• Journal of the Society of Disaster Information
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• v.14 no.1
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• pp.89-100
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• 2018

when the explosive wastes to be treated as designated wastes are brought into the wastes treatment plant by mistake and lead to an explosion in the wastes disposal process, many people and property damage are involved. Waste should be treated properly. As mentioned in this paper, ignition reac- tion tests of ignitable re-burning of explosives packing material waste (solid butadiene) confirmed that ignition was easily occurred, and that even small ignition sources were easily ignited and burned quickly and explosively. In particular, when explosives are loaded into incineration wastes in large quantities and mixed with organic compound wastes, such as fire and explosion accidents caused by explosives packing materials at waste disposal sites, flammable and oxidative gases are generated due to mutual oxidation and pyrolysis It is confirmed that there is a possibility that ignition sources such as spark ignite and instantaneously lead to explosion. It is hoped that this study will be a small reference for on - site detection in the field of fire, and it is expected that the fire - fighting agency will be recognized as a fire investigation agency and will contribute to the improvement of the credibility.

• Toxicological Research
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• v.33 no.1
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• pp.43-48
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• 2017

With ultraviolet and visible light exposure, some pharmaceutical substances applied systemically or topically may cause phototoxic skin irritation. The major factor in phototoxicity is the generation of reactive oxygen species (ROS) such as singlet oxygen and superoxide anion that cause oxidative damage to DNA, lipids and proteins. Thus, measuring the generation of ROS can predict the phototoxic potential of a given substance indirectly. For this reason, a standard ROS assay (ROS assay) was developed and validated and provides an alternative method for phototoxicity evaluation. However, negative substances are over-predicted by the assay. Except for ultraviolet A (UVA), other UV ranges are not a major factor in causing phototoxicity and may lead to incorrect labeling of some non-phototoxic substances as being phototoxic in the ROS assay when using a solar simulator. A UVA stimulator is also widely used to evaluate phototoxicity in various test substances. Consequently, we identified the applicability of a UVA simulator to the ROS assay for photoreactivity. In this study, we tested 60 pharmaceutical substances including 50 phototoxins and 10 non-phototoxins to predict their phototoxic potential via the ROS assay with a UVA simulator. Following the ROS protocol, all test substances were dissolved in dimethyl sulfoxide or sodium phosphate buffer. The final concentration of the test solutions in the reaction mixture was 20 to $200{\mu}M$. The exposure was with $2.0{\sim}2.2mW/cm^2$ irradiance and optimization for a relevant dose of UVA was performed. The generation of ROS was compared before and after UVA exposure and was measured by a microplate spectrophotometer. Sensitivity and specificity values were 85.7% and 100.0% respectively, and the accuracy was 88.1%. From this analysis, the ROS assay with a UVA simulator is suitable for testing the photoreactivity and estimating the phototoxic potential of various test pharmaceutical substances.

• Journal of Embryo Transfer
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• v.31 no.3
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• pp.299-305
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• 2016

Although cryopreservation of sperm is routinely used for clinical requirement, it has some problems, such as high generation of reactive oxygen species (ROS) and cold-shock. To reduce the detrimental damage in sperm, anti-oxidants were added to cryoprotectant for sperm. Curcumin is one of anti-oxidants, which are added in cryoprotectants. However, recent studies have demonstrated that curcumin decreases sperm viability and motility. This study was performed to identify the effect of curcumin on hydrogen peroxide ($H_2O_2$)-exposed bovine sperm, which were cryopreserved-thawed. In $H_2O_2$-exposed bovine sperm, reactive oxygen species (ROS) were significantly reduced by treatment with curcumin in a dose-dependent manner (p < 0.05). Among tested concentrations of curcumin (1 to $50{\mu}M$), 30 and $50{\mu}M$ curcumin showed anti-oxidant effect on $H_2O_2$-induced ROS generation. On the other hand, combination of 30 or $50{\mu}M$ curcumin with anti-oxidant $H_2O_2$ increased the percentage of apoptotic sperm compared to only $H_2O_2$ treatment. Sperm viability was also decreased in the combination of 30 or $50{\mu}M$ curcumin with $H_2O_2$ as judged by FDA/PI staining. $H_2O_2$-induced decrease in sperm progressive motility was recovered by treatment with $1{\mu}M$ curcumin. These results show that high concentration of curcumin has anti-oxidant effect, but it has also cytotoxic effect on bovine sperm. Sperm viability and motility might be more affected by cytotoxic signals of curcumin compared to antioxidant signals.

