Chaperonin-catalyzed rescue of kinetically trapped states in protein folding.

GroEL and GroES form a chaperonin nano-cage for single protein molecules to fold in isolation. The folding properties that render a protein chaperonin dependent are not yet understood. Here, we address this question using a double mutant of the maltose-binding protein DM-MBP as a substrate. Upon spontaneous refolding, DM-MBP populates a kinetically trapped intermediate that is collapsed but structurally disordered. Introducing two long-range disulfide bonds into DM-MBP reduces the entropic folding barrier of this intermediate and strongly accelerates native state formation. Strikingly, steric confinement of the protein in the chaperonin cage mimics the kinetic effect of constraining disulfides on folding, in a manner mediated by negative charge clusters in the cage wall. These findings suggest that chaperonin dependence correlates with the tendency of proteins to populate entropically stabilized folding intermediates. The capacity to rescue proteins from such folding traps may explain the uniquely essential role of chaperonin cages within the cellular chaperone network.

Nd:YVO4/YVO4 cascaded Raman laser pumped dual-wavelength signal wave MgO:PPLN-OPO with wide range adjustable wavelength interval.

This article presents a dual-wavelength signal wave output system capable of generating a broad range of adjustable wavelength intervals. The setup involved the creation of a dual-wavelength cascaded Raman laser featuring composite cavities operating at 1176 nm and 1313 nm. Experimental investigations were carried out on an external cavity MgO:PPLN-OPO driven by the cascaded Raman laser. By setting the crystal polarization period to 27.6-34.4 µm and the temperature to 50-130°C, adjustable tunable output of dual-wavelength signal wave at 1176 nm-MgO:PPLN-OPO (1550-2294 nm) and 1313 nm-MgO:PPLN-OPO (1768-2189 nm) was achieved with a wavelength interval of 0-218 nm. Under the conditions of a period of 34.4 µm, temperature of 90°C, and an incident Raman power of 2.6 W, the highest conversion efficiency of Raman to dual-wavelength signal wave (2212, 2182 nm) was 34.2%. Furthermore, the maximum output power of dual-wavelength signal wave was recorded at 1.02 W with an incident Raman power of 3.33 W.

Identification of distinct blood-based biomarkers in early stage of Parkinson's disease.

Parkinson's disease (PD) is a slowly progressive geriatric disease, which can be one of the leading causes of serious socioeconomic burden in the aging society. Clinical trials suggest that prompt treatment of early-stage Parkinson's disease (EPD) may slow down the disease progress and have a better response. Therefore, conducting proteomics study to identify biomarkers for the diagnosis and disease-modifying therapies of EPD is vital. We aimed at identifying distinct protein autoantibody biomarkers of EPD by using the database of GSE62283 based on the platform GPL13669 downloaded from Gene Expression Omnibus database. Differentially expressed proteins (DEPs) between the EPD group (n = 103) and the normal control (NC) group (n = 111) were identified by protein-specific t test. Cluster analysis of DEPs was conducted by protein-protein interaction network to detect hub proteins. The hub proteins were then evaluated to determine the distinct biomarkers by principal component analysis, as well as functional and pathway enrichment analysis. Their biological functions were confirmed by gene ontology functional (GO) and Kyoto encyclopedia of genes and genomes pathway enrichment (KEGG). Two biomarkers, mitochondrial ribosome recycling factor (MRRF) and ribosomal protein S18 (RPS18), distinguished the EPD samples from the NC samples, and they were regarded as high-confidence distinct protein autoantibody biomarkers of EPD. The most significant GO function was protein serine/threonine kinase activity (GO: 0004674) and most of DEPs were enriched in ATP binding in molecular function category (GO: 0005524). These results may help in establishing the prompt and accurate diagnosis of EPD and may also contribute to develop mechanism-based treatments.

IL-18 induced IL-23/IL-17 expression impairs Aß clearance in cultured THP-1 and BV2 cells.

