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Within the drainage basin, information about natural processes and human activities can be recorded in the chemical composition of riverine water. The analysis of the Guijiang River, the first level tributary of the Xijiang River, demonstrated that the chemical composition of water in the Guijiang River was mainly influenced by the chemical weathering of carbonate rocks within the drainage basin, in which CO2 was the main erosion medium, and that the weathering of carbonate rock by H2SO4 had a remarkable impact on the water chemical composition in the Guijiang River. Precipitation, human activities, the weathering of carbonate rocks and silicate rocks accounted for 2.7%, 6.3%, 72.8% and 18.2% of the total dissolved load, respectively. The stable isotopic compositions of dissolved inorganic carbon (delta13C(DIC)) indicated that DIC in the Guijiang River had been assimilated by the phytoplankton in photosynthesis. The primary production of phytoplankton contributed to 22.3%-30.9% of particulate organic carbon (POC) in the Guijiang River, which implies that phytoplankton can transform DIC into POC by photosynthesis, and parts of POC will sink into the bottom of the river in transit, which leads into the formation of burial organic carbon.

Objective: To examine differences in health-related quality of life (HRQOL) in stroke survivors with and without apathy., Design: Cross-sectional study., Setting: Acute stroke unit in a regional hospital., Participants: Stroke survivors (N=391) recruited from the acute stroke unit., Interventions: Not applicable., Main Outcome Measures: Participants were divided into apathy and nonapathy groups. Participants who scored ≥36 on the Apathy Evaluation Scale, clinician's version formed the apathy group. HRQOL was measured with the 2 component scores, mental component summary (MCS) and physical component summary (PCS), of the Medical Outcomes Study 12-Item Short-Form Health Survey (SF-12). Demographic and clinical information were obtained with the National Institutes of Health Stroke Scale (NIHSS), Barthel Index (BI), Mini-Mental State Examination (MMSE), and Geriatric Depression Scale (GDS)., Results: Thirty-six (9%) participants had apathy. The apathy group had significantly lower MCS and PCS scores. After adjusting for sex, education, diabetes mellitus, and NIHSS, MMSE, GDS, and BI scores, the MCS score in the apathy group remained significantly lower., Conclusions: Apathy has a significant negative effect on HRQOL in stroke survivors, particularly on their mental health. Interventions for apathy could improve the HRQOL of stroke survivors., (Copyright © 2014 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Background: Rapid eye movement (REM) sleep behavior disorder (RBD) is a sleep disturbance in which patients enact their dreams while in REM sleep. The behavior is typically violent in association with violent dream content, so serious harm can be done to the patient or the bed partner. The prevalence of RBD is well-known in Parkinson's disease, Lewy body dementia, and multiple systems atrophy. However, its prevalence and causes in stroke remained unclear. The aim of this study was to determine factors influencing the appearance of RBD in a prospective cohort of patients with acute ischemic stroke., Methods: A total of 2,024 patients with first-ever or recurrent acute ischemic stroke were admitted to the Acute Stroke Unit at the Prince of Wales Hospital between January 2010 and November 2011; 775 of them received an MRI scan. Within 2 days of admission, a research nurse collected demographic and clinical data and assessed the severity of each stroke using the National Institute of Health Stroke Scale (NIHSS). One hundred and nineteen of the 775 patients meeting study entry criteria formed the study sample. All eligible participants were invited to attend a research clinic 3 months after the onset of the index stroke. In the attendance, a research assistant administered the MMSE and the 13-item RBD questionnaire (RBDQ)., Results: Among 119 stroke patients, 10.9% were exhibited RBD, defined as an REM sleep behavior disorder questionnaire score of 19 or above. The proportion of patients with acute brainstem infarct was significantly higher in RBD patients than those without RBD. Compared with patients without RBD, RBD patients were more likely to have brainstem infarcts and had smaller infarct volumes. In a multivariate analysis, in which stroke location and infarct volume were inserted, brainstem infarcts were an independent predictor of RBD (odds ratio = 3.686; P = 0.032)., Conclusions: The results support the notion of a predominant role of brainstem injury in the development of RBD and suggest that patients with brainstem infarcts RBD should be evaluated by a clinical neurologist.

Purpose: The study examined the rate of remission in individuals experiencing a first episode of schizophrenia (FES) in China and explored predictors of remission in the acute phase of the illness., Design and Methods: Fifty-five FES patients were randomly treated with risperidone, olanzapine, or aripiprazole at therapeutic doses for 8 weeks, and their clinical profiles and cognition were assessed using standardized assessment instruments at entry and the end of the study., Findings: Of the 55 patients, 30 (54.5%) remitted by the end of the 8-week study. In univariate analyses, shorter duration of untreated psychosis, higher scores on both the time-based prospective memory (TBPM) and event-based prospective memory tasks and the Hopkins Verbal Learning Test-revised, and less severe negative symptoms were significantly associated with remission. In stepwise multiple logistic regression analyses, only higher scores on the TBPM significantly predicted remission. Individuals having higher scores reflecting better TBPM at baseline were more likely to achieve remission after 8 weeks of optimized antipsychotic treatment., Practice Implications: TPBM may be useful in helping clinicians identify those FES patients most likely to achieve a favorable treatment response., (© 2013 Wiley Periodicals, Inc.)

Introduction: Data on the psychometric assessment of prospective memory (PM) are limited. The Cambridge Prospective Memory Test (CAMPROMPT) and its Chinese version (CAMPROMPT-C) have been applied to a variety of clinical conditions except for chronic schizophrenia. This controlled study explored the clinical utility of the CAMPROMPT-C in patients with schizophrenia by comparing their PM performance with that of normal controls., Methods: Forty-four schizophrenia patients and 44 normal controls formed the study sample. Sociodemographic characteristics, PM, retrospective memory, and intelligence were measured in all subjects. Patients' psychopathology was rated with a standardized instrument., Results: Patients performed worse than normal controls on both the sum and subscale scores of the CAMPROMPT-C. Patients had comparable performances in PM subtypes. Bivariate analyses revealed that education level, intelligence, and retrospective memory were associated with PM functions., Discussion: The study supports the clinical utility of the CAMPROMPT-C in chronic schizophrenia and corroborated the significant relationship between PM and education, intelligence, and retrospective memory., (Copyright © 2012 Blackwell Publishing Asia Pty Ltd.)

One hundred primary ketamine users and 100 controls were recruited in Hong Kong between December 2009 and December 2011. Cognitive assessment included general intelligence, working, verbal, and visual memory, and executive functions. A Univariate General Linear Model was used to compare cognitive performance between the male and female ketamine users and controls. The female users appeared to have a higher risk of visual memory impairment than their male counterparts. Further studies are warranted to clarify the mechanism of the sex-specific effect of ketamine on cognitive functions.

Purpose: Little is known about quality of life (QOL) in Chinese patients with bipolar disorder (BD) in remission (euthymia). This study examined the QOL of such a cohort of BD patients and its demographic, clinical, and cognitive correlates., Design and Methods: Forty-seven euthymic BD patients and 47 matched healthy controls formed the study sample. Socio-demographic characteristics, prospective memory, retrospective memory, intelligence quotient, and executive functioning were measured in all participants together with patients’ psychopathology ratings., Findings: Multivariate analyses revealed that compared to controls, euthymic BD patients had significantly lower satisfaction with physical QOL domain. Only subthreshold depressive symptoms independently contributed to reduced satisfaction with physical and environmental QOL domains, whereas no variable predicted its psychological and social domains., Practice Implications: Contrary to findings from Western settings, demographic variables and cognitive deficits had no associations with any QOL domain in euthymic Chinese BD patients. Control of subthreshold depressive symptoms in euthymic BD patients might enhance their QOL.

