• Journal of Aquaculture
• /
• v.3 no.1
• /
• pp.49-63
• /
• 1990

A population ecological study was carried out to estimate survival and growth rates, biomass, biological production and turnover ratio of cultured sea squirt, Halocynthia roretzi, by growth stages, using data from in situ culture experiment off Hansando in the southern part of Korea from February 1985 to July 1986. The squirt population followed an exponential decay function and the instantaneous coefficient of total mortality (Z) was estimated to be 0.0614 $month^{-1}$(Var (Z) = 0.000126). Growths in total weight and meat weight of squirts were expressed as linear functions during the period of culture experiment. The growth of squirts showed a negative correlation with the water temperature. The mean biomass per string ranged from 2.14 kg for March of the first year to 16.26 kg for March of the next year. The biological production per string was estimated to range from 3.28 kg for the first summer (June - July) to 6.46kg for the first late winter (February-March). The peak of turnover ratio occurred in the late winter (February-March) as 3.013 and the ratios sharply declined thereafter. Based on the results of this study, management implications for culturing sea squirts were also suggested. The optimum harvest time ($t_{mb}$) when the peak biomass in terms of total weight occurred was estimated to be late June of the second year, which corresponded to 16.7 months after the main hanging. However, the time when the peak biomass in terms of meat weight was occurred was early July of the second year. The maximum harvest biomass was 17.4 kg per string in terms of total weight and 6.3 kg per string in terms of meat weight. In conclusion, the process of culture should be conducted on the basis of the knowledge of population ecological theories as shown in this study.

• Journal of Chest Surgery
• /
• v.30 no.4
• /
• pp.383-389
• /
• 1997

From March, 1992 to March, 1996, a total of 279 patients underwent coronary bypass surgery at the Sejong General Hospital, Puchon. We selected 22 patients with severe left ventricular(LV) dysfunction from them. The criteria were the presence of global or segmental abnormalities of left ventricular contraction and LV ejection fraction(EF) less than 35% based on biplane LV angiography by planimetry method. The mean age of 17 male and 5 female patients was 60$\pm$5.6years(range:47~73 years). All had the anginas, which were Canadian class II in 6, class 111 in 12 and class IV in 4. All patients except one had the history of previous myocardial infarction more than once. Seven of them had the symptoms and signs of congestive heart failure, such as dyspnea on excertion and increased pulmonary vascular markings. Their mean LVEF was 29.4$\pm$4 5%(range : 18~35%) and mean LV end-diastolic pressure was 18.7 $\pm$8. 2mmHg(range:10~42mmHg). 21 patients had 3 vessel-disease and 1 had 2 vessel-disease. Complete revascularization was tried with the use of 16 internal mammary arteries and 60 sapheuous veins and 3 radial arteries grafts. The mean number of distal anastomosis was 3.5$\pm$ 1.1. Concomitantly, one mitral valvuloplasty and annuloplasty was performed in the patient with moderate mitral regurtigation. The hospital mortality was 4.5%. During the follow-up, there were 3 late deaths. Of 18 survivors, 2 patients were lost in follow-up 24 and 27 month respectively after operation and the remaining 16 patients have bcen followed up with an average of 30.4 $\pm$ 13.4 months.15 patients had improvement with respect to angina but 8 patients still have the continuing or progressing heart failure. The 1-year, 2-year and 3-year actuarial survival rate was 85.2, 69.1, 46.1%, respectively. This study indicates that coronary artery bypass sur ery can be performed in the patients with severe LV dysfunction at acceptable risk but does not greatly contribute to the improvement of congestive heart failure.

