The Experts below are selected from a list of 18918 Experts worldwide ranked by ideXlab platform

Shinji Deguchi - One of the best experts on this subject based on the ideXlab platform.

  • Image based cellular Contractile Force evaluation with small-world network inspired CNN: SW-UNet.
    Biochemical and biophysical research communications, 2020
    Co-Authors: Daiki Matsunaga, Tsubasa S. Matsui, Hiroki Aosaki, Shinji Deguchi
    Abstract:

    We propose an image based cellular Contractile Force evaluation method using a machine learning technique. We use a special substrate that exhibits wrinkles when cells grab the substrate and contract, and the wrinkles can be used to visualize the Force magnitude and direction. In order to extract wrinkles from the microscope images, we develop a new CNN (convolutional neural network) architecture SW-UNet (small-world U-Net), which is a CNN that reflects the concept of the small-world network. The SW-UNet shows better performance in wrinkle segmentation task compared to other methods: the error (Euclidean distance) of SW-UNet is 4.9 times smaller than the 2D-FFT (fast Fourier transform) based segmentation approach, and is 2.9 times smaller than U-Net. As a demonstration, here we compare the Contractile Force of U2OS (human osteosarcoma) cells and show that cells with a mutation in the KRAS oncogene show larger Force compared to wild-type cells. Our new machine learning based algorithm provides us an efficient, automated and accurate method to evaluate the cell Contractile Force.

  • Image based cellular Contractile Force evaluation with small-world network inspired CNN: SW-UNet.
    arXiv: Biological Physics, 2019
    Co-Authors: Li Honghan, Daiki Matsunaga, Tsubasa S. Matsui, Hiroki Aosaki, Shinji Deguchi
    Abstract:

    We propose an image-based cellular Contractile Force evaluation method using a machine learning technique. We use a special substrate that exhibits wrinkles when cells grab the substrate and contract, and the wrinkles can be used to visualize the Force magnitude and direction. In order to extract wrinkles from the microscope images, we develop a new CNN (convolutional neural network) architecture SW-UNet (small-world U-Net), which is a CNN that reflects the concept of the small-world network. The SW-UNet shows better performance in wrinkle segmentation task compared to other methods: the error (Euclidean distance) of SW-UNet is 4.9 times smaller than 2D-FFT (fast Fourier transform) based segmentation approach, and is 2.9 times smaller than U-Net. As a demonstration, we compare the Contractile Force of U2OS (human osteosarcoma) cells and show that cells with a mutation in the KRAS oncogne show larger Force compared to the wild-type cells. Our new machine learning based algorithm provides us an efficient, automated and accurate method to evaluate the cell Contractile Force.

Hal F. Yee - One of the best experts on this subject based on the ideXlab platform.

  • 267 TIME DEPENDENCE OF HEPATIC STELLATE CELL Contractile Force GENERATION.
    Journal of Investigative Medicine, 2006
    Co-Authors: A. Datta, Andrew C. Melton, L. Martinez, Hal F. Yee
    Abstract:

    The Contractile Force generated by hepatic stellate cells (HSCs) contributes to the liver9s injury response. It has been postulated that HSC contractility increases with time of injury. Our aim was to test this hypothesis by directly quantitating Contractile Force generation by HSCs in primary culture, a well-characterized liver injury model. Method HSCs were grown in primary culture for 1, 4, 8, and 12 days prior to experimentation to simulate the injury response. One million HSCs were placed within a 3-dimensional collagen gel for 3 days, attached to a Force transducer, and mounted in an organ bath containing serum-free media for 1 hour. Gels containing HSCs were stimulated with 2 nM endothelin 1 (ET). Force development was recorded digitally. Select gels were then fixed, and microscopic cross-sections were cut and stained with toluidine blue. Micrographs were taken and the number of cells within each cross-section was determined. Results 2 nM ET-stimulated HSC Contractile Force development in a dose-dependent manner (Table). The number of HSCs in each cross-section was time dependent (Table). Conclusion We have for the first time directly measured the Force generated by HSCs after a range of days in culture. Both the Force of contraction and the number of cells within a cross-section of a gel increased with the number of days in culture. This suggests that the time-dependent increase in Force generation may be due to an increase in HSC number rather than an increase in Force generated by each cell.

