Molecular and cell biological aspects of neuroendocrine tumors of the gastroenteropancreatic system

Journal of Molecular Medicine

Volumn 76, Issue 9, 1998, Pages 637-647

  Wiedenmann, Bertram ^a,b,c,d,e,f   John, Mathias ^a   Ahnert Hilger, Gudrun ^a   Riecken, Ernst Otto ^a,b,g,h,i  

^a CHARITÉ UNIVERSITÄTSMEDIZIN BERLIN   (Germany)

^b UNIVERSITY OF KIEL   (Germany)

^c UNIVERSITY OF MUNICH   (Germany)

^d UNIVERSITY OF LONDON   (United Kingdom)

^e ALBERT EINSTEIN COLLEGE OF MEDICINE   (United States)

^f HARVARD UNIVERSITY   (United States)

^g UNIVERSITY OF FREIBURG   (Germany)

^h UNIVERSITY OF HAMBURG   (Germany)

ⁱ FREIE UNIVERSITÄT BERLIN   (Germany)

Author keywords

Molecular cell biology; Neuroendocrine tumor disease

Indexed keywords

PROTEIN KINASE C;

CELL ADHESION; CELL GROWTH; DIAGNOSTIC ACCURACY; DIAGNOSTIC VALUE; GASTROINTESTINAL TUMOR; HUMAN; HUMAN CELL; NEUROENDOCRINE TUMOR; NEUROSECRETORY CELL; NEUROTRANSMISSION; PANCREAS TUMOR; PATHOPHYSIOLOGY; REVIEW;

CELL DIVISION; FORECASTING; HUMANS; INTESTINAL NEOPLASMS; NEOPLASM METASTASIS; NEUROENDOCRINE TUMORS; NEUROSECRETORY SYSTEMS; PANCREATIC NEOPLASMS; RECEPTORS, CELL SURFACE; SIGNAL TRANSDUCTION; STOMACH NEOPLASMS;

EID: 0031831626     PISSN: 09462716     EISSN: None     Source Type: Journal    
DOI: 10.1007/s001090050261     Document Type: Review

References (103)

