• Korean Chemical Engineering Research
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• v.49 no.2
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• pp.238-243
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• 2011

In this study, we attempted a structural analysis in order to design a balloon type extracorporeal membrane oxygenator that can induce blood flow without using blood pumps for the purpose of complementing the weakness in the existing extracorporeal membrane oxygenator. To analyze the flow characteristic of the blood flow within the virtual model of extracorporeal membrane oxygenator, computational fluid dynamics(CFD) modeling method was used. The operating principle of this system is to make the surface of the extracorporeal membrane oxygenator keep contracting and dilating regularly by applying pressure load using a balloon, and the 'ime Function Value'that changes according to the time was applied by calculating a half cycle of sine waveform and a cycle of sine.waveform Under the assumption that the uni-directional blood flow could be induced if the balloon type extracorporeal membrane oxygenator was designed as per the method described above, we conducted a structural analysis accordingly. We measured and analyzed the velocity and pressure of blood flow at both inlet and outlet of the extracorporeal membrane oxygenator through CFD simulation. As a result of the modeling, it was confirmed that there was a flow in accord with the direction of the blood by the contraction/dilation. With CFD simulation, the characteristics of blood flow can be predicted in advance, so it is judged that this will be able to provide the most optimized design in producing an extracorporeal membrane oxygenator.

• Journal of the Korean Society of Food Science and Nutrition
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• v.41 no.1
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• pp.73-78
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• 2012

Excessive intake of trans fats is known to be a risk factor for cardiovascular diseases. Previously, we have shown that green tea extract (GTE) lowers the intestinal absorption of lipids and lipid-soluble compounds in rats. This study was conducted to investigate a possible role of GTE on the lymphatic absorption of elaidic acid, a major trans fat in the diet. Adult male Sprague-Dawley rats with lymph duct cannula were infused via an intraduodenal catheter at 3.0 mL/hr for 8 hr with a lipid emulsion containing $180.0{\mu}mol$ elaidic acid, $400.0{\mu}mol$ triolein, $20.7{\mu}mol$ cholesterol, $3.1{\mu}mol$ ${\alpha}$-tocopherol, and $396.0{\mu}mol$ sodium-taurocholate with or without (control) GTE in a 24 mL PBS buffer (pH, 6.4). Simultaneously, lymph was collected hourly for 8 hr via the lymph duct cannula. There was a significant difference in lymph flow by GTE. Also, the lymphatic absorption of elaidic acid for 8 hr was significantly lower in rats infused with GTE than in those not infused with GTE. Similarly, GTE infusion decreased the lymphatic outputs of cholesterol, oleic acid, and phospholipids, compared with the controls. These findings provide clear evidence that GTE has an inhibitory effect on the intestinal absorption of elaidic acid and other lipids. Our work here provides the foundation for further studies to examine and evaluate dietary strategies to ameliorate dietary trans fats from the diet.

• Journal of Physiology & Pathology in Korean Medicine
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• v.26 no.3
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• pp.399-407
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• 2012

To evaluate age and gender differences in the relation of cardiovascular risk factors, cognitive impairment, and subclinical carotid atherosclerosis from aged people using by a cross sectional method. Sixty-nine healthy elders living in the community who had not previously undergone carotid ultrasonography were included. We conducted life style surveys, and cognitive function tests including Korean-mini-mental state examination (K-MMSE) and clinical dementia rating-Korean. Various biomarkers from blood were assessed; fasting insulin-like growth factor-1, lipid-profile, high sensitivity C-reactive protein, total homocysteine, glucose, insulin, Homeostasis model assessment (HOMA) for insulin resistance index, vitamin B12, and folate level. Carotid intima-media thickness (C-IMT), and plaques were measured using carotid ultrasonography and aortic ultrasonography, a valid index of atherosclerosis. For the elderly subjects (aged 65-82 years), cognition impairment was more prevalent in females while subclinical atherosclerosis was more prevalentin males. Increased C-IMT has been kept in males, and C-IMT shows increasing trend and the peak at about 80 year-old in females with increasing age. The significant correlations between C-IMT and many vascular risk factors including age, triglyceride, abnormal homocysteinein male, and K-MMSE, insulin, HOMA index and abnormal aortic ultrasonography in female were different in each gender, with the exception of homocysteine (p<0.05). This data suggests that there were differences of age and gender characteristics in terms of subclinical atherosclerosis, cognitive impairment and vascular risk factors in community-living elders. Further larger and longitudinal studies across entire age are required to better understand the effects of risk factors on subclinical atherosclerosis.

