• Title/Summary/Keyword: Action potentials

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Surface Properties of Glutathione Layer Formed on Gold Surfaces Interacting with ZrO2 (이산화지르코늄과 상호작용하는 금 표면 위의 글루타싸이온층 표면 물성)

  • Park, Jin-Won
    • Korean Chemical Engineering Research
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    • v.52 no.4
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    • pp.538-543
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    • 2014
  • It is investigated that that the physical properties of Glutathione layer formed on gold surfaces may make an effect on the distribution of either gold particle adsorbed to the $ZrO_2$ surface or vice versa with the adjustment of the electrostatic interactions. For the investigation, the atomic force microscope (AFM) was used to measure the surface forces between the surfaces as a function of the salt concentration and pH value. The forces were quantitatively analyzed with the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to estimate the surface potential and charge density of the surfaces for each condition of salt concentration and pH value. The estimated-value dependence on the salt concentration was described with the law of mass action, and the pH dependence was explained with the ionizable groups on the surface. The salt concentration dependence of the surface properties, found from the measurement at pH 4 and 8, was consistent with the prediction from the law. It was found that the Glutathione layer had higher values for the surface charge densities and potentials than the zirconium dioxide surfaces at pH 4 and 8, which may be attributed to the ionized-functional-groups of the Glutathione layer.

Bone Marrow-derived Side Population Cells are Capable of Functional Cardiomyogenic Differentiation

  • Yoon, Jihyun;Choi, Seung-Cheol;Park, Chi-Yeon;Choi, Ji-Hyun;Kim, Yang-In;Shim, Wan-Joo;Lim, Do-Sun
    • Molecules and Cells
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    • v.25 no.2
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    • pp.216-223
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    • 2008
  • It has been reported that bone marrow (BM)-side population (SP) cells, with hematopoietic stem cell activity, can transdifferentiate into cardiomyocytes and contribute to myocardial repair. However, this has been questioned by recent studies showing that hematopoietic stem cells (HSCs) adopt a hematopoietic cell lineage in the ischemic myocardium. The present study was designed to investigate whether BM-SP cells can in fact transdifferentiate into functional cardiomyocytes. Phenotypically, BM-SP cells were $19.59%{\pm}9.00\;CD14^+$, $8.22%{\pm}2.72\;CD34^+$, $92.93%{\pm}2.68\;CD44^+$, $91.86%{\pm}4.07\;CD45^+$, $28.48%{\pm}2.24\;c-kit^+$, $71.09%{\pm}3.67\;Sca-1^+$. Expression of endothelial cell markers (CD31, Flk-1, Tie-2 and VEGF-A) was higher in BM-SP cells than whole BM cells. After five days of co-culture with neonatal cardiomyocytes, $7.2%{\pm}1.2$ of the BM-SP cells expressed sarcomeric ${\alpha}$-actinin as measured by flow cytometry. Moreover, BM-SP cells co-cultured on neonatal cardiomyocytes fixed to inhibit cell fusion also expressed sarcomeric ${\alpha}$-actinin. The co-cultured BM-SP cells showed neonatal cardiomyocyte-like action potentials of relatively long duration and shallow resting membrane potential. They also generated calcium transients with amplitude and duration similar to those of neonatal cardiomyocytes. These results show that BM-SP cells are capable of functional cardiomyogenic differentiation when co-cultured with neonatal cardiomyocytes.

Surface Mapping of Masseter for Botulinum Toxin Injection (교근에서 보툴리눔 독소 주사점의 표지화)

