• Journal of Chest Surgery
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• v.42 no.5
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• pp.566-575
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• 2009

Background: The function of a bioprosthetic heart valve is determined largely by the material properties of the valve cusps. The uniaxial tensile test has been studied extensively. This type of testing, however, does not replicate the natural biaxial loading condition. The objective of the present study was to investigate the regional variability of the biaxial strain versus pressure relationship based on the types of fixation liquid models. Material and Method: Porcine aortic valves and pulmonary valves were assigned to three groups: the untreated fresh group, the fixed with glutaraldehyde (GA) group, and the glutaraldehyde with solvent (e.g., ethanol) group. For each group we measured the radial and circumferential stretch characteristics of the valve as a function of pressure change. Result: Radial direction elasticity of porcine aortic and pulmonary valves were better than circumferential direction elasticity in fresh, GA fixed and GA+solvent fixed groups (p=0.00). Radial and circumferential direction elasticity of pulmonary valves were better than aortic valves in GA fixed, and GA+solvent fixed groups (p=0.00). Radial and circumferential direction elasticity of aortic valves were decreased after GA and GA+solvent fixation(p=0.00), except for circumferential elasticity of GA+solvent fixed valves (p=0.785). The radial (p=0.137) and circumferential (p=0.785) direction of elasticity of aortic valves were not significantly different between GA fixed. and GA+solvent fixed groups. Radial (p=0.910) and circumferential (p=0.718) direction of elasticity of pulmonary valve also showed no significant difference between GA fixed and GA+solvent fixed groups. Conclusion: When fixing porcine valves with GA, adding a solvent does not cause a loss of mechanical properties, but, does not improve elasticity either. Radial direction elasticity of porcine aortic and pulmonary valves was better than circumferential direction elasticity.

• Korean Journal of Social Welfare
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• v.57 no.3
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• pp.337-361
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• 2005

This study seeks the implications for the Korean family welfare policies after examining the characteristics of fertility rates and family welfare policies of advanced OECD countries, and comparatively analyzing the fertility rates among clusters of countries having similar family welfare policies. The fertility rates of most advanced OECD countries declined below the population replacement level in the 1970s, and continuously declined slowly after that period. But in the 1990s the fertility rate of some countries increased, on the other hand that of other countries declined. Such a difference of fertility rates suggests that there is some correlation between the fertility rate and the family welfare policy of each country. Advanced countries became concerned about the decline of fertility rate, established the government Population Issues Committee in order to deal with population problems, and increased family welfare supports. But the level and pattern(focusing on maternal employment supports or child-rearing supports) of each country's family welfare policies are differently developed according to its political ideology, cultural and historical background, and economic environments. A comparative assessment of the fertility rate among clusters of countries having similar family welfare policies demonstrates that the higher the level of family welfare supports is and the level of maternal employment supports in comparison with that of maternal child-rearing supports is, the higher of fertility rate is. And a comparative assessment of the fertility rate changes among clusters of countries also shows that the higher the level of family welfare supports is and the level of maternal employment supports in comparison with that of maternal child-rearing supports is, the higher the increase of fertility rate is or the lower the decrease of fertility rate is. The implications for the Korean family welfare policies are summarized as follows. First, it is necessary to establish the government Population Issues Committee which can study systematically fertility rates and population problems, and provide comprehensive population measures. Second, family welfare supports should be expanded through the establishment of family allowances, the prolongation of maternity leave and child-care leave and the upward readjustment of child-care leave benefits, and the extension of public child-care facilities. Third, maternal employment supports such as public child-care facilities and maternity leave should be given more weight than maternal child-rearing supports such as family allowance. Fourth, it is required to prepare social environments which can provide the youth with the hope that child-rearing is not difficult and gives them happiness.

• Tuberculosis and Respiratory Diseases
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• v.41 no.4
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• pp.372-378
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• 1994

