• Journal of Chest Surgery
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• v.31 no.8
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• pp.739-748
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• 1998

Background: It has been well documented that transient occlusion of the coronary artery causes myocardial ischemia and finally cell death when ischemia is sustained for more than 20 minutes. Extensive studies have revealed that ischemic myocardium cannot recover without reperfusion by adequate restoration of blood flow, however, reperfusion can cause long-lasting cardiac dysfunction and aggravation of structural damage. The author therefore attempted to examine the effect of postischemic reperfusion on myocardial ultrastructure and to determine the rationales for recanalization therapy to salvage ischemic myocardium. Materials and methods: Young Holstein-Friesian cows(130∼140 Kg body weight; n=40) of both sexes, maintained with nutritionally balanced diet and under constant conditions, were used. The left anterior descending coronary artery(LAD) was occluded by ligation with 4-0 silk snare for 20 minutes and recanalized by release of the ligation under continuous intravenous drip anesthesia with sodium pentobarbital(0.15 mg/Kg/min). Drill biopsies of the risk area (antero-lateral wall) were performed at just on reperfusion(5 minutes), 1-, 2-, 3-, 6-, 12-hours after recanalization, and at 1-hour assist(only with mechanical respiration and fluid replacement) after 12-hour recanalization. The materials were subdivided into subepicardial and subendocardial tissues. Tissue samples were examined with a transmission electron microscope (Philips EM 300) at the accelerating voltage of 60 KeV. Results: After a 20-minute ligation of the LAD, myocytes showed slight to moderate degree of ultrastructural changes including subsarcolemmal bleb formation, loss of nuclear matrix, clumping of chromatin and margination, mitochondrial destruction, and contracture of sarcomeres. However, microvascular structures were relatively well preserved. After 1-hour reperfusion, nuclear and mitochondrial matrices reappeared and intravascular plugging by polymorphonuclear leukocytes or platelets was observed. However, nucleoli and intramitochondrial granules reappeared within 3 hours of reperfusion and a large number of myocytes were recovered progressively within 6 hours of reperfusion. Recovery was apparent in the subepicardial myocytes and there were no distinct changes in the ultrastructure except narrowed lumen of the microvessels in the later period of reperfusion. Conclusions: It is likely that the ischemic myocardium could not be salvaged without adequate restoration of coronary flow and that the microvasculature is more resistant to reversible period of ischemia than subendocardium and subepicardium. Therefore, thrombolysis and/or angioplasty may be a rational method of therapy for coronarogenic myocardial ischemia. However, it may take a relatively longer period of time to recover from ischemic insult and reperfusion injury should be considered.

• Journal of Chest Surgery
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• v.42 no.1
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• pp.14-21
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• 2009

Background: Postoperative atrial fibrillation (AF) is a common complication after coronary artery bypass graft (CABG) surgery. Although postoperative AF is regarded as benign, transient and self-limited, it has been associated with increased morbidity, thromboembolic events and an increased duration and cost of hospitalization. Material and Method: From January 1994 to December 2007, 190 patients that had isolated CABG surgery were divided into two groups. Group 1 (n=139) involved those who had postoperative atrial fibrillation, and group 2 (n=51) did not have any such events. We reviewed the medical records retrospectively including the incidence of postoperative AF, patient characteristics, surgery related factors and the outcome of the patients with postoperative AF. Result: The frequency of postoperative AF was 26.8%, the conversion rate to regular sinus rhythm before discharge was 82.4%; 82.4% of the AF developed within the first three postoperative days. Although the postoperative AF group was significantly older and had a prolonged postoperative Intensive care unit (ICU) stay, there was no difference in the aortic crossclamp time or duration of hospitalization. No spontaneous defibrillation at declamping, and longer duration of cardiopulmonary bypass were significantly related to the development of postoperative AF. However, postoperative treatment with a beta blocker was associated with a decreased incidence of postoperative AF. The multivariate analysis showed that age and ICU stay were significantly associated with the development of POAF. Spontaneous defibrillation and postoperative beta blocker treatment were significantly associated with a decreased frequency of POAF. Conclusion: AF after CABG surgery is a common complication associated with increased morbidity and a longer ICU stay. Therefore, various strategies aimed at reducing AF, and its complications, such as postoperative treatment with a beta blocker should be considered.

