| 1. |
- Ahlström, Håkan, et al.
(författare)
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Pancreatic neuroendocrine tumors : diagnosis with PET
- 1995
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Ingår i: Radiology. - 0033-8419 .- 1527-1315. ; 195:2, s. 333-337
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Tidskriftsartikel (refereegranskat)abstract
- PURPOSE: To evaluate the use of carbon-11-labeled L-dihydroxyphenylalanine (L-DOPA) and hydroxytryptophan (5-HTP) in the diagnosis of pancreatic endocrine tumors with positron emission tomography (PET). MATERIALS AND METHODS: Twenty-two consecutive patients with clinically and biochemically verified pancreatic endocrine tumors were examined with computed tomography (CT) and PET with L-DOPA alone (n = 16) or both C-11-L-DOPA and C-11-5-HTP (n = 6). RESULTS: Tumor uptake of L-DOPA was found in 11 patients, eight of whom had metastatic disease. Heterogeneity of tracer uptake was noted among different lesions in the same patient (ie, high uptake in some lesions and low uptake in others). Results in patients examined with both L-DOPA and 5-HTP correlated well, but the uptake levels of 5-HTP were higher in two of three patients with positive findings. In two additional patients, CT enabled detection of tumors not detected at PET. CONCLUSION: The current PET technique can be a valuable complement to CT in demonstration of functional pancreatic endocrine tumors, in particular, glucagonomas, but is less useful in detection of nonfunctional tumors.
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| 2. |
- Ahlström, Håkan, et al.
(författare)
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Preoperative localization of endocrine pancreatic tumours by intra-arterial dynamic computed tomography
- 1990
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Ingår i: Acta Radiologica. - 0284-1851 .- 1600-0455. ; 31:2, s. 171-175
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Tidskriftsartikel (refereegranskat)abstract
- Eleven patients with biochemically confirmed endocrine pancreatic tumours were examined with intra-arterial (i.a.) dynamic computed tomography (CT) and angiography preoperatively. Seven of the patients suffered from the multiple endocrine neoplasia type 1 (MEN-1) syndrome. All patients were operated upon and surgical palpation and ultrasound were the peroperative localization methods. Of the 33 tumours which were found at histopathologic analysis of the resected specimens in the 11 patients, 7 tumours in 7 patients were correctly localized by both i.a. dynamic CT and angiography. Six patients with MEN-1 syndrome had multiple tumours and this group of patients together had 28 tumours, of which 5 (18%) were localized preoperatively by both CT and angiography. I.a. dynamic CT, with the technique used by us, does not seem to improve the localization of endocrine pancreatic tumours, especially in the rare group of MEN-1 patients, as compared with angiography.
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| 3. |
- Andersson, Torbjörn, et al.
(författare)
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Effects of Interferon on Tumor Tissue Content in Liver Metastases of Human Carcinoid Tumors
- 1990
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; :50, s. 3413-3415
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Tidskriftsartikel (refereegranskat)abstract
- In 21 patients ultrasound-guided cutting biopsies, from carcinoid metastases of the liver, were taken before and after therapy with α-interferon. Each biopsy was examined under light microscopy and the amount of tumor tissue and connective tissue was quantified and then correlated to objective response to interferon therapy. A significant reduction of the amount of tumor tissue, in spite of unaltered metastatic size and a corresponding increase in connective tissue, was seen after interferon therapy. A more pronounced reduction of tumor tissue occurred after long-term interferon therapy. A positive correlation between objective therapy response and tumor tissue reduction was also present. Patients responding poorly, or not at all, to therapy did not show any significant decrease in tumor tissue. Since treatment with immune response modifiers is expected to increase in the near future, it is important to choose the right investigations for therapy monitoring, and since all patients in this investigation had unchanged tumor size on repeated radiological examinations, it is obvious that microscopic examination of core biopsies is a better method for evaluating effects of long-term therapy than tumor size measurement with radiological techniques. Further, the results may indicate that interferon exerts a cytotoxic effect on carcinoid tumor cells in vivo.
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| 4. |
- Backlin, Carin, et al.
(författare)
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Immunohistochemical expression of insulin-like growth factor 1 and its receptor in normal and neoplastic human adrenal cortex
- 1995
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Ingår i: Anticancer Research. - 0250-7005 .- 1791-7530. ; 15:6B, s. 2453-2459
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Insulin-like growth factor 1 (IGF-1) may influence cellular growth, differentiation and secretion.MATERIAL AND METHODS:Cryosectioned normal human adrenal glands (n = 6), cortical adenoma (n = 21), and carcinoma (n = 17) were stained immunohistochemically for IGF-1 and its receptor, and human adrenocortical cancer cells expressing the receptor were analysed for influences on proliferation.RESULTS:Normal cortical parenchyma generally displayed faint IGF-1 reactivity and intracellular receptor staining. Similar labelling encompassed the adenomas, but only 6 of them were receptor reactive. IGF-1 expression was conspicuous in 11 carcinomas, and 6 of them displayed cell surface receptor reactivity. All aldosterone producing lesions were receptor antibody unreactive. Recombinant IGF-1 dose-dependently stimulated the cell proliferation, and this effect was reversed by the receptor antibody.CONCLUSION:IGF-1 may interact with function and proliferation of the human adrenal cortex with particular reference to cortical carcinomas lacking discernible aldosterone excess.
