• KIEE International Transactions on Electrophysics and Applications
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• v.4C no.4
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• pp.176-180
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• 2004

This paper presents the fabrication and test of a micro cell exciter actuated by an electromagnetic force for the study on the chondrogenic differentiation of rabbit mesenchymal stem cells (MSCs). The micro cell exciter is designed to apply compressive loading to the alginate gel mixed with the MSCs. The magnetic cell exciter consists of an actuator component and a cartridge-type chamber component. An actuator is composed of a permanent magnet, a core and a coil. The chamber has seven PMMA wells and a cell culture Petri dish. Two types of alginate gels were stimulated by the cell exciters for 10 minutes every 12 hours for 7 days. In order to determine the expression of these matrix components during differentiation, RT-PCR analysis was performed. Collagen type II was expressed in the MSCs subjected to the compressive stimulation.

• Parasites, Hosts and Diseases
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• v.37 no.1
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• pp.39-46
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• 1999

As a preliminary study for the explanation of pathobiology of Neodiplostomum seoulense infection. a 54 kDa protease was purified from the crude extract of adult worms by sequential chromatographic methods. The crude extract was subjected to DEAE-Sepharose Fast Flow column, and protein was eluted using 25 mM Tris-HC1 (pH 7.4) containing 0.05. 0.1, 0.2 and 0.4 M NaC1 in stepwise elution. The 0.2 M NaCl fraction was further purified by Q-Sepharose chromatography and protein was eluted using 20 mM sodium acetate (pH 6.4) containing 0.05, 0.1. 0.2 and 0.3 M NaCl, respectively. The 0.1M NaCl fraction showed a single protein band on SDS-PAGE carried out on a 7.5-15% gradient gel. The proteolytic activities of the purified enzyme were specifically inhibited by L-trans-epoxy-succinylleucylamide (4-guanidino) butane (E-64) and iodoacetic acid. The enzyme, cysteine protease. showed the maximum proteolytic activity at pH 6.0 in 0.1 M buffer, and degraded extracellular matrix proteins such as collagen and fibronectin with different activities. It is suggested that the cysteine protease may playa role in the nutrient uptake of N. seoulense from the host intestine.

• The Korean Journal of Physiology and Pharmacology
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• v.6 no.5
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• pp.269-274
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• 2002

A large number of factors such as osteotropic hormones, cytokines, or growth factors are related to the bone remodeling which is characterized by the coupling of osteoclast-mediated bone resorption and osteoblast-mediated bone formation. Recent investigations have indicated that cytokines such as $interleukin-1{\beta}\;(IL-1{\beta})$ and tumor necrosis $factor-{\alpha}\;(TNF-{\alpha})$ play a potential role in the bone resorption associated with a variety of pathological conditions such as inflammatory osteolytic disease. Collagen is the most abundant protein of the extracellular matrix of bone, and the participation of collagenase in bone resorption has been widely investigated. In this study, effects of $IL-1{\beta}$ and $TNF-{\alpha}$ on the release of collagenase from osteoblastic cells were measured. The gelatinase activity was also measured by gel substrate analysis (zymography) after electrophoresis of conditioned media of osteoblastic cell culture. $IL-1{\beta}$ increased the collagenase activity in ROS17/2.8 and HOS cell culture. $TNF-{\alpha}$ also increased the collagenase activity of osteoblastic cells. When two kinds of cytokines were treated simultaneously in the culture of osteoblastic cells, synergistic increase of collagenase activity was seen in ROS17/2.8 cells. $IL-1{\beta}$ and $TNF-{\alpha}$ significantly increased the collagenase activity after 6 hour treatment in the osteoblastic cell culture, and there was no additional increase according to the culture period. Osteoblastic cells released the gelatinase and molecular weight of this enzyme was measured about 70 KDa as assessed by zymogram. $IL-1{\beta}$ and $TNF-{\alpha}$ showed increase of the gelatinase activity produced by ROS17/2.8 and HOS cells. Taken together, this study suggested that $IL-1{\beta}$ and $TNF-{\alpha}$ can modulate bone metabolism, at least in part, by increased release of collagenase and gelatinase from osteoblasts.

• Korean Journal of Food Science and Technology
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• v.39 no.6
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• pp.625-629
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• 2007

This study was carried out to investigate the anti-wrinkle effects of peptides derived from collagens isolated from Asterias amurensis, which was collected in the East Sea. The molecular weights of the peptides were between 10-50 kDa, as determined through sephadek G-75 gel. The cytotoxicities against CCD-986sk cells and HEL-299 cells were measured using the MTT assay. The cytotoxicity of all the fractions(F1: Fraction No. 4-13, 116 kDa; F2: Fraction No. 25-30, 100 kDa; F3: Fraction No. 45-55, 58 kDa; F4: Fraction No. 59-63, 43 kDa; F5: Fraction No. 79-90, 24 kDa) was less than 25%, by the addition of 1.0 mg/mL. These peptides did not show any adverse effects on human skin cells. In the presence of F1 at 1.0 mg/mL, matrix metalloproteinase-1 (MMP-1) expression of UVA-induced human normal fibroblasts was reduced to 34.8%. Overall, the results seem to suggest that peptides of approximately 20 kDa have superior anti-wrinkle effects.