Jaelim Cho

Air pollution as a risk factor for depressive episode in patients with cardiovascular disease, diabetes mellitus, or asthma

BACKGROUND There is currently insufficient evidence to confirm the effect of ambient air pollution on mental disorders, especially among susceptible populations. This study investigated the short-term effect of ambient air pollution on the risk of depressive episode and the effect modification across disease subpopulations. METHODS Subjects who visited the emergency department (ED) for depressive episode from 2005 to 2009 (n=4985) in Seoul, Republic of Korea were identified from medical claims data. We conducted a time-stratified case-crossover study using conditional logistic regression. Subgroup analyses were conducted after the subjects were stratified by underlying disease (cardiovascular disease, diabetes mellitus, chronic obstructive pulmonary disease, asthma, and depressive disorder). The risk was expressed as an odds ratio (OR) per 1 standard deviation of each air pollutant. RESULTS SO2, PM10, NO2, and CO were positively associated with ED visits for depressive episode. The maximum risk was observed in the distributed lag 0-3 model for PM10 (OR, 1.120; 95% confidence interval, 1.067-1.176). PM10, NO2, and CO significantly increased the risks of ED visits for depressive episode in subjects with either underlying cardiovascular disease, diabetes mellitus, asthma, or depressive disorder. LIMITATIONS Our data may include a misclassification bias due to the validity of a diagnosis determined from medical services utilization data. CONCLUSIONS SO2, PM10, NO2, and CO significantly increased the risk of ED visits for depressive episode, especially among individuals with pre-existing cardiovascular disease, diabetes mellitus, or asthma.

Cortical thickness and hippocampal shape in pure vascular mild cognitive impairment and dementia of subcortical type

The progression pattern of brain structural changes in patients with isolated cerebrovascular disease (CVD) remains unclear. To investigate the role of isolated CVD in cognitive impairment patients, patterns of cortical thinning and hippocampal atrophy in pure subcortical vascular mild cognitive impairment (svMCI) and pure subcortical vascular dementia (SVaD) patients were characterized.

Reinforcement of molten carbonate fuel cell matrixes by adding rod-shaped γ-LiAlO2 particles

Improvement in strength of γ-LiAlO2 matrixes for a molten carbonate fuel cell (MCFC) via addition of rod-shaped γ-LiAlO2 particles has been investigated. The rod-shaped γ-LiAlO2 particles with the aspect ratio of 9–15 were obtained by heat-treating rod-shaped β-LiAlO2 particles at 800 °C for 3 h, synthesized from the reaction mixture of LiOH-γ-Al2O3-NaOH. The γ-form was very stable for more than 700 h in a molten carbonate environment at 650 °C, while the β-form showed both a phase change from β- to γ-LiAlO2 and a morphology change from rod- to bipyramid-shapes. The average pore size and the porosity of the matrix (550 μm thickness) fabricated by tape-casting of the slurry with weight ratio 1.0 of rod-shaped γ-LiAlO2 particles to commercial γ-LiAlO2 powders (2.0 μm dia.) were about 0.12 μm and 54%, respectively, after being heat-treated at 650 °C for 2 h. The strength (197 gf/mm2) of the rod- shaped particle reinforced matrixes was enhanced more than twice as much as that of the non-reinforced γ-LiAlO2 matrixes (91 gf/mm2).

Tau positron emission tomography using [18F]THK5351 and cerebral glucose hypometabolism in Alzheimer's disease

This study aims to evaluate the clinical validity of [18F]THK5351 positron emission tomography (PET) for the assessment of disease progression and symptoms in Alzheimers disease (AD). Fifty-one patients with AD dementia, 30 patients with amnestic mild cognitive impairment (aMCI), and 43 controls with normal cognition (NC) were included. All subjects underwent [18F]THK5351 PET, 3.0-T magnetic resonance imaging, and detailed neuropsychological tests. Regions of interest and voxel-based statistical analyses were performed. In patients with AD dementia, [18F]THK5351 retention was greater in most association cortices as well as the limbic area compared to NC or aMCI participants. Patients with aMCI also showed higher THK5351 retention in those areas compared to NC. [18F]THK5351 retention significantly correlated with neuropsychological test results. Negative correlations between [18F]THK5351 and [18F] fluorodeoxyglucose were observed in AD dementia and aMCI groups. Mirror images of [18F]THK5351 retention and glucose hypometabolism in [18F] fluorodeoxyglucose were noticeable in the focal variants of AD. [18F]THK5351 PET reflects disease severity and symptoms in AD. Our results suggest [18F]THK5351 is reflective of tau-related AD pathology.

