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Background: Patients with malignant midgut carcinoids are occasionally diagnosed with limited tumor spread, and surgery with radical intention is performed. Despite curative intent, recurrences occur frequently, motivating long-term... more
Background: Patients with malignant midgut carcinoids are occasionally diagnosed with limited tumor spread, and surgery with radical intention is performed. Despite curative intent, recurrences occur frequently, motivating long-term biochemical and radiological follow-up. This study aimed to compare the usefulness of various methods in detecting such recurrences. Methods: This retrospective study included 56 patients with radically operated midgut carcinoids referred to our University Hospital for evaluation and follow-up between 1985 and 2004. Patients were monitored 1–3 times per year using plasma-chromogranin A (P-CgA), urinary 5-hydroxyindoleacetic acid (U-5HIAA) concentrations as well as radiological examinations, including ultrasonography, computerized tomography or magnetic resonance investigation. In a subset of cases, somatostatin receptor scintigraphy and/or positron emission tomography with 5-hydroxytryptophan was performed. Time from operation until established recurrenc...
Research Interests: Neuroendocrinology, Survival Analysis, Positron Emission Tomography, Medicine, Humans, and 15 moreInternal Medicine, Female, Male, Magnetic Resonance, Clinical Sciences, Aged, Middle Aged, Adult, Retrospective Studies, Computerized tomography, Retrospective Study, Neurosciences, Chromogranin A, Carcinoid tumor, and Carcinoid Syndrome
Neuroendocrine tumors (NET) are malignant solid tumors that arise in hormone-secreting tissue of the diffuse neuroendocrine system or endocrine glands. Although traditionally understood to be a rare disease, the incidence and prevalence... more
Neuroendocrine tumors (NET) are malignant solid tumors that arise in hormone-secreting tissue of the diffuse neuroendocrine system or endocrine glands. Although traditionally understood to be a rare disease, the incidence and prevalence of NET have increased greatly in the past 3 decades. However, during this time, progress in diagnosis and outcome of NET has generally been modest. In order to achieve improved outcome in NET, a better understanding of NET biology combined with more reliable serum markers and better techniques to identify tumor localization and small lesions are needed. Although some NET biomarkers exist, sensitive and specific markers that predict tumor growth and behavior are generally lacking. In addition, the integration of new molecular imaging technologies in patient diagnosis and follow-up has the potential to enhance care. To discuss developments and issues required to improve diagnostics and management of NET patients, with specific focus on the latest advan...
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Research Interests: Chemotherapy, Survival Analysis, Treatment Outcome, Medicine, Humans, and 15 moreMedical Oncology, Internal Medicine, Female, Male, Cisplatin, Middle Aged, Combination chemotherapy, Adult, Survival Rate, Combination drug therapy, Side Effect, Cyclophosphamide, Medical Treatment, Combination Therapy, and Vincristine
4031 Background: The novel somatostatin analog (SSA) pasireotide has a broader binding profile than currently available SSA (octreotide and lanreotide). Results from a phase III study (NCT00690430) of pasireotide LAR (P) vs octreotide LAR... more
4031 Background: The novel somatostatin analog (SSA) pasireotide has a broader binding profile than currently available SSA (octreotide and lanreotide). Results from a phase III study (NCT00690430) of pasireotide LAR (P) vs octreotide LAR (O) in patients (pts) with NET and disease-related symptoms uncontrolled by the maximum approved dose of available SSA are shown. Methods: Pts (N=110) were randomized and stratified by predominant symptom at baseline (diarrhea [D], flushing [F], or D+F) 1:1 to P (60 mg IM) or O (40 mg IM) q28d. Primary objective was symptom response at month (M) 6. Secondary objectives included tumor response and safety. Progression-free survival (PFS) was an exploratory analysis. Results: 53 and 57 pts were enrolled in the P and O arms when the study was halted due to an interim analysis suggesting futility for symptom response. Baseline characteristics were similar between arms. Majority of primary tumor locations were small intestine (72% and 81% in the P and O ...
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Objective: High-dose somatostatin analogue treatment has shown an antiproliferative effect in one study including patients with neuroendocrine tumours. To explore this therapeutic strategy further, we have studied the effect of a... more
Objective: High-dose somatostatin analogue treatment has shown an antiproliferative effect in one study including patients with neuroendocrine tumours. To explore this therapeutic strategy further, we have studied the effect of a high-dose formula of octreotide, octreotide ...
