Common Genetic Variation Near the Phospholamban Gene Is Associated with Cardiac Repolarisation: Meta-Analysis of Three Genome-Wide Association Studies

To identify loci affecting the electrocardiographic QT interval, a measure of cardiac repolarisation associated with risk of ventricular arrhythmias and sudden cardiac death, we conducted a meta-analysis of three genome-wide association studies (GWAS) including 3,558 subjects from the TwinsUK and BRIGHT cohorts in the UK and the DCCT/EDIC cohort from North America. Five loci were significantly associated with QT interval at P<1×10⁻⁶. To validate these findings we performed an in silico comparison with data from two QT consortia: QTSCD (n = 15,842) and QTGEN (n = 13,685). Analysis confirmed the association between common variants near NOS1AP (P = 1.4×10⁻⁸³) and the phospholamban (PLN) gene (P = 1.9×10⁻²⁹). The most associated SNP near NOS1AP (rs12143842) explains 0.82% variance; the SNP near PLN (rs11153730) explains 0.74% variance of QT interval duration. We found no evidence for interaction between these two SNPs (P = 0.99). PLN is a key regulator of cardiac diastolic function and is involved in regulating intracellular calcium cycling, it has only recently been identified as a susceptibility locus for QT interval. These data offer further mechanistic insights into genetic influence on the QT interval which may predispose to life threatening arrhythmias and sudden cardiac death.     

Multiple Independent Genetic Factors at NOS1AP Modulate the QT Interval in a Multi-Ethnic Population

Extremes of electrocardiographic QT interval are associated with increased risk for sudden cardiac death (SCD); thus, identification and characterization of genetic variants that modulate QT interval may elucidate the underlying etiology of SCD. Previous studies have revealed an association between a common genetic variant in NOS1AP and QT interval in populations of European ancestry, but this finding has not been extended to other ethnic populations. We sought to characterize the effects of NOS1AP genetic variants on QT interval in the multi-ethnic population-based Dallas Heart Study (DHS, n = 3,072). The SNP most strongly associated with QT interval in previous samples of European ancestry, rs16847548, was the most strongly associated in White (P = 0.005) and Black (P = 3.6×10⁻⁵) participants, with the same direction of effect in Hispanics (P = 0.17), and further showed a significant SNP × sex-interaction (P = 0.03). A second SNP, rs16856785, uncorrelated with rs16847548, was also associated with QT interval in Blacks (P = 0.01), with qualitatively similar results in Whites and Hispanics. In a previously genotyped cohort of 14,107 White individuals drawn from the combined Atherosclerotic Risk in Communities (ARIC) and Cardiovascular Health Study (CHS) cohorts, we validated both the second locus at rs16856785 (P = 7.63×10⁻⁸), as well as the sex-interaction with rs16847548 (P = 8.68×10⁻⁶). These data extend the association of genetic variants in NOS1AP with QT interval to a Black population, with similar trends, though not statistically significant at P<0.05, in Hispanics. In addition, we identify a strong sex-interaction and the presence of a second independent site within NOS1AP associated with the QT interval. These results highlight the consistent and complex role of NOS1AP genetic variants in modulating QT interval.     

Pituitary Stalk Interruption Syndrome in 53 Postpubertal Patients: Factors Influencing the Heterogeneity of Its Presentation

Background

Pituitary stalk interruption syndrome (PSIS) may induce an isolated growth hormone (GH) deficiency or multiple hypothalamic-pituitary (HP) deficiencies. Patients with multiple HP deficiencies, primarily those with adrenocorticotropin (ACTH) deficiency, are at increased risk of morbidity and mortality. Our objective was to identify the factors influencing each symptom and the MRI features of the syndrome to enhance its diagnosis and genetic analysis.

Methods

This study was a retrospective, single-center, case-cohort study of 53 patients with PSIS who had reached pubertal age.

Results

Patients were classified as having an isolated GH deficiency (n = 24, Group 1) or HP deficiencies (n = 29, Group 2); of these, 19 had complete HP deficiency, and 10 had GH deficiency associated with TSH (n = 4), TSH and ACTH (n = 3), TSH and gonadotropin (n = 1) deficiencies or amenorrhea (n = 2). The following features were less frequent in Group 1 than in Group 2: breech presentation (4% vs 35%, P = 0.008), hypoglycemia (0% vs 59%, P<0.00001), micropenis (13% vs 69%, P<0.003), hypothalamic origin (0% vs 52%, P<0.000001), ophthalmic malformation (8% vs 38%, P<0.02) and psychomotor delay (0% vs 31%, P<0.004). The frequencies of all other malformations were similar in both groups (37% vs 59%). A visible pituitary stalk was characteristic of patients belonging to Group 1 (P<0.0002). The GH peak was greater in Group 1 than in Group 2 (P<0.0003), as was the anterior pituitary height (P = 0.01).

