Rare genetic variants in CX3CR1 and their contribution to the increased risk of schizophrenia and autism spectrum disorders

CX3CR1, a G protein-coupled receptor solely expressed by microglia in the brain, has been repeatedly reported to be associated with neurodevelopmental disorders including schizophrenia (SCZ) and autism spectrum disorders (ASD) in transcriptomic and animal studies but not in genetic studies. To address the impacts of variants in CX3CR1 on neurodevelopmental disorders, we conducted coding exon-targeted resequencing of CX3CR1 in 370 Japanese SCZ and 192 ASD patients using next-generation sequencing technology, followed by a genetic association study in a sample comprising 7054 unrelated individuals (2653 SCZ, 574 ASD and 3827 controls). We then performed in silico three-dimensional (3D) structural modeling and in vivo disruption of Akt phosphorylation to determine the impact of the detected variant on CX3CR1-dependent signal transduction. We detected a statistically significant association between the variant Ala55Thr in CX3CR1 with SCZ and ASD phenotypes (odds ratio=8.3, P=0.020). A 3D structural model indicated that Ala55Thr could destabilize the conformation of the CX3CR1 helix 8 and affect its interaction with a heterotrimeric G protein. In vitro functional analysis showed that the CX3CR1-Ala55Thr mutation inhibited cell signaling induced by fractalkine, the ligand for CX3CR1. The combined data suggested that the variant Ala55Thr in CX3CR1 might result in the disruption of CX3CR1 signaling. Our results strengthen the association between microglia-specific genes and neurodevelopmental disorders.

Hepatitis B surface antigen reduction by switching from long-term nucleoside/nucleotide analogue administration to pegylated interferon

Hepatitis B surface antigen (HBsAg) reduction during nucleoside/nucleotide analogue (NA) therapy is slow and an alternative strategy for patients receiving ongoing NA to facilitate HBsAg reduction is required. We investigated whether switching to pegylated interferon (PEG-IFN) after long-term NA administration enhances HBsAg reduction. Forty-nine patients who switched from long-term NA to 48 weeks of PEG-IFN alfa-2a were studied. The mean duration of previous NA was 48 months (sequential group). A total of 147 patients who continued NA and matched for baseline characteristics were analysed for comparison (NA continuation group). The treatment response was defined as HBsAg reduction ≥1.0 logIU/mL at the end of PEG-IFN. HBsAg reduction at week 48 was 0.81±1.1 logIU/mL in the sequential group, which was significantly higher than that in the NA continuation group (0.11±0.3 logIU/mL, P < .001). The treatment response was achieved in 29% and 2% of the sequential group and NA continuation group (P < .001), and the odds ratio of sequential therapy for the treatment response was 19 compared with the NA continuation (P < .001). In patients tested positive for hepatitis B e antigen (HBeAg), HBeAg seroconversion was higher in the sequential group (44% vs 8%, P < .001). In HBeAg-negative patients, only patients in the sequential group achieved HBsAg loss. No patient needed to resume NA administration because of HBV DNA increase accompanied by alanine aminotransferase flares. In summary, sequential therapy with PEG-IFN after long-term NA enhances the reduction of HBsAg and may represent a treatment option to promote HBsAg loss.

Asthma-like Features and Clinical Course of Chronic Obstructive Pulmonary Disease. An Analysis from the Hokkaido COPD Cohort Study

RATIONALE

Some patients with chronic obstructive pulmonary disease (COPD) have asthma-like features, such as significant bronchodilator reversibility, blood eosinophilia, and/or atopy, even if they are not clinically diagnosed as having asthma. However, the clinical significance of asthma-like features overlapping with COPD remains unclear.

OBJECTIVES

The aim of this study was to assess the effect of asthma-like features on the clinical course of patients with COPD who were adequately treated and followed-up over 10 years.

METHODS

A total of 268 patients with COPD who had been clinically considered as not having asthma by respiratory specialists were included in this study. The asthma-like features included in this study were bronchodilator reversibility (ΔFEV₁, ≥12% and ≥200 ml), blood eosinophilia (≥300 cells/μl), and atopy (positive specific IgE for any inhaled antigen). The annual changes in post-bronchodilator FEV₁ and COPD exacerbations were monitored during the first 5 years, and mortality was followed during the entire 10 years of the study.

