Search results for "RETINA"
showing 10 items of 864 documents
Biochemical Aspects of Chick Embryo Retina Development: The Effects of Glucocorticoids
1989
In chick embryo retina during development, DNA synthesis and the activities of DNA polymerase, thymidine kinase, thymidylate synthetase, and ornithine decarboxylase (ODC) declined in parallel from day 7 to 12. The administration in ovo of hydrocortisone reduced significantly, particularly at 8-10 days of incubation, both DNA synthesis and the four enzyme activities tested. The effect was dose dependent, reaching the maximum with 50-100 nmol of hydrocortisone, 8-16 h after treatment. The highest inhibition was found for ODC activity (70%), followed by thymidine kinase activity (62%) and DNA synthesis (45%), whereas activities of DNA polymerase and thymidylate synthetase were reduced only by …
Influence of hydrocortisone on chick embryo retina development
1987
Treatment of chick embryos in ovo with hydrocortisone-21-phosphate (a single dose of 150 micrograms) caused a marked reduction of retinal thymidine kinase activity 24 h later. The inhibitory effect was highest (65-70%) in 8-10-day-old embryos and declined with age, disappearing after day 15. It was accompanied by a reduction in thickness of the retinal layers. Adrenocorticotropic hormone (ACTH) treatment (10 micrograms daily for 2 days) also produced an age-dependent inhibitory effect on retinal thymidine kinase, whereas treatment with a single dose of 200 micrograms of metopirone, a compound that prevents the 11 beta-hydroxylation of steroid molecules in the adrenal glands, impeded the dec…
Identification of Insulin in Chick Embryo Retina During Development and Its Inhibitory Effect on DNA Synthesis
1992
Incubation of chick embryo retinal explants with insulin resulted in a pronounced inhibition of thymidine uptake and incorporation into trichloroacetic acid-insoluble fraction. The inhibitory effect was highest with explants from embryos at day 7 and day 8, and thereafter it declined markedly with the age of embryos until day 11. A time-course study of the effect revealed that the inhibition occurred after a lag time; both thymidine uptake and incorporation were not altered significantly after 2-6 h of incubation with insulin, but began to decrease thereafter, reaching the maximum after 16 h. The effect was also dose dependent. After 16 h of incubation, the maximal inhibition (65%) was foun…
Modulation by docosahexaenoic acid of the epinephrine-stimulated adenylate cyclase activity of the bovine retina.
1988
This work shows that unsaturated fatty acids enhance the epinephrine-stimulated adenylate cyclase activity in bovine retina. The modulating effect on the epinephrine-stimulated formation of cyclic AMP seems to be linked to the degree of unsaturation of the fatty acid. Treatment of the intact retina with docosahexaenoic acid in the concentration range 0.5 X 10(-6)-1 X 10(-3) M does not affect the enzyme activity measured in the absence of the hormone but markedly increases the cyclase activity when the tissue is incubated in the presence of 0.1 mM epinephrine. Docosahexaenoic acid enhances the maximal response to epinephrine without affecting the apparent ED50 value for this effector. Docosa…
Chick embryo retina development in vitro: the effect of insulin.
1995
In this paper we study the development of chick embryo retina cultured in vitro and the effects exerted by insulin. Retinas were removed from 7-day embryos and cultured in serum- and hormone-free medium for 7 additional days. Under these conditions retinal cells survived and underwent cholinergic differentiation, as previously ascertained by Hausman et al. (Dev. Brain Res., 1991, 59: 31-37). However, a great retardation of development was noted compared to uncultured control, 14-day retina. In fact both wet weight and DNA and protein content increased much slower than in ovo and the tubulin content decreased below even the starting value. In addition, although after 7 days in culture retina…
Intravitreal dexamethasone implant for cystoid macular edema and inflammation after scleral buckling
2015
Purpose Cystoid macular edema may occur following scleral buckling and therefore deteriorate the visual outcome. Inflammation may be the major causative factor in the development of postoperative cystoid macular edema. This case demonstrates the effectiveness of a dexamethasone implant as a treatment after the onset of choroidal inflammation and cystoid macular edema 6 months following scleral buckling and having visual acuity restored. Methods A 59-year-old phakic woman treated with scleral buckling for macula-off retinal detachment presented 2 months after surgery with cystoid macular edema with choroidal inflammation. Optical coherence tomography and fluorescein angiography were performe…
Observational outcomes in proliferative diabetic retinopathy patients following treatment with ranibizumab, panretinal laser photocoagulation or comb…
2021
Purpose Ranibizumab monotherapy showed stronger effects on area of retinal neovascularization (NV) reduction while offering better visual acuity (VA) results than panretinal laser photocoagulation (PRP) monotherapy during the first 12 months of the PRIDE study. The second year of PRIDE was an observational, non-interventional follow-up, performed to evaluate long-term anatomical and functional outcomes in proliferative diabetic retinopathy (PDR) patients under real-life conditions, prior to the approval of ranibizumab for PDR. Methods Seventy-three PDR patients (28 from the ranibizumab group; 20 from the PRP group; 25 from the combination group) were included in the observational follow-up …
Oral Propranolol for Circumscribed Choroidal Hemangioma
2011
Introduction: Several therapeutic approaches have been developed to treat choroidal hemangioma. However, all these therapies are associated with a potential risk of damaging the overlying retina. Case Report: We report a case of circumscribed choroidal hemangioma (CCH) in a 59-year-old man refractory to laser treatment. Visual acuity was 20/200 and a serous macular detachment was present. The CCH was treated with oral propanolol, whereupon visual acuity improved to 20/20 and the macular detachment resolved without systemic or local adverse effects. Discussion: Propanolol is a β-blocker commonly used in cardiology that may induce endothelium vasoconstriction and inhibit endothelial prolifera…
Intravitreal pegaptanib for refractory macular edema secondary to retinal vein occlusion
2011
Patricia Udaondo1,2, Salvador Garcia-Delpech1,3, David Salom1,3, Maria Garcia-Pous1,3, Manuel Diaz-Llopis1,31Nuevo Hospital Universitario y Politecnico La Fe, Valencia, Spain; 2University Cardenal Herrera CEU, Valencia, Spain; 3Faculty of Medicine, University of Valencia, Valencia, SpainPurpose: To assess the efficacy of intravitreal Pegaptanib sodium (Macugen®) injection in the management of refractory macular edema secondary to branch retinal vein occlusion.Methods: This is a prospective, nonrandomized, interventional case series. Five eyes of five patients with macular edema refractory to either bevacizumab or triamcinolone were treated with intravitreal injection of Pegaptanib s…
Laserfotokoagulation und photodynamische Therapie (PDT) zur Behandlung der retinalen angiomatösen Proliferation (RAP) bei feuchter altersabhängiger M…
2008
BACKGROUND: Retinal angiomatous proliferation (RAP) is a subtype of neovascular age-related macular degeneration (AMD) with particularly bad prognosis. Diverse treatment modalities are performed. PATIENTS AND METHODS: This is a retrospective review on the treatment results of 41 consecutive patients from 1 / 2003 to 12 / 2005 with RAP stage 1 - 3 (Yannuzzi classification), who were treated with laser photocoagulation, photodynamic therapy (PDT) and intravitreal injection of triamcinolone acetonide (IVT). Follow-up was 12 months minimally. RESULTS: In RAP stage I complete closure of the vascular lesion in 14 / 22 eyes was achieved by 1.2 ± 0.5 sessions of laser photocoagulation (4 × combined…