• Environmental and Resource Economics Review
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• v.14 no.4
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• pp.817-838
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• 2005

In this paper, the resource adequacy as well as the optimum fuel mix is obtained by the following procedures. First, the regulation body, the government agency, determine the reliability index as well as the optimum portfolio of the fuel mix during the planning horizon. Here, the resources with the characteristics of public goods such as demand-side management, renewable resources are assigned in advance. Also, the optimum portfolio is determined by reflecting the economics, environmental characteristics, public acceptance, regional supply and demand, etc. Second, the government announces the required amount of each fuel-type new resources during the planning horizon and the market participants bid to the government based on their own estimated fixed cost. Here, the government announces the winners of the each auction by plant type and the guaranteed fixed cost is determined by the marginal auction price by plant type. Third, the energy market is run and the surplus of each plant except their cost (guaranteed fixed cost and operating cost) is withdrew by the regulatory body. Here, to induce the generators to reduce their operating cost some incentives for each generator is given based on their performance. The performance is determined by the mechanism of the performance-based regulation (PBR). Here the free-riding performance should be subtracted to guarantee the transparent competition. Although the suggested mechanism looks like very regulated one, it provides two mechanism of the competition. That is, one is in the resource construction auction and the other is in the energy spot market. Also the advantages of the proposed method are it guarantee the proper resource adequacy as well as the desired fuel mix. However, this mechanism should be sustained during the transient period of the deregulation only. Therefore, generation resource planning procedure and market mechanisms are suggested to minimize possible stranded costs.

• Clinical and Experimental Reproductive Medicine
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• v.35 no.1
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• pp.77-82
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• 2008

Objective: This study was performed to investigate the efficacy and safety of radiofrequency (RF) myolysis under transvaginal ultrasound guidance. Methods: Transvaginal RF myolysis had been performed in one hundred nine women with uterine leiomyoma at Chung-Ang University hospital between Dec. 2004 and Mar. 2007. All patients, mean aged $42.8{\pm}5.8$ years, desired their uterine conservation. Patients underwent physical examination, transvaginal pelvic ultrasound for measurement of the lesions preoperatively. Follow up was done at 1 week, 1 month, 3 months, 6 months after RF myolysis by same physician and measurement of size and volume of myoma and improvement of myoma specific symptoms such as menorrhagia and dysmenorrhea were checked at each visit. Results: The mean maximal diameter of myomas treated by RF myolysis was $6.1{\pm}0.5\;cm$ and average time of the procedure was $16.3{\pm}8.5$ minutes. A significant decrease of myoma size and volume was observed at 1 month after myolysis. Mean reduction in maximal diameter was $29.9{\pm}4.8%$ at 1 week (p<0.001), $41.5{\pm}1.5%$ at 1 month (p=0.05), $46.2{\pm}3.9%$ at 3 months (p=0.003), $54.6{\pm}6.1%$ at 6 months (p<0.001) after RF myolysis respectively. Mean reduction in volume was $44.4{\pm}8.3%$ (p=0.001), $68.1{\pm}4.2%$ (p=0.035), 73.9$73.9{\pm}4.8%$ (p=0.042), $84.5{\pm}5.1%$ (p<0.001) at the same follow up period respectively. Significant improvement of symptom was observed at 3 months after RF myolysis. Transient low abdominal pain and prolonged vaginal bleeding were detected in 3 patients each but spontaneously resolved and no serious complication has been noticed or found. Conclusion: This study shows transvaginal RF myolysis could be a safe and effective method to treat uterine leiomyoma, allowing uterine conservation with significant volume reduction and rapid return to normal activity.

• The Korean Journal of Pain
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• v.5 no.1
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• pp.37-43
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• 1992

Postoperative hypoxemia in the absence of hypoventilation occurs more often after thoracic or upper abdominal surgery than lower abdominal operations or surgery on extremities. Although the factors which produce postoperative alveolar collapse have not been fully evaluated, the dominant factor of postoperative hypoxemia is shunt of blood passing collapsed alveoli and the postoperative pain is associated with restriction of depth of breathing, sighing and movement. In 1979, the first successful clinical usage of epidurally administered morphine for control of postoperative pain was reported by Behar and associates. This study was carried out for twenty patients who received posterolateral thoracostomy with bleb resection between May 1990 and May 1991 and who were primary spontaneous recurrent pneumothoraxes under general endotracheal anesthesia. For the relief of post-thoracotomy pain following of the general anesthesia, we selected ten patients as control group which were treated intermittently IM with injection of pethidine(50 mg) according to the conventional method and another ten patients as study group which were managed with thoracic epidural analgesia. The tip of the catheter was inserted to T4-5 epidural space through T12-L1 or L1-2 interspinous region before the induction of the general anesthesia and then the epidural analgesics(0.25% bupivacaine 15 ml+morphine 3 mg) was injected once a day via the catheter until 4 th POD in the study group. The epidural catheters were removed at postoperative 4 th day in study group. Clinical observations were done about vital signs, ABG, tidal volume, FVC and occurence of adverse effects during postoperative 2hr, 8hr, 1st day, 2nd day, 7th day in both groups. The results were as follows; (1) The values of $V_T$ and FVC were significantly improved in study group(85% and 66%) as compared with control group(76% and 61%) during the postoperative 4 day of the epidural analgesia. (2) After the end of the epidural analgesia(7th POD), the values of FVC were improved invertly rather in control group(98%) than study group(84%). It suggested that the reduction of FVC in study group were caused by the raised pain sensitivity following the end of epidural analgesia. (3) The side effects of epidural analgesia such as transient urinary retention(2 cases), itching sensation(1) and headache(1) were noted.