  • Kim, Jun Hyung;Lee, Min Jae;Kim, Hyun Ji;Son, Dae Gu;Han, Ki Hwan;Lee, So Young;Lim, Jung Guen;Choi, In Jang
    • Archives of Plastic Surgery
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    • v.32 no.3
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    • pp.311-313
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    • 2005
  • Generally, many Asian women tend to dislike the square jaw, as they believe it makes the face look wider, giving a stubborn and strong impression. Contouring of the mandible is therefore a relatively common aesthetic procedure among Asians. These days, the use of botulinum toxin for contouring of the lower face offer simple alternative to surgery. Motor point, which is the site over a muscle where its contraction may be elicited by a minimal intensity short duration electrical stimulus, is the optimal injection point of botulinum toxin. Study was undertaken to identify the location of motor point of the masseter muscle and the skin surface landmark. First, the thickest point of the masseter muscle was inspected through palpation and inspection by 3 different individual plastic surgeons and then compound muscle action potentials(CMAPs) of masseter muscle in 15 health volunteers were recorded using EMG. For the localization of the measured points, line between lateral canthus to the mandibular angle was used. Location of motor points were mapped to skin surface from lateral canthus in a percentage of the distance along the landmark line and in distance in millimeters. The clinical injection point was located at 71.69 percentile and 7.3 mm of the landmark line. The motor point test was located at 72.54 percentile and 7.1 mm of the landmark line. The depth of motor point was 16mm. There was no statistically significant difference between the clinical injection point and the motor point. We conclude that surface mapping of motor point of the masseter muscle would increase accessibility and accuracy in botulinum toxin injection for contouring of the lower face.

The Effects of Gokgisaeng on Anti-inflammation and Rat C6 Glioma Cell Migration (곡기생(槲寄生)의 항염증 효능 및 암세포 이주저해에 미치는 영향)

  • Kim, Hyun-Young;Jang, Soo-Young;Jeong, Ji-Cheon;Shin, Hyeon-Cheol
    • The Journal of Internal Korean Medicine
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    • v.34 no.1
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    • pp.31-45
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    • 2013
  • Objectives : Gokgisaeng (Korean mistletoe) is used for the treatment of inflammatory and cancer diseases in traditional Korean medicine and its major component lectins have been reported to induce nitric oxide (NO) in RAW 264.7 macrophages, and also induce apoptosis of various types of cancer cells, although its modulatory effects on cancer cell migration and macrophage activation is poorly understood. The aim of this study is to clarify molecular mechanisms of action responsible for the anti-inflammatory and antitumor migration potentials of Korean mistletoe extract (KME). Methods : We investigated the anti-inflammatory activity of KME on NO production and inducible nitric oxide synthase (iNOS) expression by lipopolysaccharide (LPS) in both RAW 264.7 macrophages and rat C6 glioma cells, and also evaluated inhibitory efficacy on glioma cell growth and migration. For assessment, XTT assay, nitrite assay, RT-PCR, scratch-wound and Boyden chamber assay, and western blot analysis were performed. Results : Previously reported, unlike the efficacy of Gokgisaeng lectin, KME inhibited NO production and iNOS expression, and suppressed pro-inflammatory mediators including IL-$1{\beta}$, IL-6, COX-2, iNOS in LPS-stimulated RAW 264.7 cells. Furthermore, KME suppressed tumor cell growth and migration, and it also inhibited LPS-induced NO release and iNOS activation by down-regulating expression of protein kinase C (PKC) and phosphorylation of ERK in C6 glioma cells. Conclusions : Our research findings provide evidence that KME can play a significant role in blocking pro-inflammatory reaction and malignant progression of tumors through the suppression of NO/iNOS by down-regulating of inflammatory signaling pathways, PKC/ERK.

Comparison of Anti-cancer Potentials of Water Extracts of Bigihwan, Daechilgithang and Mokwhyangbinranghwan in Human Hepatocellular Carcinoma Cells (인체 간암세포에서 비기환(肥氣丸), 대칠기탕(大七氣湯) 및 목향빈랑환(木香檳榔丸) 열수 추출물의 항암 활성 비교)

