Distinct Patterns Of Association Research Articles

Distinct Patterns of Association of Variants at 11q23.3 Chromosomal Region with Coronary Artery Disease and Dyslipidemia in the Population of Andhra Pradesh, India.

In our attempt to comprehensively understand the nature of association of variants at 11q23.3 apolipoprotein gene cluster region, we genotyped a prioritized set of 96 informative SNPs using Fluidigm customized SNP genotyping platform in a sample of 508 coronary artery disease (CAD) cases and 516 controls. We found 12 SNPs as significantly associated with CAD at P <0.05, albeit only four (rs2849165, rs17440396, rs6589566 and rs633389) of these remained significant after Benjamin Hochberg correction. Of the four, while rs6589566 confers risk to CAD, the other three SNPs reduce risk for the disease. Interaction of variants that belong to regulatory genes BUD13 and ZPR1 with APOA5-APOA4 intergenic variants is also observed to significantly increase the risk towards CAD. Further, ROC analysis of the risk scores of the 12 significant SNPs suggests that our study has substantial power to confer these genetic variants as predictors of risk for CAD, as illustrated by AUC (0.763; 95% CI: 0.729–0.798, p = <0.0001). On the other hand, the protective SNPs of CAD are associated with elevated Low Density Lipoprotein Cholesterol and Total Cholesterol levels, hence with dyslipidemia, in our sample of controls, which may suggest distinct effects of the variants at 11q23.3 chromosomal region towards CAD and dyslipidemia. It may be necessary to replicate these findings in the independent and ethnically heterogeneous Indian samples in order to establish this as an Indian pattern. However, only functional analysis of the significant variants identified in our study can provide more precise understanding of the mechanisms involved in the contrasting nature of their effects in manifesting dyslipidemia and CAD.

Posttraumatic stress symptoms, co-morbid psychiatric symptoms and distorted cognitions among flood victims of different ages

Background: In literature, the effect of age on posttraumatic stress disorder (PTSD) is inconclusive; the effect on flood-related PTSD is particularly unclear. Little is known on distorted cognitions among flood victims, although cognition distortions and PTSD have been linked among victims of other traumas.Aims: To investigate: (1) whether flood-related PTSD, psychiatric co-morbidity and cognitive distortions would differ according to age and (2) distinctive patterns of association between the preceding variables for different age groups.Methods: One hundred and fifty-four flood victims of different ages completed standardized questionnaires measuring PTSD, psychiatric co-morbidity and cognitive distortions.Results: Adolescents and young adults reported significantly fewer PTSD, psychiatric co-morbidity and distorted cognition symptoms than people who were older. Preoccupation with danger and hopelessness were associated with both outcomes for adolescents, people in their thirties and middle-aged/older people. For young adults, helplessness was associated with PTSD; hopelessness and preoccupation with danger with psychiatric co-morbidity.Conclusions: Adolescents and young adults buffered against flood-related psychological distress better than older people. Distorted cognitions related to distress outcomes differently depending on age.

Analysis of Glial Distribution in Drosophila Adult Brains.

Neurons and glia are the two major cell types in the nervous system and work closely with each other to program neuronal interplay. Traditionally, neurons are thought to be the major cells that actively regulate processes like synapse formation, plasticity, and behavioral output. Glia, on the other hand, serve a more supporting role. To date, accumulating evidence has suggested that glia are active participants in virtually every aspect of neuronal function. Despite this, fundamental features of how glia interact with neurons, and their spatial relationships, remain elusive. Here, we describe the glial cell population in Drosophila adult brains. Glial cells extend and tightly associate their processes with major structures such as the mushroom body (MB), ellipsoid body (EB), and antennal lobe (AL) in the brain. Glial cells are distributed in a more concentrated manner in the MB. Furthermore, subsets of glia exhibit distinctive association patterns around different neuronal structures. Whereas processes extended by astrocyte-like glia and ensheathing glia wrap around the MB and infiltrate into the EB and AL, cortex glia stay where cell bodies of neurons are and remain outside of the synaptic regions structured by EB or AL.

CLASSIFICATION OF ANXIETY DISORDERS COMORBID WITH MAJOR DEPRESSION: COMMON OR DISTINCT INFLUENCES ON RISK?

