The Experts below are selected from a list of 2934 Experts worldwide ranked by ideXlab platform
Seunghun Hong - One of the best experts on this subject based on the ideXlab platform.
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reusable floating electrode sensor for the quantitative electrophysiological monitoring of a Nonadherent Cell
ACS Nano, 2014Co-Authors: Juhun Park, Eun Jin Park, Seunghun HongAbstract:We report a reusable floating-electrode sensor based on aligned semiconducting single-walled carbon nanotubes for the quantitative monitoring of the electrophysiological responses from a Nonadherent Cell. This method allowed us to monitor and distinguish the real-time responses from normal and small-Cell lung cancer (SCLC) Cells to the addition of nicotine. The difference was attributed to the overexpressed nicotinic acetylcholine receptors (nAChRs) in the SCLC Cells. The sensor was also utilized to monitor the effect of various drugs on the Cells. The treatment with inhibitors such as genistin or daidzein was found to reduce Ca2+ influx in SCLC Cells. Moreover, tamoxifen, though known as the antiestrogen compound, was found to only partly block the binding of daidzein to nAChRs. Significantly, the activities of multiple individual Cells could be measured repeatedly using a single sensor device, enabling statistically meaningful measurements without errors from the device-to-device variations of the senso...
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Reusable Floating-Electrode Sensor for the Quantitative Electrophysiological Monitoring of a Nonadherent Cell
2014Co-Authors: Juhun Park, Eun Jin Park, Seunghun HongAbstract:We report a reusable floating-electrode sensor based on aligned semiconducting single-walled carbon nanotubes for the quantitative monitoring of the electrophysiological responses from a Nonadherent Cell. This method allowed us to monitor and distinguish the real-time responses from normal and small-Cell lung cancer (SCLC) Cells to the addition of nicotine. The difference was attributed to the overexpressed nicotinic acetylcholine receptors (nAChRs) in the SCLC Cells. The sensor was also utilized to monitor the effect of various drugs on the Cells. The treatment with inhibitors such as genistin or daidzein was found to reduce Ca2+ influx in SCLC Cells. Moreover, tamoxifen, though known as the antiestrogen compound, was found to only partly block the binding of daidzein to nAChRs. Significantly, the activities of multiple individual Cells could be measured repeatedly using a single sensor device, enabling statistically meaningful measurements without errors from the device-to-device variations of the sensor characteristics. This capability of the quantitative monitoring of Nonadherent Cells should be a major breakthrough for electrophysiology research and various biomedical applications such as drug screening and therapeutic monitoring
Brenda M Sandmaier - One of the best experts on this subject based on the ideXlab platform.
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the expression and differentiation pattern of Cell antigens and adhesion molecules on the Nonadherent Cell population in canine long term marrow culture a biphasic development of myeloid and lymphoid Cells
Tissue Antigens, 2008Co-Authors: L Krizanacbengez, Peter F Moore, Alexander Barsoukov, Brenda M SandmaierAbstract:During maturation of normal hematopoietic progenitors, there appears to be differentiation-dependent expression of adhesion receptors, which may contribute to the homing and lodging of stem progenitor Cells into the marrow and for the eventual release of mature effector Cells from the marrow cavity. Using a model of long-term marrow culture, we studied the expression pattern of different lineage Cell antigens and Cell adhesion molecules on the Nonadherent Cells in canine long-term marrow culture. CD4+ Cells became a major proportion of both the small and large Cell subsets by day 8 of culture. Small CD4+ Cells, the majority of which are negative for other T-Cell antigens during the first 2 weeks of culture, express low levels of CD4 (CD4lo) and coexpress granulocytic and/or monocytic markers. These CD4lo Cells have progenitor potential as measured by the long-term culture-initiating Cell assay and differentiate into myeloid (first wave) and lymphoid (second wave) Cells. The T Cells, which appear in 2-week-old long-term marrow culture, respond to Con A but not to alloantigen. At the same time, most of the large Cells are CD14+, CD11b+, DLA-DR+ and CD4lo+, while granulocytes are not observed. This phenotypic pattern closely resembles that found on myelomonocytic Cells developing from fetal thymic and fetal liver CD34+ precursors in a model of human fetal thymic organ culture. The Cell adhesion molecules--CD44, CD18, L-selectin, CD11a-c as well as VLAalpha4, dramatically increase from the first week of long-term marrow culture, while ICAM-1 and a new beta2 Cell adhesion molecule, alpha dbeta2, increased slightly from the third week on. In the large ("monocytic") Cell population, alpha dbeta2 was exclusively expressed by CD4+ Cells. The differentiation pattern of T-Cell antigens and adhesion molecules seen in the canine long-term marrow culture appear to mimic those required for developmental interactions between leukocytes and endothelial Cells; that is, an early expression of L-selectin and CD44, followed by the integrins, and later on by ICAM-1 and alpha dbeta2. Our data support the view that in a model of canine long-term marrow culture hematopoietic precursors retain their intrinsic developmental potential.
