A simple model to understand the effect of membrane shear elasticity and stress-free shape on the motion of red blood cells in shear flow

Soft Matter ◽  
2015 ◽  
Vol 11 (42) ◽  
pp. 8372-8382 ◽  
Author(s):  
Jules Dupire ◽  
Manouk Abkarian ◽  
Annie Viallat
Keyword(s):  
Simple Model ◽  
Shear Flow ◽  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Time Variation ◽  
Blood Cells ◽  
Shear Rates ◽  
Shear Elasticity

Time variation of the inclination (θ) and the membrane rotation (ω) of a red blood cell tumbling in a shear flow for three shear rates.

scholarly journals A theoretical investigation of the frisbee motion of red blood cells in shear flow

2021 ◽  
Vol 16 ◽  
pp. 23
Author(s):  
Thierry Mignon ◽  
Simon Mendez
Keyword(s):  
Steady State ◽  
Shear Flow ◽  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Numerical Solutions ◽  
Shear Rates ◽  
Steady State Solutions ◽  
Low Shear

The dynamics of a single red blood cell in shear flow is a fluid–structure interaction problem that yields a tremendous richness of behaviors, as a function of the parameters of the problem. A low shear rates, the deformations of the red blood cell remain small and low-order models have been developed, predicting the orientation of the cell and the membrane circulation along time. They reproduce the dynamics observed in experiments and in simulations, but they do not simplify the problem enough to enable simple interpretations of the phenomena. In a process of exploring the red blood cell dynamics at low shear rates, an existing model constituted of 5 nonlinear ordinary differential equations is rewritten using quaternions to parametrize the rotations of the red blood cell. Techniques from algebraic geometry are then used to determine the steady-state solutions of the problems. These solutions are relevant to a particular regime where the red blood cell reaches a constant inclination angle, with its membrane rotating around it, and referred to as frisbee motion. Comparing the numerical solutions of the model to the steady-state solutions allows a better understanding of the transition between the most emblematic motions of red blood cells, flipping and tank-treading.

scholarly journals Analysis of the Protein C System Under Flow and the Impact of Red Blood Cells

Blood ◽  
2014 ◽  
Vol 124 (21) ◽  
pp. 1480-1480
Author(s):  
Maria Cristina Bravo ◽  
Thomas Orfeo ◽  
Elizabeth Lavoie ◽  
Yves Dubief ◽  
Kenneth G. Mann
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Protein C ◽  
Depletion Zone ◽  
Shear Rates ◽  
Circulating Cells ◽  
The Impact ◽  
Low Shear

Abstract Introduction The rapid coagulation response to vascular injury is mediated by the formation of the extrinsictenase, intrinsictenase, and prothrombinase complexes. The prothrombotic response to injury is down-regulated by the presence of circulating active protease inhibitors as well as the protein C pathway. Protein C is activated by the thrombin-thrombomodulin complex; activated protein C (APC) then regulates thrombin generation by proteolytically inactivating factors Va and VIIIa, cofactors of the procoagulant prothrombinase and intrinsic tenasecomplexes, respectively. Previous reports have analyzed the biochemistry of the protein C system in closed systems. Our goal is to characterize the behavior of the protein C system under flow as well as the impact of circulating cells on the activation of protein C. Methods Experiments were conducted in phospholipid (3:1 ratio of synthetic phosphatidylcholine and phosphatidylserine) coated capillaries containing rabbit thrombomodulin (TM) that were preloaded with α-thrombin (αIIa) or recombinant meizothrombin (rMZ). Protein C (PC) activation was evaluated under flow at pH 7.4 and 37°C in either a buffered solution containing 2 mM CaCl2 and PC at its mean physiological concentration (65 nM) or in a mock blood mixture containing 60% of buffer containing 65 nM PC and 40% freshly prepared washed red blood cells; shear rates ranged from 100-1000 s-1. Capillary effluents were collected and then assayed for APC levels using a modified aPTT assay. To establish whether PC activation is under dilutional or diffusional control, the steady state concentrations of APC achieved at different shears were normalized to the residence time of one capillary volume specific for each shear rate. The efficiency of PC activation was also analyzed by normalizing the amount of APC generated to the amount of PC present in the mixture (1.3 pmol PC in buffer only vs. 0.78 pmol of PC in mock blood trials). Results At low shear rates (100 s-1 and 250 s-1) in the buffer only system the rMZ•TM complex generates 42-55% higher levels of APC than the αIIa•TM complex. Protein C activation by the αIIa-TM complex appears to be dilutionally controlled at shear rates ≥ 500 s-1, while diffusionally controlled at lower shear rates (≤ 250 s-1). The inclusion of red blood cells in the reaction system under flow resulted in a broader range of dilutional control (≥ 250 s-1) compared to the buffer only system (≥ 500 s-1). Normalization of the data to account for the differential amount of protein C present in a given volume indicate a two-fold greater efficiency of PC activation in the presence of red blood cells (14.7 ± 1.2 mol APC•mol-1 PC•min-1•cm-2) compared to buffer alone (6.7 ± 0.6 mol APC•mol-1 PC•min-1•cm-2). Conclusions In the presence of catalytically inert red blood cells the activation of protein C is regulated by diffusion only at the lowest shear rates tested (100 s-1). These data suggest that the dynamics and aggregation of red blood cell effects are shear dependent as red blood cells deform and migrate toward the center of the channel at increasing shear rates. We can hypothesize that at high shear rates (≥ 500 s-1), when the levels of APC generated in the red blood cell system and buffer only system are similar, the excluded volume created by the red blood cells agglomerated at the center of the capillary leaves a cell-free region adjacent to the wall which is large enough to accommodate the space needed for surface catalysis (depletion zone). Indeed the adjustment of PC concentration for excluded volume in red blood cell solutions yields the same concentration of APC generated as in the buffer solution. However, at low shear rates (100 s-1) the red blood cells do not create a distinct channel and the depletion zone extending from the capillary wall overlaps with red blood cells and maintains the diffusional control of the protein C system. These studies provide a foundation for studying the impact of circulating cells on the biochemistry of the coagulation cascade Disclosures No relevant conflicts of interest to declare.

