Genetic effects on the skin methylome in healthy older twins.

Whole-skin DNA methylation variation has been implicated in several diseases, including melanoma, but its genetic basis has not yet been fully characterized. Using bulk skin tissue samples from 414 healthy female UK twins, we performed twin-based heritability and methylation quantitative trait loci (meQTL) analyses for >400,000 DNA methylation sites. We find that the human skin DNA methylome is on average less heritable than previously estimated in blood and other tissues (mean heritability: 10.02%). meQTL analysis identified local genetic effects influencing DNA methylation at 18.8% (76,442) of tested CpG sites, as well as 1,775 CpG sites associated with at least one distal genetic variant. As a functional follow-up, we performed skin expression QTL (eQTL) analyses in a partially overlapping sample of 604 female twins. Colocalization analysis identified over 3,500 shared genetic effects affecting thousands of CpG sites (10,067) and genes (4,475). Mediation analysis of putative colocalized gene-CpG pairs identified 114 genes with evidence for eQTL effects being mediated by DNA methylation in skin, including in genes implicating skin disease such as ALOX12 and CSPG4. We further explored the relevance of skin meQTLs to skin disease and found that skin meQTLs and CpGs under genetic influence were enriched for multiple skin-related genome-wide and epigenome-wide association signals, including for melanoma and psoriasis. Our findings give insights into the regulatory landscape of epigenomic variation in skin.

Lifetime prevalence and associated factors of itch with skin conditions: atopic dermatitis, psoriasis and dry skin in individuals aged > 50†years.

BACKGROUND: Itch, common in dermatological conditions, is often accompanied by psychological distress and reduced quality of life. However, research on the prevalence and associated factors of itch with skin conditions in general populations is limited. OBJECTIVES: This cross-sectional study aimed to determine the lifetime prevalence of itch with skin conditions and to identify its associated factors in individuals aged > 50 years. METHODS: Participants from the Rotterdam Study, a population-based cohort, were interviewed to assess whether they had ever had an itchy skin condition, defining lifetime itch with skin conditions. Over 20 demographic, lifestyle, dermatological and nondermatological factors were recorded. Multivariable logistic regression analysis explored associations between these factors and itch with skin conditions, reported as odds ratios (ORs) with 95% confidence intervals (CIs). RESULTS: In total, 5246 eligible participants were included (age range 51-100 years, median age 67; 56.0% women). The results revealed a -lifetime prevalence of 33.7% for itch with skin conditions. Factors significantly associated with itch were female sex (OR 1.26, 95% CI 1.11-1.43), body mass index (1.02, 1.01-1.03), self-reported atopic dermatitis (4.29, 3.74-4.92), presence of atopic dermatitis (1.97, 1.60-2.43), self--reported psoriasis (2.31, 1.77-3.01), presence of psoriasis (2.11, 1.55-2.87), self-reported dry skin (1.95, 1.73-2.20), self-reported asthma (1.40, 1.08-1.83), renal impairment (1.45, 1.17-1.79), and clinically relevant depressive (1.85, 1.52-2.25) and anxiety symptoms (1.36, 1.11-1.66). CONCLUSIONS: This study reveals a substantial one-third lifetime prevalence of itch with skin conditions in individuals aged > 50 years. Significant associations with diverse lifestyle, demographic, dermatological and, intriguingly, nondermatological factors, including renal impairment, imply additional contributors to induction or persistence of itch in individuals with skin conditions.

Deep learning predicted perceived age is a reliable approach for analysis of facial ageing: A proof of principle study.

