• Journal of Chest Surgery
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• v.36 no.7
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• pp.457-462
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• 2003

Background: Surgical results of the Fontan procedures in patients with a single ventricle have improved. As the perioperative mortality continues to decline and late outcome is forthcoming, attention is now being directed toward late complications of the Fontan procedures. We retrospectively analyzed our experience with reoperations after Fontan procedures. Material and Method: Between January 1988 and December 2002, 24 patients underwent reoperations after Fontan procedures. The median age at Fontan procedures and reoperation was 3.3 years and 9.2 years, respectively. Types of initial Fontan procedures were atriopulmonary connection (n＝11), lateral tunnel Fontan (n＝11), and extracardiac conduit Fontan (n＝2). Indications for reoperation included atrioventricular valve regurgitation (n＝7), atrial arrhythmia (n＝8), Fontan pathway stenosis (n＝7), residual right-to-left shunt (n＝5), etc. Result: Procedures performed at reoperation included atrioventricular valve replacement (n＝6), conversion to lateral tunnel Fontan (n＝5), conversion to extracardiac conduit Fontan (n＝3), cryoablation of arrhythmia circuit (n＝7), etc. There was no operative mortality. There were 2 late deaths. Mean follow-up duration was 2.7$\pm$2.1 years. All patients except two were in NYHA class I at the latest follow-up. Among 8 patients with preoperative atrial arrhythmia, postoperative conversion to normal sinus rhythm was achieved in 7 patients. Conclusion: Reoperations after Fontan procedures could be achieved with low mortality and morbidity. Reoperation may lead to clinical improvement in patients with specific target conditions such as atrioventricular valve regurgitation, refractory atrial arrhythmia, or Fontan pathway stenosis, especially in patients with previous atriopulmonary connection.

• Journal of Chest Surgery
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• v.37 no.8
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• pp.644-651
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• 2004

Background: Refractory atrial arrhythmias in patients late after the Fontan operation result in significant morbidity and mortality. We reviewed our experience with arrhythmia surgery in patients who had Fontan operation. Material and Method: Between July 1986 and December 2003, 275 early survivors after Fontan operation were reviewed. Fourteen patients underwent. arrhythmia surgery at reoperation after Fontan operation, and mean age at reoperation was 16.8$\pm$7.1 (range: 4.5 ∼ 30.6) years. Mechanisms of arrhythmia included atrial flutter in 8 patients, and atrial fibrillation in 2. Arrhythmia surgery has evolved from isthmus cryoablation in 12 patients to right-sided maze in 2 patients. Thirty-two patients. underwent prophylactic isthmus cryoablation concomitantly at initial Fontan operation. Result: Postoperative arrhythmias occurred in 68 patients (24.7%) among 275. There was no early and late mortality after the arrhythmia surgery. After redo Fontan operation, all patients maintained normal sinus rhythm. Atrial flutter recurred in 3 patients who had sinus conversion with medication and 7 required permanent pacemakers with a mean follow-up of 26.5$\pm$29.1 (range: 2 ∼ 73) months. All patients have improved to NYHA class I or II. After prophylactic cryoablation at initial Fontan operation, 29 patients (90.6%) had sinus rhythm, 1 patient had junctional tachycardia, 1 patient had sinus nodal dysfunction, and 1 patient had AV block with a mean follow-up of 51.3$\pm$19.8 (range: 4∼80) months. Conclusion: Redo Fontan operation, and concomitant arrhythmia surgery reduced atrial arrhythmias and improved NYHA functional classification.

• The Journal of Engineering Geology
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• v.33 no.4
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• pp.543-553
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• 2023

