• Title/Summary/Keyword: Contrast agent

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Hepatoprotective Activity of Crataegii Fructus Water Extract against Cadmium-induced Toxicity in Rats (카드뮴유발 흰쥐의 간손상에 대한 산사(山査)추출물의 보호효과)

  • Shin, Jeong-Hun;Jo, Mi-Jeong;Park, Sang-Mi;Park, Sook-Jahr;Kim, Sang-Chan
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.24 no.2
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    • pp.249-257
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    • 2010
  • Crataegii Fructus is commonly used as a improving digestion, removing retention of food, promoting blood circulation and resolving blood stasis agent in East Asia. Cadmium (Cd) is widely distributed in the environment due to its use in industry. An exposure to Cd causes dysuria, polyuria, chest pain, hepatic and renal tubular diseases. The liver is the most important target organ when considering Cd-induced toxicity because Cd primarily accumulates in the liver. This study investigated the protective effect of Crataegii Fructus water extract against cadmium ($CdCl_2$, Cd)-induced liver toxicity in H4IIE cells, a rat hepatocyte-derived cell line and in rats. Cell viability was significantly reduced in Cd-treated H4IIE cells in a time and concentration-dependent manner. However, Crataegii Fructus water extract (CFE) protected the cells from Cd-induced cytotoxicity via inhibition of PARP cleavage. To induce acute toxicity in rats, Cd (4 mg/kg body weight) was dissolved in normal saline and intravenously injected into rats. The rats then received either a vehicle or silymarin (as a positive control) or CFE (50, 100 mg/kg/day) for 3 days, and were subsequently exposed to a single injection of Cd. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were significantly increased by Cd treatment. In contrast, pretreatment with CFE reduced ALT, AST and LDH. In histopathological analysis, CFE reduced the hepatic degenerative regions and the number of degenerative hepatocytes. These are considered as direct evidences that Crataegii Fructus has favorable inhibitory effects on the Cd-intoxicated liver damages. The efficacy of Crataegii Fructus shows slight lower than that of silymarin in the present study.

Effects of Triclosan on Neural Stem Cell Viability and Survival

  • Park, Bo Kyung;Gonzales, Edson Luck T.;Yang, Sung Min;Bang, Minji;Choi, Chang Soon;Shin, Chan Young
    • Biomolecules & Therapeutics
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    • v.24 no.1
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    • pp.99-107
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    • 2016
  • Triclosan is an antimicrobial or sanitizing agent used in personal care and household products such as toothpaste, soaps, mouthwashes and kitchen utensils. There are increasing evidence of the potentially harmful effects of triclosan in many systemic and cellular processes of the body. In this study, we investigated the effects of triclosan in the survivability of cultured rat neural stem cells (NSCs). Cortical cells from embryonic day 14 rat embryos were isolated and cultured in vitro. After stabilizing the culture, triclosan was introduced to the cells with concentrations ranging from $1{\mu}M$ to $50{\mu}M$ and in varied time periods. Thereafter, cell viability parameters were measured using MTT assay and PI staining. TCS decreased the cell viability of treated NSC in a concentration-dependent manner along with increased expressions of apoptotic markers, cleaved caspase-3 and Bax, while reduced expression of Bcl2. To explore the mechanisms underlying the effects of TCS in NSC, we measured the activation of MAPKs and intracellular ROS. TCS at $50{\mu}M$ induced the activations of both p38 and JNK, which may adversely affect cell survival. In contrast, the activities of ERK, Akt and PI3K, which are positively correlated with cell survival, were inhibited. Moreover, TCS at this concentration augmented the ROS generation in treated NSC and depleted the glutathione activity. Taken together, these results suggest that TCS can induce neurodegenerative effects in developing rat brains through mechanisms involving ROS activation and apoptosis initiation.

