• Journal of Plant Biology
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• 제32권4호
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• pp.343-350
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• 1989

Calcium promoted ethylene production from mungbean hypocotyl segments incubated in the presence of either auxin or cytokinin (kinetin). Time course studies indicated that the calcium effect on ethylene production had a longer latent period (about 6 h) in combination with kinetin than with auxin. Studies on the effects of agents that are known to interfere with either action or transport (uptake) of calcium on ethylene biosynthesis indicated different patterns between auxin- and kinetin-treated tissues. Auxin-induced ethylene production was inhibited by the calmodulin inhibitor, trifluoperazine (TFP), and this inhibition was overcome by high concentrations of calcium applied, but TFP had no significant effect on kinetin-induced ethylene production regardless of calcium in the medium. The calcium channel blocker, verapamil, inhibited auxin-induced, but had little effect on kinetin-induced, ethylene producton. In vivo activity of "ethylene forming enzyme (EFE)" was found to be substantially promoted by calcium treatment. The enzyme activity was further increased by kinetin when segments were simultaneously treated with calcium, but auxin did not have such an effect.an effect.

• 대한의생명과학회지
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• 제10권4호
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• pp.341-346
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• 2004

Tumor necrosis factor-α (TNF-α) or its mRNA expression are increased in acute nephrosis of various types including ischemia/reperfusion injury. This study was undertaken to determine whether pentoxifylline (PTX), an inhibitor of TNF-α production, provides a protective effect against hypoxia-induced cell injury in rabbit renal cortical slices. To induce hypoxia-induced cell injury, renal cortical slices were exposed to 100% N₂ atmosphere. Control slices were exposed to 100% O₂ atmosphere. The cell injury was estimated by measuring lactate dehydrogenase (LDH) release and p-aminohippurate (PAH) uptake. Exposure of slices to hypoxia increased the LDH release in a time-dependent manner. However, when slices were exposed to hypoxia in the presence of PTX, the LDH release was decreased. The protective effect of PTX was dose-dependent over the concentrations of 0.05∼1 mM. Hypoxia did not increase lipid peroxidation, whereas an organic hydroperoxide t-butylhydroperoxide (tBHP) resulted in a significant increase in lipid peroxidation. PTX did not affect tBHP-induced lipid peroxidation. Hypoxia decreased PAH uptake, which was significantly attenuated by PTX and glycine. tBHP-induced inhibition of PAH uptake was not altered by PTX, although it was prevented by antioxidant deferoxarnine. The PAH uptake by slices in rabbits with ischemic acute renal failure was prevented by PTX pretreatment. These results suggest that PTX may exert a protective effect against hypoxia-induced cell injury and its effect may due to inhibition of the TNF-α production, but not by its antioxidant action.

• Archives of Pharmacal Research
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• 제19권2호
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• pp.85-90
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• 1996

It has been suggested that oxygen-derived free radicals play an important role in the pathophysiology of acute gastric ulceration induced by NSAIDs and ischemia-reperfusion. Taurine is hypothetized to exert its protective effect on NSAIDs-induced gastric injury by its antioxidant properties. Protective effect of taurine on indomethacin-induced gastric mucosal lesion and its protection mechanism were investigated. Intragastric administration of 25 mg/kg of indomethacin induced hemorrhagic lesions on the glandular stomach in rats. Pretreatment with 0.25 or 0.5 g/kg of taurine one day before or for 3 days significantly reduced the gastric lesion formation and inhibited the elevation of lipid peroxide level in gastric mucosa. The luminol-dependent chemiluminescence of rat peritoneal neutrophils increased immediately after treatment of FMLP or indomethacin. Taurine (5-20 mM) inhibited chemiluminescence of neutrophils activated by FMLP. Human neutrophils (polymorphonuclear leukocytes) significantly adhered to the confluent monolayer of human umbilical vein endothelial cells (HUVEC) after coincubation with indomethacin. This neutrophil adhesion induced by indomethacin to HUVEC was prevented by taurine in a dose-dependent manner. These results indicate that the protective effect of taurine against NSAIDs-induced gastric mucosal injury is due to its antioxidant effect, which inhibits lipid peroxidation and neutrophil activation.

