A key mechanism in the pathogenesis of chronic obstructive pulmonary disease is thought to be an abnormal inflammatory response in the lungs to the inhalation of toxic particles and gases, derived from tobacco smoke, air pollution, and/or occupational exposures. This review highlights the potential participation of several alternative pathogenetic processes, particularly involving the potential participation of biological and pathobiological processes related to aging, including oxidative stress and enhanced expression of markers of senescence/aging in emphysematous lungs, and the potential for enhanced tissue destruction involving alveolar cell apoptosis.

Background: Recently, the rate of infections with non-tuberculous mycobacteria (NTM) has been increasing in Korea. Precise identification of NTM is critical to determination of the pathogen and to target treatment of NTM patients. Methods: Sixty-eight unclassified mycobacteria isolates by rpoB PCR-RFLP assay (PRA) collected in 2008 were analyzed by National Center for Biotechnology Information (NCBI) Basic Local Alignment Search Tool (BLAST) search after sequencing of 16S rRNA, hsp65, rpoB genes. Results: Nineteen strains of 68 isolates were specified as species after sequencing analysis of 3 gene types. We found 3 M. lentifulavum, 5 M. arupense, 4 M. triviale, 4 M. parascrofulaceum, and one M. obuense. One M. tuberculosis and another M. peregrinum were mutated at the Msp I recognition site needed for rpoB PRA. The remaining 49 isolates did not coincide with identical species at the 3 kinds genes. Conclusion: Sequencing analysis of 16S rRNA, hsp65, rpoB was useful for identification of NTM unclassified by rpoB PRA.

Background: Transglutaminase-2 (TG-2) has been reported to play an important role in the process of fibrosis. However, TG-2 studies on fibroproliferation of acute lung injury (ALI) are absent. The purpose of this study was to investigate the role of TG-2 in the fibroproliferation of lipopolysaccharide (LPS)-induced ALI. Methods: The male C57BL/6 mice of 5 weeks age were divided into 3 groups; control group (n=30) in which $50{\mu}L$ of saline was given intratracheally (IT), LPS group (n=30) in which LPS 0.5 mg/kg/$50{\mu}L$ of saline was given IT, and LPS+Cyst group treated with intraperitoneal 200 mg/kg of cystamine, competitive inhibitor of TG-2, after induction of ALI by LPS. TG-2 activity and nuclear factor $(NF)-{\kappa}B$ were measured in lung tissue homogenate. Tumor necrosis factor (TNF)-${\alpha}$, interleukin (IL)-$1{\beta}$, IL-6, myeloperoxidase (MPO), and transforming growth factor (TGF)-${\beta}1$ were measured using bronchoalveolar lavage fluids. Histopathologic ALI score and Mallory's phosphotunistic acid hematoxylin (PTAH) for collagen and fibronectin deposition were performed. Results: The TG-2 activities in the LPS group were significantly higher than the control and LPS+Cyst groups (p<0.05). The TNF-${\alpha}$ and IL-$1{\beta}$ concentrations and $NF-{\kappa}B$ activity were lower in the LPS+Cyst group than the LPS group (p<0.05). The LPS+Cyst group showed lower MPO, ALI score, TGF-${\beta}1$ concentration, and Mallory's PTAH stain than the LPS group, but the differences were not significant (p>0.05). Conclusion: Inhibition of TG-2 activity in the LPS-induced ALI prevented early inflammatory parameters, but had limited effects on late ALI and fibroproliferative parameters.

Background: In this study, we tried to investigate whether carbenoxolone, prunetin, and silibinin affect tumor necrosis factor (TNF)-${\alpha}$-induced MUC5AC mucin production and gene expression from human airway epithelial cells. Methods: Confluent NCI-H292 cells were pretreated with each agent (carbenoxolone, prunetin, and silibinin) for 30 min and then stimulated with TNF-${\alpha}$ for 24 hours. The MUC5AC mucin gene expression and mucin protein production were measured by reverse transcription-polymerase chain reaction and enzyme linked immunosorbent assay, respectively. Results: Carbenoxolone, prunetin and silibinin inhibited the production of MUC5AC mucin protein induced by TNF-${\alpha}$; the 3 compounds also inhibited the expression of MUC5AC mucin gene induced by TNF-${\alpha}$. Conclusion: This result suggests that carbenoxolone, prunetin and silibinin can inhibit mucin gene expression and production of mucin protein induced by TNF-${\alpha}$, by directly acting on airway epithelial cells.

Background: Primary non-Hodgkin's lymphoma of the lung is a rare entity. It is represented commonly as marginal zone B-cell lymphoma of mucosa-associated lymphoid tissue (MALT) type. Although there have been a few reviews of this lymphoma, clinical features, radiologic findings, management and prognosis have not been well defined. Methods: We reviewed the medical records of 24 patients with primary pulmonary lymphoma between January 1995 and September 2008; all diagnoses had been confirmed based on pathology. Results: The median follow-up time was 42.3 months (range, 0.1~131.2 months). Five (20.8%) patients were asymptomatic, 17 (70.8%) patients had pulmonary symptoms, and the remaining 2 (8.3%) patients presented with constitutional symptoms. There were 16 (66.7%) patients with MALT lymphoma, 4 (16.7%) patients with diffuse large B-cell lymphoma and 4 (16.7%) patients with lymphoma that had not received a WHO classification. Radiologic findings of primary pulmonary lymphoma were diverse and multiple nodule or consolidation was the most common finding regardless of pathologic lymphoma type. PET scan was carried out in 13 (54.2%) patients and all lesions showed notable FDG uptake. MALT lymphoma showed a trend of better prognosis (3-year survival, 78.8% vs. 70.0%; 5-year survival, 78.8% vs. 52.5%; p=0.310) than non-MALT lymphoma. Conclusion: Primary non-Hodgkin's lymphoma of the lung occurs with nonspecific clinical features and radiologic findings. MALT lymphoma is the most common pathologic type of primary pulmonary lymphoma. This entity of lymphoma appears to have a good prognosis and in this study, there was a trend of better outcome than non-MALT lymphoma.