Anxiety and depression display frequent comorbidity. Individuals with comorbid disorders also often have more extreme symptomatology than those with single disorders. This correlation between comorbidity and severity poses an interesting question: Are comorbid forms of anxiety and depression essentially just more severe versions of the pure disorders? In a large major depression (MD) case-control sample of individuals from the China, Oxford and VCU Experimental Research on Genetic Epidemiology project, we examined the patterns of lifetime anxiety comorbidity (including generalized anxiety disorder--GAD, panic disorder, and five phobia subtypes) among MD cases (N = 5,864) in this population. Binary and multinomial logistic regression was used to estimate associations between risk factors and outcomes including MD as well as latent class membership, which were compared using continuation ratios. We found a five-class solution to fit best, and each resulting class had a distinct pattern of association with the tested risk factors. The use of continuation ratios suggests that a class characterized by high endorsement of GAD is comparable to a more severely affected "pure MD" group. The other three classes (characterized by agoraphobia, various specific phobias, and by high endorsement of all comorbid anxiety disorders, respectively) appear to differ meaningfully from MD alone. Risk for MD resulting from environmental and psychosocial factors may also predispose individuals to GAD, and less consistently, other anxiety disorders. Presentations of MD with certain phobias display distinguishably different patterns of risk, however, and are therefore likely qualitatively distinct.

Neural plasticity in fathers of human infants

Fathering plays an important role in infants’ socioemotional and cognitive development. Previous studies have identified brain regions that are important for parenting behavior in human mothers. However, the neural basis of parenting in human fathers is largely unexplored. In the current longitudinal study, we investigated structural changes in fathers’ brains during the first 4 months postpartum using voxel-based morphometry analysis. Biological fathers (n = 16) with full-term, healthy infants were scanned at 2–4 weeks postpartum (time 1) and at 12–16 weeks postpartum (time 2). Fathers exhibited increase in gray matter (GM) volume in several neural regions involved in parental motivation, including the hypothalamus, amygdala, striatum, and lateral prefrontal cortex. On the other hand, fathers exhibited decreases in GM volume in the orbitofrontal cortex, posterior cingulate cortex, and insula. The findings provide evidence for neural plasticity in fathers’ brains. We also discuss the distinct patterns of associations among neural changes, postpartum mood symptoms, and parenting behaviors among fathers.

Similar and contrasting dimensions of social cognition in schizophrenia and healthy subjects

Schizophrenia patients experience substantial impairments in social cognition (SC) and these deficits are associated with their poor functional outcome. Though SC is consistently shown to emerge as a cognitive dimension distinct from neurocognition, the dimensionality of SC is poorly understood. Moreover, comparing the components of SC between schizophrenia patients and healthy comparison subjects would provide specific insights on the construct validity of SC. We conducted principal component analyses of eight SC test scores (representing four domains of SC, namely, theory of mind, emotion processing, social perception and attributional bias) independently in 170 remitted schizophrenia patients and 111 matched healthy comparison subjects. We also conducted regression analyses to evaluate the relative contribution of individual SC components to other symptom dimensions, which are important clinical determinants of functional outcome (i.e., neurocognition, negative symptoms, motivational deficits and insight) in schizophrenia. A three-factor solution representing socio-emotional processing, social–inferential ability and external attribution components emerged in the patient group that accounted for 64.43% of the variance. In contrast, a two-factor solution representing socio-emotional processing and social–inferential ability was derived in the healthy comparison group that explained 56.5% of the variance. In the patient group, the social–inferential component predicted negative symptoms and motivational deficits. Our results suggest the presence of a multidimensional SC construct. The dimensionality of SC observed across the two groups, though not identical, displayed important parallels. Individual components also demonstrated distinct patterns of association with other symptom dimensions, thus supporting their external validity.

Investigating exposure to violence and mental health in a diverse urban community sample: data from the South East London Community Health (SELCoH) survey.