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In a randomized, double-blind, Phase III study, we compared pasireotide long-acting release (pasireotide LAR) with octreotide long-acting repeatable (octreotide LAR) in managing carcinoid symptoms refractory to first-generation... more
In a randomized, double-blind, Phase III study, we compared pasireotide long-acting release (pasireotide LAR) with octreotide long-acting repeatable (octreotide LAR) in managing carcinoid symptoms refractory to first-generation somatostatin analogues. Adults with carcinoid tumors of the digestive tract were randomly assigned (1:1) to receive pasireotide LAR (60 mg) or octreotide LAR (40 mg) every 28 days. Primary outcome was symptom control based on frequency of bowel movements and flushing episodes. Objective tumor response was a secondary outcome. Progression-free survival (PFS) was calculated in a post hoc analysis. Adverse events were recorded. At the time of a planned interim analysis, the data monitoring committee recommended halting the study because of a low predictive probability of showing superiority of pasireotide over octreotide for symptom control (n=43 pasireotide LAR, 20.9%; n=45 octreotide LAR, 26.7%; odds ratio, 0.73; 95% confidence interval [CI], 0.27-1.97; P=0.53). Tumor control rate at month 6 was 62.7% with pasireotide and 46.2% with octreotide (odds ratio, 1.96; 95% CI, 0.89-4.32; P=0.09). Median (95% CI) PFS was 11.8 months (11.0 - not reached) with pasireotide versus 6.8 months (5.6 - not reached) with octreotide (hazard ratio, 0.46; 95% CI, 0.20-0.98; P=0.045). The most frequent drug-related adverse events (pasireotide vs octreotide) included hyperglycemia (28.3% vs 5.3%), fatigue (11.3% vs 3.5%), and nausea (9.4% vs 0%). We conclude that, among patients with carcinoid symptoms refractory to available somatostatin analogues, similar proportions of patients receiving pasireotide LAR or octreotide LAR achieved symptom control at month 6. Pasireotide LAR showed a trend toward higher tumor control rate at month 6, although it was statistically not significant, and was associated with a longer PFS than octreotide LAR.
Quantitative PET imaging with [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 has potential use in diabetes and cancer. However, the radiation dose to the kidneys has been a concern for the possibility of repeated imaging studies in humans.... more
Quantitative PET imaging with [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 has potential use in diabetes and cancer. However, the radiation dose to the kidneys has been a concern for the possibility of repeated imaging studies in humans. Therefore, we investigated the dosimetry of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 based on the biodistribution data in rats, pigs, non-human primates (NHP) and a human.Organ distribution of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 in rats (Male Lewis; n=12; 30, 60, and 80 min) was measured ex vivo. The dynamic uptake of [(68)Ga]Ga-DO3A-VS-Cys(40)-Exendin-4 in the abdomen was assessed by PET/CT scanning of pigs (male; n = 4, 0-60 min), NHP (Female; cynomolgus; n=3; 0-90 min), and human (female; n=1; 0-40, 100, 120 min).The organ distribution data in each species were extrapolated to those of a human, assuming similar distribution between the species. Residence times were assessed by trapezoidal approximation of the kinetic data. Organ doses (mGy/MBq) and the whol...
Peptide receptor radionuclide therapy (PRRT) is a promising treatment for patients with neuroendocrine tumors, giving rise to improved survival. Dosimetric calculations in relation to PRRT have been concentrated to normal organ dosimetry... more
Peptide receptor radionuclide therapy (PRRT) is a promising treatment for patients with neuroendocrine tumors, giving rise to improved survival. Dosimetric calculations in relation to PRRT have been concentrated to normal organ dosimetry in order to limit side effects. However, the relation between the absorbed dose to the tumor and treatment response has so far not been established. Better knowledge in this respect may improve the understanding of treatment effects, allow for improved selection of those patients who are expected to benefit from PRRT, and avoid unnecessary treatments. The aim of the present work was to evaluate the dose-response relationship for pancreatic neuroendocrine tumors treated with PRRT using (177)Lu-DOTATATE. Tumor-absorbed dose calculations were performed for 24 lesions in 24 patients with metastasized pancreatic neuroendocrine tumors treated with repeated cycles of (177)Lu-DOTATATE at 8-wk intervals. The absorbed dose calculations relied on sequential SP...