Background and Purpose: Cerebral microbleeds (CMBs) are common in stroke survivors and community-dwelling elderly. The clinical significance of CMBs in the outcome of poststroke depression (PSD) is unknown. This study examined the association between the 1-year outcome of PSD and CMBs., Methods: The study population comprised 774 Chinese patients with acute ischemic stroke who were admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong. Three and 15 months after the onset of the index stroke, a research assistant administered the locally validated 15-item Geriatric Depression Scale. PSD was defined as a Geriatric Depression Scale score of ≥7. Of the 213 patients with PSD at the 3-month follow-up, 135 (63.4%) attended the 15-month follow-up, at which time 89 (65.9%) patients remained depressed (nonremitters), and 46 (34.1%) had recovered (remitters). The presence and location of CMBs were evaluated with magnetic resonance imaging., Results: In comparison with the remitters, nonremitters were more likely to have lobar CMBs (18.4% versus 4.3%; P=0.024). Lobar CMBs remained an independent predictor of PSD in the multivariate analysis, with an odds ratio of 4.96 (P=0.039)., Conclusions: The results suggest that lobar CMBs may influence the outcome of PSD. The importance of CMBs in the clinical course of depression in stroke survivors warrants further investigation.

Background: Caregivers of people with chronic conditions are more likely than non-caregivers to have depression and emotional problems. Few studies have examined the effectiveness of mindfulness-based stress reduction (MBSR) in improving their mental well-being., Methods: Caregivers of persons with chronic conditions who scored 7 or above in the Caregiver Strain Index were randomly assigned to the 8-week MBSR group (n = 70) or the self-help control group (n = 71). Validated instruments were used to assess the changes in depressive and anxiety symptoms, quality of life, self-efficacy, self-compassion and mindfulness. Assessments were conducted at baseline, post-intervention and at the 3-month follow-up., Results: Compared to the participants in the control group, participants in the MBSR group had a significantly greater decrease in depressive symptoms at post-intervention and at 3 months post-intervention (p < 0.01). The improvement in state anxiety symptoms was significantly greater among participants in the MBSR group than those of the control group at post-intervention (p = 0.007), although this difference was not statistically significant at 3 months post-intervention (p = 0.084). There was also a statistically significant larger increase in self-efficacy (controlling negative thoughts; p = 0.041) and mindfulness (p = 0.001) among participants in the MBSR group at the 3-month follow-up compared to the participants in the control group. No statistically significant group effects (MBSR vs. control) were found in perceived stress, quality of life or self-compassion., Conclusions: MBSR appears to be a feasible and acceptable intervention to improve mental health among family caregivers with significant care burden, although further studies that include an active control group are needed to make the findings more conclusive.

Background and Purpose: Poststroke fatigue (PSF) is a frequent and persistent problem in stroke survivors. The neuroanatomical model of PSF remains unclear. This study examined the association between PSF and cerebral microbleeds (CMBs)., Methods: The sample comprised 199 patients with acute ischemic stroke. A psychiatrist who was blind to the subjects' radiological data administered the Chinese version of the Fatigue Severity Scale. PSF was defined as a Fatigue Severity Scale score of 4.0 or more. The locations of CMBs were evaluated with magnetic resonance imaging within 7 days of admission., Results: Of the 199 patients screened, 47 (23.6%) had PSF. The PSF group had a higher Geriatric Depression Scale score (p < 0.001) and a trend for a higher age (p = 0.074). The proportion of patients with deep CMBs was significantly higher in the PSF group (66.0 vs. 48.7%; p = 0.038). The presence of deep CMBs was a significant independent predictor of PSF with an odds ratio of 2.68 (p = 0.016)., Conclusion: The results suggest that deep CMBs are associated with a higher risk of PSF. Further studies are needed to clarify whether CMBs affect the clinical presentation, treatment response and outcome of PSF., (© 2014 S. Karger AG, Basel.)

The human AAA ATPase p97 is a molecular chaperone essential in cellular proteostasis. Single amino acid substitutions in p97 have been linked to a clinical multiple-disorder condition known as inclusion body myopathy associated with Paget's disease of the bone and frontotemporal dementia. How the mutations affect the molecular mechanism that governs the function of p97 remains unclear. Here, we show that within the hexameric ring of a mutant p97, D1 domains fail to regulate their respective nucleotide-binding states, as evidenced by the lower amount of prebound ADP, weaker ADP binding affinity, full occupancy of adenosine-5'-O-(3-thiotriphosphate) binding, and elevated overall ATPase activity, indicating a loss of communication among subunits. Defective communication between subunits is further illustrated by altered conformation in the side chain of residue Phe-360 that probes into the nucleotide-binding pocket from a neighboring subunit. Consequently, conformations of N domains in a hexameric ring of a mutant p97 become uncoordinated, thus impacting its ability to process substrate.

This study examined the frequency of violence on nurses in Chinese psychiatric hospitals and explored its risk factors and impact on nurses' quality of life (QOL). A survey was conducted with 387 frontline psychiatric nurses in China. Information about experience of workplace violence in the past 6 months, type of workplace violence, and demographic characteristics was collected by a questionnaire. Altogether 319 (82.4%) of 387 nurses reported having experienced at least one type of violent event in the past 6 months. The prevalence of sexual assault, physical and verbal harassment was 18.6%, 61.5% and 78.6%, respectively. Compared to those with no exposure to violence, nurses who were exposed to violence had lower QOL in both the physical and mental domains. Significant predictors of violence against nurses are male sex, receiving college level or higher education and working on rotating duty were independently associated with high risk of violence. Workplace violence against psychiatric nurses commonly occurs in China. Considering the deleterious effects of violence, comprehensive strategies from the perspective of nursing education and training, organizational policy, patient care and staff support are recommended to promote occupational safety in psychiatric settings in China., (Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.)

Objective: Prospective memory (PM) refers to the ability to undertake intended actions in the future. The functional significance of PM in bipolar disorder (BD) has not yet been investigated. This study examined PM impairment and its role in community living skills in clinically stable individuals with BD., Methods: Seventy-six individuals with BD and 44 healthy individuals were assessed with the Chinese version of the Cambridge Prospective Memory Test. Socio-demographic characteristics, retrospective memory (RM; the ability to recall or recognize past information), and intelligence were also measured in all participants. The clinical condition and community living skills of patients with BD were rated independently with standardized instruments., Results: Patients with BD showed PM impairment and their PM total scores independently predicted the level of community living skills in regression analyses. In follow-up analyses, the contribution was found to be accounted for by the time-based PM scores., Conclusions: Given the expanding body of research on the utility of PM in predicting functioning, these findings further support the role of PM in community living skills in individuals with BD. The results suggest that PM training might be an integral part of clinical rehabilitation devised for individuals with BD., (© 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.)

