Altered neurite morphology and cholinergic function of induced pluripotent stem cell-derived neurons from a patient with Kleefstra syndrome and autism.

The aim of the present study was to establish an in vitro Kleefstra syndrome (KS) disease model using the human induced pluripotent stem cell (hiPSC) technology. Previously, an autism spectrum disorder (ASD) patient with Kleefstra syndrome (KS-ASD) carrying a deleterious premature termination codon mutation in the EHMT1 gene was identified. Patient specific hiPSCs generated from peripheral blood mononuclear cells of the KS-ASD patient were differentiated into post-mitotic cortical neurons.

Novel experimental results in human cardiac electrophysiology: measurement of the Purkinje fibre action potential from the undiseased human heart.

Data obtained from canine cardiac electrophysiology studies are often extrapolated to the human heart. However, it has been previously demonstrated that because of the lower density of its K(+) currents, the human ventricular action potential has a less extensive repolarization reserve. Since the relevance of canine data to the human heart has not yet been fully clarified, the aim of the present study was to determine for the first time the action potentials of undiseased human Purkinje fibres (PFs) and to compare them directly with those of dog PFs.

Effects of Chelidonium majus extracts and major alkaloids on hERG potassium channels and on dog cardiac action potential - a safety approach.

Chelidonium majus or greater celandine is spread throughout the world, and it is a very common and frequent component of modern phytotherapy. Although C. majus contains alkaloids with remarkable physiological effect, moreover, safety pharmacology properties of this plant are not widely clarified, medications prepared from this plant are often used internally.

Abnormal repolarization as the basis for late potentials and fractionated electrograms recorded from epicardium in experimental models of Brugada syndrome.

Objectives: The aim of this study was to test the hypothesis that late potentials and fractionated electrogram activity are due to delayed depolarization within the anterior aspects of right ventricular (RV) epicardium in experimental models of Brugada syndrome (BrS).

Background: Clinical reports have demonstrated late potentials on signal-averaged electrocardiography (ECG) recorded in patients with BrS. Recent studies report the appearance of late potentials and fractionated activity on bipolar electrograms recorded in the epicardium of the RV outflow tract in patients with BrS.

Mechanisms underlying the development of the electrocardiographic and arrhythmic manifestations of early repolarization syndrome.

Early repolarization pattern in the ECG has been associated with increased risk for ventricular tachycardia/fibrillation (VT/VF), particularly when manifest in inferior leads. This study examines the mechanisms underlying VT/VF in early repolarization syndrome (ERS). Transmembrane action potentials (APs) were simultaneously recorded from 2 epicardial sites and 1 endocardial site of coronary-perfused canine left-ventricular (LV) wedge preparations, together with a pseudo-ECG.