1. Ahnert-Hilger G, Wiedenmann B (1992) The amphicrine pancreatic cell line AR42\J secretes GABA and amylase by separate regulated pathways. FEBS Lett 314:41-44
2. Ahnert-Hilger G, Wiedenmann B (1994) Requirements for exocytosis in permeabilized neuroendocrine cells: possible involvement of heterotrimeric G-proteins associated with secretory vesicles. Ann NY Acad Sci 733:298-306
3. Ahnert-Hilger G, Schmitt L, Grube K, Mönch E, Kvols L, Riecken EO, Lee I, Wiedenmann B (1993) Gastroenteropancreatic neuroendocrine tumors contain a common set of synaptic vesicle proteins and aminoacid neurotransmitters. Eur J Cancer 14:1982-1984
4. Ahnert-Hilger G, Schäfer T, Spicher K, Schultz G, Wiedenmann B (1994) Detection of G-protein heterotrimers on large dense core and small synaptic vesicles of neuroendocrine and neuronal cells. Eur J Cell Biol 65:26-38
5. Ahnert-Hilger G, Scherübl H, Riecken EO, Wiedenmann B (1995) Classification of neuroendocrine cells. In: Scherübl H, Hescheler J (eds) The electrophysiology of neuroendocrine cells. CRC, Boca Raton, pp 11-19
6. Ahnert-Hilger G, Stadtbäumer A, Strübing C, Scherübl H, Schultz G, Riecken EO, Wiedenmann B (1996) γ∃-Aminobutyric acid secretion from pancreatic neuroendocrine cells. Gastroenterology 110:1595-1604
7. Ahnert-Hilger G, Kutay U, Chahoud I, Rapoport T, Wiedenmann B (1996) Synaptobrevin is essential for secretion but not for the development of synaptic processes. Eur J Cell Biol 70:1-11
8. Bartz C, Ziske C, Wiedenmann B, Mölling K (1996) p53 tumor suppressor gene expression in human pancreatic neuroendocrine carcinomas. Gut 38:403-409
9. Bauerfeind R, Ohashi M, Huttner WB (1994) Biogenesis of secretory granules and synaptic vesicles: facts and hypotheses. Ann NY Acad Sci 733:233-245
10. Becker CM, Kling C, Mülhardt C, Saul B, Herkert M., Kuhse J (1994) The inhibitory glycine receptor: a candidate protein of signal transduction in neuroendocrine tissue. Ann NY Acad Sci 733:155-163
11. A-receptors in neuroendocrine gastroenteropancreatic cells. Mol Biol Cell 4 [Suppl]:639
12. A receptor in neuroendocrine gastropancreatic cells. Eur J Physiol 430:381-388
13. Bokoch GM (1996) Interplay between Ras-related and heterotrimeric GTP-binding proteins: lifestyles of the BIG and little. FASEB J 10:1290-1295
14. Bomsel M, Mostov K (1992) Role of heterotrimeric G proteins in membrane traffic. Mol Biol Cell 3:1317-1328
15. Buscail L, Estéve JP, Prats H, Bayard F, Bell GI, Vaysee N, Susini C (1993) Human somatostatin receptor hSSTR2 may mediate the antiproliferative effect of octreotide (abstract). Gastroenterology 104:816
16. Buscail L, Delesque N, Estéve JP, Saint-Laurent N, Prats H, Clerc P, Robberecht P, Bell GI, Liebow C, Schally A, Vaysse N, Susini C (1994) Stimulation of tyrosine phosphatase and inhibition of cell proliferation by somatostatin analogues: mediation by human somatostatin receptor subtypes SSTR1 and SSTR2. Proc Natl Acad Sci USA 91:2315-2319
17. Buscail L, Estéve JP, Saint-Laurent N, Bertrand V, Reisine T, O'Carroll AM, Bell GI, Schally AV, Vaysse N, Susini C (1995) Inhibition of cell proliferation by the somatostatin analogue RC-160 is mediated by somatostatin receptor subtypes SSTR2 and SSTR5 through different mechanisms. Proc Natl Acad Sci USA 92:1580-1584
18. Buscail L, Saint-Laurent N, Chastre E, Vaillant JC, Gespach C, Capellá, Kalthoff H, Lluis F, Vaysse, Susini C (1996) Loss of sst2 somatostatin receptor gene expression in human pancreatc and colorectal cancer. Cancer Res 56:1823-1827
19. Carpentier JL, Paccaud JP (1994) Molecular and cellular biology of insulin-receptor internalization. Ann NY Acad Sci 733:266-279
20. Chandrasekharappa SC, Guru SC, Manickam M, Oluferni SE, Collins FS, Emmert-Buck MR, Debelenko LV, Zhuang Z, Lubensky IA, Liotta LA, Crabtree JS, Wang Y, Roe BA, Weisemann J, Boguski MS, et al (1997) Positional cloning of the gene for multiple endocrine neoplasia-type 1. Science 276:404-107
