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)

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

Snap-frozen samples from 22 primitive neuroectodermal tumors (PNETs) primary in the central nervous system were studied with antibodies to synaptophysin, bombesin, somatostatin, substance P, vasoactive intestinal polypeptide, all classes of intermediate filaments, and desmoplakins I and II. Frozen sections were immunostained by the avidin-biotin peroxidase complex and indirect immunofluorescence microscopy methods. Selected cases were also studied by double and triple label immunofluorescence microscopy, and by two-dimensional gel electrophoresis and immunoblot analysis. We found that all 22 PNETs expressed synaptophysin extensively. Focal expression of 2 or more neuropeptides was noted in 10 samples studied. All PNETs expressed vimentin, 21 of 22 expressed glial filament protein (GFP), 16 of 22 expressed neurofilament proteins (NFP), 4 of 22 expressed desmin, and 3 of 22 expressed cytokeratins. In only one case were focal and questionable reactions with desmoplakin antibodies seen. Immunoblots confirmed the presence of desmin. Double and triple immunofluorescence revealed a number of antigenic coexpressions in individual cells including: synaptophysin with vimentin, GFP, NFP and desmin, vimentin-GFP, vimentin-NFP, vimentin-cytokeratin, vimentin-desmin and desmin-NFP; similarly, combinations of vimentin-GFP-NFP, vimentin-GFP-desmin, and vimentin-GFP-cytokeratin were found. The consistent expression of synaptophysin and 2 or more neuropeptides indicates that central nervous system PNETs have significant phenotypic features in common with neuroendocrine tumors. Their complex and variable intermediate filament complement patterns combined with their consistent expression of specific neuroendocrine differentiation markers, suggest that central nervous system PNETs comprise a distinct, albeit heterogeneous group of neoplasms.
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PMID:Primitive neuroectodermal tumors of the central nervous system. Patterns of expression of neuroendocrine markers, and all classes of intermediate filament proteins. 215 86

A case of gangliocytic paraganglioma (GP) of the ampulla of Vater is reported and the literature reviewed, with special attention to immunohistochemical studies. The present case, which occurred in a 56-year-old woman, shows the typical histological admixture of epithelioid, ganglion and spindle cells. Immunohistochemistry reveals strong reactivity for synaptophysin, Leu-7, somatostatin, S-100 protein and vimentin. A few ganglion cells are reactive for neurofilaments. Chromogranin A, myelin basic protein, desmin and cytokeratin are absent. Immunohistochemical data from literature regarding the cytoskeletal composition of GPs are not unequivocal: cytokeratin and neurofilament positivity is reported by some authors and denied by others. More uniformity is reported concerning the peptides produced by GPs: somatostatin and pancreatic polypeptide are the most frequently found antigens, followed by serotonin. General neuroendocrine markers like neuron specific enolase and protein gene product 9.5 are always positive, whereas chromogranins are rarely found. S-100 protein is always positive in the spindle cell component. Our data are in keeping with those previously reported and add the diffuse positivity for the Leu-7 antigen and the positivity of ganglion cells for synaptophysin. The nature of the tumour is still a matter of debate and it is difficult to agree with either of the proposed hypotheses--hamartoma/choristoma versus true neoplasm. However the recent reports of the occasional malignant evolution of GPs may support their true neoplastic nature.
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PMID:Duodenal gangliocytic paraganglioma. Report of a case and review of the literature. 247 67

Neuroendocrine (NE) neoplasms of the human bronchopulmonary tract were examined by electron microscopy, immunocytochemistry, and gel electrophoresis of cytoskeletal proteins from microdissected tissue samples. All samples (carcinoids, well-differentiated NE carcinoma, NE carcinomas of intermediate type, NE carcinomas of the small cell type) contained significant numbers of cells that immunostained for one or more of the following neuroendocrine markers tested: bombesin, calcitonin, ACTH, leu-enkephalin, gastrin, serotonin, somatostatin, alpha-melanocyte-stimulating hormone, vasoactive intestinal peptide, glucagon, insulin, substance P, and neuron-specific enolase. Electron microscopy revealed typical NE cell features, including variable abundant and frequently heterogeneous neurosecretory granules. Tumor cells contained filaments specifically stained with different conventional and monoclonal antibodies to cytokeratins and displayed punctate plasma membrane staining with antibodies to desmoplakins, in agreement with the electron microscopic demonstration of tonofilament bundles and desmosomes. Immunocytochemistry for NE markers and cytoskeletal proteins on consecutive sections revealed both cytokeratins and neuroendocrine substances in single cells. Using gel electrophoresis of cytoskeletal proteins of tissue regions extracted with high salt buffer and detergent, we could detect, in the tumors tested, appreciable amounts of cytokeratin polypeptides 8, 18, and 19, i.e., major cytokeratins also found in certain other lung carcinomas such as adenocarcinomas. Tumor cells were not significantly stained with antibodies to other intermediate filament proteins such as vimentin, desmin, glial filament protein, and neurofilament protein. The results show that NE substances can be synthesized in cells containing a typical epithelial cytoskeleton, i.e., cytokeratin filaments and desmosomes. These findings support the notion of an epithelial character of these tumors and appear in contrast with recent reports that neurofilaments are the only type of intermediate filaments present in carcinoids and other pulmonary NE tumors. These observations may have important implications for the histogenesis of NE carcinomas and for diagnostic pathology.
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PMID:Coexpression of neuroendocrine markers and epithelial cytoskeletal proteins in bronchopulmonary neuroendocrine neoplasms. 298 72

