The predictive value of smoking expectancy and the heritability of its accuracy.

Introduction: Among smokers, former smokers, and never-smokers, this study aimed to (a) determine the predictive value of smoking expectancy on future smoking status, and (b) test the relative contribution of genes and environment to a person's ability to accurately predict future smoking status. For smokers, smoking expectancy reflects the intention to continue smoking; for former smokers, it reflects the intention to take up smoking again; and for never-smokers, it reflects the intention to initiate smoking.

Methods: A longitudinal design was employed in which participants of the Netherlands Twin Register completed 2 consecutive surveys 2 years apart between 1993 and 2011 (3,591 adolescents aged 14-18 years), or between 1993 and 2004 (11,568 adults, aged 18+ years).

The association of alcohol intake with γ-glutamyl transferase (GGT) levels: evidence for correlated genetic effects.

Background: Blood levels of gamma-glutamyl transferase (GGT) are used as a marker for (heavy) alcohol use. The role of GGT in the anti-oxidant defense mechanism that is part of normal metabolism supposes a causal effect of alcohol intake on GGT. However, there is variability in the response of GGT to alcohol use, which may result from genetic differences between individuals.

Robust and sensitive video motion detection for sleep analysis.

In this paper, we propose a camera-based system combining video motion detection, motion estimation, and texture analysis with machine learning for sleep analysis. The system is robust to time-varying illumination conditions while using standard camera and infrared illumination hardware. We tested the system for periodic limb movement (PLM) detection during sleep, using EMG signals as a reference.

Genetic risk score analysis indicates migraine with and without comorbid depression are genetically different disorders.

Migraine and major depressive disorder (MDD) are comorbid, moderately heritable and to some extent influenced by the same genes. In a previous paper, we suggested the possibility of causality (one trait causing the other) underlying this comorbidity. We present a new application of polygenic (genetic risk) score analysis to investigate the mechanisms underlying the genetic overlap of migraine and MDD.

Anthrax toxin receptor 2 promotes human uterine smooth muscle cell viability, migration and contractility.

Objective: Previously we demonstrated anthrax toxin receptor 2 knockout (Antxr2(-/-)) mice are fertile but fail to deliver their pups at term. This parturition defect is associated with overaccumulation of extracellular matrix proteins and decreased myometrial cell content in the uterus. Myometrial cell loss in Antxr2(-/-) uterine tissue prompted us to evaluate if ANTXR2 is essential for human uterine smooth muscle cell viability and function.

[Early alcohol initiation and increased adult alcohol consumption: cause or indicator?].

Background: Early alcohol initiation is strongly associated with increased alcohol consumption and alcohol abuse/dependence in adulthood. The mechanisms that underlie this association are unclear.

Aim: To examine whether there is a causal link between early alcohol initiation and later alcohol consumption.

The effect of intramuscular progesterone on the rate of cervical shortening.

Objective: The purpose of the study was to evaluate whether 17-alpha-hydroxyprogesterone caproate (17-OHPC) exposure is associated with the rate of cervical shortening.

Study Design: Women with a history of spontaneous preterm delivery (PTD) at <37 weeks' gestation who had serial cervical length measurements (2009-2012) were identified. 17-OHPC administration and outcome data were collected.

Opinions and practice patterns of obstetricians-gynecologists in the United States regarding amniocentesis in twins.

Objective: Accurate amniocentesis-related pregnancy loss (ARL) rates for twin gestations remains elusive because of varying ARL definitions in the literature. We examined how OB/GYNs define/counsel women carrying twins about ARL.

Methods: A random sample of 1000 American College of OB/GYN (ACOG) fellows and ACOG Collaborative Ambulatory Research Network (CARN) members were mailed surveys about their opinions/practice patterns regarding amniocentesis in twins.

Gamma-ray burst progenitors and the population of rotating Wolf-Rayet stars.

In our quest for gamma-ray burst (GRB) progenitors, it is relevant to consider the progenitor evolution of normal supernovae (SNe). This is largely dominated by mass loss. We discuss the mass-loss rate for very massive stars up to 300M⊙.

The genetic architecture of liver enzyme levels: GGT, ALT and AST.

High levels of liver enzymes GGT, ALT and AST are predictive of disease and all-cause mortality and can reflect liver injury, fatty liver and/or oxidative stress. Variation in GGT, ALT and AST levels is heritable. Moderation of the heritability of these liver enzymes by age and sex has not often been explored, and it is not clear to what extent non-additive genetic and shared environmental factors may play a role.

An automatic vision-based malaria diagnosis system.

Malaria is a worldwide health problem with 225 million infections each year. A fast and easy-to-use method, with high performance is required to differentiate malaria from non-malarial fevers. Manual examination of blood smears is currently the gold standard, but it is time-consuming, labour-intensive, requires skilled microscopists and the sensitivity of the method depends heavily on the skills of the microscopist.

The use of imputed sibling genotypes in sibship-based association analysis: on modeling alternatives, power and model misspecification.