Conclusion

The factors that best discriminate patients with multiple HP deficiencies from those with an isolated GH deficiency are breech presentation, hypoglycemia, and micropenis. No patient with an isolated GH deficiency had psychomotor delay, but associated malformations and/or syndromes, with the exception of ophthalmic disorders, occurred with similar frequencies in both groups. We have also shown that each of the above characteristics is associated with a given HP deficiency and/or malformation/syndrome in the majority of cases.     

Early Hemoperfusion May Improve Survival of Severely Paraquat-Poisoned Patients

Background

Thousands of paraquat (PQ)-poisoned patients continue to die, particularly in developing countries. Although animal studies indicate that hemoperfusion (HP) within 2−4 h after intoxication effectively reduces mortality, the effect of early HP in humans remains unknown.

Methods

We analyzed the records of all PQ-poisoned patients admitted to 2 hospitals between 2000 and 2009. Patients were grouped according to early or late HP and high-dose (oral cyclophosphamide [CP] and intravenous dexamethasone [DX]) or repeated pulse (intravenous methylprednisolone [MP] and CP, followed by DX and repeated MP and/or CP) PQ therapy. Early HP was defined as HP <4 h, and late HP, as HP ≥4 h after PQ ingestion. We evaluated the associations between HP <4 h, <5 h, <6 h, and <7 h after PQ ingestion and the outcomes. Demographic, clinical, laboratory, and mortality data were analyzed.

Results

The study included 207 severely PQ-poisoned patients. Forward stepwise multivariate Cox hazard regression analysis showed that early HP <4 h (hazard ratio [HR] = 0.38, 95% confidence interval (CI) 0.16–0.86; P = 0.020) or HP <5 h (HR = 0.60, 95% CI: 0.39–0.92; P = 0.019) significantly decreased the mortality risk. Further analysis showed that early HP reduced the mortality risk only in patients treated with repeated pulse therapy (n = 136), but not high-dose therapy (n = 71). Forward stepwise multivariate Cox hazard regression analysis showed that HP <4.0 h (HR = 0.19, 95% CI: 0.05–0.79; P = 0.022) or <5.0 h (HR = 0.49, 95% CI: 0.24–0.98; P = 0.043) after PQ ingestion significantly decreased the mortality risk in repeated pulse therapy patients, after adjustment for relevant variables.

Conclusion

The results showed that early HP after PQ exposure might be effective in reducing mortality in severely poisoned patients, particularly in those treated with repeated pulse therapy.     

Is Follow-up BRAFV600E Mutation Analysis Helpful in the Differential Diagnosis of Thyroid Nodules with Negative Results on Initial Analysis?

Background

We evaluated the usefulness of follow-up BRAF^V600E mutation analysis using ultrasonography-guided fine-needle aspiration (US-FNA) in diagnosis of thyroid nodules showing negative BRAFV600E mutation on prior analysis.

Methodology/Principal Finding

A total of 49 patients (men: 6, women: 43, mean age: 50.4 years) with 49 thyroid nodules were included. Patients had undergone initial and follow-up US-FNA and subsequent BRAF^V600E mutation analysis from US-FNA aspirates. All patients had negative results on initial BRAF^V600E mutation analysis. Clinicopathologic findings, US assessment, and BRAF^V600E mutation results were analyzed according to the final pathology. Of the 49 nodules, 12 (24.5%) were malignant and 37 (75.5%) were benign. Seven (58.3%) of the 12 malignant nodules were positive for BRAF^V600E mutation on follow-up, all showing suspicious US features. Initial US-FNA cytology of the 7 nodules were non-diagnostic (n = 2), benign (n = 2), or atypia (n = 3), while follow-up were benign (n = 1), indeterminate (n = 1), suspicious for malignancy (n = 4), and malignancy (n = 1).

Conclusions/Significance

Follow-up BRAF^V600E mutation analysis may be helpful in the diagnosis of selected thyroid nodules negative for BRAF^V600E mutation on initial analysis, which are assessed as suspicious malignant on US, diagnosed as non-diagnostic, benign or atypia on follow-up US-FNA.     

