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

Adrenal-like lipoid-rich Leydig cells, which could be found in a cryptorchid testis, were investigated by light and electronmicroscopy. There were nodular and diffuse proliferation of these adrenal-like cells in the interstitium of the testis. Electronmicroscopically these cells are fasciculated and characterized by large liposomes, many tubulovesicular mitochondria, and a large smooth endoplasmatic reticulum. But the presence of crystals of Reinke in these cells underlined their relationship to Leydig cells. The clinical history of this case is characterised by an extreme adipositas (167 kg) and high urinary estrogenexcretion. This excretion could be suppressed with dexamethasone and stimulated with HCG. After orchiectomy estrogen excretion decreased for 4 months and then increased again, after ACTH stimulation performed by reason of adrenal insufficiency. At this time there is no evidence of adrenal tumor; in the contralateral, scrotal testis, spermiogenesis and Leydig cells are without pathologic changes as revealed by biopsy.
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PMID:[Adrenal-like Leydig cells (author's transl)]. 0 95

Transplantable mouse melanomas possess a melanotropin-sensitive adenylate cyclase system which is responsive to alpha-melanotropin, beta-melanotropin, adrenocorticotropin (ACTH) and prostaglandin E1. It was found that sensitivity to ACTH was not directed towards the ACTH activity but to the intrinsic melanotropin activity of the ACTH molecule. Therefore, the melanotropin-sensitive adenylate cyclase system is hormonally specific to the intrinsic melanotropin activity of peptide hormones and is unique in the melanoma tissue. The significance of the sensitivity to prostaglandin E1 is obscure at present. The melanotropin-sensitive adenylate cyclase requires the presence of Mg2+ or Mn2+, for its enzymic activity. Ca2+ inhibit the enzyme in the presence of a wide range of concentrations of Mg2+. The enzymic activity is ATP concentration-dependent and the saturation concentration appears to be 1 mM. The enzyme is very labile in the unfractionated tumor homogenates. A washed 11000 X g particulate fraction, representing about 30-60% of the total enzymic activity, was found to be more stable and could be stored at 5 degrees C for 2 h without appreciable loss of the activity. This fraction retained sensitivity to melanotropin, prostaglandin E1 and NaF. About 20% of the activity of the tumor homogenate could not be sedimented by centrifugation at 105000 X g for 60 min. This "soluble" fraction was not responsive to melanotropin, prostaglandin E1 and NaF and might be a degradative product produced by the fractionation. Cyclic AMP and alpha-melanotropin were able to increase the tyrosinase activity of isolated mouse melanoma-cells in vitro under the same conditions.
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PMID:PHrmonal specificity of the melanotropin-sensitive adenylate cyclase of mouse melanoma and effect of cyclic AMP on the tyrosinase activity of mouse melanoma cells, in vitro. 0 31

To evalute the frequency of associated and hereditary endocrinopathies in the Zollinger-Ellison syndrome, 10 patients with the syndrome were studied. In seven of them, coexisting endocrine disease was found. In six, the Zollinger-Ellison syndrome was probably a feature of multiple endocrine adenomatosis type I, whereas Cushing's syndrome in the remaining patient may have been caused by the production of an ACTH-like substance by a mixed pancreatic tumor. A total of 109 family members, including all living first degree relatives over 15 years of age, were screened for endocrine abnormalities. All six patients with evidence of multiple endocrine adenomatosis type I had relatives with endocrinopathies. In the families of the four other patients with the Zollinger-Ellison syndrome, no endocrine abnormalities were found. During this study four new cases of pituitary tumor, 17 of hyperparathyroidism, seven of the Zollinger-Ellison syndrome and one of insulinoma were detected. Although most of the disorders were asymptomatic, this clearly indicates that patients suffering from Zollinger-Ellison syndrome and also their families should undergo detailed endocrine studies.
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PMID:Prevalence of endocrine abnormalities in patients with the Zollinger-Ellison syndrome and in their families. 2 80