• Environmental Mutagens and Carcinogens
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• v.22 no.3
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• pp.142-148
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• 2002

Although ionizing radiation (IR) has been used to treat the various human cancers, IR is cytotoxic not only to cancer cells but to the adjacent normal tissue. Since normal tissue complications are the limiting factor of cancer radiotherapy, one of the major concerns of IR therapy is to maximize the cancer cell killing and to minimize the toxic side effects on the adjacent normal tissue. As an attempt to develop a method to monitor the degree of radiation exposure to normal tissues during radiotherapy, we investigated the transcriptional responses of human peripheral blood lymphocytes (PBL) following IR using cDNA microarray chip containing 1,221 (1.2 K) known genes. Since conventional radiotherapy is delivered at about 24 h intervals at 180 to 300 cGy/day, we analyzed the transcriptional responses ex-vivo irradiated human PBL at 200 cGy for 24 h-period. We observed and report on 1) a group of genes transiently induced early after IR at 2 h, 2) of genes induced after IR at 6 h, 3) of genes induced after IR at 24 h and on 4) a group of genes whose expression patters were not changed after IR. Since Biological consequences of IR involve generation of various reactive oxygen species (ROS) and thus oxidative stress induced by the ROS is known to damage normal tissues during radiotherapy, we further tested the temporal expression profiles of genes involved in ROS modulation by RT-PCR. Specific changes of 6 antioxidant genes were identified in irradiated PBL among 9 genes tested. Our results suggest the potential of monitoring post-radiotherapy changes in temporal expression profiles of a specific set of genes as a measure of radiation effects on normal tissues. This type of approach should yield more useful information when validated in in vivo irradiated PBL from the cancer patients.

• Journal of the Korean Society of Food Science and Nutrition
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• v.33 no.2
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• pp.291-298
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• 2004

Kimchi contains various antioxidative components, therefore it is expected that kimchi have the inhibitory activity on aging. Among the many factor related to aging, UV radiation is the easiest way to induce skin aging. This experiment was designed to demonstrate the antioxidative activity of dietary kimchi with and without UV radiation in tissues. Lyophilized Korean cabbage kimchi, mustard leaf kimchi and buchu kimchi were used for measurement of the contents of antioxidative components. Chlorophyll contents in buchu and mustard leaf kimchi were higher than cabbage kimchi, and the contents of carotene and ascorbic acid were higher in the mustard leaf kimchi. To clarify the antioxidative activity of various kimchi diets in vivo system, hairless mice were fed the diet containing 10% lyophilized kimchi for 20 weeks. Contents of superoxide anion and hydroxyl radical in liver were not shown significant differences, however hydrogen peroxide were significantly decreased in mustard leaf and buchu kimchi diet groups. Supplementation of all kinds of kimchi diets attenuated the hepatic NDA accumulation, especially in mustard leaf and leek kimchi group. In the skin, the contents of MDA were decreased in kimchi groups compared to control group, especially the buchu kimchi diet significantly inhibited the lipid peroxidation. To elucidate the effect of kimchi diets on photooxidation, the extent of oxidative damage in liver and skin was measured after UVB radiation treatment. The contents of lipid peroxides was decreased in mustard leaf kimchi group and cabbage kimchi group compared to control, while lipid peroxidation was increased in buchu kimchi diet group. It suggests that chlorophylls and other antioxidative nutrients in the various kimchi diets are related to antioxidation or photooxidation and it might be needed further study to certify the exact mechanisms.