Rpi-blb2 Gene-Mediated Late Blight Resistance in Plants

  • Oh, Sang-Keun
    • 한국균학회소식:학술대회논문집
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    • 2015.11a
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    • pp.26-26
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    • 2015
  • Phytophthora infestans is the causal agent of potato and tomato late blight, one of the most devastating plant diseases. P. infestans secretes effector proteins that are both modulators and targets of host plant immunity. Among these are the so-called RXLR effectors that function inside plant cells and are characterized by a conserved motif following the N-terminal signal peptide. In contrast, the effector activity is encoded by the C terminal region that follows the RXLR domain. Recently, I performed in planta functional profiling of different RXLR effector alleles. These genes were amplified from a variety of P. infestans isolates and cloned into a Potato virus X (PVX) vector for transient in planta expression. I assayed for R-gene specific induction of hypersensitive cell death. The findings included the discovery of new effector with avirulence activity towards the Solanum bulbocastanum Rpi-blb2 resistance gene. The Rpi-blb2 encodes a protein with a putative CC-NBS-LRR (a coiled-coil-nucleotide binding site and leucine-rich repeat) motif that confers Phytophthora late blight disease resistance. We examined the components required for Rpi-blb2-mediated resistance to P. infestans in Nicotiana benthamiana. Virus-induced gene silencing was used to repress candidate genes in N. benthamiana and to assay against P. infestans infections. NbSGT1 was required for disease resistance to P. infestans and hypersensitive responses (HRs) triggered by co-expression of AVRblb2 and Rpi-blb2 in N. benthamiana. RAR1 and HSP90 did not affect disease resistance or HRs in Rpi-blb2-transgenic plants. To elucidate the role of salicylic acid (SA) in Rpi-blb2-mediated resistance, we analyzed the response of NahG-transgenic plants following P. infestans infection. The increased susceptibility of Rpi-blb2-transgenic plants in the NahG background correlated with reduced SA and SA glucoside levels. Furthermore, Rpi-blb2-mediated HR cell death was associated with $H_2O_2$, but not SA, accumulation. SA affects basal defense and Rpi-blb2-mediated resistance against P. infestans. These findings provide evidence about the roles of SGT1 and SA signaling in Rpi-blb2-mediated resistance against P. infestans.

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Focal Lesion Detection of SPIO-specific agent Compared with Optimized Pulse Sequences in the Hepatic Metastases: Case Review (간 전이환자에서 최적의 펄스시퀀스에 따른 SPIO 특이성 조영제의 국소병변검출: Case review)

  • Goo, Eun-Hoe
    • Korean Journal of Digital Imaging in Medicine
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    • v.14 no.2
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    • pp.57-61
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    • 2012
  • To compare the accuracy of breath-hold magnetic resonance imaging sequences to establish the most effective superparamagnetic iron oxide-enhanced sequence for detection of hepatic metastases. A total of 100 patients(50men and 50women, mean age: 60years) with liver disease(including malignant and benign liver lesions) were investigated at 3.0T machine (GE, General Electric Medical System, Excite HD) with 8Ch body coil. Pulse sequence for MR imaging decided to the FS-T2-FSE-RT(TR/TE/Thick./Freq./Phase=12857ms/100ms/7mm/512/384), MGRE(TR/TE/Thick./Freq./Phase=100ms/9.7ms/7mm/384/288), in-out of phase echo(TR/$TE_1$, $TE_2$/Thick./Freq./Phase=140ms/2.4, 5.8ms/7mm/352/300), Images obtained before the injection of SPIO. Six sequences were optimized for lesion detection: FS-T2-FSE-RT, multigradient recalled echo data image(MGRE), T2-weighted MGRE with an 9.7msec echo time. Images were reviewed independently by five blinded observers. The accuracy of each sequence was measured by using picture archiving communication system analysis. All results were correlated with findings at multidectator computed tomography examination. Differences between the mean results of the six observers were measured by using paired student t-test analysis. Postcontrast T2-weighted MGRE sequences were the most accurate and were significantly superior to postcontrast FS-T2-FSE-RT, T2-weighted MGRE, in-out of phase MR sequences(p < .05). For all lesions that were malignant or smaller than 1 cm, respectively, contrast to noise ratio of pre and postcontrast sequences were -1and -0.3 for T2-weighted FSE, 0.53 and 4.5 in-out of phase, 7, 7.08, 5.08, 3.32, 1.7, 1.16, 0.79, 0.68 for GRE with 2.9, 7.5, 12.1, 16.6, 21.2, 25.8, 30.4, 35.0 TE values. Breath-hold various TE precontrast sequences offer improvement in sensitivity compared with fixed multigradient recalled echo sequences alone.