MEASUREMENTS AND MAIN RESULTS

Fifty-seven subjects (21%) had bronchodilator reversibility, 52 (19%) had blood eosinophilia, and 67 (25%) had atopy. Subjects with blood eosinophilia had significantly slower annual post-bronchodilator FEV₁ decline; bronchodilator reversibility and atopy did not affect the annual post-bronchodilator FEV₁ decline, and none of the asthma-like features was associated with development of COPD exacerbation. Even if subjects had two or more asthma-like features, they displayed annual post-bronchodilator FEV₁ declines and exacerbation rates similar to those of subjects with one or zero asthma-like features, as well as a lower 10-year mortality rate (P = 0.02).

CONCLUSIONS

The presence of asthma-like features was associated with better clinical course in patients with COPD receiving appropriate treatment.

Graft-Versus-Host Disease Following Liver Transplantation: Development of a High-Incidence Rat Model and a Selective Prevention Method

Graft-versus-host disease (GvHD) following liver transplantation (LT) is a rare but serious complication with no presently available animal model and no preventive measures. To develop a rat model of GvHD after LT (LT-GvHD), we preconditioned hosts with sublethal irradiation plus reduction of natural killer (NK) cells with anti-CD8α mAb treatment, which invariably resulted in acute LT-GvHD. Compared with those in the peripheral counterpart, graft CD4⁺ CD25^- passenger T cells showed lower alloreactivities in mixed leukocyte culture. Immunohistology revealed that donor CD4⁺ T cells migrated and formed clusters with host dendritic cells in secondary lymphoid organs, with early expansion and subsequent accumulation in target organs. For selectively preventing GvHD, donor livers were perfused ex vivo with organ preservation media containing anti-TCRαβ mAb. T cell-depleted livers almost completely suppressed clinical GvHD such that host rats survived for >100 days. Our results showed that passenger T cells could develop typical LT-GvHD if resistant cells such as host radiosensitive cells and host radioresistant NK cells were suppressed. Selective ex vivo T cell depletion prevented LT-GvHD without affecting host immunity or graft function. This method might be applicable to clinical LT in prediagnosed high-risk donor-recipient combinations and for analyzing immunoregulatory mechanisms of the liver.

High-resolution copy number variation analysis of schizophrenia in Japan

Recent schizophrenia (SCZ) studies have reported an increased burden of de novo copy number variants (CNVs) and identified specific high-risk CNVs, although with variable phenotype expressivity. However, the pathogenesis of SCZ has not been fully elucidated. Using array comparative genomic hybridization, we performed a high-resolution genome-wide CNV analysis on a mainly (92%) Japanese population (1699 SCZ cases and 824 controls) and identified 7066 rare CNVs, 70.0% of which were small (<100 kb). Clinically significant CNVs were significantly more frequent in cases than in controls (odds ratio=3.04, P=9.3 × 10^-9, 9.0% of cases). We confirmed a significant association of X-chromosome aneuploidies with SCZ and identified 11 de novo CNVs (e.g., MBD5 deletion) in cases. In patients with clinically significant CNVs, 41.7% had a history of congenital/developmental phenotypes, and the rate of treatment resistance was significantly higher (odds ratio=2.79, P=0.0036). We found more severe clinical manifestations in patients with two clinically significant CNVs. Gene set analysis replicated previous findings (e.g., synapse, calcium signaling) and identified novel biological pathways including oxidative stress response, genomic integrity, kinase and small GTPase signaling. Furthermore, involvement of multiple SCZ candidate genes and biological pathways in the pathogenesis of SCZ was suggested in established SCZ-associated CNV loci. Our study shows the high genetic heterogeneity of SCZ and its clinical features and raises the possibility that genomic instability is involved in its pathogenesis, which may be related to the increased burden of de novo CNVs and variable expressivity of CNVs.

Abstract P4-21-14: A randomized phase II trial of trastuzumab + capecitabine versus lapatinib + capecitabine in patients with HER2-positive metastatic breast cancer previously treated with trastuzumab and taxanes: WJOG6110B/ELTOP

Background: In patients with HER2-positive metastatic breast cancer (MBC) who progressed on trastuzumab (H)-based therapy, both continuing H beyond progression and switching to lapatinib (L) in combination with chemotherapy are valid options. However, it is unclear which strategy is more effective and how we can select a proper strategy in each patient.

