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

Thyroid associated ophthalmopathy (TAO) is a disorder involving the soft tissues and extraocular muscles of the orbit seen mainly in cases of Graves' disease. Although an immunogenic pathogenesis has been proposed, the actual mechanisms of the in vivo retrobulbar involvement are not well defined. The recent introduction of the 111In-labeled somatostatin analog, octreotide, which can bind in vivo to the cell membrane of activated lymphocytes expressing somatostatin receptors, has provided a new investigational tool for diseases with a presumed immunological background. Based on this property, octreotide scans can be expected to be positive in cases of immunological disease showing tracer accumulation within affected sites. The aim of this study was to evaluate the utility of scintigraphic imaging with octreotide of the retrobulbar space in cases of TAO, including sequential studies of patients undergoing immunosuppressive therapy. We studied a series of 51 patients who had Graves' disease with varying degrees of TAO. Nine patients had received immunosuppressive therapy. The degree of orbital inflammation was classified according to the clinical activity score of Mourits. Both planar and tomographic imaging of the orbit were carried out using 111 MBq of the 111In-labeled octreotide (OctreoScan) 2 h after tracer injection. A significant tracer accumulation in the retrobulbar space was seen in all 20 patients with a high activity score, in 8 of 16 cases with a negative score, and in 11 of 20 cases with an intermediate Mourits' score. In cases of persistent eye disease in spite of immunosuppressive therapy, the octreotide scan remained positive. Successful therapy either with prednisolone, external radiation, or i.v. immunoglobulins showed a significant diminution of tracer uptake after finishing the therapeutic regime. Three-dimensional reconstruction of the images also revealed a significant tracer accumulation in the areas of the lacrimal gland, the nasal region, and the pituitary. Controls cases (n = 30) showed no uptake in the orbital region. We conclude that 111In octreotide scintigraphy is an objective method that identifies patients with active inflammatory eye disease, i.e., having significant tracer uptake in the retrobulbar space. This uptake appears to reflect an immunological process, since immunosuppressive therapy will significantly decrease tracer accumulation.
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PMID:Evaluation of immunological mechanisms mediating thyroid-associated ophthalmopathy by radionuclide imaging using the somatostatin analog 111In-octreotide. 934 89

This study was conducted to determine the feasibility of injecting the somatostatin analogue, octreotide acetate (OA), into the vitreous cavity. Previous work suggests that octreotide effectively inhibits angiogenesis in vitro, thus its use in vivo may slow the progression of proliferative eye disease. Fifty micrograms of aqueous OA in 50 microliters aqueous solution was injected into the mid-vitreous of kitten eyes (n = 6), and OA levels were monitored over 4 days. A long-acting release form of octreotide (OA-LAR) was also injected into the mid-vitreous of rabbit eyes at doses of 0.36 (n = 16), 1.1 (n = 1), 2.1 (n = 1), 4.05 (n = 1), 8.2 (n = 1), and 36 mg (n = 3) in solution; and octreotide concentrations were measured at various time points over 42 days. OA concentrations were determined by a highly specific radioimmunoassay. Aqueous octreotide was eliminated rapidly (t1/2 = 16 hours) from the vitreous of the kitten eye, with only negligible amounts recoverable 4 days post-injection. In the long-acting form, OA in the rabbit eye reached peak levels at 28 days. By 42 days, OA levels had declined to the 14-day level. Doses of OA-LAR of 1.1 mg or less produced no gross evidence of clinical toxicity and elicited no grossly visible ocular side effects. Doses greater than 1.1 mg produced significant toxicity, including cataracts and rubeosis. The 28-day peak release for long-acting OA implies that monthly intravitreal injections could provide continual high levels of OA. Intravitreal injection of long-acting OA provides sustained, high concentrations of drug, and deserves further study as a potential treatment of proliferative eye diseases.
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PMID:Intravitreal injection of octreotide acetate. 909 Jun 17

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.
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PMID:Lanreotide in the treatment of patients with thyroid eye disease. 915 Jul 3

Most patients with Graves' disease have some evidence of ocular involvement, but this is commonly mild, requiring only local measures. A minority of patients (3-5%) have severe Graves' ophthalmopathy, for which the three main treatment procedures are represented by high-dose glucocorticoids, orbital radiotherapy and orbital decompression. Favourable results with medical treatment have been reported in approximately 60% of patients, with particular regard to inflammatory changes, newly developed eye muscle dysfunction and optic neuropathy. Orbital decompression is indicated in severe eye disease not responsive to glucocorticoids and/or irradiation, particularly in the presence of marked proptosis and optic neuropathy. Not conclusive or unsatisfactory results have been obtained with other medical treatment procedures, including immunosuppressive drugs, intravenous immunoglobulins and plasmapheresis. Recently favourable responses have been reported with somatostatin analogues. Rehabilitative surgery involving either the eye muscles or the eyelids is not infrequently required after medical treatment or decompression. Permanent control of thyroid hyperfunction by radioiodine or thyroidectomy is advisable when severe ophthalmopathy is present. Exacerbation of ophthalmopathy following radioiodine may occur but can be prevented by concomitant administration of glucocorticoids. Smoking deleteriously influences the course of ophthalmopathy and its response to treatment.
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PMID:Treating severe Graves' ophthalmopathy. 953 37

