Amplitude of low-frequency fluctuations in bipolar disorder: a resting state fMRI study

OBJECTIVES

The spontaneous low frequency fluctuations (LFF) of blood oxygenation level-dependent (BOLD) signal in resting state have been identified as a biological measure of baseline spontaneous activity in the brain. Increasingly, studies of spontaneous resting state functional connectivity have demonstrated neural network abnormalities in bipolar disorder (BD). This study used the amplitude of low frequency fluctuations (ALFF) to explore the regional functional changes in BD during resting state.

METHODS

Twenty-nine BD participants and 29 matched healthy controls (HC) were recruited to undergo resting-state functional magnetic resonance imaging scan on a 3.0T magnetic resonance imaging system. The ALFF of BOLD signal in gray matter for each participant was calculated, and then was compared between BD and HC using ALFF maps.

RESULTS

Compared to the HC group, the BD group showed increased ALFF in ventral prefrontal cortex, dorsal lateral prefrontal cortex, frontal eye field, insula, and putamen with extension into the ventral striatum, as well as decreased ALFF in the lingual gyrus (p<0.05, corrected).

LIMITATIONS

Although we observed differences in ALFF between BD and HC, we cannot conclusively state that these differences are caused by the pathophysiology of BD since most of BD participants were being treated with medications at the time of scanning.

CONCLUSIONS

Our results revealed altered regional brain activity in BD during resting state. The affected regions have been associated with BD pathophysiology. This suggests that methods using ALFF method may potentially be useful in further studies of this disorder.

Health-related quality of life and symptom severity in Chinese patients with major depressive disorder

INTRODUCTION

Patients suffering from major depressive disorder (MDD) have been reported to have substantial long-lasting limitations in multiple domains of health-related quality of life (HRQoL). The thoughtful assessment of HRQoL and the impact of treatment response on HRQoL are emerging as important issues in the care of patients with major depressive disorder.

METHODS

One hundred and three patients meeting Diagnostic and Statistical Manual of Mental Disorders (DSM-IV) criteria for MDD took fluoxetine (20 mg/d) for 6 weeks and were assessed by the Short Form 36 Health Survey (SF-36), the 17-item Hamilton Depression Rating (HAMD-17) and the Clinical Global Impression (CGI) scales. Relationships between SF-36 scores and depressive symptom severity and early change of these symptoms were tested.

RESULTS

SF-36 component scores at week 6 were higher than those at baseline (all P ≤ 0.0058). Scores for general health were significantly higher in responders than non-responders (P = 0.0009). The overall HAMD-17 and CGI scores at 2- and 6-week follow-up were significantly lower than those at baseline (P ≤ 0.0001). Higher scores for anxiety/somatization were significantly associated with poorer SF-36 scores at baseline (P = 0.0001); role-physical scores at week 6 were positively correlated with reduction rate of anxiety/somatization in 2-week follow-up (P = 0.0002).

DISCUSSION

Depressive symptom severity was associated with HRQoL in patients with MDD. HRQoL may vary with severity of depression and/or anxiety-somatization at baseline.

Sex chromosome-wide association analysis suggested male-specific risk genes for alcohol dependence

BACKGROUND

Alcohol dependence is more common among men than among women. Potential explanations for this include the role of genes in sex chromosomes (X and Y). In the present study, we scanned the entire Y chromosome and its homologs on the X chromosome in men to identify male-specific risk genes for alcohol dependence.

METHODS

Two thousand nine hundred and twenty-seven individuals in two independent cohorts were analyzed. The European-American male cohort (883 cases with alcohol dependence and 445 controls) served as the discovery cohort and the European-American female cohort (526 cases and 1073 controls) served as a contrast group. All individuals were genotyped on the Illumina Human 1M beadchip. Two thousand two hundred and twenty-four single nucleotide polymorphisms (SNPs) on the Y chromosome or in the homologs on the X chromosome were analyzed. The allele frequencies were compared between cases and controls within each cohort using logistic regression analysis.

