Osaka University

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

Functional activation of Jak1 and Jak3 by selective association with IL-2 receptor subunits

Abstract: The interleukin-2 receptor (IL-2R) consists of three subunits: the IL-2R alpha, IL-2R beta, and IL-2R gamma chains, the last of which is also used in the receptors for IL-4, IL-7, and IL-9. Stimulation with IL-2 induces the tyrosine phosphorylation and activation of the Janus kinases Jak1 and Jak3. Jak1 and Jak3 were found to be selectively associated with the "serine-rich" region of IL-2R beta and the carboxyl-terminal region of IL-2R gamma, respectively. Both regions were necessary for IL-2 signaling. Furthermore, Jak3-negative fibroblasts expressing reconstituted IL-2R became responsive to IL-2 after the additional expression of Jak3 complementary DNA. Thus, activation of Jak1 and Jak3 may be a key event in IL-2 signaling.

Adiponectin Specifically Increased Tissue Inhibitor of Metalloproteinase-1 Through Interleukin-10 Expression in Human Macrophages

Abstract: Background— Vascular inflammation and subsequent matrix degradation play an important role in the development of atherosclerosis. We previously reported that adiponectin, an adipose-specific plasma protein, accumulated to the injured artery and attenuated vascular inflammatory response. Clinically, high plasma adiponectin level was associated with low cardiovascular event rate in patients with chronic renal failure. The present study was designed to elucidate the effects of adiponectin on matrix metalloproteinases (MMPs) and tissue inhibitor of metalloproteinases (TIMPs) in human monocyte-derived macrophages. Methods and Results— Human monocyte-derived macrophages were incubated with the physiological concentrations of human recombinant adiponectin for the time indicated. Adiponectin treatment dose-dependently increased TIMP-1 mRNA levels without affecting MMP-9 mRNA levels. Adiponectin also augmented TIMP-1 secretion into the media, whereas MMP-9 secretion and activity were unchanged. Time course experim...

Cytokine Expression in Periodontal Health and Disease

Abstract: Soluble proteins that serve as mediators of cell function and are produced by various cell types, such as structural and inflammatory cells, are collectively called cytokines. Several lines of evidence have revealed that cytokines play important roles not only in tissue homeostasis but also in the pathogenesis of many infectious diseases. Recent research on biological activities in normal periodontium and the pathogenesis of periodontal diseases has clarified the involvement of various cytokines in the biological activities observed in the sites. Cytokines play crucial roles in the maintenance of tissue homeostasis, a process which requires a delicate balance between anabolic and catabolic activities. In particular, growth factors--such as fibroblast growth factor (FGF), platelet-derived growth factor (PDGF), insulin-like growth factor (IGF), transforming growth factor-beta (TGF-beta)--are thought to play important roles in modulating the proliferation and/or migration of structural cells in the periodontium and the production of various extracellular matrices by these cells. On the other hand, there is little doubt that excessive and/or continuous production of cytokines in inflamed periodontal tissues is responsible for the progress of periodontitis and periodontal tissue destruction. Particularly, inflammatory cytokines--such as IL-1 alpha, IL-1 beta, IL-6, and IL-8--are present in the diseased periodontal tissues, and their unrestricted production seems to play a role in chronic leukocyte recruitment and tissue destruction. It is possible that monitoring cytokine production or its profile may allow us to diagnose an individual's periodontal disease status and/or susceptibility to the disease. In addition, although the hypothesis is still controversial, it has been suggested that discrete T-cell subsets (Th1 and Th2) with different cytokine profiles play specific roles in the immunopathogenesis of periodontal diseases.

Stability of the wurtzite-type structure under high pressure: GaN and InN.

Abstract: High-pressure in situ x-ray-diffraction studies on GaN and InN have been carried out using an imaging-plate technique and a diamond-anvil cell up to about 60 GPa. The two compounds crystallize in the wurtzite-type structure at ambient conditions. The axial ratio c/a of GaN remains unchanged from the ambient value of 1.626 whereas c/a of InN is considerably decreased from 1.613 to 1.597 with increasing pressure to about 15 GPa. Equation-of-state data obtained for the wurtzite phase have yielded the bulk modulus of GaN to be 237(31) GPa and that of InN to be 125.5(4.6) GPa. Structural phase transition into the rocksalt-type structure takes place in GaN at 52.2 GPa and in InN at 12.1 GPa. The trend in the transition pressures of the III-V nitrides is discussed in terms of various ionicity scales.