ABSTRACT
This study investigated the function of FK506-binding protein (FKBP12.6) using adenoviral-mediated gene transfer to over-express FKBP12.6 (Ad-FKBP12.6) in adult rabbit ventricular cardiomyocytes. Infection with a beta-galactosidase-expressing adenovirus (Ad-LacZ) was used as a control. Peak-systolic intracellular [Ca(2+)] (measured with Fura-2) was higher in the Ad-FKBP12.6 group compared to Ad-LacZ (1 Hz field stimulation at 37 degrees C). The amplitude of caffeine-induced Ca(2+) release was also greater, indicating a higher SR Ca(2+) content in the Ad-FKBP12.6 group. Voltage clamp experiments indicated that FKBP12.6 over-expression did not change L-type Ca(2+) current amplitude or Ca(2+) efflux rates via the Na(+)-Ca(2+) exchanger. Ca(2+) transients comparable to those after Ad-FKBP12.6 transfection could be obtained by enhancing SR Ca(2+) content of Ad-LacZ infected cells with periods of high frequency stimulation. Line-scan confocal microscopy (Fluo-3 fluorescence) of intact cardiomyocytes stimulated at 0.5 Hz (20-21 degrees C) revealed a higher degree of synchronicity of SR Ca(2+) release and fewer non-responsive Ca(2+) release sites in the Ad-FKBP12.6 group compared to control. Ca(2+) spark morphology was measured in beta-escin-permeabilized cardiomyocytes at a free [Ca(2+)](i) of 150 nm. The average values of the spark parameters (amplitude, duration, width and frequency) were reduced in the Ad-FKBP12.6 group. Increasing [Ca(2+)](i) to 400 nm caused coherent propagating Ca(2+) waves in the Ad-FKBP12.6 group but only limited Ca(2+) release events were recorded in the control group. These data indicate that FKBP12.6 over-expression enhances Ca(2+) transient amplitude predominately by increasing SR Ca(2+) content. Moreover, there is also evidence that FKBP12.6 can enhance the coupling between SR Ca(2+) release sites independently of SR content.
Subject(s)
Calcium Signaling/physiology , Myocytes, Cardiac/physiology , Tacrolimus Binding Protein 1A/physiology , Adenoviridae/genetics , Animals , Caffeine/pharmacology , Calcium/metabolism , Calcium/pharmacology , Calcium Signaling/drug effects , Cell Membrane Permeability/drug effects , Cell Shape/drug effects , Cells, Cultured , Electric Stimulation , Escin/pharmacology , Fura-2/chemistry , Gene Expression , Genetic Vectors/genetics , Humans , Membrane Potentials/physiology , Microscopy, Confocal , Microscopy, Fluorescence , Myocytes, Cardiac/drug effects , Myocytes, Cardiac/metabolism , Patch-Clamp Techniques , Rabbits , Sarcoplasmic Reticulum/chemistry , Sarcoplasmic Reticulum/metabolism , Spectrometry, Fluorescence , Tacrolimus Binding Protein 1A/genetics , Tetrodotoxin/pharmacology , Thapsigargin/pharmacology , TransfectionABSTRACT
The principles of bioethics indicate that Prospective Payment has a moral dimension. Because Prospective Payment unifies clinical and financial decisions, it poses problems for long-term care facilities, especially those motivated by a humanitarian mission rather than financial considerations. This article outlines how Prospective Payment conflicts with the ethical principles of respect for persons, autonomy, justice, promise keeping, and fidelity.
Subject(s)
Long-Term Care , Medicare , Nursing Homes , Prospective Payment System , Social Justice , Capitation Fee , Financing, Government , Humans , Long-Term Care/economics , Nursing Homes/economics , Poverty , Principle-Based Ethics , Severity of Illness Index , United StatesABSTRACT
Project BRIDGE is a complex of activities through which individuals affected by major mental illness, developmental disability, or the effects of aging become engaged in their health care decision making. This article explains the development of BRIDGE through the profound stories of Julia Warren, Theresa Draper, and Jim Overstreet.
