33,627 results match your criteria perfusion changes

CT perfusion based ASPECTS improves the diagnostic performance of early ischemic changes in large vessel occlusion.

BMC Med Imaging 2021 Apr 12;21(1):67. Epub 2021 Apr 12.

Department of Radiology, Changhai Hospital of Shanghai, Navy Medical University (Second Military Medical University), No. 168 Changhai Road, Shanghai, 200433, China.

Background: ASPECTS scoring method varies, but which one is most suitable for predicting the prognosis still unclear. We aimed to evaluate the diagnostic performance of Automated (Auto)-, noncontrast CT (NCCT)- and CT perfusion (CTP) -ASPECTS for early ischemic changes (EICs) in acute ischemic stroke patients with large vessel occlusion (LVO) and to explore which scoring method is most suitable for predicting the clinical outcome.

Methods: Eighty-one patients with anterior circulation LVO were retrospectively enrolled and grouped as having a good (0-2) or poor (3-6) clinical outcome using a 90-day modified Rankin Scale score. Read More

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Blind spot in sepsis management - Tissue level changes in microcirculation.

Physiol Int 2021 Apr 9. Epub 2021 Apr 9.

3Department of Emergency Medicine, Clinical Centre, University of Pécs, Pécs, Hungary.

In sepsis cytokine-mediated inflammation, clotting cascade activation and glycocalyx shedding impair both function and structure of the microcirculation, compromising adequate tissue oxygenation/perfusion. Such mismatch results in "dysoxia", an imbalance in mitochondrial respiration.Microvessel injuries can be grouped into four types: cytotoxic oedema, micro-vessel heterogeneity, sluggish/absent flow, and focal anaemia. Read More

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A porcine model of endothelial glycocalyx damage by enzymatic digestion: A pilot study.

Clin Hemorheol Microcirc 2021 Apr 2. Epub 2021 Apr 2.

Department of Anesthesiology, Resuscitation and Intensive Care Medicine, University Hospital Hradec Kralove, Hradec Kralove, Czech Republic.

Background: The endothelial glycocalyx (EG) plays a vital role in the physiology and pathophysiology of human microcirculation. Having relevant EG damage model would be important tool for testing new interventions aiming at EG protection and recovery. We describe the first in vivo EG damage model in pig. Read More

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The Structural and Comparative Analysis of Intravitreal Dexamethasone Implant (Ozurdex) and Anti-VEGF Injection in Branched Retinal Vein Occlusion Patients by Optical Coherence Tomography Angiography Images Quantitation.

Semin Ophthalmol 2021 Apr 10:1-7. Epub 2021 Apr 10.

Department of Ophthalmology, Bucheon St. Mary's Hospital, College of Medicine, the Catholic University of Korea, Seoul, Republic of Korea.

: To evaluate and compare the structural changes of retinal vasculature after intravitreal dexamethasone implant (Ozurdex) insertion and antivascular endothelial growth factor (anti-VEGF) injection in patients with branched retinal vein occlusion (BRVO) using optical coherence tomography angiography (OCTA).: We retrospectively analyzed 39 patients with unilateral BRVO. Subjects were divided into two groups according to treatment agent: Ozurdex (n = 18) and anti-VEGF (n = 21). Read More

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Muscle damage in response to a single bout of high intensity concentric exercise in patients with Pompe disease.

Ann Transl Med 2021 Mar;9(5):389

Department of Neurology, Medical School, University of Pécs, Pécs, Hungary.

Background: In Pompe disease, resistance exercise could be an effective treatment to delay motor function impairment, however, the acute effects of this exercise modality are unclear.

Methods: In a prospective cohort study, we compared responses to a single bout of resistance exercise by serum markers of muscle damage and quantitative muscle magnetic resonance imaging (MRI) in patients (n=12) and age- and gender-matched healthy controls (n=12). Participants performed 50 maximal effort concentric knee flexions on a dynamometer. Read More

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Retinal and Choroidal Blood Perfusion in Patients with Bietti Crystalline Dystrophy.

Retina 2021 Apr 8. Epub 2021 Apr 8.

Southwest Hospital / Southwest Eye Hospital, Army Medical University, Chongqing, China Key Lab of Visual Damage and Regeneration & Restoration of Chongqing, China.

Purpose: To compare changes of chorioretinal blood perfusion between Bietti crystalline dystrophy (BCD) and typical retinitis pigmentosa (RP) and perform a staging and a longitudinal analysis of chorioretinal perfusion in BCD.

