Latent hypoparathyroidism in children with conotruncal cardiac defects.

Background: DiGeorge anomaly is characterized by hypoplasia or atresia of the thymus and parathyroid glands resulting in T cell-mediated deficiency, hypocalcemic hypoparathyroidism, and conotruncal cardiac defects. It usually is associated with deletions of chromosomal region 22q11. We hypothesized that the stimulated (secretory reserve) but not the constitutive secretion of parathyroid hormone would be reduced in normocalcemic children with conotruncal cardiac defects but no overt immune deficiency and would be related to the presence of a deletion in the DiGeorge chromosomal region of 22q11.

Partial median sternotomy for repair of heart defects: a cosmetic approach.

A modified median sternotomy incision that results in a cosmetically appealing scar is described. It includes the use of a low-lying short skin incision and partial transection of the sternum. The outcome in 182 infants and children indicates that this approach is safe, provides adequate exposure, and has excellent cosmetic results.

Repair of complete atrioventricular septal defect with tetralogy of Fallot.

Repair of complete atrioventricular canal with tetralogy of Fallot was performed in 9 patients. Ventricular septal defect was closed through the right atrium using a single polytetrafluoroethylene patch with ample anterior extension to avoid subaortic obstruction. The atrial septal defect was closed with a separate patch.

Myosin heavy chain mRNA during the development and regression of myocardial hypertrophy.

RNA synthesis increases during the development and decreases during the regression of pressure-overload induced myocardial hypertrophy. Until now, we have been unable to determine whether these events actually reflected changes in the messenger RNAs for the myosin heavy chain mRNA in the total RNA extracted from rat heart during the development and regression of hypertrophy. We found that the amount of MHC mRNA increased in proportion to the overall increase in total RNA during the development of hypertrophy.

Cation distributions in the hypertrophic myocardium (aortic constriction) of the rat.

Calcium, magnesium, sodium, potassium, and water distributions were determined in rat ventricular muscle during the development of myocardial hypertrophy. Hypertrophy was produced by constriction of the ascending aorta with a silver band. Sham-operated controls were treated similarly, except that the aorta was not constricted.

Cardiac involvement in adolescent hypertension. Echocardiographic determination of myocardial hypertrophy.

We measured left ventricular chamber dimension and wall thickness using M-mode echocardiography in 61 adolescents with systolic or diastolic blood pressures above the 90th percentile for age and sex and in 49 normotensive adolescents. Left ventricular posterior wall and ventricular septal thickness indexed to body surface area were significantly greater (p less than 0.001) in the hypertensive group than in the normotensive controls.

Muscle and nonmuscle cell RNA polymerase activities in early myocardial hypertrophy.

RNA polymerase was solubilized from separated rat cardiac muscle and nonmuscle cells during the development of myocardial hypertrophy 1 or 3 days after sham operation or aortic constriction. Six fractions of enzymes designated IA, IB, IIA, IIB, IIIA, and IIIB were identified by DEAE-Sephadex chromatography in each cell population. Fractions designated IA and IB, IIA and IIB, and IIIA and IIIB were similar to RNA polymerase I, II, and III, respectively, found in other eukaryotes.

Management of aortic arch interruption with prostaglandin E1 infusion and microporous expanded polytetrafluoroethylene grafts.

Prostaglandin E1 infusion and a microporous expanded polytetrafluoroethylene graft were used in the management of eight infants, all less than 4 days old, with interruption of the aortic arch. Five of the six infants receiving prostaglandin E1 responded dramatically to this therapy, with return of lower limb pulses and lessening of metabolic acidosis. There were no adverse effects attributable to the prostaglandin E1 infusion.

Hemodynamic response to vascular expansion following immunosympathectomy in spontaneously hypertensive rats.

Spontaneously hypertensive male rats (SHR) or normotensive Kyoto-Wistar (WKY) male rats underwent either sham or nerve growth factor antiserum (NGFAS) treatment during the first week of life. The NGFAS treatment prevented the development of hypertension in SHR but did not prevent the development of left ventricular groups in vivo under general anesthesia. After the recording of resting parameters, homologous whole blood was transfused until the rise in cardiac output reached a plateau.

Effect of a mild exercise program on myocardial function and the development of hypertrophy.

Cardiac function and the development of myocardial hypertrophy were studied in rats conditioned by an exercise program consisting of 8 wk of running on a treadmill. At the end of the training period a group of exercised and sedentary rats was subjected to hemodynamic evaluation under general anesthesia. Except for a slight elevation in the heart rates of the exercised animals there were no significant differences between the exercised and sedentary rats at rest.

Changes in transcriptional activity during myocardial hypertrophy.

We have demonstrated alterations in the composition of certain groups of nuclear no-histone proteins which could account for the changes in template activity. Further identification of the individual proteins essential for this regulation will aid us in our understanding of the mechanism of myocardial cell growth during hypertrophy. We also have demonstrated the existence of several different RNA polymerase enzymes and have characterized them.

Surface cooling (20 degrees C) and circulatory arrest in infants undergoing cardiac surgery. Results in ventricular septal defect, complete atrioventricular canal, and total anomalous pulmonary venous connection.

During a six-year period, 46 severely symptomatic infants (average age, 5.1 months) underwent correction of ventricular septal defect (22 patients), total anomalous pulmonary venous connection (13 patients), and complete atrioventricular canal (11 patients), with the use of surface cooling to 20 degrees C. Cardiac repair was performed during circulatory arrest, and rewarming was performed with a pump oxygenator.

Effect of prophylactic digitalization on the development of myocardial hypertrophy.

The effect of prophylactic digitalization on the development of left ventricular hypertrophy was studied in adult rats. Digitoxin, 0.1 mg/100 g body wt or solvent was given daily for 1 wk prior to either aortic constriction or sham operation and was continued until the animals were killed, either 1 or 4 wk after surgery.

Development of left ventricular hypertrophy in young spontaneously hypertensive rats after peripheral sympathectomy.

The effects of peripheral sympathectomy with nerve growth factor antiserum (NGFAS) on blood pressure, systemic hemodynamics, myocardial function, myocardial hypertrophy, and renin were studied in male spontaneously hypertensive (SH) rats of the Okamoto strain and normotensive control Kyoto-Wistar (WKY) rats. NGFAS prevented the developing of hypertension in the SH rats but did not alter blood pressure in the WKY rats. The NGFAS-treated SH rats developed the same hemodynamic abnormalities as the sham-treated rats, including increased peripheral vascular resistance and depressed cardiac output; Indices of left ventricular performance, including peak flow velocity, stroke power, stroke work, dP/dtmax, and flow acceleration (dF/dt), were diminished in the SH rats compared to the WKY rats.

Catecholamines, blood pressure, renin and myocardial function in the spontaneously hypertensive rat.

1. Neither nerve-growth-factor antiserum (NGFAS) administered subcutaneously nor 6-hydroxydopamine administered intraventricularly to immature spontaneously hypertensive rats (SHR) inhibited the development of the hypertensive syndrome. In contrast, NGFSA did not affect blood pressure in normotensive Kyoto/Wistar rats.

Heart functional responses to pressure overload in exercised and sedentary rats.

Female rats that had been subjected to a moderate treadmill running program were compared with sedentary animals on the basis of heart weight, selected biochemical measurements, and heart function. Exercised animals maintained normal growth rate, and cardiac hypertrophy was not present. Left ventricular RNA, DNA, and cytochrome c levels were unchanged.