RESULTS

We found that, after experiment-wide correction, two SNPs on the X chromosome were associated significantly with alcohol dependence in European-American men (P = 1.0 × 10 for rs5916144 and P = 5.5 × 10 for rs5961794 at 3' UTR of NLGN4X), but not in the women. A total of 26 SNPs at 3'UTR of or within NLGN4X were nominally associated with alcohol dependence in men (5.5 × 10 ≤ P ≤ 0.05), all of which were not statistically significant in women.

CONCLUSION

We conclude that NLGN4X was a significant male-specific risk gene for alcohol dependence in European-Americans. NLGN4X might harbor a causal variant(s) for alcohol dependence. A defect of synaptogenesis in neuronal circuitry caused by NLGN4X mutations is believed to play a role in alcohol dependence.

Genome-wide association studies of maximum number of drinks

Maximum number of drinks (MaxDrinks) defined as "Maximum number of alcoholic drinks consumed in a 24-h period" is an intermediate phenotype that is closely related to alcohol dependence (AD). Family, twin and adoption studies have shown that the heritability of MaxDrinks is approximately 0.5. We conducted the first genome-wide association (GWA) study and meta-analysis of MaxDrinks as a continuous phenotype. 1059 individuals were from the Collaborative Study on the Genetics of Alcoholism (COGA) sample and 1628 individuals were from the Study of Addiction - Genetics and Environment (SAGE) sample. Family sample with 3137 individuals was from the Australian twin-family study of alcohol use disorder (OZALC). Two population-based Caucasian samples (COGA and SAGE) with 1 million single-nucleotide polymorphisms (SNPs) were used for gene discovery and one family-based Caucasian sample was used for replication. Through meta-analysis we identified 162 SNPs associated with MaxDirnks (p < 10(-4)). The most significant association with MaxDrinks was observed with SNP rs11128951 (p = 4.27 × 10(-8)) near SGOL1 gene at 3p24.3. Furthermore, several SNPs (rs17144687 near DTWD2, rs12108602 near NDST4, and rs2128158 in KCNB2) showed significant associations with MaxDrinks (p < 5 × 10(-7)) in the meta-analysis. Especially, 8 SNPs in DDC gene showed significant associations with MaxDrinks (p < 5 × 10(-7)) in the SAGE sample. Several flanking SNPs in above genes/regions were confirmed in the OZALC family sample. In conclusions, we identified several genes/regions associated with MaxDrinks. These findings can improve the understanding about the pathogenesis of alcohol consumption phenotypes and alcohol-related disorders.

p21-activated kinase 4 regulation of endometrial cancer cell migration and invasion involves the ERK1/2 pathway mediated MMP-2 secretion

Endometrial cancer (EC) is one of the most common malignancy of the female genital tract. Patients with metastatic disease have a poor prognosis. So far, however, the underlying molecular mechanisms of EC metastasis are largely unknown. P21-activated kinase 4 (Pak4) is important in cell motility and oncogenesis. Here we investigated a role of Pak4 in EC cell migration and invasion. Pak4 overexpression was observed in multiple human EC cell lines. In clinical samples, expression of total and phosphorylated Pak4 (Pak4 and p-Pak4, respectively) increased significantly with progression of EC from normal tissue to lymph node metastasis; both were positively correlated with depth of myometrial and vascular space invasion, lymph nodes metastasis, and poor histological differentiation. In two human EC cell lines, Pak4 overexpression promoted cell migration and invasion in vitro. Short hairpin RNA (shRNA)-mediated stable knockdown of Pak4 inhibited the metastatic potential of EC in an ERK1/2-MMP-2-dependent manner. These results suggest that Pak4 is an important regulator of EC cell migration and invasion. Therefore, Pak4 may be a promising target for the treatment of metastatic EC.

Intestinal microbiome and digoxin inactivation: meal plan for digoxin users?

