Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A 51-year-old female was diagnosed preoperatively to have a pheochromocytoma producing ACTH. This diagnosis was based upon her paroxysmal hypertension, hyperpigmentation, and hypokalemia. Elevated levels of serum and urine corticosteroids, plasma ACTH, urinary VMA, and catecholamines fell after a right adrenal pheochromocytoma was removed. Subsequently this tumor was found to have a high content of ACTH. Review of the literature indicates a mortality rate of 57% for this syndrome. Proper preoperative recognition and management can result in total cure.
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PMID:Ectopic ACTH syndrome due to pheochromocytoma: case report and review of the literature. 22 80

A case of adrenocortical hyperfunction due to ectopic production of ACTH by a gastrin-producing tumor of the pancreas is described. Cushing's syndrome preceded the appearance of the overt Zollinger-Ellison syndrome by 2 years and was treated by bilateral adrenalectomy. The Zollinger-Ellison syndrome was initially treated with cimetidine, which successfully reduced the secretion of gastric acid. Because the pancreatic gastrinoma continued to grow, causing obstruction of the common bile duct, biliary diversion and total gastrectomy were performed. There is evidence that the pancreatic gastrinoma was the source of the ectopic production of ACTH and possibly secretion. The role of Histamine-2 blocking agents as therapy in the Zollinger-Ellison syndrome is discussed.
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PMID:Gastrinoma associated with common bile duct obstruction and the ectopic production of ACTH. 22 62

Children with neuroblastoma whose opsomyoclonus recurs or persists after initial surgery should be carefully evaluated for tumor. If no tumor is detectable, therapy with ACTH should be considered in patients whose symptomatology is severe enough to compromise normal development.
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PMID:Opsomyoclonus and neuroblastoma. Response to ACTH. 22 27

The capacity which the cells of some tumors have of synthesizing, storing, and releasing hormonal polypetides constitutes the basic characteristic of the neoplasms of the APUD system. On many occasions these polypeptides are released as hormonal precursors of high molecular weight, with a minimal biological action in comparison with the real hormone (big ACTH, big gastrin, etc.), and they have no clinical expressivity. On other occasions they reproduce, however, the clinical syndrome of the hormone released in excess. The production of multiple hormones by a single tumor is not a common event. Here we present the case of a patient with an oat-cell carcinoma of the lung and a carcinoma of the pancreas, both histopathologically primitive. In this patient a syndrome of inadequate secretion of antidiuretic hormone was detected. By means of radioimmunoassay techniques, the existence of antidiuretic hormone, ACTH with a predominance of the components of high molecular weight (big ACTH and beta-LPH) and MSH was demonstrated in the tumoral extracts from the lung, pancreas, and from a mediastinal metastatic lymph node. While the concentrations of ACTH were much greater in the lung than in the pancreas, the opposite occurred for the antidiuretic hormone. The synthesis of MSH by the hypophyseal gland or by tumors is not at present recognized, but rather is considered as a degradation product during the process of extraction. The APUD system makes up the morphologic substrate of the syndromes of familiar multiple endocrine adenomatosis. The present case could represent a variant of sporadic multiple endocrine neoplasms which would have the same anatomical basis.
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PMID:[Hormonal multiplicity of an apudoma of the lung and pancreas. Characterization of the different peptides in the tumoral extracts (author's transl)]. 22 76

