• Applied Microscopy
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• v.31 no.2
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• pp.175-184
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• 2001

This study aims demonstrate the effect of chitosan, one of the natural chelator, on the ultrastructural changes in the mouse liver caused by $HgCl_2$. The experimental group was divided in two groups; group A and group B. The group A administrated $HgCl_2$ (5.0 mg/kg) to the oral. The group B treated with $HgCl_2$ (5.0 mg/kg) and chitosan (3%) solution, 2 times/day). Each group was observed 24, 48, 72 and 96 hours after treated $HgCl_2$ and chitosan. Histological changes of the livers were investigated by electron microscope. 1. Croup A Nuclear membrane was shrinked. The inner and outer membrane of the mitochondria were dilated. Destruction of lamellae of rough endoplasmic reticulum showed. Smooth endoplasmic reticulum showed over cytoplasm. 2. Group B Nuclear membrane was more rounded, The cristae of the mitochondria were almost normal shape and electron-density showed compacted. Dilation of inner cavity of rough endoplasmic reticulum showed at the pre-time but formed typical lamellae at the 48Hrs. Smooth endoplasmic reticulum showed over cytoplasm. Therefore, we concluded that chitosan has significantly protective effects in liver to harmful $HgCl_2$.

• The Korean Journal of Nuclear Medicine
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• v.26 no.2
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• pp.380-391
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• 1992

This study was designed to evaluate a direct method of $^{99m}Tc$ labeling using $\beta-mercaptoethanol$ as a reducing agent, and to investigate whether $^{99m}Tc$ labeled specific monoclonal antibody against carcinoembryonic antigen (CEA-92) can be used for the scintigraphic localization of human colon cancer xenograft. Purified CEA-92 IgG was fragmented into F $(ab')_2$ and then labeled with $^{99m}Tc$ by transchelation method using glucarate as a chelator. Labeling efficiency, immunological reactivity and in vitro stability of $^{99m}Tc$ CEA-92 F $(ab')_2$ were measured and then injected intravenously into nude mice bearing human colon cancer (SNU-C4). Scintigrams were obtained at 24 hour after injection. Then nude mice were sacrificed and the radioactivity was measured Labeling efficiency of injected $^{99m}Tc$ CEA-92 F $(ab')_2$, immunoreative fraction and in vitro stability at 24 hour of injected $^{99m}Tc$ CEA-92 F $(ab')_2$ was 45.2%, 32.8% and 57.4%, respectively. At 24 hour after injection, % ID/g in kidney (46.77) showed high uptake, but %ID/g in tumor (1.65) was significantly higher than spleen (0.69), muscle (0.16), intestine (0.45), stomach (0.75), heart (0.48) and blood (0.45). There was no significant difference between tumor and liver (1.81). Tumor contrast as quantitated by tumor to blood ratio of $^{99m}Tc$ CEA-92 F $(ab')_2$ was increased significantly (p<0.005) until 24 hours (3.70), and there was no statistical differece from tumor to blood ratio of I-131 CEA-92 F $(ab')_2$. The scintigram demonstrated localization of radioactivity over transplanted tumor, but significant background radioactivity was also noted over kidney and abdomen. It is concluded that CEA-92 F $(ab')_2$ can be labeled with $^{99m}Tc$ by a direct transchelation method using $\beta-mercaptoethanol$ as a reducing agent and $^{99m}Tc$ labeled CEA-92 F $(ab')_2$ can be used for the scintigraphic localization of human colon cancer xenograft in nude mice model.

• Molecules and Cells
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• v.37 no.9
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• pp.656-663
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• 2014

Gintonin, a novel, ginseng-derived G protein-coupled lysophosphatidic acid (LPA) receptor ligand, elicits $[Ca^{2+}]_i$ transients in neuronal and non-neuronal cells via pertussis toxin-sensitive and pertussis toxin-insensitive G proteins. The slowly activating delayed rectifier $K^+$ ($I_{Ks}$) channel is a cardiac $K^+$ channel composed of KCNQ1 and KCNE1 subunits. The C terminus of the KCNQ1 channel protein has two calmodulin-binding sites that are involved in regulating $I_{Ks}$ channels. In this study, we investigated the molecular mechanisms of gintonin-mediated activation of human $I_{Ks}$ channel activity by expressing human $I_{Ks}$ channels in Xenopus oocytes. We found that gintonin enhances $I_{Ks}$ channel currents in concentration- and voltage-dependent manners. The $EC_{50}$ for the $I_{Ks}$ channel was $0.05{\pm}0.01{\mu}g/ml$. Gintonin-mediated activation 1 of the $I_{Ks}$ channels was blocked by an LPA1/3 receptor antagonist, an active phospholipase C inhibitor, an $IP_3$ receptor antagonist, and the calcium chelator BAPTA. Gintonin-mediated activation of both the $I_{Ks}$ channel was also blocked by the calmodulin (CaM) blocker calmidazolium. Mutations in the KCNQ1 $[Ca^{2+}]_i$/CaM-binding IQ motif sites (S373P, W392R, or R539W)blocked the action of gintonin on $I_{Ks}$ channel. However, gintonin had no effect on hERG $K^+$ channel activity. These results show that gintonin-mediated enhancement of $I_{Ks}$ channel currents is achieved through binding of the $[Ca^{2+}]_i$/CaM complex to the C terminus of KCNQ1 subunit.

