• Clinical and Experimental Pediatrics
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• v.63 no.7
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• pp.251-258
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• 2020

Exposure to environmental factors can cause interstitial lung diseases (ILDs); however, such types of ILDs are rare. From 2007 to 2011, an ILD epidemic occurred in South Korea owing to inhalational exposure to toxic chemicals in humidifier disinfectants (HDs). HD-associated ILDs (HD-ILDs) are characterized by rapidly progressing respiratory failure with pulmonary fibrosis and a high mortality rate of 43.8%-58.0%. Although 18.1%-31.1% of the general population used HDs, only a small proportion of HD users were diagnosed with HD-ILDs. This finding suggests that investigation of the pathophysiologies underlying HD-ILDs is needed in addition to the identification of susceptibility to HD-ILDs. Further, there have been several concerns regarding the diverse health effects of exposure to toxic chemicals in HDs, including those that have not been identified, and long-term prognoses in terms of pulmonary function and residual pulmonary lesions observed on follow-up chest images. In this review, we summarize the clinical features, pathologic findings, and changes in radiologic findings over time in patients with HD-ILDs and the results of previous experimental research on the mechanisms underlying the effects of toxic chemicals in HDs. Studies are currently underway to identify the pathophysiologies of HD-ILDs and possible health effects of exposure to HDs along with the development of targeted therapeutic strategies. The experience of identification of HD-ILDs has encouraged stricter control of safe chemicals in everyday life.

• Tuberculosis and Respiratory Diseases
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• v.83 no.2
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• pp.122-131
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• 2020

Hypersensitivity Pneumonitis (HP) one of the most common interstitial lung diseases (ILDs) is characterized by exposure to an inhaled inciting antigen that leads to a host immunologic reaction determining interstitial inflammation and architectural distortion. The underlying pathogenetic mechanisms are unclear. The absence of international shared diagnostic guidelines and the lack of a "gold-standard" test for HP combined with the presence of several clinical and radiologic overlapping features makes it particularly challenging to differentiate HP from other ILDs, also in expert contests. Radiology is playing a more crucial role in this process; recently the headcheese sign was recognized as a more specific for chronic-HP than the extensive mosaic attenuation. Several classification proposals and diagnostic models have been advanced by different groups, with no prospective validation. Therapeutic options for HP have been limited to antigen avoidance and immunosuppressant drugs over the last decades. Several questions about this condition remain unanswered and there is a need for more studies.

• Nuclear Engineering and Technology
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• v.33 no.3
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• pp.349-354
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• 2001

While the United Nations UN) agencies work to restrict the manufacture, sale, and use of land-mines worldwide, a massive clean-up effort is needed to find and destroy the estimated 100 million land-mines still buried around the world. Land-mines left behind from wars worldwide are one of the past century＇s main unsolved problems of war and remain the focus of humanitarian land-mine detection and removal primarily in Europe, Africa, Asia and Central and South America. For example, approximately 1 million anti-personnel mines and other various kinds which have been buried in the 249.4 km (155 miles) demilitarized zone (DMZ) of the Korean peninsular should be completely removed in historical process of the peaceful unification between South and North Korea. In this regard, the current trends of technologies linked to land-mine detection systems are surveyed.

• Tuberculosis and Respiratory Diseases
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• v.41 no.6
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• pp.604-615
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• 1994

Background: Analysis of cells in bronchoalveolar lavage(BAL) fluid had been used to predict the histologic changes of the bronchioles and alveoli in patients with interstitial lung diseases(ILD). Definitive diagnosis can be a1so made in some cases of ILD, such as histiocytosis. However, there are a few data of the cellular components in BAL fluid in normal Korean individuals and in patients with ILD. In order to evaluate the role of the cellular analysis of BAL fluid in prediction of alveolitis and differential diagnosis among ILDs, we compared the cellular components in BAL fluid from 50 normal individuals and 86 ILD patients. Method: BAL was performed by instillation and retrievement of normal saline with fiberoptic bronchoscopy. The cell number was counted by Hemocytometer. Differential count was done up to 500 cells on slides prepared by Diff-Quik stain and non-specific esterase stain. We compared the recovery rate(RR), cell numbers(CN), and percentages of each cellular components(CP). Results: The results were as follows: 1) There was no difference in RR, CN and CP between the normal smoker group and normal non-smoker group. 2) Total cell numbers recoverd in BAL fluid increased in collagen vascular diseases(CVD), hypersensitivity pneumonitis(HP), idiopathic pulmonary fibrosis(IPF), and miliary tuberculosis(Mil TBC) groups. 3) The percentage of lymphocytes increased in HP, IPF and Mil TBC groups. Macrophage percentages increased in HP, IPF, and Mil TBC groups. Neutrophil percentages were increased in CVD, HP, IPF and Mil TBC groups. Eosinophil percentages were increased in HP, IPF and Mil TBC groups. The numbers of each cells showed same findings as the percentages did. Conclusion: The analysis of cellular components of BAL fluid can predict the presence of alveolitis in many cases of ILDs. However, It was not helpful in differential diagnosis among ILDs.

