The Experts below are selected from a list of 270 Experts worldwide ranked by ideXlab platform
Paul Mitchell - One of the best experts on this subject based on the ideXlab platform.
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computer assisted retinal vessel measurement in an older population correlation between right and left eyes
Clinical and Experimental Ophthalmology, 2003Co-Authors: Harry Leung, Elena Rochtchina, Jie Jin Wang, Tien Yin Wong, Larry D. Hubbard, Ronald Klein, Paul MitchellAbstract:: This study assessed the correlation between computer-assisted retinal vessel measurements of right and left eyes, from subjects in a defined, community-based older population. Retinal photographs from participants in the Blue Mountains Eye Study were digitized. All retinal arterioles and Venules located 0.5-1.0 disc diameters from the optic disc margin were identified and a computer program measured their diameters. Pearson correlation (R2) statistic was used to assess the correlation in a random subsample of 1546 images. Substantial correlation between right and left eye measurements was found for summary indices of retinal arterioles (R2 = 0.70) and Venules (R2 = 0.77). Higher correlation was found for intragrader (R2 0.75-079) than for intergrader assessment (R2 0.67-0.72). Moderate correlation was found in arteriole-to-Venule ratio assessed by the same (R2 = 0.57) or different (R2 = 0.52) graders. Measurements from one eye can thus adequately represent the retinal vessel diameters of a person.
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Computer‐assisted retinal vessel measurement in an older population: correlation between right and left eyes
Clinical and Experimental Ophthalmology, 2003Co-Authors: Harry Leung, Elena Rochtchina, Jie Jin Wang, Tien Yin Wong, Larry D. Hubbard, Ronald Klein, Paul MitchellAbstract:This study assessed the correlation between computer-assisted retinal vessel measurements of right and left eyes, from subjects in a defined, community-based older population. Retinal photographs from participants in the Blue Mountains Eye Study were digitized. All retinal arterioles and Venules located 0.5−1.0 disc diameters from the optic disc margin were identified and a computer program measured their diameters. Pearson correlation (R2) statistic was used to assess the correlation in a random subsample of 1546 images. Substantial correlation between right and left eye measurements was found for summary indices of retinal arterioles (R2 = 0.70) and Venules (R2 = 0.77). Higher correlation was found for intragrader (R2 0.75−079) than for intergrader assessment (R2 0.67−0.72). Moderate correlation was found in arteriole-to-Venule ratio assessed by the same (R2 = 0.57) or different (R2 = 0.52) graders. Measurements from one eye can thus adequately represent the retinal vessel diameters of a person.
Gerald A Meininger - One of the best experts on this subject based on the ideXlab platform.
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arteriolar dilation produced by Venule endothelium derived nitric oxide
Microcirculation, 1997Co-Authors: Jeff C Falcone, Gerald A MeiningerAbstract:OBJECTIVE: We conducted bioassay experiments to determine whether nitric oxide produced by endothelial cells (endothelial-derived nitric oxide, or EDNO) within large Venules could act to dilate arterioles. METHODS: In these experiments parallel segments of first-order arterioles and Venules were isolated from skeletal muscle and were cannulated in series with a glass connecting tube (length: 300-500 microns). Arterioles were mechanically denuded of endothelium by a delicate yet abrasive rubbing technique. Venular endothelium remained intact. Endothelial denudation of arterioles was confirmed by the absence of dilation during exposure to acetylcholine (10(-6) mol/L). The cannulated vessels were pressurized to 30 cm H2O and the arterioles pre-constricted by approximately 50% with norepinephrine (10(-10) mol/L). RESULTS: Topical applications of acetylcholine (10(-6) mol/L) or bradykinin (10(-9) mol/L) during luminal perfusion from Venule to arteriole produced significant arteriolar dilation. In contrast, a slight arteriolar constriction was observed when the direction of flow was reversed (i.e., arteriole to Venule) in the presence of either acetylcholine (10(-6) mol/L) or bradykinin (10(-9) mol/L). Inhibition of venular EDNO with NG-monomethyl-L-arginine (L-NMMA; 10(-5) mol/L; 1 hour) completely abolished the arteriolar dilation observed in response to acetylcholine or bradykinin during Venule to arteriole perfusion. CONCLUSIONS: These results demonstrate that venular-derived EDNO can relax arteriolar vascular smooth muscle.
