• 대한의생명과학회지
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• 제6권1호
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• pp.37-43
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• 2000

흰쥐에 있어서 피부의 공기차단이 피부조직의 xanthine oxidase (XO) 활성에 미치는 영향을 검토하고자 직경 46 mm, 높이 10 mm인 petri dish-shaped glass chamber에 순간접착제 ($\alpha$-cyanoacrylate)를 이용하여 실험동물의 등 부위 피부조직에 부착시켜 10일간 공기의 접촉을 차단하였다. 공기 접촉 차단 5일째에 피부의 땀 축적량은 약 400 mg 정도이었으나, 10일째에는 약 25 mg으로 감소하였다. 5일간 피부차단 시 피부조직 중 XO 활성은 대조군에 비해 증가하였으며, 그 증가율은 chamber 내의 땀 축적량과 관련하여 10일간 피부차단군 보다 높게 나타났다. 5일간 피부차단 시 XO의 기질 농도 변화에 따른 반응 속도를 관찰한 결과, 대조군에 비해 V$_{max}$ 치가 높게 나타났다. 이상 실험 결과를 보아, 피부의 공기접촉 차단으로 피부조직 중 XO효소 활성이 증가된 것은 이 효소 단백 합성 유도에 기인되며, 이는 피부조직에서 oxygen free radical의 생성을 유도하여 외부 환경에 대한 방어장벽작용에 관여할 것으로 생각된다.

• 한국전기전자재료학회논문지
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• 제14권12호
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• pp.959-964
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• 2001

We investigated the etching characteristics of YMnO$_3$ thin films in high-density plasma etching system. In this study, YMnO$_3$ thin films were etched with CF$_4$/Ar gas chemistries in inductively coupled plasma(ICP). Etch rates of YMnO$_3$ increased up to 20% CF$_4$ in CF$_4$/(CF$_4$+Ar), but decreased with furthermore increasing CF$_4$ in CF$_4$/(CF$_4$+Ar). In optical emission spectroscopy (OES) analysis, F radical and Ar* ions in plasma at various gas chemistries decreased with increasing CF$_4$ content. Chemical states of YMnO$_3$ films exposed in plasma were investigated with x-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). There is a chemical reaction between metal (Y, Mn) and F and metal-fluorides were removed effectively by Ar ion sputtering. YF$_{x}$, MnF$_{x}$ such as YF, YF$_2$, YF$_3$ and MnF$_3$ were detected using SIMS analysis. The etch slope is about 65$^{\circ}$ and cleasn surface. surface of the etched YMnO$_3$ thin films was investigated with X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS). The etch profile was also investigated by scanning electron microscopy (SEM).EM).

• The Korean Journal of Physiology and Pharmacology
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• 제3권2호
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• pp.147-155
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• 1999

Antioxidant effects of serotonin and L-DOPA on neuronal tissues were examined by studying the oxidative damages of brain synaptosomal components. The study further explored the mechanism by which they exert protective actions. Serotonin and L-DOPA (1 ${\mu}M$ to 1 mM) significantly inhibited lipid peroxidation of brain tissues by either $Fe^{2+}$ and ascorbate or t-butyl hydroperoxide in a dose dependent fashion. Protective effect of serotonin on the peroxidative actions of both systems was greater than that of L-DOPA. Protein oxidation of synaptosomes caused by $Fe^{2+}$ and ascorbate was attenuated by serotonin and L-DOPA. Protein oxidation more sensitively responded to L-DOPA rather than serotonin. Serotonin and L-DOPA (100 ${\mu}M$) decreased effectively the oxidation of synaptosomal sulfhydryl groups caused by $Fe^{2+}$ and ascorbate. The production of hydroxyl radical caused by either $Fe^{3+},$ EDTA, H_2O_2$ and ascorbate or xanthine and xanthine oxidase was significantly decreased by serotonin and L-DOPA (1 mM). Equal concentrations of serotonin and L-DOPA restored synaptosomal $Ca^{2+}$ uptake decreased by $Fe^{2+}$ and ascorbate, which is responsible for SOD and catalase. Protective effects of serotonin and L-DOPA on brain synaptosomes may be attributed to their removing action on reactive oxidants, hydroxyl radicals and probably iron-oxygen complex, without chelating action on iron.

• 동의생리병리학회지
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• 제17권2호
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• pp.297-307
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• 2003

In the present study, we investigated the protective effect of the Puerarie Radix water extract (PRE) against CCl₄-induced hepatotoxicity and the mechanism underlying these protective effects in the rats. The pretreatment of PRE has shown to possess a significant protective effect by lowering the serum alanine and aspartate aminoteansferase (AST and ALT) and alkaline phosphatase (ALP). This hepatoprotective action was confirmed by histological observation. In addition, the pretreatment of PRE prevented the elevation of hepatic malondialdehyde (MDA) formation and the depletion of reduced glutathione (GSH) content and catalase activity in the liver of CC1₄-injected rats. The PRE also displayed hydroxide radical scavenging activity in a dose-dependent manner (IC50 = 83.6 μg/ml), as assayed by electron spin resonance (ESR) spin-trapping technique. Moreover, the expression of cytochrome P450 2E1 (CYP2E1) mRNA, as measured by reverse transcriptase-polymerase chain reaction (RT-PCR), was significantly decreased in the liver of PRE-pretreated rats when compared with that in the liver of control group. Based on these results, it was suggested that the hepatoprotective effects of the PRE may be related to antioxidant effects and regulation of CYP2E1 gene expression.