• Journal of the Korean Society of Radiology
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• v.82 no.4
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• pp.817-825
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• 2021

Hypersensitivity pneumonitis (HP) is an interstitial lung disease (ILD) characterized by an inhaled inciting antigen that leads to the inflammation of the lung parenchyma and small airway with immunologic reactions. Over the last decades, the most effective therapeutic option for HP has been limited to antigen avoidance. The differential diagnosis of HP from other ILDs is the beginning of treatment as well as diagnosis. However, the presence of several overlapping clinical and radiologic features makes differentiating HP from other ILDs particularly challenging. In 2020, a multidisciplinary committee of experts from the American Thoracic Society, Japanese Respiratory Society, and Asociación Latinoamericana del Tórax suggested a new clinical practice guideline classifying HP into nonfibrotic and fibrotic phenotypes on the basis of chest high-resolution CT (HRCT) findings. Therefore, we introduced a new diagnostic algorithm based on chest HRCT in the clinical practice guideline for the diagnosis of HP.

• Smart Structures and Systems
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• v.33 no.1
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• pp.27-39
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• 2024

The effectiveness of conventional tuned liquid dampers (TLDs) in controlling the wind-induced response of tall flexible structures has been indicated. However, the impaired control effect in the detuning condition or a considerably high mass cost of liquid may be incurred in ensuring the high-level serviceability. To provide an efficient TLD-based solution for wind-induced vibration control, this study proposes a serviceability-oriented optimal design method for isolated TLDs (ILDs) and derives analytical design formulae. The ILD is implemented by mounting the TLD on the linear isolators. Stochastic response analysis is performed for the ILD-equipped structure subjected to stochastic wind and white noise, and the results are considered to derive the closed-form responses. Correspondingly, an extensive parametric analysis is conducted to clarify a serviceability-oriented optimal design framework by incorporating the comfort demand. The obtained results show that the high-level serviceability demand can be satisfied by the ILD based on the proposed optimal design framework. Analytical design formulae can be preliminarily adopted to ensure the target serviceability demand while enhancing the structural displacement performance to increase the safety level. Compared with conventional TLD systems, the ILD exhibits higher effectiveness and a larger frequency bandwidth for wind-induced vibration control at a small mass ratio.

• Tuberculosis and Respiratory Diseases
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• v.73 no.3
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• pp.162-168
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• 2012

Background: Idiopathic pulmonary fibrosis (IPF) is a progressive disease. Effective treatment is not currently available and the prognosis is poor. The aim of our study was to identify clinical predictors of survival in patients with IPF. Methods: By using medical record database of a university hospital, we reviewed the records of patients who had been diagnosed as having IPF from January 1996 through December 2007. Results: Among 89 patients considered as having interstitial lung disease (ILD) on computed tomography (CT) of the chest, 22 were excluded because of the diagnosis of other ILDs or connective tissue disease, and finally, 67 met the criteria of IPF. The mean age at the diagnosis of IPF was 70 years (range, 41~87 years) and 43 (64%) were male. The mean survival time following the diagnosis of IPF was 40 months (range, 0~179 months). Among them, 28 cases were diagnosed as the progressive state of IPF on the follow-up CT examination, and the mean duration between diagnosis of IPF and progression was 31 months. Multivariate analysis using Cox regression model revealed that body mass index (BMI) less than 18.5 $kg/m^2$ (p=0.030; hazard ratio [HR], 12.085; 95% confidence interval [CI], 1.277~114.331) and CT progression before 36 months from the diagnosis of IPF (p=0.042; HR, 13.564; 95% CI, 1.101~167.166) were independently associated with mortality. Conclusion: Since low BMI at the diagnosis of IPF and progression on follow-up CT were associated with poor prognosis, IPF patients with low BMI and/or progression before 36 months following the diagnosis should be closely monitored.

