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Objective: Schizophrenia patients treated with antipsychotics are at higher risk of sudden cardiac death. Decreased deceleration capacity (DC) of the heart rate is an accurate predictor of cardiac mortality. We evaluated the risk of sudden cardiac death due to antipsychotic use by assessing DC and examining the association between DC and the corrected QT interval (QTc) in schizophrenia patients., Methods: We measured the DC and QTc of 138 schizophrenia patients. We then compared the DC of 86 age- and sex-matched healthy controls with that of 86 schizophrenia patients. We investigated the correlation of DC of approximately 138 schizophrenia patients with prescribed doses of antipsychotics using linear regression analysis. We compared the DC of schizophrenia patients with and without prolonged QT intervals., Results: We found DC significantly differed between schizophrenia patients on antipsychotic medication and healthy controls. Additionally, DC was negatively correlated with antipsychotic use, especially chlorpromazine, zotepine, olanzapine and clozapine, in a dose-dependent manner. There was no significant association between DC and the QTc., Conclusion: Assessing DC could facilitate monitoring and identification of increased risk of cardiac mortality in patients with schizophrenia that take antipsychotics. Assessing both DC and the QTc may enhance the accuracy of predicting sudden cardiac death., Competing Interests: Declaration of Competing Interest The authors report no other potential conflicts of interest for this work., (Copyright © 2023 Elsevier Inc. All rights reserved.)

Background: Hyperprolactinemia is a troublesome adverse effect of antipsychotics. Aripiprazole (ARP), which is one of second-generation antipsychotics, has been reported to lower serum prolactin (PRL) levels. However, few studies have compared the effect of ARP on plasma PRL levels between monopharmacy and polypharmacy with antipsychotics., Methods: We conducted a large-scale investigation of the physical risk for inpatients with schizophrenia using a questionnaire covering demographic data, the number, dose and type of antipsychotics, and serum PRL levels., Results: Sufficient data to conduct an assessment of the effect on PRL levels between antipsychotic monopharmacy and polypharmacy were obtained from 316 of the inpatients. Serum PRL levels in ARP combination group were lower than non-ARP combination group, regardless of antipsychotic monopharmacy or polypharmacy., Conclusions: The present study suggests that ARP lowers serum PRL levels regardless of monopharamacy or polypharmacy with antipsychotics.

Background: Patients with schizophrenia have an increased prevalence of metabolic disturbances compared with the general population. However, the mechanisms underlying the metabolic side effects of antipsychotics are unknown. The aim of the present study was to compare the levels of high-density lipoprotein (HDL)-cholesterol in Japanese schizophrenia patients medicated with olanzapine, risperidone, or aripiprazole monotherapy., Methods: This study was a post-hoc analysis of a nationwide survey, which included 433 Japanese outpatients with schizophrenia and 674 inpatients. A brief questionnaire was compiled that covered demographic data, systolic blood pressure, diastolic blood pressure, and HDL-cholesterol after reviewing the relevant literature and guidelines. To compare demographic and clinical characteristics, analysis of variance was performed for continuous variables and the chi-square test was performed for categorical variables. For comparisons of HDL-cholesterol levels among the three antipsychotic groups, analysis of covariance was carried out with age, diastolic blood pressure, chlorpromazine-equivalent dosage, and waist circumference as confounding variables after stratification by body mass index (BMI) for each outpatient group and inpatient group., Results: The mean age was 57.9 ± 14.0 years and the mean BMI was 23.4 ± 4.5 kg/m 2 . HDL-cholesterol levels when stratified by BMI differed significantly (p = 0.019) between the three antipsychotic groups after age, diastolic blood pressure, chlorpromazine-equivalent dosage, and waist circumference in inpatients. A significant difference in HDL-cholesterol levels was only found in the overweight inpatient group, and no significant differences in HDL-cholesterol levels were found among the three antipsychotics for outpatients of all BMI stratifications or inpatients that were underweight or of normal weight. For post-hoc analysis of HDL-cholesterol levels in overweight inpatients, HDL-cholesterol was significantly lower in the olanzapine group than in the aripiprazole group (p = 0.023)., Conclusions: This study reveals a difference in HDL-cholesterol levels in overweight Japanese inpatients with schizophrenia resulting from the use of different antipsychotics. In the post-hoc analysis of HDL-cholesterol levels in overweight inpatients, HDL-cholesterol was significantly lower in the olanzapine group than in the aripiprazole group. Further studies incorporating more detailed evaluations, including diet and physical activity, are needed to clarify the differences in HDL-cholesterol according to antipsychotic use.

