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排序方式: 共有280条查询结果,搜索用时 78 毫秒
1.
Pumiko Matsui Atsuhiko Oohira Ryujiro Shoji Hiroshi Nogami 《Differentiation; research in biological diversity》1986,31(1):29-34
The sulfated glycosaminoglycans synthesized in the forelimb plates of rats on days 12, 13, 14, and 15 of gestation were characterized by their susceptibility to various glycosaminoglycan lyases. On days 12 and 13, heparan sulfate accounted for approximately 65% of the newly synthesized sulfated glycosaminoglycans. Small amounts of dermatan sulfate and chondroitin sulfates were also observed. On day 14, the relative amount of chondroitin 4-sulfate began to increase, there being a compensatory decrease in the amount of heparan sulfate. 35S-Sulfate-labeled material was extracted from day-13 forelimb plates with 4 M guanidine/HCl without proteolysis. Using ultracentrifugation on a sucrose density gradient, the extract was separated into two peaks: a light peak (L) mainly composed of heparan sulfate, and a faster-sedimenting peak (M) mainly composed of chondroitin sulfate. The cartilage-type proteoglycan (H) was first detectable on day 14 of gestation, indicating that chondrogenesis in rat forelimb plates starts on day 14 of gestation. In addition to these previously identified glycosaminoglycans or proteoglycans, we isolated an unknown component in the glycosaminoglycan preparations obtained from limb plates during these developmental stages. This component was not found in glycosaminoglycan preparations obtained either from the brain or tail of rat fetuses at the same stages. 相似文献
2.
Yoshifumi Abe Atsuhiko Matsunaga Ryota Matsuzawa Toshiki Kutsuna Shuhei Yamamoto Kei Yoneki Manae Harada Ryoma Ishikawa Takaaki Watanabe Atsushi Yoshida 《PloS one》2016,11(3)
Walking ability is significantly lower in hemodialysis patients compared to healthy people. Decreased walking ability characterized by slow walking speed is associated with adverse clinical events, but determinants of decreased walking speed in hemodialysis patients are unknown. The purpose of this study was to identify factors associated with slow walking speed in ambulatory hemodialysis patients. Subjects were 122 outpatients (64 men, 58 women; mean age, 68 years) undergoing hemodialysis. Clinical characteristics including comorbidities, motor function (strength, flexibility, and balance), and maximum walking speed (MWS) were measured and compared across sex-specific tertiles of MWS. Univariate and multivariate logistic regression analyses were performed to examine whether clinical characteristics and motor function could discriminate between the lowest, middle, and highest tertiles of MWS. Significant and common factors that discriminated the lowest and highest tertiles of MWS from other categories were presence of cardiac disease (lowest: odds ratio [OR] = 3.33, 95% confidence interval [CI] = 1.26–8.83, P<0.05; highest: OR = 2.84, 95% CI = 1.18–6.84, P<0.05), leg strength (OR = 0.62, 95% CI = 0.40–0.95, P<0.05; OR = 0.57, 95% CI = 0.39–0.82, P<0.01), and standing balance (OR = 0.76, 95% CI = 0.63–0.92, P<0.01; OR = 0.81, 95% CI = 0.68–0.97, P<0.05). History of fracture (OR = 3.35, 95% CI = 1.08–10.38; P<0.05) was a significant factor only in the lowest tertile. Cardiac disease, history of fracture, decreased leg strength, and poor standing balance were independently associated with slow walking speed in ambulatory hemodialysis patients. These findings provide useful data for planning effective therapeutic regimens to prevent decreases in walking ability in ambulatory hemodialysis patients. 相似文献
3.
4.
