• Journal of Sensor Science and Technology
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• v.25 no.6
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• pp.435-439
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• 2016

We report a novel detection technology for glycated hemoglobin (HbA1c) that is measured primarily to identify the three-month average plasma glucose concentration. In enzymatic measuring of glycated hemoglobin, the generated hydrogen peroxide was then used as a reducing agent of gold (III) for the synthesis of gold (0). Gold nanoparticles obtained from this novel approach were measured by optical and piezoelectric methods. In optical method, we have developed polymer based film-type sensor cartridge filled with all the reagents for glycated hemoglobin analysis and the cartridge worked very well having the detection limit of 0.53% of glycated hemoglobin. On the other hand, quartz crystal microbalance (QCM) sensors also have been developed to determine the abilities of surface modified QCM sensors at various levels of the concentration of glycated hemoglobin to bind gold nanoparticles and limit of detection was 0.90%. Finally, despite of relatively lower sensitivities of QCM sensor and film-type optical sensor than well-plate based optical detection, these two sensors were available to measure the glycated hemoglobin level for diabetes patients and normal person.

• 한국생물공학회:학술대회논문집
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• 2000.11a
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• pp.52-55
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• 2000

Structually organized mono- and multilayers were developed on gold for the catalytic and affinity biosensing using hyper-branched dendrimers. For the catalytic biosensing interface, a new approach to construct a multilayered enzyme film on the electrode surface was developed. The film was prepared by layer-by-layer depositions of dendrimers and periodate-oxidized glucose oxidase. The voltammograms obtained from the GOx/dendrimer multilayered electrodes revealed that bioelectrocatalytic response is directly correlated to the number of deposited bilayers. From the analysis of voltammetric and ellipsometric signals, the coverage of active enzyme per layer during the layering steps was estimated, demonstrating the spatially-ordered multilayer formation. As an extension of the study, dendrimers having various degrees of ferrocenyl modification were prepared and used. The resulting electrodes were electrochemically characterized, and the density of ferrocenyl groups, active enzyme coverage, and sensitivity were estimated. For the affinity-sensing surrface, a biosensor system based on avidin-biotin interaction was developed. As the building block of affinity monolayer, G4 dendrimer having partial ferrocenyl-tethered surface groups was prepared and used. And the biotinylated and electroactive dendritic monolayer was used for the affinity-sensing surface interacting with avidin. Electrochemical characterization of the resulting biosensor was conducted using free enzyme in electrolyte in terms of degree of surface coverage with avidin and subsequent surface shielding.

• Preventive Nutrition and Food Science
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• v.17 no.2
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• pp.129-135
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• 2012

GPAR{elidium (G.) amansii is a red alga widely distributed in the shallow waters around East Asian countries. We investigated the effect of G. amansii on lipid accumulation and ROS (Reactive Oxygen Species) production in 3T3-L1 cells. G. amansii extracts dose-dependently inhibited lipid formation and ROS generation in cultured cells. Our results showed that anti-adipogenic effect of G. amansii was due to the reduction in mRNA expressions of PPAR${\gamma}$(peroxisome proliferator-activated receptor-${\gamma}$) and aP2 (adipocyte protein 2). G. amansii extracts significantly decreased mRNA levels of a ROS-generator, NOX4 (nicotinamide adenine dinucleotide phosphate hydrogen oxidase 4), and increased the protein levels of antioxidant enzymes including SOD1/2 (superoxide dismutases), Gpx (glutathione peroxidase), and GR (glutathione reductase), which can lead to the reduction of ROS in the cell. In addition, the G. amansii extract enhanced mRNA levels of adiponectin, one of the adipokines secreted from adipocytes, and GLUT4, glucose uptake protein. Taken together, our study shows that G. amansii extract inhibited lipid accumulation and ROS production by controlling adipogenic signals and ROS regulating genes.

• Toxicological Research
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• v.14 no.4
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• pp.541-545
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• 1998

This experiment carried out to compare the protective effects of some antioxidants to hydroxyl radicals in embryonic mouse whole brain tissue culture. The ICR mouse whole brain (13 embryonic day) was cultured in hydroxyl radical system in which radicals were generated by 20 mU / ml glucose oxidase (GO). In this experiment, to make ferrous iron from ferric iron, iron as an accelerator, and ascorbic acid as a reductant were used. For comparison of the protective effects to hydroxyl radicals, antioxidants such as desferrioxamine (DFX), laccase. water or ethanol extracts from Rhus Vemiciflua Stokes (RVS), and $\alpha$-tocopherol were used, because they relate to metal ion. The results of this experiment showed that all antioxidants protected effectively the cytotoxicity from hydroxyl radicals in the brain cultures. More than 70% of cell viabilities among different antioxidants was at 1 mM DFX, 1.43 $\mu\textrm{m}$ laccase, 12.5 $\mu\textrm{m}$ water extract, 12.5 $\mu\textrm{m}$ ethanol extract and 50 $\mu\textrm{m}$ $\alpha$-tocopherol individually, compared with 20 mU/ml GO alone. In comparison to the antioxidative activities of antioxidants, laccase and extracts from RVS showed strong antioxidative effects even at low concentration.