Methods: Twenty-eight BCD patients (56 eyes), 28 typical RP patients (56 eyes), and 28 healthy subjects (56 eyes) were enrolled. Macular structural parameters and subfoveal choroidal thickness were measured via optical coherence tomography. Read More

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Spectral Cerebral Blood Volume Accounting for Noninvasive Estimation of Changes in Cerebral Perfusion Pressure in Patients with Traumatic Brain Injury.

Acta Neurochir Suppl 2021 ;131:193-199

Brain Physics Laboratory, Division of Neurosurgery, Department of Clinical Neurosciences, Cambridge Biomedical Campus, Addenbrooke's Hospital, University of Cambridge, Cambridge, UK.

We present the application of a new method for non-invasive cerebral perfusion pressure estimation (spectral nCPP or nCPP) accounting for changes in transcranial Doppler-derived pulsatile cerebral blood volume. Primarily, we analysed cases in which CPP was changing (delta [∆],magnitude of changes]): (1) rise during vasopressor-induced augmentation of ABP (N = 16); and (2) spontaneous changes in intracranial pressure (ICP) during plateau waves (N = 14). Secondarily, we assessed nCPP in a larger cohort in which CPP presented a wider range of values. Read More

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January 2021

Perioperative Dynamics of Intracranial B-waves of Blood Flow Velocity in the Basal Cerebral Arteries in Patients with Brain Arteriovenous Malformation.

Acta Neurochir Suppl 2021 ;131:63-68

Johannes-Mueller Institute of Vegetative Physiology University Hospital Charité, Humboldt University of Berlin, Berlin, Germany.

Intracranial B-waves (8-30 mHz) of blood flow velocity (BFV) in the cerebral arteries are observed in various pathologies of the brain. Changes in B-waves of BFV in pathological arteriovenous shunting and "steal" syndrome remain poorly understood. The aim of this study was to evaluate the dynamics of the B-wave amplitude of BFV (BWA) in patients with an arteriovenous malformation (AVM) in the brain. Read More

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January 2021

Assessment of Cerebral Autoregulation in the Perifocal Zone of a Chronic Subdural Hematoma.

Acta Neurochir Suppl 2021 ;131:51-54

Lovelace Biomedical Research Institute, Albuquerque, NM, USA.

Introduction: The knowledge of conservative treatment modalities for a chronic subdural hematoma (CSDH) is still based on low-grade evidence. The purpose of this study was to evaluate the condition of the microcirculation and autoregulation in the perifocal CSDH zone for understanding of the mechanism of CSDH development.

Methods: Cerebral microcirculation was evaluated in patients with the aid of brain perfusion computed tomography (PCT) within the first day. Read More

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January 2021

Impacts of a Pressure Challenge on Cerebral Critical Closing Pressure and Effective Cerebral Perfusion Pressure in Patients with Traumatic Brain Injury.

Acta Neurochir Suppl 2021 ;131:11-16

Intensive Care Unit, Hospital de Clinicas, Universidad de la Republica, Montevideo, Uruguay.

Introduction: Cerebral critical closing pressure (CrCP) comprises intracranial pressure (ICP) and arteriolar wall tension (WT). It is the arterial blood pressure (ABP) at which small vessels close and circulation stops. We hypothesized that the increase in WT secondary to a systemic hypertensive challenge would lead to an increase in CrCP and that the "effective" cerebral perfusion pressure (CPPeff; calculated as ABP - CrCP) would give more complete information than the "conventional" cerebral perfusion pressure (CPP; calculated as ABP - ICP). Read More

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January 2021

Microcirculatory Biomarkers of Secondary Cerebral Ischemia in Traumatic Brain Injury.

Acta Neurochir Suppl 2021 ;131:3-5

Lovelace Biomedical Research Institute, Albuquerque, NM, USA.

Aim: The purpose of this study was to study changes in cerebral microcirculation parameters in the development of secondary cerebral ischemia (SCI).

Methods: A total of 202 patients with a Glasgow Coma Scale score ≤ 12 after experiencing a traumatic brain injury (TBI) were recruited for the study within 6 h of the injury. All patients were subjected to perfusion computed tomography. Read More

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January 2021

A prospective study to validate pulmonary blood mass changes on non-contrast 4DCT in pulmonary embolism patients.

Clin Imaging 2021 Mar 5;78:179-183. Epub 2021 Mar 5.