• Tuberculosis and Respiratory Diseases
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• v.87 no.2
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• pp.185-193
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• 2024

Background: The mechanisms leading to lung fibrosis are still under investigation. This study aimed to demonstrate whether antacids could prevent the development of interstitial lung disease (ILD). Methods: This population-based longitudinal cohort study was conducted between January 2006 and December 2010 in South Korea. Eligible subjects were ≥40 years of age, exposed to proton pump inhibitors (PPI)±histamine-2 receptor antagonists (H-2 blockers) or H-2 blockers only, and had no history of ILD between 2004 and 2005. Exposure to antacids was defined as the administration of either PPI or H-2 receptor antagonists for >14 days, whereas underexposure was defined as antacid treatment administered for less than 14 days. Newly developed ILDs, including idiopathic pulmonary fibrosis (IPF), were counted during the 5-year observation period. The association between antacid exposure and ILD development was evaluated using adjusted Cox regression models with variables, such as age, sex, smoking history, and comorbidities. Results: The incidence rates of ILD with/without antacid use were 43.2 and 33.8/100,000 person-years, respectively and those of IPF were 14.9 and 22.9/100,000 person-years, respectively. In multivariable analysis, exposure to antacid before the diagnosis of ILD was independently associated with a reduced development of ILD (hazard ratio [HR], 0.57; 95% confidence interval [CI], 0.45 to 0.71; p<0.001), while antacid exposure was not associated with development of IPF (HR, 0.88; 95% CI, 0.72 to 1.09; p=0.06). Conclusion: Antacid exposure may be independently associated with a decreased risk of ILD development.

• Tuberculosis and Respiratory Diseases
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• v.87 no.2
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• pp.123-133
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• 2024

Interstitial lung diseases (ILDs) are a diverse collection of lung disorders sharing similar features, such as inflammation and fibrosis. The diagnosis and management of ILD require a multidisciplinary approach using clinical, radiological, and pathological evaluation. Progressive pulmonary fibrosis (PPF) is a distinct form of progressive and fibrotic disease, occurring in ILD cases other than in idiopathic pulmonary fibrosis (IPF). It is defined based on clinical symptoms, lung function, and chest imaging, regardless of the underlying condition. The progression to PPF must be monitored through a combination of pulmonary function tests (forced vital capacity [FVC] and diffusing capacity of the lung for carbon monoxide), an assessment of symptoms, and computed tomography scans, with regular follow-up. Although the precise mechanisms of PPF remain unclear, there is evidence of shared pathogenetic mechanisms with IPF, contributing to similar disease behavior and worse prognosis compared to non-PPF ILD. Pharmacological treatment of PPF includes immunomodulatory agents to reduce inflammation and the use of antifibrotics to target progressive fibrosis. Nintedanib, a known antifibrotic agent, was found to be effective in slowing IPF progression and reducing the annual rate of decline in FVC among patients with PPF compared to placebos. Nonpharmacological treatment, including pulmonary rehabilitation, supplemental oxygen therapy, and vaccination, also play important roles in the management of PPF, leading to comprehensive care for patients with ILD. Although there is currently no cure for PPF, there are treatments that can help slow the progression of the disease and improve quality of life.

• Tuberculosis and Respiratory Diseases
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• v.85 no.4
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• pp.341-348
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• 2022

Background: An accurate diagnosis in patients with interstitial lung diseases (ILDs) by multidisciplinary discussion (MDD) based on histopathologic information is essential for optimal treatment. Transbronchial lung cryobiopsy (TBLC) has increasingly been used as a diagnostic alternative to surgical lung biopsy. This study aimed to evaluate the appropriate methods of TBLC in patients with ILD in Korea. Methods: A total of 27 patients who underwent TBLC were included. TBLC procedure details and clinical MDD diagnosis using TBLC histopathologic information were retrospectively analyzed. Results: All procedures were performed under general anesthesia with the fluoroscopic guidance in the operation room using flexible bronchoscopy and endobronchial balloon blocker. The median procedure duration was less than 30 minutes, and the median number of biopsies per participant was 2. Most of the bleeding after TBLC was not severe, and the rate of pneumothorax was 25.9%. The most common histopathologic pattern was alternative (48.2%), followed by indeterminate (33.3%) and usual interstitial pneumonia (UIP)/probable UIP (18.5%). In the MDD after TBLC, the most common diagnosis was idiopathic pulmonary fibrosis (33.3%), followed by smoking-related ILD (25.9%), nonspecific interstitial pneumonia (18.6%), unclassifiable-ILD (14.8%), and others (7.4%). Conclusion: This first single-center experience showed that TBLC using a flexible bronchoscopy and endobronchial balloon blocker with the fluoroscopic guidance under general anesthesia may be a safe and adequate diagnostic method for ILD patients in Korea. The diagnostic yield of MDD was 85.2%. Further studies are needed to evaluate the diagnostic yield and confidence of TBLC.