• 생명과학회지
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• 제8권4호
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• pp.464-471
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• 1998

This study was carried out to determine whether Kamihaengche-tang plus Yukmijihwang-tang (KCYH) exerts the protective effect against oxidant-induced liver cell injury. Cell injurt was estimated by measuring lactate dehydrogenase (LDH) and alanine aminotransferase (ALT) release, and lipid peroxidation was estimated by measuring malondialdehyde, a product of lipid peroxidation in rabbit liver slices. $H_2O_2$increased LDH release which was significantly prevented by 1% KCYHT. The protective effect of KCYH against $H_2O_2$-induced cell injury was dose-dependent in the range of 0.05-1% concentrations. Similary, KCYH inhibited $H_2O_2$ induced lipid peroxidation in a dose-dependent manner. When liver tissuse were exposed to Hg(0.5 mM), ALT activity in the medium and lipid erpoxidation in tissues were markedly increased. These changes were prevented by 1% KCYH. KCHY restored Hg-induced inhibition of cellular GSH content. These result indicate that KCYH exerts the protective effect oxidant-induced liver cell injury, and this effect is attributed to prevented to prevention of lipid peroxidation. These dffects may be due to an increase in concentration of endogenous antioxidants.

• Journal of Acupuncture Research
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• 제20권3호
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• pp.117-130
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• 2003

To study the analgesic and effect and its mechanism of eletroacupunture(EA) on the chronic inflammatory pain 50 rats were induced with arthralgesia by injecting complete freund's adjuvant(CFA). Two weeks after the injection of CFA, EA stimulation(2Hz, 0.07mA, 0.3ms) was delivered to Jogsamni($ST_{36}$) for 20 minutes. Analgesic effect was evaluated by using the tail flick latency(TFL) and the analgesic mechanism was observed by applying TFL with the pretreatment with naloxone and yohimbine. The results were as follows ; 1. TFL level for the model of adjuvant-induced arthritis decreased as time went by and it induced the hyperalgesia. 2. EA stimulation delivered to Jogsamni($ST_{36}$) for 20 minutes in the rat model of adjuvant-induced arthritis brought analgesic effect and its effect had lasted for 40 minutes after the stimulation. 3. The analgesic effect of Jogsamni($ST_{36}$) EA in the rat model of adjuvant-induced arthritis was blocked by pretreatment with naloxone(2mg/kg,i.p). This result suggests that the EA effect on the chronic inflammatory pain can be related to the endogenous opioid mechanism. 4. The analgesic effect of Jogsamni($ST_{36}$) EA in the rat model of adjuvant-induced arthritis was blocked by pretreatment with naloxone(2mg/kg,i.p). This result suggests that the EA effect on the chronic inflammatory pain can be related to the ${\alpha}_2$-adrenergic mechanism.

• Journal of Microbiology and Biotechnology
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• 제26권5호
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• pp.823-828
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• 2016

The present study investigated the protective effect of naturally purified 4-(3,4-dihydroxyphenyl)-3-buten-2-one (DHP) from Phellinus linteus against naproxen-induced gastric antral ulcers in rats. To verify the protective effect of DHP on naproxen-induced gastric antral ulcers, various doses (1, 5, and 10 μg/kg) of DHP were pretreated for 3 days, and then gastric damage was caused by 80 mg/kg naproxen applied for 3 days. DHP prevented naproxen-induced gastric antral ulcers in a dose-dependent manner. In particular, 10 μg/kg DHP showed the best protective effect against naproxen-induced gastric antral ulcers. Moreover, DHP significantly attenuated the naproxen-induced lipid peroxide level in gastric mucosa and increased the activities of radical scavenging enzymes, such as superoxide dismutase, catalase, and glutathione peroxidase, in a dose-dependent manner. A histological examination clearly demonstrated that the gastric antral ulcer induced by naproxen nearly disappeared after the pretreatment of DHP. These results suggest that DHP can inhibit naproxen-induced gastric antral ulcers through prevention of lipid peroxidation and activation of radical scavenging enzymes.