• Journal of the Korean Society of Food Science and Nutrition
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• v.45 no.10
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• pp.1391-1397
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• 2016

We investigated the hepatoprotective effects of Angelica keiskei Koidzumi extract (AK) in HepG2-overexpressing cytochrome P4502E1 (CYP2E1) and C57BL/6J mice. In HepG2 cells expressing CYP2E1, cell viability and catalase activity in the ethanol-AK co-treated group significantly increased compared to those in the ethanol-treated group. In the in vivo study with C57BL/6J mice, the AK-supplemented group with ethanol liquid diet showed significantly reduced hepatic markers, including serum aspartate aminotransferase, alanine aminotransferase, and ${\gamma}$-glutamyl transferase, compared to the ethanol group without AK supplementation. AK supplementation (20 mg/kg BW/d) also significantly attenuated reactive oxygen species generation and malondialdehyde level. Notably, a low dose of AK supplementation (20 mg/kg BW/d) suppressed expression of hepatic CYP2E1 and inhibited CYP2E1 enzyme activity. These data indicate that a low dose of AK supplementation could restrain alcohol-induced hepatic damage mediated by CYP2E1.

• Journal of Physiology & Pathology in Korean Medicine
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• v.18 no.6
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• pp.1666-1685
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• 2004

This present study was designed to screen medicinal plants for the treatment of brain diseases such as Parkinson's disease or aging. We tested the effects of the water extracts from 38 species medicinal plants on antioxidant capacity, monoamine oxidase B (MAO-B) inhibitory activity, acetylcholinesterase (AChE) inhibition and antiperoxidation activity in vitro. The water extracts from 38 species were tested on their antioxidant activity using radical scavenging effects against ABTS+. The water extract of C. sappan was showed the highest antioxidant capacity, the antioxidant activity at 1 Jig of herbal extract being 0.38mM TE. Lipid peroxidation in brain homogenates induced by NADPH and ADP-Fe/sup 2+/ was strong inhibited by C. sappan and R. palmatum extracts. Among the 38 medicinal plants investigated, R. palmatum showed significant biological activity (antioxidant capacity, MAO-B inhibiory activity, and AChE inhibitory activity). The protective efficacy of R. palmatum water extract on 1-methyl-4­phenyl-1,2,3,6-tetrahydropyridine (MPTP)-induced parkinsonism and its possible mechanism were studied in C57BL/6 mice. Treatment of R. palmatum water extract protected biomacromolecules such as lipids from oxidative damage induced by MPTP. The content of MDA in brain tissue was decreased significantly by R. palmatum extract. These results suggest that R. palmatum water extract plays on effective role in attenuating MPTP-induced neurotoxicity in mice. This protective effect of R. palmatum might be estimated the result from the inhibitory activity on monoamine oxidase B and the enhancement of antioxidant activity.

• Archives of Plastic Surgery
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• v.41 no.6
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• pp.654-660
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• 2014

Background Reactive oxygen species (ROS) damages cell molecules, and modifies cell signaling. The nuclear factor E2-related factor (Nrf2) is a critical transcription regulator, which protects cells against oxidative damage. Nrf2 expression is increased in a large number of cancers. However, little information has been reported regarding the expression of Nrf2 in skin cancers. Hence, we explored the expression of Nrf2 protein in skin cancers. Methods The Nrf2 protein expression in 24 specimens, including 6 malignant melanomas (MM), 6 squamous cell carcinomas (SCC), 6 basal cell carcinomas (BCC), and 6 normal skin tissues, was evaluated by western blotting. Immunohistochemical staining was performed. The expression of Kelch-like ECH-associated protein 1 (Keap1), the key regulator of Nrf2, was also analyzed by western blotting. Results Small interfering RNA transfection to the melanoma cell line G361 confirmed that an approximately 66 kDa band was the true Nrf2 band. The western blot revealed that the Nrf2 protein was definitely expressed in normal skin tissues, but the Nrf2 expression was decreased in MM, SCC, and BCC. Immunohistochemical examination showed that expression of Nrf2 was decreased in all skin cancer tissues compared to the normal skin tissues. Keap1 was not expressed in all malignant skin tumors and normal skin tissues by western blot. Conclusions ROS was increased in various types of cancers which proteins were highly expressed or underexpressed. This study demonstrated that the expression of Nrf2 protein was down-regulated in human malignant skin tumors. We suggest that decreased expression of Nrf2 is related to skin cancers.

