The contribution of cannabis use to the increased psychosis risk among minority ethnic groups in Europe.

BACKGROUND: We examined whether cannabis use contributes to the increased risk of psychotic disorder for non-western minorities in Europe. METHODS: We used data from the EU-GEI study (collected at sites in Spain, Italy, France, the United Kingdom, and the Netherlands) on 825 first-episode patients and 1026 controls. We estimated the odds ratio (OR) of psychotic disorder for several groups of migrants compared with the local reference population, without and with adjustment for measures of cannabis use. RESULTS: The OR of psychotic disorder for non-western minorities, adjusted for age, sex, and recruitment area, was 1.80 (95% CI 1.39-2.33). Further adjustment of this OR for frequency of cannabis use had a minimal effect: OR = 1.81 (95% CI 1.38-2.37). The same applied to adjustment for frequency of use of high-potency cannabis. Likewise, adjustments of ORs for most sub-groups of non-western countries had a minimal effect. There were two exceptions. For the Black Caribbean group in London, after adjustment for frequency of use of high-potency cannabis the OR decreased from 2.45 (95% CI 1.25-4.79) to 1.61 (95% CI 0.74-3.51). Similarly, the OR for Surinamese and Dutch Antillean individuals in Amsterdam decreased after adjustment for daily use: from 2.57 (95% CI 1.07-6.15) to 1.67 (95% CI 0.62-4.53). CONCLUSIONS: The contribution of cannabis use to the excess risk of psychotic disorder for non-western minorities was small. However, some evidence of an effect was found for people of Black Caribbean heritage in London and for those of Surinamese and Dutch Antillean heritage in Amsterdam.

Tobacco use in first-episode psychosis, a multinational EU-GEI study.

BACKGROUND: Tobacco is a highly prevalent substance of abuse in patients with psychosis. Previous studies have reported an association between tobacco use and schizophrenia. The aim of this study was to analyze the relationship between tobacco use and first-episode psychosis (FEP), age at onset of psychosis, and specific diagnosis of psychosis. METHODS: The sample consisted of 1105 FEP patients and 1355 controls from the European Network of National Schizophrenia Networks Studying Gene-Environment Interactions (EU-GEI) study. We assessed substance use with the Tobacco and Alcohol Questionnaire and performed a series of regression analyses using case-control status, age of onset of psychosis, and diagnosis as outcomes and tobacco use and frequency of tobacco use as predictors. Analyses were adjusted for sociodemographic characteristics, alcohol, and cannabis use. RESULTS: After controlling for cannabis use, FEP patients were 2.6 times more likely to use tobacco [p ⩽ 0.001; adjusted odds ratio (AOR) 2.6; 95% confidence interval (CI) [2.1-3.2]] and 1.7 times more likely to smoke 20 or more cigarettes a day (p = 0.003; AOR 1.7; 95% CI [1.2-2.4]) than controls. Tobacco use was associated with an earlier age at psychosis onset (ß = -2.3; p ⩽ 0.001; 95% CI [-3.7 to -0.9]) and was 1.3 times more frequent in FEP patients with a diagnosis of schizophrenia than in other diagnoses of psychosis (AOR 1.3; 95% CI [1.0-1.8]); however, these results were no longer significant after controlling for cannabis use. CONCLUSIONS: Tobacco and heavy-tobacco use are associated with increased odds of FEP. These findings further support the relevance of tobacco prevention in young populations.

Influence of social cognition as a mediator between cognitive reserve and psychosocial functioning in patients with first episode psychosis.