There is an increasing interest in the role of intestinal microbiome in human diseases and therapeutic agents' bioavailability, activity and toxicity. Epidemiological data show that the bioavailability of digoxin, a widely used agent for heart disease, varies among individuals. The inactivation of digoxin was found when it was incubated with gut bacterium Eggerthella lenta in vitro decades ago. However, the underlying mechanisms of digoxin inactivation are still unclear. A recent study using animal models uncovered this mystery, which suggested that arginine supplements might be a potential intervention in increasing digoxin activity by inhibiting the expression of cardiac glycoside reductase gene operons that inactivated digoxin. This perspective summarizes the connections among the intestinal microbiome, the digoxin inactivation, the metabolism of arginine. We also discuss several issues yet to be addressed in the future, making better strategies in the application of dietary arginine supplements for digoxin users.

NRG3 gene is associated with the risk and age at onset of Alzheimer disease

The Neuregulin 3 (NRG3) gene at 10q22-q24 has been implicated in multiple psychiatric traits such as cognitive impairment. We therefore hypothesized that NRG3 gene polymorphisms may play a role in Alzheimer disease (AD). This present study explored the association of NRG3 with the age at onset (AAO) of AD and the risk of developing AD. Secondary data analysis of 257 single-nucleotide polymorphisms (SNPs) in NRG3 gene was performed in 806 Alzheimer's disease patients and 782 controls using logistic regression and linear regression analyses. Eight SNPs were associated with the risk of AD (p < 0.05), while linear regression analysis showed 33 SNPs associated with the AAO of AD (p < 0.05). Two-SNP haplotype analyses based on UNPHASED revealed that the G-C haplotype from rs17685233 and rs17101017 was significantly associated with AD (p = 0.0031) and the A-G haplotype from rs504522 and rs474018 as well as the A-G haplotype from rs504522 and rs2483295 were more significantly associated with the AAO of AD (p = 6.72 × 10(-5)). Using an independent family-based sample, we found one SNP rs11192423 associated with AAO both in the case-control sample (p = 0.0155) and in the family sample (p = 0.0166). In addition, we observed nominally significant associations with AD and AAO for several flanking SNPs (p < 0.05). This is the first study demonstrating that genetic variants in the NRG3 gene play a role in AD. Our results also revealed that SNPs in the NRG3 genes were more strongly associated with AAO of AD.

Measurement of J/ψ azimuthal anisotropy in Au+Au collisions at sqrt[s(NN)]=200 GeV

The measurement of J/ψ azimuthal anisotropy is presented as a function of transverse momentum for different centralities in Au+Au collisions at sqrt[s(NN)]=200 GeV. The measured J/ψ elliptic flow is consistent with zero within errors for transverse momentum between 2 and 10 GeV/c. Our measurement suggests that J/ψ particles with relatively large transverse momenta are not dominantly produced by coalescence from thermalized charm quarks, when comparing to model calculations.

Rare SERINC2 variants are specific for alcohol dependence in individuals of European descent

OBJECTIVES

We have previously reported a top-ranked risk gene [i.e., serine incorporator 2 gene (SERINC2)] for alcohol dependence in individuals of European descent by analyzing the common variants in a genome-wide association study. In the present study, we comprehensively examined the rare variants [minor allele frequency (MAF)<0.05] in the NKAIN1-SERINC2 region to confirm our previous finding.

MATERIALS AND METHODS

A discovery sample (1409 European-American patients with alcohol dependence and 1518 European-American controls) and a replication sample (6438 European-Australian family participants with 1645 alcohol-dependent probands) were subjected to an association analysis. A total of 39,903 individuals from 19 other cohorts with 11 different neuropsychiatric and neurological disorders served as contrast groups. The entire NKAIN1-SERINC2 region was imputed in all cohorts using the same reference panels of genotypes that included rare variants from the whole-genome sequencing data. We stringently cleaned the phenotype and genotype data, and obtained a total of about 220 single-nucleotide polymorphisms in individuals of European descent and about 450 single-nucleotide polymorphisms in the individuals of African descent with 0