Objective: To examine the impact of anxiety on health-related quality of life (HRQOL) of stroke survivors., Design: Cross-sectional study., Setting: Acute stroke unit in a regional hospital., Participants: Patients (N=374) from an acute stroke unit., Interventions: Not applicable., Main Outcome Measures: The presence of anxiety was defined as a score of ≥8 on the anxiety subscale of the Hospital Anxiety Depression Scale. HRQOL was measured by the total score and 12 domain scores of the Stroke Specific Quality of Life (SSQOL) scale. Demographic characteristics and history of medical conditions were also recorded. Clinical characteristics were obtained using the following scales: National Institutes of Health Stroke Scale, Barthel Index, Mini-Mental State Examination, and Geriatric Depression Scale (GDS)., Results: Eighty-six (23%) stroke survivors had anxiety. The anxiety group had significantly more women (62.8% vs 35.1%), higher GDS scores (7.5±4.5 vs 3.5±3.6), and lower scores for total SSQOL (3.9±0.6 vs 4.5±0.6) and SSQOL domains of energy (2.0±1.2 vs 3.4±1.4), mood (3.6±1.5 vs 4.6±0.9), personality (3.4±1.7 vs 4.4±1.1), and thinking (2.4±1.2 vs 3.5±1.4), after adjustment for sex and GDS score. In subsequent multivariate regression analysis, the Hospital Anxiety Depression Scale anxiety score was negatively associated with the SSQOL total score (r=-.154) and 5 of the 12 domain scores, namely energy (r=-.29), mood (r=-.102), personality (r=-.195), thinking (r=-.136), and work/productivity (r=-.096)., Conclusions: Anxiety has a negative effect on HRQOL of stroke survivors, independent from depression. Interventions for anxiety should improve stroke survivors' quality of life., (Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Rationale: Cognitive impairment has been found to be reversible in people with substance abuse, particularly those using ketamine. Ketamine users are often poly-substance users. This study compared the cognitive functions of current and former ketamine users who were also abusing other psychoactive substances with those of non-users of illicit drugs as controls., Methods: One hundred ketamine poly-drug users and 100 controls were recruited. Drug users were divided into current (n = 32) and ex-users (n = 64) according to the duration of abstinence from ketamine (>30 days). The Beck Depression Inventory (BDI), the Hospital Anxiety Depression Scale (HADSA) and the Severity of Dependence Scale (SDS) were used to evaluate depression and anxiety symptoms and the severity of drug use, respectively. The cognitive test battery comprised verbal memory (Wechsler Memory Scale III: Logic Memory and Word List), visual memory (Rey-Osterrieth Complex Figure, ROCF), executive function (Stroop, Wisconsin Card Sorting Test, and Modified Verbal Fluency Test), working memory (Digit Span Backward), and general intelligence (Information, Arithmetic and Digit-Symbol Coding) tests., Results: Current users had higher BDI and HADSA scores than ex-users (p < 0.001 for BDI and p = 0.022 for HADSA) and controls (p < 0.001 for BDI and p = 0.002 for HADSA). Ex-users had higher BDI (p = 0.006) but equal HADSA scores (p = 1.000) compared to controls. Both current and ex-users had lower scores on Logical Memory delayed recall (p = 0.038 for current users and p = 0.032 for ex-users) and ROCF delayed recall (p = 0.033 for current users and p = 0.014 for ex-users) than controls. Current users also performed worse on ROCF recognition than controls (p = 0.002). No difference was found between the cognitive functions of current and ex-users., Conclusions: Ketamine poly-drug users displayed predominantly verbal and visual memory impairments, which persisted in ex-users. The interactive effect of ketamine and poly-drug use on memory needs further investigation., (© 2013 Elsevier Ltd. All rights reserved.)

The cytochrome bc1 complex (bc1) is the mid-segment of the cellular respiratory chain of mitochondria and many aerobic prokaryotic organisms; it is also part of the photosynthetic apparatus of non-oxygenic purple bacteria. The bc1 complex catalyzes the reaction of transferring electrons from the low potential substrate ubiquinol to high potential cytochrome c. Concomitantly, bc1 translocates protons across the membrane, contributing to the proton-motive force essential for a variety of cellular activities such as ATP synthesis. Structural investigations of bc1 have been exceedingly successful, yielding atomic resolution structures of bc1 from various organisms and trapped in different reaction intermediates. These structures have confirmed and unified results of decades of experiments and have contributed to our understanding of the mechanism of bc1 functions as well as its inactivation by respiratory inhibitors. This article is part of a Special Issue entitled: Respiratory complex III and related bc complexes., (Published by Elsevier B.V.)

Introduction: Prospective memory refers to the ability to remember to do something in the future. To date, little is known about prospective memory deficits in bipolar disorder (BD) in remission (euthymia). This study examined the nature and correlates of prospective memory in these patients., Methods: Forty-seven euthymic BD patients and 47 matched healthy controls formed the study sample. Socio-demographic and basic clinical characteristics, prospective memory (Cambridge Prospective Memory Test [CAMPROMPT]), retrospective memory (immediate Logical Memory subtests of the Wechsler Memory Scales-Revised [WMS-R]), IQ (Raven's Progressive Matrices) and executive functioning (Wisconsin Card Sorting Test) were measured in all participants; patients' symptoms were rated with the 17-item Hamilton Depression Rating Scale and the 11-item Young Mania Rating Scale., Results: Patients performed significantly worse on time-based prospective memory compared to controls. Multivariate analyses revealed that patients' lower score on Raven's Progressive Matrices significantly contributed to poor performance on time-based prospective memory, whereas lower scores on WMS-R Logical Memory subtest contributed to poor performance on event-based prospective memory; in controls, lower education level and older age significantly contributed to poor performance on time-based and event-based prospective memory, respectively., Discussion: Prospective memory deficits persist in remitted BD patients suggesting that prospective memory impairment constitutes a trait deficit in BD., (Copyright © 2012 Wiley Publishing Asia Pty Ltd.)

White matter hyperintensities (WMH) are common in stroke. The influence of WMH on health-related quality of life (HRQoL) following a lacunar stroke is unknown. This study evaluated the impact of WMH on HRQoL in acute lacunar stroke. A cohort of 160 patients with acute lacunar stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the index stroke, a research assistant administered the Short Form-36 (SF-36) to assess HRQoL. The severity of WMH was evaluated with magnetic resonance imaging (MRI). In univariate analysis, the severity of deep WMH (DWMH) negatively correlated with patients' vitality (VT; p < 0.05), social function (SF; p < 0.001), role-emotional (RE; p < 0.01), mental health (MH; p < 0.01), and mental component summary (MCS; p < 0.001) scores of HRQoL. DWMH was independently associated with all of the above five SF-36 scores (p < 0.05) in linear regression analysis. These findings suggest that DWMH has a significant impact on the HRQoL of stroke survivors. The importance of DWMH in the long-term HRQoL in lacunar stroke warrants further investigation.

Tracer diffusivities (limiting mutual diffusion coefficients) of nonassociated aromatic compounds in n-hexane and cyclohexane have been measured at 298.2 K by Taylor's dispersion method. These new data, together with other diffusivities of nonassociated pseudoplanar solutes reported in the literature, are used to determine the separate effects of solute and solvent on tracer diffusion. The data show that for a given pseudoplanar solute diffusing in different solvents at 298.2 K, the tracer diffusivity is dependent not only on the fractional viscosity of the solvent but also on a function of the solvent's molar density, molecular mass, and free volume fraction. For different pseudoplanar aromatic solutes diffusing in a particular solvent at a constant temperature, there is a linear relationship between the reciprocal of the tracer diffusivity and the molecular volume of the solutes. The results are discussed in respect to relevant theories and experimental studies in the literature. An idealized relation, developed on the basis of the Einstein equation by incorporating the newly found solute and solvent dependences, is capable of describing a total of 176 diffusivities of nonassociated pseudoplanar solutes in various solvents at different temperatures to within an average error of ±2.8%.

The serotonin receptor 2C (HTR2C) gene has been shown to play a pivotal role in major depression. We examined the association between post-stroke depression (PSD) and polymorphism in HTR2C. A cohort of 223 patients with acute lacunar stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the onset of the index stroke, a research assistant administered the locally validated 15-item Geriatric Depression Scale. PSD was defined as a geriatric depression scale score of 7 or above. Possible confounding factors, including previous history of stroke, severity of stroke, level of social support, and recent life events, were investigated. All patients were genotyped for polymorphisms of HTR2C. Separate analyses were performed for males and females. Sixty-one patients were found to have PSD. There were significant associations between the HTR2C gene and PSD status in the male patients, but not in the female ones. After adjusting for possible confounders, the rs12837651 T allele (odds ratio = 4.020) and the rs2192371 G allele (odds ratio = 2.866) were found to be significantly associated with PSD in males. Genetic variation in HTR2C receptors appears to be involved in the pathogenesis of PSD in Chinese males.

