• Journal of Chest Surgery
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• v.34 no.11
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• pp.809-822
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• 2001

Background: Ischemic preconditioning(IP) is known to be effective in the protection of myocardial necrosis, arrhythmia, and the restoration of the myocardial function in the ischemia-reperfusion state of the heart. However the exact mechanism is not clearly understood. The purpose of this study was to elucidate the trigger mechanism 7f IP on the restoration of the myocardial function after ischemia-reperfusion. Material and Method: By connecting a Langendorff perfusion apparatus with an isolated heart of a rat, the normal temperature of the heart was maintained. The experiment was conducted in seven groups, which were divided according to the preconditioning stimuli and blockage methods Group I(n=10) was a group without IP, Group II(n=10) a group of three-minute IP, Group III(n=10) a group of PEIP, Group IV(n=10) a group of clonidine IP, Group V(n=10) a group of If after reserpine, Group Vl(n=10) a group of PE & prazosin IP, and Group Vll(n=10) a group of clonidine & yohimbine IP. Hemodynamic parameters of DP, LVEDP, $\pm$dP/dT and the changes of perfusion in the coronary artery were evaluated. Result: Developed pressure and +dP/dT changed per unit time. After 20 minutes of reperfusion, those of Group II and III were 63.1$\pm$3.7%, 64.8$\pm$4.6% and 64.5$\pm$4.6%, 63.8$\pm$4.4%, which improved more significantly than those of Group I(P<0.05), However, there were no significant differences between the Groups V and Vl, and Group I. Conclusion: The Brief ischemic preconditioning and pharmacological preconditioning using $\alpha$-receptor sympatho-mimetics have protecting effects on the restoration of myocardial function after reperfusion. And the protecting effect of preconditioning seems to be related to sympathetic neurotransmitters and to the selective action of the $\alpha$$_1$-adrenergic receptor.

• Journal of Chest Surgery
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• v.36 no.4
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• pp.242-254
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• 2003

Most of the studies conducted have investigated the beneficial effects of ischemic preconditioning on normothermic myocardial ischemia. However, the effect of preconditioning could be attenuated through the use of multidose cold cardioplegia as practiced in contemporary clinical heart surgical procedures. The purpose of this study was to investigate whether preconditioning improves postischemic cardiac function in a model of 25℃ moderate hypothermic ischemic heart induced by cold cardioplegia in isolated rat hearts. Material and Method: The isolated Sprague-Dawley rat hearts were randomly assigned to four groups. All hearts were perfused at 37℃ for 20 minutes with Krebs-Henseleit solution before the baseline hemodynamic data were obtained. Group 1 consisted of preconditioned hearts that received 3 minutes of global ischemic preconditioning at 37℃, followed by 5 minutes of reperfusion before 120 minutes of cardioplegic arrest (n=6). Cold (4℃) St. Thomas Hospital cardioplegia solution was infused to induce cardioplegic arrest. Maintaining the heart at 25℃, infusion of the cardioplegia solution was repeated every 20 minutes throughout the 120 minutes of ischemic period. Group 2 consisted of control hearts that underwent no manipulations between the periods of equilibrium and 120 minutes of cardioplegic arrest (n=6). After 2 hours of cardioplegic arrest, Krebs solution was infused and hemodynamic data were obtained for 30 minutes (group 1, 2: cold cardioplegia group). Group 3 received two episodes of ischemic preconditioning before 30 min of 37℃ normothermic ischemia and 30 minutes of reperfusion (n=6). Group 4 served as ischemic controls for group 3 (group 3, 4: warm ischemia group). Result: Preconditioning did not influence parameters such as left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), rate-pressure product (RPP) and left ventricular dp/dt (LV dp/dt) in the cold cardioplegia group. (p=NS) However, preconditioning before warm ischemia attenuated the ischemia induced cardiac dysfunction, improving the LVSP, LVEDP, RPP, and LVdp/dt. Less leakage of CPK and LDH were observed in the ischemic preconditioning group compared to the control group (p<0.05). Conclusion: Ischemic preconditioning improved postischemic cardiac function after warm ischemia, but did not protect cold cardioplegic hearts.

