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

Growth hormone and prolactin were localized on thin plastic sections of rat anterior pituitary gland and mammosomatotropic tumor MtTW15 that were fixed with osmium tetroxide (alone,mixed with aldehydes, or after aldehydes). Intense immunocytochemical staining for both antigens was obtained after plastic was removed from sections with an alcoholic solution of sodium hydroxide. The results indicated that antigenic determinants of rat prolactin and growth hormone were not completely destroyed or inactivated by fixation with osmium and embedment in epoxy resin, and that removal of the polymerized epoxy resin was necessary to obtain light microscopic postembedding immunocytochemical staining of these antigens. The results also demonstrated that tissues which have been conventionally processed for morphological evaluation by electron microscopy may be suitable for postembedding immunocytochemical staining of some antigens for light microscopy.
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PMID:Immunocytochemistry with osmium-fixed tissue. I. Light microscopic localization of growth hormone and prolactin with the unlabeled antibody-enzyme method. 10 97

Forty-eight surgically removed pituitary adenomas have been investigated by electron microscopy. Distinct differences in fine structural appearances permitted their separation into 5 classes: 1) Growth hormone, (GH)-cell tumors; 2) Prolactin cell tumors; 3) Mixed adenomas composed of GH and prolactin cells; 4) Adrenocorticotrophic-Melanocyte stimulating hormone (ACTH-MSH) cell tumors; 5) Undifferentiated cell adenomas. Densely and sparsely granulated tumors were distinguished within classes 1, 2 and 4. Although these two forms appeared to represent well defined entities, they may be variants of the same tumor differing only in pace of hormone production and/or release. Number and size of secretory granules varied considerably among tumors composed of the same cell type indicating that pituitary tumor classification cannot be based solely on granule morphology. This classification takes into account morphogenesis with emphasis on clinical features and structure-function relationship.
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PMID:Ultrastructural classification of pituitary adenomas. 17 9

A boy aged 9 years and 8 months was evaluated for headache and an enlarged sella. His neurological status and visual fields were normal. After injection of radiographic contrast agent, computerized axial tomography showed evidence of an intrasellar tumor. The most striking endocrine abnormalities were growth hormone insufficiency after arginine infusion and after insulin-induced hypoglycemia, and excessively elevated prolactin levels ranging between 1220 ng/ml and 1560 ng/ml. A slightly granulated, acidophilic pituitary adenoma was selectively removed by the trans-sphenoidal approach. The function of the anterior pituitary improved post-operatively. Growth hormone secretion after insulin-induced hypoglycemia returned to normal, and the basal serum prolactin levels decreased, but are still three times higher than normal.
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PMID:Prolactin-producing pituitary adenoma in a 9 year old boy. 21 87

The structural features of 26 spontaneous pituitary tumors in aging female Long-Evans rats have been investigated by different morphologic techniques including immunoperoxidase staining and electron microscopy. By light microscopy, the tumors corresponded to chromophobic-sparsely granulated acidophilic adenomas, containing numerous pigment granules and showing congestion as well as focal hemorrhages. Positive cytoplasmic staining was obtained with Herlant's erythrosin as well as with Brookes' carmoisine methods, used to detect secretory granules of prolactin cells. Immunoperoxidase technique revealed the presence of immunoreactive prolactin in the cytoplasm of many adenoma cells. Growth hormone and TSH immuno-stainings were negative. By electron microscopy, the tumors were found to consist of prolactin cells exhibiting marked variability in subcellular morphology and differing considerably from non-tumorous resting prolactin cells. A decrease in size and number of secretory granules, proliferation of rough-surfaced endoplasmic reticulum, formation of "Nebenkerne", accumulation of free ribosomes, prominence of Golgi complex and the presence of misplaced exocytosis were characteristic features of the adenoma cells and were interpreted as indicating enhanced secretory activity. Crinophagy and transformation of secretory granules into pigment deposits were striking findings in many adenomas. Since all the adenomas seemed to derive from prolactin cells and belong to the same tumor class, it is assumed that prolactin cells in female Long-Evans rats are more susceptible to oncogenic stimuli than other hypophysial cell types.
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PMID:Spontaneous pituitary adenomas in aging rats. A light microscopic, immunocytological and fine structural study. 33 31

Eight inbred strains of mice with varying incidences of spontaneous mammary tumor were compared in regard to prolactin and growth hormone concentrations in sera, pituitary glands and urine. Serum prolactin was compared under basal conditions as well as after stimulation with perphenazine. Both hormones were measured with specific, homologous radioimmunoassays. Although some strains having a high incidence of mammary tumors had high levels of prolactin in sera, urine and pituitary glands, neither basal nor perphenazine-induced serum concentrations showed a consistent pattern across mouse strains that correlated with the incidence of mammary tumors. Growth hormone levels in sera, pituitary glands and urine also had no characteristic pattern that applied to all strains studied. The ratio of prolactin depleted from the pituitary gland to prolactin detected in serum after perphenazine injection, which reflected the metabolic clearance rate of prolactin, was highest in two strains with a high incidence of mammary tumors and relatively lower in low-tumor strains. These results suggest that if prolactin plays a part in mammary tumor development in mice, its mechanism varies with strains: while hyperprolactinemia may be the means in some strains, a peculiarity in the metabolism of the hormone may be more important in others.
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PMID:Serum, pituitary and urine concentrations of prolactin and growth hormone in eight strains of mice with varying incidence of mammary tumors. 52 68