21. Chaudhry A, Öberg K, Wilander E (1992) A study of biological behaviour based on the expression of a proliferation antigen in neuroendocrine tumors of the digestive system. Tumor Biol 13:27-35
22. Chaudhry A, Papanicolaou V, Oberg K, Heldin CH, Funa K (1992) Expression of platelet-derived growth factor and its receptors in neuroendocrine tumors of the digestive system. Cancer Res 52:1006-1012
23. Dascher C, Balch WE (1996) Mammalian Slyl regulates syntaxin 5 function in endoplasmic reticulum to golgi transport J Biol Chem 271:15866-15869
24. Dockray GH (1994) Vasoactive intestinal polypeptide and related peptides. In: Walsh JH, Dockray GH (ed) Gut peptides: biochemistry and physiology. Raven, New York, pp 447-472
25. Eriksson B, Lilja A, Ahlstrom H, Bjurling P, Bergström M, Lindner KJ, Öberg K (1994) Positron-emission tomography as a radiological technique in neuroendocrine gastrointestinal tumors. Ann NY Acad Sci 733:446-453
26. Faiss S, Scherübl H, Riecken EO, Wiedenmann B (1996) Drug therapy in metastaticneuroendoerine tumors of the gastroenteropancreatic system. Recent Res Cancer Res 142:193-207
27. Glassmeier G, Strübing C, Riecken EO, Buhr H, Neuhaus P, Ahnert-Hilger, G, Wiedenmann B, Scherübl H (1997) Electrophysiological properties of human neuroendocrine tumor cells of the gut. Gastroenterology 113:90-100
28. Gui D, Cassetta E, Anastasio G, Bentivoglio AR, Maia G, Albanese A (1994) Botulinum toxin for chronic anal fissure. Lancet 344:1127-1128
29. Haller H, Lindschau C, Luft FC (1994) Role of protein kinase C in intracellular signaling. Ann NY Acad Sci 733:313-324
30. Hanley MR (1989) Mitogenic neurotransmitters. Nature 340:97
31. Henry JP, Gasnier B, Desnos C, Scherman D, Kreici E, Massoulié J (1994) The catecholamine transporter of adrenal medulla chromafin granules. Ann NY Acad Sci 733:185-193
32. Hescheler J, Schultz G (1994) Heterotrimetric G proteins involved in the modulation of voltage-dependent calcium channels of neuroendocrine cells. Ann NY Acad Sci 733:306-313
33. Hoorens A, Lemoine N, McLellan E, Morohoshi T, Kamisawa T, Heitz PU, Stamm B, Rüschoff J, Wiedenmann B, Klöppel G (1993) Pancreatic tumors with acinar cell differentiation: an analysis of cell lineage markers, p53 expression and Ki-ras mutations. Am J Pathol 143:685-689
34. Jahn R, Niemann H (1994) Molecular mechanisms of clostridial neurotoxins. Ann NY Acad Sci 733:245-256
35. Jiang S, Kopras E, McMichael M, Bell RH Jr, Ulrich CD (1997) Vasoactive intestinal peptide (VIP) stimulates in vitro growth of VIP-1 receptor-hearing human pancreatic adenocarcinoma-derived cells. Cancer Res 57:1475-1480
36. John M, Schätzmüller B, Mayer B, Riecken EO, Wiedenmann B (1994) Verteilung und subzelluläre Lokalisation der neuronalen NO-Synthase im menschlichen Gastrointestinaltrakt. Z Gastroenterol 32:540
37. John M, Schätzmüller B, Schmitt-Graeff A, Rancso C, Buhr H, Boese-Landgraf J, Mayer B, Wiedenmann B (1995) Expression of neuronal NO synthase in the human gastrointestinal tract. Gastroenterology 108 [Suppl]A:623
38. John M, Meyerhof W, Richter D, Waser B, Schaer JC, Boese-Landgraf J, Neuhaus P, Scherübl H, Riecken EO, Reubi JC, Wiedenmann B (1996) Positive somatostatin receptor scintigraphy correlates with the presence of somatostatin receptor subtype 2 and 5. Gut 38:33-39
39. John M, Wiedenmann B, Ahnert-Hilger G, Schlatter E, Karver V, Kornhöffer M, Forssmann WG, Kuhn M (in press) Guanylin stimulates regulated secretion from human neuroendocrine pancreatic cells. Gastroenterology
40. Klöppel G, Heitz PU (1994) Classification of normal and neoplastic neuroendocrine cells. Ann NY Acad Sci 733:18-24
41. Koepp DM, Silver PA (1996) A GTPase controlling nuclear trafficking: running the right wy or walking RANdomly? Cell 87:1-4