Aim: High serum bilirubin predicts depression in non-stroke subjects, but it is unknown whether it also predicts post-stroke depression (PSD). This study examined the association between the risk of PSD and bilirubin level., Methods: Six hundred and thirty-five patients with acute ischemic stroke in Hong Kong were recruited. Serum total bilirubin, alanine transaminase and alkaline phosphatase levels were measured in all patients during their hospital stay. A psychiatrist gave the Structured Clinical Interview for DSM-IV to all patients 3 months after the index stroke, with 61 patients diagnosed with PSD: 27 with major depression, 24 with minor depression and 10 with dysthymia., Results: In the full sample, the 25%, 50% and 75% percentile bilirubin levels were 7.0, 10.0 and 14.0 μmol/L, respectively. Significant differences were found between the PSD and non-PSD groups in terms of bilirubin level (P = 0.006). In post-hoc comparisons, the proportion of patients with bilirubin ≥14.1 μmol/L was significantly higher in the PSD group (37.7% vs 19.7%, P = 0.001). In the final regression model, bilirubin level (≥14.1 μmol/L) remained a significant independent predictor of PSD, with an odds ratio of 2.4., Conclusions: High bilirubin level is associated with PSD. Further investigations are needed to clarify the underlying pathophysiological link between bilirubin level and PSD., (© 2013 The Authors. Psychiatry and Clinical Neurosciences © 2013 Japanese Society of Psychiatry and Neurology.)

Objective: Both cognitive impairment and depressive symptoms have been reported in ketamine users. However, no previous study has examined the relationship between them. This study aimed to examine cognitive functions and depressive symptoms and their relationship in young ketamine users in Hong Kong., Method: Fifty-one current ketamine users, 49 ex-ketamine users, and 100 healthy controls were recruited from counseling and youth centers in Hong Kong in this cross-sectional study. Cognitive assessment included mental and motor speed; working, verbal, and visual memory; and executive functions. Depressive symptoms were measured using the Beck Depression Inventory. One-way analyses of covariance (ANCOVA) and chi-square tests were used to analyze participants' demographic data, patterns of drug use, Beck Depression Inventory score, and performance in a cognitive battery. Cognitive functions were adjusted for age, gender, and education using ANCOVA. Correlations between the Beck Depression Inventory score and cognitive functions were examined using Pearson's correlation coefficient., Results: Cognitive impairment was found only in current ketamine users in the domains of mental and motor speed (p < .001), visual and verbal memory (p < .001), and executive functions (p < .001). Depressive symptoms were also more frequently found in current ketamine users (p < .001). Correlations between depressive symptoms and certain cognitive scores were statistically significant but modest., Conclusions: Current ketamine use is associated with cognitive impairment. Illicit substance treatment and rehabilitation services should pay attention to ketamine's cognitive effects and motivate their clients to quit using ketamine and stay abstinent.

Objective: To evaluate the relation between poststroke pain and suicidality (SI) in Chinese patients with first or recurrent stroke., Design: Cross-sectional survey., Setting: Acute stroke unit of a university-affiliated general hospital., Participants: Patients (N=496) with acute ischemic stroke admitted to the Acute Stroke Unit., Interventions: Not applicable., Main Outcome Measures: Patients were interviewed 3 months after the index stroke. SI was assessed with the Geriatric Mental State Examination. Pain was evaluated with the Faces Pain Rating Scale-Revised (FPS-R). The association between FPS-R scores and SI was examined and adjusted for potential confounders, including marital status, depression, neurologic deficits assessed by the National Institute of Health Stroke Scale, and functioning measured by the Barthel Index., Results: Thirty-seven (7.5%) of the patients had SI (the SI group). Compared with the non-SI group, patients in the SI group were more likely to experience pain (59.5% vs 37.7%), had a higher mean FPS-R score (6.0±2.5 vs 4.5±2.3), and had an FPS-R score of >4 (43.2% vs 15.9%). After adjustment for possible confounders, the FPS-R score of >4 (odds ratio=2.9) remained a significant predictor of SI in the subsequent forward logistic regression models., Conclusions: These findings should alert clinicians that the early identification and treatment of pain may reduce suicide risk in patients with stroke., (Copyright © 2013 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Hirschsprung disease (HSCR, aganglionic megacolon) is a complex genetic disorder of the enteric nervous system (ENS) characterized by the absence of enteric neurons along a variable length of the intestine. While rare variants (RVs) in the coding sequence (CDS) of several genes involved in ENS development lead to disease, the association of common variants (CVs) with HSCR has only been reported for RET (the major HSCR gene) and NRG1. Importantly, RVs in the CDS of these two genes are also associated with the disorder. To assess independent and joint effects between the different types of RET and NRG1 variants identified in HSCR patients, we used 254 Chinese sporadic HSCR patients and 143 ethnically matched controls for whom the RET and/or NRG1 variants genotypes (rare and common) were available. Four genetic risk factors were defined and interaction effects were modeled using conditional logistic regression analyses and pair-wise Kendall correlations. Our analysis revealed a joint effect of RET CVs with RET RVs, NRG1 CVs or NRG1 RVs. To assess whether the genetic interaction translated into functional interaction, mouse neural crest cells (NCCs; enteric neuron precursors) isolated from embryonic guts were treated with NRG1 (ErbB2 ligand) or/and GDNF (Ret ligand) and monitored during the subsequent neural differentiation process. Nrg1 inhibited the Gdnf-induced neuronal differentiation and Gdnf negatively regulated Nrg1-signaling by down-regulating the expression of its receptor, ErbB2. This preliminary data suggest that the balance neurogenesis/gliogenesis is critical for ENS development.

This study aimed to investigate the association between atrophy in the prefrontal cortex with executive function and verbal fluency in elderly male and female patients poststroke. Thirty elderly female patients with non-aphasic ischemic stroke aged ≥ 60 years and 30 age-matched non-aphasic male patients with ischemic stroke were recruited. Automatic magnetic resonance imaging segmentation was used to assess the volume of the whole prefrontal cortex, along with its subdivisions: anterior cingulate cortex, orbitofrontal cortex and dorsolateral prefrontal cortex. The Semantic Verbal Fluency Test was administered at 3 and 15 months poststroke. At 3 months poststroke, left dorsolateral prefrontal cortex volume was significantly correlated with Verbal Fluency Test score in female patients only (partial coefficient = 0.453, P = 0.045), after controlling for age, education, diabetes, neurological deficit, white matter lesions volume, as well as the location and volume of infarcts. At 15 months poststroke, there remained a significant association between the left dorsolateral prefrontal cortex volume and Verbal Fluency Test (partial coefficient = 0.661, P = 0.001) and between the left prefrontal cortex volume and Verbal Fluency Test (partial coefficient = 0.573, P = 0.004) in female patients after the same adjustments. These findings indicate that atrophy of the left dorsolateral prefrontal cortex contributes to the impairment of verbal fluency in elderly female patients with stroke. Sex differences may be present in the neuropsychological mechanisms of verbal fluency impairment in patients with stroke.

