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)

Diabetes mellitus, steatorrhea, cholelithiasis and a tumor distorting the duodenum prompted a work-up for somatostatinoma in a 52-year-old man. The responses of pancreatic B-cells but not of A-cells to nutrient stimuli were inhibited, and growth-hormone release was suppressed, suggesting somatostatin resistance in some target tissues. Plasma somatostatin-like immunoreactivity ranged from 9000 to 13,000 pg per milliliter (normal: 88+/-8, mean +/- S.E.M.) and was distributed in four molecular forms, including free somatostatin. The primary tumor contained 5 microgram of somatostatin-like immunoreactivity per milligram of wet tissue, distributed in three of the molecular forms noted in plasma. Plasma calcitonin was also elevated (4650 pg per milliliter; normal: less than 120). Immunocytochemical studies showed that cells of the primary tumor contained somatostatin and calcitonin but no other peptide hormones. Only somatostatin was present in the metastases. Somatostatin was localized electron microscopically in all secretory granules, irrespective of size and shape, whereas calcitonin was present only within a single subpopulation of small granules in the same cells.
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PMID:Somatostatinoma syndrome. Biochemical, morphologic and clinical features. 37 80

We report the case of a patient with Verner-Morrison syndrome due to a malignant MEN I-associated vipoma. Marked tumor-associated hypercalcemia could be treated successfully with somatostatin analogues prior to surgical therapy of the pancreatic tumor. Sixteen months after extirpation of the primary tumor recurrent tumor growth was diagnosed; at this time the patient was clinically asymptomatic and had no abnormal laboratory test results. Liver metastases and local metastases were identified using somatostatin receptor scintigraphy. We report and discuss the use of somatostatin in the treatment of tumor-associated symptoms in endocrine tumors and the possibility of identifying endocrine tumors by means of somatostatin receptor scintigraphy.
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PMID:[Somatostatin in preoperative therapy and postoperative diagnosis of a patient with Verner Morrison syndrome]. 128 41

In this review, we evaluate radiological techniques currently used to localize gastroenteropancreatic (GEP) endocrine tumors. We also describe the visualization, using intravenous (IV) administration of two isotope-labeled somatostatin analogues (123I-Tyr3-octreotide and 111In-DTPA-octreotide) of islet-cell tumors in 25 patients and carcinoids in 39 patients. The primary tumor and previously unrecognized distant metastases were visualized in 20 of the 25 patients (80%) and in 37 of the 39 patients (95%). Parallel in vitro detection of somatostatin receptors on those tumors also visualized in vivo showed that ligand binding to the tumor in vivo represents binding to specific somatostatin receptors. The detection of somatostatin receptors on tumors in vivo predicted a good suppressive effect of octreotide on hormonal hypersecretion by these tumors. It is an easy, quick, and harmless procedure that is valuable in the localization of primary endocrine pancreatic tumors and their often radiologically and clinically unrecognized metastases. Future prospective controlled studies comparing this procedure with other radiological investigative techniques should demonstrate its sensitivity and specificity and determine the place of somatostatin receptor imaging in the localization of GEP endocrine tumors.
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PMID:The visualization of gastroenteropancreatic endocrine tumors. 135 84

An example of the rare papillary cystic tumor of the pancreas was diagnosed cytologically by aspiration of the primary neoplasm. Subsequently, it metastasized, proving its low-grade malignant behavior. Diagnostic cytomorphologic features included abundant straight and branched papillary tissue fragments, and uniform, pale nuclei with folds or grooves. Although the primary tumor had a typical histologic appearance, metastases demonstrated increased nuclear pleomorphism and hyperchromasia, bizarre tumor giant cells, and an increased mitotic rate. Vimentin was diffusely positive, whereas neuron-specific enolase and somatostatin were focally and weakly reactive. Neurosecretory and zymogen granules were absent ultrastructurally. By flow cytometric study, the tumor was aneuploid (DNA Index = 1.3).
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PMID:Malignant papillary cystic tumor of the pancreas. 169 76

The article describes a case of gastrointestinal autonomic nerve tumor, which is histogenetically related to the gastrointestinal autonomic plexus (hence the name plexosarcoma). This rare and only recently recognized tumor of the gastrointestinal tract appears to have significant prognostic implications. This tumor cannot be diagnosed unequivocally by light microscopic and immunocytochemical examinations but shows characteristic electron microscopic features. The present case occurred as a gastric primary tumor and exhibited a light and electron microscopic picture similar to the one described in previous reports: areas of spindle-shaped and epithelioid cells, cytoplasmic processes with dense-core granules, and cytoplasmic intermediate filaments. Ultrastructural characteristics diagnostic of other gastrointestinal tumors, such as those originating from smooth muscle, Schwann cell, or endocrine cell types, were absent. Immunocytochemically, the tumor was diffusely positive for vimentin and neuron-specific enolase and focally positive for neurofilament triplet protein (NFTP) 160. Negative staining was observed for NFTP 200, S-100 protein, desmin, somatostatin, chromogranin, keratins (AE1/AE3), and glial fibrillary acidic protein. Although gastrointestinal autonomic nerve tumor has been reported to have a deceptively low-grade malignant appearance by light microscopy, it follows an aggressive clinical course. This tumor showed a much higher mitotic rate (one mitosis per high-power field) than the rates of tumors reported previously. Moreover, it occurred in a much younger patient (20 years of age) compared to previously reported cases (45 to 66 years of age), with the exception of one other case (16 years of age).
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PMID:Gastrointestinal autonomic nerve tumor. 184 28

