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Biomedical subjects

P C Carpenter

Publications and source records attributed to P C Carpenter.

At least 19 recordsLinked to original sources
PubMed1992

The Cushing syndrome induced by bronchial carcinoid tumors.

OBJECTIVES: To define the clinical spectrum of bronchial carcinoid tumors in patients presenting with the Cushing syndrome, to evaluate the role of chest radiographs and computed tomography in their diagnosis, to review the characteristic histologic features, and to determine patient outcome. DESIGN: Retrospective analysis of consecutive patients. SETTING: A referral-based medical center. PATIENTS: Fifteen consecutive patients with the Cushing syndrome evaluated at the Mayo Clinic with histologically proven bronchial carcinoid tumors. MEASUREMENTS: Clinical, radiographic, and histologic features. RESULTS: The Cushing syndrome was the initial clinical presentation, and bronchial carcinoid tumors were found later in all 15 patients. The diagnosis of carcinoid tumor was proved histologically in all cases. Ten biopsies showed typical carcinoid tumors, three were histologically atypical, and three were metastatic. Corticotropin was detected by immunostaining in seven of these tumors. Biochemical analysis showed marked elevations of circulating corticotropin with a mean serum value of 156 +/- 58 pmol/L (normal, 4 to 22 pmol/L). Additional clinical features included hypokalemia in six patients and glucocorticoid response to either high-dose dexamethasone or metyrapone in 6 of 13. These hormonally active carcinoid tumors were frequently radiographically occult, with 10 of 15 patients initially having normal chest radiographs. Computed tomography was successful in locating carcinoid tumors in five patients with negative chest radiographs evaluated after 1980. All five remaining patients with normal chest radiographs evaluated before 1980 eventually developed nodular lesions on standard chest radiography from 1 to 10 years later. Ten patients achieved complete remission and two patients, partial remission of the Cushing syndrome after surgical resection. Three patients continued to have symptomatic glucocorticoid excess due to metastatic disease. CONCLUSIONS: Although uncommon, the Cushing syndrome may be the initial clinical manifestation of an otherwise indolent bronchial carcinoid tumor. Radiographic imaging of occult lesions can be successfully accomplished with computed tomography. Surgical resection is curative in most patients with this disorder.

ACTH Syndrome, Ectopic↗
PubMed1990

Ovine corticotropin releasing hormone stimulation test: normal value study.

We determined the pituitary-adrenal response to 1 microgram/kg of ovine corticotropin releasing hormone (oCRH) administered as an intravenous bolus injection in 50 normal subjects. Brief facial flushing was noted in 44% of the subjects; no other side effects were reported. Plasma corticotropin levels increased from a median of 30.2 pg/ml at baseline to a median peak level of 77.8 pg/ml after administration of oCRH; the peak response occurred at the 30- to 45-minute or the 45- to 60-minute time point. Plasma cortisol levels increased from a median of 10.8 micrograms/dl at baseline to a median peak level of 22.0 micrograms/dl after administration of oCRH; the peak response occurred at the 45- to 60-minute time point. Plasma beta-endorphin levels increased from a median of 9.5 pg/ml at baseline to a median peak level of 23.0 pg/ml after administration of oCRH; the peak response occurred at the 15- to 30-minute or the 30- to 45-minute time point. The responsiveness to oCRH was unaffected by age, sex, or body mass index of the subjects.

Adrenocorticotropic Hormone↗
PubMed1988

Cushing's syndrome due to primary multinodular corticotrope hyperplasia.

In this report, a case of Cushing's syndrome due to primary multinodular corticotrope hyperplasia is described. The patient had typical features of Cushing's syndrome and dynamic pituitary-adrenal testing, which suggested an ectopic adrenocorticotropic hormone (ACTH) syndrome. Results of petrosal sinus catheterization indicated that the pituitary gland was the source of excess ACTH. Total hypophysectomy resulted in complete remission of Cushing's syndrome. Light microscopic and immunohistochemical studies revealed multinodular corticotrope hyperplasia. Plasma corticotropin releasing hormone (CRH) was undetectable, and computed tomography of the chest and abdomen disclosed no neoplastic source of CRH. We speculate that either an abnormality in hypothalamic CRH secretion or corticotrope hypersensitivity to CRH might have been responsible for Cushing's syndrome in this patient.

Adrenocorticotropic Hormone↗
PubMed1988

Estrogen replacement therapy: current recommendations.

