The dynamic interaction of simultaneously changing heart period and single vagal stimuli on atrioventricular conduction (AV interval) was quantified by subtracting the vagally induced responses of the paced heart preparation from those of the unpaced heart preparation. This difference was significantly greater (P less than 0.05) than the AV responses to changes in heart period (delta A) alone w...

Robert H. Anderson, Siew Yen Ho and Michael L. Rigby Cardiology in the Young / Volume 10 / Issue 01 / January 2000, pp 32 ­ 41 DOI: 10.1017/S1047951100006351, Published online: 19 August 2008 Link to this article: http://journals.cambridge.org/abstract_S1047951100006351 How to cite this article: Robert H. Anderson, Siew Yen Ho and Michael L. Rigby (2000). The morphologic variability in atrioven...

n engl j med 364;21 nejm.org may 26, 2011 1990 resent a diverse genetic pool that allows for adaptation and evolutionary change. Further insight into how these adaptations occur may enhance our ability to predict the emergence of new, more capable bacterial pathogens, the development of more predictive animal models, and the potential identification of critical pathways that might serve as ther...

It is generally accepted that in mammals visual information is sent to the brain along functionally specialized parallel pathways, but whether the mouse visual system uses similar processing strategies is not known. It is important to resolve this issue because the mouse brain provides a tractable system for developing a cellular and molecular understanding of disorders affecting spatiotemporal...

In view of the association of congenital heart block with maternal antibody to cellular antigen Ro (SSA), and one report linking anti-Ro with myocarditis in a patient with myositis an association between anti-Ro antibodies and cardiac disease was sought in adults with systemic lupus erythematosus (SLE). Among 67 patients with SLE, of whom 36 were anti-Ro positive, a significantly higher prevale...

DURING the repair of congenital defects of the venitricular septum, various disturbances of cardiac function may occur.1'Permanent complete heart block has been the most serious of these disturbances. Right bundle-branch block seems benign. Inereased knowledge of the anatomic features of the atrioventricular (AV) conduction system has resulted in surgical technics that have nearly eliminated co...

The two-signal model of T-cell activation is still valid after 30 years. The recent understanding of the first signal intricacy and its tight relationship with the second signal have thrown decisive light on T-cell activation processes and the complex molecular events that occur on the surface and within the T cell. Furthermore, the recognition of numerous accessory pathways that, in addition t...

We review the essential role of maternal factors in pattern formation for Xenopus laevis, focusing on VegT, Vg1, and Wnt11. Results from loss of function experiments demonstrate a clear requirement for these genes in germ layer specification, dorsal-ventral axis formation, and convergence extension. We also discuss these genes in the broader context of metazoan development, exploring whether an...

The observation of a left sided accessory pathway with decremental properties is rare. We describe the behaviour of one of these pathways which was characterized by the presence of retrograde conduction (not previously reported) and thus inducibility of atrio-ventricular orthodromic reentrant tachycardia.

DURING the repair of congenital defects of the venitricular septum, various disturbances of cardiac function may occur.1'Permanent complete heart block has been the most serious of these disturbances. Right bundle-branch block seems benign. Inereased knowledge of the anatomic features of the atrioventricular (AV) conduction system has resulted in surgical technics that have nearly eliminated co...