Microfluidic electrical impedance assessment of red blood cell mediated microvascular occlusion

Lab on a Chip ◽  
2021 ◽  
Author(s):  
Yuncheng Man ◽  
Debnath Maji ◽  
Ran An ◽  
Sanjay Ahuja ◽  
Jane A Little ◽  
...  
Keyword(s):  
Sickle Cell Disease ◽  
Blood Cell ◽  
Red Blood Cells ◽  
Sickle Cell ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Electrical Impedance ◽  
Cell Disease ◽  
Blood Disorders

Alterations in the deformability of red blood cells (RBCs), occurring in hemolytic blood disorders such as sickle cell disease (SCD), contributes to vaso-occlusion and disease pathophysiology. However, there are few...

Permeation of the luminal capillary glycocalyx is determined by hyaluronan

1999 ◽  
Vol 277 (2) ◽  
pp. H508-H514 ◽  
Author(s):  
Charmaine B. S. Henry ◽  
Brian R. Duling
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Enzyme Treatment ◽  
Apical Surface ◽  
Bright Field ◽  
Endothelial Surface ◽  
The Difference

The endothelial cell glycocalyx influences blood flow and presents a selective barrier to movement of macromolecules from plasma to the endothelial surface. In the hamster cremaster microcirculation, FITC-labeled Dextran 70 and larger molecules are excluded from a region extending almost 0.5 μm from the endothelial surface into the lumen. Red blood cells under normal flow conditions are excluded from a region extending even farther into the lumen. Examination of cultured endothelial cells has shown that the glycocalyx contains hyaluronan, a glycosaminoglycan which is known to create matrices with molecular sieving properties. To test the hypothesis that hyaluronan might be involved in establishing the permeation properties of the apical surface glycocalyx in vivo, hamster microvessels in the cremaster muscle were visualized using video microscopy. After infusion of one of several FITC-dextrans (70, 145, 580, and 2,000 kDa) via a femoral cannula, microvessels were observed with bright-field and fluorescence microscopy to obtain estimates of the anatomic diameters and the widths of fluorescent dextran columns and of red blood cell columns (means ± SE). The widths of the red blood cell and dextran exclusion zones were calculated as one-half the difference between the bright-field anatomic diameter and the width of the red blood cell column or dextran column. After 1 h of treatment with active Streptomyces hyaluronidase, there was a significant increase in access of 70- and 145-kDa FITC-dextrans to the space bounded by the apical glycocalyx, but no increase in access of the red blood cells or in the anatomic diameter in capillaries, arterioles, and venules. Hyaluronidase had no effect on access of FITC-Dextrans 580 and 2,000. Infusion of a mixture of hyaluronan and chondroitin sulfate after enzyme treatment reconstituted the glycocalyx, although treatment with either molecule separately had no effect. These results suggest that cell surface hyaluronan plays a role in regulating or establishing permeation of the apical glycocalyx to macromolecules. This finding and our prior observations suggest that hyaluronan and other glycoconjugates are required for assembly of the matrix on the endothelial surface. We hypothesize that hyaluronidase creates a more open matrix, enabling smaller dextran molecules to penetrate deeper into the glycocalyx.

