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

We report the case of a 42 year old man in whom orthotopic liver transplantation was performed successfully for unresectable hepatic metastases of a bronchial carcinoid tumor. Prior to transplantation, somatostatin therapy, pulmonary lobectomy, and systemic chemotherapy (streptozotocin and fluorouracil) were performed. After 9 months there were no signs of clinical or biological recurrence. Orthotopic liver transplantation might be indicated for unresectable and limited liver metastases of neuroendocrine tumor.
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PMID:[Orthotopic liver transplantation for metastases of bronchial carcinoid tumor]. 134 69

Upper gastrointestinal tract neuroendocrine tumors producing predominantly somatostatin have thus far been described only in the duodenum; their characteristic features include the frequent presence of psammoma bodies (psammomatous somatostinomas), and the association with von Recklinghausen's neurofibromatosis. Gastric neuroendocrine tumors, on the other hand, tend to display immunoreactivity to serotonin but may include small subpopulations producing gastrin, motilin, pancreatic polypeptide, and somatostatin. In this report we describe a neuroendocrine carcinoma of the stomach with rapidly fatal outcome, displaying neurosecretory granules by electron microscopy and immunoreactivity to pan-neuroendocrine markers, ie, chromogranin and neuron-specific enolase. The only neuroendocrine regulatory peptide detected in the tumor was somatostatin, identified by immunohistochemistry in the majority of neoplastic cells. In contrast with duodenal somatostinomas, there were no psammoma bodies and no demonstrable association with von Recklinghausen's neurofibromatosis. To our knowledge this appears to be the first report of a malignant neuroendocrine tumor with diffuse somatostatin immunoreactivity.
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PMID:Neuroendocrine carcinoma of the stomach with extensive somatostatin immunoreactivity. 135 88

In 77 percent of patients suffering from a malignant carcinoid syndrome, administration of the somatostatin analog, octreotide (SMS 201-995, Sandostatin) induced clinical improvement coupled with a decrease in 24-hour urinary 5-hydroxyindole acetic acid (5-HIAA). This finding prompted an evaluation to determine the correlation between the presence of somatostatin receptors in tumor tissue and the response to octreotide in patients with advanced, metastatic, neuroendocrine tumors. In tissues of 31 tumors (20 carcinoid, eight islet-cell carcinoma, three medullary thyroid carcinomas), the presence of somatostatin receptors was analyzed by binding of the somatostatin analog 125I-Tyr3-SMS 201-995 and autoradiography. Receptors were detected in 16 of 20 samples of carcinoid tissues; all but one patient with receptor-positive tumors improved clinically after treatment with octreotide, and the urine 5-HIAA level was reduced a median of 63 percent (range, 39-94 percent) compared to values before treatment. Of the receptor-negative carcinoid patients, only one showed clinical improvement, which was minimal, and there was a negligible reduction in 5-HIAA after octreotide therapy. All eight patients with metastatic islet-cell carcinomas were positive for somatostatin receptors. Symptomatic improvement and a > 50 percent decrease in the level of at least one of the pathologically elevated marker hormones was seen in all eight. None of the three patients with medullary carcinoma of the thyroid had a decrease in calcitonin, and all three were initially somatostatin receptor-negative. We conclude that the presence of somatostatin receptors in malignant neuroendocrine tumor tissue appears to correlate with the response to octreotide therapy. Analysis of somatostatin receptors in malignant neuroendocrine carcinoma tissue should be included in future prospective clinical trials of this synthetic peptide.
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PMID:The presence of somatostatin receptors in malignant neuroendocrine tumor tissue predicts responsiveness to octreotide. 136 90

Hepatoblastoma exhibits a wide range of epithelial and mesenchymal lines of differentiation. Neuroendocrine differentiation in this tumor has not previously been reported. We investigated seven hepatoblastomas of different subtypes (five pure epithelial hepatoblastomas, including one small-cell hepatoblastoma, and two mixed hepatoblastomas) using a broad panel of antibodies against epithelial, mesenchymal, neural, and neuroendocrine markers, alpha-1-antitrypsin (alpha 1-AT), alpha-1-antichymotrypsin (alpha 1-ACT), alpha-fetoprotein (AFP), carcinoembryonic antigen (CEA), serotonin, and 14 regulatory peptides. Chromogranin A-immunoreactive neuroendocrine tumor cells, some of which also exhibited immunoreactivity for serotonin and somatostatin, were found in the fetal and embryonal parts of the mixed hepatoblastomas. The osteoid-like material in the mixed hepatoblastomas contained cells with immunoreactivity for chromogranin A, neuron-specific enolase, keratin, and alpha 1-AT, alpha 1-ACT, AFP, and CEA, in addition to S-100 protein and vimentin. Parallels to the neuroendocrine differentiation in hepatoblastomas are found in tumors of the gastrointestinal tract and bronchopulmonary tree. These tumors may also exhibit a neuroendocrine component; that is, multidirectional differentiation may occur, as in hepatoblastoma. The immunoreactivity of some of the cells of the osteoid-like material for keratin, alpha 1-AT, alpha 1-ACT, AFP, CEA, and chromogranin A suggests that these cells--and probably the surrounding material--are of epithelial origin.
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PMID:Neuroendocrine differentiation in hepatoblastoma. An immunohistochemical investigation. 216 15