  • Kim, Min Yeong;Lee, Hyesook;Hong, Su Hyun;Park, Cheol;Choi, Yung Hyun
    • Herbal Formula Science
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    • v.28 no.1
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    • pp.15-27
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    • 2020
  • Objectives : We selected three herb-combined remedies, Bigihwan (BGH), Daechilgitang (DCGT) and Mokwhyangbinranghwan (MHBRH), through Donguibogam text-mining analysis, and evaluated their anti-cancer effects on human hepatocellular carcinoma Hep3B cells. Methods : Cytotoxicity was assessed by an MTT assay. Apoptosis rate, autophagy and ROS level were detected by flow cytometry. The autophagy was also observed by Cyto-ID staining fluorescence microscopy. The expression of autophagy, mitophagy and pexophagy regulatory proteins was detected by Western blot analysis. Results : BGH showed the strongest effect among the three prescriptions in inhibiting Hep3B cell viability, which was associated with the induction of apoptosis and autophagy. Autophagy blockers improved cell viability and reduced apoptosis after BGH and DCGT treatments, indicating that autophagy by these prescriptions enhanced Hep3B cells against their cytotoxicity. However, MHBRH enhanced the reduction of cell viability and apoptosis by autophagy blockers. Induction of autophagy by BGH treatment was associated with mitophagy due to mitochondrial dysfunction than DCGT and MHBRH-treated cells. In addition, induction of apoptosis by BGH treatment was ROS-dependent and showed the possibility of pexophagy involvement. Conclusion : Although further studies need to be conducted to study the efficacy and mechanism of accurate anticancer activity, the present results will serve as important sources of understanding the mechanism of action of herbal remedies prescribed for liver disease as documented in Donguibogam.

Herbicidal and Insecticidal Potentials of 5-Aminolevulinic acid, a Biodegradable Substance (생분해성 생리활성물질 5-aminolevulinic acid의 제초 및 살충활성)

  • Chon, Sang-Uk
    • The Korean Journal of Pesticide Science
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    • v.11 no.1
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    • pp.52-58
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    • 2007
  • ALA (5-aminolevulinic acid) has been proposed as a tetrapyrrole-dependent photodynamic herbicide and insecticide by the action of the protoporphyrinogen IX oxidase (Protox IX). The present study was conducted to determine growth responses of plant and insects to ALA, biodegradable biopesticidal substance. In the paddy condition experiment, plant height and shoot fresh weight of barnyardgrass (Echinochloa crus-galli) was more reduced by ALA than rice plants, even though both plant species show great phytotoxicity. Hairy crabgrass (Digitaria sanguinalis), a monocot weed, was more sensitive to ALA at 5mM under upland condition when ALA applied on the foliage, compared with soybean (Glycine max) as a dicot crop. ALA solutions were tested for their insecticidal and larvicidal activities against Spodaptera exigua (Hubner) and Tetranychus urticae Koch. by foliar application and leaf-dipping method. The result showed higher insecticidal activity of ALA at 10mM and its mixture with insecticide luferon against S. exigua. Strongest insecticidal activity against T. urticae was observed from the ALA solution at 10mM 72 days after application. This results show that ALA solution had potent herbicidal and insecticidal activities against agricultural pests even though their activities were lower than those of synthetic pesticides.

Sodium Butyrate Alters Cell-Cell Interactions through Up-Regulation of E-Cadherin in Human Hepatocellular Carcinoma Cells (Sodium butyrate에 의한 E-cadherin의 발현증가와 세포간 상호작용의 변화)

  • Kwun, Hyun-Jin;Jang, Kyung-Lib
    • Journal of Life Science
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    • v.19 no.6
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    • pp.705-710
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    • 2009
  • Sodium butyrate (NaBt), a naturally occurring short chain fatty acid derived from carbohydrate metabolism in the gut, is known to exhibit strong anti-cancer potentials in various human cancer cells; however, its action mechanism is poorly understood. In the present study, we demonstrated that NaBt up-regulates levels of E-cadherin, a key cell adhesion molecule implicated as a tumor suppressor, in a cell type-specific manner. Although levels of p21, a potential activator for E-cadherin expression, were also up-regulated by treatment with NaBt in several types of cells, it does not seem to be associated with the activation of E-cadherin in the NaBt-treated cells. Instead, the data from promoter analysis suggest that NaBt up-regulates expression of E-cadherin at the transcription level by enhancing its promoter strength via a CCAAT-box. The elevated E-cadherin in the presence of NaBt was primarily localized at the cell-cell contacts, converting Hep3B cells into a more differentiated form.

