Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0001430 (adenoma)
 21,222 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Normal insulin secretagogues, including glucose, usually have little influence on insulin secretion from insulinomas. Therefore, insulinomas typically cause fasting hypoglycemia with relative hyperinsulinemia. This report describes a patient with hyperinsulinemia due to an islet cell adenoma with microadenomatosis, which, upon provocative in vivo testing, was found to be profoundly responsive to hypoglycemic and hyperglycemic stimuli. A 72 hr fast followed by brisk exercise resulted in a gradual reduction of serum glucose and insulin concentrations, but did not provoke symptomatic hypoglycemia. Oral glucose tolerance testing resulted in a prompt 10-fold increase in serum insulin accompanied by a mildly symptomatic and gradual fall in serum glucose to 30 mg/dl 90 minutes after glucose ingestion. An intravenous glucose challenge caused an acute increase in serum insulin to more than 1200 microU/ml with a resulting serum glucose of 11 mg/dl 25 minutes later, associated with loss of consciousness. Although a prolonged fast has proven to be the best diagnostic test for insulin secreting tumors, many other provocative tests that use normal insulin secretagogues have been somewhat useful in this regard. The patient in this report supports the concept that insulinomas vary widely in their response to a number of normal physiologic regulators of insulin secretion, including the serum glucose concentration. A variety of provocative tests may be needed to fully evaluate the rare patient in whom there is a strong clinical suspicion of insulinoma but who has a nondiagnostic prolonged fast.
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PMID:Case report: a glucose responsive insulinoma--implication for the diagnosis of insulin secreting tumors. 147 55

The binding of 123I-Tyr-3-octreotide (SDZ-204-090; specific activity 1 mCi/nmol), a new somatostatin-receptor binding radiopharmaceutical, to human tumour membrane fractions was evaluated in presence of unlabeled Tyr-3-octreotide and octreotide (SMS-201-995; Sandostatin). Tumour tissue was obtained intraoperatively from 15 patients with different endocrine tumours (insulinoma, carcinoide, phaechromocytoma, hypophysal adenoma) and breast cancer. In equilibrium experiments, membrane fractions (200 micrograms protein/ml) were incubated with increasing concentrations of 123I-Tyr-3-octreotide (0.03-30 nM) in presence or absence of 5 microM of unlabeled agonist. Binding capacities ranged from 1-20 pmol/mg protein (Kd 4-100 nM). The IC50 values (2.5-112 nM versus 0.02-69 nM) were different for the octreotide and Tyr-3-octreotide indicating that octreotide was the better competitor as Tyr-3-octreotide for 123I-Tyr-3-octreotide binding sites. In ductal breast cancer high numbers of in vitro binding sites for the radiolabel were found. In initial clinical studies 123I-Tyr-3-octreotide was i.v.-injected (3 mCi) to 5 acromegaly patients with hypophyseal adenomas. Following rapid uptake by the liver, positive tumour imaging was obtained in 3 patients which correlated to computer tomographic findings. Positive images were obtained just some minutes after injection. Our results support recent data suggesting that the 123I-Tyr-3-octreotide would be a suitable receptor-radiopharmaceutical for the localization of endocrine tumours.
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PMID:Evaluation of somatostatin receptors in human cancer. 166

The radiologic work-up of a patient with multiple endocrine neoplasia type 1 (MEN 1) syndrome and multiple endocrine nodules, with coincidental renal cell carcinoma, is described. Parathyroid adenoma was differentiated from multiple thyroid nodules by gadolinium-enhanced MRI. Adrenal enlargement due to a nonfunctioning adenoma and a renal cell carcinoma next to a simple renal cortical cyst were identified by typical signal intensities on T1- (pre- and post-Gd-DPTA) and T2-weighted images. Insulinoma was visualized only retrospectively.
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PMID:Contrast MRI in multiple endocrine neoplasia type 1 (MEN) associated with renal cell carcinoma. 197 Sep 58

