Stiftung zur förderung der erforschung von ersatz- und ergänzungsmethoden zur einschränkung von tierversuchen

Stiftung zur Förderung der Erforschung von Ersatz- und Ergänzungsmethoden zur Einschränkung von Tierversuchen Mainzer Landstraße 55, 60329 Frankfurt am Main Completed Project
Pharmacological Screening using human embryonic stem cell Dr. Michael Reppel, Institut für Neurophysiologie, Universität Köln Pharmacological Screening using human embryonic stem cell derived

Screening of drug safety is typically performed in diverse non-human healthy species with an intact
repolarization reserve. Nevertheless, these drugs are later applied in diseased humans with a
reduced repolarization reserve. It would be optimal to set up a preclinical screening tool to estimate
the proarrhythmic potential of drugs in human cardiac tissue with a reduced repolarization reserve in
Methods and Results:

In our study spontaneously beating human embryonic stem cell-derived cardiomyocytes clusters
(hESCM) and murine ES cell-derived cardiomyocytes (mESCMs) were plated onto micro-electrode
arrays (MEAs, fig. 1) to record the extracelluar field potentials (FPs) as well as effects of several
antiarrhythmic drugs. In line with clinical observations the class III antiarrhythmic drugs (±)-sotalol,
E4031 and class I antiarrhythmic drug quinidine led to a prolongation of the cardiac repolarization
phase (FP duration, FPdur) and a decrease of the FP frequency. Verapamil (a class IV antiarrhythmic
drug) decreased the FP frequency and shortened FPdur. Both, quinidine and verapamil, but not (±)-
sotalol or E4031 decreased conduction velocities in hESCM clusters.
Moreover, (±)-sotalol exerted stronger effects on FPdur in early developmental stages of hESCMs, as
proof for a reduced repolarization reserve. The EC50 of the (±)-sotalol-induced prolongation of the
FPdur was higher in mESCMs than in hESCMs implying species-dependent differences in cardiac
repolarization. Likewise, the incidence of drug-induced early recurrent depolarization (ERDs) was
higher in mESCMs than hESCMs. Conclusion: The combined measurement of drug effects on FP
parameters in hESCMs and mESCMs serves as a reliable in vitro model for preclinical studies of drug
Copyright 2010 S. Karger AG, Basel
Fig. 1: MEA-Components (Multi Channel Systems, Germany): The standard substrate-integrated MEA culture
dish contains 60 Titanium Nitride coated gold electrodes (30 μm diameter) arranged in an 8x8 electrode grid
with an interelectrode distance of 200 μm, allowing simultaneous recording of extracellular FPs from all
electrodes at a sampling rate of 1 to 25 kHz by the use of the MEA amplifier system.
Liang H, Matzkies M, Schunkert H, Tang M, Bonnemeier H, Hescheler J, Reppel M. Human and murine
embryonic stem cell-derived cardiomyocytes serve together as a valuable model for drug safety screening.
Cell Physiol Biochem. 2010;25(4-5):459-66. Epub 2010 Mar 23.


Microsoft word - development site hedge spec.doc

Guidance on the management of hedges on or All views and opinions expressed in this proposal are purely those of the author. The content cannot necessarily be taken to represent the specific policy of any of JP Associates’ developer clients. Development Site Hedge Work Specification JP Associates 46 St Peter Street, Tiverton, EX16 6NR. The importance of hedges within the landscape is

Microsoft word - bm_paris_mar_08l.doc

European Paediatric Neurology Society Board Meeting in Paris Faculté de Médecine Paris Sud, Bicetre Hospital, Friday, March 14 – Saturday, March 15, 2008 Attending: Marc Tardieu (MT), Paul Casaer (PC), Peter Baxter (PB), Willem Arts (WA), Bernhard Schmitt (BS), Lieven Lagae (LL), Hrissanthi Ikonomidou (HI), Oebele Brouwer (OB), Colin Kennedy (CK), Richard Newton (RN), Helen Cro

Copyright © 2010-2014 Medical Pdf Finder