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Biomedical subjects

I R Curley

Publications and source records attributed to I R Curley.

5 recordsLinked to original sources

Studies in patients with hyperparathyroidism using a new two-site immunochemiluminometric assay for circulating intact (1-84) parathyroid hormone.

A recently developed chemiluminescent immunoassay for 1-84 intact parathyroid hormone (PTH) demonstrated increased specificity by virtue of two-site antibody binding and increased sensitivity by use of a chemiluminescent technique. Basal PTH levels were measured in three groups of subjects: (1) normal (n = 82), (2) hyperparathyroidism (n = 31), and (3) patients with hypercalcemia of malignancy (n = 16). There was good discrimination between normal (1.2 to 9.4 pmol/L) and hyperparathyroid subjects (9.2 to 53.4 pmol/L). In persons with hypercalcemia of malignancy all PTH levels were within the normal range (0.8 to 5.2 pmol/L) or suppressed. PTH release was stimulated by the intramuscular injection of 100 IU salmon calcitonin in 6 normal controls, 10 patients with primary hyperparathyroidism due to adenoma, and 5 with four-gland hyperplasia. There was no significant rise in PTH concentration and out of the normal range in the control subjects, but the adenoma patients demonstrated a mean rise of 24.4%, 26%, and 33%, and hyperplasia patients, a mean rise of 37%, 47%, and 37% over basal levels at 120, 180, and 240 minutes. The mean absolute rise in PTH concentration was 13.4 +/- 7.7 pmol/gm of parathyroid tissue in the adenomas and 27.2 +/- 9.5 pmol/gm of parathyroid tissue in the hyperplastic glands; this difference was significant (p less than 0.05). Serial blood samples from a central vein were taken at surgery for hyperparathyroidism, and the rate of decay of the intact hormone was studied in 9 patients after removal of the parathyroid tissue. This decay was rapid with a half-life of 300 seconds. We conclude that this new specific and sensitive intact PTH assay will provide a valuable means of investigating dynamic aspects of parathyroid physiology.

Adult↗

The association of neurofibromatosis, pheochromocytoma, and somatostatin-rich duodenal carcinoid tumor.

The association of neurofibromatosis and pheochromocytoma is well recognized; more recently, attention has been drawn to links between neurofibromatosis, pheochromocytoma, and ampullary somatostatin-rich carcinoid. Because of this association, the duodenum was explored during a recent laparotomy for resection of bilateral pheochromocytoma in a patient with von Recklinghausen's disease. A clinically unsuspected ampullary tumor was discovered; this proved to be in part a ganglioneuroma and in part a somatostatin-rich carcinoid. This paper presents full details of this carefully investigated and documented case and reviews the recent advances in this field. These studies lead us to conclude that: the clinical association of neurofibromatosis, pheochromocytoma, and D cell carcinoids ("somatostatinomas") of the ampullary region is confirmed; this association may be more common than has been previously thought, and the duodenum should be carefully examined in any patient with neurofibromatosis who undergoes laparotomy for pheochromocytoma.

Adrenal Gland Neoplasms↗

Laboratory comparison of diagnostic specificity of intact hormone and region-specific immunoassays of parathyroid hormone.

A 2-site immunochemiluminometric assay (ICMA) for intact parathyroid hormone (PTH) has been developed to overcome the problems of limited sensitivity and specificity associated with conventional PTH immunoassays. The present investigation assesses the relative merits of the 2-site intact PTH (ICMA) and a midmolecule PTH radioimmunoassay (RIA). Immunoassay profiles of dispersed hyperparathyroid cell supernatants and hyperparathyroid sera obtained during parathyroidectomy and from renal failure patients, fractionated by gel filtration chromatography, facilitated a direct comparison of the specificity of PTH immunoassays. Using gel filtration matrices which permitted the separation of intact hormone, large C-terminal fragment(s), and a small midmolecule fragment in adenomatous cell supernatant and peripheral sera, the intact PTH (ICMA) assay consistently yielded a single peak of immunoreactivity. In contrast, the midmolecule RIA yielded 2 and 3 broad peaks of immunoreactivity after fractionation of serum and adenomatous cell supernatant, respectively. There was no evidence for the secretion of a small midregion fragment in vitro or its peripheral derivation in vivo. These studies demonstrate the superior specificity of the 2-site intact PTH assay compared with a midmolecule RIA and, thus, confirm the potential diagnostic superiority of the ICMA.

Calcium↗