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Biomedical subjects

A L Barbato

Publications and source records attributed to A L Barbato.

16 recordsLinked to original sources
PubMed1990

Acquired partial corticosterone methyl oxidase type II defect in diabetes mellitus. Case of hyperreninemic hypoaldosteronism.

The aim of this study was to investigate the pathogenesis of hypoaldosteronism in diabetes. Endogenous elevation of plasma renin activity and exogenous corticotropin were used to study steroidogenesis. Observations were made over 12 yr on the evolution and treatment of hyperkalemia in a diabetic subject. In 1977, potassium, baseline cortisol, aldosterone, and renin activity were normal; renin activity increased normally with posture; and cortisol responded normally to ACTH infusion. Nine yr later, persistent hyperkalemia was documented. Upright renin activity was elevated to 5.26 ng.L-1.s-1, with concomitant elevation of 18-hydroxycorticosterone (18-OHB) and a low-normal aldosterone level. One hour after administration of 0.25 mg i.m. cosyntropin, cortisol increased normally, aldosterone increased from 220 to 360 pM, and 18-OHB increased from 3700 to 4800 pM. During treatment with fludrocortisone, fludrocortisone with furosemide, and furosemide alone, improvement of hyperkalemia was noted. Endogenous hyperreninemia and basal elevations of 18-OHB, accompanied by limited aldosterone responsiveness to renin and ACTH, suggest the presence of a partial corticosterone methyl oxidase type II defect. Evolution of hyperkalemia between 1977 and 1986 suggests this defect was acquired.

18-Hydroxycorticosterone↗
PubMed1989

Selective postoperative radioactive iodine treatment of thyroid carcinoma.

In a consecutive series of 234 patients with differentiated thyroid carcinoma of follicular cell origin (Hürthle cell tumors excluded), a radioactive iodine (131I) scan was obtained 3 to 6 months after thyroidectomy and 4 weeks after cessation of thyroid hormone treatments, only if extrathyroidal tumor extension or nodal or distant metastases were present. Twenty-one patients (9%) with 131I uptake of 3% or more (group 1) were treated with 150 to 200 mCi of 131I. Forty-four patients (19%) with less than 3% uptake (group 2) and 169 patients (72%) without evidence of metastases or extrathyroidal spread (group 3) were treated only with thyroid hormone. All patients initially underwent total thyroidectomy and modified neck dissection if cervical lymph node metastases were present. Three patients in group 1 and one patient in group 2 had recurrent tumor with a mean follow-up of 8.9 and 8.4 years. There were no recurrences in group 3 with a mean follow-up of 7.2 years. Death rate from thyroid carcinoma was 5% in group 1 (one patient) and 0% in groups 2 and 3. In conclusion, 131I scanning and therapy may be omitted in patients with differentiated thyroid carcinoma in the absence of local tumor extension or regional or distant metastases. Therapy with 131I is not demonstrated to be of benefit in this population of patients.

Adenocarcinoma↗
PubMed1988

Synthesis and secretion of insulin-like growth factor II by a leiomyosarcoma with associated hypoglycemia.

We describe a case of recurrent hypoglycemia apparently caused by secretion of insulin-like growth factor II (IGF-II) by a leiomyosarcoma. A 67-year-old woman presented with recurrent severe hypoglycemia and a large mass in the thorax. During hypoglycemia, plasma cortisol was elevated, but insulin and growth hormone levels were low. After resection of a large leiomyosarcoma, the hypoglycemia resolved. After an eight-year remission, both the tumor and symptomatic hypoglycemia recurred. During a second operation a second large tumor was removed, with relief of the patient's hypoglycemia. The tumor contained high concentrations of IGF-II mRNA and 2100 ng of IGF-II immunoreactive peptide per gram. Filtration through a BioGel P-60 gel column established that 77 percent of the IGF-II was present as a larger molecule, demonstrating incomplete processing of the pro-IGF-II peptides. A similar fraction of high-molecular-weight IGF-II was present in the serum, indicating that the tumor was the chief source of IGF-II. The high-molecular-weight IGF-II found in both the tumor and serum was fully reactive with the IGF-II receptor. Radioimmunoassay showed that the concentrations of insulin-like growth factor I (IGF-I) in tumor and serum were low, suggesting feedback inhibition of growth hormone secretion by IGF-II. Eight months after reoperation, plasma concentrations of IGF-I and IGF-II were normal, and high-molecular-weight IGF-II was virtually undetectable. We conclude that the most likely cause of this patient's recurrent hypoglycemia was IGF-II produced by the leiomyosarcoma.

