Daniel S. Bernstein

Effects of parathyroidectomy and kidney transplantation on renal osteodystrophy

Abstract Four patients with azotemic hyperparathyroidism have been studied and treated at the Peter Bent Brigham Hospital. Subtotal parathyroidectomy was performed in all of these cases, and two patients received renal homografts as well. These patients comprise a unique group in the total clinical entity of hyperparathyroidism in whom neck exploration is often justified despite persistently normal values for serum calcium concentration and urine calcium excretion. If diffuse chief cell hyperplasia is found, about seven eighths of the parathyroid tissue should be removed; severe tetany, although transient, must be anticipated in the early postoperative period. The proper combination of subtotal parathyroidectomy and renal homotransplantation in these specific patients with renal osteodystrophy may provide striking rehabilitation. Data have been presented to support the contention that subtotal parathyroidectomy should precede renal transplantation whenever possible.

Effects of decaffeinated and nondecaffeinated coffee ingestion on blood glucose and plasma radioimmunoreactive insulin responses to rapid intravenous infusion of glucose in normal man

Abstract Eight normal humans were subjected to paired standard rapid intravenous glucose tolerance tests one hour following the ingestion, on one occasion, of nondecaffeinated and, on a second occasion, of decaffeinated coffee under identical conditions. Nondecaffeinated coffee elevates fasting blood glucose, impairs glucose tolerance as reflected by a lessened fractional blood glucose disappearance rate and relative hyperglycemia, and blunts the insulinogenic response of blood glucose elevation compared to decaffeinated coffee. These effects of nondecaffeinated coffee appeared to be inversely related to the subjects control glucose tolerance.

Secondary Hyperparathyroidism in Human Kidney Transplant Recipients

76 kidney transplant recipients who were up to 4 years post transplant, were studied to assess the incidence of secondary hyperparathyroidism. All patients had good renal function with a mean serum creatinine of 1.4 mg/100 ml. Secondary hyperparathyroidism, as evidenced by increased serum parathyroid hormone levels, was present in 53 of the 76 patients (66%) and radiologic bone disease in 26 of the 76 patients (34%), while hypercalcemia (serum calcium greater than 11.0 mg/100 ml) occurred in only 6 patients (8.5%). The incidence of secondary hyperparathyroidism decreased slightly with time following transplantation, but the degree of secondary hyperparathyroidism as indicated by the levels of serum parathyroid hormone at various times following renal transplantation was essentially similar. The causes for the persistence of this condition are not totally known, but it was found that its incidence was related to the duration of dialysis prior to transplantation.

Electrochemical determination of apparent ionized serum calcium using a calcium-selective electrode: The method and values in normal humans and a comparison to total serum calcium

Abstract A new electrochemical method using a calcium-specific electrode for the anaerobic determination of serum ionized calcium is presented. The method appears to be sensitive and precise and values obtained during infusions of calcium and various hypocalcemic agents conform with theoretical expectation. Mean ionized serum calcium in 23 normal adults (ages 22–36 years) was 1.97 mequiv/l with a standard deviation of 0.08, standard error of 0.02 mequiv/l, and coefficient of variation of 4%. No age or sex correlation was observed, and ionized serum calcium did not appear to correlate with total serum calcium.

Relationship Between Magnesium and Secondary Hyperparathyroidism During Long-term Hemodialysis

Twenty-six patients with chronic renal failure treated by long-term hemodialysis were studied. Radiologic parathyroid bone disease was observed in 15 patients, and in these, serum parathyroid hormone (PTH) levels were significantly higher ( p

The effect of subtotal parathyroidectomy and renal transplantation on mineral balance and secondary hyperparathyroidism in chronic renal failure.

Abstract Subtotal parathyroidectomy results in improvement of bone disease and metastatic calcification present in some uremic patients. This improvement is not associated with any consistent changes in external mineral balance. Calcium balance may be quite negative in both the dialyzed and undialyzed uremic patient, probably due to defective intestinal absorption, and is not altered in any consistent manner by subtotal parathyroidectomy. Following successful renal transplantation the manifestations of hyperparathyroidism may resolve spontaneously and calcium balance usually becomes positive. Although both improvements follow the restoration of renal function they may not be mutually dependent or even related. The improved calcium balance appears to depend upon the correction of defective gastrointestinal absorption. In patients in whom external calcium balance does not become positive, resolution of parathyroid induced bone disease and metastatic calcification may result from the resorption of endogenous calcium from ectopic sites with redeposition into bone, a process presumably made possible by the decrease in plasma parathyroid hormone consequent to renal transplantation.

Effects of hemodialysis on secondary hyperparathyroidism in patients with chronic renal failure

Abstract In the first few weeks after the initiation of maintenance hemodialysis in nine patients with chronic renal failure, there was a progressive rise in both total and ionized serum calcium associated with a reciprocal and significant fall in the concentration of plasma parathyroid hormone. Studies in 36 additional patients with chronic renal failure already on hemodialysis indicated that this favorable trend did not continue; a progressive rise in parathyroid hormone concentration was associated with increasing duration of hemodialysis against the calcium concentration generally used by most centers. These observations are consistent with the increase in bone disease often associated with hemodialysis. Experimental increases in dialysate calcium concentration from 2.6 to 3.5 meq/liter for a 2-mo period failed to decrease parathyroid hormone secretion or cause a significant increase in predialysis calcium concentration in 36 uremic patients. Use of high calcium dialysis earlier in the course of the disease, alternate means of parathyroid suppression, and even subtotal parathyroidectomy may be necessary for the management of hyperparathyroidism in uremic patients undergoing hemodialysis.

Lipid Metabolism in Normal and Rachitic Rat Epiphyseal Cartilage

Summary Lipid synthesis in rat epiphyseal cartilage has been studied in relation to normal growth and the production of rickets. Cartilage was incubated in vitro in modified Krebs-Ringer bicarbonate buffer with added I-14C palmitic acid. In normal 28-day-old male weanling rats, the total uptake of 1-14C palmitic acid from the media showed a gradual increase with time. Fractionation of the lipids showed 64.6% of the label in free fatty acids; 19.2% in triglycerides; 12.8% in phospholipids; and 6.2% in cholesterol and cholesterol esters. In rachitic rats of comparable age, the total uptake of 1-14C palmitic acid was increased significantly, indicating an increased rate of lipid synthesis.

A physico-chemical study of calcium-albumin aggregation employing a calcium-specific electrode☆

Abstract A novel investigation of the reaction between calcium and serum albumin in a physiologic system is described. Using an electrochemical method for the determination of ionized calcium in calcium-albumin solutions, estimations of total binding site number and formulations describing the reaction were obtained in the presence of varying hydrogen ion concentrations. Total binding site number estimated by this technique agrees closely with prior thermodynamic predictions. The previous explanation of alkalemic tetany based upon increased serum protein-calcium binding appears inadequate by the presently observed effect of hydrogen ion concentrations on albumin-calcium binding.

OSTEOPOROSIS: ETIOLOGY AND THERAPY.

The etiologic process involved in human osteoporosis (excluding that due to excessive adrenocorticoid excretion) is considered of the idiopathic variety. Studies with radioisotope labeling have indicated that most forms of osteoporosis may be considered a metabolic bone disease resulting in more destruction than formation of bone.Therapy is aimed toward eliminating pain, preventing vertebral fractures, and recalcifying the skeleton.