Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01350 (gastrin)
 9,683 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Inhibition of pancreatic glucagon secretion has been reported to be mediated by glucose, insulin and somatostatin. As no human pancreatic alpha-cell lines are available to study in vitro the relative importance of insulin and glucose in the control of pancreatic glucagon release, we investigated a patient presenting with a malignant glucagonoma who underwent surgical resection of the tumour. Functional somatostatin receptors were present as octreotide administration decreased basal glucagon and insulin secretion by 52 and 74%, respectively. The removed tumour was immunohistochemically positive for glucagon, chromogranin A and pancreatic polypeptide but negative for insulin, gastrin and somatostatin. The glucagonoma cells were also isolated and cultured in vitro. Incubation experiments revealed that change from high (10 mM) to low (1 mM) glucose concentration was unable to stimulate glucagon secretion. A dose-dependent inhibition of glucagon release by insulin was however, observed at low glucose concentration. These findings demonstrate that insulin could inhibit glucagon secretion in vitro in the absence of elevated glucose concentrations. These data suggest, as observed in vivo and in vitro in several animal studies, that glucopenia-induced glucagon secretion in humans is not mediated by a direct effect of low glucose on alpha-cells but possibly by a reduction of insulin-mediated alpha-cell suppression and/or an indirect neuronal stimulation of glucagon release.
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PMID:In vivo and in vitro effects of somatostatin and insulin on glucagon release in a human glucagonoma. 923 Oct 61

Most of the neuroendocrine tumours produce and secrete a large number of peptide hormones and amines. Each of these substances cause a specific clinical syndrome: carcinoid, Zollinger-Ellison, hyperglycaemic, glucagonoma and WDHA syndrome. Specific markers for these syndromes are basal and/or stimulated levels of: urinary-5-HIAA, serum or plasma gastrin, insulin, glucagon, and VIP, respectively. About 1/3 of neuroendocrine tumours belong to the so-called "non-functioning" tumours. Therefore, general markers such as chromogranin A, pancreatic polypeptide, serum neuronspecific enolase and subunit of glycoprotein hormones have been used for screening purposes in patients without distinct clinical hormone related syndromes. Among these general tumour markers chromogranin A, although its precise function is not yet established, has been shown to be a very sensitive and specific serum marker for various types of neuroendocrine tumours. This is because it may also be increased in many cases of less well differentiated tumours of neuroendocrine origin that do not secrete known hormones. Then chromogranin A is considered the best general neuroendocrine serum or plasma marker available at the moment and is increased in 50-100% of patients with various neuroendocrine tumours. Chromogranin A serum or plasma levels reflect tumour load and may be an independent marker of prognosis in patients with midgut carcinoids.
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PMID:Tumour markers in neuroendocrine tumours. 1060 22

Most neuroendocrine tumors produce and secrete a multitude of peptide hormones and amines. Some of these substances cause a specific clinical syndrome: carcinoid, Zollinger-Ellison, hyperglycemic, glucagonoma and WDHA syndrome. Specific markers for these syndromes are basal and/or stimulated levels of urinary 5-HIAA, serum or plasma gastrin, insulin, glucagon and vasoactive intestinal polypeptide, respectively. Some carcinoid tumors and about one third of endocrine pancreatic tumors do not present any clinical symptoms and are called 'nonfunctioning' tumors. Therefore, general tumor markers such as chromogranin A, pancreatic polypeptide, serum neuron-specific enolase and subunits of glycoprotein hormones have been used for screening purposes in patients without distinct clinical hormone-related symptoms. Among these general tumor markers chromogranin A, although its precise function is not yet established, has been shown to be a very sensitive and specific serum marker for various types of neuroendocrine tumors. This is because it may also be elevated in many cases of less well-differentiated tumors of neuroendocrine origin that do not secrete known hormones. At the moment, chromogranin A is considered the best general neuroendocrine serum or plasma marker available both for diagnosis and therapeutic evaluation and is increased in 50-100% of patients with various neuroendocrine tumors. Chromogranin A serum or plasma levels reflect tumor load, and it may be an independent marker of prognosis in patients with midgut carcinoids.
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PMID:Tumor markers in neuroendocrine tumors. 1094 Jun 85

A 58-year-old patient had been treated for recurrent gastritis. Numerous gastroscopies indicated hemorrhagic gastritis combined with increasingly severe anemia. The patient was admitted with a hemoglobin of 4.4 g/dL. Gastroscopy showed marked antral angiodysplasia. Serum samples for gastrin were taken and found to be elevated (170-250 U/mL). The search for a gastrin-producing tumor with abdominal ultrasound, computed tomography, octreotide scan, and secretin test was negative, but angiography detected a pancreas tumor with a 2-cm diameter. Partial pancreatectomy and partial gastrectomy were performed. Immunohistochemical examination of the tumor did not show a gastrinoma but did show glucagon-reactive tissue. Further tumors or elevated plasma hormone levels were not detected, and a multiple endocrine neoplasia type I syndrome could be excluded. We thus found antral angiodysplasia with hypergastrinemia leading to detection of a glucagonoma diagnosed by immunohistochemistry. After more than 4 years of follow-up, the patient is without any symptoms or signs of relapse or secondary hormone syndrome.
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PMID:Immunohistochemical assessment of an asymptomatic glucagonoma in a patient with hypergastrinemia and marked antral angiodysplasia. 1127 23

