Cholesterol side-chain cleavage enzyme activity and cytochrome P-450 content in adrenal mitochondria of a patient with congenital lipoid adrenal hyperplasia (Prader disease)

An autopsied case with congenital lipoid adrenal hyperplasia (Prader disease) was presented. The cholesterol side-chain cleavage (SCC) enzyme activity in adrenal mitochondria of this case was assayed with [3H]cholesterol as substrate, combined with purified bovine adrenodoxin and adrenodoxin reductase, by measuring the amount of [3H]pregnenolone formed. The cytochrome P-450 content was also measured by recording the difference absorption spectra of carbon monoxide-complexed P-450. The cholesterol SCC enzyme activity in adrenal mitochondria of Prader disease was 0.81 nmol pregnenolone/nmol P-450 per min, which was approximately 10% of that in normal tissue. The content of cytochrome P-450 was 0.074 nmol/mg protein, which was about half of that in controls. These results indicate that there is a cholesterol SCC enzyme deficiency in adrenal mitochondria in this disease.

Surgical treatment of large ventricular septal defect with pulmonary hypertension in the first 24 months of life

A total of 74 patients under 24 months of age with large ventricular septal defects (VSD) and pulmonary hypertension were subjected to surgical treatment from 1969 through 1975. Emergency pulmonary artery (PA) banding was performed in 13 patients during the first year of life with 1 death from postoperative respiratory failure. Primary closure of the VSD was performed in 61 patients using simple hypothermia and short-term coronary perfusion, with an operative mortality of 1.6%. There were no late deaths or neurological disturbances. Normal hemodynamic data were obtained in all 7 patients who underwent postoperative cardiac catheterization from one month to five years after the primary correction. It is concluded that primary closure of a VSD in infancy is reasonable and that PA banding is indicated only for those patients less than 6 months old with a complicated defect or in an emergency situation.

A study on the mate-killer toxin by microinjection in Paramecium

The killing action by mu toxin, which is contained in the cytoplasm of stock 540,Paramecium primaurelia, was demonstrated against the various stocks of paramecia by means of microinjection. Most of the toxin is present in the soluble fraction of the host cytoplasm. The toxin was precipitated by ammonium sulphate at 50–80% saturation, and was almost completely inactivated by incubation at 60 °C for 30 min. Pre-autogamous paramecia were more sensitive than post-autogamous ones to the toxin. Paramecia which bear endosymbionts were generally resistant to the mate-killer toxin.