Kenneth L. Becker

Immunochemical heterogeneity of calcitonin in man: effect on radioimmunoassay.

Determinations of blood levels of human calcitonin by radioimmunoassay have varied considerably in different laboratories. Much of the controversy over calcitonin levels can be attributed to the multiplicity of immunoreactive forms of the hormone (iCT), the differing region specificities of the antisera utilized for measurement by radioimmunoassay, protein effects, different rates of degradation of the various iCT fractions and the specific methodology of the radioimmunoassay.

Calcitonin as a marker for bronchogenic cancer. A prospective study

A prospective study was done of serum calcitonin (HCT) levels in 61 patients with bronchogenic cancer. Initially, 52% of patients had hypercalcitonemia. Hypercalcitonemia was not confined to patients with any particular histologic type. Seventy‐eight percent of those with high calcitonin remained normocalcemic. There was no correlation between high calcitonin levels and osseous metastases. Selective thyroid venous sampling delineated two types of hypercalcitonemia: thyroidal and ectopic. To date, the ectopic type has been associated with the small cell bronchogenic carcinoma. High initial calcitonin levels decreased significantly in 75% of patients on antitumor therapy. In 13 evaluable patients calcitonin levels mirrored clinical status changes 67% of the time. Calcitonin may be a useful marker to assess the results of therapy in patients with bronchogenic cancer. Cancer 44:680‐684, 1979.

Calcitonin in tissues of thyroidectomized monkey

Immunochemical studies indicate that immunoreactive calcitonin (iCT) is present in many tissues of monkey following thyroidectomy (thx) (e.g. liver, thymus, lung). Extrathyroidal iCT may play a role in calcium metabolism.

Streptozotocin diabetes in pregnant and nonpregnant rats

Abstract The antibiotic streptozotocin has been found to be an efficacious agent for producing experimental diabetes in the pregnant rat and is markedly less lethal than methods used heretofore. The nonfasting blood sugars are the best indication of the presence of the resultant diabetes in the pregnant rat; the fasting blood sugar often remaining normal. The survival of the streptozotocin-treated pregnant rats was 74.4 per cent. Of all treated adult females previously mated, 38.8 per cent were found to have living fetuses at the time of sacrifice as opposed to 70.3 per cent in the normal controls. The average litter size of living fetuses for the non-treated group was 9.7 and for the streptozotocin-treated group was 8.0. Of the fetuses of streptozotocin-treated rats, 16.9 per cent were blighted as compared to 3.2 per cent in the normal rats. At every period of gestation, the fetuses and newborn of the streptozotocin-treated rats were lighter in weight than those of the normal controls.

Pseudohypoparathyroidism and selective deficiency of thyrotropin: An interesting association

Abstract A patient with both pseudohypoparathyroidism and hypothyroidism due to selective deficiency of thyrotropin is presented. A review of the reported cases of pseudohypoparathyroidism revealed two additional patients with isolated thyrotropin deficiency. Thus, three of twenty-one reported cases of hypothyroidism secondary to selective thyrotropin deficiency have occurred in patients with pseudohypoparathyroidism. It is further noted that hypothyroidism has frequently been suspected in patients with pseudohypoparathyroidism but in most cases this possibility has not been adequately evaluated. In view of these observations, it is suggested that pituitary and thyroid function be investigated routinely in other patients with pseudohypoparathyroidism.

The effects of zinc on ectopic bone formation.

The effect of dietary zinc deficiency was studies in ectopic bone formation subsequent to Achilles tenotomy and also following the implantation of demineralized bone matrix in the muscle of rats. Three experiments were performed. The first was designed to investigate the relationship between zinc and calcium concentration during the formation of ectopic bone in rats fed a commercial laboratory ration, the second concerned the effects of dietary zinc deficiency on ectopic bone formation, and the third studies the subsequent effects of dietary zinc repletion on ectopic bone formation. The results indicated that, with the commercial ration, zinc increased concomitantly with calcium during ectopic bone formation in rats. Dietary zinc deficiency caused a retardation of ectopic bone formation and a significant reduction of in situ zinc and calcium concentration. Dietary zinc repletion to zinc-deficient animals restored the zinc concentration in ectopic bone to a level comparable to that of zinc-sufficient animals. Thus, these experiments present strong evidence that zinc plays an active role in bone metabolism.

Management of Thyroid Disorders

Tests of thyroid function not only indicate the presence of thyroid disorders but in some instances also locate the cause. When the diagnosis is primary hypothyroidism, dosage of thyroid should be low initially and increased to full replacement level gradually. Propranolol shows promise in the treatment of hyperthyroidism.

The twin-study method in medicine and genetics.

The twin-study method has contributed greatly to our knowledge of the interrelationships of heredity and environment. Studies of monozygotic twins reared together and apart and studies of concordance for certain traits in monozygotic and in dizygotic twins are reviewed.

Pedigree analysis. 2. Clinical discrepancies and limitations.

The basic reasons for the discrepancy between predicted and observed ratios or patterns of inheritance of genetic traits are related to penetrance and expressivity. Difficulties in collection and ascertainment of human data pose additional problems in pedigree analysis.

Pedigree Analysis: 1. Dominance, Recessiveness and Sex-Linkage

Awareness of the characteristics of the classic patterns of inheritance is fundamental to proper interpretation of the mode of transmission of inherited disease. Idealized patterns are presented.