3 research outputs found

    Non-CG DNA methylation is a biomarker for assessing endodermal differentiation capacity in pluripotent stem cells.

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    Non-CG methylation is an unexplored epigenetic hallmark of pluripotent stem cells. Here we report that a reduction in non-CG methylation is associated with impaired differentiation capacity into endodermal lineages. Genome-wide analysis of 2,670 non-CG sites in a discovery cohort of 25 phenotyped human induced pluripotent stem cell (hiPSC) lines revealed unidirectional loss (Δβ=13%, P<7.4 × 10(-4)) of non-CG methylation that correctly identifies endodermal differentiation capacity in 23 out of 25 (92%) hiPSC lines. Translation into a simplified assay of only nine non-CG sites maintains predictive power in the discovery cohort (Δβ=23%, P<9.1 × 10(-6)) and correctly identifies endodermal differentiation capacity in nine out of ten pluripotent stem cell lines in an independent replication cohort consisting of hiPSCs reprogrammed from different cell types and different delivery systems, as well as human embryonic stem cell (hESC) lines. This finding infers non-CG methylation at these sites as a biomarker when assessing endodermal differentiation capacity as a readout.We thank Kerra Pearce (UCL Genomics) for array processing, and Tim Fell and Jonathan Best (CellCentric), Jason Wray (UCL) and Rosemary Drake (TAP Biosystems) for discussions. We also thank Minal Patel, Chris Kirton, Anja Kolb-Kokocinski, Willem H. Ouwehand, Richard Durbin and Fiona M. Watt on behalf of the Human Induced Pluripotent Stem Cell Initiative (HipSci) funded by grant WT098503 from the Wellcome Trust and the Medical Research Council, for sharing data and materials. This work was supported in part by a TSB/EPSRC grant (TS/H000933/1). The Vallier lab is supported by the Cambridge Hospitals National Institute for Health Research Biomedical Research Center and an ERC Starting Grant (Relieve IMDS). F.A.C.S. is funded by a PhD studentship from Fundação para a Ciência e a Tecnologia (SFRH/BD/69033/2010). The Ferguson-Smith lab is supported by grants from the MRC and Wellcome Trust, and EU-FP7 projects EPIGENESYS (257082) and BLUEPRINT (282510). The Beck lab is supported by the Wellcome Trust (084071), a Royal Society Wolfson Research Merit Award (WM100023), and EU-FP7 projects EPIGENESYS (257082) and BLUEPRINT (282510).This is the final version of the article. It first appeared from Nature Publishing Group via http://dx.doi.org/10.1038/ncomms1045

    Childhood asthma control test: a study of the psychometric properties

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    Background: The international guidelines recognize that the treatment of asthma focuses both on the current control and the risk of exacerbations, based on the management of symptoms which advocate an objective assessment. The Childhood Asthma Control Test (c-ACT) tool allows an assessment of the control of asthma in children and is used in Portugal, but has no validation. Objective: To evaluate the psychometric properties of the c-ACT tool for the Portuguese population. Methodology: A methodological, quantitative, and transversal study, on a sample of 60 children and healthcare providers, for the analysis of the psychometric properties of a measuring tool, written in Portuguese. The internal consistency was evaluated by Cronbach?s alpha, and the factorial validity and reliability of the model were analyzed using exploratory factorial analysis. Results: The tool showed internal consistency, with a Cronbach alpha of 0.716. There are statistically significant correlations between each item and the overall evaluation. Conclusion: The c-ACT tool demonstrated good psychometric properties, giving validity and reliability for use in the Portuguese population.991B-C3B6-3D4F | Salete Soaresinfo:eu-repo/semantics/publishedVersio
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