• Title/Summary/Keyword: Don cells

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Suspension culture of Stably Transformed Drosophila melanogaster S2 Cells expressing EGFP and EPO

  • Sohn, Bong-Hee;Lee, Jong-Min;Kim, Yong-Soon;Kang, Pil-Don;Lee, Sang-Uk;Chung, In-Sik
    • Proceedings of the Korean Society of Sericultural Science Conference
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    • 2003.04a
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    • pp.40-40
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    • 2003
  • Recombinant plasmids harboring heterologous genes coding enhanced green fluorescent protein (EGFP) and erythropoietin (EPO) were transfected and expressed in Drosophila melanogaster S2 cells. Stably transformed cell populations expressing EGFP or monkey EPO were isolated after 4 weeks of selection with hygromycin B. (omitted)

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R&D activities of a-Si:H thin film solar cells by LG Electronics

  • Lee, Don-Hui
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2007.04a
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    • pp.19-19
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    • 2007
  • Recently, we have developed p-i-n hydrogenated amorphous silicon (a-Si:H) single junction (SJ) thin film solar cells with RF (13,56MHz) plasma enhanced chemical vapor deposition (PECVD) systems, and also successfully fabricated the mini-modules (>300$cm^2$), using laser scribing technique to form an integrated series connection, The efficiency of a mini-module was 7.4% (Area=305$cm^2$, $I_{SC}$=0.25A, $V_{OC}$=14.74V, FF=62%).

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Comparative Study on Trichoplusia ni Tn 5B1-4 Cells and Bombyx mori BmN Cells for Recombinant Endostatin Production

  • Sohn, Bong-Hee;Lee, Jong-Min;Kang, Pil-Don;Lee, Sang-Uk;Kim, Yong-Soon;Chung, In-Sik
    • International Journal of Industrial Entomology and Biomaterials
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    • v.7 no.2
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    • pp.197-201
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    • 2003
  • The recombinant plasmids harboring a heterologous gene coding mouse endostatin were transfected and expressed stably in Trichoplusia ni Tn 5B1-4 cells and Bombyx mori BmN cells, respectively. Recombinant endostatin expressed in the stably transformed Tn 5B1-4 and BmN cells was secreted into the medium. BmN cells are relatively lower in maximum cell growth and recombinant endostatin production than Tn 5B 1-4 cells. Recombinant endostatin was also purified to homogeneity using a simple one-step ${Ni^2+}$ affinity fractionation method. Purified recombinant endostatin inhibited endothelial cell proliferation in a dose-dependent manner. The concentration at half-maximum inhibition $({ED_50})$ for recombinant endostatin was approximately 0.35 ${\mu}g$/ml.

Post-transcriptional Regulation of NK Cell Activation

  • Kim, Tae-Don;Park, Ju-Yeong;Choi, In-Pyo
    • IMMUNE NETWORK
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    • v.9 no.4
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    • pp.115-121
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    • 2009
  • Natural killer (NK) cells play key roles in innate and adaptive immune defenses. NK cell responses are mediated by two major mechanisms: the direct cytolysis of target cells, and immune regulation by production of various cytokines. Many previous reports show that the complex NK cell activation process requires de novo gene expression regulated at both transcriptional and post-transcriptional levels. Specialized un-translated regions (UTR) of mRNAs are the main mechanisms of post-transcriptional regulation. Analysis of posttranscriptional regulation is needed to clearly understand NK cell biology and, furthermore, harness the power of NK cells for therapeutic aims. This review summarizes the current understanding of mRNA metabolism during NK cell activation, focusing primarily on post-transcriptional regulation.

Interference of EGFP RNA in Human NT-2/D1 Cell Lines Using Human U6 Promoter-based siRNA PCR Products

  • Kwak, Young-Don;Sugaya, Kiminobu
    • Biotechnology and Bioprocess Engineering:BBE
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    • v.11 no.3
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    • pp.273-276
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    • 2006
  • RNA interference (RNAi), a process of sequence-specific gene suppression, has been known as a natural gene regulatory mechanism in a wide range of lower organisms. Recently, we have reported that a transfection of human U6 promoter (hU6) driven hairpin small-interference RNA (siRNA) plasmid specifically knocks down the target gene by post-transcriptional gene silencing in mammalian cells. Here we report that transfection of polymerase chain reaction (PCR) products, containing human U6 promoter with hairpin siRNA, knocks down the target gene expression in human teratocarcinoma NT-2/D1 cells. Moreover, we showed 3' end termination sequence, 5 Ts, is not critical elements for knocking down in PCR-based siRNA system. Therefore, the PCR-based siRNA system is a promising tool not only for the screening but also to temporally regulate gene expression in the human progenitor cells.

Antioxidative and Antiaging Activities and Component Analysis of Lespedeza cuneata G. Don Extracts Fermented with Lactobacillus pentosus

  • Seong, Joon Seob;Xuan, Song Hua;Park, So Hyun;Lee, Keon Soo;Park, Young Min;Park, Soo Nam
    • Journal of Microbiology and Biotechnology
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    • v.27 no.11
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    • pp.1961-1970
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    • 2017
  • Lespedeza cuneata G. Don is a traditional herb that has been associated with multiple biological activities. In this study, we investigated the antioxidative/antiaging activities and performed an active component analysis of the non-fermented and fermented (using Lactobacillus pentosus) extracts of Lespedeza cuneata G. Don. The antioxidative activities of the fermented extract were higher than those of non-fermented extracts. The elastase inhibitory activity, inhibitory effects on UV-induced MMP-1 expression, and ability to promote type I procollagen synthesis were investigated in Hs68 human fibroblasts cells. These tests also revealed that the fermented extract had increased antiaging activities compared with the non-fermented extract. A component analysis of the ethyl acetate fractions of non-fermented and fermented extracts was performed using TLC, HPLC, and LC/ESI-MS/MS to observe changes in the components before and after fermentation. Six components that were different before and after fermentation were investigated. It was thought that kaempferol and quercetin were converted from kaempferol glucosides and quercetin glucosides, respectively, via bioconversion with the fermentation strain. These results indicate that the fermented extract of L. cuneata G. Don has potential for use as a natural cosmetic material with antioxidative and antiaging effects.