• The Korean Journal of Pharmacology
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• v.1 no.1 s.1
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• pp.17-36
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• 1965

Besides it's all important analgesic action, morphine has, among others, hyperglycemic effect, though not important clinically, which is believed to be resulted from augmented glycogenolysis in the liver and muscles due to the increased liberation of epinephrine from the adrenal medulla upon the stimulation of the posterior part of hypothalamus. It is known that adrenergic blocking agents are acting inhibitory to this sort of hyperglycemia. Much, however, should as yet be studied for the drugs which affect central nervous system and release of endogenous catecholamine as far as their effects on hyperglycemia are concerned. Much is still not known about the effect of ginseng, which has been highly regarded in the Herb Medicine, as far as it's influence on the blood sugar is concerned. Author investigated the effects of chlorpromazine, reserpine and ginseng on epinephrine induced, and morphine-induced hyperglycemiae. Animals used in this experiment were healthy albino rabbits weighing approximately 2.0 kg of body weight and were all fasted for 24 hours, before the experiment undertaken. Blood sugar determination was carried out by Nelson-Somogy method. Results obtained are summarized as follows; 1. The groups of rabbits administered intravenously with epinephrine 0.02 mg/kg, and 0.05 mg/kg, showed marked and transient hyperglycemia within 15 minutes after injection. The maximal rate of elevation in blood sugar to the control level, were 28% and 57% respectively. The blood sugar returned to the control level within 3 hours. Thus, the hyperglycemic responses were paralleled with epinephrine doses. 2. The hyperglycemic responses by morphine were different according to the doses. The groups of rabbits in which 4 mg/kg of morphine was administered, did not show any hyperglycemic effect, but, in which 10 mg/kg of morphine administered, showed severe hyperglycemic effect, resulting in the maximal level within 2 hours after injection. The maximal rate of increasing in blood sugar ,level was 88%. Compared .with epinephrine-injected groups, morphjne-injected groups showed more persistent hyperglycemic effect, but returned to control blood sugar .level in 6 hours after injection. 3. The intravenous injection of chlorpromazine 2 mg/kg and 8 mg/kg evoked a slight, and persistent hyperglycemia. The maximal rate of increasing in blood sugar level were 15% and 23% respectively. These hyperglycemia gradually returned to the normal level in 5 or 6 hours after injection. Thus, the intensity of response was paralleled with the dose of chlorpromazine. 4. The intravenous injection of reserpine 0.2 mg/kg and 0.5mg/kg, showed the most persistent but steady elevation of blood sugar level in this experiments, resulting in the maximal level in 5 hours after injection. The maximal rate of increasing of blood sugar level were 18% and 39% respectively. 5. The blood sugar level from 24 hours to 30 hours after intraperitoneal administration of reserpine 1.0mg/kg, did not show statistically significant difference, compared with control groups. 6. The oral administration of ginseng extract 15 ml/kg did not. show any :change in blood sugar level. 7. The intravenous administration of epinephrine 0.05 mg/kg or morphine 4 mg/kg to the group pretreated with ginseng extract 15 ml/kg $20{\sim}30$ minutes before the experiment, evoked more marked hyperglycemic effect than the non-pretreated group. 8. The intravenous administration of epinephrine 0.02 mg/kg, morphine 4 mg/kg, or morphine 10 mg/kg to the groups pretreated with reserpine 0.2 mg/kg or 0.5 mg/kg $20{\sim}30$ minutes before experiment, produced more marked and persistent hyperglycemic effects than the groups injected with single epinephrine or morphine injection. 9. When epinephrine 0.05 mg/kg or morphine 10 mg/kg administered intravenously to the groups pretreated with the intraperitoneal administration of reserpine 1 mg/kg 24 hours before experiment morphine-induced hyperglycemia was inbibited, but epinephrine-induced hyperglycemia was augmented. 10. When epinephrine 0.05mg/kg or morphine 10 mg/kg administered intravenously to the groups pretreated with chlorpromazine, 2 mg/kg, 4 mg/kg, and 8 mg/kg $20{\sim}30$ minutes before the experiment, morphine-induced hyperglycemia was inbibited, but epinephrine-induced hyperglycemia was more persistent.