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Chemical composition of different parts of ramie (Boehmeria nivea)

  • Cho, Sunghun;Lee, Jaemin;Kim, Young Mi;Jung, Yong-Su;Kim, Ho Bang;Cho, Eun Ju;Lee, Sanghyun
    • Korean Journal of Agricultural Science
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    • v.44 no.1
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    • pp.95-103
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    • 2017
  • Ramie (Boehmeria nivea) is a perennial herbaceous plant belonging to the family Urticaceae. It was used in folk remedies for diuretic or anti-pyretic purposes and as an hepatoprotective, anti-oxidant, and anti-inflammation agent. In this study, we investigated the composition of free sugars, amino acids, fatty acids, organic acids, and total polyphenol contents in parts of ramie (root, stem, and leaf) and different harvest areas (10 areas). Overall, free sugars were found as sucrose, glucose, fructose, and galactose at concentrations ranging from 24.5 to 1173.8 mg/g. Amino acids lysine, threonine, tyrosine, phenylalanine, and histidine were detected at concentrations of 33.8 to 3735.3 mg/g. Major fatty acids were linoleic acid, palmitic acid, and linolenic acid at concentrations of 7.3 to 364.4 mg/g. In organic acids, the concentration of malic acid was highest of all with 672.2 mg/g. The content of free sugars, amino acids, fatty acids, organic acids, and total polyphenol was higher in leaves than in roots and stems. In contrast, the total polyphenol content was higher in roots with 33.7 - 219.4 mg/g than in leaves or in stems. As seen in collecting region, the contents of free sugars, amino acids, fatty acids, organic acids, and total polyphenol of Bn-33, 39, 55, 65, and 90 were higher than other samples. Chemical compositions of different parts of ramie are important factors to consider in manufacturing functional foods. The results of this study provide fundamental information on the chemical compositions of ramie parts and would help develop new functional foods from ramie leaves or the whole plant.

Cloning of the Large Subunit of Replication Protein A (RPA) from Yeast Saccharomyces cerevisiae and Its DNA Binding Activity through Redox Potential

  • Jeong, Haeng-Soon;Jeong, In-Chel;Kim, Andre;Kang, Shin-Won;Kang, Ho-Sung;Kim, Yung-Jin;Lee, Suk-Hee;Park, Jang-Su
    • BMB Reports
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    • v.35 no.2
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    • pp.194-198
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    • 2002
  • Eukaryotic replication protein A (RPA) is a single-stranded(ss) DNA binding protein with multiple functions in DNA replication, repair, and genetic recombination. The 70-kDa subunit of eukaryotic RPA contains a conserved four cysteine-type zinc-finger motif that has been implicated in the regulation of DNA replication and repair. Recently, we described a novel function for the zinc-finger motif in the regulation of human RPA's ssDNA binding activity through reduction-oxidation (redox). Here, we show that yeast RPA's ssDNA binding activity is regulated by redox potential through its RPA32 and/or RPA14 subunits. Yeast RPA requires a reducing agent, such as dithiothreitol (DTT), for its ssDNA binding activity. Also, under non-reducing conditions, its DNA binding activity decreases 20 fold. In contrast, the RPA 70 subunit does not require DTT for its DNA binding activity and is not affected by the redox condition. These results suggest that all three subunits are required for the regulation of RPA's DNA binding activity through redox potential.

Pyruvate Protection against Endothelial Cytotoxicity Induced by Blockade of Glucose Uptake

  • Chung, Se-Jin;Lee, Se-Hee;Lee, Yong-Jin;Park, Hyoung-Sook;Bunger, Rolf;Kang, Young-Hee
    • BMB Reports
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    • v.37 no.2
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    • pp.239-245
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    • 2004
  • We have previously demonstrated that the redox reactant pyruvate prevents apoptosis in the oxidant model of bovine pulmonary artery endothelial cells (BPAEC), and that the anti-apoptotic mechanism of pyruvate is mediated in part via the mitochondrial matrix compartment. However, cytosolic mechanisms for the cytoprotective feature of pyruvate remain to be elucidated. This study investigated the pyruvate protection against endothelial cytotoxicity when the glycolysis inhibitor 2-deoxy-D-glucose (2DG) was applied to BPAEC. Millimolar 2DG blocked the cellular glucose uptake in a concentration- and time-dependent manner with >85% inhibition at $\geq$5 mM within 24 h. The addition of 2DG evoked BPAEC cytotoxicity with a substantial increase in lipid peroxidation and a marked decrease in intracellular total glutathione. Exogenous pyruvate partially prevented the 2DG-induced cell damage with increasing viability of BPAEC by 25-30%, and the total glutathione was also modestly increased. In contrast, 10 mM L-lactate, as a cytosolic reductant, had no effect on the cytotoxicity and lipid peroxidation that are evoked by 2DG. These results suggest that 2DG toxicity may be a consequence of the diminished potential of glutathione antioxidant, which was partially restored by exogenous pyruvate but not L-lactate. Therefore, pyruvate qualifies as a cytoprotective agent for strategies that attenuate the metabolic dysfunction of the endothelium, and cellular glucose oxidation is required for the functioning of the cytosolic glutathione/NADPH redox system.