Pronounced Effects of HERG-Blockers E-4031 and Erythromycin on APD,Spatial APD Dispersion and Triangulation in Transgenic Long-QT Type 1 Rabbits

Background

Prolongation of action potential duration (APD), increased spatial APD dispersion, and triangulation are major factors promoting drug-induced ventricular arrhythmia. Preclinical identification of HERG/I_Kr-blocking drugs and their pro-arrhythmic potential, however, remains a challenge. We hypothesize that transgenic long-QT type 1 (LQT1) rabbits lacking repolarizing I_Ks current may help to sensitively detect HERG/I_Kr-blocking properties of drugs.

Methods

Hearts of adult female transgenic LQT1 and wild type littermate control (LMC) rabbits were Langendorff-perfused with increasing concentrations of HERG/I_Kr-blockers E-4031 (0.001–0.1 µM, n = 9/7) or erythromycin (1–300 µM, n = 9/7) and APD, APD dispersion, and triangulation were analyzed.

Results

At baseline, APD was longer in LQT1 than in LMC rabbits in LV apex and RV mid. Erythromycin and E-4031 prolonged APD in LQT1 and LMC rabbits in all positions. However, erythromycin-induced percentaged APD prolongation related to baseline (%APD) was more pronounced in LQT1 at LV base-lateral and RV mid positions (100 µM, LQT1, +40.6±9.7% vs. LMC, +24.1±10.0%, p<0.05) and E-4031-induced %APD prolongation was more pronounced in LQT1 at LV base-lateral (0.01 µM, LQT1, +29.6±10.6% vs. LMC, +19.1±3.8%, p<0.05) and LV base-septal positions. Moreover, erythromycin significantly increased spatial APD dispersion only in LQT1 and increased triangulation only in LQT1 in LV base-septal and RV mid positions. Similarly, E-4031 increased triangulation only in LQT1 in LV apex and base-septal positions.

Conclusions

E-4031 and erythromycin prolonged APD and increased triangulation more pronouncedly in LQT1 than in LMC rabbits. Moreover, erythromycin increased APD dispersion only in LQT1, indicating that transgenic LQT1 rabbits could serve as sensitive model to detect HERG/I_Kr-blocking properties of drugs.     

Sleep Deprivation Impairs Consolidation of Cued Fear Memory in Rats

Post-learning sleep facilitates negative memory consolidation and also helps preserve it over several years. It is believed, therefore, that sleep deprivation may help prevent consolidation of fearful memory. Its effect, however, on consolidation of negative/frightening memories is not known. Cued fear-conditioning (CuFC) is a widely used model to understand the neural basis of negative memory associated with anxiety disorders. In this study, we first determined the suitable circadian timing for consolidation of CuFC memory and changes in sleep architecture after CuFC. Thereafter, we studied the effect of sleep deprivation on CuFC memory consolidation. Three sets of experiments were performed in male Wistar rat (n = 51). In experiment-I, animals were conditioned to cued-fear by presenting ten tone-shock paired stimuli during lights-on (7 AM) (n = 9) and lights-off (7 PM) (n = 9) periods. In experiment-II, animals were prepared for polysomnographic recording (n = 8) and changes in sleep architecture after CuFC was determined. Further in experiment-III, animals were cued fear-conditioned during the lights-off period and were randomly divided into four groups: Sleep-Deprived (SD) (n = 9), Non-Sleep Deprived (NSD) (n = 9), Stress Control (SC) (n = 9) and Tone Control (n = 7). Percent freezing amount, a hallmark of fear, was compared statistically in these groups. Rats trained during the lights-off period exhibited significantly more freezing compared to lights-on period. In CuFC trained animals, total sleep amount did not change, however, REM sleep decreased significantly. Further, out of total sleep time, animals spent proportionately more time in NREM sleep. Nevertheless, SD animals exhibited significantly less freezing compared to NSD and SC groups. These data suggest that sleep plays an important role in the consolidation of cued fear-conditioned memory.     

