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Query: UMLS:C0027651 (tumor)
 685,946 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Six cases of Cushing's syndrome with adrenocortical tumors which showed a variety of responsiveness to ACTH were investigated in relation to their clinical pictures and laboratory findings. Abnormal responses to ACTH in tumors was analyzed by in vitro experiments with surgically obtained tumor tissues, and the ACTH responsive mechanism of the tumors was discussed. An 8 hour intravenous ACTH infusion test showed that three of these patients were ACTH responsive, and the other three unresponsive. Histological observation of the tumors revealed that ACTH responsive tumors were adenomas and that ACTH unresponsive tumors were "black adenomas" in two and a carcinoma in one. To investigate possible factors which might account for these differences in ACTH responsiveness, tumor specimens of each one of the responsive and unresponsive adenomas, and a carcinoma were subjected to in vitro studies. When incubated with ACTH or cyclic AMP, tissue sections of a responsive adenoma enhanced cortisol secretion, while that of a black adenoma failed to show any change. Steroidogenesis by carcinoma sections were significantly suppressed in the presence of ACTH or cyclic AMP. Cycloheximide abolished a stimulatory effect of ACTH and cyclic AMP on steroidogenesis in a responsive adenoma without affecting its basal secretion of cortisol. Steroidogenesis by unresponsive tumors (an adenoma and a carcinoma) were decreased by cycloheximide. Since the conversion of cholesterol to pregnenolone, the rate limiting step in steroidogenesis, takes place in adrenal mitochondria, the effect of cyclic AMP on pregnenolone formation from 14C-cholesterol by mitochondrial fractions of these tumors was examined. Cyclic AMP stimulated pregnenolone formation by mitochondrial fraction of an ACTH responsive adenoma, while with that of an unresponsive adenoma pregnenolone formation was not affected. Pregnenolone formation by cancer mitochondria was significantly suppressed by cyclic AMP. These results suggest that the unresponsiveness to ACTH of these tumors might be explained by the ineffectiveness of cyclic AMP to stimulate pregnenolone formation by tumor mitochondria, and that the steroidogenic pathway in unresponsive tumors are in an enhanced state even without cyclic AMP. It should be mentioned that all unresponsive adenomas gave a characteristic appearance of a "black adenoma". Histologically, tumors were composed of compact cells with abundant lipofuscin granules. The possible relationship between the ACTH responsiveness of adrenocortical tumors and some clinical pictures caused by them was also noticed. ACTH unresponsive adenomas resulted in shorter duration, severer conditions of the disease and higher 17-ketosteroid excretion than responsive adenomas. The growth of unresponsive tumors seemed faster than that of responsive ones.
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PMID:[Studies on the responsiveness of human adrenocortical tumors to ACTH the clinical and experimental observations (author's transl)]. 18 66

A 45-year-old women had medullary tyroid carcinoma associated with Cushing's syndrome and galactorrhoea. Elevated plasma immunoreactive ACTH and cortisol were partially suppressed by intravenous dexamethasone, appreciably raised by lysine vasopressin, and urinary excretion of 17-oxogenic steroids slightly elevated by metyrapone. A large arterio-venous increase in plasma corticotrophin releasing factor-like activity across the thyroid gland was observed and tumour tissue contained corticotrophin releasing factor-like activity. Biologically active ACTH was not detected in tumour extracts before incubation with trypsin, but after trypsinization a value of 3.2 mU per gram was obtained. Arterial plasma contained biologically active ACTH (1.5 mU/100 ml) prior to trypsinization. Venous effluent from the thyroid gland contained biologically active (9.6 mU/100 ml) and immunoreactive ACTH (970 pg/ml) before trypsinization. Tumour extracts also contained prolactin production-stimulating activity. These findings can explain the Cushing's syndrome and the galactorrhoea both of which disappeared completely after thyroidectomy.
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PMID:Medullary thyroid carcinoma: ectopic production of peptides with ACTH-like, corticotrophin releasing factor-like and prolactin production-stimulating activities. 18 33

ACTH and cAMP stimulate steroidogenesis and the mitochondrial electron transport system for steroid hydroxylation in cultured mouse adrenal cortex tumor cells. During this stimulation, the biosynthesis of adrenodoxin, a non-heme iron protein which is one of the electron transport enzymes, was examined. 14C-labeled adrenodoxin was isolated by employing a purified rabbit antibody to bovine adrenodoxin. The antibody-adrenodoxin precipitates were further purified by acrylamide gel electrophoresis. It was observed that the biosynthesis of adrenodoxin was stimulated in response to ACTH induction and that this stimulation was completely inhibited with cycloheximide and partially inhibited with chloramphenicol. As a result, it was concluded that adrenodoxin requires both mitochondrial and cytosol ribosomal activities for its synthesis and integration into adrenal mitochondria.
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PMID:Biosynthesis of adrenodoxin in mouse adrenal tumor cells. 18 50

ACTH was purified from thymic tumor associated with ectopic ACTH production by gel filtration and ion exchange chromatography. Amino acid composition and C- and N-terminal analyses indicated that this tumor ACTH was comprised of the 2-38 sequence of authentic pituitary ACTH. The observations suggest that the mode of cleavage of this tumor ACTH from its precursor is different from that of pituitary ACTH.
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PMID:Chemical characterization of ectopic ACTH purified from a malignant thymic carcinoid tumor. 18 33

