• 한국임상수의학회지
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• 제22권3호
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• pp.220-227
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• 2005

Although ketamine has been used in the field of anesthetic medicine for its safety and favourable respiratory effects, the cardiovascular effects of ketamine is still controversial. To clarify the action and mechanism of ketamine upon cardiovascular system, arterial blood pressure, tension of aortic ring, left ventricular developed pressure and heart rate were measured in rats, Ketamine produced two types of effects on arterial blood pressure in anesthetized rats; monophasic effect (blood pressure lowering) and biphasic effect (initial transient blood pressure increasing following sustained lowering), The ketamine-induced lowering of aterial blood pressure showed a concentration-dependent manner, inhibited by the pretreament of $MgCl_2$ and potentiated by the pretreatment of $CaCl_2$. The ketamine-induced lowering of aterial blood pressure was suppressed by the pretreatment of nifedipine, verapamil or lidocaine. In phenylephrine-precontracted endothelium intact (+E) aortic rings, ketamine sometimes caused a small enhancement of contraction ($112.5{\pm}3.6{\%}$). However, in many experiments, ketamine produced a concentration-dependent relaxation in +E aortic rings precontracted with either phenylephrine or KCl. Ketamine-induced relaxation was significantly greater in KCl-precontracted strips than phenylephrine-precontracted strips. In phenylephrine-precontracted +E aortic rings, the ketamine-induced vasorelaxation was not suppressed by endothelium removal or by the pretreatment of a nitric oxide synthase inhibitors, L-$N^G$-nitro-arginine and a guanylate cyclase inhibitors, methylene blue, suggesting that the ketamine-induced vasorelaxation is not dependent on the endothelial function. In addition, ketamine elicited an increase in left ventricular developed pressure in perfused hearts accompanied by decrease in heart rate. These results suggest that ketamine could evoke a hypotension due to vasorelaxation and decrease in heart rate in rats. The inhibitory effect of cardiovascular system might be associated with modulation of $Ca^{2+}$ homeostasis.

• 대한의용생체공학회:의공학회지
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• 제18권3호
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• pp.285-290
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• 1997

In this paper, the power spectral analysis and the fractal analysis of heart rate variability(HRV) were performed to evaluate the effects of brain lesion on cardiovascular system and autonomic function for 24 normal subjects and 22 hemiplegic patients. The ECG and respiration signals were recorded at tilt angles of $0^{\circ}$ and $70^{\circ}$ for 5 and 6 minutes successively under the condition of frequency controlled respiration (0.25Hz). For normal subjects, HR, LF component, HF component and fractral dimension of HRV were distinctly changed after orthostatic stress, whereas, for hemiplegic patients, those were little changed. Complexity and variability of heart rate of patients were smaller than those of normal subjects. Sympathetic tone of patients was higher than that in normal subjects. All of these results support that autonomic disorder and cardiovascular disturbance accompanied by brain lesion could be assessed by the power spectral analysis and fractal analysis of HRV.

• Journal of Chest Surgery
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• 제54권3호
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• pp.186-190
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• 2021

Background: Pre-lifting of the sternum marked a major turning point in pectus excavatum repair. The author developed the crane technique in 2002 and successfully applied it to more than 2,000 cases using sternal wire stitching. However, blind sternal suturing limited the use of the wire-stitch crane. We propose a novel screw for sternal lifting as a new tool for the crane technique. Methods: We developed a screw system strong enough to withstand the pressure needed for sternum lifting. The screw was designed to have a broader thread to hold the bony tissue securely. The screw's sustaining power was tested using the torsion, driving torque, and axial pull-out tests in a polyurethane block and ex-vivo porcine sternum. Results: The screws were easily driven into the sternum, and the head of the screw was connectable to the table-mounted retractor. In the torsion test, the 2° offset torsional yield was 4.53 N·m (reference value, 1 N·m). In the polyurethane block driving torque test, the maximum torque was 0.98 N·m (reference value, 0.70 N·m). The axial pull-out test was 446 N (reference value, 100 N). The maximum pull-out resistance in the ex-vivo porcine sternum model was 1,516 N. Conclusion: The screw crane was strong enough to sustain the chest wall weight to be lifted. Thus, the screws could effectively replace the sternal wire stitching in crane pre-lifting of the sternum. We expect that application of the screw-crane will be easy and that it will improve the safety and success rate of pectus repair surgery.

