• Tuberculosis and Respiratory Diseases
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• v.65 no.4
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• pp.269-276
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• 2008

Background: Although the prevalence of tuberculosis infections (PTBI) is one of the basic epidemiologic indices, no survey has been carried out since 1995 because the nation-wide tuberculosis prevalence survey was changed to a surveillance system. Subjects without a BCG scar are examined in a tuberculin survey. However, it is very difficult to select these subjects under high vaccination coverage. It is important to evaluate the impact of BCG vaccinations on the tuberculin response and estimate the PTBI regardless of the BCG vaccination status. Methods: A nation-wide, school-based cross-sectional tuberculin survey was carried out among first graders in elementary school in 2006. A total of 5,148 children in 40 schools were selected by quota sampling. Tuberculin testing with 0.1 ml of two tuberculin units of PPD RT23 was carried out on 4,018 children. The maximum transverse diameter of induration was measured 48 to 72 hours later. The presence of a BCG scar was checked separately. Results: There were no BCG scars in 6.3% of the subjects. The mean induration size of tuberculin testing was $3.7{\pm}4.4mm$, which included 1,882 (46.8%) subjects with an induration size of 0 mm. The PTBI was 10.9% (439 subjects) using a cut-off point of ${\geq}10mm$ (conventional method). The annual risk of tuberculosis infections (ARTI) was 1.9% when the mean age of the subjects was assumed to be 6 years. There was no difference in the PTBI according to the presence or absence of a BCG scar [11.2% vs 7.6% (OR: 1.54, 95% CI: 0.98~2.43)]. Using a mirror image technique with 16 mm as the cut-off point, the PTBI and ARTI had decreased to 2.4% and 0.4% respectively. Conclusion: PTBI and ARTI, as estimated by conventional methods, appear to be high among BCG vaccinated children. A mirror image technique is more suitable for estimating the indices in a country with an intermediate burden of tuberculosis than the conventional method.

• Journal of Chest Surgery
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• v.36 no.5
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• pp.348-355
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• 2003

Background: The prognostic significance of lymph node micrometastasis in non-small cell lung cancer remains controversial. We therefore investigated the clinicopathologic factors related to lymph node micrometastsis and evaluated the clinical relevance of micrometastasis with regard to recurrence. Material and Method: Five hundred six lymph nodes were obtained from 41 patients with stage 1 non-small ceil lung cancer who underwent curative resection between 1994 and 1998. Immunohistochemical staining using anti-cytokeratin Ab was used to detect micrometastasis in these lymph nodes. Result: Micrometastatic tumor cells were identified in pN0 lymph nodes in 14 (34.1%) of 41 patients. The presence of lymph node micrometastasis was not related to any clinicopathoiogic factor (p) 0.05). The recurrence rate was higher in patients with micrometastasis (57.1%) than in those without (37.0%), but the difference was not significant (p=0.22). Patients with micrometastasis had a lower 5-year recurrence-free survival rate (48.2%) than those without micrometastasis (64.1%), with a borderline significance (p=0.11), The S-year recurrence-free survival rate (25.0%) in the patients with 2 or more micrometastatic lymph nodes was significantly lower than that in the patients with no or single micrometastasis (p=0.02). In multivariate analysis, multiple lymph node micromestasis us was a significant independent predictor of recurrence (p=0.028, Risk ratio=3.568). Conclusion: Immunehistochemical anti-cytokeratin staining was a rapid, sensitive, and easy way of detecting lymph node micrometastasis. The presence of lymph node micrometastasis was not significantly associated with the recurrence, but had a tendency toward a poor prognosis in stage 1 non-small cell lung cancer. Especially, the presence of multiple micrometastatic lymph nodes was a significant and independent predictor of recurrence.

• Sleep Medicine and Psychophysiology
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• v.23 no.1
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• pp.16-24
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• 2016