BACKGROUND: Perceived age (PA) has been associated with mortality, genetic variants linked to ageing and several age-related morbidities. However, estimating PA in large datasets is laborious and costly to generate, limiting its practical applicability. OBJECTIVES: To determine if estimating PA using deep learning-based algorithms results in the same associations with morbidities and genetic variants as human-estimated perceived age. METHODS: Self-supervised learning (SSL) and deep feature transfer (DFT) deep learning (DL) approaches were trained and tested on human-estimated PAs and their corresponding frontal face images of middle-aged to elderly Dutch participants (n = 2679) from a population-based study in the Netherlands. We compared the DL-estimated PAs with morbidities previously associated with human-estimated PA as well as genetic variants in the gene MC1R; we additionally tested the PA associations with MC1R in a new validation cohort (n = 1158). RESULTS: The DL approaches predicted PA in this population with a mean absolute error of 2.84 years (DFT) and 2.39 years (SSL). In the training-test dataset, we found the same significant (p < 0.05) associations for DL PA with osteoporosis, ARHL, cognition, COPD and cataracts and MC1R, as with human PA. We also found a similar but less significant association for SSL and DFT PAs (0.69 and 0.71 years per allele, p = 0.008 and 0.011, respectively) with MC1R variants in the validation dataset as that found with human, SSL and DFT PAs in the training-test dataset (0.79, 0.78 and 0.71 years per allele respectively; all p < 0.0001). CONCLUSIONS: Deep learning methods can automatically estimate PA from facial images with enough accuracy to replicate known links between human-estimated perceived age and several age-related morbidities. Furthermore, DL predicted perceived age associated with MC1R gene variants in a validation cohort. Hence, such DL PA techniques may be used instead of human estimations in perceived age studies thereby reducing time and costs.

Postinfective bowel dysfunction following Campylobacter enteritis is characterised by reduced microbiota diversity and impaired microbiota recovery.

OBJECTIVES: Persistent bowel dysfunction following gastroenteritis (postinfectious (PI)-BD) is well recognised, but the associated changes in microbiota remain unclear. Our aim was to define these changes after gastroenteritis caused by a single organism, Campylobacter jejuni, examining the dynamic changes in the microbiota and the impact of antibiotics. DESIGN: A single-centre cohort study of 155 patients infected with Campylobacter jejuni. Features of the initial illness as well as current bowel symptoms and the intestinal microbiota composition were recorded soon after infection (visit 1, <40 days) as well as 40-60 days and >80 days later (visits 2 and 3). Microbiota were assessed using 16S rRNA sequencing. RESULTS: PI-BD was found in 22 of the 99 patients who completed the trial. The cases reported significantly looser stools, with more somatic and gastrointestinal symptoms. Microbiota were assessed in 22 cases who had significantly lower diversity and altered microbiota composition compared with the 44 age-matched and sex-matched controls. Moreover 60 days after infection, cases showed a significantly lower abundance of 23 taxa including phylum Firmicutes, particularly in the order Clostridiales and the family Ruminoccocaceae, increased Proteobacteria abundance and increased levels of Fusobacteria and Gammaproteobacteria. The microbiota changes were linked with diet; higher fibre consumption being associated with lower levels of Gammaproteobacteria. CONCLUSION: The microbiota of PI-BD patients appeared more disturbed by the initial infection compared with the microbiota of those who recovered. The prebiotic effect of high fibre diets may inhibit some of the disturbances seen in PI-BD. TRIAL REGISTRATION NUMBER: NCT02040922.

Senescent human melanocytes drive skin ageing via paracrine telomere dysfunction.

Cellular senescence has been shown to contribute to skin ageing. However, the role of melanocytes in the process is understudied. Our data show that melanocytes are the only epidermal cell type to express the senescence marker p16INK4A during human skin ageing. Aged melanocytes also display additional markers of senescence such as reduced HMGB1 and dysfunctional telomeres, without detectable telomere shortening. Additionally, senescent melanocyte SASP induces telomere dysfunction in paracrine manner and limits proliferation of surrounding cells via activation of CXCR3-dependent mitochondrial ROS. Finally, senescent melanocytes impair basal keratinocyte proliferation and contribute to epidermal atrophy in vitro using 3D human epidermal equivalents. Crucially, clearance of senescent melanocytes using the senolytic drug ABT737 or treatment with mitochondria-targeted antioxidant MitoQ suppressed this effect. In conclusion, our study provides proof-of-concept evidence that senescent melanocytes affect keratinocyte function and act as drivers of human skin ageing.

Younger facial looks are associate with a lower likelihood of several age-related morbidities in the middle-aged to elderly.

