• Title/Summary/Keyword: Mechanistic study

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Security Interpretation of the Restriction Boundary of Building for Antiquated Tunnel using 3 Dimensional Surveying (3차원 측량에 의한 노후 터널의 건축한계 확보 해석)

  • Bae Sang-Ho;Lee Hyung-Seok
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.24 no.3
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    • pp.251-259
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    • 2006
  • For the electrification of the existing railways, the security of the restriction boundary of building with mechanistic stability research on the antiquated tunnel must be accomplished essentially. If the tunnel don't secure its restriction boundary of building, the reconstruction based on improvement of tunnel alignment are generated and its surveying data are required. The precise surveying was conducted with the same coordinate system for three tunnels of Youngdong tramline, and the restriction boundary of building of the straight and curve section were analyzed effectively by acquiring the data of profile and cross section, profile rail-height, rail-grade, cross tunnel height, and restriction boundary of building. This study is presented for valuation data of the stability of the electrification design to construct and analyze restriction boundary of building, which compared with the drawing and its existing design using profile and cross section. After this, it is interoperable to increase the development of real-time monitoring system on the tunnel structures.

Scrophulariae Radix Aqueous Extracts Ameliorate the Pressure Overloaded Heart Failure by Transverse Aortic Constriction in Mice

  • Woo, Seong-jin;Baek, Kyung-min;Jang, Woo-seok
    • The Journal of Internal Korean Medicine
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    • v.39 no.4
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    • pp.624-636
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    • 2018
  • Objectives: The purpose of this study was to investigate the cardioprotective effect of the potent antioxidant properties of Scrophulariae Radix (SR) aqueous extracts by examining pressure overload (PO) heart failure (HF) induced by transverse aortic constriction (TAC) of C57BL/6 mice. Methods: SR (500, 250, 125 mg/kg) and resveratrol (10 mg/kg) were administered orally once a day for 14 days, after the TAC operation. Changes in mortality, the body and heart weights, histopathology of the heart, and antioxidant defense system of the heart were analyzed. Results: After the TAC operation, increases were observed in mortality, heart weights, left ventricular hypertrophy, and lytic and focal fibrotic histological change, and destruction of the heart antioxidant defense system. However, the HF signs showed dose-dependent inhibition following 14 days of continuous oral treatment with SR. A SR dose of 125 mg/kg gave a similar inhibition to that obtained with resveratrol at 10 mg/kg. Conclusions: Oral administration of SR beneficially improves PO-induced HF following TAC surgery by increasing the activity of the heart antioxidant defense system. The overall effect of SR at 125 mg/kg is similar to the effect of resveratrol at 10 mg/kg. However, more detailed mechanistic studies should be performed by screening of the biologically active compounds in SR.

The Anti-Inflammatory Activity of Eucommia ulmoides Oliv. Bark. Involves NF-κB Suppression and Nrf2-Dependent HO-1 Induction in BV-2 Microglial Cells

  • Kwon, Seung-Hwan;Ma, Shi-Xun;Hwang, Ji-Young;Ko, Yong-Hyun;Seo, Ji-Yeon;Lee, Bo-Ram;Lee, Seok-Yong;Jang, Choon-Gon
    • Biomolecules & Therapeutics
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    • v.24 no.3
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    • pp.268-282
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    • 2016
  • In the present study, we investigated the anti-inflammatory properties of Eucommia ulmoides Oliv. Bark. (EUE) in lipopolysaccharide (LPS)-stimulated microglial BV-2 cells and found that EUE inhibited LPS-mediated up-regulation of pro-inflammatory response factors. In addition, EUE inhibited the elevated production of pro-inflammatory cytokines, mediators, and reactive oxygen species (ROS) in LPS-stimulated BV-2 microglial cells. Subsequent mechanistic studies revealed that EUE suppressed LPS-induced phosphorylation of mitogen-activated protein kinases (MAPKs), phosphoinositide-3-kinase (PI3K)/Akt, glycogen synthase $kinase-3{\beta}$ ($GSK-3{\beta}$), and their downstream transcription factor, nuclear factor-kappa B ($NF-{\kappa}B$). EUE also blocked the nuclear translocation of $NF-{\kappa}B$ and inhibited its binding to DNA. We next demonstrated that EUE induced the nuclear translocation of nuclear factor erythroid 2-related factor 2 (Nrf2) and upregulated heme oxygenase-1 (HO-1) expression. We determined that the significant up-regulation of HO-1 expression by EUE was a consequence of Nrf2 nuclear translocation; furthermore, EUE increased the DNA binding of Nrf2. In contrast, zinc protoporphyrin (ZnPP), a specific HO-1 inhibitor, blocked the ability of EUE to inhibit NO and $PGE_2$ production, indicating the vital role of HO-1. Overall, our results indicate that EUE inhibits pro-inflammatory responses by modulating MAPKs, PI3K/Akt, and $GSK-3{\beta}$, consequently suppressing $NF-{\kappa}B$ activation and inducing Nrf2-dependent HO-1 activation.

