Detecting associated single-nucleotide polymorphisms on the X chromosome in case control genome-wide association studies (original) (raw)

2014, Statistical methods in medical research

In the past decade, hundreds of genome-wide association studies have been conducted to detect the significant single-nucleotide polymorphisms that are associated with certain diseases. However, most of the data from the X chromosome were not analyzed and only a few significant associated single-nucleotide polymorphisms from the X chromosome have been identified from genome-wide association studies. This is mainly due to the lack of powerful statistical tests. In this paper, we propose a novel statistical approach that combines the information of single-nucleotide polymorphisms on the X chromosome from both males and females in an efficient way. The proposed approach avoids the need of making strong assumptions about the underlying genetic models. Our proposed statistical test is a robust method that only makes the assumption that the risk allele is the same for both females and males if the single-nucleotide polymorphism is associated with the disease for both genders. Through simul...

Kinetics of endothelialization of the multilayer flow modulator and single-layer arterial stents

Vascular, 2015

The multilayer flow modulator (MFM; Cardiatis, Isnes, Belgium) is a self-expandable mesh of braided cobalt alloy wires, used for treatment of aortic and peripheral aneurysms. To further improve our understanding of this novel technology, the endothelialization kinetics of the MFM was investigated and compared with those of two marketed single-layer stents. Five porcine animal models were used in which a total of 19 stents were implanted in the iliac and carotid arteries between one and five weeks before sacrifice. All 19 stents were successfully delivered. For all devices, nonsignificant signs of inflammation or thrombosis were noted, and there was no evidence of local intolerance. The MFM developed a thin layer of endothelial cells earlier and was associated with less neointimal development than the two single-layer stents. A differing phenomenon of integration was also revealed and hypothesized as endothelialization from adhesion of circulating endothelial progenitor cells, as wel...

The effectiveness of helplines for the treatment of alcohol and illicit substance use

Journal of telemedicine and telecare, 2015

While tobacco helplines (quitlines) are thought to be effective, helplines which treat other substance use do not have an established evidence base. A review was conducted of the literature on illicit drug or alcohol (IDA) helplines. The literature search was conducted in five databases. Studies prior to 2014 were included if published in English, and involved the use of a telephone counselling helpline for the treatment of illicit drug or alcohol use. Review papers, opinion pieces, letters or editorials, case studies, published abstracts and posters were excluded. Initial searching identified 2178 articles and after removing duplicates and those meeting the exclusion criteria, there were 36 publications for review. A total of 29 articles provided descriptive information about 19 different IDA helplines which operated in the US (42%), Europe (21%), Australia (21%), Asia (11%) and Canada (5%). These services reported monthly call rates from 3.7 to over 23,000 calls per month. A total...

Dietary Sutherlandia and elderberry mitigate cerebral ischemia-induced neuronal damage and attenuate p47phox and phospho-ERK1/2 expression in microglial cells

ASN neuro, 2014

Sutherlandia (Sutherlandia frutescens) and elderberry (Sambucus spp.) are used to promote health and for treatment of a number of ailments. Although studies with cultured cells have demonstrated antioxidative and anti-inflammatory properties of these botanicals, little is known about their ability to mitigate brain injury. In this study, C57BL/6 J male mice were fed AIN93G diets without or with Sutherlandia or American elderberry for 2 months prior to a 30-min global cerebral ischemia induced by occlusion of the bilateral common carotid arteries (BCCAs), followed by reperfusion for 3 days. Accelerating rotarod assessment at 24 h after BCCA occlusion showed amelioration of sensorimotor impairment in the mice fed the supplemented diets as compared with the ischemic mice fed the control diet. Quantitative digital pathology assessment of brain slides stained with cresyl violet at 3 days after ischemia/reperfusion (I/R) revealed significant reduction in neuronal cell death in both dietar...

Quantitative imaging biomarkers: A review of statistical methods for technical performance assessment

Statistical methods in medical research, 2014

Technological developments and greater rigor in the quantitative measurement of biological features in medical images have given rise to an increased interest in using quantitative imaging biomarkers to measure changes in these features. Critical to the performance of a quantitative imaging biomarker in preclinical or clinical settings are three primary metrology areas of interest: measurement linearity and bias, repeatability, and the ability to consistently reproduce equivalent results when conditions change, as would be expected in any clinical trial. Unfortunately, performance studies to date differ greatly in designs, analysis method, and metrics used to assess a quantitative imaging biomarker for clinical use. It is therefore difficult or not possible to integrate results from different studies or to use reported results to design studies. The Radiological Society of North America and the Quantitative Imaging Biomarker Alliance with technical, radiological, and statistical exp...

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Sussman, T., Yaffe, M., McCusker, J., Burns, V., Strumpf, E., Sewitch, M., & Belzile, E. (2014). A mixed-methods exploration of family members’/friends’ roles in a self-care intervention for depressive symptoms. Chronic Illness 10(2), 93-106. doi: 10.1177/1742395313500359