Reappraisal of Atrial fibrillation: interaction between hyperCoagulability, Electrical remodelling and Vascular destabilisation in the progression of AF (RACE V) Tissue Bank Project: study design.

BACKGROUND: The development of atrial fibrillation (AF) is a complex multifactorial process. Over the past few decades, much has been learned about the pathophysiological processes that can lead to AF from a variety of specific disease models in animals. However, our ability to recognise these disease processes in AF patients is still limited, which has contributed to the limited progress in improving rhythm control in AF. AIMS/OBJECTIVES: We believe that a better understanding and detection of the individual pathophysiological mechanisms underlying AF is a prerequisite for developing patient-tailored therapies. The RACE V Tissue Bank Project will contribute to the unravelling of the main molecular mechanisms of AF by studying histology and genome-wide RNA expression profiles and combining this information with detailed phenotyping of patients undergoing cardiac surgery. METHODS: As more and more evidence suggests that AF may occur not only during the first days but also during the months and years after surgery, we will systematically study the incidence of AF during the first years after cardiac surgery in patients with or without a history of AF. Both the overall AF burden as well as the pattern of AF episodes will be studied. Lastly, we will study the association between the major molecular mechanisms and the clinical presentation of the patients, including the incidence and pattern of AF during the follow-up period. CONCLUSION: The RACE V Tissue Bank Project combines deep phenotyping of patients undergoing cardiac surgery, including rhythm follow-up, analysis of molecular mechanisms, histological analysis and genome-wide RNA sequencing. This approach will provide detailed insights into the main pathological alterations associated with AF in atrial tissue and thereby contribute to the development of individualised, mechanistically informed patient-tailored treatment for AF.

Pharmacogenomics study of thiazide diuretics and QT interval in multi-ethnic populations: the cohorts for heart and aging research in genomic epidemiology.

Thiazide diuretics, commonly used antihypertensives, may cause QT interval (QT) prolongation, a risk factor for highly fatal and difficult to predict ventricular arrhythmias. We examined whether common single-nucleotide polymorphisms (SNPs) modified the association between thiazide use and QT or its component parts (QRS interval, JT interval) by performing ancestry-specific, trans-ethnic and cross-phenotype genome-wide analyses of European (66%), African American (15%) and Hispanic (19%) populations (N=78 199), leveraging longitudinal data, incorporating corrected standard errors to account for underestimation of interaction estimate variances and evaluating evidence for pathway enrichment. Although no loci achieved genome-wide significance (P<5 × 10-8), we found suggestive evidence (P<5 × 10-6) for SNPs modifying the thiazide-QT association at 22 loci, including ion transport loci (for example, NELL1, KCNQ3). The biologic plausibility of our suggestive results and simulations demonstrating modest power to detect interaction effects at genome-wide significant levels indicate that larger studies and innovative statistical methods are warranted in future efforts evaluating thiazide-SNP interactions.

Somatic, positive and negative domains of the Center for Epidemiological Studies Depression (CES-D) scale: a meta-analysis of genome-wide association studies.

BACKGROUND: Major depressive disorder (MDD) is moderately heritable, however genome-wide association studies (GWAS) for MDD, as well as for related continuous outcomes, have not shown consistent results. Attempts to elucidate the genetic basis of MDD may be hindered by heterogeneity in diagnosis. The Center for Epidemiological Studies Depression (CES-D) scale provides a widely used tool for measuring depressive symptoms clustered in four different domains which can be combined together into a total score but also can be analysed as separate symptom domains. METHOD: We performed a meta-analysis of GWAS of the CES-D symptom clusters. We recruited 12 cohorts with the 20- or 10-item CES-D scale (32 528 persons). RESULTS: One single nucleotide polymorphism (SNP), rs713224, located near the brain-expressed melatonin receptor (MTNR1A) gene, was associated with the somatic complaints domain of depression symptoms, with borderline genome-wide significance (p discovery = 3.82 × 10-8). The SNP was analysed in an additional five cohorts comprising the replication sample (6813 persons). However, the association was not consistent among the replication sample (p discovery+replication = 1.10 × 10-6) with evidence of heterogeneity. CONCLUSIONS: Despite the effort to harmonize the phenotypes across cohorts and participants, our study is still underpowered to detect consistent association for depression, even by means of symptom classification. On the contrary, the SNP-based heritability and co-heritability estimation results suggest that a very minor part of the variation could be captured by GWAS, explaining the reason of sparse findings.

