Iodide organification defect in iodine deficiency endemic goiter.

In 17 goitrous persons in an iodine-deficient area, in 23 nongoitrous inhabitants of the same village, in 10 goitrous persons in Athens, and 8 normal controls the perchlorate discharge test was performed, either in the simple standard form or after pretreatment with either 0.5 or 2.0 mg potassium iodide or 2.5 mg carbimazole. With the simple test or with 0.5 mg potassium iodide, there was no significant discharge in any group studied. With 2.5 mg carbimazole, there was a profound discharge of the trapped iodide in both groups in the iodine-deficient area. With 2.0 mg potassium iodide, however, there was a clear discharge in the two goitrous groups (i.e. the one in the endemic area and the second in Athens), a less pronounced discharge in the controls studied in Athens, and no discharge at all in the nongoitrous inhabitants of the iodine-deficient endemic area. These findings provide evidence for an abnormality present in the patients with endemic goiter, most probably faulty iodine utilization due to impaired organic binding. The nongoitrous persons in the endemic areas, on the other hand, seem to be even more efficient in handling the trapped iodide than the controls studied in Athens. These findings may provide an explanation for previous observations that in endemic areas only part of the population develop a goiter, whereas the others adapt successfully to iodine deficiency without significantly enlarging their glands.

Thyroid scanning with gallium-67 and cesium-131.

The roles of 131Cs and 67Ga in the evaluation of solitary thyroid nodules were investigated. Radionuclide scans were performed with 67Ga and 131I in 27 patients and with 131Cs and 131I in 43 patients. Gallium-67 detected only two of eight malignant nonfunctioning nodules and 131Cs detected one of three such nodules. The contribution of 131Cs and 67Ga to the preoperative identification of malignant thyroid lesions is of doubtful value.

Serum vitamin B12 and folic acid levels in hyperthyroidism.

Serum vitamin B12 and folic acid levels were measured in 48 hyperthyroid patients and in a group of euthyroid controls. The levels of vitamin B12 ranged from 120-900 pg/ml with a mean of 429.3 +/- 30.9 pg/ml (SE). The mean serum vitamin B12 level was lower in hyperthyroid patients than in normal controls, the difference being statistically significant (t = 2.584, p less than 0.025). Serum vitamin B12 levels showed a statistically significant negative correlation with the clinical index of Grooks et al. (r = 0.344, p less than 0.05). The findings, although not excluding the involvement of auto-immune gastritis in patients with low serum vitamin B12 levels, suggest a direct action of increased thyroid hormone concentrations. Serum folic acid levels ranged from 0.5-13.8 ng/ml with a mean of 6.8 +/- 0.46 ng/ml (SE). The mean serum folic acid levels were higher in the hyperthyroid patients than in normal controls but the difference was not statistically significant (t = 1.2, p greater than 0.2). The serum folic acid levels did not show any statistically significant correlation with the clinical index of Grooks et al. The fact that no statistically significant difference was found between the mean value in hyperthyroid patients and the mean value in normal controls is probably due to the high folic acid intake in Greece.

Serial serum calcitonin concentrations to evaluate response to therapy of patients with medullary thyroid carcinoma.

Six female patients with medullary thyroid carcinoma were treated with doxorubicin (50 mg/m2) and cis-diammine dichloroplatinum (70 mg/m2) every three weeks. No patient responded to therapy as was suggested by serial serum calcitonin concentrations before and after treatment.