Ubiquitination-dependent quality control of hERG K+ channel with acquired and inherited conformational defect at the plasma membrane

Membrane trafficking in concert with the peripheral quality control machinery plays a critical role in preserving plasma membrane (PM) protein homeostasis. Unfortunately, the peripheral quality control may also dispose of partially or transiently unfolded polypeptides and thereby contribute to the loss-of-expression phenotype of conformational diseases. Defective functional PM expression of the human ether-a-go-go–related gene (hERG) K⁺ channel leads to the prolongation of the ventricular action potential that causes long QT syndrome 2 (LQT2), with increased propensity for arrhythmia and sudden cardiac arrest. LQT2 syndrome is attributed to channel biosynthetic processing defects due to mutation, drug-induced misfolding, or direct channel blockade. Here we provide evidence that a peripheral quality control mechanism can contribute to development of the LQT2 syndrome. We show that PM hERG structural and metabolic stability is compromised by the reduction of extracellular or intracellular K⁺ concentration. Cardiac glycoside–induced intracellular K⁺ depletion conformationally impairs the complex-glycosylated channel, which provokes chaperone- and C-terminal Hsp70-interacting protein–dependent polyubiquitination, accelerated internalization, and endosomal sorting complex required for transport–dependent lysosomal degradation. A similar mechanism contributes to the down-regulation of PM hERG harboring LQT2 missense mutations, with incomplete secretion defect. These results suggest that PM quality control plays a determining role in the loss-of-expression phenotype of hERG in certain hereditary and acquired LTQ2 syndromes.     

Meta-Analysis of the INSIG2 Association with Obesity Including 74,345 Individuals: Does Heterogeneity of Estimates Relate to Study Design?

The INSIG2 rs7566605 polymorphism was identified for obesity (BMI≥30 kg/m²) in one of the first genome-wide association studies, but replications were inconsistent. We collected statistics from 34 studies (n = 74,345), including general population (GP) studies, population-based studies with subjects selected for conditions related to a better health status (‘healthy population’, HP), and obesity studies (OB). We tested five hypotheses to explore potential sources of heterogeneity. The meta-analysis of 27 studies on Caucasian adults (n = 66,213) combining the different study designs did not support overall association of the CC-genotype with obesity, yielding an odds ratio (OR) of 1.05 (p-value = 0.27). The I² measure of 41% (p-value = 0.015) indicated between-study heterogeneity. Restricting to GP studies resulted in a declined I² measure of 11% (p-value = 0.33) and an OR of 1.10 (p-value = 0.015). Regarding the five hypotheses, our data showed (a) some difference between GP and HP studies (p-value = 0.012) and (b) an association in extreme comparisons (BMI≥32.5, 35.0, 37.5, 40.0 kg/m² versus BMI<25 kg/m²) yielding ORs of 1.16, 1.18, 1.22, or 1.27 (p-values 0.001 to 0.003), which was also underscored by significantly increased CC-genotype frequencies across BMI categories (10.4% to 12.5%, p-value for trend = 0.0002). We did not find evidence for differential ORs (c) among studies with higher than average obesity prevalence compared to lower, (d) among studies with BMI assessment after the year 2000 compared to those before, or (e) among studies from older populations compared to younger. Analysis of non-Caucasian adults (n = 4889) or children (n = 3243) yielded ORs of 1.01 (p-value = 0.94) or 1.15 (p-value = 0.22), respectively. There was no evidence for overall association of the rs7566605 polymorphism with obesity. Our data suggested an association with extreme degrees of obesity, and consequently heterogeneous effects from different study designs may mask an underlying association when unaccounted for. The importance of study design might be under-recognized in gene discovery and association replication so far.     

Reduced Physiological Complexity in Robust Elderly Adults with the APOE ε4 Allele

Background

It is unclear whether the loss of physiological complexity during the aging process is due to genetic variations. The APOE gene has been studied extensively in regard to its relationship with aging-associated medical illness. We hypothesize that diminished physiological complexity, as measured by heart rate variability, is influenced by polymorphisms in the APOE allele among elderly individuals.

Methodology/Principal Findings

A total of 102 robust, non-demented, elderly subjects with normal functions of daily activities participated in this study (97 males and 5 females, aged 79.2±4.4 years, range 72–92 years). Among these individuals, the following two APOE genotypes were represented: ε4 non-carriers (n = 87, 85.3%) and ε4 carriers (n = 15, 14.7%). Multi-scale entropy (MSE), an analysis used in quantifying complexity for nonlinear time series, was employed to analyze heart-rate dynamics. Reduced physiological complexity, as measured by MSE, was significantly associated with the presence of the APOE ε4 allele in healthy elderly subjects, as compared to APOE ε4 allele non-carriers (24.6±5.5 versus 28.9±5.2, F = 9.429, p = 0.003, respectively).