Antihypertensive therapy for the prevention of nephropathy in diabetic hypertensive patients.

WHAT IS KNOWN AND OBJECTIVE: Although antihypertensive recommendations exist for diabetic nephropathy, there is less guidance for diabetics with normoalbuminuria. Therefore, this review evaluates antihypertensives in preventing nephropathy in diabetic hypertensive patients. COMMENT: A literature search was performed using PubMed and Medline for primary literature from 1978 through August 2015. Search terms included diabetes mellitus, normoalbuminuria, hypertension, ACE inhibitor, ARB and calcium channel blocker. There was no literature evaluating antihypertensive therapies in preventing nephropathy in type 1 hypertensive diabetics. However, in patients with type 2 diabetes and hypertension, multiple studies demonstrate the benefit of an ACEI or ARB in preventing or delaying the onset of nephropathy, while no study demonstrated the benefit of a CCB over an ACEI or ARB. WHAT IS NEW AND CONCLUSION: Due to the lack of literature, hypertension management in type 1 diabetics with normoalbuminuria should be guided by the treatment of comorbidities. To prevent diabetic nephropathy, an ACEI or ARB should be first-line monotherapy over a CCB for the management of hypertension in patients with type 2 diabetes mellitus, hypertension and normoalbuminuria.

Drug-gene interactions and the search for missing heritability: a cross-sectional pharmacogenomics study of the QT interval.

Variability in response to drug use is common and heritable, suggesting that genome-wide pharmacogenomics studies may help explain the 'missing heritability' of complex traits. Here, we describe four independent analyses in 33 781 participants of European ancestry from 10 cohorts that were designed to identify genetic variants modifying the effects of drugs on QT interval duration (QT). Each analysis cross-sectionally examined four therapeutic classes: thiazide diuretics (prevalence of use=13.0%), tri/tetracyclic antidepressants (2.6%), sulfonylurea hypoglycemic agents (2.9%) and QT-prolonging drugs as classified by the University of Arizona Center for Education and Research on Therapeutics (4.4%). Drug-gene interactions were estimated using covariable-adjusted linear regression and results were combined with fixed-effects meta-analysis. Although drug-single-nucleotide polymorphism (SNP) interactions were biologically plausible and variables were well-measured, findings from the four cross-sectional meta-analyses were null (Pinteraction>5.0 × 10(-8)). Simulations suggested that additional efforts, including longitudinal modeling to increase statistical power, are likely needed to identify potentially important pharmacogenomic effects.

A genome-wide linkage study of individuals with high scores on NEO personality traits.

The NEO-Five-Factor Inventory divides human personality traits into five dimensions: neuroticism, extraversion, openness, conscientiousness and agreeableness. In this study, we sought to identify regions harboring genes with large effects on the five NEO personality traits by performing genome-wide linkage analysis of individuals scoring in the extremes of these traits (>90th percentile). Affected-only linkage analysis was performed using an Illumina 6K linkage array in a family-based study, the Erasmus Rucphen Family study. We subsequently determined whether distinct, segregating haplotypes found with linkage analysis were associated with the trait of interest in the population. Finally, a dense single-nucleotide polymorphism genotyping array (Illumina 318K) was used to search for copy number variations (CNVs) in the associated regions. In the families with extreme phenotype scores, we found significant evidence of linkage for conscientiousness to 20p13 (rs1434789, log of odds (LOD)=5.86) and suggestive evidence of linkage (LOD >2.8) for neuroticism to 19q, 21q and 22q, extraversion to 1p, 1q, 9p and12q, openness to 12q and 19q, and agreeableness to 2p, 6q, 17q and 21q. Further analysis determined haplotypes in 21q22 for neuroticism (P-values = 0.009, 0.007), in 17q24 for agreeableness (marginal P-value = 0.018) and in 20p13 for conscientiousness (marginal P-values = 0.058, 0.038) segregating in families with large contributions to the LOD scores. No evidence for CNVs in any of the associated regions was found. Our findings imply that there may be genes with relatively large effects involved in personality traits, which may be identified with next-generation sequencing techniques.