BackgroundGeneral population surveys have seldom examined violence as a multidimensional concept and in relation to an array of mental disorders.MethodsData from the South East London Community Health Study was used to examine the prevalence, overlap and distribution of proximal witnessed, victimised and perpetrated violence and their association with current mental disorders. We further investigated the cumulative effect of lifetime exposure to violence on current mental disorders. Unadjusted and adjusted (for confounders and violence) models were examined.ResultsIn the last twelve months, 7.4% reported witnessing violence, 6.3% victimisation and 3.2% perpetration of violence. There was a significant overlap across violence types, with some shared correlates across the groups such as being younger and male. Witnessing violence in the past year was associated with current common mental disorders (CMD) and post-traumatic stress disorder (PTSD) symptoms. Proximal perpetration was associated with current CMD, PTSD symptoms and past 12 months drug use; whereas proximal victimisation was associated with lifetime and past 12 months drug use. Lifetime exposure to two or more types of violence was associated with increased risk for all mental health outcomes, suggesting a cumulative effect.ConclusionExposure to violence needs to be examined in a multi-faceted manner: i) as discrete distal and proximal events, which may have distinct patterns of association with mental health and ii) as a concept with different but overlapping dimensions, thus also accounting for possible cumulative effects.

Abstract 22: Influence of Smoking and Sex on Genetic Associations of Body Fat Distribution: The Giant (Genetic Investigation of ANthropometric Traits) Consortium

Visceral fat and smoking are important risk factors for CVD and other long-term poor health outcomes. Central adiposity is frequently assessed in population studies using waist-to-hip ratio adjusted for BMI (WHRadjBMI). Genome-wide association studies (GWAS) have discovered loci that influence WHRadjBMI, sometimes with sex-specific effects. However, we do not know whether and how smoking behavior influences the association between genetic variants and WHRadjBMI. Our study investigates the influence of smoking and genetic variants on WHRadjBMI, with particular consideration for differential effects by sex. Forty-one GIANT GWAS (108,397 participants) were used to investigate the influence of smoking on SNP WHRadjBMI associations using sex-stratified models considering SNP main effects adjusted for smoking status, and SNP main effects stratified by smoking status. Results from each study were meta-analyzed using an inverse-variance weighted fixed-effects model for men and women separately as well as combined. A total of 19 SNPs reached genome-wide significance (p&lt;5x10-8) having adjusted the SNP effect for smoking across strata (women, men, and combined), including 11 previously reported WHRadjBMI loci. For known WHRadjBMI loci, the influence of smoking varied by sex. In women, four known WHRadjBMI SNPs (TBX15, DNM3, RSPO3, and ADAMTS9) had a greater effect in smokers vs. nonsmokers (TBX15: β(SE) = 0.0506 (0.014), p = 3.84x10-4) vs. β(SE) = 0.0382 (0.0072), p = 1.14x10-7). Three of these (TBX15, DNM3, RSPO3) have been previously associated with tobacco use disorder (TUD). In men, three known WHRadjBMI loci (ADAMTS9, DNM3, ZNRF3) had a greater effect among smokers vs nonsmokers (ZNRF3: β(SE) = 0.0365 (0.0148), p = 1.37x10-2) vs β(SE) = 0.0192 (0.0088), p = 12.87x10-2). Eight of our 19 top SNPs have not been previously associated with WHRadjBMI (within 500 kb). Of these eight loci, distinct patterns of association by smoking and sex were again noted. In addition, one locus (ABCA1) has been previously associated with TUD. In addition to identifying novel loci associated with body fat distribution, these findings underscore the importance of considering the effect of smoking when investigating the genetics of obesity related phenotypes and emphasize the need to consider sex separately when studying the effects of smoking on body fat distribution.

TMEM106B Influences Volume of Left-Sided Temporal Lobe and Interhemispheric Structures in the General Population

Frontotemporal lobar degeneration is a neurodegenerative disease characterized by brain atrophy of the frontal and anterior temporal lobes. The associated frontotemporal dementia syndromes are clinically heterogeneous, and the pattern of affected cortical regions varies among subtypes. The TMEM106B rs1990622 polymorphism is associated with frontotemporal lobar degeneration, but little is known about how it affects the brain. We investigated the rs1990622 polymorphism in relation to regional brain volumes to identify potential structures through which TMEM106B confers risk for frontotemporal lobar degeneration. In 4413 nondemented and stroke-free participants from the population-based Rotterdam Study, 150 cortical brain structures and 6 commissural regions were segmented from magnetic resonance imaging. A distinct pattern of association was found between rs1990622 and gray matter volume of left-sided temporal brain regions important for language processing, including the superior temporal gyrus (β=-88.8 μL per risk allele, p=7.64×10(-5)), which contains Wernicke's area. The risk allele was also associated with a smaller anterior commissure cross-sectional area (β=-.167 mm2 per risk allele, p=4.90×10(-5)) and posterior part of the corpus callosum (β=-15.3 μL per risk allele, p=1.23×10(-5)), both of which contain temporal lobe commissural tracts. The asymmetric, predominantly left-sided involvement suggests an effect of TMEM106B on functions lateralized to the dominant hemisphere, such as language. These results show that, in nondemented persons, TMEM106B influences the volume of temporal brain regions that are important for language processing.