BACKGROUND: Social cognition has been associated with functional outcome in patients with first episode psychosis (FEP). Social cognition has also been associated with neurocognition and cognitive reserve. Although cognitive reserve, neurocognitive functioning, social cognition, and functional outcome are related, the direction of their associations is not clear. Therefore, the main aim of this study was to analyze the influence of social cognition as a mediator between cognitive reserve and cognitive domains on functioning in FEP both at baseline and at 2 years. METHODS: The sample of the study was composed of 282 FEP patients followed up for 2 years. To analyze whether social cognition mediates the influence of cognitive reserve and cognitive domains on functioning, a path analysis was performed. The statistical significance of any mediation effects was evaluated by bootstrap analysis. RESULTS: At baseline, as neither cognitive reserve nor the cognitive domains studied were related to functioning, the conditions for mediation were not satisfied. Nevertheless, at 2 years of follow-up, social cognition acted as a mediator between cognitive reserve and functioning. Likewise, social cognition was a mediator between verbal memory and functional outcome. The results of the bootstrap analysis confirmed these significant mediations (95% bootstrapped CI (-10.215 to -0.337) and (-4.731 to -0.605) respectively). CONCLUSIONS: Cognitive reserve and neurocognition are related to functioning, and social cognition mediates in this relationship.

The role of personality dimensions, depressive symptoms and other psychosocial variables in predicting postpartum suicidal ideation: a cohort study.

Suicidability has been associated with neuroticism and psychoticism, but its role during perinatal period has not been analyzed. We explore the association between personality dimensions, depressive symptoms, and other psychosocial variables in postpartum suicidal ideation. A cohort of 1795 healthy Spanish women from the general population was assessed for suicidal ideation (EPDS-Item10) in early postpartum, 8 and 32 weeks postpartum. Sociodemographic, obstetric, and reproductive variables, psychiatric history, social support, stressful life-events during pregnancy, depressive symptoms (EPDS), and the Eysenck's personality dimensions (EPQ-RS) were also assessed at baseline. A major depressive episode (DSM-IV) was confirmed in women with EPDS>10 at follow-up assessments. Descriptive, bivariate, and multivariate analyses were conducted. Adjusted logistic regression analysis was reported as odds ratio (ORs) with 95% confidence intervals (CIs). Seven percent of mothers reported suicidal ideation during the first 8 months postpartum. Sixty-two percent of women with suicidal ideation had a major depressive episode at 8 weeks, and 70% at 32 weeks postpartum. Neuroticism and psychoticism predicted suicidal ideation throughout the first 2 weeks after delivery (OR, 1.03; 95%CI 1.01-1.06; and OR, 1.03; 95%CI 1.01-1.05 respectively). Early postpartum depressive symptoms (OR 1.2; 95%CI 1.11-1.26), personal psychiatric history (OR 2.1; 95%CI 1.33-3.27), and stressful life events during pregnancy (OR 1.88; 95%CI 1.12-3.16) also emerged as predictors of postpartum suicidal ideation. Analysis of women for postpartum suicidal ideation should include not only psychiatric symptoms but also psychosocial assessment (i.e., covering psychiatric history, stressful events, or long-standing personality vulnerabilities) in order to identify those in need of early psychosocial or psychiatric care.

Common variant at 16p11.2 conferring risk of psychosis.

Epidemiological and genetic data support the notion that schizophrenia and bipolar disorder share genetic risk factors. In our previous genome-wide association study, meta-analysis and follow-up (totaling as many as 18 206 cases and 42 536 controls), we identified four loci showing genome-wide significant association with schizophrenia. Here we consider a mixed schizophrenia and bipolar disorder (psychosis) phenotype (addition of 7469 bipolar disorder cases, 1535 schizophrenia cases, 333 other psychosis cases, 808 unaffected family members and 46 160 controls). Combined analysis reveals a novel variant at 16p11.2 showing genome-wide significant association (rs4583255[T]; odds ratio=1.08; P=6.6 × 10(-11)). The new variant is located within a 593-kb region that substantially increases risk of psychosis when duplicated. In line with the association of the duplication with reduced body mass index (BMI), rs4583255[T] is also associated with lower BMI (P=0.0039 in the public GIANT consortium data set; P=0.00047 in 22 651 additional Icelanders).

Survival analysis of the surgical treatment of hepatocellular carcinoma at a tertiary care center.