BACKGROUND: Looking older for one's chronological age is associated with a higher mortality rate. Yet it remains unclear how perceived facial age relates to morbidity and the degree to which facial ageing reflects systemic ageing of the human body. OBJECTIVES: To investigate the association between ΔPA and age-related morbidities of different organ systems, where ΔPA represents the difference between perceived age (PA) and chronological age. METHODS: We performed a cross-sectional analysis on data from the Rotterdam Study, a population-based cohort study in the Netherlands. High-resolution facial photographs of 2679 men and women aged 51.5-87.8 years of European descent were used to assess PA. PA was estimated and scored in 5-year categories using these photographs by a panel of men and women who were blinded for chronological age and medical history. A linear mixed model was used to generate the mean PAs. The difference between the mean PA and chronological age was calculated (ΔPA), where a higher (positive) ΔPA means that the person looks younger for their age and a lower (negative) ΔPA that the person looks older. ΔPA was tested as a continuous variable for association with ageing-related morbidities including cardiovascular, pulmonary, ophthalmological, neurocognitive, renal, skeletal and auditory morbidities in separate regression analyses, adjusted for age and sex (model 1) and additionally for body mass index, smoking and sun exposure (model 2). RESULTS: We observed 5-year higher ΔPA (i.e. looking younger by 5 years for one's age) to be associated with less osteoporosis [odds ratio (OR) 0.76, 95% confidence interval (CI) 0.62-0.93], less chronic obstructive pulmonary disease (OR 0.85, 95% CI 0.77-0.95), less age-related hearing loss (model 2; B = -0.76, 95% CI -1.35 to -0.17) and fewer cataracts (OR 0.84, 95% CI 0.73-0.97), but with better global cognitive functioning (g-factor; model 2; B = 0.07, 95% CI 0.04-0.10). CONCLUSIONS: PA is associated with multiple morbidities and better cognitive function, suggesting that systemic ageing and cognitive ageing are, to an extent, externally visible in the human face.

Multiscale QM/MM modelling of catalytic systems with ChemShell.

Hybrid quantum mechanical/molecular mechanical (QM/MM) methods are a powerful computational tool for the investigation of all forms of catalysis, as they allow for an accurate description of reactions occurring at catalytic sites in the context of a complicated electrostatic environment. The scriptable computational chemistry environment ChemShell is a leading software package for QM/MM calculations, providing a flexible, high performance framework for modelling both biomolecular and materials catalysis. We present an overview of recent applications of ChemShell to problems in catalysis and review new functionality introduced into the redeveloped Python-based version of ChemShell to support catalytic modelling. These include a fully guided workflow for biomolecular QM/MM modelling, starting from an experimental structure, a periodic QM/MM embedding scheme to support modelling of metallic materials, and a comprehensive set of tutorials for biomolecular and materials modelling.

Scalp hair loss is not random across follicular units: A new insight into human hair ageing.

OBJECTIVES: Scalp hair has the greatest number of hairs (typically 1-5) per follicular unit but is also the most susceptible body site to hair loss with age. Hence, we set-out to determine the degree to which scalp hair parameters change with age in women and men, any sex differences thereof and whether hair loss is random across follicular units. METHODS: A retrospective cross-sectional study of 200 Chinese men and 200 Chinese women (30-69 years). Image analysis and manual counting methods were used to measure occipital located hair parameters from 6 × 8 mm shaved scalp photographs and plucked hair microscopy images. RESULTS: Of the five hair parameters, the number of hairs per follicular unit had the greatest (negative) correlation with age in both men and women. Men had a greater number of hairs and follicular units than women on average but had a greater decrease in the number of hairs per follicular unit with age, particularly for the loss of multi-hair (3+) follicular units. The loss of hairs with age was significantly different to that expected by a random loss of hairs across follicular units and better described by a model of increased hair loss risk the greater number of hairs per follicular unit. CONCLUSIONS: We have found evidence of hair loss preferentially occurring in multi-hair follicular units, which was more pronounced in men. These data suggest that part of the reason scalp hair is more susceptible to hair loss than on other body sites is due to the greater presence of multi-hair follicular units on the scalp.