Aims: Although the relationship between body mass index and all-cause mortality is U-shaped, underweight has received comparatively less attention than obesity. There is only limited evidence to date regarding underweight among patients with schizophrenia. This is the first meta-analysis to address the prevalence of underweight in these patients., Methods: We conducted database searches (PubMed, PsycINFO) to identify studies examining underweight in patients with schizophrenia. In total, 17 studies (18 groups) with 45,474 patients were included; data were extracted independently by two authors. A meta-analysis was performed to calculate the pooled prevalence of underweight in patients., Results: The pooled prevalence of underweight was 6.2% (95% CI=4.5-8.6) for the 18 groups, which included 45,474 patients with schizophrenia. The heterogeneity was I 2 =98.9% (95% Cl=98.7-99.1%). Four studies with 4 groups, consisting of 30,014 individuals, focused on Japanese inpatients with schizophrenia. The pooled prevalence of underweight among inpatients in these 4 groups was 17.6% (95% CI=15.5-20.0). Fourteen studies were conducted with non-Japanese inpatients and included 14 groups of 15,460 patients with schizophrenia. The pooled prevalence of underweight in non-Japanese inpatients was 4.6% (95% CI=3.9-5.4). The proportion of underweight in the 18 groups significantly varied between Japanese inpatients and other patients., Conclusions: The results indicated that Japanese inpatients with schizophrenia have a high proportion of underweight. Future research should focus on evaluating interventions that target underweight., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Phenylalanine is required for the synthesis of the neurotransmitters dopamine, noradrenaline, and adrenaline. The rate-limiting step for phenylalanine metabolism is catalyzed by phenylalanine hydroxylase (PAH) and its cofactor tetrahydrobiopterin. We aimed to detect altered phenylalanine metabolism in major psychiatric disorders using the l-[1- 13 C]phenylalanine breath test ( 13 C-PBT) and serum biopterin levels. We also investigated association of PAH mutations with schizophrenia and phenylalanine metabolism. 13 C-phenylalanine (100 mg) was orally administered, and the breath 13 CO 2 / 12 CO 2 ratio was monitored for 120 min in four groups: 103 patients with schizophrenia (DSM-IV), 39 with bipolar disorder, 116 with major depressive disorder (MDD), and 241 healthy controls. Serum biopterin levels were measured by high performance liquid chromatography. Mutation screening of PAH exons was performed by direct sequencing in 46 schizophrenia patients. Association analysis was performed using six tag single nucleotide polymorphisms and the PAH Arg53His mutation by TaqMan assays in 616 schizophrenia patients and 1194 healthy controls. Analyses of covariance controlling for age, sex, and body weight showed that the index for the amount of exhaled 13 CO 2 was significantly lower in the schizophrenia group than in the other three groups (all p < 0.05). Biopterin levels in schizophrenia and MDD were significantly lower than those in controls. Biopterin levels correlated with 13 C-PBT indices in controls. PAH polymorphisms were not associated with schizophrenia or 13 C-PBT indices. 13 C-PBT revealed reduced phenylalanine metabolism in schizophrenia, though we obtained no evidence of involvement of PAH polymorphism. Serum biopterin levels were lower in schizophrenia and MDD, warranting further investigation., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Objective: Patients with schizophrenia have a higher prevalence of metabolic syndrome (MetS) than the general population. Minimizing weight gain and metabolic abnormalities in a population with an already high prevalence of obesity is of clinical and social importance. This randomized controlled trial investigated the effect of monthly nutritional education on weight change and metabolic abnormalities among patients with schizophrenia in Japan., Methods: From July 2014 to December 2014, we recruited 265 obese patients who had a DSM-IV diagnosis of schizophrenia or schizoaffective disorder. Participants were randomly assigned to a standard care (A), doctor's weight loss advice (B), or an individual nutritional education group (C) for 12 months. The prevalence of MetS and body weight were measured at baseline and 12 months., Results: After the 12-month treatment, 189 patients were evaluated, and the prevalence of MetS based on the ATP III-A definition in groups A, B, and C was 68.9%, 67.2%, and 47.5%, respectively. Group C showed increased weight loss (3.2 ± 4.5 kg) over the 12-month study period, and the change in weight differed significantly from that of group A; additionally, 26.2% of the participants in group C lost 7% or more of their initial weight, compared with 8.2% of those in group A., Conclusion: Individual nutrition education provided by a dietitian was highly successful in reducing obesity in patients with schizophrenia and could be the first choice to address both weight gain and metabolic abnormalities induced by antipsychotic medications., (Copyright © 2017 Elsevier Ltd. All rights reserved.)