RESULTS

Using a weighted regression analysis implemented in the program SCORE-Seq, we found a rare variant constellation across the entire NKAIN1-SERINC2 region that was associated with alcohol dependence in European-Americans (Fp: overall, P=1.8×10(-4); VT: overall, P=1.4×10(-4); Collapsing, P=6.5×10(-5)) and European-Australians (Fp: overall, P=0.028; Collapsing, P=0.025), but not in African-Americans, and not associated with any other disorder examined. Association signals in this region came mainly from SERINC2, a gene that codes for an activity-regulated protein expressed in the brain that incorporates serine into lipids. In addition, 26 individual rare variants were nominally associated with alcohol dependence in European-Americans (P<0.05). The associations of five of these rare variants that lay within SERINC2 showed region-wide significance (P<α=0.0006) and 25 associations survived correction for a false discovery rate (q<0.05). The associations of two rare variants at SERINC2 were replicated in European-Australians (P<0.05).

CONCLUSION

We concluded that SERINC2 was a replicable and significant risk gene specific for alcohol dependence in individuals of European descent.

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Key Words

• serinc2
• alcohol dependence
• rare variant constellations
• european descent
• association

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MESH Headings

• Black or African American/genetics
• Alcoholism/complications
• Alcoholism/genetics
• Australia
• Case-Control Studies
• Genetic Association Studies
• Genetic Variation
• Genome-Wide Association Study
• Humans
• Membrane Proteins/genetics
• Mental Disorders/genetics
• Nervous System Diseases/genetics
• Polymorphism, Single Nucleotide
• Regression Analysis
• Risk Factors
• White People/genetics

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Grants

• R01 DA016750 NIDA NIH HHS
• R01NS45012 NINDS NIH HHS
• R01MH62873 NIMH NIH HHS
• R01MH59566 NIMH NIH HHS
• R01 MH059587 NIMH NIH HHS
• R01 MH059586 NIMH NIH HHS
• U01 HG004436 NHGRI NIH HHS
• R01 MH061675 NIMH NIH HHS
• U01HG004446 NHGRI NIH HHS
• U01MH79470 NIMH NIH HHS
• U01HG004438 NHGRI NIH HHS
• R01 MH062873 NIMH NIH HHS
• R01 NS045012 NINDS NIH HHS
• U01MH79469 NIMH NIH HHS
• U01 HG004438 NHGRI NIH HHS
• R01MH59588 NIMH NIH HHS
• U10AA008401 NIAAA NIH HHS
• U01 HG004446 NHGRI NIH HHS
• K01 DA029643 NIDA NIH HHS
• G0601030 Medical Research Council
• R01MH81800 NIMH NIH HHS
• R01MH61675 NIMH NIH HHS
• P50 AA011998 NIAAA NIH HHS
• 075491/Z/04 Wellcome Trust
• R01MH59571 NIMH NIH HHS
• U01 MH046276 NIMH NIH HHS
• R01MH59586 NIMH NIH HHS
• P01 CA089392 NCI NIH HHS
• R21 AA021380 NIAAA NIH HHS
• U01 MH079469 NIMH NIH HHS
• R01MH60870 NIMH NIH HHS
• R01MH059160 NIMH NIH HHS
• R01 MH081803 NIMH NIH HHS
• R01 MH067257 NIMH NIH HHS
• U01HG004422 NHGRI NIH HHS
• P60AA011998 NIAAA NIH HHS
• R01 MH060870 NIMH NIH HHS
• R01DA013423 NIDA NIH HHS
• R01MH081803 NIMH NIH HHS
• R01 MH059571 NIMH NIH HHS
• R01 MH059565 NIMH NIH HHS
• R01MH67257 NIMH NIH HHS
• R01DA016750 NIDA NIH HHS
• U01 HG004422 NHGRI NIH HHS
• R01MH60879 NIMH NIH HHS
• R01 DA013423 NIDA NIH HHS
• R01MH59587 NIMH NIH HHS
• U01 MH079470 NIMH NIH HHS
• U01 MH046289 NIMH NIH HHS
• U01HG004436 NHGRI NIH HHS
• R01 MH059566 NIMH NIH HHS
• R21 AA020319 NIAAA NIH HHS
• Wellcome Trust
• U10 AA008401 NIAAA NIH HHS
• R01AA013320 NIAAA NIH HHS
• R01 MH059588 NIMH NIH HHS
• U01 MH046318 NIMH NIH HHS
• R01MH59565 NIMH NIH HHS
• U01MH46282 NIMH NIH HHS
• M01RR165001 NCRR NIH HHS
• R01 MH060879 NIMH NIH HHS
• R01 AA013320 NIAAA NIH HHS
• R01 AA016015 NIAAA NIH HHS

