interatomic distances leads to differing fundamental magnetic properties as compared to the equivalent lithium-zinc ferrites.

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BACKGROUND: Pathological complete response (pCR) following chemotherapy is strongly associated with both breast cancer subtype and long-term survival. Within a phase III neoadjuvant chemotherapy trial, we sought to determine whether the prognostic implications of pCR, TP53 status and treatment arm (taxane versus non-taxane) differed between intrinsic subtypes. PATIENTS AND METHODS: Patients were randomized to receive either six cycles of anthracycline-based chemotherapy or three cycles of docetaxel then three cycles of eprirubicin/docetaxel (T-ET). pCR was defined as no evidence of residual invasive cancer (or very few scattered tumour cells) in primary tumour and lymph nodes. We used a simplified intrinsic subtypes classification, as suggested by the 2011 St Gallen consensus. Interactions between pCR, TP53 status, treatment arm and intrinsic subtype on event-free survival (EFS), distant metastasis-free survival (DMFS) and overall survival (OS) were studied using a landmark and a two-step approach multivariate analyses. RESULTS: Sufficient data for pCR analyses were available in 1212 (65%) of 1856 patients randomized. pCR occurred in 222 of 1212 (18%) patients: 37 of 496 (7.5%) luminal A, 22 of 147 (15%) luminal B/HER2 negative, 51 of 230 (22%) luminal B/HER2 positive, 43 of 118 (36%) HER2 positive/non-luminal, 69 of 221(31%) triple negative (TN). The prognostic effect of pCR on EFS did not differ between subtypes and was an independent predictor for better EFS [hazard ratio (HR) = 0.40, P < 0.001 in favour of pCR], DMFS (HR = 0.32, P < 0.001) and OS (HR = 0.32, P < 0.001). Chemotherapy arm was an independent predictor only for EFS (HR = 0.73, P = 0.004 in favour of T-ET). The interaction between TP53, intrinsic subtypes and survival outcomes only approached statistical significance for EFS (P = 0.1). CONCLUSIONS: pCR is an independent predictor of favourable clinical outcomes in all molecular subtypes in a two-step multivariate analysis. CLINICALTRIALSGOV: EORTC 10994/BIG 1-00 Trial registration number NCT00017095.

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Peripheral assessment of bone density using photon absorptiometry techniques has been available for over 40 yr. The initial use of radio-isotopes as the photon source has been replaced by the use of X-ray technology. A wide variety of models of single- or dual-energy X-ray measurement tools have been made available for purchase, although not all are still commercially available. The Official Positions of the International Society for Clinical Densitometry (ISCD) have been developed following a systematic review of the literature by an ISCD task force and a subsequent Position Development Conference. These cover the technological diversity among peripheral dual-energy X-ray absorptiometry (pDXA) devices; define whether pDXA can be used for fracture risk assessment and/or to diagnose osteoporosis; examine whether pDXA can be used to initiate treatment and/or monitor treatment; provide recommendations for pDXA reporting; and review quality assurance and quality control necessary for effective use of pDXA.

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In this paper we present a new method to track bonemovements in stereoscopic X-ray image series of the kneejoint. The method is based on two different X-ray imagesets: a rotational series of acquisitions of the stillsubject knee that will allow the tomographicreconstruction of the three-dimensional volume (model),and a stereoscopic image series of orthogonal projectionsas the subject performs movements. Tracking the movementsof bones throughout the stereoscopic image series meansto determine, for each frame, the best pose of everymoving element (bone) previously identified in the 3Dreconstructed model. The quality of a pose is reflectedin the similarity between its simulated projections andthe actual radiographs. We use direct Fourierreconstruction to approximate the three-dimensionalvolume of the knee joint. Then, to avoid the expensivecomputation of digitally rendered radiographs (DRR) forpose recovery, we reformulate the tracking problem in theFourier domain. Under the hypothesis of parallel X-raybeams, we use the central-slice-projection theorem toreplace the heavy 2D-to-3D registration of projections inthe signal domain by efficient slice-to-volumeregistration in the Fourier domain. Focusing onrotational movements, the translation-relevant phaseinformation can be discarded and we only consider scalarFourier amplitudes. The core of our motion trackingalgorithm can be implemented as a classical frame-wiseslice-to-volume registration task. Preliminary results onboth synthetic and real images confirm the validity ofour approach.

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Ironstones or petroplinthites are common materials in soils under humid tropical climate, generally defined as the result of Fe oxide accumulation in areas where the water table oscillates, and may exhibit considerable morphological variability. The aim of this study was to examine the internal structure and porosity of an ironstone fragment from a Petroferric Acrudox in Minas Gerais, Brazil, by computed tomography (CT) and conventional techniques. The sample analyzed had total porosity of 59.5 %, with large macropores in the form of tubular channels and irregular vughs, the latter with variable degrees of infilling by material released from the ironstone walls or the soil matrix. The CT scan also showed that the ironstone has wide variation in the density of the solid phase, most likely due to higher concentrations or thick intergrowths of hematite and magnetite/maghemite, especially in its outer rims. The implications of these results for water retention and soil formation in ironstone environments are briefly discussed.

