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排序方式: 共有492条查询结果,搜索用时 31 毫秒
151.
Ryo Jimbo Nick Tovar Malvin N. Janal Ramy Mousa Charles Marin Daniel Yoo Hellen S. Teixeira Rodolfo B. Anchieta Estevam A. Bonfante Akihiro Konishi Katsuhiro Takeda Hidemi Kurihara Paulo G. Coelho 《PloS one》2014,9(1)
This study aimed to observe the regenerative effect of brain-derived neurotrophic factor (BDNF) in a non-human primate furcation defect model. Class II furcation defects were created in the first and second molars of 8 non-human primates to simulate a clinical situation. The defect was filled with either, Group A: BDNF (500 µg/ml) in high-molecular weight-hyaluronic acid (HMW-HA), Group B: BDNF (50 µg/ml) in HMW-HA, Group C: HMW-HA acid only, Group D: empty defect, or Group E: BDNF (500 µg/ml) in saline. The healing status for all groups was observed at different time-points with micro computed tomography. The animals were euthanized after 11 weeks, and the tooth-bone specimens were subjected to histologic processing. The results showed that all groups seemed to successfully regenerate the alveolar buccal bone, however, only Group A regenerated the entire periodontal tissue, i.e., alveolar bone, cementum and periodontal ligament. It is suggested that the use of BDNF in combination with a scaffold such as the hyaluronic acid in periodontal furcation defects may be an effective treatment option. 相似文献
152.
Ultraweak biophoton emission originates from the generation of reactive oxygen species (ROS) that are produced in mitochondria as by-products of cellular respiration. In healthy cells, the concentration of ROS is minimized by a system of biological antioxidants. However, heat shock changes the equilibrium between oxidative stress and antioxidant activity, that is, a rapid rise in temperature induces biophoton emission from ROS. Although the rate and intensity of biophoton emission was observed to increase in response to elevated temperatures, pretreatment at lower high temperatures inhibited photon emission at higher temperatures. Biophoton measurements are useful for observing and evaluating heat shock. 相似文献
153.
Katsuhiro Nakao Motoki Higa Ikutaro Tsuyama Tetsuya Matsui Masahiro Horikawa Nobuyuki Tanaka 《Journal for Nature Conservation》2013,21(6):406-413
Protected areas are the basis of modern conservation systems, but current climate change causes gaps between protected areas and the species distribution ranges. To mitigate the impact of climate change on species distribution ranges, revision of protected areas are necessary. Alternatively, active management such as excluding competitive species or transplanting target species would be effective. In this study, we assessed optimal actions (revision of protected areas or active management) in each geographical region to establish an effective spatial conservation plan in Japan. Gaps between the protected areas and future potential habitats were assessed using species distribution models and 20 future climate simulations. Fagus crenata, an endemic and dominant species in Japan, was used as a target species. Potential habitats within the protected areas were predicted to decrease from 22,122 km2 at present to 12,309 km2 under future climate conditions. Sustainable potential habitats (consistent potential habitats both at present and in future) without the protected areas extended to 13,208 km2, and were mainly found in northeast Japan. These results suggest that, in northeast Japan, revisions to protected areas would be effective in preserving sustainable potential habitats under future climate change. However, the potential habitats of southwestern Japan, in which populations were genetically different from northeastern populations, were predicted to virtually disappear both within and outside of protected areas. Active management is thus necessary in southwestern Japan to ensure intraspecific genetic diversity under future climate change. 相似文献
154.
