Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Lesions of the nucleus basalis of Meynert (NBM) have been used to mimic, in part, cholinergic deficits occurring in age-related neurodegenerative disorders, i.e., Alzheimer's disease. In our study, the effect of a persistent cholinergic denervation of the fronto-parietal cortex on neuropeptide Y (NPY) and somatostatin (SOM) was examined in young adult (3 months old) and aging (> 18 months old) rats, 1, 3 and 6 months after bilateral stereotaxic NBM lesions with quisqualic acid. In aging, non-lesioned rats a significant decrease in radioimmunologically and immunohistochemically detectable NPY and SOM was found with no further changes after lesions. Morphological markers for these peptidergic populations (cell size and number, NADPH-diaphorase histochemistry, electron microscopy) demonstrated no signs of alterations in both age groups after lesion. Densitometric analysis of peptide fibre networks displayed a heterogeneous response with a significant rarefication in young rats 1 month after the lesion, followed by restoration and a tendency towards increase 6 months post lesioning in individual animals. These findings were confirmed by radioimmunological measurements. Examination of synaptic and cytoskeletal markers, i.e., synaptophysin, GAP-43, MAP-2, Tau-1 and amyloid precursor protein, did not reveal any signs for neuronal reorganization or sprouting. These data are discussed in the context of plasticity and pathology in age-related neurodegenerative disorders with cholinergic impairment.
 ...
PMID:Neuropeptide Y and somatostatin in the neocortex of young and aging rats: response to nucleus basalis lesions. 780 68

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

According to electrophysiological studies, the subcortically denervated hippocampus has been suggested as a model for limbic epilepsy. We investigated a) whether fimbrial lesioning leads to any biochemical or morphological changes in the rat hippocampus, b) if these changes give any explanation to the previously indicated hyperexcitability, and c) if the changes are in line with the findings in other experimental models and human epilepsy. The fimbria-fornix transection was done by aspiration. Four months later, spontaneous EEG activities were recorded, and the hippocampal formation was processed for histology. In addition, a separate group of lesioned rats was used for hippocampal amino acid analysis. Hyperexcitable functioning of the hippocampus was seen as frequent and rhythmic spiking activity in 25% of the fimbria-fornix-lesioned rats, although the rest of them had spikes occasionally. The amino acids analysis revealed a notable decrease in the concentration of GABA but no significant changes in the amount of excitatory amino acids. This suggests impaired GABAergic functioning but does not exclude possible abnormalities in the release of both excitatory and inhibitory amino acids. The number of somatostatin-immunoreactive (SOM-IR) neurons, a subpopulation of GABAergic neurons, was decreased in all the areas of the hippocampus (CA3 > CA1 > hilus), but this was statistically significant only in the CA3 area. Interestingly, it is the region from which interictal spiking activity in the subcortically denervated rat presumable originates. Immunostaining for synaptophysin showed a dense band of granules in the inner molecular layer of the dentate gyrus, indicating probable synaptic reorganization of associational afferents.
 ...
PMID:Biochemical and morphological changes in the rat hippocampus following transection of the fimbria-fornix. 809 58

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

A rare insulin-immunoreactive neuroendocrine tumor of the duodenum in a 54 year old male is reported. The incidentally identified tumor was located on the anterior free wall of the duodenal bulb and measured approximately 6 mm in diameter. Uncomplicated endoscopic resection of the tumor was carried out. The lesion exhibited classic histologic features of insulinoma of the beta-islet cell type with stromal amyloid deposition. In addition to positive reactivities of chromogranin A, neuron-specific enolase, synaptophysin, Leu 7 (CD57), cystatin C, CA15-3 and cytokeratin, the non-argyrophilic tumor cells were strongly immunoreactive for insulin and C-peptide. The stromal amyloid was clearly labeled for amylin. A few cells were stained for somatostatin, whereas other hormones were negative. Interestingly, a few isolated insulin-positive cells were identified in the non-neoplastic duodenal mucosa in the proximity of the tumor. Immunoelectron microscopy using paraffin sections disclosed insulin-immunoreactive secretory granules in the cytoplasm. The patient exhibited no signs or symptoms of hypoglycemia. Serum insulin levels were not measured prior to resection. No tumors were demonstrated in the pancreas. Magnetic resonance imaging revealed a 1 cm asymptomatic pituitary mass, in association with moderately elevated serum prolactin levels. The patient is currently being followed up in the outpatient clinic.
 ...
PMID:Aberrant insulinoma of the duodenal bulb. 858 Nov 56

