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排序方式: 共有321条查询结果,搜索用时 250 毫秒
91.
Hiroyuki Kida Sadahiro Nomura Mizuya Shinoyama Makoto Ideguchi Yuji Owada Michiyasu Suzuki 《PloS one》2013,8(7)
Hypothermia has been proposed as a treatment for reducing neuronal damage in the brain induced by hypoxic ischemia. In the developing brain, hypoxic ischemia-induced injury may give rise to cerebral palsy (CP). However, it is unknown whether hypothermia might affect the development of CP. The purpose of this study was to investigate whether hypothermia would have a protective effect on the brains of immature, 3-day old (P3) mice after a challenge of cerebral ischemia. Cerebral ischemia was induced in P3 mice with a right common carotid artery ligation followed by hypoxia (6% O2, 37°C) for 30 min. Immediately after hypoxic ischemia, mice were exposed to hypothermia (32°C) or normothermia (37°C) for 24 h. At 4 weeks of age, mouse motor development was tested in a behavioral test. Mice were sacrificed at P4, P7, and 5 weeks to examine brain morphology. The laminar structure of the cortex was examined with immunohistochemistry (Cux1/Ctip2); the number of neurons was counted; and the expression of myelin basic protein (MBP) was determined. The hypothermia treatment was associated with improved neurological outcomes in the behavioral test. In the normothermia group, histological analyses indicated reduced numbers of neurons, reduced cortical laminar thickness in the deep, ischemic cortical layers, and significant reduction in MBP expression in the ischemic cortex compared to the contralateral cortex. In the hypothermia group, no reductions were noted in deep cortical layer thickness and in MBP expression in the ischemic cortex compared to the contralateral cortex. At 24 h after the hypothermia treatment prevented the neuronal cell death that had predominantly occurred in the ischemic cortical deep layers with normothermia treatment. Our findings may provide a preclinical basis for testing hypothermal therapies in patients with CP induced by hypoxic ischemia in the preterm period. 相似文献
92.
Previous studies have demonstrated task-related changes in brain activation and inter-regional connectivity but the temporal dynamics of functional properties of the brain during task execution is still unclear. In the present study, we investigated task-related changes in functional properties of the human brain network by applying graph-theoretical analysis to magnetoencephalography (MEG). Subjects performed a cue-target attention task in which a visual cue informed them of the direction of focus for incoming auditory or tactile target stimuli, but not the sensory modality. We analyzed the MEG signal in the cue-target interval to examine network properties during attentional control. Cluster-based non-parametric permutation tests with the Monte-Carlo method showed that in the cue-target interval, beta activity was desynchronized in the sensori-motor region including premotor and posterior parietal regions in the hemisphere contralateral to the attended side. Graph-theoretical analysis revealed that, in beta frequency, global hubs were found around the sensori-motor and prefrontal regions, and functional segregation over the entire network was decreased during attentional control compared to the baseline. Thus, network measures revealed task-related temporal changes in functional properties of the human brain network, leading to the understanding of how the brain dynamically responds to task execution as a network. 相似文献
93.
Hideo Shirafuji Makoto Kida Tsunehiko Asako Masahiko Yoneda 《Bioscience, biotechnology, and biochemistry》2013,77(12):2579-2584
Biochemical transformations of aminoglycoside antibiotics by Bacillus species were examined. Among 39 strains of 8 Bacillus species, 4 strains of B. brevis were found to inactivate several aminoglycoside antibiotics: neamine, xylostasin, butirosin A and kanamycin A.In the presence of Mg+2 and ATP, the cell-free extracts of B. brevis IFO 12334 catalyzed the transformation of xylostasin to its inactive form. The structure of this inactivated xylostasin was determined to be 4′-O-monoadenylylxylostain from the 13C-NMR spectra, and from biochemical and spectroscopic studies. 相似文献
94.
Hideo Shirafuji Kazuo Nakahama Ikuo Nogami Makoto Kida Masahiko Yoneda 《Bioscience, biotechnology, and biochemistry》2013,77(6):1599-1611
It has been reported that Bacillus vitellinus, a butirosin A-producing bacterium, has two enzymes: butirosin A-3′-phosphotransferase, catalyzing phosphorylation of butirosin A, and phosphatase, catalyzing dephosphorylation of butirosin A-3′-phosphate.A phosphatase-negative mutant, P-15, was derived from a potent butirosin A producer, BA-44, by NTG treatment. The mutant, P-15, was found to produce a butirosin A derivative when it was grown in a medium containing a relatively high concentration of inorganic phosphate. This compound was isolated and confirmed to be butirosin A-6′-N-diphosphate by physico-chemical analysis and 13C-NMR spectrometry.Furthermore, a mutant strain, AP-165, was derived from the phosphatase-negative mutant, P-15. This strain, AP-165, was isolated as a nonproducer on an agar piece of bouillon medium, but was found to accumulate a major product, 6′-deamino-6′-hydroxybutirosin A-6′-O-diphosphate, and a minor one, 6′-deamino-6′-hydroxybutirosin A-6′-O-monophosphate.It seems likely that these phosphorylated compounds are possible intermediates of butirosin A biosynthesis in B. vitellinus. 相似文献
95.
96.
Extensive accumulation of influenza virus NS1 protein in the nuclei causes effective viral growth in vero cells 总被引:1,自引:0,他引:1
We previously showed that modified A/Puerto Rico/8/34 (PR8) influenza master strain had improved viral rescue and growth properties in African green monkey kidney (Vero) cell line by introducing NS gene of Vero-adapted A/England/1/53 (vaEng53). In the present study, it was found that the NS1 protein derived from vaEng53 was extensively accumulated in the nuclei than that of PR8. This accumulation was caused by 7 amino acid differences in C-terminal region of NS1 protein. These results suggest that specific accumulation of NS1 protein may contribute to efficient viral replication in Vero cells. 相似文献
97.
