Adrenocortical SPECT using iodine-131 NP-59.

Adrenal scintigraphy with 131I-labeled 6-beta-iodomethyl-19-norcholesterol (NP-59) is a technically demanding and complex procedure. However, it can provide crucial and unique information about the functional status of the adrenal glands and guide the appropriate therapeutic management of patients with biochemically proven disease. Since the introduction of this new investigational drug, scintigraphic imaging has been performed using conventional planar techniques. We present an interesting case of primary aldosteronism in which planar scintigraphy and SPECT were combined in an attempt to increase the sensitivity of the study. SPECT revealed scintigraphic evidence of bilateral adrenocortical hyperplasia. Interestingly, the CT scan of this patient showed only an equivocal abnormality in the left adrenal gland, suggestive of an adenoma.

Adrenal crisis in active duty service members.

Primary adrenal insufficiency is a chronic, debilitating condition that usually produces a variety of characteristic but non-specific clinical features. Up to 25% of patients present instead with acute life-threatening adrenal crisis, marked by severe hypotension and shock. Recognition of the disease in the chronic indolent phase is critical because adrenal steroid replacement effectively relieves symptoms and prevents the development of most acute crises. To illustrate these points, we describe four case histories in which the manifestations of chronic adrenal insufficiency went unrecognized in active duty service members until they presented with near-fatal adrenal crises. The salient clinical features, diagnosis, and treatment of the disease are also reviewed.

Trial of pentoxifylline for diabetic impotence.

OBJECTIVE: To test the effectiveness of pentoxifylline as a therapy for diabetic impotence. RESEARCH DESIGN AND METHODS: A 3-month placebo-controlled double-blind treatment study was conducted at a single center. Therapeutic response was assessed subjectively by serial self-appraisals of erectile function and objectively by nocturnal penile tumescence (NPT) monitoring. RESULTS: This cohort of impotent diabetic men displayed substantial neurological and penile vascular dysfunction. Age, body mass index, duration of diabetes, duration of impotence, glycemic control, mode of therapy for non-insulin-dependent diabetes, mean testosterone, mean prolactin, and penile brachial indexes were similar in the treatment (n = 34) and placebo groups (n = 26). NPT monitoring revealed infrequent erectile events, diminished average rigidity, and decreased tumescence. Pentoxifylline did not alter overall glycemic control and did not improve neurological, vascular, or erectile function. In fact, a slight decrease in average percent rigidity from 22 +/- 3 to 17 +/- 2% (mean +/- SE, P < 0.05) was observed in the pentoxifylline-treated group. Although eight (24%) pentoxifylline-treated and five (19%) placebo-treated men reported benefit, no objective improvement was observed in nocturnal tumescence. CONCLUSIONS: Pentoxifylline is not an effective treatment for diabetic erectile dysfunction.

Thyroid adaptation to chronic tetraglycine hydroperiodide water purification tablet use.

Tetraglycine hydroperiodide tablets purify water by liberating 8 mg free iodine/tablet. The effects of ingesting four tablets daily for 3 months on thyroid size, function, and radioactive iodine uptake were studied prospectively in eight healthy volunteers. Serum inorganic iodide increased from 2.7 to approximately 100 micrograms/dL. Urinary iodide excretion rose 150-fold from a pretreatment mean of 0.276 to 40 mg/day. Radioactive iodine uptake was less than 2% after 7 days and remained below 2% in all subjects at 90 days. Mean serum T4 and T3 declined after 7 days. T4 remained below baseline, whereas T3 had recovered by the end of the treatment period. Serum TSH and the TSH response to TRH rose significantly after 7 days and remained elevated at 3 months. The average thyroid volume, determined by ultrasound, increased by 37%. Neither hyperthyroidism nor hypothyroidism was observed. The mean thyroid volume in seven subjects available for repeat determinations an average of 7.1 months after the study was not different from the baseline value. In normal subjects, a reversible TSH-dependent thyroid enlargement occurs in response to the iodine load from daily use of tetraglycine hydroperiodide water purification tablets.

An iodine load from water-purification tablets alters thyroid function in humans.

Tablets containing tetraglycine hydroperiodide are used to purify small quantities of water for drinking. Because short-term administration of stable iodide can alter thyroid function in normal adults, we evaluated the effects of these tablets on thyroid function during a military field training exercise. Fourteen normal volunteers participated in the study. After an adjustment period of 2 weeks to the field environment, half of the subjects received four dissolved water-purification tablets (32 mg free iodine) daily for 7 consecutive days while the other half served as controls. At the end of the study the treatment group showed reductions in the mean serum levels of thyroxine (14%) and total triiodothyronine (15%) and significant increments in basal thyrotropin (TSH) (122%) and the TSH response to thyrotropin-releasing hormone (49%) compared to baseline values. The basal TSH level rose above the normal range in two subjects. No significant changes in any parameter of thyroid function were observed in the control subjects. One week of daily exposure to the iodine load from four tetraglycine hydroperiodide water-purification tablets causes mild impairment of thyroid function in humans.