Somatostatin is a peptide synthesized in many tissues that can act as a neurotransmitter, a systemic hormone, or a local hormone, and inhibits the secretion of hormones or other cell products. A long-acting synthetic analogue of somatostatin (SMS 201-995) has been developed which when administered subcutaneously has a biologic half-life of 90 to 120 minutes and can be administered 2 or 3 times per day. SMS 201-995 can lower plasma concentrations of growth hormone and somatomedin-C in patients with pituitary acromegaly, but no controlled trials to assess symptomatic response or change in tumor size have been done. In patients with pituitary thyrotropin-producing pituitary tumors, SMS 201-995 has been remarkably effective in producing biochemical and clinical responses and is the drug of first choice in this syndrome when tumor resection is not possible. In patients with the carcinoid syndrome, SMS 201-995 effectively reduces diarrhea, is the best available drug for treatment of carcinoid flush (effective in approximately 90% of cases), and is useful in treating carcinoid crisis. Eighty-five percent of patients with pancreatic islet cell tumors that produce vasoactive intestinal peptide will respond to SMS 201-995 with a reduction in diarrhea that often has been resistant to all other therapy. SMS 201-995 may also be useful in treating the symptoms in some patients with glucagonomas, growth hormone releasing hormone-producing tumors and insulinomas. Whether SMS 201-995 has a significant effect on gut neuroendocrine tumor growth remains uncertain. Certain nonmalignant diseases of the gut respond to somatostatin, including secretory diarrhea and fistulas of unknown cause. In general, SMS 201-995 has proved safe with few significant side effects, but whether the long-term use of the drug will result in an iatrogenic form of the somatostatinoma syndrome is uncertain.
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PMID:NIH conference. Somatostatin and somatostatin analogue (SMS 201-995) in treatment of hormone-secreting tumors of the pituitary and gastrointestinal tract and non-neoplastic diseases of the gut. 253 88

Five peptide hormones including calcitonin (CT) and gastrin-releasing peptide (GRP), serotonin (5HT), CEA, nervous tissue specific proteins and monoclonal antibody Leu-7 were immuno-histochemically studied on 60 cases of medullary thyroid carcinoma (MTC). In addition, localization of varied products in the tumor cells and its relations with the clinical features in some cases were evaluated. MTC contains a variety of products in many cases, and CT and CEA were positive in all cases. In 50 of the 57 cases (87.7%), GRP was positive, which suggested that GRP could be a novel tumor marker for this tumor. Furthermore, in tumor cells and C-cell hyperplastic foci, identical cells were sometimes revealed to possess both CT and GRP. Existence of somatostatin (SS), substance-P (SP), beta-MSH, 5 HT, Leu-7 and NSE in the tumor cells were confirmed. NSE was positive in 32 of the 47 cases (61.8%) which could confirm that MTC possesses neuroendocrine nature. In two cases of autopsy in which the tumors were highly malignant in clinical course and undifferentiated in histology, most tumor cells showed poor stainability for peptide hormones, suggesting that specific qualities as neuroendocrine tumor had been lost. In familial cases, the tumor tended to contain multiple substances.
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PMID:[Immuno-histochemical study of medullary thyroid carcinoma]. 289 90

Twenty-five strictly defined bronchopulmonary carcinoids were studied by light microscopic immunohistochemistry by the peroxidase technique for NSE (neuron-specific enolase), serotonin, and a broad spectrum of neuropeptides. Eighteen cases were also studied by electron microscopy. Twenty-three of the twenty-five cases showed immunostaining for NSE; 24 cases displayed immunostaining for at least two of the hormones tested for; the single case that failed to show hormonal immuno-reactivity was however positive for NSE and had granules by electron microscopy. Serotonin was the most frequently demonstrated hormone followed by bombesin, vasoactive intestinal peptide, gastrin, leu-enkephalin , alpha-melanocyte stimulating hormone, somatostatin, substance P, and calcitonin. In several cases, adjacent-step sections stained for different hormones strongly indicated immunoreactivity for more than one hormone in single neoplastic cells. By electron microscopy, all 18 cases studied showed generally abundant neurosecretory granules, which, however, displayed considerable heterogeneity in their size, shape, and density. Twelve of these eighteen cases displayed evidence of squamous differentiation and 10 showed characteristic exocrine lumina. The capability of single neuroendocrine tumors and single neuroendocrine tumor cells to produce more than one immunoreactive hormone is hereby amply confirmed; these broad capabilities are certainly reflected in the heterogeneous granule populations seen by electron microscopy. The synchronous presence of squamous and exocrine features in broncho-pulmonary carcinoids indicates that they too are capable of multidirectional differentiation, which should not detract from their being regarded basically as well-differentiated neuroendocrine neoplasms. The clinical significance of strictly defining bronchial carcinoids is underscored by the fact that of 25 cases followed for 2-13 years, only one developed metastases 9 years postoperatively.
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PMID:Immunohistochemical and ultrastructural analysis of bronchopulmonary neuroendocrine neoplasms. I. Carcinoids. 637 57