OBJECTIFS: Le cuir chevelu possède le plus grand nombre de cheveux (généralement de 1 à 5) par unité folliculaire, mais c'est aussi le site le plus sensible à la perte de cheveux avec l'âge. Nous avons donc entrepris de déterminer dans quelle mesure les paramètres des cheveux du cuir chevelu changent avec l'âge chez les femmes et les hommes, quelles sont les différences entre les sexes et si la perte de cheveux est aléatoire entre les unités folliculaires. MÉTHODES: Étude transversale rétrospective portant sur 200 hommes et 200 femmes chinois (30-69 ans). Des méthodes d'analyse d'image et de comptage manuel ont été utilisées pour mesurer les paramètres des cheveux situés dans la région occipitale à partir de photographies du cuir chevelu rasé de 6x8 mm et d'images microscopiques de cheveux arrachés. RÉSULTATS: Parmi les 5 paramètres capillaires, le nombre de cheveux par unité folliculaire présentait la corrélation la plus forte (négative) avec l'âge, tant chez les hommes que chez les femmes. Les hommes avaient en moyenne un plus grand nombre de cheveux et d'unités folliculaires que les femmes, mais le nombre de cheveux par unité folliculaire diminuait davantage avec l'âge, en particulier pour la perte d'unités folliculaires à plusieurs cheveux (3+). La perte de cheveux avec l'âge était significativement différente de celle attendue par une perte aléatoire de cheveux dans les unités folliculaires, et mieux décrite par un modèle d'augmentation du risque de perte de cheveux plus le nombre de cheveux par unité folliculaire est élevé. CONCLUSIONS: Nous avons trouvé des preuves que la perte de cheveux se produit préférentiellement dans les unités folliculaires à plusieurs cheveux, ce qui était plus prononcé chez les hommes. Ces données suggèrent qu'une partie de la raison pour laquelle les cheveux du cuir chevelu sont plus sensibles à la perte de cheveux que sur d'autres sites du corps est due à la plus grande présence d'unités folliculaires à cheveux multiples sur le cuir chevelu.

Psyllium reduces inulin-induced colonic gas production in IBS: MRI and in vitro fermentation studies.

OBJECTIVE: Health-promoting dietary fibre including inulin often triggers gastrointestinal symptoms in patients with IBS, limiting their intake. Our aim was to test if coadministering psyllium with inulin would reduce gas production. DESIGN: A randomised, four-period, four-treatment, placebo-controlled, crossover trial in 19 patients with IBS. Subjects ingested a 500 mL test drink containing either inulin 20 g, psyllium 20 g, inulin 20 g+ psyllium 20 g or dextrose 20 g (placebo). Breath hydrogen was measured every 30 min with MRI scans hourly for 6 hours. Faecal samples from a subset of the patients with IBS were tested using an in vitro fermentation model. Primary endpoint was colonic gas assessed by MRI. RESULTS: Colonic gas rose steadily from 0 to 6 hours, with inulin causing the greatest rise, median (IQR) AUC(0-360 min) 3145 (848-6502) mL·min. This was significantly reduced with inulin and psyllium coadministration to 618 (62-2345) mL·min (p=0.02), not significantly different from placebo. Colonic volumes AUC(0-360 min) were significantly larger than placebo for both inulin (p=0.002) and inulin and psyllium coadministration (p=0.005). Breath hydrogen rose significantly from 120 min after inulin but not psyllium; coadministration of psyllium with inulin delayed and reduced the maximum increase, AUC(0-360 min) from 7230 (3255-17910) ppm·hour to 1035 (360-4320) ppm·hour, p=0.007.Fermentation in vitro produced more gas with inulin than psyllium. Combining psyllium with inulin did not reduce gas production. CONCLUSIONS: Psyllium reduced inulin-related gas production in patients with IBS but does not directly inhibit fermentation. Whether coadministration with psyllium increases the tolerability of prebiotics in IBS warrants further study. TRIAL REGISTRATION NUMBER: NCT03265002.

Test-retest assessment of non-contrast MRI sequences to characterise and quantify the small bowel wall in healthy participants.

