• 제목/요약/키워드: Cell-surface interaction

검색결과 214건 처리시간 0.022초

Long period application of AC field causing contrast reduction of IPS cell

  • Momoi, Yuichi;Koda, Tomonori
    • 한국정보디스플레이학회:학술대회논문집
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    • 한국정보디스플레이학회 2008년도 International Meeting on Information Display
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    • pp.870-872
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    • 2008
  • It is known that AC electric field to drive IPS mode of liquid crystal display (LCD) causes reduction of the contrast after long period of display operation. Our results are presented in this paper on a base of a model of interaction between surface of PI alignment film and LC molecules. We conclude that the surface viscosity of PI alignment film is one of the most important factors for the contrast reduction phenomenon.

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단핵구 분화에 대한 Fibronectin 및 그 단편의 역할 (A Possible Role of Fibronectin on the Differentiation of Monocyte to Macrophase)

  • Ok Sun Bang;You
    • 한국동물학회지
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    • 제36권4호
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    • pp.514-521
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    • 1993
  • Monocyte interaction with fibronectin (FN) mediates specific cell surface receptors and results in cell attachment and differentiation. Several cell-mediated activities for various fragments of FN have been documented. To investigate the regulatory mechanisms of monocyte differentiation by cell binding domains of FN and their receptors, cell attachment-, cell migration-, and its respective inhibition assay were carried out. Monocyte recognizes 38-kDa domain distinctively from its recognition of 85-kDa domain, and the heparin-binding site of the 38-kDa fragment is not involved in monocyte adhesion. Based on these experimental results, it can be suggested that monocvte/macrophase interacts with at least two different sites in FN, which is critical step in cell adhesion and (or) migration.

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Biological Effects of Different Thin Layer Hydroxyapatite Coatings on Anodized Titanium

  • Sohn, Sung-Hwa;Jun, Hye-Kyoung;Kim, Chang-Su;Kim, Ki-Nam;Ryu, Yeon-Mi;Lee, Seung-Ho;Kim, Yu-Ri;Seo, Sang-Hui;Kim, Hye-Won;Shin, Sang-Wan;Ryu, Jae-Jun;Kim, Meyoung-Kon
    • Molecular & Cellular Toxicology
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    • 제1권4호
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    • pp.237-247
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    • 2005
  • Several features of the implant surface, such as roughness, topography, and composition play a relevant role in implant integration with bone. This study was conducted in order to determine the effects of various thin layer hydroxyapatite (HA) coatings on anodized Ti surfaces on the biological responses of a human osteoblast-like cell line (MG63). MG63 cells were cultured on A (100 nm HA coating on anodized surface), B (500-700 nm HA coating on anodized surface), C ($1{\mu}m$ HA coating on anodized surface), and control (non HA coating on anodized surface) Ti. The morphology of these cells was assessed by SEM. The cDNAs prepared from the total RNAs of the MG63 were hybridized into a human cDNA microarray (1,152 elements). The appearances of the surfaces observed by SEM were different on each of the four dental substrate types. MG63 cells cultured on A, C and control exhibited cell-matrix interactions. It was B surface showing cell-cell interaction. In the expression of several genes were up-, and down-regulated on the different surfaces. The attachment and expression of key osteogenic regulatory genes were enhanced by the surface morphology of the dental materials used.

Actin Engine in Immunological Synapse

  • Piragyte, Indre;Jun, Chang-Duk
    • IMMUNE NETWORK
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    • 제12권3호
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    • pp.71-83
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    • 2012
  • T cell activation and function require physical contact with antigen presenting cells at a specialized junctional structure known as the immunological synapse. Once formed, the immunological synapse leads to sustained T cell receptor-mediated signalling and stabilized adhesion. High resolution microscopy indeed had a great impact in understanding the function and dynamic structure of immunological synapse. Trends of recent research are now moving towards understanding the mechanical part of immune system, expanding our knowledge in mechanosensitivity, force generation, and biophysics of cell-cell interaction. Actin cytoskeleton plays inevitable role in adaptive immune system, allowing it to bear dynamic and precise characteristics at the same time. The regulation of mechanical engine seems very complicated and overlapping, but it enables cells to be very sensitive to external signals such as surface rigidity. In this review, we focus on actin regulators and how immune cells regulate dynamic actin rearrangement process to drive the formation of immunological synapse.