Estrogen replacement therapy is effective for the prevention and treatment of postmenopausal osteoporosis and should be offered to all women at high risk for osteoporosis. Such therapy is particularly beneficial for prevention of spinal compression fractures; in addition, it alleviates menopausal symptoms (hot flushes, genitourinary symptoms, and changes in mood). In each patient, these benefits must be weighted against the potential risks of endometrial hyperplasia and carcinoma, breast tenderness, hypertension, vascular headaches, and the inconvenience of menstrual bleeding if the uterus is intact. The risk of endometrial cancer associated with estrogen replacement therapy can be considerably reduced by the addition of a progestin, and other side effects can be diminished or eliminated by use of the new transdermal estrogen preparations. Thus, estrogen replacement therapy should be considered in all women who have experienced natural or surgically induced menopause, and it is advisable in women who have osteoporosis or an increased risk for this disorder and no contra-indications to its use. Estrogen replacement therapy should be instituted as soon after menopause as possible and seems to be well tolerated until at least 75 years of age.

Aged↗
PubMed1988

Diagnostic evaluation of Cushing's syndrome.

The regulation of ACTH-cortisol production in the pathophysiology of the various forms of Cushing's syndrome is discussed. The diagnostic algorithms for the differential diagnosis of Cushing's syndrome are reviewed with emphasis on the precision of the evaluation, diagnostic pitfalls, and the influence of some of the more recently developed procedures on this diagnostic evaluation.

Cushing Syndrome↗
PubMed1986

Cushing's syndrome: update of diagnosis and management.

Although considerable advances have been made in the understanding of Cushing's syndrome in the recent past, many difficulties persist in the diagnosis and management of patients with hypercortisolism. Precision in the diagnosis of Cushing's syndrome and the differentiation of its various forms have gradually improved, but a substantial number of cases have laboratory or radiologic findings that can be misleading or at least difficult to interpret. Furthermore, other conditions may mimic Cushing's syndrome and add to the diagnostic difficulties. Surgical extirpation of primary adrenal lesions that cause the hypercortisolism or of the neoplasms responsible for the ectopic production of adrenocorticotropic hormone remains the treatment of choice for these problems. Currently, transsphenoidal surgical exploration is the treatment of choice for Cushing's disease.

Adenoma↗
PubMed1986

Lymphocytic hypophysitis with isolated corticotropin deficiency.

In a 32-year-old woman, acquired, isolated corticotropin deficiency resulted from postpartum lymphocytic hypophysitis. The literature suggests that lymphocytic hypophysitis may cause acquired deficiencies of anterior, and possibly posterior, pituitary hormones. Immunologic evaluation of our patient failed to uncover anticorticotroph antibodies. Prompt recognition of this potentially fatal condition is important because of the availability of effective treatment.

Adrenocorticotropic Hormone↗
PubMed1986

Primary pigmented nodular adrenocortical disease: diagnosis and management.

A rare cause of Cushing's syndrome appearing to originate in the adrenal glands is primary pigmented nodular adrenocortical disease (PPNAD). It may be variably associated with a complex of other pathologic characteristics that include cardiac myxomas, cutaneous myxomas, and lentigines, mammary myxoid lesions, testicular tumors, pituitary adenomas, and neuroectodermal tumors. We have reviewed the clinical, biochemical, radiographic, operative, and pathologic details of seven patients with PPNAD who have been evaluated at Mayo Clinic. Biochemical testing supported autonomous adrenal hyperfunction. This was based on the failure of cortisol suppression by high-dose dexamethasone, failure of pituitary stimulation by metyrapone administration, either normal or suppressed basal adrenocorticotropic hormone (ACTH) levels, normal radiographic studies of the sella turcica, and normal abdominal and thoracic computerized tomography in search of an ectopic ACTH-producing tumor. Six patients underwent bilateral total adrenalectomy without postoperative complications. Nelson's syndrome has not occurred, but acute adrenocortical insufficiency may have contributed to the death of one patient. To recognize the possible diagnosis of PPNAD preoperatively is important to proceed directly with adrenalectomy, avoiding unnecessary pituitary surgery. Moreover, if PPNAD is part of the broader pathologic complex, the possible presence of cardiac myxomas that may be multiple, recurrent, in atypical locations, and familial must be borne in mind.

Adolescent↗
PubMed1985

Ectopic ACTH syndrome. Diagnostic and therapeutic aspects.

Twenty-five patients were identified with non-pituitary, nonadrenal ACTH-secreting tumors (bronchial carcinoid, bronchial small cell carcinoma, pancreatic islet cell carcinoma, medullary thyroid carcinoma, thymic carcinoids, metastatic adenocarcinoma, and pancreatic cystadenoma). Clinical features were weakness, hypertension, cushingoid appearance, peripheral edema, personality disorders, and hyperpigmentation. Biochemical features were a markedly increased urinary free cortisol level (all patients), hypokalemia (71 percent of patients), and an elevated ACTH level (72 percent of patients). Surgical therapy consisted of bilateral total adrenalectomy (56 percent of patients). Twelve percent underwent transsphenoidal hypophysectomy and 36 percent had excision of their tumor. No surgical therapy was undertaken in 28 percent. Bilateral total adrenalectomy in patients with a slow-growing malignancy or an unknown tumor secreting ACTH is beneficial in relieving symptoms and prolonging life. Excision of nonmalignant ACTH-producing tumors yields an excellent long-term prognosis.