34 pituitary adenomas were examined by light and electron microscopical methods. Slices of tumor tissue fixed in formaldehyde or Bouin's solution, respectively, and embeded in paraffin were stained by hematoxylin-eosin, Goldner's method (including Orang G), periodic acid Schiff (PAS) reaction, and in some cases by Herlant's tetrachrom. The ultrastructure was studied using tumor tissue fixed in glutaraldehyde within 1 hour after removal. The adenomas were classified by their light microscopical characteristics as chromophilic or chromophobe tumors. Employing the PAS reaction and Goldner's staining method, 27 adenomas were found to give intense or weak staining reactions. By electron microscopical investigation , all the adenomas studied were seen to contain secretory granules more or less densely packed within the cytoplasm. The number of these granules was strongly correlated with the intensity of the tinctorial properties of the tumor tissue. Out of 11 acidophilic adenomas, 10 were observed consisting of typical STH cells. 4 acromegalic patients were found to possess heavily or poorly granulated STH cell adenomas (two patients in each of these groups). One patient with a clinical history of liver cirrhosis and gynecomastia was observed bearing an acidophilic (and erythrosinophilic) adenomatous hyperplasia of prolactin cells, 13 tumors consisted of cells exhibiting almost weak amphophilic staining properties and secretory granules of 100-250nm diameter, thus resembling cells which have been reported to produced ACTH. One of the patients suffering from these adenomas, showed the clinical signs of M. Cushing. By ultrastructural criterions, 3 adenomas with PAS-positive tumor cells were considered to be composed of gonadotropic cells. Only 7 adenomas were observed which did not give any chromophilic reaction. These tumors consisted of extreme poorly granulated cells which could not be significantly associated with one of the pituitary hormones by their morphological properties. In respect of the abundance of mitochondria, 4 out of the adenomas were designated as oncocytic tumors.
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PMID:[The ultrastructure of human pituitary adenomas (author's transl)]. 6 63

Extracts of rat anterior and intermediate-posterior pituitary were fractionated by sodium dodecyl sulfate polyacrylamide gel electrophoresis and assayed for immunoactive ACTH and endorphin. In both lobes the major forms of immunoactive ACTH have apparent molecular weights of 31,000 (31K), 20--21K, 14K, and 4.5K, and the major forms of immunoactive endorphin have apparent molecular weights of 31K (coincident with the peak of immunoactive ACTH), 13K (a betaLPH-like peptide), and 3.5K (a beta-endorphin-like peptide). However, the quantitative distribution of immunoactivity among the various forms differs greatly between the lobes. Assays using an extreme COOH-terminal ACTH antiserum indicate that the 31K ACTH/endorphin molecule in rat anterior and intermediate pituitary is similar to the pro-ACTH/endorphin molecule from mouse pituitary tumor cells. A radioimmunoassay that is specific for the NH2-terminal non-ACTH, nonendorphin segment (referred to as 16K fragment) of the mouse pro-ACTH/endorphin molecule was used to assay extracts of rat pituitary. In addition to detecting material at 31K and 20--21K, the 16K fragment radioimmunoassay detects significant amounts of cross-reactive material with an apparent molecular weight of 16K in extracts of both lobes. This result also suggests that the structure and processing of the rat 31K ACTH/endorphin molecule is similar to that of mouse tumor cell pro-ACTH/endorphin. Cell suspensions were prepared from the anterior and intermediate lobes of the rat pituitary and maintained in culture for a 24-h period. The isolated cells from both lobes incorporate [3H] phenylalanine into immunoprecipitable ACTH- and endorphin-containing molecules. By sequential immunoprecipitation with ACTH and endorphin antisera, it is possible to demonstrate directly that a single molecule (31K ACTH/endorphin) has antigenic determinants for both ACTH and endorphin. Significant amounts of 31K ACTH/endorphin are released into the culture medium by isolated anterior lobe and intermediate lobe cells. The isolated intermediate lobe cells synthesize and secrete relatively large amounts of a beta-endorphin-like molecule; the isolated anterior lobe cells secrete significant amounts of both a betaLPH-like molecule and a beta-endorphin-like molecule. These same quantitative differences between anterior and intermediate lobe tissue were observed in immunoassays of extracts of the separated lobes and probably reflect differences in the processing of the common precursor. The isolated anterior lobe cells can be stimulated to release increased amounts of immunoprecipitable ACTH and endorphin by incubation with a cyclic AMP analog and a phosphodiesterase inhibitor.
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PMID:Existence of a common precursor to ACTH and endorphin in the anterior and intermediate lobes of the rat pituitary. 8 77

