• Journal of Chest Surgery
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• v.30 no.11
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• pp.1077-1082
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• 1997

To assess the early results, risk factors and optimal timing for coronary artery bypass graft surgery(CABG) after an acute myocardial infarction(AMI), we reviewed our 19 patients who underwent CABG within 30 days after AMI, between June 1994 and October 1996. This study excluded 1 patient whose diagnosis was AMI with ventricular septal rupture. 14 of the patients were male and 5 were female. Their ages ranged from 41 to 77 years(mean age, 60.6$\pm$ 10.4 years), and the amount of time between AMI and CABG ranged from 8 hours to 24 days(mean time, 10.6$\pm$6.4 days). There were 11 anteroseptal infarctions and 8 inferior wall infarctions. 11 patients had trsnsmural infarctions and 8 had subendocardial infarctions. Indications of operations were p imary revascularization and postinfarction angina. Three patients required preoperative intra-aortic balloon pump(IABP) support, and 4 additional patients required IABP to be separated from cardiopulmonary bypass. An average of 3.6 $\pm$ 0.6 vessels per patient were bypassed. The early mortality rate for these 19 patients was 5.3% and late mortality rate was 5.5%, 1-year and 2-year actuarial survival rates were 89.5% Univariate analysis of mortality showed that an ejection fraction less than 30% and intraopretative IABP supports were associated with risk factors(p value=0.018 and 0.015 respectively). Age, sex, time to CABG, emergency operations, types and locations of infarctions were not significant. Although our studies have weak p.oints in that there was only a small number of patients and the lack of long-term results, we could conclude that early myocardial revascularization is relatively safe after AMI for those individuals with an ejection fraction greater than 30%.

• Journal of Chest Surgery
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• v.37 no.9
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• pp.768-773
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• 2004

Failure of mitral valve repair sometimes may be ascribed to severe or progressive alteration of the subvalvar apparatus. The aim of this study was to evaluate the effects of new chordae formation on mitral repair. Material and Method: From March 1997 to february 1999, 26 patients underwent mitral valve repairs with new chordae formation, we compared the symptoms and echocardiographic findings checked at preoperative state, and intraoperative period, discharge, and their last OPD visit. There were 45 male, and 11 female patients, and their mean age was 51.2$\pm$43.4 years. Etiology of the lesions was degenerative (18), rheumatic (6), infective (1) and ischemic (1). Chordal lesions were caused by rupture (18), elongation (6), and a combination of two causes (2). Associated lesions included atrial septal defect (2), tricuspid insufficiency (7), aortic insufficiency(4), and a combination of previous two factors (2). The number of mean artificial chordae was 3.6$\pm$1.6. Annuloplasty was per-formed in all cases. The CPB time was 182,1$\pm$63.7 minutes and the ACC time was 133.1$\pm$45.6 minutes. Aver-age follow up period was 49.2$\pm$7.1 months. Result: There was no early death. Early reoperation was performed in bud patients, one patient received mitral valve replacement because of an abnormality of annuloplasty and ano-ther received pericardiostomy due to postoperative pericardial effusion. During the follow up of 49.2$\pm$7.1 moths, there was no late mortality. Postoperative NYHA functional class checked at last OPD visit was class I in 22 patients (88%), class II in 2 (8%), and class III in 1 (4%). Regarding the late echocardiogram MR was absent in 20 patients (78%), 1 in 4 (15%), and II in 1 (4%). The postrepair mitral valve area was 2.2$\pm$0.35 $\textrm{cm}^2$ Conclusion: This study suggests that mitral valve repair using new chordae formation provides good early and mid term survivals and functional improvement. We think that the artificial chorda formation with polytetrafluoroethylene suture might be safe and effective technique for mitral valve repair.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.3
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• pp.1-7
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• 2018