Fragments of a pituitary tumor from a patient with acromegaly were grown in tissue culture. The tumor secreted both growth hormone and prolactin,which were recovered in high concentrations. The nonpurified hormones were characterized and compared to their respective counterparts obtained by extraction from normal pituitaries obtained at autopsy. The tissue culture and pituitary extracted hormones were eluted from Sephadex G-100 with the same partition coefficients. Growth hormone from both sources showed parallel dose-response displacement curves, by logit-log transformation, in both specific immunoassay and in a specific lymphocyte binding assay. Prolactin from both sources was compared in specific immunoassay using three different antisera. Parallel logit-log displacement curves were seen with one antiserum, while the other two antisera yielded non-parallel curves, indicating structural differences between prolactin from the two sources. Quantitative polyacrylamide gel electrophoresis was performed using multiphasic buffer systems previously developed for characterization of each hormone. By the criteria of joint 95% confidence envelopes of retardation co-efficient and relative free mobility, tissue culture growth hormone and prolactin were indistinguishable from their pituitary-extracted counterparts. This study demonstrates that, prior to purification, tissue culture derived hormone can be characterized by multiple criteria and compared to a standard preparation. Structural differences can be detected, as in the case of prolactin. When the hormones are indistinguishable, as in the case of growth hormone, it becomes worthwhile to increase the scale of tissue cultured production, with the prospect that tissue culture may serve as a source of hormone for both experimental and therapeutic use.
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PMID:Characterization of growth hormone and prolactin produced by human pituitary in culture. 83 25

Growth hormone-like activity was demonstrated in diluted plasma of rats bearing the GH-secreting tumor, MtTW15, using an in vitro bioassay. The bioassay used depends upon the ability of GH in vitro to stimulate the uptake of 3-0-methyl glucose (3-OMG) into the isolated diaphragm of the hypophysectomized rat. It was found that the effect of the diluted plasma on this system was qualitatively like that of rat pituitary GH. Theophylline, a drug which blocks the action of GH on 3-OMG uptake by the diaphragm but has no effect on the actions of insulin or somatomedin on this process, completely abolished the stimulatory action of the plasma on the transport of the sugar. Furthermore, antibodies against rat pituitary GH (ArGH) completely abolished the biological activity of the diluted plasma. When plasma was diluted to give specific concentrations of rat GH (rGH), as determined by radioimmunoassay (RIA), the plasma produced responses in the 3-OMG assay equivalent to those obtained with similar concentrations of pituitary rGH. A good correlation was also observed between the concentration of rGH in the plasma of tumor-bearing rats measured by RIA and by an in vivo bioassay in which the effects were determined of injections of diluted plasma into hypophysectomized rats on the subsequent incorporation of [3H]thymidine into costal cartilage. This in vivo biological activity was abolished by incubation of the plasma with ArGH prior to its injection into the test animals. Thus, these studies indicate that in rats bearing the MtTW15 tumor there is a good correlation between the biological and immunological activities of the rGH circulating the bloodstream.
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PMID:Correlation between the biological and immunological activities of growth hormone circulating in rats bearing MtTW15 tumors. 84 29

A patient with an enlarged, asymmetric sella turcica and visual field defects suggestive of a pituitary or parasellar tumor underwent extensive roentgenographic and pituitary function studies. No abnormalities in pituitary luteinizing hormone, follicle-stimulating hormone, thyroid-stimulating hormone, ACTH, prolactin or vasopressin secretion were detected. Growth hormone secretion was provoked by arginine infusion but not by hypoglycemia. Pneumoencephalography revealed air in the sella turcica, and no evidence of tumor. Thus, an enlarged sella turcica in a patient with visual field defects but normal pituitary function may suggest the presence of an "empty sella syndrome."
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PMID:Primary empty sella syndrome with visual field defects. 93 63

Recent evidence suggests that endocrine factors play an important role in the natural history of osteosarcoma. The occurrence of this tumor in the metaphysis of rapidly growing adolescents, coupled with increased female survival led to the investigation of the effects of various hormones on cultured osteosarcoma cells. The in vitro effects of physiologic concentrations of human growth hormone, 17beta estradiol, and progesterone on cultured osteosarcoma cells and chondrocytes are presented. Growth hormone significantly enhances 3H-thymidine incorporation in osteosarcoma cells and chondrocytes, in the presence of human serum. The use of other sera, culture media, or heat inactivation of the human serum abolishes this effect. Estradiol and progesterone, alone, or in combination produce significant suppression of DNA synthesis in cultured tumor cells. Several sera contain a heat-labile factor which has the capacity to block the suppressive effect of estradiol. This factor could be overcome by increasing the concentration of hormone, or by heat-inactivation of the serum. The use of hormone therapy in the treatment of osteosarcoma has never been reported, despite its demonstrated value in certain other malignancies. In light of these observations and considering the poor prognosis in this disease it seems reasonable to initiate a study of adjunctive hormone therapy in osteosarcama.
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PMID:Hormone suppression of DNA synthesis in cultured chondrocyte and osteosarcoma cell line. 105 8

The ultrastructure of the adrenal cortex has been examined in animals bearing a growth hormone and prolactin secreting mammotropic tumor (MtT-W 10). The large quantities of hormone secreted by the tumor caused a stimulation of zona fasciculata cells. The adrenal weight increased approximately 2-fold in tumor bearing animals. There were increases in the cellular volume of zona fasciculata cells and in the volume of mithchondria and smooth endoplasmic reticulum per cell as determined by quantitative morphometric techniques. The surface area of smooth endoplasmic reticulum and total mitochondrial membranes showed a significant increase in zona fasciculata cells as well. Injections of purified bovine growth hormone caused small but not significant increases in mitochondrial and smooth endoplasmic reticulum volumes. Growth hormone however did induce a significant increase in the surface area of mitochondrial membrane.
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PMID:Quantitative ultrastructural study of the adrenal cortex: effects of a mammotropic pituitary tumor producing growth hormone and prolactin (MtT-W10), and of injected growth hormone in the rat. 112 11


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