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Biomedical subjects

R H Caplan

Publications and source records attributed to R H Caplan.

At least 37 records · Page 2Linked to original sources

Recurrence of 131I-induced thyroid storm after discontinuing glucocorticoid therapy.

A 19-year-old woman with Graves' disease developed thyroid storm 8 days after radioactive iodine therapy. The clinical manifestations of thyroid storm promptly improved after treatment with large doses of propylthiouracil, potassium iodide, propranolol hydrochloride, and dexamethasone. Four days after discontinuing dexamethasone, the syndrome recurred and was corrected by reinstitution of the glucocorticoid. We conclude that dexamethasone was an important adjunct for treating thyroid storm and was effective mainly by reducing peripheral triiodothyronine production.

Adult↗

Hypercalcemia in a calcitriol-treated hypoparathyroid woman during lactation.

We treated a hypoparathyroid woman with calcitriol during pregnancy and did not reduce the dosage after delivery. Despite lactation, the serum calcium level increased to 15.4 mg/dL 11 days postpartum. We treated two other hypoparathyroid women during four pregnancies with either calcitriol or dihydrotachysterol. In all five pregnancies, requirements for the vitamin D preparations increased beginning at the 20-28th week of gestation. Hypercalcemia did not occur in the two women who did not breast-feed and in whom we reduced the dose of calcitriol or dihydrotachysterol after delivery. We conclude the following: 1) Calcitriol is effective for treating hypoparathyroidism during pregnancy; 2) the dose usually needs to be increased during the latter half of gestation; 3) the calcitriol dose should be reduced during lactation; and 4) both mother and infant should be monitored to detect hypercalcemia during breast-feeding. We speculate that low serum estrogen levels associated with breast-feeding promote bone resorption and diminish calcitriol needs in lactating hypoparathyroid women.

Administration, Oral↗

Adrenal insufficiency after operative removal of apparently nonfunctioning adrenal adenomas.

We describe a woman who developed adrenal insufficiency after removal of an apparently nonfunctional adrenal adenoma. She displayed no stigmata of Cushing's syndrome and had normal plasma and urinary cortisol levels. A second patient without clinical findings of Cushing's syndrome also had normal basal steroid levels. This patient displayed partial suppressibility with dexamethasone, had low-normal levels of serum corticotropin, and excreted a low concentration of urinary 17-ketosteroids. She also developed mild adrenal insufficiency after the operation. We believe the adrenal adenomas in these patients secreted enough cortisol to suppress the contralateral adrenal gland but not enough hormone to elevate basal steroid levels. Therefore, we suggest that all patients with adrenal masses be studied with the overnight dexamethasone suppression test rather than basal steroid hormone measurements to detect low levels of autonomous cortisol secretion. In addition, patients with adrenal masses that are not removed surgically should have serial adrenal function tests performed.

Adenoma↗

Spurious elevation of plasma immunoreactive adrenocorticotropic hormone in cyclic Cushing's syndrome.

We studied a 40-year-old woman with cyclic Cushing's syndrome who demonstrated abnormal high-dose dexamethasone suppression and metyrapone stimulation tests. These results, associated with persistent elevations of plasma adrenocorticotropic hormone (ACTH) levels, suggested ectopic secretion of ACTH. Surprisingly, an adrenal adenoma with atrophy of the contralateral adrenal gland was found at exploratory laparotomy. Subsequent ACTH determinations that extract ACTH from the plasma before assay suggested that the apparent increase in ACTH concentration in our routine assay was due to the presence of an interfering substance(s). We conclude that the diagnosis of Cushing's syndrome continues to depend on a battery of adrenal function tests and radiographic procedures and recommend that measurements of ACTH be performed only after extraction of ACTH from specimens.

Adrenocorticotropic Hormone↗

Thyroid gland size in pregnancy. An ultrasound and clinical study.

We estimated the size of the thyroid gland by palpation and measured thyroid gland volume with ultrasound in the immediate postpartum period and six months after delivery in 16 women. The 13% reduction in the mean thyroid gland volume detected six months after delivery implied that the thyroid gland enlarges slightly during pregnancy. Physical examination, however, did not detect any goiters during the immediate postpartum period and did not identify a change in thyroid gland size six months after delivery. The thyroid gland enlargement that occurs during pregnancy is not large enough to be detected by physical examination. We urge physicians to discard the commonly held notion that goiter frequently develops during pregnancy.

Female↗

Hürthle cell tumors of the thyroid gland. A clinicopathologic review and long-term follow-up.

