scholarly journals Erythrocyte morphological symmetry analysis to detect sublethal trauma in shear flow

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Antony P. McNamee ◽  
Michael J. Simmonds ◽  
Masataka Inoue ◽  
Jarod T. Horobin ◽  
Masaya Hakozaki ◽  
...  
Keyword(s):  
Shear Flow ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Shape Change ◽  
Bimodal Distribution ◽  
Artificial Organs ◽  
Blood Damage ◽  
Cell Radius ◽  
Highly Sensitive ◽  
Elongation Index

AbstractThe viscoelastic properties of red blood cells (RBC) facilitate flexible shape change in response to extrinsic forces. Their viscoelasticity is intrinsically linked to physical properties of the cytosol, cytoskeleton, and membrane—all of which are highly sensitive to supraphysiological shear exposure. Given the need to minimise blood trauma within artificial organs, we observed RBC in supraphysiological shear through direct visualisation to gain understanding of processes leading to blood damage. Using a custom-built counter-rotating shear generator fit to a microscope, healthy red blood cells (RBC) were directly visualised during exposure to different levels of shear (10–60 Pa). To investigate RBC morphology in shear flow, we developed an image analysis method to quantify (a)symmetry of deforming ellipsoidal cells—following RBC identification and centroid detection, cell radius was determined for each angle around the circumference of the cell, and the resultant bimodal distribution (and thus RBC) was symmetrically compared. While traditional indices of RBC deformability (elongation index) remained unaltered in all shear conditions, following ~100 s of exposure to 60 Pa, the frequency of asymmetrical ellipses and RBC fragments/extracellular vesicles significantly increased. These findings indicate RBC structure is sensitive to shear history, where asymmetrical morphology may indicate sublethal blood damage in real-time shear flow.

scholarly journals Morphological Sequence of Spontaneously Forming Parietal Thrombi as Observed by Scanning Electron Microscopy (SEM)

1977 ◽  
Author(s):  
H.J. Genz ◽  
H. Metzger ◽  
P.F. Tauber ◽  
H. Ludwig
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Thrombus Formation ◽  
Shape Change ◽  
Inhibitory Effect ◽  
Endothelial Surface ◽  
Morphological Criteria ◽  
Fibrin Network ◽  
Tissue Specimens ◽  
Cellular Control

Spontaneous thrombus formation in human mesenteric veins was studied with the SEM. Tissue specimens were prepared according to Ludwig et al., Acta anatomica, 96, 469-477(1976). Platelet shape change, thrombus formation and organization and the morphological interactions between the various corpuscular elements of blood are demonstrated. The following morphological criteria of these processes are observed :(1) Platelets adhere to distinctly altered endothelial surfaces and exhibit pores in the membrane and pseudopodia. (2) Platelet aggregation and thrombus formation occur next to each other along the endothelial surface. Thrombi contain red blood cells and also a larger number of lymphocytes, but only a few platelets are hold prisoners within the fibrin network. Once caught in the mesh, such platelets do not show shape change compared to those being in contact with the endothelium. (3) Red blood cells between the thrombus fibers undergo form changes. Lymphocytes remain unaltered, but vice versa destroy adjacent fibrin fibers leading to partial loss of thrombus stability. This destruction occurs to a much lesser degree when platelets are near to the lymphocytes. It seems conceivable that platelets exert an inhibitory effect towards lymphocyte-induced fibrin proteolysis. The data suggest that both platelets and lymphocytes possibly represent a cellular control system that is responsible for the physiological clearance of spontaneously formed thrombi.

scholarly journals Blood Crystal: Emergent Order of Red Blood Cells Under Wall-Confined Shear Flow

2018 ◽  
Vol 120 (26) ◽  
Author(s):  
Zaiyi Shen ◽  
Thomas M. Fischer ◽  
Alexander Farutin ◽  
Petia M. Vlahovska ◽  
Jens Harting ◽  
...  
Keyword(s):  
Shear Flow ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Emergent Order

Eulerian-Eulerian Multiphase Modeling of Blood Cells Segregation in Flow Through Microtubes

2017 ◽  
Author(s):  
Yertay Mendygarin ◽  
Luis R. Rojas-Solórzano ◽  
Nurassyl Kussaiyn ◽  
Rakhim Supiyev ◽  
Mansur Zhussupbekov
Keyword(s):  
Shear Stress ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Heart Diseases ◽  
Accurate Determination ◽  
Shear Stresses ◽  
High Shear ◽  
Blood Damage ◽  
Solid Phases

