Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Approximately one third of the female mice of the LTXBO strain develop spontaneous ovarian teratomas. These tumors contain a large neuroepithelial component, which includes primitive neural structures resembling embryonic neural tubes (medulloepithelial rosettes), ependymoblastic and ependymal rosettes, neuroblasts, mature ganglionic neurons, myelinated neurites, and astrocytes. The purpose of this study was to characterize these tumors according to the immunohistochemical location of some well-characterized trophic and regulatory neuropeptides and neurotransmitters, several neuronal-associated cytoskeletal proteins, and other proteins indicative of neuronal and glial differentiation. Medulloepithelial rosettes showed focal serotonin-like, opioid peptide-like and gamma-amino butyric acid-like immunoreactivity, and displayed immunostaining for the neuron-associated class III beta-tubulin isotype. The mature ganglion cells were also immunoreactive for these markers, and, in addition, for somatostatin, cholecystokinin, bombesin, glucagon, vasoactive intestinal peptide, and neuropeptide Y. Mature ganglion cells were also immunoreactive for proteins associated with the neuronal cytoskeleton (including microtubule-associated proteins, MAP2 and tau, and higher molecular weight phosphorylated and non-phosphorylated neurofilament subunits), neuron-specific enolase, and synaptophysin. Undifferentiated stem cells, ependymoblastic and ependymal rosettes, and astroglia all stained with a monoclonal antibody that recognizes all mammalian beta-tubulin isotypes, but did not react with antibodies to neuronal-associated cytoskeletal proteins or neuropeptides. Neuropeptide-like immunoreactivity and demonstration of the class III beta-tubulin isotype indicate early neuronal commitment in neoplastic primitive neuroepithelium. These patterns of immunoreactivity closely follow those encountered in the normal neurocytogenesis of the mammalian and avian forebrain, and increase the precision with which the early stages of progressive neuroepithelial differentiation can be analyzed in human embryonal tumors of the CNS.
 ...
PMID:An immunohistochemical study of neuropeptides and neuronal cytoskeletal proteins in the neuroepithelial component of a spontaneous murine ovarian teratoma. Primitive neuroepithelium displays immunoreactivity for neuropeptides and neuron-associated beta-tubulin isotype. 281 80

The histology, histochemistry, and ultrastructure of 43 VIP-producing tumors (34 from the pancreas, one jejunal, six retroperitoneal and two mediastinic), 37 of which were associated with the WDHA syndrome, have been investigated on paraffin sections of primary or metastatic tumor tissue. The pancreatic and jejunal tumors showed all structural and secretory patterns of epithelial endocrine tumors, including expression of cytokeratin, neuroendocrine markers like neuron-specific enolase, chromogranins and synaptophysin, peptides like VIP, PHM, GRH, PP, insulin, neurotensin, glucagon, somatostatin and enkephalin, secretory granules, small clear vesicles, peculiar osmiophilic bodies, and occasional formation of tubules or microacini with specialized luminal surfaces. All the remaining tumors were neurogenic, showing either neurons and nerve fibers together with Schwann cells (ganglioneuromas and ganglioneuroblastomas) or endocrine cells (pheochromocytomas) reacting with VIP, PHM, NPY, enkephalin, somatostatin, neuron-specific enolase, synaptophysin, and MAP2 (but not cytokeratin, PP, or GRH) antibodies. A possible origin of pancreatic VIPomas from transformed pancreatic PP cells or ductular stem cells partially committed to differentiation along the PP cell line is suggested.
 ...
PMID:The morphology and neuroendocrine profile of pancreatic epithelial VIPomas and extrapancreatic, VIP-producing, neurogenic tumors. 283 87

Ten cases of cerebellar haemangioblastoma were studied using the immunoperoxidase technique for glial fibrillary acidic protein (GFAP), Factor VIII-related antigen (F8RA), Ulex europeus agglutinin 1 (UEA-1), S-100 protein, neurone-specific enolase (NSE), leucocyte common antigen, synaptophysin, chromogranin and eight polypeptide hormones (bombesin, pancreatic polypeptide, somatostatin, thyroglobulin, calcitonin, glucagon, insulin and gastrin). GFAP and S-100 were demonstrated at the periphery of all tumours and in small groups of cells in the centre of four cases. Most of these cells had the morphology of reactive astrocytes but some had the appearance of stromal cells. In general stromal cells gave negative results. F8RA and UEA-1 stained the endothelial cells in each case but there was no stromal cell reactivity. NSE was present in the stromal cell component of all tumours. There was no staining for synaptophysin, for chromogranin, or any of the polypeptide hormones. It therefore appears that some haemangioblastomas contain an admixed non-neoplastic astrocytic element. NSE, F8RA and UEA-1 staining demonstrates that the endothelial and stromal cell parts of the tumour are antigenically distinct. Recent reports of polypeptide hormone expression cannot be confirmed and it is therefore unlikely that stromal cells originate from primitive peptidergic neurones.
 ...
PMID:Haemangioblastoma. An immunohistochemical study of ten cases. 339 96