Changes in the Practice of Coronary Revascularization between 2006 and 2010 in the Republic of Korea

Purpose Evidence suggests that technological innovations and reimbursement schemes of the National Health Insurance Service may have impacted the management of coronary artery disease. Thus, we investigated changes in the practice patterns of coronary revascularization. Materials and Methods Revascularization and in-hospital mortality among Koreans ≥20 years old were identified from medical claims filed between 2006 and 2010. The age- and sex-standardized procedure rate per 100000 person-years was calculated directly from the distribution of the 2008 Korean population. Results The coronary revascularization rate increased from 116.1 (95% confidence interval, 114.9-117.2) in 2006 to 131.0 (129.9-132.1) in 2010. Compared to the rate ratios in 2006, the rate ratios for percutaneous coronary intervention (PCI) and coronary artery bypass graft (CABG) surgery in 2010 were 1.16 (1.15-1.17) and 0.80 (0.76-0.84), respectively. Among patients who received PCI, the percentage with drug-eluting stents increased from 89.1% in 2006 to 93.0% in 2010. In-hospital mortality rates from PCI significantly increased during the study period (p=0.03), whereas those from CABG significantly decreased (p=0.01). The in-hospital mortality rates for PCI and CABG were higher in elderly and female patients and at the lowest-volume hospitals. Conclusion The annual volume of coronary revascularization continuously increased between 2006 and 2010 in Korea, although this trend differed according to procedure type. A high percentage of drug-eluting stent procedures and a high rate of in-hospital mortality at low-volume hospitals were noted.

Age and gender differences in medical care utilization prior to suicide

BACKGROUND Analysis of temporal patterns of medical care utilization prior to suicide may aid in developing suicide prevention programs. The aim of this study was to investigate age and gender differences in temporal patterns of medical care utilization during 1 year prior to suicide. METHODS Medical care utilization data of all suicide completers in the Republic of Korea whose death occurred in 2004 (7903 men and 3620 women) was used. Differences among the quarters in medical expenditures and number of medical care visits were analyzed using a repeated measures analysis. Total medical expenditures were compared to those of age- and gender-matched controls by multiple logistic regression analysis. RESULTS Among suicides, 84% (81% in men, 91% in women) contacted medical care in the year prior to suicide. In 10-39 year-old women, the number of medical care visits for gastrointestinal disease increased significantly during the final 3 months prior to suicide. All suicide completers showed that the number of medical care visits for psychiatric disorders increased significantly during the final 3 months with the exception of 10-19 year age group. Total medical expenditures during the year prior to suicide were elevated significantly and associated significantly with suicide risk (OR, 1.20; 95% CI, 1.19-1.21). LIMITATIONS Inaccuracies in the underlying disease and death statistics data may have led to misclassification bias. CONCLUSIONS Medical care utilization increased as the date of suicide approached. There are age and gender differences in medical care utilization in the year prior to suicide.

[18F]-THK5351 PET Imaging in Patients With Semantic Variant Primary Progressive Aphasia.