Social Reward Questionnaire (SRQ): development and validation

Human beings seek out social interactions as a source of reward. To date, there have been limited attempts to identify different forms of social reward, and little is known about how the value of social rewards might vary between individuals. This study aimed to address both these issues by developing the Social Reward Questionnaire (SRQ), a measure of individual differences in the value of different social rewards. Exploratory factor analysis (EFA) was run on an initial set of 75 items (N = 305). Based on this analysis, confirmatory factor analysis (CFA) was then conducted on a second sample (N = 505) with a refined 23-item scale. This analysis was used to test a six-factor structure, which resulted in good model fit (CFI = 0.96, RSMEA = 0.07). The factors represent six subscales of social reward defined as follows: Admiration; Negative Social Potency; Passivity; Prosocial Interactions; Sexual Reward; and Sociability. All subscales demonstrated good test-retest reliability and internal consistency. Each subscale also showed a distinct pattern of associations with external correlates measuring personality traits, attitudes, and goals, thus demonstrating construct validity. Taken together, the findings suggest that the SRQ is a reliable, valid measure that can be used to assess individual differences in the value experienced from different social rewards.

Identification of a novel Parkinson’s disease locus via stratified genome-wide association study

BackgroundParkinson’s disease (PD) is complex and heterogeneous. The numerous susceptibility loci that have been identified reaffirm the complexity of PD but do not fully explain it; e.g., it is not known if any given PD susceptibility gene is associated with all PD or a disease subtype. We also suspect that important disease genes may have escaped detection because of this heterogeneity. We used presence/absence of family history to subdivide the cases and performed genome-wide association studies (GWAS) in Sporadic-PD and Familial-PD separately. The aim was to uncover new genes and gain insight into the genetic architecture of PD.ResultsEmploying GWAS on the NeuroGenetics Research Consortium (NGRC) dataset stratified by family history (1565 Sporadic-PD, 435 Familial-PD, 1986 controls), we identified a novel locus on chromosome 1p21 in Sporadic-PD (PNGRC = 4×10-8) and replicated the finding (PReplication = 6×10-3; PPooled = 4×10-10) in 1528 Sporadic-PD and 796 controls from the National Institutes of Neurologic Disease and Stroke (NINDS) Repository. This is the fifth PD locus to be mapped to the short arm of chromosome 1. It is flanked by S1PR1 and OLFM3 genes, and is 200 kb from a multiple sclerosis susceptibility gene. The second aim of the study was to extend the stratified GWAS to the well-established PD genes. SNCA_ rs356220 was associated with both Sporadic-PD (OR = 1.37, P = 1×10-9) and Familial-PD (OR = 1.40, P = 2×10-5). HLA_rs3129882 was more strongly associated with Sporadic-PD (OR = 1.38, P = 5×10-10) than Familial-PD (OR = 1.12, P = 0.15). In the MAPT region, virtually every single nucleotide polymorphism (SNP) had a stronger effect-size and lower P-value in Familial-PD (peak P = 8×10-7) than in Sporadic-PD (peak P = 2×10-5).ConclusionsWe discovered and replicated a new locus for Sporadic-PD which had escaped detection in un-stratified GWAS. This demonstrates that by stratifying on a key variable the power gained due to diminished heterogeneity can sometimes outweigh the power lost to reduced sample size. We also detected distinct patterns of disease associations for previously established PD susceptibility genes, which gives an insight to the genetic architecture of the disease and could aid in the selection of appropriate study population for future studies.

