| 1. |
- Ahlman, Håkan, 1947, et al.
(författare)
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Somatostatin receptors on neuroendocrine tumors--a way to intraoperative diagnosis and localization.
- 1994
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Ingår i: The Yale journal of biology and medicine. - 0044-0086. ; 67:3-4, s. 215-21
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Tidskriftsartikel (refereegranskat)abstract
- Intraoperative radionuclide detection using 111In-DTPA-D-Phe1-octreotide was evaluated in five patients with midgut carcinoids and in three patients with recurrent medullary thyroid carcinoma. Three different time intervals (24, 48 and 120 hr) from injection of the radiopharmaceutical to surgery were used. At surgery, suspect tumors were measured by probe in situ and ex vivo after excision. All tissue specimens and blood samples withdrawn during surgery were measured for 111In activity, and tissue/blood activity concentration ratios were calculated. In situ measurements were valuable especially in neck surgery, where the probe was helpful not only in localization of tumors but also in the control of tumor clearance. Ex vivo measurements were helpful in diagnosing tumor tissue. All five patients with midgut carcinoids were somatostatin receptor-positive, while only three out of seven patients with medullary thyroid carcinoma were receptor-positive. The tissue/blood activity concentration ratios and probe measurement ratios were in general higher in patients with midgut carcinoid than in patients with medullary thyroid carcinoma. Of particular interest were the high tissue/blood concentration ratios in all receptor-positive patients at all time intervals studied. This fact suggests a potential role for radiolabelled octreotide in radiotherapy of these tumor types.
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| 2. |
- Nilsson, Ola, 1957, et al.
(författare)
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Praomys (Mastomys) natalensis: a model for gastric carcinoid formation.
- 1992
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Ingår i: The Yale journal of biology and medicine. - 0044-0086. ; 65:6
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Tidskriftsartikel (refereegranskat)abstract
- The gastric carcinoid tumors of Praomys (Mastomys) natalensis have been reviewed with respect to histogenesis, development, biochemistry, and morphological properties. Multicentric gastric carcinoids frequently develop in the oxyntic mucosa of aging Mastomys. The development of these tumors can be significantly enhanced by drug-induced hypergastrinemia, e.g., histamine2-receptor blockade. Spontaneous and drug-induced gastric carcinoids are endocrine in nature, as evidenced by their argyrophilic staining properties and chromogranin A content. They are also rich in histidine decarboxylase activity and produce large amounts of histamine, although other hormones, such as peptide YY and enteroglucagon, have also been demonstrated in these tumors. Ultrastructurally, gastric carcinoids are composed of tumor cells with typical secretory granules resembling those of enterochromaffin-like (ECL) cells. A close examination of the gastric carcinoids in Mastomys reveals striking similarities with gastric carcinoids developing in humans suffering from chronic atrophic gastritis type A or from the Zollinger-Ellison syndrome in combination with multiple endocrine neoplasia type 1 (MEN-1). Both these conditions are associated with hypergastrinemia and a higher risk for developing multi-centric gastric carcinoids of ECL-cell origin. The Mastomys tumor model therefore appears to be a significant experimental model in which induction and formation of gastric carcinoid tumors can be studied.
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