Anorectal malformations (ARMs, congenital obstruction of the anal opening) are among the most common birth defects requiring surgical treatment (2-5/10 000 live-births) and carry significant chronic morbidity. ARMs present either as isolated or as part of the phenotypic spectrum of some chromosomal abnormalities or monogenic syndromes. The etiology is unknown. To assess the genetic contribution to ARMs, we investigated single-nucleotide polymorphisms and copy number variations (CNVs) at genome-wide scale. A total of 363 Han Chinese sporadic ARM patients and 4006 Han Chinese controls were included. Overall, we detected a 1.3-fold significant excess of rare CNVs in patients. Stratification of patients by presence/absence of other congenital anomalies showed that while syndromic ARM patients carried significantly longer rare duplications than controls (P = 0.049), non-syndromic patients were enriched with both rare deletions and duplications when compared with controls (P = 0.00031). Twelve chromosomal aberrations and 114 rare CNVs were observed in patients but not in 868 controls nor 11 943 healthy individuals from the Database of Genomic Variants. Importantly, these aberrations were observed in isolated ARM patients. Gene-based analysis revealed 79 genes interfered by CNVs in patients only. In particular, we identified a de novo DKK4 duplication. DKK4 is a member of the WNT signaling pathway which is involved in the development of the anorectal region. In mice, Wnt disruption results in ARMs. Our data suggest a role for rare CNVs not only in syndromic but also in isolated ARM patients and provide a list of plausible candidate genes for the disorder.

Objective: The caudate nucleus may be involved in the pathogenesis of the fatigue observed in neurological disorders. However, the significance of caudate lesions in poststroke fatigue (PSF) is unknown. This study examined the association between caudate infarcts and PSF., Methods: Five hundred Chinese patients with acute ischemic stroke admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong participated in the study. All participants were assessed for PSF with the Fatigue Severity Scale (FSS) three months after their index stroke. PSF was defined as a mean FSS score of 4.0 or more. Physical functioning and depressive symptoms were measured by the Barthel Index (BI) and the Geriatric Depression Scale (GDS)., Results: One hundred and twenty-five (25.0%) of the patients had PSF. Compared to the non-fatigue group, the PSF patients were more likely to be women and had hyperlipidemia, lower BI and higher GDS scores. Caudate (8.0% versus 1.3%, p=0.001) and putamen (19.2% versus 12.0%, p=0.043) acute infarcts were more common in the PSF group, whereas pons infarcts (13.6% versus 22.2%, p=0.038) were less common. Acute caudate infarcts remained an independent predictor of PSF in the multivariate analysis, with an odds ratio of 6.4., Conclusions: The results suggest that patients with PSF are more likely to have caudate infarcts., (Copyright © 2012 Elsevier B.V. All rights reserved.)

The pH 6 antigen (Psa) of Yersinia pestis consists of fimbriae that bind to two receptors: β1-linked galactosyl residues in glycosphingolipids and the phosphocholine group in phospholipids. Despite the ubiquitous presence of either moiety on the surface of many mammalian cells, Y. pestis appears to prefer interacting with certain types of human cells, such as macrophages and alveolar epithelial cells of the lung. The molecular mechanism of this apparent selectivity is not clear. Site-directed mutagenesis of the consensus choline-binding motif in the sequence of PsaA, the subunit of the Psa fimbrial homopolymer, identified residues that abolish galactosylceramide binding, phosphatidylcholine binding, or both. The crystal structure of PsaA in complex with both galactose and phosphocholine reveals separate receptor binding sites that share a common structural motif, thus suggesting a potential interaction between the two sites. Mutagenesis of this shared structural motif identified Tyr126, which is part of the choline-binding consensus sequence but is found in direct contact with the galactose in the structure of PsaA, important for both receptor binding. Thus, this structure depicts a fimbrial subunit that forms a polymeric adhesin with a unique arrangement of dual receptor binding sites. These findings move the field forward by providing insights into unique types of multiple receptor-ligand interactions and should steer research into the synthesis of dual receptor inhibitor molecules to slow down the rapid progression of plague.

Background. Frontal lobe atrophy (FLA) is associated with late life depression. However, the role that FLA plays in the development of depression after stroke (DAS) remains unknown. This study thus examined the association between FLA and DAS. Methods. A convenience sample of 705 Chinese patients with acute ischemic stroke admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong participated in the study. A psychiatrist administered the Structural Clinical Interview for DSM-IV to all patients and made a diagnosis of DAS three months after the index stroke. Results. Eighty-five (12.1%) patients were diagnosed with DAS. In univariate analysis, the DAS patients were more likely to have severe FLA (14.1% versus 5.6%). Severe FLA remained an independent predictor of DAS in multivariate analysis, with an odds ratio of 2.6 (95% confidence intervals = 1.2-5.9). Conclusions. The results suggest that FLA may play a role in the pathogenesis of DAS, which supports the hypothesis that cumulative vascular burden may be important in predicting DAS. Further investigations are needed to clarify the impact of FLA on the clinical presentation, treatment response, and outcome of DAS in stroke survivors.

Background: Apathy is common in stroke survivors. Unlike poststroke depression, apathy after stroke has not been extensively investigated and the significance of the location of infarcts in the development of apathy following a stroke is unknown. This study examined the association between poststroke apathy (PSA) and the location of infarcts., Methods: A cohort of 185 patients with acute ischemic stroke admitted to the Stroke Unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the index stroke, a psychiatrist administered the Apathy Evaluation Scale (AES). PSA was defined as an AES score of 37 or above. The presence and location of infarcts were evaluated with magnetic resonance imaging., Results: Altogether 185 patients met the entry criteria and formed the study sample; 20 (10.8%) had PSA. PSA patients were older and had higher stroke severity and more depressive symptoms. The PSA group also had lower levels of physical and cognitive functioning. Compared with the non-PSA group, PSA patients were more likely to have acute pontine infarcts (35.0% vs. 11.5%; p = 0.011). They had a higher mean number (0.5 ± 0.7 vs. 0.1 ± 0.3; p = 0.003) and larger volume (0.6 ± 1.4 vs. 0.1 ± 0.3 ml; p = 0.002) of acute pontine infarcts. Six variables were entered into the predictive regression model: age, the presence, number and volume of acute pontine infarcts, the number of old infarcts and periventricular white matter hyperintensities scores. The volume of infarcts remained an independent predictor of PSA in the multivariate analysis, with an odds ratio of 3.9 (p = 0.007). The Geriatric Depression Scale, National Institutes of Health Stroke Scale, Barthel Index and Mini-Mental State Examination scores were also entered into the subsequent associative regression model; the volume of acute pontine infarcts remained a significant predictor (odds ratio = 3.8)., Conclusions: This is the first report of an association between pontine infarcts and the risk of PSA. The results suggest that pontine infarcts may play a role in the development of PSA. The importance of acute pontine infarcts in the pathogenesis of PSA warrants further investigation., (Copyright © 2013 S. Karger AG, Basel.)

OBJECTIVES. Cough mixture is the third most commonly abused substance in patients attending the Prince of Wales Hospital Substance Abuse Clinic. The content of the local cough mixture is not well researched. Paranoid psychosis manifesting as persecutory delusions and derogatory hallucination, as well as mood symptoms, is common in these patients. The natural history and outcome of such psychoses associated with cough mixture abuse are not well known. This study aimed to address these questions. METHODS. This was a retrospective study of cough mixture abuse in Hong Kong. Case records of cough mixture abusers currently receiving treatment at the 3 substance abuse clinics at the Prince of Wales Hospital, Alice Ho Miu Ling Nethersole Hospital, and the North District Hospital were retrieved for data collection. The patients' demographic data, duration and intake pattern of cough mixture, and use of any other drugs were documented. The presenting psychopathology, first urine toxicology results, diagnosis, treatment, number of hospitalizations, and course of the illness were also recorded. RESULTS. A total of 63 patients with the diagnosis of cough mixture abuse were identified in the database; 89% were male. The mean +/- SD age of the patients was 34.4 +/- 6.2 years; 67% were single and 83% were unemployed. The mean +/- SD age of onset of cough mixture abuse was 20 +/- 5 years. Psychiatric symptoms developed a mean +/- SD of 7.6 +/- 6.0 years after onset of abuse. According to the ICD-10 Mental and Behavioural Disorders criteria, the top psychiatric diagnoses were substance-induced psychotic disorder (67%), schizophrenia (19%), depressive disorder (11%), and dysthymia (10%). The most common ingredients in the urine sample at first presentation were promethazine (75%), pseudoephedrine (67%), codeine (60%), ephedrine (57%), zopiclone (17%), and hydrocodone (16%). Additionally, 16% of patients were in the priority follow-up group. The mean +/- SD follow-up period was 6.2 +/- 7.1 years during which there were 3.2 +/- 3.7 episodes of hospitalizations, with a mean +/- SD length of stay in each admission of 25.0 +/- 40.9 days. CONCLUSIONS. Promethazine, ephedrine, pseudoephedrine, codeine, and hydrocodone are the most common ingredients of cough mixture abused in this locality. Psychotic disorders are the most frequent psychiatric diagnosis associated with cough mixture abuse.

