• Journal of Nutrition and Health
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• 제45권4호
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• pp.347-361
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• 2012

Limited studies are available concerning the effect of heavy metal exposure on cardiovascular diseases. As environmental pollution increases, food contamination, including heavy metal contamination of fish, also increases. However, researches based on the intake of heavy metals, cardiovascular disease, and fish intakes are inconclusive. We assessed an association of heavy metal exposure with cardiovascular disease and fish intake in a nationally representative group of general Korean adults. We used data from the combined 2008-2010 Korean National Health and Nutrition Examination Survey (KNHANES), and analyzed the data of 5,139 Koreans who participated in KNHANES. All participants were older than 20 years, and were diagnosed with stroke, ischemic heart disease, or hypertension. The mean blood cadmium, lead concentration, and mercury concentration of subjects were $1.07{\pm}0.01{\mu}g/L$, $2.49{\pm}0.02{\mu}g/dL$, and $5.19{\pm}0.08{\mu}g/L$, respectively. We used the survey logistic regression model to account for the complex sample design of the cardiovascular disease risk in order to estimate the odds ratios (OR). After adjusting for age, education, income, alcohol, smoking, and BMI, the increase of serum cadmium in blood was associated with the increase in the prevalence of hypertension. Further, the increase in blood cadmium concentration was associated with the increase of both systolic blood pressure (SBP) and diastolic blood pressure (DBP). Although higher fish intakes were significantly associated with higher blood mercury concentration (p for trend < 0.0001), fish intakes did not affect either blood cadmium or lead concentration. Comparing the highest fish intake group with the lowest intake group, the OR of hypertension was 0.31 (95% CI: 0.19-0.59) in the crude model for total fish. However, these associations were no longer significant after the adjustment for potential confounding factors. In conclusion, cadmium in blood was associated with an increased risk of hypertension in the general Korean adult population. However, we found no evidence of a clear relationship between cardiovascular disease and frequency of fish consumption.

• Journal of Chest Surgery
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• 제31권5호
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• pp.531-535
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• 1998

국내에서 심장, 폐이식이 각 대학병원에서 점차 확산 시행되고는 있으나, 이에 따른 기초실험이 뒷받침되지 않고, 큰 동물에서는 많은 실험비용이 들어 보다 적은 동물을 이용하게 되었으나 이 방법은 현미경하의 미세수술기법의 발달과 더불어 발전하게 되었다. 본 연구는 현미경하의 미세수술기법으로 쥐모델에서 복부의 대동맥과 하공정맥에 다른 쥐의 공여심장의 대동맥과 폐동맥을 각각 문합술로 연결하는 방법으로 이식하여 동종이형의 장기이식에 따른 거부반응과 면역억제제를 투여하여 그에 따른 생존율을 비교하고자 하였다. 체중 150∼250 gm의 흰쥐의 심장을 공여 및 이식하는 바, 이소성의 심장이식후 면역억제제를 투여하지 않은 군과 면역억제제를 투여한 군으로 나누고, 각 군에서 복부에 이식된 심장의 박동을 매일 만져보고서 만져지지 않을 경우는 이식된 심장이 거부반응에 따른 것으로 판단하여 이의 생존율을 비교 검토하여본 바, 면역억제제를 투여하지 않은 군에서보다 투여한 군에서 오래 생존하여 동종이형의 이식에서 면역억제제를 투여하므로써 장기이식에 따른 장기성적을 향상시킴을 알 수 있었다.

• 대한한방내과학회지
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• 제29권3호
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• pp.629-640
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• 2008

Objective : The purpose of this study was to investigate the neuroprotective effect of Jukryuk on 4-vessel occlusion(4-VO) and middle cerebral artery (MCA) ischemia. Method : After administration of Jukryuk, we compared the Jukryuk-treated group, the control, and the sham groups, in view of several points as follows 1) We evaluated the damage characterized by coagulative cell change of pyramidal neurons and pronounced gliosis in each group 2) We counted the number of normal pyramidal shapes after ischemia in each group 3) Immunohistochemistry (cyclooxygenase-2) 4) In focal ischemic injury model, we measured the volume of ischemic area Results : In this experiment, the effect of Jukryuk was determined to be protecting neuron cell shape, reducing the number of neuron cells damaged by ischemia and the volume of the ischemic area. In immunohistochemistry, Jukryuk reduced cyclooxygenase-2 expression Conclusions : According to this study, Jukryuk can protect neuron cells from injury by cerebrovascular ischemia.