ACTH Syndrome, Ectopic↗
PubMed1985

The complex of myxomas, spotty pigmentation, and endocrine overactivity.

Of 40 patients (16 males and 24 females), 29 had cardiac myxoma(s), 14 had skin pigmentation (lentigo and several types of nevi) which also commonly affected the lips, 6 had skin myxoma(s), and 12 had both pigmentation and myxoma(s); 18 had primary pigmented nodular adrenocortical disease (Cushing syndrome was present in 11); 10 had myxoid mammary fibroadenomas; 9 had testicular tumor(s) (large-cell calcifying Sertoli cell tumor, Leydig cell tumor, or adrenocortical rest tumor, or a combination); and 4 had pituitary adenoma with gigantism or acromegaly. The maximum number of conditions present together was five, occurring in two patients; each of the remaining patients had at least two of the conditions. The overlap, in this sizeable number of patients, of various combinations of the same rare or very rare conditions unlikely to occur together by chance with any degree of frequency is striking evidence for a unique syndrome. The patients were young (mean age at diagnosis of the first component, 18 years). Pathologic involvement tended to be multicentric (heart and skin) and bilateral in paired organs (adrenal, breast, and testis). Thirteen patients (32%) are alive and well. Twelve patients are alive but with complications of cardiac myxoma (in 8), testicular tumors (in 2), residual Cushing syndrome (in 1), or bilateral pulmonary nodules (in 1). Twelve patients are dead: 9 of cardiac myxoma, 1 of intracranial (nonpituitary) tumor, and 2 postoperatively. The status of three is unknown.

Adolescent↗
PubMed1979

Human corticotropin (ACTH) radioimmunoassay with synthetic 1--24 ACTH.

A corticotropin antiserum was obtained from rabbits immunized with synthetic 1--24 corticotropin conjugated with bovine serum albumin. The antiserum did not cross react with synthetic alpha-melanotropin or with synthetic beta-endorphin and had a cross reactivity of 0.23% with human beta-lipotropin. We developed a radioimmunoassay with the antiserum obtained, in which we used polyethylene glycol in conjunction with a second precipitating antibody for fast (15-min) separation of antibody-bound and free corticotropin. The assay had a sensitivity of 16 ng/L and was validated on patients with various pituitary and adrenal diseases. From 103 normal subjects, the median value for corticotropin in specimens collected during the morning was 34 ng/L of plasma; the upper 95% confidence limit of the normal range was 98 ng/L.

Adrenal Gland Diseases↗
PubMed1979

Adrenal scintiscanning with NP-59, a new radioiodinated cholesterol agent.

Adrenal imaging in the past has been limited in its clinical application by the long interval between administration of dose and visualization of adrenal glands. We review our experience with the use of a newer labeling agent, NP-59, in 29 patients with various adrenal disorders and in 4 normal subjects. With this agent, identification of adrenal lesions is possible with a high degree of accuracy, and diagnostic information is usually available within 48 hours. NP-59 is particularly useful in evaluating primary aldosteronism and selected cases of Cushing's syndrome.

Adenoma↗
PubMed1979

Demonstration of steroid-producing gonadal tumors by external scanning with the use of NP-59.

Bilateral testicular Leydig cell tumors in a patient with Nelson's syndrome and a Leydig cell tumor of the ovary in a woman with a virilizing syndrome were successfully imaged with [6beta-131I]iodomethyl-19-norcholest-5(10)-en-3beta-ol (NP-59). Uptake by these tumors was comparable to uptake by adrenal glands in patients with funtioning adrenal tumors or bilateral hyperplasia. Scanning the gonads with NP-59 may be a helpful imaging procedure in localizing possible sites for exploratory surgery in certain cases of gonadal neoplasia.

Adosterol↗
PubMed1978

Increased adrenal sensitivity to angiotensin II in idiopathic hyperaldosteronism.