Objectives: We investigated factors associated with morbidity and pediatric intensive care unit (PICU) admission in children with respiratory syncytial virus (RSV) infection and explored seasonality and implication of prophylaxis., Methods: A retrospective study between 2006 and 2008 of every child with a laboratory-confirmed RSV infection was included., Results: Six hundred seventy RSV admissions were identified. Ten (1.5%) required PICU admissions. Children admitted to PICU were younger than non-PICU admissions (median [interquartile range] age, 0.3 [0.11-0.48] vs 1.18 [0.46-2.49] years; P = .001). Odds associated with PICU admissions included history of chronic lung disease (odds ratio [95% confidence interval], 18.08 [2.29-114.95]; P = .010), history of acyanotic heart disease (7.61 [1.04-42.59], P = .043), and neurodevelopmental conditions (mental retardation, cerebral palsy, or neuromuscular disease; 8.41 [1.63-38.57], P = .012). Odds of bacterial coinfections was 13.50 (1.77-81.29), P = .017. There appeared no significant PICU predilection in terms of sex, history of prematurity, cyanotic heart disease, seizure disorders, chromosomal disorders, or malignancy. Admissions associated with proven RSV infections accounted for 2.4% of PICU annual admissions. The duration of PICU stay was generally brief (median, 3 days). However, median length of hospital stay was significantly longer in the PICU category (8.5 vs 3 days, P < .001). There was no death in the study period. Only 5 (0.75%) of 665 patients were readmitted to the pediatric infectious disease isolation ward in consecutive years, and none required PICU support. Twenty (3%) of admissions involved neonates younger than 30 days. There was no definite seasonality, but incidence was lowest between October and January., Conclusions: Most infants have mild disease and do not require PICU support. Young infants with history of chronic lung disease, congenital heart disease, and neurodevelopmental conditions appear to be at significantly increased risk for PICU support. There is no winter seasonality for RSV disease in Hong Kong. Therefore, any prophylaxis for at-risk population should provide adequate coverage for the warmer months in subtropical regions., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Background: Although patients harboring confluent white matter hyperintensities (WMH) are at high risk of cognitive decline, this risk varies among individuals. We investigated the predictors for cognitive decline in stroke patients with confluent WMH., Methods: We followed up 100 stroke patients with confluent WMH who were participants of the VITAmins TO Prevent Stroke study for 2 years. We investigated the association between clinical features, apolipoprotein E status, imaging measures (infarcts, microbleeds, volumes of WMH, cortical gray matter [cGM], lateral ventricles, and hippocampi), and B vitamins with changes in cognitive measures (clinical dementia rating scale, Mini-Mental State Examination, Mattis dementia rating scale--initiation/perseveration subscale). We performed Pittsburgh compound B imaging among dementia converters., Results: Multivariate regression analysis showed that increase in clinical dementia rating scale grade was associated with cGM atrophy, absence of hyperlipidemia, and lower diastolic blood pressure at baseline. cGM atrophy and absence of hyperlipidemia were also associated with deterioration in Mini-Mental State Examination and Mattis dementia rating scale--initiation/perseveration subscale scores. Pittsburgh compound B retention typical of Alzheimer's disease was found only in 10% of dementia converters. Incident stroke and B vitamins were not associated with cognitive decline., Conclusions: Among stroke patients with confluent WMH, cGM atrophy and absence of hyperlipidemia are important predictors for cognitive decline. Significant cognitive decline can occur in the absence of incident stroke or Alzheimer's pathology., (Copyright © 2012 The Alzheimer's Association. Published by Elsevier Inc. All rights reserved.)

Mesothelin is a tumor differentiation antigen that is highly expressed in many epithelial cancers, with limited expression in normal human tissues. Binding of mesothelin on normal mesothelial cells lining the pleura or peritoneum to the tumor-associated cancer antigen 125 (CA-125) can lead to heterotypic cell adhesion and tumor metastasis within the pleural and peritoneal cavities. This binding can be prevented by MORAb-009, a humanized monoclonal antibody against mesothelin currently under clinical trials. We show here that MORAb-009 recognizes a non-linear epitope that is contained in the first 64-residue fragment of the mesothelin. We further demonstrate that the recognition is independent of glycosylation state of the protein but sensitive to the loss of a disulfide bond linking residues Cys-7 and Cys-31. The crystal structure of the complex between the mesothelin N-terminal fragment and Fab of MORAb-009 at 2.6 Å resolution reveals an epitope encompassing multiple secondary structural elements of the mesothelin, including residues from helix α1, the loops linking helices α1 and α2, and between helices α4 and α5. The mesothelin fragment has a compact, right-handed superhelix structure consisting of five short helices and connecting loops. A residue essential for complex formation has been identified as Phe-22, which projects its side chain into a hydrophobic niche formed on the antibody recognition surface upon antigen-antibody contact. The overlapping binding footprints of both the monoclonal antibody and the cancer antigen CA-125 explains the therapeutic effect and provides a basis for further antibody improvement.

Objective: Cerebral microbleeds (CMBs) are common in stroke survivors. The clinical significance of CMBs in the development of suicidality (SI) following stroke is unknown. This study examined the association between SI and CMBs. The aim of the study reported here was to determine the relationship between CMBs and SI in ischemic stroke survivors., Methods: A cohort of 367 patients with acute ischemic stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. SI was assessed with the geriatric mental state examination at three months following the subjects' index stroke. Depressive symptoms were assessed using the geriatric depression scale (GDS). A qualified psychiatrist administered the Chinese version of the Structured Clinical Interview for DSM-IV to diagnose depressive disorders. The presence and location of CMBs were evaluated with magnetic resonance imaging (MRI)., Results: Compared with the non-SI patients, SI patients were more likely to have CMBs in any brain region (36.6% vs. 20.2%, p = 0.017), specifically more lobar (29.3% vs. 13.5%, p = 0.008) and thalamic CMBs (19.5% vs. 7.5%, p = 0.018). Presence of CMBs (odds ratio was 2.5, p = 0.026) and lobar CMBs (odds ratio 2.6, p = 0.034) were independent predictors of SI in the multivariate analysis., Conclusions: The results suggest that lobar CMBs may play roles in the development of SI. The importance of CMBs in the pathogenesis of SI in stroke survivors warrants further investigation., (Copyright © 2012 The Academy of Psychosomatic Medicine. All rights reserved.)

The mesothelin-specific monoclonal antibody MORAb-009 is capable of blocking the binding of mesothelin to CA-125 and displays promising anticancer potential. It is currently undergoing clinical trials. In order to understand the basis of the interaction between MORAb-009 and mesothelin at atomic resolution, both the Fab fragment of MORAb-009 and the complex between the Fab and an N-terminal fragment of mesothelin (residues 7-64) were crystallized. The crystals of the Fab diffracted X-rays to 1.75 Å resolution and had the symmetry of space group P4(1)2(1)2, with unit-cell parameters a = b = 140.6, c = 282.0 Å. The crystals of the mesothelin-Fab complex diffracted to 2.6 Å resolution and belonged to the hexagonal space group P6(4), with unit-cell parameters a = b = 146.2, c = 80.9 Å. Structural analyses of these molecules are in progress.

