• Tuberculosis and Respiratory Diseases
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• v.57 no.6
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• pp.543-552
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• 2004

Background : Airway remodeling of the asthmatic airway, the result of persistent inflammation in the bronchial wall, is associated with irreversible airway obstruction and the severity of asthma. Previous reports had represented that adminitering CpG-oligodeoxynucleotides (CpG-ODN) before sensitization or challenge by allergens inhibits the development of eosinophilic airway inflammation in a murine model of asthma, but the effects of CpG-ODNs on chronic inflammation and airway remodeling had not been characterized. To investigate the influence of CpG-ODNs on chronic inflammation and remodeling of the airway, we performed studies using a murine model of chronic allergen-induced asthma. Methods : Balb/C mice were sensitized to ovalbumin(OVA) and subsequently exposed to nebulized OVA by means of inhalation twice weekly for 7 weeks. CpG-ODNs($30{\mu}g$) was administered intraperitoneally at sensitization. After final inhalation, mice were evaluated for airway hyperresponsiveness, chronic airway inflammation and remodeling. Results : The mice exposed to chronic and recurrent airway challenge with OVA had persistent airway hyperresponsiveness, chronic inflammation and airway remodeling. Mice treated with CpG-ODNs exhibited decreased bronchial hyperresponsiveness, OVA-specific IgE, chronic inflammation and evidence of airway remodeling, including goblet cell hyperplasia and subepithelial fibrosis. Conclusion : CpG-ODNs was thought to prevent chronic inflammation and remodeling changes in a murine model of chronic asthma.

• Korean Journal of Remote Sensing
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• v.37 no.2
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• pp.321-335
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• 2021

Particulate matter (PM10 and PM2.5 with a diameter less than 10 and 2.5 ㎛, respectively) can be absorbed by the human body and adversely affect human health. Although most of the PM monitoring are based on ground-based observations, they are limited to point-based measurement sites, which leads to uncertainty in PM estimation for regions without observation sites. It is possible to overcome their spatial limitation by using satellite data. In this study, we developed machine learning-based retrieval algorithm for ground-level PM10 and PM2.5 concentrations using aerosol parameters from Geostationary Ocean Color Imager (GOCI) satellite and various meteorological parameters from a numerical weather prediction model during January to December of 2019. Gradient Boosted Regression Trees (GBRT) and Light Gradient Boosting Machine (LightGBM) were used to estimate PM concentrations. The model performances were examined for two types of feature sets-all input parameters (Feature set 1) and a subset of input parameters without meteorological and land-cover parameters (Feature set 2). Both models showed higher accuracy (about 10 % higher in R2) by using the Feature set 1 than the Feature set 2. The GBRT model using Feature set 1 was chosen as the final model for further analysis(PM10: R2 = 0.82, nRMSE = 34.9 %, PM2.5: R2 = 0.75, nRMSE = 35.6 %). The spatial distribution of the seasonal and annual-averaged PM concentrations was similar with in-situ observations, except for the northeastern part of China with bright surface reflectance. Their spatial distribution and seasonal changes were well matched with in-situ measurements.

• Tuberculosis and Respiratory Diseases
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• v.58 no.3
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• pp.230-242
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• 2005