Background: Semantic variant primary progressive aphasia (svPPA) has been associated with a variety of proteinopathies, mainly transactive response DNA-binding protein, but also with tau and &bgr;-amyloid. Recently selective tau tracers for positron emission tomography (PET) have been developed to determine the presence of cerebral tau deposits in vivo. Here, we investigated the topographical distribution of THK5351 in svPPA patients. Materials and Methods: Five svPPA patients, 14 Alzheimer’s disease patients, and 15 age-matched normal controls underwent [18F]-THK5351 PET scans, magnetic resonance imaging, and detailed neuropsychological tests. [18F]-fluorodeoxyglucose PET was obtained in 3 svPPA patients, whereas the remaining 2 underwent amyloid PET using [18F]-flutemetamol. Tau distribution among the 3 groups was compared using regions of interest–based and voxel-based statistical analyses. Results: In svPPA patients, [18F]-THK5351 retention was elevated in the anteroinferior and lateral temporal cortices compared with the normal controls group (left>right), and in the left inferior and temporal polar region compared with Alzheimer’s disease patients. [18F]-THK5351 retention inversely correlated with glucose metabolism, whereas regional THK retention correlated with clinical severity. [18F]-flutemetamol scans were negative for &bgr;-amyloid. Conclusions: These findings show that [18F]-THK5351 retention may be detected in cortical regions correlating with svPPA pathology.

The Werther effect of two celebrity suicides: an entertainer and a politician

Purpose Suicide is a major health problem in Korea. Extensive media exposure of celebrity suicide may induce imitative suicide, a phenomenon called the Werther effect. We examined the increased suicide risk following the suicides of an entertainer and a politician, and identified the relative suicide risks. Methods News articles about the celebrity suicides were obtained from three major newspapers and analysed for quantitative and qualitative features. Imitative suicide risk was investigated by applying a Poisson time series autoregression model with suicide mortality data from the National Statistics Office for 1.5 years before and 1.5 years after each celebrity’s suicide. The period with a significantly increased number of suicides immediately after the celebrity’s suicide determined the Werther effect band. The relative risk during this period was examined for different ages, genders, and suicide methods. Results News reports were more numerous and they contained more positive definitions about the entertainer’s suicide. The risk of suicide deaths rose markedly after both celebrity suicides. However, the Werther effect band was longer for the entertainer (6 weeks) than for the politician (4 weeks). The relative suicide risk was significant for almost all ages and both genders during that of both individuals. Use of the same suicide method was a prominent risk factor after both celebrity suicides. Conclusions Our results confirm the existence of imitative suicide behaviours, suggesting a facilitation effect of media reports. Guidelines for responsible media reporting need to be implemented to enhance public mental health in Korea.

Factors Associated with a Low-sodium Diet: The Fourth Korean National Health and Nutrition Examination Survey

OBJECTIVES The low-sodium diet is a known preventive factor for hypertension and cardiovascular disease. Factors associated with low-sodium diets should be identified to reduce sodium intake effectively. This study was conducted to identify factors correlated with a low-sodium diet. METHODS This cross-sectional study analyzed data from a total of 14,539 Koreans aged 20 years or older, who participated in the Fourth (2007-2009) Korean National Health and Nutrition Examination Survey. A low-sodium diet was defined as having ≤2,000 mg/day based on 24-hour recalls. Multiple logistic regression models were used to assess sex, age, education, number of family members, household income, occupation, alcohol drinking, total energy intake, frequency of eating out, and hypertension management status for their associations with low-sodium diets. RESULTS Among all participants, only 13.9% (n=2,016) had low-sodium diets. In the multivariate analysis, 40-49 years of age, clerical work jobs, higher total energy intake, and frequent eating out were inversely associated with low-sodium diets. And female sex and living-alone were associated with low-sodium diets. Lower frequency of eating out was significantly associated with low-sodium diets, even after adjusting for total energy intake and other potential confounders. Adjusted odds ratios (95% confidence interval) for a low-sodium diet were 1.97 (1.49-2.61), 1.47 (1.13-1.91), 1.24 (0.96-1.61), and 1.00 (reference) in people who eat out <1 time/month, 1-3 times/month, 1-6 times/week, and ≥1 time/day, respectively. CONCLUSIONS Our study suggests that sex, age, number of family members, occupation, total energy intake, and lower frequency of eating out were associated with a low-sodium diet in Korean adults.

Characteristics of Exposure to Humidifier Disinfectant by Lung Injury Patients

In South Korea, many cases of humidifier disinfectant-associated lung injury (HDLI) have been reported among people who used humidifier products containing humidifier disinfectant (HD). The objective of this study is to characterize exposure to HD among a total of 221 HDLI patients who used HD. Info...