• Title/Summary/Keyword: Membrane permeability

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Thiol Methyltransferase Activity in Cholestatic Rat Liver Induced by Commom Bile Duct Ligation

  • Joo, Il;Kwak, Chun-Sik;Yoon, Chong-Guk
    • Biomedical Science Letters
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    • v.10 no.1
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    • pp.43-48
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    • 2004
  • Changes of thiol methyltransferase (TMT) activity in cholestatic rat liver were studied. Hepatic subcellular and serum TMT activities were determined in cholestatic rat induced by common bile duct (CBD) ligation over a period 28 days. The mitochondrial and microsomal TMT activities in cholestatic rat liver were found to be significantly increased between the 1st and the 28th day after CBD ligation. The TMT activity in serum was significantly increased throughout the experiments. The Vmax values of the above hepatic TMT in cholestatic rat were significantly increased at the 7th day after CBD ligation. However, the Km values of the above hepatic enzymes did not vary in all the experimental groups. Therefore, the results indicate that the biosynthesis of TMT was increased in cholestatic rat liver. The elevated serum TMT activity is most likely caused by increased hepatocytes membrane permeability due to cholestasis mediated liver cell necrosis.

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Effect of Acanthopanax senticosus Extracts on Alcohol Degradation and Anti-Inflammatory Activity in Mice (가시오가피 추출물의 알코올 분해 및 항염증 효과)

  • Yoon, Taek-Joon;Jo, Seon-Yoong
    • The Korean Journal of Food And Nutrition
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    • v.23 no.4
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    • pp.542-548
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    • 2010
  • This study was conducted to investigate the effects of Acanthopanax senticosus extracts(ASE) on alcohol administered mice. The administration of Acanthopanax senticosus extracts(60 mg/kg) had beneficial actions toward alcohol degradation in acute alcohol treated mice. In the acute alcohol degradation experiment, serum alcohol concentration were lower 3 and 6 hours after taking ethanol(5 g/kg) in ASE treated mice. The oral administration of ASE showed decreased gastric mucous membrane damage produced in ethanol treated mice. In addition, intraperitoneal(i.p.) administration of ASE showed antiinflammatory effects in inhibition tests of vascular permeability produced by acetic acid. ASE also reduced concentrations of nitric oxide(NO), tumor necrosis alpha(TNF)-${\alpha}$ and interleukin(IL)-6 in macrophages that were activated by LPS. These results demonstrate that Acanthopanax senticosus extracts possesses the potential to stimulate alcohol degradation and inhibit inflammatory effects in mice.

Protective Effects of Palmul-tang on Hypoxia-induced Apoptosis in H9c2 Cardiomyoblast Cells (팔물탕이 저산소증에 의한 배양심근세포고사에 미치는 영향)

  • 임은경;신선호
    • The Journal of Korean Medicine
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    • v.25 no.2
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    • pp.67-76
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    • 2004
  • Objectives : This study was designed to investigate the protective mechanisms of Palmul-tang on hypoxia-induced cytotoxicity in H9c2 cardiomyoblast cells. Methods : In this study, we used H9c2 cells. Cells were subjected to hypoxia in the absence and presence of $1000\mu\textrm{g}/ml$ Palmul-tang for 24 hrs. Cells were treated with various concentrations of Palmul-tang for 24 hrs. Cell viability was measured by MTT assay. Hypoxia markedly decreased the viability of H9c2 cells, which was characterized with apparent apoptotic features such as chromatin condensation as well as fragmentation of genomic DNA and nuclei. Results : Palmul-tang significantly reduced hypoxia-induced cell death and apoptotic characteristics. Also, Palmul-tang prevented mitochondrial dysfunction including the disruption of mitochondrial membrane permeability transition (MPT) and an increase in expression of apoptogenic Bcl-2 proteins in hypoxia-H9c2 cells. Conclusions; This study suggests that the protective effects of Palmul-tang against hypoxic damages may be mediated by the modulation of Bcl-2, Bax expression.

