• Tuberculosis and Respiratory Diseases
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• v.39 no.6
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• pp.490-501
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• 1992

Background: Isocyanate is the most significant cause of occupational asthma in this country. The mechanism of isocyanate induced bronchoconstriction is unclear. Subjects and Method: To observe its immunologic and clinical findings, we performed methacholine bronchial challenge test (MBCT), toluene diisocyanate (TDI)-bronchoprovocation test (BPT) and RAST to TDI-, diphenylmethane diisocyanate (MDI)-, and hexamethylene diisocyanate (HDI)-human serum albumin (HSA) conjugate in 22 isocyanate-sensitive asthmatic workers. Results: BPT revealed early (11), dual (5), and late only (6) asthmatic responses. Their latent period ranged from 3 to 120 months (mean:45.9 months). Three cases (13.6%)showed a negative response on initial MBCT, but following MBeT performed 24 hours after TDI-BPT revealed the development of airway hyperresponsivenss. Twelve (54.5%) workers had increased specific IgE to TDI-HSA, seven (31.8%) had to MDI-HSA, and nine (40.9%) had to HDI-HSA conjugate. The prevalence of specific IgE was not associated with latent period, type of asthmatic responses, smoking, and atopic status. After 3 months' avoidance from workplace, airway hyperresponsiveness was improved in 10 (38.3%), among 12 followed cases. Conclusion: It is suggested that isocyanate can induce IgE-mediated bronchoconstriction in 59.1% of isocyanate-sensitive asthmatic workers. Isocyanate-induced asthma can occur even though MBeT showed a negative result, and measurement of the changes of airway hyperresponsivenss after isocyanate-BPT could be helpful to diagnose isocyanate-sensitive asthma.

• Tuberculosis and Respiratory Diseases
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• v.40 no.6
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• pp.700-708
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• 1993

Background: Lung cancer has become one of the most common cancers in Korea. It is important to determine the accurate histologic types and stages because of different therapeutic modlaity, especially in small cell carcinoma. This study was designed to evaluate diagnostic yields according to variable diagnostic methods in lung cancer. Methods: The records of 683 patients with a confirmed diagnosis of primary lung cancer during the period of 7 years, from January, 1986 until December, 1992 at Presbyterian Medical Center were analyzed retrospectively. Results: 1) Age and sex distributions Male: female sex ratio was 5.57:1 and age distributions were 7th decade 41.4%, 6th decade 30.2%, 8th decade 17.0%, 5th decade 7.9%, 4th decade 2.5%, 9th decade 1.3%, and 3rd decade 0.2% in decreasing order. 2) The frequencies according to histologic cell types were squamous cell carcinoma 44.7%, small cell carcinoma 23.9%, adenocarcinoma 22.8%, alveolar cell carcinoma 2.5%, large cell carcinoma 1.2%. mixed forms 1.2%, undifferenciated cell carcinoma 0.6% and malignant fibrous histiocytoma 0.2%(1 case) in decreasing order. 3) The most common locations of lung cancer were in left upper lobe and right lower lobe, and no differences of diagnostic methods according to locations were noted. 4) In central lesions, bronchoscopic examination was very accurate and frequently used diagnostic method, and in peripheral lesions, transthoracic lung biopsy(TTLB) was apparent1y accurate method. 5) The diagnostic yields of bronchoscopic biopsy, bronchial brushing, sputum cytology, transthoracic lung biopsy and transbronchial lung biopsy(TBLB) were 81.3%, 57.5%, 31.1%, 69.6% and 61.6%, respectively. 6) The concordance rates between the histologic diagnosis with bronchial brushing and sputum-cytology were 91.3% and 98.4%, respectively. 7) It was appropriate in lung cancer to repeat sputum cytology 3 to 5 times. Conclusion: Bronchoscopic examination is important to determine the histologic cell types in lung cancer. In addition, we should be interrested in improving diagnostic yields of sputum cytology as an easy method.