Shulamit Levenberg - One of the best experts on this subject based on the ideXlab platform.
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stationary nanoliter droplet array with a substrate of choice for single adherent Nonadherent Cell incubation and analysis
Proceedings of the National Academy of Sciences of the United States of America, 2014Co-Authors: Jonathan Shemesh, Tom Ben Arye, Jonathan Avesar, Joo H Kang, Amir Fine, Michael Super, Amit Meller, Donald E Ingber, Shulamit LevenbergAbstract:Microfluidic water-in-oil droplets that serve as separate, chemically isolated compartments can be applied for single-Cell analysis; however, to investigate encapsulated Cells effectively over prolonged time periods, an array of droplets must remain stationary on a versatile substrate for optimal Cell compatibility. We present here a platform of unique geometry and substrate versatility that generates a stationary nanodroplet array by using wells branching off a main microfluidic channel. These droplets are confined by multiple sides of a nanowell and are in direct contact with a biocompatible substrate of choice. The device is operated by a unique and reversed loading procedure that eliminates the need for fine pressure control or external tubing. Fluorocarbon oil isolates the droplets and provides soluble oxygen for the Cells. By using this approach, the metabolic activity of single adherent Cells was monitored continuously over time, and the concentration of viable pathogens in blood-derived samples was determined directly by measuring the number of colony-formed droplets. The method is simple to operate, requires a few microliters of reagent volume, is portable, is reusable, and allows for Cell retrieval. This technology may be particularly useful for multiplexed assays for which prolonged and simultaneous visual inspection of many isolated single adherent or Nonadherent Cells is required.
Juhun Park - One of the best experts on this subject based on the ideXlab platform.
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reusable floating electrode sensor for the quantitative electrophysiological monitoring of a Nonadherent Cell
ACS Nano, 2014Co-Authors: Juhun Park, Eun Jin Park, Seunghun HongAbstract:We report a reusable floating-electrode sensor based on aligned semiconducting single-walled carbon nanotubes for the quantitative monitoring of the electrophysiological responses from a Nonadherent Cell. This method allowed us to monitor and distinguish the real-time responses from normal and small-Cell lung cancer (SCLC) Cells to the addition of nicotine. The difference was attributed to the overexpressed nicotinic acetylcholine receptors (nAChRs) in the SCLC Cells. The sensor was also utilized to monitor the effect of various drugs on the Cells. The treatment with inhibitors such as genistin or daidzein was found to reduce Ca2+ influx in SCLC Cells. Moreover, tamoxifen, though known as the antiestrogen compound, was found to only partly block the binding of daidzein to nAChRs. Significantly, the activities of multiple individual Cells could be measured repeatedly using a single sensor device, enabling statistically meaningful measurements without errors from the device-to-device variations of the senso...