Aged↗
PubMed1988

Plasma catecholamine changes during excision of pheochromocytoma.

Sequential changes in plasma norepinephrine (NE) and epinephrine (EPI) concentration were correlated with changes in blood pressure and cardiac rate in 14 patients undergoing surgery because of pheochromocytoma. All patients had elevated preoperative plasma catecholamine levels that increased during induction of anesthesia, intubation, and skin incision, but mean values did not become significantly higher than preoperative values until tumor manipulation. Episodes of hypertension were associated with increased plasma catecholamine levels, and plasma catecholamine levels and blood pressure decreased dramatically after tumor resection. NE and EPI were usually secreted simultaneously, but release of either NE or EPI alone occurred on some occasions. There were marked variations in the concentration ratio of NE to EPI in plasma at different periods of observation, which suggests that pheochromocytomas release varying amounts of catecholamines in a random fashion. Studies of the effect of the duration of preoperative preparation on intraoperative blood pressure, pulse rate, and cardiac arrhythmias failed to demonstrate that treatment for 14 days or longer was more effective than treatment for 4 to 7 days. Neither the brief nor the prolonged period of therapy prevented development of severe hypertension during tumor manipulation.

Adolescent↗
PubMed1983

Fine needle aspiration biopsy of thyroid nodules.

The clinical value of the fine needle aspiration of thyroid nodules was evaluated by comparing preoperative cytology to subsequent pathology in 109 patients undergoing thyroidectomy. Preoperative cytology was reported as insufficient cellular material (31 patients), benign goiter (27 patients), follicular neoplasm (22 patients), thyroiditis (12 patients), suspicious for papillary carcinoma (nine patients), Hurthle cell neoplasm (five patients), medullary carcinoma (one patient), lymphoma (one patient), and metastatic adenocarcinoma (one patient). Operative findings demonstrated that the overall sensitivity of fine needle aspiration in diagnosing thyroid neoplasia (carcinoma or adenoma) was 88% and its specificity was 80%. Operation verified the cytologic diagnosis of medullary carcinoma, lymphoma, metastatic adenocarcinoma, and seven of nine papillary carcinomas. Of the five patients with an aspiration biopsy diagnosis of Hurthle cell neoplasm, three patients had carcinoma and one had an adenoma. Four carcinomas and 12 follicular adenomas were found in patients with a cytologic diagnosis of follicular neoplasm. Thyroiditis was confirmed at operation in all 12 patients with this diagnosis on fine needle aspiration. One carcinoma was found in the 27 patients with benign goiter diagnosed on cytology. Fine needle aspiration is a valuable tool that can lead to earlier diagnosis and treatment of thyroid cancer. However, a negative aspiration does not supplant good clinical judgement in determining the need for thyroidectomy.

Adenocarcinoma↗
PubMed1982

Prior irradiation and the development of coexistent differentiated thyroid cancer and hyperparathyroidism.

Twelve patients with coexistent well-differentiated thyroid carcinoma and primary hyperparathyoidism were studied to determine the frequency of previous radiation exposure. Eight were found to have received prior irradiation. External radiation was administered to the head and neck region for benign conditions such as tonsillar enlargement, acne, scrofula, and thyroid enlargement. One patient received 131I therapy for carcinoma of the thyroid. The observation that 67% of the patients in this series had previous radiation to the head and neck strongly implicates radiation exposure in the development of coexistent well-differentiated thyroid carcinoma and hyperparathyroidism.

Adult↗
PubMed1982

Simultaneous primary hyperparathyroidism and nodular thyroid disease.