Genome-wide association analysis of coffee drinking suggests association with CYP1A1/CYP1A2 and NRCAM.

Coffee consumption is a model for addictive behavior. We performed a meta-analysis of genome-wide association studies (GWASs) on coffee intake from 8 Caucasian cohorts (N=18 176) and sought replication of our top findings in a further 7929 individuals. We also performed a gene expression analysis treating different cell lines with caffeine. Genome-wide significant association was observed for two single-nucleotide polymorphisms (SNPs) in the 15q24 region. The two SNPs rs2470893 and rs2472297 (P-values=1.6 × 10(-11) and 2.7 × 10(-11)), which were also in strong linkage disequilibrium (r(2)=0.7) with each other, lie in the 23-kb long commonly shared 5' flanking region between CYP1A1 and CYP1A2 genes. CYP1A1 was found to be downregulated in lymphoblastoid cell lines treated with caffeine. CYP1A1 is known to metabolize polycyclic aromatic hydrocarbons, which are important constituents of coffee, whereas CYP1A2 is involved in the primary metabolism of caffeine. Significant evidence of association was also detected at rs382140 (P-value=3.9 × 10(-09)) near NRCAM-a gene implicated in vulnerability to addiction, and at another independent hit rs6495122 (P-value=7.1 × 10(-09))-an SNP associated with blood pressure-in the 15q24 region near the gene ULK3, in the meta-analysis of discovery and replication cohorts. Our results from GWASs and expression analysis also strongly implicate CAB39L in coffee drinking. Pathway analysis of differentially expressed genes revealed significantly enriched ubiquitin proteasome (P-value=2.2 × 10(-05)) and Parkinson's disease pathways (P-value=3.6 × 10(-05)).

Plasma proprotein convertase subtilisin kexin type 9 levels are related to markers of cholesterol synthesis in familial combined hyperlipidemia.

BACKGROUND AND AIMS: Two recent independent studies showed that patients with familial combined hyperlipidemia (FCHL) have elevated plasma levels of proprotein convertase subtilisin kexin type 9 (PCSK9) and markers of cholesterol synthesis. Both PCSK9 expression and cholesterol synthesis are downstream effects of hepatic activation of sterol regulatory element binding protein 2 (SREBP2). The present study was conducted to study the relationship between plasma PCSK9 and markers of cholesterol synthesis in FCHL. METHODS AND RESULTS: Markers of cholesterol synthesis (squalene, desmosterol, lathosterol), cholesterol absorption (campesterol, sitosterol, cholestanol) and PCSK9 were measured in plasma of FCHL patients (n = 103) and their normolipidemic relatives (NLR; n = 240). Plasma PCSK9, lathosterol and desmosterol levels were higher in FCHL patients than their NLR (p < 0.001, age and sex adjusted). Heritability calculations demonstrated that 35% of the variance in PCSK9 levels could be explained by additive genetic effects (p < 0.001). Significant age- and sex-adjusted correlations were observed for the relationship between PCSK9 and lathosterol, both unadjusted and adjusted for cholesterol, in the overall FCHL population (both p < 0.001). Multivariate regression analyses, with PCSK9 as the dependent variable, showed that the regression coefficient for FCHL status decreased by 25% (from 0.8 to 0.6) when lathosterol was included. Nevertheless, FCHL status remained an independent contributor to plasma PCSK9 (p < 0.001). CONCLUSIONS: The present study confirms the previously reported high and heritable PCSK9 levels in FCHL patients. Furthermore, we now show that high PCSK9 levels are, in part, explained by plasma lathosterol, suggesting that SREBP2 activation partly accounts for elevated PCSK9 levels in FCHL.

A systematic, genome-wide, phenotype-driven mutagenesis programme for gene function studies in the mouse.

