Preservation of adenosine 5'-triphosphate and mitochondrial function during hypercalcemic reperfusion using verapamil cardioplegia

Immediate hypercalcemic reperfusion results in ventricular dysfunction and loss of high-energy stores. The purpose of this study was to evaluate the effect of verapamil cardioplegia on the preservation of myocardial energy stores, mitochondrial ultrastructure, and ventricular dysfunction in the postischemic rat heart during immediate hypercalcemic reperfusion. Rats in the control group were subjected to cardioplegia with potassium, while rats in groups 1 to 3 were subjected to the same with verapamil (0.5 mg/L). The control and group 1 rats underwent normocalcemic reperfusion and groups 2 and 3 rats underwent hypercalcemic reperfusion. Myocardial samples were analyzed for adenosine 5'-triphosphate (ATP) content and mitochondrial ultrastructural damage. Hemodynamic parameters of heart rate, aortic flow (AF), and postischemic rate of aortic pressure change (dP/dT) also were evaluated. Data were analyzed using analysis of variance. The ATP stores were preserved at greater than 100% control levels in hearts subjected to verapamil cardioplegia. There was no evidence of irreversible mitochondrial damage. Heart rate, AF, and dP/dT were significantly (p < 0.05) depressed in hearts subjected to verapamil cardioplegia. This study suggests verapamil cardioplegia preserves ATP and mitochondrial function during immediate hypercalcemic reperfusion but does not improve postischemic hemodynamics.

Unusual location of an atrial myxoma complicated by a secundum atrial septal defect

Myxomas occur most commonly in the left atrium arising from the fossa ovalis. We report the case of a left atrial myxoma originating from the base of the right inferior pulmonary vein. This large myxoma filled a large secundum atrial septal defect, which was diagnosed intraoperatively. The unusual position of this myxoma and operative management of the associated atrial septal defect are discussed.

T-cryptantigen determination affects mortality in necrotizing enterocolitis

Testing of infants suspected of having necrotizing enterocolitis for evidence of exposure of the Thomsen-Friedenreich cryptantigen (TCA) has been advocated, because patients with TCA exposure can have severe hemolytic reactions when undergoing transfusion with plasma containing blood products. We compared 62 patients who were managed with knowledge of TCA exposure status during a four year period with 66 patients who were not screened during a comparable four year period. Evidence of hemolysis after blood transfusion occurred significantly more frequently in patients who were not screened (42 versus 15 percent, p < 0.05) and there was significantly greater mortality (18.0 versus 4.5 percent, p < 0.05) in the group that was not screened. These findings suggest that screening for TCA exposure is not only of diagnostic and prognostic value in necrotizing enterocolitis, but is important for patient management and outcome.

Melanotic schwannoma of the sympathetic ganglia: pathological and clinical characteristics

Reports of melanin-producing tumors of Schwann cell origin are extremely rare. Reports of only 9 such tumors arising from sympathetic ganglia have been published previously. Two new cases of melanotic schwannoma of sympathetic ganglia are reported. The pathological and clinical characteristics of these unusual melanotic tumors are discussed.