OBJECTIVE: Quantitative Magnetic Resonance Imaging sequences have been investigated as objective imaging biomarkers of fibrosis and inflammation in Crohn's disease. AIM: To determine the repeatability and inter- and intra-observer agreement of these measures in the prepared small bowel wall. METHODS: Ten healthy participants were scanned at 3 T on 2 separate occasions using T1 and T2 relaxometry, IVIM-DWI and MT sequences. Test-retest repeatability was assessed using the coefficient of variation (CoV) and intra-class correlation coefficients (ICCs) were used to evaluate the intra- and inter-observer agreement RESULTS: Test-retest repeatability in the bowel wall was excellent for apparent diffusion coefficient (ADC), magnetisation transfer ratio (MTR), T1, and diffusion coefficient D (CoV 5%, 7%, 8%, and 10%, respectively), good for perfusion fraction (PF) (CoV 20%) and acceptable for T2 (CoV 21%). Inter-observer agreement was good for the T2, D and ADC (ICC = 0.89, 0.86, 0.76, respectively) and moderate for T1 (ICC = 0.55). Intra-observer agreement was similar to inter-observer agreement. DISCUSSION: This study showed variable results between the different parameters measured. Test-retest repeatability was at least acceptable for all parameters except pseudo-diffusion coefficient D*. Good inter- and intra-observer agreement was obtained for T2, ADC and D, with these parameters performing best in this technical validation study.

Chronic diarrhoea in adults: what not to miss.

PURPOSE OF REVIEW: Chronic diarrhoea remains a diagnostic challenge, with numerous causes and few effective symptomatic treatments. This review focuses on new methods for diagnosis of common disorders and alerts readers to rarer causes through a systematic approach to the underlying mechanisms. RECENT FINDINGS: New strategies are emerging to stratify the need for endoscopic investigation. Faecal immunochemical testing, combined with standard blood tests, shows promise in excluding colorectal cancers, adenoma and inflammatory bowel disease, challenging the current use of faecal calprotectin. Serum analysis for markers of bile acid synthesis has been refined, potentially streamlining diagnostic pathways of bile acid malabsorption for those who are unable to access nuclear medicine scans, but the positive predictive value of faecal elastase in low prevalence populations has been questioned. Novel markers such as volatile organic compounds and stool DNA analyses continue to develop. SUMMARY: A systematic approach to investigation of chronic diarrhoea will ensure all relevant causes are considered and minimize the chance of a missed diagnosis. Combination of clinical features with noninvasive testing supports a judicious approach to endoscopic investigations but further innovation will be needed to resolve the diagnostic challenge that diarrhoea poses.

Prevalence and determinants for xerosis cutis in the middle-aged and elderly population: A cross-sectional study.

BACKGROUND: Determinants and the extent of dry skin in healthy middle-aged and elderly populations have not been well established. OBJECTIVE: We aimed to identify the prevalence and determinants for generalized dry skin (GDS) and localized dry skin (LDS) within a large prospective population-based cohort of middle-aged and elderly individuals of the Rotterdam Study. METHODS: Dry skin was physician-graded as none, localized, or generalized. For GDS and LDS, separate multivariable logistic regression analyses were performed to search for association with participant characteristics, lifestyle factors, environmental factors, several comorbidities, and drug exposure. RESULTS: Among the 5547 eligible participants, 60% had dry skin, of whom a fifth had GDS. Age, female sex, skin color, body mass index, outside temperature, eczema, and chemotherapy in the past were significant determinants for both GDS and LDS. Smoking, the use of statins and diuretics, poorer self-perceived health, and several dermatologic conditions increased the likelihood of having GDS only. Daily cream use was associated with less LDS. LIMITATIONS: Interobserver variability and residual confounding could have influenced our results. Because of our cross-sectional design, we could not infer causality. CONCLUSION: We identified factors significantly associated with dry skin in a general middle-aged and elderly population, with health parameters more strongly associated with GDS.

A healthy diet in women is associated with less facial wrinkles in a large Dutch population-based cohort.

