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911.
Shin-Ichi Izumi Toshiaki Furukawa Yuji Koyama Akira Ishida 《Somatosensory & motor research》2013,30(4):322-329
Knee flexion is a movement that initiates rising from a sitting position, which is a common therapeutic exercise for patients unable to ambulate. We investigated how voluntary isometric biceps femoris contraction affects motor evoked potential (MEP) amplitude following transcranial magnetic stimulation, background electromyographic (EMG) amplitude, and H-reflex amplitude in ipsilateral leg muscles. Subjects were seated on the edge of a bed with their hips and knees flexed at 90°, and the soles of their feet on the floor. MEP and background EMG were recorded from the tibialis anterior (TA) and soleus (SOL), and H reflexes from SOL of 30 volunteers. Background EMG and MEP also were recorded while voluntarily contracting tested muscles. Biceps femoris contraction increased MEP and background EMG for TA and SOL ( p < 0.01). Maximal background EMG and MEP increased with increasing voluntary contraction of tested muscles ( p < 0.005). Regression slope differed little between TA and SOL. Biceps femoris contraction facilitated MEP comparably for TA and SOL, while SOL background EMG exceeded that of TA ( p < 0.02). The relationship between MEP facilitation and background EMG changed to favor more efficient facilitation in TA ( p < 0.05), but not SOL ( p > 0.1). MEP recorded from TA and SOL with subthreshold stimuli using needle electrodes were more frequent with biceps femoris contraction ( p < 0.04). H-reflex amplitude of SOL decreased during biceps femoris contraction ( p < 0.001). We concluded that biceps femoris contraction affects leg muscle MEP, background EMG, and H reflexes differently. 相似文献
912.
913.
Shingo Kawai Toshiaki Umezawa Takayoshi Higuchi 《Bioscience, biotechnology, and biochemistry》2013,77(8):2325-2330
A non-phenolic β-O-4 lignin substructure model, 4-ethoxy-3-methoxyphenylglycerol-β-syringaldehyde ether (I), was metabolized by a ligninolytic culture of Coriolus versicolor. Based on the identification of the metabolic products (II~XI), the following reactions were found to occur in the culture; a) oxidation (III) and reduction (II) at the benzyl (Cα′) position of the substrate (I), b) β-ether cleavage to give arylglycerols (IV, V), and c) Cα-Cβ cleavage of the arylglycerols and/or arylglycerol moiety of the substrate (I). In addition, β-deoxy diol (VI) and γ-formylglycerol (VII) were obtained as degradation products from substrate (I). 相似文献
914.
915.
Fukashi Horiuchi Keimei Fujimoto Toshiaki Ozaki Yoshihiko Nishizawa 《Bioscience, biotechnology, and biochemistry》2013,77(13):2003-2007
Several 3,5-dialkyl-4-hydroxybenzylidenemalononitriles and related compounds were tested for their fungicidal and acaricidal activities. The influence of structural variation on biological activity was studied by preparing and using a total of 22 compounds of benzylidenemalononitrile analogues.Amongst the compounds tested 3,5-di-tert-butyl and amyl-4-hydroxybenzylidenemalononitrile were most effective against fungus, Piricularia oryzae Car. and mite, Tetranychus telarius L. 相似文献
916.
Mamoru Ozaki Tatsumi Kariya Hiroshi Kato Toshiaki Kimura 《Bioscience, biotechnology, and biochemistry》2013,77(3):451-456
Microbial transformation of the nucleoside analogue antibiotic showdomycin was performed using some Streptomyces species. Both the growing culture and the resting cells of Streptomyces sp. No. 383 arrested the antibacterial activity of showdomycin. The inactivated showdomycin was isolated from the reaction mixture by carbon chromatography and was identified with an isoshowdomycin sample which has been chemically derived from showdomycin. It is conjectured that the conversion of showdomycin to isoshowdomycin results from isomerization by an enzyme of Streptomyces sp. No. 383. 相似文献
917.
Purification and Partial Characterization of Alkaline Xylanase from Escherichia coli Carrying pCX311
Hiroshi Honda Toshiaki Kudo Koki Horikoshi 《Bioscience, biotechnology, and biochemistry》2013,77(11):3165-3169
Xylanase produced by E. coli HB 101 carrying plasmid pCX311, which contains the xylanase A gene of alkalophilic Bacillus sp. strain C-125, was purified by ammonium sulfate precipitation, DEAE-cellulose column chromatography and Sephadex G-75 gel filtration. The purified enzyme had a molecular weight of 43,000. The pH and temperature optima for its activity were 6~10 and 70°C, respectively. The enzyme retained full activity after incubation at 50°C for 10 min. These enzymatic properties of the xylanase were almost the same as those of xylanase A. But this enzyme was less stable than xylanase A at low pHs. Furthermore, we could purify a larger amount of alkaline xylanase from E. coli than from alkalophilic Bacillus sp. strain C-125. 相似文献
918.
Isosclerone, mp 74~76°C, , a new metabolite of Sclerotinia sclerotiorum, was isolated and its absolute structure was determined as (4S)-3,4-dihydro-4,8-dihydroxy-1(2H)-naphthalenone. It stimulated the root elongation of rice seedlings by ca. 30% at concentrations of 1~10 ppm, and inhibited the growth of shoots and roots at high concentrations above 50 ppm. 相似文献
919.
Tsuyostri Habe Shimada Mikio Toshiaki Umezawa Takayoshi Higuchi 《Bioscience, biotechnology, and biochemistry》2013,77(12):3505-3510
The mechanism of C-C and ether bond cleavages of Cα-or Cβ-deuterated β-O-4 and β-l lignin substructure models and the vicinal diol compounds catalyzed by the enzyme system from Phanerochaete chrysosporium culture was investigated. The enzymatic oxidation of β-O-4 lignin model compounds in the presence of H2O2 and O2 yielded C6-Cα-derived benzaldehyde, and Cβ-Cγ-derived product together with the arylglycerol product. Likewise, the β-l models and the diol compounds also underwent the C-C bond cleavage, yielding C6-Cβ-derived benzaldehyde and the arylglycol product. The results demonstrated that the d-labels at Cα and Cβ of the substrates were retained in the products after the Cα-Cβ and ether bond cleavages. 相似文献
920.
Osamu Ohno Maho Morita Kazuhiro Kitamura Toshiaki Teruya Kozo Yoneda Masaki Kita Hideo Kigoshi Kiyotake Suenaga 《Bioorganic & medicinal chemistry letters》2013,23(5):1467-1471
Aplyronine A (1) and mycalolide B (2), which are cytotoxic actin-depolymerizing marine macrolides, were revealed to induce apoptosis in human leukemia HL60 cells and human epithelial carcinoma HeLa S3 cells. Based on these results, actin-depolymerizing compounds were expected to exhibit apoptosis-inducing activity in cancer cells. Compounds 3–6, which were synthesized based on the side-chain structure of aplyronine A, were evaluated for their actin-depolymerizing activities in vitro and cytotoxicities against HL60 cells. The growth-inhibitory activities of 3–6 were well correlated with their actin-depolymerizing activities, and derivative 6 was shown to induce the disruption of actin filaments and apoptosis in HL60 cells. These results suggested that actin-depolymerizing agents 1, 2, and 6-induced apoptosis in HL60 cells may have been due to their actin-depolymerizing activity. 相似文献