BACKGROUND Right ventricular pacing (RVP) during supraventricular tachycardia produces progressive QRS fusion before the QRS morphology becomes stable. This transition zone (TZ) may provide useful information for differentiating orthodromic reciprocating tachycardia (ORT) from atrioventricular nodal reentrant tachycardia and atrial tachycardia independent of entrainment success. METHODS AND R...

To test the hypothesis that alterations in electrical activation sequence contribute to depressed systolic function in the infarct border zone, we examined the anatomic correlation of abnormal electromechanics and infarct geometry in the canine post-myocardial infarction (MI) heart, using a high-resolution MR-based cardiac electromechanical mapping technique. Three to eight weeks after an MI wa...

We analyzed the patterns of interectopic continuous electrical activity recorded within interectopic intervals of sustained ventricular tachycardias. These arrhythmias were induced in dogs that were studied 4 days after left anterior descending coronary artery occlusion. Standard ECG leads and electrograms from the His bundle and left ventricular epicardium, both infarct and normal zone, were r...

During mammalian cortical development, division of progenitor cells occurs at the apical ventricular zone. Apical complex proteins and adherens junctions regulate the different modes of division. Here, we have identified the membrane-associated guanylate kinase protein membrane palmitoylated protein 3 (MPP3) as an essential protein for the maintenance of these complexes. MPP3 localizes at the a...

Important clues to how the mammalian cerebral cortex develops are provided by the analysis of genetic diseases that cause cortical malformations [1-5]. People with Miller-Dieker syndrome (MDS) or isolated lissencephaly sequence (ILS) have a hemizygous deletion or mutation in the LIS1 gene [3,6]; both conditions are characterized by a smooth cerebral surface, a thickened cortex with four abnorma...

PURPOSE Coronary flow reserve (CFR) in the non-infarcted myocardium is often impaired following acute myocardial infarction (AMI). However, the clinical significance of CFR in the non-infarcted myocardium is not fully understood. The objective of the present study was to assess whether a relationship exists between CFR and left ventricular remodeling following AMI. MATERIALS AND METHODS We en...

Radial Glia (RG) cells constitute the major population of neural progenitors of the mouse developing brain. These cells are located in the ventricular zone (VZ) of the cerebral cortex and during neurogenesis they support the generation of cortical neurons. Later on, during brain maturation, RG cells give raise to glial cells and supply the adult mouse brain of Neural Stem Cells (NSC). Here we u...

Neurons generated in adulthood are found throughout the canary telencephalon. We are interested in the factors that control the rate of proliferation of stem cells that give rise to these new neurons. The rate of incorporation of newly generated neurons into vocal-control regions varies seasonally. This difference could reflect a higher rate of neurogenesis, a lower rate of cell death, or an al...

Humans with heterozygous inactivating mutations of the Lis1 gene display type I lissencephaly, a severe form of cortical dysplasia hypothesized to result from abnormal neuronal migration. Previously we reported the construction of an allelic series of the Lis1 gene in mice to analyze the effects of graded reduction of LIS1 protein on the pathogenesis of this disorder and demonstrated a cell aut...