Dosimetric anchoring of in vivo and in vitro studies for perfluorooctanoate and perfluorooctanesulfonate.

In order to compare between in vivo toxicity studies, dosimetry is needed to translate study-specific dose regimens into dose metrics such as tissue concentration. These tissue concentrations may then be compared with in vitro bioactivity assays to perhaps identify mechanisms relevant to the lowest observed effect level (LOEL) dose group and the onset of the observed in vivo toxicity. Here, we examine the perfluorinated compounds (PFCs) perfluorooctanoate (PFOA) and perfluorooctanesulfonate (PFOS).

Spatial heterogeneity of the restitution portrait in rabbit epicardium.

Spatial heterogeneity of repolarization can provide a substrate for reentry to occur in myocardium. This heterogeneity may result from spatial differences in action potential duration (APD) restitution. The restitution portrait (RP) measures many aspects of rate-dependent restitution: the dynamic restitution curve (RC), S1-S2 RC, and short-term memory response.

A low-cost high-efficiency fiber-optic coupler for recording action potentials within the myocardial wall.

We present a high-efficiency, low-cost wavelength division multiplexer to record cardiac optical action potentials (APs) within the myocardial wall using optical fibers. APs with signal-to-noise ratio as high as 60, without spatial or temporal averaging, and as high as 200, with median-filtering, were recorded in rabbit ventricle.