Enduring cognitive impairment in patients with schizophrenia represents a global health burden. The Japanese-language version of the Brief Assessment of Cognition in Schizophrenia (BACS) and the Japanese Adult Reading Test were administered to 288 patients with chronic schizophrenia and 308 unrelated healthy control subjects. The Japanese version of self-reported Social Functioning Scale (SFS) was administered to a subpopulation of 157 patients with schizophrenia. In patients with schizophrenia, premorbid IQ and age were significantly related to most of the BACS subdomains, composite score, and intra-individual variability of BACS subdomains, whereas negative symptoms were significantly related to all BACS indices. Dosages of the first-generation antipsychotics had a significant negative impact on Tower of London task and intra-individual variability of BACS subdomains. The relationship of symbol coding with age was significantly lower in patients than in healthy control subjects. Multiple regression analysis revealed that negative symptoms were significantly negatively related to the total SFS scale, whereas better performance of token motor task was associated with higher total SFS. The present study revealed the role of premorbid IQ, age, and negative symptoms in predicting cognitive performance, and the significant correlation of negative symptoms and token motor task with social function in patients with schizophrenia., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Background: Patients with schizophrenia have significantly shorter life expectancy than the general population, and a problem they commonly face is an unhealthy lifestyle, which can lead to obesity and metabolic syndrome. There is a very clear need to determine the prevalence of obesity, hypertension, hyperlipidemia, and diabetes mellitus which are components of metabolic syndrome in patients with schizophrenia, but there has been a paucity of large-scale studies examining this situation in Japan. The aim of our study was to address this need., Setting & Participants: We conducted a large-scale investigation of the prevalence of obesity, hypertension, hyperlipidemia, and diabetes mellitus using a questionnaire in 520 outpatient facilities and 247 inpatient facilities of the Japan Psychiatric Hospitals Association between January 2012 and July 2013. There were 7,655 outpatients and 15,461 inpatients with schizophrenia., Results: The outpatients had significantly higher prevalence of obesity, hypertension, hypertriglyceridemia, hyper-LDL cholesterolemia, and diabetes mellitus than the inpatients. The prevalence of hypo-HDL cholesterolemia was higher in inpatients than outpatients. Age-specific analysis showed the prevalence of obesity, hypertension, hypertriglyceridemia, hyper-LDL cholesterolemia, and diabetes mellitus among outpatients to be 2- to 3-fold higher than among