Methods: We conducted an open label, multicenter, randomized phase II trial to comparatively evaluate efficacy and safety of H + capecitabine (X) (HX) or L + X (LX) in women with HER2-positive MBC who were previously treated with taxanes and progressed on H-containing regimens. Patients treated with more than two chemotherapy regimens for MBC were excluded. Those treated with pertuzumab and/or T-DM1 were allowed to enroll in this study. Patients with brain metastases were also included if they are asymptomatic. Patients received H (4mg/kg loading then 2mg/kg weekly or 8mg/kg loading then 6mg/kg every 3 weeks) and X (2500 mg/m2/day on days 1-14 every 3weeks) in HX arm and L (1250 mg/day) and X (2000 mg/m2/day on days 1-14 every 3weeks) in LX arm until progression or intolerable toxicity. The primary endpoint was progression-free survival (PFS) and secondary endpoints included overall survival (OS), objective response rate (ORR), proportion of subjects progressing with brain metastases as site of first progression, and safety.We also assessed biomarkers in tumor tissues and circulating cell-free DNA.

Results: Between May 2011 and December 2014, 86 patients (43 in HX arm and 43 in LX arm) were enrolled in this study. Median age was 58 years (range 34-81), ECOG performance status was 0 (63%), 1 (35%), or 2 (2%), 63% had hormone receptor-positive disease, 15% had brain metastases, 56% had relapsed after primary surgery, and 23% had received adjuvant or neo-adjuvant trastuzumab. Median follow-up time was 44.6 months. Median PFS was 6.1 months in HX arm and 7.1 months in LX arm (hazard ratio 0.81 90% CI 0.55-1.21; p=0.39), median OS was 31.0 months in HX arm and not reached in LX arm (hazard ratio 0.58 95% CI 0.26-1.31; p=0.18), ORR was 40% in HX arm and 41% in LX arm (p=1.00), disease control rate was 73% in HX arm and 92% in LX arm (p=0.038), and proportion of subjects progressing with brain metastases as site of first progression was 5% in HX arm and 5% in LX arm. Grade 3-4 toxicities included hand-foot syndrome (21% in HX arm and 21% in LX arm) and diarrhea (9% in HX arm and 16% in LX arm). In subgroup analyses, PFS benefit in LX arm compared to HX arm was significantly larger among patients who had received previous systemic treatment for metastatic disease for less than 1 year (interaction p=0.007). Subgroup analyses by biomarkers will be presented at the meeting.

Conclusions: In women with HER2-positive MBC previously treated with trastuzumab and taxanes, lapatinib + capecitabine tended to yield better PFS and OS than trastuzumab beyond progression + capecitabine, although they were not statistically significant.Background: In patients with HER2-positive metastatic breast cancer (MBC) who progressed on trastuzumab (H)-based therapy, both continuing H beyond progression and switching to lapatinib (L) in combination with chemotherapy are valid options. However, it is unclear which strategy is more effective and how we can select a proper strategy in each patient.

Methods: We conducted an open label, multicenter, randomized phase II trial to comparatively evaluate efficacy and safety of H + capecitabine (X) (HX) or L + X (LX) in women with HER2-positive MBC who were previously treated with taxanes and progressed on H-containing regimens. Patients treated with more than two chemotherapy regimens for MBC were excluded. Those treated with pertuzumab and/or T-DM1 were allowed to enroll in this study. Patients with brain metastases were also included if they are asymptomatic. Patients received H (4mg/kg loading then 2mg/kg weekly or 8mg/kg loading then 6mg/kg every 3 weeks) and X (2500 mg/m2/day on days 1-14 every 3weeks) in HX arm and L (1250 mg/day) and X (2000 mg/m2/day on days 1-14 every 3weeks) in LX arm until progression or intolerable toxicity. The primary endpoint was progression-free survival (PFS) and secondary endpoints included overall survival (OS), objective response rate (ORR), proportion of subjects progressing with brain metastases as site of first progression, and safety.We also assessed biomarkers in tumor tissues and circulating cell-free DNA.