  • ca2 i independent Contractile Force generation by rat hepatic stellate cells in response to endothelin 1
    American Journal of Physiology-gastrointestinal and Liver Physiology, 2006
    Co-Authors: Andrew C. Melton, Anuj Datta, Hal F. Yee
    Abstract:

    The Contractile Force generated by hepatic stellate cells in response to endothelin-1 contributes to sinusoidal blood flow regulation and hepatic fibrosis. This study's aim was to directly test the...

  • Myosin mediates Contractile Force generation by hepatic stellate cells in response to endothelin-1.
    Journal of biomedical science, 2002
    Co-Authors: Sammy Saab, Andrew C. Melton, Binh N. Tran, Steven P Tam, Pisit Tangkijvanich, Helen Wong, Hal F. Yee
    Abstract:

    Although endothelin-1-stimulated Contractile Force generation by stellate cells is believed to play an important role in hepatic pathophysiology, the molecular signals that mediate this process are incompletely understood. The aim of this study was to test the hypothesis that myosin mediates the Contractile Force generated by stellate cells in response to endothelin-1. Contractile Force generation by primary and immortalized stellate cells was directly and quantitatively measured. Myosin phosphorylation and reorganization, and actin stress fiber formation were investigated in immortalized stellate cells. Endothelin-1 stimulated a rapid and robust generation of Contractile Force by primary and immortalized stellate cells with a similar dose dependence. Myosin phosphorylation, actin stress fiber assembly, and reorganization of myosin to stress fibers were induced by concentrations of endothelin-1 that also stimulated stellate cell contraction. BQ-123, a selective endothelin receptor antagonist, inhibited myosin phosphorylation and Contractile Force generation. Y-27632, which selectively inhibits rho-associated kinase, also blocked endothelin-1-stimulated myosin phosphorylation and Contractile Force generation with a similar dose dependence. These results suggest that endothelin-1-stimulated Contractile Force generation by stellate cells is mediated by myosin.

  • RhoA/Rho-Associated Kinase Mediates Fibroblast Contractile Force Generation☆
    Biochemical and biophysical research communications, 2001
    Co-Authors: Hal F. Yee, Andrew C. Melton, Binh N. Tran
    Abstract:

    The intracellular signals governing Contractile Force generation by non-muscle cells remain uncertain. Our aim was to test the hypothesis that the rhoA/rho-associated kinase signaling pathway is a principal mediator of Contractile Force generation in non-muscle cells. We measured myosin II regulatory light chain (MLC) phosphorylation and directly quantitated Force generation by chicken embryo fibroblasts in the absence and presence of selective inhibitors of rhoA, and its downstream effector, rho-associated kinase. Inactivation of rhoA, with C3 transferase, inhibited serum-stimulated MLC phosphorylation and Contractile Force generation. Y-27632, an inhibitor of rho-associated kinase, reduced basal Contractile tension, and inhibited both serum and endothelin-1 stimulated MLC phosphorylation and Contractile Force generation. The results of this study provide novel evidence indicating that the rhoA/rho-associated kinase signaling pathway is a principal mediator of MLC phosphorylation and consequent Contractile Force generation by non-muscle cells.

  • rhoa rho associated kinase mediates fibroblast Contractile Force generation
    Biochemical and Biophysical Research Communications, 2001
    Co-Authors: Hal F. Yee, Andrew C. Melton, Binh N. Tran
    Abstract:

    The intracellular signals governing Contractile Force generation by non-muscle cells remain uncertain. Our aim was to test the hypothesis that the rhoA/rho-associated kinase signaling pathway is a principal mediator of Contractile Force generation in non-muscle cells. We measured myosin II regulatory light chain (MLC) phosphorylation and directly quantitated Force generation by chicken embryo fibroblasts in the absence and presence of selective inhibitors of rhoA, and its downstream effector, rho-associated kinase. Inactivation of rhoA, with C3 transferase, inhibited serum-stimulated MLC phosphorylation and Contractile Force generation. Y-27632, an inhibitor of rho-associated kinase, reduced basal Contractile tension, and inhibited both serum and endothelin-1 stimulated MLC phosphorylation and Contractile Force generation. The results of this study provide novel evidence indicating that the rhoA/rho-associated kinase signaling pathway is a principal mediator of MLC phosphorylation and consequent Contractile Force generation by non-muscle cells.

