Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Somatostatin receptors have been identified on the cellular surface of a subset of patients with small cell lung cancer (SCLC) and may be associated with a less aggressive evolution of the tumor. Moreover, medical therapy with somatostatin analogues holds promise for neoplastic growth control. We performed planar imaging in 22 patients with histologically proven SCLC at 2-4 and 24 hours after the injection of 111-185 MBq of 111In-DTPA-octreotide (Octreoscan, Byk-Gulden). Tumor uptake was observed in 19 patients in both early and late scans, while 2 patients previously treated with chemotherapy showed negative early and late scans. One patient had a positive early scan and a negative late scan. All the scintigraphic studies showed more extensive disease than expected by CT. No significant modification in tumor uptake of radiooctreotide was observed in three patients studied before and after chemotherapy. In conclusion, 111In-octreotide is a suitable radiopharmaceutical for the in vivo evaluation of the somatostatin receptors of small lung cancer. The prognostic and therapeutical implications of this nuclear technique must be further investigated, however.
 ...
PMID:111In-octreotide scintigraphy in small cell lung cancer. 900 64

Primary cardiac tumors are rare, and there are no reports of patients with a functional gastroenteropancreatic tumor syndrome caused by such a tumor. This case report describes a patient with a cardiac gastrinoma causing Zollinger-Ellison syndrome. Evidence is presented that this tumor represents a primary cardiac tumor. The exact identification of this gastrinoma in an extra-abdominal site was facilitated by the use of [111In-DTPA-DPhe1]octreotide scanning for somatostatin receptors, which these tumors characteristically possess in high numbers. The recent availability of this novel localization method may facilitate identification of extra-abdominal sites in an increasing proportion of patients with gastrinomas and related neuroendocrine functional tumors in which no intra-abdominal primary tumor is currently found.
 ...
PMID:Primary cardiac gastrinoma causing Zollinger-Ellison syndrome. 902 11

Radiolabeled somatostatin analogs have shown uptake in a variety of tumors. These include carcinoid, Merkel cell carcinoma, pheochromocytoma, islet cell tumor, and other tumors with somatostatin receptors. Radiolabeled somatostatin analog imaging with Indium-111-DTPA-pentetreotide permits whole body imaging, providing a new safe and effective means for detection of primary tumors and metastatic foci in neoplasms with somatostatin receptors. This imaging modality is helpful in screening the entire body as well as evaluating questionable foci of disease identified by conventional imaging modalities. This case report demonstrates the utility of computed tomography (CT) and radiolabeled somatostatin imaging as complementary modalities in the workup of a patient with metastatic carcinoid tumor.
 ...
PMID:Metastatic carcinoid tumor imaged with CT and a radiolabeled somatostatin analog: a case report. 906 82

Vapreotide (RC-160), a somatostatin analog, was labeled with 99mTC by a direct method and also by using CPTA [1,4,8,11-tetraazacyclotetradecane] as a bifunctional chelating agent. The labeled compounds were evaluated in nude mice bearing experimental human prostate cancers. In these studies, 111In-DTPA-D-Phe-Octreotide (111In-DTPA-octreotide) served as a standard and 99mTc-oxytocin as a receptor-non-specific control. 99mTc-octreotide was also used. The 24 htumor uptake of 99mTc-RC-160 was nearly 400% higher, (p < 0.05), than that of 111In-DTPA-octreotide and diminished upon receptor blocking. In all tissues except the kidneys, the uptake of 99mTc-RC-160 was also higher than that of 111In-DTPA-octreotide. The uptake of 99mTc-RC-160 was influenced by the amount of peptide injected and the best tumor/muscle and tumor/blood ratios were obtained when only one micrograms of the peptide (200 Ci/mmol) was administered.
 ...
PMID:Radiolabeled somatostatin analogs in prostate cancer. 908 Apr 82