• Journal of Acupuncture Research
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• v.19 no.5
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• pp.92-111
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• 2002

Objective : Carthami Flos has been used as a herb to promote blood circulation to remove blood stasis in oriental medicine for many centuries, and Amun(GV15) has been used as a meridian point to treat apoplexy etc. To investigate treatment of cerevral vascular disease(CVA) by promoting blood circulation and removing blood stasis(活血化瘀法), we observed the experimental effects and mechanism of auqa-acupunture of Carthami Flos(ACF) injected into GV15 on cerevral hemodynamics and cardiovascular system of rats. Method : Aqua-acupuncture of Carthami Flos(ACF) was injected into GV15, and then we investigated experimental effects and mechanism of ACF on the cerebral hemodynamics[regional cerebral blood flow(rCBF), pial arterial diameter(PAD), meal arterial blood pressure(MABP)] and cardiovascular system[cardiac muscle contractile force(CMF), heart rate(HR)I by pretreatment with methylene blue(MTB) and indomethacin(IDN). The changes in rCBF, MABP, CMF and HR were tested by Laser Doppler Flowmetry(LDF), and the changes in PAD was determinated by video microscopy methods and video analyzer. Results :The results were as follows in normal rats ; The changes of rCBF and PAD were significantly increased by ACF($120{\mu}{\ell}/kg$) in a injected time-dependent manner, but MABP was not changed by ACF. The changes of cardiovascular system were increased by ACF in a injected time-dependent manner. And pretreatment with MTB was significantly inhibited ACE induced increase of rCBF and PAD, and was decreased ACF induced increase of HR. And pretreatment with IDN was increased ACF induced MABP and CMF. And the results were as follows in cerebral ischemic rats ; The changes of rCBF was increased stabilizly by treatment with ACF($120{\mu}{\ell}/kg$) in during the period of cerebral reperfusion, but pretreatment with MTB was increased ACF induced increase of rCBF during the period of cerebral reperfusion. The results were as follows in normal rats ; The changes of rCBF and PAD were significantly increased by ACF($120{\mu}{\ell}/kg$) in a injected time-dependent manner, but MABP was not changed by ACF. The changes of cardiovascular system were increased by ACF in a injected time-dependent manner. And pretreatment with MTB was significantly inhibited ACF induced increase of rCBF and PAD, and was decreased ACF induced increase of HR. And pretreatment with IDN was increased ACF induced MABP and CMF. And the results were as follows in cerebral ischemic rats ; The changes of rCBF was increased stabilizly by treatment with ACF($120{\mu}{\ell}/kg$) in during the period of cerebral reperfusion, but pretreatment with MTB was increased ACF induced increase of rCBF during the period of cerebral reperfusion Conclusions : In conclusion, ACF causes a diverse response of rCBF, PAD an HR, and action of ACF is mediated by cyclic GMP. I suggested that ACF has an anti-ischemic effect through the improvement of crebral hemodynamics in a transient cerebral ischemia.

• The Korean Journal of Nuclear Medicine
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• v.38 no.3
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• pp.225-232
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• 2004

