• Tuberculosis and Respiratory Diseases
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• v.54 no.1
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• pp.104-113
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• 2003

Background : Rhinovirus(RV) infections frequently trigger dyspnea and paroxysmal cough in adult patients with asthma and are the most prevalent cause of the common cold. However, the mechanisms of a RV-induced airway inflammation is unclear. Since the RV does not directly destroy the airway epithelium, it is presumed that the immune response to the RV contributes to the pathogenesis of the respiratory symptoms. In order to test this hypothesis, this study characterized the time-sequenced alterations in interleukin(IL)-8 elaboration from the human bronchial epithelial cells and evaluated the role of NF(nuclear factor)-${\kappa}B$ in the RV-induced IL-8 production by pretreating the inhibitors of NF-${\kappa}B$ activation. Methods : The ability of RV-infected human bronchial epithelial cells and BEAS-2B cells to produce the IL-8 was compared with the controls. This study infected BEAS-2B cells with the RV14 obtained from the American Type Culture Collection. The supernatants were harvested from the RV infected BEAS-2B cells and the controls at 2hr, 4hr, 6hr, 12hr, 24hr, 48hr from the inoculation time. This study measured the IL-8 concentration using the ELISA kits. In order to elucidate the role of NF-${\kappa}B$ in the RV-induced IL-8 production, the effect of the NF-${\kappa}B$ inhibitors was evaluated on RV-induced IL-8 production. Results: The BEAS-2B cells produced small amounts of IL-8 that accumulated slowly with time in the culture. The RV was a potent stimulator of the IL-8 proteins production by BEAS-2B human bronchial epithelial cells. Antioxidants, N-acetyl-L-cysteine(NAC),\ and pyrrolidine dithiocarbamate(PDTC), blocked the IL-8 elaboration by the RV-infected BEAS-2B cells, which was dose-dependent, but N-Tosyl-L-phenylalanine chloromethyl ketone(TPCK) did not. Conclusion: Some antioxidants inhibited the RV-induced IL-8 production by blocking the NF-${\kappa}B$, which may have a therapeutic potential in asthma.

• Journal of Life Science
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• v.24 no.3
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• pp.318-322
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• 2014

Chlamydophila pneumonia is a common cause of community-acquired pneumonia throughout the world. It causes mild pneumonia or bronchitis in adolescents and young adults. Older adults may experience more severe disease and repeated infections. To the best of our knowledge, no study has attempted to investigate the prevalence of C. pneumonia in a closed community in Korea. We compared the infection rate of C. pneumonia among university dormitory residents using the miro-immunofluorescence (MIF) method. Antibody titers of IgG (1:32 or more) indicate past infection of C. pneumonia. A recent infection was defined as serum with a high titer of IgG (1:512 or more) or a positive IgM (1:16 or more). The past infection rate of C. pneumonia among the university dormitory residents was 71.7%. The recent infection rate of C. pneumonia according to IgG and IgM titers was 28.3% and 23.3%, respectively. The past infection positive rate according to the number of residence months was 1 month (50%), 7 months (71.4%), 13 months (66.7%), and 35 months (89.5%). The recent infection positive rate according to IgG antibody titers was 1 month (50%), 7 months (28.6%), 13 months (33.3%), and 35 months (10.5%). The recent infection rate of C. pneumonia according to IgM antibody titers was 1 month (41.7%), 7 months (28.6%), 13 months (26.7%), and 35 months (5.3%). The results suggest that the past infection rate of C. pneumonia is increased by the number of residence months in a closed community and that the recent infection rate of C. pneumonia according to IgG and IgM serological tests is decreased by the number of residence months.

• Journal of Life Science
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• v.30 no.11
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• pp.947-955
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• 2020

The foot-and-mouth disease virus (FMDV), a member of the Aphthovirus genus in the Picornaviridae family, affects wild and domesticated ruminants and pigs. During replication of the FMDV RNA (ribonucleic acid) genome, FMDV-encoding RNA polymerase 3D acts in a highly location-specific manner. This suggests that specific RNA structures recognized by 3D polymerase within non-coding regions of the FMDV genome assist with binding during replication. One such region is the cis-acting replication element (CRE), which functions as a template for RNA replication. The FMDV CRE adopts a stem-loop conformation with an extended duplex stem, supporting a novel 15-17 nucleotide loop that derives stability from base-stacking interactions, with the exact RNA nucleotide sequence of the CRE producing different RNA secondary structures. Here, we show that CRE sequences of FMDVs isolated in Korea from 2010 to 2017 exhibit A and O genotypes. Interestingly, variations in the RNA secondary structure of the Korean FMDVs are consistent with the phylogenetic relationships between these viruses and reveal the specificity of FMDV infections for particular host species. Therefore, we conclude that each genetic clade of Korean FMDV is characterized by a unique functional CRE and that the evolutionary success of new genetic lineages may be associated with the invention of a novel CRE motif. Therefore, we propose that the specific RNA structure of a CRE is an additional criterion for FMDV classification dependent on the host species. These findings will help correctly analyze CRE sequences and indicate the specificity of host species for future FMDV epidemics.

