11 research outputs found

    Genome-wide meta-analysis of myopia and hyperopia provides evidence for replication of 11 loci

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    Refractive error (RE) is a complex, multifactorial disorder characterized by a mismatch between the optical power of the eye and its axial length that causes object images to be focused off the retina. The two major subtypes of RE are myopia (nearsightedness) and hyperopia (farsightedness), which represent opposite ends of the distribution of the quantitative measure of spherical refraction. We performed a fixed effects meta-analysis of genome-wide association results of myopia and hyperopia from 9 studies of European-derived populations: AREDS, KORA, FES, OGP-Talana, MESA, RSI, RSII, RSIII and ERF. One genome-wide significant region was observed for myopia, corresponding to a previously identified myopia locus on 8q12 (p = 1.25610-8), which has been reported by Kiefer et al. as significantly associated with myopia age at onset and Verhoeven et al. as significantly associated to mean spherical-equivalent (MSE) refractive error. We observed two genomewide significant association

    Solvent effects on the conformations and hydrogen bond structure of partially methylated p-tert-butylcalix[4]arenes

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    The effect of the solvent on the conformations of unsubstituted p-tert-butylcalix[4]arene (1) and its methyl ethers 2–6 has been investigated by 1H NMR spectroscopy. The conformational distribution of the 1,2-dimethyl ether 4 and of the tetramethyl ether 6 is strongly influenced by the solvent used. The exact geometry of the cone conformation of the 1,3-dimethyl ether 3 and of the 1,2-dimethyl ether 4 changes from distinct C2 symmetry in CCl4 to close to C4 symmetry in CS2. It seems that inclusion of a small solvent molecule (e.g. CS2) in the cone conformation can take place. Spectra recorded at temperatures up to 125°C in CDCl2CDCl2 showed that the mono- and 1,3-di-methyl ethers are fixed in the cone conformation, whereas the unsubstituted calix[4]arene and the tetramethyl ether are flexible. These observations support a concerted mechanism for the cone-to-cone interconversion in 1, in which two or more phenol rings rotate simultaneously.The hydrogen bonding in partially methylated calix[4]arenes was investigated by IR spectroscopy. In all calix[4]arenes with neighbouring hydroxy groups, a strong cooperativity effect of 80% or more was observed. The exact geometry of the cone conformation affects the strength of the hydrogen bonds, because it influences the O–H O angle in the calix[4]arene. The effect of the solvent on the geometry of the cone conformation is translated in differences of up to 79 cm–1 in the OH-stretch frequencies for spectra recorded in CCl4 and in CS2. \u

    Genome-wide association identifies nine common variants associated with fasting proinsulin levels and provides new insights into the pathophysiology of type 2 diabetes

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    OBJECTIVE - Proinsulin is a precursor of mature insulin and C-peptide. Higher circulating proinsulin levels are associated with impaired b-cell function, raised glucose levels, insulin resistance, and type 2 diabetes (T2D). Studies of the insulin processing pathway could provide new insights about T2D pathophysiology. RESEARCH DESIGN AND METHODS - We have conducted a meta-analysis of genome-wide association tests of ;2.5 million genotyped or imputed single nucleotide polymorphisms (SNPs) and fasting proinsulin levels in 10,701 nondiabetic adults of European ancestry, with follow-up of 23 loci in up to 16,378 individuals, using additive genetic models adjusted for age, sex, fasting insulin, and study-specific covariates. RESULTS - Nine SNPs at eight loci were associated with proinsulin levels (P < 5 Ă— 10-8). Two loci (LARP6 and SGSM2) have not been previously related to metabolic traits, one (MADD) has been associated with fasting glucose, one (PCSK1) has been implicated in obesity, and four (TCF7L2, SLC30A8, VPS13C/ C2CD4A/B, and ARAP1, formerly CENTD2) increase T2D risk. The proinsulin-raising allele of ARAP1 was associated with a lower fasting glucose (P = 1.7 3 10-4), improved b-cell function (P = 1.1 Ă— 10-5), and lower risk of T2D (odds ratio 0.88; P = 7.8 Ă— 10-6). Notably, PCSK1 encodes the protein prohormone convertase 1/3, the first enzyme in the insulin processing pathway. A genotype score composed of the nine proinsulin-raising alleles was not associated with coronary disease in two large case-control datasets. CONCLUSIONS - We have identified nine genetic variants associated with fasting proinsulin. Our findings illuminate the biology underlying glucose homeostasis and T2D development in humans and argue against a direct role of proinsulin in coronary artery disease pathogenesis
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