• Tuberculosis and Respiratory Diseases
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• v.48 no.1
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• pp.33-44
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• 2000

Background: To evaluate airway responses and inflammation to antigen in Sprague-Dawley rat asthma model, we examined airway responses, serial histologic changes of the lung, and the relationship between airway responses and airway inflammation after antigen airway challenge. Methods: Sprague-Dawley rats were sensitized with subcutaneous injection of 10 ${\mu}g$ ovalbumin(OA). Antigen airway challenges were done 14~16 days after sensitization and the sensitized rats were sacrificed 1h($A_E$), 6~8h($A_L$) and 1day($A_D$) after airway challenge, to examine the histologic changes of the lung. Airway responses were measured by body plethysmograph and recorded by enhanced pause(Penh) as an index of airway obstruction 6~8h after antigen challenges. Nonsensitized controls(10 rats) were also challenged with antigen and sacrificed 1 day later. Histopathologic examination of two trachea, large bronchi, small bronchi, and vessels was performed to evaluate the severity of inflammation and eosinophilic infiltration with H&E stain. Results: In 17 of 20 rats(85%) in both groups, we observed airway responses. Among them, an early response(ER) in 15 rats(75%), an dual response in 5(25%), and an late response(LR) only in 2 rats(10%) displayed. There were no significant differences in the severity of inflammation among the trachea, large bronchi, small bronchi and vessels in all groups after antigen challenge(p>0.05) and between early and late responders. The significant eosinophil infiltration was observed in 5 rats(50%) of AL(p<0.05) compared with in AE and controls. Also, eosinophil infiltration was observed in higher trend in LR(57.1%) compared to ER(40%)(p>0.05). Conclusion: Sprague-Dawley rats sensitized with subcutaneous injection of OA showed a significant airway responses to antigen challenge. But antigen challenges caused a little eosinophil infiltration and no significant airway inflammation. Asthma model of Sprague-Dawley rats could be useful for antigen-induced airway responses, but this model has a limitation for the study of human asthma because of no significant pathologic change.

• Tuberculosis and Respiratory Diseases
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• v.44 no.1
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• pp.114-123
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• 1997

Background : To assess the diagnostic role of bronchoscopic lavage for the evaluation of pneumonia in intensive care unit(ICU), the results were compared to blind endobronchial specimen. Method : From September 1993 to August 1996, twenty-eight ICU patients suspected pneumonia on the basis of clinical evidence and performed bronchoscopy under the diagnostic or therapeutic purpose were studied retrospectively for the clinical findings including culture of bronchoscopic and blind endobronchial specimen. Bronchoscopic specimen was got through small amount of bronchoalveolar lavage with 20-40ml saline, one or two times on the suspected site. Results : l. Main reasons of ICU admission were respiratory and impending respiratory failure Nosocomial pneumonia was most common with 16 cases; each for community acquired and immunocompromised type with 6 cases. Diagnostic purpose of bronchoscopy was performed in 20 cases as 71 percent in total, whereas therapeutic removal of secretion in 8 cases. The complication during bronchoscopic evaluation was trivial. 2. The agreement between blind endobronchial and bronchoscopic specimen on microbial culture was only 39.3 percent. However, 2 cases each for aspergillosis and tuberculosis were diagnosed under bronchoscopic evaluation. 3 The application of mechanical ventilation occured significantly frequently in multidrug resistant pneumonia compared with other pneumonia in terms of bronchoscopic specimen. 4. The application of mechanical ventilation was significantly common in nosocomial pneurmonia compared with other types of pneumonia. Conclusion : The selective bronchoalveolar lavage and therapeutic removal of bronchial secretion with bronchoscopy in ICU patient accompanying pneumonia is a very useful tool with safety. The multidrug resistant pneumonia or nosocomial pneumonia could be closely associated with the use of mechanical ventilation.