Conclusions/Significance

This finding suggests a role for the APOE gene in the diminished physiological complexity seen in elderly populations.     

Camera Traps Can Be Heard and Seen by Animals

Camera traps are electrical instruments that emit sounds and light. In recent decades they have become a tool of choice in wildlife research and monitoring. The variability between camera trap models and the methods used are considerable, and little is known about how animals respond to camera trap emissions. It has been reported that some animals show a response to camera traps, and in research this is often undesirable so it is important to understand why the animals are disturbed. We conducted laboratory based investigations to test the audio and infrared optical outputs of 12 camera trap models. Camera traps were measured for audio outputs in an anechoic chamber; we also measured ultrasonic (n = 5) and infrared illumination outputs (n = 7) of a subset of the camera trap models. We then compared the perceptive hearing range (n = 21) and assessed the vision ranges (n = 3) of mammals species (where data existed) to determine if animals can see and hear camera traps. We report that camera traps produce sounds that are well within the perceptive range of most mammals’ hearing and produce illumination that can be seen by many species.     

Identifying Genetic Variants for Heart Rate Variability in the Acetylcholine Pathway

Heart rate variability is an important risk factor for cardiovascular disease and all-cause mortality. The acetylcholine pathway plays a key role in explaining heart rate variability in humans. We assessed whether 443 genotyped and imputed common genetic variants in eight key genes (CHAT, SLC18A3, SLC5A7, CHRNB4, CHRNA3, CHRNA, CHRM2 and ACHE) of the acetylcholine pathway were associated with variation in an established measure of heart rate variability reflecting parasympathetic control of the heart rhythm, the root mean square of successive differences (RMSSD) of normal RR intervals. The association was studied in a two stage design in individuals of European descent. First, analyses were performed in a discovery sample of four cohorts (n = 3429, discovery stage). Second, findings were replicated in three independent cohorts (n = 3311, replication stage), and finally the two stages were combined in a meta-analysis (n = 6740). RMSSD data were obtained under resting conditions. After correction for multiple testing, none of the SNPs showed an association with RMSSD. In conclusion, no common genetic variants for heart rate variability were identified in the largest and most comprehensive candidate gene study on the acetylcholine pathway to date. Future gene finding efforts for RMSSD may want to focus on hypothesis free approaches such as the genome-wide association study.     

Insights into Nasal Carriage of Staphylococcus aureus in an Urban and a Rural Community in Ghana

The epidemiology of Staphylococcus aureus in the community in Ghana was never investigated prior to this study. The aims of the study were: i) to assess prevalence of nasal S. aureus carriage in Ghanaian people living in an urban and a rural area, and ii) to identify phenotypic and genotypic traits of strains isolated from the two communities. Nasal swabs were collected from healthy individuals living in an urban community situated in the suburb of the capital city, Accra (n = 353) and in a rural community situated in the Dangme-West district (n = 234). The overall prevalence of nasal carriage was 21% with a significantly higher prevalence in the urban (28%) than in the rural community (11%) (p<0.0001). The levels of antimicrobial resistance were generally low (<5%) except for penicillin (91%) and tetracycline (25%). The only two (0.3%) MRSA carriers were individuals living in the urban area and had been exposed to hospitals within the last 12 months prior to sampling. Resistance to tetracycline (p = 0.0009) and presence of Panton-Valentine leukocidin (PVL) gene (p = 0.02) were significantly higher among isolates from the rural community compared to isolates from the urban community. Eleven MLST clonal complexes (CC) were detected based on spa typing of the 124 S. aureus isolates from the two communities: CC8 (n = 36), CC152 (n = 21), CC45 (n = 21), CC15 (n = 18), CC121 (n = 6), CC97 (n = 6), CC30 (n = 5), CC5 (n = 5), CC508 (n = 4), CC9 (n = 1), and CC707 (n = 1). CC8 and CC45 were less frequent in the rural area than in the urban area (p = 0.02). These results reveal remarkable differences regarding carriage prevalence, tetracycline resistance, PVL content and clonal distribution of S. aureus in the two study populations. Future research may be required to establish whether such differences in nasal S. aureus carriage are linked to socio-economic differences between urban and rural communities in this African country.     