Research Interests: Nuclear medicine, Positron Emission Tomography, Prospective studies, Humans, Kidney, and 14 moreFemale, Male, Radionuclide imaging, Clinical Sciences, Aged, Middle Aged, Radiometry, Single Photon Emission Computed Tomography, Adult, Time Factors, Radiopharmaceuticals, X ray Computed Tomography, Radioisotopes, and Neuroendocrine Tumors
Positron emission tomography (PET) with 11C-labeled 5-hydroxytryptophane (5-HTP) is a sensitive technique to visualize neuroendocrine tumours (NETs), due to high intracellular uptake of amine-precursors like L-dihydroxyphenylalanine... more
Positron emission tomography (PET) with 11C-labeled 5-hydroxytryptophane (5-HTP) is a sensitive technique to visualize neuroendocrine tumours (NETs), due to high intracellular uptake of amine-precursors like L-dihydroxyphenylalanine (L-DOPA) and 5-HTP. NETs are often small and difficult to localize in spite of overt clinical symptoms due to hormonal excess. In our study, 38 consecutive NET patients underwent 11C-5-HTP-PET and morphological imaging by CT within 12 weeks prior to surgery. Surgical, histopathological and 5-HTP PET findings were correlated. 11C-5-HTP-PET corresponded to the surgical findings in 31 cases, was false negative in six, and true negative in one case resulting in 83.8% sensitivity and 100% specificity. Positive predicted value was 100%. In 11 patients 11C-5-HTP-PET was the only imaging method applied to localize the tumour. Thus, we could demonstrate that functional imaging by 11C-5-HTP-PET in many cases adds vital preoperative diagnostic information and in mo...
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Phospholipase C beta 3 (PLCB3) plays an important role in the signal transduction of the seven transmembrane receptors. The gene is located in the vicinity of the Multiple Endocrine Neoplasia type 1 (MEN1) gene on chromosome 11q13.... more
Phospholipase C beta 3 (PLCB3) plays an important role in the signal transduction of the seven transmembrane receptors. The gene is located in the vicinity of the Multiple Endocrine Neoplasia type 1 (MEN1) gene on chromosome 11q13. Transfection of PLCB3 to neuroendocrine cell lines lacking expression suppresses the neoplastic phenotype and affects the gene expression of S100A3 and human mismatch repair protein, suggesting a role for PLCB3 in neuroendocrine tumorigenesis. We used RNA-RNA in situ hybridisation for PLCB3 on a total of 82 samples including 34 from MEN1 patients. We show that the PLCB3 transcript is missing in 8 out of 14 MEN1-associated neoplasias as well as in 4 out of 10 bronchial carcinoids, 2 out of 10 exocrine pancreatic cancers and one sporadic adrenocortical carcinoma. Low or lack of PLCB3 expression in a subset of endocrine tumours, together with earlier published in vitro data on suppressor characteristics upon transfection, indicate that PLCB3 could be involve...
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Somatostatin analogs and alpha-interferon induce good responses as single drugs in the treatment of endocrine pancreatic tumors. We examined the efficacy and tolerability of the combination of alpha-interferon and somatostatin analogs in... more
Somatostatin analogs and alpha-interferon induce good responses as single drugs in the treatment of endocrine pancreatic tumors. We examined the efficacy and tolerability of the combination of alpha-interferon and somatostatin analogs in 16 patients with metastatic endocrine pancreatic tumors. All patients except one had received prior treatment and were in a progressive state. Doses of alpha-interferon and somatostatin analogs were individually titrated. The alpha-interferon doses varied between 9 and 25 million units per week and were combined with 100-1500 microg of octreotide or 6000 microg of lanreotide daily. Radiological response was seen in 3 of 16 (19%) patients (median duration 23 mo). Biochemical response was seen in 10 of 16 (62.5%) patients (median duration 22 mo). All three patients previously progressing on both alpha-interferon and somatostatin analog as single drugs achieved a stabilization of the disease when treated with the combination (median duration 10 mo). Se...
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To evaluate the prolonged release (PR) of the long-acting somatostatin analog lanreotide in patients with gastrointestinal neuroendocrine tumors and its effect on hormone-related symptomatology, tumor markers, tumor size, tolerability,... more
To evaluate the prolonged release (PR) of the long-acting somatostatin analog lanreotide in patients with gastrointestinal neuroendocrine tumors and its effect on hormone-related symptomatology, tumor markers, tumor size, tolerability, and quality of life (QOL). Eligible patients had the following substantial daily symptoms: for patients with carcinoid tumors, three or more stools and/or 1.5 or more flushing episodes; for patients with gastrinoma, greater than 50% elevated basic acid output; and for patients with vasoactive intestinal peptide-secreting tumors (VIPomas), four or more stools and/or a stool volume of >/= 800 mL, a measurable tumor, and an elevated biochemical tumor marker (>/= two times the upper limit of the normal reference range). Lanreotide PR was administered intramuscularly every 14 days at 30 mg for 6 months. We measured efficacy by studying symptoms, tumor markers, tumor size, and QOL. Side effects were scored according to the National Cancer Institute...
