• 제목/요약/키워드: oxygen scavenger

검색결과 199건 처리시간 0.027초

19~20세기 생활민속자료에 사용된 셀룰로오스 나이트레이트의 강화와 접착 연구 (Consolidation and Adhesion of Cellulose Nitrate of Folklore Artifacts in the 19~20th Century)

  • 오준석;이새롬;황민영
    • 보존과학회지
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    • 제34권6호
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    • pp.459-470
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    • 2018
  • 19~20세기 생활민속자료(갓끈 장식, 구슬 및 대롱, 안경테, 안경집 장식, 망건 풍잠 및 관자, 저고리 단추 등)에 사용된 셀룰로오스 나이트레이트는 열화에 의해 균열과 미세 균열이 일어나 부서지고 있다. 균열에 의해 부서진 셀룰로오스 나이트레이트 생활민속자료의 보존을 위해 수용성 아크릴 에멀젼 접착제 4종에 대해 강화와 접착을 평가하였다. 강화처리를 위한 저농도의 아크릴 에멀젼의 점도는 Plextol D 498이 가장 낮았다. 그리고 유리전이온도(Tg)가 상온이하의 접착제 필름은 인장응력과 탄성률은 감소하고 변형률은 증가하여 유연성이 높았다. 인공 태양광 가속 열화 후에는 Plextol D 498과 Primal AC 35 필름은 접착력과 유연성을 유지하였고, Plextol D 498과 Dispersion K 52는 황변이 거의 일어나지 않아, Plextol D 498이 가속 열화에 가장 안정적이었다. 저농도 아크릴 에멀젼의 셀룰로오스 나이트레이트로의 침투성은 Plextol D 498이 가장 우수하였다. Plextol D 498 에멀젼을 사용하여 열화에 의해 부서진 갓끈의 중앙장식에 대한 보존처리는 저농도로(1%, 3%) 수 회 강화처리 후 고농도로(20%) 조각을 접착하여, 열화에 의해 부서지는 현상을 막을 수 있었고 접착이 잘 유지되었다. 보존처리 후 산소와 수분으로 부터의 열화를 막기 위해, 저습도용 탈산소제와 함께 산소 차단 필름으로 밀봉하였다.

The role of antioxidant and DNA damage in the UVB-induced skin tumors of hairless mice

  • Bito, Toshinori;Budiyanto, Arief;Ueda, Masato;Ichihashi, Masamitsu
    • Journal of Photoscience
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    • 제9권2호
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    • pp.146-149
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    • 2002
  • Oxidative stress evoked hy Ultraviolet (UV) exposure has been suggested to be involved in UV-induced skin carcinogenesis. In this study, the role of oxidative stress in UV-carcinogenesis was evaluated by applying N-Acetylcysteine (NAC) in animal model of hairless-mouse. NAC is known to be a precursor of glutathione, which was converted to glutathione in cytoplasm, acting as an intracellular free radical scavenger. The glutathione levels in hairless mouse skin after one time application of NAC increased significantly. With and without the pre-treatment of NAC, hairless-mice were exposed to UVB three times a week, at total dose 274.4 kJ in 80 times, and the timing of tumor-development, incidence of skin tumor and the histopathology of tumors were observed. 8-hydroxy-2'-deoxyguanosine (8-0HdG), a typical form of oxidative damage in DNA has been also investigated in the course of experiment. The decrease of 8-0HdG formation of UVB- exposed skin compared to controls was observed in the early stage of experiment in the NAC-treated mice. In addition, initial tumor development delayed significantly in NAC-treated group. Finally the number of the tumor developed in the NAC-treated mice was fewer though not significant. These results suggest that antioxidants may have inhibitory effect in the initial step of UVB-induced carcinogenesis of hairless mice.

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Hypoxia Induces Paclitaxel-Resistance through ROS Production

  • Oh, Jin-Mi;Ryu, Yun-Kyoung;Lim, Jong-Seok;Moon, Eun-Yi
    • Biomolecules & Therapeutics
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    • 제18권2호
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    • pp.145-151
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    • 2010
  • Oxygen supply into inside solid tumor is often diminished, which is called hypoxia. Many gene transcriptions were activated by hypoxia-inducible factor (HIF)-$1{\alpha}$. Here, we investigated the effect of hypoxia on paclitaxel-resistance induction in HeLa cervical tumor cells. When HeLa cells were incubated under hypoxia condition, HIF-$1{\alpha}$ level was increased. In contrast, paclitaxel-mediated tumor cell death was reduced by the incubation under hypoxia condition. Paclitaxel-mediated tumor cell death was also inhibited by treatment with DMOG, chemical HIF-$1{\alpha}$ stabilizer, in a dose-dependent manner. A significant increase in intracellular ROS level was detected by the incubation under hypoxia condition. A basal level of cell density was increased in response to 10 nM $H_2O_2$. HIF-$1{\alpha}$ level was increased by treatment with various concentration of $H_2O_2$. The increased level of HIF-$1{\alpha}$ by hypoxia was reduced by the treatment with N-acetylcysteine (NAC), a well-known ROS scavenger. Paclitaxel-mediated tumor cell death was increased by treatment with NAC. Taken together, these findings demonstrate that hypoxia could play a role in paclitaxel-resistance induction through ROS-mediated HIF-$1{\alpha}$ stabilization. These results suggest that hypoxia-induced ROS could, in part, control tumor cell death through an increase in HIF-$1{\alpha}$ level.

