The Experts below are selected from a list of 4551 Experts worldwide ranked by ideXlab platform
Jennifer C Sullivan - One of the best experts on this subject based on the ideXlab platform.
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vasa recta pericyte density is negatively associated with Vascular Congestion in the renal medulla following ischemia reperfusion in rats
American Journal of Physiology-renal Physiology, 2017Co-Authors: Ryan G Crislip, Paul M Oconnor, Qingqing Wei, Jennifer C SullivanAbstract:Recent evidence suggests that a greater density of pericytes in renal cadaveric allografts is associated with better recovery following transplant. The physiological mechanism(s) through which peri...
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vasa recta pericyte density is negatively associated with Vascular Congestion in the renal medulla following ischemia reperfusion in rats
American Journal of Physiology-renal Physiology, 2017Co-Authors: Ryan G Crislip, Paul M Oconnor, Jennifer C SullivanAbstract:Recent evidence suggests that a greater density of pericytes in renal cadaveric allografts is associated with better recovery following transplant. The physiological mechanism(s) through which pericyte density may be beneficial is not well understood. The goal of this study was to test the hypothesis that lower medullary pericyte density is associated with greater renal injury following ischemia reperfusion (IR) in a rat model, providing a basis for future studies to better understand pericytes in a pathological environment. To test our hypothesis, we determined the association between medullary pericyte density and renal injury in spontaneously hypertensive rats (SHR) following 45 min of warm bilateral IR. We found that there was a significant negative relationship between pericyte density and plasma creatinine (slope = −0.03, P = 0.02) and blood urea nitrogen (slope = −0.5, P = 0.01) in female but not male SHR. Pericyte density was negatively associated with medullary peritubular capillary (PT) Congestion in both sexes following IR (male: slope = −0.04, P = 0.009; female: slope = −0.03, P = 0.0001). To further test this relationship, we used a previously reported method to reduce pericyte density in SHR. Medullary erythrocyte Congestion in vasa recta (VR) and PT significantly increased following IR in both sexes when pericyte density was pharmacologically decreased (VR: P = 0.03; PT: P = 0.03). Our data support the hypothesis that pericyte density is negatively associated with the development of IR injury in SHR, which may be mediated by erythrocyte Congestion in the medullary vasculature.
Paul M Oconnor - One of the best experts on this subject based on the ideXlab platform.
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ischemic renal injury can renal anatomy and associated Vascular Congestion explain why the medulla and not the cortex is where the trouble starts
Seminars in Nephrology, 2019Co-Authors: Sarah C Ray, June Mason, Paul M OconnorAbstract:The kidneys receive approximately 20% of cardiac output and have a low fractional oxygen extraction. Quite paradoxically, however, the kidneys are highly susceptible to ischemic injury (injury associated with inadequate blood supply), which is most evident in the renal medulla. The predominant proposal to explain this susceptibility has been a mismatch between oxygen supply and metabolic demand. It has been proposed that unlike the well-perfused renal cortex, the renal medulla normally operates just above the threshold for hypoxia and that further reductions in renal perfusion cause hypoxic injury in this metabolically active region. An alternative proposal is that the true cause of ischemic injury is not a simple mismatch between medullary metabolic demand and oxygen supply, but rather the susceptibility of the outer medulla to Vascular Congestion. The capillary plexus of the renal outer medullary region is especially prone to Vascular Congestion during periods of ischemia. It is the failure to restore the circulation to the outer medulla that mediates complete and prolonged ischemia to much of this region, leading to injury and tubular cell death. We suggest that greater emphasis on developing clinically useful methods to help prevent or reverse the Congestion of the renal medullary vasculature may provide a means to reduce the incidence and cost of acute kidney injury.
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vasa recta pericyte density is negatively associated with Vascular Congestion in the renal medulla following ischemia reperfusion in rats
American Journal of Physiology-renal Physiology, 2017Co-Authors: Ryan G Crislip, Paul M Oconnor, Qingqing Wei, Jennifer C SullivanAbstract:Recent evidence suggests that a greater density of pericytes in renal cadaveric allografts is associated with better recovery following transplant. The physiological mechanism(s) through which peri...
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vasa recta pericyte density is negatively associated with Vascular Congestion in the renal medulla following ischemia reperfusion in rats
American Journal of Physiology-renal Physiology, 2017Co-Authors: Ryan G Crislip, Paul M Oconnor, Jennifer C SullivanAbstract:Recent evidence suggests that a greater density of pericytes in renal cadaveric allografts is associated with better recovery following transplant. The physiological mechanism(s) through which pericyte density may be beneficial is not well understood. The goal of this study was to test the hypothesis that lower medullary pericyte density is associated with greater renal injury following ischemia reperfusion (IR) in a rat model, providing a basis for future studies to better understand pericytes in a pathological environment. To test our hypothesis, we determined the association between medullary pericyte density and renal injury in spontaneously hypertensive rats (SHR) following 45 min of warm bilateral IR. We found that there was a significant negative relationship between pericyte density and plasma creatinine (slope = −0.03, P = 0.02) and blood urea nitrogen (slope = −0.5, P = 0.01) in female but not male SHR. Pericyte density was negatively associated with medullary peritubular capillary (PT) Congestion in both sexes following IR (male: slope = −0.04, P = 0.009; female: slope = −0.03, P = 0.0001). To further test this relationship, we used a previously reported method to reduce pericyte density in SHR. Medullary erythrocyte Congestion in vasa recta (VR) and PT significantly increased following IR in both sexes when pericyte density was pharmacologically decreased (VR: P = 0.03; PT: P = 0.03). Our data support the hypothesis that pericyte density is negatively associated with the development of IR injury in SHR, which may be mediated by erythrocyte Congestion in the medullary vasculature.