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In humans, a well-developed serotonin system is localized to the pancreatic islets while being absent in exocrine pancreas. Assessment of pancreatic serotonin biosynthesis could therefore be used to estimate the human endocrine pancreas.... more
In humans, a well-developed serotonin system is localized to the pancreatic islets while being absent in exocrine pancreas. Assessment of pancreatic serotonin biosynthesis could therefore be used to estimate the human endocrine pancreas. Proof of concept was tested in a prospective clinical trial by comparisons of type 1 diabetic (T1D) patients, with extensive reduction of β-cells, with healthy volunteers (HVs). C-peptide-negative (i.e., insulin-deficient) T1D subjects (n = 10) and HVs (n = 9) underwent dynamic positron emission tomography with the radiolabeled serotonin precursor [(11)C]5-hydroxy-tryptophan ([(11)C]5-HTP). A significant accumulation of [(11)C]5-HTP was obtained in the pancreas of the HVs, with large interindividual variation. A substantial and highly significant reduction (66%) in the pancreatic uptake of [(11)C]5-HTP in T1D subjects was observed, and this was most evident in the corpus and caudal regions of the pancreas where β-cells normally are the major constit...
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To investigate possible changes in somatostatin receptor expression during treatment with high dose lanreotide, eight patients with neuroendocrine tumors were investigated by [(111)In-DTPA-D-Phe1]-octreotide scintigraphy before and during... more
To investigate possible changes in somatostatin receptor expression during treatment with high dose lanreotide, eight patients with neuroendocrine tumors were investigated by [(111)In-DTPA-D-Phe1]-octreotide scintigraphy before and during treatment. The spleen-to-background ratio decreased in all patients, whereas tumor-to-background ratio revealed a heterogeneous pattern with an average increase of 50% (-79% to +1,087%). This finding indicates that lanreotide treatment may influence the binding of radioactively labeled somatostatin to the spleen, while changes in the binding to functioning somatostatin receptors in tumor cells are more complex and not clearly related to treatment.
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Pharmacologic or surgical manipulation with growth hormone secretion or with the physiologic release of somatostatin and growth hormone-releasing hormone affects some rat liver enzymes, especially the sex-differentiated ones. We... more
Pharmacologic or surgical manipulation with growth hormone secretion or with the physiologic release of somatostatin and growth hormone-releasing hormone affects some rat liver enzymes, especially the sex-differentiated ones. We investigated the effects of two somatostatin analogs on several enzyme functions in six patients with carcinoid syndrome, using codeine as a probe drug. Codeine was given intravenously and its N- and O-demethylation, as well as 6-glucuronidation catalyzed by CYP3A, CYP2D6, and uridine diphosphate-glucuronosyltransferase, respectively, were studied before and during treatment with somatostatins. After 3 days of treatment with somatostatins the partial metabolic clearance of codeine by N-demethylation decreased by 21% to 64% in all patients (mean change, 44%; p < 0.05), and the clearance by O-demethylation was decreased by 20% to 69% in five of the patients (mean change in all patients, 35%; p < 0.05). In contrast, the partial clearance by 6-glucuronidation and the total systemic clearance of codeine were unchanged. Our results may be caused by the inhibition of growth hormone secretion induced by the somatostatins, inasmuch as direct metabolic interactions with these peptide drugs are improbable. The decline in CYP3A4 and CYP2D6 activity might have clinical implications when substrates of these enzymes with low therapeutic indices are combined with somatostatin analogs. Because the formation of morphine from codeine was altered, the analgesic effect of this drug may be reduced during concomitant treatment with somatostatins.
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In three patients with carcinoid liver and/or lymph node metastases, we studied the process of tumor tracer uptake and decarboxylation by means of positron emission tomography (PET) using 5-hydroxy-L-tryptophan (5-HTP) 11C-labeled in the... more
In three patients with carcinoid liver and/or lymph node metastases, we studied the process of tumor tracer uptake and decarboxylation by means of positron emission tomography (PET) using 5-hydroxy-L-tryptophan (5-HTP) 11C-labeled in the beta-position (HTP) and later the same day with 5-HTP 11C-labeled in the carboxyl group (HTC). With HTP, in which the 11C-label follows the molecule through decarboxylation to form 11C-serotonin, a high tumor accumulation of the tracer was found. With HTC, in which the label is rapidly eliminated from the tissues as 11CO2 if decarboxylation takes place, there was virtually no uptake by the tumors. By utilizing data from PET scanning with both tracers, we could quantify the decarboxylation rate and tissue accumulation of [11C]-serotonin and hence the enzymatic action of aromatic amino acid decarboxylase.
