• Tuberculosis and Respiratory Diseases
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• v.48 no.2
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• pp.246-259
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• 2000

Background: As one of the etiologies of acute respiratory distress syndrome(ARDS), sepsis is one of the morbid causes of this cryptogenic malady. Even though many documents on the role of endotoxin(ETX) in the pathogenesis of ARDS have been issued, still the underlying mechanism associated with oxidative stress and activation of $PLA_2$ has been controversial. In the present study, the role of phospholipase $A_2(PLA_2)$ in the neutrophilic respiratory burst, which is presumed to cause acute lung injury during sepsis, was probed. Method: In glutathione-depleted Sprague-Dawley rats, lung leak, infiltration of neutrophils, $PLA_2$ activity and lipid peroxidation in the lung were measured after intratracheal instillation of endotoxin(delete). In addition, gamma glutamyl transferase(GGT) activity and the amount of pulmonary surfactant were measured. Morphologically, the changes in ultrastructure and cytochemical demonstration of oxidants were presented to confirm the neutrophilic oxidative stress and to elucidate the effects of $PLA_2$ activation on(delete) oxidative stress. Results: Instillation of ETX to glutathione-depleted rats intensified lung leak and lipid peroxidation when compared with non-glutathione depleted rats treated with the endotoxin. Moreover, oxidative stress was confirmed by the assay of GGT and malondialdehyde. Functionally, the depletion of glutathione altered the secretion of pulmonary surfactant from alveolar type II cells. Ultrastructurally and cytochemicaliy, oxidative stress was also confirmed after treatment of with ETX and diethylmaleate(DEM). Conclusion: The endotoxin-induced acute lung injury was mediated by oxidative stress, which in turn was provoked by the neutrophilic respiratory burst. The activation of $PLA_2$ in the lung seems to playa pivotal role in the oxidative stress of the lung.

• Clinical and Experimental Pediatrics
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• v.51 no.7
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• pp.713-721
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• 2008

Purpose : This study aims to describe the clinical characteristics of severe meconium aspiration syndrome (MAS) which required mechanical ventilation over 48 h and to delineate the progress of respiratory failure and radiographic findings in severe MAS. Methods : Twelve infants admitted to the Neonatal Intensive Care Unit (NICU) of the Seoul National University Bundang Hospital diagnosed with severe MAS from January 2004 to July 2007 were analyzed retrospectively. Results : The presence of persistent pulmonary hypertension of the newborn (PPHN) is the only independently significant risk factor for a longer hospital stay and longer duration of mechanical ventilation. Surfactant replacement therapy (SRT) was not randomized but only performed in infants with radiographic findings for respiratory distress syndrome (RDS). In the presence of radiographic findings for RDS, the duration of high-frequency oscillatory ventilation was significantly longer. PPHN developed in 8 infants (75%). The PPHN group had a significantly longer duration of mechanical ventilation. All infants who received SRT showed radiographic improvement within 12 h, but there was no significant change in the severity score during the same period. Infants without the PPHN complications showed significant decrease in the severity score within 12 h after SRT, whereas infants with PPHN complications did not. Conclusion : The clinical course of severe MAS differed significantly depending on the development of PPHN. SRT conferred radiographic improvement in infants who showed radiographic findings for RDS, but did not influence the clinical course of MAS significantly.

• Clinical and Experimental Pediatrics
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• v.46 no.7
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• pp.655-660
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• 2003

Purpose : The relationship between chest X-ray findings and respiratory indices, including the arterial-alveolar oxygen partial pressure ratio($a/APO_2$) and the ventilatory index(VI), indicators of the clinical respiratory status in neonates with respiratory distress syndrome(RDS), was examined in the present study. Methods : The records of 50 neonates, randomly chosen from 174 neonates treated with pulmonary surfactant(PS) in the Neonatal Intensive Care Unit of Kyunghee University Hospital from 1996 to 2000 were analyzed retrospectively. Chest radiographs taken at the time after birth were classified into four groups according to Bomsel's classification. The $a/APO_2$ and VI values were calculated and compared with the corresponding chest radiographs. Results : Among the 50 cases of RDS examined, three cases were classified into grade I(6%), eight cases into grade II(16%), 20 cases into grade III(40%), and 19 cases into grade IV(38%). The mean $a/APO_2$ of the cases classified into grades I or II was 0.32 and the mean $a/APO_2$ of those classified into grades III and IV was 0.18 and 0.09, respectively. The mean VI was 0.049 for the cases classified into grades I or II and 0.076 and 0.161 for those classified into grades III and IV, respectively. Conclusion : The severity of RDS according to chest X-ray findings correlate to the values of respiratory indices, $a/APO_2$ and VI.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.24 no.3
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• pp.263-271
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• 2014