inpatients. In individuals aged ≥60 years, the prevalence of obesity and DM among outpatients was about 3-fold higher than among inpatients., Conclusion: Japanese outpatients with schizophrenia were more likely to have physical risk such as obesity, hypertension, hyperlipidemia, and diabetes mellitus than inpatients. The physical risk to patients with schizophrenia may be affected by environmental parameters, such as type of care. The physical risk to Japanese patients with schizophrenia demands greater attention., Competing Interests: Toshiyuki Someya has received research support or honoraria from Asahi Kasei Pharma Corp., Astellas Pharma Inc., Daiichi Sankyo Co., Ltd., Dainippon Sumitomo Pharma Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan, K.K., GlaxoSmithKline K.K., Janssen Pharmaceutical K.K., Meiji Seika Pharma Co., Ltd., Mitsubishi Tanabe Pharma Co., Ltd., Mochida Pharmaceutical Co., Ltd., MSD K.K., Otsuka Pharmaceutical Co., Ltd., Pfizer Japan Inc., Shionogi & Co., Ltd., Tsumura & Co., and Yoshitomi Pharmaceutical Industries. Yutaro Suzuki has received research support or honoraria from Janssen Pharmaceutical K.K., Mitsubishi Tanabe Pharma Co., Ltd., and Otsuka Pharmaceutical Co., Ltd. The other authors declare no potential conflicts of interest. Kazutaka Shimoda has received research support or honoraria from Daiichi Sankyo Co., Ltd., Dainippon Sumitomo Pharma Co., Ltd., Eisai Co., Ltd., Eli Lilly Japan, K.K., GlaxoSmithKline K.K., Meiji Seika Pharma Co., Ltd., Novartis Pharma K.K., Otsuka Pharmaceutical Co., Ltd., Pfizer Japan Inc., Shionogi & Co., Ltd., Takeda Pharmaceutical Co., Ltd., Tsumura & Co., Yoshitomi Pharmaceutical Industries, Ltd., Asahi Kasei Pharma Corporation, Astellas Pharma Inc., Janssen Pharmaceutical K.K., Kowa Pharmaceutical Co., Ltd., Meiji Seika Pharma Co., Mitsubishi Tanabe Pharma Corporation, Ltd., MSD K.K., Novartis Pharma K.K., and Ono Pharmaceutical Co., Ltd. Norio Yasui-Furukori has received research support or honoraria from Astellas Pharma Inc., Dainippon Sumitomo Pharma Co., Ltd., Eli Lilly Japan, K.K., GlaxoSmithKline K.K., Janssen Pharmaceutical K.K., Meiji Seika Pharma Co., Mochida Pharmaceutical Co. Ltd., MSD K.K., Otsuka Pharmaceutical Co. Ltd., Pfizer Japan Inc., Takeda Pharmaceutical Co. Ltd., and Yoshitomi Pharmaceutical Industries. Norio Sugawara has received grant or research support from the Grant-in-Aid for Young Scientists (B), Ministry of Education, Culture, Sports, Science and Technology, Japan Grant B., the Karoji Memorial Fund for Medical Research Grant, and the Senshin Medical Research Foundation. There are no patents, products in development, or marketed products to declare. This does not alter the authors’ adherence to PLOS ONE’s policies on sharing data and materials, as detailed online in the guide for authors. The other authors declare no potential conflicts of interest.

