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匹配条件: “ Eric Hill” ,找到相关结果约15279条。
Polarized secretion of Leukemia Inhibitory Factor
Eric J Hill, Ann B Vernallis
BMC Cell Biology , 2008, DOI: 10.1186/1471-2121-9-53
Abstract: When Caco-2 was grown on permeable supports, LIF was secreted constitutively with around 40% secreted into the apical chamber. Stimulation with IL-1β increased LIF production. After treating the apical surface with IL-1β, the percentage secreted apically remained similar to the untreated, whereas, when the cells were stimulated at the basolateral surface only 20% was secreted apically. In MDCK cells, an endogenous LIF-like protein was detected entirely in the apical compartment. The two mLIF isoforms showed no difference in their secretion patterns in MDCK. Interestingly, about 70% of murine and human LIF was secreted apically from MDCK over a 400-fold range of expression levels within clones and a 200,000-fold range across clones.The site of stimulation affected the polarity of LIF secretion, while, signal peptides and expression levels did not. Exogenous LIF is transported in MDCK without readily saturated steps.Most cells secrete a variety of cytokines, either continuously or in response to stimulation. The spatial regulation of cytokine secretion is important since it determines which neighbouring cells respond, but little is known about how cytokine secretion in the constitutive pathway is regulated. With their prominent apical and basolateral domains, epithelial cells have been studied extensively for their ability to sort membrane proteins to specific domains. Sorting depends on hierarchical signals and occurs in multiple stages of the secretory pathway [as reviewed in [1-3]]. Lipid raft-associated and independent pathways have been identified for transport from the trans-Golgi to the apical membrane [4]. Less is known about the sorting of secreted proteins. N-glycans and O-glycans as well as proteinaceous patches have been proposed as sorting signals. Lectins may cooperate with lipid rafts in the transport routes [5].LIF is a secreted, glycosylated cytokine, of the IL-6 family, that exhibits pleiotropic activities in a wide range of tissues and cell types. L
Test-retest standard error of measurements for full-torso surface topography parameters obtained with the arms at 30 and 90 degrees of elevation in healthy teenagers
Watkins E,Parent Eric,Emrani M,Hill D
Scoliosis , 2010, DOI: 10.1186/1748-7161-5-s1-o6
Differences in measures of full-torso surface topography among healthy teenagers are independent of growth indicators
Parent Eric,Watkins E,Emrani M,Hill D
Scoliosis , 2010, DOI: 10.1186/1748-7161-5-s1-o9
化学进展 , 2012,
Abstract: 超分子化学和界面的结合有效地促进了超分子化学和胶体与界面科学的发展。刺激响应性超分子界面,因在外界刺激作用下能够引起界面物理化学性质的改变并带来新的界面功能,而受到广泛的关注。近年来,溶液中基于偶氮苯环糊精主客体相互作用的超分子组装体已经得到了广泛的研究。我们将溶液中基于偶氮苯环糊精主客体作用的可控可逆超分子组装体转移到界面上,构筑了具有刺激响应性的功能化超分子界面,并实现了表面浸润性的可逆调控、生物大分子的可控吸附与脱附、光可控的生物电化学催化等功能。我们期待类似的概念可以拓展到其他超分子体系,构筑具有特定结构的功能界面。
Brace treatment for adolescent idiopathic scoliosis – Protocols of the Canadian Spinal Deformity Study Group Surgeons
Hill Douglas L,Parent Eric C,Lou Edmond,Moreau Marc J
Scoliosis , 2010, DOI: 10.1186/1748-7161-5-s1-o39
Design and Implementation of an Embedded NIOS II System for JPEG2000 Tier II Encoding
John M. McNichols,Eric J. Balster,William F. Turri,Kerry L. Hill
International Journal of Reconfigurable Computing , 2013, DOI: 10.1155/2013/140234
Abstract: This paper presents a novel implementation of the JPEG2000 standard as a system on a chip (SoC). While most of the research in this field centers on acceleration of the EBCOT Tier I encoder, this work focuses on an embedded solution for EBCOT Tier II. Specifically, this paper proposes using an embedded softcore processor to perform Tier II processing as the back end of an encoding pipeline. The Altera NIOS II processor is chosen for the implementation and is coupled with existing embedded processing modules to realize a fully embedded JPEG2000 encoder. The design is synthesized on a Stratix IV FPGA and is shown to out perform other comparable SoC implementations by 39% in computation time. 1. Introduction One of the most recent image compression schemes, JPEG2000, offers a wide range of features and flexibility over the existing JPEG standard [1]. A block diagram of the JPEG2000 encoder is shown in Figure 1. The encoder consists of two main parts: the discrete wavelet transform (DWT) and the embedded block coding with optimal truncation (EBCOT) coder. The wavelet transform takes an image in the spatial domain and transforms it to the wavelet domain. The wavelet domain consists of a frequency representation with the addition of spatial information as well. Once the wavelet transform is completed, the coefficients are scalar quantized if lossy compression is chosen. The quantized wavelet coefficients are then entropy encoded using EBCOT, a two-tier coding algorithm which first divides each wavelet subband into code blocks (typically or ). EBCOT is composed