Experimental Studies on the Effect of Gamibaegi-eum

  • Kim Won-Ill
    • 대한한의학회지
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    • 제25권4호
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    • pp.61-78
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    • 2004
  • Objective : This study was undertaken to determine whether Gamibaegi-eum (BGU) in vitro and in vivo exerts a beneficial effect against cell injury induced by reactive oxygen species (ROS) in the human intestine. Methods : Effects of BGU in vitro on cell injury were examined using Caco-2 cells, cultured human intestinal cell line. Exposure of cells to H₂O₂ induced increases in the loss of cell viability in a time and dose-dependent fashion. Results : BGU prevented H₂O₂-induced cell death and its effect was dose-dependent over a concentration range of 0.05­1%. H₂O₂-induced cell death was prevented by catalase, the hydrogen peroxide scavenger enzyme, and deferoxamine, the iron chelator. However, the potent antioxidant DPPD did not affect H₂O₂-induced cell death. H₂O₂ increased lipid peroxidation, which was inhibited by BGU and DPPD. H₂O₂ caused DNA damage in a dose-dependent manner, which was prevented by BGU, catalase, and deferoxamine, but not DPPD. BGU restored ATP depletion induced by H₂O₂. BGU inhibited generation of superoxide and H₂O₂ and scavenged directly H₂O₂. Oral administration of mepirizole in vivo at a dose of 200mg/kg resulted in ulcer lesions in the stomach and the proximal duodenum. Pretreatment of BGU(0.1%/kg, orally) and catalase (800Units/kg, i.v.) significantly decreased the size of ulcers. Mepirizole increased lipid peroxidation in the mucosa of the duodenum, suggesting an involvement of ROS. Pretreatment of BGU and catalase significantly inhibited lipid peroxidation induced by mepirizole. Morphological studies showed that mepirizole treatment causes duodenal injury and its effect is prevented by BGU. Conclusion : These results indicate that BGU exerts a protective effect against cell injury in vitro and in vivo through antioxidant action. The present study suggests that BGU may playa therapeutic role in the treatment of human gastrointestinal diseases mediated by ROS.

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대장암세포주에서 적양 추출물의 미토콘드리아/Caspases 경로를 통한 Apoptosis 유도 작용 (Extract of Alnus japonica Induces Apoptosis of Human Colon Adenocarcinoma Cells through the Mitochondria/Caspase Pathway)

  • 전병국;백순기;우원홍;문연자
    • 동의생리병리학회지
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    • 제26권2호
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    • pp.199-205
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    • 2012
  • An extract of Alnus japonica (Betulaceae) cortex has been traditionally used for purifying blood, and curing feces containing blood, enteritis, diarrhea, alcoholism and cut wounds. In the present study, we demonstrated that the ethanol extract of Alnus japonica (EAJ) exhibited significantly cytotoxicity in human colon adenocarcinoma HT-29 cells. The results showed that the induction of apoptosis in HT-29 cells by EAJ was characterized by chromatin condensation and activation of caspase-3. EAJ-induced activation of caspase-9 and -3 caused the cleavage of poly ADP-ribose polymerase (PARP) and the release of cytochrome c. The expressions of Bcl-2 and Bid were reduced by EAJ in HT-29 cells, whereas pro-apoptotic protein Bak was increased in the cells. EAJ-induced, dose-dependent induction of apoptosis was accompanied by sustained phosphorylation of MAP kinases (JNK and p38 MAPK), ASK1, and p53. NAC administration, a scavenger of ROS, reversed EAJ-induced cell death. In conclusion, these results indicated that EAJ can cause apoptosis through a ROS-mitochondria-caspases-dependent pathway in human HT-29 cells.

