Purpose: To assess the effect of changes in end-tidal partial pressure of O(2) (PETO(2)) on cerebrovascular reactivity (CVR) estimated from changes in blood oxygen level-dependent (BOLD) signal during cyclic changes in end-tidal partial pressure of CO(2) (PETCO(2)).
Materials And Methods: BOLD response to fixed cyclic step changes in PETCO(2) (range = 30.4-48.8 mmHg) and PETO(2) (range = 100.6-444.0 mmHg) was studied in four healthy volunteers.
Results: The BOLD reactivity to PETCO(2) and PETO(2) were 0.283 (0.188-0.379) (median, range) and 0.004 (0.003-0.006)%/mmHg, respectively, in the whole brain; 0.438 (0.382-0.614) vs. 0.006 (0.004-0.009)%/mmHg, respectively, in the gray matter; and 0.075 (0.065-0.093) vs. 0.002 (0.001-0.002)%/mmHg, respectively, in the white matter.
Conclusion: The BOLD reactivity to PETO(2) was much smaller than that to PETCO(2). However, BOLD reactivity can be significantly distorted by CO(2)-induced changes in PETO(2). We conclude that PETO(2) should be carefully controlled during studies that use BOLD reactivity as an indicator of CVR.
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http://dx.doi.org/10.1002/jmri.21102 | DOI Listing |
Horm Behav
January 2025
Department of Integrative Biology, University of Texas at Austin, Austin, TX 78712, United States of America. Electronic address:
Individual variation in stress coping styles is widespread and consequential to health and fitness. Proactive (bold behavior, low stress reactivity, low cognitive flexibility) and reactive (shy behavior, high stress reactivity, high cognitive flexibility) coping styles are found in many species, but the developmental forces shaping them remain elusive. We examined how social influences, specifically mating interactions, shape the development of adult female coping styles with a manipulative rearing experiment using El Abra swordtails, Xiphophorus nigrensis.
View Article and Find Full Text PDFAlzheimers Res Ther
January 2025
Functional Imaging Unit, Department of Clinical Physiology and Nuclear Medicine, Copenhagen University Hospital Rigshospitalet, Valdemar Hansens Vej 1-23, Glostrup, 2600, Denmark.
Background: Accumulation of β-amyloid (Aβ) in the brain is a hallmark of Alzheimer's Disease (AD). Cerebral deposition of Aβ initiates deteriorating pathways which eventually can lead to AD. However, the exact mechanisms are not known.
View Article and Find Full Text PDFNeuroimage
January 2025
Department of Radiology, Mayo Clinic, Rochester, MN, USA. Electronic address:
AJNR Am J Neuroradiol
December 2024
From the Department of Neurosurgery (AW., J.F., L.M.H., J.P., M.G., V.S., C.H.B.v.N., L.R., G.E., M.S.), Clinical Neuroscience Center (AW., J.F., L.M.H., J.P., T.S., M.G., V.S., C.H.B.v.N., S.W., A.R.L., Z.K., L.R., G.E., M.S.), Department of Neuroradiology (Z.K.) and Department of Neurology (S.W., A.R.L.), University Hospital Zurich, Zurich, Switzerland; University of Zurich (AW., J.F., L.M.H., J.P., T.S., M.G., V.S., C.H.B.v.N., S.W., A.R.L., Z.K., L.R., G.E., M.S.), Zurich, Switzerland; cereneo Center for Neurology and Rehabilitation (A.R.L.), Vitznau, Switzerland.
Background And Purpose: Identifying and assessing hemodynamic and flow status in patients with symptomatic internal carotid artery (ICA) occlusion is crucial for evaluating recurrent stroke risk. The aim of this study was to analyze the correlation between two quantitative imaging modalities: (1) blood oxygenation level-dependent (BOLD) cerebrovascular reactivity (CVR) and (2) quantitative magnetic resonance angiography (qMRA) with non-invasive optimal vessel analysis (NOVA), measuring volume flow rate (VFR). Comparing these modalities is relevant for assessing collateral circulation and hemodynamic impairment.
View Article and Find Full Text PDFJ Virol Methods
December 2024
Veterinary Diagnostic Laboratory, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA; Department of Diagnostic Medicine/Pathobiology, College of Veterinary Medicine, Kansas State University, Manhattan, KS, USA. Electronic address:
The emergence of SARS-CoV-2 raised concerns about the potential for interspecies transmission, particularly among domestic animals. We evaluated the seroprevalence of SARS-CoV-2 antibodies in domestic cats from various sites in North America. A total of 216 serum samples collected between December 2019 and February 2022, were analyzed using four different enzyme-linked immunosorbent assays (ELISAs), including a commercial surrogate virus neutralization test (sVNT), a commercial double antigen test (dN ELISA), and two in-house developed indirect ELISAS based on receptor-binding domain (RBD iELISA) and the nucleocapsid (N iELISA) proteins, respectively.
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