1/19. Significant gene expression of insulin-like growth factor ii and proliferating cell nuclear antigen in a rapidly growing recurrent pituitary acth-secreting adenoma.BACKGROUND: We quantified the expression of various growth-related factors in an adrenocorticotropic hormone (ACTH)-secreting adenoma that had recurred very rapidly as invasive macroadenoma. methods/RESULTS: A 43-year-old woman underwent successful transsphenoidal surgery for Cushing's disease. Seven years later, she was admitted to our ward for further endocrine examinations. In spite of a very high plasma ACTH level, the serum cortisol level was normal. Discrepancies between ACTH and cortisol levels were detected on the basis of diurnal rhythms, dexamethasone suppression tests, and corticotropin-releasing hormone test. The patient showed no clinical features of Cushing's disease. magnetic resonance imaging of the pituitary showed an almost empty sella, and no microadenoma was found. These results, along with those of Sephadex column gel filtration and high-performance liquid chromatography of plasma-immunoreactive ACTH, suggested that the patient's residual corticotrophs secreted biologically inactive ACTH. Two years later, the patient suddenly developed diplopia and right abducens nerve palsy. She was slightly moonfaced and centrally obese. Her plasma ACTH and serum and urinary free cortisol levels were elevated, although discrepancies between ACTH and cortisol still existed. magnetic resonance imaging revealed a large pituitary mass with suprasellar and cavernous sinus extensions. The tumor was excised, and the proopiomelanocortin gene and the expression of growth-related factors were analyzed. No mutations were found in the ACTH-coding region of the proopiomelanocortin gene. A significant expression of insulin-like growth factor II and proliferating cell nuclear antigen mRNAs was demonstrated. A high MIB-1 antibody labeling index was also detected in the adenoma tissue, suggesting high Ki-67 expression. CONCLUSION: These growth- and proliferation-related factors might be involved in the rapid growth and aggressiveness of this patient's pituitary adenoma.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
2/19. Absence of Cushingoid phenotype in a patient with Cushing's disease due to defective cortisone to cortisol conversion.Cushing's syndrome invariably presents with a classical phenotype comprising central adiposity, prominence of dorsal, supraclavicular and temporal fat pads, bruising, abdominal striae, proximal myopathy, and hypertension. We report the case of a 20-yr-old student with pituitary-dependent Cushing's syndrome who was spared this classical phenotype because of a defect in the peripheral conversion of cortisone to cortisol. She presented to her general practitioner with secondary amenorrhea. Clinical examination revealed normal fat distribution (body mass index, 20.9 kg/m(2)), absence of hirsutism, myopathy, or bruising; her blood pressure ranged from 115/70 to 122/82 mm Hg. She was investigated for biochemical hypercortisolemia because of a mildly elevated random circulating cortisol (serum cortisol, 661 nmol/liter). Cushing's syndrome was confirmed on the basis of repeatedly elevated urinary free cortisols (831-1049; reference range, <350 nmol/24 h), failure of low-dose dexamethasone suppression (611 nmol/liter) and loss of circadian cortisol secretion. Investigations suggested Cushing's disease; there was suppression after high-dose dexamethasone (<20 nmol/liter) and a 950% increase in ACTH after stimulation with CRH. Pituitary magnetic resonance imaging revealed a 3-mm adenoma within the pituitary gland. Urinary corticosteroid metabolites were analyzed by gas chromatography-mass spectrometry and demonstrated a decreased THF allo-THF/THE ratio of 0.66 (mean /- SE in Cushing's disease, 1.74 /- 0.24) suggesting a defect in 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), an enzyme that converts the inactive glucocorticoid cortisone to active cortisol. Transphenoidal microadenomectomy was performed, and histology confirmed the diagnosis of a corticotroph adenoma. Postoperatively, serum cortisol was undetectable and replacement therapy was commenced. Subsequent investigations revealed a significantly impaired ability to convert an oral dose of cortisone acetate (25 mg) to cortisol, reduced serum cortisol to cortisone ratios, and a reduced serum half-life for cortisol (57.3 min). These results provide strong evidence for a partial defect in 11beta-HSD1 activity and concomitant increase in cortisol clearance rate. We have described a case of Cushing's disease that failed to present with a classical phenotype, and we postulate that this is due to a partial defect of 11beta-HSD1 activity, the defect in cortisone to cortisol conversion increasing cortisol clearance and thus protecting the patient from the effects of cortisol excess. This observation may help to explain individual susceptibility to the adverse effects of glucocorticoids.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