Plasma concentration of three methylated arginines, endogenous nitric oxide synthase inhibitors, is not studied in schizophrenic patients. The purpose of this study was to determine plasma concentrations of N(G)-monomethyl-L-arginine (l-NMMA), N(G),N(G)-dimethyl-L-arginine (ADMA), N(G),N(G')-dimethyl-L-arginine (SDMA), and l-arginine in 56 male and 45 female schizophrenic patients undergoing antipsychotic drug treatment versus those of 39 male and 24 female healthy controls. Plasma concentrations of methylated arginines and l-arginine were measured using newly developed high performance liquid chromatography with fluorescence detection which we previously reported. Methylated arginine levels were slightly but significantly higher in schizophrenic patients. L-Arginine levels and the l-arginine/(ADMA+l-NMMA) ratio were higher in schizophrenic patients than in healthy controls. It is considered that pharmacological treatment of schizophrenic patients may lower methylated arginine levels that are increased by the disease, and increase L-arginine levels, eliciting an improvement in nitric oxide (NO) bioavailability., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

The pathophysiology of schizophrenia may involve N-methyl-D-aspartate receptor (NMDAR) hypofunction. D-3serine and glycine are endogenous l-serine-derived NMDAR co-agonists. We hypothesized that the l-serine synthesis pathway could be involved in schizophrenia. We measured the activity of phosphoserine phosphatase (PSP), a rate-limiting enzyme in l-serine synthesis, in peripheral blood mononuclear cells of 54 patients with schizophrenia and 49 normal control subjects. Plasma amino acid (l-serine, d-serine, glycine, glutamine, and glutamate) levels were measured by high performance liquid chromatography. Peripheral blood mRNA expression levels of PHGDH, PSAT1, PSP, and SR, determined by quantitative real-time PCR were compared between patients and controls. PSP activity was higher in patients than in controls, especially in male patients. In male patients, the plasma l-serine concentration was higher than that in controls. In patients, PSP activity was negatively correlated with plasma d-serine and glycine levels. Furthermore, PSP activity was positively correlated with plasma l-serine concentration. These results were statistically significant only in male patients. PSP, PSAT1, and PHGDH mRNA levels were lower in patients than in controls, except when the PHGDH expression level was compared with ACTB expression. In summary, we found the l-serine synthesis system to be altered in patients with schizophrenia, especially in male patients., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Patients with schizophrenia have a higher risk of metabolic syndrome (MetS). MetS prevalence varies with ethnicity. Although environmental factors, such as lack of physical activity and unbalanced diet, can lead to MetS, these may differ between outpatients and inpatients with schizophrenia. The Japanese mental health care system differs from that in other countries. However, few studies have investigated the prevalence of MetS in Japanese patients with schizophrenia. Therefore, we conducted a nationwide survey to clarify the prevalence of MetS in Japanese outpatients and inpatients with schizophrenia. We investigated the risk of MetS by questionnaire in 520 facilities for outpatients and 247 facilities for inpatients. There were 7655 outpatients and 15,461 inpatients with schizophrenia. MetS prevalence was based on the National Cholesterol Education Program Adult Treatment Panel III (ATP III-A) and the Japan Society for the Study of Obesity (JASSO). The overall MetS prevalence in outpatients using the ATP III-A definition was 34.2%, with 37.8% in men and 29.4% in women, compared with 13.0% in inpatients, with 12.3% in men and 13.9% in women. MetS prevalence in outpatients was approximately 2- to 3-fold higher than in inpatients. In conclusion, MetS prevalence in Japanese outpatients was approximately 3-fold higher than in inpatients. Therefore, we should pay more attention to the risk of physical disease in Japanese patients with schizophrenia, considering the difference in health characteristics between outpatients and inpatients., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Objectives: To clarify the prevalence of underweight and overweight/obesity, and laboratory data for nutritional status in Japanese outpatients and inpatients with schizophrenia., Design: Cross-sectional study., Setting: A questionnaire conducted in inpatient and outpatient facilities in Japan., Participants: The population of adult patients with schizophrenia in Japan (N=23,116)., Main Outcome Measures: The prevalence of underweight and undernutrition in Japanese inpatients and outpatients with schizophrenia., Results: We conducted a large-scale investigation of the prevalence of underweight and undernutrition in 520 outpatient facilities and 247 inpatient facilities belonging to the Japan Psychiatric Hospitals Association between January 2012 and July 2013. There were 7655 outpatients and 15,461 inpatients with schizophrenia. There was a significant difference in the distribution of three body mass index levels between outpatients and inpatients (p<0.001). The proportion of underweight inpatients with schizophrenia was significantly higher than that among outpatients (p<0.001). Age-specific analysis revealed that the proportion of underweight individuals aged ≥ 40 years was higher in inpatients than in outpatients and in the general Japanese population. The proportion of individuals with hypocholesterolaemia was significantly higher in inpatients with schizophrenia than in outpatients (p<0.001). There was a significant difference in the severity of underweight between outpatients and inpatients with schizophrenia; the proportion of severe underweight in inpatients was twofold higher than in outpatients., Conclusions: The prevalence of underweight and undernutrition in Japanese inpatients with schizophrenia was higher than in outpatients and the general population. Therefore, the physical risk of inpatients should be carefully considered in clinical practice., (Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/)