Effects of Maleic Hydrazide on the Inhibition of Lateral Shoots Growth in Grapes (MH(Maleic hydrazide)처리가 포도 부초 생장억제 및 품질에 미치는 영향)

  • Park, Il-Yong;Kim, Ki-Chul;Hwang, Yong-Soo;Lee, Jae-Chang
    • Korean Journal of Agricultural Science
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    • v.29 no.1
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    • pp.8-14
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    • 2002
  • Spray of maleic hydrazide (MH) was confirmed to be highly effective on the inhibition of lateral shoot growth regardless of grape cultivars and application concentration examined in this experiment. The optimal spray times were 30 days aft er full bloom in 'Kyoho' and 35 days in 'Campbell Early'. However, the optimum season of application should be adjusted depending on the vine vigor. The apical buds of lateral shoot was significantly affected at the concentration of $3,900mg{\cdot}L^{-1}$ resulting in the death and/or abscission. Thus the optimal concentration of MH seemed to be $1,950mg{\cdot}L^{-1}$. The inhibition effect by MH application was derive d from the decrease of node number and length. No adverse effect on fruit quality was found by MH application. In contrast, there was a tendency of anthocyanin in crease in 'Campbell Early' grapes. Results indicated that MH could be an effective agent to reduce the labor charge through the inhibition of later shoot growth.

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A Study on Effective Application of $Methylenediphosphonate-^{99m}Tc$ ($Methylenediphosphonate-^{99m}Tc$의 효과적 이용에 관한 연구)

  • Kim, Jae-Rok;Awh, Ok-Doo;Park, Kyung-Bae;Koo, Hyeon-Sook
    • The Korean Journal of Nuclear Medicine
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    • v.16 no.1
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    • pp.55-61
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    • 1982
  • Biodistribution studies has been carried out to elucidate the cause of poor bone imagings often encountered in using $methylenediphosphonate(MDP)-^{99m}Tc$ and to establish effective conditions in using the popular bone imaging agent. After 150 minutes from the I.V. injection of $MDP-^{99m}Tc$ to mice, the radioactivities accumulated at bone(B), liver(L), and stomach(S) were counted. The radiochemical purity (RCP), the volume, the radioactivity concentration and the amount of radioactivity of $MDP-^{99m}Tc$ were controlled. Data were expressed either in %cpm/g organ or % cpm/organ. The organ distribution ratios(B/L and B/S) were correlated with the RCP, the volume of injection, the radioactivity concentration etc. Results indicated that the RCP plays a major role in biodistributions. High radioactivity concentration and injection of a small amount is recommended. Negligible effect was observed with the amount of radioactivity. It has been confirmed that the up-to-date methods of RCP determinations cannot sensitively detect the sharply affecting trace impurities. A particular biodistribution pattern of crossed B/L and B/S lines was observed in case of using $MDP-^{99m}Tc$ of low RCP. In such a case, rather a higher dosage would be effective for improving the contrast between bone and liver.

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Development of a High-Speed Endoscopic OCT System and Its Application to Three-Dimensional Intravascular Imaging in Vivo (고속 내시경적 OFDI 시스템 개발과 이를 이용한 3차원 생체 혈관 내부 이미징)

  • Cho, Han Saem;Jang, Sun-Joo;Oh, Wang-Yuhl
    • Korean Journal of Optics and Photonics
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    • v.25 no.2
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    • pp.67-71
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    • 2014
  • Intravascular optical coherence tomography (OCT) enables imaging of the three-dimensional (3D) microstructure of a blood vessel wall. While 3D vascular visualization provides detailed information of the vessel wall and intraluminal structures, a longitudinal imaging pitch that is several times bigger than the imaging resolution of the system has limited true high-resolution 3D imaging. In this paper we demonstrate high-speed intravascular OCT in vivo, acquiring images at a rate of 350 frames per second. A 47-mm-long rabbit aorta was imaged in 3.7 seconds, after a short flush with contrast agent. The longitudinal imaging pitch was 34 micrometers, comparable to the transverse imaging resolution of the system. Three-dimensional volume rendering showed greatly enhanced visualization of tissue microstructure and stent struts, relative to what is provided by conventional intravascular imaging speeds.