The Experts below are selected from a list of 267 Experts worldwide ranked by ideXlab platform
Michael F Marmor - One of the best experts on this subject based on the ideXlab platform.
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an experimental model of retinal pigment epithelial and neurosensory serous Detachment
Retina-the Journal of Retinal and Vitreous Diseases, 1996Co-Authors: Chris H Chon, Xiao Ying Yao, Roopa Dalal, A Takeuchi, Rosa Y Kim, Michael F MarmorAbstract:PURPOSE The authors document an animal model of retinal pigment epithelial (RPE) Detachments. METHODS N-ethylmaleimide (NEM) and sodium iodate (sulfhydryl-alkylating agents) were injected into the vitreous of Dutch pigmented rabbits. Subretinal fluid samples were withdrawn 0.5 and 3 hours after NEM injections and analyzed for albumin content by gel electrophoresis. Selected eyes were examined histologically. RESULTS Injections of 9.2 micrograms NEM caused wrinkling of the retina within 15 minutes, at which time fluorescein angiography revealed multifocal RPE Detachments. At this stage, histologic sections showed moderate choroidal edema and RPE Detachment. Elevated retinal Detachments developed over the next 15 to 25 minutes. Histologic sections showed massive choroidal edema and RPE fragmentation. The albumin concentration of subretinal fluid rose from 60% of serum level at 30 minutes after NEM to 80% after 3 hours. Sodium iodate did not cause choroidal edema or RPE Detachment. CONCLUSION In rabbits, intravitreal NEM causes the rapid appearance of choroidal edema and RPE Detachment, followed by serous retinal Detachment. The initial effect probably is caused by an alteration of choroidal vascular permeability. The relationship of these effects to sulfhydryl alkylation is unclear because sodium iodate failed to produce RPE Detachments. N-ethylmaleimide effects may model aspects of clinical RPE and serous retinal Detachments.
G Brasseur - One of the best experts on this subject based on the ideXlab platform.
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subretinal fluid in primary rhegmatogenous retinal Detachment physiopathology and composition
Survey of Ophthalmology, 2004Co-Authors: J C Quintyn, G BrasseurAbstract:During retinal Detachment, subretinal fluid is present, whose composition and physiopathology are still little known. Under normal conditions, osmotic and oncotic pressures help keep the retina in place, but the main retinal attachment force is provided by active transport in the pigment epithelium. Subretinal fluid composition varies according to Detachment duration; total protein concentration in subretinal fluid increases with time. In addition, all proteins are qualitatively modified. The detached retina loses its oxygen supply, and it then uses the anaeorbic pathway to degrade glucose. Thus, long-duration retinal Detachments feature increased lactic acid and dextrose concentrations. Phospholipids are also increased in subretinal fluid, reflecting retinal degradation. This review presents data on the physiopathology and composition of the subretinal fluid in retinal Detachments.
Chris H Chon - One of the best experts on this subject based on the ideXlab platform.
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an experimental model of retinal pigment epithelial and neurosensory serous Detachment
Retina-the Journal of Retinal and Vitreous Diseases, 1996Co-Authors: Chris H Chon, Xiao Ying Yao, Roopa Dalal, A Takeuchi, Rosa Y Kim, Michael F MarmorAbstract:PURPOSE The authors document an animal model of retinal pigment epithelial (RPE) Detachments. METHODS N-ethylmaleimide (NEM) and sodium iodate (sulfhydryl-alkylating agents) were injected into the vitreous of Dutch pigmented rabbits. Subretinal fluid samples were withdrawn 0.5 and 3 hours after NEM injections and analyzed for albumin content by gel electrophoresis. Selected eyes were examined histologically. RESULTS Injections of 9.2 micrograms NEM caused wrinkling of the retina within 15 minutes, at which time fluorescein angiography revealed multifocal RPE Detachments. At this stage, histologic sections showed moderate choroidal edema and RPE Detachment. Elevated retinal Detachments developed over the next 15 to 25 minutes. Histologic sections showed massive choroidal edema and RPE fragmentation. The albumin concentration of subretinal fluid rose from 60% of serum level at 30 minutes after NEM to 80% after 3 hours. Sodium iodate did not cause choroidal edema or RPE Detachment. CONCLUSION In rabbits, intravitreal NEM causes the rapid appearance of choroidal edema and RPE Detachment, followed by serous retinal Detachment. The initial effect probably is caused by an alteration of choroidal vascular permeability. The relationship of these effects to sulfhydryl alkylation is unclear because sodium iodate failed to produce RPE Detachments. N-ethylmaleimide effects may model aspects of clinical RPE and serous retinal Detachments.
J C Quintyn - One of the best experts on this subject based on the ideXlab platform.
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subretinal fluid in primary rhegmatogenous retinal Detachment physiopathology and composition
Survey of Ophthalmology, 2004Co-Authors: J C Quintyn, G BrasseurAbstract:During retinal Detachment, subretinal fluid is present, whose composition and physiopathology are still little known. Under normal conditions, osmotic and oncotic pressures help keep the retina in place, but the main retinal attachment force is provided by active transport in the pigment epithelium. Subretinal fluid composition varies according to Detachment duration; total protein concentration in subretinal fluid increases with time. In addition, all proteins are qualitatively modified. The detached retina loses its oxygen supply, and it then uses the anaeorbic pathway to degrade glucose. Thus, long-duration retinal Detachments feature increased lactic acid and dextrose concentrations. Phospholipids are also increased in subretinal fluid, reflecting retinal degradation. This review presents data on the physiopathology and composition of the subretinal fluid in retinal Detachments.
Yikun Zhang - One of the best experts on this subject based on the ideXlab platform.
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the influence of a weak upper ductile Detachment on the longmen shan fold and thrust belt eastern margin of the tibetan plateau insights from sandbox experiments
Journal of Asian Earth Sciences, 2020Co-Authors: Jian Cui, Zhuxin Chen, Dong Jia, Hongwei Yin, Maomao Wang, Xiaogen Fan, Li Shen, Chuang Sun, Yikun ZhangAbstract:Abstract The topic of the Longmen Shan fold-and-thrust belt has been vigorously debated due to the steep topography in contrast with the low convergence rate and earthquake hazards. The Longmen Shan fold-and-thrust belt is characterized by two main Detachments: a strong lower Detachment at 15–17 km depth in the hinterland and a weak upper Detachment at ~7 km depth in the Sichuan Basin. Nevertheless, how the two Detachments control deformation in the Longmen Shan remains unclear. In this study, we focus on the mechanical strengths of the two Detachments in the study area and design three analog models to investigate the kinematics and mechanisms of the Longmen Shan fold-and-thrust belt. All three model experiments have the same strong lower Detachments at the basement, but different upper Detachments. The results indicate that for Model 1 with no upper Detachment and Model 2 with a strong frictional upper Detachment, the strain and deformation only concentrate near the mobile backwall, and particle image velocimetry analysis reveals that both models deform in the forward in-sequence style. However, for Model 3 with a weak ductile upper Detachment, the strain and deformation propagate into the foreland, and the model deforms in the out-of-sequence style consistent with the Longmen Shan fold-and-thrust belt. The model results indicate that the spatial relation of strong lower Detachment and weak upper Detachment may be one of the important factors producing the current structural pattern and the out-of-sequence style of the Longmen Shan fold-and-thrust belt.