The potassium voltage-gated channel KCNH2 is a well-known gene in which mutations induce familial QT interval prolongation. KCNH2 is suggested to be a risk gene for schizophrenia. Additionally, the disturbance of autonomic control, which affects the QT interval, is known in schizophrenia. Therefore, we speculate that schizophrenic patients have characteristic features in terms of the QT interval in addition to the effect of antipsychotic medication. The QT interval of patients with schizophrenia not receiving antipsychotics (n = 85) was compared with that of patients with schizophrenia receiving relatively large doses of antipsychotics (n = 85) and healthy volunteers (n = 85). The QT interval was corrected using four methods (Bazett, Fridericia, Framingham or Hodges method). In ANCOVA with age and heart rate as covariates, patients not receiving antipsychotic treatment had longer QT intervals than did the healthy volunteers, but antipsychotics prolonged the QT interval regardless of the correction method used (P<0.01). Schizophrenic patients with and without medication had a significantly higher mean heart rate than did the healthy volunteers, with no obvious sex-related differences in the QT interval. The QT interval prolongation may be manifestation of a certain biological feature of schizophrenia.

Background: The Hermansky-Pudlak Syndrome Type 4 (HPS4) gene, which encodes a subunit protein of the biogenesis of lysosome-related organelles complex (BLOC)-3, which is involved in late endosomal trafficking, is associated with schizophrenia; however, its clinical relevance in schizophrenia remains unknown. The purpose of the present study was to investigate whether HPS4 is associated with cognitive functions in patients with schizophrenia and healthy controls and with the clinical profiles of patients with schizophrenia., Methods: We investigated the association of variants of HPS4 with clinical symptoms and cognitive function in Japanese patients with schizophrenia (n = 240) and age-matched healthy control subjects (n = 240) with single nucleotide polymorphisms (SNP)- or haplotype-based linear regression. We analyzed five tagging SNPs (rs4822724, rs61276843, rs9608491, rs713998, and rs2014410) of HPS4 and 2-5 locus haplotypes of these five SNPs. The cognitive functions of patients and healthy subjects were evaluated with the Brief Assessment of Cognition in Schizophrenia, Japanese-language version, and the patients were assessed for their symptomatology with the Positive and Negative Symptom Scale (PANSS)., Results: In patients with schizophrenia, rs713998 was significantly associated with executive function under the dominant genetic model (P = 0.0073). In healthy subjects, there was a significant association between working memory and two individual SNPs under the recessive model (rs9608491: P = 0.001; rs713998: P = 0.0065) and two haplotypes (rs9608491-713998: P = 0.0025; rs61276843-9608491-713998: P = 0.0064). No significant association was found between HPS4 SNPs and PANSS scores or premorbid IQ, as measured by the Japanese version of the National Adult Reading Test., Conclusions: These findings suggested the involvement of HPS4 in the working memory of healthy subjects and in the executive function deficits in schizophrenia.

