• Title/Summary/Keyword: C-H activation

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The Effect of Propofol on Hypoxic damaged-HaCaT Cells

  • Park, Chang-Hoon;Kwak, Jin-Won;Park, Bong-Soo;Kim, Yong-Ho;Kim, Yong-Deok;Yoon, Ji-Uk;Yoon, Ji-Young;Kim, Cheul-Hong
    • Journal of The Korean Dental Society of Anesthesiology
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    • v.14 no.1
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    • pp.41-47
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    • 2014
  • Background: Autophagy is a self-eating process that is important for balancing sources of energy at critical times in development and in response stress. Autophagy also plays a protective role in removing clearing damaged intracellular organelles and aggregated proteins as well as eliminating intracellular pathogens. The purpose of the present study was to examine the protective effect of propofol against hypoxic damage using keratinocytes. Methods: Human keratinocytes (HaCaT cells) were obtained from the American Type Culture Collection. Propofol which were made by dissolving them in DMSO were kept frozen at $-4^{\circ}C$ until use. The stock was diluted to their concentration with DMEM when needed. Prior to propofol treatment cells were grown to about 80% confluence and then exposed to propofol at different concentrations (0, 25, 50, 75, $100{\mu}M$) for 2 h pretreatment. Cell viability was measured using a quantitative colorimetric assay with thiazolyl blue tetrazolium bromide (MTT assay), and fluorescence microscopy and western blot analysis were used for evaluation of autophagy processes. Results: The viability of propofol-treated HaCaT cells was increased in a dose-dependent manner. Propofol did not show any significant toxic effect on the HaCaT cells. The autophagy inhibitor, 3-methyladenine, reduced cell viability of hypoxia-injured HaCat cells. Fluorescence microscopy and western blot analysis showed propofol induce autophagy pathway signals. Conclusions: Propofol enhanced viability of hypoxia-injured HaCaT cells and we suggest propofol has cellular protective effects by autophagy signal pathway activation.

Development of Light-weight Fire Protection Materials Using Fly Ash and Light-weight Aggregate (플라이애시 및 경량골재를 활용한 경량 내화성 마감재료 개발)

  • Song, Hun;Chu, Yong-Sik;Lee, Jong-Kyu;Lee, Sea-Hyun
    • Journal of the Korean Recycled Construction Resources Institute
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    • v.6 no.4
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    • pp.95-102
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    • 2012
  • The serious issue of tall building is to ensure the fire resistance of high strength concrete. Therefore, Solving methods are required to control the explosive spalling. The fire resistant finishing method is installed by applying a fire resistant material as a light-weight material to structural steel and concrete surface. This method can reduce the temperature increase of the reinforcement embedded in structural steel and concrete at high temperature due to the installation thickness control. This study is interested in identifying the effectiveness of light-weight fire protection material compounds including the inorganic admixture such as fly ash, meta-kaolin and light-weight aggregate as the fire resistant finishing materials through the analysis of fire resistance and components properties at high temperature. Also, this paper is concerned with change in microstructure and dehydration of the light-weight fire protection materials at high temperatures. The testing methods of fire protection materials in high temperature properties are make use of SEM and XRD. The study results show that the light-weight fire resistant finishing material composed of fly ash, meta-kaolin and light-weight aggregate has the thermal stability of the slight decrease of compressive strength at high temperature. These thermal stability is caused by the ceramic binding capacity induced by alkali activation reaction by the reason of the thermal analysis result not showing the decomposition of calcium hydrate. Developed light-weight fire protection materials showed good stability in high Temperatures. Thus, the results indicate that it is possible to fireproof panels, fire protection of materials.

