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Yuichiro Higuchi Kenji Kawai Masahumi Yamamoto Miyuki Kuronuma Yasuhiko Ando Ikumi Katano Masato Nakamura Hiroshi Suemizu 《Experimental Animals》2014,63(1):55-62
The interaction between transplanted cells and host tissues is important for the growth
and maintenance of transplanted cells. To analyze the mechanisms of these interactions, a
systemic fluorescent protein-expressing mouse is a useful recipient. In this study, we
generated a novel NOG strain, which strongly expresses enhanced green fluorescent protein
(EGFP; PgkEGFP-NOG), especially in the liver, kidney, gastrointestinal tract, and testis.
Because the host tissues expressed EGFP, xenotransplanted human cancer cells were clearly
identified as EGFP-negative colonies in PgkEGFP-NOG mice. Immunohistochemical analysis
revealed that EGFP-expressing stromal tissues formed a complicated tumor microenvironment
within xenograft tissues. Moreover, a similar microenvironment was observed in human iPS
cell-derived teratomas. Collectively, these results indicated that a suitable
microenvironment is essential for the growth and maintenance of xenotransplanted cells and
that PgkEGFP-NOG mice represent a useful animal model for analyzing the mechanisms of
microenvironment formation. 相似文献
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Uno M Kitazato KT Suzue A Matsuzaki K Harada M Itabe H Nagahiro S 《Free radical biology & medicine》2005,39(8):1109-1116
We assess the availability of plasma biomarkers to monitor the brain damage and the therapeutic efficacy of edaravone. The study consisted of 51 patients with ischemic cerebral infarcts. They were divided into 2 groups: GI (n = 24) had cortical lesions, and GII (n = 27) had lesions in the basal ganglia or brain stem. Edaravone was administered to 27 randomly selected patients (GIa, n = 13; GIIa, n = 14) and its efficacy was studied by comparing their plasma OxLDL, S-100B, and MnSOD levels to those in patients without edaravone (GIb, n = 11, GIIb, n = 13). Three days after the start of edaravone, plasma OxLDL was significantly lower in GIa than GIb patients (0.177 +/- 0.024 ng/microg apoB vs 0.219 +/- 0.026, P < 0.05). In GIIa patients, pre- and posttreatment plasma OxLDL was not significantly different (0.156 +/- 0.013 vs 0.152 +/- 0.020). In GIa patients, S-100B and MnSOD were significantly lower than in GIb patients (P < 0.05). The neurological condition at the time of discharge had recovered in GIa but not GIb patients. Ours is the first evidence to confirm the efficacy of edaravone by plasma biomarkers. In patients with cortical infarcts, edaravone reduced oxidative damage, thereby limiting the degree of brain damage. 相似文献
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Shin-nosuke Hashida Masahumi Johkan Kazuyoshi Kitazaki Kazuhiro Shoji Fumiyuki Goto Toshihiro Yoshihara 《Plant and Soil》2014,374(1-2):715-725
Aims
Nitrous oxide (N2O) is a strong greenhouse effective gas (GHG); the primary human source of N2O is agricultural activities. Excessive nitrogen (N) fertilization of agricultural land is now widely recognized as a major contributor. In soil, the microbial processes of nitrification and denitrification are the principal sources of N2O. However, it remains poorly understood how conventional hydroponics influences GHG emission. Here, we compared GHG fluxes from soil and rockwool used for hydroponics under identical nutrient conditions.Methods
Tomato plants (Solanum lycopersicum, momotaro) were grown in soil or by hydroponics using rockwool. In situ emissions of CH4, CO2, and N2O, and the abundance of genes involved in nitrification and denitrification were measured during cultivation.Results
Hydroponics with rockwool mitigated CO2 emission by decreasing the microbial quantity in the rhizosphere. Dilution of the nutrient solution significantly decreased N2O emission from rockwool. Although proliferation of nitrifiers or denitrifiers in the rhizosphere did not induce N2O emission, reuse or long-term use of rockwool induced a 3.8-fold increase in N2O emission.Conclusions
Our data suggest that hydroponics has a lower environmental impact and that adequate fertilizer application, rather than bacterial control, governs N2O fluxes in hydroponic cultivation using rockwool. 相似文献6.