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Oligonucleotides (ODN) are key molecules for the aim of preventing translation of a gene product or monitoring gene expression in tissues. However, multiple methodological and biological hurdles need to be solved before in vivo... more
Oligonucleotides (ODN) are key molecules for the aim of preventing translation of a gene product or monitoring gene expression in tissues. However, multiple methodological and biological hurdles need to be solved before in vivo application in humans will be possible. For positron emission tomography (PET) investigations, a 20-mer DNA-locked nucleic acid (LNA) mixmer ODN specific for rat chromogranin-A mRNA was labeled with (68)Ga and its uptake was examined in vivo in rats with and without blocking of scavenger receptors by polyribonucleotides. In addition, uptake studies of (68)Ga-LNA were performed with respect to time and concentration in human and rat cell lines. The human cell lines did not express the target mRNA. Both polyinosinic acid (poly-I) and polyadenylic acid (poly-A) reduced the uptake in rat tissues and in human cell lines. Poly-I was found to be more effective in the liver whereas poly-A was more effective in the kidney. In addition, the blockade by poly-I was statistically significant in the pancreas, adrenal gland, bone marrow, intestine, testis, urinary bladder, muscle, parotid gland, and heart, whereas poly-A also caused significant reduction in pancreas, adrenal gland, and bone marrow but not as much as in kidney. Cell culture study showed a 2-phase dose-dependent uptake characteristic with a saturable and a passive diffusion-like phase; however, these 2 phases were not so well expressed in the rat cell line. The results suggest that scavenger receptors or other saturable processes unrelated to hybridization may be involved in the tissue uptake of (68)Ga-LNA and in the clearance of antisense ODN through the liver, kidney, spleen, and bone marrow. The fact that these processes may be sequence-dependent suggests that proof of in vivo hybridization through imaging may not be obtained by only comparing sense and antisense sequences and proving dose-dependency.
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In vivo monitoring of gene expression may be accomplished using a most advanced imaging technology such as positron emission tomography (PET). However, a range of methodological and biological hurdles needs exploration. In the present... more
In vivo monitoring of gene expression may be accomplished using a most advanced imaging technology such as positron emission tomography (PET). However, a range of methodological and biological hurdles needs exploration. In the present study, 20-mer DNA-LNA (locked nucleic acid) mixmer oligonucleotides specific for rat Chromogranin-A (Chg-A) mRNA were labeled with 68Ga and their biodistribution were investigated in rats; namely, two Antisense (LNA1, LNA2--differing only in the positioning of LNA modification), Mismatched, and Sense sequences. In addition, in vivo and in vitro metabolite analysis of LNA1 and LNA2 was compared, and hybridization in solution was performed to verify the hybridization ability after labeling. Furthermore, semiquantitative polymerase chain reaction was carried out to find organs expressing Chg-A mRNA in the rat. The biodistribution patterns altered according to the sequence and the positioning of LNA modification. The pattern of Mismatched--differing only in two nucleotides from the two Antisenses--was similar to that of Sense, whereas the pattern of LNA1 and LNA2 showed differences. Uptake in the adrenal gland was twofold higher with LNA2 compared to the other three oligonucleotides. Intact LNA2 could be observed in the 60-minute sample in vivo, whereas in vitro, the intact compound of both Antisenses could also be detected after 2 hours. Hybridization in solution revealed that the two Antisenses retained their hybridization abilities after 68Ga-labeling. With decreasing magnitude, Chg-A mRNA was expressed in the adrenal gland, intestine, testis, and pancreas. This study further supported LNA-DNA mixmer to be a favorable modification for antisense targeting approach with respect to hybridization and longer plasma residence; however, the organ uptake was dominated by processes irrelevant to specific hybridization.
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The present study was undertaken to investigate if pretreatment with pharmacological agents could change the organ uptake of 11C-labelled L-DOPA, and especially if the urinary excretion could be decreased. L-[beta-11C]DOPA was injected IV... more
The present study was undertaken to investigate if pretreatment with pharmacological agents could change the organ uptake of 11C-labelled L-DOPA, and especially if the urinary excretion could be decreased. L-[beta-11C]DOPA was injected IV into unanesthetized Sprague-Dawley rats. After 20 min the rats were decapitated and organs taken out for radioactivity measurements. The uptake in the organs was investigated in animals only given the tracer, and in animals pretreated with drugs such as decarboxylase inhibitors carbidopa and benserazide as well as the monoamine oxidase inhibitors deprenyl, clorgyline, and the COMT inhibitor OR-486. A marked decrease in the urinary radioactivity was observed after carbidopa and benserazide administration. HPLC analysis revealed that under native conditions the major part of urinary radioactivity existed as dopamine, which was eliminated by the decarboxylase inhibitors. After pretreatment with the COMT inhibitor OR-486, the radioactivity uptake in the pancreas increased fourfold as compared to non-treated animals. HPLC analysis showed that this correlated with a marked increase in radiolabelled DOPAC. In the other organs and with the other drugs, only small effects were observed. With L-[beta-11C]fluoroDOPA as a tracer, similar results were observed although the increase in the pancreas by OR-486 had a lower magnitude. These studies suggest that it might be possible to improve the diagnostic ratio of L-[beta-11C]DOPA or L-[18F]fluoroDOPA in whole-body PET studies by pretreating the patient with decarboxylase inhibitor for reducing the urinary excretion and potentially increase the target organ uptake by COMT inhibition.