• Journal of Gastric Cancer
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• v.5 no.3 s.19
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• pp.191-199
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• 2005

Background: Though infections of Helicobacter pylori (H. pylori) are closely associated with activation of host angiogenesis, the underlying mechanisms, as well as the strategy for its prevention, have not been identified. Here, we investigated a causal role of H. pylori infection in angiogenesis of gastric mucosa and a potent inhibitory effect of a gastric proton pump inhibitor (PPI) on the gastropathy. Materials and Methods: A comparative analysis of CD 34 expression in tissues obtained from 20 H. pylori-associated gastritis and 18 H. pylori-negative gastritis patients was performed. Expression of $HIF-1{\alpha}$ and VEGF were tested by using RT-PCR. To evaluate the direct effect of H. pylori infection on differentiation of endothelial HUVEC cells, we carried out an in vitro angiogenesis assay. Results: H. pyfori-associated gastritis tissues showed significantly higher density of $CD34^+$ blood vessels than did H. pylori-negative gastritis tissues, and the levels were well correlated with expressions of $HIF-1{\alpha}$. Conditioned media from H. pylori-infected gastric mucosal cells stimulated a tubular formation of HUVEC cells. We also found a significant inhibitory effect of PPI, an agent frequently used for H. pylori eradication, on H. pylori-induced angiogenesis. This drug effectively inhibited the phosphorylation of MAP kinase ERK1/2, which is a principal signal for H. pylori-induced angiogenesis. Conclusion: The fact that PPls can down-regulate H. pylori-induced angiogenesis suggest that anti-angiogenic treatment using PPI may be a preventive approach for H. pylori-associated carcinogenesis.

• Tuberculosis and Respiratory Diseases
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• v.40 no.4
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• pp.390-394
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• 1993

Background: Bronchiectasis is characterized by chronic sputum production and complications such as hemoptysis and repeated infections. Even though some patients are cured by surgical resection of bronchiectatic lesions, most bronchiectasis patients can not be treated surgically because of multiple site involvement, and they are treated by medical measures such as postura1 drainage and antibiotics when indicated. Recently there have been some reports that low-dose longterm erythromycin treatment is effective on bronchiectsis, and it is well known that low-dose longterm erythromycin treatment is the treatment of choice in diffuse panbronchiolitis which is characterized by chronic sputum production and dyspnea. To evaluate the efficacy of erythromycin, we tried erythromycin on twenty five stable bronchiectasis patients for more than six months. Methods: We tried erythromycin 250 mg b.i.d. for more than 6 months. We checked respiratory symptoms, chest PA, spirometry, and side effects before treatment and after 3 and 6 months of treatment. Results: 1) 32% of the patients showed marked improvement of symptoms and PFT. 32% showed slight improvement of symptoms with little change of PFT, and 36% showed no change of symptoms and signs. 2) Analysis of the patients showing marked improvement revealed that most of them had diffuse bronchiectasis and paranasal sinus involvement. Conclusion: These results suggest that low-dose longterm erythromycin treatment can be tried on diffuse bronchiectasis patients with sinus involvement. And further studies will be followed on the mechanism of erythromycin in bronchiectasis.

• Tuberculosis and Respiratory Diseases
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• v.40 no.4
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• pp.410-415
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• 1993

