A Novel Nicotinamide Adenine Dinucleotide Correction Method for Intracellular Ca2+ Measurement with Fura-2-Analog in Live Cells.

To measure [Ca] quantitatively, fura-2 analogs, which are ratiometric fluoroprobes, are frequently used. However, dye usage is intrinsically limited in live cells because of autofluorescence interference, mainly from nicotinamide adenine dinucleotide (NADH). More specifically, this is a major obstacle when measuring the mitochondrial [Ca] quantitatively using fura-2 analogs because the majority of NADH is in the mitochondria.

A Novel Nicotinamide Adenine Dinucleotide Correction Method for Mitochondrial Ca(2+) Measurement with FURA-2-FF in Single Permeabilized Ventricular Myocytes of Rat.

Fura-2 analogs are ratiometric fluoroprobes that are widely used for the quantitative measurement of [Ca(2+)]. However, the dye usage is intrinsically limited, as the dyes require ultraviolet (UV) excitation, which can also generate great interference, mainly from nicotinamide adenine dinucleotide (NADH) autofluorescence. Specifically, this limitation causes serious problems for the quantitative measurement of mitochondrial [Ca(2+)], as no available ratiometric dyes are excited in the visible range.

The role of the alternative complement pathway in early graft loss after intraportal porcine islet xenotransplantation.

Background: Intraportal islet transplantation (ITx) causes instant blood-mediated inflammatory reaction (IBMIR), resulting in an early loss of transplanted islets. Porcine islets, transplanted intraportally into nonhuman primates (NHPs), induce complement activation, contributing to the development of IBMIR; however, the exact mechanism is not clear.

Methods: Complement activation were compared after incubation of purified adult porcine islets in 20% human serum with or without complement inhibitors, C1 esterase inhibitor (C1E-inh), anti-factor B, and purified human factor H.

Increased human tumor necrosis factor-α levels induce procoagulant change in porcine endothelial cells in vitro.

Background: Intravascular thrombosis and systemic coagulation abnormalities are major hurdles to successful xenotransplantation and are signs of acute humoral rejection. Increased expression of tissue factor (TF) is associated with the development of microvascular thrombosis in xenografts. To develop an effective strategy to prevent accelerated coagulation in xenografts, we investigated the mechanism by which porcine endothelial cells (PECs) become procoagulant after contact with human blood.

The role of phagocytosis in IL-8 production by human monocytes in response to lipoproteins on Staphylococcus aureus.

Cytokine responses to microbes are triggered by pattern recognition receptors, such as Toll-like receptors (TLRs), which sense pathogen-associated molecular patterns. Cell wall-associated triacylated lipoproteins in Staphylococcus aureus are known to be native TLR2 ligands that mediate host inflammatory responses against S. aureus.

Stretch-activated currents in cardiomyocytes isolated from rabbit pulmonary veins.

Evidence is growing of a relationship between atrial dilation and atrial fibrillation (AF), the most prevalent type of arrhythmia. Pulmonary veins, which are important ectopic foci for provoking AF, are of increasing interest in relation to the early development of AF. Here, using single cardiomyocytes isolated from rabbit pulmonary veins, we characterised the stretch-activated currents induced by swelling and axial mechanical stretching.

Simulation of spontaneous action potentials of cardiomyocytes in pulmonary veins of rabbits.

Atrial fibrillation is the most prevalent arrhythmia, but the mechanisms by which it develops are not clear. Recently, over 90% of paroxysmal atrial fibrillation was found to be located inside the main pulmonary veins (PVs). We found that single cardiac myocytes isolated from the main PVs of rabbits generate spontaneous action potentials (SAP).

Intracellular osmotic gradient generation in rat ventricle myocyte by using a micro-perfusion system.

This experimental study describes the fabrication and analysis of a micro-perfusion system that can be used in many bioengineering experiments to create rapid, large regional intracellular changes within single ventricular myocytes. The myocyte was a kind of osmometer since the cell volume was found to be strongly dependent on the perfusion solution osmolarity. This volume change was measured, indirectly, by measuring the cell width change using video-microscopy and image analysis software.

Simulation of Ca2+-activated Cl- current of cardiomyocytes in rabbit pulmonary vein: implications of subsarcolemmal Ca2+ dynamics.

In recent studies, we recorded transiently activated outward currents by the application of three-step voltage pulses to induce a reverse mode of Na+-Ca2+ exchange (NCX). We found that these currents were mediated by a Ca2+-activated Cl- current. Based on the recent reports describing the atrial Ca2+ transients, the Ca2+ transient at the subsarcolemmal space was initiated and then diffused into the cytosolic space.