of Tier I and Tier II encoders. Tier I produces independent embedded bitstreams for each code block using a context-based arithmetic encoder (MQ coder), the context for which is generated by the bit-plane coder. Tier II then reorders the individual compressed bitstreams and applies rate-distortion slope optimization to form the final JPEG2000 bitstream. Figure 1: Block diagram of JPEG2000 encoder. While JPEG2000 offers a number of improvements and additional features over JPEG and other image encoding standards, these benefits come with much greater computational cost. JPEG2000 is approximately 4 times more computationally expensive than the original JPEG [2]. Due to these high costs, it becomes impractical to utilize JPEG2000 in applications which require real-time processing of high-resolution images, such as wide area imagery or medical imagery. To solve this problem, developers continue to turn to hardware implementations to yield the throughput necessary to meet frame rates for high-resolution
The Role of Temperature in Determining Species' Vulnerability to Ocean Acidification: A Case Study Using Mytilus galloprovincialis
Kristy J. Kroeker, Brian Gaylord, Tessa M. Hill, Jessica D. Hosfelt, Seth H. Miller, Eric Sanford
PLOS ONE , 2014, DOI: 10.1371/journal.pone.0100353
Abstract: Ocean acidification (OA) is occurring across a backdrop of concurrent environmental changes that may in turn influence species' responses to OA. Temperature affects many fundamental biological processes and governs key reactions in the seawater carbonate system. It therefore has the potential to offset or exacerbate the effects of OA. While initial studies have examined the combined impacts of warming and OA for a narrow range of climate change scenarios, our mechanistic understanding of the interactive effects of temperature and OA remains limited. Here, we use the blue mussel, Mytilus galloprovincialis, as a model species to test how OA affects the growth of a calcifying invertebrate across a wide range of temperatures encompassing their thermal optimum. Mussels were exposed in the laboratory to a factorial combination of low and high pCO2 (400 and 1200 μatm CO2) and temperatures (12, 14, 16, 18, 20, and 24°C) for one month. Results indicate that the effects of OA on shell growth are highly dependent on temperature. Although high CO2 significantly reduced mussel growth at 14°C, this effect gradually lessened with successive warming to 20°C, illustrating how moderate warming can mediate the effects of OA through temperature's effects on both physiology and seawater geochemistry. Furthermore, the mussels grew thicker shells in warmer conditions independent of CO2 treatment. Together, these results highlight the importance of considering the physiological and geochemical interactions between temperature and carbonate chemistry when interpreting species' vulnerability to OA.
NT2 Derived Neuronal and Astrocytic Network Signalling
Eric J. Hill, Cristina Jiménez-González, Marta Tarczyluk, David A. Nagel, Michael D. Coleman, H. Rheinallt Parri
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0036098
Abstract: A major focus of stem cell research is the generation of neurons that may then be implanted to treat neurodegenerative diseases. However, a picture is emerging where astrocytes are partners to neurons in sustaining and modulating brain function. We therefore investigated the functional properties of NT2 derived astrocytes and neurons using electrophysiological and calcium imaging approaches. NT2 neurons (NT2Ns) expressed sodium dependent action potentials, as well as responses to depolarisation and the neurotransmitter glutamate. NT2Ns exhibited spontaneous and coordinated calcium elevations in clusters and in extended processes, indicating local and long distance signalling. Tetrodotoxin sensitive network activity could also be evoked by electrical stimulation. Similarly, NT2 astrocytes (NT2As) exhibited morphology and functional properties consistent with this glial cell type. NT2As responded to neuronal activity and to exogenously applied neurotransmitters with calcium elevations, and in contrast to neurons, also exhibited spontaneous rhythmic calcium oscillations. NT2As also generated propagating calcium waves that were gap junction and purinergic signalling dependent. Our results show that NT2 derived astrocytes exhibit appropriate functionality and that NT2N networks interact with NT2A networks in co-culture. These findings underline the utility of such cultures to investigate human brain cell type signalling under controlled conditions. Furthermore, since stem cell derived neuron function and survival is of great importance therapeutically, our findings suggest that the presence of complementary astrocytes may be valuable in supporting stem cell derived neuronal networks. Indeed, this also supports the intriguing possibility of selective therapeutic replacement of astrocytes in diseases where these cells are either lost or lose functionality.