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Evaluation of the Genetic Toxicity of Synthetic Chemicals (XI) - a Synthetic Sulfonylurea Herbicide, Pyrazosulfuron-ethyl-

  • Ryu, Jae-Chun;Kim, Eun-Young;Kim, Young-Seok;Yun, Hye-Jung
    • Environmental Mutagens and Carcinogens
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    • v.24 no.1
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    • pp.33-39
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    • 2004
  • To validate and to estimate the chemical hazard playa very important role to environment and human health. The detection of many synthetic chemicals including agrochemicals that may pose a genetic hazard in our environment is of great concern at present. Since these substances are not limited to the original products, and enter the environment, they have become widespread environmental pollutants, thus leading to a variety of chemicals that possibly threaten the public health. Pyrazosulfuron-ethyl [Ethyl-5-(4,6-dimethoxypyrimidin-2-ylcarbamoylsulfamoyl)-1-methylpyrazole-4-carboxylate, $C_{14}H_{18}N{6}O_{7}S,$ M.W. =414.39, CAS No. 93697-74-6], is one of well known rice herbicide belong in the sulfonyl urea group. To clarify the genotoxicity of this agrochemical, Ames bacterial reversion assay, in vitro chromosomal aberration assay with Chinese hamster lung (CHL) fibroblast and bone marrow micronucleus assay in mice were subjected. In Ames assay, although pyrazosulfuron-ethyl revealed cytotoxic at 5,000-140 $\mug/plate$ in Salmonella typhimurium TA100, no dose-dependent mutagenic potential in 4.4~70 $\mug/plate$ of S. typhimurium TA 98, TA 100, TA1535 and TA 1537 both in the absence and presence of S-9 metabolic activation system was observed. Using CHL fibroblasts, the 50% cell growth inhibition concentration $(IC_{50})$ of pyrazosulfuron-ethyl was determined as 1,243 $\mug/mL,$ and no chromosomal aberration was observed both in the absence and presence of S-9 mixture in the concentration range of 311-1,243 $\mug/mL.$ And also, in vivo micronucleus assay using mouse bone marrow, pyrazosulfuron-ethyl revealed no remarkable induction of MNPCE (micronucleated polychromatic erythrocytes/1000 polychromatic erythrocytes) in the dose range of 625-2,500 mg/kg body weight when administered orally. Consequently, Ames bacterial gene mutation with Salmonella typhimurium, in vitro chromosome aberration with mammalian cells and in vivo bone marrow micronucleus assay revealed no clastogenic potential of pyrazosulfuron-ethyl in this study.

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Protection by Chrysanthemum zawadskii extract from liver damage of mice caused by carbon tetrachloride is maybe mediated by modulation of QR activity

  • Seo, Ji-Yeon;Lim, Soon-Sung;Park, Ji-A;Lim, Ji-Sun;Kim, Hyo-Jung;Kang, Hui-Jung;YoonPark, Jung-Han;Kim, Jong-Sang
    • Nutrition Research and Practice
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    • v.4 no.2
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    • pp.93-98
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    • 2010
  • Our previous study demonstrated that methanolic extract of Chrysanthemum zawadskii Herbich var. latilobum Kitamura (Compositae) has the potential to induce detoxifying enzymes such as NAD(P)H:(quinone acceptor) oxidoreductase 1 (EC 1.6.99.2) (NQO1, QR) and glutathione S-transferase (GST). In this study we further fractionated methanolic extract of Chrysanthemum zawadskii and investigated the detoxifying enzyme-inducing potential of each fraction. The fraction (CZ-6) shown the highest QR-inducing activity was found to contain (+)-(3S,4S,5R,8S)-(E)-8-acetoxy-4-hydroxy-3-isovaleroyloxy-2-(hexa-2,4-diynyliden)-1,6-dioxaspiro [4,5] decane and increased QR enzyme activity in a dose-dependent manner. Furthermore, CZ-6 fraction caused a dose-dependent enhancement of luciferase activity in HepG2-C8 cells generated by stably transfecting antioxidant response element-luciferase gene construct, suggesting that it induces antioxidant/detoxifying enzymes through antioxidant response element (ARE)-mediated transcriptional activation of the relevant genes. Although CZ-6 fraction failed to induce hepatic QR in mice over the control, it restored QR activity suppressed by $CCl_4$ treatment to the control level. Hepatic injury induced by $CCl_4$ was also slightly protected by pretreatment with CZ-6. In conclusion, although CZ-6 fractionated from methanolic extract of Chrysanthemum zawadskii did not cause a significant QR induction in mice organs such as liver, kidney, and stomach, it showed protective effect from liver damage caused by $CCl_4$.

