Coated platelets, formed by collagen and thrombin activation, have been characterized in different ways: i) by the formation of a protein coat of α-granular proteins; ii) by exposure of procoagulant phosphatidylserine; or iii) by high fibrinogen binding. Yet, their functional role has remained unclear. Here we used a novel transglutaminase probe, Rhod-A14, to identify a subpopulation of platele...

Let A be a d x n matrix and T = T(n-1) be the standard simplex in Rn. Suppose that d and n are both large and comparable: d approximately deltan, delta in (0, 1). We count the faces of the projected simplex AT when the projector A is chosen uniformly at random from the Grassmann manifold of d-dimensional orthoprojectors of Rn. We derive rhoN(delta) > 0 with the property that, for any rho < rhoN...

Rat hearts were loaded with the fluorescent calcium indicators fura 2, indo 1, rhod 2, or fluo 3 to determine cytosolic calcium levels in the perfused rat heart. With fura 2, however, basal tissue fluorescence increased above anticipated levels, suggesting accumulation of intermediates of fura 2-AM deesterification. To examine this process, we separated the intermediates of the deesterification...

OBJECTIVE The aim of this study was to evaluate the morphology and permeability of root canal walls irradiated with Er,Cr:YSGG laser after conventional endodontic treatment. BACKGROUND Laser irradiation can be used for dentinal tubule exposure, smear layer removal, and disinfection. Another potential, interesting application is as an adjunct to endodontic treatment, especially in the intracan...

The ability to image calcium signals at subcellular levels within the intact depolarizing heart could provide valuable information toward a more integrated understanding of cardiac function. Accordingly, a system combining two-photon excitation with laser-scanning microscopy was developed to monitor electrically evoked [Ca(2+)](i) transients in individual cardiomyocytes within noncontracting La...

Mitochondrial ATP-sensitive potassium (mitoK(ATP)) channels play a key role in ischemic preconditioning of the heart. However, the mechanism of cardioprotection remains controversial. We measured rhod-2 fluorescence in adult rabbit ventricular cardiomyocytes as an index of mitochondrial matrix Ca(2+) concentration ([Ca(2+)](m)), using time-lapse confocal microscopy. To simulate ischemia and rep...

Localized subcellular changes in Ca(2+) serve as important cellular signaling elements, regulating processes as diverse as neuronal excitability and gene expression. Studies of cellular Ca(2+) signaling have been greatly facilitated by the availability of fluorescent Ca(2+) indicators. The respective merits of different indicators to monitor bulk changes in cellular Ca(2+) levels have been wide...

Rubart, Michael, Exing Wang, Kenneth W. Dunn, and Loren J. Field. Two-photon molecular excitation imaging of Ca2 transients in Langendorff-perfused mouse hearts. Am J Physiol Cell Physiol 284: C1654–C1668, 2003. First published February 12, 2003; 10.1152/ajpcell.00469. 2002.—The ability to image calcium signals at subcellular levels within the intact depolarizing heart could provide valuable in...

Scaduto, Russell C., Jr., and Lee W. Grotyohann. Hydrolysis of Ca2 -sensitive fluorescent probes by perfused rat heart. Am J Physiol Heart Circ Physiol 285: H2118–H2124, 2003; 10.1152/ajpheart.00881.2001.—Rat hearts were loaded with the fluorescent calcium indicators fura 2, indo 1, rhod 2, or fluo 3 to determine cytosolic calcium levels in the perfused rat heart. With fura 2, however, basal ti...