• Journal of Chest Surgery
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• 제55권1호
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• pp.10-19
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• 2022

Background: According to the eighth TNM (tumor-node-metastasis) staging system, the presence of separate tumor nodules in the same lobe is designated as a T3 descriptor. However, it remains unclear whether adjuvant chemotherapy confers survival advantages in this setting. Methods: We retrospectively identified 142 pathologic T3N0M0 patients with additional pulmonary nodules in the same lobe from a single-institutional database from 2004 to 2019. The main outcomes were overall survival and recurrence-free survival. Multivariable Cox regression was used to identify the benefit of adjuvant chemotherapy while adjusting for other variables. Results: Sixty-one patients received adjuvant chemotherapy (adjuvant group) and 81 patients did not receive adjuvant therapy after surgery (surgery-only group). There were no demonstrable differences between the 2 groups regarding hospital mortality and postoperative complications, indicating that treatment selection had not significantly occurred. However, the use of adjuvant chemotherapy was associated with improved 5-year overall survival (70% vs. 59%, p=0.006) and disease-free survival (60% vs. 46%, p=0.040). A multivariable Cox model demonstrated that adjuvant chemotherapy was associated with a survival advantage (adjusted hazard ratio, 0.54; p<0.001). In exploratory analyses of subgroups, the effect of adjuvant chemotherapy seemed to be insufficient in those with small main tumors (<4 cm). Conclusion: Adjuvant chemotherapy was associated with better survival in T3 cancers with an additional tumor nodule in the same lobe. However, the role of adjuvant chemotherapy in patient subgroups with small tumors or those without risk factors should be determined via large studies.

• 대한의용생체공학회:학술대회논문집
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• 대한의용생체공학회 1997년도 춘계학술대회
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• pp.165-170
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• 1997

In this paper, we consider the aortic sinus baroreceptor, which is the most representative baroreceptors sensing the variance of pressure in the cardiovascular system(CVS), and propose heart activity control model to observe the effect of delay time in heart period and stroke volume under the regulation of baroreflex in arotic sinus. The proposed heart activity baroreflex regulation model contains CVS electric circuit sub-model, baroreflex regulation sub-model and time delay sub-model. In these models, applied electric circuit sub-model is researched by B.C.Choi and the baroreflex regulation sub-model transforms the input, the arotic pressure of CVS electric circuit sub-model, to outputs, heart period and stroke volume by mathematical nonlinear feedback. We constituted the time delay sub-model to observe sensitivity of heart activity baroreflex regulation model by using the variable value to represent the control signal transmission time from the output of baroreflex regulation model to efferent nerve through central nervous system. The simulation object of this model is to observe variability of the CVS by variable value in time delay sub-model. As simulation results, we observe three patterns of CVS variability by the time delay. First, if the time delay is over 2.5 sec, arotic pressure, stroke volume and heart rate is observed nonperiodically and irregularly. Second, if the time delay is from between 0.1 sec and 0.25 sec, the regular oscillation is observed. Finally, if time delay is under 0.1 sec, then heart rate and arotic pressure-heart rate trajectory is maintained in stable state.

• 대한의용생체공학회:의공학회지
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• 제16권4호
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• pp.415-424
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• 1995

Combined models, specified by two or more modeling formalisms, can represent a wide variety of complex systems. This paper describes a methodology for the development of combined models in two model types of discrete event and continuous process. The methodology is based on transformation of continuous state space into discrete one to homomorphically represent dynamics of continuous processes in discrete events. This paper proposes a formal structure which can combine model of the DES and the CS within a framework. The structure employs the DEVS formalism for the DES models and differential or polynomial equations for the CS models. To employ the proposed structure to specify a DEVS/CS combined model, a modeler needs to take the following steps. First, a modeler should identify events in the CS and transform the states of the CS into the DES. Second, a modular employs the formalism to specify the system as the DES. Finally, a moduler developes sub-models for the CS and continguos states of the DES and establishs one-to-one correspondence between the sub-models and such states. The proposed formal structre has been applied to develop a DEVS/CS combined model for the human cardiovascular system. For this, the cardiac cycle is partitioned into a set of phases based on events identified through observation. For each phase, a CS model has been developed and associated with the phase. To validate the DEVS/CS combined model developed, then simulate the model in the DEVSIM + + environment, which is a model simulation results with the results obtained from the CS model simulation using SPICE. The comparison shows that the DEVS/CS combined model adequately represents dynamics of the human heart system at each phase of cardiac cycle.