Daiki Matsunaga - One of the best experts on this subject based on the ideXlab platform.

  • Image based cellular Contractile Force evaluation with small-world network inspired CNN: SW-UNet.
    Biochemical and biophysical research communications, 2020
    Co-Authors: Daiki Matsunaga, Tsubasa S. Matsui, Hiroki Aosaki, Shinji Deguchi
    Abstract:

    We propose an image based cellular Contractile Force evaluation method using a machine learning technique. We use a special substrate that exhibits wrinkles when cells grab the substrate and contract, and the wrinkles can be used to visualize the Force magnitude and direction. In order to extract wrinkles from the microscope images, we develop a new CNN (convolutional neural network) architecture SW-UNet (small-world U-Net), which is a CNN that reflects the concept of the small-world network. The SW-UNet shows better performance in wrinkle segmentation task compared to other methods: the error (Euclidean distance) of SW-UNet is 4.9 times smaller than the 2D-FFT (fast Fourier transform) based segmentation approach, and is 2.9 times smaller than U-Net. As a demonstration, here we compare the Contractile Force of U2OS (human osteosarcoma) cells and show that cells with a mutation in the KRAS oncogene show larger Force compared to wild-type cells. Our new machine learning based algorithm provides us an efficient, automated and accurate method to evaluate the cell Contractile Force.

  • Image based cellular Contractile Force evaluation with small-world network inspired CNN: SW-UNet.
    arXiv: Biological Physics, 2019
    Co-Authors: Li Honghan, Daiki Matsunaga, Tsubasa S. Matsui, Hiroki Aosaki, Shinji Deguchi
    Abstract:

    We propose an image-based cellular Contractile Force evaluation method using a machine learning technique. We use a special substrate that exhibits wrinkles when cells grab the substrate and contract, and the wrinkles can be used to visualize the Force magnitude and direction. In order to extract wrinkles from the microscope images, we develop a new CNN (convolutional neural network) architecture SW-UNet (small-world U-Net), which is a CNN that reflects the concept of the small-world network. The SW-UNet shows better performance in wrinkle segmentation task compared to other methods: the error (Euclidean distance) of SW-UNet is 4.9 times smaller than 2D-FFT (fast Fourier transform) based segmentation approach, and is 2.9 times smaller than U-Net. As a demonstration, we compare the Contractile Force of U2OS (human osteosarcoma) cells and show that cells with a mutation in the KRAS oncogne show larger Force compared to the wild-type cells. Our new machine learning based algorithm provides us an efficient, automated and accurate method to evaluate the cell Contractile Force.

Binh N. Tran - One of the best experts on this subject based on the ideXlab platform.

  • Myosin mediates Contractile Force generation by hepatic stellate cells in response to endothelin-1.
    Journal of biomedical science, 2002
    Co-Authors: Sammy Saab, Andrew C. Melton, Binh N. Tran, Steven P Tam, Pisit Tangkijvanich, Helen Wong, Hal F. Yee
    Abstract:

    Although endothelin-1-stimulated Contractile Force generation by stellate cells is believed to play an important role in hepatic pathophysiology, the molecular signals that mediate this process are incompletely understood. The aim of this study was to test the hypothesis that myosin mediates the Contractile Force generated by stellate cells in response to endothelin-1. Contractile Force generation by primary and immortalized stellate cells was directly and quantitatively measured. Myosin phosphorylation and reorganization, and actin stress fiber formation were investigated in immortalized stellate cells. Endothelin-1 stimulated a rapid and robust generation of Contractile Force by primary and immortalized stellate cells with a similar dose dependence. Myosin phosphorylation, actin stress fiber assembly, and reorganization of myosin to stress fibers were induced by concentrations of endothelin-1 that also stimulated stellate cell contraction. BQ-123, a selective endothelin receptor antagonist, inhibited myosin phosphorylation and Contractile Force generation. Y-27632, which selectively inhibits rho-associated kinase, also blocked endothelin-1-stimulated myosin phosphorylation and Contractile Force generation with a similar dose dependence. These results suggest that endothelin-1-stimulated Contractile Force generation by stellate cells is mediated by myosin.

