The personality traits with depression and suicidal ideation among Thai medical students: a university-based multiregional study.

BACKGROUND: The prevalence of depression in medical students was greater than in the general population. Knowing of predictive factors for depression among medical students is useful. The objectives of this study included the assessment of personality traits as well as the association between the personality traits and the presence of symptoms of depression, and suicidal ideation among medical students covering several regions of Thailand. METHODS: From April to July 2023, a cross-section study was conducted. The participants included first to sixth-year medical students studying at three Faculties of Medicine in Thailand; Prince of Songkla University; Ramathibodi Hospital, Mahidol University; and Chiang Mai University. Using the online process, the questionnaires were composed of three sections; demographic data; the International Personality Item Pool-NEO (IPIP-NEO), Thai version; and the Patient Health Questionnaire-9 (PHQ-9), Thai version. Demographics, personality traits, depression, and suicidal ideation were analyzed using descriptive statistics. The results were presented as frequency, mean, and standard deviation (SD) or median and interquartile range (IQR). The association between independent variables and the presence of depression was identified using binary logistic regression analysis, and the association with suicidal ideation was identified using ordinal logistic regression analysis. RESULTS: The 868 medical students participated in this study. Most of them were female (63.5%), Buddhist (82.0%), and first-year medical students (31.8%). The mean age (SD) was 20.8 (2.2) years, and the mean cumulative Grade Point Average (SD) was 3.5 (0.4). They reported the median (IQR) score of PHQ-9 as 6.0 (3.0-9.0), 238 participants (27.4%) presented with depression, and 138 (15.9%) participants reported suicidal ideation. According to the IPIP-NEO, participants with depression or suicidal ideation had higher Neuroticism scores and lower Extraversion, Agreeableness, and Conscientiousness scores compared to those without such issues. An increase in the Neuroticism score was linked to higher odds of depression, while an increase in the Conscientiousness score was associated with lower odds of depression. Suicidal ideation significantly increased with higher Neuroticism scores and the presence of a psychiatric illness. CONCLUSIONS: More than a quarter of Thai medical students reported depression. A higher Neuroticism and lower Extraversion, Agreeableness, and Conscientiousness scores related to depression. Therefore, medical schools may benefit from knowing medical students' personality traits, to identify coping mechanisms and predict those at a higher risk of developing depression in the future.

Personality traits among major depressive disorder in southern Thailand: a hospital-based case-control study.

BACKGROUND: Residual depression can cause functional impairment. This study aimed to assess personality traits among individuals with depression, to compare the results with personality traits found in outpatients without psychiatric disorders recruited from general practitioner settings, and to study the association between personality traits and the age-onset of depression, duration of treatment, and the presence of depressive residual symptoms. METHODS: A case-control study surveyed Thai individuals with depression and outpatients without psychiatric disorders recruited from general practitioner settings at an outpatient clinic of Songklanagarind hospital, in 2022. The questionnaires were: (1) demographic data, (2) the PHQ-9 Thai version, and (3) the International Personality Item Pool-NEO (IPIP-NEO) Thai version. The difference between personality traits and the assigned clinical group were analyzed using the Student's t-test and the Wilcoxon rank sum test. A generalized linear model was performed to examine differences of personality traits between the assigned clinical group (case-control), and the presence of depressive residual symptoms. The association between personality traits and treatment profiles was assessed by using an analysis of the variance test and the Kruskal-Wallis test. RESULTS: In regards to 73 individuals with depression in the case group, and 73 gender-and age-matched outpatients without psychiatric disorders recruited from general practitioner settings in the control group; 78.1% of cases and 82.2% of controls were female. Thirty-eight (52.1%) cases had depressive residual symptoms. Regarding the IPIP-NEO Thai version, there was a statistically significant difference in Neuroticism, Extraversion, and Conscientiousness domains between the case and the control groups. In comparison to the control group, the case group scored higher on the Neuroticism domain, and lower on the Extraversion and Conscientiousness domains. Every 0.18-point reduction in the Neuroticism score and every 0.09-point increment in regards to the Openness score were associated with a 1-year increment of age-onset of depression. This study found an association between a higher score of Neuroticism and a lower score of Conscientiousness with the presence of depressive residual symptoms. CONCLUSION: Different personality profiles were found between individuals with depression and outpatients without psychiatric disorders recruited from general practitioner settings. Individuals with depressive residual symptoms featured a higher score of Neuroticism and a lower score of Conscientiousness. A higher score of Neuroticism and a lower score of Openness were associated with age-onset of depression, but no personality traits were associated with treatment duration.