INTRODUCTION AND AIMS: Hepatocellular carcinoma (HCC) is a primary malignant tumor of liver epithelial cells and is the most frequent primary liver cancer. The broadening of transplantation and resectability criteria has made therapeutic decisions more complex. Our aim was to describe the clinical and survival characteristics of patients with HCC treated through resection or liver transplantation at our hospital and identify the presence of factors that enable outcome prediction and facilitate therapeutic decision-making. MATERIALS AND METHODS: Patients with HCC that underwent surgery with curative intent at the Hospital Universitario Marqués de Valdecilla, within the time frame of 2007 and 2017, were retrospectively identified. Survival, mortality, disease-free interval, and different outcome-related variables were analyzed. RESULTS: Ninety-six patients with a mean follow-up after surgery of 44 months were included. Overall mortality and recurrence were higher in the resection group. Mean survival was 51.4 months in the liver transplantation group and 37.5 months in the resection group, and the disease-free interval was 49.4 ±â€¯37.2 and 27.4 ±â€¯28.7 months, respectively (p = 0.002). The tumor burden score was statistically significant regarding risk for recurrence and specific mortality. CONCLUSIONS: There appears to be no patient subgroup in whom the results of surgical resection were superior or comparable to those of transplantation. Tumor burden determination could be a useful tool for patient subclassification and help guide therapeutic decision-making.

Truths and myths about augmentation techniques in the treatment of fragility fractures. / Verdades y mentiras de las técnicas de cementación en el tratamiento de las fracturas por fragilidad.

The main event of osteoporosis is fragility fractures. Vertebral compression fractures are the most commonly fragility fracture related to osteoporosis. Our goal is to review the available literature to confirm or deny concepts learned about spinal cementation and adapt our clinical practice according to scientific evidence. In the complex world of spine surgery, constant innovations seek to improve the quality of life of patients. Among these, vertebral augmentation has emerged as an increasingly popular technique, but often shrouded in myths and misunderstandings. In this systematic review, we will thoroughly explore the truths behind vertebral augmentation, unraveling common myths and providing a clear insight into this technique. As specialists in the field, it is crucial to understand the reality surrounding these interventions to offer our patients the best possible information and make informed decisions.

Self-reported suicidal ideation among individuals with first episode psychosis and healthy controls: Findings from the international multicentre EU-GEI study.

INTRODUCTION: Suicidal ideation is common among individuals with first episode psychosis (FEP), with prevalence estimates up to 56.5 %. Despite its high prevalence, relatively little is known about how sociodemographic, clinical and/or developmental characteristics contribute to the experience of suicidal ideation in individuals with FEP. METHODS: In this cross-sectional study (FEP n = 551 and controls n = 857), univariate logistic regression analyses were performed to study the associations of sociodemographic, clinical, and developmental factors with suicidal ideation in individuals with FEP as well as controls. Suicidal ideation was assessed using the Community Assessment of Psychic Experiences (CAPE). In addition, multivariate logistic regression analyses were conducted based on a stepwise approach. RESULTS: In FEP, only depressive symptoms remained significantly associated with suicidal ideation when all correlates were integrated into one model. In the multivariate model in controls, depressive symptoms, positive symptoms, and traumatic childhood experiences were significantly associated with suicidal ideation. CONCLUSIONS: This study showed that depressive symptoms are an important factor relating to suicidal ideation in individuals with FEP, over and above other clinical, sociodemographic, and developmental factors. This underscores the relevance of screening for suicidal ideation in individuals with FEP, and highlights the need for a better understanding of the diagnostic uncertainty and course of mood symptoms in early psychosis. LIMITATIONS: Cross-sectional study design, self-reported questionnaires.

Conceptual study for velocity space resolved thermal ion loss detection in tokamaks.

A new concept for velocity space thermal ion loss detection is presented. This diagnostic provides pitch angle resolved measurements that are unfeasible with current diagnostics. It uses the same detection principle as the Fast-Ion Loss Detector with a scintillator as the active component and includes a double slit configuration to measure simultaneously the escaping counter- and co-current ions. Simulations show a gyroradius range between 0.15 and 1.00 cm with a resolution below 0.15 cm (for a gyroradius of 1 cm) and a pitch angle range between 30° and 150° with a resolution below 8° for both counter- and co-current ions. The formation of a sheath in front of the detector and its associated electric field may impact the detection principle. Preliminary simulations with a homogeneous electric field show a decrease in the measurable velocity space range, whereas the gyroradius and pitch angle resolution barely change. The strike map is sensitive to the sheath electric field.

