Korean version of the MNREAD acuity chart.

To investigate the efficacy of the Korean version of the Minnesota low vision reading chart. A Korean version consisting of 38 items was prepared based on the MNREAD acuity chart developed by the University of Minnesota. A linguist composed the representative sentences, each containing nine words from second and third grade levels of elementary school. Reading ability was measured for 20-35-year-old subjects with normal visual acuity (corrected visual acuity of logMAR 0.0 or better). The maximum reading speed (words per minute [wpm]) for healthy participants, reading acuity (smallest detectable font size), and critical print size (smallest font size without reduction of reading speed) were analyzed. The average age of the subjects was 28.3 ± 2.6 years (male:female ratio, 4:16). The average reading time for 38 sentences was 3.66 ± 0.69 s, with no differences in the average maximum reading speed between sentences (p = 0.836). The maximum reading speed was 174.2 ± 29.3 and 175.4 ± 27.8 in the right and left eye, respectively. Reading acuity was measured as logMAR 0.0 or better in 80% of the cases. All subjects showed a critical print size of 0.2 logMAR or better. The overall reading ability can be measured using the Korean version of the MNREAD acuity chart, thereby making it useful in measuring the reading ability of those with Korean as their native language.

Analyzing correlation between epicardial fat area and metabolic syndrome risk factor by using low-dose Lung CT.

OBJECTIVES: To study about the blood count of a risk factor related to physical measurement and metabolic syndrome, and the area of epicardial fat for medical checkup patients. METHODS: From April 1(st) to November 15(th) in 2014, we measured the area of epicardial fat in the adult out patients under 60 years of age, who are in good health; and the patients took the blood test and low-dose lung CT. In order to identify the relationship between the area of epicardial fat and the risk factor of metabolic syndrome, we conducted correlation analysis. Then, we performed multiple regression analysis to evaluate an independent correlation of epicardial area. In addition, we computed the cut-off value of epicardial fat area by using ROC (Receiver Operating Characteristic) curve to foresee a metabolic syndrome factor that has the most proper sensitivity and specificity. RESULTS: Waist circumference, fasting blood sugar, triglyceride, high-density lipoprotein (HDL) cholesterol, systolic blood pressure, and diastolic blood pressure were shown to be the factors that affect the area of epicardial fat. Therefore, if waist circumference, fasting blood sugar, triglyceride, systolic blood pressure, and diastolic blood pressure were increased, the area of epicardial fat would be significantly increased (P<0.05); and if high-density lipoprotein cholesterol was increased, the area of epicardial fat would be significantly decreased (P<0.05). Out of metabolic syndrome factors, waist circumference's ROC curve area was 0.79 (Confidence Interval 0.73-0.84, P<0.05), which was the highest. The sensitivity was 83.7% when specificity was 70.1%, which proves that they are important factors for the diagnosis. In brief, metabolic syndrome is a disease that mostly appears in obesity patients, so we should try to monitor and cure the disease. CONCLUSION: The risk factors of metabolic syndrome can be managed through health care, and if we try to decrease the risk factors, we will be able to shrink epicardial fat area and decrease metabolic syndrome at the same time.

A randomized comparison of energy consumption when using different canes, inpatients after stroke.