Cardiovascular Diseases, the common name for various Heart Diseases, are responsible for nearly 17.3 million deaths annually and remain the leading global cause of death in the world. It is estimated that this number will grow to more than 23.6 million by 2030, with almost 80% of all cases taking place in low and middle income countries. Surgical treatment of these diseases involves the use of blood-wetted devices, whose relatively recent development has given rise to numerous possibilities for design improvements. However, blood can be damaged when flowing through these devices due to the lack of biocompatibility of surrounding walls, thermal and osmotic effects and most prominently, due to the excessive exposure of blood cells to shear stress for prolonged periods of time. This extended exposure may lead to a rupture of membrane of red blood cells, resulting in a release of hemoglobin into the blood plasma, in a process called hemolysis. Moreover, exposure of platelets to high shear stresses can increase the likelihood of thrombosis. Therefore, regions of high shear stress and residence time of blood cells must be considered thoroughly during the design of blood-contacting devices. Though laboratory tests are vital for design improvements, in-vitro experiments have proven to be costly, time-intensive and ethically controversial. On the other hand, simulating blood behavior using Computational Fluid Dynamics (CFD) is considered to be an inexpensive and promising tool to help predicting blood damage in complex flows. Nevertheless, current state-of-the-art CFD models of blood flow to predict hemolysis are still far from being fully reliable and accurate for design purposes. Previous work have demonstrated that prediction of hemolysis can be dramatically improved when using a multiphase (i.e., phases are plasma, red blood cells and platelets) model of the blood instead of assuming the blood as a homogeneous mixture. Nonetheless, the accurate determination of how the cells segregate becomes the critical issue in reaching a truthful prediction of blood damage. Therefore, the attempt of this study is to develop and validate a numerical model based on Granular Kinetic Theory (GKT) for solid phases (i.e., cells treated as particles) that provides an improved prediction of blood cells segregation within the flow in a microtube. Simulations were based on finite volume method using Eulerian-Eulerian modeling for treatment of three-phase (liquid-red blood cells and platelets) flow including the GKT to deal with viscous properties of the solid phases. GKT proved to be a good model to predict particle concentration and pressure drop by taking into account the contribution of collisional, kinetic and frictional effects in the stress tensor of the segregated solid phases. Preliminary results show that the improved segregated model leads to a better prediction of spatial distribution of blood cells. Simulations were performed using ANSYS FLUENT platform.

Computer Modeling of Fluid-Stress-Induced Blood Damage in a Mechanical Ventricular Assist Device

2009 ◽  
Author(s):  
Alexandrina Untaroiu ◽  
Houston G. Wood ◽  
Paul E. Allaire
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Damage Index ◽  
Computational Domain ◽  
Ventricular Assist ◽  
Blood Damage ◽  
History Of ◽  
Number Of Particles

Congestive heart failure results the heart is unable to pump the required amount of blood to maintain the systemic circulation. World-wide, millions of patients are diagnosed with congestive heart failure every year, many of which ultimately become candidates for heart transplants. The limited number of available donor hearts, however, has resulted in a tremendous demand for alternative, supplemental circulatory support in the form of artificial heart pumps to serve as a “Bridge-to-Transplant”. The prospect of artificial heart pumps used for long-term support of congestive heart failure patients is directly dependent upon excellent blood compatibility. High fluid stress levels may arise due to high rotational speeds and narrow clearances between the stationary and rotating parts of the pump. Thus, fluid stress may result in damage to red blood cells and activation of platelets, contributing to thrombus formation. Therefore, it is essential to evaluate levels of blood trauma for successful design of a mechanical Ventricular Assist Device. Estimating the fluid stress levels that occur in a blood pump during the design phase also provides valuable information for optimization considerations. This study describes the CFD evaluation of blood damage in a magnetically suspended axial pump that occurs due to fluid stress. Using CFD, a blood damage index, reflecting the percentage of damaged red blood cells, was numerically estimated based on the scalar fluid stress values and exposure time to such stresses. A number of particles, with no mass and reactive properties, was injected at the inflow of the computational domain and traveled along their corresponding streamlines. A Lagrangian particle tracking technique was employed to obtain the stress history of each particle along its streamline, making it possible to consider the damage history of each particle. Maximum scalar stresses of approximately 430 Pa were estimated to occur along the tip surface of the impeller blades, more precisely at the leading edge of the impeller blades. The maximum time required for the vast majority of particles to pass through the pump was approximately 0.085sec. A small number of particles (approximately 5%), which traveled through the narrow gap between the stationary and rotating part of the pump, exited the computational domain in approximately 0.2 sec. The mean value of blood damage index was found to be 0.15% with a maximum value of approximately 0.47%. These values are one order of magnitude lower than the approximated damage indices published in the literature for other Ventricular Assist Devices. The low blood damage index indicates that red blood cells traveling along the streamlines considered are not likely to be ruptured, mainly due to the very small time of exposure to high stress.

