H. E. Black

Ultimobranchial thyroid neoplasms in bulls. A syndrome resembling medullary thyroid carcinoma in man.

A syndrome of ultimobranchial thyroid neoplasms which shares many similarities with medullary thyroid carcinoma in man occurs frequently in populations of adult bulls. The results of this investigation demonstrated that ultimobranchial neoplasms were composed of poorly differentiated parafollicular (C—) cells with extensive aggregations of microfilaments, clusters of ribosomes, and prominent Golgi apparatuses. Secretion granules often were interspersed between microfilaments. Other more columnar neoplastic cells assumed a ductal pattern. The prominent stroma contained amyloid fibrils and collagen fibers. By comparison, cells comprising medullary thyroid carcinoma were more differentiated parafollicular cells with well developed cytoplasmic organelles and numerous membrane‐limited secretion granules. Calcitonin activity was demonstrated by biologic assay in both ultimobranchial adenomas (466 ± 84 MRC mU/g) and carcinomas (409 ± 93 MRC mU/g) but serum calcium and phosphorus levels were within normal limits. Plasma calcitonin‐like activity was increased significantly 1 hour after calcium infusion but rapidly returned to baseline values. Parathyroid glands from bulls with ultimobranchial neoplasms had ultrastructural evidence of atrophy and secretory inactivity. Numerous lipofuscin, granules and cytosegresomes but few secretory granules were present in chief cells. Aggregations of amyloid fibrils surrounded chief cells and capillaries. Multiple endocrine tumors (pheochromocytomas and pituitary acidophil adenomas) and vertebral osteosclerosis with ankylosing spondylosis frequently were detected in bulls coincidentally with ultimobranchial thyroid neoplasms.

Urinary and plasma hydroxyproline during pregnancy, parturition and lactation in cows with parturient hypocalcemia

Abstract The urinary excretion and plasma concentration of total hydroxyproline were evaluated in cows which developed a syndrome of several hypocalcemia and paresis near parturition and compared to normal cows at selected intervals from 1 month prepartum to 1 month postpartum. Urinary excretion and plasma concentration of hydroxyproline did not increase during the last month of gestation in cows that developed parturient paresis. This was accompanied by a decline in the serum concentration of phosphorus from 4 weeks to 3 days prepartum and a decrease in serum calcium at 3 days prepartum. A decrease in urinary hydroxyproline occurred approximately 48 hours prepartum just prior to the time cows developed hypocalcemia. The increase in urinary and plasma hydroxyproline from day 1 prepartum to day 3 postpartum suggested an increased catabolism of bone matrix. Differences were not demonstrated during this interval between cows which developed parturient paresis and cows which maintained their calcium concentration near normal through parturition. The greater levels of hydroxyproline in postpartal lactating cows compared to prepartal nonlactating cows, with an increase near parturition, suggest that catabolism of bone matrix contributes to the maintenance of calcium homeostasis during this critical period of rapid calcium turnover.

Calcitonin Activity in Ultimobranchial Neoplasms from Bulls

Ultimobranchial neoplasms from 5 bulls (hat were extracted and assayed individually contained approximately 68% as much calcitonin activity (452 ± 68 MRC mU/g) as thyroid glands from control bulls (663 ± 165 MRC mU/g). These results were consistent with the ultrastructural finding that thyroid neoplasms in old bulls were composed of primitive ultimobranchial cells which contained few mature secretory granules characteristic of parafollicular (C-) cells. Significant difference in calcitonin concentration was not detected between thyroid glands of control cows (617 ± 106 MRC mU/g) and bulls without ultimobranchial neoplasms.