• Journal of Chest Surgery
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• v.36 no.5
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• pp.242-254
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• 2003

Background: Most of the studies conducted have investigated the beneficial effects of ischemic preconditioning on normothermic myocardial ischemia. However, the effect of preconditioning could be attenuated through the use of multidose cold cardioplegia as practiced in contemporary clinical heart surgical procedures. The purpose of this study was to investigate whether preconditioning improves postischemic cardiac function in a model of $25^{\circ}C$ moderate hypothermic ischemic heart induced by cold cardioplegia in isolated rat hearts. Material and Method: The isolated Sprague-Dawley rat hearts were randomly assigned to four groups All hearts were perfused at 37$^{\circ}C$ for 20 minutes with Krebs-Henseleit solution before the baseline hemodynamic data were obtained, Group 1 consisted of preconditioned hearts that received 3 minutes of global ischemic preconditioning at 37$^{\circ}C$, followed by 5 minutes of reperfusion before 120 minutes of cardioplegic arrest (n=6). Cold (4$^{\circ}C$) St. Thomas Hospital cardioplegia solution was infused to induce cardioplegic arrest. Maintaining the heart at $25^{\circ}C$, infusion of the cardioplegia solution was repeated every 20 minutes throughout the 120 minutes of ischemic period. Group 2 consisted of control hearts that underwent no manipulations between the periods of equilibrium and 120 minutes of cardioplegic arrest (n=6). After 2 hours of cardioplegic arrest, Krebs solution was infused and hemodynamic data were obtained for 30 minuts (group 1, 2: cold cardioplegia group). Group 3 received two episodes of ischemic preconditioning before 30 min of 37$^{\circ}C$ normothermic ischemia and 30 minutes of reperfusion (n=6) Group 4 soloed as ischemic controls for group 3 (group 3, 4: warm ischemia group). Result: Preconditioning did not influence parameters such as left ventricular systolic pressure (LVSP), left ventricular end-diastolic pressure (LVEDP), rate-pressure product (RPP) and left ventricular dp/dt (LV dp/dt) in the cold cardioplegia group. (p=NS) However, preconditioning before warm ischemia attenuated the ischemia induced cardiac dysfunction, Improving the LVSP, LVEDP, RPP, and LV dp/dt. Less leakage of CPK and LDH were observed in the ischemic preconditioning group compared to the control group (p<0.05). Conclusion: Ischemic preconditioning improved postischemic cardiac function after warm ischemia, but did not protect cold cardioplegic hearts.

• Journal of the Korean Society of Radiology
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• v.10 no.1
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• pp.29-37
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• 2016

This study aims to improve the satisfaction level of the patient who undergoes CT contrast examination by developing and applying pretreatment process system, which not only can reduce the side effects caused by the test but also can help carry out the test smoothly. The subjects were 214 patients who booked CT contrast examination from January 2014 to February 2014 but could not carry out their test on schedule. We analyzed the reasons for the delay and conducted follow-up survey on them. We analyzed the usefulness of pretreatment process system by contemplating and developing pretreatment process system and applying it to the patients for whom follow-up survey was conducted from January 2015 to February 2015. The number of outpatients who came to the hospital form January to February 2014 was 2,846 and the number of patients who could not undergo the test was 214, accounting for 7.52% of the total. The specific reason for the delay includes 214 cases of unknown creatinine 98 with 120 minutes of average delay time, 40 cases of creatinine over 1.3(19%) with 30minutes of average delay time, 34 cases of past contrast media side effect 6% with 40 minutes of average delay time and 25 cases of lack of pretreatment such as fasting, etc. 11% with 120minutes of average delay time. The number of CT scan has been increasing ever since the development of CT and the frequency of using the contrast media is expected to increase. If we can employ pretreatment process system in order to effectively control the side effect of contrast media and help the CT contrast examination to be smoothly conducted on schedule, I'm sure we could improve the quality of our medical service and increase our patients' satisfaction who come to our CT scan room.