Feng Jie Jin Tadashi Takahashi Michiyo Utsushikawa Toshi Furukido Michiyo Nishida Masahiro Ogawa Masahumi Tokuoka Yasuji Koyama 《Molecular genetics and genomics : MGG》2010,283(1):1-12
We aim to create an Aspergillus oryzae mutant with a highly reduced chromosome, but better growth, by eliminating the nonessential regions coding various dispensable
functions for its better industrial use. In our previous study, we successfully determined the outline of essential and nonessential
regions by constructing a series of large chromosomal deletions in A. oryzae chromosome 7. Based on these results, we here constructed two mutants, designated RkuAF7A and RkuAF7B, lacking 24.7 and 24%
(725 and 705 kb) of wild type chromosome 7, respectively, using multiple large-scale chromosomal deletions in a recursive
pyrG-mediated transformation system. Both showed higher amylase activity in DPY liquid medium and faster growth rate on malt agar
medium relative to the parent strain. The two mutants also displayed soft fluffy hyphal morphology when grown in DPY liquid
media. In addition, the gene expression profile obtained by DNA microarray indicated that although the deletion regions were
fewer than 2% of the whole genome, the effect on whole gene expression exceeded 20%. Among these, the genes involved in secondary
metabolism showed a relatively large change in their gene expression levels. Together, the constructed mutants showing better
growth and potential usefulness is possibly suitable for further industrial use. 相似文献
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Shiga H Yoshii H Ohe H Yasuda M Furuta T Kuwahara H Ohkawara M Linko P 《Bioscience, biotechnology, and biochemistry》2004,68(1):66-71
Powdery encapsulation of shiitake flavors, extracted from dried shiitake, was investigated by spray drying. Flavor retention increased with an increase in drying air temperature and solid content, and decreased with an increase in dextrose equivalents of maltodextrin. A heat-treatment of the extract liquid made the lenthionine concentration increase, but did not influence the concentrations of the other flavors. The formation of lenthionine with heat-treatment could be described by the consecutive unimolecular-type first order reaction. Lenthionine content in a spray-dried powder prepared with the heated extracted liquid significantly increased. alpha-Cyclodextrin was the most suitable encapsulant of alpha-, beta-, and gamma-cyclodextrins to prepare the spray-dried powder, including lenthionine. The flavor retentions were markedly increased by using of alpha-cyclodextrin and maltodextrin in combination as an encapsulant. 相似文献
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Masahumi Okada Hiromitsu Yoshimoto Kazumi Nishioka Atsushi Mori 《Molecular simulation》2013,39(1-3):179-192
Abstract The Mechanism of atomic intermixing process in crystalline microclusters is studied by molecular dynamics simulation for a two-dimensional system with the Lennard-Jones potential. Temperature is chosen so that a cluster consists of solid-like core region and the region of surface melting. It is found that atomic intermixing in the solid-like core region is caused by the motion of a dislocation through the cluster as well as the random walk of a vacancy in the cluster. Generation of a dislocation or a vacancy occurs at the interfacial region between the liquid-like surface and the solid-like core regions due to large scale fluctuation of the configuration of atoms in the region of surface melting and the opportune collective motion of atoms in the solid-like core region. The rate per atom of atomic intermixing, the basic quantity of our interest (for the definition see the text), in the solid-like core of the microcluster is three to four orders of magnitude larger than that in the bulk crystal. 相似文献
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Abstract Molecular dynamics simulation is carried out to study the mechanism of self diffusion which is characteristic of solid-like microclusters. A two-dimensional system with the Lennard-Jones potential is employed and the temperatures near the triple point of the two-dimensional bulk system are adopted for the simulation. The results show that: a) microclusters consist of two regions, i.e., solid-like cores and liquid-like surface regions, b) the size dependence of the diffusion coefficient for microclusters is weak, and the value of the solid-like core region is not much different from that of the bulk liquid, c) the activation energy of diffusion for microclusters is twenty to thirty times larger than that for the bulk liquid, d) the diffusion mechanism in the solid-like region involves the collective motion of small domains containing ten to twenty atoms which results in the formation of low density regions, sometimes even vacancy clusters, between them, and atoms in the low density regions change their positions to cause diffusion. 相似文献
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