Though not conclusive, our primary findings indicate that a feature common to many of our tumor and ICD patients is depressed cortisol production. Additionally, the response to ACTH adrenal cortex stimulation tests, at 2-hour intervals between rest and stimulation, have ranged from negative to substantially less than would be expected in normal subjects. Peripheral plasma cortisol values for dogs, at rest and 2 hours after ACTH stimulation, respectively, have been reported as 2-10 and 25-30 mug/dl, 3-8 and 7.5-18 mug/dl, and 1-12.5 and 9.5-22 mug/dl. For representative patients, our resting values have been 1.2-5.2 mug/dl, vs 1.2-7.6 mug after ACTH stimulation (Table 2). Altogether we have studied 42 cases in detail, and we feel that a post-ACTH level of 8.0 mug/dl or less is a conservative indication of adrenocortical insufficiency; all levels have been between 1 and 8 mug/dl. We believe these low cortisol levels indicate either a genetically-induced adrenal cortical insufficiency (evident at 2 months to 1 year of age) or an immune complex adrenal cortical suppression (occurring after 1 year of age in association with other immunodeficiency disorders). Our studies demonstrate a need for biphasic therapy. We have found it necessary to not only initiate cortisone acetate therapy to support the deficient adrenal cortical secretion, but also use other immunosuppressive drugs to control the ICD. If the target organ has been suppressed or destroyed, the need for supplementation is obvious. However, other immune-injury moieties must be suppressed also, eg, ANA, anti-IgG antibodies, etc.
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PMID:Canine immune complex diseases. 13 91

Enzyme histochemical and ultrastructural studies of a "dexamethasone-suppressed" virilizing adrenocortical adenoma and the attached cortex revealed that tumor cells showed little activities of some lysosomal enzymes and scarcity of lipofuscins and dense bodies of lysosomal type, forming a marked contrast to the cells of zona reticularis and the virilizing adenomas previously reported. The other findings of tumor cells, such as a pattern of activities of dehydrogenases including 3beta-hydroxysteroid dehydrogenase and the morphology of mitochondria, were those of reticularis cells. The findings showed that scantiness of lipofuscins did not rule out the possibility of adenoma producing adrenal androgen, dehydroepiandrosterone. Most of the tumor cells as well as reticularis cells were positive for alkaline phosphatase, the activity of which was interpreted as the effect of ACTH stimulation.
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PMID:Enzyme histochemical and electron microscopic study of a virilizing adrenocortical adenoma. 15 60

Among 74 histochemically and ultrastructurally studied pituitary adenomas, 12 apparently chromophobe tumors were characterized by the presence of numerous argyrophil cells. All these argyrophil adenomas failed to reveal presence of GH, prolactin or ACTH cells. Two tumors were found to consist of well granulated cells reacting intensely with anti-TSH antibodies and resembling TSH cells of the normal pituitary. The remaining argyrophil adenomas did not show TSH immunostaining and, with one exception, failed to react with an anti-HCG serum staining gonadotroph cells of human pituitary. They were composed of small, closely apposed cells with small compact or vesicular granules. These tumor cells seem to correspond to some small argyrophil cells found in non-neoplastic pituitary, which differ from TSH cells and from all other types of functionally identified adenohypophyseal cells.
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PMID:Argyrophil pituitary tumors showing TSH cells or small granule cells. 15 28

The transplantable rat pituitary tumor MtT-F4 failed to grow in rats hypophysectomized at the time of transplantation, but did grow in thyroxine-treated hypophysectomized rats. In the latter rats, the tumor did not stimulate the adrenals to the same extent as in control rats. When the tumor did not stimulate the adrenals to the same extent as in control rats. When the tumor cells were isolated and incubated in vitro, those from hypophysectomized thyroxine-treated rats released much less ACTH into the incubation medium than the tumor cells from control rats. They also released significantly less growth hormone than tumor cells from intact, intact thyroxine-treated, and thyroidectomized thyroxine-treated rats. Prolactin release by the isolated tumor cells in vitro was the same in all groups studied. The results suggest that the hypophysectomy and thyroxine treatment of the host rat might selectively influence the production of hormones by the MtT-F4 transplantable rat pituitary tumor.
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PMID:Changes of endocrine properties of a transplantable, multihormonal, pituitary tumor (MtT-F4) after hypophysectomy of host rats. 16 35

This report describes the clinical and biochemical features of 30 cases of ectopic ACTH-producing tumors diagnosed by the detection of ACTH in the tumor tissues. Several uncommon tumors, such as tumors of the esophagus, stomach, and larynx, were included in this series. None of the patients with bronchogenic carcinoma showed signs of classical Cushing's syndrome, whereas 7 of the remaining 13 patients with other tumors were Cushingoid in appearance. Adrenocortical hyperfunction was present in 61 percent at the first examination and developed during the course of the disease in 18 percent more. In the remaining patients (21 percent), adrenocortical function remained within normal limits. These results indicate that there exist ectopic ACTH-producing tumors without clinical and biochemical sequelae of excess hormone. In some of the tumor extracts studied, MSH and CRF-like activities and serotonin were detected. This suggests that multiple hormone production is not uncommon in ectopic ACTH-producing tumors.
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PMID:Studies on ectopic ACTH-producing tumors. II. Clinical and biochemical features of 30 cases. 16 76


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