Robert S. Hattner

Effect of Prolonged Bed Rest on Bone Mineral

Abstract Three healthy adult males were restricted to complete bed rest for periods of 30–36 weeks. Urinary calcium excretion was elevated throughout bed rest, averaging 61 mg./day above the base-line value of 193 mg./day. Maximum urine calcium excretion occurred during the seventh week and was 136 mg./day above the base-line value. Fecal calcium excretion was also increased during bed rest. Sweat calcium was unchanged and represented only 2 per cent of calcium output. Mean calcium balances for the three subjects during bed rest were −202, −207, and −254 mg./day. The measured calcium loss during the entire bed rest period averaged 4.2 per cent of the estimated total body calcium. Calcium balance became more normal but remained negative during the three-week period of reambulation. Phosphorus excreted in the urine and phosphorus balance patterns were similar to calcium patterns. Serum calcium and phosphorus levels did not change appreciably during bed rest, but both levels fell during reambulation. Urinary hydroxyproline and pyrophosphate were mildly elevated during bed rest and fell with reambulation. Gamma ray transmission scanning of the os calcis revealed large losses of mineral during bed rest. The decreased mass in the central portion of this bone ranged from 25 per cent to 45 per cent. Mineral reaccumulated in the central os calcis following reambulation at a rate similar to its rate of loss during bed rest. Bone dissolution during bed rest may occur to a greater extent in weight-bearing bones than in the remainder of the skeleton, and the process appears to be reversible.

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.

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.

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.

Normal cerebellar MIBG localization: implications in the interpretation of delayed scans

In the I-131 MIBG scans of 14 patients with neuroblastoma (86%) or pheochromocytoma/paraganglioma (14%) that were studied more than 48 hours after administration of the radiopharmaceutical, 12 (86%) had discernible cerebellar MIBG localization. A few had midbrain or diffuse cerebral uptake as well. None of the patients had cerebellar or other central nervous system signs or symptoms, and the localization is consistent with the known distribution density of central nervous system catecholamine receptors. This suggests that cerebellar MIBG localization is normal in delayed scans and that it should not be confused with neuraxial metastasis of adrenergic neuronal neoplasms.

Normal cholescintigram in In-111 WBC positive acute acalculous cholecystitis. The converse photopenic 'rim' sign.

The authors report a case of a patient with acute acalculous cholecystitis whose cholescintigram was negative, but showed a pericholecystic photopenic halo. The diagnosis was confirmed by an ln-111 WBC scan and histopathology.

Loch im kopf (hole in the head).

Differentiated thyroid carcinoma occasionally metastasizes to bone, and it has a propensity for flat bones (skull, scapula, and pelvis), and the appendicular skeleton. These lesions are often purely lytic, and the skeletal scintigraphic appearance is often that of a photopenic abnormality surrounded by a zone of increased activity

Surprise struma. Suppurative thyroiditis found by In-111 WBC imaging.

A 53-year-old woman with a long history of severe systemic lupus erythematosus immunosuppressed by therapeutic glucocorticosteroid therapy became febrile and severely ill. History and physical examination failed to Indicate a source of infection. Cultures of body fluids were obtained and blood cultures grew Aspergillis nigricans; broad spectrum antibacterial and antifungal antibiosis was begun. An In-111 WBC scan showed thyroid localization, and a CT scan showed a goiter with multiple thyroid abscesses. Needle aspiration culture material from the thyroid was sterile by microscopy and culture. The patient recovered uneventfully