Purpose : Transient wall motion abnormality and contractile dysfunction of the left ventricle (LV) can be observed in patients with coronary artery disease due to post-stress myocardial stunning. To understand clinical characteristics of stress induced LV dysfunction, we have compared the findings of exercise stress test, myocardial perfusion SPECT and coronary angiography between subjects with and without post-stress LV dysfunction. Materials and Methods : Among subjects who underwent exercise stress test, myocardial perfusion SPECT and coronary angiography within a month of interval, we enrolled 36 patients with post-stress LV election fraction (LVEF) was $\geq5%$ lower than rest (stunning group) and 16 patients with difference of post-stress and rest LVEF was lesser than 1 %(non-stunning group) for this study. Treadmill exercise stress gated myocardial perfusion SPECT was performed with dual head SPECT camera using 740 MBq Tc-99m MIBI and coronary angiography was also performed by conventional Judkins method. Results : Stunning group had a significantly higher incidence of hypercholesterolemia than non-stunning group(45.5 vs. 7.1%, p=0.01). Stunning group also had higher incidence of diabetes mellitus and lower incidence of hypertension, but these were not statistically significant. Stunning group had larger and more severe perfusion defect in stress perfusion myocardial SPECT than non-stunning group(extent 18.2 vs. 9.2%, p=0.029; severity 13.5 vs. 6.9, p=0.040). Stunning group also had higher degree of reversibility of perfusion defect, higher incidence of positive exercise stress test and higher incidence of having severe stenosis ($80{\sim}99%$) in coronary angiography than non-stunning group, but these were not statistically significant. In stunning group, all of 4 patients without perfusion defect had significant coronary artery stenosis and had received revascularization treatment. Conclusion : Patients with post-stress LV dysfunction had larger and more severe perfusion defect and severe coronary artery stenosis than patients without post-stress LV dysfunction. All of the patients without perfusion defect in stunning group had significant coronary artery stenosis and needed revascularization. Therefore, we suggest that invasive diagnostic procedures and therapeutic interventions might be needed in patients with post-stress LV dysfunction.

• Childhood Kidney Diseases
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• v.3 no.1
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• pp.57-63
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• 1999

Purpose : To evaluate the diagnostic significance of simultaneous examination of hematuria and proteinuria in the urinary mass screening for early detection ot incipient renal diseases. Method and Object : During the period of 4 months from August to December in 1997, we did urinary mass screening on students of first grade of high school (16 years aged group) nationwide together with Korean Association of Health(KAH). In the first screening test, Comber-10 $N^{(R)}$ M dipsticks were used to detect proteinuria, hematuria, pyuria and nitrite simultaneously. Total 26,508 students (16 years aged group) from 33 high schools in every province in Korea, respectively, complied to the urinary mass screening. After then, one high school in Seoul was selected to reveal the true incidence of incipient renal diseases among students who showed hematuria in the initial screening through intensive examinations. Those who had hematuria and/or proteinuria visited the Paik hospital, and underwent blood tests and ultrasonographic examinations. The results were evaluated. Results 1) The initial screening revealed that the prevalence of proteinuria, hematuria, pyuria and positive nitrite urine, were $0.73\%,\;2.69\%,\;0.23\%\;and\;0.03\%$, respectively. 2) The first urinary screening among 875 students from one high school in Seoul selected fir the second test showed proteinuria, hematuria, pyuria and positive nitrite urine, were $0.91\%,\;4.68\%,\;0.34\%\;and\;0\%$, respectively. a) Total 8 among 875 students showed proteinuria, but one of them had orthostatic proteinuria and those remaining 7 students had transient proteinuria. b) There were 41 students who had hematuria in the initial screening. Among 33 who complied the second test, only one student showed asymptomatic isolated hematuria and those remaining students were normal. Conclusion : 1) Because of high false positive hematuria rate in the urinary mass screening, it dosen't seem to be appropriate that hematuria screening using dipsticks be included in the urinary mass screening. 2) A unified organization is needed from the fret that so various results of urinary mass screening came out. 3) Positive rates of pyuria and nitrite were so low that validity of urinary mass screening for urinary tract infection needs more studies.

• Journal of Chest Surgery
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• v.39 no.6 s.263
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• pp.434-439
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• 2006

Background: Deep hypothermic circulatory arrest during repair of aortic arch anomalies may induce neurological complications or myocardial injury. So we surveyed if the regional cerebral and myocardial perfusion might eliminate those potential side effects. Material and Method: From March 2000 to December 2004, 62 neonates or infants with aortic arch anomaly underwent one stage biventricular repair using the regional perfusion technique by single surgeon. Preoperative diagnosis of the arch anomaly consisted of coarctation (n=46), interruption of the aorta (n=12), hypoplastic left heart syndrome (n=2) and truncus areteriosus (n=2). Combined anomalies were ventricular septal defect (n=51), TAPVR (n=1), PAPVR (n=1) and atrioventricular septal defect (n=2). Arterial cannula was inserted at the innominate artery. Result: The mean regional perfusion time of brain was $28{\pm}10min$. Operative mortality rates was 0 (0/62). Late death was 1 (1/62) during $11{\pm}7$ months of follow-up. Neurologic complications consisted of transient chorea in 1 case. There was no reoperation associated with arch anolamy. Pulmonary complication associated with arch repair occurred in f case which was managed by aortopexy. Conclusion: One-tage rch repair using the regional profusion is safe and effective in minimizing the neurologic and myocardial complications.