Susceptibility of density-fractionated erythrocytes to subhaemolytic mechanical shear stress

2018 ◽  
Vol 42 (3) ◽  
pp. 151-157 ◽  
Author(s):  
Antony P McNamee ◽  
Kieran Richardson ◽  
Jarod Horobin ◽  
Lennart Kuck ◽  
Michael J Simmonds
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Shear Stresses ◽  
Mechanical Stimuli ◽  
Cell Deformability ◽  
Red Blood Cell Deformability ◽  
Cell Age ◽  
Low Shear

Introduction: Accumulating evidence demonstrates that subhaemolytic mechanical stresses, typical of circulatory support, induce physical and biochemical changes to red blood cells. It remains unclear, however, whether cell age affects susceptibility to these mechanical forces. This study thus examined the sensitivity of density-fractionated red blood cells to sublethal mechanical stresses. Methods: Red blood cells were isolated and washed twice, with the least and most dense fractions being obtained following centrifugation (1500 g × 5 min). Red blood cell deformability was determined across an osmotic gradient and a range of shear stresses (0.3–50 Pa). Cell deformability was also quantified before and after 300 s exposure to shear stresses known to decrease (64 Pa) or increase (10 Pa) red blood cell deformability. The time course of accumulated sublethal damage that occurred during exposure to 64 Pa was also examined. Results: Dense red blood cells exhibited decreased capacity to deform when compared with less dense cells. Cellular response to mechanical stimuli was similar in trend for all red blood cells, independent of density; however, the magnitude of impairment in cell deformability was exacerbated in dense cells. Moreover, the rate of impairment in cellular deformability, induced by 64 Pa, was more rapid for dense cells. Relative improvement in red blood cell deformability, due to low-shear conditioning (10 Pa), was consistent for both cell populations. Conclusion: Red blood cell populations respond differently to mechanical stimuli: older (more dense) cells are highly susceptible to sublethal mechanical trauma, while cell age (density) does not appear to alter the magnitude of improved cell deformability following low-shear conditioning.

scholarly journals Small Red Blood Cell Fraction on the UF-1000i Urine Analyzer as a Screening Tool to Detect Dysmorphic Red Blood Cells for Diagnosing Glomerulonephritis

2019 ◽  
Vol 39 (3) ◽  
pp. 271
Author(s):  
Hyunjung Kim ◽  
Young Ok Kim ◽  
Yonggoo Kim ◽  
Jin-Soon Suh ◽  
Eun-Jung Cho ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Screening Tool ◽  
Cell Fraction

scholarly journals Patient-Specific Adhesion of Sickle Red Blood Cells in Shear-Gradient Microscale Flow

Blood ◽  
2017 ◽  
Vol 130 (Suppl_1) ◽  
pp. 964-964
Author(s):  
Erdem Kucukal ◽  
Jane A. Little ◽  
Umut A. Gurkan
Keyword(s):  
Shear Rate ◽  
Blood Cell ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Flow Direction ◽  
Patient Specific ◽  
Shear Rates ◽  
Microscale Flow ◽  
Shear Gradient ◽  
Equity Ownership