Objective: We encountered two Japanese siblings who had Hermansky-Pudlak syndrome (HPS) and major mental disorders (schizophrenia and major depression) as well. As it is known that HPS is caused by a local mutation in one of the human genes, named HPS1 to HPS8 and PLDN (HPS9), encoding subunit proteins involved in endosomal trafficking pathways, here, we report the mutation causing the siblings disease and a case-control association study of schizophrenia using polymorphisms of a gene to be screened in the mutation analysis., Methods: We analyzed three HPS-causing genes, HPS1, HPS4, and HPS7, to identify a genetic mutation involved in the siblings. A case-control association study of nine tagging single-nucleotide polymorphisms of the entire genetic region of the HPS4 gene resulting from the screening in the siblings was carried out for schizophrenic patients (n=422) and controls (n=578)., Results: The two patients with HPS were homozygous for nonsense mutation (T/T) for the c.541C>T (rs119471022) in the HPS4 gene, which is mapped to human chromosome 22q12.1. The same nonsense mutation existed in the heterozygous state (C/T) in their mother and in two other siblings. The genotypic distribution of rs9608491 (C/T) in intron 4 showed a trend toward an association with schizophrenia as indicated by a corrected P-value of 0.053 controlling for multiple testing. Haplotype analyses showed that two of two-locus haplotypes, and all of three-locus, four-locus, and five-locus haplotypes, as they share rs9608491, yielded significant evidence for association with schizophrenia as shown by the following omnibus P-values. When rs4822724, rs61276843, rs9608491, rs713998, and rs2014410, five haplotype tagging single-nucleotide polymorphisms, are assigned serial numerals (1, 2, 3, 4, and 5), the omnibus P-values for the resulting haplotypes were P=0.0039 for 2-3, P=0.0142 for 3-4, P=0.0083 for 1-2-3, P=0.0187 for 2-3-4, P=0.0191 for 3-4-5, P=0.0270 for 1-2-3-4, P=0.0246 for 2-3-4-5, and 0.0261 for 1-2-3-4-5., Conclusion: These results suggest that the HPS4 gene confers a susceptibility to schizophrenia.

We herein report a case of lung transplantation in a patient with schizophrenia. The findings show that patients with schizophrenia can be considered for lung transplant after careful evaluation of psychiatric status and indications., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Phenylalanine is an essential amino acid required for the synthesis of catecholamines including dopamine. Altered levels of phenylalanine and its metabolites in blood and cerebrospinal fluid have been reported in schizophrenia patients. This study attempted to examine for the first time whether phenylalanine kinetics is altered in schizophrenia using L-[1-(13)C]phenylalanine breath test ((13)C-PBT). The subjects were 20 chronically medicated schizophrenia patients (DSM-IV) and the same number of age- and sex-matched controls. (13)C-phenylalanine (99 atom% (13)C; 100 mg) was administered orally and the breath (13)CO(2) /(12)CO(2) ratio was monitored for 120 min. The possible effect of antipsychotic medication (risperidone (RPD) or haloperidol (HPD) treatment for 21 days) on (13)C-PBT was examined in rats. Body weight (BW), age and diagnostic status were significant predictors of the area under the curve of the time course of Δ(13)CO(2) (‰) and the cumulative recovery rate (CRR) at 120 min. A repeated measures analysis of covariance controlled for age and BW revealed that the patterns of CRR change over time differed between the patients and controls and that Δ(13)CO(2) was lower in the patients than in the controls at all sampling time points during the 120 min test, with an overall significant difference between the two groups. Chronic administration of RPD or HPD had no significant effect on (13)C-PBT indices in rats. Our results suggest that (13)C-PBT is a novel laboratory test that can detect altered phenylalanine kinetics in chronic schizophrenia patients. Animal experiments suggest that the observed changes are unlikely to be attributable to antipsychotic medication.

l-Serine is required for the synthesis of glycine and d-serine, both of which are NMDA receptor co-agonists. Although roles for d-serine and glycine have been suggested in schizophrenia, little is known about the role of the l-serine synthesizing cascade in schizophrenia or related psychiatric conditions. Here we report a patient with schizophrenia carrying a balanced chromosomal translocation with the breakpoints localized to 3q13.12 and 9q21.2. We examined this proband and her son with schizotypal personality disorder for chromosomal abnormalities, molecular expression profiles, and serum amino acids. Marked decrease of l-serine and glutamate was observed in the sera of the patient and her son, compared with those in normal controls. Interestingly, expression of PSAT1 gene, which is located next to the breakpoint and encodes one of the enzymes in the l-serine synthesizing cascade, was reduced in both patient and her son. Direct effect of impaired PSAT1 gene expression on decreased serum l-serine level was strongly implicated by rat astrocyte experiments. In summary, we propose an idea that PSAT1 may be implicated in altered serine metabolism and schizophrenia spectrum conditions., (Copyright © 2010 Elsevier Ireland Ltd and the Japan Neuroscience Society. All rights reserved.)