Background and Objectives: Obstructive sleep apnea (OSA) is often undiagnosed but is an important risk factor affecting the health of an individual. The level of awareness of the illness among patients with OSA is low and is not correlated with severity of the illness. This study was conducted to compare awareness of OSA symptoms and illness between patients with OSA and simple snorers. Materials and Methods: Two hundred eighty-two patients who were suspected of having OSA participated in this study. All subjects underwent overnight polysomnography. Those with an apnea-hypopnea index (AHI) ${\geq}5$ were classified as the OSA group, while those with an AHI < 5 were classified as the simple snoring group. A sleep questionnaire, which included items on awareness of the illness, OSA, and sleep symptoms, was administered to all subjects and their bed-partners. Results: Simple snorers were much more aware of their symptoms such as snoring, irregular breathing, and apnea than were patients with OSA. Bed-partners of simple snorers were also more aware of the participants' sleep symptoms than were partners of patients with OSA. However, the duration of OSA symptoms was longer in the OSA group. In the correlation analysis, the level of awareness of OSA symptoms was negatively correlated with AHI, age, body mass index, and Epworth Sleepiness Scale score. Among the sleep questionnaire and polysomnography results, only Pittsburgh Sleep Quality Index was positively correlated with level of awareness of OSA symptoms. The minority of the respondents had heard about the treatment methods of continuous positive airway pressure and oral appliance and preferred them as treatment options. Conclusion: This study suggests that simple snorers are more aware of their symptoms than are patients with OSA. A higher severity of OSA, represented by a higher AHI, is correlated with lower awareness of one's OSA symptoms.

• Tuberculosis and Respiratory Diseases
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• v.45 no.4
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• pp.754-759
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• 1998

Background : Lung cancer is an important public health problem because of rapidly increasing malignancy in both sexes in relation with high smoking rate in Korea. Despite advances in therapeutic modalities and supportive cares, 5-year survival rate has improved only marginally during the past 2 decades. Therefore, the early detection of lung cancer is strongly needed for better prognosis and we conducted this study to review the clinical factors resulting in delayed diagnosis of lung cancer. Method: The clinical data such as presenting symptoms, duration for diagnosis, disease entities causing misdiagnosis or delayed diagnosis, were analyzed retrospectively in 154 patients with primary lung cancer diagnosed at Chungnam National university hospital from January to December in 1995. Results : 63 patients(40.9%) out of 154 patients were delayed diagnosed with the duration of 6.3 months compared with 3.6 months in patients diagnosed without delay. In delayed diagnosed group, Cough & sputum and dyspnea as presenting symptom were more critical than hemoptysis and chest pain, and doctor's delay was more critical than patient's delay. Tuberculosis(30/63) was most frequent disease entity causing delayed diagnosis, followed by pneumorua(9/63), COPD(6/63), heart diseases(5/63), etc.. Conclusion: It should be emphasized that any respiratory symptom be checked with chest X-ray to differentiate lung cancer and periodic check of chest X-ray be also needed for the longterm patients with any disease, especially with high risk group.

• Tuberculosis and Respiratory Diseases
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• v.44 no.2
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• pp.329-337
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• 1997

Background : Since endotracheal tube is the most important factor involved in the imposed work of breathing during mechanical ventilation, extubation of endotracheal tube is supposed to reduce respiratory work of patient. However, some patients show labored breathing after extubation despite acceptable blood gases. We investigated the changes of work of breathing before and after extubation and the factors involved in the change of WOB after extubation. Methods : The subjects were 34 patients(M : F = 20 : 14, mean age = $61{\pm}17yre$) who recovered from respiratory failure after ventilatory support and were considered to be ready for extubation. The patients with clinical or radiologic evidences of upper airway obstruction before endotracheal intubation for mechanical ventilation were excluded. Vital sign, physical examination, chest X-ray, work of breathing and other respiratory mechanic indices were measured prior to, immediately, 6, 24 and 48 hours after extubation serially. Definition of weaning failure after extubation was resumption of ventilatory support or reintubation of endotracheal tube within 48 hour after extubation because of respiratory failure. The patients were classified into group 1(decreased work of breathing), group 2(unchanged work of breathing) and group 3(increased work of breathing) depending on the statistical difference in the change of work of breathing before and after extubation. Results : Work of breathing decreased in 33%(11/34, group 1), unchanged in 41%(14/34, group 2) and increased in 26%(9/34, group 3) of patients after extubation compared with before extubation. Weaning failure occurred 9%(1/11) of group, 1, 28.6%(4/14) of group 2 and 44%(4/9) of group 3 after extubation(p = 0.07). The change of work of breathing after extubation was positively correlated with change of mean airway resistance(mRaw). (r = 0.794, p > 0.01). In three cases of group 3 whose respiratory indices could be measured until 48 hr after extubation, the change in work of breathing paralleled with the sequential change of mRaw. The work of breathing was peaked at 6 hr after extubation, which showed a tendency to decrease thereafter. Conclusions : Reversible increase of work of breathing after extubation may occur in the patients who underwent extubation, and the increase in mRaw could be responsible for the increase in work of breathing. In addition, the risk of weaning failure after extubation may increase in the patients who have increased WOB immediately after extubation.