Of 351 patients treated for primary hyperparathyroidism from 1966 to 1981, 70 (20%) had grossly evident nodular thyroid disease at the time of subtotal parathyroidectomy. These patients have been reviewed to determine if prior radiation exposure may play a role in their coexistence and if combined subtotal parathyroidectomy and thyroidectomy are safe and efficacious. Thirty-three of the 70 patients (47%) had received prior radiation therapy for benign conditions of the head and neck. Nine of 15 patients with nonmedullary thyroid carcinoma had received previous irradiation. In addition to subtotal parathyroidectomy, 28 patients underwent total thyroidectomy, 14 underwent bilateral subtotal thyroidectomy, and 28 underwent unilateral lobectomy. There were no deaths and no permanent recurrent laryngeal nerve injury from combined subtotal parathyroidectomy and thyroidectomy. Two patients in whom parathyroid tissue was not autotransplanted required calcium and vitamin D supplementation. This study shows that (1) primary hyperparathyroidism and nodular thyroid disease occur simultaneously with sufficient frequency to warrant careful preoperative and intraoperative evaluation of both glands, (2) radiation probably does play a role in the pathogenesis of coexistent primary hyperparathyroidism and nodular thyroid disease, and (3) in experienced hands combined subtotal parathyroidectomy and thyroidectomy can be safely performed.

Adenoma↗
PubMed1981

Familial thyroid hormone resistance.

Eight patients with thyroid hormone resistance were found in four generations of a kindred containing 19 members. Results of studies in this family are consistent with an autosomal dominant mode of inheritance for this disorder. The affected family members were clinically euthyroid but all had goiters and markedly increased serum thyroid hormone levels: thyroxine (T4) = 21.1 +/- 2.1 microgram/dl; triiodothyronine (T3) = 323 +/- 60 ng/dl; free T4 = 5.4 +/- 0.9 ng/dl; and free T3 = 1,134 +/- 356 pg/dl (mean +/- SD). Serum thyrotropin (TSH) levels were normal or slightly elevated in six patients and responded normally to the administration of thyrotropin-releasing hormone (TRH) and L-triiodothyronine. Two patients who had previously undergone subtotal thyroidectomy had elevated baseline serum TSH levels and exaggerated TSH responses to the administration of TRH suggesting subclinical hypothyroidism despite elevated total and free thyroid hormone levels. The absence of thyrotoxicosis and normal serum TSH levels despite elevated serum free T3 and T4 levels in the untreated members of this family are consistent with resistance of pituitary and peripheral tissues to the actions of thyroid hormones. In addition, the absence of hypothyroidism and normal responsiveness of serum TSH to TRH and L-triiodothyronine administration in untreated family members suggest that the thyroid has compensated for the hormone resistance by increased secretory activity under the control of pituitary TSH secretion.

Adolescent↗
PubMed1981

Unexpected parathyroid disease discovered at thyroidectomy in irradiated patients.

Eight of 23 patients undergoing total thyroidectomy for radiation-associated nodular thyroid disease were found to have unsuspected parathyroid hyperplasia or adenoma at operation. The total serum calcium level was normal preoperatively in each patient. Serum ionized calcium and parathyroid hormone levels were measured in five patients preoperatively and were normal in each case. These pathologic findings in normocalcemic patients may represent a preclinical form of hyperparathyroidism, which would be further evidence linking radiation to the pathogenesis of hyperparathyroidism. The parathyroid glands should be evaluated both pre-operatively and at operation in all patients who have a history of radiation and require thyroidectomy.

Adenoma↗
PubMed1978

Anorexia nervosa.

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Adolescent↗
PubMed1977

Serum cortisol appearance-disappearance in adrenal insufficiency after oral cortisone acetate.

Six patients with long-standing idiopathic primary adrenal insufficiency were given 25 mg of cortisone acetate orally on two occasions. Circulating serum cortisol levels were determined hourly for five hours after ingestion. Two patients were additionally studied with an oral dose of 20 mg of cortisol. Marked patient to patient variation in peak hormone and in fifth hour hormone levels was observed. Both values were lowest in the two chronically symptomatic patients who had been maintained on empiric glucocorticoid replacement. Specific information on blood cortisol levels in treated Addisonian individuals has not been previously reported.

Addison Disease↗