3/19. meningioma presenting with Cushing's syndrome: an unusual clinical presentation.We report a patient with a meningioma presenting with Cushing's syndrome, an unprecedented paraneoplastic presentation. Molecular studies, bioassay, and high-performance liquid chromatography of tumor specimens demonstrated the synthesis and secretion of bioactive corticotropin-releasing hormone. To our knowledge, this appears to be the first report of a hormone-secreting meningioma and, further, the first clearly proven case of Cushing's syndrome due to ectopic corticotropin-releasing hormone secretion without concomitant corticotropin production.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
4/19. Pseudo-cushing syndrome caused by fenofibrate interference with urinary cortisol assayed by high-performance liquid chromatography.Urinary free cortisol (UFC) excretion over 24 h reflects the production rate of cortisol and is used commonly in the diagnosis of cushing syndrome. We report on two patients evaluated for cushing syndrome who had elevated UFC when analyzed by HPLC but normal values for the analysis performed by RIA and HPLC-mass spectrometry/mass spectrometry (HPLC-MS/MS). Other laboratory testing was inconsistent with the diagnosis of cushing syndrome and raised doubts about the diagnosis. We identified a probable cause of analytical interference as coming from fenofibrate (Tricor), medication taken by the patients. fenofibrate peak overlapped with the HPLC peak of cortisol and produced an MS/MS transition overlapping the major transition of cortisol. A second MS/MS transition was free from interference. In summary, fenofibrate administration may cause false elevation of UFC values determined by HPLC or HPLC-MS/MS in patients evaluated for cushing syndrome. An HPLC-MS/MS method using multiple mass transitions, rather than a single transition, allows accurate quantitation of urinary cortisol in patients taking fenofibrate.- - - - - - - - - - ranking = 4keywords = chromatography (Clic here for more details about this article) |
5/19. Cushing's syndrome after intra-articular and intradermal administration of triamcinolone acetonide in three pediatric patients.BACKGROUND: Intra-articular and intradermal steroids are often used for their antiinflammatory effect. There is limited experience with intra-articular and intralesional administration of corticosteroids in the pediatric age group. DESIGN/methods: We performed a retrospective chart review of 3 pediatric patients who developed Cushing's syndrome after local administration of triamcinolone acetonide (TCA). RESULTS: Two females 9 and 17 years old, received intra-articular injections of TCA. One patient received multiple injections of TCA into the interphalangeal joints (cumulative dose: 120 mg), whereas the other received a single injection of 40 mg, a dose that is considered to be in the therapeutic range, into the hip joint. The third patient, a 7-year-old female, received multiple intralesional injections of TCA. These patients developed signs and symptoms of hypercortisolism that appeared 4 to 6 weeks after local administration of TCA and lasted for 4 to 6 months after the last dose of TCA. TCA was detectable in the plasma and urine by the liquid chromatography/tandem mass spectrometry method 4 to 5 months after the last dose of the steroid. CONCLUSIONS: We noted evidence for Cushing's syndrome in 3 pediatric patients after intra-articular or intradermal administration of TCA. One of them had received a therapeutic dose of TCA. The possibility of hypothalamic-pituitary-adrenal axis suppression should be considered in patients who have received intra-articular or intradermal steroid injections, particularly in those who have had multiple or relatively high doses.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
6/19. Aberrant production and regulation of proopiomelanocortin-derived peptides in ectopic Cushing's syndrome.A 64 year old woman with a pancreatic islet cell tumor developed Cushing's syndrome. Glucocorticoid secretion did not decrease after low or high dose dexamethasone administration, and the Cushing's syndrome was cured by removal of tumor tissue. immunohistochemistry and radioimmunoassays revealed the presence of immunoreactive ACTH, beta-endorphin and alpha-msh in the tumor cells. Gel-permeation chromatography confirmed that beta-endorphin was the predominant opioid peptide produced by the tumor. The tumor was shown to contain a single 1.2 kilobase rna species which hybridized to a 32P human POMC-cDNA; this POMC rna was identical in size to that isolated from a normal human pituitary. In dispersed monolayer culture, CRF failed to elicit ACTH release from the tumor cells, but dexamethasone caused a paradoxical increase in ACTH secretion in vitro. This study demonstrates that aberrant regulation of POMC synthesis and peptide processing can be seen in tumors which synthesize a POMC rna identical in size to that made in the pituitary gland.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