Research Interests: Nuclear medicine, Drug interactions, Enzyme Inhibitors, Positron Emission Tomography, Dopamine, and 11 moreAnimals, Male, Aromatic amino acid, Levodopa, Clinical Sciences, High Pressure Liquid Chromatography, Rats, Single Photon Emission Computed Tomography, Autoradiography, Monoamine oxidase, and Whole Body
Methods have been developed to label oligonucleotides (ODNs) in the... more
Methods have been developed to label oligonucleotides (ODNs) in the 5'-position with (76)Br via a prosthetic group on a hexylamino-linker. The purpose of the study was to explore whether the labelling procedure would prevent specific hybridisation by using reverse transcription-polymerase chain reaction (RT-PCR) followed by sequencing of the PCR product. Antisense ODNs (30 mer, specific for rat Chromogranin A [CgA] mRNA) with phosphodiester (O-ODN) or phosphothioate (S-ODN) backbone, either unlabelled or labelled with (76)Br, served as one of the primers in individual PCR reactions. Using O-ODN as a primer, irrespective of being labelled or not, a selected 225-bp PCR fragment was successfully amplified. However, no amplification was obtained using S-ODN as a primer. The proper PCR products were only detected in the sample prepared from the adrenal gland, but not in that from the heart, liver or kidney. Autoradiographic recording of the gel, after gel electrophoresis, revealed radioactive signals corresponding to the amplified PCR products. The sequence of the PCR product matched the rat CgA mRNA sequence obtained from the EMBL database. RT-PCR is an attractive method to identify the selective binding of modified ODNs to target mRNA. This method confirmed that the labelling with (76)Br did not change the hybridisation ability of antisense O-ODN.
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The aim of this pilot study was to explore the impact of peptide mass on binding of [(68)Ga]-DOTATOC to neuroendocrine tumour somatostatin receptors in vivo using a tracer of variable specific radioactivity (SRA) and to show the logistic... more
The aim of this pilot study was to explore the impact of peptide mass on binding of [(68)Ga]-DOTATOC to neuroendocrine tumour somatostatin receptors in vivo using a tracer of variable specific radioactivity (SRA) and to show the logistic feasibility of sequential PET scans in the same patient. Nine patients with gastroenteropancreatic neuroendocrine tumours were included. Six of them underwent three sequential PET-CT examinations with intravenous injections of [(68)Ga]-DOTATOC proceeded by 0, 50 and 250 or 500 microg of octreotide, administered 10 min before the tracer. Three patients were examined by dynamic and static PET/CT for pharmacokinetic and dosimetric calculations. The [(68)Ga]-DOTATOC synthesis included preconcentration and purification of the generator eluate and microwave heating in a semi-automated in-house procedure. [(68)Ga]-DOTATOC synthesis and quality control were accomplished within 30 min and radiochemical purity was >95%. The tracer accumulation in the tumours varied and depended on the total amount of the administered peptide. In five of six patients, the highest tumour-to-normal tissue ratio was found when 50 microg of octreotide was preadministered. One patient showed a continuously increasing tumour uptake. Dosimetrically, a large variation in organ doses was found (kidney: 0.086-0.168 mSv/MBq; liver: 0.026-0.096 mSv/MBq; spleen: 0.046-0.226 mSv/MBq). The effective dose (0.015, 0.0067 and 0.0042 mSv/MBq) was correlated to the total amount of decays. Three sequential PET-CT examinations using (68)Ga-based tracer was carried out in 1 day. The use of high SRA [(68)Ga]-DOTATOC and unlabelled octreotide indicates an optimal mass leading to better image contrast. [(68)Ga]-DOTATOC-PET-CT employing variable SRA may be utilised for accurate quantification of tumour uptake with subsequent dosimetry for personalized therapy management.
