| 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 All tissue specimens and blood samples withdrawn during surgery were measured for 111In activity, and tissue/blood activity concentration ratios were calculated.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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Growth factors and carcinoid tumours.
- 1993
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Ingår i: Acta oncologica (Stockholm, Sweden). - 0284-186X. ; 32:2, s. 115-24
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Tidskriftsartikel (refereegranskat)abstract
- The presence of growth factors and their receptors in human midgut carcinoids and in gastric carcinoids of Mastomys have been investigated. Human midgut carcinoid tumours produce IGF-I as demonstrated by immunocytochemistry and radioimmunoassay. IGF-I receptors were detectable in half of the tumours and stimulation of cultured tumour cells with IGF-I enhanced DNA synthesis. IGF-I may therefore act as an autocrine stimulator of carcinoid tumour growth. Expression of TGF-alpha and EGF-receptors could also be demonstrated in midgut carcinoids by immunocytochemistry and Northern analysis, suggesting that TGF-alpha participates in the autocrine modulation of carcinoid growth. Co-culture of human midgut carcinoid tumours and rat fetal cholinergic neurons demonstrated secretion of a potent neuronotrophic factor by cultured tumour cells. IGF-I and TGF-alpha may account for these neuronotrophic effects, but carcinoid tumours may also secrete an as yet unidentified growth factor. Gastric (ECL cell) carcinoids developed rapidly in Mastomys during hypergastrinemia due to histamine2-receptor blockade, suggesting that gastrin is an essential growth factor for these carcinoids.
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| 3. |
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| 4. |
- 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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| 5. |
- Ahlman, Håkan, 1947, et al.
(författare)
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Clinical efficacy of octreotide scintigraphy in patients with midgut carcinoid tumours and evaluation of intraoperative scintillation detection.
- 1994
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Ingår i: The British journal of surgery. - 0007-1323. ; 81:8, s. 1144-9
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Tidskriftsartikel (refereegranskat)abstract
- 111In-diethylenetriamine penta-acetate-D-Phe1-octreotide scintigraphy was evaluated in a group of 27 patients with disseminated midgut carcinoid tumour. Additional information gained by the intraoperative use of a scintillation detector was studied in five patients with midgut carcinoid tumours and in two with endocrine pancreatic tumours. In 19 patients tumours not recognized by non-invasive radiological methods were visualized in 27 locations, most commonly in liver and para-aortic lymph nodes. Three false-negative tumour locations were noted (ovarian and peritoneal). With guidance from scintigraphic findings, nine patients underwent surgical tumour reduction, leading to complete remission in three. Clinically suspect tumour lesions were measured by the detector in situ, and ex vivo after excision. After excision the tissue:blood activity concentration ratios were calculated. In situ measurements were helpful in the localization of tumours and in the control of adequate clearance of tumour tissue. High tissue:blood activity concentration ratios at 1, 2 and 5 days in the five patients with midgut carcinoid tumour indicate a potential role for radiation therapy with radiolabelled octreotide in patients with somatostatin receptor-positive tumours.
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| 6. |
- Ahlman, Håkan, 1947, et al.
(författare)
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Adrenocortical carcinoma--diagnostic and therapeutical implications.
- 1993
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Ingår i: The European journal of surgery = Acta chirurgica. - 1102-4151. ; 159:3, s. 149-58
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Tidskriftsartikel (refereegranskat)abstract
- To evaluate the results of treatment of a consecutive series of patients with adrenocortical carcinoma who presented during the six year period 1985 to 1991.
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| 7. |
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| 8. |
- Ahlman, Håkan, 1947, et al.
(författare)
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Clinical management of gastric carcinoid tumors.
- 1994
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Ingår i: Digestion. - 0012-2823. ; 55 Suppl 3, s. 77-85
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Tidskriftsartikel (refereegranskat)abstract
- Four types of gastric carcinoids have been identified: (1) multiple small body-fundus carcinoids associated with chronic atrophic gastritis type A (A-CAG); (2) sporadic solitary lesions without specific pathogenetic background (non-A-CAG); (3) carcinoidosis associated with Zollinger-Ellison/MEN 1 syndrome, and (4) rare tumors, e.g. gastrin cell tumors, neuroendocrine carcinomas and mixed endocrine-exocrine tumors. In a retrospective study of 15 patients with gastric carcinoids (11 A-CAG, 3 non-A-CAG and 1 gastrin cell tumor) over a 10-year period, the histopathological and clinical features were assessed. The A-CAG-type carcinoids were clinically silent with lymph node metastases in 2/11 cases but no hepatic metastases. The non-A-CAG-type carcinoids were malignant with disseminated disease, hormonal symptoms and increased urinary excretion of the main histamine metabolite, MeImAA. Five patients with A-CAG tumors were subjected to antrectomy to remove hypergastrinemia, which is thought to be of pathogenetic importance for these tumors. During the observation period (1.5-8 years) 1 patient developed recurrent tumors, while the other 4 showed persistent argyrophil cell hyperplasia. A prospective treatment protocol of these tumors is suggested with endoscopic removal of less numerous, small lesions as first-step therapy, followed by antrectomy at recurrence. Larger lesions should be excised in combination with antrectomy. Gastrectomy is reserved for the rare cases of invasive tumors with lymph node metastases. As evident from the outcome of patients with non-A-CAG tumors radical surgery should be performed whenever practicable.
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| 9. |
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| 10. |
- Basson, M D, et al.
(författare)
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Biology and management of the midgut carcinoid.
- 1993
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Ingår i: American journal of surgery. - 0002-9610. ; 165:2, s. 288-97
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Forskningsöversikt (refereegranskat)abstract
- Midgut carcinoid tumors derive from gut entoderm. These tumors may cause a complex of symptoms comprising the carcinoid syndrome by secreting a wide variety of bioactive agents in addition to serotonin. Such symptoms generally follow metastases to the liver but may also occur in primary ovarian or retroperitoneal tumors. After localization and biochemical characterization, the bioactivity of these tumors should be blocked by octreotide, sometimes in combination with other pharmacologic antagonists, so that primary resection may be performed safely. If curative resection is impossible, then a cytoreductive management scheme should be employed that includes surgical debulking and hepatic arterial embolization, followed by palliation with octreotide.
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