Recent studies have provided overwhelming evidence of the involvement of microglia-related molecular networks in the pathogenesis of Alzheimer's diseases (AD). The potential involvement of pro-inflammatory cytokines interleukin (IL)-18, IL-23 and IL-17 on amyloid (Aß) clearance is still unclear. In this study, we addressed that there might be a net relationship among IL-18, IL-23, and IL-17 and they can affect Aß clearance in cultured macrophage/microglia cells. In human macrophage cell line THP-1, Aß42 incubation could increase the expression of IL-18, IL-23 and IL-17 in a concentration dependent manner. THP-1 cell could clear Aß42 in the culture medium time-dependently, but its capacity of Aß clearance was impaired by IL-18, IL-23 or IL-17 treatment. Similarly, the capacity of the microglia cell line BV2 to clear Aß42 was impaired by IL-18, IL-23 or IL-17 treatment. In co-cultures of BV2 with APP/PS1 neuron, Aß was efficiently cleared by BV2 cell, but Aß clearance was impaired by IL-18, IL-23 or IL-17 treatment. The effects of IL-18, IL-23 and IL-17 could be blocked by their corresponding neutralizing antibodies. In addition, the inhibitory effects of IL-18 were blocked by IL-23 or IL-17 neutralizing antibodies while the inhibitory effects of IL-23 were blocked by IL-17 neutralizing antibodies. Our study provides evidences showing that amyloid induced IL-18/IL-23/IL-17 axis could impair macrophage and microglia-mediated Aß clearance. Thus, IL-18/IL-23/IL-17 axis might be a therapeutic target in AD.

Evolution of the Raman beam quality in a folded-coupled-cavity Nd:YVO4/YVO4 Raman laser.

An end-pumped actively $Q$Q-switched ${\rm Nd}\!:\!{{\rm YVO}_4}/{{\rm YVO}_4}$Nd:YVO4/YVO4 Raman laser with a folded coupled cavity is demonstrated to study the evolution of Raman beam quality. The theoretical mechanism of the beam cleanup effect of stimulated Raman scattering is analyzed. The beam quality ($M^2$M2) of the Raman beam and the fundamental beams before and after the Raman conversion are measured experimentally. The results show that with the incident pump power increasing, the ${M^2}$M2 of the fundamental beam increases from 1.85 to 3.08, while the ${M^2}$M2 of the Raman beam increases from 1.21 to 1.69. The beam quality of the Raman laser and its degradation are better than that of the fundamental laser.

Increased serum levels of interleukin-18, -23 and -17 in Chinese patients with Alzheimer's disease.

AIMS: To evaluate the serum levels of interleukin (IL)-18, IL-23 and IL-17 in Chinese patients with Alzheimer's disease (AD), and explore correlations between the three cytokines and relevant parameters. METHODS: Serum concentrations of IL-18, IL-23 and IL-17 were measured by ELISA for 53 AD patients and 53 sex- and age-matched healthy controls in a community of elderly individuals in a Shanghai suburb. RESULTS: Serum concentrations of IL-18, IL-23 and IL-17 were significantly higher in AD patients than controls. The serum level of IL-23 was observed to be significantly higher (p = 0.049) in female AD patients than male AD patients. In addition, a significantly inverse correlation was found between IL-18 and MMSE score (rs = -0.356, p = 0.011) for all AD patients. CONCLUSION: Elevated IL-18, IL-23 and IL-17 levels are observed in AD patients and differences may exist between males and females. Besides, IL-18 may correlate with the severity of AD.

Suicide mortality trends in the Nordic countries 1980-2009.

BACKGROUND AND AIM: The Nordic countries provide a suitable setting for comparing trends in suicide mortality. The aim of this report is to compare suicide trends by age, gender, region and methods in Denmark, Finland, Iceland, Norway and Sweden 1980-2009. METHODS: Suicide statistics 1980-2009 were analyzed for men and women aged 15 years and above and the age group 15-24 years. Regional suicide rates in 2009 were presented in maps. RESULTS: The suicide rates across the Nordic countries declined from 25-50 per 100,000 in 1980 to 20-36 in 2009 for men and from 9-26 in 1980 to 8-11 in 2009 for women. The rates in Finland were consistently higher than those of the other countries. A significant increase of suicides in young women in Finland and Norway and a lack of a decline among young women in Sweden were noted. The male- female ratio of suicide converged to approximately 3:1 across the region during the study period. Rural areas in Finland, Norway and Sweden saw the highest suicide rates, whereas the rates in the capital regions of Denmark, Norway and Sweden were lower than the respective national rates. CONCLUSIONS: We hold that the overall decline of suicide rates in the Nordic countries reflects the socio-economic development and stability of the region, including the well-functioning healthcare. The increasing rates in Finland and Norway and the unchanged rate in Sweden of suicide in young women are an alarming trend break that calls for continued monitoring.

Construction and Simulation of High-Quality Development of China's Resource-Based Cities Driven by Innovation Based on System Dynamics.