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

The immunocytochemical characterization of cell lines originating from thyroid medullary carcinoma, i.e. human TT cells and rat rMTC 6-23 cells, was undertaken. The immunocytochemical studies were supplemented by ultrastructural studies, including ultrastructural immunocytochemistry, and by radioimmunological estimation of calcitonin secretion to the medium. In rMTC 6-23 cells (subcultures 24 to 30), no hormone presence was demonstrated immunocytochemically, which corresponded to the absence of secretory granules at the ultrastructural level. Of various proteins sought, only neuron-specific enolase could be demonstrated. Nevertheless, the cells secreted calcitonin into the medium. TT cells (passages 145 to 160) produced secretory granules. The granules contained calcitonin, calcitonin gene-related peptide, somatostatin, neurotensin, met-enkephalin, leu-enkephalin, gastrin releasing peptide, parathyroid hormone-related protein, functional proteins of the chromogranin group and synaptophysin. Other functional proteins found in the cytosol of TT cells included non-specific enolase, calbindin and tyrosine hydroxylase. Receptor for calcitriol was localized in the cell nucleus. Marker proteins were localized in the cytosol (carcinoembryonic antigen) and in the cell skeleton (alpha-tubulin, cytokeratin). Following changes in ionized calcium levels in the medium, changes in calcitonin secretion and in immunocytochemical detectability of some hormones and functional proteins were observed. TT cells demonstrated the expression of numerous hormones and functional proteins associated with calcitonin secretion. Further, the cells in their ultrastructure, immunocytochemical and secretory characteristics, resemble more closely normal parafollicular cells of the thyroid and, in our opinion, represent a more appropriate model for functional studies.
 ...
PMID:Immunocytochemical characterization of two thyroid medullary carcinoma cell lines in vitro. 878 64

Neuroendocrine gut and pancreatic tumours have provided a diagnostic and therapeutic challenge over the years. These rather slowly growing neoplasms have been assigned a good prognosis but when liver metastases are present the prognosis is not better than that of most other malignant tumours. Despite the development of improved diagnostic procedures many patients are still referred at a stage of the disease too late for surgical cure, at which time medical treatment is warranted. The diagnosis is based on histopathological diagnosis including silver stainings (Grimelius, Masson) and immunohistochemistry for chromogranin A and synaptophysin. Analysis of chromogranin A in the plasma is an important adjunct in the screening for various types of neuroendocrine gut and pancreatic tumours. About 80%-100% of patients with verified neuroendocrine gastrointestinal tumours have elevated circulating levels of this glycoprotein. Depending on clinical symptoms the chromogranin A analysis is supplemented by other peptide hormone analyses as well as urinary 5-HIAA for patients with midgut carcinoid tumours. In the past the localization procedures were based on CT, MRI and ultrasound investigations but in recent years somatostatin receptor scintigraphy (octreoscan) and endoscopic ultrasonography have significantly improved the diagnostic potential. Almost 80% of neuroendocrine gastrointestinal tumours present somatostatin receptor subtype 2 binding 111Indium-labelled octreotide which can be used for staging of the disease, and which also indicates whether or not somatostatin analogues can be used in the treatment of these tumours. Surgery is still a cornerstone in the treatment of neuroendocrine gastrointestinal tumours, even if the patients are beyond cure. Debulking procedures and bypassing operations are important for improving clinical condition and facilitating impending medical treatment, and during the past decade a more aggressive surgical approach has emerged. The medical treatment is based on chemotherapy, and the use of somatostatin analogues and alpha-interferons. Chemotherapy, in particular the combination of streptozotocin with 5-FU or doxorubicin, is still first-line treatment for most endocrine pancreatic tumours, while somatostatin analogues and alpha-interferons are considered first-line for classical midgut carcinoids. Chemotherapy and biotherapy can be combined in many patients, and changes from one medical treatment to another during the course of the disease is mandatory for control of the disease. It is important to realise that most patients with malignant tumours are not cured by medical treatment but that the disease can be controlled for extended periods of time. In the future it will be possible to individualize treatments on the basis of new information about such features of tumour biology as proliferation capacity, expression of adhesion molecules, and growth factors and their receptors.
 ...
PMID:Neuroendocrine gastrointestinal tumours. 883 99


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