Characterization of Biocompatible Polyelectrolyte Complex Multilayer of Hyaluronic Acid and Poly-L-Lysine

  • Hahn, Sei-Kwang;Allan S. Hoffman
    • Biotechnology and Bioprocess Engineering:BBE
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    • 제9권3호
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    • pp.179-183
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    • 2004
  • A biocompatible polyelectrolyte complex multilayer (PECML) film consisting of poly-L-lysine (PLL) as a polycation and hyaluronic acid (HA) as a polyanion was developed to test its use for surface modification to prevent cell attachment and protein drug delivery. The formation of PECML through the electrostatic interaction of HA and PLL was confirmed by contact angle measurement, ESCA analysis, and HA content analysis. HA content increased rapidly up to 8 cycles for HA/PLL deposition and then slightly increased with an increasing number of deposition cycle. In vitro release of PLL in the PECML continued up to 4 days and ca. 25% of HA remained on the chitosan-coated cover glass after in vitro release test for 7 days. From the results, PECML of HA and PLL appeared to be stable for about 4 days. The surface modification of the chitosan-coated cover glass with PECML resulted in drastically reduced peripheral blood mononuclear cell (PBMC) attachment. Concerned with its use for protein drug delivery, we confirmed that bovine serum albumin (BSA) as a model protein could be incorporated into the PECML and its release might be triggered by the degradation of HA with hyaluronidase.

Identification of Amino Acid Residues Involved in the Interaction between Measles Virus Haemagglutin (MVH) and Its Human Cell Receptor(Signaling Lymphocyte Activation Molecule, SLAM)

  • Xu, Qin;Zhang, Peng;Hu, Chunling;Liu, Xin;Qi, Yipeng;Liu, Yingle
    • BMB Reports
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    • 제39권4호
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    • pp.406-411
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    • 2006
  • Signaling lymphocyte activation molecule (SLAM; also known as CD150) is a newly identified cellular receptor for measles virus (MV). The interaction between MV Haemagglutin (MVH) and SLAM is an initial step for MV entry. We have identified several novel SLAM binding sites at residues S429, T436 and H437 of MVH protein and MVH mutants in these residues dramatically decrease the ability to interaction with the cell surface SLAM and fail to co-precipitation with SLAM in vivo as well as malfunction in syncytium formation. At the same time, K58, S59 and H61 of SLAM was also identified to be critical for MVH and SLAM binding. Further, these residues may be useful targets for the development of measles therapy.

T 세포 접촉에 의한 단핵구 활성화에서 ${\beta}_2$ Integrin의 역할에 관한 면역화학적 연구 (Immunochemical study on the Role of ${\beta}_2$ Integrin in the Activation of Monocytes Upon Direct Contact with T Lymphocytes)

  • 이석초;이호;오귀옥;김형섭
    • Journal of Periodontal and Implant Science
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    • 제29권2호
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    • pp.333-350
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    • 1999
  • The modulation of leukocyte cell surface adhesion molecules may influence the development of cellular events that determine the course of the inflammatory process. Direct interaction between activated T cells and monocytes resulted in a large production of $IL-1{\beta}$ by monocytes. In this reactions, adhesion molecules play an important part, yet the role of them in Tmonocytes interaction remain unclear. This study was undertaken in an effort to elucidate, 1) the influence of 1.25(OH)$_2D_3-induced$ differentiation on the monocyte responsiveness to direct contact with T lymphocytes, and 2) the role of adhesion molecules on the T-monocyte direct interaction. Initially, I observed that direct contact of monocyte cell line THP-1 with stimulated fixed T cell line HuT78 markedly induces IL-1${\beta}$ production by THP-1. $IL-1{\beta}$ production was higher when THP-1 had been previously exposed to 1.25(OH)$_2D_3$ as compared to control, with ${\alpha}$- 1.25(OH)$_2D_3$ dose-dependent and exposure time-dependent manner. It was shown that 1.25(OH)$_2D_3$ also increased the expression of ${\beta}_2$ integrin adhesion receptor Mac-1(CD11b/CD18) dose- and timedependently, but did not increase the expression of human leukocyte antigen- D(HLA-D) and intercellular adhesion molecule-1(ICAM-1). The $IL-1{\beta}$ producing activity of THP-1 cells correlated well with the ability to induce the Mac-1 expression on THP-1 surface. Monoclonal antibody raised against relevant cell surface glycoproteins on THP-1 were tested for their ability to block the response of THP-1 to T cells. Antibody to Mac-1 only partially blocked $IL-1{\beta}$ production by THP-1, whereas antibodies to ICAM-1 and HLA-D did not. These data indicate that regulation of Mac-1 expression on THP-1 cells can alter the responsiveness of these cells to contact by activated T cells, however other unknown structures on the THP-1 cells may be involved in this process also.