Innovation is the primary driving force for development; the high-quality development of resource-based cities is ultimately driven by innovation. We constructed an innovation-driven high-quality development system for resource-based cities, including resource, economic, social, and environmental subsystems; according to the interaction between the internal elements of each subsystem, a dynamic model of the innovation-driven high-quality development system of resource-based cities was established, and we selected policy adjustment variables to simulate six policy scenarios. Thus, we simulated high-quality development trends from 2008 to 2035. The results indicate that the policy scenario of increasing innovation investment can promote high-quality development; the policy of increasing innovation investment has a significant effect on economic growth, while it damages the urban ecological environment, and the ideal policy scenario is the environmental priority mode, which appropriately increases innovation investment and reasonably allocates it within the system.

Evaluation of anthropometric indices for metabolic syndrome in Chinese adults aged 40 years and over.

BACKGROUND: The prevalence of metabolic syndrome (MetS) is increasing worldwide with a marked impact in cardiovascular disease (CVD) and diabetes risk. AIM OF THE STUDY: To evaluate the anthropometric indices for metabolic syndrome (MetS) and determine the optimal cut-off values of waist circumference (WC), body mass index (BMI), and waist height ratio (WHtR) for MetS in Chinese adults aged 40 years and over. METHODS: A sample of Chinese adults aged 40 years and over including 430 men and 638 women was investigated. Blood pressure, weight, height, and WC were measured; HDL-cholesterol (HDL-C), Triglyceride (TG), and plasma glucose were examined. Receiver operating characteristics (ROC) curve analyses were used to evaluate the optimal cut-off point of WC, BMI, and WHtR for MetS. RESULTS: According to the ROC curve analysis, the optimal cut-off point for WC was found to be 84.0 cm in men and 80.0 cm in women; for BMI, it was 26.0 in men and 25.0 in women; and for WHtR, it was 0.5 in both men and women. WHtR has the highest predictive value for fast plasma glucose in women, while BMI has the better prediction of dyslipidemia in men. CONCLUSIONS: Anthropometric indices (WC, BMI, and WHtR) are useful screening tools for obesity, MetS, and CVD risk factors. BMI may be a better indicator than the others for screening obesity, dyslipidemia, and other risk components in Chinese men aged 40 years and over, while WHtR may be better for Chinese women, especially among those aged 70 years and over.

Serotonin transporter gene polymorphism in Chinese patients with poststroke depression: a case-control study.

BACKGROUND AND PURPOSE: We sought to compare the distribution of the serotonin transporter gene SLC6A4 polymorphism between depressed and nondepressed poststroke patients. METHODS: Patients with cerebral stroke admitted to hospital during a 1-year period were enrolled in a 1:1 case-control study. All cases and controls were genotyped for polymorphism of the serotonin transporter-linked promoter region and the single-nucleotide polymorphism rs25531. RESULTS: Among 367 patients with cerebral stroke, 57 (15.5%) were diagnosed with poststroke depression at 1 month after stroke. In the patients with poststroke depression, 7 genotypes of the serotonin transporter gene SLC6A4 were detected, and the frequency of S/S homozygotes was significantly higher (P=0.049) than that in controls. CONCLUSIONS: S/S homozygosity may be positively associated with the occurrence of poststroke depression in Chinese patients.

Glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1) null polymorphisms, smoking, and their interaction in oral cancer: a HuGE review and meta-analysis.

The association between glutathione S-transferase M1 (GSTM1) and glutathione S-transferase T1 (GSTT1) null polymorphisms and oral cancer is not consistent across studies, and data on their interaction with smoking in oral cancer are lacking. The authors systematically searched PubMed and SciVerse Scopus for case-control studies examining the association between null genotypes of the GSTM1 and GSTT1 genes and oral cancer. Twenty-eight case-control studies published in English were identified. Summary odds ratios were derived via random-effects models. The summary odds ratio for the GSTM1 null genotype was 1.43 in Asians (95% confidence interval (CI): 1.14, 1.78; P < 0.01, I (2) = 73%) and 0.98 in Caucasians (95% CI: 0.76, 1.28; P = 0.91, I (2) = 0%). Case-only analysis of 6 studies (552 cases) showed an inverse multiplicative interaction between GSTM1 null polymorphisms and smoking (ever/high levels of smoking vs. never/low levels) (odds ratio (OR) = 0.51, 95% CI: 0.32, 0.82; P = 0.01, I (2) = 34%). The GSTT1 null genotype was not significantly associated with oral cancer in Asians (OR = 1.07, 95% CI: 0.82, 1.38; P = 0.63, I (2) = 65%) or Caucasians (OR = 1.04, 95% CI: 0.41, 2.65; P = 0.93, I (2) = 55%). In conclusion, the GSTM1 null genotype may be associated with a higher risk of oral cancer in Asians but not in Caucasians, and this effect may be modified by smoking status. The GSTT1 null genotype may not be associated with oral cancer.