Inhibition of C-Peptide secretion by exogenous insulin was studied during euglycemic clamp in 13 patients with histologically verified causes of organic hyperinsulinaemia (10 with beta cell adenoma; 2 with beta cell carcinoma and 1 with beta cell hyperplasia) and in 10 healthy controls. Euglycemic clamps were performed using artificial endocrine pancreas (Clamp Mode 9:1) while insulin infusion (Humulin Normal-Lilly) rate was 0.1 U/kg BW/h. Blood samples for serum insulin (RIA INEP) and C-Peptide (RIA-Biodata) were taken at 0; 30; 60; 90 and 120 min. Statistical analysis was done using SPSS on IBM-PC with Wilcoxon sum rank test and one way ANOVA. All the patients were studied before the operation and in four of them clamp studies were repeated after the operation. Statistically significant suppression of C-Peptide values in 120 min was established in the control group (p less than 0.05) while there was no significant suppression in insulinoma group (p greater than 0.05), except in one patient with beta cell hyperplasia. Various types of responses (suppression, no change, paradoxical increase) were observed after the operation in the insulinoma group. Possible mechanisms and the meanings of the absence of insulin induced C-Peptide suppression in insulinoma group are discussed. It is concluded that euglycemic hyperinsulinemic clamp study could be useful and a complementary test to other established tests for the confirmation of the diagnosis of insulinoma. Further work on beta cell response after the operation in patients with insulinoma is necessary.
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PMID:How reliable is the euglycaemic hyperinsulinemic clamp test for the confirmation of autonomous endogenous hyperinsulinemia? 216 78

The effects of octreotide in vivo and in vitro on hormone release, in vivo [123I]Tyr3-octreotide scanning, and in vitro [125I]Tyr3-octreotide autoradiography were compared in five patients with endocrine pancreatic tumors. [123I]Tyr3-octreotide scanning localized the primary tumor and/or previously unknown metastases in four of the five patients. The patient with a negative scan had an insulinoma that did not respond to octreotide in vivo. No Tyr3-octreotide-binding sites were subsequently found at autoradiography of the tumor, whereas somatostatin-14 receptors were present at a high density. In parallel, culture studies with the cells prepared from this adenoma showed that insulin release was not affected by octreotide, while both somatostatin-14 and -28 significantly suppressed hormone release. Culture studies of the tumor cells from two gastrinomas showed a dose-dependent inhibition of gastrin release by octreotide. Octreotide exerted direct antiproliferative effects in one of these gastrinomas, which had been shown to be rapidly growing in vivo. Both gastrinomas had specific somatostatin receptors, as measured by in vitro receptor autoradiography. Somatostatin release by the cultured somatostatinoma cells from one of these patients was suppressed by octreotide. In conclusion, 1) the [123I]Tyr3-octreotide scanning procedure is valuable in the localization of primary endocrine pancreatic tumors as well their often clinically not yet recognized metastases; 2) the in vitro detection of somatostatin receptors in those tumors that were also visualized in vivo after injection of [123I] Tyr3-octreotide indicates that the ligand binding to the tumor in vivo indeed represents binding to specific somatostatin receptors; and 3) the parallel between the presence of somatostatin receptors on tumors and in in vivo and in vitro effects of octreotide on hormonal release from these tumors indicate that a positive scan predicts a good suppressive effect of octreotide on hormonal hypersecretion by these tumors.
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PMID:Parallel in vivo and in vitro detection of functional somatostatin receptors in human endocrine pancreatic tumors: consequences with regard to diagnosis, localization, and therapy. 216 29

Eighteen cases of insulinoma treated at the Instituto Nacional de la Nutricion in Mexico City are presented. The cases were operated on between 1959 and 1988, and include 10 women and 8 men with a mean age of 38. The duration of symptoms ranged between 4 and 96 months with a median of 27; 78% of the patients had neuropsychiatric symptoms, 61% seizures, and 55% loss of consciousness. One of the patients had evidence of type I multiple endocrine neoplasia. Diagnosis was established in all the patients with the demonstration of Whipple's triad and also with an elevated insulin determination in the last nine patients. In six cases the insulinoma was enucleated; in two a Whipple procedure was performed; in nine a distal pancreatectomy and in the remaining patient only resection of hepatic metastases; 67% of the tumors were diagnosed as benign solitary adenomas, 16.5% as carcinomas and the same number as hyperplasia. Operative mortality was 5.5%, and morbidity 44%. The three carcinomas survived 6, 8 and 36 months. Disappearance of the hypoglycemic symptoms was obtained in 93% of the cases of adenoma and hyperplasia.
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PMID:[Surgical treatment of insulinoma. Experience at the Salvador Zubiran National Nutrition Institute]. 255 Oct 25

We reported a case of sporadic multiple endocrine neoplasia type 1, with multiple insulinoma, parathyroid adenoma, and pituitary tumor. Measurement of hormone contents and immunohistochemical studies of the pancreatic tumors showed that the tumors contained insulin, glucagon, somatostatin, and pancreatic polypeptide. Furthermore, the concentrations of these hormones were different in each tumor. Insulin extracted from the pancreatic tumors analyzed by reversed-phase high performance liquid chromatography revealed no structural abnormalities. On the other hand, in gel filtration evaluation of the extract of the parathyroid adenoma, it was found that the tumor extract contained a macromolecular parathyroid hormone (molecular weight 20,000 to 25,000).
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PMID:A case of multiple endocrine neoplasia (MEN) type 1; the immunohistochemical and ultrastructural studies of its tumors and the analysis of hormones in tumor extracts. 256 30