As part of a research dedicated to the field evaluation of the durability of concrete subjected to freezing-thawing, this study analyzes the relationship between the surface roughness and the relative dynamic elastic modulus through image analysis. Four mix compositions with water-to-binder ratios (W/B) of 40%, 50%, 60% and 70% and without AE agent were considered to provoke early freezing. The basic physical properties of the mixes including the relative dynamic elastic modulus and the compressive strength were first evaluated experimentally according to W/B. Then, tests were performed to measure the surface roughness followed by photographs and SEM image analysis. The measured surface roughness tended to increase with larger number of freezing-thawing cycles regardless of W/B. The relative dynamic elastic modulus appeared to increase gradually with the number of cycles for the relatively denser mixes with W/B of 40% and 50%. Besides, the surface roughness increased only at rupture for the mixes with W/B of 60% and 70%. Moreover, the analysis of the photographs of the surface of the mixes with W/B of 40% and 50% revealed that the degradation progressed gradually from the surface with the freezing-thawing cycles. However, for the mixes with W/B of 60% and 70%, apparent change of the surface remained very insignificant until rupture at which damage like cracking could be observed. Consequently, the analysis of surface photograph or the measurement of the surface roughness presented some limitation in assessing the degree of freezing-thawing-induced degradation in case of relatively porous specimens. On the other hand, the photograph and surface roughness appeared to be sufficient for assessing such degradation for the mixes with W/B of 40% and 50%. Accordingly, the image of the surface and the surface roughness are potentially applicable on site for the assessment of freezing-thawing damages in relatively dense mixes.

• ALGAE
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• v.35 no.3
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• pp.253-262
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• 2020

Haematococcus pluvialis is a commercial microalga that can produce high quantities of astaxanthin. Under induced conditions, some important changes in the subcellular structures related to astaxanthin accumulation were observable. For example, a large number of astaxanthin granules, oil structures and starch granules appeared in the thick-walled cells; Astaxanthin granules gradually dissolved into the oil structures and spread throughout the entire cell with the fusion and diffusion process of oil structures during the middle and late stages of induction; The plastoglobules were closed to the newly formed structures, and some plastoglobules would abnormally increase in size under stress. Based on observations of cell damage, the degradation of membrane structures, such as chloroplasts, was found to be the primary form of damage during the early stage of induction. During the middle stage of induction, some transparent holes were exposed in the dissolving astaxanthin granules in the cytoplasm. In thick-walled cells, these transparent holes were covered by oil substances dissolving astaxanthin, thereby avoiding further damage to cells. Given the relatively few oil structures, in non-thick-walled cells, the transparent holes expanded to form multiple transparent areas, eventually resulting in the rupture and death of cells. These results suggested that the high level of synthesis and the wide range diffusion of oil explained the expansion of astaxanthin in H. pluvialis.

• Journal of Chest Surgery
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• v.42 no.3
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• pp.355-360
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• 2009

Background: Benign teratoma is mostly asymptomatic, but this tumor rarely ruptures into the adjacent structure such as the pleural space, pericardium, lung parenchyma or tracheobronchial tree. Thus, it is important to differentiate ruptured teratoma from unruptured teratoma. This study evaluated the difference between ruptured and unruptured benign teratoma. Material and Method: Twenty-four cases of surgically resected benign teratomas were reviewed retrospectively. The clinical symptoms, chest CT findings and operative findings of the ruptured teratoma were compared with those of the unruptured teratoma. Especially, the tumor size, wall thickness, location of the mass, internal septation, homogeneity, calcification and ancillary findings were evaluated on CT. Result: Of the 24 patients, 7 patients were diagnosed with ruptured teratoma. Severe symptoms were more commonly found for ruptured teratoma than for unruptured teratoma. The ruptured teratoma had a tendency to display calcification and such ancillary findings as collapse or consolidation of the lung parenchyma. For the ruptured teratoma, the resection was performed by sternotomy or thoracotomy, and more lung resection was included. Conclusion: Calcification within the mass and changes in the lung parenchyma on the preoperative CT findings can be diagnostic signs of a ruptured teratoma. The demonstration of ruptured teratoma is important not only for making the early diagnosis, but also for the surgical planning.