OBJECTIVES: To investigate the differences in oxygen consumption associated with gait in hemiplegic patients according to the type of cane they use. DESIGN: A randomized crossover design. SETTING: University hospital-based rehabilitation center, Korea. SUBJECTS: Thirty consecutive patients (mean ± SD age, 56.3 ± 3.2 years) with chronic stroke, 17 (56.7%) males and 13 (43.3%) females. INTERVENTIONS: At approximately the same time of day for three consecutive days, each participant completed a walk with one of three randomly assigned types of canes: a single-point cane, a quad cane, and a hemi-walker. MAIN OUTCOME MEASURE: Energy expenditure (O2 rate, mL/kg/min), energy cost (O2 cost, mL/kg/m), and heart rate (HR) via a portable gas analyzer, a 10-meter walk test (10MWT), and a 6-minute walk test (6MWT). RESULTS: Energy expenditure, gait endurance, and gait velocity for a single-point cane were higher (p<0.001 or p=0.005) than for any other type of cane. Energy cost (0.5 ± 0.2 mL/kg/m vs. 0.6 ± 0.2 mL/kg/m vs. 0.6 ± 0.2 ml/kg/m, respectively, p=0.001) was lower for the single-point cane, except for HR (p ≥ 0.05) after the Bonferroni correction (0.05/5=0.01). CONCLUSIONS: A single-point cane requires less oxygen use at a given speed, or permits greater speed for the same oxygen consumption.

A pilot study of indoor air quality in screen golf courses.

The aims of this study were to provide basic data for determining policies on air quality for multi-user facilities, including the legal enrollment of the indoor air quality regulation as designated by the Ministry of Environment, and to establish control plans. To this end, concentrations of ten pollutants (PM10, carbon monoxide (CO), carbon dioxide (CO2), nitrogen dioxide (NO2), formaldehyde (HCHO), total volatile organic compounds (TVOCs), radon (Rn), oxone (O3), total bacteria counts (TBC), and asbestos) in addition to nicotine, a smoking index material used to determine the impact of smoking on the air quality, were investigated in indoor game rooms and lobbies of 64 screen golf courses. The average concentration of none of the ten pollutants in the game rooms and lobbies of screen golf courses was found to exceed the limit set by the law. There were, however, pollutant concentrations exceeding limits in some screen golf courses, in order to establish a control plan for the indoor air quality of screen golf courses, a study on the emission sources of each pollutant was conducted. The major emission sources were found to be facility users' activities such as smoking and the use of combustion appliances, building materials, and finishing materials.

The Relationship between Rehabilitation and Changes in Depression in Stroke Patients.

[Purpose] This study investigated the primary factors behind changes in depressive symptoms among stroke patients after 8 weeks of rehabilitation (physical, occupational, and cognitive therapy). [Methods] This study was conducted using a literature review, and electronic medical records from January, 2008 to December, 2009. Data were collected for 120 subjects with chronic stroke. [Results] Cardiac disorder, left-brain lesion, early-stage depression, activities of daily living, and cognitive function were significant predictors of the changes in depression in chronic stroke patients. [Conclusion] Post-stroke depression can be controlled by rehabilitation. Also, clinicians should comprehend and share the psychological and physical affliction, develop back-up programs, and make them comprehensively available to support the psychological and physical health of subjects with chronic stroke.

Increased range of motion and decreased strength of the thumb in massage practitioners with thumb pain.

The purpose of this study was to compare the range of motion (ROM) and strength of the metacarpophalangeal (MP) and interphalangeal (IP) joints among massage practitioners with and without thumb pain and control subjects. Sixteen massage practitioners with thumb pain, 16 practitioners without thumb pain, and 16 control subjects participated in this study. ROM of flexion, extension, and abduction in the MP joint; ROM of flexion and extension in the IP joint of the thumb; strength of the flexor pollicis brevis (FPB), extensor pollicis brevis (EPB), abductor pollicis brevis, flexor pollicis longus (FPL), and extensor pollicis longus measured in all subjects. ROM of extension and abduction in the MP joint were significantly increased in massage practitioners with and without thumb pain compared with control subjects. ROM of extension in the IP joint was significantly increased in massage practitioners with thumb pain compared with those without thumb pain. The strength of the EPB and FPL muscle was significantly decreased in massage practitioners with thumb pain compared with those without thumb pain and control subjects, respectively. In addition, there was significantly increased EPB/FPB strength in massage practitioners without thumb pain compared to those with thumb pain and control subjects.

Distribution features of biological hazardous pollutants in residential environments in Korea.

