Cardiomyocytes fuse with surrounding noncardiomyocytes and reenter the cell cycle

The concept of the plasticity or transdifferentiation of adult stem cells has been challenged by the phenomenon of cell fusion. In this work, we examined whether neonatal cardiomyocytes fuse with various somatic cells including endothelial cells, cardiac fibroblasts, bone marrow cells, and endothelial progenitor cells spontaneously in vitro. When cardiomyocytes were cocultured with endothelial cells or cardiac fibroblasts, they fused and showed phenotypes of cardiomyocytes. Furthermore, cardiomyocytes reentered the G2-M phase in the cell cycle after fusing with proliferative noncardiomyocytes. Transplanted endothelial cells or skeletal muscle–derived cells fused with adult cardiomyocytes in vivo. In the cryoinjured heart, there were Ki67-positive cells that expressed both cardiac and endothelial lineage marker proteins. These results suggest that cardiomyocytes fuse with other cells and enter the cell cycle by maintaining their phenotypes

High energy electron observation by Polar Patrol Balloon flight in Antarctica

We accomplished a balloon observation of the high-energy cosmic-ray electrons in 10-1000GeV to reveal the origin and the acceleration mechanism. The observation was carried out for 13 days at an average altitude of 35km by the Polar Patrol Balloon (PPB) around Antarctica in January 2004. The detector is an imaging calorimeter composed of scintillating-fiber belts and plastic scintillation counters sandwiched between lead plates. The geometrical factor is about 600cm^2sr, and the total thickness of lead absorber is 9 radiation lengths. The performance of the detector has been confirmed by a test flight at the Sanriku Balloon Center and by an accelerator beam test using the CERN-SPS (Super Proton Synchrotron at CERN). The new telemetry system using the Iridium satellite, the power system supplied by solar panels and the automatic flight level control operated successfully during the flight. We collected 5.7×10^3 events over 100GeV, and selected the electron candidates by a preliminary data analysis of the shower images. We report here an outline of both detector and observation, and the first result of the electron energy spectrum over 100GeV obtained by an electronic counter

コガタ クライオサンプラー ヲ モチイタ ショウワキチ デノ セイソウケン タイキ サイシュ ジッケン ダイ49ジタイ ジッケン ホウコク

第49次南極地域観測隊(第49次隊)夏期間に昭和基地において,新たに開発した小型クライオサンプラーを用いた成層圏大気採取実験を実施した.小型クライオサンプラーは高圧ネオンガスを断熱膨張させて液体ネオンを製造し,希薄な成層圏大気を固化・液化採取するものであり,既存の大型サンプラーが必要とした液体ヘリウムが不要であること,小型軽量であるために満膨張時容積1000-2000 m3の小型プラスチック気球を用いて成層圏まで飛揚させることが可能であるという特徴がある.2007年12月30日と2008年1月4日に計4機の小型サンプラーを放球し,すべて回収に成功した.そのうち,2機は高度18 km及び25kmの成層圏大気の採取に成功した.採取された大気試料は国内に持ち帰られた後,各種温室効果気体濃度と同位体比の分析が行われた.As a part of summer observations of the 49th Japanese Antarctic Research Expedition, stratospheric whole air sampling experiments were conducted at Syowa Station using newly developed compact cryogenic air samplers. The compact sampler uses liquefied neon (produced in-situ) as a refrigerant to solidify or liquefy atmospheric constituents. Because of its reduced size and weight, the sampler can be launched using small-size balloons (1000–2000 m3 in volume). On December 30, 2007 and January 4, 2008, a total of 4 samplers were launched from Syowa Station and recovered on the same day as their launches. Two of them functioned as designed and collected stratospheric air samples at altitudes of 18 and 25 km. The air samples were analyzed for greenhouse gas concentrations and stable isotopes after return to Japan