We report a critical role for the T-box transcription factor Tbx5 in development and maturation of the cardiac conduction system. We find that Tbx5 is expressed throughout the central conduction system, including the atrioventricular bundle and bundle branch conduction system. Tbx5 haploinsufficiency in mice (Tbx5(del/+)), a model of human Holt-Oram syndrome, caused distinct morphological and f...

A single suction electrode catheter was used for His bundle electrogram recording. His bundle pacing, and low-energy (20 or 30 J) His bundle ablation in seven dogs. The suction electrode catheter was actively fixed to the atrial endocardium at the His bundle level. Electrophysiologic studies were performed in the control state, immediately after, and late (greater than 40 days) after His bundle...

A 19-year-old woman developed a recurrent supraventricular tachycardia (SVT) 3 months after catheter ablation of a typical slow-fast type atrioventricular nodal re-entrant tachycardia (AVNRT). During the procedure, the slow pathway was mapped and ablated anterior to the bottom of the coronary sinus (CS) ostium. She was referred to our institute and underwent electrophysiological testing a year ...

This study concerns two cases of chronic 2 degrees atrioventricular (A-V) block with left bundle branch block (LBBB). Pathological studies included serial section of the conduction systems. Case 1 had type I 2 degrees block with LBBB. Electrophysiological studies revealed type I 2 degrees block proximal to the His bundle recording site and a prolonged H-V interval (60 msec). Pathologically ther...

The electrochemical midpoint potentials (E(m)'s) of 13 cytochromes, in globin (c, c(2), c(551), c(553)), four-helix bundle (c', b(562)), alpha beta roll (b(5)), and beta sandwich (f) motifs, with E(m)'s spanning 450 mV were calculated with multiconformation continuum electrostatics (MCCE). MCCE calculates changes in oxidation free energy when a heme-axial ligand complex is moved from water into...

Small peptide analogues representing the C-terminal portion of angiotensin I sequence were designed as inhibitors of human renin. Among synthesized compounds, benzyloxycarbonyl (-"Z")-(1-naphthyl)Ala-His-leucinal (ES-188), Z-(1-naphthyl)Ala-His-statine ethyl ester (ES-226), and Z-(1-naphthyl)Ala-His-statine 2-methylbutylamide (ES-254) markedly inhibited human and primate renins (inhibitory conc...

The reaction center from Rhodobacter sphaeroides uses light energy for the reduction and protonation of a quinone molecule, Q(B). This process involves the transfer of two protons from the aqueous solution to the protein-bound Q(B) molecule. The second proton, H(+)(2), is supplied to Q(B) by Glu-L212, an internal residue protonated in response to formation of Q(A)(-) and Q(B)(-). In this work, ...

We regret to report that there is a flaw in some of the data reported in the article. We have recently determined that a background mutation arose during the construction of the oye strains and that this mutation is responsible for the ROS accumulation, accelerated aging, and apoptotic markers reported for the oye strains. We have identified the background mutation that is causing the reported ...