Octreotide, a potent synthetic somatostatin (SM) analogue, was recently evaluated and found to have a beneficial effect in thyroid eye disease (TED), mostly in those patients with a positive Octreoscan-111. Lanreotide (LRT; Somatuline-Ipsen), a new SM long-acting analogue, is more active than natural SM and shows a much longer duration of action. The aim of the present preliminary study was to evaluate the therapeutic effect of LRT in the treatment of TED. Five patients, three males and two females, mean age 50.6 +/- 7.6 S.D. (45-64) years, all with severe symptoms of TED were studied. A similar number of patients, matched for age, sex and severity of ophthalmopathy served as controls. All the patients and controls were investigated with orbital scintigraphy using 111 In DTPA-D-Phe1-octreotide (Octreoscan-111) and selected on the basis of positive octreoscan. The NOSPECS system, as adapted by Donaldson et al. (Journal of Clinical Endocrinology and Metabolism 1973 37 276-285) and a disease activity score, as proposed recently by an International Workshop, have been followed in this study in order to evaluate the response to treatment. The five patients who comprised the treatment group received 0.04 g LRT i.m. once every 2 weeks over a period of 3 months, after which the Octreoscan-111 was repeated. The control patients were given an injection of water i.m., also once every 2 weeks for 3 months, after which they were evaluated clinically. No Octreoscan-111 was performed in the controls. All patients and controls were evaluated by the same physician, who was unaware of the type of treatment used. A decrease in the NOSPECS score and the clinical activity score was regarded as a positive response, while no change or an increase in the NOSPECS score along with no clinical improvement was regarded as a negative response. After 3 months of treatment with LRT, four patients showed a statistically significant improvement in ophthalmopathy in both eyes and one in one eye. Three of the control patients with TED did not show any change, one showed a minor improvement in one eye and no change in the other and one showed deterioration in both eyes. An interesting finding was that orbital Octreoscan-111 activity was absent in all the patients after LRT treatment. In conclusion, these preliminary results show that LRT has a beneficial effect on patients with TED, and that since it has to be given only once every 2 weeks, it is probably superior to any other form of SM treatment. However, as the number of patients was small, further studies are needed to confirm our results.
 ...
PMID:Lanreotide in the treatment of patients with thyroid eye disease. 915 Jul 3

Small cell lung cancer (SCLC) expresses somatostatin receptors that can be traced with 111In-DTPA-octreotide scintigraphy. Although this technique is currently employed for staging and follow-up of neuroendocrine tumors of the gastrointestinal tract, its role in the clinical work-up of SCLC is at present under discussion. A better imaging contrast is desirable and recent reports suggest that this aim could be achieved by pretreatment with cold octreotide. Here we report on the results of 111In-DTPA-octreotide scintigraphy in 12 SCLC patients carried out before and after octreotide treatment. The patients were treated for 7 days with octreotide 200 micrograms three times a day s.c. Uptake was studied at 5 h with whole body planar and SPET imagings. In all cases studied, pretreatment with octreotide was followed by enhancement of tumor imaging. In one patient a better contrast of the lesions was found at the parenchymal and mediastinal levels as well as at brain level, allowing a clear definition of otherwise questionable metastases. After octreotide treatment, a decrease in background uptake in the subdiaphragmatic area was observed in most cases, allowing a better imaging of liver metastases. The enhancement effect was confirmed by semiquantitative analysis of scintigraphic uptake. Taken together, our results seem to indicate that cold octreotide enhancement can improve 111In-DTPA-octreotide imaging and optimize its clinical role in SCLC.
 ...
PMID:Intensification of 111In-DTPA-octreotide scintigraphy by means of pretreatment with cold octreotide in small cell lung cancer. 923 58