Ectopic ACTH syndrome is a clinicopathologic condition produced by certain tumors which release hormone that is indistinguishable from ACTH. It orginates the chemical and clinical anomalies characteristic of Cushing's syndrome by its action on the adrenal glands. The tumors may be present in any organ, though they are most frequently found in the lungs, thymus, pancreas or gastrointestinal tract. They may be benign or malignant, though usually the latter. Secretion of the hormone is completely autnomous; it is release in a way similar to that of the hypophysis. Not infrequently other hormones besides ACTH are also produced, such as MSH, serotonin, and CRF. Ectopic ACTH is of higher molecular weight than hypophyseal ACTH, which suggest it may be comprised of the latter bounded covalently to a peptide. The clinical course is rapid, so that not all of the symptoms of Cushing's syndrome develop. Moon face, osteoporosis, and obesity are typically lacking; melanodermia and hypokalemic alkalosis ofter appear. Laboratory data include an increase in ACTH and cholesterol concentrations, disappearance of the nictameral rhythm, and an increase in urinary excretion of 17-hydroxycorticoids and 17-ketosteroids. Stimulation and supression tests are abnormal. The prognosis is poor and the only possible treatment is a complete surgical removal of the tumor. Irradiation or chemotherapy could be applied as well as the correction of the adrenal hyperfunction by the administration of drugs or by total bilateral adrenalectomy.
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PMID:[Ectopic ACTH syndrome (author's transl)]. 22 77

Under study was the hypophysis influence on the growth of human melanoma explants, cultivated in the abdominal cavity of mice and rats. The heterotransplants growth was compared in intact and hypophysectomized animals exposed to ACTH, and also the effect of the murine hypophysis explanted into the adjacent chamber compartments on the melanoma explants growth was investigated. The growth was assessed by a square area of the explants growth zones. ACTH and the hypophysis explanted were found to render a stimulating effect on the growth of tumor heterotransplants. Hypophysectomy in rats would suppress the growth of all melanoma explants under investigation. When injecting ACTH into hypophysectomized animals the growth of melanoma heterotransplants in the chambers does not differ from that in control series.
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PMID:[Effect of hypophysectomy, hypophyseal explants and ACTH on the growth of human melanomas in diffusion chambers]. 22 25

Tumor tissues obtained from two patients with the ectopic ACTH syndrome caused by medullary carcinoma of the thyroid and malignant epithelial thymoma were dispersed by tryptic digestion and mechanical agitation. Using the isolated cells, the effects of various agents on ACTH secretion and intracellular cAMP concentrations were studied. Addition of rat median eminence extract significantly stimulated ACTH secretion and increased levels of intracellular cAMP in both cell preparations, and a dose-response relationship appeared to exist between the dose of rat median eminence extract added and either ACTH secretion or intracellular cAMP formation in the thymic tumor cells. High concentrations of calcium also produced a marked ACTH secretion in both cases. In the thymic tumor cells, norepinephrine, serotonin, and TRH were found to be effective in increasing ACTH secretion and intracellular cAMP levels, whereas biogenic amines, hypothalamic hormones, and gastrointestinal hormones did not affect hormone secretion in the thyroid tumor cells. These results suggest that a corticortropin-releasing factor-like substance(s), as yet unspecified, may play some role in stimulating ectopic ACTH secretion by certain tumors, that both intracellular cAMP and Ca++ may be involved in ectopic hormone secretion, and that the inappropriate hormonal secretory responses of some tumors to a variety of stimuli might be mediated by altered membrane receptors of the neoplastic cells.
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PMID:Effect of hypothalamic extract and other factors on release of adrenocorticotropin from and adenosine 3',5'-monophosphate levels in dispersed nonpituitary tumor cells. 22 71

A 35-yr-old woman with Nelson's syndrome presented with amenorrhea and virilization. Serum testosterone (T) concentration was 605 ng/dl and fell to 33 ng/dl when dexamethasone was administered. The MCR of T fell from 1383 to 991 liters/day and the T production rate decreased by 96%. With administration of synthetic ACTH, T concentration rose to 338 ng/dl. Plasma ACTH concentration paralleled T during repeated suppression testing, suggesting that T secretion was dependent on ACTH hypersecretion. Preoperative and intraoperative ovarian vein catheterization suggested that the predominant source of androgen production was from the right ovarian vein. Laporatomy revealed multiple paraovarian tumors in the right mesosalpinyx and mesovarium. Incubation of tumor slices and ovarian tissue with [3H]pregnenolone and [14C]17-hydroxyprogesterone demonstrated conversion of both precursors to T by the tumor and confirmed that the tumors were the source of androgen excess. The microscopic appearance of the tumors closely resembled the morphology of testicular and paratesticular tumors of men with congenital adrenal hyperplasia and Nelson's syndrome. The analogous dependency of the tumors on ACTH hypersecretion in men with paratesticular tumors and in this woman with paraovarian tumors suggests that the tumors may arise in both males and females from a common steroid-secreting cell of adrenogenital origin.
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PMID:Adrenocorticotropin-dependent virilizing paraovarian tumors in Nelson's syndrome. 22 75

