The Experts below are selected from a list of 20115 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, Larry D. Hubbard, Jie Jin Wang, Elena Rochtchina, Ronald Klein, Tien Yin Wong, 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, Larry D. Hubbard, Jie Jin Wang, Elena Rochtchina, Ronald Klein, Tien Yin Wong, 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.
Duxin Qing - One of the best experts on this subject based on the ideXlab platform.
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tanshinone iia elicited vasodilation in rat coronary arteriole roles of nitric oxide and potassium channels
European Journal of Pharmacology, 2009Co-Authors: Guobao Wu, Enxiang Zhou, Duxin QingAbstract:Abstract Salvia miltiorrhiza has been widely used in the treatment of various cardiovascular diseases due to its ability to improve coronary microcirculation and increase coronary blood flow. Tanshinone IIA, the major active lipophilic ingredient responsible for the beneficial actions of Salvia miltiorrhiza, was shown to induce vasodilation in coronary arteries. But its effects on coronary Arterioles remain unknown. The purpose of this study was to investigate the effects of tanshinone IIA on isolated rat coronary arteriole and the underlying mechanisms. Coronary Arterioles were carefully dissected, cannulated and pressurized. Tanshinone IIA-elicited vascular inner diameter change was recorded by a computerized diameter tracking system. To investigate the mechanisms governing the vasodilative effects of tanshinone IIA, the roles of endothelium, endothelium-derived vasoactive factors and potassium channels were assessed respectively. Endothelium denudation, inhibition of nitric oxide synthase (NOS), inhibition of the cytochrome P450 epoxygenase, and blockade of the large conductance calcium(Ca2+)-activated potassium channels (BKca) significantly decreased the vasodilation elicited by Tanshinone IIA. The results indicated that tanshinone IIA induces an endothelium-dependent vasodilation in coronary Arterioles; nitric oxide (NO) and cytochrome P450 metabolites contribute to the vasodilation; activation of BKca channels plays an important role in the vasodilation.
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tanshinone iia elicited vasodilation in rat coronary arteriole roles of nitric oxide and potassium channels
European Journal of Pharmacology, 2009Co-Authors: Guobao Wu, Enxiang Zhou, Duxin QingAbstract:Abstract Salvia miltiorrhiza has been widely used in the treatment of various cardiovascular diseases due to its ability to improve coronary microcirculation and increase coronary blood flow. Tanshinone IIA, the major active lipophilic ingredient responsible for the beneficial actions of Salvia miltiorrhiza, was shown to induce vasodilation in coronary arteries. But its effects on coronary Arterioles remain unknown. The purpose of this study was to investigate the effects of tanshinone IIA on isolated rat coronary arteriole and the underlying mechanisms. Coronary Arterioles were carefully dissected, cannulated and pressurized. Tanshinone IIA-elicited vascular inner diameter change was recorded by a computerized diameter tracking system. To investigate the mechanisms governing the vasodilative effects of tanshinone IIA, the roles of endothelium, endothelium-derived vasoactive factors and potassium channels were assessed respectively. Endothelium denudation, inhibition of nitric oxide synthase (NOS), inhibition of the cytochrome P450 epoxygenase, and blockade of the large conductance calcium(Ca2+)-activated potassium channels (BKca) significantly decreased the vasodilation elicited by Tanshinone IIA. The results indicated that tanshinone IIA induces an endothelium-dependent vasodilation in coronary Arterioles; nitric oxide (NO) and cytochrome P450 metabolites contribute to the vasodilation; activation of BKca channels plays an important role in the vasodilation.
Adam Sapirstein - One of the best experts on this subject based on the ideXlab platform.
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Astrocyte Inositol Triphosphate Receptor Type 2 and Cytosolic Phospholipase A2 Alpha Regulate Arteriole Responses in Mouse Neocortical Brain Slices
2016Co-Authors: David J Linden, Adam SapirsteinAbstract:Functional hyperemia of the cerebral vascular system matches regional blood flow to the metabolic demands of the brain. One current model of neurovascular control holds that glutamate released by neurons activates group I metabotropic glutamate receptors (mGluRs) on astrocytes, resulting in the production of diffusible messengers that act to regulate smooth muscle cells surrounding cerebral Arterioles. The acute mouse brain slice is an experimental system in which changes in arteriole diameter can precisely measured with light microscopy. Stimulation of the brain slice triggers specific cellular responses that can be correlated to changes in arteriole diameter. Here we used inositol trisphosphate receptor type 2 (IP3R2) and cytosolic phospholipase A2 alpha (cPLA2a) deficient mice to determine if astrocyte mGluR activation coupled to IP3R2-mediated Ca 2+ release and subsequent cPLA2a activation is required for arteriole regulation. We measured changes in astrocyte cytosolic free Ca2+ and arteriole diameters in response to mGluR agonist or electrical field stimulation in acute neocortical mouse brain slices maintained in 95 % or 20 % O2. Astrocyte Ca 2+ and arteriole responses to mGluR activation were absent in IP3R2 2/2 slices. Astrocyte Ca2+ responses to mGluR activation were unchanged by deletion of cPLA2a bu
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astrocyte inositol triphosphate receptor type 2 and cytosolic phospholipase a2 alpha regulate arteriole responses in mouse neocortical brain slices