• Journal of Korean Neurosurgical Society
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• v.29 no.8
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• pp.1126-1135
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• 2000

Objectives : The goal of surgical management of cerebral arteriovenous malformation(AVM) is elimination of the lesion without development of new neurological deficits. To improve the management results of cerebral AVMs in the future, this article discusses about surgical complications of the AVM and their management. Material and Methods : During the past 18 years, 116 patients with cerebral AVMs were managed by surgery. Among these cases, 7 cases died, 7 cases developed new neurological deficits, 11 cases residual AVM and 5 cases intracerebral hematoma(ICH) after surgery. The author analyzes the causes of those complications and investigates the methods to minimized those complications based on the review of the literatures. Results : One stage removal of AVM and ICH in the poor neurological state were performed in 5 of 7 death cases. Subtotal removal of ICH followed by delayed AVM surgery after recovery is regard as one method to improve the outcome of patient with large ICH. Postoperative new neurological deficits developed owing to normal perfusion pressure breakthrough(NPPB) in 3, judgement error in 2, preoperative embolization in 1 and cortical injury in 1 case(s). Proper management of NPPB, accurate anatomical knowledge and physiological monitoring during operation, and well trained skill for embolization are regard as methods to minimize those complications. Residual AVMs after surgery were noticed in 11 cases, in which unintended 6 cases due to inaccurate dissection of peripheral margin of AVM, and intended 3 cases due to massive brain swelling during operation, 1 cases due to diffuse type and 1 case due to multiple type of AVM. Accurate dissection of peripheral margin of AVM and mild hypotension during operation may help to avoid this complication. Postoperative hemorrhage occurred in 3 cases due to rupture of the residual AVM and in 2 cases due to oozing from the AVM bed. Complete resection of AVM, complete control of bleeding points at AVM bed and mild hypotension during early postoperative period are the methods to avoid this complication. Conclusion : A precise but flexible therapeutic strategy and refined skill for endovascular, radiosurgical and microsurgical techniques are required to successful treatment of cerebral AVM. Adequate timing of AVM resection, accurate anatomical knowledge, proper management of NPPB and accurate dissection of peripheral margin of AVM are the key points for avoiding complications of the AVM surgery.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.49-54
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• 2005

Purpose: Complete rupture of metacarpophalangeal ulnar collateral ligament of thumb needs surgical exploration and repair, owing to the interposition of the adductor aponeurosis (Stener lesion) which interferes in healing process. We performed arthroscopic diagnosis and treatment on ulnar collateral ligament injury of thumb and evaluated it's efficiency. Materials and Methods: Arthroscopy was perfomed on 13 patients of whom injured on complete ruture of metacarpophalangeal ulnar collateral ligament. Follow-up period was over 1 year and mean age was 35.6 years old. Ulnar collateral ligament tears and Stener lesion were diagnosed and treated by arthroscopy procedure. Results were interpreted by joint instability, pinch power, grip power and range of motion on metacarpophalangeal joint of thumb. Results: We found 5 Stener lesions in 13 cases. There was no appreciable postoperative instability. Pinch and grip power were recovered to 92%, 94% of uninjured thumb respectively. Range of motion on metacarpophalangeal joint was mean $52^{\circ}$, almost equal to uninjured thumb. Conclusions: Arthroscopic treatment in metacapophalangeal ulnar collateral ligament injury of thumb is useful method that Stener lesion can be clearly comfirmed and treated. Also soft tissue injuries can be minimized, thereby early functional recovery can be expected.