Background: Pressure support ventilation(PSV) is a new form of mechanical ventilatory support that assists spontaneous inspiraory effort of an intubated patient with a clinician-selected amount of positive airway pressure. Low level pressure support during inspiration can overcome the resistive component of inspiratory work imposed by an endotracheal tube. However the clinical efficacy of PSV as a weaning method has not been established yet. Object: The aim of study was to evaluate the efficacy of PSV when it is added to intermittent mandatory ventilation(IMV) in facilitating weaning precess compaired to IMV mode alone. Method: When the subject patients became clinically stable with their arterial blood gas analysis in acceptable range, they underwent weaning process either by IMV alone or by IMV plus PSV. The level of pressure support was held constant throught the weaning period. For the patients who required mechanical ventilation for less than 72 hr, 2h weaning trial was performed with IMV rate starting from 6/min. For the patients who required mechanical ventilation more than 72 hr, 7 hr weaning trial was performed with IMV rate starting from 8/min. For the patients who failed three consecutive trials of weaning, retrial of weaning was attempted over 3 days with IMV rate starting from 8/min. Clinical characteristics, APACHE II score and nutritional status were compared. For all patients, heart rate, mean blood pressure and respiratory rate were mornitored for 48 hrs after weaning trial started. Results: The total number of weaning trial was 37 in 23 patients(18 by IMV, 19 by IMV+PSV). Total ventilation time, APACHE II score and nutritional status were not statistically different between the two groups. The weaning success rate were not statistically different(38.3% by IMV, 42.1% by IMV+PSV) and the changes of mean blood pressure, heart rate, respiratory rate during first 48 hours were not different between the two groups. Conclusion: Low level PSV when added to IMV for weaning trial does not seem to improve the success rate of weaning from mechanical ventilation. PSV at 10cm $H_2O$ did not induce significant physiologic changes during weaning process.

• Tuberculosis and Respiratory Diseases
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• v.41 no.4
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• pp.389-396
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• 1994

Background : The two most important purposes of fiberoptic bronchoscopy in lung cancer patients are obtaining tissue diagnosis and staging. The direct sign of lung cancer on FOB includes visible tumor, with smooth or nodular surface, with or without necrosis and infiltration. Variant cell types of lung cancer have their characteristic biological behaviors respectively. For example, squamous cell carcinoma grows slowly, invades locally and has easy necrosis resulting in cavitation, whereas adenocarcinoma shows early metastasis, small cell carcinoma shows rapid growth and higher early metastasis rate. Based on this, it could be hypothesized that each cell type may have characteristic bronchoscopic finding. Method : To answer this question, we reviewed 106 cases which were diagnosed as primary lung cancer and had bronchoscopically visible specific cancerous lesions. Results : The results were as follows. 1) Squamous cell carcinoma accounted for 66 cases(62.2%), adenocarcinoma 15 cases(14.2%), large cell carcinoma 3 cases(2.8%). 2) The endobronchial tumor lesion was arbitrarily classified into 5 types according to gross characteristics. Type A, multilobulating mass with necrosis, accounted for 24.5%, type B, multilobulating mass without necrosis, 25.5%, type C, round beefy mass, 9.4%, type D, infiltration with mucosal irregularity, 6.6%, and type E, infiltration without mucosal irregularity, 34%. 3) The analysis of correlation between endobronchial tumor pattern and specific cell type revealed that squamous cell carcinoma had relation with the morphologic type B and small cell carcinoma had relation with the morphologic type E, but adenocarcinoma had no preponderance in morphologic type. The gross appearance had influence on the diagnostic yields of biopsies and the diagnostic yields of lobulating mass types(type A, B) were higher than those of other types. Conclusion : From the above observations, it could be concluded that squamous cell carcinoma and small cell carcinoma have relations with specific types of bronchoscopic morphology, but not the case in adenocarcinoma.

• Tuberculosis and Respiratory Diseases
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• v.40 no.5
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• pp.519-531
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• 1993

Background: Lymphangioleiomyomatosis(LAM) is a very rare disease occurring in women of reproductive age and leading to progressive respiratory failure despite therapy. But the natural history of this disease is uncertain and although anti-estrogenic agents have been used for more than twenty years, it's efficacy is still in debate. This study was performed to enhance understanding of this fatal disease in Korea by examining clinical, radiological, and pathologic findings of all the previously reported cases of LAM on Korea along with four new cases of LAM whom we report in this paper. Method: Out of twlve cases of LAM previously unpublished and published in domestic papers, two cases whose diagnoses were considered doubtful after review of clinical, radiological, and pathologic findings at "Asian Congress on Lymphangioleiomyomatosis" at Kyoto, Japan in feburary of 1993 were excluded from this study. Six cases which were reported previously and four new cases of LAM whom we report in this paper were analysed for the clinical, radiological, and pathologic characteristics. Results: All ten patients were women with mean age of $33{\pm}7$. The most common symptom was exertional dyspnea and most patients had history of pneumothoraces. Pulmonary function tests showed decreased diffusing capacity. on high resolution computed tomography(HRCT), all the cases had characteristic cysts. Most of the patients did not respond to hormonal therapy. Conclusion: In women of reproductive age, presenting with dyspnea who has a history of pneumothorax, LAM should always be considered as one of the diagnostic possibilities. If suspected, HRCT should be done to look for characteristic cysts and if needed, open lung biopsy should be done to confirm the diagnosis.