Background : Spirometry should be compared with the normal predictive values obtained from the same population using the same procedures, because different ethnicity and different procedures are known to influence the spirometry results. This study was performed to obtain the normal predictive values of the Forced Vital Capacity(FVC), Forced Expiratory Volume in 1 Second($FEV_1$), Forced Expiratory Volume in 6 Seconds($FEV_6$), and $FEV_1/FVC$ for a representative Korean population. Methods : Based on the 2000 Population Census of the National Statistical Office of Korea, stratified random sampling was carried out to obtain representative samples of the Korean population. This study was performed as a part of the National Health and Nutrition Survey of Korea in 2001. The lung function was measured using the standardized methods and protocols recommended by the American Thoracic Society. Among those 4,816 subjects who had performed spirometry performed, there was a total of 1,212 nonsmokers (206 males and 1,006 females) with no significant history of respiratory diseases and symptoms, with clear chest X-rays, and with no significant exposure to respiratory hazards subjects. Their residence and age distribution was representative of the whole nation. Mixed effect models were examined based on the Akaike's information criteria in statistical analysis, and those variables common to both genders were analyzed by regression analysis to obtain the final equations. Results : The variables affecting the normal predicted values of the FVC and $FEV_6$ for males and females were $age^2$, height, and weight. The variables affecting the normal predicted values of the $FEV_1$ for males and females were $age^2$, and height. The variables affecting the normal predicted values of the $FEV_1/FVC$ for male and female were age and height. Conclusion : The predicted values of the FVC and $FEV_1$ was higher in this study than in other Korean or foreign studies, even though the difference was < 10%. When compared with those predicted values for Caucasian populations, the study results were actually comparable or higher, which might be due to the stricter criteria of the normal population and the systemic quality controls applied to the whole study procedures together with the rapid physical growth of the younger generations in Korea.

• Journal of Radiation Protection and Research
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• v.40 no.4
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• pp.216-222
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• 2015

Facilities processing raw materials containing naturally occurring radioactive materials (NORM) may give rise to enhanced radiation dose to workers due to chronic inhalation of airborne particulates. Internal radiation dose due to particulate inhalation varies depending on particulate properties, including size, shape, density, and absorption type. The objective of the present study was to assess inhalation dose sensitivity to physicochemical properties of airborne particulates. Committed effective doses to workers resulting from inhalation of airborne particulates were calculated based on International Commission on Radiological Protection 66 human respiratory tract model. Inhalation dose generally increased with decreasing particulate size. Committed effective doses due to inhalation of $0.01{\mu}m$ sized particulates were higher than doses due to $100{\mu}m$ sized particulates by factors of about 100 and 50 for $^{238}U$ and $^{230}Th$, respectively. Inhalation dose increased with decreasing shape factor. Shape factors of 1 and 2 resulted in dose difference by about 18 %. Inhalation dose increased with particulate mass density. Particulate mass densities of $11g{\cdot}cm^{-3}$ and $0.7g{\cdot}cm^{-3}$ resulted in dose difference by about 60 %. For $^{238}U$, inhalation doses were higher for absorption type of S, M, and F in that sequence. Committed effective dose for absorption type S of $^{238}U$ was about 9 times higher than dose for absorption F. For $^{230}Th$, inhalation doses were higher for absorption type of F, M, and S in that sequence. Committed effective dose for absorption type F of $^{230}Th$ was about 16 times higher than dose for absorption S. Consequently, use of default values for particulate properties without consideration of site specific physiochemical properties may potentially skew radiation dose estimates to unrealistic values up to 1-2 orders of magnitude. For this reason, it is highly recommended to consider site specific working materials and conditions and use the site specific particulate properties to accurately access radiation dose to workers at NORM processing facilities.

• KIPS Transactions on Software and Data Engineering
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• v.9 no.4
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• pp.129-136
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• 2020

PM2.5 which is a very tiny air particulate matter even smaller than PM10 has been issued in the environmental problem. Since PM2.5 can cause eye diseases or respiratory problems and infiltrate even deep blood vessels in the brain, it is important to predict PM2.5. However, it is difficult to predict PM2.5 because there is no clear explanation yet regarding the creation and the movement of PM2.5. Thus, prediction methods which not only predict PM2.5 accurately but also have the interpretability of the result are needed. To predict hourly PM2.5 of Seoul city, we propose a method using random forest with the adjusted bootstrap number from the time series ground data preprocessed on different sources. With this method, the prediction model can be trained uniformly on hourly information and the result has the interpretability. To evaluate the prediction performance, we conducted comparative experiments. As a result, the performance of the proposed method was superior against other models in all labels. Also, the proposed method showed the importance of the variables regarding the creation of PM2.5 and the effect of China.