Recent studies have shown successful therapy with the long-acting somatostatin (SM) analogues octreotide and lanreotide in patients with thyroid eye disease (TED). In one such study it was also found that response to low-dose octreotide treatment (300 microg) in these patients was correctly predicted by [111In-DTPA-D-Phe1]-octreotide scintigraphy and concluded that this parameter should be used as a predictive test of the effectiveness of treatment with nonradioactive octreotide. It has also been suggested that octreoscan-111 may be seen as a parameter of disease activity in TED. However, it remains to be clarified whether octreoscan-111 predicts the therapeutic outcome better than the clinical activity score, or magnetic resonance imaging (MRI) or finally measurement of glucosaminoglycan (GAG) in the plasma and/or urine. The exact mechanism of action of SM analogues has not yet been fully clarified. Three explanations may be offered. First, SM suppresses insulin-like growth factor 1 (IGF-1) activity and inhibits IGF-1-mediated effects. A second possible mechanism could be the direct inhibition of the release of cytokines from T-lymphocytes, and finally, SM analogues may act on target cells through specific cell surface receptors. In view of the encouraging therapeutic results reported thus far in several studies, SM analogues may provide a valuable therapeutic alternative to corticosteroids, especially in patients who cannot tolerate the latter. However, further prospective, placebo-controlled studies with a large number of patients are needed before we can reach final conclusions.
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PMID:Somatostatin analogues in the treatment of thyroid eye disease. 962 41

Orbital lymphocytic infiltration in thyroid eye disease (TED), as well as identification of somatostatin (SMS) receptors on activated lymphocytes, has provided a rationale for receptor imaging with the radiolabeled SMS analog Pentetreotide. In 80 patients with TED, single-photon emission computed tomography (SPECT) images of the orbit were performed 4 and 24 hours after injection of Pentetreotide. Semiquantitative evaluation was performed using the SPECT slices with irregular regions of interests placed over the orbits and both hemispheres. In contrast to controls (median 5 counts per voxel per millibecquerel (cts/vox/MBq) injected activity), TED patients showed threefold increased orbital accumulation of Pentetreotide (15 cts/vox/MBq, p = 0.003). When considering patients with active TED only, even higher uptake was registered (23 cts/vox/MBq, p = 0.0006 vs. controls, sensitivity for active TED 61/68, 90%; specificity 12/12, 100%). In 40 patients with active TED, the radionuclide accumulation decreased sharply after completion of immunosuppressive therapy. A high pretreatment Pentetreotide orbit-to-brain ratio correlated with a response to therapy (positive and negative predictive values 28/32, 88%, and 8/8, 100%, respectively). In conclusion, SMS receptor scintigraphy may be regarded as a semiobjective tool in the evaluation of TED, both at initial stages as well as during treatment.
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PMID:Somatostatin receptor scintigraphy in thyroid eye disease. 966 96

Octreotide, a potent synthetic long-acting somatostatin analogue, has been shown to have a beneficial effect in thyroid eye disease (TED). Orbital scintigraphy using ocetreoscan-111 is a useful study, which can be used to visualize somatostatin-receptor-bearing cells and also to select patients who might benefit from octreotide therapy. One major limitation of this therapy is that the drug must be administered parenterally and used several times daily. Lanreotide, a new somatostatin analogue, has a much longer duration of action in comparison with octreotide, and has recently been found to have a beneficial effect in the treatment of thyroid eye disease. The aim of this study was to investigate the orbital Indium-111-pentetreotide activity after treatment with octreotide and lanreotide in patients with thyroid ophthalmopathy. Fourteen patients were studied. 12 with bilateral and 2 with unilateral thyroid eye disease, (10 females and 4 males) and all with moderately severe symptoms of ophthalmopathy. All were treated with antithyroid drugs and were euthyroid at the time of the study. All patients were investigated with orbital scintigraphy using octreoscan-111 and selected for study on the basis of a positive octreoscan. Five patients received 30 mg lanreotide intramuscularly once every 2 weeks over a period of 3 months, and 5 patients received octreotide 100 microg subcutaneously thrice daily for 3 months. Four patients served as controls and received no treatment. The octreoscan-111 scintigraphy was repeated in all patients 3 months after the first examination. The NOSPECS classification and the clinical activity score (CAS) of thyroid ophthalmopathy were also evaluated before and 3 months after the initiation of treatment. All patients who received treatment had a negative follow-up octreoscan while controls had a positive octreoscan. NOSPECS score and CAS were improved with treatment, but unchanged in control patients. The reduced uptake of octreoscan may be the result of blocking of somatostatin receptors, or reduction in receptor-expressing tissues, downregulation of somatostatin receptors in target tissues, or a combination of these factors.
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PMID:Somatostatin receptor scintigraphy before and after treatment with somatostatin analogues in patients with thyroid eye disease. 1003 76

