Osaka University

About: Osaka University is a education organization based out in Osaka, Japan. It is known for research contribution in the topics: Laser & Population. The organization has 83778 authors who have published 185669 publications receiving 5158122 citations. The organization is also known as: Ōsaka daigaku.

Dectin-1 is required for host defense against Pneumocystis carinii but not against Candida albicans.

Abstract: Dectin-1 is a C-type lectin involved in the recognition of beta-glucans found in the cell walls of fungi. We generated dectin-1-deficient mice to determine the importance of dectin-1 in the defense against pathogenic fungi. In vitro, beta-glucan-induced cytokine production from wild-type dendritic cells and macrophages was abolished in cells homozygous for dectin-1 deficiency ('dectin-1-knockout' cells). In vivo, dectin-1-knockout mice were more susceptible than wild-type mice to pneumocystis infection, even though their cytokine production was normal. However, pneumocystis-infected dectin-1-knockout macrophages did show defective production of reactive oxygen species. In contrast to those results, wild-type and dectin-1-knockout mice were equally susceptible to candida infection. Thus, dectin-1 is required for immune responses to some fungal infections, as protective immunity to pneumocystis, but not to candida, required dectin-1 for the production of antifungal reactive oxygen species.

Expansion-contraction of photoresponsive artificial muscle regulated by host-guest interactions

Abstract: The development of stimulus-responsive polymeric materials is of great importance, especially for the development of remotely manipulated materials not in direct contact with an actuator. Here we design a photoresponsive supramolecular actuator by integrating host-guest interactions and photoswitching ability in a hydrogel. A photoresponsive supramolecular hydrogel with α-cyclodextrin as a host molecule and an azobenzene derivative as a photoresponsive guest molecule exhibits reversible macroscopic deformations in both size and shape when irradiated by ultraviolet light at 365 nm or visible light at 430 nm. The deformation of the supramolecular hydrogel depends on the incident direction. The selectivity of the incident direction allows plate-shaped hydrogels to bend in water. Irradiating with visible light immediately restores the deformed hydrogel. A light-driven supramolecular actuator with α-cyclodextrin and azobenzene stems from the formation and dissociation of an inclusion complex by ultraviolet or visible light irradiation.

Phosphorylation of Myosin-Binding Subunit (Mbs) of Myosin Phosphatase by Rho-Kinase in Vivo

Abstract: Rho-associated kinase (Rho-kinase), which is activated by the small GTPase Rho, phosphorylates myosin-binding subunit (MBS) of myosin phosphatase and thereby inactivates the phosphatase activity in vitro. Rho-kinase is thought to regulate the phosphorylation state of the substrates including myosin light chain (MLC), ERM (ezrin/radixin/moesin) family proteins and adducin by their direct phosphorylation and by the inactivation of myosin phosphatase. Here we identified the sites of phosphorylation of MBS by Rho-kinase as Thr-697, Ser-854 and several residues, and prepared antibody that specifically recognized MBS phosphorylated at Ser-854. We found by use of this antibody that the stimulation of MDCK epithelial cells with tetradecanoylphorbol-13-acetate (TPA) or hepatocyte growth factor (HGF) induced the phosphorylation of MBS at Ser-854 under the conditions in which membrane ruffling and cell migration were induced. Pretreatment of the cells with Botulinum C3 ADP-ribosyltransferase (C3), which is thought to interfere with Rho functions, or Rho-kinase inhibitors inhibited the TPA- or HGF-induced MBS phosphorylation. The TPA stimulation enhanced the immunoreactivity of phosphorylated MBS in the cytoplasm and membrane ruffling area of MDCK cells. In migrating MDCK cells, phosphorylated MBS as well as phosphorylated MLC at Ser-19 were localized in the leading edge and posterior region. Phosphorylated MBS was localized on actin stress fibers in REF52 fibroblasts. The microinjection of C3 or dominant negative Rho-kinase disrupted stress fibers and weakened the accumulation of phosphorylated MBS in REF52 cells. During cytokinesis, phosphorylated MBS, MLC and ERM family proteins accumulated at the cleavage furrow, and the phosphorylation level of MBS at Ser-854 was increased. Taken together, these results indicate that MBS is phosphorylated by Rho-kinase downstream of Rho in vivo, and suggest that myosin phosphatase and Rho-kinase spatiotemporally regulate the phosphorylation state of Rho-kinase substrates including MLC and ERM family proteins in vivo in a cooperative manner.

Hard X-Ray Detector (HXD) on Board Suzaku

Abstract: The Hard X-ray Detector (HXD) on board Suzaku covers a wide energy range from 10 keV to 600 keV by combination of silicon PIN diodes and GSO scintillators. The HXD is designed to achieve an extremely low in-orbit background based on a combination of new techniques, including the concept of well-type active shield counter. With an effective area of 142 cm at 20 keV and 273 cm at 150 keV, the background level at the sea level reached ∼ 1×10 cts s cm keV at 30 keV for the PIN diodes, and ∼ 2×10 cts s cm keV at 100 keV, and ∼ 7×10 cts s cm keV at 200 keV for the phoswich counter. Tight active shielding of the HXD results in a large array of guard counters surrounding the main detector parts. These anti-coincidence counters, made of ∼4 cm thick BGO crystals, have a large effective area for sub-MeV to MeV γ-rays. They work as an excellent γ-ray burst monitor with limited angular resolution ( ∼ 5). The on-board signal-processing system and the data transmitted to the ground are also described.