BACKGROUND: Little is known about the effects of different dietary patterns on facial wrinkling. OBJECTIVE: We aimed to investigate the association between diet and facial wrinkles in a population-based cohort of 2753 elderly participants of the Rotterdam study. METHODS: Wrinkles were measured in facial photographs by digitally quantifying the area wrinkles occupied as a percentage of total skin area. Diet was assessed by the Food Frequency Questionnaire. Adherence to the Dutch Healthy Diet Index (DHDI) was calculated. In addition, we used principal component analysis (PCA) to extract relevant food patterns in men and women separately. All food patterns and the DHDI were analyzed for an association with wrinkle severity using multivariable linear regression. RESULTS: Better adherence to the Dutch guidelines was significantly associated with less wrinkles among women but not in men. In women, a red meat and snack-dominant PCA pattern was associated with more facial wrinkles, whereas a fruit-dominant PCA pattern was associated with fewer wrinkles. LIMITATIONS: Due to the cross-sectional design of our study, causation could not be proven. Other health-conscious behaviors of study participants could have influenced the results. CONCLUSION: Dietary habits are associated with facial wrinkling in women. Global disease prevention strategies might benefit from emphasizing that a healthy diet is also linked to less facial wrinkling.

p38 MAPK activation upregulates proinflammatory pathways in skeletal muscle cells from insulin-resistant type 2 diabetic patients.

Skeletal muscle is the key site of peripheral insulin resistance in type 2 diabetes. Insulin-stimulated glucose uptake is decreased in differentiated diabetic cultured myotubes, which is in keeping with a retained genetic/epigenetic defect of insulin action. We investigated differences in gene expression during differentiation between diabetic and control muscle cell cultures. Microarray analysis was performed using skeletal muscle cell cultures established from type 2 diabetic patients with a family history of type 2 diabetes and clinical evidence of marked insulin resistance and nondiabetic control subjects with no family history of diabetes. Genes and pathways upregulated with differentiation in the diabetic cultures, compared with controls, were identified using Gene Spring and Gene Set Enrichment Analysis. Gene sets upregulated in diabetic myotubes were associated predominantly with inflammation. p38 MAPK was identified as a key regulator of the expression of these proinflammatory gene sets, and p38 MAPK activation was found to be increased in the diabetic vs. control myotubes. Although inhibition of p38 MAPK activity decreased cytokine gene expression from the cultured diabetic myotubes significantly, it did not improve insulin-stimulated glucose uptake. Increased cytokine expression driven by increased p38 MAPK activation is a key feature of cultured myotubes derived from insulin-resistant type 2 diabetic patients. p38 MAPK inhibition decreased cytokine expression but did not affect the retained defect of impaired insulin action in the diabetic muscle cells.

The Relationships Between Poor Sleep Efficiency and Mild Cognitive Impairment in Parkinson Disease.

BACKGROUND: Mild cognitive impairment (MCI) and sleep disturbances are common features in Parkinson disease (PD). This study sought to investigate whether patients with MCI in PD (PD-MCI) have more pronounced sleep disturbance compared to those without PD-MCI and whether phenotypic presentations differ according to the PD-MCI subtypes. METHODS: A total of 95 patients with idiopathic PD (53 meeting criteria for PD-MCI and 42 who were not cognitively impaired) and 22 controls underwent neurological and neuropsychological examination. They wore actigraphy watches for 2 weeks, from which measures of nocturnal sleep efficiency were calculated. RESULTS: Patients with PD-MCI has significantly poorer sleep efficiency compared to those without PD-MCI. This effect was particularly apparent in those with multiple-domain PD-MCI, compared to those with single-domain PD-MCI. Furthermore, patients in the PD-MCI group had significantly more nontremor features. CONCLUSIONS: These data suggest that PD-MCI is associated with greater sleep disturbance and nontremor features of PD. This is further evidence for the potential role that sleep disturbance plays in the heterogeneity of PD.

Prevalence and outcomes of laser treatment of aggressive posterior retinopathy of prematurity.