Changes in rates, methods and characteristics of suicide attempters over a 15-year period: comparison between Stockholm, Sweden, and Würzburg, Germany.

PURPOSE: To investigate age and sex-specific changes in rates, methods used and characteristics of suicide attempters receiving medical care, over a 15-year period in two European WHO catchment areas (Stockholm, Sweden; and Würzburg, Germany). METHODS: The data for this study were obtained from the WHO/EURO Multicentre Study on Suicidal Behaviour for the period 1989-2003. Sex-specific, person-based suicide attempt rates were calculated for each year separately for the age groups 15-24 and 25 or above. The Chi-square test for trend was applied to estimate changes in proportions of socio-demographic and socio-economic variables. RESULTS: Significantly, increasing trends in suicide attempt rates occurred in young females, and in males and females aged 25 or above in Würzburg. On the contrary, men 25 years and above showed a significant decrease in suicide attempt rates in Stockholm. Young females in Würzburg tended to use less violent methods for their attempts whereas in Stockholm young females were increasingly inclined to attempt suicide using violent methods. In Stockholm, young female suicide attempters tended to be more often economically inactive, particularly due to an increasing proportion of students. Young females in Würzburg were often less well educated, as were their young male counterparts. This contrasted with trends in the education of men and women of 25 or above in Stockholm. CONCLUSIONS: The results of this study suggest temporal changes in trends, methods used and in the social profile of suicide attempters.

Cognitive impairment and associated factors among the elderly in the Shanghai suburb: findings from a low-education population.

OBJECTIVE: Our purpose was to investigate the prevalence of cognitive impairment and associated factors among elderly people in the Shanghai suburb. METHODS: A population-based survey was conducted for people aged 60 years and over in a community of 2 towns (Huaxin and Xujing) in Qingpu district, located in the western suburb of Shanghai. Face-to-face interviews were carried out to collect relevant information with prepared questionnaires. The Chinese version of the Mini-Mental State Examination was used to screen subjects with cognitive impairment, and the criteria of cognitive impairment were adjusted for education level. Univariate and multivariate logistic regression analyses were performed to evaluate factors putatively associated with cognitive impairment. RESULTS: There were 2,809 subjects (1,010 men and 1,799 women) aged 60 years and over (mean: 70.6, SD: 6.6) included in the study, and 198 people (42 men and 156 women) had cognitive impairment, with a prevalence of 7.0% (95% CI: 6.1-7.9) for both genders, 4.2% (95% CI: 3.6-4.8) for men and 8.7% (95% CI: 8.0-9.4) for women among the elderly. The prevalence rates of cognitive impairment increased with age. Although a number of factors were found to be significantly associated with the risk of cognitive impairment from the univariate analysis, only age (OR: 2.245, 95% CI: 1.755-2.872) and preferring a nonsalty diet (OR: 0.647, 95% CI: 0.460-0.912) were left in the final model of multivariate logistic regression analysis. CONCLUSION: The prevalence of cognitive impairment among the elderly in the Shanghai suburb is relatively high, compared with that previously reported from other areas in China, but lower than that from western countries. Factors associated with cognitive impairment need to be further investigated in the future.

Statins in prevention of repeat revascularization after percutaneous coronary intervention--a meta-analysis of randomized clinical trials.

