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

ACTH, 8-Br-cAMP, and serum deprivation arrested Y-1 functional mouse adrenal tumor cells in the G1 phase of the cell cycle. Though ACTH and 8-Br-cAMP treated cells were larger with increased macromolecular synthetic rates compared to cells arrested in G1 by serum removal, a similar 8- to 10-hours lag to initiation of DNA synthesis was observed after either ACTH or 8-Br-cAMP removal or after serum addition. After the 8- to 10-hour lag period, cells entered S phase exponentially. ACTH or 8-Br-cAMP opposed serum induced DNA synthesis initiation only when added prior to S. Once commitment to DNA synthesis occurred, ACTH or 8-Br-cAMP addition did not inhibit DNA synthesis although 8-Br-cAMP induced a secondary block in G2. Though ACTH and 8-Br-cAMP inhibited serum induced initiation of DNA synthesis and did not affect serum induced cellular hypertrophy, both substances increased the steroidogenic capacity of the cell. ACTH and 8-Br-cAMP thus appear to specifically oppose the stimulatory effects of serum on initiation of DNA synthesis while inducing the differentiated function of the cell.
 ...
PMID:Hormonal regulation of initiation of DNA synthesis and of differentiated function in Y-1 adrenal cortical cells. 19 11

The presenting signs, symptoms, roentgenographic findings, endocrine evaluations, treatment, and results in 68 cases of presumed pituitary adenomas treated over an 18-year period are discussed. The most common symptoms were headache, acromegalic changes, visual symptoms, and amenorrhea. Most common physical findings were obesity, acromegaly, and visual field defects, usually bitemporal hemianopsia. Roentgenographic evidence of sellar erosion was almost universal but angiography and pneumoencephalography were required to evaluate suprasellar extension. Brain scan was not considered a particularly useful diagnostic tool. Endocrine status was best evaluated by a battery of tests including 17-OH, 17-KS, T3, T4, PBI, ACTH stimulation, and FSH and STH levels. (Prolactin levels are currently being obtained, also). Surgical specimens were obtained in 29 patients, with subsequent diagnoses of 22 chromophobe adenomas, five eosinophilie adenomas, one cystic adenoma, and one necrotic tumor. All five eosinophilic tumors came from acromegalic patients. Patients treated by operation alone or operation followed by radiotherapy generally had less "medical morbidity" than did patients who received radiotherapy alone.
 ...
PMID:Review of 18 years' experience with pituitary tumors. 19 48

A somatic cell genetic approach was used to study the role of cyclic nucleotides in adrenal steroidogenesis. 8-Bromoadenosine 3',5'-monophosphate (8BrcAMP) stimulated steroidogenesis (K'd=0.1 mM) in cultured mouse adrenocortical tumor cells (Clone Y1). In addition, 8BrcAMP inhibited Y1 cell growth and caused Y1 cell monolayers to assume a rounded morphology. As a consequence, 8BrcAMP (at concentrations greater than or equal to 0.4 mM) reduced the relative plating efficiency of Y1 cells to less than 10(-5). Y1 cells were mutagenized with ethyl methanesulfonate (300 microgram/ml) and grown in the presence of 0.4 mM 8BrcAMP. A surviving colony (8BrcAMPr-1) was shown to be resistant to growth inhibition (relative plating efficiency at 1.0 mM 8BrcAMP=50 percent)) and to morphological changes induced by 8BrcAMP. 8BrcAMPr-1 cells had diminished steroidogenic responses to cyclic nucleotides and to ACTH (less than or equal to 33 percent of maximum). In 8BrcAMP(R)-1 cells, adenylate cyclase activity remained responsive to ACTH, and cyclic AMP phosphodiesterase activity was not increased. These data suggest that 8BrcAMPr-1 cells are defective at a point common to cyclic AMP action on growth, morphology and steroidogenesis. The associated decrease in responsiveness of the steroidogenic pathway to ACTH suggests that ACTH-regulated steroidogenesis is via a cyclic nucleotide-mediated mechanism.
 ...
PMID:Isolation of mutant adrenocortical tumor cells resistant to cyclic nucleotides. 20 May 6

ACTH, cholera toxin, cyclic AMP but not pregnenolone-induced steroidogenesis in Y-1 functional mouse adrenal tumor cells was significantly inhibited by delta-9-tetrahydrocannabinol, cannabidiol, and cannabinol. The inhibition of steroidogenesis could not be correlated with a general depression in cell function or viability. The data suggest that cannabinoids inhibit corticosteroidogenesis at a site between the synthesis of cAMP and of pregnenolone.
 ...
PMID:Inhibition of cortiocosteroidogenesis by delta-9-tetrahydrocannabinol. 20 49

