Search Results - "Lewis, Nia C"

Technical recommendations for the use of carotid duplex ultrasound for the assessment of extracranial blood flow by Thomas, Kate N, Lewis, Nia C S, Hill, Brigid G, Ainslie, Philip N

“…Duplex ultrasound is an evolving technology that allows the assessment of volumetric blood flow in the carotid and vertebral arteries during a range of…”
Get more information

Effect of acute hypoxia on regional cerebral blood flow: effect of sympathetic nerve activity by Lewis, Nia C S, Messinger, Laura, Monteleone, Brad, Ainslie, Philip N

“…We examined 1) whether global cerebral blood flow (CBF) would increase across a 6-h bout of normobaric poikilocapnic hypoxia and be mediated by a larger…”
Get full text

Static autoregulation in humans: a review and reanalysis by Numan, Tianne, Bain, Anthony R, Hoiland, Ryan L, Smirl, Jonathan D, Lewis, Nia C, Ainslie, Philip N

“…Abstract Introduction Cerebral autoregulation (CA) is a theoretical construct characterized by the relationship between mean arterial pressure (MAP) and…”
Get full text

Impact of hypocapnia and cerebral perfusion on orthostatic tolerance by Lewis, Nia C. S., Bain, Anthony R., MacLeod, David B., Wildfong, Kevin W., Smith, Kurt J., Willie, Christopher K., Sanders, Marit L., Numan, Tianne, Morrison, Shawnda A., Foster, Glen E., Stewart, Julian M., Ainslie, Philip N.

“…Key points Vasovagal syncope (a common form of fainting) is frequently associated with excessive breathing and leads to reductions in carbon dioxide…”
Get full text

Impact of sympathetic nervous system activity on post‐exercise flow‐mediated dilatation in humans by Atkinson, Ceri L., Lewis, Nia C.S., Carter, Howard H., Thijssen, Dick H.J., Ainslie, Philip N., Green, Daniel J.

“…Key points Previous studies indicate a transient reduction in arterial function following large muscle group exercise, but the mechanisms involved are unknown…”
Get full text

Regulation of cerebral blood flow by arterial PCO2 independent of metabolic acidosis at 5050 m by Caldwell, Hannah G., Smith, Kurt J., Lewis, Nia C.S., Hoiland, Ryan L., Willie, Christopher K., Lucas, Samuel J.E., Stembridge, Michael, Burgess, Keith R., MacLeod, David B., Ainslie, Philip N.

“…Key points We investigated the influence of arterial PCO2 (PaCO2) with and without experimentally altered pH on cerebral blood flow (CBF) regulation at sea…”
Get full text

Cerebral Pressure–Flow Relationship in Lowlanders and Natives at High Altitude by Smirl, Jonathan D, Lucas, Samuel J E, Lewis, Nia C S, duManior, Gregory R, Smith, Kurt J, Bakker, Akke, Basnyat, Aperna S, Ainslie, Philip N

“…We investigated if dynamic cerebral pressure–flow relationships in lowlanders are altered at high altitude (HA), differ in HA natives and after return to sea…”
Get full text

Slow breathing as a means to improve orthostatic tolerance: a randomized sham-controlled trial by Lucas, Samuel J E, Lewis, Nia C S, Sikken, Elisabeth L G, Thomas, Kate N, Ainslie, Philip N

“…Endogenous oscillations in blood pressure (BP) and cerebral blood flow have been associated with improved orthostatic tolerance. Although slow breathing…”
Get full text

Chemoreceptor Responsiveness at Sea Level Does Not Predict the Pulmonary Pressure Response to High Altitude by Hoiland, Ryan L., BHK, Foster, Glen E., PhD, Donnelly, Joseph, MBChB, Stembridge, Mike, MSc, Willie, Chris K., PhD, Smith, Kurt J., MSc, Lewis, Nia C., PhD, Lucas, Samuel J.E., PhD, Cotter, Jim D., PhD, Yeoman, David J., BSc, Thomas, Kate N., BSc, Day, Trevor A., PhD, Tymko, Mike M., BHSc, Burgess, Keith R., MD, Ainslie, Philip N., PhD

“…BACKGROUND The hypoxic ventilatory response (HVR) at sea level (SL) is moderately predictive of the change in pulmonary artery systolic pressure (PASP) to…”
Get full text

Hypoxia, not pulmonary vascular pressure, induces blood flow through intrapulmonary arteriovenous anastomoses by Tremblay, Joshua C., Lovering, Andrew T., Ainslie, Philip N., Stembridge, Mike, Burgess, Keith R., Bakker, Akke, Donnelly, Joseph, Lucas, Samuel J.E., Lewis, Nia C.S., Dominelli, Paolo B., Henderson, William R., Dominelli, Giulio S., Sheel, A. William, Foster, Glen E.