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A majority of neuroendocrine gastroenteropancreatic (GEP) tumors can be detected by conventional radiological methods and scintigraphic techniques. Still there are problems to visualize small tumor lesions and non-functioning tumors. The... more
A majority of neuroendocrine gastroenteropancreatic (GEP) tumors can be detected by conventional radiological methods and scintigraphic techniques. Still there are problems to visualize small tumor lesions and non-functioning tumors. The aim of this study was to investigate some of the monoamine processing pathways of neuroendocrine GEP-tumors and try to find a new tracer substance for in vivo characterization and visualization by Positron Emission Tomography (PET). Autoradiography of tumor sections from 8 midgut carcinoids (MGC) and 8 endocrine pancreatic tumors (EPT) was performed with (11)C-labeled tracers for serotonin and dopamine transporters, serotonin HT2A-, dopamine D1- and muscarinic receptors and for monoamine oxidase A (MAO-A). The in vitro results initiated PET studies with (11)C-Harmine in 4 patients with MGC and 7 patients with EPT (one insulinoma, two glucagonomas and four non-functioning EPT). The MAO-A-ligand Harmine expressed specific in vitro binding of 87 +/-21% for MGC and 125 +/- 50% for EPT, compared to reference tissue (rat brain, 100%). All other substances showed relatively low specific binding. (11)C-harmine-PET could visualize tumors in all patients. The mean standardized uptake value (SUV) for MGC was 7.5 +/- 3.9 and for EPT 12.9 +/- 2.7, whereas the SUV of normal liver, intestine and pancreas were 3.1 +/- 0.5, 3.4 +/- 1.2 and 8.9 +/- 3.0 respectively. This study demonstrates in vitro and in vivo that neuroendocrine GEP-tumors are characterized by a high MAO-A-expression, thereby adding to the similarities of neuronal and neuroendocrine tissue. It also indicates a possible application for (11)C-harmine as a new PET-tracer for neuroendocrine GEP-tumors with the potential to visualize also non-functioning EPT's.
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We administered Ro 40-7592, an inhibitor of the enzyme catechol-O-methyltransferase (COMT) that crosses the blood-brain barrier, to rats and monitored extracellular catecholamine levels in the corpus striatum before and after the... more
We administered Ro 40-7592, an inhibitor of the enzyme catechol-O-methyltransferase (COMT) that crosses the blood-brain barrier, to rats and monitored extracellular catecholamine levels in the corpus striatum before and after the intraperitoneal administration of a bolus of l-dopa. Acute administration of Ro 40-7592 increased basal levels of l-dopa and dihydroxyphenylacetic acid (DOPAC) and decreased basal homovanillic acid (HVA) levels, but did not affect basal dopamine levels. In rats treated with Ro 40-7592, l-dopa administration produced a greater increase in striatal levels of l-dopa, dopamine, and DOPAC than it did in controls, while HVA formation was attenuated. We conclude that inhibition of COMT activity promotes central dopamine synthesis and release following administration of pharmacologic doses of l-dopa.
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Treatment with combined streptozotocin and liposomal doxorubicin is safe and efficient in patients with endocrine pancreatic tumors (EPTs). No cardiac toxicity was reported. The combination of streptozotocin and doxorubicin has been shown... more
Treatment with combined streptozotocin and liposomal doxorubicin is safe and efficient in patients with endocrine pancreatic tumors (EPTs). No cardiac toxicity was reported. The combination of streptozotocin and doxorubicin has been shown to be superior to streptozotocin and fluorouracil in the treatment of metastatic EPTs. However, the risk of cardiac toxicity from anthracyclins hampers the usefulness of the drug combination. Liposomal doxorubicin has a lower frequency of cardiac adverse events compared to doxorubicin. We wanted to assess the efficacy and safety of combined streptozotocin and liposomal doxorubicin in patients with metastatic EPTs. Thirty patients with metastatic EPTs were recruited from three medical centers in Norway and Sweden during a time period of 3 years. All patients had histopathologically confirmed diagnoses and bidimensionally measurable lesions. 30 mg/m(2) of liposomal doxorubicin was administered on day 1 of each cycle. During the first course, 1 g of streptozotocin was given on 5 consecutive days. Thereafter, 2 g of streptozotocin was given on day 1 only. Treatment was repeated every 3 weeks. Twelve of 30 patients (40%) achieved an objective radiological response with a median duration of 9 months. Stabilization of disease was achieved in 17 of 30 patients (57%) for a median duration of 11 months. Only one patient had progressive disease as best response. The 2-year progression-free survival was 18% and the 2-year overall survival was 72%. The treatment was well tolerated. None of the patients experienced cardiac toxicity. We conclude that combined streptozotocin and liposomal doxorubicin is a safe and efficient treatment for EPTs. The efficacy seems to be comparable to that of combined streptozotocin and doxorubicin, whereas the cardiac toxicity clearly favors using the liposomal drug combination.