Recent prospective cohort studies have shown that patients discharged on statins after percutaneous coronary intervention (PCI) are at lower risks of repeat revascularization and mortality when compared to those not on statins after discharge. However, few randomized clinical trials among post-PCI patients confirmed these beneficial effects. It is needed to evaluate the effects of post-procedural statin therapy on individual clinical outcomes to facilitate the further investigation on identifying the underlying mechanism(s). A meta-analysis of randomized clinical trials was conducted to examine the effects of statin therapy initiated after coronary angioplasty on repeat revascularization, all-cause mortality and myocardial infarction (MI). From relevant reports on Medline (from inception to October 2009), six randomized clinical trials comprising 2979 patients were included. Relative risks were evaluated for pooled data via random effect models. Compared with controls, post-PCI statin therapy was associated with a significantly decreased risk of repeat revascularization (risk ratio (RR)=0.73, 95% confidence interval (CI), 0.55-0.98, p=0.04), nonsignificantly decreased risks of all-cause mortality (RR=0.88, 95% CI, 0.35-2.21, p=0.79), MI (RR=0.76, 95% CI, 0.49-1.18, p=0.23), and target lesion or target vessel revascularization (RR=0.58, 95% CI, 0.24-1.39, p=0.22). In conclusion, statin therapy after PCI can reduce the risk of repeat revascularization. Further investigation is needed to identify the underlying mechanism(s).

Energy transfer versus charge separation in type-II hybrid organic-inorganic nanocomposites.

Hybrid organic-inorganic nanomaterials have the potential of providing synergetic properties. Blends of semiconductor nanocrystals and conjugated polymers in particular promise novel optoelectronic properties. Effective design of tailored optoelectronic properties requires a deep understanding of the photophysics of these composite materials, which includes charge separation and Dexter and Förster energy transfer. We performed a detailed and quantitative spectroscopic investigation of a type II aligned hybrid system consisting of a blue emitting conducting polymer and CdTe nanocrystals. Although charge separation is expected from the type II alignment, we find a dominant (70% efficiency) energy transfer process. We discuss all possible de-excitation pathways for the excitons in terms of the alignment of energy levels, time scales, and physical geometry of the system. This allows us to conclude that energy transfer occurs via the Förster mechanism and provides a clear guideline for the design of novel hybrid materials.

TRPC6 mRNA levels in peripheral leucocytes of patients with Alzheimer's disease and mild cognitive impairment: A case-control study.

BACKGROUND: Transient receptor potential canonical (TRPC) 6 inhibits Aß in Alzheimer's disease (AD) mouse brain and improves the behavioral performance. AIMS: To evaluate the association of TRPC6 expression in peripheral leucocytes from AD and mild cognitive impairment (MCI) patients and to explore its potential value in early diagnosis of AD. METHODS: TRPC6 mRNA levels in peripheral leucocytes were detected by quantitative real-time PCR. The Spearman correlation test was used to ascertain the associations between TRPC6 and the scores of MMSE, ADL, CSDD, CDR. The Receiver Operating Characteristic (ROC) curve was drawn to evaluate the diagnostic potential of TRPC6 for AD and MCI. RESULTS: There were 108 CE, 136 MCI, 164 Con and 60 PD in the study. The expression of TRPC6 mRNA level in peripheral leucocytes was significantly lower: 1) in patients with AD and MCI compared to Con; 2) in AD compared to MCI; 3) in hospitalized AD compared to AD from communities. There was a significantly positive correlation between TRPC6 mRNA and MMSE score (p = .001, R = 0.327). Significantly inverse correlations were found between TRPC6 and CDR score (p < 0.001, R = -0.303) as well as between TRPC6 and ADL score (p = .001, R = -0.342) for all AD. The area under curve of ROC was 0.881 for the classification of AD, and 0.706 for the classification of MCI, respectively. CONCLUSION: TRPC6 expression is inversely correlated with cognitive performance of AD. TRPC6 in peripheral leucocytes may be a potential biomarker for the diagnosis of AD.

Serum haptoglobin in Chinese patients with Alzheimer's disease and mild cognitive impairment: A case-control study.

BACKGROUND: Serum level of Haptoglobin (Hp) maybe associated with Alzheimer's disease (AD) and mild cognitive impairment (MCI). OBJECTIVE: To investigate associations between serum Hp and AD, as well as between Hp and MCI. METHODS: Serum levels of Hp were measured and analyzed for 51 patients with AD, 139 patients with MCI and their healthy controls matched with sex and age. All study subjects were from a survey among residents aged 60 years and over in a community located in the southwest suburb of Shanghai. RESULTS: Serum levels of Hp were observed significantly higher in AD and MCI cases than controls (both p < 0.0001). A significant positive correlation was found between Hp and Activities of Daily Living (ADL) score (rs = 0.430, p = 0.007), as well as between Hp and Clinical Dementia Rating (CDR) score (rs = 0.359, p = 0.027) in all AD patients. According to the receiver operating characteristic (ROC) curve analysis, the optimal cut-off point for Hp was found to be 67.50 µg/ml (sensitivity, 0.902; specificity, 0.745) in AD patients, and 44.76 µg/ml (sensitivity, 0.986; specificity, 0.403) in MCI patients. CONCLUSION: Elevated serum levels of Hp were observed in AD and MCI patients than controls. In addition, Hp may correlate with the severity of AD.

