Publications

Whole isolated rat glomeruli (WG) were incubated with bacterial collagenase to separate epithelial cells (EC) from the cores of glomerular tufts (GC), which consisted of mesangial and endothelial cells, as demonstrated by electron microscopy. Lysates of WG, EC, and GC and of renal tubules were prepared by hypo-osmotic shock and freeze-thawing. Activities of the following acidic lysosomal hydrolases were measured: acid phosphatase, beta-glucuronidase, cathepsin-D, non-specific esterase, and aryl sulfatases A and B. The glomerular cell preparations showed activities of all studied enzymes. GC had higher activities than EC, save for nonspecific esterase. Studies of the recovery of acid phosphatase and beta-glucuronidase revealed that approximately 2/3 of the hydrolase activities present in WG was still measureable after collagenase treatment and that the bulk of this was found in the GC lysates. These findings demonstrate that the rat glomerulus and its cell components have considerable biochemical activities of acidic hydrolytic enzymes. These appear to be most prominent in the combined mesangial and endothelial cells of the GC components.

In six normal subjects and 6 patients with primary cardiomyopathy, left ventricular performance was evaluated at rest and during isometric handgrip exercise after 4 days of oral N-acetylprocainamide (NAPA) at each of the three dosage levels (3, 4, 5, and 6 gm/day). Changes in heart rate, blood pressure, and echocardiographic performance indices were noted during isometric exercise, but no effect of NAPA could be demonstrated. In five additional patients with ventricular dysrhythmias due to cardiac diseases, NAPA was given by vein until dysrhythmias were controlled and then a maintenance infusion was continued for 48 hr. Continuous ECG recordings showed excellent dysrhythmia control in four of the five patients, but no effect of NAPA on heart rate, blood pressure, mean pulmonary artery pressure, mean pulmonary artery wedge pressure, or cardiac output was demonstrated, either at the peak of initial infusion (serm NAPA 27 +/- 6.7 microgramsm/ml) or at steady state during the maintenance infusion (16 +/- 4.5 microgramm/ml). We conclude that NAPA by vein and mouth in clinically appropriate doses should be safe in patients with the reduced left ventricular performance due to cardiac disease.

To assess the degree to which use of hospital tests and procedures changed over a five-year period, we studied 1203 patients who were hospitalized at the University of California. San Francisco, in either 1972 or 1977 with one of 10 diagnoses: acute asthma, acute myocardial infarction, lung cancer, respiratory-distress syndrome of the newborn, cataract excision, cesarean section or vaginal delivery, kidney transplantation, stapedectomy, or total hip replacement. After careful adjustment for case severity, the total number of tests and procedures per hospital stay was found to be relatively unchanged over the five-year period for most but not all the diagnoses. However, the use of certain new diagnostic procedures (such as determination of arterial blood gases, ultrasonography, fetal monitoring, and radioisotope scanning) did increase significantly. Although generalization from these limited observations must be cautious, the data suggest that a "technology imperative" may apply more to the introduction of new technologies than to the expanding use of older, established tests and procedures. Effective cost-containment strategies must recognize the complexities of technology use among different diagnoses.