A case of metastatic carcinoid tumor in the right occipital lobe originating from a primary tumor in the right colon is reported in a 68-year-old man. The tumor had a high bromodeoxyuridine labeling index. Although immunohistochemical studies of the tumor specimen showed positive reactivity for serotonin and somatostatin, blood levels of serotonin and urinary 5-hydroxyindoleacetic acid content were normal. This suggests that coexistence of somatostatin with serotonin in the tumor tissue might lead to inhibition of serotonin release by "autocrine regulation." The neurological complications of carcinoid tumors, including intracranial metastasis, are discussed briefly.
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PMID:Metastatic intracranial carcinoid with immunohistochemical observation. Case report. 197 87

The authors investigated the humoral and tissue expression of six antigens associated with medullary thyroid cancer (MTC): calcitonin (CT), calcitonin gene-related peptide (CGRP), carcinoembryonic antigen (CEA), neuron-specific enolase (NSE), somatostatin (SRIF), and thyroglobulin (TG). The antigens were studied in the neoplastic C cells using immunohistochemistry with specific antisera and in the plasma using specific radioimmunoassay. Eighteen patients (8 male and 10 female patients, aged 12-72 years) were studied. Mean follow-up was 70.7 months (range, 2-179 months). Nine patients (50%) died of their disease after a mean follow-up of 47.2 months (range, 2-116 months). By immunostaining, primary tumors expressed CT and CEA in all cases and NSE was positive in 90%, CGRP in 66%, SRIF in 63%, and TG in 58%. Metastatic tissues were positive in all cases of CT staining, 92.8% of CEA, 71.4% of NSE, 73.3% of CGRP, 38.5% of SRIF, and only 13.3% of TG staining. In positive cases the percentage of positive cells and the degree of staining were variable among the different antigens. The expression of an antigen in the neoplastic cells was associated with the hypersecretion of the corresponding antigen in the circulation in the case of CT and CEA. The levels of these antigens were elevated in all patients with metastases and could accurately predict the appearance of new metastases or indicate the effective treatment of previous metastases by surgery. In the case of NSE, CGRP, and SRIF, few patients had increased plasma concentrations of the antigens and these usually occurred during very advanced phases of the disease. Detectable levels of serum TG were never observed. When the outcome of the disease was compared with the expression of CT, CEA, NSE, CGRP, and TG, no correlation could be found. On the contrary, SRIF expression in the primary tumor could differentiate two groups of patients with different survival rates. SRIF-positive patients had survival rates of 100% and 50% at five and seven years, respectively, whereas SRIF-negative patients had survival rates of 40% at five years and 25% at seven years.
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PMID:Medullary thyroid cancer. An immunohistochemical and humoral study using six separate antigens. 199 39

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

In this study, liver metastases from a patient with a pancreatic glucagonoma producing the syndrome have been investigated histologically, ultrastructurally, and immunocytochemically. A comparison has also been made between the metastases and the primary pancreatic tumor investigated in a parallel study. In the metastatic tissue, glucagon-, pancreatic polypeptide (PP)-, and somatostatin-containing cells were found together with a majority of cells without any immunoreactivity. Glucagon-positive cells were much more numerous than PP- and somatostatin-immunoreactive cells. As in the primary tumor, double immunogold staining of ultrathin sections demonstrated the co-existence of glucagon and PP immunoreactivities in most of the granulated cells, but PP immunolabeling was often faint, so that it probably could not be revealed by the PAP method in light microscopical sections. Such a finding, together with the histological and ultrastructural features, is consistent with an ontogenic and phylogenetic primitiveness of the metastatic cell population.
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PMID:A malignant tumor of the pancreas producing glucagonoma syndrome: immunocytochemistry and ultrastructure of liver metastases and comparison with the primary tumor. 254 78

The authors evaluated the presence of somatostatin (SRIF) in the plasma and in the tumor tissue of a total of 22 patients with medullary thyroid cancer (MTC) and studied the effect of exogenous SRIF administration on basal and pentagastrin (PG)-stimulated plasma calcitonin (CT) and carcinoembryonic antigen (CEA) levels. Mean plasma SRIF concentrations were significantly higher than those found in normal controls, with five of 15 patients having plasma SRIF levels above the mean + 2 SD of normal controls. High immunoreactive SRIF concentrations were found in the extract of three tumor tissues but not in one follicular thyroid cancer or in one toxic diffuse goiter. By immunoperoxidase staining seven of 11 (63.6%) primary MTC and five of 13 (38.5%) metastases expressed SRIF antigen in a low number of cells and with a weak degree of staining. As expected, CT was expressed in almost 100% of the cases with positivity in most of the cells and strong degree of staining. Patients with positive SRIF staining in the primary tumor had longer survival than SRIF negative patients. Infusion of synthetic SRIF (11 micrograms/minute/45 minutes) produced a significant reduction of plasma CT (but not CEA) levels in 12 of the 15 patients submitted to this test. Maximal percent decrease of plasma CT ranged from 10.8% to 72.7% of the basal value and was usually observed between 30 and 45 minutes from the beginning of the infusion. When infused together with the injection of PG, SRIF was able to significantly (P less than 0.05) inhibit the PG-induced CT release in five of six patients tested. These results demonstrate the following: SRIF is present in a few cells of many primary MTC and less frequently in their metastases; tentatively, the expression of SRIF antigen in the tumor seems to be associated with longer survival; increased SRIF concentrations are found in the plasma of some patients with metastatic involvement; and treatment with exogenous SRIF reduces the basal and PG-induced CT (but not CEA) release from the tumor.
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PMID:Somatostatin in medullary thyroid cancer. In vitro and in vivo studies. 256 68


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