Bioenergetic and hemodynamic consequences of cellular redox manipulations by 0.2 -20 mM pyruvate were compared with those due to adrenergic stress (0.7 -1.1 pM norepinephrine) using isolated working guinea-pig hearts under the conditions of normoxia, low-flow ischemia, and reperfusion. 5 mM glucose (+ 5 U/l insulin) + 5 mM lactate were the basal energy-yielding substrates. To stabilize left ventricular enddiastolic pressure, ventricular filling pressure was held at 12 cmHzO under all conditions; this preload control minimized FrankStarling effects on ventricular inotropism. Global low-flow ischemia was induced by reducing aortic pressure to levels (20 -10 cmH20) below the coronary autoregulatory reserve. Reactants of the creatine kinase, including H + and other key metabolites, were measured by enzymatic, HPLC, and polarographic techniques.In normoxic hearts, norepinephrine stimulations of inotropism, heart rate x pressure product, and oxygen consumption (MV02) were associated with a fall in the cytosolic phosphorylation potentialas judged by the creatine kinase equilibrium. In contrast, infusion of excess pyruvate ( 5 mM) markedly increased . [Pi]) ratio at constant (normoxia) or increased (reperfusion) MVO2. In postischemic hearts the effect of pyruvate required the presence of glucose. It is proposed that pyruvate energization may improve ion pumping by the sarcoplasmic reticulum and hence Ca2+-handling by the latter which, in turn, might increase the contractile state; decreased intracellular [Pi] due to improved phosphate fixation may also be contributory. In addition, augmented pyruvate dehydrogenase flux during reperfusion seemed to expedite cellular reenergization and functional recovery in the postischemic hearts.Correspondence to R. Biinger, Department of Physiology, F. E. Hebert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD 20814-4799, USA Abbreviations. Kcpk, Kldhr Kgapdh, Kpgkr equilibrium constant of creatine kinase, lactate dehydrogenase, glyceraldehyde-3-phosphate dehydrogenase, and 3-phosphoglycerate kinase, respectively; pH,, intracellular pH; MV02, myocardial oxygen uptake; dy, mean hydrostatic pressure gradient across left ventricle; HR . dp, product of spontaneous heart rate and pressure; C{CrP + Cr}, total myocardial content of creatine phosphate plus creatine; Gro-3-P, sn-glycerol 3-phosphate; {ATP}, total myocardial ATP content and [ATP], mean intracellular ATP concentration (similarly for other metabolites).

The authors reviewed the prenatal (11 infants) and postnatal (17 infants) sonograms and the clinical, surgical, and pathologic findings in 17 infants with an ovarian cyst to determine the sonographic features and natural history of neonatal ovarian cysts. An uncomplicated cyst (nontwisted, nonhemorrhagic) was completely anechoic and the cyst wall was imperceptible with sonography (five cases). A twisted or hemorrhagic cyst was cystic with a fluid-debris level, cystic with a retracting clot, septated with or without internal echoes, or solid (12 cases). These complicated cysts contained liquid and/or organized hematoma. Eleven of the 12 complicated cysts had a thin, highly echogenic wall. Cyst torsion commonly occurred in utero and could be diagnosed on prenatal sonograms by a typical sonographic appearance (eight cases). All of these infants were asymptomatic after birth. Four infants with hemorrhagic or twisted cysts were symptomatic. All cysts except one that resolved spontaneously were treated surgically, including three twisted cysts that showed no change in size over a 1-8-month interval. All of the cysts were of follicular origin.

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The authors retrospectively evaluated radiologic, clinical, and pathologic findings in 19 cases of lymphangioma of the retroperitoneum. The tumors were judged confined to one compartment of the retroperitoneum in 68% of the cases, whereas in 32% of cases the tumor involved more than one compartment. Abdominal radiography depicted the mass in all cases. Excretory urography demonstrated organ displacement without tumor invasion in all cases. Sonography showed multiloculated fluid in 61% of cases and a unicameral mass in 39% of cases. All but one of the multiloculated lymphangiomas had thick septa. Sonography also depicted the fluid as uncomplicated in 56% of cases. The remainder had debris that sometimes layered in the dependent portion of the cyst. Computed tomography (CT) showed a unicameral mass in 57% and a septated mass in 43% of cases. CT also showed thin, smooth walls in 79% and thick, irregular walls in 21% of cases. At CT the fluid contents were found to be homogeneous and of fluid attenuation in 64% and were complex in 36% of cases. The attenuation of fluid in one case was the same as that of retroperitoneal fat. In two cases the mass contained mural calcification. The most characteristic radiologic finding of lymphangioma of the retroperitoneum is an elongated tumor containing uncomplicated fluid with or without septa. Chyle and mural calcification are very uncommon in this location.

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