42. Krenning EP, Bakker WH, Breeman AP, Koper JW, Kooij PPM, Ausema L, Lameris JS, Lamberts SWJ (1989) Localization of endocrine related tumors with radioiodinated analogue of somatostatin. Lancet I:242-245
43. Krenning EP, Kwekkeboom Oel Y, de Jong RJB, Dop FJ, Reubi JC, Lamberts SWJ (1994) Somatostatin-receptor scintigraphy in gastroenteropancratic tumors. Ann NY Acad Sci 733:416-424
44. Krenning EP, Koou PM, Bakker WH, Breeman WAP, Postema PTE, Kwekkeboom DJ, Oei HY, de Jong M, Visser TJ, Reus AEM, Lamberts SWJ (1994) Radiotherapy with a radiolabeled somatostatin analogue, (111In-DTPA-D-Phe 1)-octreotide: a case history. Ann NY Acad Sci 733:496-507
45. Kuhn M, Raida M, Adermann K, Schulz-Knappe P, Gerzer R, Heim JM, Forssmann WG (1993) The circulating bioactive form of human guanylin is a high molecular weight peptide (10.3\kDa). FEBS Lett 318:205-209
46. Kuhn M, Kulaksiz H, Adermann K, Rechkemmer G, Forssmann WG (1994) Radioimmunoassay for circulating human guanylin. FEBS Lett 341:218-222
47. Langley K (1994) The neuroendocrine concept today. Ann NY Acad Sci 733:1-18
48. Leube RE, Kaiser P, Seiter A, Zimbelmann R, Franke WW, Rehm H, Knaus P, Prior P, Betz H, Reinke H, Beyreuther K, Wiedenmann B (1987) Synaptophysin: molecular organization and mRNA expression as determined from cloned cDNA. EMBO J 6:3261-3268
49. Leube RE, Wiedenmann B, Franke WW (1989) Topogenesis and sorting of synaptophysin: synthesis of a synaptic vesicle protein from a gene transfected into non-neuroendocrine cells. Cell 59:433-146
50. Leube RE, Leimer U, Grund C, Franke WW, Harth N, Wiedenmann B (1994) Sorting of synaptophysin into special vesicles in non-neuroendocrine epithelial cells. J Cell Biol 127:1589-1601
51. Lindberg I, Ahn SC, Breslin MB (1994) Cellular distributions of the prohormone processing enzymes PC1 and PC2. Mol Cell Neurosci 5:614-622
52. Lindberg I, van den Hurk WH Bui C, Batie CJI (1995) Enzymatic characterization of immunopurified prohormone convertase 2: potent inhibition by a 7B2 peptide. Biochemistry 34:5486-5493
53. Martin TFJ (1997) Stages of regulated exocytosis. Trends Cell Biol 7:271-276
54. Mayer B (1994) Nitric oxide/cyclic GMP-mediated signal transduction. Ann NY Acad Sci 733:357-365
55. Meffert MK, Premack BA, Schulman H (1994) Nitric oxide stimulates calcium-independant synaptic vesicle release. Neuron 12:1235-1244
56. Moertel CG (1987) An odyssey in the land of small tumors. J Clin Oncol 5:1503-1522
57. Öberg K (1994) Expression of growth factors and their receptors in neuroendocrine gut and pancreatic tumors, and prognostic factors for survival. Ann NY Acad Sci 733:46-55
58. O'Connor DT, Wu H, Gill BM, Rozansky DJ, Tang K, Mahata SK, Mahata M, Eskeland NL, Videen JS, Zhang X, Takiyyuddin MA, Parmer RJ (1994) Transcriptional basis of the widespread neuroendocrine expression of chromogranin A and evidence of its diverse biological actions, intracellular and extracellular. Ann NY Acad Sci 733:36-45
59. O'Connor V, Duggan M, Siebert A, Bommert K, DeBello W, Augustine G, Betz H (1994) Molecular approaches to neurotransmitter release. Ann NY Acad Sci 733:290-297
60. Pasricha PJ, Ravich WJ, Kalloo AN (1993) Effects of intrasphincteric botulinum toxin on the lower esophageal sphincter in piglets. Gastroenterology 105:1045-1049
61. Pasricha PJ, Ravich WJ, Hendrix TR, Sostre S, Jones B, Kalloo AA (1994) Treatment of achalasia with intrasphincteric Injection of botulinum toxin. A pilot trial. Ann Intern Med 121:590-591
62. Raulf F, Perez J, Hoyer D, Bruns C (1994) Differential expression of five somatostatin receptor subtypes, SSTR1-5, in the CNS and peripheral tissue. Digestion 55 [Suppl 3]:46-53
63. Reetz-Thomas A, Hell JW, During MJ, Walch-Solimena C, Jahn R, De Camilli P (1993) A γ-aminobutyric acid transporter driven by a proton pump is present in synaptic-like microvesieles of pancreatic β∃-cells. Proc Natl Acad Sci USA 90:5317-5321