Neuropeptides such as gastrin releasing peptide and pituitary adenylate cyclase activating polypeptide (PACAP) stimulate CCK secretion from CCK producing cells. We hypothesized that in addition to somatostatin, galanin may also play an inhibitory role on CCK secretion. The effect of galanin on CCK secretion was studied in a CCK-producing murine neuroendocrine tumor cell line, STC-1. Galanin below 10 nM did not affect basal CCK secretion but dose- and time-dependently inhibited KCl-stimulated CCK secretion. Galanin also inhibited forskolin-, bombesin- and PACAP- but not dibutyryl cAMP- or beta-TPA-stimulated CCK secretion. The inhibitory effect of galanin was reduced partially by a blocker of ATP-sensitive K+ channel (K+ ATP), glibenclamide, and prevented by pretreatment of the cells with PTX. The results indicated galanin regulates CCK secretion by modulation of K+ ATP and cAMP production through receptors coupled to a PTX-sensitive G protein.
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PMID:Galanin inhibits cholecystokinin secretion in STC-1 cells. 748 89

Gastrointestinal neuroendocrine tumors are rare neoplasms that cause classic clinical syndromes because of the excess secretion of specific gastrointestinal hormones. The two most important tumors clinically are insulinomas and gastrinomas. The clinical management of patients with these disorders usually involves the localization and surgical removal of the responsible tumor. Many radiological techniques can be used for tumor localization, including preoperative and intraoperative ultrasound, endoscopic ultrasound, CT, MRI, radionuclide scanning, angiography, and venous sampling. However, there are conflicting claims as to the relative accuracy of these procedures, and many of these investigations are difficult to justify because of their high cost, degree of invasiveness, or lack of precise anatomic information that is obtained. If surgical resection of a neuroendocrine tumor is planned, intraoperative sonography should always be used to detect occult nonpalpable tumors and to discern the relationship of the tumor to vital adjacent pancreatic ductal anatomy. The choice of preoperative imaging is more controversial, and depends on the clinical problem, local expertise, and availability of imaging techniques. Sonography and contrast-enhanced helical CT are the most commonly used preoperative imaging methods, because of their relatively low cost and widespread availability. Radionuclide scanning with a somatostatin analogue, which is a relatively new procedure, may be valuable in patients with symptoms of tumor recurrence.
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PMID:Imaging of gastrointestinal neuroendocrine tumors. 757 79

Diagnosis of ectopic acromegaly was made in a 21-year-old female patient who 3 years before had undergone a right pneumectomy for a disseminated bronchial carcinoid. Plasma growth hormone-releasing hormone (GHRH) concentrations were markedly elevated (6440 ng/l; normal value < 100 ng/l), as were serum GH (187 micrograms/l; normal < 5 micrograms/l) and plasma insulin-like growth factor I (IGF-I) levels (6.7 U/ml; normal < 2 U/ml). Retrospective immunohistochemical examination of the carcinoid tumor was positive for GHRH and the tumoral content of GHRH was 2130 ng/g wet weight. Subcutaneous treatment with octreotide was begun and first resulted in a profound inhibition of GH hypersecretion, normalization of plasma IGF-I and only partial reduction of GHRH concentrations. However, the initial dose of 3 x 100 micrograms had to be increased gradually to 4 x 750 micrograms because of a progressive deterioration of the hormonal control. After 15 months of intermittent therapy, octreotide was administered by continuous sc infusion. This treatment improved compliance, allowed the daily dose of octreotide to be reduced to 1500 micrograms and normalized serum GH levels. A near-normalization of the plasma IGF-I concentrations was also obtained, whereas the suppression of plasma GHRH concentrations remained incomplete. Despite favorable evolution of the endocrine parameters, intramedullar metastases were diagnosed and required radiation therapy. This observation emphasizes the superiority of continuous over intermittent administration of octreotide in the treatment of ectopic acromegaly. It also shows that the somatostatin analog acts more at the pituitary level to inhibit GH secretion than at the site of the neuroendocrine tumor.
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PMID:Subcutaneous octreotide treatment of a growth hormone-releasing hormone-secreting bronchial carcinoid: superiority of continuous versus intermittent administration to control hormonal secretion. 758 49


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