Nakagawa H Miyazaki S Abe T Umadome H Tanaka K Nishimura K Komori M Matsuo S 《The international journal of biochemistry & cell biology》2011,43(3):423-430
ER-to-Golgi protein transport is carried out by transport vesicles which are formed at the ER-exit sites with recruitment of cytoplasmic coat proteins. Vesicle formation is initiated by assembly of the small G protein (Sar1) onto the ER membrane. Sar1 assembly onto the ER membrane is suppressed by protein kinase inhibitor H89, suggesting participation of H89-sensitive kinase in this process. The present study identified an effector of H89-sensitive kinase by LC-MS PMF analysis combined with 1D- and 2D-PAGE autoradiography, and examined the changes on the effector and Sar1 translocation induced by H89. H89 significantly suppressed the phosphorylation of 55 kDa protein with dosage dependency, and phosphorylation of 55 kDa, pI 5.5 protein spot in 2-D-autoradiography was drastically diminished by H89. LC-MS PMF analysis showed that the protein spot was β-tubulin. H89 significantly suppressed Sar1 translocation onto the ER. These findings indicate that β-tubulin is one of downstream effectors of H89-sensitive kinase, and that suppression of ER-coupled β-tubulin phosphorylation decreases Sar1 translocation onto the ER, suggesting that phosphorylation of β-tubulin regulates Sar1 translocation. 相似文献
155.
Katsuhiro Nakao Tetsuya Matsui Masahiro Horikawa Ikutaro Tsuyama Nobuyuki Tanaka 《Plant Ecology》2011,212(2):229-243
To assess the impact of Quercus acuta, a dominant species in the evergreen broad-leaved forests of Japan, and its habitat shifts as a result of climate change,
we predicted the potential habitats under the current climate and two climate change scenarios using a random forest (RF).
The presence/absence records of Q. acuta were extracted from the Phytosociological Relevè Data Base as response variables, and four climatic variables (warmth index,
WI; minimum temperature of the coldest month, TMC; summer precipitation, PRS; and winter precipitation, PRW) were used as
predictor variables. The mean decrease in the Gini criterion revealed that WI was the most influential factor followed by
TMC. The RF revealed a considerable increase in potential habitats (PHs) under the climate change scenarios for 2081–2100
(RCM20, 180,141 km2; MIROC, 175,635 km2) relative to the current climate (150,542 km2). The land use variables were used for masking PH. The PH masked by land use (PHLU) was approximately half of the PH under
the current conditions (74,567 km2). Under the climate change scenarios and 1 km migration options, the PHLU were not increased relative to its value under
the current conditions. The distribution of Q. acuta was restricted by the northward shift in northern Honshu, but expanded as a result of the upward shift into the mountain
areas of Western Japan. Habitat fragmentation reduced the ability of migration to respond to climate change in the lowland
areas of Japan. 相似文献
156.
Mano N Nozawa M Sato M Mori M Yamaguchi H Kanda K Nogami M Goto J Shimada M 《Journal of chromatography. B, Analytical technologies in the biomedical and life sciences》2011,879(13-14):968-974
Ion suppression can negatively affect the performance characteristics of LC/ESI-MS/MS based methods, and we wished to identify sources of ion suppression in an assay for quantitating sirolimus in human whole blood. We first compared the peak areas of sirolimus and ascomycin added to human blood samples treated with and without extraction using octadecyl silyl (ODS)-silica gel after protein precipitation, and we found that water-soluble compounds cause the ion suppression for both drugs. Post-column infusion studies indicated that compounds retained in the sample after ODS extraction and protein precipitation caused ion suppression. MS analysis of these compounds suggested they were hydroxyl group-possessing phosphocholines, and this was confirmed using purified lysophosphatidylcholine variants. Therefore, we included a HybridSPE treatment step after the ODS extraction into the preanalytical workflow to remove phosphocholines, and this successfully eliminated the observed ion suppression for determining sirolimus concentration in human whole blood by LC/ESI-MS/MS. Sirolimus is a highly lipophilic molecule, and this study demonstrates the impact that preanalytical extraction and purification steps can have on a laboratory's ability to accurately detect and quantitate this and other lipophilic drugs. 相似文献
157.