Results: Between May 2011 and December 2014, 86 patients (43 in HX arm and 43 in LX arm) were enrolled in this study. Median age was 58 years (range 34-81), ECOG performance status was 0 (63%), 1 (35%), or 2 (2%), 63% had hormone receptor-positive disease, 15% had brain metastases, 56% had relapsed after primary surgery, and 23% had received adjuvant or neo-adjuvant trastuzumab. Median follow-up time was 44.6 months. Median PFS was 6.1 months in HX arm and 7.1 months in LX arm (hazard ratio 0.81 90% CI 0.55-1.21; p=0.39), median OS was 31.0 months in HX arm and not reached in LX arm (hazard ratio 0.58 95% CI 0.26-1.31; p=0.18), ORR was 40% in HX arm and 41% in LX arm (p=1.00), disease control rate was 73% in HX arm and 92% in LX arm (p=0.038), and proportion of subjects progressing with brain metastases as site of first progression was 5% in HX arm and 5% in LX arm. Grade 3-4 toxicities included hand-foot syndrome (21% in HX arm and 21% in LX arm) and diarrhea (9% in HX arm and 16% in LX arm). In subgroup analyses, PFS benefit in LX arm compared to HX arm was significantly larger among patients who had received previous systemic treatment for metastatic disease for less than 1 year (interaction p=0.007). Subgroup analyses by biomarkers will be presented at the meeting.

Conclusions: In women with HER2-positive MBC previously treated with trastuzumab and taxanes, lapatinib + capecitabine tended to yield better PFS and OS than trastuzumab beyond progression + capecitabine, although they were not statistically significant.

Citation Format: Takano T, Tsurutani J, Takahashi M, Yamanaka T, Sakai K, Ito Y, Fukuoka J, Kimura H, Kawabata H, Tamura K, Matsumoto K, Aogi K, Sato K, Nishio K, Nakagawa K, Saeki T. A randomized phase II trial of trastuzumab + capecitabine versus lapatinib + capecitabine in patients with HER2-positive metastatic breast cancer previously treated with trastuzumab and taxanes: WJOG6110B/ELTOP [abstract]. In: Proceedings of the 2016 San Antonio Breast Cancer Symposium; 2016 Dec 6-10; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2017;77(4 Suppl):Abstract nr P4-21-14.

Abstract P2-05-24: Prognostic value of circulating PIK3CA mutations revealed with digital PCR in patients with HER2-positive advanced breast cancer: Results of West Japan Oncology Group study 6110BTR

This abstract was withdrawn by the authors.

Distribution of Serotonergic Neurons in the Central Nervous System: A Peroxidase-Antiperoxidase Study with Anti-Serotonin Antibodies

Distribution of serotonin (5-HT) neurons in the central nervous system (CNS) of various vertebrates was investigated with a highly sensitive immunohistochemical technique. Antibodies were raised in rabbits against an antigen prepared by coupling 5-HT to bovine thyroglobulin. 5-HT neurons were found to be distributed more widely and densely than has been heretofore described. Serotonergic neuronal somata are organized according to certain basic patterns, but there are interspecific differences with regard to the distribution of 5-HT fibers. The processes of 5-HT neurons form a dense plexus by ramification and anastomosis in almost all areas of the CNS, including the ventricular surfaces. In the light of our observations, Golgi's reticular theory may have to be revised.

MR Imaging of Monostotic Fibrous Dysplasia of the Clivus

We describe the MR appearance of a case of monostotic fibrous dysplasia confined to the clivus. The lesion showed intermediate signal intensity on T2-weighted images which is uncommon among clival diseases.

Gynandroblastoma of postmenopausal women: a case report

Gynandroblastoma, an extremely rare ovarian tumour that usually consists of both Sertoli stromal cell and granulosa cell tumours, often produces both androgenic and estrogenic effects. The authors herein report a case of gynandroblastoma with the longest disease-free period reported to date. A 66-year-old woman without metrorrhagia or hirsutism presented with abdominal pain and slightly elevated serum estradiol levels. Her uterus was enlarged, and endometrial curettage performed to reduce endometrial thickness prior to laparotomy led to a diagnosis of atypical endometrial hyperplasia. She was diagnosed of ovarian tumour. The pathology report revealed that the right ovarian tumour was a "gynandroblastoma". Such lesions are classified as borderline malignant. Postoperative adjuvant therapy was not administered in this case because only a few recurrent or fatal cases have been reported. The lesion was classified as pTlaN0M0 according to Union for International Cancer Control (UICC). The patient is alive and has been disease-free for 77 months post-surgery.

