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https://www.readbyqxmd.com/read/27910802/near-infrared-spectroscopy-evaluated-cerebral-oxygenation-during-anesthesia
#1
Henrik Sørensen
Likely, maintained organ and notably cerebral perfusion, secures rapid recovery following anesthesia. To secure cerebral blood flow (CBF) at least mean arterial pressure (MAP) and the arterial carbon dioxide tension (PaCO2) need to be considered. CBF is "autoregulated", i.e. stays more or less stable within a MAP of 50-150 mmHg, but the lower limit appears to depend on the central blood volume and/or cardiac output, illustrated by a decrease in CBF at a MAP of 80 mmHg with a compromised central blood volume, while CBF remains constant with a MAP < 40 mmHg, if the central blood volume is maintained...
December 2016: Danish Medical Journal
https://www.readbyqxmd.com/read/27902691/do-vascular-networks-branch-optimally-or-randomly-across-spatial-scales
#2
Elif Tekin, David Hunt, Mitchell G Newberry, Van M Savage
Modern models that derive allometric relationships between metabolic rate and body mass are based on the architectural design of the cardiovascular system and presume sibling vessels are symmetric in terms of radius, length, flow rate, and pressure. Here, we study the cardiovascular structure of the human head and torso and of a mouse lung based on three-dimensional images processed via our software Angicart. In contrast to modern allometric theories, we find systematic patterns of asymmetry in vascular branching, potentially explaining previously documented mismatches between predictions (power-law or concave curvature) and observed empirical data (convex curvature) for the allometric scaling of metabolic rate...
November 2016: PLoS Computational Biology
https://www.readbyqxmd.com/read/27902540/macular-perivenous-retinal-whitening-and-presumed-retino-ciliary-sparing-in-a-recurrent-central-retinal-vein-occlusion-associated-with-the-antiphospholipid-syndrome-and-cryoglobulinemia
#3
Dov B Sebrow, Jesse J Jung, Jason Horowitz, Jeffrey G Odel, K Bailey Freund
PURPOSE: Macular perivenous retinal whitening results from hypoperfusion-induced ischemia of the middle retina that can occur in central retinal vein occlusion (CRVO). We describe an unusual case of recurrent CRVO with macular perivenous retinal whitening and retino-ciliary venous sparing in the setting of 2 prothrombotic diseases, antiphospholipid syndrome and Type II cryoglobulinemia. METHODS: A 50-year-old man presented with intermittent loss of vision in his right eye related to a recurrent CRVO...
November 29, 2016: Retinal Cases & Brief Reports
https://www.readbyqxmd.com/read/27895423/increased-cd4-cd45ra-foxp3-low-cells-alter-the-balance-between-treg-and-th17-cells-in-colitis-mice
#4
Ya-Hui Ma, Jie Zhang, Xue Chen, You-Fu Xie, Yan-Hua Pang, Xin-Juan Liu
AIM: To investigate the role of regulatory T cell (Treg) subsets in the balance between Treg and T helper 17 (Th17) cells in various tissues from mice with dextran sulfate sodium-induced colitis. METHODS: Treg cells, Treg cell subsets, Th17 cells, and CD4(+)CD25(+)FoxP3(+)IL-17(+) cells from the lamina propria of colon (LPC) and other ulcerative colitis (UC) mouse tissues were evaluated by flow cytometry. Forkhead box protein 3 (FoxP3), interleukin 17A (IL-17A), and RORC mRNA levels were assessed by real-time PCR, while interleukin-10 (IL-10) and IL-17A levels were detected with a Cytometric Beads Array...
November 14, 2016: World Journal of Gastroenterology: WJG
https://www.readbyqxmd.com/read/27891625/validation-of-the-multiplex-ligation-dependent-probe-amplification-assay-and-its-application-on-the-distribution-study-of-the-major-alleles-of-17-blood-group-systems-in-chinese-donors-from-guangzhou
#5
Yanli Ji, Jizhi Wen, Barbera Veldhuisen, Lonneke Haer-Wigman, Zhen Wang, Martin Lodén-van Straaten, Ling Wei, Guangping Luo, Yongshui Fu, C Ellen van der Schoot
BACKGROUND: Genotyping platforms for common red blood cell (RBC) antigens have been successfully applied in Caucasian and black populations but not in Chinese populations. In this study, a genotyping assay based on multiplex ligation-dependent probe amplification (MLPA) technology was applied in a Chinese population to validate the MLPA probes. Subsequently, the comprehensive distribution of 17 blood group systems also was obtained. STUDY DESIGN AND METHODS: DNA samples from 200 Chinese donors were extracted and genotyped using the blood-MLPA assay...