Sulforaphane Restores Cellular Glutathione Levels and Reduces Chronic Periodontitis Neutrophil Hyperactivity In Vitro
Irundika H. K. Dias, Ian L. C. Chapple, Mike Milward, Melissa M. Grant, Eric Hill, James Brown, Helen R. Griffiths
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0066407
Abstract: The production of high levels of reactive oxygen species by neutrophils is associated with the local and systemic destructive phenotype found in the chronic inflammatory disease periodontitis. In the present study, we investigated the ability of sulforaphane (SFN) to restore cellular glutathione levels and reduce the hyperactivity of circulating neutrophils associated with chronic periodontitis. Using differentiated HL60 cells as a neutrophil model, here we show that generation of extracellular O2. - by the nicotinamide adenine dinucleotide (NADPH) oxidase complex is increased by intracellular glutathione depletion. This may be attributed to the upregulation of thiol regulated acid sphingomyelinase driven lipid raft formation. Intracellular glutathione was also lower in primary neutrophils from periodontitis patients and, consistent with our previous findings, patients neutrophils were hyper-reactive to stimuli. The activity of nuclear factor erythroid-2-related factor 2 (Nrf2), a master regulator of the antioxidant response, is impaired in circulating neutrophils from chronic periodontitis patients. Although patients’ neutrophils exhibit a low reduced glutathione (GSH)/oxidised glutathione (GSSG) ratio and a higher total Nrf2 level, the DNA-binding activity of nuclear Nrf2 remained unchanged relative to healthy controls and had reduced expression of glutamate cysteine ligase catalytic (GCLC), and modifier (GCLM) subunit mRNAs, compared to periodontally healthy subjects neutrophils. Pre-treatment with SFN increased expression of GCLC and GCM, improved intracellular GSH/GSSG ratios and reduced agonist-activated extracellular O2. - production in both dHL60 and primary neutrophils from patients with periodontitis and controls. These findings suggest that a deficiency in Nrf2-dependent pathways may underpin susceptibility to hyper-reactivity in circulating primary neutrophils during chronic periodontitis.
Effects of Lithium and Valproic Acid on Gene Expression and Phenotypic Markers in an NT2 Neurosphere Model of Neural Development
Eric J. Hill, David A. Nagel, John D. O’Neil, Elizabeth Torr, Elizabeth K. Woehrling, Andrew Devitt, Michael D. Coleman
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0058822
Abstract: Mood stabilising drugs such as lithium (LiCl) and valproic acid (VPA) are the first line agents for treating conditions such as Bipolar disorder and Epilepsy. However, these drugs have potential developmental effects that are not fully understood. This study explores the use of a simple human neurosphere-based in vitro model to characterise the pharmacological and toxicological effects of LiCl and VPA using gene expression changes linked to phenotypic alterations in cells. Treatment with VPA and LiCl resulted in the differential expression of 331 and 164 genes respectively. In the subset of VPA targeted genes, 114 were downregulated whilst 217 genes were upregulated. In the subset of LiCl targeted genes, 73 were downregulated and 91 were upregulated. Gene ontology (GO) term enrichment analysis was used to highlight the most relevant GO terms associated with a given gene list following toxin exposure. In addition, in order to phenotypically anchor the gene expression data, changes in the heterogeneity of cell subtype populations and cell cycle phase were monitored using flow cytometry. Whilst LiCl exposure did not significantly alter the proportion of cells expressing markers for stem cells/undifferentiated cells (Oct4, SSEA4), neurons (Neurofilament M), astrocytes (GFAP) or cell cycle phase, the drug caused a 1.4-fold increase in total cell number. In contrast, exposure to VPA resulted in significant upregulation of Oct4, SSEA, Neurofilament M and GFAP with significant decreases in both G2/M phase cells and cell number. This neurosphere model might provide the basis of a human-based cellular approach for the regulatory exploration of developmental impact of potential toxic chemicals.

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