  • RhoA/Rho-Associated Kinase Mediates Fibroblast Contractile Force Generation☆
    Biochemical and biophysical research communications, 2001
    Co-Authors: Hal F. Yee, Andrew C. Melton, Binh N. Tran
    Abstract:

    The intracellular signals governing Contractile Force generation by non-muscle cells remain uncertain. Our aim was to test the hypothesis that the rhoA/rho-associated kinase signaling pathway is a principal mediator of Contractile Force generation in non-muscle cells. We measured myosin II regulatory light chain (MLC) phosphorylation and directly quantitated Force generation by chicken embryo fibroblasts in the absence and presence of selective inhibitors of rhoA, and its downstream effector, rho-associated kinase. Inactivation of rhoA, with C3 transferase, inhibited serum-stimulated MLC phosphorylation and Contractile Force generation. Y-27632, an inhibitor of rho-associated kinase, reduced basal Contractile tension, and inhibited both serum and endothelin-1 stimulated MLC phosphorylation and Contractile Force generation. The results of this study provide novel evidence indicating that the rhoA/rho-associated kinase signaling pathway is a principal mediator of MLC phosphorylation and consequent Contractile Force generation by non-muscle cells.

  • rhoa rho associated kinase mediates fibroblast Contractile Force generation
    Biochemical and Biophysical Research Communications, 2001
    Co-Authors: Hal F. Yee, Andrew C. Melton, Binh N. Tran
    Abstract:

    The intracellular signals governing Contractile Force generation by non-muscle cells remain uncertain. Our aim was to test the hypothesis that the rhoA/rho-associated kinase signaling pathway is a principal mediator of Contractile Force generation in non-muscle cells. We measured myosin II regulatory light chain (MLC) phosphorylation and directly quantitated Force generation by chicken embryo fibroblasts in the absence and presence of selective inhibitors of rhoA, and its downstream effector, rho-associated kinase. Inactivation of rhoA, with C3 transferase, inhibited serum-stimulated MLC phosphorylation and Contractile Force generation. Y-27632, an inhibitor of rho-associated kinase, reduced basal Contractile tension, and inhibited both serum and endothelin-1 stimulated MLC phosphorylation and Contractile Force generation. The results of this study provide novel evidence indicating that the rhoA/rho-associated kinase signaling pathway is a principal mediator of MLC phosphorylation and consequent Contractile Force generation by non-muscle cells.

Andrew C. Melton - One of the best experts on this subject based on the ideXlab platform.

  • 267 TIME DEPENDENCE OF HEPATIC STELLATE CELL Contractile Force GENERATION.
    Journal of Investigative Medicine, 2006
    Co-Authors: A. Datta, Andrew C. Melton, L. Martinez, Hal F. Yee
    Abstract:

    The Contractile Force generated by hepatic stellate cells (HSCs) contributes to the liver9s injury response. It has been postulated that HSC contractility increases with time of injury. Our aim was to test this hypothesis by directly quantitating Contractile Force generation by HSCs in primary culture, a well-characterized liver injury model. Method HSCs were grown in primary culture for 1, 4, 8, and 12 days prior to experimentation to simulate the injury response. One million HSCs were placed within a 3-dimensional collagen gel for 3 days, attached to a Force transducer, and mounted in an organ bath containing serum-free media for 1 hour. Gels containing HSCs were stimulated with 2 nM endothelin 1 (ET). Force development was recorded digitally. Select gels were then fixed, and microscopic cross-sections were cut and stained with toluidine blue. Micrographs were taken and the number of cells within each cross-section was determined. Results 2 nM ET-stimulated HSC Contractile Force development in a dose-dependent manner (Table). The number of HSCs in each cross-section was time dependent (Table). Conclusion We have for the first time directly measured the Force generated by HSCs after a range of days in culture. Both the Force of contraction and the number of cells within a cross-section of a gel increased with the number of days in culture. This suggests that the time-dependent increase in Force generation may be due to an increase in HSC number rather than an increase in Force generated by each cell.

