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Chakravarthy U.,Queens University of Belfast | McKay G.J.,Queens University of Belfast | De Jong P.T.V.M.,Netherlands Institute of Neuroscience | Rahu M.,National Institute for Health Development | And 10 more authors.
Ophthalmology | Year: 2013

Objective: To study associations between severity stages of early and late age-related macular degeneration (AMD) and genetic variations in age-related maculopathy susceptibility 2 (ARMS2) and complement factor H (CFH) and to investigate potential interactions between smoking and ARMS2. Design: Population-based, cross-sectional European Eye Study in 7 countries in Europe. Participants: Four thousand seven hundred fifty participants, 65 years of age and older, recruited through random sampling. Methods: Participants were classified on the basis of the more severely affected eye into 5 mutually exclusive AMD severity stages ranging from no AMD, 3 categories of early AMD, and late AMD. History of cigarette smoking was available and allowed classification into never, former, and current smokers, with the latter 2 groups combined into a single category of ever smokers for analysis. Genotyping was performed for single nucleotide polymorphisms rs10490924 and rs4146894 in ARMS2 and rs1061170 in CFH. Associations were analyzed by logistic regression. Main Outcome Measures: Odds ratios (ORs) for stage of AMD associated with genetic variations in ARMS2 and CFH and interactions between ARMS2 and smoking status. Results: Early AMD was present in 36.4% and late AMD was present in 3.3% of participants. Data on both genotype and AMD were available for 4276 people. The ORs for associations between AMD stage and ARMS2 increased monotonically with more severe stages of early AMD and were altered little by adjustment for potential confounders. Compared with persons with no AMD, carriers of the TT genotype for rs10490924 in ARMS2 had a 10-fold increase in risk of late AMD (P<3×10-20). The ORs for associations with CFH were similar for stage 3 early AMD and late AMD. Interactions between rs10490924 in ARMS2 and smoking status were significant in both unadjusted and adjusted models (P = 0.001). The highest risk was observed in those doubly homozygous for rs10490924 and rs1061170 in CFH (OR, 62.3; 95% confidence interval, 16-242), with P values for trend ranging from 0.03 (early AMD, stage 1) to 1×10-26 (late AMD). Conclusions: A strong association was demonstrated between all stages of AMD and genetic variation in ARMS2, and a significant gene-environment interaction with cigarette smoking was confirmed. Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article. © 2013 American Academy of Ophthalmology.

Kamran Ikram M.,Erasmus Medical Center | Xueling S.,National University of Singapore | Jensen R.A.,University of Washington | Cotch M.F.,U.S. National Institutes of Health | And 67 more authors.
PLoS Genetics | Year: 2010

There is increasing evidence that the microcirculation plays an important role in the pathogenesis of cardiovascular diseases. Changes in retinal vascular caliber reflect early microvascular disease and predict incident cardiovascular events. We performed a genome-wide association study to identify genetic variants associated with retinal vascular caliber. We analyzed data from four population-based discovery cohorts with 15,358 unrelated Caucasian individuals, who are members of the Cohort for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium, and replicated findings in four independent Caucasian cohorts (n = 6,652). All participants had retinal photography and retinal arteriolar and venular caliber measured from computer software. In the discovery cohorts, 179 single nucleotide polymorphisms (SNP) spread across five loci were significantly associated (p<5.0×10-8) with retinal venular caliber, but none showed association with arteriolar caliber. Collectively, these five loci explain 1.0%-3.2% of the variation in retinal venular caliber. Four out of these five loci were confirmed in independent replication samples. In the combined analyses, the top SNPs at each locus were: rs2287921 (19q13; p = 1.61×10-25, within the RASIP1 locus), rs225717 (6q24; p = 1.25×10-16, adjacent to the VTA1 and NMBR loci), rs10774625 (12q24; p = 2.15×10-13, in the region of ATXN2,SH2B3 and PTPN11 loci), and rs17421627 (5q14; p = 7.32×10-16, adjacent to the MEF2C locus). In two independent samples, locus 12q24 was also associated with coronary heart disease and hypertension. Our population-based genome-wide association study demonstrates four novel loci associated with retinal venular caliber, an endophenotype of the microcirculation associated with clinical cardiovascular disease. These data provide further insights into the contribution and biological mechanisms of microcirculatory changes that underlie cardiovascular disease.