• Molecules and Cells
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• v.43 no.4
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• pp.408-418
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• 2020

The sinus node (SN) is located at the apex of the cardiac conduction system, and SN dysfunction (SND)-characterized by electrical remodeling-is generally attributed to idiopathic fibrosis or ischemic injuries in the SN. SND is associated with increased risk of cardiovascular disorders, including syncope, heart failure, and atrial arrhythmias, particularly atrial fibrillation. One of the histological SND hallmarks is degenerative atrial remodeling that is associated with conduction abnormalities and increased right atrial refractoriness. Although SND is frequently accompanied by increased fibrosis in the right atrium (RA), its molecular basis still remains elusive. Therefore, we investigated whether SND can induce significant molecular changes that account for the structural remodeling of RA. Towards this, we employed a rabbit model of experimental SND, and then compared the genome-wide RNA expression profiles in RA between SND-induced rabbits and sham-operated controls to identify the differentially expressed transcripts. The accompanying gene enrichment analysis revealed extensive pro-fibrotic changes within 7 days after the SN ablation, including activation of transforming growth factor-β (TGF-β) signaling and alterations in the levels of extracellular matrix components and their regulators. Importantly, our findings suggest that periostin, a matricellular factor that regulates the development of cardiac tissue, might play a key role in mediating TGF-β-signaling-induced aberrant atrial remodeling. In conclusion, the present study provides valuable information regarding the molecular signatures underlying SND-induced atrial remodeling, and indicates that periostin can be potentially used in the diagnosis of fibroproliferative cardiac dysfunctions.

• Korean Journal of Plant Resources
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• v.29 no.5
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• pp.532-538
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• 2016

Menopause is characterized by a decrease in estrogen production by the ovaries. Furthermore, the risk of developing chronic diseases including cardiovascular disease, obesity, and diabetes increases in menopausal women. In this study, we evaluated the ability of Caragana sinica (CS) to affect lipid and glucose metabolism in an ovariectomized Sprague-Dawley rat model of induced menopause. The animals were divwided randomly into three groups: sham-operated rats (SHAM), ovariectomized rats (OVX), and ovariectomized rats treated with 1% water extract of CS (OVX-CS). The OVX-CS treated mice showed a significant decrease in body weight, adipose tissue, triglyceride, and total cholesterol. Improved lipid and glucose profiles were also observed, and were attributed to suppression of hepatic lipogenesis and adipokine production and regulation of glucose-regulating enzyme activity. Therefore, these findings indicate a potential use for CS as a functional food for menopause-induced hyperlipidemia and hyperglycemia.

• Health Policy and Management
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• v.26 no.2
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• pp.125-134
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• 2016

Background: Glycemic control is an effective way to reduce the cardiovascular complications of diabetes, but more than half of the adults with diabetes in Korea are improperly controlling their glycemic levels. The purpose of this study is to identify the factors associated with poor glycemic control in type 2 diabetes patients. Methods: This study analyzed 1,261 subjects ${\geq}30years$ old diagnosed with type 2 diabetes who participated in the fifth Korean National Health and Nutrition Examination Survey (2010-2012). Poor glycemic control rates were defined as hemoglobin A1c (HbA1c) level ${\geq}7%$. To shed light on the causes of poor glycemic control, socio-demographics, diabetes severity, health status, and health behavior factors were adjusted and logistic regression was done. Results: Of the total 1,261 patients, 53.0% of patients with type 2 diabetes had HbA1c ${\geq}7%$. After running a logistic regression model, the odds ratio of poor glycemic control was higher in high school graduates than elementary school graduates; in people living in Chungcheong and Jeolla/Jeju than those living in Seoul; in the group with diabetes for over 5 years had diabetes less than 5 years; in a group with insulin and oral hypoglycemic agent treatment than non-treatment; in a group with hypertriglyceridemia than without hypertriglyceridemia; and in the group with slept less than 6 hours slept 7-8 hours. Conclusion: We need a comprehensive public health policy to reduce the poor glycemic control rates in type 2 diabetes patients. We should recognize the education levels, duration of diabetes, diabetes treatment, hypertriglyceridemia, and sleep duration were associated with poor glycemic control.

• Journal of Chest Surgery
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• v.37 no.2
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• pp.113-118
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• 2004

The studies on cryopreserved arterial allograft have been focused on cooling methods, pre-treatment, cryoprotectant agents, and preservation temperature. But recently, several studies have reported that thawing methods also play an important role in the occurrence of macroscopic and microscopic cracks. This study was designed to investigate the cell injury after thawing, using a rabbit model to clarify the effect of thawing methods on cryopreserved arteries. Material and Method: Segments of the rabbit aorta were obtained and divided into 3 groups (n=60) according to whether the specimens were fresh (control, n=20), cryopreserved and rapidly thawed (RT) at 37$^{\circ}C$ (n=20), or cryopreserved and subjected to controlled, automated slow thawing (ST)(n=20). Cell damage was established using the TUNEL method and the morphological changes were also evaluated. Result: In the group that was rapidly thawed, the expression of TUNEL (＋) cells increased significantly more than in the slowly thawed group. In addition, the endothelial denudation, microvesicles and edema were significant in the rapidly thawed group compared with those changes in the slowly thawed group. Conclusion: Our study suggests that the rapid thawing method may be one of the major causes of cellular damage and delayed rupture in cryopresewed arterial allografts. The expression of TUNEL (＋) cells and structural changes were significantly low in the slowly thawed group, which might have contributed to the improvement of graft failure after transplantation.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.5
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• pp.2219-2231
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• 2012