  • ca2 i independent Contractile Force generation by rat hepatic stellate cells in response to endothelin 1
    American Journal of Physiology-gastrointestinal and Liver Physiology, 2006
    Co-Authors: Andrew C. Melton, Anuj Datta, Hal F. Yee
    Abstract:

    The Contractile Force generated by hepatic stellate cells in response to endothelin-1 contributes to sinusoidal blood flow regulation and hepatic fibrosis. This study's aim was to directly test the...

  • Myosin mediates Contractile Force generation by hepatic stellate cells in response to endothelin-1.
    Journal of biomedical science, 2002
    Co-Authors: Sammy Saab, Andrew C. Melton, Binh N. Tran, Steven P Tam, Pisit Tangkijvanich, Helen Wong, Hal F. Yee
    Abstract:

    Although endothelin-1-stimulated Contractile Force generation by stellate cells is believed to play an important role in hepatic pathophysiology, the molecular signals that mediate this process are incompletely understood. The aim of this study was to test the hypothesis that myosin mediates the Contractile Force generated by stellate cells in response to endothelin-1. Contractile Force generation by primary and immortalized stellate cells was directly and quantitatively measured. Myosin phosphorylation and reorganization, and actin stress fiber formation were investigated in immortalized stellate cells. Endothelin-1 stimulated a rapid and robust generation of Contractile Force by primary and immortalized stellate cells with a similar dose dependence. Myosin phosphorylation, actin stress fiber assembly, and reorganization of myosin to stress fibers were induced by concentrations of endothelin-1 that also stimulated stellate cell contraction. BQ-123, a selective endothelin receptor antagonist, inhibited myosin phosphorylation and Contractile Force generation. Y-27632, which selectively inhibits rho-associated kinase, also blocked endothelin-1-stimulated myosin phosphorylation and Contractile Force generation with a similar dose dependence. These results suggest that endothelin-1-stimulated Contractile Force generation by stellate cells is mediated by myosin.

  • RhoA/Rho-Associated Kinase Mediates Fibroblast Contractile Force Generation☆
    Biochemical and biophysical research communications, 2001
    Co-Authors: Hal F. Yee, Andrew C. Melton, Binh N. Tran
    Abstract:

    The intracellular signals governing Contractile Force generation by non-muscle cells remain uncertain. Our aim was to test the hypothesis that the rhoA/rho-associated kinase signaling pathway is a principal mediator of Contractile Force generation in non-muscle cells. We measured myosin II regulatory light chain (MLC) phosphorylation and directly quantitated Force generation by chicken embryo fibroblasts in the absence and presence of selective inhibitors of rhoA, and its downstream effector, rho-associated kinase. Inactivation of rhoA, with C3 transferase, inhibited serum-stimulated MLC phosphorylation and Contractile Force generation. Y-27632, an inhibitor of rho-associated kinase, reduced basal Contractile tension, and inhibited both serum and endothelin-1 stimulated MLC phosphorylation and Contractile Force generation. The results of this study provide novel evidence indicating that the rhoA/rho-associated kinase signaling pathway is a principal mediator of MLC phosphorylation and consequent Contractile Force generation by non-muscle cells.

  • rhoa rho associated kinase mediates fibroblast Contractile Force generation
    Biochemical and Biophysical Research Communications, 2001
    Co-Authors: Hal F. Yee, Andrew C. Melton, Binh N. Tran
    Abstract:

    The intracellular signals governing Contractile Force generation by non-muscle cells remain uncertain. Our aim was to test the hypothesis that the rhoA/rho-associated kinase signaling pathway is a principal mediator of Contractile Force generation in non-muscle cells. We measured myosin II regulatory light chain (MLC) phosphorylation and directly quantitated Force generation by chicken embryo fibroblasts in the absence and presence of selective inhibitors of rhoA, and its downstream effector, rho-associated kinase. Inactivation of rhoA, with C3 transferase, inhibited serum-stimulated MLC phosphorylation and Contractile Force generation. Y-27632, an inhibitor of rho-associated kinase, reduced basal Contractile tension, and inhibited both serum and endothelin-1 stimulated MLC phosphorylation and Contractile Force generation. The results of this study provide novel evidence indicating that the rhoA/rho-associated kinase signaling pathway is a principal mediator of MLC phosphorylation and consequent Contractile Force generation by non-muscle cells.