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https://www.readbyqxmd.com/read/28933655/cerebrovascular-reactivity-measurement-in-cerebral-small-vessel-disease-rationale-and-reproducibility-of-a-protocol-for-mri-acquisition-and-image-processing
#1
Michael J Thrippleton, Yulu Shi, Gordon Blair, Iona Hamilton, Gordon Waiter, Christian Schwarzbauer, Cyril Pernet, Peter Jd Andrews, Ian Marshall, Fergus Doubal, Joanna M Wardlaw
Background Impaired autoregulation may contribute to the pathogenesis of cerebral small vessel disease. Reliable protocols for measuring microvascular reactivity are required to test this hypothesis and for providing secondary endpoints in clinical trials. Aims To develop and assess a protocol for acquisition and processing of cerebrovascular reactivity by MRI, in subcortical tissue of patients with small vessel disease and minor stroke. Methods We recruited 15 healthy volunteers, testing paradigms using 1- and 3-min 6% CO2 challenges with repeat scanning, and 15 patients with history of minor stroke...
January 1, 2017: International Journal of Stroke: Official Journal of the International Stroke Society
https://www.readbyqxmd.com/read/28927237/augmented-association-between-blood-pressure-and-proteinuria-in-hyperuricemic-patients-with-non-nephrotic-chronic-kidney-disease
#2
K Kohagura, M Kochi, T Miyagi, R Zamami, K Nagahama, K Yonemoto, Y Ohya
Background: Hyperuricemia (HU) may enhance susceptibility to hypertensive renal damage via disrupted autoregulation of glomerular hemodynamics. The effect of HU on the association between blood pressure (BP) and proteinuria remains unknown in patients with chronic kidney disease (CKD). Methods: In total, 109 patients with non-nephrotic CKD (55 men and 54 females) who underwent renal biopsy were recruited. Arteriolar hyalinosis was semiquantitatively assessed via arteriole grading...
September 13, 2017: American Journal of Hypertension
https://www.readbyqxmd.com/read/28925890/the-use-of-hemodynamic-and-cerebral-monitoring-to-study-pharmacodynamics-in-neonates
#3
A Smits, L Thewissen, A Dereymaeker, E Dempsey, A Caicedo, Gunnar Naulaers
BACKGROUND: Drugs acting on the cardiovascular and central nervous system often display relatively fast clinical responses, which may differ in neonates compared to children and adults. Introduction of bedside monitoring tools might be of additional value in the pharmacodynamic (PD) assessment of such drugs in neonates. METHODS: We aim to provide an overview of the frequently used monitoring tools to assess drug effects on the hemodynamic status as well as the cerebral circulation, oxygenation and cerebral metabolism in neonates...
September 18, 2017: Current Pharmaceutical Design
https://www.readbyqxmd.com/read/28912128/aging-modifies-the-effect-of-cardiac-output-on-middle-cerebral-artery-blood-flow-velocity
#4
Anne-Sophie G T Bronzwaer, Jasper Verbree, Wim J Stok, Mat J A P Daemen, Mark A van Buchem, Matthias J P van Osch, Johannes J van Lieshout
An association between cerebral blood flow (CBF) and cardiac output (CO) has been established in young healthy subjects. As of yet it is unclear how this association evolves over the life span. To that purpose, we continuously recorded mean arterial pressure (MAP; finger plethysmography), CO (pulse contour; CO-trek), mean blood flow velocity in the middle cerebral artery (MCAV; transcranial Doppler ultrasonography), and end-tidal CO2 partial pressure (PetCO2) in healthy young (19-27 years), middle-aged (51-61 years), and elderly subjects (70-79 years)...