We constructed two mesophilic anaerobic chemostats that were continuously fed with synthetic wastewater containing butyrate
as the sole source of carbon and energy. Steady-state conditions were achieved at dilution rates between 0.025 and 0.7 day−1. Butyrate, fed into the chemostat, was almost completely mineralized to CH4 and CO2 at dilution rates below 0.5 day−1. The butyrate-degrading methanogenic communities in the chemostats at dilution rates between 0.025 and 0.7 day−1 were monitored based on the 16S rRNA gene, using molecular biological techniques including clone library analysis, denaturing
gradient gel electrophoresis, and quantitative real-time polymerase chain reaction. The aceticlastic methanogen Methanosaeta and the hydrogenotrophic methanogen Methanoculleus dominated in methanogens at low dilution rates, whereas the aceticlastic methanogen Methanosaeta, Methanosarcina, the hydrogenotrophic methanogen Methanoculleus, and Methanospirillum dominated at high dilution rates. Bacteria affiliated with the family Syntrophaceae in the phylum Proteobacteria predominated at the low dilution rate of 0.025 day−1, whereas bacteria affiliated with the phylum Firmicutes and Candidate division OP3 predominated at high dilution rates. A significant quantity of bacteria closely related to the
genus Syntrophomonas was detected at high dilution rates. Dilution rate showed an apparent effect on archaeal and bacterial communities in the
butyrate-fed chemostats. 相似文献
98.
The main focus of the present investigation is to examine obstructed kidneys due to unilateral ureteral obstruction (UUO) model in adult mice using segment-specific tubular marker and to confirm the detailed morphological evaluation of UUO that is a typical model for the tubulointerstitial fibrosis which is an endpoint outcome of chronic renal diseases. Adult mice were subjected to UUO, and kidneys were harvested 1, 3, 7 days after surgical operation. Expansion of interstitial space both in the cortex and the medulla was confirmed 3 days after UUO by HE- and azan-staining. Interstitial fibrosis developed especially around dilated tubules. Immunohistochemistry for segment-specific antibodies revealed that the proximal tubules and the descending limb of Henle's loop did not dilate until 7 days after UUO, whereas initial dilation of the ascending limb of Henle's loop appeared to occur one day after surgery. The segment from the distal tubules to the collecting ducts began dilating one day after surgery and afterward significantly dilated. The downstream segment of nephron was involved in dilating earlier than the upstream of nephron in obstructed kidney examined in the present study. Moreover, the tubules accompanying apoptosis of tubular epithelia significantly dilated compared with those without apoptotic tubular epithelia. From the above-mentioned findings, we conclude that tubular dilatation of distal segment (from the ascending limb of Henle's loop to the collecting ducts) of nephron develops tubular epithelial apoptosis caused by accumulated urine, which would link to tubular disappearance and its replacement with fibrous tissue in UUO kidney of adult mice. 相似文献
99.
The terephthalate 1,2-dioxygenase system (TERDOS) was found in cell extracts of Delftia tsuruhatensis strain T7 (=IFO16741) grown in terephthalate-salt medium. The cell extract was separated by anion exchange chromatography to yield two fractions (R and Z) that were necessary for oxygenation of terephthalate with NADH and Fe(2+). The oxygenase component of TERDOS (TerZ) was purified from fraction Z by gel filtration chromatography to near homogeneity. An alpha(3)beta(3) subunit structure was deduced from the molecular masses of 235, 46 and 17 kDa of the native complex and the alpha- and beta-subunits, respectively. The N-terminal amino acid sequences of the two subunits of TerZ allowed polymerase chain reaction primers to be deduced and the DNA sequence of the alpha-subunit was determined. The amino acid sequence of the alpha-subunit (TerZalpha) showed significant similarities to the large subunits of multicomponent ring-hydroxylating oxygenases. Two motifs in the deduced amino acid sequence, a Rieske [2Fe-2S] center and a mononuclear Fe(II) binding site, were observed. Phylogenetic analyses indicated that TerZalpha and the large oxygenase component subunits ortho-halobenzoate 1,2-dioxygenase and salicylate-5-hydroxylase form a cluster that is distant from the rest of the large oxygenase subunits of multicomponent ring-hydroxylating oxygenases. 相似文献
100.
Dyrk1A phosphorylated multiple proteins in the clathrin-coated vesicle (CCV) preparations obtained from rat brains. Mass spectrometric analysis identified MAP1A, MAP2, AP180, and α- and β-adaptins as the phosphorylated proteins in the CCVs. Each protein was subsequently confirmed by [(32)P]-labeling and immunological methods. The Dyrk1A-mediated phosphorylation released the majority of MAP1A and MAP2 and enhanced the release of AP180 and adaptin subunits from the CCVs. Furthermore, Dyrk1A displaced adaptor proteins physically from CCVs in a kinase-concentration dependent manner. The clathrin heavy chain release rate, in contrast, was not affected by Dyrk1A. Surprisingly, the Dyrk1A-mediated phosphorylation of α- and β-adaptins led to dissociation of the AP2 complex, and released only β-adaptin from the CCVs. AP180 was phosphorylated by Dyrk1A also in the membrane-free fractions, but α- and β-adaptins were not. Dyrk1A was detected in the isolated CCVs and was co-localized with clathrin in neurons from mouse brain sections and from primary cultured rat hippocampus. Previously, we proposed that Dyrk1A inhibits the onset of clathrin-mediated endocytosis in neurons by phosphorylating dynamin 1, amphiphysin 1, and synaptojanin 1. Current results suggest that besides the inhibition, Dyrk1A promotes the uncoating process of endocytosed CCVs. 相似文献