Many antipsychotic drugs cause QT prolongation, although the effect differs based on the particular drug. We sought to determine the potential for antipsychotic drugs to prolong the QTc interval (>470 ms in men and >480 ms in women) using the Bazett formula in a "real-world" setting by analyzing the electrocardiograms of 1017 patients suffering from schizophrenia. Using logistic regression analysis to calculate the adjusted relative risk (RR), we found that chlorpromazine (RR for 100 mg=1.37, 95% confidence interval (CI)=1.14 to 1.64; p<.005), intravenous haloperidol (RR for 2 mg=1.29, 95% CI=1.18 to 1.43; p<.001), and sultopride (RR for 200 mg=1.45, 95% CI=1.28 to 1.63; p<.001) were associated with an increased risk of QTc prolongation. Levomepromazine also significantly lengthened the QTc interval. The second-generation antipsychotic drugs (i.e., olanzapine, quetiapine, risperidone, and zotepine), mood stabilizers, benzodiazepines, and antiparkinsonian drugs did not prolong the QTc interval. Our results suggest that second-generation antipsychotic drugs are generally less likely than first-generation antipsychotic drugs to produce QTc interval prolongation, which may be of use in clinical decision making concerning the choice of antipsychotic medication., (Copyright 2010 Elsevier Inc. All rights reserved.)

Accumulating evidence from both genetic and clinico-pharmacological studies suggests that D-serine, an endogenous coagonist to the NMDA subtype glutamate receptor, may be implicated in schizophrenia (SZ). Although an association of genes for D-serine degradation, such as D-amino acid oxidase and G72, has been reported, a role for D-serine in SZ has been unclear. In this study, we identify and characterize protein interacting with C-kinase (PICK1) as a protein interactor of the D-serine synthesizing enzyme, serine racemase (SR). The binding of endogenous PICK1 and SR requires the PDZ domain of PICK1. The gene coding for PICK1 is located at chromosome 22q13, a region frequently linked to SZ. In a case-control association study using well-characterized Japanese subjects, we observe an association of the PICK1 gene with SZ, which is more prominent in disorganized SZ. Our findings implicating PICK1 as a susceptibility gene for SZ are consistent with a role for D-serine in the disease.

Disrupted-In-Schizophrenia-1 (DISC1), originally identified at the breakpoint of a chromosomal translocation that is linked to a rare familial schizophrenia, has been genetically implicated in schizophrenia in other populations. Schizophrenia involves subtle cytoarchitectural abnormalities that arise during neurodevelopment, but the underlying molecular mechanisms are unclear. Here, we demonstrate that DISC1 is a component of the microtubule-associated dynein motor complex and is essential for maintaining the complex at the centrosome, hence contributing to normal microtubular dynamics. Carboxy-terminal-truncated mutant DISC1 (mutDISC1), which results from a chromosomal translocation, functions in a dominant-negative manner by redistributing wild-type DISC1 through self-association and by dissociating the DISC1-dynein complex from the centrosome. Consequently, either depletion of endogenous DISC1 or expression of mutDISC1 impairs neurite outgrowth in vitro and proper development of the cerebral cortex in vivo. These results indicate that DISC1 is involved in cerebral cortex development, and suggest that loss of DISC1 function may underlie neurodevelopmental dysfunction in schizophrenia.

Molecular mechanisms underlying the pathogenesis of schizophrenia remains elusive. The difficulty in accessing the mechanisms stems from, at least in part, multiple etiologies for schizophrenia. We have studied DISC1, as it was identified as a candidate gene for a schizophrenia-associated mental condition with the single etiology. Thus far, we have obtained evidence that DISC1 may have implications in neurodevelopment. This concept fits with many historical observations found for schizophrenia in association with neurodevelopmental abnormalities. DISC1 may become one of the key molecules in studying the pathogenesis of schizophrenia.