• Journal of Chest Surgery
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• 제55권5호
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• pp.364-377
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• 2022

An anatomical understanding of the atrial myocardium is crucial for surgeons and interventionists who treat atrial arrhythmias. We reviewed the anatomy of the inter-nodal and intra-atrial conduction systems. The anterior inter-nodal route (#1) arises from the sinus node and runs through the ventral wall of the atrial chambers. The major branch of route #1 approaches the atrioventricular node from the anterior aspect. Other branches of route #1 are Bachmann's bundle and a vestibular branch around the tricuspid valve. The middle inter-nodal route (#2) begins with a broad span of fibers at the sinus venarum and extends to the superior limbus of the oval fossa. The major branch of route #2 joins with the branch of route #1 at the anterior part of the atrioventricular node. The posterior inter-nodal route (#3) is at the terminal crest and gives rise to many branches at the pectinate muscles of the right atrium and then approaches the posterior atrioventricular node after joining with the vestibular branch of route #1. The branches of the left part of Bachmann's bundle and the branches of the second inter-nodal route form a thin myocardial network at the posterior wall of the left atrium. These anatomical structures could be categorized into major routes and side branches. There are 9 or more anatomical circles in the atrial chambers that could be structural sites for macro re-entry. The implications of normal and abnormal structures of the myocardium for the pathogenesis and treatment of atrial arrhythmias are discussed.

• 한국컴퓨터정보학회논문지
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• 제27권5호
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• pp.21-28
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• 2022

심혈관질환은 심장질환과 혈관질환 등 순환기계통에 생기는 모든 질병을 통칭한다. 심혈관질환은 2019년 사망의 1/3을 차지하는 전 세계 사망의 주요 원인이며, 사망자는 계속 증가하고 있다. 이와 같은 질병을 인공지능을 활용해 환자의 데이터로 미리 예측이 가능하다면 질병을 조기에 발견해 치료할 수 있을 것이다. 본 연구에서는 심혈관질환 중 하나인 심장질환을 예측하는 모델들을 생성하였으며 Accuracy, Precision, Recall의 측정값을 지표로 하여 모델들의 성능을 비교한다. 또한 Decision Tree의 성능을 향상시키는 방법에 대해 기술한다. 본 연구에서는 macOS Big Sur환경에서 Jupyter Notebook으로 Python을 사용해 scikit-learn, Keras, TensorFlow 라이브러리를 이용하여 실험을 진행하였다. 연구에 사용된 모델은 Decision Tree, KNN(K-Nearest Neighbor), SVM(Support Vector Machine), DNN(Deep Neural Network)으로 총 4가지 모델을 생성하였다. 모델들의 성능 비교 결과 Decision Tree 성능이 가장 높은 것으로 나타났다. 본 연구에서는 노드의 특성배치를 변경하고 트리의 최대 깊이를 3으로 지정한 Decision Tree를 사용하였을 때 가장 성능이 높은 것으로 나타났으므로 노드의 특성 배치 변경과 트리의 최대 깊이를 설정한 Decision Tree를 사용하는 것을 권장한다.

• Journal of Chest Surgery
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• 제43권1호
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• pp.20-24
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• 2010