Flux and composition of interstellar dust at Saturn from Cassini's Cosmic Dust Analyzer

Interstellar dust (ISD) is the condensed phase of the interstellar medium. In situ data from the Cosmic Dust Analyzer on board the Cassini spacecraft reveal that the Saturnian system is passed by ISD grains from our immediate interstellar neighborhood, the local interstellar cloud. We determine the mass distribution of 36 interstellar grains, their elemental composition, and a lower limit for the ISD flux at Saturn. Mass spectra and grain dynamics suggest the presence of magnesium-rich grains of silicate and oxide composition, partly with iron inclusions. Major rock-forming elements (magnesium, silicon, iron, and calcium) are present in cosmic abundances, with only small grain-to-grain variations, but sulfur and carbon are depleted. The ISD grains in the solar neighborhood appear to be homogenized, likely by repeated processing in the interstellar medium.

Postoperative Psychiatric Complications in Living Liver Donors

BACKGROUND

To understand the impact of psychologic variables on donor quality of life, we studied long-term data on postoperative psychiatric complications in living liver donors. This study is a focused psychological investigation of diagnoses, treatments, and long-term clinical courses of living liver donors with psychiatric complications.

METHODS

Of the 142 donors who underwent live-donor liver transplantation at Nagoya University Hospital between April 2004 and July 2014, we investigated those without a history of mental illness who had developed such illness after transplantation and required psychiatric treatment.

RESULTS

A total of 6 (4.2%) donors developed the following psychiatric complications after transplantation: major depressive disorder (n = 2), panic disorder (n = 2), conversion disorder (n = 1), and substance use disorder (n = 1). Concerning psychiatric treatment, all donors received antianxiety drugs, 3 took antidepressants, and supportive psychiatric therapy was concomitantly provided to all subjects. The average treatment period was 53.3 months. Regarding subject outcomes, 3 donors achieved remission, and the other 3 continued treatment. All subjects showed improvement in Global Assessment of Functioning Scale.

CONCLUSION

It is important to accurately diagnose postoperative psychiatric complications and provide long-term treatment in close coordination with transplant surgeons.

Investigation of Rare Single-Nucleotide PCDH15 Variants in Schizophrenia and Autism Spectrum Disorders

Both schizophrenia (SCZ) and autism spectrum disorders (ASD) are neuropsychiatric disorders with overlapping genetic etiology. Protocadherin 15 (PCDH15), which encodes a member of the cadherin super family that contributes to neural development and function, has been cited as a risk gene for neuropsychiatric disorders. Recently, rare variants of large effect have been paid attention to understand the etiopathology of these complex disorders. Thus, we evaluated the impacts of rare, single-nucleotide variants (SNVs) in PCDH15 on SCZ or ASD. First, we conducted coding exon-targeted resequencing of PCDH15 with next-generation sequencing technology in 562 Japanese patients (370 SCZ and 192 ASD) and detected 16 heterozygous SNVs. We then performed association analyses on 2,096 cases (1,714 SCZ and 382 ASD) and 1,917 controls with six novel variants of these 16 SNVs. Of these six variants, four (p.R219K, p.T281A, p.D642N, c.3010-1G>C) were ultra-rare variants (minor allele frequency < 0.0005) that may increase disease susceptibility. Finally, no statistically significant association between any of these rare, heterozygous PCDH15 point variants and SCZ or ASD was found. Our results suggest that a larger sample size of resequencing subjects is necessary to detect associations between rare PCDH15 variants and neuropsychiatric disorders.

An Evaluation of Sensor Performance for Harmful Compounds by Using Photo-Induced Electron Transfer from Photosynthetic Membranes to Electrodes