• 동의생리병리학회지
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• 제23권3호
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• pp.631-638
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• 2009

GLEDITSIAE SPINA (GS) has been used as folk remedies traditionally for treatment of antiphlogistic and antifebrile agents. An ethanol extract and its fraction of GS were assessed to determine the mechanism of its antioxidant activity. Also, inhibitory effect of extract from GS and its fraction measuring the inhibitory effect on $Cu^{2+}$-induced human low-density lipoprotein (LDL) oxidation. GS ethanol extract and its fraction exhibited a concentration-dependent reactive oxygen species (ROS) and reactive nitrogen species (RNS) scavenging activities, including trolox equivalent antioxidant capacity (TEAC), OPPH radical, superoxide anion, hydroxyl radicals, peroxynitrite and nitric oxide, using different assay systems. Furthermore, the GS ethanol extract and its fraction showed dose-dependent protection of LDL oxidation induced by $CuSO_4$. In addition, the GS ethanol extract and its fraction were characterized as containing a high amount of total phenolics. These results suggest that GS ethanol extract and its fraction might be helpful for preventing oxidative stress and protecting LDL oxidation.

• 생약학회지
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• 제36권4호통권143호
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• pp.324-331
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• 2005

The roots of Rosa rugosa have been used to treat diabetes mellitus in the folkloric society of Korea. To demonstrate the active component for the rat obesity induced by high fat diet for 6 weeks, the phytochemical fractionation and the pharmacological activity test were performed on this crude drug. It was shown that the methanolic extract and its EtOAc fraction inhibited the weight increase of the rat body, abdominal fat pad and hyperlipidemia at 200 mg/kg dose. Further, the triterpenoids, euscaphic acid and tormentic acid, isolated from R. rugosa roots were active at 30 mg/kg in the same assay. The two components shifted serum total-, HDL, and LDL-cholesterol levels toward the values of the unteated group, suggesting that the active compounds has hypolipidemic effects. The rats fad euscaphic acid and tormentic acid also reduced thiobarbituric acid-reactive substance (TBARS) and hydroxyl radical in the rat blood and increased superoxide dismutase activity compared to the control. TBARS values and carbonyl contest of the hepatic protein were reduced by treatment with the two triterpenoids. Antioxidative enzyme (SOD, glutathione peroxidase, and catalase) activities in hepatic were increased by treatment of rats with the triterpenoids, which suggests that triterpenoids inhibited the reduction of hepatic antioxidative activity caused by high fat diet. Taken together, these results support that euscaphic acid and tormentic acid improve a high fat diet-induced hyperlipidemia via the activation of antioxidative mechanism.

• Journal of the Korean Wood Science and Technology
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• 제26권3호
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• pp.53-62
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• 1998

In this research, 7 species of white rot fungi were used for determining the resistance against pentachlorophenol (PCP). Three fungi with good PCP resistance were selected for evaluating the biodegradability, and biodegradation mechanism by HPLC and GC/MS spectrometry. Among 7 fungi, there were significant differences on PCP resistance on 4 different PCP concentrations. In the concentrations of 50 and 100ppm ($\mu$g of PCP per g of 2% malt extract agar), most fungi were easily able to grow, and well suited to newly PCP-added condition, but in that of more than 250ppm, the mycelia growths of Ganoderma lucidum 20435, G. lucidum 20432, Pleurotus ostreatus, and Daldinia concentrica were significantly inhibited or even stopped by the addition of PCP to the culture. However, Trametes versicolor, Phanerochaete chrysosporium, and Inonotus cuticularis still kept growing at 250ppm, indicating the potential utilization of wood rot fungi to high concentrated PCP biodegradation. Particularly, P. chrysosporium even showed very rapid growth rate at more than 500ppm of PCP concentration. Three selected fungi based on the above results showed an excellent biodegradability against PCP. P. chrysosporium degraded PCP up to 84% on the first day of incubation, and during 7 days, most of added PCP were degraded. T. versicolor also showed more than 90% of biodegradability at 7th day, and even though the initial stage of degradation was very slow, I. cuticularis has been approached to 90% at 21 st day after incubation with dense growing pattern of mycelia. Therefore, the PCP biodegradability was definitely dependent on the rapid suitability of fungi to newly PCP-added condition. In addition, the PCP biodegradation by filtrates of P. chrysosporium, T. versicolor, and I. cuticularis was very minimal or limited, suggesting that the extracellular enzyme system may be not so significantly related to the PCP biodegradation. Among the biodegradation metabolites of PCP, the most abundant one was pentachloroanisole which resulted in a little weaker toxicity than PCP, and others were tetrachlorophenol, tetrachloro-hydroquinone, benzoic acid, and salicylic acid, suggesting that PCP may be biodegraded by several sequential reactions such as methylation, radical-induced oxidation, dechlorination, and hydroxylation.

