Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0007095 (carcinoid)
 6,990 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

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.
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PMID:Prolonged suppression of a corticotropin-producing bronchial carcinoid by oral bromocriptine. 303 81

According to modern knowledge, acromegaly can develop in at least three ways. A pituitary adenoma with growth hormone overproduction is the most frequent. Much rarer is ectopic growth hormone secretion by extra-hypophyseal tumors. A further possibility is the production of growth hormone releasing factor (GRF) by hypothalamic or ectopic tumors. This involves the secretion of a substance which selectively stimulates the GH producing cells of the pituitary. Special features of the clinical and morphological picture of this condition are described, based on the authors own observations. Two patients developed acromegaly: one had a retroperitoneal paraganglioma and the other a bronchial carcinoid. Ectopic GRF secretion could be confirmed radioimmunologically and immunohistologically in both cases. As a result of the on-going, tumor related GRF stimulation the patients developed nodular or diffuse GH-cell hyperplasia in the adenohypophysis. Since ectopic GH secretion does not cause hyperplasia of the adenohypophyseal cells, morphologic examination of the hypophysis can contribute to the differential diagnosis in such cases.
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PMID:[New aspects of the pathogenesis of acromegaly-somatoliberinomas]. 308 70

Five corticotropin-producing tumours were examined for peptides related to the corticotropin-beta-lipotropin precursor. Two were basophil pituitary adenomas and three were bronchial carcinoids. The cells of the two pituitary adenomas stained with antisera against beta-endorphin and against pro-gamma-melanotropin, the NH2-terminal fragment of the corticotropin-beta-lipotropin precursor, but not with antisera against alpha-melanotropin or beta-lipotropin. The corticotropin-storing tumor cells of the bronchial carcinoids stained with antisera against beta-endorphin, beta-lipotropin or pro-gamma-melanotropin. Only one of the three bronchial carcinoids contained cells reacting with the antiserum against alpha-melanotropin. Although the two types of corticotropin-storing tumours (pituitary adenoma and bronchial carcinoid) differed with respect to beta-lipotropin content, the over-all picture indicates that the proteolytic processing of the corticotropin precursor proceeds along similar lines in tumour cells and in pituitary corticotrophs. An acetic acid extract of one of the bronchial tumours was subjected to gel chromatography and immunochemical analysis of material related to pro-gamma-melanotropin. The immunoreactive material displayed a considerable size heterogeneity, with the predominant components having a molecular weight larger than that of authentic pro-gamma-melanotropin.
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PMID:Evidence for the presence of pro-gamma-melanotropin, the NH2-terminal fragment of the corticotropin-beta-lipotropin precursor, in corticotropin-producing tumours. 627 99

This report describes the histologic, immunocytochemical, and ultrastructural study of a multihormonal carcinoid tumor of the pancreas, secreting a growth hormone releasing factor (GRF) which provoked acromegaly. The patient presented a nonfamilial multiple endocrine neoplasia, type 1. The absence of radiologic signs of a pituitary adenoma in conjunction with elevated plasma levels of pancreatic polypeptide, glucagon, somatostatin, as well as growth hormone (GH), led to the discovery of the tumor. Its surgical excision produced a rapid disappearance of most of the clinical and biologic disorders. No immunoreactive GH was found in the tumor using radioimmunoassay and immunocytochemistry. In contrast, three peptides with GH-releasing activity were extracted and characterized. Immunocytochemistry showed that the GRF-reactive cells, together with rare somatostatin-storing cells, made up areas which demonstrated a medullary pattern of growth with extracellular amyloid deposits. Under electron microscopic examination, actively secreting cells were observed which carried endocrine granules of 100 to 150 nm in diameter. The other regions of the tumor presented a different type of growth and were composed of pancreatic polypeptide-, glucagon-, or somatostatin-reacting cells. Cells immunostained with antisera raised against beta-endorphin were also noted. These data suggest that GRF may be a new biologic marker for pancreatic endocrine tumors.
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PMID:Multihormonal carcinoid tumor of the pancreas. Secreting growth hormone-releasing factor as a cause of acromegaly. 643 52

A parathyroid adenoma occurred synchronously with a thymic carcinoid tumor in a 34-year-old man. A sibling was known to have an insulinoma, pituitary adenoma, and parathyroid hyperplasia. The simultaneous occurrence of these tumors, in association with the noted family history, suggests a possible multiple endocrine adenomatosis variant. A description of both tumors is provided along with a review of the literature on thymic carcinoid tumors.
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PMID:Carcinoid tumor of the thymus associated with a parathyroid adenoma. 707 13

Inferior petrosal sinus sampling (IPSS) for adrenocorticotropic hormone (ACTH) levels in patients with Cushing's syndrome has become a useful method to distinguish ACTH-secreting pituitary tumors (Cushing's disease) from other causes of the syndrome, principally ectopic adrenocorticotropin secretion by an occult tumor. Although the test is generally regarded as highly specific, the authors recently encountered two patients whose IPSS measurements were false-positive for Cushing's disease. The results of IPSS suggested a pituitary origin of ACTH secretion in both patients, but transsphenoidal surgery failed to disclose a pituitary adenoma or to improve postoperative plasma cortisol levels. Both patients subsequently were found to have an ACTH-secreting carcinoid tumor of the lung. The false-positive IPSS studies were due to periodic hormonogenesis. The patients must be hypercortisolemic at the time IPSS is performed for the study to be valid.
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PMID:False-positive inferior petrosal sinus sampling in the diagnosis of Cushing's disease. Report of two cases. 749 Jun 27