Eiji Takita Katsunori Kohda Hajime Tomatsu Shigeru Hanano Kanami Moriya Tsutomu Hosouchi Nozomu Sakurai Hideyuki Suzuki Atsuhiko Shinmyo Daisuke Shibata 《DNA research》2013,20(6):583-592
Ligation, the joining of DNA fragments, is a fundamental procedure in molecular cloning and is indispensable to the production of genetically modified organisms that can be used for basic research, the applied biosciences, or both. Given that many genes cooperate in various pathways, incorporating multiple gene cassettes in tandem in a transgenic DNA construct for the purpose of genetic modification is often necessary when generating organisms that produce multiple foreign gene products. Here, we describe a novel method, designated PRESSO (precise sequential DNA ligation on a solid substrate), for the tandem ligation of multiple DNA fragments. We amplified donor DNA fragments with non-palindromic ends, and ligated the fragment to acceptor DNA fragments on solid beads. After the final donor DNA fragments, which included vector sequences, were joined to the construct that contained the array of fragments, the ligation product (the construct) was thereby released from the beads via digestion with a rare-cut meganuclease; the freed linear construct was circularized via an intra-molecular ligation. PRESSO allowed us to rapidly and efficiently join multiple genes in an optimized order and orientation. This method can overcome many technical challenges in functional genomics during the post-sequencing generation. 相似文献
5.
S. P. Shrivastava G. P. Georghiou T. R. Fukuto 《Entomologia Experimentalis et Applicata》1971,14(3):333-348
A mosquito larval enzyme system requiring NADPH2 as cofactor for metabolism of the N-methylcarbamate insecticides propoxur, carbaryl, carbofuran and aldicarb has been demonstrated. Freshly prepared homogenate catalyzes various oxidative reactions involving initial hydroxylation of benzene, naphthalene, and furan rings, hydroxylation of N-methyl group, O-dealkylation, N-dealkylation and thioether oxidation to sulfoxides and sulfones. The reactions are primarily oxidative; however, in certain cases, trace amounts of hydrolysis products are also obtained. Inhibitors of mixed function oxidases and synergists inhibit the metabolism of propoxur. Mosquito larval mixed function oxidases appear to be different from those of other insects, in respect to enzyme stability, presence of endogenous inhibitors, and certain requirements for incubation conditions.
Zusammenfassung Für die Umwandlung der N-Methylcarbamat-Insektizide Propoxur, Carbaryl, Carbofuran und Aldicarb wird in Mückenlarven ein NADPH2-benötigendes Enzymsystem nachgewiesen. Frisch hergestellte Homogenate katalysieren verschiedene oxydative Reaktionen wie die Hydroxylierung von Benzol, Naphtalin und Furan-Ringen, die Hydroxylierung von N-Methyl-Gruppen, die O-dealkylierung, die N-dealkylierung und Thioäther-Oxydation zu Sulfoxyden und Sulfonen. Die Reaktionen sind primär oxydativ; jedoch werden in bestimmten Fällen auch Spuren von Hydrolyse-Produkten erhalten. Inhibitoren der Oxydasen gemischter Funktion und Synergisten verhindern den Abbau von Propoxur. Oxydasen gemischter Funktion der Mückenlarven scheinen von denen anderer Insekten im Hinblick auf die Enzym-Stabilität, die Anwesenheit endogener Inhibitoren und gewisse Anforderungen an die Inkubationsbedingungen verschieden zu sein.相似文献
6.
Atsuhiko Toyoshima Takao Yasuhara Masahiro Kameda Jun Morimoto Hayato Takeuchi Feifei Wang Tatsuya Sasaki Susumu Sasada Aiko Shinko Takaaki Wakamori Mihoko Okazaki Akihiko Kondo Takashi Agari Cesario V. Borlongan Isao Date 《PloS one》2015,10(6)
Objective
Intra-arterial stem cell transplantation exerts neuroprotective effects for ischemic stroke. However, the optimal therapeutic time window and mechanisms have not been completely understood. In this study, we investigated the relationship between the timing of intra-arterial transplantation of allogeneic mesenchymal stem cells (MSCs) in ischemic stroke model in rats and its efficacy in acute phase.Methods
Adult male Wistar rats weighing 200 to 250g received right middle cerebral artery occlusion (MCAO) for 90 minutes. MSCs (1×106cells/ 1ml PBS) were intra-arterially injected at either 1, 6, 24, or 48 hours (1, 6, 24, 48h group) after MCAO. PBS (1ml) was intra-arterially injected to control rats at 1 hour after MCAO. Behavioral test was performed immediately after reperfusion, and at 3, 7 days after MCAO using the Modified Neurological Severity Score (mNSS). Rats were euthanized at 7 days after MCAO for evaluation of infarct volumes and the migration of MSCs. In order to explore potential mechanisms of action, the upregulation of neurotrophic factor and chemotactic cytokine (bFGF, SDF-1α) induced by cell transplantation was examined in another cohort of rats that received intra-arterial transplantation at 24 hours after recanalization then euthanized at 7 days after MCAO for protein assays.Results
Behavioral test at 3 and 7 days after transplantation revealed that stroke rats in 24h group displayed the most robust significant improvements in mNSS compared to stroke rats in all other groups (p’s<0.05). Similarly, the infarct volumes of stroke rats in 24h group were much significantly decreased compared to those in all other groups (p’s<0.05). These observed behavioral and histological effects were accompanied by MSC survival and migration, with the highest number of integrated MSCs detected in the 24h group. Moreover, bFGF and SDF-1α levels of the infarcted cortex were highly elevated in the 24h group compared to control group (p’s<0.05).Conclusions
These results suggest that intra-arterial allogeneic transplantation of MSCs provides post-stroke functional recovery and reduction of infarct volumes in ischemic stroke model of rats. The upregulation of bFGF and SDF-1α likely played a key mechanistic role in enabling MSC to afford functional effects in stroke. MSC transplantation at 24 hours after recanalization appears to be the optimal timing for ischemic stroke model, which should guide the design of clinical trials of cell transplantation for stroke patients. 相似文献7.