Department of Radiation Oncology, Beaumont Health System, OUWB School of Medicine, United States of America; Department of Computational and Applied Mathematics, Rice University, United States of America. Electronic address:

Purpose: Limited diagnostic options exist for patients with suspected pulmonary embolism (PE) who cannot undergo CT-angiogram (CTA). CT-ventilation methods recover respiratory motion-induced lung volume changes as a surrogate for ventilation. We recently demonstrated that pulmonary blood mass change, induced by tidal respiratory motion, is a potential surrogate for pulmonary perfusion. Read More

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Teleradiology-based stroke network in Western and Southern Transdanubia in Hungary

Orv Hetil 2021 04 10;162(17):668-675. Epub 2021 Apr 10.

6 Pécsi Tudományegyetem, Általános Orvostudományi Kar, Klinikai Központ, Neurológiai Klinika, Pécs.

Összefoglaló. Bevezetés: A stroke kezelésének lehetőségei az utóbbi években jelentősen megváltoztak: a thrombolysis után bevezetésre került a mechanikus thrombectomia, és a terápiás időablak is jelentősen kitágult az utóbbi évek nagy multicentrikus tanulmányai alapján. Ezek a lehetőségek új igényeket fogalmaztak meg a képalkotó diagnosztikával szemben: az ischaemia okozta morfológiai elváltozások mellett az artériás és a kollaterális rendszer állapotát, valamint bizonyos esetekben az agy szöveti perfúzióját is szükséges meghatározni. Read More

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Changes in the proteome of extracellular vesicles shed by rat liver after sub-toxic exposure to acetaminophen.

Electrophoresis 2021 Apr 10. Epub 2021 Apr 10.

Proteomics Core, COBRE CCRD, Rhode Island Hospital, One Hoppin Street, Providence, RI 02903, USA.

To identify changes in extracellular vesicles (EVs) secreted by the liver following drug induced liver injury (DILI), rats were treated with a subtoxic dose (500 mg/kg) of the analgesic drug, acetaminophen (APAP). EVs were collected by liver perfusion of sham and APAP treated rats. Changes in EVs morphology were examined by transmission electron microscopic analysis of negatively stained vesicles. Read More

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Multimodal molecular imaging detects early responses to immune checkpoint blockade.

Cancer Res 2021 Apr 9. Epub 2021 Apr 9.

Radiation Biology Branch, National Cancer Institute

Immune checkpoint blockade (ICB) has become a standard therapy for several cancers; however, the response to ICB is inconsistent and a method for non-invasive assessment has not been established to date. To investigate the capability of multi-modal imaging to evaluate treatment response to ICB therapy, hyperpolarized 13C MRI using [1-13C] pyruvate and [1,4-13C2] fumarate and dynamic contrast enhanced (DCE) MRI were evaluated to detect early changes in tumor glycolysis, necrosis, and intratumor perfusion/permeability, respectively. Mouse tumor models served as platforms for high (MC38 colon adenocarcinoma) and low (B16-F10 melanoma) sensitivity to dual ICB of PD-L1 and CTLA-4. Read More

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Quantifying the spatiotemporal influence of acute myocardial ischemia on volumetric conduction velocity.

J Electrocardiol 2021 Mar 23;66:86-94. Epub 2021 Mar 23.

Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, UT, USA; Department of Biomedical Engineering, University of Utah, Salt Lake City, UT, USA; Nora Eccles Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, USA.

Introduction: Acute myocardial ischemia occurs when coronary perfusion to the heart is inadequate, which can perturb the highly organized electrical activation of the heart and can result in adverse cardiac events including sudden cardiac death. Ischemia is known to influence the ST and repolarization phases of the ECG, but it also has a marked effect on propagation (QRS); however, studies investigating propagation during ischemia have been limited.

Methods: We estimated conduction velocity (CV) and ischemic stress prior to and throughout 20 episodes of experimentally induced ischemia in order to quantify the progression and correlation of volumetric conduction changes during ischemia. Read More

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Structural and physiological changes of the human body upon SARS-CoV-2 infection.

J Zhejiang Univ Sci B 2021 Apr;22(4):310-317

Dr. Li Dak Sum & Yip Yio Chin Center for Stem Cells and Regenerative Medicine, Department of Orthopedic Surgery, the Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310058, China.

Since December 2019, the novel coronavirus (severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)) has spread to many countries around the world, developing into a global pandemic with increasing numbers of deaths reported worldwide. To data, although some vaccines have been developed, there are no ideal drugs to treat novel coronavirus pneumonia (coronavirus disease 2019 (COVID-19)). By examining the structure of the coronavirus and briefly describing its possible pathogenesis based on recent autopsy reports conducted by various teams worldwide, this review analyzes the possible structural and functional changes of the human body upon infection with SARS-CoV-2. Read More

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APOE moderates the effect of hippocampal blood flow on memory pattern separation in clinically normal older adults.