For the purpose of determining the significance of CGRP for endocrine tumors, we attempted to establish CGRP radioimmunoassay (RIA) system and to measure plasma CGRP levels in patients with endocrine tumor. One ml of plasma (EDTA-2K + aprotinin 500.KIE/ml) was applied to Sep-Pak C 18 column, and was eluted by 90% MeOH plus 0.1% TFA. The eluted samples were used for RIA. RIA was performed by two day-one day system (delayed assay). B/F separation was made by two Ab-PEG method. Cross-reactivity of antisera was 0.0025% and below 0.0001% against PTH and calcitonin in human, respectively. The standard curve of CGRP showed a dose response curve. Results of dilution and reproduction tests were excellent. Normal range of serum CGRP was 6.7 +/- 3.0 pg/ml (M +/- SD) and the cut-off level was determined to be 12.7 pg/ml. Plasma CGRP showed 128,323 and 2,010 pg/ml in three preoperative patients with medullary thyroid carcinoma, indicating extremely high levels. On the other hand, plasma CGRP levels increased in 2/7, 2/4, 2/5, and 0/3 in patients with parathyroid adenoma, benign insulinoma, carcinoid and pheochromocytoma, respectively. Correlation between CGRP level and calcitonin levels was significant (r = 0.789) in only 16 patients with medullary thyroid carcinoma. This study suggests that our CGRP RIA system was satisfactory for clinical use and measurement of CGRP may be potentially useful for clearing the pathophysiology of neuroendocrine tumors, although CGRP level was raised in patients with medullary thyroid carcinoma.
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PMID:[Radioimmunoassay of plasma calcitonin gene-related peptide (CGRP) levels in patients with endocrine tumor]. 278 8

This report is based on 31 years of experience with 116 cases of hyperinsulinism. Six cases had hypertrophy of the islets of Langerhans, 3 had widespead metastasis from malignant insulinomas, and 107 were benign adenoma cases. An immunoreactive insulin to glucose ratio of 0.3 of the peripheral venous blood before operation is of great value in diagnosing hyperinsulinism. Intraoperatively, immunoreactive insulin assay of the portal blood (IRI) is very valuable in determining if an insulinoma remains. The dividing line is 100 microU.ml-1. In localizing the tumor, "differential" PTPC is important before operation. During the operation, fine needle aspiration cytology may assist in ascertaining if the palpable tumor is an insulinoma. Multiple fine needle aspiration cytology examinations can sometimes reveal an insulinoma in an indurated pancreas. Portal vein blood IRI and blood sugar assays may serve to confirm if removal of the insulinoma is complete. Removal of the insulinoma controls hypoglycemia satisfactorily, but the brain damage incurred by prolonged hypoglycemia cannot be significantly altered. Removal of the tumor should be by enucleation, and the raw surface of the pancreas should be drained not sutured.
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PMID:Insulinoma: 31 years of tumor localization and excision. 284 57

The usefulness and the limits of the artificial endocrine pancreas in the surgical management of insulinoma has been evaluated in three male patients who underwent pancreatic resection because of previously detected adenoma. In particular, blood glucose and contemporary levels of insulin and C-peptide were continuously monitored before, during and after surgery, to record the temporal relationship between the removal of insulinomas and the variations of these parameters. In the pre-resection phase, only two cases revealed hypoglycemia and required dextrose infusion to correct hypoglycemia and reach euglycemic levels, whereas all the patients showed elevated insulin and C-peptide levels. After anesthesia and surgical incision, the pancreas was observed and manipulated in search of adenoma. In all patients this manoeuvre caused an increase of insulin and C-peptide levels and in two cases a slight decrease of blood glucose levels. After adenoma resection, a prompt increase of glycemia was observed only in one patient, in the other two the time which elapsed before significant blood glucose changes was more prolonged (55 and 80 min. respectively). On the contrary, a rapid fall in insulin and C-peptide levels was observed in all cases. We conclude that artificial endocrine pancreas has the advantage of maintaining the normoglycemia before and during surgery, preventing the risk of dangerous hypoglycemia in basal conditions and following manipulation of pancreas while localizing adenoma. However, the prolonged interval elapsed before significant blood glucose variations limits the usefulness of the artificial endocrine pancreas in localizing intraoperatively previously undetected adenomas.
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PMID:The artificial endocrine pancreas in the surgical treatment of insulinoma. Usefulness and limits. 299 75


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