“…Key points Blood flow through intrapulmonary arteriovenous anastomoses (IPAVA) is increased by acute hypoxia during rest by unknown mechanisms. Oral…”
Get full text

Post-exercise blood pressure reduction is greater following intermittent than continuous exercise and is influenced less by diurnal variation by Jones, Helen, Taylor, Chloe E, Lewis, Nia C S, George, Keith, Atkinson, Greg

“…Recently, we reported that circadian variation exists in the response of blood pressure (BP) following a bout of uninterrupted exercise. The usual phenomenon…”
Get more information

Shear-mediated dilation of the internal carotid artery occurs independent of hypercapnia by Hoiland, Ryan L, Smith, Kurt J, Carter, Howard H, Lewis, Nia C S, Tymko, Michael M, Wildfong, Kevin W, Bain, Anthony R, Green, Daniel J, Ainslie, Philip N

“…Evidence for shear stress as a regulator of carotid artery dilation in response to increased arterial CO was recently demonstrated in humans during sustained…”
Get more information

Conduit artery structure and function in lowlanders and native highlanders: relationships with oxidative stress and role of sympathoexcitation by Lewis, Nia C. S., Bailey, Damian M., duManoir, Gregory R., Messinger, Laura, Lucas, Samuel J. E., Cotter, James D., Donnelly, Joseph, McEneny, Jane, Young, Ian S., Stembridge, Mike, Burgess, Keith R., Basnet, Aparna S., Ainslie, Philip N.

“…Key points Information describing alterations in vascular function during either acute or prolonged normobaric or hypobaric hypoxia is sparse and often…”
Get full text

The Contribution of Arterial Blood Gases in Cerebral Blood Flow Regulation and Fuel Utilization in Man at High Altitude by Willie, Christopher K, MacLeod, David B, Smith, Kurt J, Lewis, Nia C, Foster, Glen E, Ikeda, Keita, Hoiland, Ryan L, Ainslie, Philip N

“…The effects of partial acclimatization to high altitude (HA; 5,050 m) on cerebral metabolism and cerebrovascular function have not been characterized. We…”
Get full text

Aerobic exercise training does not alter vascular structure and function in chronic obstructive pulmonary disease by Gelinas, Jinelle C., Lewis, Nia C., Harper, Megan I., Melzer, Bernie, Agar, Gloria, Rolf, J. Douglass, Eves, Neil D.

“…New Findings What is the central question of this study? Chronic obstructive pulmonary disease (COPD) is associated with endothelial dysfunction, arterial…”
Get full text

Impact of transient hypotension on regional cerebral blood flow in humans by Lewis, Nia C S, Smith, Kurt J, Bain, Anthony R, Wildfong, Kevin W, Numan, Tianne, Ainslie, Philip N

“…We examined the impact of progressive hypotension with and without hypocapnia on regional extracranial cerebral blood flow (CBF) and intracranial velocities…”
Get more information

Ventricular‐Arterial Coupling in Breast Cancer Patients After Treatment With Anthracycline‐Containing Adjuvant Chemotherapy by Koelwyn, Graeme J., Lewis, Nia C., Ellard, Susan L., Jones, Lee W., Gelinas, Jinelle C., Rolf, J. Douglass, Melzer, Bernie, Thomas, Samantha M., Douglas, Pamela S., Khouri, Michel G., Eves, Neil D.

“…Background. Anthracycline‐containing chemotherapy (Anth‐C) is associated with long‐term cardiovascular mortality. Although cardiovascular risk assessment has…”
Get full text

Resting pulmonary haemodynamics and shunting: a comparison of sea‐level inhabitants to high altitude Sherpas by Foster, Glen E., Ainslie, Philip N., Stembridge, Mike, Day, Trevor A., Bakker, Akke, Lucas, Samuel J. E., Lewis, Nia C. S., MacLeod, David B., Lovering, Andrew T.

“…Key points Evolutionary pressure to improve gas exchange and/or resting pulmonary haemodynamics in hypoxic environments may have led to differences in the…”
Get full text

UBC‐Nepal expedition: The use of oral antioxidants does not alter cerebrovascular function at sea level or high altitude by Hansen, Alexander B., Hoiland, Ryan L., Lewis, Nia C. S., Tymko, Michael M., Tremblay, Joshua C., Stembridge, Michael, Nowak‐Flück, Daniela, Carter, Howard H., Bailey, Damian M., Ainslie, Philip N.

“…New Findings What is the central question of the study? Does the use of antioxidants alter cerebrovascular function and blood flow at sea level (344 m) and/or…”
Get full text

Diurnal variation in vascular function: role of sleep by Jones, Helen, Lewis, Nia C S, Thompson, Andrew, Marrin, Kelly, Green, Daniel J, Atkinson, Greg

“…Although vascular function is lower in the morning than afternoon, previous studies have not assessed the influence of prior sleep on this diurnal variation…”
Get more information