Twenty-six consecutive patients with ACTH-dependent Cushing syndrome were subjected to simultaneous, bilateral inferior petrosal sinus sampling for ACTH assay before and after ACTH-releasing hormone (CRH) stimulation. The baseline ACTH inferior petrosal sinus/periphery (IPS/P) ratio was > or = 2 in 12 of 26 patients (46%), whereas the CRH-stimulated IPS/P ratio was > or = 3 in 19 of 26 patients (73%). A pituitary adenoma, ACTH-secreting at immunostaining, was surgically proved in all of the 19 patients who had an ACTH IPS/P ratio > or = 2 basally or > or = 3 after the CRH test but also in three other patients who did not have such ratios. The value of the basal IPS/P ratio and the complete lack of ACTH increase after CRH led to the diagnosis of an ectopic ACTH syndrome in four patients: a bronchial carcinoid was found in three patients, and the site of the tumor was still unknown in the other. In conclusion, the CRH test improved the diagnostic accuracy of inferior petrosal sinus sampling from 61.5% (12 pituitary, 4 ectopic) to 92.0% (19 pituitary, 4 ectopic). Thus it should be performed during the diagnostic process.
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PMID:Corticotropin-releasing hormone test: improvement of the diagnostic accuracy of simultaneous and bilateral inferior petrosal sinus sampling in patients with Cushing syndrome. 774 Aug 3

To differentiate between ectopic ACTH syndrome and Cushing's disease, we examined the gene expression of CRF, POMC and glucocorticoid receptor in pituitary adenomas and in ectopic ACTH-producing tumors. CRF increased plasma ACTH levels in all patients with Cushing's disease and in some patients with ectopic ACTH syndrome whose tumors contained CRF and CRF mRNA. In CRF non-responders, no CRF was detected in tumors that contained no CRF mRNA or contained only long-size CRF mRNA. Dexamethasone (Dex) decreased plasma ACTH levels in all patients with Cushing's disease and in the patients with ectopic ACTH-producing bronchial carcinoid. These tumors contained glucocorticoid receptor mRNA. CRF increased and Dex decreased ACTH release and POMC mRNA levels in pituitary adenoma and bronchial carcinoid cells. PMA increased POMC mRNA levels only in carcinoid cells. These results reveal characteristics of ectopic ACTH-producing tumors: long-size CRF mRNA, PMA-induced POMC gene expression, two ectopic ACTH syndrome subtypes (tumors containing ACTH with CRF and tumors without CRF), and Dex-induced decrease in ACTH release and POMC mRNA levels in some bronchial carcinoid.
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PMID:[Synthesis and release of CRF and ACTH in ectopic CRF/ACTH-producing tumors]. 795 79

To differentiate between ectopic ACTH syndrome and Cushing's disease, gene expression of corticotropin-releasing hormone (CRH), proopiomelanocortin (POMC), and glucocorticoid receptor was examined in 10 pituitary adenomas (Cushing's disease) and in 10 ectopic ACTH-producing tumors. CRH increased plasma ACTH levels in all patients with Cushing's disease and in five patients with ectopic ACTH syndrome whose tumors contained CRH and CRH mRNA. In five CRH nonresponders, CRH was not detected in tumors that contained no CRH mRNA or that contained only long-size CRH mRNA. Dexamethasone (Dex) decreased plasma ACTH levels in all patients with Cushing's disease and in three patients with ectopic ACTH-producing bronchial carcinoid. These tumors contained glucocorticoid receptor mRNA. CRH increased and Dex decreased ACTH release and POMC mRNA levels in pituitary adenoma and bronchial carcinoid cells. PMA increased POMC mRNA levels only in carcinoid cells. These results reveal characteristics of ectopic ACTH-producing tumors: long-size CRH mRNA and PMA-induced POMC gene expression. In addition, there are two ectopic ACTH syndrome subtypes: tumors containing ACTH with CRH (CRH responder) and tumors without CRH. Dex decreases ACTH release and POMC mRNA levels in some bronchial carcinoids. Therefore, CRH and Dex tests have limited usefulness in differentiating between Cushing's disease and ectopic ACTH syndrome.
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PMID:Corticotropin-releasing hormone, proopiomelanocortin, and glucocorticoid receptor gene expression in adrenocorticotropin-producing tumors in vitro. 825 33

A 44-year-old women was treated for hyperparathyroidism resulting from parathyroid hyperplasia. Several months later, following a flu-like episode, she developed fever, confusion, abdominal pain, and diffuse petechiae, with severe thrombocytopenia and hemolytic anemia. She died on the 11th day of hospitalization. At autopsy she had multiple endocrine neoplasia type I, with two islet cell tumors, adrenal adenoma, pituitary adenoma, and bronchial carcinoid with liver metastasis. Florid visceral microthrombi involved arterioles and capillaries of the heart, including the conduction system. Brain, kidney, pancreas, adrenal, and portal areas of the liver were also heavily involved, but thrombi were rare in the liver sinusoids and the lungs. PAS-positive subendothelial deposits were demonstrated. In spite of the disseminated malignancy, the morphologic and laboratory findings were inconsistent with disseminated intravascular coagulation (DIC), and supported the clinical diagnosis of TTP. To the best of our knowledge this is the first report association of TTP with MEN and raises the question of a genetic linkage and/or hormonal interaction.
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PMID:Fatal thrombotic thrombocytopenic purpura (TTP) presenting concurrently with metastatic multiple endocrine neoplasia (MEN) type I. 887 34


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