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These studies define the time table and origin of supraspinal axons regenerating across a complete spinal transection in postnatal Monodelphis domestica. After lumbar (L1) spinal cord injection of fluorophore–dextran amine conjugate on postnatal (P) day 4, a consistent number of neurons could be labeled. The numbers of labeled neurons remained stable for several weeks, but subsequently declined by P60 in control animals and by P35 in animals with complete spinal transection (T4–T6) performed at P7. In control animals, 25–40% of neurons labeled with a fluorophore injected (L1) at P4 could also be double-labeled by a second fluorophore injected (T8–T10) at different older ages. In spinally transected animals, total numbers of neurons labeled with the second marker were initially lower compared with age-matched controls, but were not significantly different by 3 weeks after injury. The proportion of double-labeled neurons in spinally transected animals increased from approximately 2% 1 week after injury (P14) to approximately 50% by P60, indicating that a substantial proportion of neurons with axons transected at P7 is able to regenerate and persist into adulthood. However, the proportion of axons originating from regenerating neurons made only a small contribution at older ages to total numbers of fibers growing through the injury site, because much of development of the spinal cord occurs after P7. Evidence was obtained that degenerating neurons with both apoptotic and necrotic morphologies were present in brainstem nuclei; the number of neurons with necrotic morphology was much greater in the brainstem of animals with spinal cords transected at P7. J. Comp. Neurol. 466:422–444, 2003. © 2003 Wiley-Liss, Inc. [ABSTRACT FROM AUTHOR]

The incidence of persistent left superior vena cava (PLSVC) is approximately 0.5% in the general population; however, the coexistent absence of the right SVC has a reported incidence in tertiary centers of 0.1%. The vast majority of reports are limited to pediatric cardiology. Likewise, sinus of Valsalva aneurysm is a rare congenital anomaly, with a reported incidence of 0.1?3.5% of all congenital heart defects. We present a 71-year-old patient undergoing preoperative evaluation for incidental finding of aortic root aneurysm, and found to have all three in coexistence. Suggestive findings were demonstrated on cardiac catheterization and definitive diagnosis was made by magnetic resonance imaging. The use of MRI for the diagnosis of asymptomatic adult congenital heart disease will be reviewed. [ABSTRACT FROM AUTHOR]