Effect of Seatangle and Seamustard Intakes on Carcinogen Induced DNA Adduct Formation and the Absorption of Calcium and Iron (다시마와 미역의 섭취가 발암물질에 의한 DNA 손상과 칼슘 및 철 흡수에 미치는 영향)

  • 성미경
    • Journal of Nutrition and Health
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    • v.33 no.7
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    • pp.717-724
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    • 2000
  • A number of epidemiological studies has indicated lifestyles including dietary habits are closely related to the development of certain forms of cancer. These findings have led several investigators to identify the ways in which these factors mdulate the risk of cancer. Seaweeds are rich sources of non-digestible polysaccharides which possibly posses physiological functions. In vitro studies showed several components in seaweeds inhibit tumor cell growth and mutagenicity of known food mutagens. On the other hand non-digestible polysaccharides of different food sources negatively affect mineral nutrition by decreasing mineral absorption. The objectives of this study was to investigate the effect of major seaweed intake on azoxymethane(AOM) - induced DNA damage a known cancer initiation step and on apparent absorption of calcium and iron. To accomplish these objectives twenty five ICR mice were divided into five groups and fed one of the following diets for 10 days : control diet d, diet containing 10% water-soluble fraction of seamustard or seatangle diet containing 10% water-insoluble fraction of seamustard or seatangle. AOM was injected 6 hours before sacrifice and N7-methylated guanines from the colonic DNA were quantified using a gas chromatography -mass spectroscopy. Fecal samples were collected on days 4 and 8. Caclium and iron contents of the diets and feces were analyzed using an atomic absorption spectrophotometry to determine the apparent absorption of these minerals. Results are as follows. AOM-induced guanine methylation of colon was decreased in animals fed diets containing water-soluble fractions of seamustard or seatangle compared to those in animals fed control diet although only the seatnagle fed group showed statistically significant effect. Apparent calcium absorption was significantly reduced in animals fed diets containing water-insoluble fractions of seaweeds. Iron absorption was significantly decreased and negatively balanced in animals fed diets containing water-insoluble fractions of both seaweeds, and water-soluble fraction of seatangle. In conclusion, seamustard and seatangle intakes may effectively prevent colon tumorigenesis by reducing a carcinogen-induced DNA damages, and more mechanistic studies on possible role of seaweeds on carcinogenesis are required. Also, adverse effects of seaweed diets cintaming a large amount of polysaccharides on mineral nutrition should be carefully monitored.

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Kalopanaxsaponin A Exerts Anti-Inflammatory Effects in Lipopolysaccharide-Stimulated Microglia via Inhibition of JNK and NF-κB/AP-1 Pathways

