Dementia-Free Survival and Risk Factors for Dementia in a Hospital-Based Korean Parkinson's Disease Cohort

BACKGROUND AND PURPOSE: Few studies of dementia in Parkinson's disease (PD) have had long-term follow-ups. Moreover, information on the duration from the onset to the development of dementia in patients with PD is lacking. The aim of this study was to determine the median dementia-free survival time from the onset of PD to the development of dementia. METHODS: In total, 1,193 Korean patients with PD were recruited and assessed at regular intervals of 3–6 months. We interviewed the patients and other informants to identify impairments in the activities of daily living. The Hoehn and Yahr stage and scores on the Unified Parkinson's Disease Rating Scale and Mini Mental State Examination were evaluated annually. We used Kaplan-Meier survival analysis to estimate the cumulative proportion of dementia-free patients over time. Risk factors predicting dementia were also evaluated using Cox proportional-hazards regression models. RESULTS: The median dementia-free survival time in the Korean PD population was 19.9 years. Among the 119 patients who subsequently developed dementia, the mean duration from the onset of PD to the development of dementia was 10.6 years. A multivariate analysis identified age at onset and education period as the significant predictors of dementia. CONCLUSIONS: This is the first report on dementia-free survival in patients with PD based on longitudinal data analysis from the disease onset. The median dementia-free survival time in Korean PD patients was found to be longer than expected.

The Prevalence of High Myopia in 19 Year-Old Men in Busan, Ulsan and Gyeongsangnam-Do / 예방의학회지

OBJECTIVES: The purpose of this study was to estimate the prevalence and correlated factors of high myopia in 19 year-old men in Southeast Korea. METHODS: This retrospective study was based on the medical checkup data of conscription during 2005. The study subjects were 19 years old men in Busan, Ulsan and Gyeongsangnam-do. The health checkup data of the conscripts consisted of noncycloplegic autorefraction test, the biometric data and social factors. To analyze the social and biometric effects, we classified the biometric factors into 4 or 5 groups and the social factors into 3 groups. High myopia was defined as a spherical equivalent of under -6.0 diopter. Data analysis was performed using the chi square test for trends and multiple logistic regression analysis. The SAS(version 9.1) program was used for all the analyses. RESULTS: The prevalence of high myopia was 12.39% (6256 / 50 508). The factors correlated with high myopia were the residence area (OR, 2.07; 95% CI, 1.77 to 2.4 for small city; OR, 2.01; 95% CI, 1.72 to 2.34 for metropolis; the reference group was rural area), academic achievement (OR, 1.43; 95% CI, 1.34 to 1.53 for students of 4-and 6-year-course university; the reference group was high school graduates & under) and blood pressure (OR, 1.54; 95% CI, 1.10 to 2.16 for hypertension; OR, 1.09; 95% CI, 1.02 to 1.17 for prehypertension; OR, 1.10; 95% CI, 1.01 to 1.20 for hypotension; the reference group was normal blood pressure). CONCLUSIONS: More than one tenth of the young men were high myopia as one of the risk factor for visual loss. Further studies on high myopia and its complications are needed to improve eye health in Southeast Korea.

Development of Ancient DNA Isolation Method for Improved PCR Amplification / 체질인류학회지

Ancient DNA analyses are widely used for evolutionary and phylogenetic study of mankind in anthropology and archeology. However, the DNA extraction from particularly poorly preserved ancient human samples is often unsuccessful in these analyses. In the present study, to improve the success rate of ancient DNA analysis, we introduced a high grade ancient DNA purification method using ion-exchange columns. We compared the success rate of ancient DNA analysis of this new method with that of the two methods that have been used for ancient DNA extraction, GENECLEAN(R) kit (Qbiogene) and Qiaquick column (Qiagen). Twelve ancient bone samples from Korea and Mongolia that are about 500 to 5,000 years old by an archeological estimation were used. As the DNA analysis methods, polymerase chain reaction (PCR) methods for the amplification of a mitochondrial DNA HV1 segment, a male sex determination marker DNA and M175 marker DNA that is used for the determination of O haplogroup of Y chromosome that is reportedly a common one in modern Korean people. The method developed in this study remarkably increased the success rate of DNA analysis compared with the other two methods. Using the GENECLEAN(R) kit, only two samples were amplifiable for the mitochondrial DNA, no samples for the male sex determination marker and M175 marker DNAs. Using the Qiaquick columns, nine samples were amplifiable for mitochondirial DNA, nine samples for male sex determination marker and six samples for M175 marker. The developed method allowed for the amplification of mitochondrial DNA from all samples, male sex determination marker from eight samples and M175 marker from eight samples. The results demonstrate that ion-exchange columns can be useful for the improved ancient DNA extraction in anthropology and archeology.

Alpha-tocopherol Prevents H2O2-induced Tight Junction Occludin Disruption in Blood-Brain Barrier / 체질인류학회지

Vitamin E is the most important lipid-soluble antioxidant in humans. Although alpha-tocopherol is suggested that it has protective effect from many diseases, little is known about the prevention of occludin alteration in tight junction of blood-brain barrier (BBB) under pathologic insults producing reactive oxygen species (ROSs). In this study, the effects of alpha-tocopherol on H2O2-induced tight junction occludin were studied. Primary culture of rat brain microvessel endothelial cells was investigated with confocal microscopy, Western blot, and cell viability assay. Alpha-tocopherol had no apparent cytotoxicity up to 2.8 mM. The preincubation with alpha-tocopherol suppressed the H2O2-induced cytotoxicity in Alamar Blue assay and phase contrast microscopy. In confocal laser microscopy and Western blot, H2O2-induced loss of occludin was suppressed by preincubation with alpha-tocopherol. The present findings provide evidence that alpha-tocopherol may be beneficial for cellular protection from pathologic insults. Since alpha-tocopherol was demonstrated to have far fewer adverse effects, it would become a noteworthy nutrient or drug for the treatment of neurodegenerative diseases.

Developing a Statistical Software for Predicting Hospital Bankruptcy using Data Mining Tool / 대한의료정보학회지

Since the hospital bankruptcy rate is increasing, it has been an important issue to predict the bankruptcy of hospital using the existing hospital management information. Fortunately, the implementation of data mining methodology and decision support system(DSS) are becoming popular. Therefore, this study developed the statistical software for predicting hospital bankruptcy using data mining tool. Stepwise procedures were taken as follows: 1) adopting the HGLM and Logit Models; 2) implementing the input and output processes; 3) linking to the iBITs interface, the data miming tool; and 4) evaluating the software by fitting the hospital management data in practice. The software is written in Visual C++ 5.0 under windows NT/95, and allows the interconnection with other interfaces and libraries. This program initiates encouragement of implementation of DSS models using data mining methodology, in health care fields. This kind of software will play a pivotal role in improving the efficiency and adequacy of managing health care institutions.