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Cigarette smoking, psychopathology and cognitive function in first-episode drug-naive patients with schizophrenia: a case-control study

BACKGROUND

Although patients with chronic schizophrenia have substantially higher smoking rates than either the general population or patients with other mental illnesses, drug-naive patients with a first episode of schizophrenia have received little systemic study. This study examined smoking rates, the association between smoking and symptom severity and cognitive function in Chinese first-episode schizophrenia (FES) patients using cross-sectional and case-control designs.

METHOD

Two hundred and forty-four drug-naive FES patients and 256 healthy controls matched for gender, age and education completed the Fagerström Test for Nicotine Dependence (FTND) and the Repeatable Battery for the Assessment of Neuropsychological Status (RBANS). Patients were also rated on the Positive and Negative Symptom Scale (PANSS).

RESULTS

The rate and quantity of smoking were not significantly higher among FES patients compared to the general population. Among patients, smokers scored higher than non-smokers on the total PANSS and the positive symptom subscale scores. There were no significant associations between cognitive function and smoking in either FES patients or healthy controls.

CONCLUSIONS

In contrast to studies in patients with chronic schizophrenia, drug-naive FES patients did not smoke more frequently than the general population. Furthermore, patients with psychotic disorders who smoked did not exhibit significant cognitive differences compared with those who did not smoke. However, smoking may have other detrimental effects on physical and mental health, for example on positive symptoms.

Association between common alcohol dehydrogenase gene (ADH) variants and schizophrenia and autism

Humans express at least seven alcohol dehydrogenase (ADH) isoforms that are encoded by ADH gene cluster (ADH7-ADH1C-ADH1B-ADH1A-ADH6-ADH4-ADH5) at chromosome 4. ADHs are key catabolic enzymes for retinol and ethanol. The functional ADH variants (mostly rare) have been implicated in alcoholism risk. In addition to catalyzing the oxidation of retinol and ethanol, ADHs may be involved in the metabolic pathways of several neurotransmitters that are implicated in the neurobiology of neuropsychiatric disorders. In the present study, we comprehensively examined the associations between common ADH variants [minor allele frequency (MAF) >0.05] and 11 neuropsychiatric and neurological disorders. A total of 50,063 subjects in 25 independent cohorts were analyzed. The entire ADH gene cluster was imputed across these 25 cohorts using the same reference panels. Association analyses were conducted, adjusting for multiple comparisons. We found 28 and 15 single nucleotide polymorphisms (SNPs), respectively, that were significantly associated with schizophrenia in African-Americans and autism in European-Americans after correction by false discovery rate (FDR) (q < 0.05); and 19 and 6 SNPs, respectively, that were significantly associated with these two disorders after region-wide correction by SNPSpD (8.9 × 10(-5) ≤ p ≤ 0.0003 and 2.4 × 10(-5) ≤ p ≤ 0.0003, respectively). No variants were significantly associated with the other nine neuropsychiatric disorders, including alcohol dependence. We concluded that common ADH variants conferred risk for both schizophrenia in African-Americans and autism in European-Americans.