• Proceedings of the Korean Society of Applied Pharmacology
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• 1993.04a
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• pp.85-85
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• 1993

뇌동맥계는 일과성 저혈압에 반응하여 혈관확장이 야기되고, 혈압 상승시에는 혈관수축이 일어남으로서 뇌혈류가 일정하게 조절된다. 이러한 자가조절은 뇌손상 등의 병적 상태에서 야기된다. 연구의 목적은 \circled1 Cromakalim, CGRP(calcitonin-gene related peptide), 및 substance P에 의하여 뇌연막동맥의 직경이 어떻게 변동하는가를 관찰하고 \circled2 이들 신경성 peptide의 작용에 대하여 $K^{＋}$ 통로 개방 봉쇄제인 glibenclamide의 전처치 효과를 검색하고 \circled3 Capsaicin 전처치가 뇌혈류 자가조절에 어떻게 영향을 미치는가를 검색하였다. 그 결과는 다음과 같다. 1. 뇌혈류 자가조절은 대퇴동맥을 통한 사혈에 의하여 혈압하강을 일으킬 때 뇌연막 동맥은 이완하였고, reservoir내의 혈액을 체내로 주입함로서 혈압반전을 일으켰을 때는 혈관 수축이 일어났다. 2. 연막동맥은 glibenclamide (1~3$\mu$M)의 관류에 의하여는 영향을 받아니하였다. 3. 혈압변동에 따른 혈관직경의 변화를 회기직선으로 분석하였다. Glibenclamide 1과 3$\mu$M의 전처치 관류에 의하여 혈압하강에 따른 혈관 이완경사도와 혈압반전에 따른 혈관수축 경사도가 대조군에 비하여 현저히 약화되었다. 4. Cromakalim (0.1-30$\mu$M)의 각 농도를 대뇌표면에 관류시 연막동맥의 기초직경은 약물농도에 의존하여 증가되었고, 이는 glibenclamide (1$\mu$M) 전처치 관류에 의하여 억제되었다. 5. CGRP (0.1~100 nM)와 substance P (0.1~10nM)도 용량에 의존하여 혈관이완을 일으켰다. 전자는 glibenclamide (1$\mu$M) 전처치 관류에 의하여 억제되었으나 후자는 영향을 받지 아니하였다. 6. Capsaicin(50 nmol: intracisternally) 주사에 의하여 뇌혈류자가조절의 변동이 초래되었다. 이상의 결과들을 종합하면 CGRP가 혈압변동에 의하여 반사적으로 유리되고, 이는 glibenclamide-sensitive $K^{＋}$ 통로에 작용하는 것으로 시사된다.

• Journal of the Korean Chemical Society
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• v.38 no.1
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• pp.74-79
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• 1994

The participation of superoxide in initiating tissue damage derived from xenobiotics is best illustrated by paraquat intoxication. In the present study, the roles of superoxide dismutase and catalase on paraquat-induced cell injury were investigated using primary cultured rat skin fibroblast. The degree of cell injury was assassed by the conversion of reduced MTT to a blue formazan. Paraquat produced concentration-and time-related cell injury in cultured rat skin fibroblast. Paraquat induced-cell injury was aggravated by pretreatment of aminotriazol (AT: 10 mM), an catalase inhibitor, and attenuated by addition of catalase (100∼500 unit/ml). However, the effects of diethyldithiocarbamate (DDC : 10 mM), copper- and zinc-containing superoxide dismutase (Cu, Zn-SOD) inhibitor, and Cu, Zn-SOD on paraquat-induced injury were not significant. These results suggest that hydrogen peroxide might be more responsible factor than superoxide in the pathogenesis of paraquat-induced cell injury.

• Journal of the Korea Convergence Society
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• v.9 no.1
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• pp.473-483
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• 2018

The purpose of this study was to identify the effects of bowel preparation convergence program for colonoscopy. This study used a nonequivalent control group pretest-posttest design. A sample of 75 clients, who were scheduled for colonoscopy, was included. The experimental group was given bowel preparation convergence program including audiovisual education, walking-exercise and telephone counseling. The data were collected using a structured questionnaire and colonoscopy monitoring and were analyzed using SPSS 21.0 program. The experimental group reported significantly higher compliance of taking bowel preparation agents and test satisfaction(p=.002; p=.001), lower test difficulty and test discomfort than those of the control group(p=.002; p=.001). There were significant differences in level of bowel cleansing and test time required except compliance of diet restriction between groups(p<.001; p=.001; p=.108). This findings indicate that bowel preparation convergence program can be an effective nursing intervention for colonoscopy. The convergence intervention for diagnostic test is needed to be developed in clinical practice.