Abstract The pathophysiology of sickle cell disease (SCD) involves altered biophysical properties of red blood cells (RBCs) and increased cellular adhesion, which can synergistically trigger recurrent and painful vaso-occlusive events in the microcirculatory network. RBC adhesion to the endothelial wall is heterogeneous and may initiate such occlusions by disrupting the local flow thus activating platelets and promoting subsequent cell-cell interactions. Moreover, these episodic events take place within a wide range of dynamically changing shear rates at the microscale. In order to better understand the role of shear rate on this process, we quantified shear-dependent RBC adhesion to endothelial proteins fibronectin (FN) and laminin (LN) utilizing a microfluidic system that can simulate physiologically relevant shear gradients of microcirculatory blood flow at a single flow rate. Whole blood samples were collected from 20 patients (10 males and 10 females) with homozygous SCD (HbSS). Samples were perfused through FN and LN immobilized shear-gradient microchannels (Fig. 1A) in which the shear rate continuously changes along flow direction. Computational simulations characterized the flow dynamics near the adherent RBCs (Fig. 1B). Based on the numerical results, a rectangular "field of interest (FOI)", along which the shear rate dropped approximately three-fold, was chosen for quantification of shear-dependent RBC adhesion. We observed changes in RBC adhesion to LN and FN in the shear gradient flow. Figure 1C and 1D show typical adhesion curves of surface adherent RBCs for an individual SCD sample within the FOI. To assess patient specific shear-dependent adhesion, we defined a parameter, "shear dependent adhesion rate (SDAR)", which is the slope of the adhesion curves based on normalized RBC adhesion numbers. A higher SDAR value was indicative of marked numbers of adherent RBCs that detach at higher shear rates whereas the effect of shear rate on RBC detachment was less for a lower SDAR. We observed an inverse relationship between SDAR and number of persistently adherent RBCs at high shear rates. Shear-dependent RBC adhesion to LN was heterogeneous among SCD patients. Patients with higher WBC counts constituted the low SDAR population with a threshold SDAR value of 60 (Fig. 1E, p=0.005, ANOVA). WBCs from patients with higher SDARs (and fewer persistently adhered cells) were all within the normal range. Patients in the low SDAR group also had significantly elevated absolute neutrophil counts (Fig. 1F, p=0.006, ANOVA), and ferritin levels (Fig. 1G, p=0.007, ANOVA). The mean ferritin level of those with low SDAR was nearly ten times greater than normal (mean= [3272.3 ± 791.9] μg/L vs. [784.5±219.6] μg/L). No white blood cell (WBC) adhesion was observed in the experiments. Here, we report a novel shear dependent adhesion ratio of sickle RBCs utilizing LN and FN functionalized microchannels. The approach presented here enabled us to create a shear gradient throughout the channel which may simulate the physiological flow conditions in the post-capillary venules. We further analyzed shear-dependent RBC adhesion in a patient specific manner and identified patient groups with low and high SDAR. The findings also suggested a link between lower shear dependent sickle RBC adhesion to LN and patient clinical phenotypes including inflammation and iron overload. Acknowledgments: This work was supported by grant #2013126 from the Doris Duke Charitable Foundation, National Heart Lung and Blood Institute R01HL133574, and National Science Foundation CAREER Award 1552782. Figure 1: Shear-dependent sickle RBC adhesion in microscale flow. (A) Macroscopic image of the shear-gradient microchannel with the arrow indicating flow direction. (B) Velocity and shear rate contours on a 2D plane above the bottom surface. The dashed rectangular area indicates the field of interest (FOI) where the experimental data were obtained. (C, D) Typical distribution of adherent deformable and non-deformable RBCs in LN and FN functionalized microchannels with the shear gradient. Dashed lines represent the adhesion curves and the corresponding equations were used to quantify shear dependent adhesion data. Shear-dependent RBC adhesion was lower (nSDAR<60) in patients with elevated white blood cell counts (E), absolute neutrophil counts (F), and serum ferritin levels (G). The dashed rectangles indicate the normal clinical values. Figure 1 Figure 1. Disclosures Little: Hemex Health: Equity Ownership. Gurkan: Hemex Health: Employment, Equity Ownership.

scholarly journals PO-283 Correlation Analysis between Blood Cell Viability, Five Elements and Competition Performance of Elite Men’s Rowers

2018 ◽  
Vol 1 (5) ◽  
Author(s):  
Junbei Bai
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Aerobic Capacity ◽  
Red Blood Cell ◽  
Iron Content ◽  
Blood Cells ◽  
White Blood Cells ◽  
Cell Activity ◽  
Ordinary People ◽  
Five Elements

Objective To observe the national elite male rowers blood, red blood cell activity and serum copper, zinc, calcium, magnesium and iron content of the five elements, and compared with the ordinary people. Aimed to investigate the between athletes, athletes and ordinary differences between the two sets of indicators and to explore the impact of element contents in red blood cell activity and five factors. Trying to bring two sets of indicators and specific combining ability, used in training on the monitoring function, and for the future to provide some references for further study. Methods It was included 22 athletes and 22 ordinary men, as the research object, in the collection of blood, measuring red blood cell activity in the blood content of the five elements, simultaneous measurement of physical indicators , will be doing all the data at the differences between the two groups compared to the group to do correlation analysis. The recent record of 2000m, 6000m rowing Dynamometer test results, and red blood cell activity associated with the five elements of content analysis. Results 1. Athletes indicators related to aerobic exercise were significantly higher than ordinary people. The white blood cells of athletes group were average.It shows that athletes have high aerobic capacity, while white blood cells are more stable than normal people. The members of the national rowing men's iron, magnesium content was significantly higher than ordinary group, the iron content is higher than the normal reference value; blood calcium levels were significantly lower than ordinary people, and lower than the normal reference value. The total number of red blood cells and the number of living cells was very significant positive correlation in two groups subjects; Red blood cell activity and red blood cell diameter is proportional, and red blood cell roundness in inverse proportion to the relationship; from this experiment a special ability to see red blood cell activity and there is no correlation. In both groups, hemoglobin was positively correlated with iron content, while iron was positively correlated with copper content. Conclusions 1. Increasing the number and volume of red blood cells can effectively increase the activity of red blood cells; red blood cell activity has no correlation with specific ability, and can not be used as an indicator to determine specific ability. The content of iron and magnesium in rowers is higher than that in ordinary people, which indicates that the adjustment of aerobic capacity and nerve control is very effective. The lower calcium content indicates that the injury caused by calcium loss should be prevented and the urgency of calcium supplementation should be emphasized. In training, we should pay attention to increasing hemoglobin content and aerobic capacity by supplementing iron. We can further consider the effect of supplementing copper to promote iron supplementation.

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