Rapid, simple, and low-cost screening procedures are necessary for the detection of harmful compounds in the effluent that flows out of point sources such as industrial outfall. The present study investigated the effects on a novel sensor of harmful compounds such as KCN, phenol, and herbicides such as 3-(3,4-dichlorophenyl)-1,1-dimethylurea (DCMU), 2-chloro-4-ethylamino-6-isopropylamino-1,3,5-triazine (atrazine), and 2-N-tert-butyl-4-N-ethyl-6-methylsulfanyl-1,3,5-triazine-2,4-diamine (terbutryn). The sensor employed an electrode system that incorporated the photocurrent of intra-cytoplasmic membranes (so-called chromatophores) prepared from photosynthetic bacteria and linked using carbon paste electrodes. The amperometric curve (photocurrent-time curve) of photo-induced electron transfer from chromatophores of the purple photosynthetic bacterium Rhodobacter sphaeroides to the electrode via an exogenous electron acceptor was composed of two characteristic phases: an abrupt increase in current immediately after illumination (I₀), and constant current over time (Ic). Compared with other redox compounds, 2,5-dichloro-1,4-benzoquinone (DCBQ) was the most useful exogenous electron acceptor in this system. Photo-reduction of DCBQ exhibited Michaelis-Menten-like kinetics, and reduction rates were dependent on the amount of DCBQ and the photon flux intensity. The Ic decreased in the presence of KCN at concentrations over 0.05 μM (=μmol·dm(-3)). The I₀ decreased following the addition of phenol at concentrations over 20 μM. The Ic was affected by terbutryn at concentrations over 10 μM. In contrast, DCMU and atrazine had no effect on either I₀ or Ic. The utility of this electrode system for the detection of harmful compounds is discussed.

Practices for Supporting and Confirming Decision-Making Involved in Kidney and Liver Donation by Related Living Donors in Japan: A Nationwide Survey

This nationwide survey investigated the actual practices for supporting and confirming the decision-making involved in related living-organ donations in Japan, focusing on organ type and program size differences. Answers to a questionnaire survey were collected from 89 of the 126 (71%) kidney and 30 of the 35 (86%) liver transplantation programs in Japan that were involved in living-donor transplantations in 2013. In 70% of the kidney and 90% of the liver transplantation programs, all donors underwent "third-party" interviews to confirm their voluntariness. The most common third parties were psychiatrists (90% and 83%, respectively). Many programs engaged in practices to support decision-making by donor candidates, including guaranteeing the right to withdraw consent to donate (70% and 100%, respectively) and prescribing a set "cooling-off period" (88% and 100%, respectively). Most donors were offered care by mental health specialists (86% and 93%, respectively). Third parties were designated by more of the larger kidney transplant programs compared with the smaller programs. In conclusion, the actual practices supporting and confirming the decision to donate a living organ varied depending on the organ concerned and the number of patients in the program.

Influence of the Fukushima Dai-ichi Nuclear Power Plant accident on environmental radioactivity in Aomori Prefecture

Radioactive nuclides with a short half-life, such as (131)I and (134)Cs, were detected in environmental samples collected in Aomori Prefecture after the Tokyo Electric Power Company Fukushima Dai-ichi Nuclear Power Plant accident in March 2011. In addition, the observed (137)Cs concentration was increased over the background level. The gaseous (131)I concentration in air observed in April was higher than that observed in March immediately after the accident. Using a backward trajectory analysis, the authors found that the air mass had passed the vicinity of the Fukushima Dai-ichi Nuclear Power Plant when the gaseous (131)I concentration in air was increasing. Maximum (131)I and radioactive Cs concentrations in daily fallout samples collected in Aomori city were observed on 28 April, when (131)I was also detected in air. (134)Cs and (137)Cs concentration ratios in pine needles and pasture grass were nearly equal to 1, which indicates that the source of these radionuclides was the nuclear power plant accident.

Discrimination between natural and other gamma ray sources from environmental gamma ray dose rate monitoring data

In this study, a method to discriminate between natural and other γ-ray sources from environmental γ-ray dose rate monitoring data was developed, and it was successfully applied to actual monitoring data around nuclear facilities. The environmental dose rate is generally monitored by NaI(Tl) detector systems in the low dose rate range. The background dose rate varies mainly as a result of the deposition of (222)Rn progeny in precipitation and shielding of the ground by snow cover. Increments in the environmental dose rate due to radionuclides released from nuclear facilities must be separated from these background variations. The method in the present study corrects for the dose rate variations from natural sources by multiple regression analysis based on the γ-ray counting rates of single-channel analysers opened in the energy ranges of γ-rays emitted by (214)Bi and (208)Tl. Assuming a normal distribution of the results and using the one-sided type I error of 0.01 while ignoring the type II error, the detection limit of the γ-ray dose rate from artificial sources was 0.77 nGy h(-1).