• Tuberculosis and Respiratory Diseases
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• v.47 no.3
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• pp.331-338
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• 1999

Background: Nearly 10% of cancer patients will develop a second primary cancer within ten years after surgical removal of the primary tumor. The detection of risk factors for developing multiple primary tumors would be important This study was conducted to evaluate the clinical characteristics and abnormal p53 expression of lung cancer associated with multiple primary cancer(MPC). Method: Clinical characteristics and abnormal p53 expression were compared between 20 cases of lung cancer(NSCLC ; 16 cases, SCLC ; 4 cases) associated with MPC and 26 cases of primary non-small cell lung cancer. Result: MPC associated with lung cancer was gastric cancer(8), lung cancer(2), esophageal cancer(2), colon cancer(2), laryngeal cancer(1), bladder cancer(1), small bowel cancer(l), adrenal cancer(1), hepatocellular carcinoma(1), and breast cancer (1) in order. The clinical stage of primary NSCLC was relatively advanced, but NSCLC associated with MPC was even distribution at each stage. The detected incidences of abnormal p53 expressions were 62.5% in NSCLC associated with MPC and 76.9% in primary NSCLC(p>0.05). Conclusion: There was no difference in abnormal p53 expression between non-small cell carcinoma associated with multiple primary cancer and primary non-small cell carcinoma.

• Tuberculosis and Respiratory Diseases
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• v.49 no.2
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• pp.169-178
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• 2000

Background : Usually fever subsides within one week in over 90% of pulmonary tuberculosis (TBp) patients after the start of short-course anti-tuberculosis therapy, but occasionally it persists over two weeks after treatment. When the fever persists, drug resistance, combined infection, or drug fever, and so on, are considered as an etiology and, in some cases, drugs are changed. But inadvertent discontinuation of a short-course regimen inevitably will extend the duration of treatment, and the treatment completion may be delayed. This study was performed to investigate the causes of prolonged fever (PF) and to identify the predictors of PF in drug-susceptible TBp patients in Korea. Method : Five hundred-ninety-eight patients, who were admitted to Asan Medical Center from January 1996 to March 1999, diagnosed with TBp and prescribed short-course, anti-tuberculosis treatment, were reviewed. PF was defined as having fever over two weeks despite treatment. The causes of PF were analyzed. Drug-sus-ceptible TBp patients who presented no causes for PF, except turberculosis itself, were selected(n=22), and they were compared with those who had no fever at diagnosis (n=22) and those who had fever at diagnosis, which had subsided within two weeks after treatment (n=22). Clinical, laboratory, and radiological parameters were compared among the three groups. Results : Twenty-eight (4.8%) of 598 patients showed PF over two weeks despite short-course treatment. The causes of PF were drug fever (n=2), multi-drug resistant tuberculosis (n=3), disseminated Mycobacterium kansasii infection (n=1), and drug-susceptible tuberculosis itself (n=22). The patients with PF had more risk factors for tuberculosis, long duration of symptoms before treatment, night sweats, weight long, numerous acid fast bacilli on sputum smear, anemia, hyponatremia, hypoalbuminemia, over three lung cavity numbers and extensive infiltration, indicating that they had prolonged and extensive lung diseases. Conclusion : The main cause of PF in TBp despite short-course regimen seems to be drug-susceptible but extensive disease in Korea. Any changes to the drug regiment provided for TBp patients with prolonged fever despite treatment should be carefully considered.

• Tuberculosis and Respiratory Diseases
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• v.55 no.4
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• pp.370-377
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• 2003