This research has been conducted continuously since 2009 as part of a cohort of studies examining relationships between asthma and genetic factors, dietary habits, and environmental factors. Based on data from environmental research on house dust mites and endotoxins, which are widely known as pollutants in bedding that cause asthma in pregnant women and children, this work was conducted to obtain basic data that can be used in future cohort studies that analyze links between distribution of biological hazards and physical features of residential environments. The detection rates of house dust mite allergens, Der p1 and Der f1, were 52.7 and 86.5%, respectively, indicating that Der f1 is a dominant species in domestic indoor environments. According to comparisons between concentrations of house dust mites and endotoxins in bedding of pregnant women and children, Der p1 and endotoxins showed significantly lower concentrations in bedding of pregnant women compared with those in bedding of children, whereas Der f1 showed no significant difference in concentration according to bedding.

Current status of trace metal pollution in soils affected by industrial activities.

There is a growing public concern over the potential accumulation of heavy metals in soil, owing to rapid industrial development. In an effort to describe the status of the pollutions of soil by industrial activities, relevant data sets reported by many studies were surveyed and reviewed. The results of our analysis indicate that soils were polluted most significantly by metals such as lead, zinc, copper, and cadmium. If the dominant species are evaluated by the highest mean concentration observed for different industry types, the results were grouped into Pb, Zn, Ni, Cu, Fe, and As in smelting and metal production industries, Mn and Cd in the textile industry, and Cr in the leather industry. In most cases, metal levels in the studied areas were found to exceed the common regulation guideline levels enforced by many countries. The geoaccumulation index (I(geo)), calculated to estimate the enrichment of metal concentrations in soil, showed that the level of metal pollution in most surveyed areas is significant, especially for Pb and Cd. It is thus important to keep systematic and continuous monitoring of heavy metals and their derivatives to manage and suppress such pollution.

Exposure level and distribution characteristics of airborne bacteria and fungi in Seoul metropolitan subway stations.

The exposure level and distribution characteristics of airborne bacteria and fungi were assessed in the workers' activity areas (station office, bedroom, ticket office and driver's seat) and passengers' activity areas (station precinct, inside the passenger carriage, and platform) of the Seoul metropolitan subway. Among investigated areas, the levels of airborne bacteria and fungi in the workers' bedroom and station precincts were relatively high. No significant difference was found in the concentration of airborne bacteria and fungi between the underground and above ground activity areas of the subway. The genera identified in all subway activity areas with a 5% or greater detection rate were Staphylococcus, Micrococcus, Bacillus and Corynebacterium for airborne bacteria and Penicillium, Cladosporium, Chrysosporium, Aspergillus for airborne fungi. Staphylococcus and Micrococcus comprised over 50% of the total airborne bacteria and Penicillium and Cladosporium comprised over 60% of the total airborne fungi, thus these four genera are the predominant genera in the subway station.

Distribution characteristics of airborne bacteria and fungi in the general hospitals of Korea.

The objective of this study is to provide fundamental data related to size-based characteristics of bioaerosol distributed in the general hospital. Measurement sites are main lobby, ICU, surgical ward and biomedical laboratory and total five times were sampled with six-stage cascade impactor. Mean concentrations of airborne bacteria and fungi were the highest in main lobby as followed by an order of surgical ward, ICU and biomedical laboratory. The predominant genera of airborne bacteria identified in the general hospital were Staphylococcus spp. (50%), Micrococcus spp. (15-20%), Corynebacterium spp. (5-20%), and Bacillus spp. (5-15%). On the other hand, the predominant genera of airborne fungi identified in the general hospital were Cladosporium spp. (30%), Penicillium spp. (20-25%), Aspergillus spp. (15-20%), and Alternaria spp. (10-20%). The detection rate was generally highest on stage 5 (1.1-2.1 microm) for airborne bacteria and on stage 1 (>7.0 microm) for airborne fungi.

Respiratory health effects among schoolchildren and their relationship to air pollutants in Korea.