  • Jeong, Yeon-Hui;Hyun, Jin-Won;Le, Tien Kim Van;Kim, Dong-Hyun;Kim, Hee-Sun
    • Biomolecules & Therapeutics
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    • v.21 no.5
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    • pp.332-337
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    • 2013
  • Microglial activation plays an important role in the development and progression of various neurological disorders such as cerebral ischemia, multiple sclerosis, and Alzheimer's disease. Thus, controlling microglial activation can serve as a promising therapeutic strategy for such brain diseases. In the present study, we showed that kalopanaxsaponin A, a triterpenoid saponin isolated from Kalopanax pictus, inhibited inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and tumor necrosis factor (TNF)-${\alpha}$ expression in lipopolysaccharide (LPS)-stimulated microglia, while kalopanaxsaponin A increased anti-inflammatory cytokine interleukin (IL)-10 expression. Subsequent mechanistic studies revealed that kalopanaxsaponin A inhibited LPS-induced DNA binding activities of NF-${\kappa}B$ and AP-1, and the phosphorylation of JNK without affecting other MAP kinases. Furthermore, kalopanaxsaponin A inhibited the intracellular ROS production with upregulation of anti-inflammatory hemeoxygenase-1 (HO-1) expression. Based on the previous reports that JNK pathway is largely involved in iNOS and proinflammatory cytokine gene expression via modulating NF-${\kappa}B$/AP-1 and ROS, our data collectively suggest that inhibition of JNK pathway plays a key role in anti-inflammatory effects of kalopanaxsaponin A in LPS-stimulated microglia.

CB6F1-Tg rasH2 Mouse Carrying Human Prototype c-Ha-ras Gene As an Alternative Model For Carcinogenicity Testing For Pharmaceuticals

  • Usui, T.;Urano, K.;Suzuki, S.;Hioki, K.;Maruyama, Ch.;Tomisawa, M.;Ohnishi, Y.;Suemizu, H.;Yamamoto, S.
    • Toxicological Research
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    • v.17
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    • pp.293-297
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    • 2001
  • The international pharmaceutical and regulatory communities had been recognizing the limited utility of conventional rodent carcinogenicity study particularly on the second species, mouse, after intense investigation of carcinogenicity data base worldwide, and a new scheme for carcinogenicity testing for pharmaceuticals was proposed at the Expert Working Group on Safety in the International Conference on Harmonization (ICH) in 1996. CB6F 1-Tg rasH2 mouse carrying human prototype c-Ha-ras gene with its own promoter/enhancer is one oj the new carcinogenicity assay model for human cancer risk assessment. Studies have been conducted since 1992 to validate the transgenic (Tg) mice for rapid carcinogenicity test-ing, short term (26 weeks) studies with genotoxic (by Salmonella), non-genotoxic carcinogens, genotoxic non-carcinogens, non-genotoxic non-carcinogens revealed relatively high concordance oj the response of the Tg mouse with classical bioassay across classes of carcinogenic agents. Mechanistic basis for carcinogensis in the model are being elucidated in terms of the role of overexpression and/or point mutation of the transgene. This report review the initial studies of validation of the model and preliminary results of on-going ILSI HESI ACT project will be presented.

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Absorption Characteristics of Aqueous Sodium Glycinate Solution with Carbon Dioxide and Its Mechanistic Analysis (Sodium Glycinate 수용액의 CO$_2$ 흡수특성 및 반응 메커니즘 해석)

  • Shim, Jae-Goo;Kim, Jun-Han;Jang, Kyung-Ryong
    • Journal of Korean Society of Environmental Engineers
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    • v.30 no.4
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    • pp.430-438
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    • 2008
  • The experiments for separation and recovery of CO$_2$ were conducted by aqueous sodium glycinate solution, which is one of the amino acid salts, as an absorbent of CO$_2$ in this study. Absorption capacities of aqueous MEA and sodium glycinate solution according to partial pressure of CO$_2$ were evaluated by vapor-liquid equilibrium tests of 20 wt% and 30 wt% above-mentioned absorbents, respectively. In addition, the pilot scale(2 t-CO$_2$/day) experiments based on prior results were carried out. As a result, CO$_2$ removal efficiency of aqueous sodium glycinate solution was lower than that of aqueous MEA solution. This phenomenon means that CO$_2$ removal efficiency of aqueous sodium glycinate solution mainly depends on its molecular structure. Consequently, the first application of certain amino acid salt, as an absorbent of CO$_2$, to pilot plant of 2 t-CO$_2$/day scale was carried out in our country.