Plasma aldosterone increases briskly during upright posture in patients with idiopathic hyperaldosteronism, despite only small increases in PRA and presumably small increases in angiotensin II. To examine the postulate that small increments in angiotensin II mediate these brisk increases in aldosterone, we infused graded doses of angiotensin II into normal subjects and patients with idiopathic hyperaldosteronism and compared the changes in levels of plasma aldosterone in the two groups. Supplemental sodium and dexamethasone were given before the infusion to minimize the influence of endogenous angiotensin II and ACTH. In response to the infusion of angiotensin II, increases in the levels of plasma aldosterone of patients with idiopathic hyperaldosteronism were significantly greater than those of normal subjects. In addition, levels of plasma aldosterone increased at a lower rate of infusion of angiotensin II in patients than in normal subjects. It is concluded that patients with idiopathic hyperaldosteronism have increased adrenal sensitivity to angiotensin II. This increased sensitivity may explain the brisk increases in aldosterone that occur during upright posture in these patients.

Adrenal Glands↗
PubMed1978

Laboratory medicine. Series on clinical testing. 2. Fractionation of urinary ketosteroids. Procedure and clinical significance.

Ketosteroids, the excretory metabolities of adrenal and gonadal steroids, can be analyzed individually in urine by a simple extraction procedure followed by separation and quantitation by the use of gas/liquid chromatography. The ketosteroids quantitatively detected by the technique are androsterone, etiocholanolone, dehydroepiandrosterone, 11-hydroxyandrosterone, 11-hydroxyetiocholanolone, 11-ketandrosterone, and 11-ketoetiocholanolone. Other steroid metabolities detected are pregnanediol, pregnanetriol, delta5-pregnenetriol, and 11-ketopregnanetriol. In comparison with concentrations of these steroids observed in urine specimens collected from healthy individuals, abnormal results occur in specimens from patients with testicular disease, Cushing's syndrome, adrenal hyperplasia, and several types of female hirsutism. Characteristic profiles for each of these diseases are presented.

11-Hydroxycorticosteroids↗
PubMed1978

Transsphenoidal removal of pituitary microadenoma in Cushing's disease.

Twenty-two of 32 patients with Cushing's disease seen at the Mayo Clinic during a 3-year period were carefully studied radiologically (triaxial spiral tomograms of the sella and bilateral carotid arteriograms with magnification and subtraction techniques). Eighteen of these 22 pat-ents had radiologic evidence of small pituitary gland tumors and underwent transsphenoidal microsurgical exploration of the pituitary. A microadenoma (less than 10 mm) was found in 17 of the 18 patients. Hypercortisolism was corrected, and a clinical remission occurred in 16 of the 18 patients; the hypercortisolism persisted in 2 patients. A period of hypocortisolism occurred after removal of the pituitary tumor in all patients who experienced a remission. Remissions have been associated with normal anterior pituitary and adrenocortical function in a large percentage of patients who were adequately studied 6 months or more after pituitary surgery.

Adenoma↗
PubMed1976

Isolation, determination of structure and synthesis of the acid-labile conjugate of aldosterone.

1. After administration of 600mg of 3H-labelled aldosterone to human volunteers, 57 mg of homogeneous acid-labile conjugate was isolated from the urine and identified as aldosterone 18 beta-D-glucosiduronic acid. 2. Esterification and acetylation of the conjugate gave a tetra-acetate methyl ester, which, by measurement of the optical rotation and nuclear-magnetic-resonance spectrum, was shown to be a beta-glucosiduronate. This tetra-acetate methyl ester was synthesized in approx. 10% yield by the Koenigs-Knorr procedure. 3. Removal of the acetyl and methyl ester groups from the tetra-acetate methyl ester with alkali was accompanied by almost complete isomerization at C-17 to give 17-isoaldosterone 18 beta-D-glucosiduronic acid. 4. To prevent inversion at C-17 during removal of the acetate and ester groups of beta-glucosiduronate (a) the 3,20-disemicarbazone was prepared, (b) the acetate and ester groups were removed from the disemicarbazone by treatment with alkali, and (c) the semicarbazone groups were removed from the product at pH 2.0, and aldosterone 18 beta-D-glucosiduronic acid was obtained in 47% overall yield. 5. In the presence of components used to synthesize beta-glucosiduronate by the Koenigs-Knorr reaction this substance is converted slowly into the alpha-glucosiduronate; this conversion is responsible, in part, for the low yield of beta-glucosiduronate. 6. Two additional conjugates were obtained in the Koenigs-Knorr reaction; a provisional structure was assigned to one substrate. The other substance is a C-18 alpha-glucosiduronate. Removal of the acetyl and ester groups from C-18 alpha-glucosiduronate gave the alpha-glucosiduronic acid in 84% yield and the 17-isoaldosterone alpha-glucosiduronic acid in 12% yield. 7. The rate at which several types of beta-glucuronidase hydrolyse the foregoing steroidal alpha- and beta-glucosiduronic acids is given.

Aldosterone↗