• Journal of Chest Surgery
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• v.21 no.2
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• pp.231-239
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• 1988

Currently numerous methods are in use for myocardial hypothermia as a myocardial preservation modality for cardiac operation. During cardiac ischemia after crystalloid cardioplegia[4C GIK solution], topical cold saline[Group I, a=9], topical ice slush[Group II, n=9] and topical ice chip[Group III, a=10] have been compared for myocardial surface cooling in the isolated rat heart model of cardiopulmonary bypass. During postischemic period, hemodynamic functions[aortic flow, coronary flow, peak aortic pressure and heart rate], biochemical enzymatic activities and cellular injuries with electron microscope were evaluated in this isolated rat heart perfusion model. Postischemic aortic flow, cardiac output and peak aortic pressure in Group I and Group II recovered better than Group III.[p< 0.05] Postischemic creatine kinase and lactate dehydrogenase leakages in Group II and Group III increased more than Group l and postischemic mitochondrial swelling in Group III was more severe than Group I, and Group II.[p< 0.05] These results suggest that topical cold saline was the better method than topical ice slush or topical ice chip as a myocardial preservation modality in the isolated rat heart model of cardiopulmonary bypass.

• The Journal of the Acoustical Society of Korea
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• v.29 no.1E
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• pp.11-27
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• 2010

Nowadays, ultrasound Doppler imaging is widely used in assessing cardiovascular functions in the human body. However, a major drawback of ultrasonic Doppler methods is that they can provide information on blood flow velocity along the ultrasound beam propagation direction only. Thus, the blood flow velocity is estimated differently depending on the angle between the ultrasound beam and the flow direction. In order to overcome this limitation, there have been many researches devoted to estimating both axial and lateral velocities. The purpose of this article is to survey various two-dimensional velocity estimation methods in the context of Doppler imaging. Some velocity vector estimation methods can also be applied to determine tissue motion as required in elastography. The discussion is mainly concerned with the case of estimating a two-dimensional in-plane velocity vector involving the axial and lateral directions.

• Journal of Mechanical Science and Technology
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• v.17 no.7
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• pp.1073-1082
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• 2003

Many researchers have investigated the blood flow characteristics through bileaflet mechanical heart valves using computational fluid dynamics (CFD) models. Their numerical approach methods can be classified into three types; steady flow analysis, pulsatile flow analysis with fixed leaflets, and pulsatile flow analysis with moving leaflets. The first and second methods have been generally employed for two-dimensional and three-dimensional calculations. The pulsatile flow analysis interacted with moving leaflets has been recently introduced and tried only in two-dimensional analysis because this approach method has difficulty in considering simultaneously two physics of blood flow and leaflet behavior interacted with blood flow. In this publication, numerical calculation for pulsatile flow with moving leaflets using a fluid-structure interaction method has been performed in a three-dimensional geometry. Also, pulsatile flow with fixed leaflets has been analyzed for comparison with the case with moving leaflets. The calculated results using the fluid-structure interaction model have shown good agreements with results visualized by previous experiments. In peak systole. calculations with the two approach methods have predicted similar flow fields. However, the model with fixed leaflets has not been able to predict the flow fields during opening and closing phases. Therefore, the model with moving leaflets is rigorously required for advanced analysis of flow fields.

• Journal of Chest Surgery
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• v.38 no.1 s.246
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• pp.67-71
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• 2005

The major etiology of superior vena cava (SVC) syndrome is malignancy. Radiologic endovascular intervention is the treatment of choice for patients with SVC syndrome due to malignant disease, which is unresponsive to radiation therapy and chemotherapy. However, it is not clear whether endovascular intervention can replace open surgery as the primary method of management of benign SVC syndrome. We report two cases of benign SVC syndrome resulting from dialysis catheters placed in the central veins. One patient underwent bypass surgery between innominate vein and right atrium by expanded polytetrafluoroethylene. Another patient had large thrombi in SVC and other central veins. We removed them under cardiopulmonary bypass to prevent pulmonary embolism, and SVC was repaired and augmented by autologous pericardium. Prompt symptomatic relief and angiographic improvements of collateral flow were achieved in both patients.

• Journal of Chest Surgery
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• v.39 no.6 s.263
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• pp.456-461
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• 2006

Background: Distal anastomosis using artificial vascular graft is difficult when luminal size mismatch occurred owing to severe occlusion of popliteal artery and its branches. So we reconstructed blood flow to ischemic lower limb by using autologous greater saphenous vein in situ graft (GSVISG) as vascular graft material. Material and Method: From July 2000 to July 2005, 26 patients treated using GSVISG. We analyzed clinical results retrospectively by chart review. Result: There was no in hospital or early postoperative death and 6 late deaths occurred during follow up period. Postoperative complications were 5 cases of early graft obstruction, 2 cases of wound dehiscence, 1 case of graft aneurysmal change, 1 case of seroma formation at inguinal wound and 1 case of graft injury during valvulotomy. Overall patency rate during follow up period was 69.3%. Conclusion: Greater saphenous vein in situ graft is acceptable vascular graft for arterial occlusive disease of lower extremity.