The objective of this study is to investigate the relationship between five air pollutants (PM(10), SO(2), NO(2), O(3), CO) measured on the daily basis, and adverse health symptoms using epidemiological surveillance data. The generalized estimated equation (GEE) model, a logistic regression analysis model, was used to estimate the effects of air pollution on children's daily health symptoms, focusing on the morbidity including both respiratory and allergic symptoms in four different cities. Analysis of the effects of each pollutant on children's respiratory and allergic symptoms demonstrated that CO affected all symptoms in all the study areas. When the concentration of SO(2) and NO(2) was elevated, upper respiratory symptoms increased significantly. In contrast, when the concentration of O(3) rose, the symptoms decreased significantly. The relationship between measured concentrations and health symptoms was site-dependent for each pollutant.

Relationship between particulate matter measured by optical particle counter and mortality in Seoul, Korea, during 2001.

This study was performed to examine the relationship between particulate matter exposure and mortality in Seoul, Korea, during the year 2001. Particulate matter data were collected using an optical particle counter (OPC) and national monitoring stations in Seoul. The size-resolved aerosol number concentrations of particles 0.3-25 microm in diameter and mass concentrations of PM10 (particulate matter less than 10 microm in diameter) and PM2.5 (less than 2.5 microm in diameter) were measured. Meteorological data such as air temperature and relative humidity were provided by the Korea Meteorological Administration. Daily mortality was analyzed using a generalized additive Poisson model, with adjustment for the effects of seasonal trend, air temperature, humidity, and day of the week as confounders, in a nonparametric approach. We used S-Plus for all analyses. Model fitness, using loess smoothing, was based on stringent convergence criteria to minimize the default convergence criteria in the S-Plus generalized additive models module. The IQR (interquartile range) increase of fine particle (10.21 number/cm3 [the total number of particles per cubic centimeter]) and respiratory particle (10.38 number/cm3) number concentration were associated with a 5.73% (5.03%-6.45%) and a 5.82% (5.13%-6.53%) increase in respiratory disease-associated mortality, respectively. Mortality effects in the elderly (aged over 65 years) were increased by more than 0.51% to 2.59%, and the relative risks of respiratory-related and cardiovascular-related mortality were increased by 0.51% to 1.06% compared with all-cause mortality. These findings support the hypothesis that air pollution is harmful to sensitive subjects, such as the elderly, and has a greater effect on respiratory- and cardiovascular-related mortality than all-cause mortality. However, our results using OPC data did not support the hypothesis that PM2.5 would have more adverse health effects than PM10 in number concentration but not in mass concentration.

Assessment of Korean farmer's exposure level to dust in pig buildings.

The purpose of the study was to assess Korean farmer's exposure level to dust in pig buildings and dust emissions by investigating airborne concentrations of total and respirable dust. Five main types of pig buildings operating currently in Korea were selected. For area air sampling, 30 sites per each building type were visited during spring (March-May) and autumn (September-November) seasons. For personal air sampling, concentrations of total and respirable dust were measured for 2-3 hours, during cleaning the pig building before the end of the daily shift, by attaching air sampling equipment near to the farmer's breathing zone. Measurement were taken for 8 hours, e.g. average daily work time (09:00-17:00), at 0.5 m above the floor at three locations on the central alley in the pig building. Emission rates of total and respirable dust were estimated by multiplying the mean concentration of total and respirable dust measured near the air outlet by the mean ventilation rate, and expressed either per area or per pig of live weight. The ranges of farmer's exposure level to total dust and respirable dust in the pig buildings were estimated as 0.6-6.7 mg m(-3) and 0.3-3.5 mg m(-3), respectively. The pig buildings operated with a deep-litter bed system showed the highest dust level while the naturally ventilated pig buildings with slats represented the lowest dust level (p<0.05). Emission rates ranged from 35-400 mg h(-1) m(-2) for total dust and from 4-40 mg h(-1) m(-2) for respirable dust, respectively, indicating a similar pattern for the distribution of exposure level. Korean farmers' exposure level to dust in all the pig buildings investigated was below the exposure limit value equal in Korea equal to 10 mg m(-3), while it exceeded the threshold limit values (TLVs) established in other developed countries. In comparison with previous studies performed in other countries, mean exposure level in the pig buildings of Korea was generally lower for total dust and higher for respirable dust based on the area sampling method.