• Journal of Chest Surgery
• /
• v.30 no.8
• /
• pp.752-759
• /
• 1997

Profound hypothermia protects . cerebral function during total circulatory arrest(TCA) in the surgical treatment of a variety of cardiac and aortic diseases. Despite its importance, there is no ideal technique to monitor the brain injury from ischemia. Since 1994, we have developed compressed spectral array(CSA) of electroencephalography(EEG) and monitored cerebral activity to reduce ischemic injury. The purposes of this study are to analyse the efficacy of CSA and to establish objective criteria to consistently identify the safe level of temperature and arrest time. We studied 6 patients with aortic dissection(AD, n=3) or aortic arch aneurysm(n=3, ruptured in 2). Body temperatures from rectum and esophagus and the EEG were monitored continuously during cooling and rewarming period. TCA with cerebral ischemia was performed in 3 patients and TCA with selective cerebral perfusion was performed in 3 patients. Total ischemic time was 30, 36 and 56 minutes respectively for TCA group and selective perfusion time was 41, 56 and 92 minutes respectively for selective perfusion group. The rectal temperatures for flat EEG were between 16.1 and 22. $1^{\circ}C$ (mean: 18.4 $\pm$ 2.0): the esophageal temperatures between 12.7 and $16.4^{\circ}C$ (mean $14.7\pm1.6).$ The temperatures at which EEG reappeared $5~15.4^{\circ}C$ for esophagus. There was no neurological defic t and no surgical mortality in this series. In summary, the electrical cerebral activity Teappeared within 23 minutes at the temperature less than $16^{\circ}C$ for rectum. It seemed that $15^{\circ}C$ of esophageal temperature was not safe for 20 minutes of TCA and continuous monitoring the EEG with CSA to identify the electrocerebral silence was useful.

• Journal of Chest Surgery
• /
• v.40 no.10
• /
• pp.659-666
• /
• 2007

Background: Preserving the subvalvular apparatus after mitral valve replacement (MVR) results in better ventricular function and a better outcome. In conjunction, mitral valve repair (MVr) is associated with a better outcome, yet little is known about the hemodynamics and outcomes between patients undergoing MVr and MVR with chordal preservation. We prospectively evaluated the hemodynamic changes and outcomes of patients undergoing MVr and MVR with chordal preservation. Material and Method: Fifty-four patients with mitral regurgitation (MR) who under-went MVR with chordal preservation (n=21) or MVr (n=33) were studied. The patients' characteristics, the intra-and postoperative hemodynamics and the use of cardiac medications, the postoperative outcome and the complications were recorded during the hospital stay. All the patients were followed up for at least 6 months post-operatively for determining their morbidity and mortality. Result: The patients' characteristics were similar between the groups, except for the presence of atrial fibrillation and congestive heart failure which was more frequent in the MVR group. Also, the preoperative left ventricular ejection fraction was lower in the MVR group than in the MVr group ($64{\pm}9%$ versus $69{\pm}5%$, respectively, p=0.043). There were no significant differences of the hemodynamics between the groups. The use of inotropic drugs and pacemakers during the 12hrs postoperatively was more common in the MVR group than in the MVr group (48% versus 24%, p=0.025 and 52% versus 24%, p=0.035, respectively). The other postoperative outcomes were similar in both groups for at least the 6 months follow-up period. Conclusion: MVR with chordal preservation was comparable with regard to the hemodynamics and clinical outcomes, supporting the beneficial effect of preserving the subvalvular apparatus after MVR.

• Tuberculosis and Respiratory Diseases
• /
• v.54 no.4
• /
• pp.395-402
• /
• 2003