Domain-Specific Effects of Prenatal Exposure to PCBs, Mercury, and Lead on Infant Cognition: Results from the Environmental Contaminants and Child Development Study in Nunavik

Background: Polychlorinated biphenyls (PCBs), methylmercury (MeHg), and lead (Pb) are environmental contaminants known for their adverse effects on cognitive development.Objectives: In this study we examined the effects of prenatal exposure to PCBs, MeHg, and Pb on cognitive development in a sample of Inuit infants from Arctic Québec.Methods: Mothers were recruited at local prenatal clinics. PCBs, mercury (Hg), Pb, and two seafood nutrients—docosahexaenoic acid (DHA) and selenium (Se)—were measured in umbilical cord blood. Infants (n = 94) were assessed at 6.5 and 11 months of age on the Fagan Test of Infant Intelligence (FTII), A-not-B test, and Bayley Scales of Infant Development–2nd Edition (BSID-II).Results: Multiple regression analyses revealed that higher prenatal PCB exposure was associated with decreased FTII novelty preference, indicating impaired visual recognition memory. Prenatal Hg was associated with poorer performance on A-not-B, which depends on working memory and is believed to be a precursor of executive function. Prenatal Pb was related to longer FTII fixation durations, indicating slower speed of information processing.Conclusions: PCBs, MeHg, and Pb each showed specific and distinct patterns of adverse associations with the outcomes measured during infancy. By contrast, none of these exposures was associated with performance on the BSID-II, a global developmental measure. The more focused, narrow band measures of cognitive function that appeared to be sensitive to these exposures also provide early indications of long-term impairment in specific domains that would otherwise not likely be evident until school age.Citation: Boucher O, Muckle G, Jacobson JL, Carter RC, Kaplan-Estrin M, Ayotte P, Dewailly É, Jacobson SW. 2014. Domain-specific effects of prenatal exposure to PCBs, mercury, and lead on infant cognition: results from the Environmental Contaminants and Child Development Study in Nunavik. Environ Health Perspect 122:310–316; http://dx.doi.org/10.1289/ehp.1206323

Network-based analysis reveals distinct association patterns in a semantic MEDLINE-based drug-disease-gene network.

BackgroundA huge amount of associations among different biological entities (e.g., disease, drug, and gene) are scattered in millions of biomedical articles. Systematic analysis of such heterogeneous data can infer novel associations among different biological entities in the context of personalized medicine and translational research. Recently, network-based computational approaches have gained popularity in investigating such heterogeneous data, proposing novel therapeutic targets and deciphering disease mechanisms. However, little effort has been devoted to investigating associations among drugs, diseases, and genes in an integrative manner.ResultsWe propose a novel network-based computational framework to identify statistically over-expressed subnetwork patterns, called network motifs, in an integrated disease-drug-gene network extracted from Semantic MEDLINE. The framework consists of two steps. The first step is to construct an association network by extracting pair-wise associations between diseases, drugs and genes in Semantic MEDLINE using a domain pattern driven strategy. A Resource Description Framework (RDF)-linked data approach is used to re-organize the data to increase the flexibility of data integration, the interoperability within domain ontologies, and the efficiency of data storage. Unique associations among drugs, diseases, and genes are extracted for downstream network-based analysis. The second step is to apply a network-based approach to mine the local network structure of this heterogeneous network. Significant network motifs are then identified as the backbone of the network. A simplified network based on those significant motifs is then constructed to facilitate discovery. We implemented our computational framework and identified five network motifs, each of which corresponds to specific biological meanings. Three case studies demonstrate that novel associations are derived from the network topology analysis of reconstructed networks of significant network motifs, further validated by expert knowledge and functional enrichment analyses.ConclusionsWe have developed a novel network-based computational approach to investigate the heterogeneous drug-gene-disease network extracted from Semantic MEDLINE. We demonstrate the power of this approach by prioritizing candidate disease genes, inferring potential disease relationships, and proposing novel drug targets, within the context of the entire knowledge. The results indicate that such approach will facilitate the formulization of novel research hypotheses, which is critical for translational medicine research and personalized medicine.

Mitochondrial Ribosomal RNA (rRNA) Methyltransferase Family Members Are Positioned to Modify Nascent rRNA in Foci near the Mitochondrial DNA Nucleoid

We have identified RNMTL1, MRM1, and MRM2 (FtsJ2) as members of the RNA methyltransferase family that may be responsible for the three known 2'-O-ribose modifications of the 16 S rRNA core of the large mitochondrial ribosome subunit. These proteins are confined to foci located in the vicinity of mtDNA nucleoids. They show distinct patterns of association with mtDNA nucleoids and/or mitochondrial ribosomes in cell fractionation studies. We focused on the role of the least studied protein in this set, RNMTL1, to show that this protein interacts with the large ribosomal subunit as well as with a series of non-ribosomal proteins that may be involved in coupling of the rate of rRNA transcription and ribosome assembly in mitochondria. siRNA-directed silencing of RNMTL1 resulted in a significant inhibition of translation on mitochondrial ribosomes. Our results are consistent with a role for RNMTL1 in methylation of G(1370) of human 16 S rRNA.