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This 6-month, open, non-controlled, multicenter, dose-titration study evaluated the efficacy and safety of 28-day prolonged-release (PR) lanreotide in the treatment of carcinoid syndrome. Eligible patients had a carcinoid tumor with... more
This 6-month, open, non-controlled, multicenter, dose-titration study evaluated the efficacy and safety of 28-day prolonged-release (PR) lanreotide in the treatment of carcinoid syndrome. Eligible patients had a carcinoid tumor with > or =3 stools/day and/or > or =1 moderate/severe flushing episodes/day. Six treatments of 28-day PR lanreotide were administered by deep subcutaneous injection. The dose for the first two injections was 90 mg. Subsequent doses could be titrated (60, 90, 120 mg) according to symptom response. Seventy-one patients were treated. Flushing decreased from a mean of 3.0 at baseline to 2.3 on day 1, and 2.0 on day 2, with a daily mean of 2.1 for the first week post-treatment (p < 0.05). Diarrhea decreased from a mean of 5.0 at baseline to 4.3 on day 1 (p < 0.05), and 4.5 on day 2, with a daily mean of 4.4 for the first week post-treatment (p < 0.001). Symptom frequency decreased further after the second and third injections, and reached a plateau after the fourth injection. By month 6, flushing and diarrhea had significantly decreased from baseline by a mean of 1.3 and 1.1 episodes/day, respectively (both p < or = 0.001); 65% of patients with flushing as the target symptom and 18% of diarrhea-target patients achieved > or =50% reduction from baseline. Median urinary 5-hydroxyindoleacetic acid and chromogranin A levels decreased by 24 and 38%, respectively. Treatment was well tolerated. 28-day PR lanreotide was effective in reducing the symptoms and biochemical markers associated with carcinoid syndrome.
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The differentiation between Parkinson's disease (PD), progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) is important for prognostic and therapeutic purposes. In order to evaluate the diagnostic capability of... more
The differentiation between Parkinson's disease (PD), progressive supranuclear palsy (PSP) and multiple system atrophy (MSA) is important for prognostic and therapeutic purposes. In order to evaluate the diagnostic capability of two tests reflecting these items, patients fulfilling strict clinical criteria for PD (n=35), MSA (n=36) and PSP (n=14), were consecutively included. An analysis of neurofilament protein (NFL), a marker of axonal degeneration in the cerebrospinal fluid (CSF) and a levodopa test, recorded with optoelectronic technique were performed. Using discriminant analyses, the test's abilities to predict the clinical PD or non-PD (MSA and PSP) diagnoses were compared. Whereas the CSF-NFL and levodopa tests predicted 79 and 85% correct diagnoses respectively, the combined test predicted 90% correct diagnoses. We conclude that the CSF-NFL and levodopa tests provide detailed information of clinical variables on which the clinical diagnostic criteria are based. As they are pathologically unrelated, the diagnostic precision increases compared to clinical diagnoses when they are combined.
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The expression of certain tyrosine kinase receptors (TKR) has been shown to have a prognostic value in many tumor entities. In recent years, inhibitors and monoclonal antibodies directed towards these receptors have been developed.... more
The expression of certain tyrosine kinase receptors (TKR) has been shown to have a prognostic value in many tumor entities. In recent years, inhibitors and monoclonal antibodies directed towards these receptors have been developed. Several have shown antitumoral effects and have been tested in clinical trials. We wanted to investigate whether midgut carcinoid tumors express TKR and therefore would be suitable for clinical trials with TKR inhibitors (TKRI) or monoclonal antibodies. Tumor tissue from 36 patients (24 women and 12 men) with a malignant midgut carcinoid tumor was obtained. The tissues were examined with immunohistochemistry, using polyclonal antibodies against platelet-derived growth factor receptor-alpha (PDGFRalpha), platelet-derived growth factor receptor-beta (PDGFRbeta), epidermal growth factor receptor (EGFR) and c-kit. Human BON1 cells were cultivated and stimulated with PDGF-BB. We also present a case report of a patient with a malignant midgut carcinoid tumor who had stabilization of tumor growth during treatment with imatinib. Immunohistochemical staining for PDGFRalpha in tumor cells showed immunoreaction for the receptor in 13/34 (38%) for PDGFRbeta in 29/33 (88%), and 24/33 (73%) were immunoreactive for EGFR. No tumor tissue showed immunoreaction for c-kit. In tumor stroma PDGFRalpha was expressed in 35%, PDGFRbeta in 94% and EGFR in 9%. We show that human neuroendocrine tumor cells respond to PDGF, indicating that these tumors express functional PDGF receptors. Malignant midgut carcinoid tumors may express three of the four TKR tested in this investigation. Therefore, these tumors might be susceptible for treatment with TKRI or monoclonal antibodies and this should be further explored in clinical trials.