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The Development of gasket for Proton Exchange Membrane Fuel Cell (고분자 전해질 연료전지용 Gasket 개발)

  • Chun, Hyun-A;Seoung, Dong-Muk;Kim, Tae-Min
    • 한국신재생에너지학회:학술대회논문집
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    • 2007.06a
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    • pp.166-168
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    • 2007
  • 고분자 전해질 연료전지는 다수의 단위 cell을 적층하여 stack을 형성하게 되며, 각 단위 cell 은 분리판과 MEA 사이에 gasket을 장착하게 된다. 이때 장착된 gasket은 분리판과 MEA사이의 일정한 gap을 유지하여 가스를 균일하게 분배되도록 할 뿐만 아니라, 가스 유출을 막는 sealing 재(材)로서의 역할을 한다. 따라서 고분자 전해질 연료전지의 성능확보를 위해서는 내구성 및 가스 기밀성이 우수한 gasket 개발이 무엇보다 중요하다. 본 연구에서는 이러한 gasket 물성을 만족시킬 수 있는 고분자 전해질 연료전지용 gasket을 개발하고자 하였으며, 이를 검증하기 위하여 가혹 조건에서 실험을 수행하였다. 그 결과 종래의 gasket 보다 열적, 화학적 및 가스기밀성 변에서 우수한 고분자 전해질 연료전지용 gasket을 얻을 수 있었다.

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Characterization of a paraquat resistance of Ochrobactrum anthropi JW-2. (Ochrobactrum anthropi JW-2의 paraquat 내성에 관한 특성)

  • 원성혜;이병현;조진기
    • Microbiology and Biotechnology Letters
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    • v.28 no.1
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    • pp.1-7
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    • 2000
  • The bacterial strain JW-2 which conferred resistance against paraquat (1,1'-dimethyl-4,4'-bipyridinium dichloride) was isolated from soil. The strain was identified as an Ochrobactrum anthropi based on its morphological, physiological, biological and fatty acid composition, and was designated as Ochrobactrum anthropi JW-2. We compard paraquat resistance of O. anthropi JW-2 with Escherichia coli J105. In the presence of 100mM paraquat, E. coli JM105 was not grown whereas the growth rate of O. anthropi was about 70% of control. We compared the sensitivity of O. anthropi JW-2 and E. coli J105 to redox-cycling compounds such as paraquat, plumbagin or menadione, which are known to exacebate wuperoxide generation. O. anthropi JW-2 did not show cross-resistance to plumbagin or menadione. superoxide dismutase activity was increased in paraqunt-treated E. coli JM105 while it was not increased in O.anthropi JW-2. These results suggest that the mechanism of paraquat resistance in O.anthropi JW-2 is probably due to selectively decreased permeability toward paraquat by membrane protein.

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Interactive Effects of UV-B and Pesticides on Photosynthesis and Nitrogen Fixation of Anabaena doliolum

  • Chandrai, Lar;Vandana, Pandey
    • Journal of Microbiology and Biotechnology
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    • v.12 no.3
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    • pp.423-430
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    • 2002
  • The effects of UV-B and commercial grade pesticides (butachlor and carbofuran), individually and in combination, were studied on a variety of physiological processes of rice field cyanobacterium Anabaena doliolum. Butachlor was found to be $2-12\%$ more toxic than carbofuran and $4-24\%$ than UV-B on the growth, photosynthesis, lipid peroxidation, membrane permeability, and nitrogenase activity of the test cyanobacterium. Of the three photosynthesis inhibitors, the butachlor-induced inhibition of whole chain was approximately 3 and $21\%$ higher than carbofuran and UV-B, respectively. Although the interaction of the stress factors caused a significant inhibition (P<0.01), it was still less than the additive effect on the parameters investigated, except for PSI.