• Tuberculosis and Respiratory Diseases
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• v.53 no.6
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• pp.612-618
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• 2002

Background : Bronchoscopy is an important diagnostic and a therapeutic tool in chest medicine. However, most patients feel that a bronchoscopy is an unpleasant procedure, and it is important to sedate the patients appropriately, particularly where repetitive examinations are required. Midazolam is a sedative drug with amnestic qualities and a rapid 2 hour half-life. This study have attempted to determine the safety, appropriate dosage, and the effect of midazolam premedication in patients who underwent a bronchoscopy. Methods : One hundred and eighty consecutive patients undergoing bronchoscopy were enrolled in this study. The patients received a midzolam doses of 0.03 mg/kg, 0.06 mg/kg, or a placebo. An additional dose of lidocaine, the total number of coughs, and the duration of the procedures were recorded with monitoring the the blood pressure, heart rate, and oxygen saturation. The level of satisfaction was assessed by the patient, bronchoscopist, and the nurse. Results : The blood pressure, pulse rates, oxygen saturation, number of coughs, lidocaine dose, and procedure time in the 3 groups were similar. There was a trend for the midazolam 0.03 mg/kg group to satisfy bronchoscopists more than the other two groups. The nurses' acceptability was lower in the midazolam 0.06 mg/kg group than the other groups. The patients' acceptablity was greater in both the midazolam 0.03 mg/kg and 0.06 mg/kg groups than in the control group. Conclusion : Sedation with low doses of intravenous midazolam is a safe technique for fiberoptic bronchoscopy with a low morbidity and high acceptable to patients and bronchoscopists.

• Tuberculosis and Respiratory Diseases
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• v.53 no.6
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• pp.644-649
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• 2002

Background : Pulmonary hamartomas are the most common form of benign tumors, occurring in approximately 0.2% of routine autopsies. However, only a few reports on the clinical characteristics of pulmonary hamartoma in Korea have been published. Materials and Methods : The charts, X-rays and pathological specimens of 29 pulmonary hamartoma patients who were diagnosed by a pathological examination from 1990 to 1999 at the Catholic Medical Center were retrospectively reviewed. Results : The peak incidence of the tumor occurred in the sixth decade of life (37.5%). Seventeen patients (58.6%) were asymptomatic and 12 patients (41.4%) had symptoms. Chest discomfort was the most common symptom (31.0%). A total of 25 tumors (86.2%) were parenchymal, and 4 (13.8%) were endobronchial. Twenty cases were in the right lung and 9 cases were in the left lung (approximately 1:2.2). The RLL was the most commonly involved lobe (31.0%). Calcification was noted in 5 cases(19.2%) on a plain X-ray and in 5 cases (29.4%) on chest CT. Accompanied neoplasms were observed in 2 cases. Twenty-four hamartomas (82.8%) were diagnosed by a surgical resection and 4 cases(13.8%) were diagnosed by a fine needle aspiration biopsy. Twenty-six hamartomas (89.7%) were managed by a surgical resection. The follow up ranged from 4 to 55 months (mean, 19.6 months) and no recurrent pulmonary hamartomas were noted. Conclusion : Pulmonary hamartoma is more common in females and more commonly in the right lung. Calcification was noted only in 19.2% on a plain chest X-ray and 29.4% on a chest CT. No recurrent hamartomas had developed during the follow up period.

• Tuberculosis and Respiratory Diseases
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• v.52 no.5
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• pp.441-452
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• 2002

