排序方式: 共有26条查询结果,搜索用时 15 毫秒
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Géza Tamás Szabó Bettina Tarr Krisztina Pálóczi Katalin Éder Eszter Lajkó Ágnes Kittel Sára Tóth Bence György Mária Pásztói Andrea Németh Xabier Osteikoetxea Éva Pállinger András Falus Katalin Szabó-Taylor Edit Irén Buzás 《Cellular and molecular life sciences : CMLS》2014,71(20):4055-4067
Under physiological and pathological conditions, extracellular vesicles (EVs) are present in the extracellular compartment simultaneously with soluble mediators. We hypothesized that cytokine effects may be modulated by EVs, the recently recognized conveyors of intercellular messages. In order to test this hypothesis, human monocyte cells were incubated with CCRF acute lymphoblastic leukemia cell line-derived EVs with or without the addition of recombinant human TNF, and global gene expression changes were analyzed. EVs alone regulated the expression of numerous genes related to inflammation and signaling. In combination, the effects of EVs and TNF were additive, antagonistic, or independent. The differential effects of EVs and TNF or their simultaneous presence were also validated by Taqman assays and ELISA, and by testing different populations of purified EVs. In the case of the paramount chemokine IL-8, we were able to demonstrate a synergistic upregulation by purified EVs and TNF. Our data suggest that neglecting the modulating role of EVs on the effects of soluble mediators may skew experimental results. On the other hand, considering the combined effects of cytokines and EVs may prove therapeutically useful by targeting both compartments at the same time. 相似文献
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An important task in vision is to detect objects moving within a stationary scene. During normal viewing this is complicated by the presence of eye movements that continually scan the image across the retina, even during fixation. To detect moving objects, the brain must distinguish local motion within the scene from the global retinal image drift due to fixational eye movements. We have found that this process begins in the retina: a subset of retinal ganglion cells responds to motion in the receptive field centre, but only if the wider surround moves with a different trajectory. This selectivity for differential motion is independent of direction, and can be explained by a model of retinal circuitry that invokes pooling over nonlinear interneurons. The suppression by global image motion is probably mediated by polyaxonal, wide-field amacrine cells with transient responses. We show how a population of ganglion cells selective for differential motion can rapidly flag moving objects, and even segregate multiple moving objects. 相似文献
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PLETHORA proteins as dose-dependent master regulators of Arabidopsis root development 总被引:1,自引:0,他引:1
Galinha C Hofhuis H Luijten M Willemsen V Blilou I Heidstra R Scheres B 《Nature》2007,449(7165):1053-1057
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Inhibition of growth factor-induced differentiation of PC12 cells by microinjection of antibody to ras p21 总被引:51,自引:0,他引:51
The protein products (p21) of the ras cellular proto-oncogenes are thought to transduce membrane signals necessary for the induction of cell division. However, there is uncertainty as to the precise role of ras p21 in mediating ligand-membrane receptor signals leading to cell differentiation. Treatment of rat phaeochromocytoma cells (PC12) with nerve growth factor (NGF) results in the induction of a number of phenotypic characteristics of sympathetic neurones, including cessation of cell division and outgrowth of neuronal processes (neurites). Here we report that microinjection of antibody to ras p21 into PC12 cells inhibited neurite formation and resulted in temporary regression of partially extended neurites, an effect which was observed up to 36 h after initiation of NGF treatment. Neurite formation induced by cyclic AMP was unaffected by injection of anti-p21 antibody. These results indicate that p21 is involved in the initiation phase of NGF-induced neurite formation in PC12 cells and has a role in hormone-mediated cellular responses distinct from cell proliferation. 相似文献
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Helgadottir A Manolescu A Helgason A Thorleifsson G Thorsteinsdottir U Gudbjartsson DF Gretarsdottir S Magnusson KP Gudmundsson G Hicks A Jonsson T Grant SF Sainz J O'Brien SJ Sveinbjornsdottir S Valdimarsson EM Matthiasson SE Levey AI Abramson JL Reilly MP Vaccarino V Wolfe ML Gudnason V Quyyumi AA Topol EJ Rader DJ Thorgeirsson G Gulcher JR Hakonarson H Kong A Stefansson K 《Nature genetics》2006,38(1):68-74
Variants of the gene ALOX5AP (also known as FLAP) encoding arachidonate 5-lipoxygenase activating protein are known to be associated with risk of myocardial infarction. Here we show that a haplotype (HapK) spanning the LTA4H gene encoding leukotriene A4 hydrolase, a protein in the same biochemical pathway as ALOX5AP, confers modest risk of myocardial infarction in an Icelandic cohort. Measurements of leukotriene B4 (LTB4) production suggest that this risk is mediated through upregulation of the leukotriene pathway. Three cohorts from the United States also show that HapK confers a modest relative risk (1.16) in European Americans, but it confers a threefold larger risk in African Americans. About 27% of the European American controls carried at least one copy of HapK, as compared with only 6% of African American controls. Our analyses indicate that HapK is very rare in Africa and that its occurrence in African Americans is due to European admixture. Interactions with other genetic or environmental risk factors that are more common in African Americans are likely to account for the greater relative risk conferred by HapK in this group. 相似文献
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Riassunto In questo lavoro si descrive una nuova metodica per la determinazione della massa secca dei nuclei delle cellule nervose o gliali mediante il microscopio ad interferenza. Sono riferiti i valori della massa secca, dei volumi e della concentrazione dei nuclei isolati sia da tessuto liofilizzato che da tessuto fresco.
This investigation was supported by a grant to this Department from the Consiglio Nazionale delle Ricerche (No. 04/76/4/3482). 相似文献
This investigation was supported by a grant to this Department from the Consiglio Nazionale delle Ricerche (No. 04/76/4/3482). 相似文献
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Designing models of complex phenomena is a difficult task in engineering that can be tackled by composing a number of partial
models to produce a global model of the phenomena. We propose to embed the partial models in software agents and to implement
their composition as a cooperative negotiation between the agents. The resulting multiagent system provides a global model
of a phenomenon. We applied this approach in modelling two complex physiological processes: the heart rate regulation and
the glucose-insulin metabolism. Beyond the effectiveness demonstrated in these two applications, the idea of using models
associated to software agents to give reason of complex phenomena is in accordance with current tendencies in epistemology,
where it is evident an increasing use of computational models for scientific explanation and analysis. Therefore, our approach
has not only a practical, but also a theoretical significance: agents embedding models are a technology suitable both to representing
and to investigating reality.
相似文献
Francesco AmigoniEmail: |
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