Aya Obana-Koshino Hitomi Ono Jiro Miura Manabu Sakai Hitoshi Uchida Wataru Nakamura Kanji Nohara Yusuke Maruyama Atsuhiko Hattori Takayoshi Sakai 《PloS one》2015,10(4)
Many organs, including salivary glands, lung, and kidney, are formed by epithelial branching during embryonic development. Branching morphogenesis occurs via either local outgrowths or the formation of clefts that subdivide epithelia into buds. This process is promoted by various factors, but the mechanism of branching morphogenesis is not fully understood. Here we have defined melatonin as a potential negative regulator or “brake” of branching morphogenesis, shown that the levels of it and its receptors decline when branching morphogenesis begins, and identified the process that it regulates. Melatonin has various physiological functions, including circadian rhythm regulation, free-radical scavenging, and gonadal development. Furthermore, melatonin is present in saliva and may have an important physiological role in the oral cavity. In this study, we found that the melatonin receptor is highly expressed on the acinar epithelium of the embryonic submandibular gland. We also found that exogenous melatonin reduces salivary gland size and inhibits branching morphogenesis. We suggest that this inhibition does not depend on changes in either proliferation or apoptosis, but rather relates to changes in epithelial cell adhesion and morphology. In summary, we have demonstrated a novel function of melatonin in organ formation during embryonic development. 相似文献
8.
Etsuko FUJII Atsuhiko KATO Yu Jau CHEN Koichi MATSUBARA Yasuyuki OHNISHI Masami SUZUKI 《Experimental Animals》2015,64(2):181-190
Patient-derived xenografts (PDXs) of tumors are increasingly becoming important tools for
translational research in oncology. The NOD.Cg-Prkdcscid
Il2rgtm1Sug/Jic (NOG) mouse is an efficient host for PDXs. Thus as
a basis for future development of methods to obtain PDXs from various disease types, we
have studied the factors that affect the outcome of transplantation of human colorectal
cancer in NOG mice. Of the original donor cases examined, 73% had successful engraftment.
The outcome of donor-matched tissues was consistent in most cases, and was thought to show
that the condition of the host did not affect engraftment. Next we analyzed the tumor
aggressiveness in terms of histology grade of the original tumor and found that they were
related to engraftment. Detailed histopathological examination of the transplanted tissues
strongly indicated that lymphocytes engrafted with the tumor cells affect engraftment. As
a factor related to transplantation of lymphocytes, we studied the human IgG concentration
in the serum of tumor-bearing mice, but there was no tendency for higher concentrations to
result in unsuccessful engraftment. Finally, we studied the type, density and location of
T cells in the original donor tissue to determine the immune contexture and found that the
unsuccessful engraftment cases tended to have an adequate or coordinated immune contexture
compared to successful engraftment cases. From these results, we concluded that the
aggressiveness and the T cell infiltration of the original tumor affect the outcome of
transplantation in the NOG mouse. 相似文献
9.
10.
Yang J Ii M Kamei N Alev C Kwon SM Kawamoto A Akimaru H Masuda H Sawa Y Asahara T 《PloS one》2011,6(5):e20219