Association of neck circumference and cognitive impairment among Chinese elderly.

Objectives: To investigate the association between neck circumference (NC) and cognitive impairment and interactions between relevant variables to the risk of cognitive impairment. Methods: A population-based survey was conducted among elderly inhabitants aged 60 years and over from a community in Shanghai suburb. Multivariate logistic regression analyses were performed to evaluate associations and log likelihood ratio tests to examine interactions. Results: Cognitive impairment was identified in 269 (10.8%) subjects from 2,500 participants. Higher BMI (OR = 1.55; 95% CI = 1.11-2.16), higher WHR (OR = 1.44; 95% CI = 1.07-1.95), and higher total cholesterol (TC) (OR = 1.52; 95% CI = 1.09-2.13) were significantly associated with the increased risk of cognitive impairment. Significant interactions were observed between TC and a few other relevant variables, respectively. Conclusions: NC was associated with the high risk of cognitive impairment. Additive effects of NC with TC on cognitive impairment were observed.

Birth weight and risk of type 2 diabetes, abdominal obesity and hypertension among Chinese adults.

OBJECTIVE: To investigate the association between birth weight and risk of type 2 diabetes, abdominal obesity and hypertension among Chinese adults. RESEARCH METHODS AND PROCEDURES: Nine hundred and seventy-three individuals from a population-based cross-sectional survey for the prevalence of type 2 diabetes conducted in Shanghai in 2002 were enrolled and followed up to 2004 with yearly examination. Birth weight was classified into four categories: <2500, 2500-2999, 3000-3499 and >or=3500 g. RESULTS: In this study, there were 373 males and 600 females, with a mean age of 46.2+/-9.9 years. Fasting plasma glucose was higher in subjects with the lowest birth weight (<2500 g) compared with those with the highest birth weight. Waist circumference and systolic blood pressure showed U-shaped relationships with birth weight. Birth weight was found to be an independent risk factor for type 2 diabetes, abdominal obesity and hypertension. For type 2 diabetes, the crude odds ratio (95% confidence interval) was 3.17 (1.48-6.78) in the lowest birth weight category when compared with that in the highest birth weight category (>or=3500 g) and the ratio increased to 3.97 (1.71-9.22) after adjustment for related variables. The highest prevalence of type 2 diabetes (34.5%) was observed among those with the lowest birth weight and abdominal obesity. CONCLUSIONS: Birth weight is inversely associated with the risk of type 2 diabetes. Subjects with the lowest or the highest birth weight were associated with a high risk of developing abdominal obesity and hypertension. Low birth weight coupled with abdominal obesity is a strong predictor of type 2 diabetes.

Life time suicidal thoughts in an urban community in Hanoi, Vietnam.

BACKGROUND: Suicidal thought is a risk factor and a stage in the suicidal process from planning to attempting and dying by suicide. To date, studies on suicidal thought in the general population, especially in Asian communities, have been limited. METHOD: The WHO SUPRE-MISS (the multisite intervention study on suicidal behaviours) community survey questionnaire was filled in for 2,280 randomly selected residents of the DongDa district of Hanoi, Vietnam by means of face-to-face interviews. This multi-factor questionnaire includes such variables as sociodemographic information, suicidal thought and history of suicide attempts, physical health, alcohol consumption and medication. RESULTS: Prevalence rates for life time suicidal thoughts, suicide plans and suicide attempts were 8.9%, 1.1% and 0.4% respectively. Suicidal thoughts are associated with multiple characteristics, such as female gender, single/widowed/separated/divorced marital status, low income, lifestyle (use of alcohol, sedatives and pain relief medication), but not with low education or employment status. Having no religion and being a Buddhist appear to be protective factors for suicidal thought. The ratio of suicidal thoughts, suicide plans and suicide attempts on a lifetime basis is 22.3:2.8:1. CONCLUSION: In Vietnam, as in Western and other Asian countries, suicidal thoughts are associated with similar negative psychosocial risk factors, lifestyle and emotional problems, which implies that suicide preventive measure developed elsewhere can be adjusted to Vietnamese condition. Understanding the unique and common risks in a culture may assist in prediction and control.