BACKGROUND: To describe outcomes in a cohort of extremely premature infants treated for aggressive posterior retinopathy of prematurity by diode laser panretinal photocoagulation. DESIGN: Retrospective study. PARTICIPANTS: Fifteen eyes in eight infants. METHODS: A review was carried out on infants between 23 and 25.6 weeks gestational age admitted to The Royal Brisbane and Women's Hospital neonatal intensive care unit between 1992 and 2009. MAIN OUTCOME MEASURES: Success of treatment, visual and refractive outcomes. RESULTS: Five hundred fifty-four infants were admitted to neonatal intensive care unit, 373 survived till screening, and 304 had retinopathy of prematurity. Sixty-six infants required treatment, and eight of these had aggressive posterior retinopathy of prematurity (2.5% of all infants with retinopathy of prematurity). Mean gestational age was 24.2 weeks, mean birthweight was 634 g, and treatment occurred at mean 34.1 weeks post-menstrual age. The mean total number of burns per eye was 2967. Five of 15 treated eyes required retreatment. Two patients subsequently died of unrelated causes. Regression occurred in 9 of 11 remaining eyes; one eye progressed to stage 4b and another to stage 5 retinopathy of prematurity. Vitrectomy was performed in two eyes. Five eyes had 6/12 vision, one had 3/60, and three had no perception of light. Of the remaining two eyes, one had good fixation and the other had poor fixation. CONCLUSIONS: Despite good structural outcomes, visual outcomes for conventional laser treatment of aggressive posterior retinopathy of prematurity are poor.

Oxygen-supplemented and topography-guided epithelium-on corneal crosslinking with pulsed irradiation for progressive keratoconus.

PURPOSE: To investigate the effects of customized topography-guided epithelium-on crosslinking (epi-on CXL) with oxygen supplementation on procedural efficacy and corrected distance visual acuity (CDVA) in patients with progressive keratoconus (KC) at 1 year. SETTING: Private eye clinic, Brisbane, Australia. DESIGN: Retrospective, single-center, nonrandomized case series. METHODS: Topography-guided epi-on CXL using the Mosaic system was performed on patients with progressive KC. Oxygen goggles; transepithelial riboflavin; and pulsed, high UV-A irradiance (1 second on, 1 second off; 30 mW/cm2) were applied to enhance oxygen kinetics and bioavailabilities of riboflavin and UV-A. Guided by baseline topography, a higher UV-A dose (15 J/cm2) was applied to the area of steepest anterior curvature with decreasing fluence (as low as 7.2 J/cm2) toward the outer 9 mm. Postoperative CDVA and maximum keratometry (Kmax) were evaluated. RESULTS: 102 eyes (80 patients) were followed for 11.5 ± 4.8 months. At the latest follow-up, mean CDVA (logMAR), mean K, and Kmax (diopters [D]) improved from 0.18 ± 0.28, 46.2 ± 3.8, and 53.0 ± 5.67 at baseline to 0.07 ± 0.18, 45.8 ± 3.7, and 51.9 ± 5.56, respectively (P < .001). 3 eyes (3%) lost more than 1 CDVA line, and another 3 eyes (3%) had increased Kmax greater than 2 D. 43 eyes were followed for at least 12 months (n = 43): mean CDVA, mean K, and Kmax improved from 0.19 ± 0.33 logMAR, 46.5 ± 3.5 D, and 53.6 ± 5.67 D to 0.07 ± 0.17 logMAR, 46.0 ± 3.5 D, and 52.33 ± 5.49 D, respectively (P ≤ .002). No complications were observed. CONCLUSIONS: Tailoring oxygen-supplemented epi-on CXL with differential UV-A energy distributions, guided by baseline topography, in patients with KC seems to be safe and effective. At 1 year, study reports sustained improved CDVA and corneal stabilization.

Quality of vision clinical outcomes for a new fully-refractive extended depth of focus Intraocular Lens.

