Pharmacokinetics of the thymidine analog 2'-fluoro-5-[(14)C]-methyl-1-beta-D-arabinofuranosyluracil ([(14)C]FMAU) in rat prostate tumor cells.

2'-Fluoro-5-[(14)C]-methyl-1-beta-D-arabinofuranosyluracil (FMAU) is an analog of thymidine (TdR) that is resistant to catabolism, is incorporated into DNA, and has been labeled with (11)C for use with positron emission tomography. We compared the uptake and metabolism of [(14)C]FMAU with that of [(3)H]TdR in fast- and slow-growing cell lines of a rat prostate tumor. Although FMAU was incorporated much less rapidly than TdR, FMAU behaved very similarly to TdR with respect to correlation between uptake velocity and cell growth rate, saturability of cellular incorporation, and intracellular metabolite pools. Thus, FMAU warrants further evaluation as an in vivo indicator of tumor cell division.

Postoperative acute pulmonary edema: a rare presentation of pheochromocytoma.

A 39-year-old white female underwent an uneventful vaginal hysterectomy for dysfunctional bleeding. Evaluating a mild aortic insufficiency murmur preoperatively an echocardiogram revealed normal left ventricular wall motion and function. Postoperatively the patient developed severe abdominal pain, acute hypertension (200/100 mmHg), and sinus tachycardia. Within minutes she decompensated into acute pulmonary edema. ECG demonstrated acute ST segment elevation in the precordial leads consistent with acute infarction. Emergency left heart catheterization showed normal coronary vessels with severe left ventricular dysfunction. An abdominal ultrasound was obtained, revealing a right adrenal mass. Plasma epinephrine was 334, norepinephrine 34,543 pg/ml; urine epinephrine 45, urine norepinephrine 2,137 micrograms/24 hours. She was started on prazosin and nifedipine sustained release with good blood pressure control. Four days later, an echocardiogram demonstrated the left ventricular wall motion reverting to normal. The adrenal tumor was subsequently resected successfully. Acute pulmonary edema causing dilated cardiomyopathy is a rare complication of pheochromocytoma that has been seldomly reported. A progressive fatal course is common: reversibility and survival depend on identifying and removing the pheochromocytoma.

Prolonged suppression of a corticotropin-producing bronchial carcinoid by oral bromocriptine.

The addition of orally administered bromocriptine mesylate to cyproheptadine hydrochloride therapy completely normalized urinary-free cortisol levels for three months in a 21-year-old woman with Cushing's syndrome in whom results from standard dexamethasone suppression and metyrapone stimulation tests as well as baseline corticotropin levels were originally compatible with a diagnosis of an occult pituitary adenoma. When transsphenoidal exploration of the sella turcica was unsuccessful and hypercortisolism persisted, the source of corticotropin was discovered using petrosal sinus and venal caval catheterization. A 1 X 1.5-cm carcinoid tumor of the lung was identified and removed, thereby correcting the hypercortisolism. The tumor was demonstrated by immunoperoxidase staining to contain corticotropin. Orally administered bromocriptine, with or without cyproheptadine therapy, may be useful in the palliative treatment of some patients with carcinoid or other ectopic corticotropin-producing tumors. We postulate that bromocriptine therapy acted directly on carcinoid tumor cells to directly inhibit corticotropin production by a dopaminergic mechanism.