In vivo confirmation of hydration-induced changes in human-skin thickness, roughness and interaction with the environment

Skin properties, structure and performance can be influenced by many internal and external factors, such as age, gender, lifestyle, skin diseases and a hydration level that can vary in relation to the environment. The aim of this work was to demonstrate the multifaceted influence of water on human skin through a combination of in vivo confocal Raman spectroscopy and images of volar-forearm skin captured with laser scanning confocal microscopy. By means of this pilot study, we have both qualitatively and quantitatively studied the influence of changing the depth-dependent hydration level of the stratum corneum (SC) on the real contact area (RCA), surface roughness and the dimensions of the primary lines and presented a new method for characterising the contact area for different states of the skin. The hydration level of the skin and the thickness of the SC increased significantly due to uptake of moisture derived from liquid water or, to a much lesser extent, from humidity present in the environment. Hydrated skin was smoother and exhibited higher RCA values. The highest rates of water uptake were observed for the upper few μm of skin and for short exposure times

A genome-wide association study of anorexia nervosa

Anorexia nervosa (AN) is a complex and heritable eating disorder characterized by dangerously low body weight. Neither candidate gene studies nor an initial genome wide association study (GWAS) have yielded significant and replicated results. We performed a GWAS in 2,907 cases with AN from 14 countries (15 sites) and 14,860 ancestrally matched controls as part of the Genetic Consortium for AN (GCAN) and the Wellcome Trust Case Control Consortium 3 (WTCCC3). Individual association analyses were conducted in each stratum and meta-analyzed across all 15 discovery datasets. Seventy-six (72 independent) SNPs were taken forward for in silico (two datasets) or de novo (13 datasets) replication genotyping in 2,677 independent AN cases and 8,629 European ancestry controls along with 458 AN cases and 421 controls from Japan. The final global meta-analysis across discovery and replication datasets comprised 5,551 AN cases and 21,080 controls. AN subtype analyses (1,606 AN restricting; 1,445 AN binge-purge) were performed. No findings reached genome-wide significance. Two intronic variants were suggestively associated: rs9839776 (P=3.01×10−7) in SOX2OT and rs17030795 (P=5.84×10−6) in PPP3CA. Two additional signals were specific to Europeans: rs1523921 (P=5.76×10−6) between CUL3 and FAM124B and rs1886797 (P=8.05×10−6) near SPATA13. Comparing discovery to replication results, 76% of the effects were in the same direction, an observation highly unlikely to be due to chance (P= 4×10−6), strongly suggesting that true findings exist but that our sample, the largest yet reported, was underpowered for their detection. The accrual of large genotyped AN case-control samples should be an immediate priority for the field

A genome-wide association study of anorexia nervosa suggests a risk locus implicated in dysregulated leptin signaling

J. Kaprio, A. Palotie, A. Raevuori-Helkamaa ja S. Ripatti ovat työryhmän Eating Disorders Working Group of the Psychiatric Genomics Consortium jäseniä. Erratum in: Sci Rep. 2017 Aug 21;7(1):8379, doi: 10.1038/s41598-017-06409-3We conducted a genome-wide association study (GWAS) of anorexia nervosa (AN) using a stringently defined phenotype. Analysis of phenotypic variability led to the identification of a specific genetic risk factor that approached genome-wide significance (rs929626 in EBF1 (Early B-Cell Factor 1); P = 2.04 x 10(-7); OR = 0.7; 95% confidence interval (CI) = 0.61-0.8) with independent replication (P = 0.04), suggesting a variant-mediated dysregulation of leptin signaling may play a role in AN. Multiple SNPs in LD with the variant support the nominal association. This demonstrates that although the clinical and etiologic heterogeneity of AN is universally recognized, further careful sub-typing of cases may provide more precise genomic signals. In this study, through a refinement of the phenotype spectrum of AN, we present a replicable GWAS signal that is nominally associated with AN, highlighting a potentially important candidate locus for further investigation.Peer reviewe

A water-responsive, gelatine-based human skin model

The properties of human skin strongly depend on hydration. Skin friction, elasticity and roughness change significantly in the presence of water. This paper presents a new bio-mimicking gelatine-based physical skin model that simulates the frictional behaviour of human skin against a widely-used standard textile under dry and wet conditions and over a broad range of applied normal load (0.5–5 N) and amount of water at the interface (0–100 μl/cm2). The proposed skin model shows good agreement with the frictional behaviour of human skin both in dry and wet conditions. In addition, the tensile Young's modulus and surface roughness exhibit changes as a function of the amount of water that are similar to those of human skin. Potential applications of the model are in the testing and development of textile materials that mechanically interact with human skin.ISSN:0301-679