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)

We report a case of a human gastric composite tumor occurring seven years after a partial gastrectomy for a low grade B cell MALT lymphoma. Histological examination of the tumor revealed two intimately intermingled components: 1. A moderately to poorly differentiated tubulo-acinar adenocarcinoma with signet-ring cells; and 2. Isolated or clustered small neuroendocrine cells without atypia expressing chromogranin A, somatostatin and/or glucagon, serotonin (5-HT) and, the 5-HT2B receptors. In addition to immunohistochemical detection, the presence of 5-HT2B receptors was shown pharmacologically through [125I]-DOI binding. Since 5-HT2B receptors have been demonstrated to have autocrine functions and, mitogenic and transforming properties, these results suggest a role of 5-HT in neuroendocrine malignant transformation. On the other hand, the expression of somatostatin and the detection by reverse transcriptase polymerase chain reaction (RT-PCR) of somatostatin receptor subtypes 2, 3, and 5, which have been shown to be involved in tumor regression, might account for the long evolution of this case (> 5 yr). This case illustrates the importance of local humoral modulation in tumor growth. Moreover, ultrastructural results favor a unique origin of the tumor cells from one amphicrine cell type.
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PMID:Histological, immunohistochemical, ultrastructural and biochemical study of human gastric composite tumor: expression of the serotonin-2B receptor by the neuroendocrine component. 1147 72

Somatostatin receptor (SSTR) scintigraphy and gallium-67 citrate ((67)Ga) scintigraphy have been used for visualisation of Hodgkin's lymphoma and non-Hodgkin's lymphoma. However, experience with B-cell lymphoma of the mucosa-associated lymphoid tissue (MALT) type is very limited. The aim of this study was to prospectively compare the (67)Ga scintigraphy results with those obtained by (111)In-DOTA- dPhe(1)-Tyr(3)-octreotide ((111)In-DOTA-TOCT) and (111)In-DOTA-lanreotide ((111)In-DOTA-LAN) scintigraphy in patients with proven MALT-type lymphoma. Comparative scintigraphic examinations using (67)Ga, (111)In-DOTA-TOCT and (111)In-DOTA-LAN were performed in 18 patients (11 female and 7 male, median age 64+/-15 years) with histologically verified MALT-type lymphomas of various origin. Planar and single-photon emission tomography imaging acquisitions were performed after injection of a mean dose of 185+/-26 MBq (67)Ga and 165+/-20 MBq (111)In-DOTA-TOCT or (111)In-DOTA-LAN. All scintigraphic results were correlated with other conventional examinations including gastroscopy, colonoscopy, endosonoscopy, ophthalmologic investigation, CT of the thorax and abdomen and bone marrow biopsy. This comparative study showed that (67)Ga scintigraphy found abnormalities in 10 of 16 patients (63%) and detected 18 of 31 clinically involved sites (58%), but was false positive in three patients. (111)In-DOTA-TOCT found abnormalities in 9 of 15 patients (60%) and detected 15 of 27 clinical lesions (56%); it was false positive in two patients. (111)In-DOTA-LAN scintigraphy showed abnormalities in 7 of 11 patients (64%) and found 12 of 22 clinical lesions (55%). False-positive (111)In-DOTA-LAN scan results were found in two patients. For supra-diaphragmatic lesions, (67)Ga scintigraphy detected 12 of 16 sites (75%). (111)In-DOTA-TOCT scintigraphy revealed 7 of 15 lesions (47%). (111)In-DOTA-LAN showed 6 of 12 positive sites (50%). For infra-diaphragmatic involvement, the sensitivities of (67)Ga, (111)In-DOTA-TOCT and (111)In-DOTA-LAN were 40%, 67% and 60%, respectively. It is concluded that MALT-type lymphoma can be visualised by (67)Ga, (111)In-DOTA-TOCT and (111)In-DOTA-LAN scintigraphy. Although there were no statistically significant differences in patient-related and site-related sensitivities when using (67)Ga compared with (111)In-DOTA-TOCT and (111)In-DOTA-LAN, the sensitivity of (67)Ga tended to be superior to that of (111)In-DOTA-TOCT and (111)In-DOTA-LAN for supra-diaphragmatic lesions but inferior for infra-diaphragmatic involvement. In selected cases, the combination of (67)Ga and (111)In-DOTA-LAN or (111)In-DOTA-TOCT may increase the diagnostic efficiency in patients with MALT-type lymphoma.
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PMID:111In-DOTA- dPhe1-Tyr3-octreotide, 111In-DOTA-lanreotide and 67Ga citrate scintigraphy for visualisation of extranodal marginal zone B-cell lymphoma of the MALT type: a comparative study. 1276 34

Somatostatin receptor scintigraphy is useful in diagnosing tumors with increased expression of somatostatin receptors. The correct use of this technique reveals the localization of neuroendocrine primary tumors and unknown metastases in approximately 90% of patients. However, somatostatin receptor scintigraphy also can image many other human tumors expressing somatostatin receptors, including malignant lymphomas and thymomas. The sensitivity of somatostatin receptor scintigraphy to image somatostatin receptor-positive tumors is very high, but due to the variable expression of specific receptor subtypes, the specificity can be relatively low. This drawback is crucial in evaluating lymphoproliferative diseases, or, in general, when immune cells are involved. The sensitivity of somatostatin receptor scintigraphy for Hodgkin's lymphoma is 95%-100%, whereas for non-Hodgkin's lymphoma it is around 80%. It has been shown that the uptake of [(111)In-DTPA(0)]octreotide in lymphomas is lower compared to the uptake in neuroendocrine tumors. This is mainly attributed to the low number of receptors on immune cells compared to neuroendocrine cells; however, ligand-induced internalization and differential receptor regulation may also participate in determining this phenomenon. Therefore, caution should be taken when interpreting data from some studies. Several new ligands are currently under study to improve these limits and the expression of other neuropeptide receptors is being investigated to provide a molecular basis for in vivo multireceptor targeting of tumors. With the use of currently available somatostatin analogs, somatostatin receptor scintigraphy does not seem to have a significant impact in patients with lymphomas for diagnostic purposes. There are a few exceptions, however. Among these, the staging and restaging of extragastric lymphoma MALT-type may present some advantages. Conversely, somatostatin receptor scintigraphy in the imaging of thymic malignancies could enhance both our diagnostic and therapeutic capabilities. Somatostatin receptor scintigraphy is diagnostically relevant in differentiating malignant from benign lesions, especially in those patients with associated paraneoplastic syndromes, and is the main criterion to select patients suitable for therapy with somatostatin analogs. Recent findings emerging from in vitro studies on somatostatin receptor physiology in immune cells will certainly reopen and expand the potential applications of somatostatin analogs for in vivo diagnostic and therapeutic options.
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PMID:Initial staging of lymphoma with octreotide and other receptor imaging agents. 1609 91