Background : Patients with chronic obstructive pulmonary disease (COPD) are at increased risk for osteoporosis, which has implications for mobility and even mortality. The goal of this pilot study was to evaluate bone mineral density (BMD) and risk factors for osteoporosis in a limited number of men with COPD. Methods : We checked BMD, $FEV_1$(% of predicted) and investigated risk factors for osteoporosis in 44 male patients with COPD who visited our hospital from January to August 2002. Results : Mean(${\pm}$) age was $69{\pm}9$ yrs, body mass index(BMI) $21{\pm}3kg/m^2$, $FEV_1$ $50{\pm}18%$ of predicted, lumbar spine T-score $-3.0{\pm}1.2$, lumbar spine Z-score $-2.0{\pm}1.2$, and lumbar spine BMD $0.76{\pm}0.13g/cm^2$. Osteoporosis(T-score below -2.5) was present in 27 patients(61.4%) and osteopenia(T-score between -1 and -2.5) in 17(38.6%). None of the patients had normal BMD. There was no relationship between BMD and $FEV_1$(% of predicted). There were significant differences in smoking, alcohol consumption, exercise, cumulative steroid dose, BMI and BMD among the three groups according to $FEV_1$(% of predicted) (group1 : ${\geq}65%$, group2 : 50-64%, group3 : ${\leq}49%$), except age. However, there were no significant differences in these variables between the osteopenia and osteoporosis groups, except BMI. Linear Regression(Stepwise) analysis showed that lumbar BMD was correlated with BMI & exercise. Conclusion : BMD is significantly reduced in men with COPD. There was no relationship between BMD and pulmonary function.

• Tuberculosis and Respiratory Diseases
• /
• v.62 no.1
• /
• pp.11-18
• /
• 2007

Background: Patients with chronic obstructive pulmonary disease (COPD) have often been reported to suffer from depression and anxiety possibly due to the exacerbation, hospitalization and mortality of COPD. However,scarce data are available in Korea. This study assessed degree of depression and anxiety, and evaluated the factors associated with depressive symptoms in COPD. Methods: The cross-sectional data on the lung function measurements, smoking behavior, body mass index (BMI), age, gender, depressive symptoms using Beck Depression Inventory (BDI) and anxiety using the State-Trait Anxiety Inventory (STAI) were evaluated in 72 outpatients with COPD and 50 controls without underling lung diseases from September, 2005 to October, 2006 in the Ewha medical center. Results: 1) The age, body mass index (BMI) and serum albumin levels were similar in the patients and controls. The BDI scores (16(0-37) vs. 12(1-30), p=0.001) and the prevalence of depression (36% vs. 6%, p<0.0001) were higher in the COPD patients than in the controls. In the COPD group, the prevalence of depression increased with increasing GOLD stage (p=0.008). The prevalence was 18%(4/22), in mild cases, 30%(6/20) in moderate cases, 52%(13/25) in severe cases and 60%(3/5) in very severe cases. 2) The SAI and TAI scores were higher in the COPD patients (44(20-67) and 47(20-66)) than in the healthy controls (39(26-65) and 44(33-90)). There were a significant correlation between the depression and anxiety scores (p<0.001). 3) A lower BMI, lower postbronchodilator $FEV_1$, current smoking behavior and severity of COPD were univariately associated with the depressive group in COPD, 4) while multivariate logistic analysis revealed only the severe-to-very severe group (OR 3.9, 95% CI 1.2 to 12.9) to be independently associated with depressive symptoms. Conclusion: COPD is strongly associated with depression and anxiety. Therfore, screening for psychological problems in COPD patients is essential, particularly in patients with severe-to-very severe COPD.

• Tuberculosis and Respiratory Diseases
• /
• v.52 no.1
• /
• pp.46-53
• /
• 2002