Until recently there was no imaging technique available which could demonstrate pathological changes in orbital tissues and could be regarded as a reliable measure of inflammation in thyroid eye disease (TED). Pentetreotide (a synthetic derivative of somatostatin) labelled with 111In has been used to localize tumours which possess surface or membrane receptors for somatostatin in vivo using a gamma camera (1). This technique visualizes somatostatin receptors in endocrine-related tumours in vivo and predicts the inhibitory effect of the somatostatin analogue octreotide on hormone secretion by the tumours (1). By applying 111In-DTPA-d-Phe octreotide scintigraphy (octreoscan), accumulation of the radionuclide was also detected in both the thyroid and orbit of patients with Graves' disease (2-4). If peak activity in the orbit 5h after injection of radiolabelled octreotide is set at 100%, a decrease to 40+/-4% is found at 24h, significantly different from the decrease in blood pool radioactivity, which is 15+/-4% at 24h. Accumulation of the radionuclide is most probably due to the presence in the orbital tissue of activated lymphocytes bearing somatostatin receptors (5). Alternative explanations are binding to receptors on other cell types (e.g. myoblasts, fibroblasts or endothelial cells) or local blood pooling due to venous stasis by the autoimmune orbital inflammation.
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PMID:The role of octreoscan in thyroid eye disease. 1022 98

Graves' ophthalmopathy is an debilitating disease impairing the quality of life of affected individuals. Despite recent progress in the understanding of its pathogenesis, treatment is often not satisfactory. In mild cases, local therapeutic measures (artificial tears and ointments, sunglasses, nocturnal taping of the eyes, prisms) can control symptoms and signs. In severe forms of the disease (3-5%), aggressive measures are required. If the disease is active, high-dose glucocorticoids and/or orbital radiotherapy, or orbital decompression represent the mainstay of treatment. If the disease is severe but inactive, orbital decompression is preferred. Novel treatments such as somatostatin analogs or intravenous immunoglobulins are under evaluation. Rehabilitative (extraocular muscle or eyelid) surgery is often needed after treatment and inactivation of eye disease. Correction of both hyper- and hypothyroidism is crucial for the ophthalmopathy. Antithyroid drugs and thyroidectomy do not influence the course of the ophthalmopathy, whereas radioiodine treatment may cause the progression of preexisting ophthalmopathy, especially in smokers. The exacerbation, however, is prevented by glucocorticoids. In addition, thyroid ablation may prove beneficial for the ophthalmopathy in view of the pathogenetic model relating eye disease to autoimmune reactions directed against antigens shared by the thyroid and the orbit.
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PMID:Management of Graves' ophthalmopathy: reality and perspectives. 1078 63

Retinal photocoagulation reduces the incidence of severe visual loss in proliferative diabetic retinopathy (PDR). Reduced levels of VEGF/VPF might result in an improved function of the blood-retina barrier and cause a decrease of blood derived intraocular growth factors such as IGF-I. This study investigates whether retinal photocoagulation is able to normalize the concentrations of IGF-I, IGF-II and IGF-BP3 in the vitreous humor of patients undergoing vitrectomy. Levels of IGFs and the permeability marker, albumin, were measured in serum and vitreous of 52 patients. Three groups were compared: controls without proliferating eye disease (n = 19) and patients with PDR with (PDR+; n = 25) and without (PDR-; n = 8) previous retinal photocoagulation. IGF-I, IGF-II, IGF-BP3 and albumin were determined by immunological methods and were confirmed to be increased in patients with PDR compared to controls. Retinal photocoagulation influenced neither the intraocular concentration of the permeability marker albumin (PDR+: 253.2 +/- 46 mg/dl; PDR-: 256.4 +/- 66.5 mg/dl) nor the levels of IGFs (PDR+: IGF-I: 1.2 +/- 0.1 ng/ml; p = 0.38; IGF-II: 34.8 +/- 2.2 ng/ml; p = 0.1; IGF-BP3: 75.7 +/- 9.7 ng/ml; p = 0.27; PDR-: IGF-I: 1.1 +/- 0.2ng/ml; IGF-II: 29.3 +/- 5.2 ng/ml; IGF-BP3: 61.5 +/- 18.3 ng/ml). Systemic levels of albumin and IGFs were not changed significantly by retinal photocoagulation. These results demonstrate that previous retinal photocoagulation in patients undergoing vitrectomy does not functionally reestablish the blood-retina barrier despite decreases in VEGF/VPF. The lack of influence on intraocular concentrations of the serum-derived growth factors, IGF-I, IGF-II and IGF-BP3, might in part explain the failure of previous photocoagulation in the investigated patients. These results suggest that a combined treatment with retinal photocoagulation and growth hormone-lowering drugs, such as somatostatin analogues, could be a useful treatment, which may prevent further loss of visual acuity in patients with PDR.
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PMID:Retinal photocoagulation does not influence intraocular levels of IGF-I, IGF-II and IGF-BP3 in proliferative diabetic retinopathy-evidence for combined treatment of PDR with somatostatin analogues and retinal photocoagulation? 1144 Feb 79


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