Abstract:
We conducted a case-control genome-wide association study (GWAS) of human longevity, comparing 664,472 autosomal SNPs in 763 long-lived individuals (LLI; mean age: 99.7 years) and 1085 controls (mean age: 60.2 years) from Germany. Only one association, namely that of SNP rs4420638 near the APOC1 gene, achieved genome-wide significance (allele-based P=1.8×10(-10)). However, logistic regression analysis revealed that this association, which was replicated in an independent German sample, is fully explicable by linkage disequilibrium with the APOE allele ɛ4, the only variant hitherto established as a major genetic determinant of survival into old age. Our GWAS failed to identify any additional autosomal susceptibility genes. One explanation for this lack of success in our study would be that GWAS provide only limited statistical power for a polygenic phenotype with loci of small effect such as human longevity. A recent GWAS in Dutch LLI independently confirmed the APOE-longevity association, thus strengthening the conclusion that this locus is a very, if not the most, important genetic factor influencing longevity.

Abstract:
Purpose. To better understand the long-term effect of idiopathic epiretinal membrane (IEM) peeling on retinal anatomy, foveal structure and the thickness of individual retinal layers were analyzed with frequency-domain optical coherence tomography (fdOCT). The long-term postoperative course of macular thickness was followed. Methods. FdOCT scans were obtained from the horizontal midline in 33 eyes long-term (mean 46 ± 13 months) postoperatively and 30 eyes of age-matched controls. Raw images were exported and the thickness of retinal layers was measured with a manual segmentation procedure aided by a customized computer program. Macular thickness was quantified over time with the time-domain (td) OCT Fast Macular Thickness program. Results. Thickness of retinal layers between the outer nuclear and the ganglion cell plus inner plexiform layers in the horizontal midline of the fovea and the nasal parafovea were greater than normal while that of RPE and photoreceptor, and RNFL layers was not different from controls. Twelve of 33 eyes had a foveal pit while the median foveal shape was distorted. Central macular thickness quantified with tdOCT remained increased while the decrease of nasal macular thickness towards normal values was incomplete and delayed to 35 months postoperatively. The superior, temporal, and inferior macular thickness returned to normal after 12-14 months postoperatively. Conclusions. Long-term postoperatively the fovea and the nasal parafovea remain thickened between the outer nuclear and the ganglion cell layer while the superior, temporal, and inferior macular thickness returns to normal. Long-term observations are required in the assessment of macular recovery from mechanical stress.

Abstract:
Genetic matching potentially provides a means to alleviate the effects of incomplete Mendelian randomization in population-based gene-disease association studies. We therefore evaluated the genetic-matched pair study design on the basis of genome-wide SNP data (309 790 markers; Affymetrix GeneChip Human Mapping 500K Array) from 2457 individuals, sampled at 23 different recruitment sites across Europe. Using pair-wise identity-by-state (IBS) as a matching criterion, we tried to derive a subset of markers that would allow identification of the best overall matching (BOM) partner for a given individual, based on the IBS status for the subset alone. However, our results suggest that, by following this approach, the prediction accuracy is only notably improved by the first 20 markers selected, and increases proportionally to the marker number thereafter. Furthermore, in a considerable proportion of cases (76.0%), the BOM of a given individual, based on the complete marker set, came from a different recruitment site than the individual itself. A second marker set, specifically selected for ancestry sensitivity using singular value decomposition, performed even more poorly and was no more capable of predicting the BOM than randomly chosen subsets. This leads us to conclude that, at least in Europe, the utility of the genetic-matched pair study design depends critically on the availability of comprehensive genotype information for both cases and controls.European Journal of Human Genetics advance online publication, 21 January 2009; doi:10.1038/ejhg.2008.266.

Abstract:
Understanding the genetic structure of the European population is important, not only from a historical perspective, but also for the appropriate design and interpretation of genetic epidemiological studies. Previous population genetic analyses with autosomal markers in Europe either had a wide geographic but narrow genomic coverage [1, 2], or vice versa [3-6]. We therefore investigated Affymetrix GeneChip 500K genotype data from 2,514 individuals belonging to 23 different subpopulations, widely spread over Europe. Although we found only a low level of genetic differentiation between subpopulations, the existing differences were characterized by a strong continent-wide correlation between geographic and genetic distance. Furthermore, mean heterozygosity was larger, and mean linkage disequilibrium smaller, in southern as compared to northern Europe. Both parameters clearly showed a clinal distribution that provided evidence for a spatial continuity of genetic diversity in Europe. Our comprehensive genetic data are thus compatible with expectations based upon European population history, including the hypotheses of a south-north expansion and/or a larger effective population size in southern than in northern Europe. By including the widely used CEPH from Utah (CEU) samples into our analysis, we could show that these individuals represent northern and western Europeans reasonably well, thereby confirming their assumed regional ancestry.

Abstract:
PURPOSE: Population-based data about patterns and prevalence of antidepressant drug use is limited in Europe and presently unavailable for Germany. Therefore, we have identified patterns and prevalence of antidepressant use among outpatients on a population-based scale in the German state of Baden-Wuerttemberg. METHODS: We conducted a historical cohort study using a computerised prescription database referring to all members of the major German public health insurance company AOK. We assessed the prevalence of antidepressant drug use over a 3-year period, calculated the number of prescription items purchased per patient and compared first-line and second-line treatments. RESULTS: The 1-year prevalence of antidepressant drug use among more than 4,000,000 health insurance members was 7.4% (male: 4.3%; female: 10.2%). Importantly, almost 40% of the patients received only a single prescription item from 2000 to 2002. Though the use of serotonin-reuptake inhibitors (SSRIs) markedly increased by about 65% within the study period, these are primarily used as second-line drugs and still much less frequently than St. John's wort or tricyclic antidepressants such as amitryptiline or doxepin. CONCLUSIONS: The prevalence of antidepressant drug use is higher than previously reported for other European countries. The preferred use of St. John's wort and tricyclics over SSRIs and other modern-type antidepressants in Germany is quite unique in Europe and different from the US. The identified drug use pattern leaves a major room for improvement in view of the numerous single prescription items purchased.

Abstract:
The mathematical concept previously introduced for the forensic interpretation of DNA mixtures using non-associated genetic markers has been adapted to the assessment of haplotypes. Such calculus is required, for example, when Y-chromosomal markers are used in forensics. In addition to outlining the general mathematical framework, we devise two approaches to its practical computational implementation, involving either the inclusion-exclusion principle of probability theory or a recursion in the number of unknown contributors invoked. The two approaches scale differently, depending upon the complexity of the case and the diversity of the markers used. The performance of Y-chromosomal microsatellites (Y-STRs) as a means of trace donor discrimination has been assessed by simulation, using the derived formulas. Based upon data from the Y-chromosomal Haplotype Reference Database (YHRD), the exclusion chance of a non-contributor is shown to vary between 95% in the case of two contributors, and 70% for five contributors. With only one additional contributor, half of all contributing suspects would yield a log-likelihood ratio in favour of donorship of 1.61 or higher, although the median drops to 0.66 with four additional contributors. It must be emphasised that these estimates of the discriminatory power of Y-STRs are likely to be conservative since the simulations involved only haplotypes known to occur in YHRD.