PLOS ONE, 2012Co-Authors: Lihua He, David J Linden, Adam SapirsteinAbstract:Functional hyperemia of the cerebral vascular system matches regional blood flow to the metabolic demands of the brain. One current model of neurovascular control holds that glutamate released by neurons activates group I metabotropic glutamate receptors (mGluRs) on astrocytes, resulting in the production of diffusible messengers that act to regulate smooth muscle cells surrounding cerebral Arterioles. The acute mouse brain slice is an experimental system in which changes in arteriole diameter can precisely measured with light microscopy. Stimulation of the brain slice triggers specific cellular responses that can be correlated to changes in arteriole diameter. Here we used inositol trisphosphate receptor type 2 (IP3R2) and cytosolic phospholipase A2 alpha (cPLA2α) deficient mice to determine if astrocyte mGluR activation coupled to IP3R2-mediated Ca2+ release and subsequent cPLA2α activation is required for arteriole regulation. We measured changes in astrocyte cytosolic free Ca2+ and arteriole diameters in response to mGluR agonist or electrical field stimulation in acute neocortical mouse brain slices maintained in 95% or 20% O2. Astrocyte Ca2+ and arteriole responses to mGluR activation were absent in IP3R2−/− slices. Astrocyte Ca2+ responses to mGluR activation were unchanged by deletion of cPLA2α but arteriole responses to either mGluR agonist or electrical stimulation were ablated. The valence of changes in arteriole diameter (dilation/constriction) was dependent upon both stimulus and O2 concentration. Neuron-derived NO and activation of the group I mGluRs are required for responses to electrical stimulation. These findings indicate that an mGluR/IP3R2/cPLA2α signaling cascade in astrocytes is required to transduce neuronal glutamate release into arteriole responses.
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, Larry D. Hubbard, Jie Jin Wang, Elena Rochtchina, Ronald Klein, Tien Yin Wong, 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, Larry D. Hubbard, Jie Jin Wang, Elena Rochtchina, Ronald Klein, Tien Yin Wong, 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.
Guobao Wu - One of the best experts on this subject based on the ideXlab platform.
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tanshinone iia elicited vasodilation in rat coronary arteriole roles of nitric oxide and potassium channels
European Journal of Pharmacology, 2009Co-Authors: Guobao Wu, Enxiang Zhou, Duxin QingAbstract:Abstract Salvia miltiorrhiza has been widely used in the treatment of various cardiovascular diseases due to its ability to improve coronary microcirculation and increase coronary blood flow. Tanshinone IIA, the major active lipophilic ingredient responsible for the beneficial actions of Salvia miltiorrhiza, was shown to induce vasodilation in coronary arteries. But its effects on coronary Arterioles remain unknown. The purpose of this study was to investigate the effects of tanshinone IIA on isolated rat coronary arteriole and the underlying mechanisms. Coronary Arterioles were carefully dissected, cannulated and pressurized. Tanshinone IIA-elicited vascular inner diameter change was recorded by a computerized diameter tracking system. To investigate the mechanisms governing the vasodilative effects of tanshinone IIA, the roles of endothelium, endothelium-derived vasoactive factors and potassium channels were assessed respectively. Endothelium denudation, inhibition of nitric oxide synthase (NOS), inhibition of the cytochrome P450 epoxygenase, and blockade of the large conductance calcium(Ca2+)-activated potassium channels (BKca) significantly decreased the vasodilation elicited by Tanshinone IIA. The results indicated that tanshinone IIA induces an endothelium-dependent vasodilation in coronary Arterioles; nitric oxide (NO) and cytochrome P450 metabolites contribute to the vasodilation; activation of BKca channels plays an important role in the vasodilation.
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tanshinone iia elicited vasodilation in rat coronary arteriole roles of nitric oxide and potassium channels
European Journal of Pharmacology, 2009Co-Authors: Guobao Wu, Enxiang Zhou, Duxin QingAbstract:Abstract Salvia miltiorrhiza has been widely used in the treatment of various cardiovascular diseases due to its ability to improve coronary microcirculation and increase coronary blood flow. Tanshinone IIA, the major active lipophilic ingredient responsible for the beneficial actions of Salvia miltiorrhiza, was shown to induce vasodilation in coronary arteries. But its effects on coronary Arterioles remain unknown. The purpose of this study was to investigate the effects of tanshinone IIA on isolated rat coronary arteriole and the underlying mechanisms. Coronary Arterioles were carefully dissected, cannulated and pressurized. Tanshinone IIA-elicited vascular inner diameter change was recorded by a computerized diameter tracking system. To investigate the mechanisms governing the vasodilative effects of tanshinone IIA, the roles of endothelium, endothelium-derived vasoactive factors and potassium channels were assessed respectively. Endothelium denudation, inhibition of nitric oxide synthase (NOS), inhibition of the cytochrome P450 epoxygenase, and blockade of the large conductance calcium(Ca2+)-activated potassium channels (BKca) significantly decreased the vasodilation elicited by Tanshinone IIA. The results indicated that tanshinone IIA induces an endothelium-dependent vasodilation in coronary Arterioles; nitric oxide (NO) and cytochrome P450 metabolites contribute to the vasodilation; activation of BKca channels plays an important role in the vasodilation.