November 27, 2016: Transfusion
https://www.readbyqxmd.com/read/27889577/brain-uptake-and-metabolism-of-the-endocannabinoid-anandamide-labeled-in-either-the-arachidonoyl-or-ethanolamine-moiety
#6
Kun Hu, Shilpa Sonti, Sherrye T Glaser, Richard I Duclos, Samuel J Gatley
INTRODUCTION: Anandamide (N-arachidonoylethanolamine) is a retrograde neuromodulator that activates cannabinoid receptors. The concentration of anandamide in the brain is controlled by fatty acid amide hydrolase (FAAH), which has been the focus of recent drug discovery efforts. Previous studies in C57BL/6 mice using [(3)H-arachidonoyl]anandamide demonstrated deposition of tritium in thalamus and cortical areas that was blocked by treatment with an FAAH inhibitor and that was not seen in FAAH-knockout mice...
November 9, 2016: Nuclear Medicine and Biology
https://www.readbyqxmd.com/read/27888936/finite-element-model-to-study-temperature-distribution-in-skin-and-deep-tissues-of-human-limbs
#7
Mamta Agrawal, K R Pardasani
The temperature of body tissues is viewed as an indicator of tissue response in clinical applications since ancient times. The tissue temperature depends on various physical and physiological parameters like blood flow, metabolic heat generation, thermal conductivity of tissues, shape and size of organs etc. In this paper a finite element model has been proposed to study temperature distribution in skin and deep tissues of human limbs. The geometry of human limb is taken as elliptical tapered shape. It is assumed that outer surface of the limb is exposed to the environment...
December 2016: Journal of Thermal Biology
https://www.readbyqxmd.com/read/27888419/unravelling-cardiovascular-disease-using-four-dimensional-flow-cardiovascular-magnetic-resonance
#8
Vivian P Kamphuis, Jos J M Westenberg, Roel L F van der Palen, Nico A Blom, Albert de Roos, Rob van der Geest, Mohammed S M Elbaz, Arno A W Roest
Knowledge of normal and abnormal flow patterns in the human cardiovascular system increases our understanding of normal physiology and may help unravel the complex pathophysiological mechanisms leading to cardiovascular disease. Four-dimensional (4D) flow cardiovascular magnetic resonance (CMR) has emerged as a suitable technique that enables visualization of in vivo blood flow patterns and quantification of parameters that could potentially be of prognostic value in the disease process. In this review, current image processing tools that are used for comprehensive visualization and quantification of blood flow and energy distribution in the heart and great vessels will be discussed...
November 25, 2016: International Journal of Cardiovascular Imaging
https://www.readbyqxmd.com/read/27884959/cardiac-responses-to-exercise-distinguish-postural-orthostatic-tachycardia-syndrome-variants
#9
Paolo T Pianosi, Darrell R Schroeder, Philip R Fischer
We previously showed that one-third of adolescents with postural orthostatic tachycardia syndrome (POTS) have hyperkinetic circulation. In a subsequent cohort, we compare participants with POTS grouped according to cardiac output (Q˙) versus oxygen uptake (V˙O2) function, whose circulatory response to exercise lay at the lower end of this distribution. We hypothesized that such grouping determines the circulatory response to incremental-protocol, upright, cycle ergometry by whatever blend of flow and resistance adjustments best maintains normal blood pressure...
November 2016: Physiological Reports
https://www.readbyqxmd.com/read/27882633/tailoring-renal-clearance-and-tumor-targeting-of-ultrasmall-metal-nanoparticles-with-particle-density
#10
Shaoheng Tang, Chuanqi Peng, Jing Xu, Bujie Du, Qingxiao Wang, Rodrigo D Vinluan, Mengxiao Yu, Moon J Kim, Jie Zheng
Identifying key factors that govern the in vivo behavior of nanomaterials is critical to the clinical translation of nanomedicines. Overshadowed by size-, shape-, and surface-chemistry effects, the impact of the particle core density on clearance and tumor targeting of inorganic nanoparticles (NPs) remains largely unknown. By utilizing a class of ultrasmall metal NPs with the same size and surface chemistry but different densities, we found that the renal-clearance efficiency exponentially increased in the early elimination phase while passive tumor targeting linearly decreased with a decrease in particle density...