Genetic and psychosocial stressors have independent effects on the level of subclinical psychosis: findings from the multinational EU-GEI study.

AIMS: Gene x environment (G×E) interactions, i.e. genetic modulation of the sensitivity to environmental factors and/or environmental control of the gene expression, have not been reliably established regarding aetiology of psychotic disorders. Moreover, recent studies have shown associations between the polygenic risk scores for schizophrenia (PRS-SZ) and some risk factors of psychotic disorders, challenging the traditional gene v. environment dichotomy. In the present article, we studied the role of GxE interaction between psychosocial stressors (childhood trauma, stressful life-events, self-reported discrimination experiences and low social capital) and the PRS-SZ on subclinical psychosis in a population-based sample. METHODS: Data were drawn from the EUropean network of national schizophrenia networks studying Gene-Environment Interactions (EU-GEI) study, in which subjects without psychotic disorders were included in six countries. The sample was restricted to European descendant subjects (n = 706). Subclinical dimensions of psychosis (positive, negative, and depressive) were measured by the Community Assessment of Psychic Experiences (CAPE) scale. Associations between the PRS-SZ and the psychosocial stressors were tested. For each dimension, the interactions between genes and environment were assessed using linear models and comparing explained variances of 'Genetic' models (solely fitted with PRS-SZ), 'Environmental' models (solely fitted with each environmental stressor), 'Independent' models (with PRS-SZ and each environmental factor), and 'Interaction' models (Independent models plus an interaction term between the PRS-SZ and each environmental factor). Likelihood ration tests (LRT) compared the fit of the different models. RESULTS: There were no genes-environment associations. PRS-SZ was associated with positive dimensions (ß = 0.092, R2 = 7.50%), and most psychosocial stressors were associated with all three subclinical psychotic dimensions (except social capital and positive dimension). Concerning the positive dimension, Independent models fitted better than Environmental and Genetic models. No significant GxE interaction was observed for any dimension. CONCLUSIONS: This study in subjects without psychotic disorders suggests that (i) the aetiological continuum hypothesis could concern particularly the positive dimension of subclinical psychosis, (ii) genetic and environmental factors have independent effects on the level of this positive dimension, (iii) and that interactions between genetic and individual environmental factors could not be identified in this sample.

[Magnetic resonance imaging postprocessing techniques in the study of brain connectivity]. / Técnicas de análisis de posproceso en resonancia magnetica para el estudio de la conectividad cerebral.

Brain connectivity is a key concept for understanding brain function. Current methods to detect and quantify different types of connectivity with neuroimaging techniques are fundamental for understanding the pathophysiology of many neurologic and psychiatric disorders. This article aims to present a critical review of the magnetic resonance imaging techniques used to measure brain connectivity within the context of the Human Connectome Project. We review techniques used to measure: a) structural connectivity b) functional connectivity (main component analysis, independent component analysis, seed voxel, meta-analysis), and c) effective connectivity (psychophysiological interactions, causal dynamic models, multivariate autoregressive models, and structural equation models). These three approaches make it possible to combine and use different statistical techniques to elaborate mathematical models in the attempt to understand the functioning of the brain. The findings obtained with these techniques must be validated by other techniques for analyzing structural and functional connectivity. This information is integrated in the Human Connectome Project where all these approaches converge to provide a representation of all the different models of connectivity.

[Assessment of the new CKD-EPI equation to estimate the glomerular filtration rate]. / Valoración de la nueva ecuación CKD-EPI para la estimación del filtrado glomerular.