Study on Normal Nerve Conduction Parameters (신경전도검사의 정상치에 관한 연구)

  • Han, Song-Yee;Kim, Dae-Seong;Park, Kyu-Hyun
    • Annals of Clinical Neurophysiology
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    • v.1 no.2
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    • pp.118-125
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    • 1999
  • Background and Aims : Nerve conduction study is invaluable in clinical neurology, especially for assessing peripheral neuropathies. Abnormal nerve conduction studies may result not only from peripheral nerve dysfunction itself, but also from other various mechanical, technical, and physiological factors such as age, sex, height and temperature. So we conducted this study to establish the our own normal values. Methods : In this study, from March. 1997 to July. 1998, 40 Korean adults among person came to Health Promotion Center over the age of 20 without any suspicion of neurological deficits were analysed to determine the effect of compound effects of several physiological factors. Results : The nerve conduction velocities of the upper extremity and proximal segments were faster than those of the lower extremity and distal segments. Physiological factors such as age, height and temperature affect the results of nerve conduction studies in multiple regression analysis. The sex difference is recognized over peroneal motor nerve. There are no sex differences in amplitude transformed into normal distribution. The significant physiological factor affecting the amplitude of nerve conduction is age, whereas height and temperature play no role. Conclusions : In multiple regression analysis, height is widespread variable for the nerve conduction velocities and temperature is important variable for lower extremities. The parametric statistical analysis cannot be applied to the amplitude of the compound muscle or nerve action potentials because of marked left shift in distribution. Sqareroot transformation of the CMAP and CNAP may be useful in normalizing the distribution. The most significant physiological factor affection the amplitude is age. Sex differences are not seen in nerve conduction study.

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Electrostatic Interaction between Mercaptoundecanoic-acid Layers on Gold and ZrO2 Surfaces (금 표면 위의 메르캡토언데카노익산층 표면과 이산화지르코늄 표면 사이의 정전기적 상호작용)

  • Park, Jin-Won
    • Applied Chemistry for Engineering
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    • v.25 no.6
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    • pp.607-612
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    • 2014
  • The physical properties of mercaptoundecanoic-acid layer formed on gold surfaces, which may affect the distribution of either gold particles adsorbed to the zirconium dioxide surface or vice versa, were investigated. To conduct this investigation, the surface forces were measured between the surfaces with respect to the salt concentration and pH value using atomic force microscope (AFM). The forces were quantitatively converted by the Derjaguin-Landau-Verwey-Overbeek (DLVO) theory to the surface potential and charge density of surfaces. The converted-value dependence on the salt concentration and pH was described with the law of mass action, and the dependence was consistent with the theoretical prediction. It was found that the mercaptoundecanoic-acid layer had higher values for the surface charge densities and potentials than the $ZrO_2$ surfaces, which may be attributed to the ionized-functional-groups of the mercaptoundecanoic-acid layer.

Audio Stress Effect on Visual ERP Stimulated by 3-dimensional Environment (청각 스트레스가 3차원 시자극 유발전위에 미치는 영향 분석)

  • 박찬희;홍철운;김남균
    • Journal of Biomedical Engineering Research
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    • v.23 no.4
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    • pp.301-308
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    • 2002
  • This research was performed to analyze quantitatively how spiritual stress affects some ERPs on human through sight stimulus after the settlement of visual and auditory integration environment in three dimension space. We measured ERPs in the normal state and spiritual stress sessions separately. The subjects were 10 normal men and women and vital signs was recorded from Fpl, Fz, Cz, Pz, O1, O2's scalps. The experiment was done in isolated room where electro-magnetic effect do not affect. The result showed that P300's amplitude was a little higher under stress session and latent period in this resulted in longer time. We recorded through voltage variation the activity of brain which is in charge of human's perception. cognition, process of action and evaluated the effect of spiritual stress. We expected that the result of this research can be used to evaluate the malfunction of brain.