November 24, 2016: Angewandte Chemie
https://www.readbyqxmd.com/read/27881397/a-simple-method-to-ensure-homogeneous-drug-distribution-during-intrarenal-infusion
#11
Dmitry D Postnov, Max Salomonsson, Charlotte M Sorensen, Olga V Sosnovtseva
Intrarenal drug infusion plays an important role in renal experimental research. Laminar flow of the blood can cause streaming and inhomogeneous intrarenal distribution of infused drugs. We suggest a simple method to achieve a homogeneous intravascular distribution of drugs infused into the renal artery of anesthetized rats. The method employs a multiple sidehole catheter inserted into the renal artery, which enables an efficient drug mixing with the arterial blood. To verify the efficiency of this method we use laser speckle imaging and renal artery flowmetry...
November 23, 2016: American Journal of Physiology. Renal Physiology
https://www.readbyqxmd.com/read/27881059/natural-products-with-antiplatelet-action
#12
Gabriela Elisa Hirsch, Paulo Ricardo Nazário Viecili, Amanda Spring de Almeida, Sabrina Nascimento, Fernando Garcez Porto, Juliana Otero, Aline Schmidt, Brenda da Silva, Mariana Migliorini Parisi, Jonatas Zeni Klafke
BACKGROUND: Complex hemostatic mechanisms are involved in the pathophysiology of various diseases, including cardiovascular diseases. Among them, dysregulation of platelet activity is linked to the progression of atherosclerosis and mainly involves platelet aggregation and a decrease in blood flow in the vascular endothelium. The major platelet activation pathways mediated by agonists involve the arachidonic acid pathway, adenosine diphosphate pathway, serotonin pathway, nitric oxide pathway, and action of free radicals on molecules involved in platelet aggregation...
November 23, 2016: Current Pharmaceutical Design
https://www.readbyqxmd.com/read/27876371/approaches-for-treatment-of-aortic-arch-aneurysm-a-numerical-study
#13
Asaph Nardi, Idit Avrahami
Aortic arch aneurysm is a complex pathology which requires coverage of one or more aortic arch vessels. In this study we explore the hemodynamic behavior of the aortic arch in aneurysmatic and treated cases with three currently available treatment approaches: Surgery Graft, hybrid Stent-Graft and chimney Stent Graft. The analysis included four models of the time-dependent fluid domains of aneurysmatic arch and of the surgery, hybrid and chimney endovascular techniques. Dimensions of the models are based on typical anatomy, and boundary conditions are based on typical physiological flow...
November 12, 2016: Journal of Biomechanics
https://www.readbyqxmd.com/read/27873373/cardiac-output-and-blood-flow-redistribution-in-the-fetus-with-d-loop-transposition-of-the-great-arteries-and-intact-ventricular-septum-insights-into-the-pathophysiology
#14
Max E Godfrey, Kevin G Friedman, Monika Drogosz, Abraham M Rudolph, Wayne Tworetzky
OBJECTIVES: Although the postnatal physiology of D-loop transposition of the great arteries with intact ventricular septum (DTGA-IVS) is well established, little is known about fetal DTGA-IVS. In the normal fetus, the pulmonary valve (PV) is larger than the aortic valve (AoV), there is exclusive right to left flow at the foramen ovale (FO) and ductus arteriosus (DA), and the left ventricle (LV) ejects 40% of combined ventricular output (CVO) through the aorta, primarily to the brain. In DTGA-IVS, the LV ejects O2 -rich blood to the pulmonary artery, theoretically leading to pulmonary vasodilation, increased branch pulmonary arterial flow and reduced DA flow...
November 22, 2016: Ultrasound in Obstetrics & Gynecology
https://www.readbyqxmd.com/read/27865773/particulate-suspension-effect-on-peristaltically-induced-unsteady-pulsatile-flow-in-a-narrow-artery-blood-flow-model
#15
Sara I Abdelsalam, Kambiz Vafai
This work is concerned with theoretically investigating the pulsatile flow of a fluid with suspended particles in a flow driven by peristaltic waves that deform the wall of a small blood artery in the shape of traveling sinusoidal waves with constant velocity. The problem formulation in the wave frame of reference is presented and the governing equations are developed up to the second-order in terms of the asymptotic expansion of Womersley number which characterizes the unsteady effect in the wave frame. We suppose that the flow rate imposed, in this frame, is a function versus time...