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Arteriolar Dilation Produced by Venule Endothelium‐Derived Nitric Oxide
Microcirculation, 1997Co-Authors: Jeff C Falcone, Gerald A MeiningerAbstract:OBJECTIVE: We conducted bioassay experiments to determine whether nitric oxide produced by endothelial cells (endothelial-derived nitric oxide, or EDNO) within large Venules could act to dilate arterioles. METHODS: In these experiments parallel segments of first-order arterioles and Venules were isolated from skeletal muscle and were cannulated in series with a glass connecting tube (length: 300-500 microns). Arterioles were mechanically denuded of endothelium by a delicate yet abrasive rubbing technique. Venular endothelium remained intact. Endothelial denudation of arterioles was confirmed by the absence of dilation during exposure to acetylcholine (10(-6) mol/L). The cannulated vessels were pressurized to 30 cm H2O and the arterioles pre-constricted by approximately 50% with norepinephrine (10(-10) mol/L). RESULTS: Topical applications of acetylcholine (10(-6) mol/L) or bradykinin (10(-9) mol/L) during luminal perfusion from Venule to arteriole produced significant arteriolar dilation. In contrast, a slight arteriolar constriction was observed when the direction of flow was reversed (i.e., arteriole to Venule) in the presence of either acetylcholine (10(-6) mol/L) or bradykinin (10(-9) mol/L). Inhibition of venular EDNO with NG-monomethyl-L-arginine (L-NMMA; 10(-5) mol/L; 1 hour) completely abolished the arteriolar dilation observed in response to acetylcholine or bradykinin during Venule to arteriole perfusion. CONCLUSIONS: These results demonstrate that venular-derived EDNO can relax arteriolar vascular smooth muscle.
Harry Leung - One of the best experts on this subject based on the ideXlab platform.
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computer assisted retinal vessel measurement in an older population correlation between right and left eyes
Clinical and Experimental Ophthalmology, 2003Co-Authors: Harry Leung, Elena Rochtchina, Jie Jin Wang, Tien Yin Wong, Larry D. Hubbard, Ronald Klein, Paul MitchellAbstract:: This study assessed the correlation between computer-assisted retinal vessel measurements of right and left eyes, from subjects in a defined, community-based older population. Retinal photographs from participants in the Blue Mountains Eye Study were digitized. All retinal arterioles and Venules located 0.5-1.0 disc diameters from the optic disc margin were identified and a computer program measured their diameters. Pearson correlation (R2) statistic was used to assess the correlation in a random subsample of 1546 images. Substantial correlation between right and left eye measurements was found for summary indices of retinal arterioles (R2 = 0.70) and Venules (R2 = 0.77). Higher correlation was found for intragrader (R2 0.75-079) than for intergrader assessment (R2 0.67-0.72). Moderate correlation was found in arteriole-to-Venule ratio assessed by the same (R2 = 0.57) or different (R2 = 0.52) graders. Measurements from one eye can thus adequately represent the retinal vessel diameters of a person.
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Computer‐assisted retinal vessel measurement in an older population: correlation between right and left eyes
Clinical and Experimental Ophthalmology, 2003Co-Authors: Harry Leung, Elena Rochtchina, Jie Jin Wang, Tien Yin Wong, Larry D. Hubbard, Ronald Klein, Paul MitchellAbstract:This study assessed the correlation between computer-assisted retinal vessel measurements of right and left eyes, from subjects in a defined, community-based older population. Retinal photographs from participants in the Blue Mountains Eye Study were digitized. All retinal arterioles and Venules located 0.5−1.0 disc diameters from the optic disc margin were identified and a computer program measured their diameters. Pearson correlation (R2) statistic was used to assess the correlation in a random subsample of 1546 images. Substantial correlation between right and left eye measurements was found for summary indices of retinal arterioles (R2 = 0.70) and Venules (R2 = 0.77). Higher correlation was found for intragrader (R2 0.75−079) than for intergrader assessment (R2 0.67−0.72). Moderate correlation was found in arteriole-to-Venule ratio assessed by the same (R2 = 0.57) or different (R2 = 0.52) graders. Measurements from one eye can thus adequately represent the retinal vessel diameters of a person.
Jeff C Falcone - One of the best experts on this subject based on the ideXlab platform.
