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951.
Zurgil N Solodeev I Gilburd B Shafran Y Afrimzon E Avtalion R Shoenfeld Y Deutsch M 《Cell biochemistry and biophysics》2004,40(2):97-113
Cell death is a major event in the pathophysiology of atherosclerosis. Oxidized low-density lipoprotein (Ox-LDL), which plays
a key role in the atherogenesis, has a powerful cytotoxic effect and causes necrosis or apoptosis of different types of cells.
In the present work we studied the mechanism of cell death in two model systems: T lymphocytes and monocytes cell line, exposed
to Ox-LDL. Ox-LDL, but not native low-density lipoprotein (LDL), was found to be cytotoxic to both cell types in a dose and
time dependent manner. Apoptotic cell deat was analyzed by evaluating cell size, nucleus DNA content and plasma membrane asymmetry.
Early cytoplasmic condensation resulting from cell shrinkage was measured by monitoring fluorescence polarization (FP) of
fluorescein labeled cells. The redical scavenger superoxide dismutase (SOD), in a time- and dose-dependent manner, reduced
the apoptotic effect of Ox-LDL. Hyperpolarization of fluorescein-labeled cells preceded the appearance of phosphatidylserine
(PS) on the plasma membrane. This sensitive parameter for early apoptosis detected different cell death kinetics, as well
as varying sensitivity to the inhibitory effect of SOD in monocytes and lymphocytes. Such data suggest that reactive oxygen
species generation are involved, in Ox-LDL-induced apoptosis and that monocytes are more susceptible to cell death triggered
by oxidative stress. 相似文献
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953.
Peter DA Alemu Y Xenos M Weisberg O Avneri I Eshkol M Oren T Elazar M Assaf Y Bluestein D 《Journal of biomechanical engineering》2012,134(4):041001
Drug-resistant hypertensive patients may be treated by mechanical stimulation of stretch-sensitive baroreceptors located in the sinus of carotid arteries. To evaluate the efficacy of endovascular devices to stretch the carotid sinus such that the induced strain might trigger baroreceptors to increase action potential firing rate and thereby reduce systemic blood pressure, numerical simulations were conducted of devices deployed in subject-specific carotid models. Two models were chosen--a typical physiologic carotid and a diminutive atypical physiologic model representing a clinically worst case scenario--to evaluate the effects of device deployment in normal and extreme cases, respectively. Based on the anatomical dimensions of the carotids, two different device sizes were chosen out of five total device sizes available. A fluid structure interaction (FSI) simulation methodology with contact surface between the device and the arterial wall was implemented for resolving the stresses and strains induced by device deployment. Results indicate that device deployment in the carotid sinus of the physiologic model induces an increase of 2.5% and 7.5% in circumferential and longitudinal wall stretch, respectively, and a maximum of 54% increase in von Mises arterial stress at the sinus wall baroreceptor region. The second device, deployed in the diminutive carotid model, induces an increase of 6% in both circumferential and longitudinal stretch and a 50% maximum increase in von Mises stress at the sinus wall baroreceptor region. Device deployment has a minimal effect on blood-flow patterns, indicating that it does not adversely affect carotid bifurcation hemodynamics in the physiologic model. In the smaller carotid model, deployment of the device lowers wall shear stress at sinus by 16% while accelerating flow entering the external carotid artery branch. Our FSI simulations of carotid arteries with deployed device show that the device induces localized increase in wall stretch at the sinus, suggesting that this will activate baroreceptors and subsequently may control hypertension in drug-resistant hypertensive patients, with no consequential deleterious effects on the carotid sinus hemodynamics. 相似文献
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958.
Insects utilize diverse families of ion channels to respond to environmental cues and control mating, feeding, and the response to threats. Although degenerin/epithelial sodium channels (DEG/ENaC) represent one of the largest families of ion channels in Drosophila melanogaster, the physiological functions of these proteins are still poorly understood. We found that the DEG/ENaC channel ppk23 is expressed in a subpopulation of sexually dimorphic gustatory-like chemosensory bristles that are distinct from those expressing feeding-related gustatory receptors. Disrupting ppk23 or inhibiting activity of ppk23-expressing neurons did not alter gustatory responses. Instead, blocking ppk23-positive neurons or mutating the ppk23 gene delayed the initiation and reduced the intensity of male courtship. Furthermore, mutations in ppk23 altered the behavioral response of males to the female-specific aphrodisiac pheromone 7(Z), 11(Z)-Heptacosadiene. Together, these data indicate that ppk23 and the cells expressing it play an important role in the peripheral sensory system that determines sexual behavior in Drosophila. 相似文献
959.
Victor Yashunsky Tal Marciano Vladislav Lirtsman Michael Golosovsky Dan Davidov Benjamin Aroeti 《PloS one》2012,7(10)
We demonstrate that a live epithelial cell monolayer can act as a planar waveguide. Our infrared reflectivity measurements show that highly differentiated simple epithelial cells, which maintain tight intercellular connectivity, support efficient waveguiding of the infrared light in the spectral region of 1.4–2.5 µm and 3.5–4 µm. The wavelength and the magnitude of the waveguide mode resonances disclose quantitative dynamic information on cell height and cell-cell connectivity. To demonstrate this we show two experiments. In the first one we trace in real-time the kinetics of the disruption of cell-cell contacts induced by calcium depletion. In the second one we show that cell treatment with the PI3-kinase inhibitor results in a progressive decrease in cell height without affecting intercellular connectivity. Our data suggest that infrared waveguide spectroscopy can be used as a novel bio-sensing approach for studying the morphology of epithelial cell sheets in real-time, label-free manner and with high spatial-temporal resolution. LY294002相似文献
960.
Titus MA Zeithaml B Kantor B Li X Haack K Moore DT Wilson EM Mohler JL Kafri T 《PloS one》2012,7(1):e30192