September 2017: Physiological Reports
https://www.readbyqxmd.com/read/28905113/influence-of-increased-heart-rate-and-aortic-pressure-on-resting-indices-of-functional-coronary-stenosis-severity
#5
Lorena Casadonte, Bart-Jan Verhoeff, Jan J Piek, Ed VanBavel, Jos A E Spaan, Maria Siebes
Baseline assessment of functional stenosis severity has been proposed as a practical alternative to hyperemic indices. However, intact autoregulation mechanisms may affect intracoronary hemodynamics. The aim of this study was to investigate the effect of changes in aortic pressure (Pa) and heart rate (HR) on baseline coronary hemodynamics and functional stenosis assessment. In 15 patients (55 ± 3% diameter stenosis) Pa, intracoronary pressure (Pd) and flow velocity were obtained at control, and during atrial pacing at 120 bpm, increased Pa (+30 mmHg) with intravenous phenylephrine (PE), and elevated Pa while pacing at sinus heart rate (PE + sHR)...
September 13, 2017: Basic Research in Cardiology
https://www.readbyqxmd.com/read/28904458/can-transcranial-color-doppler-spectral-signatures-be-a-novel-biomarker-for-monitoring-cerebrovascular-autoregulation-and-intracranial-pressure-a-speculative-synthesis
#6
Sandhya Mangalore, Kotresh, Rakshith Srinivasa, Alangar Sathyaranjandas Hegde, Rangashetty Srinivasa
BACKGROUND: Trans Cranial Colour Doppler (TCCD) has been extensively used in various neurological and neurosurgical conditions causing severe raise in the intracranial pressure (ICP). MATERIAL AND METHOD: Our study explores the sequential evolution of TCCD flow pattern by correlating with pupillary reactivity, Glasgow coma scale (GCS), and imaging. Our cohort consisted of thirty patients with ten patients in each subgroup admitted to the neuro-Intensive Care Unit (NICU) for various neurological and neurosurgical causes...
July 2017: Annals of Indian Academy of Neurology
https://www.readbyqxmd.com/read/28902182/gestational-age-dependent-relationship-between-cerebral-oxygen-extraction-and-blood-pressure
#7
Zachary A Vesoulis, Steve M Liao, Amit M Mathur
BackgroundPremature infants may lack mature cerebrovascular autoregulatory function and fail to adapt oxygen extraction to decreasing systemic perfusion.MethodsInfants ≤28 weeks of gestational age (GA) were recruited. Systemic oxygen saturation (SpO2), mean arterial blood pressure (MABP), and cerebral saturation (near-infrared spectroscopy, SctO2) were measured continuously over the first 72 h. Resulting data underwent error-processing. For each remaining 10 m window, the mean MABP and fractional tissue oxygen extraction (FTOE) were calculated...
September 13, 2017: Pediatric Research
https://www.readbyqxmd.com/read/28898284/optic-nerve-head-and-retinal-blood-flow-regulation-during-isometric-exercise-as-assessed-with-laser-speckle-flowgraphy
#8
Katarzyna J Witkowska, Ahmed M Bata, Giacomo Calzetti, Nikolaus Luft, Klemens Fondi, Piotr A Wozniak, Doreen Schmidl, Matthias Bolz, Alina Popa-Cherecheanu, René M Werkmeister, Gerhard Garhöfer, Leopold Schmetterer
The aim of the present study was to investigate regulation of blood flow (BF) in the optic nerve head (ONH) and a peripapillary region (PPR) during an isometric exercise-induced increase in ocular perfusion pressure (OPP) using laser speckle flowgraphy (LSFG) in healthy subjects. For this purpose, a total of 27 subjects was included in this study. Mean blur rate in tissue (MT) was measured in the ONH and in a PPR as well as relative flow volume (RFV) in retinal arteries (ART) and veins (VEIN) using LSFG. All participants performed isometric exercise for 6 minutes during which MT and mean arterial pressure were measured every minute...