• 약학회지
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• 제45권6호
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• pp.739-745
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• 2001

Of all pesticides, carbamates are known to be most common, since alternatives such as organophosphates have long lifetime and are extremely toxic to produce a delayed neurotoxic effect. Although a number of studies about toxicity of carbofuran, a most widely used carbamate, have been reported, its cardiovascular toxicity has not yet been studied. In the present study, we investigated its cardiovascular toxic effect in anesthetized rat in vivo and in isolated Langendorff rat heart, In anesthetized rat model, carbofuran (10 mg/kg) significantly reduced heart rate, and transiently increased blood pressure. In isolated rat heart, carbofuran (10${\mu}{\textrm}{m}$) caused a significant depression in the left ventricular developed pressure (LVDP), indicating contractile dysfunction by carbofuran. Carbofuran (10${\mu}{\textrm}{m}$) also decreased coronary flow rate (CFR) in isolated heart, indicating carbofuran-induced coronary dysfunction. These results suggest that carbofuran can cause cardiac dysfunction in rat in vivo and vitro.

• 한국정밀공학회지
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• 제25권1호
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• pp.151-159
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• 2008

The parameter-based cardiovascular impedance simulator that is able to overcome the limits of conventional mock circulatory systems is critical for the development and test of biomedical devices including artificial heart. The concept of impedance simulator was validated mathematically in a previous study using high-gain feedback linearization control which, however, may cause serious difficulties and limits for practical implementation. In this study, therefore, practical applicability of the impedance simulator is investigated considering the physical limits such as motor speed and torque. Simple PID controller which do not require complex model of the simulator is used considering the practical implementation. Design guidelines of the impedance simulator are also provided based on the results.

• Journal of Chest Surgery
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• 제44권2호
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• pp.89-98
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• 2011

Background: Although considerable efforts have been made to improve the graft patency in coronary artery bypass surgery, the role of biomechanical factors remains underrecognized. The aim of this study is to investigate the influences of geometric configurations of the bypass graft on hemodynamic characteristics in relation to anastomosis. Materials and Methods: The Numerical analysis focuses on understanding the flow patterns for different values of inlet and distal diameters and graft angles. The Blood flow field is treated as a two-dimensional incompressible laminar flow. A finite volume method is adopted for discretization of the governing equations. The Carreau model is employed as a constitutive equation for blood. In an attempt to obtain the optimal aorto-coronary bypass conditions, the blood flow characteristics are analyzed using in vitro models of the end-to-side anastomotic angles of $45^{\circ}$, $60^{\circ}$ and $90^{\circ}$. To find the optimal graft configurations, the mass flow rates at the outlets of the four models are compared quantitatively. Results: This study finds that Model 3, whose bypass diameter is the same as the inlet diameter of the stenosed coronary artery, delivers the largest amount of blood and the least pressure drop along the arteries. Conclusion: Biomechanical factors are speculated to contribute to the graft patency in coronary artery bypass grafting.

• 대한한의학회지
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• 제29권5호
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• pp.52-66
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• 2008

Objectives :Ginkgo-Chunghyul-dan (GCHD) is newly developed herbal medicine to prevent and treat stroke. In this study, we investigated whether the GCHD had antioxidant activity and anti-platelet aggregation effect in vitro and hypolipidemic activities in vivo. Methods :Anti-oxidant activity of GCHD was measured using the Blois method, anti-platelet effect of GCHD was assessed by the Born method, and hypolipidemic activities of GCHD were evaluated in corn oil- or Triton WR-1339-induced and cholesterol-fed rats. Results :GCHD showed anti-oxidant activity in the study inhibiting the formation of 1-diphenyl-2-picrylhydrazyl radicals and xanthine oxidase activity. GCHD had anti-platelet aggregation activity. GCHD significantly lowered total cholesterol (TC), triglyceride (TG), and low density lipoprotein cholesterol (LDL-C) in high cholesterol diet and Triton WR-1339 induced model TG in corn oil-induced model. GCHD had no acute toxicity at a single dosage. Conclusion : These results suggest that GCHD has the potential to treat hyperlipidemia and stroke.