November 16, 2016: Mathematical Biosciences
https://www.readbyqxmd.com/read/27863293/the-conical-stent-in-coronary-artery-improves-hemodynamics-compared-with-the-traditional-cylindrical-stent
#16
Yi Yu, Yujie Zhou, Qian Ma, Shuo Jia, Sijing Wu, Yan Sun, Xiaoli Liu, Yingxin Zhao, Yuyang Liu, Dongmei Shi
OBJECTIVES: This study sought to explore the efficacy of the conical stent implantation in the coronary artery by comparing the effects of cylindrical and conical stents on wall shear stress (WSS) and velocity of flow and fractional flow reserve (FFR). BACKGROUND: The traditional cylindrical stent currently used in the percutaneous coronary intervention (PCI) has a consistent diameter, which does not match the physiological change of the coronary artery. On the contrary, as a new patent, the conical stent with tapering lumen is consistent with the physiological change of vascular diameter...
November 8, 2016: International Journal of Cardiology
https://www.readbyqxmd.com/read/27861620/prazosin-can-prevent-glucocorticoid-mediated-capillary-rarefaction
#17
Erin R Mandel, Emily C Dunford, Anastassia Trifonova, Ghoncheh Abdifarkosh, Trevor Teich, Michael C Riddell, Tara L Haas
Glucocorticoids (GC) elicit skeletal muscle capillary rarefaction, which can subsequently impair blood distribution and muscle function; however, the mechanisms have not been established. We hypothesized that CORT would inhibit endothelial cell survival signals but that treatment with the alpha-1 adrenergic receptor inhibitor prazosin, which leads to angiogenesis in skeletal muscle of healthy rats, would reverse these effects and induce angiogenesis within the skeletal muscle of corticosterone (CORT)-treated rats...
2016: PloS One
https://www.readbyqxmd.com/read/27857954/heat-stress-gastrointestinal-permeability-and-interleukin-6-signaling-implications-for-exercise-performance-and-fatigue
#18
REVIEW
Nicole Vargas, Frank Marino
Exercise in heat stress exacerbates performance decrements compared to normothermic environments. It has been documented that the performance decrements are associated with reduced efferent drive from the central nervous system (CNS), however, specific factors that contribute to the decrements are not completely understood. During exertional heat stress, blood flow is preferentially distributed away from the intestinal area to supply the muscles and brain with oxygen. Consequently, the gastrointestinal barrier becomes increasingly permeable, resulting in the release of lipopolysaccharides (LPS, endotoxin) into the circulation...
April 2016: Temperature: Multidisciplinary Biomedical Journal
https://www.readbyqxmd.com/read/27857350/two-dimensional-phase-unwrapping-in-doppler-fourier-domain-optical-coherence-tomography
#19
Yimin Wang, David Huang, Ya Su, X Steve Yao
For phase-related imaging modalities using interferometric techniques, it is important to develop effective method to recover phase information that is mathematically wrapped. In this paper, we propose and demonstrate a two-dimensional (2D) method to achieve effective phase unwrapping in Doppler Fourier-domain (FD) optical coherence tomography (OCT), and recover the discontinuous phase distribution in retinal blood flow successfully for the first time in Doppler OCT studies. The proposed method is based on phase gradient approach in the axial dimension, with phase denoising performed through 2D window moving average in the sampled phase image using complex Doppler OCT data...
November 14, 2016: Optics Express
https://www.readbyqxmd.com/read/27855985/can-time-averaged-flow-boundary-conditions-be-used-to-meet-the-clinical-timeline-for-fontan-surgical-planning
#20
Zhenglun Alan Wei, Phillip M Trusty, Mike Tree, Christopher M Haggerty, Elaine Tang, Mark Fogel, Ajit P Yoganathan
Cardiovascular simulations have great potential as a clinical tool for planning and evaluating patient-specific treatment strategies for those suffering from congenital heart diseases, specifically Fontan patients. However, several bottlenecks have delayed wider deployment of the simulations for clinical use; the main obstacle is simulation cost. Currently, time-averaged clinical flow measurements are utilized as numerical boundary conditions (BCs) in order to reduce the computational power and time needed to offer surgical planning within a clinical time frame...
November 10, 2016: Journal of Biomechanics
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