As the human genome project approaches completion, the challenge for mammalian geneticists is to develop approaches for the systematic determination of mammalian gene function. Mouse mutagenesis will be a key element of studies of gene function. Phenotype-driven approaches using the chemical mutagen ethylnitrosourea (ENU) represent a potentially efficient route for the generation of large numbers of mutant mice that can be screened for novel phenotypes. The advantage of this approach is that, in assessing gene function, no a priori assumptions are made about the genes involved in any pathway. Phenotype-driven mutagenesis is thus an effective method for the identification of novel genes and pathways. We have undertaken a genome-wide, phenotype-driven screen for dominant mutations in the mouse. We generated and screened over 26,000 mice, and recovered some 500 new mouse mutants. Our work, along with the programme reported in the accompanying paper, has led to a substantial increase in the mouse mutant resource and represents a first step towards systematic studies of gene function in mammalian genetics.

Trends in outcomes of 862 giant hiatus hernia repairs over 30 years.

PURPOSE: Laparoscopic giant hiatus hernia repair is technically difficult with ongoing debate regarding the most effective surgical technique. Repair of small hernia has been well described but data for giant hernia is variable. This study evaluated trends in outcomes of laparoscopic non-mesh repair of giant paraesophageal hernia (PEH) over 30 years. METHODS: Retrospective analysis of a single-surgeon prospective database. Laparoscopic non-mesh repairs for giant PEH between 1991 and 2021 included. Three-hundred-sixty-degree fundoplication was performed routinely, evolving into "composite repair" (esophagopexy and cardiopexy to the right crus). Cases were chronologically divided into tertiles based on operation date (Group 1, 1991-2002; Group 2, 2003-2012; Group 3, 2012-2021) with trends in casemix, operative factors and outcomes evaluated. Hernia recurrence was plotted using weighted moving average and cumulative sum (CUSUM) analysis. RESULTS: 862 giant PEH repairs met selection criteria. There was an increasing proportion of "composite repair" after the first decade (Group 1, 2.7%; Group 2, 81.9%; Group 3, 100%; p < 0.001). There were less anatomical hernia recurrence (Group 1, 36.6%; Group 2, 22.9%; Group 3, 22.7%; p < 0.001) and symptomatic recurrence (Group 1, 34.2%; Group 2, 21.9%; Group 3, 7%; p < 0.001) over time. The incidence of anatomical recurrence declined over time, decreasing from 30.8% and plateauing below 17.6% near the study's end. Median followup (months) in the first decade was higher but followup between the latter two decades comparable (Group 1, 49 [IQR 20, 81]; Group 2, 30 [IQR 15, 65]; Group 3, 24 [14, 56]; p < 0.001). There were 10 (1.2%) Clavien-Dindo grade ≥ III complications including two perioperative deaths (0.2%). CONCLUSION: Hernia recurrence rates decreased with increasing case volume. This coincided with the increasing adoption of "composite repair", supporting the possible improvement in recurrence rates with this approach.

Snacking practices from infancy to adolescence: parental perspectives from longitudinal lived experience research in England.

Consumption of snacks and ultra-processed foods (UPF) high in fat, salt and sugar (HFSS) is associated with rising rates of obesity and growing socioeconomic disparities in nutrition. While infancy, childhood and adolescence are critical periods for development of dietary preferences, there remains a dearth of research exploring factors that underpin snacking behaviour over this time. This review aims to address this gap by drawing from qualitative lived experience research, with 122 families of different socioeconomic position (SEP), to explore how the (i) home food environment, (ii) food environment and (iii) social value and meanings of food shape parental provision of snacks. This review shows that snacking holds important meanings in everyday family life, with infants integrated into existing snacking practices from an early age. Price promotions, low-cost and long shelf-lives all make UPF and HFSS snacks an appealing option for many low-SEP parents; while children's requests and preferences for HFSS snacks present a challenge across SEP. However, higher-SEP parents can ensure fresh fruits are always available as an alternative snack, while fruit is described as a financially risky expenditure for low-SEP families. The present findings also indicate that retailers and producers are increasingly promoting 'healthier' snacks through product packaging and marketing, such as 'meets one of your five a day', despite these products displaying similar nutritional profiles to traditional UPF and HFSS snacks. We outline a series of policy recommendations, including extending Healthy Start Vouchers and the Fruit and Vegetable Scheme in schools and action to address misleading product marketing and packaging.

Comparison of transgene expression in Aedes aegypti generated by mariner Mos1 transposition and ΦC31 site-directed recombination.