Exome-wide association study of replicable nonsynonymous variants conferring risk for alcohol dependence

OBJECTIVE

In the present study, we scanned the whole exome in three independent samples to search for replicable risk nonsynonymous (ns) variants (ns single-nucleotide polymorphisms [nsSNPs]) for alcohol dependence.

METHOD

A total of 10,554 subjects in three independent samples were analyzed for association with alcohol dependence, including one European American sample (1,409 cases with alcohol dependence and 1,518 controls), one African American sample (681 cases and 508 controls), and one European Australian sample (a total of 6,438 family subjects with 1,645 alcohol-dependent probands). RNA expression of the risk genes in human, mouse, and rat brains was also explored.

RESULTS

We identified a total of 70 nsSNPs at 65 genes with nominally replicable associations; 22 nsSNPs at 21 genes among them survived corrections for multiple testing in meta-analysis (α = .0007). By incorporating the information from bioinformatics and RNA expression analyses, we identified at least two of the most promising risk genes for alcohol dependence: APOER2 and UBAP2.

CONCLUSIONS

The gene coding for apolipoprotein E receptor 2 (APOER2) and the gene coding for ubiquitin-associated protein-2 (UBAP2) are among the most appropriate for follow-up in human and nonhuman species as contributors to risk for alcohol dependence.

Exposure to bisphenol A disrupts meiotic progression during spermatogenesis in adult rats through estrogen-like activity

The effect of bisphenol A (BPA) on the reproductive system is highly debated but has been associated with meiotic abnormalities. However, evidence is lacking with regard to the mechanisms involved. In order to explore the underlying mechanisms of BPA-induced meiotic abnormalities in adult male rats, we exposed 9-week-old male Wistar rats to BPA by gavage at 0, 2, 20 or 200 μg/kg body weight (bw)/day for 60 consecutive days. 17β-Estradiol (E2) was administered at 10 μg/kg bw/day as the estrogenic positive control. Treatments with 200 μg/kg bw/day of BPA and E2 significantly decreased sperm counts and inhibited spermiation, characterized by an increase in stage VII and decrease in stage VIII in the seminiferous epithelium. This was concomitant with a disruption in the progression of meiosis I and the persistence of meiotic DNA strand breaks in pachytene spermatocytes,and the ataxia-telangiectasia-mutated and checkpoint kinase 2 signal pathway was also activated; Eventually, germ cell apoptosis was triggered as evaluated by terminal dUTP nick-end labeling assay and western blot for caspase 3. Using the estrogen receptor (ER) antagonist ICI 182780, we determined that ER signaling mediated BPA-induced meiotic disruption and reproductive impairment. Our results suggest that ER signaling-mediated meiotic disruption may be a major contributor to the molecular events leading to BPA-related male reproductive disorders. These rodent data support the growing association between BPA exposure and the rapid increase in the incidence of male reproductive disorders.

Sex differences of gray matter morphology in cortico-limbic-striatal neural system in major depressive disorder

Sex differences are observed in both epidemiological and clinical aspects of major depressive disorder (MDD). The cortico-limbic-striatal neural system, including the prefrontal cortex, amygdala, hippocampus, and striatum, have shown sexually dimorphic morphological features and have been implicated in the dysfunctional regulation of mood and emotion in MDD. In this study, we utilized a whole-brain, voxel-based approach to examine sex differences in the regional distribution of gray matter (GM) morphological abnormalities in medication-naïve participants with MDD. Participants included 29 medication-naïve individuals with MDD (16 females and 13 males) and 33 healthy controls (HC) (17 females and 16 males). Gray matter morphology of the cortico-limbic-striatal neural system was examined using voxel-based morphometry analyzes of high-resolution structural magnetic resonance imaging scans. The main effect of diagnosis and interaction effect of diagnosis by sex on GM morphology were statistically significant (p < 0.05, corrected) in the left ventral prefrontal cortex, right amygdala, right hippocampus and bilateral caudate when comparing the MDD and HC groups. Posthoc analyzes showed that females with MDD had significant GM decreases in limbic regions (p < 0.05, corrected), compared to female HC; while males with MDD demonstrated significant GM reduction in striatal regions, (p < 0.05, corrected), compared to HC males. The observed sex-related patterns of abnormalities within the cortico-limbic-strial neural system, such as predominant prefrontal-limbic abnormalities in MDD females vs. predominant prefrontal-striatal abnormalities in MDD males, suggest differences in neural circuitry that may mediate sex differences in the clinical presentation of MDD and potential targets for sex-differentiated treatment of the disorder.