2017: PloS One
https://www.readbyqxmd.com/read/28887332/the-cerebro-cardiovascular-response-to-periodic-squat-stand-maneuvers-in-healthy-subjects-a-time-domain-analysis
#9
Sam C Barnes, Naomi Ball, Victoria Joanna Haunton, Thompson G Robinson, Ronney B Panerai
BACKGROUND: Squat-stand maneuvers (SSMs) have been used to improve the coherence of transfer function analysis (TFA) estimates during the assessment of dynamic cerebral autoregulation (dCA). There is a need to understand the influence of peripheral changes resulting from SSMs on cerebral blood flow, which might confound estimates of dCA. METHODS: 29 healthy subjects underwent recordings at rest (5 min standing) and 15 SSMs (0.05Hz). Heart rate (3-lead ECG), end-tidal CO2 (capnography), blood pressure (Finometer), cerebral blood velocity (CBV, transcranial Doppler, MCA) and the angle of the thigh (tilt sensor) were measured continuously...
September 8, 2017: American Journal of Physiology. Heart and Circulatory Physiology
https://www.readbyqxmd.com/read/28885563/the-effect-of-sepsis-on-the-erythrocyte
#10
REVIEW
Ryon M Bateman, Michael D Sharpe, Mervyn Singer, Christopher G Ellis
Sepsis induces a wide range of effects on the red blood cell (RBC). Some of the effects including altered metabolism and decreased 2,3-bisphosphoglycerate are preventable with appropriate treatment, whereas others, including decreased erythrocyte deformability and redistribution of membrane phospholipids, appear to be permanent, and factors in RBC clearance. Here, we review the effects of sepsis on the erythrocyte, including changes in RBC volume, metabolism and hemoglobin's affinity for oxygen, morphology, RBC deformability (an early indicator of sepsis), antioxidant status, intracellular Ca(2+) homeostasis, membrane proteins, membrane phospholipid redistribution, clearance and RBC O₂-dependent adenosine triphosphate efflux (an RBC hypoxia signaling mechanism involved in microvascular autoregulation)...
September 8, 2017: International Journal of Molecular Sciences
https://www.readbyqxmd.com/read/28884722/-severe-carotid-stenosis-cerebral-autoregulation-in-the-ipsilateral-region
#11
V B Semenyutin, G А Asaturyan, А А Nikiforova, G К Panuntsev, V A Aliev, V B Iblyaminov, A V Savello, А Patzak, K V Laptev, I P Dudanov, О А Pavlov
AIM: To study cerebral autoregulation (CA) in region of the stenotic carotid artery. MATERIAL AND METHODS: The study involved 35 patients with critical stenosis of the carotid arteries, including 24 patients were asymptomatic and 11 patients with symptomatic course. Blood flow velocity in middle cerebral arteries was monitored using Multi Dop X (DWL, Germany) with simultaneous noninvasive systemic blood pressure registration (CNAP, Austria). CA was assessed by calculating the phase shift (PS) between spontaneous oscillations of blood flow velocity and blood pressure within the range of systemic Mayer waves (80-120 mHz)...
2017: Zhurnal Nevrologii i Psikhiatrii Imeni S.S. Korsakova
https://www.readbyqxmd.com/read/28880397/transcranial-doppler-a-stethoscope-for-the-brain-neurocritical-care-use
#12
REVIEW
Chiara Robba, Danilo Cardim, Mypinder Sekhon, Karol Budohoski, Marek Czosnyka
Transcranial Doppler (TCD) ultrasonography is a noninvasive bedside monitoring technique that can evaluate cerebral blood flow hemodynamics in the intracranial arterial vasculature. TCD allows assessment of linear cerebral blood flow velocity, with a high temporal resolution and is inexpensive, reproducible, and portable. The aim of this review is to provide an overview of the most commonly used TCD derived signals and measurements used commonly in neurocritical care. We describe both basic (flow velocity, pulsatility index) and advanced concepts, including critical closing pressure, wall tension, autoregulation, noninvasive intracranial pressure, brain compliance, and cerebrovascular time constant; we also describe the clinical applications of TCD to highlight their utility in the diagnosis and monitoring of cerebrovascular diseases as the "stethoscope for the brain...