Effect of Snake Venom Toxin on Inhibition of Colorectal Cancer HT29 Cells Growth via Death Receptors Mediated Apoptosis

  • Shim, Yoon Seop;Song, Ho Sueb
    • Journal of Acupuncture Research
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    • 제31권2호
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    • pp.87-98
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    • 2014
  • Objectives : We investigated whether snake venom toxin(SVT) from Vipera lebetina turanica sensitizes HT29 human epithelial colorectal cancer cells to tumor necrosis factor(TNF)-related apoptosis-inducing ligand(TRAIL) induced apoptosis in cancer cells. Methods : Cell viability assay was used to assess the inhibitory effect of TRAIL on cell growth of HT29 human colorectal cancer cells. And 6-diamidino-2-phenylindole(DAPI), terminal deoxynucleotidyl transferase mediated dUTP nick end labeling assay(TUNEL) staining assay were used to evaluate cell-apoptosis. Western blot analysis were conducted to observe apoptosis related proteins and death receptor. To assess whether the synergized inhibitory effect of SVT and TRAIL on reactive oxygen species(ROS) generation was reversed by strong anti-oxidative agent. Results : SVT with TRAIL inhibited HT29 cell growth different from TRAIL alone. Consistent with cell growth inhibition, the expression of TRAIL receptors; Expression of death receptor(DR)4 and DR5 was significantly increased and intrinsic pro-apoptotic cleaved caspase-3, -9 was subsequently increased together with increase of Bax/Bcl-2 ratio and extrinsic pro-apototic caspase-8 was also activated. In addition, the expression of anti-apoptotic survival proteins, a marker of TRAIL resistance(eg, cFLIP, survivin, X-linked inhibitor of apoptosis protein(XIAP) and Bcl-2) was suppressed by the combination treatment of SVT and TRAIL. Pretreatment with the ROS scavenger N-acetylcysteine abolished the SVT and TRAIL-induced upregulation of DR4 and DR5 expression and expression of the intrinsic pro-apoptotic caspase-3 and-9. Conclusion : The collective results suggest that SVT facilitates TRAIL-induced apoptosis in $HT_{29}$ human epithelial colorectal cancer cells through up-regulation of the TRAIL receptors; DR4 and DR5 and consecutive induction of bilateral apoptosis via regulating apoptosis related proteins.

Attenuation of ROS Generation by KCNE1 Genes in Cisplatin-treated Auditory Cells

  • Kim, Eun Sook;Park, Sang-Ho;Park, Raekil
    • 대한임상검사과학회지
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    • 제45권3호
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    • pp.114-119
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    • 2013
  • Potassium is essential for the proper functioning of the ears. The inner ear's endolymph differs from all other extracellular fluids (in its positive potential) and in the ionic compositions in the various parts of the endolymphatic space. Ion concentration of the endolymph is 150 mM of potassium, which is comparable to the concentrations in other organs. Cisplatin (cis-diamminedichloroplatinum II: CDDP) is one of the most effective anticancer drugs, widely used against various tumors. However, its clinical use is limited by the onset of severe side effects, including ototoxicity and nephrotoxicity. For ototoxicity, a number of evidences in cytotoxic mechanism of cisplatin, including perturbation of redox status, increase in lipid peroxydation, and formation of DNA adduct, have been suggested. Therefore, in this study, the author investigated the relationship between the potassium ions on cisplatin-induced cytotoxicity in HEI-OC1 cells associated with reactive oxygen species (ROS). KCNE1 gene expression by the concentration of intracellular potassium appeared in the plasma membrane and increased the concentration of intracellular potassium. Cisplatin decreased the viability of HEI-OC1 cells, but the KCNE1 gene increased. Also, the KCNE1 gene significantly suppressed generation of intracellular ROS by cisplatin. Western blot analysis showed that the KCNE1 gene increased phase II detoxification enzymes markers such as superoxide dismutase 1 (SOD1), superoxide dismutase (SOD2), NAD(P)H:quinine oxidoreductases (NQO1), which were associated with the scavenger of ROS. These results suggest that the KCNE1 gene for intracellular potassium concentration ultimately prevents ROS generation from cisplatin and further contributes to protect auditory sensory hair cells from ROS produced by cisplatin.

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저준위 방사선에 의해 유도된 방사선저항의 기전 (Mechanism of Radioresistance Induced by Low-Dose Irradiation)

  • 박상희;조철구;류성렬;이연희
    • Journal of Radiation Protection and Research
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    • 제21권2호
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    • pp.99-105
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    • 1996
  • 림프구와 림프종에 고준위 방사선(8Gy)을 조사했을 때. 저준위 방사선을 먼저 조사한 경우 세포 생존률이 3.7배 증가하는 것이 관찰되었다 세포 생존률은 고준위 방사선 조사로 발생되는 산소 라디칼의 제거. 변성된 유전자와 단백질의 제거, 변화된 세포의 제거 등으로 증가할 수 있다. 본 연구에서는 저준위 방사선 조사로 유도되는 방사선 저항기전을 알아보기 위하여, 고준위 방사선 조사시 발생되는 산소 라디칼을 제거하는 효소들의 활성과 방사선 보호제로 알려진 glutathione의 양을 측정하였다 림프종의 경우 저준위 방사선 조사시 peroxidase의 활성이 133.3%로 증가하였다. 림프구의 경우는 superoxide dismutase, glucose-6-phoshpate dehydrogenase와 glutathione의 활성이 각각 138.5%. 122.4%. 120.8%로 증가하였으며. 이들 효소들의 활성은 저 준위방사선 조사 간격이 7 시간일 때 가장 증가되었다.