Selection and characterization of vaccine strain for Enterovirus 71 vaccine development.

Enterovirus 71 (EV71) has recently emerged as an important neurotropic virus in Asia because effective medications and prophylactic vaccine against EV71 infection are not available. Based on the success of inactivated poliovirus vaccine, the Vero cell-based chemically inactivated EV71 vaccine candidate could be developed. Identification of EV71 vaccine strain which can grow to high titer in Vero cell and induce cross-genotype virus neutralizing antibody responses represents the first step in vaccine development. In this report we describe the characterization and validation of a clinical isolate E59 belonging to B4 sub-genotype based on VP1 genetic analysis. Before selected as the vaccine strain, the genetic stability of E59 in passage had been analyzed based on the nucleotide sequences obtained from the Master Virus Seed, Working Seed banks and the virus harvested from the production lots, and found to be identical to those found in the original isolate. These results indicate that E59 vaccine strain has strong genetic stability in passage. Using this vaccine strain the prototype EV71 vaccine candidate was produced from 20L of Vero cell grown in serum-containing medium. The production processes were investigated, characterized and quantified to establish the potential vaccine manufacturing process including the time for virus harvest, the membrane for diafiltration and concentration, the gel-filtration chromatography for the down-stream virus purification, and the methods for viral inactivation. Finally, the inactivated virion vaccine candidate containing sub-microgram of viral proteins formulated with alum adjuvant was found to induce strong virus neutralizing antibody responses in mice and rabbits. Therefore, these results provide valuable information for cell-based EV71 vaccine development.

Development of a quantitative enzyme linked immunosorbent assay for monitoring the Enterovirus 71 vaccine manufacturing process.

Enterovirus 71 (EV71), the etiologic agent causes outbreaks with significant mortality in young children in Asia and currently there is no vaccine available. In this study, we report a quantitative enzyme linked immunosorbent assay (Q-ELISA) to determine the concentration of the EV71 VP2 antigen. EV71 virus-like particles (VLPs) were produced in the baculovirus expression system and used as the EV71 antigen reference standard. Antisera from both EV71-immunized chickens and rabbits were very efficient and useful as capture antibodies to bind various forms of EV71 antigens, whereas a commercial VP2-specific virus neutralizing monoclonal antibody MAB979 was found to be suitable for quantifying the amount of VP2 antigen. This Q-ELISA was used successfully to determine VP2 content at each stage of EV71 vaccine manufacturing process, particularly during the upstream harvest, downstream purification and viral inactivation steps. The amount of VP2 antigen and the magnitude of neutralizing titers were found to be dose-dependent in mice immunized with vaccine candidates. These results indicate that Q-ELISA could provide off-line timely quantitative measurements of VP2 antigen throughout the production cycle to evaluate critical attributes and conditions that may affect virus yields in culture media, the quality of purification methods, the stability and potency of final vaccine formulations.

[Gastric acid secretion and absorption of levodopa in patients with Parkinson's disease--the effect of supplement therapy to gastric acid].

Since an oral regimen of levodopa has been instituted for treatment of Parkinson's disease, its absorption and metabolism has been well demonstrated. However, its chemical characteristics of high solubility in acid solution and low solubility in water have not been well known. We paid attention to this characteristic and studied the relationship between its absorption and gastric acid secretion in 38 patients with Parkinson's disease who became refractory to therapy of levodopa. We measured the pH and amount of collected fasting gastric juice. Gastric acid secretion was decreased in 22 patients (58%). In ten of these 22 patients, 30 ml of lemon juice was prescribed in every administration of levodopa as a supplement to gastric acid for two weeks. Increases of L-dopa concentration after 60 min. and 180 min. were observed after lemon juice supplement therapy. Among the Parkinson symptoms, rigidity, akinesia, and small step gait were improved in every case except one patient who showed decrease of L-dopa concentration at 180 minutes. However, improvement of tremor was less remarkable. We consider this supplement therapy to gastric acid is one of the effective and useful methods in the management of Parkinson's disease.