• Journal of Plant Biology
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• 제32권4호
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• pp.265-274
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• 1989

The effect of Ca2+ on auxin-induced ehtylene production in etiolated mungbean (Vigna radiata W.) hypocotyls was studied. Auxin-induced ethylene production by mungbean seedlings which had been germinated in the presence of 5-10mM Ca2+ (High Ca2+ ; HC) is greater than that by seedlings which had been germinated in distilled water (Low Ca2+ ; LC). The effect of Ca2+ on auxin-induced ethylene production was greatly increased after 12hr of incubation period. The stimulation of auxin-induced ethylene production by Ca2+ was specific, since divalent cations, such as Mg2+ and Mn2+ did not enhance auxin-induced ethylene production. Calcium also promoted ethylene evoluation induced by methionine and 1-Aminocyclopropane-1-carboxylic acid(ACC). The effect of Ca2+ on auxin-induced ethylene production was not caused by increase in free IAA or ACC contents of hypocotyl tissue. Dimethyl sulfoxide and Triton X-100, that disrupts the emembranes, inhibited ethylene production to a greater extent in LC segments than in HC segments. Addition of Ca2+ to the incubation medium for LC segments resulted in enchancement of ethylene production probalby because the membrane integrity is supported under these conditions. Comparison of activity of Ethylene Forming Enzyme(EFE) in LC and HC hypocotyl segments indicated that the enzyme activity of HC was about 2 times higher than that of L.C. It is suggested that Ca2+ increases the activity of plasma membrane-bound EFE through its stabilizing effect onn the membrane, which in turn brings about promotion of ethylene production.

• Journal of Information Technology Applications and Management
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• 제13권1호
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• pp.67-75
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• 2006

In this paper, we investigate the economic repercussion effects of the domestic satellite industry. The market size of the satellite industry between 2005 and 2009 is forecasted based on the world market forecast. By using the Input-Output analysis technique, three kinds of repercussion effects (domestic production, value added, workers induced by the satellite industry) between 2005 and 2009 are calculated.

• 대한전기학회논문지
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• 제36권2호
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• pp.122-128
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• 1987

In this paper, the photo-induced of a-$Sc_{75} Ge_{25}$thin films has been investigated as a function of annealing, exposure and obliqueness. The photo-induced effect consists of photo-thermal and photo-optical effect, which the photo-optical effect increases with increasing obliqueness. As the results, these photo-induced effects are related to the creation of atomic and electronic metastable state due to the surface defects.

• 대한의생명과학회지
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• 제24권4호
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• pp.357-364
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• 2018

Manganese (Mn) is used as main materials in various chemical processes of industry, but it suggested that Mn brings about its toxicant by fume or dust through respiratory system and skin barrier. Mn toxicant induces the loss of mental health and life quality by cerebrovascular and skin diseases. Nevertheless, it lefts much unknown on the mechanism and the effectively therapeutic methods about Mn toxicant. Therefore, this study was evaluated the cytotoxicity induced by manganese dioxide ($MnO_2$) in cultured NIH3T3 fibroblasts, and also, the correlation between $MnO_2$-induced cytotoxicity and oxidative stress was examined. While, the effect of Eclipta prostrata L. (EP) extract belong to Compositae was assessed against $MnO_2$-induced cytotoxicity in the view of antioxidative effect for searching the natural resources mitigating or preventing the $MnO_2$-induced cytotoxicity. In this study, $MnO_2$-induced cytotoxicity was revealed as mid-toxic by Borenfreud and Puerner's toxic criteria, and catalase (CAT), an antioxidant prevented $MnO_2$-induced cytotoxicity by the remarkable increase of cell viability in these cultures. While, in the protective effect of EP extract on $MnO_2$-induced cytotoxicity, EP extract effectively prevented the cytotoxicity induced by $MnO_2$ via antioxidative effects such as xanthine oxidase (XO) inhibitory ability and DPPH-radical scavenging ability. From the above results, EP extract showed the effective prevention against $MnO_2$-induced cytotoxicity correlated with oxidative stress by antioxidative effects. Conclusively, this study may be useful to research or development the alternatively therapeutic agent from natural resources like EP extract for the treatment of diseases resulted in oxidative stress.