Implantation of MtT-F4 tumor, a mammotropic tumor that secretes large quantities of ACTH, GH and prolactin, into male Fisher rats induced the development of hyperlipidemia. Free fatty acid, triglyceride and cholesterol levels in the plasma were significantly increased at 31 days after tumor implantation. Blood glucose and glycerol levels remained normal, while uric acid concentration in the blood was significantly decreased. The concentrations of the serum lipoproteins were significantly increased, while, only small changes in the distribution of the serum lipids and the composition of the lipoproteins were observed. Following stimulation of isolated adipose tissue cells with ACTH, the lipolytic response and the accumulation of cyclic AMP was higher in cells derived from the rats with the tumor, although the accumulation of cyclic GMP was not different from control adipocytes. Further, when the isolated adipose tissue cells were stimulated with dibutyryl cyclic AMP no difference was observed between the control and tumor bearing groups. Clofibrate administered in the diet resulted in a complete elimination of the tumor effect on serum triglycerides and to a great extent prevented the rise in serum cholesterol. The tumor-induced increase in the concentration of the high density lipoproteins was not affected, but the elevation of the d less than 1.063 lipoproteins was not affected, but the elevation of the d less than 1.063 lipoproteins was partially reversed. The increased lipolytic response and accumulation of cyclic AMP following stimulation by ACTH was not altered in adipocytes derived from tumor bearing rats. However, clofibrate treatment resulted in a significantly greater accumulation of cyclic GMP in fat cells stimulated with ACTH from both control and tumor bearing rats. Clofibrate in the diet did not alter the levels of GH or prolactin or serum lipids in the control rats nor were the elevated hormone levels of the tumor bearing rats changed.
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PMID:Experimental hyperlipidemia in rats. 22 51

Two variant cell lines (Y6 and OS3), derived from the ACTH-sensitive mouse adrenocortical tumor clone Y1, are defective in the ACTH-sensitive adenylate cyclase system. This study further characterizes the nature of the defects in Y6 and OS3 cells using ACTH1-10, ACTH4-10, and cholera toxin. In Y1 cells, ACTH1-39, ACTH1-10, and ACTH4-10 stimulated steroidogenesis to the same maximum level with Kd' values of 5 x 10(-11) M, 5 x 10(-7) M and 10(-4) m respectively. ACTH1-10 (0.4 mM) and ACTH4-10 (3.2 mM) increased the accumulation of adenosine 3',5'-monophosphate (cAMP) in Y1 cells two- to three-fold. Cholera toxin increased steroidogenesis and cAMP accumulation in Y1 cells with Kd' values of 0.4 ng/mL and 9 ng/mL respectively. Y6 and OS3 cells responded to added cholera toxin with increased cAMP accumulation and increased steroidogenesis but did not respond to ACTH1-39, ACTH1-10, or ACTH4-10 at concentrations effective in Y1 cells. These data are interpreted to suggest that Y6 and OS3 cells are defective in a process or component that links the principal binding regions of the ACTH receptor to the catalytic subunit of the adenylate cyclase system. Attempts to were made to assess the interactions of ACTH with the principal binding regions of the ACTH receptor by analysis of binding of radioactive, iodinated ACTH1-24. ACTH binding, however, showed low affinity, high capacity, and no target-tissue specificity, and was considered not to be useful in evaluating the integrity of the ACTH receptor.
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PMID:Evaluation of receptor function in ACTH-responsive and ACTH-insensitive adrenal tumor cells. 22 81


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