64. Regnier-Vigouroux A, Tooze SA, Huttner WB (1991) Newly synthesized synaptophysin is transported to synaptic-like microvesicles via constitutive secretory vesicles and the plasma membrane. EMBO J 11:4795-4804
65. Rosewicz S, Wiedenmann B (1997) Pancreatic carcinoma. Lancet 349:485-489
66. Rosewicz S, Franke WW, Ruppert S, Schweitzer E, Riecken EO, Wiedenmann B (1992) An amphicrine pancreatic cell line: AR42\J cells combine exocrine and neuroendocrine properties. Eur J Cell Biol 59:80-91
67. Rothman JE (1994) Mechanisms of intracellular transport. Nature 372:55-63
68. Saraste J, Lahtinen U, Goud B (1995) Localization of the small GTP-binding protein rab1p to early compartments of the secretory pathway. J Cell Sci 108:1541-1552
69. Schaer JC, Waser B, Mengod G, Reubi JC (1997) Somatostatin receptor subtypes sst1, sst2, sst3 and sst5 expression in human pituitary, gastroentero-pancreatic and mammary tumors: comparison of mRNA analysis with receptor autoradiography. Int J Cancer 70:530-537
70. Schäfer T, Hodel A, Heuss C, Burger MM (1994) The andocken protein of chromaffin granules. Ann NY Acad Sci 733:279-290
71. Seherübl H, Bäder M, Fett U, Hamm B, Schmidt-Gayk H, Koppenhagen K, Dop M, Riecken EO, Wiedenmann B (1993) Somatostatin-receptor imaging of neuroendocrine gastroenteropancreatic tumors. Gastroenterology 105:1705-1709
72. Scherübl H, Hescheler J, Bychkov R, Cuber JC, John M, Riecken EO, Wiedenmann B (1994) Electrical activity and calcium channels in neuroendocrine cells. Ann NY Acad Sci 733:335-340
73. Schimmoller F, Itin C, Pfeffer S (1997) Vesicle traffic: get your coat! Curr Biol 7:R235-R237
74. Schmidt A, Hannah MJ, Huttner WB (1997) Synaptic-like microvesicles of neuroendocrine cells originate from a novel compartment that is continuous with the plasma membrane and devoid of transferrin receptor. J Cell Biol 137:445-458
75. Schuldiner S, Shirvan A, Stern-Bach Y, Steiner-Mordoch S, Yelin R, Laskar O (1994) From bacterial antibiotic resistance to neorotransmitler uptake: a common theme of cell survival. Ann NY Acad Sci 733:174-185
76. Seidah NG, Hamelin J, Mamarbachi M, Dong W, Tardos H, Mbikay M, Chretien M, Day R (1996) cDNA structure, tissue distribution, and chromosomal localization of rat PC7, a novel mammalian proprotein convertase closest to yeast kexin-like proteinases. Proc Natl Acad Sci USA 93:3388-3393
77. Seidah NG, Benjannet S, Pareek S, Savaria D, Hamelin J, Goulet B, Laliberte J, Lazure C, Chretien M, Murphy RA (1996) Cellular processing of the nerve growth factor precursor by the mammalian pro-protein convertases. Biochem J 314:951-960
78. Song L, Fricker L (1995) Processing of procarboxypeptidase E into carboxypeptidase E occurs in secretory vesicles. J Neurochem 65:444-453
79. Strübing C, Ahnert-Hilger G, Wiedenmann B, Hescheler J, Wobus A (1995) Differentiation of pluripotent embryonic stem (ES) cells into the neuronal lineage in vitro gives rise to mature inhibitory and excitatory neurons. Mech Dev 53:275-287
80. 2+-channel regulation in embryonic stem (ES) cell-derived neurons. Eur J Neurosci 9:824-832
81. Südhof TC, Jahn R (1991) Proteins of synaptic vesicles involved in exocytosis and membrane recycling. Neuron 6:665-677
82. Tixier-Vidal A, Faivre-Baumann A, Picart R, Wiedenmann B (1988) Immunoelectron microscopic localization of synaptophysin in a golgi subcompartment of developing hypothalamic neurons. Neuroscience 26:847-861
83. Tixier-Vidal A, Barret A, Faivre-Bauman A, Huttner W, Wiedenmann B (1992) Differential expression and subcellular localization of secretogranin II and synaptophysin during early development of mouse hypothalamic neurons in culture. Neuroscience 47:967-978