This study conducted to investigate incidence rate and association of serum lipid profiles with incidence of ischemic heart disease. Study subjects consisted of 417,642 adults aged 30 years and over, who underwent physical examination and responded to questionnaire from health examination center of 19 university general hospitals. Hazard ratio of risk factor for ischemic heart disease (IHD) were calculated by Cox's proportional hazard regression model adjusted for ages, BMI and lifestyle (drinking, smoking and exercising). For TC/HDL ratio, hazard ratio of IHD in male increased from 1.21 times to 1.84 times increase with TC/HDL ratio, and that in female also increased from 1.26 times to 1.86 times. For TG/HDL ratio, hazard ratio of IHD in male increased from 1.17 times to 1.49 times increase with TG/HDL ratio, and that in female also increased from 1.42 times to 1.97 times. For LDL/HDL ratio, hazard ratio of IHD in male increased from 1.26 times to 1.82 times increase with LDL/HDL ratio, and that in female also increased from 1.26 times to 1.68 times. In conclusion serum lipid indexes are the significant risk factors for cardiovascular diseases. The higher the concentration of TC, LDL and TG is, the lower the concentration of HDL is, hazard ratio for IHD increased. Ratio of TC/HDL, TG/HDL and LDL/HDL were also verified to be significant risk factors for IHD.

• The Korean Journal of Food And Nutrition
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• v.31 no.3
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• pp.425-434
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• 2018

Metabolic syndrome is a risk factor for cardiovascular and type 2 diabetes. This study was conducted to examine the relevance between nutrition intake, meal quality, and high-sensitivity C-reactive protein in Koreans with metabolic syndrome. The 2,536 subjects, aged 19~64, who participated in 2015 National Nutrition Survey were included in this study. The 24-hour recall method was employed to analyze nutrition intake and dietary quality. Subjects were grouped into either the non-metabolic syndrome group (n=1,938) or the metabolic syndrome group (n=598). Total males and females were divided into 3 groups according to the high-sensitivity C-reactive protein (hs-CRP) level to study its relationship to metabolic syndrome and its components, including odds ratio (OR) and confidence interval (CI). Results showed the homeostasis model assessment of insulin resistance (HOMA-IR) value was higher in the metabolic syndrome group (3.37) than non-metabolic syndrome group (1.57) (p<0.001). In the Index of Nutrition Quality, males in the non-metabolic syndrome group showed higher niacin (p<0.05) than males in metabolic syndrome group. Females in the non-metabolic syndrome group had higher vitamin $B_1$ (p<0.01), vitamin $B_2$ (p<0.001), niacin (p<0.05), calcium (p<0.001), and phosphate (p<0.01). Female in the high hs-CRP group showed high OR in blood glucose component (OR 2.488, 95% CI: 1.269~4.879) and metabolic syndrome risk (OR 2.856, 95% CI: 1.292~6.314). Females in the middle hs-CRP group had high triglycerides component (OR 2.956, 95% CI: 1.920~4.551), compared to the low hs-CRP group. The study showed females with higher hs-CRP had a higher risk of metabolic syndrome.

• Archives of Pharmacal Research
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• v.25 no.5
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• pp.697-703
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• 2002

We investigated that the role of nitric oxide (NO) on ischemic rats in brain and heart. Ischemia was induced by both common carotid arteries (CCA) occlusion for 24h following reperfusion. Then tissue samples were removed and measured NOx. In brain, NOx was increased by about 40% vs. normal and it was significantly inhibited by aminoguanidine, selective iNOS inhibitor. This result showed that NOx concentration was increased by iNOS. We investigated the role of $Ca^{2+}$ during ischemia. Nimodipine, L-type calcium channel blocker, didn't inhibit the increases of NOx concentration during ischemia. It suggested that increased NOx was due to calcium-independent NOS. MK-801, which N-methyl-D-aspartate (NMDA) receptor antagonist, didn't significantly prevent the increases of NOx. In heart, ischemia caused NOx decrease and it is inconsistent with NOx increase in brain. Aminoguanidine and nimodipine didnt affect on NOx decrease. But MK-801 more lowered NOx concentration than those of ischemia control group. It seemed that $Ca^{2+}$ influx in heart partially occurred via NMDA receptor and inhibited by NMDA receptor antagonist. The mean arterial pressure (MAP) in ischemic rats after 24h of CCA occlusion was decreased when compared to normal value, whereas the heart rates (HR) was not different between two groups. Aminoguanidine or MK801 had no effect on MAP or HR, but nimodipine reduced MAP. There was no difference the effects of aminoguanidine, nimodipine, or MK-801, on MAP and HR between normal rats and ischemic rats. In summary, ischemic model caused an increase of NOx concentration, suggesting that this may be produced via iNOS, which is calcium independent in brain. However in heart, ischemia decreased NOx concentration and NMDA receptor was partially involved. The basal MAP was decreased in ischemic rats but HR was not different from normal control, suggesting that increased NOx in brain of ischemic rat may result in the hypotension.