Gastroenteropancreatic (GEP) neoplasms originate from any of the various cell types belonging to the neuroendocrine system. A general characteristic of GEP endocrine tumours is that the vast majority produce and secrete a multitude of peptide hormones and amines. Many patients with malignant metastasising tumours present clinical symptoms related to hormone hyperproduction. These include the so-called carcinoid syndrome, characterised by flushing, diarrhoea, wheezing and right heart disease, which is predominantly associated with the serotonin- and tachykinins-producing carcinoids of the midgut. Several types of syndrome associated with GEP endocrine tumors are caused by overproduction of a specific hormone. For instance, the well-known Zollinger-Ellison syndrome is gastrin-mediated. The so-called 'insulinoma syndrome' depends on excessive production of insulin and proinsulin, resulting in hypoglycemia. The 'glucagonoma syndrome' is characterised by necrolytic migratory erythema, diabetes and diarrhoea. The Verner-Morrison syndrome, which is brought about by high circulating levels of vasointestinal peptide (VIP). produces severe secretory diarrhoea. Finally the 'somatostatinoma syndrome' involves gallbladder dysfunction and gallstones, diarrhoea with or without steatorrhea, and impaired glucose tolerance. The biochemical diagnosis of endocrine digestive tumors is based on general and specific markers. The best general markers are chromogranin A (CgA) and pancreatic polypeptide (PP). Specific markers for endocrine tumors include insulin, gastrin, glucagon, vaso intestinal polypeptide (VIP), somatostatin and the primary cathabolic product of serotonin, 5-hydroxyndoleacetic acid (5-HIAA). Localisation procedures commonly applied, in the diagnosis of endocrine tumours include ultrasound (US), computed tomography (CT) and somatostatin receptor scintigraphy (SRS).
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PMID:Epidemiology, clinical features and diagnosis of gastroenteropancreatic endocrine tumours. 1176 60

Neuropilin-2 (NP-2) is a cell surface transmembrane protein originally characterized as a receptor for the type 3 semaphorins, and more recently for a number of vascular endothelial growth factor (VEGF) isoforms. NP-2 expression has been recently localized to a subset of neuroendocrine cells in the gastrointestinal tract. The aim of this study was to define the expression pattern of NP-2 in normal pancreatic islets and to determine the utility of NP-2 expression as a diagnostic marker of pancreatic endocrine tumours. Paraffin-embedded tissue sections from 30 endocrine pancreatic tumours (EPTs) and from normal pancreas were immunostained with a rabbit polyclonal antibody generated towards NP-2. Nineteen of the tumours were hormonally functional (nine insulinomas, nine gastrinomas, and one glucagonoma). The NP-2 staining pattern was correlated with islet cell hormone expression. In addition, NP-2 expression was evaluated in other normal neuroendocrine tissues and neuroendocrine neoplasms. In normal pancreas, NP-2 stained a distinct subset of islet cells situated primarily at the islet periphery. Double immunohistochemical staining revealed co-localization with glucagon-expressing cells. Moderate to strong NP-2 staining was present in 27 of 30 EPTs. Serial staining of the pancreatic tumours with insulin, gastrin, glucagon, pancreatic polypeptide (PP) or somatostatin did not reveal a distinct pattern of co-localization. NP-2 expression was not detected in neuroendocrine cells outside the gastroenteropancreatic system, or in their corresponding neoplasms, except for focal staining in one bronchial carcinoid tumour. In conclusion, the vast majority of EPTs examined expressed NP-2, suggesting its utility as a diagnostic marker for these tumours. The function of NP-2 in islet cell biology or tumourigenesis remains to be elucidated.
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PMID:Neuropilin-2 is a novel marker expressed in pancreatic islet cells and endocrine pancreatic tumours. 1221 66