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arteriolar dilation produced by Venule endothelium derived nitric oxide
Microcirculation, 1997Co-Authors: Jeff C Falcone, Gerald A MeiningerAbstract:OBJECTIVE: We conducted bioassay experiments to determine whether nitric oxide produced by endothelial cells (endothelial-derived nitric oxide, or EDNO) within large Venules could act to dilate arterioles. METHODS: In these experiments parallel segments of first-order arterioles and Venules were isolated from skeletal muscle and were cannulated in series with a glass connecting tube (length: 300-500 microns). Arterioles were mechanically denuded of endothelium by a delicate yet abrasive rubbing technique. Venular endothelium remained intact. Endothelial denudation of arterioles was confirmed by the absence of dilation during exposure to acetylcholine (10(-6) mol/L). The cannulated vessels were pressurized to 30 cm H2O and the arterioles pre-constricted by approximately 50% with norepinephrine (10(-10) mol/L). RESULTS: Topical applications of acetylcholine (10(-6) mol/L) or bradykinin (10(-9) mol/L) during luminal perfusion from Venule to arteriole produced significant arteriolar dilation. In contrast, a slight arteriolar constriction was observed when the direction of flow was reversed (i.e., arteriole to Venule) in the presence of either acetylcholine (10(-6) mol/L) or bradykinin (10(-9) mol/L). Inhibition of venular EDNO with NG-monomethyl-L-arginine (L-NMMA; 10(-5) mol/L; 1 hour) completely abolished the arteriolar dilation observed in response to acetylcholine or bradykinin during Venule to arteriole perfusion. CONCLUSIONS: These results demonstrate that venular-derived EDNO can relax arteriolar vascular smooth muscle.
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Arteriolar Dilation Produced by Venule Endothelium‐Derived Nitric Oxide
Microcirculation, 1997Co-Authors: Jeff C Falcone, Gerald A MeiningerAbstract:OBJECTIVE: We conducted bioassay experiments to determine whether nitric oxide produced by endothelial cells (endothelial-derived nitric oxide, or EDNO) within large Venules could act to dilate arterioles. METHODS: In these experiments parallel segments of first-order arterioles and Venules were isolated from skeletal muscle and were cannulated in series with a glass connecting tube (length: 300-500 microns). Arterioles were mechanically denuded of endothelium by a delicate yet abrasive rubbing technique. Venular endothelium remained intact. Endothelial denudation of arterioles was confirmed by the absence of dilation during exposure to acetylcholine (10(-6) mol/L). The cannulated vessels were pressurized to 30 cm H2O and the arterioles pre-constricted by approximately 50% with norepinephrine (10(-10) mol/L). RESULTS: Topical applications of acetylcholine (10(-6) mol/L) or bradykinin (10(-9) mol/L) during luminal perfusion from Venule to arteriole produced significant arteriolar dilation. In contrast, a slight arteriolar constriction was observed when the direction of flow was reversed (i.e., arteriole to Venule) in the presence of either acetylcholine (10(-6) mol/L) or bradykinin (10(-9) mol/L). Inhibition of venular EDNO with NG-monomethyl-L-arginine (L-NMMA; 10(-5) mol/L; 1 hour) completely abolished the arteriolar dilation observed in response to acetylcholine or bradykinin during Venule to arteriole perfusion. CONCLUSIONS: These results demonstrate that venular-derived EDNO can relax arteriolar vascular smooth muscle.
D N Granger - One of the best experts on this subject based on the ideXlab platform.
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role of cd11 cd18 in shear rate dependent leukocyte endothelial cell interactions in cat mesenteric Venules
Journal of Clinical Investigation, 1991Co-Authors: M A Perry, D N GrangerAbstract:In vivo microscopy was used to assess the relationships among shear rate (and shear stress), leukocyte rolling velocity, and leukocyte adherence in a cat mesentery preparation. Shear rate in individual Venules and arterioles of 25-35 microns diameter were varied over a wide range by graded occlusion of an arterial loop. There was a linear decline in leukocyte rolling velocity (Vwbc) as red cell velocity (Vrbc) was reduced. The ratio Vwbc/Vrbc remained constant despite variations in shear stress from 5-25 dyn/cm2. A reduction in shear stress was associated with an increased leukocyte adherence, particularly when Vwbc was reduced below 50 microns/s. Reduction in wall shear rate below 500 s-1 in arterioles allowed 1-3 leukocytes to adhere per 100 microns length of vessel, while Venules exposed to the same shear rates had 5-16 adherent leukocytes. In arterioles, leukocyte rolling was only observed at low shear rates. At shear rates less than 250 s-1 leukocyte rolling velocity was faster in arterioles than Venules, and the ratio Vwbc/Vrbc for arterioles was 0.08 +/- 0.02, which was fourfold higher than the ratio obtained in Venules at similar shear rates. Pretreatment with the CD18-specific antibody (mAb) IB4 increased leukocyte rolling velocity in Venules by approximately 20 microns/s at red cell velocities below 2,000 microns/s. mAb IB4 largely prevented the leukocyte adherence to arterioles and Venules, and increased the ratio Vwbc/Vrbc observed in Venules at low shear elicit a CD18-dependent adhesive interaction between leukocytes and microvascular endothelium, and that differences in shear rates cannot explain the greater propensity for leukocyte rolling and adhesion in Venules than arterioles.