Chiral phase transition in charge ordered 1T-TiSe2

It was recently discovered that the low-temperature, charge-ordered phase of 1T-TiSe(2) has a chiral character. This unexpected chirality in a system described by a scalar order parameter could be explained in a model where the emergence of relative phase shifts between three charge density wave components breaks the inversion symmetry of the lattice. Here, we present experimental evidence for the sequence of phase transitions predicted by that theory, going from disorder to nonchiral and finally to chiral charge order. Employing x-ray diffraction, specific heat, and electrical transport measurements, we find that a novel phase transition occurs ~7 K below the main charge ordering transition in TiSe(2), in agreement with the predicted hierarchy of charge-ordered phases.

NKAIN1-SERINC2 is a functional, replicable and genome-wide significant risk gene region specific for alcohol dependence in subjects of European descent

OBJECTIVE

We aimed to identify novel, functional, replicable and genome-wide significant risk regions specific for alcohol dependence using genome-wide association studies (GWASs).

METHODS

A discovery sample (1409 European-American cases with alcohol dependence and 1518 European-American controls) and a replication sample (6438 European-Australian family subjects with 1645 alcohol dependent probands) underwent association analysis. Nineteen other cohorts with 11 different neuropsychiatric disorders served as contrast groups. Additional eight samples underwent expression quantitative locus (eQTL) analysis.

RESULTS

A genome-wide significant risk gene region (NKAIN1-SERINC2) was identified in a meta-analysis of the discovery and replication samples. This region was enriched with 74 risk SNPs (unimputed); half of them had significant cis-acting regulatory effects. The distributions of -log(p) values for the SNP-disease associations or SNP-expression associations in this region were consistent throughout eight independent samples. Furthermore, imputing across the NKAIN1-SERINC2 region, we found that among all 795 SNPs in the discovery sample, 471 SNPs were nominally associated with alcohol dependence (1.7×10(-7)≤p≤0.047); 53 survived region- and cohort-wide correction for multiple testing; 92 SNPs were replicated in the replication sample (0.002≤p≤0.050). This region was neither significantly associated with alcohol dependence in African-Americans, nor with other non-alcoholism diseases. Finally, transcript expression of genes in NKAIN1-SERINC2 was significantly (p<3.4×10(-7)) associated with expression of numerous genes in the neurotransmitter systems or metabolic pathways previously associated with alcohol dependence.

CONCLUSION

NKAIN1-SERINC2 may harbor a causal variant(s) for alcohol dependence. It may contribute to the disease risk by way of neurotransmitter systems or metabolic pathways.

Genome-wide significant association signals in IPO11-HTR1A region specific for alcohol and nicotine codependence

BACKGROUND

Alcohol and nicotine codependence can be considered as a more severe subtype of alcohol dependence. A portion of its risk may be attributable to genetic factors.

METHODS

We searched for significant risk genomic regions specific for this disorder using a genome-wide association study. A total of 8,847 subjects underwent gene-disease association analysis, including (i) a discovery cohort of 818 European American cases with alcohol and nicotine codependence and 1,396 European American controls, (ii) a replication cohort of 5,704 Australian family subjects with 907 affected offspring, and (iii) a replication cohort of 449 African American cases and 480 African American controls. Additionally, a total of 38,714 subjects of European or African descent in 18 independent cohorts with 10 other nonalcoholism neuropsychiatric disorders were analyzed as contrast. Furthermore, 90 unrelated HapMap CEU individuals, 93 European brain tissue samples, and 80 European peripheral blood mononuclear cell samples underwent cis-acting expression quantitative locus (cis-eQTL) analysis.