INTRODUCTION: A recent report by the CKD-EPI Chronic Kidney Disease Epidemiology Collaboration) group describes a new equation to estimate the glomerular filtration rate (GFR). This equation has been developed from a population of 8,254 subjects who had the GFR measured by iothalamate clearance (mean 68 mL/min/1.73 m2, SD 40 mL/min/1.73 m2). It includes variables such as serum creatinine, age, sex and race with different formula according to race, sex and creatinine value. The CKD-EPI equation improved the accuracy and precision results of the current first-choice MDRD-IDMS (Modification of Diet in Renal Disease-Isotopic Dilution Mass Spectrometry) formula, specially for GFR > 60 mL/min/1.73 m2 in a group of 3,896 subjects. METHODS: The goal of our study was to compare the estimated GFR by using the new equation CKD-EPI with MDRD-IDMS in a wide cohort of 14,427 patients (5,234 women and 9,193 men), and to analyze the impact of the new CKD-EPI formula on the staging of patients with CKD. RESULTS: Mean estimated GFR was 0.6 mL/min/1.73 m2 higher with CKD-EPI as compared to MDRD-IDMS for the whole group, 1.9 mL/min/1.73 m2 higher for women and 0.2 mL/min/1.73 m2 lower for men. The percentage of CKD staging concordancy between equations varied from 79.4 % for stage 3A and 98.6% for stage 5. For those patients younger than 70 years, 18.9 % and 24 % MDRD-IDMS stages 3B and 3A were reclassified as CKD 3A and 2 by CKD-EPI, respectively. For the same stages in the group younger than 70 years, the percentage of reclassified patients increased up to 34.4% and 33.4%, respectively. CONCLUSION: The new CKD-EPI equation to estimate the GFR reclassifies an important number of patients to higher CKD stages (higher GFR), specially younger women, classified as CKD stage 3 by MDRD-IDMS.

Impact of radical nephrectomy on kidney function and prognostic factors for adverse cardiovascular events. / Impacto de la nefrectomía radical en la función renal y factores pronósticos de eventos cardiovasculares adversos.

INTRODUCTION AND OBJECTIVES: To analyze the evolution of kidney function after radical nephrectomy and to evaluate risk factors for adverse cardiovascular events during a long follow-up. MATERIAL AND METHODS: Retrospective study of patients submitted to radical nephrectomy due to renal cancer from January of 1996 to January of 2016. We evaluated their renal function after nephrectomy and during follow-up. We analyzed the possible predictive factors for adverse cardiovascular events with univariate and multivariate logistic regression analyses. RESULTS: There was an acute drop in glomerular filtration rate (GFR) after nephrectomy (21.2ml/min), which stabilized during follow-up in most cases. We evaluated the possible predictive factors for adverse cardiovascular events with logistic regression analyses, which presented previous cardiovascular disease (0,270, 95% CI 0,123-0,594, P<.001), diabetes (0,364, 95% CI 0,162-0,818 P=.015) and de novo hypertension (0,239, 95% CI 0,098-0,581, P=.002) as independently associated with the occurrence of adverse cardiovascular events. CONCLUSION: There was a deleterious effect in renal function after nephrectomy which remained stable during subsequent years in most patients. Approximately half of our patients had a GFR lower than 60mL/min after nephrectomy. Previous cardiovascular disease, diabetes and de novo hypertension were shown as risk factors for adverse cardiovascular events.

Examining the independent and joint effects of genomic and exposomic liabilities for schizophrenia across the psychosis spectrum.

