Impairment in the goal-directed corticostriatal learning system as a biomarker for obsessive-compulsive disorder.

Background: Compulsive behaviors in obsessive-compulsive disorder (OCD) have been related to impairment within the associative cortical-striatal system connecting the caudate and prefrontal cortex that underlies consciously-controlled goal-directed learning and behavior. However, little is known whether this impairment may serve as a biomarker for vulnerability to OCD.

Methods: Using resting-state functional magnetic resonance imaging (fMRI), we employed Granger causality analysis (GCA) to measure effective connectivity (EC) in previously validated striatal sub-regions, including the caudate, putamen, and the nucleus accumbens, in 35 OCD patients, 35 unaffected first-degree relatives and 35 matched healthy controls.

The nature of prospective memory deficit in patients with obsessive-compulsive disorder.

We comprehensively examined prospective memory (PM) performance in patients with obsessive-compulsive disorder (OCD), and explored the cognitive and psychopathological correlates of PM in this clinical population. Fifty-eight OCD patients and 58 healthy controls were assessed with computer-based PM tasks and related neurocognitive functions, and the participants also reported frequency of PM failures and compulsive behaviours in daily life. OCD patients had intact activity-based PM performance but had lower accuracy in time-based PM and longer reaction time to event-based PM cues compared to healthy controls.

Identification of MCI using optimal sparse MAR modeled effective connectivity networks.

Capability of detecting causal or effective connectivity from resting-state functional magnetic resonance imaging (R-fMRI) is highly desirable for better understanding the cooperative nature of the brain. Effective connectivity provides specific dynamic temporal information of R-fMRI time series and reflects the directional causal influence of one brain region over another. These causal influences among brain regions are normally extracted based on the concept of Granger causality.

Graph theoretical analysis of sedation's effect on whole brain functional system in school-aged children.

The neurophysiological mechanism underlying sedation, especially in school-aged children, remains largely unknown. The recently emerged resting-state functional magnetic resonance imaging (rsfMRI) technique, capable of delineating brain's functional interaction pattern among distributed brain areas, proves to be a unique and powerful tool to study sedation-induced brain reorganization. Based on a relatively large school-aged children population (n=28, 10.

Neurological soft signs in obsessive-compulsive disorder: the effect of co-morbid psychosis and evidence for familiality.

Patients with obsessive-compulsive disorder (OCD) have increased rates of neurological soft signs (NSS) when compared to healthy controls. However, previous findings have been confounded by the presence of co-morbidity with disorders themselves associated with increased NSS, such as schizophrenia. Moreover, it remains unclear whether NSS in OCD reflect a vulnerability to this disorder.

The Chinese version of the Obsessive-Compulsive Inventory-Revised scale: replication and extension to non-clinical and clinical individuals with OCD symptoms.

Background: The Obsessive-Compulsive Inventory-Revised (OCI-R) was designed to evaluate the severity of obsessive-compulsive symptoms in both clinical and non-clinical samples. The aim of the study was to evaluate the psychometric properties of a Chinese version of this scale.

Methods: The Chinese version of the OCI-R was administered to both a non-clinical sample (209 undergraduate students) and a clinical sample (56 obsessive-compulsive disorder (OCD) patients).

[Prevalence of internet addiction and the related factors in middle school students in Guangzhou].

Objective: To study the status of and the factors contributing to Internet addiction among middle school students in Guangzhou.

Methods: Cluster sampling method was used to recruit an urban middle school, a rural junior middle school and a rural senior high school to conduct the survey with the stressful life event questionnaire, the trait-oriented coping styles questionnaire and the Internet Addiction Test.

Results: The majority of respondents were classified as normal users of the Internet (n=1392, 89.

Effect of pathological use of the internet on adolescent mental health: a prospective study.

Objective: To examine the effect of pathological use of the Internet on the mental health, including anxiety and depression, of adolescents in China. It is hypothesized that pathological use of the Internet is detrimental to adolescents’ mental health.

Design: A prospective study with a randomly generated cohort from the population.

Factors associated with Internet addiction among adolescents.

This research examined factors associated with Internet addiction in adolescence using a population-based cross-sectional survey with self-reported questionnaires. Participants were recruited from high school students, ages 13 to 18 years, registered on the secondary school registry in Guangzhou city using a stratified random sampling technique. Internet addiction was assessed using the Internet Addiction Test (IAT).

Cryptochrome1 maybe a candidate gene of schizophrenia.

During the last 10 years, we have witnessed major progress in the genetic study of schizophrenia, but gene-mapping efforts have been hampered by the complex mode of inheritance and the likelihood of multiple genes of small effect. In view of the complexity, it may be instructive to understand the biological bases for pathogenesis. Extensive disruption in circadian function is known to occur among schizophrenia patients.

MR diffusion-weighed imaging of rabbit liver.

Aim: To study the techniques of MR diffusion-weighed imaging (DWI) for normal rabbit liver.

Methods: After 15 normal New Zealand white rabbits and one New Zealand white rabbit implanted with VX-2 tumor were anesthetized with 3% soluble pentobarbitone, DWI was performed respectively for different b values, repetition times (TR) or thicknesses, when other parameters were the same and magnetic resonance imaging (MRI) was performed respectively, or with different field of views (FOV) or coil when other parameters were the same. The distinction between groups was analyzed by SPSS10.