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Introduction: Growth is a central process in paediatrics. Weight and height evaluation are therefore routine exams for every child but in some situation, particularly inflammatory bowel disease (IBD), a wider evaluation of nutritional status needs to be performed. Objectives: To assess the accuracy of bio-impedance analysis (BIA) compared to the gold standard dual energy X-ray absorptiometry (DEXA) in estimating percentage body fat (fat mass; FM) and lean body mass (fat free mass; FFM) in children with inflammatory bowel disease (IBD). To compare FM and FFM levels between patients with IBD and healthy controls. Methods: Twenty-nine healthy controls (12 females; mean age: 12.7 ± 1.9 years) and 21 patients (11 females; 14.3 ± 1.3 years) were recruited from August 2011 to October 2012 at our institution. BIA was performed in all children and DEXA in patients only. Concordance between BIA and DEXA was assessed using Lin's concordance correlation and the Bland-Altman method. Between-group comparisons were made using analysis of variance adjusting for age. Results: BIA-derived FM% showed a good concordance with DEXA-derived values, while BIA-derived FFM% tended to be slightly higher than DEXA-derived values (table). No differences were found between patients and controls regarding body mass index (mean ± SD: 19.3 ± 3.3 vs. 20.1 ± 2.8 kg/m2, respectively; age-adjusted P = 0.08) and FM% (boys: 25.3 ± 10.2 vs. 22.6 ± 7.1%, for patients and controls, respectively; P = 0.20; girls: 28.2 ± 5.7 vs. 26.4 ± 7.7%; P = 0.91). Also, no differences were found regarding FFM% in boys (74.9 ± 10.2 vs. 77.4 ± 7.1%; P = 0.22) and girls (71.8 ± 5.6 vs. 73.5 ± 7.7%; P = 0.85). Conclusion: BIA adequately assesses body composition (FM%) in children with IBD and could advantageously replace DEXA, which is more expensive and less available. No differences in body composition were found between children with IBD and healthy controls.

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An x-ray photoelectron spectroscopy (XPS) analysis of Nb/Al wedge bilayers, oxidized by both plasma and natural oxidation, is reported. The main goal is to show that the oxidation state¿i.e., O:(oxidize)Al ratio¿, structure and thickness of the surface oxide layer, as well as the thickness of the metallic Al leftover, as functions of the oxidation procedure, can be quantitatively evaluated from the XPS spectra. This is relevant to the detailed characterization of the insulating barriers in (magnetic) tunnel junctions

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DnaSP is a software package for the analysis of DNA polymorphism data. Present version introduces several new modules and features which, among other options allow: (1) handling big data sets (~5 Mb per sequence); (2) conducting a large number of coalescent-based tests by Monte Carlo computer simulations; (3) extensive analyses of the genetic differentiation and gene flow among populations; (4) analysing the evolutionary pattern of preferred and unpreferred codons; (5) generating graphical outputs for an easy visualization of results. Availability: The software package, including complete documentation and examples, is freely available to academic users from: http://www.ub.es/dnasp

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The elucidation of mechanisms underlying telencephalic neural development has been limited by the lack of knowledge regarding the molecular and cellular aspects of the ganglionic eminence (GE), an embryonic structure that supplies the brain with diverse sets of GABAergic neurons. Here, we report a comprehensive transcriptomic analysis of this structure including its medial (MGE), lateral (LGE) and caudal (CGE) subdivisions and its temporal dynamics in 12.5 to 16 day-old rat embryos. Surprisingly, comparison across subdivisions showed that CGE gene expression was the most unique providing unbiased genetic evidence for its differentiation from MGE and LGE. The molecular signature of the CGE comprised a large set of genes, including Rwdd3, Cyp26b1, Nr2f2, Egr3, Cpta1, Slit3, and Hod, of which several encode cell signaling and migration molecules such as WNT5A, DOCK9, VSNL1 and PRG1. Temporal analysis of the MGE revealed differential expression of unique sets of cell specification and migration genes, with early expression of Hes1, Lhx2, Ctgf and Mdk, and late enrichment of Olfm3, SerpinE2 and Wdr44. These GE profiles reveal new candidate regulators of spatiotemporally governed GABAergic neuronogenesis.

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BACKGROUND: DNA sequence polymorphisms analysis can provide valuable information on the evolutionary forces shaping nucleotide variation, and provides an insight into the functional significance of genomic regions. The recent ongoing genome projects will radically improve our capabilities to detect specific genomic regions shaped by natural selection. Current available methods and software, however, are unsatisfactory for such genome-wide analysis. RESULTS: We have developed methods for the analysis of DNA sequence polymorphisms at the genome-wide scale. These methods, which have been tested on a coalescent-simulated and actual data files from mouse and human, have been implemented in the VariScan software package version 2.0. Additionally, we have also incorporated a graphical-user interface. The main features of this software are: i) exhaustive population-genetic analyses including those based on the coalescent theory; ii) analysis adapted to the shallow data generated by the high-throughput genome projects; iii) use of genome annotations to conduct a comprehensive analyses separately for different functional regions; iv) identification of relevant genomic regions by the sliding-window and wavelet-multiresolution approaches; v) visualization of the results integrated with current genome annotations in commonly available genome browsers. CONCLUSION: VariScan is a powerful and flexible suite of software for the analysis of DNA polymorphisms. The current version implements new algorithms, methods, and capabilities, providing an important tool for an exhaustive exploratory analysis of genome-wide DNA polymorphism data.