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.

Genetic analysis of human predisposition to hepatosplenic disease caused by schistosomes reveals the crucial role of connective tissue growth factor in rapid progression to severe hepatic fibrosis

Schistosome worms inhabit mammalian mesenteric veins. Their eggs cause chronic inflammation, which progresses to periportal fibrosis in 5 to 30% of cases, increasing portal blood pressure and leading to esophageal varices. Episodes of bleeding cause hepatic necrosis and may ultimately lead to hepatic failure and the death of the patient. Schistosome infections can also cause pulmonary hypertension and heart failure. The mechanisms of fibrogenesis and fibrolysis are beginning to be unraveled, but it remains unclear why disease occurs only in certain subjects, as also observed for other types of chronic liver inflammation, as in hepatitis C or B. We summarize here the results that showed that fibrosis progression is determined by a genetic locus on chromosome 6. The CCN2 gene at this locus, encodes CTGF that is a crucial regulator of fibrosis. Two groups of CCN2 polymorphisms independently modulate the progression of hepatic fibrosis. These results were obtained in an Asian population, but were extended to humans living in Africa and South America and are presently tested in liver fibrosis of other etiological origins.

Expression of regulatory T and helper T cells in peripheral blood of patients with pregnancy-induced hypertension

OBJECTIVE

To analyze the expression of regulatory T cells and helper T cells in peripheral blood of patients with pregnancy-induced hypertension (PIH).

MATERIALS AND METHODS

Twenty-seven patients hospitalized with PIH were consecutively collected for detection of regulatory T cells (CD4+ CD25+ Treg and CD4+ CD25+ Foxp3+Treg) and helper T (CD+3, CD+4, CD+8, CD+4/CD+8) cells in peripheral blood. Meanwhile, 20 normal hospitalized pregnant women served as the control group.

RESULTS

In the comparison of regulatory T cells, the level of serum CD4+ CD25+ Treg and CD4+ CD25+ Foxp3+Treg in PIH group was significantly lower than control group (all p < 0.05). In the comparison of help T cells, the expression level of serum CD+4/CD+8 in PIH group was obviously higher than control group, while the expression level of CD+8 was significantly lower than control group (all p < 0.05).

CONCLUSIONS

There were obvious abnormal expressions of regulatory T cell and helper T cells in peripheral blood of patients with PIH.

BDNF Val66Met variant and smoking in a Chinese population

Several recent studies have supported the hypothesis that brain-derived neurotrophic factor (BDNF), a member of the neurotrophic factor family, might be associated with nicotine addiction. Association studies have also suggested that the BDNF gene might play a role in the susceptibility to nicotine dependence but results appear contradictory. The present work was therefore undertaken to examine the association of smoking with the BDNF Val66Met gene polymorphism in Chinese population. The BDNF Val66Met gene polymorphism was examined in 628 healthy male volunteers including 322 smokers and 306 non-smokers. Also, the BDNF serum levels were measured in 136 smokers and 97 nonsmokers. Our results showed no significant association between the BDNF Val66Met polymorphism or serum levels among smokers and non-smokers. Smokers with the Met allele however started smoking significantly earlier than those with the Val/Val genotype (mean age at smoking initiation of 17.4, 17.9 and 21.2 years for Met/Met, Met/Val, and Val/Val, respectively; both p<0.05). No other significant differences between other variables such as number of cigarettes per day, smoking severity as measured by the Fagerstrom Test for Nicotine Dependence (FTND) score and carbon monoxide (CO) levels (all p>0.05). In addition, there was no main effect of genotype on serum BDNF levels. Our findings suggest that the BDNF Val66Met polymorphism may not be involved in susceptibility to smoking among the Chinese male population, but may influence the age at which smoking is initiated. However, the findings must be interpreted with caution because of the relatively small sample size for an association study. Results should be confirmed in a larger cohort.

Rapid one-step derivatization of Se(VI) to a piazselenol for the spectrofluorimetric determination of selenium in biological material

A spectrofluorimetric method for the determination of total selenium in biological samples has been developed. After oxidative destruction, the sample is reacted with a mixture of bromide and 2,3-diamino-1,4-dibromonaphthalene (Br(2)-DAN) without pH adjustment. Selenium(VI) is rapidly reduced by bromide to Se(IV) which then forms 4,7-dibromo-5,6-benzopiazselenol (Br(2)-DAN-Se). The conversion of Se(VI) to Br(2)-DAN-Se is completed in 6 min at 100 degrees C. The piazselenol is extracted to cyclohexane and the fluorescence measured at 577 nm with excitation at 518 nm. The procedure has been validated by determinations on reference materials with selenium concentrations ranging from 4 to 1460 ng g(-1). The advantages of the method are the fast reduction of Se(VI) by hydrobromic acid and the properties of Br(2)-DAN, which permit the piazselenol formation to be carried out in a strongly acidic medium and at high temperature. The limit of detection is 0.6 ng g(-1) as estimated by three times the standard deviation of the blank determination (n = 7). The rate of reduction of Se(VI) to Se(IV) in hydrobromic acid was investigated as a function of concentration and temperature. The new kinetic data together with previous kinetic and equilibrium data for the piazselenol formation were used to model and optimize the simultaneous reduction-derivatization procedure.