Effect of manual feeding on the level of farmer's exposure to airborne contaminants in the confinement nursery pig house.

The objective of the study is to demonstrate an effect of manual feeding on the level of farmer's exposure to airborne contaminants in the confinement nursery pig house. The levels of all the airborne contaminants besides respirable dust, total airborne fungi and ammonia were significantly higher in the treated nursery pig house with feeding than the control nursery pig house without feeding. Although there is no significant difference in respirable dust and total airborne fungi between the treatment and the control, their concentrations in the treated nursery pig house were also higher than the control nursery pig house. The result that the level of ammonia in the treated nursery pig house is lower than the control nursery pig house would be reasoned by the mechanism of ammonia generation in the pig house and adsorption property of ammonia to dust particles. In conclusion, manual feeding by farmer increased the exposure level of airborne contaminants compared to no feeding activity.

Odor reduction rate in the confinement pig building by spraying various additives.

The objective of this on-site experiment was to evaluate and compare the effectiveness of currently utilized various additives, i.e. tap water, salt water, digested manure, microbial additive, soybean oil, artificial spice and essential oil, to reduce odor emissions from the confinement pig building. Odor reduction rates were evaluated with respect to sensual odor (odor concentration index, odor intensity and odor offensiveness) and odorous compounds (ammonia and sulfuric odorous compounds). Of the additives investigated in this study, salt water, artificial spice and essential oil had a positive effect on reducing odor generation. The effectiveness of salt water was only observed on ammonia, showing the reduction rates as a function of time (t=immediately, 1h, 3h, 5h, and 24h after spraying) were 0.1%, 20%, 36%, 11% and 0.2% as compared to initial level before spraying. The odor intensity and offensiveness were lessened by spraying artificial spice and essential oil of which maximum reduction rates ranged from 60% to 80%. Additionally, the essential oil had a significant effect on reducing sulfuric odorous compounds for 24h after spraying, which implicates that it functioned as not only a masking agent but also as an antimicrobial agent.

Spatial distribution of particulate matter (PM10 and PM2.5) in Seoul Metropolitan Subway stations.

The aims of this study are to examine the concentrations of PM10 and PM2.5 in areas within the Seoul Metropolitan Subway network and to provide fundamental data in order to protect respiratory health of subway workers and passengers from air pollutants. A total of 22 subway stations located on lines 1-4 were selected based on subway official's guidance. At these stations both subway worker areas (station offices, rest areas, ticket offices and driver compartments) and passengers areas (station precincts, subway carriages and platforms) were the sites used for measuring the levels of PM. The mean concentrations of PM10 and PM2.5 were relatively higher on platforms, inside subway carriages and in driver compartments than in the other areas monitored. The levels of PM10 and PM2.5 for station precincts and platforms exceeded the 24-h acceptable threshold limits of 150 microg/m3 for PM10 and 35 microg/m3 for PM2.5, which are regulated by the U.S. Environmental Protection Agency (EPA). However, levels measured in station and ticket offices fell below the respective threshold. The mean PM10 and PM2.5 concentrations on platforms located underground were significantly higher than those at ground level (p<0.05).

Influence of extreme seasons on airborne pollutant levels in a pig-confinement building.