• Tuberculosis and Respiratory Diseases
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• v.62 no.3
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• pp.197-202
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• 2007

Background: Cigarette smoking is an important risk factor for chronic bronchitis and COPD. Airway epithelial cells exposed to cigarette smoke components such as nicotine, cotinine and benzopyrene can generate reactive oxygen species (ROS) and be subject to oxidative stress. This oxidative stress can induce the inflammatory response in the lung by the oxidant itself or by the release of proinflammatory cytokines. It has been reported that nicotine stimulates ROS, which are associated with NF-${\kappa}B$. Methods: Beas2B cells were treated with nicotine, cotinine and benzopyrene. RT PCR was used to measure the expression of several antioxidant factors using the total RNA from the Beas2B cells. The level of superoxide dismutase(CuZnSOD), thioredoxin, glutathione reductase expression was examined. Results: 0.5 to 4 hours after the benzopyrene, nicotine and cotinine theatments, the level of thioredoxin and glutathione reductase expression decreased. Longer exposure to these compounds for 24 to 72 hours inhibited the expression of most of these antioxidant factors. Conclusion: During exposure to smoke compounds, thioredoxin and glutathione reductase are the key antioxidant factors induced sensitively between 0.5 and 4 hours but the levels these antioxidants decrease between 24 hour and 72hours.

• Tuberculosis and Respiratory Diseases
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• v.64 no.1
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• pp.33-38
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• 2008

Alcaligenes xylosoxidans is a catalase and oxidase positive, motile, nonfermentative and gram-negative rod bacterium. A. xylosoxidans infection is a rare cause of pulmonary infection and little information concerning treatment is available. The majority of patients that develop A. xylosoxidans infection belong to a high-risk group due to an immunocompromised condition or due to pulmonary cystic fibrosis. We report two rare cases of immunocompentent patients that developed a pulmonary infection due to A. xylosoxidans. A 77-year-old man was admitted with a lung abscess. The patient denied having any prior medical illness. A culture of bronchial washing fluid showed the presence of A. xylosoxidans. Despite appropriate antibiotic treatment, the patient died from acute respiratory distress syndrome (ARDS). Another patient, a 61-year-old man without an underlying disease, was admitted with empyema. Under the condition of a closed thoracostomy, a high fever persisted and the empyema was also aggravated. A. xylosoxidans was detected from a culture of pleural fluid. Susceptible antibiotic treatment was provided and surgical intervention was performed. We report these cases with a review of the literature.

• Tuberculosis and Respiratory Diseases
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• v.64 no.1
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• pp.22-27
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• 2008

Background: Staphylococcus aureus frequently colonizes and infects hospitalized patients. Respiratory infections with Staphylococcus aureus are common in patients with compromised airway defenses. However the mechanisms of S. aureus invasion from colonization to the epithelium are unclear. Cell invasion by S. aureus would require destruction of the extracellular matrix, which is believed to be the result of increased matrix metalloproteinases (MMP) activity. Methods: In this study, respiratory epithelial cells were infected with S. aureus. After removing the extracellular bacteria by washing, the internalized bacteria in the cells were assessed by counting the colonized forming units (CFUs). The cell adhesion proteins, dysadherin and E-cadherin, were evaluated by Western blotting. The MMPs in the bacterial invasion were evaluated by pretreating the cells with GM6001, a MMP inhibitor. Results: The internalization of S. aureus was found to be both time and dose dependent, and the increase in MMP 2 and 9 activity was also dependent on the incubation time and the initial amount of bacterial inoculation. The invasion of S. aureus was attenuated by GM6001 after 12 hours incubation with a multiply of infection (MOI)=50. The expression of dysadherin, a membrane protein, was increased in a time and dose dependent manner, while the expression of E-cadherin was decreased. Conclusion: MMPs may mediate the invasion of S. aureus into epithelial cells.

