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141.
Kanako Ishihara Kumiko Nakajima Satoko Kishimoto Fumiaki Atarashi Yasukazu Muramatsu Akitoyo Hotta Satomi Ishii Yasuyuki Takeda Masanori Kikuchi Yutaka Tamura 《Microbiology and immunology》2013,57(10):684-691
To determine and compare the extent of contamination caused by antimicrobial‐resistant lactic acid bacteria (LAB) in imported and domestic natural cheeses on the Japanese market, LAB were isolated using deMan, Rogosa and Sharpe (MRS) agar and MRS agar supplemented with six antimicrobials. From 38 imported and 24 Japanese cheeses, 409 LAB isolates were obtained and their antimicrobial resistance was tested. The percentage of LAB resistant to dihydrostreptomycin, erythromycin, and/or oxytetracycline isolated from imported cheeses (42.1%) was significantly higher than that of LAB resistant to dihydrostreptomycin or oxytetracycline from cheeses produced in Japan (16.7%; P = 0.04). Antimicrobial resistance genes were detected in Enterococcus faecalis (tetL, tetM, and ermB; tetL and ermB; tetM) E. faecium (tetM), Lactococcus lactis (tetS), Lactobacillus (Lb.), casei/paracasei (tetM or tetW), and Lb. rhamnosus (ermB) isolated from seven imported cheeses. Moreover, these E. faecalis isolates were able to transfer antimicrobial resistance gene(s). Although antimicrobial resistance genes were not detected in any LAB isolates from Japanese cheeses, Lb. casei/paracasei and Lb. coryniformis isolates from a Japanese farm‐made cheese were resistant to oxytetracycline (minimal inhibitory concentration [MIC], 32 µg/mL). Leuconostoc isolates from three Japanese farm‐made cheeses were also resistant to dihydrostreptomycin (MIC, 32 to > 512 µg/mL). In conclusion, the present study demonstrated contamination with antimicrobial‐resistant LAB in imported and Japanese farm‐made cheeses on the Japanese market, but not in Japanese commercial cheeses. 相似文献
142.
Masahito Kawano Rey IshiiYuki Yoshioka Takehito FukudaMinoru Tamura 《Archives of biochemistry and biophysics》2013
Noxa1 activates Nox2 together with Noxo1 and Rac in a pure reconstitution system, but the resulting activity is considerably lower than that induced by p67phox and p47phox. In this study, we found that C-terminal-truncated forms of Noxa1 exhibited higher activities than full-length Noxa1. Of the truncations examined, Noxa1(1-225) showed the highest ability for activation. Kinetic studies revealed that Noxa1(1-225) had a threefold higher Vmax value than full-length Noxa1 with a similar EC50 value. The affinities of Noxo1 and RacQ61L were not much altered by the truncation. Conversely, the affinity of FAD for the Nox2 complex was enhanced after the truncation. In the absence of Noxo1, Noxa1(1-225) showed much higher activity with a lower EC50 than full-length Noxa1. Noxa1(1-225) showed comparable activity to that of p67phox with either Noxo1 or p47phox, although the stability was lower than that with p67phox and p47phox. These findings indicate that the role of the C-terminal half of Noxa1 is autoinhibition. The data suggest a two-step autoinhibition mechanism, comprising self-masking to interrupt the binding to the oxidase, and holding of the activation domain in a suboptimal position to the oxidase. This study reveals that when both types of inhibition are released, Noxa1 achieves high-level superoxide production. 相似文献
143.
Shin-ichi Ikeda Yoshifumi Tamura Saori Kakehi Kageumi Takeno Minako Kawaguchi Takahiro Watanabe Fumihiko Sato Takeshi Ogihara Akio Kanazawa Yoshio Fujitani Ryuzo Kawamori Hirotaka Watada 《Biochemical and biophysical research communications》2013
Exercise enhances insulin sensitivity in skeletal muscle, but the underlying mechanism remains obscure. Recent data suggest that alternatively activated M2 macrophages enhance insulin sensitivity in insulin target organs such as adipose tissue and liver. Therefore, the aim of this study was to determine the role of anti-inflammatory M2 macrophages in exercise-induced enhancement of insulin sensitivity in skeletal muscle. C57BL6J mice underwent a single bout of treadmill running (20 m/min, 90 min). Twenty-four hours later, ex vivo insulin-stimulated 2-deoxy glucose uptake was found to be increased in plantaris muscle. This change was associated with increased number of CD163-expressing macrophages (i.e. M2-polarized macrophages) in skeletal muscle. Systemic depletion of macrophages by pretreatment of mice with clodronate-containing liposome abrogated both CD163-positive macrophage accumulation in skeletal muscle as well as the enhancement of insulin sensitivity after exercise, without affecting insulin-induced phosphorylation of Akt and AS160 or exercise-induced GLUT4 expression. These results suggest that accumulation of M2-polarized macrophages is involved in exercise-induced enhancement of insulin sensitivity in mouse skeletal muscle, independently of the phosphorylation of Akt and AS160 and expression of GLUT4. 相似文献
144.
Yuusuke Tamura Kyouhei Hayashi Naoki Omori Yuji Nishiura Kana Watanabe Nobuyuki Tanaka Masahiko Fujioka Naoki Kouyama Akira Yukimasa Yukari Tanaka Takeshi Chiba Hideki Tanioka Hirohide Nambu Hideo Yukioka Hiroki Sato Takayuki Okuno 《Bioorganic & medicinal chemistry letters》2013,23(1):90-95
Optimization of HTS hit 1 for NPY Y5 receptor binding affinity, CYP450 inhibition, solubility and metabolic stability led to the identification of some orally available oxygen-linker derivatives for in vivo study. Among them, derivative 4i inhibited food intake induced by the NPY Y5 selective agonist, and chronic oral administration of 4i in DIO mice caused a dose-dependent reduction of body weight gain. 相似文献
145.
