• Clinical and Experimental Pediatrics
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• 제63권7호
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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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• 제83권2호
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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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• 제33권3호
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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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• 제41권6호
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• pp.604-615
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• 1994

연구배경: 기관지 폐포세척액의 세포구성에 대한 분석은 미만성 간질성 폐질환에서 폐조직검사를 보완하거나 대신할 수 있는 검사방법이며 폐포염의 성격을 가장 신속하게 알 수 있고, 미만성 간질성 폐질환의 감별진단을 가능케 한다. 그러나 아직 기관지폐포세척세포에 대한 분석자료가 많지 않은 점에 착안하여 정상인의 기관지폐포세척세포와 여러 미만성 간질성 폐질환의 기관지폐포세척세포를 비교분석하여 차이를 알아보고 일차적 감별진단에 도움이 될 수 있는지를 알아보았다. 방법: 굴곡성 기관지내시경을 이용하여 정상인과 미만성 간질성 폐질환 환자의 기관지폐포세척액을 채취하여 세포를 염색하여 감별, 계수하였으며, 흡연군과 비흡연군간의 차이 및 정상군과 여러 미만성 간질성 폐질환환자의 기관지폐포세척세포의 백분율, 절대수치 및 분포의 차이를 비교분석하였다. 결과: 정상군에서 흡연군과 비흡연군간에는 세척액회수율, 총세포수, 세척액 ml당 세포수, 임파구백분율 및 임파구수, 대식세포백분율 및 대식세포수, 호중구백분율 및 호중구수, 호산구백분율 및 호산구수, FEV1(%), FVC(%)에서 유의한 차이가 없었다. 총세포수는 교원성질환, 과민성폐장염, 특발성폐섬유증, 속립성결핵에서 의미있게 증가하였고 임파구백분율은 과민성폐장염, 특발성폐섬유증, 속립성결핵에서 의미있게 증가하였으며, 대식세포는 특발성폐섬유증, 속립성결핵에서 의미있게 증가하였다. 호중구는 교원성 질환, 과민성폐장염, 특발성폐섬유증, 속립성결핵에서 그리고 호산구는 교원성 질환, 과민성폐장염, 특발성폐섬유증에서 의미있게 증가하였으며, 질환별로 폐포염의 양상을 알 수 있었으나 각 질환간의 염증세포의 빈도의 차이는 관찰되지 않았다. 결론: 굴곡성 기관지내시경을 이용한 기관지 폐포세척액의 세포구성에 대한 분석을 통해 많은 ILD 증례에서 폐포염의 존재를 알 수 있으나 ILD의 감별진단에 응용하기는 어렵다.

• 대한영상의학회지
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• 제82권4호
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• pp.817-825
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• 2021

과민성폐렴(hypersensitivity pneumonitis)은 기도를 통해 흡입된 항원물질이 세기관지와 폐포에 면역매개 염증병변을 일으켜 발생하는 간질성폐질환(interstitial lung disease)이다. 다양한 유기물질이 발생원인으로 작용할 수 있기에 환자의 흉부영상검사와 임상증상을 통해 과민성폐렴을 의심하고 직업 또는 주변 환경을 통해 노출되는 항원을 파악하는 것이 과민성폐렴 진단의 핵심이다. 하지만 다양한 임상증상과 진행 형태로 인해 간질성폐질환 환자의 진단에서 과민성폐렴을 정확히 감별할 수 있느냐는 풀기 쉽지 않은 주제이다. 이에 2020년 미국흉부학회, 일본호흡기학회 그리고 라틴아메리카흉부학회는 과민성폐렴 진단에 대한 새로운 임상진료지침을 발표하였다. 이번 임상진료지침은 과민성폐렴 진단에 있어서 흉부 고해상도 전산화단층촬영(high-resolution CT; 이하 HRCT)의 역할을 강조하며 과민성폐렴에 대한 새로운 분류 기준도 제시하고 있다. 본 종설은 흉부 HRCT 내용을 포함해 새롭게 소개된 과민성폐렴 진단에 대한 전반을 살펴보고자 한다.

• Smart Structures and Systems
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• 제33권1호
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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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• 제73권3호
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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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• 제87권2호
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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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• 제87권2호
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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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• 제85권4호
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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.