Religious Congregations and Social Justice Participation: A Multilevel Examination of Social Processes and Leadership

Religious congregations have potential to be mediating structures for social justice participation. However, research has yet to examine the specific social processes or leadership characteristics within congregations that may promote social justice participation. In this study, we use data from 176,901 participants nested within 1,938 congregations to test how social processes (i.e., religious attendance at worship services, extra-worship participation, bonding social capital, a congregational norm for justice) and leadership characteristics (i.e., leader modeling of justice, horizontal leadership style) predict personal social justice involvement through the congregation (i.e., participation in social justice activities sponsored by the congregation) as well as personal social justice involvement outside the congregation (i.e., participation in social justice activities not sponsored by the congregation). We use multilevel logistic regression to examine these social processes and leadership characteristics at both individual and congregational levels of analysis. Results showed distinct patterns of associations at individual and congregational levels of analysis and that different social processes and leadership characteristics predicted personal social justice participation through or outside the congregation. These findings reveal the importance of social processes and leadership characteristics in understanding how congregations may mediate social justice participation. Implications for community psychology research and practiced also are discussed.

Affect recognition across manic and euthymic phases of bipolar disorder in Han-Chinese patients

Patients with bipolar disorder (BD) have affect recognition deficits. Whether affect recognition deficits constitute a state or trait marker of BD has great etiopathological significance. The current study aims to explore the interrelationships between affect recognition and basic neurocognitive functions for patients with BD across different mood states, using the Diagnostic Analysis of Non-Verbal Accuracy-2, Taiwanese version (DANVA-2-TW) as the index measure for affect recognition. To our knowledge, this is the first study examining affect recognition deficits of BPD across mood states in the Han Chinese population.Twenty-nine manic patients, 16 remitted patients with BD, and 40 control subjects are included in the study. Distinct association patterns between affect recognition and neurocognitive functions are demonstrated for patients with BD and control subjects, implicating alternations in emotion associated neurocognitive processing. Compared to control subjects, manic patients but not remitted subjects perform significantly worse in the recognition of negative emotions as a whole and specifically anger, after adjusting for differences in general intellectual ability and basic neurocognitive functions. Affect recognition deficit may be a relatively independent impairment in BD rather than consequences arising from deficits in other basic neurocognition. The impairments of manic patients in the recognition of negative emotions, specifically anger, may further our understanding of core clinical psychopathology of BD and have implications in treating bipolar patients across distinct mood phases.

Shades of vulnerability: latent structures of clinical caseness in prodromal and early phases of schizophrenia

The underlying structures of clinical caseness and need of care in prodromal (i.e., at-risk) and early phases of schizophrenia remain poorly characterized in their essential psycho-behavioral coherence. To identify the schizophrenia proneness-related subtypes within a population of young help-seekers referred to a dedicated, community-based early detection program (Programma 2000). A sample of consecutive referrals (n=168) for suspected psychosis or first-episode schizophrenia spectrum psychosis received a detailed clinical assessment, including the early recognition inventory for the retrospective assessment of the onset of schizophrenia checklist. We used exploratory factor analysis (EFA) to determine the underlying dimensional structure and latent class analysis (LCA) to identify putative vulnerability subtypes. EFA identified four factors: dysphoria (irritability tension), paranoid autocentrism, introversive withdrawal, and disturbed subjective experience. LCA distinguished three classes, interpretable as carrying different degrees of "proneness to schizophrenia psychosis," which best captured the underlying continuum of clinical severity. The validity of the three classes was supported by distinct patterns of association with major clinical variables (i.e., diagnostic staging at referral). Vulnerability to schizophrenia psychosis in young help-seekers may manifest in three major clinical prototypes, presenting common levels of dysphoria and social withdrawal but different degrees of paranoid autocentrism and disturbed subjective experience. Overall, the results provide the empirical background to dissect shared features of clinical caseness from more schizophrenia-specific vulnerability components. This is of value for the refinement of the clinical staging model as well as for the pragmatic implementation of multiple-gate screening programs.