We reviewed the pathology and clinical follow-up of 26 patients with H urthle cell adenomas and three patients harboring H urthle cell carcinomas, who were treated at our medical center from 1950 to 1979. Although benign lesions could not be distinguished from malignant tumors by cytologic features alone, other pathologic features allowed differentiation. A total thyroidectomy was performed in only one patient; the remaining patients were treated by less extensive operations. None of the patients with benign adenomas, including those with tumors greater than 2 cm in diameter, experienced recurrent or metastatic disease. The period of observation varied from two to 22 years (mean, 8.5 +/- 7.7 years). We conclude that lobectomy is a satisfactory operation for removal of benign H urthle cell tumors, and reserve total or near-total thyroidectomy for cases displaying pathologic evidence of malignancy.

Adenoma↗

Peripheral resistance to thyroid hormone in a family: heterogeneity of clinical presentation.

We describe a family with thyroid hormone resistance. Juvenile Graves disease was diagnosed in the propositus, an 8-month-old boy. He was initially given propylthiouracil, and at 22 months of age underwent subtotal thyroidectomy. A diagnosis of hyperthyroidism was made in a younger sister at 3 months of age. Because of the unusual occurrence of juvenile Graves disease in two siblings, we evaluated the parents. The mother was euthyroid on physical examination and by thyroid hormone measurements. The father, although clinically euthyroid, had markedly elevated thyroid hormone values. In the three affected members, serum thyrotropin concentrations and results of thyrotropin-releasing hormone infusion tests were inappropriate for the elevated serum thyroid hormone levels. The father was given increasing doses of triiodothyronine. Complete suppression of TRH-induced TSH release did not occur until a daily dose of 300 micrograms triiodothyronine was administered. Furthermore, this large dose of T3 did not produce clinical evidence of hyperthyroidism or result in changes in his systolic ejection time intervals. This family therefore had the unusual feature of clinical heterogeneity. The two children had mainly pituitary resistance to thyroid hormone and were hyperthyroid; the euthyroid father, on the other hand, had generalized tissue resistance to thyroid hormone.

Adult↗

Serum concentrations of the iodothyronines in elderly subjects: decreased triiodothyronine (T3) and free T3 index.

In four groups of subjects free of thyroid disease, the following determinations were made: serum concentrations of thyroxine (T4), triiodothyronine (T3), reverse T3(rT3) and diiodothyronine (T2), and calculated indices of free thyroxine (FT4) and free triiodothyronine (FT3). Group A comprised healthy subjects aged 16-64; Group B, 24 healthy elderly subjects aged 68-95; Group C, 23 elderly patients with mild well-controlled chronic illnesses, aged 70-85; Group D, 40 nursing home residents aged 66-100. Serum T4 and T2 concentrations and the FT4 index were not affected by age; the rT3 concentration was slightly but significantly elevated only in Group D patients. Serum T3 concentration was significantly lower in all groups of elderly subjects and decreased FT3 index measurements were detected after age 75. It was concluded that old age, without complicating illness, is accompanied only by a decrease in the serum level of T3 and the FT3 index; values for other iodothyronines are unchanged. Clinicians should consider the age-related changes in T3 and FT3 values when interpreting thyroid function tests.

Adolescent↗

Recurrent Cushing's disease: successful treatment by pituitary irradiation or trans-sphenoidal hypophysectomy in two cases.

Two patients developed recurrent Cushing's disease 3 and 7 years after total bilateral adrenalectomy. In the first patient, a 65-year-old man, the adrenal tissue was not localized by radioactive cholesterol scintigraphy. Plain x-ray films of the skull revealed a normal sella turcica. Although clinical improvement resulted from the discontinuation of cortisone replacement therapy, urinary free cortisol levels remained elevated and the patient was treated with pituitary irradiation. Serum and urine cortisol levels gradually returned to normal. Four years after irradiation, the plasma adrenocorticotropic hormone (ACTH) concentration was elevated, but tomography of the sella turcica and urinary cortisol excretion remained normal. The second patient, a 41-year-old man, displayed elevated ACTH levels and x-ray evidence of a pituitary tumor at the time of recurrent Cushing's disease. After trans-sphenoidal hypophysectomy, the hypercortisolism abated and the ACTH concentration returned to normal. Adrenal scintigraphy frequently locates cortisol-secreting tissue in patients with recurrent Cushing's disease, and some investigators suggest treatment by the surgical removal of the adrenal remnant. Although the etiology of Cushing's disease is controversial, current evidence suggests that most cases result from ACTH-producing pituitary tumors. We suggest, therefore, that the anterior pituitary gland may be a more suitable target than the adrenal remnant for the treatment of recurrent Cushing's disease.

Adenoma↗