• Journal of Chest Surgery
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• v.45 no.2
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• pp.80-84
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• 2012

Background: The aim of this study is to evaluate our institutional results of the aortic valve replacement through minimally invasive approaches compared with conventional sternotomy. Materials and Methods: From August 1997 to July 2010, 838 patients underwent primary isolated aortic valve replacement. Of them, 73 patients underwent surgery through minimally invasive approaches (MIAS group) whereas 765 patients underwent surgery through the conventional sternotomy (CONV group). Clinical outcomes were compared using a propensity score matching design. Results: Propensity score matching yielded 73 pairs of patients in which there were no significant differences in baseline profiles between the two groups. Patients in the MIAS group had longer aortic cross clamp than those in the CONV group ($74.9{\pm}27.9$ vs.. $66.2{\pm}27.3$, p=0.058). In the MIAS group, conversion to full sternotomy was needed in 2 patients (2.7%). There were no significant differences in the rates of low cardiac output syndrome (4 vs. 8, p=0.37), reoperation due to bleeding (7 vs. 6, p=0.77), wound infection (2 vs. 4, p=0.68), or requirements for dialysis (2 vs. 1, p=0.55) between the two groups. Postoperative pain was significantly less in the MIAS group than the conventional group (pain score, $3.79{\pm}1.67$ vs. $4.32{\pm}1.56$; p=0.04). Conclusion: Both minimally invasive approaches and conventional sternotomy had comparable early clinical outcomes in patients undergoing primary isolated aortic valve replacement. Minimally invasive approaches significantly decrease postoperative pain.

• Communications of the Korean Mathematical Society
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• v.13 no.3
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• pp.465-473
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• 1998

A real m $\times$ n matrix A is semipositive (SP) if there is a vector x $\geq$ 0 such that Ax > 0, inequalities being entrywise. A is minimally semipositive (MSP) if A is semipositive and no column deleted submatrix of A is semipositive. We give a necessary and sufficient condition for the sign pattern matrix with n positive entries to be minimally semipositive.

• Journal of the Korea Institute of Military Science and Technology
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• v.16 no.3
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• pp.250-254
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• 2013

Faster and cheaper transportation of the war supplies to the frontlines is essential for winning a war. This paper proposes a method to select the optimal location of the strategic military base, e.g., the Quartermaster Corps, that minimally connects three frontlines using the optimization technique. The results are also compared to the Steiner Tree theoty.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2009.06a
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• pp.57-58
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• 2009

• Journal of Chest Surgery
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• v.33 no.2
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• pp.183-185
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• 2000

With the marked decrease in operative mortality in simple heart diseases there have been several reports on the minimally invasive and cosmetic techniques including submammary incision right parasternal approach right anterolateral thoracotomy partial sternotomy and subxiphoid approach. We report here subxiphoid approach without sternotomy for the repair of atrial septal defect as the procedure that has less invasive technique and more cosmetic effect.

• 대한치주과학회:학술대회논문집
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• 2004.05a
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• pp.11-12
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• 2004

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.1
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• pp.117-122
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• 2012

Aim: To elucidate the effects of hyperthermic $CO_2$ pneumoperitoneum on human gastric AGS cells. Methods: Based on a newly devised in vitro study model, we evaluated the anti-cancer effects of HT-$CO_2$ ($42-44^{\circ}C$ for 2-4h) on human gastric cancer cells, and also the corresponding mechanisms. Results: HT-$CO_2$ ($42-44^{\circ}C$ for 2-4h) severely inhibited cell proliferation as assessed by Cell Counting Kit-8 assay, while inducing apoptosis in a temperature- and time-dependent manner demonstrated by annexin-V/PI flow cytometry and morphological analysis (Hoechst/PI fluorescence). In addition, it was found that HT-$CO_2$ ($42-44^{\circ}C$ for 2-4h) promoted the up-regulation of Bax by western blotting. Significantly, it could also suppress gastric cancer cell invasion and metastasis by in vitro invasion and motility assay. Conclusion: In conclusion, HT-$CO_2$ had an efficacious cytotoxic effect on gastric cancer cells through Bax-induced mitochondrial apoptotic signaling. Our studies indicate that it may serve as a potential therapy for peritoneal carcinomatosis of gastric cancer. Further investigations in vivo using animal models are now urgently needed.

