In Vivo Tracking of Transplanted Mononuclear Cells Using Manganese-Enhanced Magnetic Resonance Imaging (MEMRI)

BACKGROUND: Transplantation of mononuclear cells (MNCs) has previously been tested as a method to induce therapeutic angiogenesis to treat limb ischemia in clinical trials. Non-invasive high resolution imaging is required to track the cells and evaluate clinical relevance after cell transplantation. The hypothesis that MRI can provide in vivo detection and long-term observation of MNCs labeled with manganese contrast-agent was investigated in ischemic rat legs. METHODS AND FINDINGS: The Mn-labeled MNCs were evaluated using 7-tesla high-field magnetic resonance imaging (MRI). Intramuscular transplanted Mn-labeled MNCs were visualized with MRI for at least 7 and up to 21 days after transplantation in the ischemic leg. The distribution of Mn-labeled MNCs was similar to that of ¹¹¹In-labeled MNCs measured with single-photon emission computed tomography (SPECT) and DiI-dyed MNCs with fluorescence microscopy. In addition, at 1-2 days after transplantation the volume of the site injected with intact Mn-labeled MNCs was significantly larger than that injected with dead MNCs, although the dead Mn-labeled MNCs were also found for approximately 2 weeks in the ischemic legs. The area covered by CD31-positive cells (as a marker of capillary endothelial cells) in the intact Mn-MNCs implanted site at 43 days was significantly larger than that at a site implanted with dead Mn-MNCs. CONCLUSIONS: The present Mn-enhanced MRI method enabled visualization of the transplanted area with a 150-175 µm in-plane spatial resolution and allowed the migration of labeled-MNCs to be observed for long periods in the same subject. After further optimization, MRI-based Mn-enhanced cell-tracking could be a useful technique for evaluation of cell therapy both in research and clinical applications

Surface-dependent quenching of Qdot emission can be a new tool for high resolution measurements

Abstract Single quantum dots (Qdots) are often used in the field of single-molecule imaging. Qdots are sensitive to changes in the physical interactions between the Qdots and the surrounding materials. However, the spectral changes in a single Qdot emission have not been studied in detail. Low-temperature plasma treatment of glass surfaces reduced the intensity of the 655 nm emission peak of Qdot655 on glass surfaces, but did not significantly change the intensity of the 580 nm emission. Silanization of the glass surface increases the thickness of the silane layer, and the 655 nm emission peak increased. When single Qdots on the untreated glass were imaged, plasma treatment decreased the intensity of red emission and increased yellow emission. When Qdots were brought close to the glass surface in the range of 28–0 nm, the red emission intensity decreased and the yellow emission intensity increased slightly. When single actin filaments were labeled with Qdots, fluctuations of the yellow and red emission of the Qdot were detected, which reflected the very small distance changes. Our results indicate that the local interaction of Qdots with the glass surface improves the spatial and temporal resolution of optical measurements of biomolecules labeled with Qdots

Finding Small Changes using Sensor Networks

Abstract. A sensor network makes environments smarter by sensing small changes of physical quantities using heterogeneous networked sensors, such as small sensor nodes and fixed type sensors. This paper illustrates our experimental setting developed in an ordinary office using prototype sensor nodes and reports how a sensor network detects small changes in a smart environment.

分布型TOPMODELを用いた大規模流域に対する降雨流出解析

本研究は修正分布型TOPMODELを3つの大流域 (アマゾン川、ブラマプトラ川、揚子江)に適用し、その降雨 追跡(流出)モデルとしての特性を評価するものである。修正分布型TOPMODELにおいては、従来のTOPMODELで 一定値を利用していた流域内の流下流速を小流域の特性を反映して変化させ、セル毎の降水量と蒸発散量の 変化を考慮し、最終的にモンテカルロ法で最適化し決定する。修正分布型TOPMODELではGRDCの日観測流量に 対してナッシュ係数でそれぞれアマゾン川 0.48、ブラマプトラ川 0.82、揚子江 0.78 を得ており、本手法が信 頼に足る方法であることを裏付けている。The objective of this study is to apply a modified distributed TOPMODEL approach to three large-scale basins as a Rainfall Routing Model (RRM): the Amazon, the Brahmaputra and the Yangtze basins. This modified approach uses a multi-velocities parameterization to routing the flow. The modified model also uses spatially distributed rainfall and evapotranspiration data through a cell-to-cell routing method. Monte Carlo method was used to find the best set of parameters. The modified model obtained Nash-Sutcliffe coefficient values of 0.48, 0.82 and 0.78 for the Amazon, the Brahmaputra and the Yangtze basins, respectively. The simulations showed that the modified TOPMODEL approach seems to be a reasonable hydrological model to estimate stream flow discharges in large-scale river basins.本研究は修正分布型TOPMODELを3つの大流域 (アマゾン川、ブラマプトラ川、揚子江)に適用し、その降雨 追跡(流出)モデルとしての特性を評価するものである。修正分布型TOPMODELにおいては、従来のTOPMODELで 一定値を利用していた流域内の流下流速を小流域の特性を反映して変化させ、セル毎の降水量と蒸発散量の 変化を考慮し、最終的にモンテカルロ法で最適化し決定する。修正分布型TOPMODELではGRDCの日観測流量に 対してナッシュ係数でそれぞれアマゾン川 0.48、ブラマプトラ川 0.82、揚子江 0.78 を得ており、本手法が信 頼に足る方法であることを裏付けている。The objective of this study is to apply a modified distributed TOPMODEL approach to three large-scale basins as a Rainfall Routing Model (RRM): the Amazon, the Brahmaputra and the Yangtze basins. This modified approach uses a multi-velocities parameterization to routing the flow. The modified model also uses spatially distributed rainfall and evapotranspiration data through a cell-to-cell routing method. Monte Carlo method was used to find the best set of parameters. The modified model obtained Nash-Sutcliffe coefficient values of 0.48, 0.82 and 0.78 for the Amazon, the Brahmaputra and the Yangtze basins, respectively. The simulations showed that the modified TOPMODEL approach seems to be a reasonable hydrological model to estimate stream flow discharges in large-scale river basins

