Search results for "MESH: Membrane Potentials"
showing 3 items of 3 documents
Trefoil factor TFF1-induced protection of conjunctival cells from apoptosis at premitochondrial and postmitochondrial levels.
2008
PURPOSE. Goblet cells of the conjunctival epithelium synthesize and secrete TFF1 (Trefoil factor 1), a small protease-resistant peptide that, together with mucins, is responsible for the rheologic properties of the tear film. This study aimed to determine whether TFF1, whose synthesis increases in inflammatory conditions such as pterygium, could protect conjunctival cells from apoptosis. METHODS. Chang conjunctival cells, either wild-type or expressing TFF1 through stable transfection, were exposed to benzalkonium chloride (BAK) and ultraviolet (UV) irradiation to trigger apoptosis. The authors used cell fractionation to detect lipid raft‐associated proteins, coimmunoprecipitation to explor…
FRET multiphoton spectral imaging microscopy of 7-ketocholesterol and Nile Red in U937 monocytic cells loaded with 7-ketocholesterol.
2004
To show the effect of 7-ketocholesterol (7KC) on cellular lipid content by means of flow cytometry and the interaction of 7KC with Nile Red (NR) via ultraviolet fluorescence resonance energy transfer (FRET) excitation of NR on U937 monocytic cells by means of 2-photon excitation confocal laser scanning microscopy (CLSM).Untreated and 7KC-treated U937 cells were stained with NR and analyzed by flow cytometry and CLSM. 3D sequences of images were obtained by spectral analysis in a 2-photon excitation CLSM and analyzed by the factor analysis of medical image sequences (FAMIS) algorithm, which provides factor curves and images. Factor images are the result of the FAMIS image processing method, …
Changes in the proton-motive force in Escherichia coli in response to external oxidoreduction potential.
1999
International audience; The pH homeostasis and proton-motive force (Deltap) of Escherichia coli are dependent on the surrounding oxidoreduction potential (ORP). Only the internal pH value and, thus, the membrane pH gradient (DeltapH) component of the Deltap is modified, while the membrane potential (DeltaPsi) does not change in a significant way. Under reducing conditions (Eh < 50 mV at pH 7.0), E. coli decreases its Deltap especially in acidic media (21% decrease at pH 7.0 and 48% at pH 5.0 for a 850-mV ORP decrease). Measurements of ATPase activity and membrane proton conductance (CH+m) depending on ORP and pH have shown that the internal pH decrease is due to an increase in membrane prot…