Induction of Apoptosis and Cell Cycle Arrest by Jageum-Jung in HepG2 Hepatoma Cells (자금정(紫金錠)이 간암세포주 HepG2의 세포고사 및 세포주기에 미치는 영향)

  • Cho, Young-Kee;Jeon, Ji-Young;Shin, Yong-Jeen;Seol, Jae-Kyun;Rhee, Jae-Hwa;Won, Jin-Hee;Moon, Goo
    • The Journal of Internal Korean Medicine
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    • v.28 no.4
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    • pp.694-708
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    • 2007
  • Objectives : Jageum-Jung is used as an anti-cancer agent in oriental medicine, but the mechanism by which it induces cell death in cancer cells is still unclear. The purpose of this study was to investigate the effects of Jageum-Jung on apoptosis and cell cycle arrest in HepG2 hepatoma cells. Methods : Various cancer cell lines including HepG2, C6 glioma, SH-SY5Y, PANC-1, and MCF-7 cells, were used. Apoptosis was determined by DAPI nuclei staining and flow cytometry in HepG2 cells treated with various concentrations (from 25 to 200 ${\mu}g/ml$) of $H_2O$ extract of Jageum-Jung (JGJ) for 48 hrs. Expression of cell cycle arrest mediators including Rb, p53, p21, cyclin B1, cdk4, and cyclin E proteins were measured by Western blot analysis. To estimate intracellular hydrogen peroxide levels and intracellular nitric oxide levels, HepG2 cells were stained with DCFH-DA dye and DAF dye, subjected on flow cytometric analysis. Results : 1. Jageum-Jung decreased the viability of HepG2 cells in a dose-dependent manner. 2. Jageum-Jung induced the catalytic activation of caspase-3 in HepG2 cells. 3. Jageum-Jung increased the intracellular hydrogen peroxide and NO in HepG2 cells. 4. Jageum-Jung increased the expression of Rb, p53 and p21 in HepG2 cells. 5. Jageum-Jung induced the expression of cyclin B1, cdk4, and cyclin E in HepG2 cells. Conclusions : Taken together, we suggest that Jageum-Jung exhibits cytotoxic effects on HepG2 cells, causing apoptosis and cell cycle arrest. The results showed that Jageum-Jung may do so by regulating the expression of specific target molecules that promote efficient apoptotic cell death following $G_2$/M phase arrest in a dose-dependent manner.

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Characterization of Phytase from Bacillus coagulans IDCC 1201 (Bacillus coagulans IDCC 1201이 생산하는 Phytase의 특성)

  • Lee Seung-Hun;Kwon Hyuk-Sang;Koo Kyo-Tan;Kang Byung-Hwa;Kim Tae-Yong
    • Microbiology and Biotechnology Letters
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    • v.34 no.1
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    • pp.28-34
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    • 2006
  • A native extracellular acid phosphatase, phytase (EC 3.1.3.8), from Bacillus coagulans IDCC 1201 (commercially known as Lactobacillus sporogenes) used as probiotics, was characterized. Though some strains of B. coagulans have been evaluated with regard to several health-promoting effects, it has not been reported to produce phytase. Partially purified phytase front the strain IDCC 1201 had a pH optimum of 4.0 and a temperature optimum of $50^{\circ}C$, respectively. The requirement for divalent cations was studied and cobalt ion remarkably increased the enzyme activity. The removal of metal ions from the enzyme by EDTA decreased activity below 50%. The enzyme activity depleted restored when the assay was performed in the presence of $Co^{2+}$. Also, $Co^{2+}$ is the most active stimulator and has unique activation effect at high temperature. The phytase was specific for sodium phytate and p-nitrophenylphosphate, which is different from other known Bacilli phytases. The putative amino acid sequences of the phytase from B. coagulans IDCC 1201 were very similar to that of the phytase from B. subtilis strain 168. Based on these data, we concluded that the phytase from B. coagulans IDCC 1201 is a $Co^{2+}$-dependent acid phosphatase. Therefore, the strain B. coagulans IDCC 1201 is thought to be a valuable addititive for livestocks as well as a beneficial probiotics for human.

