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61.
Emiko Matsunaga Yujiro Higuchi Kazuki Mori Nao Yairo Takuji Oka Saki Shinozuka Kosuke Tashiro Minoru Izumi Satoru Kuhara Kaoru Takegawa 《PloS one》2015,10(9)
β-D-galactofuranose (Galf) is a component of polysaccharides and glycoconjugates and its transferase has been well analyzed. However, no β-D-galactofuranosidase (Galf-ase) gene has been identified in any organism. To search for a Galf-ase gene we screened soil samples and discovered a strain, identified as a Streptomyces species by the 16S ribosomal RNA gene analysis, that exhibits Galf-ase activity for 4-nitrophenyl β-D-galactofuranoside (pNP-β-D-Galf) in culture supernatants. By draft genome sequencing of the strain, named JHA19, we found four candidate genes encoding Galf-ases. Using recombinant proteins expressed in Escherichia coli, we found that three out of four candidates displayed the activity of not only Galf-ase but also α-L-arabinofuranosidase (Araf-ase), whereas the other one showed only the Galf-ase activity. This novel Galf-specific hydrolase is encoded by ORF1110 and has an optimum pH of 5.5 and a Km of 4.4 mM for the substrate pNP-β-D-Galf. In addition, this enzyme was able to release galactose residue from galactomannan prepared from the filamentous fungus Aspergillus fumigatus, suggesting that natural polysaccharides could be also substrates. By the BLAST search using the amino acid sequence of ORF1110 Galf-ase, we found that there are homolog genes in both prokaryotes and eukaryotes, indicating that Galf-specific Galf-ases widely exist in microorganisms. 相似文献
62.
Taichiro Miyake Kosuke Soda Yasushi Itoh Yoshihiro Sakoda Hirohito Ishigaki Tomoya Nagata Hideaki Ishida Misako Nakayama Hiroichi Ozaki Hideaki Tsuchiya Ryuzo Torii Hiroshi Kida & Kazumasa Ogasawara 《Journal of medical primatology》2010,39(1):58-70
Background Highly pathogenic avian influenza virus (HPAIV) infection has a high mortality rate in humans. Secondary bacterial pneumonia with HPAIV infection has not been reported in human patients, whereas seasonal influenza viruses sometimes enhance bacterial pneumonia, resulting in substantial morbidity and mortality. Therefore, if HPAIV infection were accompanied by bacterial infection, an increase in mortality would be expected. We examined whether a vaccine against HPAIV prevents severe morbidity caused by mixed infection with HPAIV and bacteria.
Methods H7N7 subtype of HPAIV and Streptococcus pneumoniae were inoculated into cynomolgus macaques with or without vaccination of inactivated whole virus particles .
Results Vaccination against H7N7 HPAIV decreased morbidity caused by HPAIV and pneumonia caused by S. pneumoniae . Bacterial replication in lungs was decreased by vaccination against HPAIV, although the reduction in bacterial colonies was not significant.
Conclusions Vaccination against HPAIV reduces pneumonia caused by bacterial superinfection and may improve prognosis of HPAIV-infected patients. 相似文献
Methods H7N7 subtype of HPAIV and Streptococcus pneumoniae were inoculated into cynomolgus macaques with or without vaccination of inactivated whole virus particles .
Results Vaccination against H7N7 HPAIV decreased morbidity caused by HPAIV and pneumonia caused by S. pneumoniae . Bacterial replication in lungs was decreased by vaccination against HPAIV, although the reduction in bacterial colonies was not significant.
Conclusions Vaccination against HPAIV reduces pneumonia caused by bacterial superinfection and may improve prognosis of HPAIV-infected patients. 相似文献
63.
Akihiko Murai Kosuke Kurosaki Katsu Yamane Yoshihiko Nakamura 《Progress in biophysics and molecular biology》2010,103(2-3):310-317
In this paper, we present a system that estimates and visualizes muscle tensions in real time using optical motion capture and electromyography (EMG). The system overlays rendered musculoskeletal human model on top of a live video image of the subject. The subject therefore has an impression that he/she sees the muscles with tension information through the cloth and skin. The main technical challenge lies in real-time estimation of muscle tension. Since existing algorithms using mathematical optimization to distribute joint torques to muscle tensions are too slow for our purpose, we develop a new algorithm that computes a reasonable approximation of muscle tensions based on the internal connections between muscles known as neuronal binding. The algorithm can estimate the tensions of 274 muscles in only 16 ms, and the whole visualization system runs at about 15 fps. The developed system is applied to assisting sport training, and the user case studies show its usefulness. Possible applications include interfaces for assisting rehabilitation. 相似文献
64.
Tomoya Mita Kosuke Azuma Takashi Nomiyama Takahisa Hirose Ryuzo Kawamori Hirotaka Watada 《Biochemical and biophysical research communications》2010,395(4):477-483
Epidemiological studies suggest that insulin resistance is an independent risk factor for cardiovascular disease. However, there is little information on the role of insulin resistance in atherosclerogenesis independent of LDL cholesterol level. The aim of this study was to investigate the impact of systemic insulin resistance on monocyte adhesion to endothelial cells and atherosclerotic lesions independent of LDL cholesterol level. KKAy mice are obese mice with spontaneous diabetes and insulin resistance, and normal levels of LDL cholesterol. In parallel with systemic insulin resistance, decreased insulin signal, and the increased expression of monocyte chemoattractant protein-1 (MCP-1) were noted in macrophages isolated from KKAy mice. These mice showed enhanced monocyte adhesion to the endothelial cells of the thoracic artery. Furthermore, these mice showed expanded atherosclerotic lesions when fed high cholesterol diet. Our data indicate that insulin resistance promotes the atherosclerogenesis independent of LDL cholesterol level. Decreased insulin signaling in macrophages associated with systemic insulin resistance could be involved, at least in part, in this pathological process. 相似文献
65.