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Reusable Floating-Electrode Sensor for the Quantitative Electrophysiological Monitoring of a Nonadherent Cell
2014Co-Authors: Juhun Park, Eun Jin Park, Seunghun HongAbstract:We report a reusable floating-electrode sensor based on aligned semiconducting single-walled carbon nanotubes for the quantitative monitoring of the electrophysiological responses from a Nonadherent Cell. This method allowed us to monitor and distinguish the real-time responses from normal and small-Cell lung cancer (SCLC) Cells to the addition of nicotine. The difference was attributed to the overexpressed nicotinic acetylcholine receptors (nAChRs) in the SCLC Cells. The sensor was also utilized to monitor the effect of various drugs on the Cells. The treatment with inhibitors such as genistin or daidzein was found to reduce Ca2+ influx in SCLC Cells. Moreover, tamoxifen, though known as the antiestrogen compound, was found to only partly block the binding of daidzein to nAChRs. Significantly, the activities of multiple individual Cells could be measured repeatedly using a single sensor device, enabling statistically meaningful measurements without errors from the device-to-device variations of the sensor characteristics. This capability of the quantitative monitoring of Nonadherent Cells should be a major breakthrough for electrophysiology research and various biomedical applications such as drug screening and therapeutic monitoring
Michel Bornens - One of the best experts on this subject based on the ideXlab platform.
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Cell Distribution of Stress Fibres in Response to the Geometry of the Adhesive Environment
2016Co-Authors: Emilie Dressaire, Yong Chen, Michel BornensAbstract:Cells display a large variety of shapes when plated in classical culture conditions despite their belonging to a common Cell type. These shapes are transitory, since Cells permanently disassemble and reassemble their cytoskeleton while moving. Adhesive micropatterns are commonly used to confine Cell shape within a given geometry. In addition the micropattern can be designed so as to impose Cells to spread upon adhesive and nonadhesive areas. Modulation of the pattern geometry allows the analysis of the mechanisms governing the determination of Cell shape in response to external adhesive conditions. In this study, we show that the acquisi-tion of Cell shape follows two stages where initially the Cell forms contact with the micropattern. Here, the most distal contacts made by the Cell with the micropattern define the apices of the Cell shape. Then secondly, the Cell borders that link two apices move so as to minimise the distance between the two apices. In these Cell borders, the absence of an underlying adhesive substrate is overcome by stress fibres forming between the apices, which in turn are marked by an accumulation of focal adhesions. By inhibiting myosin function, Cell borders on nonadhesive zones become more concave, suggesting that the stress fibres work against the membrane tension in the Cell border. Moreover, this suggested that traction forces are unevenly distributed in stationary, nonmigrating, Cells. By comparing the stress fibres in Cells with one, two, or three Nonadherent Cell borders it was reasoned that stress fibre strength is inversely proportional to number. We conclude that Cells of a given area can generate the same total sum of tractional forces but that these trac-tional forces are differently spaced depending on the spatial distribution of its adher
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Cell distribution of stress fibres in response to the geometry of the adhesive environment
Cytoskeleton, 2006Co-Authors: Manuel Thery, A Pepin, Emilie Dressaire, Yong Chen, Michel BornensAbstract:Cells display a large variety of shapes when plated in classical culture conditions despite their belonging to a common Cell type. These shapes are transitory, since Cells permanently disassemble and reassemble their cytoskeleton while moving. Adhesive micropatterns are commonly used to confine Cell shape within a given geometry. In addition the micropattern can be designed so as to impose Cells to spread upon adhesive and nonadhesive areas. Modulation of the pattern geometry allows the analysis of the mechanisms governing the determination of Cell shape in response to external adhesive conditions. In this study, we show that the acquisition of Cell shape follows two stages where initially the Cell forms contact with the micropattern. Here, the most distal contacts made by the Cell with the micropattern define the apices of the Cell shape. Then secondly, the Cell borders that link two apices move so as to minimise the distance between the two apices. In these Cell borders, the absence of an underlying adhesive substrate is overcome by stress fibres forming between the apices, which in turn are marked by an accumulation of focal adhesions. By inhibiting myosin function, Cell borders on nonadhesive zones become more concave, suggesting that the stress fibres work against the membrane tension in the Cell border. Moreover, this suggested that traction forces are unevenly distributed in stationary, nonmigrating, Cells. By comparing the stress fibres in Cells with one, two, or three Nonadherent Cell borders it was reasoned that stress fibre strength is inversely proportional to number. We conclude that Cells of a given area can generate the same total sum of tractional forces but that these tractional forces are differently spaced depending on the spatial distribution of its adherence contacts. Cell Motil. Cytoskeleton 63:341–355, 2006. ' 2006 Wiley-Liss, Inc.