Glucagonoma of the pancreas is a rare tumor with distinct clinical manifestations, such as necrolytic migratory erythema,weight loss, anemia, diabetes mellitus, and hypoamino-acidemia. We report the case of a 68-year-old Japanese man who underwent curative resection for malignant glucagonoma of the pancreas diagnosed through anemia and diabetes mellitus. The patient had had diabetes mellitus for 20 years. Anemia was diagnosed in 1998. On admission, the hemoglobin level was 8.3g/dl, but the levels of serum iron, vitamin B12, and erythropoietin and, the number of reticulocytes were within normal limits. The levels of carcinoembryonic antigen (CEA), carbohydrate antigen (CA)19-9, and DUPAN-2 were also within normal limits, and exocrine function of the pancreas (PFD, 75%) was normal. Ultrasonography (US) revealed a hypoechoic tumor in the distal pancreas. Computed tomography (CT) demonstrated a high-density area 4 cm in diameter with calcification. The serum glucagon level was very high (2360 pg/ml), but the levels of other hormones such as somatostatin or gastrin were within normal limits, while insulin was low. Glucagonoma of the pancreas was diagnosed, and distal pancreatectomy with splenectomy was performed. Histological examination revealed a malignant endocrine tumor,which was immunohistochemically positive for chromogranin A and glucagon. Two months after the operation, the serum glucagon level had decreased to within normal limits and the hemoglobin level had increased to 10.4 g/dl. The case of glucagonoma reported here was found through diagnostic examinations of anemia and treated by surgical resection, by which the patient's anemia was largely alleviated. Therefore, we recommend checking patients who have diabetes mellitus and anemia in order to diagnose and treat glucagonoma in its early stage.
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PMID:Malignant glucagonoma of the pancreas diagnoses through anemia and diabetes mellitus. 1291 65

Over the last decade somatostatin receptor scintigraphy using various derivatives of long-acting somatostatin analogues has gained its place in the management of pancreatic islet-cell tumours. Scintigraphy is based on the high-affinity binding of such somatostatin analogues to receptors over-expressed by these tumour types. Following the introduction of (111)In-DTPA-D-Phe(1)-octreotide, clinical studies with radiolabelled DOTA-Tyr(3)-octreotide and DOTA-Tyr(3)-octreotate derivatives have shown considerable improvement of imaging results with increased tumour uptake. One of the newer developments, (68)Ga-labelled DOTA-Tyr(3)-octreotide, has shown promising results in patients with pancreatic islet-cell tumours, based on the high-affinity binding to the somatostatin receptor subtype 2 in combination with positron emission tomography (PET) technology. Other peptides--such as ligands for the gastrin/CCK2 receptors or vasoactive intestinal peptide (VIP)--have also been studied for imaging pancreatic cell tumours. Whereas small-sized gastrinoma, somatostatinoma, glucagonoma, carcinoid and VIPoma are frequently detected by somatostatin receptor scintigraphy, insulinoma may escape detection due to reduced receptor expression. Following peptide receptor scintigraphy, a change in patient management is reported in up to 30% of patients. When labelled with (90)Y or (177)Lu, some somatostatin analogues have been applied to patients in advanced stages of the disease. Despite positive response data in 50% of patients, long-term results and survival rates are lacking.
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PMID:Nuclear medicine in the detection and management of pancreatic islet-cell tumours. 1576 96

Several circulating or urinary tumour markers can be used for the diagnosis and follow-up of functioning and clinically non-functioning neuroendocrine tumours of the pancreatic islet cells and intestinal tract. Among the specific tumour markers are serotonin and its metabolites--e.g. 5-hydroxyindoleacetic acid (5-HIAA)--in carcinoid tumours and the carcinoid syndrome, insulin and its precursors or breakdown products in insulinoma, and gastrin in gastrinoma. Plasma vasointestinal polypeptide (VIP) determinations have been used in the diagnosis of VIPoma, plasma glucagon for glucagonoma, and serum somatostatin for somatostatinoma. Among the tumour-non-specific markers are: chromogranins, neuron-specific enolase (NSE), alpha-subunits of the glycoprotein hormones, catecholamines, pancreatic polypeptide (PP), ghrelin and adrenomedullin.
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PMID:Biochemistry of neuroendocrine tumours. 1738 64

Duodeno-pancreatic neuroendocrine tumours (DP-ETs) are increasingly diagnosed today due to the widespread use of modern imaging methods. Duodeno-pancreatic endocrine tumours should be treated by radical surgical resection, which offers a high chance for cure when the disease is localized. A high index of suspicion is required in these patients for the presence of a multiple endocrine neoplasia type syndrome. We present four patients with DP-ET surgically treated at our department between 2000 and 2004. Histological/immunohistochemical diagnosis was somatostatin-producing tumour in the first patient, oncocytic endocrine tumour positive for neurone-specific enolase and focally for chromogranin in the second patient, glucagonoma and pancreatic polypeptide-producing endocrine pancreatic tumour in the third patient, and gastrin, somatostatin, calcitonin, insulin and adrenocorticotropic hormone (ACTH)-producing tumour in the fourth. The second patient died 6.5 years following surgery due to disseminated disease.
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PMID:Duodeno-pancreatic neuroendocrine tumours. 1970 40


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