배경: 전격성 심근염은 드물지만 사망을 초래할 수도 있는 치명적인 질병으로서, 급성기 치료가 예후에 매우 중요한 것으로 알려져 있고 이러한 급성기 치료에 순환 보조 장치가 도움이 될 수 있다. 이에 전격성 심근염 환자에서 급성기에 순환 보조 장치를 사용하여 치료한 결과를 보고하고자 한다. 대상 및 방법: 2006년 9월부터 2008년 10월까지 전격성 심근염으로 순환 보조 장치를 삽입한 9명의 환자를 대상으로 후향적 연구를 시행하였다. Capiox emergency bypass system (Terumo Inc, Tokyo, Japan)을 사용하였고 경피적으로 삽입하여 순환 보조 장치를 운용하였다. 환자들은 모두 심실 빈맥 또 는 강심제에 반응하지 않는 심인성 쇼크 상태에서 순환 보조를 받았고 심초음파상 평균 심구출률은 $20{\pm}6%$였다. 결과: 3명이 순환 보조 장치를 유지하던 도중 사망하였고 한 명의 환자가 순환 보조 장치를 유지하던 중 심장 이식 수술을 받았다. 나머지 환자들은 평균 $107{\pm}70$시간 순환 보조 장치 유지 후 성공적으로 발관하여 퇴원 후 심초음파상 심구출률 $56{\pm}7%$로 경과 관찰 중이다. 결론: 전격성 심근염은 급성기에 매우 치명적일 수 있으나 치료 후 예후는 양호한 질환으로 이러한 급성기 치료에 순환 보조 장치가 매우 유용하게 사용될 수 있다. 또한 순환 보조 장치의 도입 시점, 운용 방법 등에 대한 연구를 통하여 합병증을 줄일 수 있도록 노력해야 할 것이다.

• 대한본초학회지
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• 제23권2호
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• pp.179-192
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• 2008

Objectives : Draconis Resina (DR) has been used as a traditional Korean herbal medicine since ancient times, and today it is used as a medication for wounds, tumors, diarrhea, rheumatism, in the itching of insect bites and with other conditions in the folk medicine. The aim of this study was to determine whether fractionated extracts of DR inhibit free radical generation, intracellular oxidation, production of nitrite, an index of NO, PGE2, iNOS, COX-2 and proinflammatory cytokines in lipopolysaccharide (LPS)-treated RAW 264.7 macrophages, Methods : DR extract prepared with methanol, and then fractionated with hexane, dichloromethane, ethylacetate, n-butanol and water. Inhibitory effect of DR onto free radical generation was determined by measuring DPPH, superoxide anions and nitric oxide scavenging activities in vitro. Cytotoxic activity of extracts on RAW 264.7 cells was measured using 5-(3-caroboxymeth-oxyphenyl)-2H-tetra-zolium inner salt (MTS) assay. Intracelluar oxidation was analysed by DCF-DA assay. The nitric oxide (NO) production was measured by Griess reagent system. The levels of iNOS and COX-2 expression were confirmed by western blot. And proinflammatory cytokines were measured by ELISA kit. Results : Our results indicated that fractionated extracts, especially dichloromethane and ethyl acetate extracts, significantly inhibited free radical generation, the LPS-induced H202, NO, PGE2 production and iNOS, COX-2 expression accompanied by an attenuation of TNF-${\alpha}$, IL-$1{\beta}$ and IL-6 formation in macrophages. Conclusions : Our results indicate that dichloromethane and ethyl acetate extracts of DR have potential as an agent of chronic inflammatory diseases.

• 생명과학회지
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• 제22권4호
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• pp.545-551
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• 2012

중년 비만여성들을 대상으로 다리 근육의 정맥 혈류를 제한한 가압 걷기 트레이닝 그룹 15명으로 연구대상자를 선정하여 3주간의 가압 걷기 트레이닝을 실시한 결과 다음과 같은 결론을 얻었다. 첫째, 가압 걷기 트레이닝을 통해 LBM에서 트레이닝 전보다 후에 1.2 kg이 증가, FM과 %fat에서는 각각 2.8 kg, 3.3% 감소하였으며, 통계적으로도 유의한 차이를 나타냈다($p$<0.05). 둘째, 가압 걷기 트레이닝을 통해 $VO_2max$와 VEmax에서 트레이닝 전보다 후에 각각 3.6 ml/kg/min, 6.0 l/min 증가하였고, HRmax에서는 7 beat/min으로 감소하였으며 통계적으로도 유의한 차이를 나타냈다($p$<0.05). 셋째, 가압 걷기 트레이닝을 통해 심혈관 반응에서 트레이닝 전보다 후에서 운동 강도가 증가함에 따라 CO과 TVC가 증가하는 것으로 나타났으며, 통계적으로도 유의한 차이를 나타냈다($p$<0.05). 이상의 결과로부터 가압 걷기 트레이닝을 통해서 호흡 순환계 및 심혈관 기능의 증가와 근육량 증가에 따른 체성분의 변화를 유발할 수 있다는 것을 제시하였다. 본 연구의 결과를 토대로 향후 연구에서는 연구대상자의 범위를 넓혀 노년층까지 효과를 검증하는 연구와 3주 이상의 운동을 적용시키면 보다 높은 임상학적 효과가 나타날 것으로 판단된다.