White matter microstructure between the pre-SMA and the cingulum bundle is related to response conflict in healthy subjects

INTRODUCTION

Response conflict involves selectively attending to relevant information and suppressing distracting, irrelevant information. The medial frontal cortex (MFC) is considered to be involved in response conflict. However, it remains unclear which white matter connectivity is associated with response conflict. This study aimed to delineate the neural connectivity of response conflict in healthy subjects and investigate the association between white matter microstructure and performance of a response conflict task.

METHOD

Twenty-eight healthy subjects underwent functional magnetic resonance imaging (fMRI) during the Flanker task and diffusion MRI. We identified the presupplementary motor area (pre-SMA) using fMRI. Furthermore, we delineated the white matter connectivity between the pre-SMA and the cingulum bundle (CB), which is located in the MFC, using probabilistic tractography. We calculated the mean diffusivity (MD), index of white matter microstructure, of this tract and evaluate the association between MD and performance of the Flanker task.

RESULT

The mean MD of this tract was significantly and positively associated with performance of the Flanker task.

CONCLUSION

The present study suggests the white matter connectivity between the pre-SMA and the CB is related to the response conflict in healthy subjects and finer white matter microstructure is associated with smaller response conflict.

Genetic analyses of GII.17 norovirus strains in diarrheal disease outbreaks from December 2014 to March 2015 in Japan reveal a novel polymerase sequence and amino acid substitutions in the capsid region

A novel GII.P17-GII.17 variant norovirus emerged as a major cause of norovirus outbreaks from December 2014 to March 2015 in Japan. Named Hu/GII/JP/2014/GII.P17-GII.17, this variant has a newly identified GII.P17 type RNA-dependent RNA polymerase, while the capsid sequence displays amino acid substitutions around histo-blood group antigen (HBGA) binding sites. Several variants caused by mutations in the capsid region have previously been observed in the GII.4 genotype. Monitoring the GII.17 variant's geographical spread and evolution is important.

Identification of Rare, Single-Nucleotide Mutations in NDE1 and Their Contributions to Schizophrenia Susceptibility

BACKGROUND

Nuclear distribution E homolog 1 (NDE1), located within chromosome 16p13.11, plays an essential role in microtubule organization, mitosis, and neuronal migration and has been suggested by several studies of rare copy number variants to be a promising schizophrenia (SCZ) candidate gene. Recently, increasing attention has been paid to rare single-nucleotide variants (SNVs) discovered by deep sequencing of candidate genes, because such SNVs may have large effect sizes and their functional analysis may clarify etiopathology.

METHODS AND RESULTS

We conducted mutation screening of NDE1 coding exons using 433 SCZ and 145 pervasive developmental disorders samples in order to identify rare single nucleotide variants with a minor allele frequency ≤5%. We then performed genetic association analysis using a large number of unrelated individuals (3554 SCZ, 1041 bipolar disorder [BD], and 4746 controls). Among the discovered novel rare variants, we detected significant associations between SCZ and S214F (P = .039), and between BD and R234C (P = .032). Furthermore, functional assays showed that S214F affected axonal outgrowth and the interaction between NDE1 and YWHAE (14-3-3 epsilon; a neurodevelopmental regulator).

CONCLUSIONS

This study strengthens the evidence for association between rare variants within NDE1 and SCZ, and may shed light into the molecular mechanisms underlying this severe psychiatric disorder.

Prophylactic intra-arterial administration of fasudil hydrochloride for vasospasm following subarachnoid haemorrhage

PURPOSE

We evaluated patients treated with prophylactic intra-arterial administration of fasudil hydrochloride (IAF) after subarachnoid haemorrhage (SAH).

MATERIALS AND METHODS

Between August 1998 and December 2012, 92 patients with aneurysmal SAH were treated with IAF for angiographic vasospasm without ischemic symptoms after their follow-up angiography. Patients comprised 50 women and 42 men, aged 24-83 (mean 56.6) years. IAF consisted of 15 mg of fasudil hydrochloride dissolved in 20 ml physiological saline and injected through a catheter during approximately 15 min, after diagnostic angiography. The clinical outcome was evaluated using the Glasgow Outcome Scale (GOS) at discharge and ischemic lesions resulting from vasospasm were assessed on computed tomography (CT) scan at discharge.