Transgenic mosquitoes generated by transposable elements (TEs) often poorly express transgenes owing to position effects. To avoid these effects, the ΦC31 site-directed recombination system was used to insert transgenes into a locus favourable for gene expression in Aedes aegypti. We describe phenotypes of mariner Mos1 TE and ΦC31 transgenic mosquitoes expressing the enhanced green fluorescent protein (EGFP) reporter in midguts of blood-fed females. Mosquitoes of nine TE-generated lines [estimated transformation frequency (TF): 9.3%] clearly expressed the eye-specific selection marker but only 2/9 lines robustly expressed the EGFP reporter. The piggyBac TE-generated ΦC31 docking strain, attP26, supported recombination with attB site containing donors at an estimated TF of 1.7-4.9%. Using a codon-optimized ΦC31 integrase mutant instead of the 'wild-type' enzyme did not affect TF. Site-directed recombination of line attP26 with an attB-containing donor expressing EGFP from the Ae. aegypti carboxypeptidase promoter produced one transgenic line with blood-fed females expressing the reporter in midgut tissue. Docking strain attP26 also supported robust expression of Flock House virus B2 from the Ae. aegypti polyubiquitin promoter. Our data confirm that eye-specific selection marker expression alone is not a reliable indicator for robust gene-of-interest expression in Ae. aegypti and that the ΦC31 system can ensure predictable transgene expression in this mosquito species.

Genetic risk factors for cerebral small-vessel disease in hypertensive patients from a genetically isolated population.

BACKGROUND: Asymptomatic cerebral lesions on MRI such as white matter lesions (WML), lacunes and microbleeds are commonly seen in older people. We examined the role of a series of candidate genes involved in blood pressure regulation and amyloid metabolism. MATERIALS AND METHODS: The study was embedded in a family-based cohort sampled from a Dutch genetically isolated population. We selected individuals between 55 and 75 years of age with hypertension (N=129). Volumes of WML and presence of lacunes and microbleeds were assessed with MRI. We studied three genes involved in blood pressure regulation (angiotensin, angiotensin II type 1 receptor, α-adducin) and two genes involved in the amyloid pathway (apolipoprotein E (APOE) and sortilin-related receptor gene (SORL1)). RESULTS: All participants had WML (median volume, 3.1 ml; interquartile range, 1.5-6.5 ml); lacunar infarcts were present in 15.5% and microbleeds in 23.3%. Homozygosity for the APOE ε4 allele was associated with lacunes (OR, 4.8; 95% CI, 1.2 to 19.3). Individuals carrying two copies of the variant allele of four single nucleotide polymorphism (SNPs) located at the 3'-end of SORL1 (rs1699102, rs3824968, rs2282649, rs1010159) had significantly more often microbleeds (highest OR, 6.87; 95% CI, 1.78 to 26.44). CONCLUSION: The association of SORL1 with microbleeds suggests that the amyloid cascade is involved in the aetiology of microbleeds in populations with hypertension.

Motivation to obtain preferred foods is enhanced by ghrelin in the ventral tegmental area.

Ghrelin is an orexigenic peptide that acts within the central nervous system to stimulate appetite and food intake via the growth hormone secretagogue receptor (GHS-R). It has been hypothesized that ghrelin modulates food intake in part by stimulating reward pathways in the brain and potentially stimulating the intake of palatable foods. Here we examined the effects of chronic ghrelin administration in the ventral tegmental area (VTA) via osmotic minipumps on 1) ad libitum food intake and bodyweight; 2) macronutrient preference; and 3) motivation to obtain chocolate pellets. In the first study rats receiving ghrelin into the VTA showed a dose-dependent increase in the intake of regular chow, also resulting in increased body weight gain. A second study revealed that intra-VTA delivery of the ghrelin receptor antagonist [Lys-3]-GHRP-6 selectively reduced caloric intake of high-fat chow and reduced body weight gain relative to control and ghrelin treated rats. The third study demonstrated that food restricted rats worked harder for food pellets when infused with ghrelin than when infused with vehicle or ghrelin receptor antagonist treated rats. Finally, rats trained on an FR1 schedule but returned to ad libitum during ghrelin infusion, responded at 86% of baseline levels when they were not hungry, whereas saline infused rats responded at 36% of baseline. Together, these results suggest that ghrelin acts directly on the VTA to increase preference for and motivation to obtain highly-palatable food.

