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Smith College

Transcranial Doppler

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Articles 1 - 3 of 3

Full-Text Articles in Social and Behavioral Sciences

Cerebral Hemodynamics After Short- And Long-Term Reduction In Blood Pressure In Mild And Moderate Hypertension, Rong Zhanf, Sarah Witkowski, Qi Fu, Jurgen A.H.R. Claassen, Benjamin D. Levine Jan 2007

Cerebral Hemodynamics After Short- And Long-Term Reduction In Blood Pressure In Mild And Moderate Hypertension, Rong Zhanf, Sarah Witkowski, Qi Fu, Jurgen A.H.R. Claassen, Benjamin D. Levine

Exercise and Sport Studies: Faculty Publications

This study tested the hypothesis that acute reduction in blood pressure (BP) at the initial stage of antihypertensive therapy compromises brain perfusion and dynamic cerebral autoregulation in patients with hypertension. Cerebral blood flow velocity and BP were measured in patients with mild and moderate hypertension and in healthy volunteers at baseline upon reduction of BP within 1 to 2 weeks of administration of losartan/hydrochlorothiazide and after 3 to 4 months of treatment. The transfer function between beat-to-beat changes in BP and cerebral blood flow velocity was estimated to assess dynamic autoregulation. After 1 to 2 weeks of treatment, BP was …


Inhibition Of Nitric Oxide Inhibition Of Nitric Oxide Synthase Does Not Alter Dynamic Cerebral Autoregulation In Humans, Rong Zhang, Thad E. Wilson, Sarah Witkowski, Jian Cui, Craig G. Crandall, Benjamin D. Levine Jan 2004

Inhibition Of Nitric Oxide Inhibition Of Nitric Oxide Synthase Does Not Alter Dynamic Cerebral Autoregulation In Humans, Rong Zhang, Thad E. Wilson, Sarah Witkowski, Jian Cui, Craig G. Crandall, Benjamin D. Levine

Exercise and Sport Studies: Faculty Publications

The aim of this study was to determine whether inhibition of nitric oxide synthase (NOS) alters dynamic cerebral autoregulation in humans. Beat-to-beat blood pressure (BP) and cerebral blood flow (CBF) velocity (transcranial Doppler) were measured in eight healthy subjects in the supine position and during 60° head-up tilt (HUT). NOS was inhibited by intravenous N G-monomethyl-L-arginine (L-NMMA) infusion. Dynamic cerebral autoregulation was quantified by transfer function analysis of beat-to-beat changes in BP and CBF velocity. Pressor effects of L-NMMA on cerebral hemodynamics were compared with those of phenylephrine infusion. In the supine position, L-NMMA increased mean BP from 83 ± …


Skin Cooling Maintains Cerebral Blood Ffow Velocity And Orthostatic Tolerance During Tilting In Heated Humans, Thad E. Wilson, Jian Cui, Rong Zhang, Sarah Witkowski, Craig G. Crandall Jan 2002

Skin Cooling Maintains Cerebral Blood Ffow Velocity And Orthostatic Tolerance During Tilting In Heated Humans, Thad E. Wilson, Jian Cui, Rong Zhang, Sarah Witkowski, Craig G. Crandall

Exercise and Sport Studies: Faculty Publications

Orthostatic tolerance is reduced in the heat-stressed human. The purpose of this project was to identify whether skin-surface cooling improves orthostatic tolerance. Nine subjects were exposed to 10 min of 60° head-up tilting in each of four conditions: normothermia (NT-tilt), heat stress (HT-tilt), normothermia plus skin-surface cooling 1 min before and throughout tilting (NT-tiltcool), and heat stress plus skin-surface cooling 1 min before and throughout tilting (HT-tiltcool). Heating and cooling were accomplished by perfusing 46 and 15°C water, respectively, though a tube-lined suit worn by each subject. During HT-tilt, four of nine subjects developed presyncopal symptoms resulting in the termination …