Genetic Association Study of TNFAIP3, IFIH1, IRF5 Polymorphisms with Polymyositis/Dermatomyositis in Chinese Han Population

Background

Single-nucleotide polymorphisms (SNPs) in the TNFAIP3, IFIH1, and IRF5 genes have been associated with several auto-inflammation diseases, while the susceptibility between these genes and idiopathic inflammatory myopathies (IIMs) were not reported. This study aimed to investigate whether TNFAIP3, IFIH1, and IRF5 gene polymorphisms confer susceptibility for the IIMs in Chinese Han population.

Methods

A large case–control study of Chinese subjects with polymyositis (PM) (n = 298) and dermatomyositis (DM) (n = 530) was accomplished. 968 healthy and ethnically matched controls were available for comparison. Six SNPs in the TNFAIP3 region (rs2230926 and rs5029939), the IFIH1 gene (rs1990760 and rs3747517) and the IRF5 region (rs4728142 and rs729302) were assessed and genotyped using the Sequenom MassArray iPLEX platform.

Results

Our study indicated a strong allele association was observed in PM/DM and PM patients for rs2230926 (OR: 1.61, 95%CI: 1.20–2.16, P_c = 7.5×10⁻³; OR: 1.88, 95%CI: 1.30–2.74, P_c = 4.0×10⁻³, respectively) and rs5029939 (OR: 1.64, 95%CI: 1.21–2.21, P_c = 6.0×10⁻³; OR: 1.88, 95%CI: 1.28–2.76, P_c = 5.5×10⁻³,respectively). And rs2230926 and rs5029939 were significantly associated with interstitial lung disease (ILD) in PM/DM and PM patients (P_c = 0.04 and P_c = 0.016; P_c = 0.02 and P_c = 0.03, respectively). In addition, rs4728142 allele and genotype had significant association with PM/DM patients (P_c = 0.026 and P_c = 0.048, respectively). Further analysis with three logistic regression genetic models revealed statistically significant difference in the genotypic distribution in the PM/DM, PM or DM patients when the additive and dominant models were used.

Conclusions

This was the first study to reveal TNFAIP3 and IRF5 polymorphisms were associated with PM/DM patients or these patients with ILD, indicating that TNFAIP3 and IRF5 might be the susceptibility gene for PM/DM patients in Chinese Han population.     

Leucocyte Telomere Length and Risk of Type 2 Diabetes Mellitus: New Prospective Cohort Study and Literature-Based Meta-Analysis

Background

Short telomeres have been linked to various age-related diseases. We aimed to assess the association of telomere length with incident type 2 diabetes mellitus (T2DM) in prospective cohort studies.

Methods

Leucocyte relative telomere length (RTL) was measured using quantitative polymerase chain reaction in 684 participants of the prospective population-based Bruneck Study (1995 baseline), with repeat RTL measurements performed in 2005 (n = 558) and 2010 (n = 479). Hazard ratios for T2DM were calculated across quartiles of baseline RTL using Cox regression models adjusted for age, sex, body-mass index, smoking, socio-economic status, physical activity, alcohol consumption, high-density lipoprotein cholesterol, log high-sensitivity C-reactive protein, and waist-hip ratio. Separate analyses corrected hazard ratios for within-person variability using multivariate regression calibration of repeated measurements. To contextualise findings, we systematically sought PubMed, Web of Science and EMBASE for relevant articles and pooled results using random-effects meta-analysis.

Results

Over 15 years of follow-up, 44 out of 606 participants free of diabetes at baseline developed incident T2DM. The adjusted hazard ratio for T2DM comparing the bottom vs. the top quartile of baseline RTL (i.e. shortest vs. longest) was 2.00 (95% confidence interval: 0.90 to 4.49; P = 0.091), and 2.31 comparing the bottom quartile vs. the remainder (1.21 to 4.41; P = 0.011). The corresponding hazard ratios corrected for within-person RTL variability were 3.22 (1.27 to 8.14; P = 0.014) and 2.86 (1.45 to 5.65; P = 0.003). In a random-effects meta-analysis of three prospective cohort studies involving 6,991 participants and 2,011 incident T2DM events, the pooled relative risk was 1.31 (1.07 to 1.60; P = 0.010; I ² = 69%).

Conclusions/Interpretation

Low RTL is independently associated with the risk of incident T2DM. To avoid regression dilution biases in observed associations of RTL with disease risk, future studies should implement methods correcting for within-person variability in RTL. The causal role of short telomeres in T2DM development remains to be determined.     