Fujita R Tanaka Y Saihara Y Yamakita M Ando D Koyama K 《Journal of physiological anthropology》2011,30(5):195-201
The objectives of this paper were to determine the level of oxidative stress in atrophied gastrocnemius, and to verify the effect of molecular hydrogen (H2) saturated alkaline electrolyzed water (HSW) on gastrocnemius atrophy by modifying the redox status, indicated by 8-hydroxy-2'-deoxyguanosine (8-OHdG), malondialdehyde (MDA), and superoxide dismutase (SOD)-like activity. Female Wistar rats were divided into four groups: (1) the control (CONT); (2) the Hindlimb unloading (HU, for 3 weeks) given purified normal water (HU-NW); (3) the HU given alkaline electrolyzed reduced water (HU-AEW); and (4) the HU given HSW (HU-HSW). We showed that 8-OHdG, but not MDA, significantly increased by 149% and 145% in HU-NW and HU-AEW, respectively, when compared with CONT. In contrast, there was a trend toward suppression in 8-OHdG levels (increased by 95% compared with CONT) by treatment of HSW, though this effect was not prominent. Additionally, SOD-like activity significantly increased in both HU-NW (184%) and HU-AEW (199%) when compared with CONT. This result suggests the elevation of O2-· in the atrophied gastrocnemius. However, upregulation of SOD-like activity in the HU-HSW was increased by only 169% compared with CONT, though this difference is too small to detect statistical significance. HU led to 13% and 15% reduction of gastrocnemius wet weights in HU-NW and HU-AEW, respectively, compared with CONT. And the reduction of gastrocnemius wet weights in HU-HSW was attenuated by 7% compared with CONT. The gastrocnemius wet weights in the HU-HSW group were significantly greater than those in the HU-AEW, but not statistically significant with HU-NW. These results indicate that HU causes an increase in oxidative stress, but, in this experimental protocol, continuous consumption of HSW during HU does not demonstrate successful attenuation of oxidative stress and HU-mediated gastrocnemius atrophy. 相似文献
158.
Jitka Simandlova Jennifer Zagelbaum Miranda J. Payne Wai Kit Chu Igor Shevelev Katsuhiro Hanada Sujoy Chatterjee Dylan A. Reid Ying Liu Pavel Janscak Eli Rothenberg Ian D. Hickson 《The Journal of biological chemistry》2013,288(47):34168-34180
Efficient repair of DNA double strand breaks and interstrand cross-links requires the homologous recombination (HR) pathway, a potentially error-free process that utilizes a homologous sequence as a repair template. A key player in HR is RAD51, the eukaryotic ortholog of bacterial RecA protein. RAD51 can polymerize on DNA to form a nucleoprotein filament that facilitates both the search for the homologous DNA sequences and the subsequent DNA strand invasion required to initiate HR. Because of its pivotal role in HR, RAD51 is subject to numerous positive and negative regulatory influences. Using a combination of molecular genetic, biochemical, and single-molecule biophysical techniques, we provide mechanistic insight into the mode of action of the FBH1 helicase as a regulator of RAD51-dependent HR in mammalian cells. We show that FBH1 binds directly to RAD51 and is able to disrupt RAD51 filaments on DNA through its ssDNA translocase function. Consistent with this, a mutant mouse embryonic stem cell line with a deletion in the FBH1 helicase domain fails to limit RAD51 chromatin association and shows hyper-recombination. Our data are consistent with FBH1 restraining RAD51 DNA binding under unperturbed growth conditions to prevent unwanted or unscheduled DNA recombination. 相似文献
159.
Kouji Sakai Tomoki Yoshikawa Fumio Seki Shuetsu Fukushi Maino Tahara Noriyo Nagata Yasushi Ami Tetsuya Mizutani Ichiro Kurane Ryoji Yamaguchi Hideki Hasegawa Masayuki Saijo Katsuhiro Komase Shigeru Morikawa Makoto Takeda 《Journal of virology》2013,87(12):7170-7175
A canine distemper virus (CDV) strain, CYN07-dV, associated with a lethal outbreak in monkeys, used human signaling lymphocyte activation molecule as a receptor only poorly but readily adapted to use it following a P541S substitution in the hemagglutinin protein. Since CYN07-dV had an intrinsic ability to use human nectin-4, the adapted virus became able to use both human immune and epithelial cell receptors, as well as monkey and canine ones, suggesting that CDV can potentially infect humans. 相似文献
160.
Satoshi Ikeda Katsuhiro Harada Akihiko Ohwatashi Yurie Kamikawa Akira Yoshida Kazumi Kawahira 《PloS one》2013,8(3)