AIMS: Psychosis spectrum disorder has a complex pathoetiology characterised by interacting environmental and genetic vulnerabilities. The present study aims to investigate the role of gene-environment interaction using aggregate scores of genetic (polygenic risk score for schizophrenia (PRS-SCZ)) and environment liability for schizophrenia (exposome score for schizophrenia (ES-SCZ)) across the psychosis continuum. METHODS: The sample consisted of 1699 patients, 1753 unaffected siblings, and 1542 healthy comparison participants. The Structured Interview for Schizotypy-Revised (SIS-R) was administered to analyse scores of total, positive, and negative schizotypy in siblings and healthy comparison participants. The PRS-SCZ was trained using the Psychiatric Genomics Consortiums results and the ES-SCZ was calculated guided by the approach validated in a previous report in the current data set. Regression models were applied to test the independent and joint effects of PRS-SCZ and ES-SCZ (adjusted for age, sex, and ancestry using 10 principal components). RESULTS: Both genetic and environmental vulnerability were associated with case-control status. Furthermore, there was evidence for additive interaction between binary modes of PRS-SCZ and ES-SCZ (above 75% of the control distribution) increasing the odds for schizophrenia spectrum diagnosis (relative excess risk due to interaction = 6.79, [95% confidential interval (CI) 3.32, 10.26], p < 0.001). Sensitivity analyses using continuous PRS-SCZ and ES-SCZ confirmed gene-environment interaction (relative excess risk due to interaction = 1.80 [95% CI 1.01, 3.32], p = 0.004). In siblings and healthy comparison participants, PRS-SCZ and ES-SCZ were associated with all SIS-R dimensions and evidence was found for an interaction between PRS-SCZ and ES-SCZ on the total (B = 0.006 [95% CI 0.003, 0.009], p < 0.001), positive (B = 0.006 [95% CI, 0.002, 0.009], p = 0.002), and negative (B = 0.006, [95% CI 0.004, 0.009], p < 0.001) schizotypy dimensions. CONCLUSIONS: The interplay between exposome load and schizophrenia genetic liability contributing to psychosis across the spectrum of expression provide further empirical support to the notion of aetiological continuity underlying an extended psychosis phenotype.

Traumatic neuroma of extrahepatic bile ducts after orthotopic liver transplantation.

Traumatic neuromas (TN) of the biliary tree causing strictures have only occasionally been described after liver transplantation. Herein, we have reported 15 cases of TN that were detected between 1 and 17 months after transplantation (median: 4 months) during surgery for obstructive jaundice (12 cases), after alterations of liver function tests (two cases), or incidentally discovered after retransplantation (n = 1) we resected the lesion and the biliary anastomosis. Pathological examination and immunostaining for S-100 protein were performed to study the nerve fascicles. After a median follow-up time of 64 months (range = 0-127), 10 patients are alive without any complication related to the previous biliary TN. We propose the following classification: type I: TN originating from and located in the main biliary tract wall, and type II: TN arising from the surrounding tissues next to the main biliary tract. We conclude that TN are not uncommon after liver transplantation and that they are sometimes symptomatic, causing a biliary stricture that requires surgical treatment. We propose a classification to help patient selection for surgery. In our opinion, resection of the TN is the operation of choice, together with resection of the involved biliary tract in type I TN.

Liver Transplant From Controlled Cardiac Death Donors Using Normothermic Regional Perfusion: Comparison With Liver Transplants From Brain Dead Donors.

BACKGROUND: Liver transplantation from donors after either controlled or uncontrolled cardiac death (DCD) is associated with considerable rates of primary nonfunction (PNF) and ischemic cholangiopathy (IC). Normothermic regional perfusion (NRP) could significantly reduce such rates. METHODS: Retrospective study to analyze short-term (mortality, PNF, vascular complications) and long-term (IC, survival) complications in 11 liver transplants from controlled DCDs using NRP with extracorporeal membrane oxygenation (ECMO) (group 1). They were compared with 51 patients transplanted with grafts from donors after brain death (DBD) (group 2). Mean recipient age, sex, and Model for End-stage Liver Disease (MELD) score were not significantly different. RESULTS: In group 1, mean functional warm ischemia time was 15.8 (range, 7-40) minutes and 94.1 (range, 20-150) minutes on NRP. The ischemic damage was minimal, as shown by the slight alanine aminotransferase (ALT) and aspartate aminotransferase (AST) rises in the donor serum after 1 hour on NRP and similar rises 24 hours after transplantation in both groups. No patient had IC or acute renal failure. No significant difference was found between the groups for vascular or biliary complications. One group 1 patient had PNF (9.1%), resulting in death. Overall retransplantation and in-hospital death rates were 8.1% and 4.8%, respectively, with no significant difference between groups. Estimated mean survival was 24.6 (95% confidence interval [CI], 20.2-29.1) months in group 1 and 32.3 (95% CI, 30.4-34.2) months in group 2 (not a statistically significant difference). CONCLUSION: In our experience, liver transplants from controlled DCDs using NRP with ECMO is associated with a low risk of PNF and IC, with short- and long-term results comparable to those in DBD transplants.