Modulation of Pituitary Somatostatin Receptor Subtype (sst1-5) mRNA Levels by Growth Hormone (GH)-Releasing Hormone in Purified Somatotropes

  • Park, Seung-Joon;Park, Hee-Soon;Lee, Mi-Na;Sohn, Sook-Jin;Kim, Eun-Hee;Jung, Jee-Chang;Frohman, Lawrence A.;Kineman, Rhonda D.
    • The Korean Journal of Physiology and Pharmacology
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    • v.7 no.2
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    • pp.79-84
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    • 2003
  • We have previously reported that expression of the somatostatin receptor subtypes, sst1-5, is differentially regulated by growth hormone (GH)-releasing hormone (GHRH) and forskolin (FSK), in vitro. GHRH binds to membrane receptors selectively located on pituitary somatotropes, activates adenylyl cyclase (AC) and increases sst1 and sst2 and decreases sst5 mRNA levels, without significantly altering the expression of sst3 and sst4. In contrast FSK directly activates AC in all pituitary cell types and increases sst1 and sst2 mRNA levels and decreases sst3, sst4 and sst5 expression. Two explanations could account for these differential effects: 1) GHRH inhibits sst3 and sst4 expression in somatotropes, but this inhibitory effect is masked by expression of these receptors in unresponsive pituitary cell types, and 2) FSK inhibits sst3 and sst4 expression levels in pituitary cell types other than somatotropes. To differentiate between these two possibilities, somatotropes were sequentially labeled with monkey anti-rat GH antiserum, biotinylated goat anti-human IgG, and streptavidin-PE and subsequently purified by fluorescent-activated cell sorting (FACS). The resultant cell population consisted of 95% somatotropes, as determined by GH immunohistochemistry using a primary GH antiserum different from that used for FACS sorting. Purified somatotropes were cultured for 3 days and treated for 4 h with vehicle, GHRH (10 nM) or FSK ($10{\mu}M$). Total RNA was isolated by column extraction and specific receptor mRNA levels were determined by semi-quantitative multiplex RT-PCR. Under basal conditions, the relative expression levels of the various somatostatin receptor subtypes were sst2>sst5>sst3=sst1> sst4. GHRH treatment increased sst1 and sst2 mRNA levels and decreased sst3, sst4 and sst5 mRNA levels in purified somatotropes, comparable to the effects of FSK on purified somatotropes and mixed pituitary cell cultures. Taken together, these results demonstrate that GHRH acutely modulates the expression of all somatostatin receptor subtypes within GH-producing cells and its actions are likely mediated by activation of AC.

Immune-Enhancing Effects of Polysaccharides Isolated from Phellinus linteus Mycelium on Mori ramulus (상지에 배양한 상황버섯 균사체로부터 분리된 다당류의 면역증강 효과)

  • Park, Hye-Mi;Hong, Joo-Heon
    • Journal of the Korean Society of Food Science and Nutrition
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    • v.46 no.1
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    • pp.26-33
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    • 2017
  • The objective of this study was to examine the immune-enhancing effects of polysaccharides isolated from Phellinus linteus mycelium on Mori ramulus. Crude polysaccharides were isolated by pressurized extraction ($121^{\circ}C$, $1.2kgf/cm^2$, 3 h), ethanol precipitation, and lyophilization. In addition, crude polysaccharides were further fractionated into unabsorbed fractions (PF-1, fraction No. 3~15) and absorbed fractions (PF-2, fraction No. 24~33) by DEAE-sepharose CL-6B column chromatography in order to isolate immune-regulating polysaccharides. The major constituents in PF-1 and PF-2 were total sugar (75.51% and 52.38%), total protein (1.63% and 8.41%), uronic acid (17.53% and 15.04%), and ${\beta}-glucan$ (28.33% and 25.04%), respectively. PF-1 increased production of nitric oxide (NO) and cytokines, such as tumor necrosis factor-alpha ($TNF-{\alpha}$) and interleukin-6 (IL-6) in a dose-dependent manner. The mRNA expression levels of inducible NO synthetase, cyclooxygenase-2, $TNF-{\alpha}$, and IL-6 markedly increased as determined by polymerase chain reaction analysis. The above data led us to conclude that macrophage activation of purified polysaccharides was higher than that of crude polysaccharides. The polysaccharides isolated from P. linteus mycelium on M. ramulus investigated herein are useful as natural immune-enhancing agents.