Missense mutations that occur at the interface between two functional domains in the AAA protein p97 lead to suboptimal performance in its enzymatic activity and impaired intracellular functions, causing human disorders such as inclusion body myopathy associated with Paget's disease of the bone and frontotemporal dementia (IBMPFD). Much progress has been made in characterizing these mutants at cellular, sub-cellular and molecular levels, gaining a substantial understanding of the involvement of p97 in various cellular pathways. At the tissue level, patient biopsies revealed co-localization of p97 with pathologic proteineous inclusions and rimmed vacuoles, which can be reproduced in various cellular and animal models of IBMPFD. At the subcellular level, alterations in p97's ability to bind various adaptor proteins have been demonstrated for some but not all binding partners. Biochemical and biophysical characterizations of pathogenic p97 revealed altered nucleotide binding properties in the D1-domains compared to the wild type. Structural studies showed that mutant p97 are capable of undergoing a uniform transition in the N-domain from a Down- to an Up-conformation in the presence of ATPγS, while in the wild-type p97, this conformational change can only be demonstrated in solutions but not in crystals. These structural and biochemical analyses of IBMPFD mutants shed new light into the mechanism of p97 function., (Published by Elsevier Inc.)

Purpose: The aim of this study was to compare the frequency of anxiety symptoms between patients with frontal lobe epilepsy (FLE) and generalized epilepsy (GE)., Methods: Forty and 78 patients with FLE and GE respectively were enrolled in the study. Anxiety symptoms were measured with the Hamilton anxiety rating scale (HARS) and the anxiety subscale of the hospital anxiety and depression scale (HADSA)., Results: Compared to the GE group, the FLE group had significantly higher HARS (10.9±8.7 vs. 7.9±6.8, p=0.039) scores. Significant correlations were also found between anxiety symptoms and epilepsy-related variables, particularly with the seizure frequency and the number of currently taken anti-epileptic drugs., Conclusion: Anxiety symptoms are more common in patients with FLE in comparison to those with GE. Further studies are warranted to clarify the relationship between anxiety symptoms and FLE., (Copyright © 2012 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.)

The aim of this cross-sectional study was to determine the socio-demographic and clinical factors associated with depressive symptoms in the family caregivers of Hong Kong Chinese stroke patients. One hundred and twenty-three patients at a stroke clinic and their family caregivers formed the study sample. The depressive symptoms of both the patients and their family caregivers were rated with the Chinese version of the 15-item Geriatric Depression Scale (GDS). Participants' socio-demographic data and clinical characteristics served as the independent variables in relation to the caregivers' GDS scores. Patients' and caregivers' somatic and psychological conditions were measured with 10 scales. In univariate analysis, caregivers' GDS scores were significantly correlated with certain of their characteristics [Modified Life Event Scale (MLES), Cumulative Illness Rating Scale (CIRS) and Lubben Social Network Scale (LSNS) scores, sex and being a housewife] and those of the patients (GDS score and being a housewife). Multiple regression analysis showed caregivers' MLES and CIRS scores and patients' GDS scores to be independent correlates of caregivers' GDS scores. Adverse events encountered by caregivers in the past 6 months, their current health problems and patients' depressive symptoms were found to be the principal factors associated with caregivers' depressive symptoms., (© 2011 Blackwell Publishing.)

Background and Purpose: This study examined the association between poststroke anxiety symptoms (PSA) and frontal lobe infarcts., Methods: A cohort of 693 patients was recruited. PSA was defined as an anxiety subscale of the Hospital Anxiety and Depression Scale score of 8 or above. The presence and location of infarcts were evaluated with MRI., Results: Compared with the non-PSA group, PSA patients were more likely to have right frontal acute infarcts. Right frontal infarcts remained independent predictors of PSA in the multivariate analysis, with an odds ratio of 4.44 (P=0.002)., Conclusions: The results suggest that right frontal acute infarcts may play a role in the development of PSA.

Hirschsprung disease (HSCR, congenital colon aganglionosis) is a relatively common complex genetic condition caused by abnormal development of the enteric nervous system (ENS). Through a recent genome-wide association study conducted on Chinese HSCR patients, we identified a new HSCR contributing locus, neuregulin 1 (NRG1; 8p12), a gene known to be involved in the development of the ENS. As genes in which disease-associated common variants are found are to be considered as candidates for the search of deleterious rare variants (RVs) in the coding sequences, we sequenced the NRG1 exons of 358 sporadic HSCR patients and 333 controls. We identified a total of 13 different heterozygous RVs including 8 non-synonymous (A28G, E134K, V266L, H347Y, P356L, V486M, A511T, P608A) and 3 synonymous amino acid substitutions (P24P, T169T, L483L), a frameshift (E239fsX10), and a c.503-4insT insertion. Functional analysis of the most conserved non-synonymous substitutions, H347Y and P356L, showed uneven intracellular distribution and aberrant expression of the mutant proteins. Except for T169T and V486M, all variants were exclusive to HSCR patients. Overall, there was a statistically significant over-representation of NRG1 RVs in HSCR patients (p = 0.008). We show here that not only common, but also rare variants of the NRG1 gene contribute to HSCR. This strengthens the role of NRG1.

Background: Cerebral microbleeds may contribute to cognitive deficits in stroke. Cognitive impairment that does not meet the criteria for dementia (cognitive impairment no dementia) is common in stroke, and patients with such impairment can revert to normal cognition., Aims and Hypothesis: This study examined the association between cerebral microbleeds and the reversion of cognitive impairment no dementia., Method: A total of 328 Chinese patients with acute ischemic stroke admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong participated in the study. All subjects were assessed for cognitive impairment no dementia with a neuropsychological test battery at three- and 15 months following the index stroke. Of the 180 patients with cognitive impairment no dementia at three-months poststroke, 143 (79 · 4%) attended the 15-month follow-up. Twenty-nine subjects had reverted from cognitive impairment no dementia to normal cognitive status (reverters), 98 were nonreverters and 16 had progressed to dementia., Results: In univariate analysis, the reverters were found to be younger, less likely to have hypertension and cerebral microbleeds, and to have smaller white matter hyperintensity volumes. In multivariate analysis, the absence of cerebral microbleeds remained an independent predictor of reversion with an odds ratio of 4.3. Absence of deep cerebral microbleeds predicted the reversion of the language domain, whereas the absence of lobar cerebral microbleeds predicted the reversion of the visuomotor speed domain., Conclusions: The results suggest that the absence of cerebral microbleeds may be associated with a higher likelihood of a reversible cognitive impairment in stroke patients. The mechanism of how this occurs is not well understood., (© 2011 The Authors. International Journal of Stroke © 2011 World Stroke Organization.)

