Use of thiazide diuretics to reduce the hypercalciuria of hypoparathyroidism during pregnancy.

A pregnant patient with idiopathic hypoparathyroidism is presented. Her hypomagnesemic hypocalcemia was unresponsive to conventional therapy, or magnesium supplementation. Sodium restriction with thiazide therapy successfully reduced her renal calcium wastage to control her symptoms and raise her serum calcium levels.

Deficiency of superoxide dismutase in endemic goiter tissue.

Superoxide dismutase (SOD) activity and its concentration were measured in thyroid tissues obtained from patients with Graves' disease, Hashimoto's thyroiditis, differentiated thyroid cancer, and endemic goiter (before and after iodine supplementation) as well as in normal thyroid tissue (paranodular tissue) from patients with follicular adenomas. SOD activity was measured by pyrogallol assay in ethanol-chloroform extracts of the thyroid homogenates. The SOD concentration in the thyroid extract was measured as immunoreactive SOD by electroimmunoassay. Endemic goiter tissues (n = 10) contained significantly lower SOD activity [mean, 1.9 +/- 1.9 (+/- SD) vs. 7.5 +/- 3.9 ng purified SOD/micrograms DNA; P less than 0.02] and concentration (mean, 0.2 +/- 0.1 vs. 0.8 +/- 0.5 ng SOD/microgram DNA; P less than 0.01) compared with those of normal tissues. No other pathological thyroid tissues had such consistently low SOD levels. Lactate dehydrogenase activity, a marker of cytosolic enzyme, was not lower in endemic goiter tissues than in normal tissues, suggesting that both tissues possessed functioning cells capable of producing cytosolic enzyme. Thyroid tissue from endemic goiter patients previously treated with iodized oil injection also had low SOD activity and concentration. Western blot analysis indicated that SOD protein in the endemic goiter tissue did not differ from that in normal thyroid tissue. We conclude that there is deficiency of cytosolic SOD in endemic goiter tissue. Since the deficiency of cytosolic SOD causes more prolonged exposure to oxygen free radicals, the decrease in SOD might contribute to the degenerative changes frequently found in these tissues.

Aldosteronism in pregnancy: association with virilization of female offspring.

We have described a case of maternal primary aldosteronism in which there is virilization of the female offspring. The most common causes of virilization are considered unlikely on the basis of clinical and laboratory data. The report illustrates the exacerbation of aldosteronism that occurs postpartum and emphasizes a conservative approach to intravenous potassium therapy during delivery.

Thyroid hormone formation catalyzed by human thyroid peroxidase: a new and physiological measurement of thyroid peroxidase.

This report describes a method for measurement of TPO activity by the amount of thyroid hormone production. Thyroid hormone formation was accomplished by incubating purified iodine-poor Tg with human TPO for 60 min at 37 C in the presence of free DIT, KI, and an H2O2 source. Newly formed T3 and T4 were measured by radioimmunoassay of the Tg hydrolysates. With this method, TPO-catalyzed iodination of Tg and thyroid hormone formation were measured simultaneously from eight normal thyroid glands and 15 thyroid glands from MMI-treated patients with Graves' disease. Graves' disease TPO showed iodinating activity and T4 formation which was higher than that of TPO from normal thyroids, and there was a positive linear correlation between the iodinating activity and the amount of T4 formation. T3 production by highly active TPO, however, dissociates from the amount of T4 formation and the degree of Tg iodination. Thus, if the activity of TPO is to be measured by the amount of thyroid hormone production, T4 should be used rather than T3. The method of thyroid hormone formation described here provides a new and physiological measurement of TPO activity and should be useful for investigation of the role of human TPO in thyroid hormone formation.

Elevated thyroxine-binding globulin with X-chromosome linked inheritance.

A new kindred with elevated levels of serum thyroxine-binding globulin (TBG) as an inherited trait has been reported. Of the twenty-four family members tested, three males and nine females had elevated serum TBG. The pedigree was consistent with an X-chromosome linked mode of inheritance.

Ectopic ACTH syndrome due to salivary gland adenoid cystic carcinoma.

A 68-year-old woman developed Cushing syndrome associated with a submaxillary salivary gland adenoid cystic carcinoma. High levels of immunoreactive adrenocorticotrophic hormone (ACTH) were found in the tumor and peripheral blood. Urinary 17-hydroxycorticosteroid levels decreased following administration of dexamethasone, suggesting possible suppression of ectopic ACTH production. however, there was no specific in vitro binding of dexamethasone by tumor cytosol. A trial of metyrapone therapy resulted in control of hypokalemia and hyperglycemia. Both plasma cortisol and 11-deoxycortisol levels decreased with metyrapone administration, suggesting that this agent may inhibit not only 11-beta-hydroxylation, but also possibly earlier steps in glucocorticoid synthesis.

Drug-induced hyponatraemia in psychogenic polydipsia.

Two patients with psychogenic polydipsia developed hyponatraemia, one in association with administration of hydrochlorothiazide and the other with that of tolbutamide. It is suggested that the increased fluid intake in such patients may make them more susceptible to the development of hyponatraemia from thiazide or sulphonylurea compounds.

Atypical adrenal insufficiency with failure of the pituitary feedback receptor. A case with associated diabetes mellitus and selective IgA deficiency with steatorrhea.

A 59 year old woman with insulin-dependent diabetes mellitus and chronic diarrhea was found to have mild steatorrhea, selective plasma IgA deficiency and adrenal insufficiency. Significant adrenal secretion of corticosteroids resulted only after prolonged stimulation with large doses of exogenous ACTH. Plasma ACTH levels were not elevated during clinical adrenal insufficiency or after metyrapone administration but did respond normally to vasopressin and insulin-induced hypoglycemia. These studies were interpreted as showing both primary adrenal insufficiency and impaired pituitary reserve for ACTH secretion in response to the feedback stimulus. No deficiency was found in secretion of other pituitary tropic hormones. Jejunal biopsy showed a lack of IgA-containing plasma cells. With cortisone replacement, diarrhea subsided and a malabsorption pattern on a film of the small bowel was no longer seen. IgA deficiency has been noted frequently with steatorrhea but rarely with diabetes and only once previously with adrenal insufficiency.

Co-existent diabetes mellitus and diabetes insipidus, a familial disease.

Three male siblings with diabetes mellitus are described, two of whom also had coexistent diabetes insipidus. The co-existence of diabetes mellitus and insipidus appears to represent a single genetic abnormality and may or may not be accompanied by primary optic atrophy. Chlorpropamide was effective in controlling the symptoms of diabetes mellitus and diabetes insipidus.