• Tuberculosis and Respiratory Diseases
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• v.62 no.2
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• pp.105-112
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• 2007

Background: Oxidative stress may play an important role in the pathogenesis of endotoxin-induced acute lung injury (ALI). This study evaluated the therapeutic effect of ${\alpha}$-lipoic acid, a nonenzymatic antioxidant, in a rat model of lipopolysaccharide (LPS) induced ALI. Materials and Methods: ALI was induced in Sprague-Dawley rats by instilling LPS (E.coli, 3mg/Kg) into the trachea. The rats were classified into the control, control+${\alpha}$-lipoic acid, LPS, and LPS+${\alpha}$-lipoic acid groups.The lung lavage neutrophil count, cytokine-induced neutrophil chemoattractant (CINC), lung myeloperoxidase (MPO), and cytokine concentrations (TNF-${\alpha}$, IL-$1{\beta}$, IL-6 and IL-10) were measured at 2 h and 6 h after LPS administration. Results: The total cell and neutrophil counts of the LPS+${\alpha}$-lipoic acid groups were significantly lower than the LPS groups. The protein concentration in the BAL fluid was similar in the LPS groups and LPS+${\alpha}$-lipoic acid groups. The TNF-${\alpha}$, IL-$1{\beta}$, and IL-6 concentrations in the BAL fluid were not decreased by the ${\alpha}$-lipoic acid treatment in the LPS treated rats. Conclusions: Although ${\alpha}$-lipoic acid decreased the level of LPS-induced neutrophil infiltration into the lung, it could not attenuate the LPS-induced ALI at the dose administered in this study.

• Journal of Service Research and Studies
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• v.13 no.1
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• pp.63-75
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• 2023

Due to the development of industry, interest in air pollutants has increased. Air pollutants have affected various fields such as environmental pollution and global warming. Among them, environmental diseases are one of the fields affected by air pollutants. Air pollutants can affect the human body's skin or respiratory tract due to their small molecular size. As a result, various studies on air pollutants and environmental diseases have been conducted. Asthma, part of an environmental disease, can be life-threatening if symptoms worsen and cause asthma attacks, and in the case of adult asthma, it is difficult to cure once it occurs. Factors that worsen asthma include particulate matter and air pollution. Asthma is an increasing prevalence worldwide. In this paper, we study how air pollutants correlate with the number of emergency room admissions in asthma patients and predict the number of future asthma emergency patients using highly correlated air pollutants. Air pollutants used concentrations of five pollutants: sulfur dioxide(SO₂), carbon monoxide(CO), ozone(O₃), nitrogen dioxide(NO₂), and fine dust(PM₁₀), and environmental diseases used data on the number of hospitalizations of asthma patients in the emergency room. Data on the number of emergency patients of air pollutants and asthma were used for a total of 5 years from January 1, 2013 to December 31, 2017. The model made predictions using two models, Informer and LTSF-Linear, and performance indicators of MAE, MAPE, and RMSE were used to measure the performance of the model. The results were compared by making predictions for both cases including and not including the number of emergency patients. This paper presents air pollutants that improve the model's performance in predicting the number of asthma emergency patients using Informer and LTSF-Linear models.

• Tuberculosis and Respiratory Diseases
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• v.50 no.1
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• pp.12-28
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• 2001