Objective: To evaluate the relationship between insomnia and suicidality (SI) in Chinese patients with first or recurrent stroke., Design: Cross-sectional survey., Setting: Acute stroke unit of a general hospital., Participants: Patients (N=787) with acute ischemic stroke admitted to the acute stroke unit of a university-affiliated regional hospital in Hong Kong., Interventions: Not applicable., Main Outcome Measures: Suicidality (SI) was assessed with the Geriatric Mental State Examination at 3 months after subjects' index stroke. Insomnia symptoms were evaluated with a standard insomnia questionnaire. The association between insomnia symptoms and SI was examined and adjusted for potential confounders, including age, sex, marital status, previous stroke, depression, fatigue, Mini-Mental State Examination score, and neurologic deficits measured with the National Institutes of Health Stroke Scale., Results: Eighty-seven patients (11.1%) were found to have SI (SI group). Frequent awakening was significantly more common in the SI group than in the non-SI group and remained a significant predictor of SI in forward logistic regression analysis (odds ratio, 1.7) after adjusting for possible confounders., Conclusions: These findings should alert clinicians to the potential danger of insomnia and the importance of its early identification and treatment in stroke patients., (Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

This study aimed to assess insight in Chinese schizophrenia patients and to identify its relationship with socio-demographic and clinical factors, executive functions and quality of life (QOL). A cohort of 139 clinically stable schizophrenia patients was selected by consecutively screening patients diagnosed with schizophrenia who were attending the outpatient department of a university-affiliated psychiatric hospital in China. Participants' socio-demographic and clinical characteristics, including psychotic symptoms, depression and insight, as well as QOL and executive functions, were periodically assessed with standardized rating instruments. Patients received standard psychiatric care and were followed up for 1 year. Impaired insight was found to be common in stable Chinese schizophrenia patients (76.3%), with merely 5% showing improvement over the 1-year follow-up. Insight was inversely correlated with positive and negative symptoms at all but the 12-month assessment and with both the physical and mental components of QOL at baseline and the 12-month assessment. Insight was not associated with depressive symptoms or executive functions. Standard psychiatric care does not improve the level of insight in clinically stable Chinese schizophrenia outpatients, which warrants the introduction of specific therapeutic interventions that enhance insight., (© 2011 Blackwell Publishing.)

Objective: Many lacunar stroke patients complained of cognitive decline after stroke. This study aims to investigate the factors underlying post-stroke cognitive complaints in these patients., Methods: Seventy-five consecutive lacunar stroke patients without major depression were recruited for the study. Stroke severity was measured using NIHSS score and MRI was performed during the acute admission period. At 3 months, objective psychometric performance and depressive symptoms were assessed. Post-stroke cognitive complaints were corroborated by a proxy. Using logistic regression we examined the contribution of demographic features, stroke severity, objective psychometric scores, depressive symptoms, and imaging features (white matter lesion volume and infarct measures) to post-stroke cognitive complaints., Results: Thirty-two (42.7%) patients had post-stroke cognitive complaints. Patients with post-stroke cognitive complaints had more depressive symptoms and worse psychometric performance than those without. In the multivariate logistic regression model, only the severity of depressive symptoms was independently associated with post-stroke cognitive complaints., Conclusions: This study suggests that post-stroke cognitive complaints are frequent among lacunar stroke patients without major depression and are prominently determined by the subclinical depressive symptomatology., (Copyright © 2010 John Wiley & Sons, Ltd.)

Objective: To assess the effect of poststroke emotional incontinence (PSEI) on health-related quality of life (HRQOL)., Design: Cross-sectional observational study., Setting: Psychiatric clinic., Participants: Stroke survivors (N=385; consecutive series) discharged from the acute stroke unit between December 2004 and June 2007., Interventions: Not applicable., Main Outcome Measures: Chinese (Hong Kong) version of the 36-Item Short Form Health Survey (SF-36) for HRQOL., Results: Fifty-eight (15.1%) patients had PSEI. After adjustment for possible demographic and clinical confounders, subjects with PSEI had significantly lower physical and mental summary scores, particularly in the General and Mental Health, Social Function, and Role-Emotional subscales of the SF-36., Conclusion: PSEI has an independent effect on HRQOL. Longitudinal studies of stroke are warranted to confirm and extend this finding., (Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)

Objective: Silicosis is the most common type of pneumoconiosis in Hong Kong. This study explored the clinical correlates of the caregiving burden and quality of life (QOL) among pneumoconiosis caregivers in Hong Kong., Methods: The study sample included 112 patients with pneumoconiosis and their caregivers. Caregiving burden was measured using the Caregiving Burden Scale (CBS), and caregivers' QOL was assessed using the physical and mental components (PCS and MCS, respectively) of the Medical Outcomes Short Form-36. Pearson's correlation coefficient and Spearman's ρ were calculated to examine the relationship between CBS, PCS, and MCS scores and caregivers' and patients' sociodemographic variables. Stepwise regression analyses were performed to determine the independent correlates of CBS, PCS, and MCS scores., Results: Caregiving burden was correlated with certain patient characteristics (duration of disease, severity of dyspnea, exercise tolerance, depressive symptoms, daily functioning, and community living skills) and with caregivers' variables (depressive symptoms and availability of family support). Regression analysis showed that patients' daily functioning (β = -.345), caregivers' depressive symptoms (β = .509), and the availability of family support (β = .240) were independent correlates of caregiving burden, explaining 45% of the variance. The independent correlates of PCS included patients' severity of coexisting diseases (β = -.179) and caregivers' depressive symptoms (β = -.521). Both patients' (β = -.155) and caregivers' (β = -.633) depressive symptoms and patients' severity of dyspnea (β = -.183) were independent correlates of the MCS., Conclusion: Caring for pneumoconiosis patients entails a significant caregiving burden for caregivers, and adversely affects their QOL. Caregivers' depressive symptoms are related to both their caregiving burden and QOL., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background and Purpose: Cerebral microbleeds (CMB) are common in stroke survivors and the community-dwelling elderly. The clinical significance of CMB in the development of depression after a stroke is unknown. This study examined the association between poststroke depression (PSD) and CMB., Methods: A cohort of 235 patients with acute lacunar stroke admitted to the stroke unit of a university-affiliated regional hospital in Hong Kong was recruited. Three months after the onset of the index stroke, a research assistant administered the locally validated 15-item Geriatric Depression Scale. PSD was defined as a Genetic Depression Scale score of ≥7. The presence and location of CMB were evaluated with MRI., Results: In comparison with the non-PSD group, PSD patients were more likely to have lobar CMB (33.3% versus 19.9%; P=0.022). Lobar CMB remained an independent predictor of PSD in the multivariate analysis, with an odds ratio of 2.08 (P=0.032)., Conclusions: The results suggest that lobar CMB may play a role in the development of PSD. The importance of CMB in the pathogenesis of depression in stroke survivors and the general elderly population warrants further investigation.

Objective: To ascertain the clinical and sociodemographic factors associated with family caregivers' burden in Chinese patients with stroke in Hong Kong., Design: Cross-sectional design., Setting: Stroke Clinic., Participants: Patients (N=123) from a stroke clinic and their family caregivers., Interventions: Not applicable., Main Outcome Measures: Predictive factors of family caregivers' burden in Chinese stroke patients in Hong Kong. Caregivers' burden was assessed with the Caregiving Burden Scale (CBS). Patients' and caregivers' sociodemographic data and clinical characteristics were recorded. Physical and psychological conditions were measured and rated with the following instruments: Cumulative Illness Rating Scale, Geriatric Depression Scale (GDS), Barthel Index, Instrumental Activities of Daily Living, Mini-Mental State Examination, Lubben Social Network Scale, Modified Life Event Scale (MLES), Hospital Anxiety and Depression Scale (HADS), and a single question about fatigue., Results: In the univariate analysis, the CBS score had significant correlations with certain characteristics of caregivers (sex, GDS, HADS, depressive symptoms, fatigue, and MLES) and those of patients' (sex, age, education, GDS). Regression analysis revealed that caregivers' GDS and patients' education were the independent correlates of the CBS., Conclusions: The severity of depressive symptoms in Chinese stroke caregivers and patients' education are independent factors associated with the caregivers' burden. Further studies evaluating interventions on caregivers' burden should include the assessment and management of mood disorders., (Copyright © 2011 American Congress of Rehabilitation Medicine. Published by Elsevier Inc. All rights reserved.)