Background: Pulmonary aspergilloma is relatively common in korea. It arises from the colonization and proliferation of Aspergillus in preexisting lung parenchymal cavities, in particular tuberculosis. The most common symptom in this disorder is hemoptysis, which mayor may not be massive and life threatening. A routine chest radiography and computed tomography (CT) are the most important diagnostic procedures. A surgical resection of the aspergilloma has recently been recommended, because of the relatively low incidence of postoperative complications than in the past. A more concentrated sample of patients with aspergilloma, who either underwent a thoracotomy or tested positive for aspergillus antibodies, were reviewed. Method : The medical records of twenty-two patients with aspergilloma, who had a proven thoracotomy (9 cases), or who tested positive for the diagnostic procedure and/or aspergillus antibodies (13 cases) from January 1995 to December 2000, were reviewed retrospectively. Results : The most common underlying lung disease was a current or old healed tuberculosis, and 3 patients had cultures of mycobacterium other than tuberculosis (MOTT). The mean time until the aspergilloma was detected 5.91 years in the healed tuberculosis cases. The others cases involved a lung abscess, bronchiectasis and without lung disease. The extrapulmonary disease was alcoholism and diabetes. Hemoptysis was most common in 72.7%. A computed tomography (CT) is useful for diagnosis. The right upper lobe, especially the posterior segment, is the most common location. Bronchial artery embolization is ineffective for a long term follow-up. A lobectomy is most common in a thoracotomy, and intra-operative and post-operative complications are rare. During follow-up, the mortality rate, not from the aspergilloma but from respiratory failure, was 13.6%. Conclusion : Aspergilloma is a common cavitary lung disease, It mainly arises from tuberculosis, either current or healed, but extra-pulmonary disease including alcoholism or diabetes are other possible risk factors. Their most common problem in aspergilloma is hemoptysis. Surgery has a low risk of post-operative complications and is recommended in relatively preserved lung function or healthy patients. Medical maneuvers including embolization, and the local insertion of certain materials needs to be studied more closely.

• Journal of Chest Surgery
• /
• v.32 no.3
• /
• pp.281-286
• /
• 1999

Background: The purpose of this study is to analyze the types of complications, the incidences of complications, and preoperative and postoperative risk factors affecting the incidence of the complication. Material and Method: Between August 1990 and August 1997 in Asan Medical Center, 42 patients(24 men and 18 women) underwent surgical resection for pulmonary aspergilloma. The mean age was 46.6${\pm}$11.5 years(range 29 to 69 years). Hemoptysis(90%) was the most common presentation. Pulmonary tuberculosis was the most common predisposing cause(81%). The associated diseases were bronchiectasis(n=11), active puolmonary tuberculosis(n=9), diabetes mellitus(n=8), lung carcinoid(n=1), and acute myeloblastic leukemia(n=1). Lobectomy was done in 32 cases(76%), segmentectomy or wedge resection in 4, pneumonectomy in 2, and lobectomy combined with segmentectomy in 4. Result: Operative mortality was 2%. The most common postoperative complication was persistent air leakage(n=6). The variables such as age, sex, pulmonary function test, amount and duration of hemoptysis, associated diseases(diabetes mellitus, active pulmonary tuberculosis), mode of preoperative management(steroid, antifungal agent, bronchial arterial embolization), and modes of operative procedures were statistically insignificant. The radiologic extent of infiltration to normal lung parenchyme was statistically significant(p=0.04). Conclusion: We conclude that the extent of the infiltration to normal lung parenchyme in preoperative radiologic studies should be carefully evaluated to reduce the postoperative complications in surgery for pulmonary aspergilloma.

• Journal of Chest Surgery
• /
• v.32 no.9
• /
• pp.806-812
• /
• 1999

Background: Selection of reconstruction route in esophageal cancer surgery is based on the patient's status, characteristics of tumor, surgeon's preference and experience. Of the various routes, it has been documented that subcutaneous or substernal route may prolong operation time and may be vulnerable to postoperative respiratory complications. This study was designed to evaluate whether the selection of reconstruction route affects the surgical outcomes. Material and Method: Of 131 patients who have undergone resection and reconstruction for esophageal cancer, posterior mediastinal route(Group I, n=34), substernal route (Group II, n=31), and subcutaneous route(Group III, n=21) were retrospectively reviewed in 86 patients. Results of early operations and morbidities were compared between the groups. Result: There was a male prevalence(79 of males vs. 7 of females). There were 81 squamous cell cancers and 5 adenocarcinomas. There were no differences between groups in weight, height, age, cancer staging and location, and in the preoperative anesthetic risk evaluation and pulmonary function test(p=NS). Postoperative mechanical ventilation time was longer in Group I(20.6 hours) than in Group II(7.8 hours) or III(3.4 hours)(p=0.005). Duration of stay in the intensive care unit was prolonged in Group III(6.4 days) compared to Group I (3.9 days) or II(3.1 days)(p=0.043). No differences were noted in the duration of hospital stay between the groups(p=NS). Blood transfusion was needed in 30 out of 34 patients in Group I compared to 14/31 in Group II or 15/21 in Group III(p=0.001). The mean amount of transfusion for each patient was also higher in Group I(3,833 mL) than in Group II(1535 mL) or Group III(1419 mL)(p=0.04), but there was no difference in the inreoperation due to bleeding. Ea ly mortality rate was substantially higher in Group I(17.6%) but the differences between the groups were insignificant(p=NS). Although sepsis was a more prevalent cause of death in Group I, it was not related to anastomotic leak. Other morbidities did not differ between the groups(p=NS). Conclusion: In above results show that the reconstruction route does not affect the outcome of esophageal cancer surgery. We believe that the selection of reconstruction route can be based on the surgeon's preference and experience.