• Journal of the Korean Society of Food Science and Nutrition
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• v.29 no.2
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• pp.268-273
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• 2000

To investigate an effect of the ethanol extract of Lycium chinense(EELC) on the activities of enzymes scavenging oxygen free radicals or detoxicating alcohol. The ground Lycium chinense was extracted with 30% edible ethanol and then diluted with 6% ethanol to contain 2% EELC(w/v). Three different groups of male Sprague-Dawley rats had taken a drink EELC, ethanol(ETH) or water(control), respectively for 2 months. At the end of experimental period, the animals were sacrificed and obtained the following findings. The EELC-treated animals showed the highest activity of hepatic glucose-6-phosphatase among three groups. The activities of xanthine oxidase and cytochrome p-450 from EELC treatment group were lower than those from ETH-treated group. However, the activity of superoxide dismutase was higher in the EELC-treated group than the ETH-treated(p<0.005). Furthermore, hepatic alcohol or aldehyde dehydrogenase activity, and glutathione content and glutathione peroxidase were significantly higher in EELC-treated animals than in ETH-treated those. The activity of glutathione S-transferase in liver was appeared the orderly higher value in EELC, ETH and control-treated group. As the result, EELC may affect the reduction of oxygen free radical production and help the detoxication of ethanol.

• Journal of the Korean Society of Food Culture
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• v.34 no.4
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• pp.456-462
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• 2019

This study investigated the bread-making properties of rice bread supplemented with HPMC (hydroxypropyl methylcellulose) 1~3% and gluzyme (glucose oxidase), fungamyl (fungal ${\alpha}$-amylase) and pentopan (xylanase+hemicellulases) (0.0015~0.0090%). The viscoelastic properties of the dough with HPMC 1~3% were analyzed. When the rice flour was supplemented with HPMC 1~3%, the viscoelastic properties of the dough tended to increase as the amount of added HPMC was increased. The physicochemical characteristics of the rice bread with HPMC, gluzyme, fungamyl, and pentopan were analyzed. Supplementing the rice flour with HPMC, gluzyme, fungamyl, and pentopan had a significant effect on the volume (p<0.01) and specific volume (p<0.001) of the rice bread. Supplementing the rice flour with 3% HPMC and 0.0045% or 0.0090% pentopan had a significant effect on increasing the volume (p<0.01) and specific volume (p<0.001) of the rice bread. Supplementing the rice flour with 3% HPMC, 0.0023% gluzyme and 0.0015% fungamyl had a significant effect on increasing the volume (p<0.01) and specific volume (p<0.001) of the rice bread. These results suggest that supplementing the rice flour with HPMC, gluzyme, fungamyl and pentopan is effective for the production of rice bread.

• The Korean Journal of Physiology
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• v.17 no.2
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• pp.125-133
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• 1983

Red cell glycolytic intermediates, metabolites and metabolic ratios were studied. Glycolytic intermediates were measured in neutralized perchloric acid extracts of red cell suspensions after 3 hr incubation at $37^{\circ}C$ in the presence and absence of saponin. Adenosine triphosphate(ATP), adenosine diphosphate(ADP), pyruvate and lactate were measured by enzymatic procedures involving stoichiometric oxidation or reduction of a pyridine nucleotide. Glucose was determined using glucose oxidase after zinc hydroxide extraction. The redox state was calculated from the lactate dehydrogenase equilibrium. Adenosine triphosphatase activity(ATPase) was measured by determining the amount of phosphate released from ATP by washed erythrocyte membranes(ghost) during 20 min. incubation. Both total hydrolysis and the amount of hydrolysis that occured in the presence of ouabain were measured. The second measurement yields Mg-ATPase and represents nonspecific ATPase activity of the membranes. The difference between total and Mg-ATPase activity can be attributed to Na-K-ATPase. For the measurement of sodium fluxes, human erythrocytes were preincubated in $^{22}Na$ for 3 hr at $37^{\circ}C$, washed and suspended in a tracer-free medium. The amount of $^{22}Na$ transported out of cells at any time was determined by analysis of supernatant samples taken at various time after addition of the labeled cells to isotope-free medium. The cells and medium were separated and the radioactivity appearing in the medium was measured. From the total radioactivity in the suspension and the radioactivity appearing in the medium at known time, the rate constant for sodium release was computed. The results are summarized as follows: 1) ATP and ATP/ADP were found to increase at every concentration of saponin tested whereas ADP declined at every cone. of saponin. The increase in pyruvate and lactate were observed at every cone, of saponin and thus $NAD^+/NADH$ computed from pyruvate/lactate also increased. Glucose utilization was stimulated by saponin. 2) $Na^+-K^+-ATPase$ activities showed a biphasic response to saponin, first increasing in lower concentration and then decreasing in higher concentration of saponin. 3) The efflux of sodium was significantly increased by saponin in the range of 5 to 10 mg%. The stimulatory effect of saponin on the rate constants for active(ouabain-sensitive) sodium efflux was inhibited by addition of ouabain.