Background: The lung abscess predominantly occurs on a dependent region, because its major predisposing factor is aspiration. However, a lung abscess appeared on a nondependent region occasionally. Traditionally bronchoscopy has been performed in patients with lung abscess on a nondependent region for evaluating the endobronchial obstruction such as bronchogenic carcinoma. But the clinical characteristics and necessities of bronchoscopy in patients with lung abscess located at nondependent region have not been discussed previously. Thus, we investigated the underlying etiologies and the necessities of bronchoscpy in patients with lung abscess in a nondependent region. Method: Fifteen patients with cavitary lesion on a nondependent location have been studied retrospectively by reviewing their clinical records, chest PAs, computerized tomograms, and bronchoscopic findings. Results: 1) Most patients were older than 30 years except one, and their mean age was 51 years. The ratio of male to female was 6.5:1. 2) The underlying etiologies were bacterial infections in 13 cases, and tuberculous infection in two cases. However, bronchogenic carcinoma was not found as its etiology. 3) Among thirteen bacterial lung abcess, tweleve cases located at right middle lobe. 4) The findings of bronchoscopy were non-speicifc mucosal change in 8 cases and segmental obstructions in 2 cases. There were no malignant evidences in the finings of cytology and bronchscopic biopsy. 5) Among thirteen bacterial lung abcess, eleven patients showed good clinical reponse to antibiotic therapy. Conclusion: The necessity of early bronchoscopy may need to be re-evaluated in the lung abscess on a nondependent region, unless evidences of bronchial obstruction or bronchogenic carcinoma exist. The pulmonary tuberculosis shoud be regarded as the underlying etiology of the nondependent lung abscess.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.805-812
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• 1998

Background: Among the variety of opportunistic infections, pneumonia comprises the major morbidity in immunocompromised patients. Pneumocystis carnii pneumonia (PCP) and cytomegalovirus (CMV) pneumonia are common infectious illness of immunocompromised hosts. Although there are many reports regarding to the co-infection of PCP and CMV diagnosed by bronchoalveolar lavage (BAL) fluid examination, the effects of CMV co-infection on the outcome of PCP is still controversial. The purpose of this investigation is to evaluate the effects of CMV detected by BAL fluid examination on the clinical course of PCP in the immunocompromised patients other than human immunodeficiency virus infection. Method: Ten patients with PCP were enrolled and retrospective analysis of their medical records were done. HIV infected persons were excluded. The PCP was diagnosed by BAL fluid examination with Calcofluor-White staining. CMV was detected in BAL fluid by Shell-vial culture system. Chest radiographic findings were reviewed. We used Fisher's exact test and Mann-Whitney U test for statistical analysis of data. Results: The underlying disorders of patients were idiopathic pulmonary fibrosis (n=1), renal transplantation (n=4), necrotizing vasculitis (n=l), systemic lupus erythematosus (n=1), brain tumor (n=1), chronic myelogenous leukemia (n=1), unidentified (n=1). There were no difference in clinical course, APACHE III score, arterial blood gas analysis, white blood cell count, lymphocyte count, serum albumin concentration, chest radiographic findings and mortality between patients with PCP alone (n=4) and those with CMV co-infection (n=6). Univariate analysis regarding to the factors that associated with mortality of PCP were revealed that the application of mechanical ventilation (p=0.028), the level of APACHE III score (p=0.018) and serum albumin concentration (p=0.048) were related to the mortality of patients with PCP. Conclusion: The clinical course of PCP patients co-infected by CMV were not different from PCP only patients. Instead, accompanied respiratory failure, high APACHE III score and poor nutritional status were associated with poor outcome of PCP.

• Tuberculosis and Respiratory Diseases
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• v.44 no.2
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• pp.401-408
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• 1997

Background : Pulmonary sequestration is a rare congenital malformation, which is manifested by formation of nonfunctioning lung tissue lacking normal communication with the tracheobronchial tree. The preoperative diagnostic rate has been relatively low, and without consideration of pulmonary sequestration, unexpected bleeding from aberrant vessels may be a serious problem during the operation. The purpose of our study is to describe the clinical features of pulmonary sequestration based on a review of 15 cases treated by operation. Method : Fifteen patients with pulmonary sequestration who had undergone surgical treatment from 1991 through May 1996 at Yongdong Severance Hospital and Severance Hospital were reviewed retrospectively. Results : The mean age of the patients was 22.5 years (range 5~57), and male to female ratio was 9 : 6. Clinical presentations varied from recurrent respiratory infections such as fever, cough, and sputum or chest pain to no symptom. The chest simple X-rays showed multicystic shadow(10/15) and solid mass-like shadow(5/15). The chest CT scans, done in twelve cases, showed multicystic lesion with or without lung infiltration(8/12), solid mass-like lesion(4/12), The chest MRIs, done in three cases, revealed the aberrant arteries originating from descending aorta(2/3). Aortograms, done in four cases, showed the aberrant arteries originating from descending thoracic aorta(2/4), abdominal aorta(I/4), and intercostal artery(1/4). and the venous returns were via the pulmonary veins. Pulmonary sequestration was considered preoperatively in six patients of fifteen. Other preliminary diagnosis were lung tumor(3/15), lung abscess(21/15), bronchiectasis(2/15), and mediastinal tumor(2/15). In the operative findings, twelve cases were of intralobar type and three cases of extralobar type. The left lower lobe was most often affected(9/15) and one extralobar sequestration was in the pericardium. The aberrant arteries originated from descending thoracic aorta(6/15), abdominal aorta(1/15), internal thoracic arteries (2/15), intercostal artery(1/15), pericardiophrenic artery(1/15), but in four cases, the origins could not be defined. There was no mortality or complication postoperatively. Conclusion : In our study, preoperative diagnostic rate was relatively low, and clinical features were similar to previous reports. Preoperative vigorous diagnostic approach including aortography is strongly advocated not only for its diagnostic value, but also for accurate localization of the aberrant vessels, which is major concern to surgical procedure.