September 7, 2017: Journal of Neuroscience Research
https://www.readbyqxmd.com/read/28871418/time-spent-with-impaired-autoregulation-is-linked-with-outcome-in-severe-infant-paediatric-traumatic-brain-injury
#13
Konstantin Hockel, Jennifer Diedler, Felix Neunhoeffer, Ellen Heimberg, Carmen Nagel, Martin U Schuhmann
BACKGROUND: It could be shown in traumatic brain injury (TBI) in adults that the functional status of cerebrovascular autoregulation (AR), determined by the pressure reactivity index (PRx), correlates to and even predicts outcome. We investigated PRx, cerebral perfusion pressure (CPP) and intracranial pressure (ICP) and their correlation to outcome in severe infant and paediatric TBI. METHODS: Seventeen patients (range, 1 day to 14 years) with severe TBI (median GCS at presentation, 4) underwent long-term computerised ICP and mean arterial pressure (MAP) monitoring using dedicated software to determine CPP and PRx and optimal CPP (CPP level where PRx shows best autoregulation) continuously...
September 4, 2017: Acta Neurochirurgica
https://www.readbyqxmd.com/read/28863786/prdm13-forms-a-feedback-loop-with-ptf1a-and-is-required-for-glycinergic-amacrine-cell-genesis-in-the-xenopus-retina
#14
Nathalie Bessodes, Karine Parain, Odile Bronchain, Eric J Bellefroid, Muriel Perron
BACKGROUND: Amacrine interneurons that modulate synaptic plasticity between bipolar and ganglion cells constitute the most diverse cell type in the retina. Most are inhibitory neurons using either GABA or glycine as neurotransmitters. Although several transcription factors involved in amacrine cell fate determination have been identified, mechanisms underlying amacrine cell subtype specification remain to be further understood. The Prdm13 histone methyltransferase encoding gene is a target of the transcription factor Ptf1a, an essential regulator of inhibitory neuron cell fate in the retina...
September 1, 2017: Neural Development
https://www.readbyqxmd.com/read/28862703/fine-tuning-and-autoregulation-of-the-intestinal-determinant-and-tumor-suppressor-homeobox-gene-cdx2-by-alternative-splicing
#15
Camille Balbinot, Marie Vanier, Olivier Armant, Asmaa Nair, Julien Penichon, Christine Soret, Elisabeth Martin, Thoueiba Saandi, Jean-Marie Reimund, Jacqueline Deschamps, Felix Beck, Claire Domon-Dell, Isabelle Gross, Isabelle Duluc, Jean-Noël Freund
On the basis of phylogenetic analyses, we uncovered a variant of the CDX2 homeobox gene, a major regulator of the development and homeostasis of the gut epithelium, also involved in cancer. This variant, miniCDX2, is generated by alternative splicing coupled to alternative translation initiation, and contains the DNA-binding homeodomain but is devoid of transactivation domain. It is predominantly expressed in crypt cells, whereas the CDX2 protein is present in crypt cells but also in differentiated villous cells...
September 1, 2017: Cell Death and Differentiation
https://www.readbyqxmd.com/read/28861914/a-novel-mas-iii-selective-arsr-transcriptional-repressor
#16
Jian Chen, Venkadesh Sarkarai Nadar, Barry P Rosen
Microbial expression of genes for resistance to heavy metals and metalloids is usually transcriptionally regulated by the toxic ions themselves. Arsenic is a ubiquitous, naturally occurring toxic metalloid widely distributed in soil and groundwater. Microbes biotransform both arsenate (As(V)) and arsenite (As(III)) into more toxic methylated metabolites methylarsenite (MAs(III)) and dimethylarsenite (DMAs(III)). Environmental arsenic is sensed by members of the ArsR/SmtB family. The arsR gene is autoregulated and is typically part of an operon that contains other ars genes involved in arsenic detoxification...