Ryan G Crislip - One of the best experts on this subject based on the ideXlab platform.
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vasa recta pericyte density is negatively associated with Vascular Congestion in the renal medulla following ischemia reperfusion in rats
American Journal of Physiology-renal Physiology, 2017Co-Authors: Ryan G Crislip, Paul M Oconnor, Qingqing Wei, Jennifer C SullivanAbstract:Recent evidence suggests that a greater density of pericytes in renal cadaveric allografts is associated with better recovery following transplant. The physiological mechanism(s) through which peri...
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vasa recta pericyte density is negatively associated with Vascular Congestion in the renal medulla following ischemia reperfusion in rats
American Journal of Physiology-renal Physiology, 2017Co-Authors: Ryan G Crislip, Paul M Oconnor, Jennifer C SullivanAbstract:Recent evidence suggests that a greater density of pericytes in renal cadaveric allografts is associated with better recovery following transplant. The physiological mechanism(s) through which pericyte density may be beneficial is not well understood. The goal of this study was to test the hypothesis that lower medullary pericyte density is associated with greater renal injury following ischemia reperfusion (IR) in a rat model, providing a basis for future studies to better understand pericytes in a pathological environment. To test our hypothesis, we determined the association between medullary pericyte density and renal injury in spontaneously hypertensive rats (SHR) following 45 min of warm bilateral IR. We found that there was a significant negative relationship between pericyte density and plasma creatinine (slope = −0.03, P = 0.02) and blood urea nitrogen (slope = −0.5, P = 0.01) in female but not male SHR. Pericyte density was negatively associated with medullary peritubular capillary (PT) Congestion in both sexes following IR (male: slope = −0.04, P = 0.009; female: slope = −0.03, P = 0.0001). To further test this relationship, we used a previously reported method to reduce pericyte density in SHR. Medullary erythrocyte Congestion in vasa recta (VR) and PT significantly increased following IR in both sexes when pericyte density was pharmacologically decreased (VR: P = 0.03; PT: P = 0.03). Our data support the hypothesis that pericyte density is negatively associated with the development of IR injury in SHR, which may be mediated by erythrocyte Congestion in the medullary vasculature.
Shriram Varadharajan - One of the best experts on this subject based on the ideXlab platform.
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headache in cerebral venous sinus thrombosis revisited exploring the role of Vascular Congestion and cortical vein thrombosis
Cephalalgia, 2018Co-Authors: Ravinderjeet Singh, Girish Baburao Kulkarni, Jitender Saini, Shriram Varadharajan, M VeerendrakumarAbstract:Background and purposeHeadache constitutes the most common symptom of cerebral venous sinus thrombosis (CVST), but its pathophysiology is unclear. We sought to investigate the potential mechanism f...
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effect of hyperosmolar therapy on cerebroVascular circulation and dynamics in patient with cerebral venous sinus thrombosis p1 244
Neurology, 2016Co-Authors: Ravinder Singh, Girish Baburao Kulkarni, Jitender Saini, Shriram VaradharajanAbstract:Objective: We investigated the effects of mannitol infusion on clinical and imaging parameters in patients with cerebral venous sinus thrombosis (CVST). Background: Hyperosmolar therapy is commonly used in varied neurological and neurosurgical patients. Effects of hyperosmolar therapy is still unsettled specially site of action of these hyperosmolar agents on different parts of cerebral circulation. Patients with CVST were selected as they have preserved arterial inflow allowing mannitol to exert its action on different components of cerebral circulation which was then studied radiologically. Methods: Five patients with CVST without parenchymal lesions were prospectively included. Each patient underwent clinical assessment and magnetic resonance imaging (MRI) of the brain. We looked at Vascular Congestion with susceptibility weighted imaging (SWI), cerebral perfusion with pulsed arterial spin labelling (pulse ASL) and venous sinuses with conventional sequences of MRI as well as MR venogram. Following infusion of placebo (normal saline) and mannitol (1 gm/kg) parameters were repeated. Results: Patient age ranged between 20-60 years. There were 3 males and 2 females. All patient had prominent Vascular Congestion most marked on side of headache. (when headache was unilateral). Following normal saline infusion there was no change in headache, Vascular Congestion, venous sinuses size though there was mild increase in cerebral blood flow (< 5 [percnt]). Following mannitol infusion patient reported dramatic reduction (2 patients) or abolition (3 patients) of headache with concomitant significant reduction in Vascular Congestion and improved hemispheric perfusion (10- 25 [percnt] increase) with no change in sinus caliber as compared to baseline. Conclusion: Mannitol results in Vascular deCongestion and also improves cerebral perfusion possibly along with intracranial pressure (ICP) reduction. Patient’s headache improves which could be due to Vascular deCongestion or ICP reduction thus also suggesting them as potential underlying mechanism of headache in patients with CVST. Disclosure: Dr. Singh has nothing to disclose. Dr. Kulkarni has nothing to disclose. Dr. Saini has nothing to disclose. Dr. Varadharajan has nothing to disclose.
M Veerendrakumar - One of the best experts on this subject based on the ideXlab platform.
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headache in cerebral venous sinus thrombosis revisited exploring the role of Vascular Congestion and cortical vein thrombosis
Cephalalgia, 2018Co-Authors: Ravinderjeet Singh, Girish Baburao Kulkarni, Jitender Saini, Shriram Varadharajan, M VeerendrakumarAbstract:Background and purposeHeadache constitutes the most common symptom of cerebral venous sinus thrombosis (CVST), but its pathophysiology is unclear. We sought to investigate the potential mechanism f...