Objectives: Along with the several cases of pulmonary disorders caused by exposure to indium that have been reported in Japan, China, and the United States, cases of Korean workers involved in processes that require handling of indium compounds with potential risk of exposure to indium compounds have also been reported. We performed biological monitoring for workers in various target manufacturing processes of indium, indium oxide, and indium tin oxide(ITO)/indium zinc oxide(IZO) in domestic factories. Materials: As biological exposure indices, we measured serum concentrations of indium using inductively coupled plasma mass spectrometry, and Krebs von den Lungen 6(KL-6) and surfactant protein D(SP-D) using enzyme-linked immunosorbent assays. We classified the ITO/IZO target manufacturing process into powdering, mixing, molding, sintering, polishing, bonding, and finishing. Results: The powdering process workers showed the highest serum indium level. The mixing and polishing process workers also showed high serum indium levels. In the powdering process, the mean indium serum concentration in the workers exceeded $3{\mu}g/L$, the reference value in Japan. Of the powdering, mixing, and polishing process workers, 83.3%, 50.0%, and 24.5%, respectively, had values exceeding the reference value in Japan. We suppose that the reason of the higher prevalence of high indium concentrations in powder processing workers was that most of the particles in the powdering process were respirable dust smaller than $10{\mu}m$. The mean KL-6 and SP-D concentrations were high in the powdering, mixing, and polishing process workers. Therefore, the workers in these processes who were at greater risk of exposure to indium powder were those who had higher serum levels of indium, as well as KL-6 and SP-D. We observed significant differences in serum indium, KL-6, and SP-D levels between the process groups. Conclusions: Five among the seven reported cases of "indium lung" in Japan involved polishing process workers. Polishing process workers in Korea also had high serum levels of indium, KL-6, and SP-D. The outcomes of this study can be used as essential bases for establishing biological monitoring measures for workers handling indium compounds, and for developing health-care guidelines and special medical surveillance in Korea.

• Neonatal Medicine
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• v.18 no.2
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• pp.257-264
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• 2011

Purpose: The development of postnatal pneumothorax and its common causes and clinical aspects were studied to promote early diagnosis and proper management. Methods: A retrospective study of neonates who were hospitalized in the neonatal intensive care unit at Soonchunhyang University Bucheon Hospital from 2001 to 2010 was performed. Term neonates were divided into a spontaneous pneumothorax group and a secondary pneumothorax group. The secondary group was divided into term and preterm groups. Results: Of 4,414 inpatients, 57 (1.3%) were diagnosed with pneumothorax. Of term newborn patients, 28 (80%) had a secondary pneumothorax, and seven (20%) had a spontaneous pneumothorax. No differences were observed for gender, birth weight, resuscitation, or duration of admission between the spontaneous and control groups. The duration of treatment with a thoracostomy (20 patients, 57%) was longer in the spontaneous group (5.4${\pm}$2.9 days vs. 2.7${\pm}$2.0 days) than that in the control group. Patients with respiratory distress syndrome (RDS) developed a pneumothorax 22.8 hours after surfactant treatment, whereas patients with transient tachypnea of the newborn (TTN), pneumonia, and meconium aspiration syndrome (MAS) developed pneumothorax after 16.6 hours. Of 50 patients with a secondary pneumothorax, 19 (38%) had RDS, 11 (22%) had MAS, 7 (14%) had TTN, and six (12%) had pneumonia. Among term newborns, 42.9% were treated only with 100% oxygen. Among preterm newborns, 72.6% and 27.3% needed a thoracostomy or ventilator care, respectively. Conclusion: A pneumothorax is likely to develop when pulmonary disease occurs in neonates. Therefore, it is important to carefully identify pneumothorax and provide appropriate treatment.