• Journal of Chest Surgery
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• v.34 no.11
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• pp.823-830
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• 2001

Background: Paraplegia is a serious complication of thoracic or thoracoabdominal aortic operations, which is related to ischemic injury of the spinal cord induced by low perfusion pressure during cross clamping of the aorta. Ischemic preconditioning of heart or brain with reversible sublethal ischemic injury induces resistance to subsequent lethal ischemia. The aim of this study is to investigate whether ischemic tolerance could be induced by the preconditioning of the spinal cord using swine model. Material and Method: The animals were randomly assigned to three groups: sham group(n=3), control group(n=6) and pre-conditioning group(n=8). In the sham group, we performed the left thoracotomy only without any ischemic injury. In the preconditioning group, the swine received reversible spinal cord ischemic injury by aortic clamping for 20 minutes, whereas control group had no previous aortic cross- clamping. Forty-eight hours later, the aorta was clamped for 30 minutes in both groups. Neurological examination was done 24 hours later, then the animals were euthanized for histopathology and malonedialdehyde(MDA) spectrophotometry assay of the spinal cord. Result: Statistically significant difference in neurological outcome was observed between the control and preconditioning groups at 24 hours after ischemic injury. The incidence of paraplegia and severe paresis was 100% in the control group, and 62.5% in the preconditing group(p=0.028). There was no statistically significant difference in histopathology and MDA assay of the ischemic spinal cord between these two groups with borderline statistical difference in MDA assay(p=0.0745). Conclusion: In the present swine study, ischemic preconditioning could induce tolerance against 30 minute ischemic insult of the spinal cord, although the animals did not completely recover(stand-up or walk). We expect that combining this preconditioning with other currently existing protection methods might lead to a synergistic effect, which warrants further investigation.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.8 no.2
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• pp.296-305
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• 1998

A study was performed to evaluate an effect of toluene or ethanol pretreatment on the toluene metabolism. A slight liver damage in rats was induced by administration of 0.2 ml of toluene or 0.2 ml of 50% ethanol per 100 g of body weight intraperitoneally every other day for four weeks except the last day before sacrifice. One day before sacrifice, toluene was administered to rats pretreated ethanol or toluene and the control. Rats were sacrificed at the 1st, the 2nd, the 3rd and the 4th week after the first administration of xenobiotics mentioned above. Based on the histopathological findings, liver weight per body weight, serum alanine aminotransferase and hepatic glutathione content, toluene- or ethanol-pretreated groups showed the reversible liver injury. By the treatment of one dose of toluene, the contents of hippuric acid in urine was higher in the group pretreated with toluene or ethanol than control. The contents of cytochrome P-450, benzylalcohol dehydrogenase and benzaldehyde dehydrogenase activities were generally more increased in toluene- or ethanol-pretreated rats than control. $K_m$ values of the benzylalcohol dehydrogenase in pooled liver samples from toluene- and ethanol-pretreated groups were similar each other. $V_{max}$ values of toluene- or ethanol-pretreated group was higher than control. In conclusion, the toluene metabolism is accelerated in rats pretreated with toluene or ethanol.

• Journal of Food Hygiene and Safety
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• v.18 no.2
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• pp.87-93
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• 2003

This study was performed to investigate aflatoxin reduction resulting from the pre-treatment and the cooking and processing of corn. Aflatoxin was produced by Aspergillus parasiticus ATCC 15517 on a type of corn imported from the United States. The aflatoxin-produced com (AC) was pre-treated in three ways in order to reduce aflatoxin: exposure to sun light for 7 days (SC); ultraviolet irradiation for 56 hours (UC); and washing with water three times (WC). Four kinds of cooking and processing methods (boiling, steaming, baking, and popping) were used to reduce aflatoxin in the AC control, SC, UC, and WC. These treatments produced com gruel, com cakes, com bread and popcorn. The aflatoxin content in the samples was determined by high performance liquid chromatography. The total aflatoxin level of the AC was significantly decreased by sun light and UV (p<0.05), and decreased by washing. After cooking and processing the AC, SC, UC, and WC, and averaging the total aflatoxin levels in the final products, the greatest reduction was found in the com gruel, then the popcorn, then the corn cakes, and the least reduction in the com bread. These results indicate that sunlight and ultraviolet energy could be effective factors in aflatokin degradation in corn before cooking and processing. This study also indicates that boiling, steaming, baking and popping were helpful in reducing the aflatoxin level in the com and that the most helpful factors were exposure time to heat. More research is needed to reduce the aflatoxin level down to below the maximum tolerable level of aflatoxin in foods.