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Shaohua Hu^*, Ning Wang^†
Molecular & Cellular Biomechanics, Vol.3, No.2, pp. 49-60, 2006, DOI:10.3970/mcb.2006.003.049
Abstract One fundamental question in cell biology is how mechanical stresses are distributed inside the cytoplasm. Recently we have developed a synchronous detection approach to map cytoplasmic displacements and stresses using yellow fluorescent protein tagged mitochondria as fiducial markers of the cytoskeleton (CSK) in response to a localized load applied via an RGD-coated magnetic bead (7). We have shown that stresses are propagated to remote sites in the cytoplasm, a finding that contradicts continuum model predictions. Here we show that long distance force propagation in the cytoplasm was abolished when the contractile prestress in the CSK was lowered by relaxing agents… More >

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Guanbin Song^∗,†, Toshiro Ohashi^†, Naoya Sakamoto^†, Masaaki Sato^†
Molecular & Cellular Biomechanics, Vol.3, No.2, pp. 61-68, 2006, DOI:10.3970/mcb.2006.003.061
Abstract Expression of adhesion molecules may play an important role in the interaction of tumor cells with vascular endothelial cells during tumor invasion and metastasis. In this study, the adhesive force of human hepatoma HepG2 cells to human umbilical vein endothelial cells (HUVECs) was investigated using a micropipette aspiration technique. Expression of an adhesion molecule, E-selectin, was also observed by immunofluorescence microscopy. In particular, the adhesive force after stimulation of HUVECs with recombinant human interleukin-1β (rhIL-1β) was examined. The results demonstrated that the adhesive force of HepG2 cells to stimulated HUVECs is significantly higher than that of unstimulated control cells, and… More >

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Jui-Ming Yang^*, Philip R. LeDuc^∗,†
Molecular & Cellular Biomechanics, Vol.3, No.2, pp. 69-78, 2006, DOI:10.3970/mcb.2006.003.069
Abstract Inorganic and organic integrated systems detect, process, and respond to signals from solid media. Advances in fluidic systems have offered an alternative to traditional signaling methods through the development of aqueous signaling systems. Here, we show an experimentally simple mechanically governed fluidic system that creates three-dimensional molecular multiphase separation in a combination of discrete and continuous gradients analogous to digital and analog signals that can be used for controlled spatiotemporal cellular stimulation. We accomplish the pattern formation by fabricating a compartmentalized multi-level fluidics device where a network of capillaries converges into a main channel. Simultaneous control of the fluid streams… More >

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Meghan H. Hoskins^*, Cheng Dong^∗,†
Molecular & Cellular Biomechanics, Vol.3, No.2, pp. 79-88, 2006, DOI:10.3970/mcb.2006.003.079
Abstract It has been determined previously that polymorphonuclear leukocytes, or PMNs, can facilitate melanoma cell extravasation through the endothelium under shear conditions [1,2]. The interactions between melanoma cells and PMNs are mediated by the β₂-integrins expressed by PMNs and intercellular adhesion molecules (ICAM-1) expressed on melanoma cells. In this study, the kinetics of these interactions was studied using a parallel plate flow chamber. The dissociation rates were calculated under low force conditions for ICAM-1 interactions with both β₂-integrins, LFA-1 (CD11a/CD18) and Mac-1 (CD11b/CD18), together and separately by using functional blocking antibodies on PMNs. The kinetics of PMNs stimulated with IL-8 was… More >

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