Three cases of clinically benign pancreatic papillary cystic tumors in young female patients were studied by immunohistochemistry and electron microscopy in order to define the cellular nature of this type of neoplasm. Two of the tumors showed focal cytokeratin- and desmoplakin-positivity as evidence of focal epithelial differentiation, while the tumor cells were in all cases positive for vimentin--the intermediate filament protein typical of (but not specific for) mesenchymal cells. Electron microscopy showed some cell-cell junctions, but there was no evidence of acinar or islet cell differentiation. The tumors were at least focally positive for neuron-specific enolase, and small clusters of polypeptide hormone immunoreactive cells were present in all cases (glucagon 3/3, somatostatin 2/3, insulin 2/3). However, the tumors were negative for synaptophysin and neurofilament proteins, unlike most islet cell tumors. Trypsin and chymotrypsin immunoreactivity was found in all tumors, but because many nonpancreatic carcinomas were also positive, we doubt whether these two enzyme proteins can act as specific markers for pancreatic acinar cell differentiation. Two of the tumors that were studied immunohistochemically for the presence of nuclear estrogen receptors, were negative. Therefore no proof of the suggested hormone dependence of this tumor could be obtained. We conclude that papillary cystic tumor is a neoplasm of primitive pancreatic epithelial cells, that may exhibit focal endocrine cell differentiation.
 ...
PMID:Papillary cystic tumor of the pancreas. An analysis of cellular differentiation by electron microscopy and immunohistochemistry. 367 83

The studies were performed on pig embryos between 23rd and 31st day of intrauterine life. Immunocytochemical markers of neuroendocrine cells, i.e. neuron-specific enolase, chromogranin and synaptophysin as well as basal hormones, i.e. insulin, glucagon, somatostatin, pancreatic polypeptide and, additionally, serotonin and gastrin were detected in serial sections. Our studies indicate that differentiation of pancreatic endocrine cells does not take place unitemporally. At the first stage, the cells acquire the traits of neuroendocrine cells and secrete more than one hormone while final specialization toward cells secreting individual hormones take places at a later stage.
 ...
PMID:Immunocytochemical studies on pancreatic endocrine cells at early stages of development of the pig. 784 63

Enterocolitis (EC) remains the most serious complication of Hirschsprung's disease (HD). The aetiology of EC is uncertain. Ischemic and bacterial causes, and recently rotavirus infection, have been suggested to explain the occurrence of EC. The gut has an abundance of neuroendocrine (NE) cells which modulate gut function by endocrine, paracrine, or neurocrine routes. We studied NE cell populations in the bowel from 16 patients with HD (six of whom had clinical evidence of EC) and rectal tissue from 6 controls. Immunohistochemical studies were carried out using monoclonal and polyclonal antibodies against chromogranin A, synaptophysin (general markers of NE cells), 5-Hydroxytryptamine (5-HT), somatostatin, peptide YY (PYY), and glucagon/glicentin (neuropeptides). The six patients who had clinical evidence of EC prior to defunctioning colostomy showed histological evidence of EC in the defunctioned bowel. Using immunocytochemistry and serial tissue sectioning it was found that the number of NE cells in the aganglionic segment of colon in patients with HD was significantly (P < .05) increased compared with the numbers in the ganglionic segment. However, in the ganglionic colon, there was a significant (P < .05) reduction in NE cells in EC patients compared with non-EC patients. These results were seen both with the generic endocrine cell marker chromogranin A, which stains virtually all endocrine cells, and with specific markers for 5-HT, PYY, and glucagon/glicentin, which identify distinct subpopulations of endocrine cells. These differences may be partially responsible for previous conflicting reports of NE cell distribution in HD.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Regional reduction in intestinal neuroendocrine cell populations in enterocolitis complicating Hirschsprung's disease. 790 60