• Journal of Chest Surgery
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• v.29 no.8
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• pp.850-860
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• 1996

Oxygen free radicals and their metabolites have been implicated as possible causes of reperrusion injury In animal models. Their role in the clinical setting is still controversial. The aim of this study was to evaluate the degree of tissue damage, oxidative stress. and changes in the antioxidant enzyme system in patients undergoing cor nary artery bypass graft operations(CABG) with myocardial protection by cold blood cardioplegia. In patients undergoing CABG(n:10). the levels of lactate dehydrogenate(LDH), creatine phosphokinase MB fraction(CK-MB), and malondialdehyde(M DA) were measured In the coronary sinus effluent before aortic cross clamping and 20 minutes after reperfusion. At the same time, the myocardial tissue activities of superoxide dismutase(SOD). catalase(CAT), glutathione peroxiddse(GSHPX), glutathione reductase (GSSGRd), and glucose 6-phosphate dehydrogenate(GfPDH ) were determined in the right atrial auricle excised before aortic cross clamping and in the left atrial auricle excised 20 minutes after reperfuslon. The levels of increased significantly after reperrusion(p< U.05). There were no significant changes in CAT and CfPDH levels. Western blot analysis was performed to study the induction of antioxidant enzyme and demonstrated increased amount of Cu,Zn-SOD.

• Journal of Nutrition and Health
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• v.29 no.1
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• pp.22-31
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• 1996

The purpose of this study was to investigate the effect of vitamin E and selenium on the antioxidative defense mechanism in the liver of streptozotocin(STZ)-induced diabetic rats. Sprague-Dawley male rats(120$\pm$10gm) were randomly assigned to one control and five STZ-diabetic groups. Diabetic groups were classified to STZ-0E (vitamin E free diet), STZ-40E(40mg vitamin E/kg of diet), STZ-400E(400mg vitamin E/kg of diet), STZ-S(0.5ppm Se/kg of diet) and STZ-400ES(400mg vitamin E and 0.5ppm Se/kg of diet) according to the level of vitamin E and selenium supplementation. Diabetes was experimentally induced by intravenous adminstration of 55mg/kg of STZ in citrate buffer(pH 4.3) after 4-weeks feedng of six experimental diets. Animals were sacrificed at the 4th day of diabetic states. Activities of the serum glutamic oxaloacetate transaminase(GOT) and the glutaminc pyruvate transaminase(GPT) in STZ-0E, STZ-40E and STZ-S rats were higher than those of control. Liver xanthine oxidase activities were similar to serum GOT and GPT. Liver superoxide dismutase(SOD) activities were higher in STZ-0E and STZ-40E groups by 33%, 22%, respectively than that of control. Glutathione S-transferase(GST) activities of liver were similar to GSH-Px activities. The contents of vitamin E in liver tissue were significantly lower STZ-0E, STZ-40E and STZ-S groups by 50%, 36%, 45% than that of control. Reduced glutathione(GSH) contents of liver were lower STZ-0E, STZ-40E, STZ-400E, STZ-S and STZ-400ES groups by 57%, 51%, 19%, 18%, 12% than that of control. Lipid peroxide values (LPO) in liver were higher 5.6, 2.3 and 2.3 times in STZ-0E, STZ-40E and STZ-S group than that of control. The present results indicate that STZ-induced diabetic rats are more sensitive to oxidative stress, leading to the acceleration of lipid peroxidation process, which can be more accelerated by feeding the low level of dietary vitamin E. In the coincident supplementation of high dietary vitamin E and selenium antioxidative enzymes activities and physiolosical antioxidants were increased more than those of the separate supplementation of vitamin E or selenium. Therefore, dietary vitamin E and selenium reduced peroxidative damage of tissue, promoting antioxidative defense mechanism against lipid peroxidation by diabetes.