Switched Current
Mostrando 13-24 de 32 artigos, teses e dissertações.
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13. Calcium-activated outward current in voltage-clamped hippocampal neurones of the guinea-pig.
Slow clamp currents were recorded from CA1 and CA3 pyramidal neurones in slices of guinea-pig hippocampus maintained in vitro, using a single micro-electrode sample-and-hold technique. Depolarizing voltage commands evoked a time- and voltage-dependent outward current which was suppressed by removing external Ca or by adding Cd (0.5 mM) or Mn (5 mM). This Ca-
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14. Human immunoglobulin selection associated with class switch and possible tolerogenic origins for Cδ class-switched B cells
Current paradigms of peripheral B cell selection suggest that autoreactive B cells are controlled by clonal deletion, anergy, and developmental arrest. We report that changes to the human antibody repertoire likely resulting from these mechanisms both for a well-characterized autoreactivity from antibodies encoded by the VH4-34 gene and for other hallmarks o
American Society for Clinical Investigation.
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15. Isolation of calcium current and its sensitivity to monovalent cations in dialysed ventricular cells of guinea-pig.
The ion selectivity of the Ca2+ channels in single ventricular cells of guinea-pig was studied using a 'giga-ohm seal' patch electrode for voltage clamp and internal dialysis. To isolate the Ca2+ channel current, currents through the Na+ channel and K+ channels were minimized by replacing external Na+ with Tris+ and removing K+ from both sides of the membran
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16. Self-organization of self-assembled photonic materials into functional devices: Photo-switched conductors
Linear porphyrin arrays self-assembled by either hydrogen bonding or metal ion coordination self-organize into lipid bilayer membranes. The length of the transmembrane assemblies is determined both by the thermodynamics of the intermolecular interactions in the supermolecule and by the dimension and physical chemical properties of the bilayer. Thus, the size
National Academy of Sciences.
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17. A rapid population method for action spectra applied to Halobacterium halobium.
We have developed a simple and rapid technique for measuring the action spectra for phototaxis of populations of microorganisms and applied it to halobacteria. A microscope with a dark-field condenser was used to illuminate the cell suspension in a sealed chamber with light of wavelength greater than 750 nm; in this region of the spectrum, the halobacteria s
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18. Gating properties of the cAMP-gated channel in toad olfactory receptor cells.
1. Inside-out membrane patches were excised from different parts of isolated olfactory receptor cells of the toad, and the gating properties of cAMP-gated channels were investigated under low concentrations of divalent cations. 2. At +50 mV, an outward current was observed when 1 mM cAMP was applied to the cytoplasmic side of membrane patches excised from ci
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19. Properties of an electrogenic sodium-potassium pump in isolated canine Purkinje myocytes.
1. Purkinje myocytes were isolated from canine Purkinje strands by collagenase exposure and gentle trituration. The myocytes were studied by a switched single-micro-electrode voltage-clamp technique at 37 degrees C in Tyrode solution containing 8 mM-K+ and 2 mM-Ca2+. 2. The dose-response relation for the cardiotonic steroid dihydroouabain (DHO) was obtained
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20. Pharmacological and physiological properties of the after-hyperpolarization current of bullfrog ganglion neurones.
1. The slowly decaying, calcium-dependent after-hyperpolarization (a.h.p.) that follows action potentials in bullfrog ganglion B cells has previously been shown to be generated by a potassium current called IAHP. We have recorded IAHP using a switched, single-electrode hybrid clamp where current-clamp mode was changed to voltage-clamp mode immediately after
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21. Induced overexpression of Na+/Ca2+ exchanger transgene: altered myocyte contractility, [Ca2+]i transients, SR Ca2+ contents, and action potential duration
We have produced mice in which expression of the rat cardiac Na+/Ca2+ exchanger (NCX1) transgene was switched on when doxycycline was removed from the feed at 5 wk. At 8 to 10 wk, NCX1 expression in induced (Ind) mouse hearts was 2.5-fold higher but protein levels of sarco(endo)plasmic reticulum Ca2+-ATPase, α1- and α2-subunits of Na+-K+-ATPase, phospholam
American Physiological Society.
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22. 5-Azacytidine and sodium butyrate induce expression of aromatase in fibroblasts from chickens carrying the henny feathering trait but not from wild-type chickens.
Male chickens with the henny feathering trait have a female feathering pattern. In two henny-feathered breeds, the Sebright bantam and the Golden Campine, the synthesis of estrogen is increased as a consequence of increased activity of aromatase, a cytochrome P-450 enzyme that converts androgen to estrogen. The activity of the enzyme is elevated in tissue sl
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23. Treatment of cardiomyopathy and rhabdomyolysis in long-chain fat oxidation disorders using an anaplerotic odd-chain triglyceride
The current dietary treatment of long-chain fatty acid oxidation defects (high carbohydrate with medium-even-chain triglycerides and reduced amounts of long-chain fats) fails, in many cases, to prevent cardiomyopathy, rhabdomyolysis, and muscle weakness. We hypothesized that the apparent defect in energy production results from a depletion of the catalytic i
American Society for Clinical Investigation.
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24. The 'window' component of the low threshold Ca2+ current produces input signal amplification and bistability in cat and rat thalamocortical neurones.
1. The mechanism underlying a novel form of input signal amplification and bistability was investigated by intracellular recording in rat and cat thalamocortical (TC) neurones maintained in slices and by computer simulation with a biophysical model of these neurones. 2. In a narrow membrane potential range centred around -60 mV, TC neurones challenged with s