Brock O.,Netherlands Institute of Neuroscience | Bakker J.,University of Liege | Baum M.J.,Boston University
Methods in Molecular Biology | Year: 2013

Behavioral testing methods are described for determining whether female mice can discriminate between volatile urinary pheromones of conspecifics of the same vs. opposite sex and/or in different endocrine conditions, for determining sexual partner preference, for quantifying receptive (lordosis) behavior, and for monitoring the expression of male-typical mounting behavior in female mice. © 2013 Springer Science+Business Media, LLC.

Littink K.W.,Rotterdam Eye Hospital | Littink K.W.,Radboud University Nijmegen | Van Genderen M.M.,Bartimeus Institute for the Visually Impaired | Van Schooneveld M.J.,Netherlands Institute of Neuroscience | And 9 more authors.
Ophthalmology | Year: 2012

Purpose: To determine the genetic defect and to describe the clinical characteristics in patients with retinitis punctata albescens (RPA) and fundus albipunctatus (FAP). Design: Case series/observational study. Participants: We included 13 patients affected by RPA or FAP. Methods: Thirteen patients were collected from 8 families with a retinal dystrophy characterized by tiny, yellow-white dots on funduscopy, typical for FAP or RPA. All patients underwent full ophthalmologic examinations, including visual field assessment. Fundus photography, and electroretinography were performed in 12 patients, and optical coherence tomography and fundus autofluorescence were performed in 4 patients. DNA samples of all patients were screened for mutations in RLBP1 and for mutations in RDH5 in patients who did not carry mutations in RLBP1. DNA samples of 2 sibling pairs of nonconsanguineous families who carried mutations neither in RLBP1 nor in RDH5 were analyzed by genome-wide homozygosity mapping. Sequence analysis was performed of LRAT, a candidate gene in a shared homozygous region. Main Outcome Measures: We assessed DNA sequence variants, best-corrected visual acuity, fundus appearance, visual field measurements, electroretinogram responses, optical coherence tomography, and fundus autofluorescence. Results: A homozygous frameshift mutation was identified in LRAT in 4 patients with RPA. Mutations in RLBP1 were identified in 7 patients with RPA and in 1 patient with FAP and cone dystrophy. One patient had compound heterozygous mutations in RDH5 and suffered from FAP with mild maculopathy. Conclusions: A genetic defect was identified in LRAT as a novel cause of RPA. LRAT is therefore the fourth gene involved in the visual cycle that may cause a white-dot retinopathy. We also revealed that mutations in RLBP1 may lead to FAP with cone dystrophy. Financial Disclosure(s): The authors have no proprietary or commercial interest in any materials discussed in this article. © 2012 American Academy of Ophthalmology.

de Oliveira R.B.,University of Newcastle | Graham B.,University of Newcastle | Howlett M.C.H.,University of Newcastle | Howlett M.C.H.,Netherlands Institute of Neuroscience | And 8 more authors.
Journal of Neuroscience Methods | Year: 2010

The dissociative anesthetic ketamine that acts as an N-methyl-D-aspartate (NMDA) antagonist has been reported to improve neurological damage after experimental ischemic challenges. Here we show that deep anesthesia with ketamine before euthanasia by decapitation improves the quality of neonatal mouse neuronal brain slice preparations. Specifically we found that neurons of the locus coeruleus (LC) and hypoglossal motor neurons had significantly higher input resistances, and LC neurons that generally are difficult to voltage control, could be more reliably voltage clamped compared to control neurons. © 2010 Elsevier B.V.

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