Given an abstract of a paper, generate a title for this paper such that conveys the key focus of the paper.

Abstract: The purpose of the study was to compare the renal effects of low doses of exogenous dopamine to assess the responsiveness of renal dopaminergic receptors in normotensive and hypertensive subjects. Eight hypertensive patients and seven normotensive volunteer subjects were studied. Inulin and para-aminohippuric (PAH) clearances, natriuresis, and fractional excretion of sodium increased significantly after intravenous dosing with dopamine (2 micrograms/min/kg) in both groups. These increases were significantly higher in hypertensive than in normotensive subjects: 31.8% +/- 3.7% vs. 16.2% +/- 1.2% for inulin clearance (P less than 0.01), 83.3% +/- 10.5% vs. 41.1% +/- 3.4% for PAH clearance (P less than 0.01), and 331% +/- 38% vs. 216% +/- 26% for natriuresis (P less than 0.01). These findings suggest hyperresponsiveness to dopamine during hypertension. This enhanced response to exogenous dopamine can be considered as a further argument favoring the existence of a deficit in dopaminergic activity during hypertension. Dopamine also induced a significant reduction in blood pressure and increased heart rate in hypertensive subjects but no significant change in blood pressure and heart rate occurred in normotensive subjects.
Enhanced dopamine renal responsiveness in patients with hypertension.

Abstract: Although nondialyzed, chronically uremic patients and patients undergoing maintenance hemodialysis often show evidence for wasting and calorie malnutrition and have low dietary energy intakes, their energy expenditure has never been systematically evaluated. It is possible that low energy intakes are an adaptive response to reduced energy needs; alternatively, energy expenditure could be normal or high and the low energy intakes would be inappropriate. Energy expenditure was therefore measured by indirect calorimetry in 12 normal individuals, 10 nondialyzed patients with chronic renal failure, and 16 patients undergoing maintenance hemodialysis. Energy expenditure was measured in the resting state, during quiet sitting, during controlled exercise on an exercise bicycle, and for four hours after ingestion of a test meal. Resting energy expenditure (kcal/min/1.73 m2) in the normal subjects, chronically uremic patients and hemodialysis patients was, respectively, 0.94 +/- 0.24 (SD), 0.91 +/- 0.20, and 0.97 +/- 0.10. There was also no difference among the three groups in energy expenditure during sitting, exercise, or the postprandial state. Within each group, energy expenditure during resting and sitting was directly correlated. During bicycling, energy expenditure was directly correlated with work performed, and the regression equation for this relationship was similar in each of the three groups. These findings suggest that for a given physical activity, energy expenditure in nondialyzed, chronically uremic patients and maintenance hemodialysis patients is not different from normal. The low energy intakes of many of these patients may be inadequate for their needs.
Energy expenditure in patients with chronic renal failure.

Abstract: This study compares the clinical results of two basic variations of the modified Fontan/Kreutzer operation, direct atriopulmonary connection without an interposed valve versus atrioventricular connection using the native pulmonary valve and the potential pumping capability of the subpulmonary ventricular chamber. From January 1979 through June 1985, 84 patients with tricuspid atresia and ventriculoarterial concordance underwent the modified Fontan/Kreutzer operation at the Mayo Clinic. Sixty patients had atriopulmonary connection and 24 patients had atrioventricular connections. Preoperative characteristics of the two patient groups were similar, but there was a greater frequency of Waterston shunts in the atriopulmonary group (38% versus 17%) and greater frequency of Glenn shunts in the atrioventricular group (46% versus 15%). Mean pulmonary arteriolar resistance was 1.9 +/- 0.7 units in the atriopulmonary group and 1.1 +/- 0.8 units in the atrioventricular group (p less than 0.01). Early postoperatively, mean right atrial pressure was slightly higher in the atriopulmonary group than in the atrioventricular group (18 +/- 3 versus 16 +/- 3 mm Hg, p less than 0.01), but this difference was not reflected in the early or late results. Operative mortality was 5% for patients with atriopulmonary connections and 4% for patients with atrioventricular connections. At 3.5 years postoperatively, the overall survival rate was 89% +/- 4% for patients with atriopulmonary connection and 88% +/- 7% for patients with atrioventricular connections. We conclude that there is no important difference in the clinical outcome of patients undergoing modified Fontan/Kreutzer repair for tricuspid atresia with atrioventricular concordance with either of the two operative methods. The choice of the connection should be dictated by the anatomy, such as presence of pulmonary valve or arterial stenoses, size of outlet chamber, and the presence of anomalous coronary arteries.

Comparison of atriopulmonary versus atrioventricular connections for modified Fontan/Kreutzer repair of tricuspid valve atresia.