Hippocampus 2021 Apr 9. Epub 2021 Apr 9.

Department of Neurology, Memory and Aging Center, University of California, San Francisco (UCSF), San Francisco, California, USA.

Pattern separation, the ability to differentiate new information from previously experienced similar information, is highly sensitive to hippocampal structure and function and declines with age. Functional MRI studies have demonstrated hippocampal hyperactivation in older adults compared to young, with greater task-related activation associated with worse pattern separation performance. The current study was designed to determine whether pattern separation was sensitive to differences in task-free hippocampal cerebral blood flow (CBF) in 130 functionally intact older adults. Read More

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Changes in Noninvasive Arterial Stiffness and Central Blood Pressure After Endovascular Abdominal Aneurysm Repair.

J Endovasc Ther 2021 Apr 9:15266028211007460. Epub 2021 Apr 9.

Department of Surgery, Ziekenhuis Rijnstate, Arnhem, The Netherlands.

Purpose: To evaluate the impact of elective endovascular aneurysm repair (EVAR) on the carotid-femoral pulse wave velocity (cfPWV) and central pressure waveform, through 1-year follow-up.

Materials And Methods: A tonometric device was used to measure cfPWV and estimate the central pressure waveform in 20 patients with an infrarenal abdominal aortic aneurysm scheduled for elective EVAR. The evaluated central hemodynamic parameters included the central pressures, the augmentation index (AIx), and the subendocardial viability ratio (SEVR). Read More

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A Swept source optical coherence tomography angiography study: Imaging artifacts and comparison of non-perfusion areas with fluorescein angiography in diabetic macular edema.

PLoS One 2021 8;16(4):e0249918. Epub 2021 Apr 8.

Department of Ophthalmology, Kepler University Clinic, Johannes Kepler University, Linz, Austria.

Purpose: Swept Source Optical coherence tomography angiography (SS-OCTA) is a novel technique to visualize perfusion and vascular changes like ischemia in patients with diabetic retinopathy. The aim of this study was to compare non-perfusion areas on conventional fluorescein angiography (FA) with those on SS-OCTA using detailed manual annotation in patients with diabetic macular edema (DME) and to evaluate possible artifacts caused by DME on SS-OCTA.

Methods: 27 eyes of 21 patients with DME were analyzed in this prospective, cross-sectional study; on all, standard ophthalmological examination, SS-OCTA and FA imaging were performed. Read More

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Ferumoxytol-enhanced magnetic resonance T1 reactivity for depiction of myocardial hypoperfusion.

NMR Biomed 2021 Apr 8:e4518. Epub 2021 Apr 8.

Physics and Biology in Medicine Graduate Program, David Geffen School of Medicine at UCLA, Los Angeles, California, USA.

Myocardial T1 reactivity, defined as the relative change in T1 between rest and vasodilator-induced stress, has been proposed as a magnetic resonance imaging (MRI) biomarker of tissue perfusion. We hypothesize that the superparamagnetic iron-oxide nanoparticle, ferumoxytol, sensitizes T1 to changes in the intramyocardial vascular compartment and improves the sensitivity and specificity of T1 reactivity as an imaging biomarker of tissue perfusion. We aim to assess the diagnostic performance of ferumoxytol-enhanced (FE) myocardial T1 reactivity in swine models of myocardial hypoperfusion. Read More

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Age corrected changes in intracranial haemodynamics after carotid endarterectomy.

J Cardiovasc Surg (Torino) 2021 Apr 8. Epub 2021 Apr 8.

Department of Vascular Surgery, Department of Clinical Neurophysiology, Martini Ziekenhuis Groningen, Groningen, the Netherlands.

Background: Transcranial Doppler ultrasound (TCD) is a frequently used method to monitor brain perfusion during and following carotid endarterectomy (CEA). Our aim was to define the normally occurring changes of intracranial haemodynamics in patients undergoing CEA measuring recently developed TCD parameters.

Methods: A retrospective, single-centre cohort study was performed. Read More

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Feasibility of Doppler Ultrasound for Cortical Cerebral Blood Flow Velocity Monitoring During Major Non-cardiac Surgery of Newborns.

Front Pediatr 2021 22;9:656806. Epub 2021 Mar 22.

Department of Anaesthesiology, Erasmus MC University Medical Centre, Rotterdam, Netherlands.

Newborns needing major surgical intervention are at risk of brain injury and impaired neurodevelopment later in life. Disturbance of cerebral perfusion might be an underlying factor. This study investigates the feasibility of serial transfontanellar ultrasound measurements of the pial arteries during neonatal surgery, and whether perioperative changes in cerebral perfusion can be observed and related to changes in the perioperative management. Read More

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Pulmonary hypertension is attenuated and ventilation-perfusion matching is maintained during chronic hypoxia in deer mice native to high altitude.