Two cases of paraganglioma of the urinary bladder are reported. Their immunohistochemical profiles and the clinical features are compared with other cases in the literature. The three pan-endocrine markers (neuron-specific enolase, synaptophysin and chromogrannin) were positive in both cases. Positivity to other neuropeptides (including the present two cases and those in literature) includes adrenocorticotropic hormone (three out of five cases), calcitonin (two out of nine cases), gastrin (two out of six cases), glial fibrillary acidic protein (one out of five cases), glucagon (two out of six cases), serotonin (five out of nine cases), and somatostatin (four out of eight cases). A previously unmentioned association between paraganglioma of the urinary bladder and carcinoid in the gastrointestinal tract is noted in one of the present cases. This peculiar association highlights the importance of multiplicity of tumours of the neuroendocrine system other than the classical multiple endocrine neoplasia syndromes.
 ...
PMID:Paraganglioma of the urinary bladder: an immunohistochemical study and report of an unusual association with intestinal carcinoid. 810 19

Six extragonadal teratomas that contained pancreatic tissue were retrieved from archival material at the University of Minnesota Hospital, Minneapolis. The neuroendocrine cells were studied immunohistochemically for insulin, glucagon, somatostatin, pancreatic polypeptide, vasoactive intestinal polypeptide, gastrin, chromogranin, and synaptophysin. Pancreatic tissue from autopsies of 10 stillbirths (20 to 40 weeks' gestational age) was evaluated similarly. The features of the teratomatous pancreatic tissue were compared with those of the fetal pancreata and with data from previous studies of normal pancreatic development and adult pancreata. The pancreatic tissue in all six teratomas contained abundant mature islets that contained beta, alpha, delta, and pancreatic polypeptide cells; however, they also showed widespread nesidioblastosis with the same cell types, resembling third-trimester fetal and neonatal pancreata. Increased proportions of alpha and delta cells were observed in three and five cases (relative to those of adult tissue), respectively, providing further evidence of immaturity. Two cases showed a lack of alpha cells. None of the teratomas contained pancreatic cells that were positive for vasoactive intestinal polypeptide or gastrin. Mechanisms that regulate neuroendocrine cell differentiation in the normal pancreas also seem to operate in the teratomatous pancreas; they may eventuate in features similar to those of the late fetal and neonatal pancreas. Abnormal differentiation in teratomas may result in deficient hormone production.
 ...
PMID:Immunohistochemical characterization of teratomatous and fetal neuroendocrine pancreas. 831 55

Two cases are described of an unusual form of primary adenocarcinoma of the pancreas characterized histologically by their striking resemblance with a neuroendocrine neoplasm. The tumors were composed of a population of relatively small, uniform cells arranged in sheets admixed with small microglandular structures resulting in a cribriform pattern of growth. The tumor cells displayed scant cytoplasm with indistinct cell borders and round to oval nuclei with irregular clumping of chromatin and small, inconspicuous nucleoli. Immunohistochemical studies in both cases showed positivity of the neoplastic cells with CAM 5.2 antibodies and negative staining with a battery of neuroendocrine-related markers including chromogranin, NSE and synaptophysin, as well as with a variety of peptide hormones including insulin, glucagon, vasoactive intestinal polypeptide, gastrin and serotonin. Ultrastructural examination revealed a cohesive population of cells forming abortive glandular lumens lined by imperfectly formed microvilli and showing well-developed junctional complexes. No dense core neurosecretory granules or zymogen granules could be identified in any of the cells, supporting a ductal type of differentiation for these tumors. The main importance of recognizing this rare variant of pancreatic adenocarcinoma lies in avoiding misdiagnosis with other primary and metastatic neuroendocrine neoplasms of this organ. Immunohistochemical and ultrastructural examination will be of value in such cases for differential diagnosis.
 ...
PMID:Microglandular carcinoma of the pancreas: immunohistochemical and ultrastructural study of an unusual variant of pancreatic carcinoma that may closely resemble a neuroendocrine neoplasm. 916 70

Seventeen rectal neuroendocrine tumors ("Rectal Carcinoids") were studied by immunohistochemistry using antibodies directed against neuroendocrine markers: chromogranin A, neuron-specific enolase, synaptophysin, neuroendocrine peptides (ACTH, glicentin, glucagon, pancreatic polypeptide, somatostatin, vasoactive intestinal peptide) and antibody against serotonin. All patients with tumors measuring 1 cm or less had no specific symptoms and survived between fifteen months and eight years. Only one patient with a 6 cm poorly differentiated neuroendocrine carcinoma died less than one year after diagnosis. Only five out of seventeen tumors secreted serotonin. Most tumors were derived from L cell secreting glucagon, glicentin or pancreatic polypeptide.
 ...
PMID:[Immunohistochemical study of 17 cases of rectal neuroendocrine tumors]. 876 75


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