Background: Difficult-to-treat asthma afflicts a small percentage of the asthma population. However, these patients remain refractory to treat, and account for 40% to 50% of the health costs of asthma treatment, incurring significant morbidity. We conducted a multi-center cross-sectional study to characterize difficult-to-treat asthma in Korea. Methods: Subjects with difficult-to-treat asthma and subjects with controlled asthma were recruited from 5 outpatient clinics of referral hospitals. We reviewed medical records of previous 6 months and obtained patient-reported questionnaires composed of treatment compliance, asthma control, and instruments for stress, anxiety, and depression. Results: We recruited 21 subjects with difficult-to-treat asthma and 110 subjects with controlled asthma into the study. The subjects with difficult-to-treat asthma were associated with longer treatment periods, more increased health care utilization, more medication (oral corticosteroids, number of medication), and more anxiety disorder compared to those of well-controlled asthmatics. There was no difference in age, gender, history of allergy, serum IgE, blood eosinophil count, or body mass index between the 2 groups. Conclusion: Difficult-to-treat asthma is characterized by increased health care utilization and more co-morbidity of anxiety.

Background: Rhinolaryngoscopy and sputum examination are popular tests for the evaluation of chronic cough. Little is known about the relationship between symptoms and rhinolaryngoscopic findings or sputum eosinophilia in chronic cough patients. Methods: One hundred patients, who had chronic cough with normal chest radiography and who also had undergone both rhinolaryngoscopy and induced sputum analysis, were reviewed retrospectively. Eleven associated symptoms of chronic cough were asked; postnasal drip (PND) and laryngopharyngeal reflux (LPR) were examined by rhinolaryngoscopy. Induced sputum analysis was performed for evaluation of sputum eosinophilia. Cross tabulation analyses with chi-square tests were used to evaluate the relationship between symptoms and objective findings. Results: The most frequent symptom was sputum (70%). The prevalence of PND and LPR on rhinolaryngoscopy were 56% (56/100) and 25.6% (22/86), respectively. Sputum eosinophilia was observed in 23 (23.7%) of 97 patients. The dyspnea (p=0.001), sputum (p=0.003), nasal obstruction (p=0.023), and postnasal drip sense (p=0.025) were related with PND on rhinolaryngoscopy. LPR on rhinolaryngoscopy was not related with any symptoms. Dyspnea (p=0.003), wheezing (p=0.005), nasal obstruction (p=0.013), and belching (p=0.018) were related with sputum eosinophilia. Conclusion: Any symptoms might not be related with LPR on laryngoscopy. Some symptoms might be related with PND on rhinoscopy or with sputum eosinophilia.

Lymphoid interstitial pneumonia (LIP) is a rare benign lymphoproliferative interstitial lung disease. LIP has been associated with autoimmune disorders, HIV, viral infections, and so on. Once underlying systemic diseases have been excluded, a diagnosis of idiopathic LIP can be made. Although 6 cases of pathologically confirmed LIP have occurred in Korea, thus far none has been associated with primary Sjogren's syndrome. A 44-year-old man was admitted to hospital due to a dry cough and dypsnea on exertion that had been ongoing for 2 months. A chest radiography showed multiple and variable-sized cystic lesions, on both lungs and both interstitial infiltration and consolidation in both lower lung fields. Tests for autoantibody showed positive results of anti-nuclear antibody and anti-Ro/La antibody. The patient underwent a video assisted thoracoscopic surgery biopsy and pathologically confirmed LIP. We report the first known case of LIP-associated with primary Sjogren's syndrome in Korea.

Progressive ptosis and headache developed in a 50-year-old woman with non-small cell lung cancer. Although brain magnetic resonance imaging showed improved cerebellar metastasis after prior radiotherapy without any other abnormality, the follow-up examination taken 6 months later revealed metastasis to the cavernous sinus. The diagnosis of metastasis to the cavernous sinus is often difficult because it is a very rare manifestation of lung cancer, and symptoms can occur prior to developing a radiologically detectable lesion. Therefore, when a strong clinical suspicion of cavernous sinus metastasis exists, thorough neurologic examination and serial brain imaging should be followed up to avoid overlooking the lesion.

Capillary hemangioma of the trachea is an extremely rare benign tumor in adults. We present the case of a 28-year-old woman with hemoptysis owing to a tumor of the proximal trachea. The tumor was removed by rigid bronchoscopy. The resulting specimens showed capillary hemangioma without any signs of malignant transformation. This presentation is the first case in Korea. Although tracheal capillary hemangioma is a rare disease, we should consider it as a possible cause of hemoptysis in the young adult.

Spinal epidural emphysema is rare and has been described secondary to following medical intervention, such as lumbar puncture and epidural analgesia, pneumothorax or pneumomediastinum, degenerative disk disease, epidural abscess, and trauma. Rarely, it occurs after chest tube placement. We report a case of spinal epidural emphysema incidentally noted on HRCT after chest tube placement.