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| 5. |
- Bergström, Mats, et al.
(författare)
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In vivo demonstration of enzyme activity in endocrine pancreatic tumors : decarboxylation of carbon-11-DOPA to carbon-11-dopamine
- 1996
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Ingår i: Journal of Nuclear Medicine. - 0161-5505 .- 1535-5667. ; 37:1, s. 32-37
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Tidskriftsartikel (refereegranskat)abstract
- METHODS:We used PET to characterize the uptake and decarboxylation of 11C-L-DOPA in vivo in two patients with endocrine pancreatic tumors: one glucagonoma and one gastrinoma.RESULTS:With L-DOPA labeled with 11C in the beta position, in which the radioactive label follows the molecule through decarboxylation to dopamine, significant uptake was observed in the tumors. With L-DOPA labeled in the carboxyl group, in which the label is rapidly eliminated from the tissue as 11CO2 if decarboxylation takes place, an almost complete lack of uptake is noted.CONCLUSION:This study shows that, using selective position labeling, an in vivo action of enzymatic activity can be observed with PET and that significant decarboxylation occurs in the tested endocrine pancreatic tumors. Also, marked retention of radioactivity occurs after treatment with somatostatin analogs. It is hypothesized that this is a reflection of a reduction of exocytosis which is induced by this treatment.
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| 6. |
- Carling, Tobias, et al.
(författare)
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Hyperparathyroidism of multiple endocrine neoplasia type 1 : candidate gene and parathyroid calcium sensing protein expression
- 1995
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Ingår i: Surgery. - 0039-6060 .- 1532-7361. ; 118:6, s. 924-931
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Tidskriftsartikel (refereegranskat)abstract
- BACKGROUND:Hyperparathyroidism affects most patients with multiple endocrine neoplasia type 1 (MEN 1). This study investigates expression of the candidate MEN1 gene phospholipase C beta 3 (PLC beta 3) and expression and function of a putative calcium sensing protein (CAS) in hyperparathyroidism of MEN 1.METHODS:In 31 parathyroid glands from 17 patients with MEN 1, CAS distribution was studied immunohistochemically and parallel sections were explored for PLC beta 3 mRNA expression by in situ hybridization. Enzymatically dispersed parathyroid cells were analyzed for cytoplasmic calcium concentrations [Ca2+]i and parathyroid hormone (PTH) release.RESULTS:All glands exhibited a heterogeneously reduced CAS immunoreactivity, especially meager in nodularly assembled parathyroid cells. Calcium regulated [Ca2+]i and PTH release tended to be more deranged in the glands possessing the lowest immunostaining. Parathyroid PLC beta 3 invariably was homogeneously expressed, and this included even MEN 1 patients with reduced PLC beta 3 expression in endocrine pancreatic tumors.CONCLUSIONS:The findings support variable calcium insensitivity of [Ca2+]i and PTH release in hyperparathyroidism of MEN 1, apparently coupled to heterogeneously reduced CAS expression. For clarification of the role of PLC beta 3 in MEN 1 parathyroid tumorigenesis further study of this protein is required.
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| 7. |
- Chaudhry, Arvind, et al.
(författare)
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Different splice variants of CD44 are expressed in gastrinomas but not in other subtypes of endocrine pancreatic tumors
- 1994
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Ingår i: Cancer Research. - 0008-5472 .- 1538-7445. ; 54:4, s. 981-986
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Tidskriftsartikel (refereegranskat)abstract
- Endocrine pancreatic tumors are neuroendocrine neoplasms with malignant potential and give rise to varied clinical syndromes due to excessive secretion of multiple hormones. In this study 22 endocrine pancreatic tumors and 11 carcinoid tumors were examined for the expression of CD44 using a monoclonal antibody. CD44 gene activity of 11 endocrine pancreatic tumor tissues and five carcinoid tumor tissues was also studied by amplifying messenger RNA with the polymerase chain reaction followed by electrophoresis and blot hybridization. Strong immunoreactivity was detected on all gastrinomas examined (P < 0.001), and in two non-functioning endocrine pancreatic tumors. Such immunoreactivity was not observed in other subtypes of endocrine pancreatic tumors. In the normal human pancreas, the acinar portion and ductal epithelial cells stained strongly positive but pancreatic islet cells did not show any significant immunostaining. Furthermore, in endocrine pancreatic tumors with metastatic disease, CD44-positive tumors had a tendency to metastasize to lymph nodes (P = 0.005), as compared with CD44-negative tumors which were locally invasive or metastasized to the liver. Although, in this limited material and short follow-up, we were not able to show any statistical significance, patients with CD44-negative endocrine pancreatic tumors had prolonged survival time compared with patients with CD44-positive tumors (73% versus 59% at 5 years; P = 0.7). Of 10 carcinoid tumors examined, all three foregut carcinoids and one midgut carcinoid stained strongly positive, whereas all other midgut carcinoids were negative. Analysis of CD44 splice variants showed that in all five gastrinomas there was overproduction of alternatively spliced larger molecular variants as compared with other types of endocrine pancreatic tumors and carcinoid tumors. The band pattern from one case of carcinoid tumor with a fulminant clinical course was similar to that of gastrinomas, whereas other carcinoid tumors expressed the epithelial form of CD44. The earlier identified splice variants which confer metastatic behavior on a pancreatic tumor cell line were not expressed in neuroendocrine tumors. Our data indicate that CD44 expression in endocrine pancreatic tumors correlates with the ability to give rise to lymph node metastases and may play a vital role in determining the fate of metastasizing cells. Moreover, because gastrin is not detectable in the normal human pancreas, the pancreatic ductal cell positivity for CD44 strengthened the ductal origin concept of gastrinomas. The band pattern of CD44 splice variants suggests that the previously described splice variants conferring metastatic behavior do not accompany metastatic activity of neuroendocrine tumors.