When phenotypic, but no genotypic data are available for relatives of participants in genetic association studies, previous research has shown that family-based imputed genotypes can boost the statistical power when included in such studies. Here, using simulations, we compared the performance of two statistical approaches suitable to model imputed genotype data: the mixture approach, which involves the full distribution of the imputed genotypes and the dosage approach, where the mean of the conditional distribution features as the imputed genotype. Simulations were run by varying sibship size, size of the phenotypic correlations among siblings, imputation accuracy and minor allele frequency of the causal SNP.

Increases in alcohol consumption in women and elderly groups: evidence from an epidemiological study.

Background: In most Western countries, alcohol consumption continues to increase, specifically among women and older adults. Insight into these trends may aid intervention strategies. Here we present data on alcohol consumption by age and sex as well as associations between alcohol use and demographic lifestyle/traits.

Direct measurement of the permeability of human cervical tissue.

The mechanical integrity of the uterine cervix is critical for a pregnancy to successfully reach full term. It must be strong to retain the fetus throughout gestation and then undergo a remodeling and softening process before labor for delivery of the fetus. It is believed that cervical insufficiency (CI), a condition in pregnancy resulting in preterm birth (PTB), is related to a cervix with compromised mechanical strength which cannot resist deformation caused by external forces generated by the growing fetus.

Ovarian reserve and anti-Mullerian hormone (AMH) in mothers of dizygotic twins.

This study aimed to explore if natural dizygotic (DZ) twinning is associated with earlier menopause and lower anti-Mullerian hormone (AMH) values. We investigated if advanced biological reproductive aging, which can be responsible for the multiple follicle growth in familial twinning, is similar to mechanisms that occur in normal ovarian aging, reflected by earlier menopause in mothers of DZ twins and lower levels of AMH. A total of 16 mothers of DZ twins enrolled with the Netherlands Twin Register (average age at first assessment: 35.

Meta-analysis of telomere length in 19,713 subjects reveals high heritability, stronger maternal inheritance and a paternal age effect.

Telomere length (TL) has been associated with aging and mortality, but individual differences are also influenced by genetic factors, with previous studies reporting heritability estimates ranging from 34 to 82%. Here we investigate the heritability, mode of inheritance and the influence of parental age at birth on TL in six large, independent cohort studies with a total of 19,713 participants. The meta-analysis estimate of TL heritability was 0.

The Adult Netherlands Twin Register: twenty-five years of survey and biological data collection.

Over the past 25 years, the Adult Netherlands Twin Register (ANTR) has collected a wealth of information on physical and mental health, lifestyle, and personality in adolescents and adults. This article provides an overview of the sources of information available, the main research findings, and an outlook for the future. Between 1991 and 2012, longitudinal surveys were completed by twins, their parents, siblings, spouses, and offspring.

Borderline personality traits and substance use: genetic factors underlie the association with smoking and ever use of cannabis, but not with high alcohol consumption.

Borderline personality disorder (BPD) and substance use disorders often co-occur. Both disorders are heritable and family studies showed that there are familial factors that increase the risk for BPD as well as substance use/abuse. This is the first study that investigates whether the association of borderline personality traits (BPT) with substance use reflects an underlying genetic vulnerability or nongenetic familial influences.

Sex differences in genetic architecture of complex phenotypes?

We examined sex differences in familial resemblance for a broad range of behavioral, psychiatric and health related phenotypes (122 complex traits) in children and adults. There is a renewed interest in the importance of genotype by sex interaction in, for example, genome-wide association (GWA) studies of complex phenotypes. If different genes play a role across sex, GWA studies should consider the effect of genetic variants separately in men and women, which affects statistical power.

Efficient nucleus detector in histopathology images.

In traditional cancer diagnosis, (histo)pathological images of biopsy samples are visually analysed by pathologists. However, this judgment is subjective and leads to variability among pathologists. Digital scanners may enable automated objective assessment, improved quality and reduced throughput time.

New loci associated with birth weight identify genetic links between intrauterine growth and adult height and metabolism.

Birth weight within the normal range is associated with a variety of adult-onset diseases, but the mechanisms behind these associations are poorly understood. Previous genome-wide association studies of birth weight identified a variant in the ADCY5 gene associated both with birth weight and type 2 diabetes and a second variant, near CCNL1, with no obvious link to adult traits. In an expanded genome-wide association meta-analysis and follow-up study of birth weight (of up to 69,308 individuals of European descent from 43 studies), we have now extended the number of loci associated at genome-wide significance to 7, accounting for a similar proportion of variance as maternal smoking.

Developmental prediction model for early alcohol initiation in Dutch adolescents.

Objective: Multiple factors predict early alcohol initiation in teenagers. Among these are genetic risk factors, childhood behavioral problems, life events, lifestyle, and family environment. We constructed a developmental prediction model for alcohol initiation below the Dutch legal drinking age (16 years), elaborating on the pathways identified by earlier studies.