Dual Phase Conductive CO2 Membranes: Mechanism, Microstructure, and Electrical Conductivity (Dual Phase 전도성 CO2 분리막: 메커니즘, 미세구조 및 전기전도도)

  • Lee, Shi-Woo;Yu, Ji-Haeng;Woo, Sang-Kuk
    • Journal of the Korean Ceramic Society
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    • v.44 no.8
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    • pp.424-429
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    • 2007
  • Novel conductive $CO_2$ membranes composed of dual phases, molten carbonates and electronic conducting ceramics, were investigated. As the microstructure control of electronic conducting ceramic supports is extremely important to keep the molten carbonates stable in the membranes by a capillary force applied by the pore structure of the supports, we have scrutinized the microstructure of the electronic conducting supports utilizing microscopic images and gas permeability measurement. From the evaluation of the electrical conductivities of the molten carbonates and the electronic conducting ceramic supports, we found that the ionic conductivity of the molten carbonates could determine $CO_2$ flux through the dual phase membranes if the surface exchange rate were relatively high enough.

A Study on the Development of the Wheel Tracking Test and Evaluation Method on Blind Type of Waterproofing Layer (비노출 방수층의 윤하중 시험 및 평가방법 개발에 관한 실험적 연구)

  • Song Je-Young;Eom Deok-Jun;Kwak Kyu-Sung;Oh Sang-Keun
    • Journal of the Korea Institute of Building Construction
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    • v.6 no.1 s.19
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    • pp.67-72
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    • 2006
  • There are a lot of problem about waterproofing membrane coating for concrete deck of bridge and waterproofing sheets for concrete of deck of bridge because it couldn't confirm waterproofing's defeat after construction. These problems make a waterproofing material damage and condrete deck of bridge damage. So It needs a lot of money for repair work and reinforcement work. Therefor the structure slab of using waterproofing material protect invasion of water. Also, Concrete deck of bridge need a endurance permeability for the reduction repair payment. In this study, An experimental study on the quality standardization test method waterproofing layer on working of live load.

Effect of Carbon Tetrachloride on the Changes of Guanase Activity in-Rats Fed Low or High Proteins Diet (食餌性 蛋白質含量에 따른 흰쥐에 사염화탄소 投與가 Guanase 活性變動에 미치는 영향)

  • Kang, Hoe-Yang
    • Journal of Environmental Health Sciences
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    • v.14 no.1
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    • pp.87-101
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    • 1988
  • The effect of hepatic injury produced by CCL, was studied on rats receiving a low protein-high carbohydrate (7% casein), standard protein (20% casein) and a high protein diet (30% casein). The rats fed low protein diet are resistant to CCl$_4$ in its effects on the liver as judged by histology, serum enzymes(guanase, ALT) and the content of hepatic protein. On the other hand, the pretreatment of hydrocortisone before injection of CCl$_4$ to the rats fed a standard diet, slightly decreased both serum ALT and guanase activities. In the pretreatment of actinomycin D, the liver and serum guanase activities were significantly decreased. It indicates that the cause of increasing serum guanase is based on the alteration of membrane permeability and the result of accelerated enzyme synthesis in liver cells of CCl$_4$ intoxicated rats.

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Effects of Intravenous Administration of Taurocholate on Hepatic Monoamine Oxidase A and B Activities in Cholestatic Rats

  • Do Jun-Young;Kwak Chun-Sik
    • Biomedical Science Letters
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    • v.10 no.4
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    • pp.421-427
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    • 2004
  • The possible mechanisms of decreased monoamine oxidase (MAO) A and B activities in cholestatic rat liver were studied. Hepatic and serum MAG activities were determined from the experimental rats with common bile duct ligation (CBDL). The Michaelis-Menten constants in these hepatic enzymes were also measured. The activities of mitochondrial MAO A and B, and mircosomal MAO B as well as their Vmax values were found to be decreased significantly in CBDL plus taurocholic acid (TCA) injected group than in the control group, such as CBDL alone groups. However, their Km values in the experimental groups did not vary. Serum MAO activity increased significantly in the CBDL plus TCA injected group than in the control group. The above results suggest that TCA represses biosynthesis of the MAO in the liver. The elevated activity of the serum MAO is believed to be caused by the increment of membrane permeability ofhepatocytes upon TCA mediated liver cell necrosis.

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