106 research outputs found

    Endothelial Progenitor Cells Promote Directional Three-Dimensional Endothelial Network Formation by Secreting Vascular Endothelial Growth Factor

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    Endothelial progenitor cell (EPC) transplantation induces the formation of new blood-vessel networks to supply nutrients and oxygen, and is feasible for the treatment of ischemia and cardiovascular diseases. However, the role of EPCs as a source of proangiogenic cytokines and consequent generators of an extracellular growth factor microenvironment in three-dimensional (3D) microvessel formation is not fully understood. We focused on the contribution of EPCs as a source of proangiogenic cytokines on 3D microvessel formation using an in vitro 3D network model. To create a 3D network model, EPCs isolated from rat bone marrow were sandwiched with double layers of collagen gel. Endothelial cells (ECs) were then cultured on top of the upper collagen gel layer. Quantitative analyses of EC network formation revealed that the length, number, and depth of the EC networks were significantly enhanced in a 3D model with ECs and EPCs compared to an EC monoculture. In addition, conditioned medium (CM) from the 3D model with ECs and EPCs promoted network formation compared to CM from an EC monoculture. We also confirmed that EPCs secreted vascular endothelial growth factor (VEGF). However, networks cultured with the CM were shallow and did not penetrate the collagen gel in great depth. Therefore, we conclude that EPCs contribute to 3D network formation at least through indirect incorporation by generating a local VEGF gradient. These results suggest that the location of EPCs is important for controlling directional 3D network formation in the field of tissue engineering

    Design study of an image slicer module for a multiobject spectrograph

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    We investigate an image slicer module for an optical multiobject spectrograph, wide-field optical spectrograph (WFOS), which is one of the first-light instruments of the Thirty Meter Telescope (TMT). The image slicer divides the target image into three slices, thus providing a one-third narrower slit width. By positioning a suite of such modules at the telescope focal surface, multiobject spectroscopy with high spectral resolution can be achieved. Three optical designs are developed: a two-mirror design, a four-mirror design, and a flat-mirror design. Comparing them, the flat-mirror design is found to be the most preferable for WFOS. From a tolerance analysis, the tolerances of manufacturing and assembling appear challenging but not insurmountable. We describe how the steep field curvature of TMT requires at least nine module variants, tuned to reduce defocus in specific focal surface zones. Finally, we introduce a viable mechanical packaging concept

    Design study of an image slicer module for a multiobject spectrograph

    Get PDF
    We investigate an image slicer module for an optical multiobject spectrograph, wide-field optical spectrograph (WFOS), which is one of the first-light instruments of the Thirty Meter Telescope (TMT). The image slicer divides the target image into three slices, thus providing a one-third narrower slit width. By positioning a suite of such modules at the telescope focal surface, multiobject spectroscopy with high spectral resolution can be achieved. Three optical designs are developed: a two-mirror design, a four-mirror design, and a flat-mirror design. Comparing them, the flat-mirror design is found to be the most preferable for WFOS. From a tolerance analysis, the tolerances of manufacturing and assembling appear challenging but not insurmountable. We describe how the steep field curvature of TMT requires at least nine module variants, tuned to reduce defocus in specific focal surface zones. Finally, we introduce a viable mechanical packaging concept

    Farber's disease (disseminated lipogranulomatosis): the first case reported in Japan.

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    We report the first case in Japan, i.e., the first case among oriental subject of Farber's disease. This is a rare disorder of lipid metabolism in infancy subsequent to a genetically-determined defect in ceramide degradation. Main features are characterized clinically by hoarseness, joint swelling, subcutaneous nodules and retarded psychomotor development. Lipid analysis and pathological investigation on the material obtained from a subcutaneous nodule confirmed clearly the presence of ceramide and intracytoplasmic inclusion bodies characteristic for Farber's disease. In this case, we experienced also corneal opacity and striking abnormalities in electroencephalogram, which have apparently not been noticed in the 17 cases hitherto reported.</p

    琉球弧の奄美群島におけるユリ科ウケユリの自生地

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    ユリ科ウケユリは琉球列島固有植物で,絶滅が危惧されているが,近年の自生地の現状が不明であった。本研究は,鹿児島県の奄美大島,加計呂麻島,与路島,請島,徳之島においてウケユリの自生地を探索し,現存個体数とその生育環境を調査したものである。2007 年3 月から2008 年7 月に対象地域をほぼ網羅的に踏査した結果,奄美大島9 箇所,加計呂麻島2 箇所,請島6 箇所,徳之島1 箇所の計18 箇所において,374 個体の生育を確認した。このうち292 個体は茎に5 枚以上の葉をつけた大株で,その中の137 個体は花または若い果実をつけていた。さらに,実生の可能性がある小型の16個体と,枯れた茎をつけた66 個体を確認した。生育場所は北緯27°50′から28°20′,東経128°55′から129°25′,標高174mから595mの範囲内に点在する露岩のほぼ垂直な壁面であった。ウケユリは林冠の被覆が無く日当りがよい岩壁の中部や上部に多く生育していた。露岩の周辺はスダジイなどを優占種とする常緑広葉樹の二次林であった

    Blockade of constitutively activated ERK signaling enhances cytotoxicity of microtubule-destabilizing agents in tumor cells.

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    The extracellular signal-regulated kinase (ERK) signaling pathway is constitutively activated in many human tumor cell types. Given the cytoprotective role of this pathway, we examined whether its specific blockade might sensitize human tumor cells to the induction of apoptosis by various anticancer drugs. Although blockade of ERK signaling alone did not induce substantial cell death, it resulted in marked and selective enhancement of the induction of apoptosis by microtubule-destabilizing agents in tumor cells in which the ERK pathway is constitutively activated. The synergistic activation of c-Jun NH(2)-terminal kinase by the combination of an ERK pathway inhibitor and a microtubule-destabilizing agent appeared to be responsible, at least in part, for this effect. These results suggest that administration of the combination of an ERK pathway inhibitor and a microtubule-destabilizing agent is a potential chemotherapeutic strategy for the treatment of tumor cells with constitutive activation of the ERK pathway
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