Mood changes after delivery: role of the serotonin transporter gene.

BACKGROUND: Polymorphic variations in the serotonin transporter gene (5-HTT) moderate the depressogenic effects of tryptophan depletion. After childbirth there is a sharp reduction in brain tryptophan availability, thus polymorphic variations in 5-HTT may play a similar role in the post-partum period. AIMS: To study the role of 5-HTT polymorphic variations in mood changes after delivery. METHOD: One thousand, eight hundred and four depression-free Spanish women were studied post-partum. We evaluated depressive symptoms at 2-3 days, 8 weeks and 32 weeks post-partum. We used diagnostic interview to confirm major depression for all probable cases. Based on two polymorphisms of 5-HTT (5-HTTLPR and STin2 VNTR), three genotype combinations were created to reflect different levels of 5-HTT expression. RESULTS: One hundred and seventy-three women (12.7%) experienced major depression during the 32-week post-partum period. Depressive symptoms were associated with the high-expression 5-HTT genotypes in a dose-response fashion at 8 weeks post-partum, but not at 32 weeks. CONCLUSIONS: High-expression 5-HTT genotypes may render women more vulnerable to depressive symptoms after childbirth.

Left orbitofrontal and superior temporal gyrus structural changes associated to suicidal behavior in patients with schizophrenia.

Suicidal attempts are relatively frequent and clinically relevant in patients with schizophrenia. Recent studies have found gray matter differences in suicidal and non-suicidal depressive patients. However, no previous neuroimaging study has investigated possible structural abnormalities associated to suicidal behaviors in patients with schizophrenia. A whole-brain magnetic resonance voxel-based morphometric examination was performed on 37 male patients meeting the DSM-IV criteria for schizophrenia. Thirteen (35.14%) patients had attempted suicide. A non-parametric permutation test was computed to perform the comparability between groups. An analysis of covariance (AnCova) model was constructed with a statistical threshold of p<0.05 corrected for multiple comparisons. After controlling for age and severity of illness, results showed significant gray matter density reduction in left superior temporal lobe (p=0.03) and left orbitofrontal cortex (p=0.04) in patients who had attempted suicide when comparing with non-suicidal patients. Although sample size limitations and potential clinical heterogeneity preclude definitive conclusions, these data point to structural differences in key cerebral areas. Neuroimaging studies are necessary to expand our knowledge of biological mechanisms underlying suicide in schizophrenia.

Non-linear quantization error reduction for the temperature measurement subsystem on-board LISA Pathfinder.

Laser Interferometer Space Antenna (LISA) Pathfinder is a mission to test the technology enabling gravitational wave detection in space and to demonstrate that sub-femto-g free fall levels are possible. To do so, the distance between two free falling test masses is measured to unprecedented sensitivity by means of laser interferometry. Temperature fluctuations are one of the noise sources limiting the free fall accuracy and the interferometer performance and need to be known at the ∼10 µK Hz-1/2 level in the sub-millihertz frequency range in order to validate the noise models for the future space-based gravitational wave detector LISA. The temperature measurement subsystem on LISA Pathfinder is in charge of monitoring the thermal environment at key locations with noise levels of 7.5 µK Hz-1/2 at the sub-millihertz. However, its performance worsens by one to two orders of magnitude when slowly changing temperatures are measured due to errors introduced by analog-to-digital converter non-linearities. In this paper, we present a method to reduce this effect by data post-processing. The method is applied to experimental data available from on-ground validation tests to demonstrate its performance and the potential benefit for in-flight data. The analog-to-digital converter effects are reduced by a factor between three and six in the frequencies where the errors play an important role. An average 2.7 fold noise reduction is demonstrated in the 0.3 mHz-2 mHz band.