• International Journal of Stem Cells
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• v.15 no.3
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• pp.247-257
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• 2022

Background and Objectives: Although human-induced pluripotent stem cells (hiPSC) can be efficiently differentiated into cardiomyocytes (CMs), the heterogeneity of the hiPSC-CMs hampers their applications in research and regenerative medicine. Retinoic acid (RA)-mediated signaling pathway has been proved indispensable in cardiac development and differentiation of hiPSC toward atrial CMs. This study was aimed to test whether RA signaling pathway can be manipulated to direct the differentiation into sinoatrial node (SAN) CMs. Methods and Results: Using the well-characterized GiWi protocol that cardiomyocytes are generated from hiPSC via temporal modulation of Wnt signaling pathway by small molecules, RA signaling pathway was manipulated during the differentiation of hiPSC-CMs on day 5 post-differentiation, a crucial time point equivalent to the transition from cardiac mesoderm to cardiac progenitor cells in cardiac development. The resultant CMs were characterized at mRNA, protein and electrophysiology levels by a combination of qPCR, immunofluorescence, flow cytometry, and whole-cell patch clamp. The results showed that activation of the RA signaling pathway biased the differentiation of atrial CMs, whereas inhibition of the signaling pathway biased the differentiation of sinoatrial node-like cells (SANLCs). Conclusions: Our study not only provides a novel and simple strategy to enrich SANLCs but also improves our understanding of the importance of RA signaling in the differentiation of hiPSC-CMs.

• Journal of the East Asian Society of Dietary Life
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• v.15 no.3
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• pp.283-291
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• 2005

This study was penonned to provide basic data that predict the usefulness of Gastrodiae rhizoma as food materials for oriental medicinal cuisine(YakSun). We measured the changes of regional cerebral blood flow(rCBF) and blood pressure(BP) in rats, following the intravenous injection of Gastrodiae rhizoma water extract The measurement was continually monitored by laser-doppler flowmeter and pressure transducer in anesthetized adult Sprague-Dawley rats for about two to two and half hours through the data acquisition system composed of MacLab and Macintosh computer. The results of this experiment were as follows. Gastrodiae rhizoma increased the changes of rCBF in rats significantly. The rCBF of Gastrodiae rhizoma did not change by pretreated propranolol, atropin, methylene blue and indomethacin. But the rCBF of Gastrodiae rhizoma was increased by pretreated L-NNA. Gastrodiae rhizaoma decreased the changes of BP significantly. The BP of Gastrodiae rhizoma did not change by pretreated propranolol, atropin, methylene blue and indomethacin. But the BP of Gastrodiae rhizoma was decreased by pretreated L-NNA. These results indicated that Gastrodiae rhizoma might increase the rCBF and the BP which related to nitric oxide synthesis. Also these results indicate that Gastrodiae rhizoma can be used as a safe and clinically applicable to diet therapy of cerebral cardiovascular disease.

• Journal of Chest Surgery
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• v.10 no.2
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• pp.250-267
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• 1977

Open heart surgery has been performed on 20 patients, using hemodilution principle under the moderate hypothermia from Dec. 1975 through Aug. 1977 at the Department of Thoracic and Cardiovascular Surgery, Kyungpook National University School of Medicine. All these patients, body surface area ranged from 0.53 to 1.67$M^2$, were divided into two groups as a child group [below 15 yrs] and a adult group[above 15 yrs]. The oxygenator were primed with fresh ACD blood, 5 per cent dextrose, Hartmann`s solution, 15 per cent mannitol, sodium bicarbonate, dexamethasone and antibiotics. The average flow rate was 2.0 L/$M^2$/min. in child group and 2.3L/$M^2$/min. in adult group. The degree of hemodilution in child and adult group was 30.7% and 29.3% respectively. The minimal value of rectal temperature was $30.84{\pm}0.7^{\circ}C.$, in child group and $30.0{\pm}1.5^{\circ}C.$, in adult group. We studied the changes of hemodynamic status, blood components, electrolyte, acid-base status. blood lactic acid and urine output during and after cardiopulmonary bypass.

• Biomolecules & Therapeutics
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• v.10 no.2
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• pp.89-98
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• 2002

In this study general pharmacological profiles of KI-60606 on the central nervous system, the cardiovascular system and the other organs were investigated. The dosages given were 0,5, 10 and 25 mg/kg and drugs were administered intravenously. The animals used for this study were mice, rats, cats and guinea pigs. KI-60606 showed no effects on general behavior, motor coordination, spontaneous locomotor activity, hexobarbital-induced hypnosis time, body temperature, analgesic activity, anticonvulsant activity and contraction of nictitating membrane in cats. Furthermore KI-60606 showed no effects on blood pressure, heart rate, LVP (left ventricular peak systolic pressure), LVEDP (left ventricular end diastolic pressure), LVDP (left ventricular developing pressure), DP(double product), CFR(coronary flow rate), smooth muscle contraction using guinea pig ileum and gastric secretion at all dosage tested except the increase of gastrointestinal transport and urinary $K^+$ excretion.

• Proceedings of the Polymer Society of Korea Conference
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• 2006.10a
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• pp.259-259
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• 2006

PAU is the block copolymer consists of a small amount of a small amount of poly(${\gamma}-methyl-L-glutamate$) (PMLG) and the polyurethane. The urethane segments are hydrophobic and then strongly interact with the other hydrophobic materials such as PTFE, and the PMLG segments with the ${\alpha}-helix$ structure possess the cytocompatibility. Therefore, PAU can be easily coated onto the PTFE fiber and acts as an artificial extracellular matrix with the high cytocompatibility Results shows, the immobilization, cultured and functions of porcine hepatocytes is greatly improved.