Background and Object : Immunostimulatory CpG-oligodeoxynucleotides (ISS CpG-ODN) up-regulate the $T_{H1}$-type immune response and down-regulate the $T_{H2}$-type response. This study was performed to investigate the immune response changes resulting from ISS CpG-ODN on bronchial hyperresponsiveness, eosinophilic inflammation and mucus hypersecretion in rat asthma. Materials and Methods : 10 normal controls(NC) and 26 asthmatic rats, which were generated by ovalbumin(OVA) sensitization and challenge, were studied. The asthmatic rats were randomized into 11 asthma controls(AC) and 15 in the asthma-CpG treatment group(CpG). The CpG group was administered ISS CpG-ODN intramuscularly and the AC group was administered a placebo(0.9% NaCl) on day 15 and 20. After CpG-ODN or placebo administration, we measured the IFN-${\gamma}$($T_{H1}$-type cytokine) and IL-4($T_{H2}$-type cytokine) levels in the bronchoalveolar lavage fluid(BALF), the specific airway resistance(sRaw), eosinophilic fraction in BALF, eosinophilic infiltration, goblet cell dysplasia and MUC5AC gene expression in the lung tissue. Results : In the BALF of the CpG group, the IFN-${\gamma}$ concentration was significantly high and the IL-4 concentration was significantly low when compared with the AC group. Both the sRaw and eosinophilic fraction, and infiltration into the BALF and lung tissue significantly lower in the CpG group when compared with the AC group. However, little difference in goblet cell dysplasia and MUC5AC gene expression was observed between the CpG group and the AC group. Conclusion : ISS CpG-ODN decreases bronchial hyperresponsiveness and eosinophilic inflammation in the rat asthma model through the up-regulation of the $T_{H1}$-type immune response with the down-regulation of the $T_{H2}$-type response. However, the effect of these immune response changes on mucus hypersecretion was is not remarkable in this study.

• Tuberculosis and Respiratory Diseases
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• v.55 no.2
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• pp.154-164
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• 2003

Background : Until the early 1990's in Korea, treatment outcomes of patients with pulmonary tuberculosis in the private sector were reported to be inferior to those of the public health center under the National Tuberculosis Programme. The purpose of this study was to analyze the clinical characteristics and the treatment efficacy of the patients with pulmonary tuberculosis recently diagnosed at a private general hospital. Materials and Methods : The study included all pulmonary tuberculosis patients diagnosed at Samsung Medical Center and notified to the public health center from August 2000 to January 2001. Results : Of the 232 patients included in the study during a 6-month period, 188 were (81.0%) initial treatment cases and 44 (19.0%) were re-treatment cases. Eighty-three (35.8%) patients had smear-positive sputa, and 27 (11.6%) had smear-negative, culture-positive sputa. Initial sputum examinations were not performed in 47 (20.3%) patients. A six-month, short-course treatment using isoniazid, rifampin, ethambutol and pyrazinamide was prescribed for 31.4% of the patients under the initial treatment. The success rate (cured plus treatment completed) of the initial treatment for the smear-positive patients was 69.1%. Eleven (13.3%) of the 83 patients with smear-positive pulmonary tuberculosis discontinued their treatment without notice. Conclusions : To improve the treatment efficacy and decrease the default rates of the patients with pulmonary tuberculosis in the private sector, further efforts are required in line with the Korean Academy of Tuberculosis and Respiratory Disease Treatment Guidelines and in the implementation of an appropriate model of public-private mix for tuberculosis control in Korea.

• Tuberculosis and Respiratory Diseases
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• v.53 no.4
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• pp.431-438
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• 2002

Background : In order to investigate the usefulness and safety of Natural Stent, we performed this study in a canine model of tracheal stenosis induced using Nd-YAG laser. Materials and Methods : After tracheal stenosis was induced in 12 Mongrel dogs using Nd-YAG laser, either Dumon (n=6) or Natural (n=6) stent was inserted into the trachea. To assess the degree of stent migration and mucostasis, bronchoscopy was performed every week for 4 weeks, after which all stents were removed. One week after stent removal, tracheal stenosis was evaluated by bronchoscopy. Results : The degree of stent migration was not different between the dogs with Dumon stent ($3.0{\pm}0.8$) and those with Natural ($2.0{\pm}1.0$), nor was the degree of mucostasis, at Dumon ($1.7{\pm}0.5$) and Natural Stent ($1.5{\pm}0.6$), respectively. One week after stent removal, the degree of tracheal stenosis was not different between the Dumon ($1.5{\pm}0.5$) and the Natural group ($1.0{\pm}0.4$). In addition, there was no death and the degree of tracheal stenosis remained always within the safe limit (less than 2.0) in all animals. Conclusion : In a canine model of tracheal stenosis induced using Nd-YAG laser, the usefulness and safety of Natural Stent were similar to those of Dumon Stent. A clinical trial is necessary to document the usefulness and safety of Natural Stent in patients with tracheal stenosis.