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Weikun Tang,1 Junpeng Fan,1 Yide He,1 Bihai Huang,2 Huihui Liu,1 Daiwen Pang,2 Zhixiong Xie11College of Life Sciences, 2College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, People's Republic of ChinaAbstract: Quantum dots (QDs) have many potential clinical and biological applications because of their advantages over traditional fluorescent dyes. However, the genotoxicity potential of QDs still remains unclear. In this paper, a plasmid-based system was designed to explore the genotoxic mechanism of QDs by detecting changes in DNA configuration and biological activities. The direct chemicobiological interactions between DNA and mercaptoacetic acid-coated CdSe-core QDs (MAA–QDs) were investigated. After incubation with different concentrations of MAA–QDs (0.043, 0.13, 0.4, 1.2, and 3.6 µmol/L) in the dark, the DNA conversion of the covalently closed circular (CCC) DNA to the open circular (OC) DNA was significantly enhanced (from 13.9% ± 2.2% to 59.9% ± 12.8%) while the residual transformation activity of plasmid DNA was greatly decreased (from 80.7% ± 12.8% to 13.6% ± 0.8%), which indicated that the damages to the DNA structure and biological activities induced by MAA–QDs were concentration-dependent. The electrospray ionization mass spectrometry data suggested that the observed genotoxicity might be correlated with the cadmium–mercaptoacetic acid complex (Cd–MAA) that is formed in the solution of MAA–QDs. Circular dichroism spectroscopy and transformation assay results indicated that the Cd–MAA complex might interact with DNA through the groove-binding mode and prefer binding to DNA fragments with high adenine and thymine content. Furthermore, the plasmid transformation assay could be used as an effective method to evaluate the genotoxicities of nanoparticles.Keywords: genotoxicity, MAA CdSe quantum dots, cadmium–MAA complex, transformation assay, DNA&nbsp

Aims To date there have been no studies investigating prescription patterns of benzodiazepine agents (BZDs) in Chinese outpatients with schizophrenia. This study examined the frequency and socio-demographic and clinical correlates of BZD prescription in Hong Kong (HK) and Beijing (BJ), China. Methods Five hundred and five clinically stable outpatients with schizophrenia were randomly selected and interviewed in HK and BJ using standardized assessment instruments. Basic socio-demographic and clinical data and psychotropic drug prescriptions were collected at the time of a diagnostic interview. Results One-hundred and fifty one (29.9%) patients were prescribed BZDs in the whole sample; 25.1% and 34.8% of the HK and BJ samples, respectively. Use of BZDs was associated with sex, employment status, history of suicide, less use of clozapine, more frequent use of typical antipsychotics (APs), higher doses of APs, severity of positive symptoms, extrapyramidal side effects (EPS) and insomnia. In multiple logistic regression analysis, severity of depressive symptoms, study site, sex, employment status, less use of clozapine and history of suicide remained significantly associated with BZDs. Conclusion Although the ethnic and clinical characteristics of the two samples were nearly identical, there was a wide variation in the frequency of BZD prescriptions between HK and BJ suggesting that socio-cultural and economic factors as well as traditions of psychiatric training and practice all played a role in determining the use of BZDs. Prescription of BZDs in either site was not in line with current recommendation.

Most prescription pattern surveys have found a high rate of antipsychotic polypharmacy. To date few studies have investigated antipsychotic polypharmacy in Chinese patients with schizophrenia in general and outpatients in particular. This study examined the frequency and sociodemographic and clinical correlates of antipsychotic polypharmacy in Hong Kong (HK) and Beijing (BJ), China. Three hundred and ninety-eight clinically stable outpatients with schizophrenia were randomly selected and interviewed in HK and BJ using standardized assessment instruments. Antipsychotic polypharmacy was found in 17.6% ( N=70) of the whole sample and in 28% and 7.1% of the HK and BJ samples, respectively. Polypharmacy was associated with monthly income, severity of negative symptoms and extrapyramidal side effects (EPS), use of depot antipsychotic and anticholinergic drugs, doses of antipsychotics, and the number of hospitalizations. In multiple logistic regression analysis, younger age, number of hospitalizations, site (HK vs. BJ), and the use of depot antipsychotics were all significantly associated with antipsychotic polypharmacy. Although the ethnic and clinical characteristics of the two cohorts were nearly identical, there was a wide variation in the prescription frequency of antipsychotic polypharmacy between HK and BJ, suggesting that sociocultural and economical factors and traditions of psychiatric practice all played a role in determining antipsychotic polypharmacy. Clinicians should bear in mind that, at least for clinically stable patients, no scientifically sound therapeutic principles for antipsychotic polypharmacy exist.

Background: There are few data on the psychiatric morbidity of postnatal women in Hong Kong, and even fewer data on their clinical outcome. This study targets these issues. Methods: A prospective design was used. Women were screened by Edinburgh Postnatal Depression Scale (EPDS, with 9/10 as cut-off), and 12-item General Health Questionnaire (GHQ-12, with 4/5 as cut-off) within 4-6 weeks following delivery over a 20-month period. Those suspected for a psychiatric disorder were contacted by telephone and were offered a referral to a postnatal depression disorder (PND) clinic. Women were re-evaluated with EPDS, GHQ-12, and Beck Depression Inventory (BDI, with 10/11 cut-off) at the clinic. Psychiatric diagnoses, treatments and outcome were evaluated at 6-month and 12-month after the women’s first attendance. Results: Altogether 7,833 questionnaires were sent out and 6,212 were mailed back. Scores were above the cutoff for 2,107 women. Only 120 women reported persistent symptoms but only 96 attended the PND clinic. The most common diagnose was mood disorders (56.3%). No postpartum psychosis was found. Only 11.1% of women with MDD recovered one year after delivery. Conclusion: Depression is the main psychiatric morbidity in Hong Kong postnatal women. Compliance of referral and treatment and treatment outcome of PND are poor, suggesting extrending psychoeducation for patients and relatives and developing a comprehensive treatment model would be essential in improving postnatal psychiatric care.

Background To date, no study has investigated the use of depot antipsychotic medication (DA) in Chinese outpatients with schizophrenia. This study explored the frequency and sociodemographic and clinical correlates of DA in schizophrenia outpatients in both Hong Kong (HK) and Beijing (BJ), China. Methods 505 clinically stable outpatients with schizophrenia were randomly selected and interviewed in HK and BJ using standardized assessment instruments. Their basic sociodemographic and clinical data and psychotropic drug prescriptions were collected at the time of a diagnostic interview. Results 117 (23.2%) patients were prescribed DA, 36.1 and 10% of the HK and BJ samples, respectively. Prescription of DA was associated with a history of suicide, less use of clozapine, more frequent antipsychotic polypharmacy (APP), more frequent admissions, and study site (HK vs. BJ). In multiple logistic regression analysis, study site, less frequent prescription of clozapine, history of suicide, and more frequent use of APP remained significantly associated with DA. Conclusion There was wide variation in the frequency of DA prescribing between HK and BJ even though the ethnic and clinical characteristics of the two samples were nearly identical. This suggests that sociocultural and economic factors, as well as traditions in psychiatric training and practice all played a role in determining the use of DA.