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.

Essential function for the kinase TAK1 in innate and adaptive immune responses.

Abstract: Transforming growth factor-beta-activated kinase 1 (TAK1) has been linked to interleukin 1 receptor and tumor necrosis factor receptor signaling. Here we generated mouse strains with conditional expression of a Map3k7 allele encoding part of TAK1. TAK1-deficient embryonic fibroblasts demonstrated loss of responses to interleukin 1beta and tumor necrosis factor. Studies of mice with B cell-specific TAK1 deficiency showed that TAK1 was indispensable for cellular responses to Toll-like receptor ligands, CD40 and B cell receptor crosslinking. In addition, antigen-induced immune responses were considerably impaired in mice with B cell-specific TAK1 deficiency. TAK1-deficient cells failed to activate transcription factor NF-kappaB and mitogen-activated protein kinases in response to interleukin 1beta, tumor necrosis factor and Toll-like receptor ligands. However, TAK1-deficient B cells were able to activate NF-kappaB but not the kinase Jnk in response to B cell receptor stimulation. These results collectively indicate that TAK1 is key in the cellular response to a variety of stimuli.

Tyrosinase inhibitors from natural and synthetic sources: structure, inhibition mechanism and perspective for the future.

Abstract: Tyrosinase is known to be a key enzyme in melanin biosynthesis, involved in determining the color of mammalian skin and hair. Various dermatological disorders, such as melasma, age spots and sites of actinic damage, arise from the accumulation of an excessive level of epidermal pigmentation. In addition, unfavorable enzymatic browning of plant-derived foods by tyrosinase causes a decrease in nutritional quality and economic loss of food products. The inadequacy of current conventional techniques to prevent tyrosinase action encourages us to seek new potent tyrosinase inhibitors. This article overviews the various inhibitors obtained from natural and synthetic sources with their industrial importance.

Functional SNPs in the lymphotoxin-alpha gene that are associated with susceptibility to myocardial infarction.

Abstract: By means of a large-scale, case-control association study using 92,788 gene-based single-nucleotide polymorphism (SNP) markers, we identified a candidate locus on chromosome 6p21 associated with susceptibility to myocardial infarction. Subsequent linkage-disequilibrium (LD) mapping and analyses of haplotype structure showed significant associations between myocardial infarction and a single 50 kb halpotype comprised of five SNPs in LTA (encoding lymphotoxin-alpha), NFKBIL1 (encoding nuclear factor of kappa light polypeptide gene enhancer in B cells, inhibitor-like 1) and BAT1 (encoding HLA-B associated transcript 1). Homozygosity with respect to each of the two SNPs in LTA was significantly associated with increased risk for myocardial infarction (odds ratio = 1.78, chi(2) = 21.6, P = 0.00000033; 1,133 affected individuals versus 1,006 controls). In vitro functional analyses indicated that one SNP in the coding region of LTA, which changed an amino-acid residue from threonine to asparagine (Thr26Asn), effected a twofold increase in induction of several cell-adhesion molecules, including VCAM1, in vascular smooth-muscle cells of human coronary artery. Moreover, the SNP, in intron 1 of LTA, enhanced the transcriptional level of LTA. These results indicate that variants in the LTA are risk factors for myocardial infraction and implicate LTA in the pathogenesis of the disorder.

Real-Space Observation of Current-Driven Domain Wall Motion in Submicron Magnetic Wires

Abstract: We report direct observation of current-driven magnetic domain wall (DW) displacement by using a well-defined single DW in a microfabricated magnetic wire with submicron width. Magnetic force microscopy visualizes that a single DW introduced in a wire is displaced back and forth by positive and negative pulsed current, respectively. The direct observation gives quantitative information on the DW displacement as a function of the intensity and the duration of the pulsed current. The result is discussed in terms of the spin-transfer mechanism.