In a series of 79 cases of primary esophageal carcinoma resected at The Center for Adult Diseases, Osaka, there were six tumors with specific histopathologic features valid for the diagnosis of argyrophil cell carcinoma. Of the 6 tumors, 3 were studied electron microscopically and assay for ACTH content was performed on 4 tumors. Clinically, the ages of the 6 patients ranged from 56 to 71 years; two were women and four men. Four of the 6 patients died with widespread tumor recurrences within 9 months of operation. Microscopically, the 6 tumors were composed largely or almost entirely of small, spindle-shaped cells resembling those of oat cell carcinoma of the lung, and were characterized by the arrangement of tumor cells in solid sheets or anastomosing cords, the presence of argyrophil tumor cells, and the deposits of amyloid. Electron microscopically, the three tumors contained neurosecretory-type granules. Using bioassay or radioimmunoassay ACTH activity in the tumor tissues was detected in 3 out of the 4 tumors determined. From the light and electron microscopic characteristics and the assay evidence, it seems reasonable to conclude that the 6 tumors are endocrine polypeptide producing tumors (apudomas) that arise from argyrophil cells normally found among the basal cells of the esophageal mucosa, and that they represent a distinct histopathologic entity clearly distinguishable from other types of esophageal carcinomas.
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PMID:Argyrophil cell carcinoma (apudoma) of the esophagus. A histopathologic entity. 18 84

The case of a 40-year-old woman with primary small cell carcinoma of the cervix is reported. She developed widespread metastates and florid Cushing's syndrome. Serum ACTH levels were greatly elevated and no site of production other than the tumor could be demonstrated at autopsy. The tumor cells demonstrated features characteristic of cells of the APUD series. Such cells have been demonstrated in normal cervical epithelium; it is likely that they may become malignant, giving rise to tumors with a potential to secrete polypeptide hormones. This case suggests that endocrine active "Apudomas" may arise from the uterine cervix. Certainly, patients with small cell carcinoma of the cervix should be investigated with appropriate serum assays for polypeptide hormones.
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PMID:Small cell nonkeratinizing carcinoma of the cervix associated with ACTH production. 18 71

Two cases of intrathoracic tumor, different in histology and accompanied by hyperamylasemia, were studied ultrastructurally, histochemically, and biochemically. The ultrastructure of the tumor cell cytoplasm showed many zymogen granules in case 1 and smaller cored granules in addition to zymogen granules in case 2. Both tumors contained not only a large amount of amylase, which was electrophoretically of saliva type with three components, but also significant amounts of immunoreactive ACTH and beta-MSH. Starch film and immunofluorescence showed that the tumor cells stored amylase. It was concluded from these findings that the tumor cells ectopically producing amylase, which showed differentiation toward the cells with zymogen production, could differentiate toward the cells of ACTH-MSH system at the same time.
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PMID:Ultrastructural, histochemical, and biochemical studies of two cases with amylase, ACTH, and beta-MSH producing tumor. 18 72

Plasma 16 beta-hydroxydehydroepiandrosterone (16 beta-OH-DHEA) levels were measured by radioimmunoassay in normal and pathological conditions in man. 16 beta-OH-DHEA levels in normal subjects rose sharply during adolescence and then declined slowly throughout adult life: 192 pg/ml age 7-11, 395 pg/ml age 15-19, 330 pg/ml age 20-39, 261 pg/ml age 40-59, and 124 pg/ml over 60-years-old. No marked difference was seen between male and female subjects. 16 beta OH-DHEA rose significantly (p less than .01) during adrenocorticotropin (ACTH) stimulation, declined (p less than .005) during dexamethasome suppression and during gonadal suppression, rose (p less than .05) during gonadal stimulation and following administration of WIN 24540, an inhibitor of 3 beta-o1-dehydrogenase (p less than .005). 16 beta-OH-DHEA levels in adrenal venous blood were higher than in inferior vena cava blood but the levels in hepatic venous blood were not higher than in arterial blood. These results indicate that 16 beta-OH-DHEA is secreted directly by the adrenal cortex and probably the gonads. 16 beta-OH-DHEA levels were elevated in normal pregnant women, pregnant women with toxemia and in patients with Cushing's disease, ectopic ACTH-producing tumor and congenital adrenal hyperplasia but not in patients with low-renin essential hypertension.
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PMID:Plasma 16 beta-hydroxydehydroepiandrosterone in normal and pathological conditions in man. 18 75

The pituitary-adrenocortical system of rat fetuses was stimulated (larger adrenals at birth) by maternal adrenalectomy, or suppressed (smaller adrenals at birth) by implantation of an ACTH secreting pituitary tumor (MtTF4). Offspring were delivered by caesarean section and fostered to untreated females. Offspring of intact females delivered by caesarean section and normally delivered offspring of intact mothers both fostered to untreated lactating females served as controls. Body growth in the first three weeks of life was delayed in offspring of tumor bearing mothers in Control-fostered subjects as compared to the 2 other groups. At 70 days of age female offspring of the tumor implanted and adrenalectomized mothers, as well as the Control-caesarean females, had smaller adrenals than Control-fostered animals of the same sex. The adrenal size of males was not significantly affected. No significant differences were found in resting concentrations of corticosterone in plasma, although offspring of adrenalectomized mothers had high values. Suppressed adrenal response to ether stress was found in offspring of tumor bearing mothers. The supposition is that interference with maternal pituitary-adrenocortical activity during pregnancy has a long lasting effect on fetal hypothalamo-pituitary-adrenocortical system.
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PMID:The effect of maternal and fetal corticosteroids on the development of function of the pituitary-adrenocortical system. 18 20

The unusual finding of peptic esophagitis and duodenal ulceration in a dog was associated with a malignant pancreatic islet cell tumor producing gastrin and ACTH. The finding of a gastrinoma in a non-human species introduces the potential for developing an animal model for the study of the protean genetic biochemical, physiologic and metabolic aspects of the Zollinger-Ellison syndrome.
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PMID:Canine Zollinger-Ellison syndrome. 18 26


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