Mechanistic insights of metal acetylacetonate-aided dehydrocoupling of liquid-state ammonia borane NH3BH3

  • Pereza, Manon;Mieleb, Philippe;Demirci, Umit B.
    • Advances in Energy Research
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    • v.4 no.2
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    • pp.177-187
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    • 2016
  • Ammonia borane $NH_3BH_3$ solubilized in organic solvent is a potential liquid-state chemical hydrogen storage material. In this study, metal acetylacetonates like $Fe(O_2C_5H_7)_3$, $Co(O_2C_5H_7)_2$, $Ni(O_2C_5H_7)_2$, $Pd(O_2C_5H_7)_2$, $Pt(O_2C_5H_7)_2$ and $Ru(O_2C_5H_7)_3$ are considered for assisting dehydrocoupling of ammonia borane in diglyme (0.135 M) at $50^{\circ}C$. The molar ratio between ammonia borane and metal acetylacetonate is fixed at 100. A protocol for the separation of the soluble and insoluble fractions present in the slurry is proposed; it consists in using acetonitrile to make the precipitation of metal-based compounds easier and to solubilize boron-based intermediates/products. The nature of the metal does not affect the dehydrocoupling mechanisms, the $^{11}B\{^1H\}$ NMR spectra showing the formation of the same reaction intermediates. The aforementioned metal acetylacetonates do mainly have effect on the kinetics of dehydrocoupling. Dehydrocoupling takes place heterogeneously and dehydrogenation of ammonia borane in these conditions leads to the formation of polyborazylene via intermediates like e.g., B-(cyclodiborazanyl) amine-borane and borazine. Our main results are reported and discussed herein.

Comparison of Biological Activities in Crude Extracts of Mantis (사마귀류 추출물의 생물학적 활성 비교)

  • Heo, Jin-Chul;Hwang, Jae-Sam;Kang, Seok-Woo;Yun, Chi-Young;Lee, Sang-Han
    • Current Research on Agriculture and Life Sciences
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    • v.25
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    • pp.7-12
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    • 2007
  • In order to investigate the availability of insect resources for agrobiotechnological or medical purposes, we examined antioxidant (DPPH and FRAP assay) and cell viability by oxidant stress and NO inhibition assay by treatment of the extracts of Statilia maculata Thunberg, Tenodera angustipennis Saussure and Tenodera aridifolia Stoll. We found that Tenodera angustipennis Saussure and Tenodera aridifolia Stoll extract (DW, etanol, methanol) had high levels of anti-oxidant activity, whereas Tenodera aridifolia Stoll extract showed increased cell viability by hydrogen peroxide and inhibition of NO production. These findings suggest that Statilia maculata Thunberg, Tenodera angustipennis Saussure and Tenodera aridifolia Stoll, extract have potentials to be developed for agrobiotechnology or medicinal use, indicating that mechanistic study including inhibition against molecular inflammation will show a possibility for the development of useful insect resources.

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Inhibition of $\alpha$-Glucosidase Activity by Quercetin (Quercetin에 의한 $\alpha$-glucosidase 활성 저해)

  • Lee, Dong-Sun;Kim, Jong-Guk;Lee, Sang-Han
    • Microbiology and Biotechnology Letters
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    • v.34 no.4
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    • pp.368-372
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    • 2006
  • Quercetin is a flavonoid molecule that is known to tie in various sources of natural products such as vegetables and fruits. It has been proven that quercetin plays a crucial role in the prevention of colon cancer as well as homeostasis as radical scavenger in human body. It is also well-known that glycosidases, including $\alpha$-glucosidase, are involved in a variety of degenerative metabolic disorders. In the course of screening useful $\alpha$-glucosidase inhibitors, we screened out quercetin as a $\alpha$-glucosidase inhibitor from chemical libraries. Quercetin was shown to be a reversible, slow-binding, and noncompetitive inhibitor of yeast a-glucosidase with a K$_i$ value of $6.3\times10^{-8}$ M when it was included with an enzyme mixture. Together, these results show that quercetin has potential in treating disorders including diabetes, although the further mechanistic study is needed.