• Journal of the Korean Arthroscopy Society
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• v.3 no.1
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• pp.40-43
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• 1999

Arthroscopic anterior cruciate ligament(ACL) reconstruction using four-strand hamstring tendon with looping around transfixing screw in femoral tunnel requires osteointegration between the grafted tendon and bone for stability of the knee. Authors have experienced a histologic finding of osteointegration between the grafted autogenous hamstring tendon and bone in femoral tunnel after arthroscopic ACL reconstruction. A patient received arthroscopic ACL reconstruction with autogenous four strand hamstring tendon for the ACL injury. Traumatic re-rupture of mid-substance of ACL graft was developed at thirteenth week after operation. During the procedures of arthroscopic revision at fifteenth week after initial ACL reconstruction, biopsy was performed at the site of interface between grafted tendon and bone in femoral tunnel. Integration between the grafted tendon and bone was evident by demonstrating the continuity of collagen fiber between bond and tendon. This histologic finding and the low incidence of early graft failure suggest that free tendon autograft attached to bone by looping around a transfixing screw in femoral tunnel undergoes adequate osteointegration between 12 and 15 weeks after surgery and authors thought that insertion of bone chip into the femoral tunnel would accelerate osteointegration procedure.

• The korean journal of orthodontics
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• v.28 no.3 s.68
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• pp.419-429
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• 1998

This study was carried out in order to study early histologic changes and repair reaction appling to extrusive force for 3rd premolar of adult dogs. After 1 week of extrusive force with elastic chain, one of dogs was sacrified and after 3 weeks retention period, another dog was sacrified. The paraffin sections of samples were stained with Hematoxylin - Eosin and Masson's Trichrome and were examed by light microscopy . The obtained results as follows 1. In Hematoxylin - Eosin and Masson Trichrome stain of control group , the periodontal ligament width was constant from apical third to cervical third of the root and periodontal fiber arrangement was horizontal or oblique in cervical third. oblique in middle third, oblique in apical third of root. in alveolar bone, smooth appearance was shown 2. In Group 1, all periodontal fiber arrangement was oblique toward tooth, and the periodontal ligament width increased Partially PDL was ruptured in apex. In MT stain, immature bone formation was seen at alveolar crest area. Active bone formation was observed along the one side of alveolus, and apical portion of pulp was involved with blood vessel rupture , vacuolization of pulp tissue and hyperemia 3. In Group 2, most periodontal ligament arrangement and PDL width was repaired and fiber density increased. In MT stain, mineralization of immature bone on the alveolar crest was progressed. In pulp, vacuole and hyperemia was diminished and fibrotic change was diminished 4. After 3 week periodontal ligament has more repair ability than pulp tissue. pulp was involved with vacuolization and fibrosis, so it takes more time for repair.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.146-153
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• 2004

As the experience of coronary artery bypass grafting (CABG) has been accumulated, the number of reoperation after CABG is increasing. We analyzed our clinical experience of redo-CABG. Material and Method: Fourteen patients who underwent redo-CABG between Jan. 1994 and Dec. 2002 were included in this study. The mean period from the first operation to reoperation was 66$\pm$56 (3∼157) months, and the average ages were 62.8$\pm$8.7 (51∼78) years. The survivors were followed up 39$\pm$29 (4∼101) months postoperatively. Indications of reoperation were stenosis or occlusion of previous grafts in 11 patients, progression of native coronary artery disease in one patient, and both etiologies in two patients. Result: There were two in-hospital mortalities (14.3%) resulting from low cardiac output syndrome, Postoperative morbidities were perioperative myocardiac infarction in 2 patients (14.3%), mediastinitis in one patient (7.2%), duodenal perforation in one patient, ischemic necrosis of the lower extremity in one patient, gastric perforation after mesenteric infarct in one patient, delayed brain infarct in one patient, and intraoperative splenic rupture in one patient. There was one late mortality at six months postoperatively during the follow up. There was no angina recurrence during the follow up. Conclusion: Although redo CABG demonstrated relatively high operative mortalities and morbidities, postoperative status and clinical outcome of the survivors were favorable.