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Neuroprotective Effect of Anthocyanin on Experimental Traumatic Spinal Cord Injury

  • Kim, Kyoung-Tae;Nam, Taek-Kyun;Park, Yong-Sook;Kim, Young-Baeg;Park, Seung-Won
    • Journal of Korean Neurosurgical Society
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    • 제49권4호
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    • pp.205-211
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    • 2011
  • Objective : We investigated the neuroprotective effect of anthocyanin, oxygen radical scavenger extracted from raspberries, after traumatic spinal cord injury (SCI) in rats. Methods : The animals were divided into two groups : the vehicle-treated group (control group, n=20) received an oral administration of normal saline via stomach intubation immediately after SCI, and the anthocyanin-treated group (AT group, n=20) received 400 mg/kg of cyanidin 3-O-${\beta}$-glucoside (C3G) in the same way. We compared the neurological functions, superoxide expressions and lesion volumes in two groups. Results : At 14 days after SCI, the AT group showed significant improvement of the BBB score by $16.7{\pm}3.4%$, platform hang by $40.0{\pm}9.1%$ and hind foot bar grab by $30.8{\pm}8.4%$ (p<0.05 in all outcomes). The degree of superoxide expression, represented by the ratio of red fluorescence intensity, was significantly lower in the AT group ($0.98{\pm}0.38$) than the control group ($1.34{\pm}0.24$) (p<0.05). The lesion volume in lesion periphery was $32.1{\pm}2.4\;{\mu}L$ in the control and $24.5{\pm}2.3\;{\mu}L$ in the AT group, respectively (p<0.05), and the motor neuron cell number of the anterior horn in lesion periphery was $8.3{\pm}5.1$ cells/HPF in the control and $13.4{\pm}6.3$ cells/HPF in the AT group, respectively (p<0.05). Conclusion : Anthocyanin seemed to reduce lesion volume and neuronal loss by its antioxidant effect and these resulted in improved functional recovery.

상심자 추출물의 ROS, RNS 및 염증 촉진 인자 제어 효과 (ROS-, RNS-Scavenging and Anti-inflammatory Activities of Mori Fructus)

  • 박순재;정지천
    • 대한한의학회지
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    • 제29권1호
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    • pp.106-116
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    • 2008
  • Objectives : Peroxynitrite $(ONOO^-)$, superoxide anion radical $({\cdot}O_2^-)$ and nitric oxide (NO) are cytotoxic because they can oxidize several cellular components such as proteins, lipids and DNA. They have been implicated in the aging processes, and age-related diseases such as Alzheimer's disease, rheumatoid arthritis, cancer and atherosclerosis. The aim of this study was to investigate the $ONOO^-$, NO, and $({\cdot}O_2^-)$ scavenging and anti-inflammatory activities of Mori Fructus in ob/ob mice. Methods : Mice were grouped and treated for 5 weeks as follows. Both the normal lean (C57/BL6J black mice) and control obese (ob/ob mice) groups received the standard chow. The experimental groups were fed a diet of chow supplemented with 7.5, 15 and 30 mg Mori Fructus per 1 kg of body weight for 14 days. For this study, the fluorescent probes, namely 2',7'-dichlorodihydrofluorescein diacetate (DCFDA), 4,5-diaminofluorescein (DAF-2) and dihydrorhodamine 123 (DHR 123) were used. Western blotting was performed using anti-phospho $I{\kappa}B-\alpha$, anti-IKK-$\alpha$, anti-NF-${\kappa}B$ (p50, p65), anti-COX-2 and anti-iNOS respectively. Results : Mori Fructus inhibited the generation of $ONOO^-$, NO and $({\cdot}O_2^-)$ in the lipopolysaccharide (LPS)-treated mouse kidney postmitochondria in vitro. The generation of $ONOO^-$, NO and $({\cdot}O2^-)$ were inhibited in the Mori Fructus-administered ob/ob mice groups. The GSH/GSSG ratio decreased in the ob/ob mice, whereas they improved in the Mori Fructus-administered groups. Mori Fructus inhibited the expression of phospho $I{\kappa}B-\alpha$, IKK-$\alpha$, COX-2, iNOS genes, and thereby the activation of NF-$I{\kappa}B$. Conclusions : These results suggest that Mori Fructus is an effective $ONOO^-$, $({\cdot}O_2^-)$ and NO scavenger, and therefore it might be a potential therapeutic drug against the inflammation process and inflammation-related diseases.

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