RASopathic Skin Eruptions during Vemurafenib Therapy

Purpose

Vemurafenib is a potent inhibitor of V600 mutant BRAF with significant impact on progression-free and overall survival in advanced melanoma. Cutaneous side effects are frequent. This single-center observational study investigates clinical and histological features of these class-specific cutaneous adverse reactions.

Patients and Methods

Patients were all treated with Vemurafenib 960 mg b.i.d. within local ethic committees approved clinical trials. All skin reactions were collected and documented prospectively. Cutaneous reactions were classified by reaction pattern as phototoxic and inflammatory, hair and nail changes, keratinocytic proliferations and melanocytic disorders.

Results

Vemurafenib was well tolerated, only in two patients the dose had to be reduced to 720 mg due to arthralgia. 26/28 patients (93%) experienced cutaneous side effects. Observed side effects included UVA dependent photosensitivity (n = 16), maculopapular exanthema (n = 14), pruritus (n = 8), folliculitis (n = 5), burning feet (n = 3), hair thinning (mild alopecia) (n = 8), curly hair (n = 2) and nail changes (n = 2). Keratosis pilaris and acanthopapilloma were common skin reactions (n = 12/n = 13), as well as plantar hyperkeratosis (n = 4), keratoacanthoma (n = 5) and invasive squamous cell carcinoma (n = 4). One patient developed a second primary melanoma after more than 4 months of therapy (BRAF and RAS wild type).

Conclusion

Vemurafenib has a broad and peculiar cutaneous side effect profile involving epidermis and adnexa overlapping with the cutaneous manifestations of genetic diseases characterized by activating germ line mutations of RAS (RASopathy). They must be distinguished from allergic drug reaction. Regular skin examination and management by experienced dermatologists as well as continuous prophylactic photo protection including an UVA optimized sun screen is mandatory.     

Organisational Culture in Residential Aged Care Facilities: A Cross-Sectional Observational Study

Background

Organisational culture is increasingly recognised as important for provision of high-quality long-term care. We undertook this study to measure organisational culture in residential aged care facilities in two Australian states.

Methodology/Principal Findings

Cross-sectional observational study in 21 residential aged care facilities in Western Australia (n = 14) and Queensland (n = 7), Australia. Staff and next-of-kin of residents participated. Measurement comprised surveys of facility staff and residents'' next-of-kin, and structured observation of indicators of care quality. Staff tended to rate organisational culture positively. Some qualitative feedback from staff emphasised negative perceptions of communication, leadership and teamwork. Staffing levels were perceived as a dominant challenge, threatening care quality. Direct observation revealed variability within and between facilities but suggested that most facilities (n = 12) were in the typical range, or were quality facilities (n = 8).

Conclusion

There was scope to strengthen organisational culture in participating aged care facilities.     

Complex Patterns of Genomic Admixture within Southern Africa

Within-population genetic diversity is greatest within Africa, while between-population genetic diversity is directly proportional to geographic distance. The most divergent contemporary human populations include the click-speaking forager peoples of southern Africa, broadly defined as Khoesan. Both intra- (Bantu expansion) and inter-continental migration (European-driven colonization) have resulted in complex patterns of admixture between ancient geographically isolated Khoesan and more recently diverged populations. Using gender-specific analysis and almost 1 million autosomal markers, we determine the significance of estimated ancestral contributions that have shaped five contemporary southern African populations in a cohort of 103 individuals. Limited by lack of available data for homogenous Khoesan representation, we identify the Ju/''hoan (n = 19) as a distinct early diverging human lineage with little to no significant non-Khoesan contribution. In contrast to the Ju/''hoan, we identify ancient signatures of Khoesan and Bantu unions resulting in significant Khoesan- and Bantu-derived contributions to the Southern Bantu amaXhosa (n = 15) and Khoesan !Xun (n = 14), respectively. Our data further suggests that contemporary !Xun represent distinct Khoesan prehistories. Khoesan assimilation with European settlement at the most southern tip of Africa resulted in significant ancestral Khoesan contributions to the Coloured (n = 25) and Baster (n = 30) populations. The latter populations were further impacted by 170 years of East Indian slave trade and intra-continental migrations resulting in a complex pattern of genetic variation (admixture). The populations of southern Africa provide a unique opportunity to investigate the genomic variability from some of the oldest human lineages to the implications of complex admixture patterns including ancient and recently diverged human lineages.