Association of functional dopamine-beta-hydroxylase (DBH) 19 bp insertion/deletion polymorphism with smoking severity in male schizophrenic smokers

Recent evidence suggests that a dopamine beta-hydroxylase (DBH) polymorphism may play a role in determining an individual's predisposition to developing nicotine dependence. The mechanism for such an association may reflect nicotine's mediation of drug reward in the brain through actions on dopamine, a key mediator of drug reward. Because schizophrenia patients have usually high rates of nicotine use, they are a model group to study such an association. In this study, we hypothesized that the functional polymorphism of DBH (DβH5'-Ins/Del) was associated with smoking in patients with schizophrenia. This polymorphism was genotyped in 636 chronic male schizophrenia (smoker/nonsmoker=490/146) and 396 male controls (smoker/nonsmoker=231/165) using a case-control design. The cigarettes smoked per day (CPD) and smoking behaviors were evaluated by clinician-administered questionnaires and the Fagerstrom Test for Nicotine Dependence (FTND). The results showed no significant differences in DBH 5'-Ins/Del genotype and allele distributions between the patients and healthy controls or between smokers and nonsmokers in either patients or healthy controls alone. However, schizophrenic smokers with the Del allele smoked fewer cigarettes each day and had lower FTND score than those with Ins/Ins genotype. These results suggest that the DBH 5'-Ins/Del polymorphism may influence smoking severity among schizophrenic smokers.

Rare ADH variant constellations are specific for alcohol dependence

AIMS

Some of the well-known functional alcohol dehydrogenase (ADH) gene variants (e.g. ADH1B*2, ADH1B*3 and ADH1C*2) that significantly affect the risk of alcohol dependence are rare variants in most populations. In the present study, we comprehensively examined the associations between rare ADH variants [minor allele frequency (MAF) <0.05] and alcohol dependence, with several other neuropsychiatric and neurological disorders as reference.

METHODS

A total of 49,358 subjects in 22 independent cohorts with 11 different neuropsychiatric and neurological disorders were analyzed, including 3 cohorts with alcohol dependence. The entire ADH gene cluster (ADH7-ADH1C-ADH1B-ADH1A-ADH6-ADH4-ADH5 at Chr4) was imputed in all samples using the same reference panels that included whole-genome sequencing data. We stringently cleaned the phenotype and genotype data to obtain a total of 870 single nucleotide polymorphisms with 0< MAF <0.05 for association analysis.

RESULTS

We found that a rare variant constellation across the entire ADH gene cluster was significantly associated with alcohol dependence in European-Americans (Fp1: simulated global P = 0.045), European-Australians (Fp5: global P = 0.027; collapsing: P = 0.038) and African-Americans (Fp5: global P = 0.050; collapsing: P = 0.038), but not with any other neuropsychiatric disease. Association signals in this region came principally from ADH6, ADH7, ADH1B and ADH1C. In particular, a rare ADH6 variant constellation showed a replicable association with alcohol dependence across these three independent cohorts. No individual rare variants were statistically significantly associated with any disease examined after group- and region-wide correction for multiple comparisons.

CONCLUSION

We conclude that rare ADH variants are specific for alcohol dependence. The ADH gene cluster may harbor a causal variant(s) for alcohol dependence.

The soluble tachyzoite antigen of Toxoplasma gondii has a protective effect on mouse allografts

BACKGROUND

Infection with some types of parasites can significantly prolong allograft survival in mice. It is unknown whether the soluble tachyzoite antigen (STAg) from Toxoplasma gondii has the same effect and by what mechanism it acts.

METHODS

A mouse model of cardiac and skin allograft transplantation was established between BALB/c (H-2(d)) and C57BL/6(H-2(b)) mice. T gondii STAg was prepared, and 5 μg was administered subcutaneously to recipient mice 4 days before transplantation. The graft status was checked daily, and histologic and immunohistochemical assays were used to evaluate rejection. The serum cytokine levels from the recipient mice were analyzed by Luminex.

RESULT

The administration of 5 μg STAg 4 days before transplantation significantly prolonged the survival time of the heart and skin allografts to 85.17 ± 14.06 and 24.17 ± 2.32 days, respectively. Immunohistochemical staining showed that the CD4(+) and CD8(+) T lymphocytes were markedly reduced in the allografts at day 7 posttransplantation. Notably, interleukin (IL)-12, IL-2, and IL-17 levels were significantly reduced in the serum of mice treated with STAg compared with untreated mice 7 days after transplantation. In contrast, the levels of the antiinflammatory cytokine IL-10 were elevated.

CONCLUSION

A single administration of STAg before transplantation can significantly prolong the allograft survival time, which is accompanied by impaired lymphocyte infiltration and a reduced Th1 response.

Cognitive and serum BDNF correlates of BDNF Val66Met gene polymorphism in patients with schizophrenia and normal controls

Studies suggest that a functional polymorphism of the brain-derived neurotrophic factor gene (BDNF Val66Met) may mediate hippocampal-dependent cognitive functions. A few studies have reported its role in cognitive deficits in schizophrenia including its association with peripheral BDNF levels as a mediator of these cognitive deficits. We assessed 657 schizophrenic inpatients and 445 healthy controls on the repeatable battery for the assessment of neuropsychological status (RBANS), the presence of the BDNF Val66Met polymorphism and serum BDNF levels. We assessed patient psychopathology using the Positive and Negative Syndrome Scale. We showed that visuospatial/constructional abilities significantly differed by genotype but not genotype × diagnosis, and the Val allele was associated with better visuospatial/constructional performance in both schizophrenic patients and healthy controls. Attention performance showed a significant genotype by diagnosis effect. Met allele-associated attention impairment was specific to schizophrenic patients and not shown in healthy controls. In the patient group, partial correlation analysis showed a significant positive correlation between serum BDNF and the RBANS total score. Furthermore, the RBANS total score showed a statistically significant BDNF level × genotype interaction. We demonstrated an association between the BDNF Met variant and poor visuospatial/constructional performance. Furthermore, the BDNF Met variant may be specific to attentional decrements in schizophrenic patients. The association between decreased BDNF serum levels and cognitive impairment in schizophrenia is dependent on the BDNF Val66Met polymorphism.