Am J Physiol Regul Integr Comp Physiol 2021 Apr 7. Epub 2021 Apr 7.

Department of Biology, McMaster University, Canada.

Hypoxia at high altitude can constrain metabolism and performance, and can elicit physiological adjustments that are deleterious to health and fitness. Hypoxic pulmonary hypertension is a particularly serious and maladaptive response to chronic hypoxia, which results from vasoconstriction and pathological remodeling of pulmonary arteries, and can lead to pulmonary edema and right ventricle hypertrophy. We investigated whether deer mice (Peromyscus maniculatus) native to high altitude have attenuated this maladaptive response to chronic hypoxia, and whether evolved changes or hypoxia-induced plasticity in pulmonary vasculature might impact ventilation-perfusion (V-Q) matching in chronic hypoxia. Read More

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Pulmonary Functional Imaging: Part 1-State-of-the-Art Technical and Physiologic Underpinnings.

Radiology 2021 Apr 6:203711. Epub 2021 Apr 6.

From the Department of Radiology, Fujita Health University School of Medicine, Toyoake, Aichi, Japan (Y.O.); Joint Research Laboratory of Advanced Medical Imaging, Fujita Health University School of Medicine, Toyoake, Aichi, Japan (Y.O.); Division of Functional and Diagnostic Imaging Research, Department of Radiology, Kobe University Graduate School of Medicine, Kobe, Hyogo, Japan (Y.O.); Department of Radiology, Research Institute of Radiology, Asan Medical Center, University of Ulsan College of Medicine, Seoul, South Korea (J.B.S.); Department of Medicine, Robarts Research Institute, and Department of Medical Biophysics, Western University, London, Canada (G.P.); Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine (SKKU-SOM), Seoul, Korea (K.S.L.); Department of Radiology, Penn Medicine, University of Pennsylvania, Philadelphia, Pa (W.B.G.); Departments of Medical Physics and Radiology (S.B.F., M.L.S.), UW-Madison School of Medicine and Public Health, Madison, Wis; and Center for Pulmonary Functional Imaging, Brigham and Women's Hospital and Harvard Medical School, 75 Francis St, Boston, MA 02215 (H.H.).

Over the past few decades, pulmonary imaging technologies have advanced from chest radiography and nuclear medicine methods to high-spatial-resolution or low-dose chest CT and MRI. It is currently possible to identify and measure pulmonary pathologic changes before these are obvious even to patients or depicted on conventional morphologic images. Here, key technological advances are described, including multiparametric CT image processing methods, inhaled hyperpolarized and fluorinated gas MRI, and four-dimensional free-breathing CT and MRI methods to measure regional ventilation, perfusion, gas exchange, and biomechanics. Read More

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Effect of magnesium sulphate on the intracranial pressure of preeclampsia patients using ultrasound-guided optic nerve sheath diameter: A pilot study.

Saudi J Anaesth 2021 Jan-Mar;15(1):14-18. Epub 2021 Jan 5.

Department of Anesthesia, Corniche Hospital, Abu Dhabi, United Arab Emirates.

Background: Increased intracranial pressure (ICP) is a known complication of pre-eclampsia with severe features. The use of magnesium sulphate (MgSO) is the standard treatment and is associated with marked reduction of cerebral perfusion pressure (CPP) and prevention of cerebral damage. Optic nerve sheath diameter (ONSD) ultrasonography is a bedside tool used to reflect changes in the ICP. Read More

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January 2021

Structural Stability and Biophysical Properties of the Mega-Protein Erythrocruorin Are Regulated by Polyethylene Glycol Surface Coverage.

Biomacromolecules 2021 Apr 6. Epub 2021 Apr 6.

William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, Ohio 43210, United States.

A wide variety of hemoglobin-based oxygen carriers (HBOCs) have been designed for use as red blood cell (RBC) substitutes in transfusion medicine, organ perfusion, oxygen delivery to hypoxic tissues, and a myriad of other applications. However, hemoglobin (Hb) derived from annelids (erythrocruorins [Ecs]) comprise a natural class of HBOC, since they are larger in size (30 nm in diameter) and contain more heme groups per molecule (144 heme groups) compared to human Hb (hHb; 5 nm in diameter and 4 heme groups). The larger size of Ec compared to hHb reduces tissue extravasation from the vascular space, thus, reducing vasoconstriction, systemic hypertension, and tissue oxidative injury when used as an RBC substitute. Read More

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