66.
Yasutoshi Kido Kosuke Nakamura Takashi Suzuki Hiroyuki Saimoto Daijiro Ohmori Shigeharu Harada 《BBA》2010,1797(4):443-450
The trypanosome alternative oxidase (TAO) functions in the African trypanosomes as a cytochrome-independent terminal oxidase, which is essential for their survival in the mammalian host and as it does not exist in the mammalian host is considered to be a promising drug target for the treatment of trypanosomiasis. In the present study, recombinant TAO (rTAO) overexpressed in a haem-deficient Escherichia coli strain has been solubilized from E. coli membranes and purified to homogeneity in a stable and highly active form. Analysis of bound iron detected by inductively coupled plasma-mass spectrometer (ICP-MS) reveals a stoichiometry of two bound iron atoms per monomer of rTAO. Confirmation that the rTAO was indeed a diiron protein was obtained by EPR analysis which revealed a signal, in the reduced forms of rTAO, with a g-value of 15. The kinetics of ubiquiol-1 oxidation by purified rTAO showed typical Michaelis-Menten kinetics (Km of 338 μM and Vmax of 601 μmol/min/mg), whereas ubiquinol-2 oxidation showed unusual substrate inhibition. The specific inhibitor, ascofuranone, inhibited the enzyme in a mixed-type inhibition manner with respect to ubiquinol-1. 相似文献
67.
Akira Ikari Kosuke Atomi Keishi Kinjo Yohei Sasaki Junko Sugatani 《Life sciences》2010,86(19-20):766-773
AimsLoss of magnesium (Mg2+) inhibits cell proliferation and augments nephrotoxicant-induced renal injury, but the role of Mg2+ has not been clarified in detail. We examined the effect of extracellular Mg2+ deprivation on a MEK–ERK cascade and cell proliferation using a renal epithelial cell line, Madin-Darby canine kidney (MDCK) cells.Main methodsMDCK cells were cultured in Mg2+-containing or Mg2+-free media. A HA-tagged constitutively active (CA)-MEK1 and a dominant negative (DN)-MEK1 were transfected into MDCK cells. The level of protein was examined by Western blotting. The intracellular free Mg2+ concentration ([Mg2+]i) was measured using a fluorescent dye, mag-fura 2. Cell proliferation was determined by WST-1 assay. Dead cells were identified by staining with annexin V-FITC and propidium iodide.Key findingsIn the presence of fetal calf serum (FCS), Mg2+ deprivation decreased phosphorylated-ERK1/2 (p-ERK1/2) levels and [Mg2+]i. Re-addition of Mg2+ increased p-ERK1/2 levels, which were inhibited by U0126, a specific inhibitor of a MEK–ERK cascade. Glutathione-S-transferase pull-down and coimmunoprecipitation assays showed that CA-MEK1 and DN-MEK1 binds with ERK1/2 in the presence of Mg2+. In contrast, neither CA-MEK1 nor DN-MEK1 bound to ERK1/2 in the absence of Mg2+. These results indicate that the MEK–ERK cascade is regulated by [Mg2+]i. Cell proliferation was increased by the treatment with FCS or the expression of CA-MEK1 in the presence of Mg2+, but was inhibited by Mg2+ deprivation. Mg2+ deprivation did not increase the number of dead cells.SignificanceMg2+ is involved in the regulation of the MEK–ERK cascade and cell proliferation in MDCK cells. 相似文献
68.
Jung-Soo Kim Kosuke Okamoto Shinobu Arima Bruce K Rubin 《Journal of applied physiology》2006,101(2):486-491
Vasoactive intestinal peptide (VIP) and nitric oxide (NO) are neurotransmitters involved in the regulation of bronchial and pulmonary vascular tone. Published studies of the effects of VIP on airway mucus secretion have yielded conflicting results. The purpose of this study was to determine the effect of VIP on mucus secretion in the ferret trachea and if this effect was influenced by NO. We used a sandwich enzyme-linked lectin assay to measure mucin secretion and a turbidimetric assay to measure lysozyme (serous cell) secretion from ferret tracheal segments. VIP (10(-7) M) increased mucin secretion over 2 h. VIP (10(-9) to 10(-5) M) stimulated mucin secretion in a dose-dependent fashion. VIP-induced mucin secretion was partially blocked by a VIP receptor antagonist (a chimeric VIP-pituitary adenylate cyclase-activating peptide analog, VIP receptor antagonist) at a 10-fold excess concentration. At all concentrations tested, neither NG-nitro-L-arginine methyl ester, an inhibitor of NO synthase, nor S-nitroso-N-acetyl-penicillamine, an NO donor, had any significant effect on constitutive or VIP-induced mucus secretion. We conclude that VIP-stimulated mucin and lysozyme secretion was both time dependent and dose dependent and that NO neither stimulates nor inhibits mucus secretion in the ferret trachea. 相似文献
69.