RESULTS

Forty-eight patients underwent surgical clipping and 44 patients underwent endovascular coiling. Angiographic improvement was observed in all patients (100 %). At discharge, 76 (83.0 %) of 92 patients showed good recovery on GOS. Nine patients developed progression of delayed ischemic neurological deficits (DIND) and three of these patients had ischemic lesions on CT scans. No patient had any significant changes in vital signs or any other adverse effects resulting from IAF.

CONCLUSION

IAF therapy was safe and effective for patients with vasospasm following SAH. Prophylactic IAF therapy may prevent symptomatic vasospasm.

Resequencing and association analysis of PTPRA, a possible susceptibility gene for schizophrenia and autism spectrum disorders

Background

The PTPRA gene, which encodes the protein RPTP-α, is critical to neurodevelopment. Previous linkage studies, genome-wide association studies, controlled expression analyses and animal models support an association with both schizophrenia and autism spectrum disorders, both of which share a substantial portion of genetic risks.

Methods

We sequenced the protein-encoding areas of the PTPRA gene for single nucleotide polymorphisms or small insertions/deletions (InDel) in 382 schizophrenia patients. To validate their association with the disorders, rare (minor allele frequency <1%), missense mutations as well as one InDel in the 3′UTR region were then genotyped in another independent sample set comprising 944 schizophrenia patients, 336 autism spectrum disorders patients, and 912 healthy controls.

Results

Eight rare mutations, including 3 novel variants, were identified during the mutation-screening phase. In the following association analysis, L59P, one of the two missense mutations, was only observed among patients of schizophrenia. Additionally, a novel duplication in the 3′UTR region, 174620_174623dupTGAT, was predicted to be located within a Musashi Binding Element.

Major Conclusions

No evidence was seen for the association of rare, missense mutations in the PTPRA gene with schizophrenia or autism spectrum disorders; however, we did find some rare variants with possibly damaging effects that may increase the susceptibility of carriers to the disorders.

Some new perspectives on transplantation immunity and tolerance

To provoke a rejection response, an allograft's antigens must be presented to the host by accessory cells of the graft's MHC genotype. Tolerance induction, too, in neonatal rodents is an MHC-restricted response: third party grafts on tolerant animals survive longer if they are MHC-compatible with the tolerizing cells, rather than the host. In this article, Willys Silvers and his colleagues review the evidence for these observations and discuss their implications.

Novel rare variants in F-box protein 45 (FBXO45) in schizophrenia

The ubiquitin ligase F-box protein 45 (FBXO45) is critical for synaptogenesis, neuronal migration, and synaptic transmission. FBXO45 is included in the 3q29 microdeletion region that confers a significant risk for schizophrenia, as shown by rare structural variant studies. Thus, FBXO45 is considered a prominent candidate for mediating schizophrenia pathogenesis. Here, we investigated rare, deleterious single nucleotide variants (SNVs) as well as small insertions and deletions (INDELs) in FBXO45 that may contribute to schizophrenia susceptibility. Using Sanger sequencing, we performed mutation screening in FBXO45 exon regions in 337 schizophrenia patients. Novel missense or nonsense variants were followed up with a genetic association study in an independent sample set of 601 schizophrenia patients and 916 controls, a case report for assessing the clinical consequence of the mutations, a pedigree study for measuring mutation inheritance in the proband's family, bioinformatics analyses for evaluating mutation effect on protein structure and function, and mRNA expression analysis for examining mutation transcriptional influence on FBXO45 expression. One heterozygous, novel, and rare missense mutation (R108C) was identified in a single schizophrenia patient and in his healthy mother. At age 20, this patient was diagnosed with paranoid schizophrenia and carried some clinical features of 3q29 deletion phenotypes, including premorbid IQ decline. With follow-up genotyping, this mutation was not found in either the schizophrenia group (0/601) or the healthy control group (0/916). Bioinformatics analyses predicted that R108C probably pathologically impacted the structure and function of the FBXO45 protein. The relative expression of FBXO45 in SCZ case with R108C mutation was relatively low when compared to 50 schizophrenia patients and 52 healthy controls. The R108C mutation in FBXO45 is a rare variant with a modest effect on schizophrenia risk that may disrupt the structure and function of the FBXO45 protein. Our findings also suggest that FBXO45 may be a new attractive candidate gene for schizophrenia.