September 1, 2017: Molecular Microbiology
https://www.readbyqxmd.com/read/28860964/inter-individual-relationships-between-sympathetic-arterial-baroreflex-function-and-cerebral-perfusion-control-in-healthy-males
#17
Trevor Witter, Yu-Chieh Tzeng, Terry O'Donnell, Jessica Kusel, Bridget Walker, Mary Berry, Chloe E Taylor
Maintenance of adequate cerebral perfusion during normal physiological challenges requires integration between cerebral blood flow (CBF) and systemic blood pressure control mechanisms. Previous studies have shown that cardiac baroreflex sensitivity (BRS) is inversely related to some measures of cerebral autoregulation. However, interactions between the sympathetic arterial baroreflex and cerebral perfusion control mechanisms have not been explored. To determine the nature and magnitude of these interactions we measured R-R interval, blood pressure, CBF velocity, and muscle sympathetic nerve activity (MSNA) in 11 healthy young males...
2017: Frontiers in Neuroscience
https://www.readbyqxmd.com/read/28840161/impairment-of-cerebral-autoregulation-in-pediatric-extracorporeal-membrane-oxygenation-associated-with-neuroimaging-abnormalities
#18
Fenghua Tian, Michael Craig Morriss, Lina Chalak, Ramgopal Venkataraman, Chul Ahn, Hanli Liu, Lakshmi Raman
Extracorporeal membrane oxygenation (ECMO) is a life-supporting therapy for critically ill patients with severe respiratory and/or cardiovascular failure. Cerebrovascular impairment can result in hemorrhagic and ischemic complications commonly seen in the patients supported on ECMO. We investigated the degree of cerebral autoregulation impairment during ECMO as well as whether it is predictive of neuroimaging abnormalities. Spontaneous fluctuations of mean arterial pressure (MAP) and cerebral tissue oxygen saturation ([Formula: see text]) were continuously measured during the ECMO run...
October 2017: Neurophotonics
https://www.readbyqxmd.com/read/28835309/impaired-cerebral-autoregulation-and-elevation-in-plasma-glial-fibrillary-acidic-protein-level-during-cardiopulmonary-bypass-surgery-for-chd
#19
Ronald B Easley, Bradley S Marino, Jacky Jennings, Amy E Cassedy, Kathleen K Kibler, Ken M Brady, Dean B Andropoulos, Marissa Brunetti, Charles W Hogue, Eugenie S Heitmiller, Jennifer K Lee, James Spaeth, Allen D Everett
BACKGROUND: Cerebrovascular reactivity monitoring has been used to identify the lower limit of pressure autoregulation in adult patients with brain injury. We hypothesise that impaired cerebrovascular reactivity and time spent below the lower limit of autoregulation during cardiopulmonary bypass will result in hypoperfusion injuries to the brain detectable by elevation in serum glial fibrillary acidic protein level. METHODS: We designed a multicentre observational pilot study combining concurrent cerebrovascular reactivity and biomarker monitoring during cardiopulmonary bypass...
August 24, 2017: Cardiology in the Young
https://www.readbyqxmd.com/read/28826503/tissue-specific-regulation-of-bmp-signaling-by-drosophila-n-glycanase-1
#20
Antonio Galeone, Seung Yeop Han, Chengcheng Huang, Akira Hosomi, Tadashi Suzuki, Hamed Jafar-Nejad
Mutations in the human N-glycanase 1 (NGLY1) cause a rare, multisystem congenital disorder with global developmental delay. However, the mechanisms by which NGLY1 and its homologs regulate embryonic development are not known. Here we show that Drosophila Pngl encodes an N-glycanase and exhibits a high degree of functional conservation with human NGLY1. Loss of Pngl results in developmental midgut defects reminiscent of midgut-specific loss of BMP signaling. Pngl mutant larvae also exhibit a severe midgut clearance defect, which cannot be fully explained by impaired BMP signaling...
August 4, 2017: ELife
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