RESULTS

We identified a significant risk region for alcohol and nicotine codependence between IPO11 and HTR1A on chromosome 5q that was reported to be suggestively associated with alcohol dependence previously. In the European American discovery cohort, 381 single nucleotide polymorphisms (SNPs) in this region were nominally associated with alcohol and nicotine codependence (p < 0.05); 57 associations of them survived region- and cohort-wide correction (α = 3.6 × 10(-6) ); and the top SNP (rs7445832) was significantly associated with alcohol and nicotine codependence at the genome-wide significance level (p = 6.2 × 10(-9) ). Furthermore, associations for 34 and 11 SNPs were replicated in the Australian and African American replication cohorts, respectively. Among these replicable associations, 4 reached genome-wide significance level in the meta-analysis of European Americans and European Australians: rs7445832 (p = 9.6 × 10(-10) ), rs13361996 (p = 8.2 × 10(-9) ), rs62380518 (p = 2.3 × 10(-8) ), and rs7714850 (p = 3.4 × 10(-8) ). Cis-eQTL analysis showed that many risk SNPs in this region had nominally significant cis-acting regulatory effects on HTR1A or IPO11 mRNA expression. Finally, no markers were significantly associated with any other neuropsychiatric disorder examined.

CONCLUSIONS

We speculate that this IPO11-HTR1A region might harbor a causal variant for alcohol and nicotine codependence.

Association of the dopamine β-hydroxylase 19 bp insertion/deletion polymorphism with positive symptoms but not tardive dyskinesia in schizophrenia

OBJECTIVE

Overactivity of dopaminergic neurotransmission is a putative mechanism of tardive dyskinesia (TD). Dopamine beta-hydroxylase (DBH) is a key enzyme in the conversion of dopamine to norepinephrine, and plasma DBH activity is altered in TD patients. This study examined whether the functional DBH 5'-Ins/Del polymorphism was associated with TD severity in Chinese patients with schizophrenia.

METHODS

We compared the rate of this polymorphism in patients with (n = 312) and without TD (n = 435), and healthy controls (n = 625). The severity of TD was assessed using the Abnormal Involuntary Movement Scale (AIMS) and psychopathology using the Positive and Negative Syndrome Scale (PANSS).

RESULTS

There were no significant differences in the distribution of the allele and genotype frequencies between the patients and controls, or between the patients with and without TD. Also, there was no significant difference in the AIMS total score between the three genotype groups. However, the PANSS positive symptom subscore was significantly higher in patients with Del/Del genotype (13.2 ± 5.2) than those with Ins/Del (11.2 ± 4.9) and Ins/Ins (11.1 ± 3.1) genotypes (both p < 0.05).

CONCLUSION

These results suggest that although the DBH 5'-Ins/Del polymorphism was not associated with susceptibility to TD in patients with schizophrenia, it might be related to positive symptoms of schizophrenia.

Observation of an energy-dependent difference in elliptic flow between particles and antiparticles in relativistic heavy ion collisions

Elliptic flow (v(2)) values for identified particles at midrapidity in Au + Au collisions, measured by the STAR experiment in the beam energy scan at RHIC at sqrt[s(NN)] = 7.7-62.4 GeV, are presented. A beam-energy-dependent difference of the values of v(2) between particles and corresponding antiparticles was observed. The difference increases with decreasing beam energy and is larger for baryons compared to mesons. This implies that, at lower energies, particles and antiparticles are not consistent with the universal number-of-constituent-quark scaling of v(2) that was observed at sqrt[s(NN)] = 200 GeV.