• Journal of Korean Neurosurgical Society
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• v.57 no.2
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• pp.100-107
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• 2015

Objective : To report a minimally invasive treatment option using percutaneous pedicle screw fixation with adjuvant treatment for metastatic thoraco-lumbar and lumbar spinal tumors. Methods : This is a retrospective study of charts of patients with spinal metastases. All were older than 18 years of age and were considered to have more than 3 months of life expectancy. The patients had single or two level lesions, and compression fracture or impending fracture. Exclusion criterion was metastasis showing severe epidural compression with definite neurological symptoms. Usually spinal segments from one level above to below pathology were stabilized. Visual analog scale (VAS) score for pain assessment and Frankel scale for neurological deficit were used, while pre- and post-operative performance status was evaluated using the Eastern Cooperative Oncology Group (ECOG). Results : Twelve patients (nine men, three women; median age 54.29 years) underwent surgery. All patients presented with back pain with/without radicular pain. There were no early complications and perioperative mortalities. Following surgery, a significant difference between average pre- and post-operative VAS scores was found (p=0.003). Overall, 91.8% of patients (11/12) experienced improvement in their ECOG score post-operatively. The mean ambulation time was 196.9 days [95% confidence interval (CI), 86.2-307.6 days; median, 97 days]. During follow-up, nine patients died and the mean overall survival time in enrolled twelve patients was 249.9 days (95% CI, 145.3-354.4 days; median, 176 days). Conclusion : Minimally invasive treatment using percutaneous pedicle screw fixation with adjuvant treatment is a good alternative treatment option for potential instability of the thoraco-lumbar and lumbar spinal metastasis.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2533-2539
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• 2014

Aim: To take a deeper insight into the relationship between the root of the inferior mesenteric artery (IMA) and the autonomic nerve plexuses around it by cadaveric anatomy and explore anatomical evidence of autonomic nerve preservation in high ligation of the IMA in laparoscopic surgery for colorectal cancer. Methods: Anatomical dissection was performed on 11 formalin-fixed cadavers and 12 fresh cadavers. Anatomical evidence-based autonomic nerve preservation in high ligation of the IMA was performed in 22 laparoscopic curative resections of colorectal cancer. Results: As the upward continuation of the presacral nerves, the bilateral trunks of SHP had close but different relationships with the root of the IMA. The right trunk of SHP ran relatively far away from the root of IMA. When the apical lymph nodes were dissected close to the root of the IMA along the fascia space in front of the anterior renal fascia, the right trunk of SHP could be kept in suit under the anterior renal fascia. The left descending branches to SHP constituted a natural and constant anatomical landmark of the relationship between the root of IMA and the left autonomic nerves. Proximal to this, the left autonomic nerves surrounded the root of the IMA. Distally, the left trunk of the SHP departed from the root of IMA under the anterior renal fascia. When high ligation of the IMA was performed distal to it, the left trunk of SHP could be preserved. The distance between the left descending branches to SHP and the origin of IMA varied widely from 1.3 cm to 2.3 cm. Conclusions: The divergences of the bilateral autonomic nerve preservation around the root of the IMA may contribute to provide anatomical evidence for more precise evaluation of the optimal position of high ligation of the IMA in the future.

• Journal of Korean Neurosurgical Society
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• v.48 no.3
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• pp.225-229
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• 2010

Objective : The authors introduce a minimally invasive muscle sparing transmuscular microdiscectomy (MSTM) to treat herniated lumbar disc disease. Its results are compared with conventional subperiosteal microdiscectomy (CSM) to validate the effectiveness. Methods : Muscle sparing transmuscular microdiscectomy, which involves muscle dissection approach using the natural fat cleavage plane between the multifidus to expose the interlaminar space, was performed in 23 patients to treat a single level unilateral lumbar radiculopathy. The creatine phosphokinase (CPK)-MM serum levels were measured on admission and at 1, 3, and 5 days postoperatively. Postoperative pain was evaluated using a 10-point visual analogue scale (VAS) and recorded on admission and at 1, 3, and 5 days postoperatively. The results were compared to those from the conventional subperiosteal microdiscectomy (43 patients). Results : The CPK-MM levels were significantly lower in the serum of the MSTM group compared to the CSM group on postoperative days three and five (p = 0.03 and p = 0.02, respectively). The clinical scales for back pain using VAS were significantly lower in the MSTM group than in the CSM group on postoperative days three (p = 0.04). The mean VAS scores for leg pain in both groups showed no significant differences during the early postoperative period. Conclusion : Muscle sparing transmuscular microdiscectomy is a minimally invasive surgical option to treat lumbar radiculopathy due to herniated disc. The approach affected minimal injury to posterior lumbar supporting structures with alleviated postoperative back pain.