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Your search keyword '"Jennifer G. Sambrook"' showing total 2 results
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2 results on '"Jennifer G. Sambrook"'

1. Powerful identification of cis-regulatory SNPs in human primary monocytes using allele-specific gene expression.

Author

Jonas Carlsson Almlöf, Per Lundmark, Anders Lundmark, Bing Ge, Seraya Maouche, Harald H H Göring, Ulrika Liljedahl, Camilla Enström, Jessy Brocheton, Carole Proust, Tiphaine Godefroy, Jennifer G Sambrook, Jennifer Jolley, Abigail Crisp-Hihn, Nicola Foad, Heather Lloyd-Jones, Jonathan Stephens, Rhian Gwilliam, Catherine M Rice, Christian Hengstenberg, Nilesh J Samani, Jeanette Erdmann, Heribert Schunkert, Tomi Pastinen, Panos Deloukas, Alison H Goodall, Willem H Ouwehand, François Cambien, and Ann-Christine Syvänen

Subjects
Medicine, Science
Abstract

A large number of genome-wide association studies have been performed during the past five years to identify associations between SNPs and human complex diseases and traits. The assignment of a functional role for the identified disease-associated SNP is not straight-forward. Genome-wide expression quantitative trait locus (eQTL) analysis is frequently used as the initial step to define a function while allele-specific gene expression (ASE) analysis has not yet gained a wide-spread use in disease mapping studies. We compared the power to identify cis-acting regulatory SNPs (cis-rSNPs) by genome-wide allele-specific gene expression (ASE) analysis with that of traditional expression quantitative trait locus (eQTL) mapping. Our study included 395 healthy blood donors for whom global gene expression profiles in circulating monocytes were determined by Illumina BeadArrays. ASE was assessed in a subset of these monocytes from 188 donors by quantitative genotyping of mRNA using a genome-wide panel of SNP markers. The performance of the two methods for detecting cis-rSNPs was evaluated by comparing associations between SNP genotypes and gene expression levels in sample sets of varying size. We found that up to 8-fold more samples are required for eQTL mapping to reach the same statistical power as that obtained by ASE analysis for the same rSNPs. The performance of ASE is insensitive to SNPs with low minor allele frequencies and detects a larger number of significantly associated rSNPs using the same sample size as eQTL mapping. An unequivocal conclusion from our comparison is that ASE analysis is more sensitive for detecting cis-rSNPs than standard eQTL mapping. Our study shows the potential of ASE mapping in tissue samples and primary cells which are difficult to obtain in large numbers.

Published
2012
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2. Association between Walking Speed and Age in Healthy, Free-Living Individuals Using Mobile Accelerometry—A Cross-Sectional Study

Author

Carmel Moore, Christian Lederer, Willem H. Ouwehand, Michaela Schimpl, Jennifer G. Sambrook, Martin Daumer, Anneke Neuhaus, and John Danesh

Subjects
Male, Aging, Anatomy and Physiology, Epidemiology, Cross-sectional study, Blood Pressure, Walking, Body Mass Index, 0302 clinical medicine, Interquartile range, 030212 general & internal medicine, Musculoskeletal System, Gait, Multidisciplinary, Epidemiology of Aging, Middle Aged, Databases as Topic, Health, Medicine, Female, Public Health, Algorithms, Research Article, Biotechnology, Adult, Drugs and Devices, medicine.medical_specialty, Adolescent, Science, Acceleration, Bioengineering, Context (language use), Biology, Medical Devices, Young Adult, 03 medical and health sciences, medicine, Humans, Sports and Exercise Medicine, Aged, Evolutionary Biology, Population Biology, Body Weight, Reproducibility of Results, Actigraphy, Body Height, Preferred walking speed, Cross-Sectional Studies, Gait analysis, Physical therapy, Exertion, Preventive Medicine, Physiological Processes, Organism Development, human activities, Body mass index, 030217 neurology & neurosurgery, Developmental Biology
Abstract

ContextWalking speed is a fundamental parameter of human motion and is increasingly considered as an important indicator of individuals' health status.ObjectiveTo evaluate the relationship of gait parameters, and demographic and physical characteristics in healthy men and women.Design, setting, and participantsRecruitment of a subsample (n = 358) of male and female blood donors taking part in the Cambridge CardioResource study. Collection of demographic data, measurement of physical characteristics (height, weight and blood pressure) and assessment of 7-day, free-living activity parameters using accelerometry and a novel algorithm to measure walking speed. Participants were a median (interquartile range[IQR]) age of 49 (16) years; 45% women; and had a median (IQR) BMI of 26 (5.4).Main outcome measureWalking speed.ResultsIn this study, the hypothesis that walking speed declines with age was generated using an initial 'open' dataset. This was subsequently validated in a separate 'closed' dataset that showed a decrease of walking speed of -0.0037 m/s per year. This is equivalent to a difference of 1.2 minutes, when walking a distance of 1 km aged 20 compared to 60 years. Associations between walking speed and other participant characteristics (i.e. gender, BMI and blood pressure) were non-significant. BMI was negatively correlated with the number of walking and running steps and longest non-stop distance.ConclusionThis is the first study using accelerometry which shows an association between walking speed and age in free-living, healthy individuals. Absolute values of gait speed are comparable to published normal ranges in clinical settings. This study highlights the potential use of mobile accelerometry to assess gait parameters which may be indicative of future health outcomes in healthy individuals.

Published
2011

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