Background : Anti-apoptotic proteins may be involved in tumor development, progression and the response to treatment, Bcl-2 is by far the most studied anti-apoptotic protein. A novel inhibitor of apoptosis, designated survivin, and the heat shock proteins (HSPs) have recently been found in many human cancers. Immunohistochemical methods were used to determine the expression level of survivin, HSP70 and bcl-2 in non-small cell lung cancer (NSCLC) to evaluate their clinical significance. Materials and Methods : Tissue array slides were obtained from 99 surgically resected NSCLCs. Immunohistochemical staining was performed by an immuno-peroxidase technique using an avidin-biotinylated horseradish peroxidase complex. Anti-survivin rabbit polyclonal antibodies, anti-HSP70 mouse monoclonal antibodies and anti-bcl-2 mouse monoclonal antibodies were used as the primary antibodies. Results : Positive staining of survivin was detected in 33.3% of the cases. Survivin positivity is associated with to females and recurrence. A nonstatistically significant trend toward increased survivin expression was observed in non-smokers, and its expression inversely correlated with the number of cigarettes smoked in smokers. HSP70 was detected in 84.8% but this did not correlated with the clinicopathologic characteristics. Bcl-2 was detected in 18.2% and its expression correlated to tumor recurrence. No significant difference in the median survival time was noted in a comparison of all cases with survivin expression and those without. There was no association between HSP70 or bcl-2 expression and survival. Conclusion : Survivin expression was significantly associated with females and tumor recurrence. In addition its expression was inversely associated with the number of cigarettes smoked. However, HSP70 and bcl-2 expression were not associated with the clinical parameters or survival. This suggests that measuring the survivin levels may be useful in identifying patients at high risk for disease recurrence. Therefore, survivin might be a new diagnostic/therapeutic target in cancer.

• Tuberculosis and Respiratory Diseases
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• v.50 no.3
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• pp.334-342
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• 2001

Background : RpoB gene mutations have been found in about 96-98% of rifampicin (RMP)-resistant Mycobacterium tuberculosis. Recent reports confirm that the in laboratory settings a rpoB gene mutation can be used as a surrogate marker for multi-drug resistant tuberculosis. However, its usefulness in clinical applications has not been evaluated. This study was performed to confirm whether mutation analysis of the rpoB gene of M. tuberculosis is useful in clinical settings. Methods : The medical records of 33 patients in whom rpoB gene analysis was conducted using an INNOLiPA Rif. TB assay (LiPA) from June, 1998, to July, 2000, at the Asan Medical Center were retrospectively reviewed in 33 patients. The clinical characteristics in addition to the drug susceptibility and LiPA results were analyzed. The drug susceptibility test was considered as a gold standard method for M. tuberculosis susceptibility and these results were compared with those of the rpoB gene study and sequencing analysis. Sequencing analysis of the rpoB gene was done in cases where there was a discrepancy between the results of the drug susceptibility an d rpoB gene study. Results : The mean age and sex ratio was $42{\pm}18$, and 24:9 (M:F), respectively. There were 19 RMP susceptible (58%) and 14 RMP-resistant cases (42%) according to the rpoB gene study. The mean time from the request to reporting the results of the rpoB gene study was $5.2{\pm}2.6$ days. The mean gap from reporting the rpoB gene study to reporting the susceptibility was $56{\pm}35$ days. Twenty-eight cases (85%) showed identical results compared with the drug susceptibility results, whereas five cases (15%) showed contradictory results. When compared with the sequencing analysis, of the five cases that showed contradictory results, two had LiP A analysis errors and the remaining three were identical to the sequencing results. The rpoB gene study was of assistance in choosing the appropriate drugs in 28 cases (85%). Conclusions : An rpoB gene study using an LiP A assay was useful in rapidly diagnosing RMP-resistant tuberculosis, which enabled a proper choice of the appropriate drugs in clinical practices. However, an LiPA assay always should be performed in conjunction with microscopy, culture, and susceptibility tests.

• Tuberculosis and Respiratory Diseases
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• v.66 no.4
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• pp.295-299
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• 2009

Background: There are various etiologies causing bronchiectasis, but the cases without definite causes account for a quite high proportion. It is also uncertain that immunoglobulin G subclass deficiency (IgGSD) is associated with bronchiectasis. Therefore, we tried to measure the frequency of IgGSD in patients with bronchiectasis of unclear etiology, and to observe the clinical features of those patients with bronchiectasis and IgGSD. Methods: For the outpatients of a university hospital who were diagnosed as bronchiectasis by chest CT, we produced comprehensive history taking and physical examinations, and finally selected 31 patients with bronchiectasis of unclear etiology. Results: Two patients had total immunoglobulin G deficiency. The frequency of IgGSD was comparatively high (n=14). When we compared IgGSD group to normal immunoglobulin G subclass group, there were no significant differences in sex, age, and the frequency of sinusitis, bronchial asthma, and the abnormal lung function. Conclusion: In cases of bronchiectasis without definite causes, it can be considered to measure the level of immunoglobulin G subclass. It is also probably worthwhile to further evaluate the relationship between IgGSD and bronchiectasis.