Background : Pneumocystis carinii pneumonia (PCP) is one of the most common cause of infection in patients with HIV infection. Recently, the incidence of PCP have been increasing in immunocompromised hosts without HIV infection. We compared the clinical characteristics of PCP between HIV infected and non-infected persons. Patients and Methods : We retrospectively reviewed the charts of 25 patients diagnosed as PCP from 1996 to 2002. Age, sex, underlying conditions, use of immunosuppressants, clinical courses, laboratory findings, treatment and prognosis were compared between HIV infected and non-infected persons. Results : Twenty-five patients with PCP were identified. 16 were HIV infected, and 9 were HIV non-infected. The mean age of overall patients was $43.4{\pm}13.2$ years. Underlying conditions in HIV non-infected persons were hematologic malignancy (7 cases), solid organ transplant (1 case), and autoimmune disease (1 case). Seven cases (77.8%) of HIV non-infected persons had a history of steroid use. Mean duration of symptoms was longer in HIV infected persons than in HIV non-infected persons, but it was not statistically significant. PaO2 was lower in HIV infected persons ($61.2{\pm}16.9$ mmHg vs. $65.4{\pm}15.4$), but it was not statistically significant. Chest X ray showed typical ground glass opacity in 12 cases (75%) of HIV infected persons and in 4 cases (44.4%) of HIV non-infected persons. Twelve cases (75%) of HIV infected persons were treated with steroid, as were 6 cases (66.7%) of HIV non-infected persons. Ventilator care was needed in 6 cases (37.5%) of HIV infected persons and in 2 cases (22.2%) of HIV non-infected persons. Mortality of HIV infected persons was 50%, and that of HIV non-infected persons was 11.1%. Conclusions : PCP showed some different clinical characteristics between HIV infected and non-infected persons. Prospective studies regarding the risk factors of PCP, prophylaxis, treatment and prognosis in HIV infected and non-infected persons are warranted.

• Tuberculosis and Respiratory Diseases
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• v.55 no.4
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• pp.353-360
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• 2003

Background : Although most patients with tuberculous pleurisy respond well to anti-tuberculous drugs, some are known to progress into severe pleural thickening which needs decortication despite adequate anti-tuberculous treatment. Therefore, the purpose of this study was to identify factors associated with the development of severe pleural thickening in patients who finally underwent pleural decortication in tuberculous pleurisy. Patients and Methods : From retrospective medical records review, 121 patients initially diagnosed as tuberculous pleurisy without initial pleural fluid loculation were enrolled between January 1998 and December 2002. They were separated into two groups: 85 patients in group 1 who improved by anti-tuberculous drugs only, and 36 patients in group 2 who had progressed into pleural adhesion and finally underwent pleural decortication despite adequate (more than 6 months) anti-tuberculous treatment. Results : Males were more common in group 2 (M/F=31/5) than in group 1 (M/F=53/32) (p=0.010). Group 2 patients tended to have lower pleural fluid glucose level ($58{\pm}4$ mg/dL) than group 1 ($89{\pm}3$ mg/dL) (p=0.001) and higher pleural fluid adenosine deaminase level ($86{\pm}5$ IU/L) than group 1 ($76{\pm}3$ IU/L), (p=0.038). There were no significant differences in age, symptom duration, pleural fluid amount, or pleural fluid LDH level between groups 1 and 2. Conclusions : There was a relative risk of tuberculous pleurisy progression into severe pleural thickening which needed decortication in the case of male patients, low pleural fluid glucose or high adenosine deaminase level. But further, large-scale, prospective studies should be investigated.

• Journal of Yeungnam Medical Science
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• v.18 no.2
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• pp.215-225
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• 2001

Background: There are many evidences that inflammation is an important determinant of the development of atherosclerosis and one of the systemic markers of inflammation, C-reactive protein(CRP), is associated with extent of coronary artery disease and risk of coronary events. We assessed the time response of CRP response after coronary angioplasty and it's influence on the clinical restenosis in angina patients. Materials and Methods: Patients included 36 angina patients undergoing single vessel angioplasty. Levels of CRP were measured before and 12, 24, 48, and 72 hours after angioplasty. Clinical restenosis was assessed at 6 months after procedure. Results: Baseline CRP level was $0.30{\pm}0.01$ mg/dL in stable and $0.46{\pm}0.28$ mg/dL in unstable angina patients(p<0.05). After angioplasty, CRP level was increased with peak at 24 hour and persisted to 72 hours after angioplasty. At 24 hour after angioplasty, the magnitude of CRP change was $0.32{\pm}0.31$ mg/dL in stable and $0.79{\pm}0.73$ mg/dL in unstable angina patient(p<0.05). The change of CRP level was not associated with troponin-T after angioplasty. In unstable angina patients, clinical restenosis was developed in 8% of patients with low baseline CRP levels and in 50% of those with high baseline CRP levels more than 0.6 mg/dL(p<0.05). Conclusion: In unstable angina patients, inflammatory response is more increased than stable angina patients, and increased inflammatory response effects on the restenosis after coronary angioplasty.