Kyushu University

About: Kyushu University is a education organization based out in Fukuoka, Japan. It is known for research contribution in the topics: Population & Catalysis. The organization has 68284 authors who have published 135190 publications receiving 3055928 citations. The organization is also known as: Kyūshū Daigaku.

Single-molecule imaging analysis of Ras activation in living cells

Abstract: A single-molecule fluorescence resonance energy transfer (FRET) method has been developed to observe the activation of the small G protein Ras at the level of individual molecules. KB cells expressing H- or K-Ras fused with YFP (donor) were microinjected with the fluorescent GTP analogue BodipyTR-GTP (acceptor), and the epidermal growth factor-induced binding of BodipyTR-GTP to YFP-(H or K)-Ras was monitored by single-molecule FRET. On activation, Ras diffusion was greatly suppressed/immobilized, suggesting the formation of large, activated Ras-signaling complexes. These complexes may work as platforms for transducing the Ras signal to effector molecules, further suggesting that Ras signal transduction requires more than simple collisions with effector molecules. GAP334-GFP recruited to the membrane was also stationary, suggesting its binding to the signaling complex. The single-molecules FRET method developed here provides a powerful technique to study the signal-transduction mechanisms of various G proteins.

Nationwide survey of hemophagocytic lymphohistiocytosis in Japan.

Abstract: Hemophagocytic lymphohistiocytosis (HLH), a disorder of the mononuclear phagocyte system, can be classified into two distinct forms: primary HLH (FHL) and secondary HLH. To clarify the epidemiology and clinical outcome for each HLH subtype, we conducted a nationwide survey of HLH in Japan. Since 799 patients were diagnosed in 292 institutions of Japan between 2001 and 2005, the annual incidence of HLH was estimated as 1 in 800,000 per year. Among them, 567 cases were actually analyzed in this study. The most frequent subtype was Epstein-Barr virus (EBV)-associated HLH, followed by other infection- or lymphoma-associated HLH. Age distribution showed a peak of autoimmune disease- and infection-associated HLH in children, while FHL and lymphoma-associated HLH occurred almost exclusively in infants and the elderly, respectively. The 5-year overall survival rate exceeded 80% for patients with EBV- or other infection-associated HLH, was intermediate for those with FHL or B-cell lymphoma-associated HLH, and poor for those with T/NK cell lymphoma-associated HLH (<15%). Although this nationwide survey establishes the heterogeneous characteristics of HLH, the results should be useful in planning prospective studies to identify the most effective therapy for each HLH subtype.

Complete electric dipole response and the neutron skin in 208Pb.

Abstract: A benchmark experiment on Pb-208 shows that polarized proton inelastic scattering at very forward angles including 0 degrees is a powerful tool for high-resolution studies of electric dipole (E1) and spin magnetic dipole (M1) modes in nuclei over a broad excitation energy range to test up-to-date nuclear models. The extracted E1 polarizability leads to a neutron skin thickness r(skin) = 0.156(-0.021)(+0.025) fm in Pb-208 derived within a mean-field model [Phys. Rev. C 81, 051303 (2010)], thereby constraining the symmetry energy and its density dependence relevant to the description of neutron stars.