• Clinical and Experimental Pediatrics
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• v.62 no.10
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• pp.367-373
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• 2019

Bronchopulmonary dysplasia (BPD) is a chronic lung disease of preterm infants with multiple factors affected from prenatal to postnatal periods. Despite significant advances in neonatal care over almost 50 years, BPD rates have not decreased; in fact, they may have even increased. Since more preterm infants, even at periviable gestational age, survive today, different stages of lung development affect the pathogenesis of BPD. Hence, the definition of BPD has changed from "old" to "new." In this review, we discuss the various definitions of BPD, risk factors from the prenatal to postnatal periods, management strategies by phase, and future directions for research.

• Journal of Environmental Health Sciences
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• v.44 no.2
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• pp.107-114
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• 2018

Objectives: The objectives of this study are to describe strategy for exposure assessment of humidifier disinfectant (HD) used in the national program to associate the use of HD with lung injury. Methods: Strategy and method employed to evaluate HD use characteristics were developed to associate health effects including HD associated with lung injury (HDLI). We developed HD-specific questionnaire to assess potential HD exposure, which was consistently used in the national program. Trained environmental health scientists visited the residences of registered subjects and investigated HD use characteristics. Results: Major HD exposure related variables were type of HD brand/s used; HD volume added to the humidifier, frequency of HD addition, and time spent in room/s with the humidifier; duration of HD use in the household in average months/year, weeks/month, and days/week; average sleeping hours in a room with an operating humidifier containing a disinfectant; number of HD brands used and type of HD; average distance of the bed from the humidifier in meters. Conclusions: We concluded that estimated airborne HD concentration was significantly associated with the risk of HDLI.

• Journal of Environmental Health Sciences
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• v.42 no.6
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• pp.365-374
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• 2016

Objectives: Studies are needed to examine the characteristics of health effects reported by people who used humidifier disinfectant (HD), including the distribution of victims. Methods: We analyzed the distribution of health effects including lung injury that were asserted by a total of 699 individuals who registered with the first through third national programs to determine health effects associated with the use of HD. Results: We found that HD-associated lung injury (HDLI) occurred every year from 2002 through 2011, and in 2011 for 37.2% (n=96) of the total of 258 clinically evaluated HDLI victims. More than half of the victims responded that they were victimized between 2010 and 2011. This was consistent among all classifications by sex, age, HD brand and HD chemical ingredient. Conclusion: This study assumed that the major reason for the outbreak of the health effect between 2010 and 2011 could be the variations in concentrations and physical properties related to polyhexamethylene guanidine (PHMG). Further studies are necessary to examine if some factors related to the chemical disinfectants contained in HD brands may have caused the massive outbreak of health effects including HDLI.

• Tuberculosis and Respiratory Diseases
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• v.65 no.6
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• pp.464-470
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• 2008

Background: This study examined the role of neutrophilc oxidative stress in an $O_2-induced$ acute lung injury (ALI). Methods: For 48 h, experimental rats were exposed to pure oxygen (normobaric hyperoxia) in a plastic cage. Forty-eight hours after $O_2$ breathing, the rats were sacrificed and the parameters for ALI associated with neutrophilic oxidative stress were assessed Results: Normobaric pure oxygen induced ALI, which was quite similar to ARDS. The $O_2-induced$ neutrophilic oxidative stress was identified by confirming of the increase in lung myeloperoxidase, BAL neutrophils, malondialdehyde (MDA), cytosolic phospholipase $A_2$ ($cPLA_2$) activity in the lung, histological changes and BAL cytospin morphology. Conclusion: In part, ALI-caused by oxygen is affected by neutrophils especially by the generation of free radicals.

• Journal of Trauma and Injury
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• v.18 no.1
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• pp.53-63
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• 2005

Purpose: This study was designed to determine if methylene blue inhibited the lipid peroxidation, the production of NO, and the gene expression of iNOS in acute lung injury induced by paraquat and if the inhibitory effect was dose dependent. Methods: Female Sprague-Dawley rats were divided into four groups: the control group, the group treated with paraquat only, the group treated with paraquat and a low dose of methylene blue (2 mg/kg), and the group treated with paraquat and a high dose of methylene blue (20 mg/kg). Methylene blue was administered via the jugular vein 1 h after paraquat administration, and animals were sacrificed 6 and 24 h after paraquat administration. Malondialdehyde (MDA) as lipid peroxidation, reduced glutathione (GSH) as an antioxidant defense, the plasma NO concentration, and the expression of iNOS mRNA in the lung tissue were measured Results: Lung MDA contents decreased, with no significant difference between the methylene-blue groups and the paraquat-only group. Lung GSH contents were significantly elevated at 24 h in the methylene-blue groups compared with the paraquat-only group. Plasma NO concentrations were significantly reduced at 6 and 24 h in the methylene-blue groups compared with the paraquat-only group. There was also a significant decrease in the plasma NO concentration at 6 h in the high-dose methylene-blue group compared with the low-dose methylene-blue group. The expression of iNOS mRNA in the lung tissue was slightly decreased in the methylene-blue groups. It was also markedly increased at 24 h in the paraquat-only group compared with the methylene-blue groups. The gene expression was relatively decreased in the high-dose methylene-blue group compared with the low-dose methylene-blue group. Conclusion: This study suggests that methylene blue has an inhibitory effect on the plasma NO concentration and the expression of iNOS mRNA in lung injury induced by paraquat. No inhibitory effect of methylene blue on lipid peroxidation or dose-dependent inhibitory effects were clearly shown.