• Journal of Life Science
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• v.11 no.6
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• pp.561-567
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• 2001

To isolate and purify fibrinolytic active substance from Sarcodon aspratus(N $H_4$)$_2$S $O_4$ precipitation, DE52 anion exchange column chromatography, Sephacryl-S 200gel filtration chromatography and Mono S cation FPLC were carried out and the characterizations of the purified enzyme were investigated. The bound active fraction on DE52 anion exchange column chromatography were eluted with 0.2 M NaCI and the fibrionlytic enzyme was purified after following Sephacryl-S200 gel fitration chromatography and Mono S cation EPLC. The specific activity of purified enzyme was 55.2 U/mg protein and increased 11.3 fold comparing crude extract and the yield was 49.5%. 12% SDS-PAGE electrophoresis and gel filtration chromatography revealed that Sarcodon aspratus fibrionloytic enzyme was highly purified and had 29.300 Da molecular weight. Enzyme activity of the purified fibrinolytic enzyme from Sarcodon aspratus was increased on higher pH and was stable until pH 10.5. On temperature dependent stability, the enzyme activity was decrease sharply but remained 25% relative activity on 8$0^{\circ}C$. This enzyme activity was inhibited by heavy metal ion, C $U^{2+}$ and $Co^{3+}$ with 68% and 38%, respectively. And also, the enzyme activity was inhibited with $Ca^{2+}$ chelator EDTA and serine protease inhibitor PMSF. These results from this study suggested that the fibrinolycit enzyme from Sarcodon aspratus is a serine protease and the enzyme activity was increased by $Ca^{2+}$ or $Mg^{2+}$ ion.n.ion.n.

• Journal of Veterinary Clinics
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• v.32 no.2
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• pp.135-140
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• 2015

Trans-10, cis-12-conjugated linoleic acid (t10c12-CLA) has been shown to participate in the regulation of anti-inflammatory effects. The objectives of this study were to examine the effects of t10c12-CLA on reactive oxygen species (ROS) and nitric oxide (NO) production and nuclear factor-kappaB (NF-${\kappa}B$) activation in lipopolysaccharide (LPS)-stimulated RAW 264.7 cells and to determine whether these effects were associated with change of intracellular calcium ion ($Ca^{2+}$). ROS production was increased in LPS-stimulated RAW 264.7 cells, and this effect was suppressed by 1,2-bis-(o-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid-acetoxymethyl ester (BAPTA/AM), a calcium chelator. t10c12-CLA suppressed ROS production in LPS-stimulated RAW 264.7 cells, which was further more decreased by treatment with BAPTA/AM. These indicated that t10c12-CLA decreases $Ca^{2+}$-dependent ROS production in LPS-stimulated RAW 264.7 cells. Similarly, NF-${\kappa}B$ p65 DNA binding activity and NO production were decreased by treatment with either t10c12-CLA, BAPTA/AM, or t10c12-CLA and BAPTA/AM combination. However, there were no differences between t10c12-CLA and BAPTA/AM treatment in NO production of LPS-stimulated RAW 264.7 cells. These data indicate that t10c12-CLA inhibits the increases in ROS and NO production and the NF-${\kappa}B$ activation in LPS-stimulated condition. These results suggested that CLA exerts potent anti-inflammatory effects by suppression of LPS-induced ROS and NO production, and NF-${\kappa}B$ activationn via $Ca^{2+}$-dependent pathway.

• 한국해양학회지
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• v.28 no.1
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• pp.52-68
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• 1993

Effects of iron and/or chelator addition on primary production in the equatorial Upwelling system were studied during the TOGA(Tropical oceans and Global Atmosphere) and EPOCS (Equatorial Pacific ocean Climate Studies) cruises in June and November-December of 1989. Changes in the phytoplankton biomass and the degree of iron stress were estimated using the changes in vivo fluorescence before and after the addition of DCMU, which is an inhibitor of photosynthetic electron transposer system. Nitrate uptake was measured using /SUP 45/N labeled KNO$_3$ to estimate the new production. When samples were taken from the Upwelling area where nitrate concentration was higher than 5 uM, there were significant differences between the control and cheated iron treatments in vivo fluorescence and in nitrate uptake capacity. However, CFC (Cellular fluorescence capacity) did not show any significant difference between the control and treatments until nutrient limitation becomes severse and cells become shifted-down. Outside of the Upwelling area where surface nitrate concentration was low (below 0.5 uM), there was no significant difference between the control and treatments in vivo fluorescence and CFC. It is evident that primary and new production in the equatorial Pacific Upwelling region are limited by the availability of iron. However, the physiology of phytoplankton indigenous to this region does not appear to be iron stressed judging from CFC values.