• Tuberculosis and Respiratory Diseases
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• v.49 no.2
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• pp.207-216
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• 2000

Background : The occurrence of lung complications after allogenic bone marrow transplantation(BMT) has been reported as 40-60 percent. The risk factors for lung complications are whole body irradiation, high dose chemotherapy, graft versus host disease, old age and CMV infection. The prevalence of graft versus host disease is less in Korea than in Western countries, but frequency of CMV infection is higher. Therefore, the pattern of lung complications may be different in Korea from those in Western countries. Methods : A retrospective cohort study was performed on one hundred consecutive adult patients who underwent allogenic bone marrow transplantation from December, 1993 to May, 1999 at Asan Medical Center. Lung complications were divided into two groups by the time of development, within 30days (pre-engraftment) and beyond 30 days (post-engraftment), and then subdivided into infectious and non-infectious complication. Infectious complications were defined as having the organism in blood, BAL fluid, pleural fluid or sputum, or compatible clinical findings in patients, which improved with antibiotics or an anti-fungal therapy. Result: 1) Eighty three episodes of lung complications had occurred in 54 patients. 2) Within thirty days after BMT, non-infectious complications were more common than infections, but this pattern was reversed after 30 days. After one year post-BMT, there was no infectious complication except in cases of recurrence of underlying disease or development of chronic GVHD. 3) Among the non-infectious complications, pleural effusion (27 episodes) was most common, followed by pulmonary edema (8 episodes), bronchiolitis obliterans(2 episodes), diffuse alveolar hemorrhage (1 episode) and bronchiloitis obliterans with organizing pneumonia (1 episode). 4) The infectious complications were pneumonia (bacterial: 9 episodes, viral: 4 episodes, fungal : 5 episodes, pneumocystis carinii : 1 episode), pulmonary tuberculosis(3 episodes) and tuberculous pleurisy (3 episodes). 5) Lung complications were more frequent in CMV positive patients and in patients with delayed recovery of neutrophil count. 6) The mortality was higher in the patients with lung complications. Conclusion : Lung complications developed in 54% after allogenic BMT and were associated with higher mortality.

• Tuberculosis and Respiratory Diseases
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• v.58 no.4
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• pp.385-391
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• 2005

Background : The incidence of nontuberculous mycobacterium (NTM) infections in Korea is increasing. This retrospective study was performed to examine the recovery rate of NTM from respiratory specimens as well as the isolated NTM colony characteristics, and to assess the clinical significance of a NTM isolation. Methods : The results of the respiratory specimens requested for an acid-fast bacilli (AFB) examination during 2002 at Asan Medical Center, along with the patients clinical characteristics were analyzed. Results : A total 26,820 respiratory specimens were requested for the acid-fast bacilli (AFB) smear and culture during the study period. The proportion of M. tuberculosis and NTM isolation was 5.7% and 2.2%, respectively. Among the AFB smear and culture positive specimens, 12.2% were found to be NTM. The scotochromogen showing a low colony count < 20, which appeared to be contaminants, were isolated in 31.8% of the 584 NTM isolates. Excluding the low-colony scotochromogens, the M. avium-intracellulare complex was the most common NTM isolates (42.1%), and was also the most common causative organism for NTM pulmonary diseases. 8.4% (23/275) and 17.8% (49/275) of patients with NTM isolates met the American and British Thoracic Society diagnostic criteria for NTM pulmonary disease, respectively. Conclusion : In case of a positive AFB-smear or culture result, the possibility of NTM being a causative organism should always be considered, even in Korea, which has an intermediate incidence of tuberculosis.