Cognition and gait show a distinct pattern of association in the general population

BackgroundWith brain aging, cognition and gait deteriorate in several domains. However, the interrelationship between cognitive and gait domains remains unclear. We investigated the independent associations between cognitive and gait domains in a community-dwelling population. MethodsIn the Rotterdam Study, 1232 participants underwent cognitive and gait assessment. Cognitive assessment included memory, information processing speed, fine motor speed, and executive function. Gait was summarized into seven independent domains: Rhythm, Variability, Phases, Pace, Tandem, Turning, and Base of Support. With multivariate linear regression, independent associations between cognitive and gait domains were investigated. ResultsInformation processing speed associated with Rhythm, fine motor speed with Tandem, and executive function with Pace. The effect sizes corresponded to a 5- to 10-year deterioration in gait. ConclusionsCognition and gait show a distinct pattern of association. These data accentuate the close, but complicated, relation between cognition and gait, and they may aid in unraveling the broader spectrum of the effects of brain aging.

Role of genetic heterogeneity and epistasis in bladder cancer susceptibility and outcome: a learning classifier system approach.

Background and objectiveDetecting complex patterns of association between genetic or environmental risk factors and disease risk has become an important target for epidemiological research. In particular, strategies that provide multifactor interactions or heterogeneous patterns of association can offer new insights into association studies for which traditional analytic tools have had limited success.Materials and methodsTo concurrently examine these phenomena, previous work has successfully considered the application of learning classifier systems (LCSs), a flexible class of evolutionary algorithms that distributes learned associations over a population of rules. Subsequent work dealt with the inherent problems of knowledge discovery and interpretation within these algorithms, allowing for the characterization of heterogeneous patterns of association. Whereas these previous advancements were evaluated using complex simulation studies, this study applied these collective works to a ‘real-world’ genetic epidemiology study of bladder cancer susceptibility.Results and discussionWe replicated the identification of previously characterized factors that modify bladder cancer risk—namely, single nucleotide polymorphisms from a DNA repair gene, and smoking. Furthermore, we identified potentially heterogeneous groups of subjects characterized by distinct patterns of association. Cox proportional hazard models comparing clinical outcome variables between the cases of the two largest groups yielded a significant, meaningful difference in survival time in years (survivorship). A marginally significant difference in recurrence time was also noted. These results support the hypothesis that an LCS approach can offer greater insight into complex patterns of association.ConclusionsThis methodology appears to be well suited to the dissection of disease heterogeneity, a key component in the advancement of personalized medicine.

Non-compressible arterial disease and the risk of coronary calcification in type-2 diabetes

ObjectiveAnkle–brachial index (ABI) screening is recommended for the detection of asymptomatic peripheral arterial disease (PAD) in at-risk populations, including diabetics. A low ABI identifies obstructive lower extremity vascular disease and predicts CVD events and increased mortality. A high ABI represents non-compressible arterial disease (NCAD), and is also associated with increased mortality and vascular events. Our objective is to investigate whether low and high ABI have distinct patterns of association with cardiovascular disease (CVD) risk factors and subclinical atherosclerosis in individuals with type-II diabetes mellitus. MethodsThe Penn Diabetes Heart Study (PDHS) is a prospective observational cohort of diabetic individuals without clinically evident CVD. Multivariate logistic and Tobit linear regression were used to compare CVD risk factors and coronary artery (CAC) among 1863 subjects with PAD (ABI ≤ 0.9), NCAD (ABI ≥ 1.4 or non-compressible) or normal ABI (0.91–1.39). ResultsCompared to those with normal ABI, PAD was associated with smoking, obesity, and lower HDL-c; while diabetes duration and reduced renal function were associated with NCAD. Both PAD and NCAD were independently associated with increased CAC compared to those with normal ABI, and these relationships were not attenuated in multiply adjusted models. ConclusionNCAD bears a distinct relationship to traditional CVD risk factors among diabetics, though like PAD is independently associated with increased CAC. These findings support the recognition of NCAD as a high-risk phenotype and provide additional relevance to ABI screening in diabetics.