Understanding airborne pollutant levels in a pig-confinement building in seasons with extreme weather (ie, summer and winter) is important for managing air quality, which affects the health of farmers and others in the neighboring environment. The authors evaluated airborne pollutants-total dust, total airborne bacteria, and total airborne gram-negative bacteria-which had higher concentrations in summer than in winter, and concentrations of respirable dust, gaseous pollutants, and total airborne fungi, which were lower in summer than in winter. The authors found significant differences between summer and winter measurements for respirable dust and gaseous pollutants (p < .05). Total dust was positively correlated with bioaerosols and ammonia (p < .05), whereas respirable dust was positively correlated with odor concentration index (p < .05) and hydrogen sulfide (p < .01).

Effect of ventilation rate on gradient of aerial contaminants in the confinement pig building.

The principal aim of this study was to compare the aerial contaminants concentrations between the levels of ventilation rate and determine the variation pattern of aerial contaminants affected by the ventilation rate. As a result, there was not significant difference in total dust and total airborne microorganisms among three levels of ventilation rate (P>0.05) whereas the increased ventilation rate lowered the levels of respirable dust and gaseous compounds (P<0.05). Based on the results, it was concluded that the suspended gases in the confinement pig building generally followed the air streamline formed by the ventilation whereas the ventilation rate had little effect on the gradient of particulates, especially total dust, due to gravity generated by their size and weight. The findings that the concentrations of total airborne microorganisms were not also significantly different among the ventilation rates could be explained in terms of the fact that airborne microorganisms are easily adsorbed on the surface of dust particle.

Molecular analysis of hprt mutation in B6C3F1 mice exposed to ozone alone and combined treatment of 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone and/or dibutyl phthalate for 32 and 52 weeks.

Potential toxicological interactions of 4-(N-methyl-N-nitrosamino)-1-(3-pyridyl)-1-butanone (NNK) and/or dibuthyl phthalate (DBP) on ozone were investigated after 32- and 52-wk exposures using hprt mutation assay. Male and female B6C3F1 mice exposed to ozone (0.5 ppm), NNK (1.0 mg/kg), DBP (5,000 ppm), and two or three combinations of these toxicants 6 h per day for 32- and 52-wk showed increases in the frequencies of TG rlymphocytes compared to the control groups. Additive interactions were noted from two combination groups compared to the ozone alone in both sexes of 32- and 52-wk studies. The most common specific mutation type in the hprt genes of test materials-treated male and female mice was transversion with very few transition. The results indicate that such dominant transversion may be responsible for toxicity and combined exposure to ozone, NNK, and DBP induces additive genotoxicities compared to ozone alone.

Comparative study of PM2.5 - and PM10 - induced oxidative stress in rat lung epithelial cells.

Accurate estimation of the exposure-response relationship between ambient urban particulate matters (PM) and public health is important for regulatory perspective of ambient urban particulate matters (PM). Ambient PM contains various transition metals and organic compounds. PM10 (aerodynamic diameter less than 10 micro m) is known to induce diverse diseases such as chronic cough, bronchitis, chest illness, etc. However, recent evaluation of PM2.5 (aerodynamic diameter less than 2.5 micro m) against health outcomes has suggested that the fine particles may be more closely associated with adverse respiratory health effects than particles of larger size. This study was performed to evaluate PM2.5-induced oxidative stress in rat lung epithelial cell in order to provide basic data for the risk assessment of PM2.5. PM2.5 showed higher cytotoxicity than PM10. Also, PM 2.5 induced more malondialdehyde (MDA) formation than PM10. In Hoechst 33258 dye staining and DNA fragmentation assay, apopotic changes were clearly detected in PM2.5 treated cells in compared to PM10. Expression of catalase mRNA was increased by PM2.5 rather than PM10. PM2.5 induced higher Mth1 mRNA than PM10. In pBR322 DNA treated with PM2.5, production of single strand breakage of DNA was higher than that of PM10. In Western blot analysis, PM2.5 induced more Nrf-2 protein, associated with diverse transcriptional and anti-oxidative stress enzymes, compared to PM10. Our data suggest that PM2.5 rather than PM10 may be responsible for PM-induced toxicity. Additional efforts are needed to establish the environmental standard of PM2.5.