• Journal of the Korean Society of Food Science and Nutrition
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• v.40 no.2
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• pp.321-326
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• 2011

The aim of the present study was to investigate antihyperglycemic effect of Gleditschiae Spina (GS) in streptozotocin (STZ)-nicotinamide (NA)-induced type 2 diabetic rats. The rats were divided into four groups: normal control (NC), diabetic control (DC), diabetic rats supplemented with acarbose (AC, 4 mg/kg), and with GS ethanol extracts (GSE, 50 mg/kg). Weekly fasting blood glucose (FBG) for 10 weeks and oral glucose tolerance test (OGTT) at 10th week were monitored using glucose oxidase-peroxidase reactive strips. The FBG level was significantly reduced in AC group after 8 weeks and in GSE group at the end of period. The AUCs for the glucose response from OGTT and blood glucose level after sacrifice were significantly lower in the AC and GSE groups than the DC group. GSE supplementation significantly increased plasma total radical-trapping antioxidant potential (TRAP) in STZ-NA-induced diabetic rats, compared with DC group. The present study indicates that GSE could ameliorate type 2 diabetes and be comparable to acarbose, a standard hypoglycemic drug. Also, we suggest that GSE may possess antioxidant activity against the STZ-NA-induced oxidative stress.

• Journal of Korean Society of Forest Science
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• v.101 no.3
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• pp.517-525
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• 2012

In this study, a 4-year-old mountain ginseng was mixed and ripened with 4-year-matured persimmon vinegar, and then it was diluted 5 times and orally administerd to rats. Afterwards, by analyzing the protein expression rate which affects both the carbohydrate metabolism and the lipid metabolism, this study examined the anti-obesity effect of the fusion material. The rats were divided into a control group (CON), a persimmon vinegar group (PV) and a mountain ginseng+persimmon vinegar fusion material group (MPV). The weight gain rate was found to be low in PV and MPV, and the concentration of glucose was also low in PV and MPV. However, GLUT-2 was found to be significantly high in these two groups on the contrary. Both the concentration of free fatty acid and CPT-1 protein expression rate were high in PV and MVP, but MVP was higher than PV. Cytochrome C oxidase was found to be higher in MPV than in CON. AMPK, $PPAR-{\gamma}$ and $PGC1-{\alpha}$ were all high in PV and MPV, but MPV was higher than PV. All the results above verified the thermogenesis effect of the fusion material, leading to an increase of energy metabolism, and it was thought that the fusion material could be effectively used for anti-obesity. However, it seems necessary to verify the anti-obesity effect through various further studies.

• Journal of Nutrition and Health
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• v.36 no.2
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• pp.117-124
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• 2003

This study was designed to test the effect of Korean traditional tea materials on oxygen-free radical metabolism in lead (Pb) -administered rats. Male rats were divided into normal, Pb-control (Pb-Con) and Pb-water extract of green tea (Camellia sinensis; GT) , persimmon leaf (Diospyros kaki; PL) , safflower seed (Carhamus tinctorius: SS) , Du-Zhong (Eucommia ulmoides; EU) groups, respectively. Pb intoxication was induced by administration of lead acetate (25 mg/kg. B.W., oral) weekly. The extract was administered based on 1.26 g of raw material/kg B.W./day for 4 weeks. When the GT, PL, SS and EU were supplemented to the Pb-administered rats, hepatic lipid peroxide levels were significantly lower compared to the Pb-Con group. Hepatic cytochrom P-450 content and aminopyrine N-demethylase activity was lower in the Pb-Con group than in the normal group, whereas xanthine oxidase activity was significantly elevated in Pb-administered rats. The water extract of GT, PL, SS and EU supplementation attenuated changes in enzyme activities generating reactive oxygen species in the liver. Hepatic superoxide dismutase, catalase and glucose 6-phosphate dehydrogenase activities were significantly higher in the Pb-Con group than in the normal group, while monoamine oxidase activity also tended to increase in the Pb-administered rats. However, glutathione peroxidase and glutathione S-transferase activities, and glutathione content significantly decreased through Pb intoxication. The supplementation of GT, PL, SS and EU induced alleviation changes of hepatic antioxidant enzyme activity.