• Journal of Chest Surgery
• /
• v.36 no.9
• /
• pp.651-658
• /
• 2003

Since the first implanted in September 1997, the use of On-X prosthetic heart valve has been increasing around in the world. This study was designed to assess the feasibility, safety, and the postoperative hemodynamics with this new valve in clinical setting. Material and Method: The current study was carried out on 52 patients undergoing aortic valve replacement with this prosthesis between April 1999 to August 2002 at Chonnam National University Hospital to evaluate the surgical results. 52％ of the patients were male and the average age at implant was 50$\pm$13 years. The study followed the guidelines of the AATS/STS. Preoperatively, 32(61.5％) patients were in NYHA functional class III or IV and 2 patients had previous aortic valve surgery. Concomitant cardiac surgery was performed in 71.1％. The implanted valve sizes were 19 mm in 13 patients, 21 mm in 26, 23 mm in 10 and 25 mm in 3, respectively. Mean follow-up was 16.6$\pm$10.5 months (1∼39 months). Echocardiographic assessment was performed pre- and immediate postoperatively, as well as 3, 6, 12 months after surgery, evaluating pressure loss and regression of left ventricular hypertrophy. Result: Mean cardiopulmonary bypass time was 191$\pm$94.7 minutes with an aortic cross-clamp time of 142$\pm$51.7 minutes. There was no early and late mortality, Freedom from adverse events at 1 year in the study were as follows: thromboembolism, 95.6$\pm$6％; bleeding events, 90.2$\pm$4％; paravalvular leakage 92.3$\pm$4％; and overall valve-related morbidity at 1 year was 76.6$\pm$3％. There were no cases of valve thrombosis, prosthetic valve endocarditis and structural or non-structural failure. Left ventricular function at 12 months after surgery (EF=62.7$\pm$9.8％) revealed a statistically significant improvement compared to preoperative investigation (EF=55.8$\pm$15.9％, p=0.006). Left ventricular mass index was 247.3$\pm$122.3 g/$m^2$ on preoperative echocardiographic study, but regressed to 155.5$\pm$58.2 g/$m^2$ at postoperative 1 year (p=0.002). Over the follow-up period a further decrease of peak transvalvular gradients was observed in all patients: 62.5$\pm$38.0 mmHg on preoperative assessment, 18.2$\pm$6.8 mmHg at immediate postoperative period (p < 0.0001), 7.6$\pm$5.09 mmHg (p<0.0001) at 6 month, 18.0$\pm$10.8 mmHg (p<0.0001) at 1 year. Conclusion: The On-X prosthetic heart valve performs satisfactorily in the first 1 year period. Clinical outcome by examining NYHA functional classification revealed especially good results. Effective regression of left ventricular hypertrophy and statistically significant decrease of transvalvular gradient were observed over the first year, but longer-term follow-up of this patient group is needed to establish the expected rates for late valve-related events as well as the long-term clinical efficacy of this valve.