• Journal of Chest Surgery
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• v.35 no.2
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• pp.87-93
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• 2002

Background: Predicting the important role of intercellular adhesion molecule-1 expression on the acute ischemia-reperfusion injury, we set out to demonstrate it by assessing the degree of expression of ICAM-1 after warm ischemia-reperfusion in canine unilateral lung ischemia model. Material and Method: Left unilateral lung ischemia was induced by clamping the left hilum for 100 minutes in seven adult mongrel dogs. After reperfusion, various hemodynamic pararmeters and blood gases were analyzed for 4 hours, while intermittently clamping the right hilum in order to allow observation of the injured Ieft lung function. The pulmonary venous blood was collected serially to measure TNF- and cICAM-1 level. After 4 hours of reperfusion, the lung tissue was biopsied to assess cICAM-1 expression, and to measure tissue malondialdehyde(MDA) and ATP level. Result: The parameters including arterial oxygen partial pressure, pulmonary vascular resistance and tissue MDA and ATP level suggested severe lung damage. Serum TNF-$\alpha$ level was 8.76$\pm$2.37 ng/ml at 60 minutes after reperfusion and decreased thereafter. The cICAM-1 level showed no change after the reperfusion during the experiment. The tissue cICAM-1 expression was confirmed in 5 dogs. Conclusion: The increase of TNF-$\alpha$ Ievel and expression of tissue ICAM-1 were demonstrated after ischemia reperfusion injury in canine lung model.

• IMMUNE NETWORK
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• v.23 no.5
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• pp.42.1-42.21
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• 2023

When the lungs are infected with bacteria, alveolar macrophages (AMs) are recruited to the site and play a crucial role in protecting the host by reducing excessive lung inflammation. However, the regulatory mechanisms that trigger the recruitment of AMs to lung alveoli during an infection are still not fully understood. In this study, we identified a critical role for NADPH oxidase 4 (NOX4) in the recruitment of AMs during Staphylococcus aureus lung infection. We found that NOX4 knockout (KO) mice showed decreased recruitment of AMs and increased lung neutrophils and injury in response to S. aureus infection compared to wildtype (WT) mice. Interestingly, the burden of S. aureus in the lungs was not different between NOX4 KO and WT mice. Furthermore, we observed that depletion of AMs in WT mice during S. aureus infection increased the number of neutrophils and lung injury to a similar level as that observed in NOX4 KO mice. Additionally, we found that expression of intercellular adhesion molecule-1 (ICAM1) in NOX4 KO mice-derived lung endothelial cells was lower than that in WT mice-derived endothelial cells. Therefore, we conclude that NOX4 plays a crucial role in inducing the recruitment of AMs by controlling ICAM1 expression in lung endothelial cells, which is responsible for resolving lung inflammation during acute S. aureus infection.

• Journal of Trauma and Injury
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• v.24 no.2
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• pp.155-158
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• 2011

Mechanical ventilation is usually the treatment of choice for severe respiratory failure associated with trauma. However, in case of severe hypoxia, mechanical ventilation may not be sufficient for gas exchange in lungs. Patients with Acute Respiratory Distress Syndrome (ARDS) undergo difficulties in oxygen and carbon dioxide exchange. Extracorporeal Membrane Oxygenation (ECMO) is the ideal therapeutic option for those patients with severe traumatic injuries. ECMO allows lungs to reserve their functions and decreases further lung injuries while increasing survival rate at the same time. We report two cases of patients with traumatic ARDS and Multiple Organ Failure including compromised heart function. The preservation of lung function was successful using ECMO therapy.

• Journal of Neurocritical Care
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• v.11 no.2
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• pp.63-70
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• 2018

Management of mechanical ventilation is essential for patients with neuro-critical illnesses who may also have impairment of airways, lungs, respiratory muscles, and respiratory drive. However, balancing the approach to mechanical ventilation in the intensive care unit (ICU) with the need to prevent additional lung and brain injury, is challenging to intensivists. Lung protective ventilation strategies should be modified and applied to neuro-critically ill patients to maintain normocapnia and proper positive end expiratory pressure in the setting of neurological closed monitoring. Understanding the various parameters and graphic waveforms of the mechanical ventilator can provide information about the respiratory target, including appropriate tidal volume, airway pressure, and synchrony between patient and ventilator, especially in patients with neurological dysfunction due to irregularity of spontaneous respiration. Several types of asynchrony occur during mechanical ventilation, including trigger, flow, and termination asynchrony. This review aims to present the basic interpretation of mechanical ventilator waveforms and utilization of waveforms in various clinical situations in the neuro-ICU.

• Molecules and Cells
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• v.43 no.9
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• pp.774-783
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• 2020

The lung has a vital function in gas exchange between the blood and the external atmosphere. It also has a critical role in the immune defense against external pathogens and environmental factors. While the lung is classified as a relatively quiescent organ with little homeostatic turnover, it shows robust regenerative capacity in response to injury, mediated by the resident stem/progenitor cells. During regeneration, regionally distinct epithelial cell populations with specific functions are generated from several different types of stem/progenitor cells localized within four histologically distinguished regions: trachea, bronchi, bronchioles, and alveoli. WNT signaling is one of the key signaling pathways involved in regulating many types of stem/progenitor cells in various organs. In addition to its developmental role in the embryonic and fetal lung, WNT signaling is critical for lung homeostasis and regeneration. In this minireview, we summarize and discuss recent advances in the understanding of the role of WNT signaling in lung regeneration with an emphasis on stem/progenitor cells.