Failure of cimetidine to reduce postoperative hypocalcemia in patients with primary hyperparathyroidism undergoing neck exploratory operation.

BACKGROUND: Although use of histamine H2 antagonists for chronic treatment of primary hyperparathyroidism (PHP) is ineffective, pretreatment with cimetidine has been reported to reduce the incidence of postoperative hypocalcemia in patients with PHP undergoing neck exploratory operation. The current investigation was conducted to determine the validity of this assertion. METHODS: In a randomized, double-blind, placebo-controlled trial, 20 patients with PHP were treated with either cimetidine or placebo for 10 to 14 days before neck exploratory operation. Clinical outcome and biochemical indexes before and after drug treatment in both groups were compared. RESULTS: Cimetidine treatment resulted in a modest increase in preoperative parathyroid hormone level but did not affect any other parameter, including serum calcium level or renal tubular reabsorption of phosphate. Intraoperative time was similar in both groups. Mean postoperative calcium nadir was identical regardless of therapy (8.3 mg/dl), and seven (70%) patients from each group had at least one serum calcium measurement less than 8.5 mg/dl. CONCLUSIONS: Cimetidine treatment before neck exploratory operation for PHP does not diminish the frequency or severity of postoperative hypocalcemia.

Effect of cold remedies on metabolic control of NIDDM.

OBJECTIVE: To compare the effects of two cough syrup formulations (one with sugar and alcohol and one without) on the metabolic control of NIDDM. RESEARCH DESIGN AND METHODS: A prospective, blinded cross-over study was performed at the Endocrinology Clinic of a U.S. Army Medical Center on 20 volunteers with NIDDM, treated with diet alone or diet plus an oral hypoglycemic agent. After a 7-day lead-in period, patients took 3-day courses of each cough syrup (10 ml 4 times/day) with an intervening 4-day wash-out period. Fasting and postprandial blood glucose and lipids before and immediately after each course were compared. RESULTS: No differences in pretherapy and posttherapy values were found with either formula. Values taken after the sugar- and alcohol-containing formula were not different from those taken after the alcohol- and sugar-free formula. CONCLUSIONS: We conclude that patients with NIDDM can take standard daytime cough formulas, in short courses of standard doses, without adverse effect on blood glucose or lipids.

Densely calcified adrenals with preserved cortical function.

A patient with preserved adrenocortical function despite densely calcified adrenals is described. Similar cases have demonstrated a discrepancy between the apparent destruction of the glands, as judged by the extent of calcification radiographically, and their functional integrity. This case provided a unique opportunity to compare the results of adrenal function testing, adrenal appearance by computed tomograms, and adrenal histology with an actual clinical response to a variety of stresses capable of precipitating acute adrenal insufficiency.

Clinically silent congenital adrenal hyperplasia masquerading as ectopic adrenocorticotropic hormone syndrome.

A 64-year-old man with an asymptomatic pulmonary mass discovered on routine chest roentgenography was found to have substantial bilateral adrenal enlargement by abdominal computed tomography. Percutaneous adrenal aspiration biopsy showed cytologically normal adrenal glands. A diagnosis of subclinical 21-hydroxylase deficiency was established by stimulation testing with adrenocorticotropic hormone. The adrenal size and appearance by computed tomographic scanning in congenital adrenal hyperplasia and particularly in its subclinical form have not been well defined. This case demonstrates that marked adrenal enlargement can occur and may provide the only clue to the diagnosis in an asymptomatic patient without other clinical stigmata of adrenal hyperplasia.

Resolution of recurrent thyroid cysts with tetracycline instillation.

Nine patients with recurrent purely cystic thyroid nodules after one or two previous cyst aspirations were treated with repeat cyst aspiration and instillation of intracystic tetracycline hydrochloride. All but two of the patients' cysts resolved completely and have not recurred after a follow-up period of 12 to 50 months (mean = 40). The remaining patients had a partial response that left them with clinically insignificant lesions. The procedure was well tolerated and obviated the need for further therapy in all patients. Cyst aspiration and tetracycline instillation is a safe and effective treatment of recurrent purely cystic thyroid nodules that eliminates the need for surgical excision.

Gonadotrophin releasing hormone provokes prolactin release in hypergonadotrophic hypogonadal women: a response not altered by dexamethasone.

The prolactin response to 100 micrograms of intravenous gonadotrophin releasing hormone was studied in seven hypergonadotrophic hypogonadal and four eugonadal women. Prolactin rose from a mean basal level of 7.3 +/- 1.6 ng/ml to a mean peak level of 20.8 +/- 5.2 ng/ml in the hypogonadal women, and did not change significantly from a mean basal level of 7.7 +/- 1.2 ng/ml in the eugonadal women. Dexamethasone suppression did not alter the gonadotrophin or prolactin response to GnRH. Hypergonadotrophic hypogonadal women, like some patients with acromegaly, anorexia nervosa, and anovulatory disorders, show an augmented release of prolactin after GnRH administration.