Molecular Cloning and Characterization of a P38-Like Mitogen-Activated Protein Kinase from Echinococcus granulosus

  • Lu, Guodong;Li, Jing;Zhang, Chuanshan;Li, Liang;Bi, Xiaojuan;Li, Chaowang;Fan, Jinliang;Lu, Xiaomei;Vuitton, Dominique A.;Wen, Hao;Lin, Renyong
    • Parasites, Hosts and Diseases
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    • v.54 no.6
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    • pp.759-768
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    • 2016
  • Cystic echinococcosis (CE) treatment urgently requires a novel drug. The p38 mitogen-activated protein kinases (MAPKs) are a family of Ser/Thr protein kinases, but still have to be characterized in Echinococcus granulosus. We identified a 1,107 bp cDNA encoding a 368 amino acid MAPK protein (Egp38) in E. granulosus. Egp38 exhibits 2 distinguishing features of p38-like kinases: a highly conserved T-X-Y motif and an activation loop segment. Structural homology modeling indicated a conserved structure among Egp38, EmMPK2, and H. sapiens $p38{\alpha}$, implying a common binding mechanism for the ligand domain and downstream signal transduction processing similar to that described for $p38{\alpha}$. Egp38 and its phosphorylated form are expressed in the E. granulosus larval stages vesicle and protoscolices during intermediate host infection of an intermediate host. Treatment of in vitro cultivated protoscolices with the p38-MAPK inhibitor ML3403 effectively suppressed Egp38 activity and led to significant protoscolices death within 5 days. Treatment of in vitro-cultivated protoscolices with $TGF-{\beta}1$ effectively induced Egp38 phosphorylation. In summary, the MAPK, Egp38, was identified in E. granulosus, as an anti-CE drug target and participates in the interplay between the host and E. granulosus via human $TGF-{\beta}1$.

DNA Microarray Analysis of the Gene Expression Profile of Activated Human Umbilical Vein En-dothelial Cells. (올리고 마이크로어래이를 이용한 활성화된 인간 제대 정맥 내피세포의 유전자 발현 조사)

  • 김선용;오호균;이수영;남석우;이정용;안현영;신종철;홍용길;조영애
    • Journal of Life Science
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    • v.14 no.5
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    • pp.874-881
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    • 2004
  • Angiogenesis has been implicated in progression of inflammation, arthritis, psoriasis, atherosclerosis as well as tumor growth and metastasis. Intensive studies have been carried out to develop a strategy for cancer treatment by blocking angiogenesis. During angiogenesis, endothelial proliferation and migration essentially occurs upon activation. In this study, we compared the expression profiles of human umbilical endothelial cells activated by incubating in vitro in the rich medium containing several growth factors, and non-activated ones. cDNA targets derived from total RNAs of HUVEC activated for 13 h in M199 medium containing endothelial cell growth supplement, 20% fetal bovine serum, and heparin, after reaching 70~80% confluency, or non-activated, were hybridized onto oligonucleotide microarrays containing 1,8864 genetic elements. Unsupervised hierarchical clustering analysis resulted in two subgroups on dendrogram exhibiting activated and non-activated HUVECs. We then extracted 122 outlier genes which were shown to be up-regulated or under-expressed by at least 2-folds in activated HUVECs. Among these, 32 annotated genes were up-regulated and 38 were down-regulated in activated HUVECs. Interestingly, genes involved in cell proliferation, motility, and inflammation/ immune response were up-regulated in activated HUVEC, whereas genes for cell adhesion or vessel morphogenesis/function were down-regulated. Unexpectedly, the expression of genes well-characterized as angiogenesis markers was not changed except Eph-B4, which was down-regulated about 4 folds. 52 unknown genes were also up- or down-regulated. Therefore, these results could provide an opportunity to targeting new vascular molecules for the development of anti-angiogenic molecules.