Comparative fitness assessment of Anopheles stephensi transgenic lines receptive to site-specific integration.

Genetically modified mosquitoes that are unable to transmit pathogens offer opportunities for controlling vector-borne diseases such as malaria and dengue. Site-specific gene recombination technologies are advantageous in the development of these insects because antipathogen effector genes can be inserted at integration sites in the genome that cause the least alteration in mosquito fitness. Here we describe Anopheles stephensi transgenic lines containing phi C31 attP'docking' sites linked to a fluorescent marker gene. Chromosomal insertion sites were determined and life-table parameters were assessed for transgenic mosquitoes of each line. No significant differences in fitness between the transgenic and nontransgenic mosquitoes were detected in this study. These transgenic lines are suitable for future site-specific integrations of antiparasite transgenes into the attP sites.

JavaCyte, a novel open-source tool for automated quantification of key hallmarks of cardiac structural remodeling.

Many cardiac pathologies involve changes in tissue structure. Conventional analysis of structural features is extremely time-consuming and subject to observer bias. The possibility to determine spatial interrelations between these features is often not fully exploited. We developed a staining protocol and an ImageJ-based tool (JavaCyte) for automated histological analysis of cardiac structure, including quantification of cardiomyocyte size, overall and endomysial fibrosis, spatial patterns of endomysial fibrosis, fibroblast density, capillary density and capillary size. This automated analysis was compared to manual quantification in several well-characterized goat models of atrial fibrillation (AF). In addition, we tested inter-observer variability in atrial biopsies from the CATCH-ME consortium atrial tissue bank, with patients stratified by their cardiovascular risk profile for structural remodeling. We were able to reproduce previous manually derived histological findings in goat models for AF and AV block (AVB) using JavaCyte. Furthermore, strong correlation was found between manual and automated observations for myocyte count (r = 0.94, p < 0.001), myocyte diameter (r = 0.97, p < 0.001), endomysial fibrosis (r = 0.98, p < 0.001) and capillary count (r = 0.95, p < 0.001) in human biopsies. No significant variation between observers was observed (ICC = 0.89, p < 0.001). We developed and validated an open-source tool for high-throughput, automated histological analysis of cardiac tissue properties. JavaCyte was as accurate as manual measurements, with less inter-observer variability and faster throughput.

Orthopyroxene exsolution in augite: a two-step, diffusion-transformation process.

Orthopyroxene lamellae exsolved from augite on (100) are shown to grow by a two-step process involving (i) the diffusion of calcium and (magnesium, iron) to form clinohypersthene and (ii) the inversion of clinohypersthene to orthopyroxene, probably by glide twinning. If complete inversion is prevented by cooling or steep concentration gradients, the two-step process produces orthopyroxene with narrow margins of clinohypersthene. Measured elemental concentration gradients at (100) lamellar interfaces support this mechanism.

Lack of TAR-DNA binding protein-43 (TDP-43) pathology in human prion diseases.

AIMS: TAR-DNA binding protein-43 (TDP-43) is the major ubiquitinated protein in the aggregates in frontotemporal dementia with ubiquitin-positive, tau-negative inclusions and motor neurone disease. Abnormal TDP-43 immunoreactivity has also been described in Alzheimer's disease, Lewy body diseases and Guam parkinsonism-dementia complex. We therefore aimed to determine whether there is TDP-43 pathology in human prion diseases, which are characterised by variable deposition of prion protein (PrP) aggregates in the brain as amyloid plaques or more diffuse deposits. MATERIAL AND METHODS: TDP-43, ubiquitin and PrP were analysed by immunohistochemistry and double-labelling immunofluorescence, in sporadic, acquired and inherited forms of human prion disease. RESULTS: Most PrP plaques contained ubiquitin, while synaptic PrP deposits were not associated with ubiquitin. No abnormal TDP-43 inclusions were identified in any type of prion disease case, and TDP-43 did not co-localize with ubiquitin-positive PrP plaques or with diffuse PrP aggregates. CONCLUSIONS: These data do not support a role for TDP-43 in prion disease pathogenesis and argue that TDP-43 inclusions define a distinct group of neurodegenerative disorders.