• Nutrition Research and Practice
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• 제6권6호
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• pp.513-519
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• 2012

Aged garlic extract (AGE) is known to have a protective effect against immune system, endothelial function, oxidative stress and inflammation. We examined the effects of exercise with and without aged garlic extract administration on body weight, lipid profiles, inflammatory cytokines, and oxidative stress marker in high-fat diet (HFD)-induced obese rats. Forty-five Sprague-Dawley rats were fed either a HFD (HFD, n = 40) or a normal diet (ND, n = 5) for 6 weeks and thereafter randomized into ND (n = 5), HFD (n = 10), HFD with AGE (n = 10), HFD with Exercise (n = 10), or HFD with Exercise+AGE (n = 10) for 4 weeks. AGE groups were administered at a dose of 2.86 g/kg body weight, orally. Exercise consisted of running 15-60 min 5 days/week with gradually increasing intensity. AGE (P<0.01), Exercise, and Exercise+AGE (P<0.001) attenuated body weight gain and food efficiency ratio compared to HFD. Visceral fat and liver weight gain were attenuated (P<0.05) with all three interventions with a greater effect on visceral fat in the Exercise+AGE than AGE (P<0.001). In reducing visceral fat (P<0.001), epididymal fat (P<0.01) and liver weight (P<0.001), Exercise+AGE was effective, but exercise showed a stronger suppressive effect than AGE. Exercise+AGE showed further additive effects on reducing visceral fat and liver weight (P<0.001). AGE significantly attenuated the increase in total cholesterol and low-density lipoprotein-cholesterol compared with HFD (P<0.05). Exercise+AGE attenuated the increase in triglycerides compared with HFD (P<0.05). Exercise group significantly decrease in C-reactive protein (P<0.001). These results suggest that AGE supplementation and exercise alone have anti-obesity, cholesterol lowering, and anti-inflammatory effects, but the combined intervention is more effective in reducing weight gain and triglycerides levels than either intervention alone.

• Journal of Chest Surgery
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• 제31권2호
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• pp.208-211
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• 1998

반사성 교감신경 위축증은 과도하며 지속적인 통증, 혈관운동성 및 그 밖의 자율성 장애, 기능회복의 지연과 이영양성 변화를 특징으로 하는 중요한 임상양상이다. 이 증후군은 임상에서 자주 마주치는 문제중 하나일뿐더러 정확한 진단과 치료가 결정적이기 때문에 중요하다. 유발인자는 사고나 수술, 또는 다양한 질환이 될 수 있다. 정확한 진단과 치료는 증상의 빠른 소실과 완전한 회복을 기대할 수 있다. 56세 남자환자로 1996년 5월 좌측 제2수지 원위관절부 완전절단상을 입었고, 고대부속병원 재건성형외과에서 응급으로 재접합술을 시행받았다. 그 후, 좌측 제 2수지의 경감되지 않는 지속적인 통증과 좌측상지 근위부로 퍼져가는 통증 및 좌측 견갑부 운동장애를 호소해 왔다. 많은 치료법이 사용되었지만 효과적이지는 못하였다. 그리하여 좌측 흉부 교감신경절제술을 본 과에서 시행하였다. 이 후 성공적으로 통증이 완화되었고, 견갑부 운동상태도 향상되었기에 문헌고찰과 함께보고하는 바이다.