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소유역 지표유출의 시간적 . 공간적 재현을 위한 GIS응용모형 (GIS Application Model for Temporal and Spatial Simulation of Surface Runoff from a small watershed)

  • 정하우;김성준;최진용;김대식
    • Spatial Information Research
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    • 제3권2호
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    • pp.135-146
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    • 1995
  • 본 연구의 목적은 소유역 지표유출의 시각적.공간적 재현을 위한 GIS의 응용 및 호환 모형 GISCELWAB을 개발하는 것이다. 이 모형은 세가지의 모형으로 구성되었다. 분포형 수문모형인 격자 물수지 모형 CELWAB과 CELWAB 모형의 입력자료를 자동으로 추출하는 입력자료 추출모형GISINDATA 와 CELWAB모형의 계산결과를 도형화하여 도시하도록 구성된 출력자료처리 모형GISOUTDISP로 구성되었다. GISINDATA는 모형의 입력자료 구성에 소모되는 시간을 절약하고 자료의 객관적 정확성을 갖도록 하기 위하여 개발되었으며, GISOUTDISP는 CELWAB 모형의 결과르 도형화하고 도시하여 유역전체에 대한 유출현상을 시간적, 공간적으로 재현하는 것을 가능하게 하였다.

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CD29 및 CD98 활성 매개에 의한 Jurkat T 세포의 유착과 그 활용 (Cell-cell Adhesion of Jurkat T Cells Induced by CD29 and CD98 Activation and its Application)

  • 김병훈;조재열
    • 약학회지
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    • 제53권3호
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    • pp.119-124
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    • 2009
  • Cell-cell adhesion managed by various adhesion molecules plays an important role in regulating functional activation of cells. This event mediates attachment of inflammatory cells to endothelial cells, interaction of antigen-presenting cells with T cells and metastatic adherence of cancer cells to epithelial tissue cells. Therefore, this cellular response is considered as one of therapeutic target to treat various cancers and inflammatory diseases. To develop proper model for evaluation of functional activation of adhesion molecules, the ability of U937 and Jurkat T cells responsive to various adhesion inducers such as phorbal-12-myristate-13-acetate (PMA), staurosporin and monoclonal antibodies to CD29, CD43 and CD98 was investigated using quantitative cell-cell adhesion assay. U937 cells made more cell-cell clusters by the treatment of antibodies to CD29 and CD43 than Jurkat T cells, while Jurkat T cells exhibited increased cell-cell adhesion ability in CD98 antibody treatment. In agreement, the surface levels of CD29 and CD98 were highly observed in U937 and Jurkat T cells, respectively. Therefore, our data suggest that Jurkat T and U937 cells can be used for model system to evaluate functional activation of adhesion molecules such as CD29 and CD98.

경사진 자외선조사를 이용한 셀의 프리틸트각의 입사각도 의존성 (Liquid crystal alignment and pretilt angle generation using oblique UV light irradiation on polymer surface)

  • 서대식;한정민;박두석;박태규;황율연
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 1998년도 춘계학술대회 논문집
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    • pp.267-270
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    • 1998
  • In this study, we investigated the generation of pretilt angle for nematic liquid crystal (NLC) in a cell with oblique non-polarized ultraviolet (UV) light irradiation on polyimide (PI) surfaces. It was found that the monodomain alignment of the NLC is obtained in a cell with an angle of incidence of 70∼85$^{\circ}$on PI surface. We consider that the monodomain alignment of NLC is attributed to anisotropic dispersion force effect due to Photo-depolymerization of polymer on PI surfaces. Also, pretilt angle of NLC is generated about 3$^{\circ}$ with an angle of incidence of 70∼75$^{\circ}$. It is considered that the pretilt angle generation in NLC is attributed to interaction between the LC molecules and the polymer surfaces.

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