Context Modeling in OWL for Smart Building Services

This article presents an approach to context-aware services for “smart buildings ” based on Web and Semantic Web techniques. The services striven for are first described, then their realization using Web and Semantic Web services is explained. Finally, advantages of the approach are stressed.

DNA-dependent protein kinase enhances DNA damage-induced apoptosis in association with Friend gp70

Friend leukemia virus (FLV) infection strongly enhances gamma-irradiation-induced apoptosis of hematopoietic cells of C3H hosts leading to a lethal anemia. Experiments using p53 knockout mice with the C3H background have clarified that the apoptosis is p53-dependent and would not be associated with changes of cell populations caused by the infection with FLV. In bone marrow cells of FLV + total body irradiation (TBI)-treated C3H mice, the p53 protein was prominently activated to overexpress p21 and bax suggesting that apoptosis-enhancing mechanisms lay upstream of p53 protein in the signaling pathway. Neither of DNA-dependent protein kinase (DNA-PK)-deficient SCID mice nor ataxia telangiectasia mutated (ATM) gene knockout mice with the C3H background exhibited a remarkable enhancement of apoptosis or p53 activation on FLV + TBI-treatment indicating that DNA-PK and ATM were both essential. ATM appeared necessary for introducing DNA damage-induced apoptosis, while DNA-PK enhanced p53-dependent apoptosis under FLV-infection. Surprisingly, viral envelope protein, gp70, was co-precipitated with DNA-PK but not with ATM in FLV + TBI-treated C3H mice. These results indicated that FLV-infection enhances DNA damage-induced apoptosis via p53 activation and that DNA-PK, in association with gp70, might play critical roles in modulating the signaling pathway

Rab27a is essential for the formation of neutrophil extracellular traps (NETs) in neutrophil-like differentiated HL60 cells.

Neutrophils play a crucial role in host defence. In response to a variety of inflammatory stimulation, they form neutrophil extracellular traps (NETs). NETs are extracellular structures composed of chromatin fibers decorated with antimicrobial proteins and developing studies indicate that NETs contribute to extracellular microbial killing. While the intracellular signaling pathways that regulate NET formation remain largely unknown, there is growing evidence that generation of reactive oxygen species (ROS) is a key event for NET formation. The Rab family small GTPase Rab27a is an important component of the secretory machinery of azurophilic granules in neutrophils. However, the precise mechanism of NET formation and whether or not Rab27a contributes to this process are unknown. Using neutrophil-like differentiated HL60 cells, we show here that Rab27a plays an essential role in both phorbol myristate acetate (PMA)- and Candida albicans-induced NET formation by regulating ROS production. Rab27a-knockdown inhibited ROS-positive phagosome formation during complement-mediated phagocytosis. To investigate the role of Rab27a in neutrophil function in detail, both primary human neutrophils and neutrophil-like differentiated HL60 cells were treated with PMA, and NET formation process was assessed by measurement of release of histone H3 into the medium, citrullination of the arginine in position 3 of histone H4 and chase of the nuclear change of the living cells in the co-existence of both cell-permeable and -impermeable nuclear indicators. PMA-induced NET formation occured sequentially in both neutrophil-like differentiated HL60 cells and primary neutrophils, and Rab27a-knockdown clearly inhibited NET formation in association with reduced ROS production. We also found that serum-treated Candida albicans triggers NET formation in a ROS-dependent manner, and that Rab27a-knockdown inhibits this process as well. Our findings demonstrate that Rab27a plays an important role in NET formation induced by both Candida albicans infection and PMA treatment by regulating ROS production