The quantitative uptake kinetics of (2-[18F]fluoropropionyl-(D)phe1)-octreotide (I), a somatostatin (SRIF) receptor-specific tracer, was measured by PET. Conventional organ biodistribution and in vivo stabilities of the tracer as well as in vivo displacement and SRIF receptor blocking were determined. The 18F-fluorinated octreotide was compared with ([67Ga]-DFO-B-succinyl-(D)phe1)-octreotide (II) and ([86Y]-DTPA-(D)phe1)-octreotide (III). Initially, 2-10 MBq of the labeled tracers were injected into male Lewis rats bearing an exocrine pancreatic islet cell tumor. PET measurements were performed dynamically between 0 and 120 min postinjection. Organ distributions were determined 5, 15, 30, 60, and 120 min postinjection. The extent of metabolic degradation was analyzed in serial blood and urine samples as well as in homogenized samples of tumor, liver, and kidney. The uptake of (I) by the tumor was rapid (maximum accumulation at 1-2 min postinjection) and high (about 0.5 +/- 0.2% ID/g), followed by a fast and continuous release with koff = 10 +/- 2. 10(-5) s-1. The tracer was found to remain intact in vivo up to 120 min postinjection. Specific binding of (I) to SRIF receptors in the adrenals, the pancreas, and the pituitary gland was demonstrated in vivo by pretreatment and displacement experiments. Compound (II) also showed a fast uptake by the tumor. Its tumor residence half-life was longer (koff = 3.0 +/- 0.5 . 10(-5) s-1). Compound (II) was also predominantly excreted intact. One hour postinjection, the remaining activity in the blood pool was found to be bound to serum proteins. Early uptake kinetics for compound (III) were also rapid but reached only half the tumor uptake of (II). Compared to (I), the release of 86Y-activity from the tumor was slower (koff = 3.1 +/- 1.3 . 10(-5) s-1). Compared to (II), compound (III) was considerably less stable in vivo. The main critical organs for (II) and (III) are kidneys and bones, whereas (I) is predominantly accumulated in the liver. The in vivo behavior of (I) closely resembles 14C-labeled octreotide. Thus, 18F-labeled octreotide may be of interest in the quantitation and investigation of in vivo properties of somatostatin receptors by PET. However, the short residence of (2-[18F]fluoropropionyl-(D)phe1)-octreotide in tumors and its hepatobiliary excretion may complicate the interpretation of abdominal tumors.
 ...
PMID:PET-pharmacokinetics of 18F-octreotide: a comparison with 67Ga-DFO- and 86Y-DTPA-octreotide. 925 25

Somatostatin receptors have been identified in a variety of neuroendocrine tumors and activated leukocytes. A high density of somatostatin receptors is also present in most intestinal intramural veins of patients with inflammatory bowel disease. We present a case of a 25-yr-old female with severe Crohn's disease unresponsive to medical therapy, including adrenocorticotropic hormone (ACTH) administration. The patient underwent (111)In-DTPA octreotide scintigraphy to evaluate the potential role of somatostatin receptor imaging in inflammatory bowel disease. Despite the lack of significant somatostatin receptors in the affected bowel, an unexpected prominent activity of (111)In-DTPA octreotide was noted in the adrenal glands on the SPECT images, presumably resulting from excessive stimulation by ACTH. The expression of somatostatin receptors in the stimulated adrenals may be used to image other adrenal pathologies and could potentially indicate response to therapy.
 ...
PMID:Adrenal glands imaging with indium-111-DTPA-D-Phe1-octreotide following ACTH therapy. 929 15

The somatostatin analogue octreotide may be used in the diagnosis of carcinoid and other neuroendocrine tumours. Radionuclide scanning following intravenous injection of 111Indium-labelled octreotide (111In-DTPA-pentetreotide) provides a sensitive, non-invasive method of localising somatostatin-positive tumours. The technique may also be used to identify patients who may respond to 'cold' octreotide therapy and to monitor therapeutic efficacy.
 ...
PMID:Octreotide scanning for carcinoid tumours. 933 23

The multiple aspects of radioligand-receptor interactions do not only show a major impact of certain cell surface-bound receptors in the pathophysiology of human disease: the concept of radioligand-receptor interactions has also been extended to the clinic. In particular, naturally occurring peptides, when radiolabelled, are clinically useful for the imaging diagnosis of human disease and have future implications for the treatment of tumour expressing certain target receptors using radiolabelled peptide tracers. The finding that receptors for VIP (vasoactive intestinal peptide) and SST (somatostatin) are overexpressed on tumour cells presents a breakthrough into this direction. Recent data indicate that [123I]-VIP receptor scintigraphy is clinically useful for the in vivo localization of small primary adenocarcinomas, liver metastases and certain endocrine tumours of the gastrointestinal tract. After the successful clinical introduction of the SST analogues [123I]-Tyr3-octreotide and [111In]-DTPA-D-Phe1-octreotide for localization diagnosis of neuroendocrine tumours in 1989, P829, labelled with the more cost-effective radionuclide 99mTc, nowadays promises to be a potential novel diagnostic imaging agent for tumours expressing SST/VIP receptors. Furthermore, the novel SST analogue [90Y]-MAURITIUS is entering the clinic for treatment of VIP/SST receptor-expressing tumours.
 ...
PMID:Mack Forster Award Lecture. Receptor nuclear medicine: vasointestinal peptide and somatostatin receptor scintigraphy for diagnosis and treatment of tumour patients. 937 55


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>