The current status of domestic a agalmatolite mines in South Korea was investigated with a view to establishing a stable supply of agalmatolite and managing its demand. Most mined agalmatolite deposits were formed through hydrothermal alteration of Mesozoic volcanic rocks. The physical characteristics of pyrophyllite, the main constituent mineral of agalmatolite, are as follows: specific gravity 2.65~2.90, hardness 1~2, density 1.60~1.80 g/cm³, refractoriness ≥29, and color white, gray, grayish white, grayish green, yellow, or yellowish green. Among the chemical components of domestic agalmatolite, SiO₂ and Al₂O₃ contents are respectively 58.2~67.2 and 23.1~28.8 wt.% for pyrophyllite, 49.2~72.6 and 16.5~31.0 wt.% for pyrophyllite + dickite, 45.1 and 23.3 wt.% for pyrophyllite + illite, 43.1~82.3 and 11.4~35.8 wt.% for illite, and 37.6~69.0 and 19.6~35.3 wt.% for dickite. Domestic agalmatolite mines are concentrated mainly in the southwest and southeast of the Korean Peninsula, with some occurring in the northeast. Twenty-one mines currently produce agalmatolite in South Korea, with reserves in the order of Jeonnam (45.6%) > Chungbuk (30.8%) > Gyeongnam (13.0%) > Gangwon (4.8%), and Gyeongbuk (4.8%). The top 10 agalmatolite-producing mines are in the order of the Central Resources Mine (37.9%) > Wando Mine (25.6%) > Naju Ceramic Mine (13.4%) > Cheongseok-Sajiwon Mine (5.4%) > Gyeongju Mine (5.0%) > Baekam Mine (5.0%) > Minkyung-Nohwado Mine (3.3%) > Bugok Mine (2.3%) > Jinhae Pylphin Mine (2.2%) > Bohae Mine. Agalmatolite has low thermal conductivity, thermal expansion, thermal deformation, and expansion coefficients, low bulk density, high heat and corrosion resistance, and high sterilization and insecticidal efficiency. Accordingly, it is used in fields such as refractory, ceramic, cement additive, sterilization, and insecticide manufacturing and in filling materials. Its scope of use is expanding to high-tech industries, such as water treatment ceramic membranes, diesel exhaust gas-reduction ceramic filters, glass fibers, and LCD panels.

• Journal of Chest Surgery
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• v.39 no.7 s.264
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• pp.511-519
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• 2006

Background: Loss of cardiomyocytes in the myocardial infarction leads to regional contractile dysfunction, and necrotized cardiomyocytes in infracted ventricular tissues are progressively replaced by fibroblasts forming scar tissue. Although cardiomyoplasty, or implantation of ventricular assist device or artificial heart was tried in refractory heart failure, the cardiac transplantation was the only therapeutic modality because these other therapeutic strategies were not permanent. Cell transplantation is tried instead of cardiac transplantation, especially bone marrow is the most popular donated organ. But because bone marrow aspiration procedure is invasive and painful, and it had the fewer amounts of cellular population, the adipose tissue is recommended for harvesting of mesenchymal stem cells. Material and Method: After adipose tissues were extracted from abdominal subcutaneous adipose tissue and intra-abdominal adipose tissue individually, the cellular components were obtained by same method. These cellular components were tried to transformation with the various titers of 5-azacytidine to descript the appropriate concentration of 5-azacytidine and possibility of transformation ability of adipose tissue. Group 1 is abdominal subcutaneous adipose tissue and Group 2 is intra-abdominal adipose tissue-retroperitoneal adipose tissue and omentum. Cellular components were extracted by collagenase and $NH_4Cl$ et al, and these components were cultured by non-induction media - DMEM media containing 10% FBS and inducted by none, $3{\mu}mol/L,\;6{\mu}mol/L,\;and\;9{\mu}mol/L$ 5-azacytidine after the 1st and 2nd subculture. After 4 weeks incubation, tile cell blocks were made, immunostaining was done with the antibodies of CD34, heavy myosin chain, troponin T, and SMA. Result: Immunostaining of the transformed cells for troponin T was positive in the $6{\mu}mol/L\;&\;9{\mu}mol/L$ 5-azacytidine of Group 1 & 2, but CD34 and heavy myosin chain antibodies were negative and SMA antibody was positive in the $3{\mu}mol/L\;&\;6{\mu}mol/L$ 5-azacytidne of Group 2. Conclusion: These observations confirm that adult mesenchymal stem cells isolated from the abdominal subcutaneous adipose tissues and intra-abdominal adipose tissues can be chemically transformed into cardiomyocytes. This can potentially be a source of autologous cells for myocardial repair.