7/19. A pituitary adenoma secreting high molecular weight adrenocorticotropin without evidence of Cushing's disease.We report a patient with hypersecretion of a high mol wt ACTH from an aggressive corticotropic pituitary tumor who did not have hypercortisolism. Basal plasma ACTH levels were clearly elevated (26-121 pmol/L), whereas basal and stimulated serum cortisol levels were in the normal range. The pituitary source of the ACTH hypersecretion was confirmed by selective venous catheterization. Gel chromatography of the patient's plasma showed two peaks of ACTH immunoreactivity, one major peak eluting near the void volume (high mol wt form of ACTH), accounting for more than 95% of the ACTH detected, and a very small peak at the expected position of ACTH-(1-39). plasma ACTH levels were not altered by metyrapone or bromocriptine. During high dose dexamethasone administration plasma ACTH decreased, but was not fully suppressed. Immunohistochemical evaluation of tumor tissue demonstrated ACTH immunoreactivity in 40% of the tumor cells. The patient died from postoperative complications after a second operation performed after tumor recurrence. This patient's course confirms the observations of relatively rapid growth and high recurrence rate in clinically silent corticotropic pituitary adenomas.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
8/19. multiple endocrine neoplasia with Cushing's syndrome due to paraganglioma producing corticotropin-releasing factor and adrenocorticotropin.A male patient with corticotropin-releasing factor (CRF) and adrenocorticotropin (ACTH)-producing syndrome is described. Soon after being referred to us the patient developed pneumonia, anaemia, oedema and respiratory distress, and died on the 24th day after admission. autopsy and histology revealed that he had a rare type of multiple endocrine neoplasia (type 1 paraganglioma) with a mediastinal paraganglioma, parathyroidal hyperplasia, pancreatic islet cell adenoma, duodenal multiple carcinoid tumours and adrenocortical nodular hyperplasia. It was not possible to examine the pituitary. The paraganglioma contained a large amount of immunoreactive (IR)-CRF (606 ng/g wet weight), IR-ACTH (59.4 ng/g wet weight), IR-human proopiomelanocortin n-terminal (1-76) peptide (hNT, 156.8 ng/g wet weight) and IR-beta-lipotropin (beta-LPH, 146.9 ng/g wet weight). The major IR-ACTH, beta-LPH and IR-hNT were eluted at ACTH-(1-39), beta-LPH and hNT marker positions, respectively. Big ACTH was not detected. IR-CRF eluted at the human CRF marker position on Sephadex G-75 chromatography and high performance liquid chromatography (HPLC). The IR-CRF fraction from the HPLC showed CRF bioactivity which paralleled that of synthetic human CRF in monolayer cultured rat anterior pituitary cells. Our results suggest that not only ACTH but CRF produced by the paraganglioma was responsible for the patient's Cushing's syndrome.- - - - - - - - - - ranking = 2keywords = chromatography (Clic here for more details about this article) |
9/19. A case of pituitary dependent Cushing's disease with clinical and biochemical features of the ectopic ACTH syndrome.A case of atypical pituitary dependent Cushing's disease is reported. The patient presented with clinical symptoms similar to those of the ectopic ACTH syndrome; notably a marked hypokalaemic alkalosis, widely fluctuating plasma cortisol levels, greatly elevated plasma ACTH levels, and failure to suppress both plasma cortisol and ACTH levels following high dose oral dexamethasone. However, a large aggressive pituitary tumour was detected by skull X-ray and computed tomography. Removal of the pituitary tumour led to full remission of the patient's Cushing's syndrome. pro-opiomelanocortin (POMC) related peptides in the plasma and tumour tissue extract of this patient have been characterized by gel-filtration and Concanavalin-A sepharose affinity chromatography, indicating processing of POMC in a manner more usually associated with ectopic tumours.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
10/19. Effect of ovine corticotrophin releasing factor, bromocriptine, and dopamine on release of ACTH and beta-endorphin in a patient with Cushing's disease.Release of immunoreactive ACTH and beta-endorphin (beta-EP) in response to corticotrophin-releasing factor (CRF) and dopaminergic agents was studied in vivo and in vitro in a patient with Cushing's disease. Iv administration of synthetic ovine (o) CRF significantly stimulated plasma ACTH release, accompanied by increase of plasma cortisol levels. Oral administration of bromocriptine significantly suppressed plasma cortisol levels. Although reduced responses of plasma ACTH and cortisol to o-CRF was observed 1 month after removal of the pituitary adenoma, these normalized 6 months after operation. in vitro perifusion of the pituitary adenoma obtained by surgery revealed that o-CRF also stimulated ACTH and beta-EP release in a dose-responsive manner (10(-9)M 10(-5)M) and that dopamine suppressed their basal secretion. Gel exclusion chromatography of the perfusates showed that the predominant component of ACTH and beta-EP before and after o-CRF stimulation coeluted with standard ACTH and beta-EP, respectively. The present data suggest that o-CRF is a potent secretagogue for ACTH and beta-EP release from the human pituitary adenoma causing Cushing's disease and that ACTH secretion from certain adenomas, possibly originating from the intermediate lobe of the pituitary gland, is partly regulated by a dopaminergic mechanism.- - - - - - - - - - ranking = 1keywords = chromatography (Clic here for more details about this article) |
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