• 한국정보과학회논문지:컴퓨팅의 실제 및 레터
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• 제9권6호
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• pp.610-622
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• 2003

메타데이타 레지스트리는 동적인 메타데이타 관리와 다양한 이질적인 메타데이타간 상호운용성 증진을 위한 목적으로 개발되었다. 구축된 메타데이타 레지스트리는 새로운 데이타베이스 설계시 표준 지침을 제공함으로써 근본적이고 데이타 통합 메커니즘을 제공한다. 그러나 대규모 분산 데이터베이스에 대한 점진적인 통합을 위한 상황에서, 기 구축된 데이타베이스에 대한 인덱스를 생성하고 일관성 있는 표준 지침서인 메타데이타 레지스트리를 구축하는데 한계가 있다. 특히, 각 단위 데이타베이스에 대한 이용률 통계 정보 부재 및 단위 기간 내 주어진 비용이 제한된 경우, 우선적으로 통합할 데이타베이스 선택을 통한 점진적인 메타데이타 레지스트리의 체계적인 구축 방법을 제공하지 않는다. 이 논문에서는 이와 같은 환경에서, 점진적으로 메타데이타 레지스트리를 구축할 수 있는 방법론을 제안하고 점진적인 메타데이타 레지스트리 구축을 위해 데이타 가시성과 계층적 메타데이타 레지스트리 구조를 정의한다. 또한 정의한 개념, 구조 및 방법을 실제 도메인에 적용하기 위해 개발된 시스템과 적용한 결과를 기술한다.

• 한국식품과학회지
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• 제30권1호
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• pp.192-198
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• 1998

제초제 paraquat의주된 독성 기전이 인체내 대사과정중 생성되는 superoxide anion radical $(O_{2-})$에 의한 것이라고 최근 보고된 바, 항산화작용을 갖는 taurine을 가지고 paraquat 독성 경감 효과 및 억제 기전에 관한 실험을 하게 되었으며 다음과 같은 결론을 얻게 되었다. 혈액생화학적인자 분석을 종합해 보면 paraquat의 독성 경감효과는 taurine, aloesin, ${\beta}-carotene$ 중 taurine이 가장 우수하였으며, aloesin도 효과가 있는 것으로 나타났다. In vivo에서 taurine은 혈액생화학적 검사에서 paraquat에 의해 유도된 간독성 지표인 sGPT. sGOT치, 신장독성 지표인 BUN, creatinine치 및 조직 손상의 지표인 ALP, MDA치를 정상으로 회복시켰다. 폐조직중의 MDA량, ALP 활성 및 collagen 량이 정상치로 회복이 되었다. 이로써 taurine은 paraquat의 폐독성 및 각 장기의 독성을 효과적으로 경감 시켜 준다는 사실을 확인할 수 있었다.

• KSBB Journal
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• 제28권4호
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• pp.230-237
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• 2013

Amyloid ${\beta}$ peptide (A${\beta}$) still best known as a molecule to cause Alzheimer's disease (AD). AD is characterized by the accumulation and deposition of A${\beta}$ within the brain, leading to neuronal cell loss and perturbation of synaptic function by causing free radical formation, inflammation and apoptosis. We investigated the inflammatory action of A${\beta}$ on two types of brain cells, neuronal cells (SH-SY5Y) and neuroglia cells (C6), and its mechanism. We measured the production of NO-iNOS, TNF-${\alpha}$, and ICAM-1 using RT-PCR and Western blot analysis less than the concentration of cytotoxic effects (> 70% survivability). A${\beta}$ had no effect on the production of NO and TNF-${\alpha}$, but significantly increases of iNOS and ICAM-1. Based on this, we suggest that the inflammatory effect of A${\beta}$ results from the action of ICAM-1 in neuronal cells, rather than the release of inflammatory mediators such as NO and TNF-${\alpha}$ in neuroglia cells. In addition, we confirmed whether p53 was related to the action of A${\beta}$ by using SH-SY5Y ($p53^{-/-}$) dominant cells. Neither the expression of p53 nor the cytotoxicity of SH-SY5Y ($p53^{-/-}$) cells were directly affected by A${\beta}$. However, ICAM-1 was not expressed in SH-SY5Y ($p53^{-/-}$) cells. This means that p53- independent pathway exists in the expression of ICAM-1 by A${\beta}$ while p53 plays a role as an on-and-off switch.