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| 8. |
- Chaudhry, A, et al.
(författare)
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Expression of transforming growth factor b1, b2, b3 in neuroendocrine tumors of the digestive system
- 1994
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Ingår i: Anticancer Res. ; 14, s. 2085-
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Tidskriftsartikel (refereegranskat)abstract
- Ligand induced activation of the beta-receptor for platelet-derived growth factor (PDGF) leads to activation of Src family tyrosine kinases. We have explored the possibility that the receptor itself is a substrate for Src. We show that Tyr934 in the kinase domain of the PDGF receptor is phosphorylated by Src. Cell lines expressing a beta-receptor mutant, in which Tyr934 was replaced with a phenyalanine residue, showed reduced mitogenic signaling in response to PDGF-BB. In contrast, the mutant receptor mediated increased signals for chemotaxis and actin reorganization. Whereas the motility responses of cells expressing wild-type beta-receptors were attenuated by inhibition of phosphatidylinositol 3'-kinase, those of cells expressing the mutant receptor were only slightly influenced. In contrast, PDGF-BB-induced chemotaxis of the cells with the mutant receptor was attenuated by inhibition of protein kinase C, whereas the chemotaxis of cells expressing the wild-type beta-receptor was less affected. Moreover, the PDGF-BB-stimulated tyrosine phosphorylation of phospholipase C-gamma was increased in the mutant receptor cells compared with wild-type receptor cells. In conclusion, the characteristics of the Y934F mutant suggest that the phosphorylation of Tyr934 by Src negatively modulates a signal transduction pathway leading to motility responses which involves phospholipase C-gamma, and shifts the response to increased mitogenicity.
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| 9. |
- Edgren, M, et al.
(författare)
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Biological characteristics of adrenocortical carcinoma : A study of p53, IGF, EGF-r, Ki-67 and PCNA in 17 adrenocortical carcinomas
- 1997
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Ingår i: Anticancer Research. - 0250-7005 .- 1791-7530. ; 17:2B, s. 1303-1310
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Tidskriftsartikel (refereegranskat)abstract
- Adrenocortical carcinoma (ACC) is a rare neoplasm with a poor prognosis. Prognostic factors are needed to identify patients who should be treated aggressively and those for which a less aggressive approach is warranted. As a result of advances within the field of immunohistochemistry, investigations of Ki-67, PCNA, IGF, EGF-r and p53 were performed in 17 ACC. The aim of this study was to clarify the role of Ki-67, PCNA, EGF-r, IGF and p53 in correlation to tumour behaviour and outcome. This retrospective study includes 16 patients, 10 women and 6 men, with a median age of 46 years. Nine tumours were hormonally functioning and 7 were non-functioning. The results obtained revealed that all tumours expressed PCNA and Ki-67 with median values of 59% and 14%, respectively, while p53 was negative in 88%, IGF negative in 82% and EGF-r positive in 94% of the tumours. No correlation was found between p53, IGF, EGF-r and survival rate. There was no interdependence between PCNA and Ki-67, or between PCNA, Ki-67 and the survival rate.
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| 10. |
- Elvin, A, et al.
(författare)
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Duplex Doppler ultrasound in carcinoid metastases
- 1991
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Ingår i: European Radiology. - 0938-7994 .- 1432-1084. ; 1:2, s. 108-112
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Tidskriftsartikel (refereegranskat)abstract
- In a prospective study, the role of duplex Doppler ultrasound in monitoring interferon treatment-related changes in carcinoid metastases was evaluated. The Doppler findings from the tumours were correlated to the clinical and laboratory status of the patients to test the hypothesis that successful treatment results in increased vascular resistance. The patients were divided into 4 groups: untreated (n = 10), progressive disease (n = 17), stable disease (n = 20) and objective response (n = 18). In 7 cases Doppler evaluation was made before and after treatment. No significant difference in Doppler values were found between the groups, and at present duplex Doppler ultrasound does not seem to play a role in the evaluation of tumour therapy in carcinoid patients.
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