• Tuberculosis and Respiratory Diseases
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• v.44 no.4
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• pp.942-948
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• 1997

Benign Tracheobroncheal tumor is a rare disease such as 1.9% of all tumor of pulmonary origin. Because clinical manifestation of benign tracheal tumor resembles that of broncheal asthma, these patients are usually treated in a way that used in broncheal asthma. Therefore, the diagnosis is delayed. We experienced a case of tracheal neurilemmoma that cured by bronchoscopic laser therapy. A 23-year-old woman visited our hospital because of progressing dyspnea especially during inspiration. She was treated with aminophylline and 2 agonist under the impression of bronchial asthma at a local clinic. But because the symptoms were not relieved and pulmonary function test revealed variable extrathoracic lesion, we conducted bronchoscopy and biopsy. There were $1.5{\times}2cm$ sized movable mass with stalk attached right anterior wall of bronchus. The biopsy result was neurilemmoma. Therefore we conducted bronchoscopic Laser therapy four times and the lesion disappeared in bronchoscopy and chest CT.

• Tuberculosis and Respiratory Diseases
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• v.61 no.4
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• pp.339-346
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• 2006

Background: There has no known epidemiologic survey on the frequency of complementary-alternative medicine (CAM) use in the treatment of adult asthma in Korea. This study examined the current use of CAM by asthma patients in Korea. Methods: One hundred adults with asthma, who had been admitted to Kyunghee university hospital between January 2000 and December 2003, were enrolled in this survey. They received a structured questionnaire interview and a clinical assessment of prevalence and pattern of CAM use. Results: 53% patients had an experience of at least one type of CAM during their asthma management. Users of CAM had more hospital visits than those who had never used CAM($1.46{\pm}0.68$ vs. $2.11{\pm}1.20$, p=0.001). Those in their $50^{th}$ decades had more experience of CAM (80%) than the other age groups. The methods of CAM used by our patients are as follows: Diet/nutritional therapy in 35 patients(69%), herbal therapy in 28 patients(53%), acupuncture in 9 patients(17%), moxa treatment in 6 patients(11%), breathing exercises in 1 patient(2%). Conclusions: More than 50% of patients with bronchial asthma have used CAM. A more detailed and large scaled study will be needed to define the actual status of the use of CAM in the treatment for asthma. Inaddition, further research on the scientific validation of the clinical efficacy of CAM in asthma management should be followed.

• Tuberculosis and Respiratory Diseases
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• v.72 no.3
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• pp.293-301
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• 2012

Background: Ventilator-associated pneumonia (VAP) requires prompt and appropriate treatment. Since methicillin-resistant Staphylococcus aureus (MRSA) is a frequent pathogen in VAP, rapid identification of it, is pivotal. Our aim was to evaluate the utility of quantitative polymerase chain reaction (qPCR) as a useful method for etiologic diagnoses of MRSA pneumonia. Methods: We performed qPCR for mecA, S. aureus-specific femA-SA, and S. epidermidis-specific femA-SE genes from bronchoalveolar lavage or bronchial washing samples obtained from clinically-suspected VAP. Molecular identification of MRSA was based on the presence of the mecA and femA-SA gene, with the absence of the femA-SE gene. To compensate for the experimental and clinical conditions, we spiked an internal control in the course of DNA extraction. We estimated number of colony-forming units per mL (CFU/mL) of MRSA samples through a standard curve of a serially-diluted reference MRSA strain. We compared the threshold cycle (Ct) value with the microbiologic results of MRSA. Results: We obtained the mecA gene standard curve, which showed the detection limit of the mecA gene to be 100 fg, which corresponds to a copy number of 30. We chose cut-off Ct values of 27.94 (equivalent to $1{\times}10^4$ CFU/mL) and 21.78 (equivalent to $1{\times}10^5$ CFU/mL). The sensitivity and specificity of our assay were 88.9% and 88.9% respectively, when compared with quantitative cultures. Conclusion: Our results were valuable for diagnosing and identifying pathogens involved in VAP. We believe our modified qPCR is an appropriate tool for the rapid diagnosis of clinical pathogens regarding patients in the intensive care unit.