84. Tixier-Vidal A, Barret A, Picart R, Mayau V, Vogt D, Wiedenmann B, Goud, B (1993) The small GTP-binding protein, Rab 6p, is associated with both golgi and synaptic vesicle membranes during synaptogenesis of hypothalamic neurons in culture. J Cell Sci 105:935-947
85. Todisco A, Campbell V, Dickinson CJ, DelValle, Yamada T (1994) Molecular basis for somatostatin action: inhibition of c-fos expression and AP-1 binding Am J Phys 267:G245-253
86. Todisco A, Seva C, Takeuchi Y, Dickinson CJ, Yamada T (1995) Somatostatin inhibits AP-1 function via multiple protein phosphatases Am J Physiol 269:G160-166
87. Toliat MR, Berger W, Ropers HH, Neuhaus P, Wiedenmann B (1997) Mutations in the MEN I gene in sporadic neuroendocrine tumors of the gastroenteropancreatic system. Lancet 350:1223
88. Uhl GR, Hartig PR (1992) Transporter explosion: update on up-take. Trends Neurosci 13:421-425
89. Varlamov O, Leiter EH, Fricker L (1996) Induced and spontaneous mutations at Ser202 of carboxypeptidase E. Effect on enzyme expression, activity, and intracellular routing. J Biol Chem 271:13981-13986
90. Virgolini I, Raderer M, Kurtaran A, Angelberger P, Banyi S, Yang Q, Li S, Banyai M, Pidlich J, Niederle M, Scheithauer W, Valent P (1994) Vasoactive intestinal polypeptide-receptor imaging for the localization of intestinal adenocarcinomas and endocrine tumors. N Engl J Med 331:1116-1121
91. Whelan J. Poon D, Weil PA, Stein RW (1989) Insulin gene regulation: the role of positive-and negative-acting transcription factors in pancreas beta-cell-type-specific expression. In: Hanahan D, McDevitt HO, Cahill GF Jr (eds) Perspectives on the molecular biology and immunology of the pancreatic beta-cell. Cold Spring Harbor Laboratory, Cold Spring Harbor, pp 61-66
92. Wiedenmann B, Franke WW (1985) Identification and localization of synaptophysin, an integral membrane glycoprotein of Mr 38,000 characteristic of presynaptic vesicles. Cell 41:1017-1028
93. Wiedenmann B, Huttner W (1989) Synaptophysin and the secretogranins/chromogranins - widespread components of distinct types of neuroendocrine vesicles and new tools in tumor diagnosis. Virchows Arch B 58:95-121
94. Wiedenmann B, Franke WW, Kuhn C, Moll R, Gould VE (1986) Synaptophysin: a novel marker protein for neuroendocrine cells and neoplasms. Proc Natl Acad Sci USA 83:3500-3504
95. Wiedenmann B, Rehm H, Franke WW (1987) Synaptophysin, an integral membrane protein of vesicles present in normal and neoplastic neuroendocrine cells. Ann NY Acad Sci 493:500-503
96. A-receptors in neuroendocrine gastropancreatic cells. Gastroenterology 104:A851
97. A-receptors in neuroendocrine gastropancreatic cells. Dig Dis Sci 39 [Suppl]:1799
98. Wiedenmann B, Ahnert-Hilger G, Kvols L, Riecken EO (1994) New molecular aspects for the diagnosis and treatment of neuroendocrine gastroenteropancreatic tumor. Ann NY Acad Sci 733:515-527
99. Wiedenmann B, Bäder M, Scherübl H, Fett U, Zimmer T, Hamm B, Koppenhagen K, Riecken EO (1994) Gastroenteropancreatic tumor imaging with somatostatin-receptor scintigraphy. Semin Oncol 21:29-32
100. Wiedenmann B, Rancso C, Ahnert-Hilger G, John M, Stein H, Riecken EO (1997) Secretory vesicles in neuroendocrine cells markers for intestinal tumor differentiation. Gastroenterology 112 [Suppl]:A419
101. Zimmer T, Ziegler K, Bäder M, Fett U, Hamm B, Riecken EO, Wiedenmann B (1994) Localization of neuroendocrine tumors of the upper gastrointestinal tract. Gut 35:471-475
102. Zimmer T, Stölzel U, Bäder M, Fett U, Foss HD, Riecken EO, Rehfeld J, Wiedenmann B (1995) Diarrhea as the only symptom and normal serum gastrin concentrations in a duodenal gastrinoma. N Engl J Med 333:634-636
103. Zimmer T, Stölzel U, Bäder M, Koppenhagen K, Hamm B, Riecken EO, Wiedenmann B (1996) Endoscopie ultrasonography and somatostatin receptor scintigraphy in the preoperative localization of insulinomas and gastrinomas. Gut 39:562-568