A 37-year-old woman had symptoms of Cushing's disease for two years. Galactorrhea was present. The diagnosis was confirmed by finding intermittently elevated urinary 17-hydroxysteroids, absent circadian rhythm, and elevated plasma ACTH. Plasma prolactin was slightly elevated. Films of the sella turcica were normal. A 9 mm basophilic microadenoma was removed by the transphenoidal approach. Immunocytochemical and electron-microscopic studies showed that the tumor was composed exclusively of ACTH secreting cells. Endocrine re-evaluation one year later revealed normal adrenal function. Serum prolactin had returned to normal. This case provides further evidence that Cushing's disease can be caused by a pituitary microadenoma insufficient in size to deform the sella.
 ...
PMID:Cure of Cushing's disease by transsphenoidal removal of a microadenoma from a pituitary gland despite a radiographically normal sella turcica. 20 60

A patient who developed a pituitary tumor after adrenalectomy for Cushing's disease (Nelson's syndrome) is presented. The literature reviewed shows less than a 10 percent incidence of this disorder for which extremely elevated plasma ACTH levels are diagnostic. Special radiologic technics may be required to detect small pituitary tumors, but pituitary hormone levels may be elevated in the cerebrospinal fluid if there is suprasellar tumor extension. The different modalities available for treatment of Nelson's syndrome are discussed.
 ...
PMID:Nelson's syndrome: case report and review of the literature. 20 34

Eighteen cases of medullary carcinoma of the thyroid were analyzed immunohistochemically for calcitonin- and ACTH-containing cells, and tumor cells in 8 cases were examined by an electron microscope and analyzed by manual and computer procedures with particular attention paid to the size and quality of secretory granules. Calcitonin- and ACTH-containing cells were found singly or in clusters in 14 and 11 tumors, respectively. In 4 cases, calcitonin-positive cell clusters and an increase in number of singly scattered C cells were seen apart from the main tumor, suggesting a multicentric nature of certain medullary carcinomas. Some ACTH-containing cells were apparently also positive for calcitonin. In a case of familial Sipple disease, follicular lining cells were replaced in areas with ACTH-containing cells. Three to five frequency distribution curves of the size of secretory granules were obtained in all of 6 cases analyzed, and at least two different types of granule matrix were identified.
 ...
PMID:Immunohistochemical and ultrastructural analysis of medullary carcinoma of the thyroid in relation to hormone production. 20 64

The histochemical activity of alkaline phosphatase (Al-Pase), the induction of which is one of the effects of ACTH on the adrenocortical cells, was examined in 10 adrenocortical tumors causing Cushing's syndrome and in 65 adrenal cortices. All of the compact cells in every gland, and almost all, about half, or a small proportion in the four tumors showed Al-Pase activity. These tumors decreased in steroidogenesis after the administration of dexamethasone. No compact cells exhibited the activity in six tumors, none of which was "dexamethasone-suppressible". Three of the seven attached glands examined were halfway between those of typical Cushing's syndrome and those of other than Cushing's syndrome from the viewpoint of compact/clear cell morphology. All of the tumors that had Al-Pase-positive clear cells increased in steroidogenesis after ACTH administration. These results suggested that Al-Pase activity of tumor cells was also ACTH effect and that a decrease in steroidogenesis of tumors after dexamethasone administration was due not to fluctuations but to suppression of intrinsic ACTH.
 ...
PMID:Correlation of alkaline phosphatase staining of cortisol-producing adrenocortical tumors with dexamethasone suppression and ACTH stimulation. 20 55

The surface topologies of mouse adrenal cortex tumor cells of primary or clonal origin grown as monolayer cell cultures were observed by scanning electron microscopy following their exposure to substances that effect steroid release and/or cell rounding. ACTH induced cell rounding with a concomitant profuse development of fine microvilli in a non-synchronously dividing cell population. This was less pronounced with other steroidogenic substances and absent in EGTA or trypsin-treated cells. Morphological alterations occurred most rapidly with cAMP and least rapidly with dbcAMP. The rapid development of fine microvilli with ACTH is proposed to be a specific hormone mediated response.
 ...
PMID:Scanning electron microscopy of induced cell rounding of mouse adrenal cortex tumor cells in culture. 20 10

Pituitary adenomas should be classified not only by their tinctorial affinities but also by their degree of differentiation. Then useful correlation to the clinical data can be obtained; On this principle our own collection of 299 tumors was classified in undifferentiated acidophilic, highly differentiated acidophilic GH cell-, highly differentiated acidophilic prolactin cell-adenomas, in undifferentiated mucoid cell-, highly differentiated mucoid ACTH cell-, highly differentiated mucoid TSH cell-adenomas, in chromophobic adenomas of small cell type and of large cell type, and in oncocytic adenomas. 95% of the cases with acromegaly based on undifferentiated acidophilic or highly differentiated GH cell adenomas. All patients with hypothalamic-hypophyseal Cushing's syndrome or Nelson's syndrome had undifferentiated mucoid cell adenomas or highly differentiated ACTH cell adenomas. In cases with hyperprolactinemia prolactin cell adenomas or chromophobic adenomas of large cell type with ultrastructurally demonstrated very highly developed rough endoplasmic reticulum or endocrinologically inactive chromophobic adenomas of small cell type were found. In the latter cases the prolactin is probably produced not by the tumor but by the surrounding tumor-free pituitary tissue.
 ...
PMID:[Morphological classification of pituitary adenomas and its value for clinical diagnosis]. 20 6


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>