BACKGROUND/OBJECTIVE: To evaluate the visual performance of a purely refractive extended depth of focus (EDF) intraocular lens (IOL). SUBJECTS/METHODS: A prospective, multi-center, randomized, subject/evaluator-masked study. Subjects were bilaterally implanted with the EDF test (Model ZEN00V, N = 60) or an enhanced monofocal control (Model ICB00, N = 57) IOL. Monocular corrected distance (CDVA), intermediate (DCIVA), near acuities (DCNVA) and patient reported visual symptoms were evaluated at the 6-month visit. Monocular mesopic contrast sensitivity (CS) and depth of focus (DOF) testing were assessed at 3 months. RESULTS: CDVA (Mean ± SD) was -0.06 ± 0.08 for test and -0.05 ± 0.08 logMAR for control groups. DCIVA was 0.13 ± 0.08 for test and 0.18 ± 0.14 logMAR for control groups (p = 0.0127). DCNVA was 0.37 ± 0.10 for test and 0.43 ± 0.16 logMAR for control groups (p = 0.0137). Test lens was statistically superior for intermediate and near. Overall, 91.7% (halos), 95.0% (starbursts) and 95.0% (glare) of test lens patients reported that they did not experience, were not bothered, or were slightly bothered by specific visual symptoms, compared to 98.2%, 100% and 96.5% in the control group. The DOF range over which monocular visual acuity was 0.20 logMAR or better was -1.6 D for the test lens. Mesopic CS was comparable between both groups, falling within 0.11 log units for all measured cycles per degree with and without glare. CONCLUSION: The EDF IOL demonstrated extended range of vision and statistically superior intermediate and near performance compared to the monofocal IOL. Distance visual acuity, contrast sensitivity and dysphotopsia profile were similar to the monofocal IOL.

Single-crystal adsorption calorimetry and density functional theory of CO chemisorption on fcc Co{110}.

Using single-crystal adsorption calorimetry (SCAC) and density functional theory (DFT), the interaction of carbon monoxide on fcc Co{110} is reported for the first time. The results indicate that adsorption is consistent with molecular chemisorption at all coverages. The initial heat of adsorption of 140 kJ mol(-1) is found in the range of heat values calorimetrically measured on other ferromagnetic metal surfaces, such as nickel and iron. DFT adsorption energies are in good agreement with the experimental results, and comparison between SCAC and DFT for CO on other ferromagnetic surfaces is made. The calculated dissociation barrier of 2.03 eV implies that dissociation at 300 K is unlikely even at the lowest coverage. At high coverages during the adsorption-desorption steady state regime, a pre-exponential factor for CO desorption of 1.2 × 10(17) s(-1) is found, implying a localised molecular adsorbed state prior to desorption in contrast to what we found with Ni surfaces. This result highlights the importance of the choice of the pre-exponential factor in evaluating the activation energy for desorption.

NCKX5, a natural regulator of human skin colour variation, regulates the expression of key pigment genes MC1R and alpha-MSH and alters cholesterol homeostasis in normal human melanocytes.

Natural human skin colour is determined both by environmental exposure to ultraviolet light and through inherited genetic variation in a very limited number of genes. Variation of a non-synonymous single-nucleotide polymorphism (nsSNP; rs1426654) in the gene (SLC24A5) encoding the NCKX5 protein is associated with differences in constitutive skin colour in South Asians. The nsSNP encodes the substitution of alanine for threonine at residue 111 (A111T) near a transmembrane region required for exchanger activity, a region which is highly conserved across different species and between NCKX family members. We have shown that NCKX5 is located at the trans-Golgi network of melanocytes and functions as a potassium-dependent sodium-calcium exchanger. When heterologously expressed, the 111T variant of NCKX5 shows significantly lower exchanger activity than the A111 variant. We have postulated that lower exchanger activity causes the reduced melanogenesis and lighter skin in Thr111-positive individuals. We used gene expression microarrays with qPCR replication and validation to assess the impact of siRNA-mediated knockdown of SLC24A5 on the transcriptome of cultured normal human melanocytes (NHM). Very few genes associated with melanogenesis were altered at the transcript level except for MC1R, suggesting that SLC24A5 interacts with at least one well-characterized melanogenic signalling pathway. More surprisingly, the expression of a number of cholesterol homeostatic genes was altered after SLC24A5 knockdown, and the total cholesterol content of NHM was increased. Cholesterol has previously been identified as a potential melanogenic regulator, and our data imply that NCKX5 exchanger function influences natural variation in skin pigmentation via a novel, unknown mechanism affecting cellular sterol levels.