A case of a primary carcinoid tumor of the testis which occurred in a 57-year-old man is reported. The patient was treated by orchiectomy, and no clinical features of a carcinoid syndrome had been noted. The tumor measured 4.0 X 3.2 X 2.0 cm in size and was yellowish in color. Histochemically, the tumor cells were composed in part of argentaffin and in part of argyrophil. Immunohistochemically, the argentaffin tumor cells were positive for neuron-specific-enolase. No tumor cells were positive, however, for neurofilaments, vimentin, keratin, desmin, GFAP, S-100 protein, ACTH, and somatostatin. Electronmicroscopy revealed numerous neurosecretory granules. Tumorous tissue presented a histomorphology of a pure carcinoid tumor composed of parts of argentaffin and argyrophil.
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PMID:[A case of primary carcinoid tumor of the testis]. 318 66

The study of intrahepatic bile duct epithelial cells (i.e., cholangiocytes) has been limited by the lack of a polarized in vitro model that allows easy access to both apical and basolateral cell surfaces. Therefore, we developed a cell line of polarized normal rat cholangiocytes (NRCs) and established conditions that produced a confluent monolayer of cells grown on collagen-coated filters of tissue culture inserts. We passaged NRCs at high density to collagen-coated, tissue-culture inserts and measured transepithelial electrical resistance. We evaluated ultrastructural features by transmission and scanning electron microscopy. gamma-glutamyl-transpeptidase (gamma GT) was visualized in cultured cells by enzyme histochemistry, and cytokeratin (CK)-7, CK-19, vimentin, and desmin staining was done by immunohistochemistry. We studied the biologic responsiveness and functional polarity of NRCs by measuring their levels of cyclic AMP after addition of forskolin with or without somatostatin to either the apical or basolateral chambers. When seeded with approximately 1 x 10(5) cells/cm2, the NRCs formed a confluent monolayer in 72 hr. Transepithelial electrical resistance increased over time, achieving a maximum of 625 (+- 25) ohms.cm2 by 1 week after confluence. Transmission and electron microscopy scanning showed the apical cell surface to be tightly packed with microvilli with a heterogeneous display of cilia ranging from none to 20 to 30 cilia/cell. On transmission, apically positioned tight junctions and vesicles were apparent; nuclei were oriented basally and the basolateral surface was characterized by membrane interdigitations. NRCs stained positively for the cholangiocyte marker proteins, gamma-glutamyl-transpeptidase, CK-7, and CK-19, and negative for the mesenchymal markers, vimentin, and desmin. Exposure of the basolateral (but not the apical) cell surface to somatostatin caused a 60% inhibition of forskolin-induced increases in intracellular levels of cyclic AMP, suggesting the presence of somatostatin receptors exclusively on the basolateral plasma membrane domain. We have developed a unique model of primary cultures of normal rat cholangiocytes in which the apical and basolateral surfaces are easily accessible; the cells develop intermediate-strength tight junctions, retain their cholangiocyte phenotype, display morphologic and functional polarity, and are responsive to hormones. This model should be useful for the assessment of vectorial transport of solutes and other constituents of blood and bile, as well as for studying growth regulation of cholangiocytes.
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PMID:Development and characterization of polarized primary cultures of rat intrahepatic bile duct epithelial cells. 856 94

Some cytologic specimens may be limited in quantity, and this may hamper or preclude the performance of immunocytochemistry (ICC) in cases where more than one antibody (ab) is required by ICC to arrive at a definitive diagnosis. There is very little information in the cytology literature regarding the use of ICC for specimens that are limited in quantity. In this study, we describe a method, derived from the principles of double immunolabelling, whereby more than one ab test can be repeatedly used on the same Papanicolaou stained slide. Multiple cytologic scrape preparations fixed in 95% ethanol were obtained from fresh surgical specimens including carcinomas of the breast, endometrium, stomach, ovary and colon. Nonneoplastic tissues included tonsil (2), lymph node (2) and myometrium. Papanicolaou stained slides or unstained slides were subjected to two sequential ICC procedures, the first in which the ab was known to be nonreactive with the cells (insulin, glucagon, or somatostatin) and the second in which the ab was known to be positive in the cells. Positive controls for the known positive abs included a single-step ICC procedure as well as the tissue section. The test abs included CAM 5.2, AE1/3, K903, LCA, L26, UCHL-1, s-100, mCEA, GCDFP-15, vimentin, muscle specific actin and desmin. Identical two-step ab procedures were carried out on the tissues from the same surgical specimens. For Papanicolaou stained cytologic specimens, abs were reactive and gave excellent results for the repeat second-step ICC method. There was no false positive or false negative staining. This "repeat ICC" method also gave excellent results on the tissue sections. Immunocytochemistry can be performed more than once on the very same cytologic specimen if the initial ICC antibody attempt is negative. This method may be especially useful in situations where more than one antibody is needed on a very limited cytologic sample size.
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PMID:Immunocytochemistry on cytologic specimens of limited quantity. 948 46

Malignant mesenchymal neoplasms of the pancreas are rare and malignant islet cell tumors with sarcomatous dedifferentiation are rarer still. We present a case of malignant islet cell tumor with sarcomatous differentiation, which to our knowledge is only the second reported case showing such a combination of morphologic features. Clinically, the neoplasm was not hormonally active and immunohistochemical staining was negative for gastrin, glucagon, insulin and somatostatin. The sarcomatous component strongly reacted with an antibody directed against vimentin, and a minority of cells stained strongly with antisera directed against desmin and smooth muscle actin. The spindle cell component was nonreactive with antibodies directed against Factor VIII. The myogenous direction of differentiation in the present tumor is similar to that seen in the prior case report of malignant islet cell tumor with rhabdomyosarcomatous differentiation.
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PMID:Malignant islet cell tumor with sarcomatous differentiation. 1170 83