Association between Insufficient Physical Activity and Hearing Loss in Korean Adults

Background@#Insufficient physical activity is a major risk factor for cardiovascular disease, and some studies report relationship between physical activityand hearing. We aimed to analyze association between hearing loss and physical activity level in Korean adults. @*Methods@#We used data from the 6th Korea National Health and Nutrition Examination Survey. Insufficient physical activity was defined as a combinedphysical activity of less than 150 minutes per week.. Hearing loss was identified when the audible threshold decreased more than 40 dB. Weperformed multiple logistic regression analysis of major covariates and stratified the participants by age (≥60 versus <60). @*Results@#We analyzed 3,237 participants for whom no values were missing. In the final multivariate logistic analysis, the odds ratio of hearing loss was1.227 (95% confidence interval [CI], 1.008–1.494) in the all frequency group and 1.361 (95% CI, 1.073–1.727) in the low frequency group. The resultfor the high frequency group was not statistically significant. In the group aged ≥60 years, the odds ratio of hearing loss in the all, low, and highfrequency groups were 1.277 (95% CI, 1.011–1.613), 1.405 (95% CI, 1.074–1.839), and 1.298 (95% CI, 1.013–1.662), respectively. @*Conclusion@#In this study, insufficient physical activity was associated with hearing loss in Korean adults. This result was more significant in the groupaged ≥60 years. Further studies should aim to validate these results and determine the causal relationship between physical inactivity and hearingloss.

The association between quality of direct supervisor's behavior and depressive mood in Korean wage workers: the 4th Korean Working Conditions Survey

BACKGROUND: Workers spend most of their social lives at work and have relationships of varying nature with people in the workplace. Direct supervisors, in particular, have a direct and lasting impact on workers, which may influence workers' mental health. Depression is very prevalent worldwide, and social concern about the disease is on the rise. The aim of this study is to investigate the effect of direct supervisors' behavior on the depressive mood of Korean wage workers. METHODS: We used data from the 4th Korean Working Conditions Survey held in 2014; 22,212 participants were included in the analysis. The quality of a direct supervisor's behavior was categorized from 0 (= lowest) to 5 (= highest) points. The degree of depressive mood was measured on a scale from “normal mood” to “likely depression” based on the 5-item World Health Organization Well-Being Index (WHO-5) questionnaire. Multiple logistic regression was used to analyze the association between the quality of the direct supervisor's behavior and the depressive mood of wage workers. RESULTS: After multivariable adjustment, significantly increased odds ratio (OR) for likely depression was found in the 4, 3, 2, 1, and 0 points of the quality of the direct supervisor's behavior compared to 5 points. After stratification for the level of satisfaction with working conditions, the OR of the unsatisfied groups was higher than that of the satisfied groups. CONCLUSIONS: Likely depression was found to be significantly associated with a low quality of direct supervisor's behavior. This association was stronger in workers who were not satisfied with their working conditions. This study suggests that proper management of the direct supervisor's behavior is needed to reduce the risk of depression among Korean wage workers.

Study on Effective Preservation of Bovine Pericardium Using Decellularization and alpha-galactosidase for Eliminating Xenoreactive Antigen / 대한흉부외과학회지

BACKGROUND: Effective decellularization and fixation process is critical, in order to use xenogenic valves clinically. In the present study, we decellularized bovine pericardium using sodium dodecyl sulfate (SDS) and N-lauroyl sarcosinate, treated with alpha-galactosidase, and then fixed in various manners, to find out the most effective tissue preservation & fixation procedure. MATERIAL AND METHOD: Bovine pericardium was decellularized with SDS and N-lauroyl sarcosinate, and treated with alpha-galactosidase. Both groups were fixed differently, by varying glutaraldehyde (GA) or EDC (1-ethyl-3-(3-dimethyl aminopropyl)-carbodiimide)/N-hydroxysuccinamide (NHS) treatment conditions. Thereafter, physical examination, tensile strength test, thermal stability test, cytotoxicity test, pronase test, pronase-ninhydrin test, purpald test, permeability test, compliance test, H&E staining, DNA quantification, and alpha-galactose staining were carried out to each groups. RESULT: GA fixed groups showed better physical properties and thermal stability than EDC/NHS fixed groups. EDC/NHS-GA dual fixed groups showed better physical properties and thermal stability than EDC/NHS fixed groups, and showed better thermal stability than GA fixed groups. In pronase test and pronase-ninhydrin test, GA fixed groups and EDC/NHS-GA dual fixed groups showed stronger crosslinks than EDC/NHS groups. Permeability and compliance tended to increase in EDC/NHS-GA dual fixed groups, compared to GA fixed groups. But, EDC/NHS-GA dual fixed groups had stronger tensile strength and lower cytotoxicity than GA fixed groups. CONCLUSION: We have verified that EDC/NHS-GA dual fixation can make effective crosslinks and lower the toxicity of GA fixation. Henceforth, we will verify if EDC/NHS-GA dual fixation can lower calcifications & tissue failure in vivo experiment.