Kenji Sugimoto Kosuke Tamura Chihiro Tohda Naoki Toyooka Hideo Nemoto Yuji Matsuya 《Bioorganic & medicinal chemistry》2013,21(15):4459-4471
As an extended study on development of anti-Alzheimer’s disease agent, we newly synthesized various dihydrofuran-fused perhydrophenanthrenes via o-quinodimethane chemistry. This study revealed that the introduction of carbon side-chain on 8-position or removal of the acetal moiety on 3-position arose a cytotoxicity on rat cortical neurons. On the other hand, the ethereal or thio-ethereal substituent on 8-position enhanced the elongation effect on Aβ-damaged neurons. The necessity of the cyano group on 10b position was also proved in this structure–activity-relationship study. 相似文献
146.
Youichi Kawakita Masaki Seto Tomohiro Ohashi Toshiya Tamura Tadashi Yusa Hiroshi Miki Hidehisa Iwata Hidenori Kamiguchi Toshimasa Tanaka Satoshi Sogabe Yoshikazu Ohta Tomoyasu Ishikawa 《Bioorganic & medicinal chemistry》2013,21(8):2250-2261
A novel 7,6 fused bicyclic scaffold, pyrimido[4,5-b]azepine was designed to fit into the ATP binding site of the HER2/EGFR proteins. The synthesis of this scaffold was accomplished by an intramolecular Claisen-type condensation. As the results of optimization lead us to 4-anilino and 6-functional groups, we discovered 6-substituted amide derivative 19b, which has a 1-benzothiophen-4-yloxy group attached to the 4-anilino group. An X-ray co-crystal structure of 19b with EGFR demonstrated that the N-1 and N-3 nitrogens of the pyrimido[4,5-b]azepine scaffold make hydrogen-bonding interactions with the main chain NH of Met793 and the side chain of Thr854 via a water-mediated hydrogen bond network, respectively. In addition, the NH proton at the 9-position makes an additional hydrogen bond with the carbonyl group of Met793, as we expected. Compound 19b revealed potent HER2/EGFR kinase (IC50: 24/36 nM) and BT474 cell growth (GI50: 18 nM) inhibitory activities based on its pseudo-irreversible (PI) profile. 相似文献
147.
Hiroto Tamura Maiko Yoshioka Momoko Hasegawa Akifumi Hosoda Masato Matsugi Miki Akamatsu 《Bioorganic & medicinal chemistry》2013,21(11):2968-2974
Although flavones act as potent androgen receptor (AR) antagonists, it remains unclear how flavones interact with AR. The aim of this in silico study was to investigate the molecular recognition processes of newly synthesized 5,4′-difluoroflavone with the highest activity (IC50 value = 0.19 μM) in the AR-ligand binding domain (AR-LBD). The results demonstrated that at its 4′-position of 5,4′-difluoroflavone the substituents may face Arg752 and that in AR-LBD, the submolecular bulk of substituents is unfavorable for AR antagonists and the negative electrostatic interaction site prefers the stronger hydrogen bond capability of substituents of AR antagonists. The prediction model is a valuable tool for designing a novel AR antagonist. 相似文献
148.
Tomoyoshi Hosokawa Kunio Ando Gakuzo Tamura 《Bioscience, biotechnology, and biochemistry》2013,77(11):2865-2869
γ-Aminobutyric acid (GABA), a hypotensive compound, and alanine accumulated in tea leaves under anaerobic conditions. Since the 15N in 15N-glutamic acid was well incorporated in GABA and alanine during anaerobic incubation, glutamic acid seemed to be a source of nitrogen for the increased GABA and alanine. GOT and GPT were the predominant amino acid transaminases in tea leaves. Although glutamate decarboxylase and GPT seemed to be important for GABA and alanine accumulation, the activities of these enzymes did not increase under anaerobic conditions. Glutamate decarboxylase, which formed GABA from glutamate, was purified 52.4-fold. This enzyme, with an optimum pH at 5.8, was activated by pyridoxal phosphate and used only l-glutamic acid as a substrate. 相似文献
149.
Kanzo Sakata Akira Sakurai Saburo Tamura 《Bioscience, biotechnology, and biochemistry》2013,77(10):1993-1999
The structures of ezomycins A1. and A2, antifungal antibiotics produced by a strain of Streptomyces, were determined as 1 and 2, respectively, by degradative and spectrometric studies. 相似文献
150.
Kei Arima Teiiti Narasaki Yoshio Nakamura Gakuzo Tamura 《Bioscience, biotechnology, and biochemistry》2013,77(8):924-929
About 2000 strains of microorganisms were examined for lipoprotein lipase producibilities and some microorganisms were found to produce lipases similar to animal lipoprotein lipases.Microorganisms were cultured on solid media containing a serum-activated olive oil emulsion, and strains which formed a clear zone around the colony were collected. The collected microorganisms were cultured on liquid media containing 0.5% of olive oil by shaking and the culture filtrates were tested for lipoprotein lipase activity by a turbidity method. The superior lipoprotein lipase producers obtained belonged to genera of Serratia, Pseudomonas, Mucor, and Streptomyces. 相似文献