J Thorac Cardiovasc Surg
October 2013
Objective: Simultaneous inhibition of the cardiac equilibrative-p-nitrobenzylthioinosine (NBMPR)-sensitive (es) type of the equilibrative nucleoside transport 1 (ENT1) nucleoside transporter, with NBMPR, and adenosine deaminase, with erythro-9-[2-hydroxy-3-nonyl]adenine (EHNA), prevents release of myocardial purines and attenuates myocardial stunning and fibrillation in canine models of warm ischemia and reperfusion. It is not known whether prolonged administration of hypothermic cardioplegia influences purine release and EHNA/NBMPR-mediated cardioprotection in acutely ischemic hearts.
Methods: Anesthetized dogs (n = 46), which underwent normothermic aortic crossclamping for 20 minutes on-pump, were divided to determine (1) purine release with induction of intermittent antegrade or continuous retrograde hypothermic cardioplegia and reperfusion, (2) the effects of postischemic treatment with 100 μM EHNA and 25 μM NBMPR on purine release and global functional recovery, and (3) whether a hot shot and reperfusion with EHNA/NBMPR inhibits purine release and attenuates ventricular dysfunction of ischemic hearts.
Objective: To determine the role of the p-nitrobenzylthioinosine-sensitive equilibrative nucleoside transporter 1 (es-ENT1) in postmyocardial infarction reperfusion injury-mediated ventricular fibrillation and regional dysfunction. We used erythro-9 (2-hydroxy-3-nonyl)-adenine and p-nitrobenzylthioinosine to inhibit both adenosine deamination and transport in a canine model of off pump acute myocardial infarction.
Methods: Anesthetized adult dogs (n = 37), instrumented to monitor the percentage of systolic segmental shortening and wall thickening using sonomicrometry, underwent 90 minutes of left anterior descending coronary artery occlusion and 120 minutes of reperfusion.
Objective: The inhibition of adenosine deaminase with erythro-9 (2-hydroxy-3-nonyl)-adenine (EHNA) and the es-ENT1 transporter with p-nitro-benzylthioinosine (NBMPR), entraps myocardial intracellular adenosine during on-pump warm aortic crossclamping, leading to a complete recovery of cardiac function and adenosine triphosphate (ATP) during reperfusion. The differential role of entrapped intracellular and circulating adenosine in EHNA/NBMPR-mediated protection is unknown. Selective (8-cyclopentyl-1,3-dipropyl-xanthine) or nonselective [8-(p-sulfophenyl)theophyline] A1 receptor antagonists were used to block adenosine A1-receptor contribution in EHNA/NBMPR-mediated cardiac recovery.
View Article and Find Full Text PDFWe present a new approach, based on the curvelet transform, for the fusion of magnetic resonance and computed tomography images. The objective of this fusion process is to obtain images, with as much detail as possible, for medical diagnosis. This approach is based on the application of the additive wavelet transform on both images and the segmentation of their detail planes into small overlapping tiles.
View Article and Find Full Text PDF