• Korean Journal of Food Science and Technology
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• v.47 no.4
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• pp.460-467
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• 2015

Sea urchin roe obtained from Anthocidaris crassispina and Pseudocentrotus depressus was briefly salt-fermented (5%), followed by ethanol treatment (1%) and the physicochemical properties as well as antioxidant activity were investigated. Compared to raw sea urchin roes, the salted one showed a significantly low amount of water (p<0.001) high salinity (p<0.05), ash content (p<0.001) and Na content (p<0.001). With salt-fermentation, the redness (p<0.05) and yellowness (p<0.001) of roe decreased noticeably, indicating the decomposition of endogenous carotenoids. Accordingly, the salted roe showed a lower DPPH radical scavenging activity than its unsalted counterpart. Additionally, it showed a significantly lower metal-chelating activity (p<0.05) and metal chelator content (e.g. ortho-phenolics) displayed by a negligible difference in titratable acidity. The salted roe showed significantly increased hardness (p<0.05) and total reducing capacity (p<0.001), which were attributed to the protein coagulation and the release of antioxidants bound to macromolecules after the ethanol treatment, respectively.

• Korean Journal of Clinical Laboratory Science
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• v.50 no.2
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• pp.205-210
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• 2018

Salvianolic acid B, which is a compound in the Salvia miltiorrhiza, has diverse biological activities, In particular, the antioxidative effects were reported to be involved in the protection of hepatocytes, neurons, and various cell types. On the other hand, some phenolic compounds, such as ferulic acid, which is regarded as an antioxidant, plays a pro-oxidative role in the specific transitional metal environment, which could explain the anticancer effect. This study examined the pro-oxidative effects of salvianolic acid B in the presence of $Cu^{2+}$. Treatment with both salvianolic acid B and $Cu^{2+}$ induced the transition of supercoiled DNA to the open circular or linear form but not in the sole salvianolic acid B or $Cu^{2+}$ treatments. Salvianolic acid B reduced the $Cu^{2+}$ to $Cu^+$ using neocuproine, a $Cu^+$ specific chelator. In addition, catalase, an enzyme that breaks down the $H_2O_2$ to water and molecular oxygen, inhibited the DNA breakage. $H_2O_2$, a reactive oxygen species, has detrimental effects on biological molecules, particularly DNA. Overall, the reduction of $Cu^{2+}$ by salvianolic acid B could lead to the production of $H_2O_2$ followed by DNA breakage. These results suggest that the pro-oxidative effects could be the one of the anti-cancer mechanisms of salvianolic acid B, which remains to be explained.

• Korean Journal of Food Science and Technology
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• v.27 no.1
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• pp.19-24
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• 1995

The effect of several inhibitors such as ascorbic acid on the lipoxygenase in soybeans known to catalyze reaction resulting in racid off-flavors was examined in the soybean homogenates by the oxygen electrode method. Among 8 compounds added at homogenizing process, 10 mM ascorbic acid inhibited lipoxygenase-1 and lipoxygenase-2/3 activities to 41.7 and 49.8%, respectively. Inactivation of lipoxygenase-2/3 was highly accelerated by homogenization for 15 min at room temperature, so the activity was inhibited 70.8% comparing with the homogenization of 3 min. When soybean homogenates with 10 mM ascorbic acid was stored at $25^{\circ}C$ for 72 hrs, lipoxygenase-2/3 activities lowered to 52.8% whereas L-1 activities lowered to 15.8%. Since it is reported that lipoxygenase-2 is responsible for the off-flavor of soybean products, the inhibitory effect of ascorbic acid among several inhibitors investigated might be useful in soybean processing.

• Journal of Radiation Protection and Research
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• v.22 no.4
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• pp.237-250
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• 1997

It has been reported that chitosan has little genetic toxicity as one of natural and nontoxic chelator and reduces the internal retention of radiostrontium in the mouse. This study is to examine that when water soluble chitosan is provided to the mouse on 17 days of pregnancy before and after radiostrontium contamination, how effectively it can inhibit an acute transfer of radiostrontium to fetus through placenta contaminated. Water soluble chitosan powder is mixed with general food for 60 days and 10%(Group 1) and 1%(Group 2) are provided respectively, and it is observed that the group with radiostrontium contamination on 17 days of pregnancy can inhibit more effectively the transfer of radiostrontium to fetus through placenta than control group with general food and the groups (Group 3, Group 4) with 10% and 1% of chitosan powder respectively after radiostrontium contamination (p<0.01, Table 1). It is found that when the pregnant mouse contaminated by radiostrontium on 17 days of pregnancy is prefed by chitosan, the transfer of radiostrontium to fetus through placenta can be inhibited.