The influence of chlorpromazine on the potential-induced shape change of human erythrocyte

1991 ◽  
Vol 11 (4) ◽  
pp. 213-221 ◽  
Author(s):  
J. Hartmann ◽  
R. Glaser
Keyword(s):  
Red Blood Cells ◽  
Human Erythrocyte ◽  
Blood Cells ◽  
Characteristic Time ◽  
Time Course ◽  
Transmembrane Potential ◽  
Shape Change ◽  
Human Erythrocytes

The effect of chlorpromazine (CPZ) on the shape of human erythrocytes with different values of transmembrane potential (TMP) was investigated. The shape of red blood cells with negative values of the TMP remained unchanged after the formation of stomatocytes by chlorpromazine, while cells with positive TMP showed a characteristic time course of shape change during the incubation with CPZ. Experiments with vanadate show that this might be due to a difference in the activity of the phospholipid-translocase at different values of TMP.

Threshold shear stress for the transition between tumbling and tank-treading of red blood cells in shear flow: dependence on the viscosity of the suspending medium

2013 ◽  
Vol 736 ◽  
pp. 351-365 ◽  
Author(s):  
Thomas M. Fischer ◽  
Rafal Korzeniewski
Keyword(s):  
Shear Flow ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Theoretical Models ◽  
Red Cells ◽  
Theoretical Modelling ◽  
Glass Capillary ◽  
Basic Model ◽  
A Value ◽  
The Subject

AbstractRed blood cells are the subject of diverse studies. One branch is the observation and theoretical modelling of their behaviour in a shear flow. This work deals with the flow of single red cells suspended in solutions much more viscous than blood plasma. Below a critical shear rate (${\dot {\gamma } }_{t} $) the red cells rotate with little change of their resting shape. Above that value they become elongated and aligned in the shear field. We measured${\dot {\gamma } }_{t} $at viscosities (${\eta }_{0} $) ranging from 10.7 to 104 mPa s via observation along the vorticity of a Poiseuille flow in a glass capillary;${\eta }_{0} {\dot {\gamma } }_{t} $decreased steeply with increasing${\eta }_{0} $up to a value of 25 mPa s and remained constant for higher values. Present theoretical models are not in keeping with the measured data. Modifications of basic model assumptions are suggested.

Role of membrane viscosity in the orientation and deformation of a spherical capsule suspended in shear flow

1985 ◽  
Vol 160 ◽  
pp. 119-135 ◽  
Author(s):  
D. Barthes-Biesel ◽  
H. Sgaier
Keyword(s):  
Relaxation Time ◽  
Shear Flow ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Liquid Droplets ◽  
Regular Perturbation ◽  
Shear Rates ◽  
Freely Suspended ◽  
Spherical Capsule

Red blood cells or artificial vesicles may be conveniently represented by capsules, i.e. liquid droplets surrounded by deformable membranes. The aim of this paper is to assess the importance of viscoelastic properties of the membrane on the motion of a capsule freely suspended in a viscous liquid subjected to shear flow. A regular perturbation solution of the general problem is obtained when the particle is initially spherical and undergoing small deformations. With a purely viscous membrane (infinite relaxation time) the capsule deforms into an ellipsoid and has a continuous flipping motion. When the membrane relaxation time is of the same order as the shear time, the particle reaches a steady ellipsoidal shape which is oriented with respect to streamlines at an angle that varies between 45° and 0°, and decreases with increasing shear rates. Furthermore it is predicted that the deformation reaches a maximum value, which is consistent with experimental observations of red blood cells.

scholarly journals Heterogeneous timing of asexual cycles in Plasmodium falciparum quantified by extended time-lapse microscopy

2018 ◽  
Author(s):  
Heungwon Park ◽  
Shuqiang Huang ◽  
Katelyn A. Walzer ◽  
Lingchong You ◽  
Jen-Tsan Ashley Chi ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
Single Cells ◽  
Time Lapse ◽  
Bimodal Distribution ◽  
Host Cells ◽  
Cycle Period ◽  
Human Red Blood Cells ◽  
Asexual Cycle

ABSTRACTMalarial fever arises from the synchronous bursting of human red blood cells by the Plasmodium parasite. The released parasites re-infect neighboring red blood cells and undergo another asexual cycle of differentiation and proliferation for 48 hours, before again bursting synchronously. The synchrony of bursting is lost during in vitro culturing of the parasite outside the human body, presumably because the asexual cycle is no longer entrained by host-specific circadian cues. Therefore, most in vitro malaria studies have relied on the artificial synchronization of the parasite population. However, much remains unknown about the degree of timing heterogeneity of asexual cycles and how artificial synchronization may affect this timing. Here, we combined time-lapse fluorescence microscopy and long-term culturing to follow single cells and directly measure the heterogeneous timing of in vitro asexual cycles. We first demonstrate that unsynchronized laboratory cultures are not fully asynchronous and the parasites exhibit a bimodal distribution in their first burst times. We then show that synchronized and unsynchronized cultures had similar asexual cycle periods, which indicates that artificial synchronization does not fundamentally perturb asexual cycle dynamics. Last, we demonstrate that sibling parasites descended from the same schizont exhibited significant variation in asexual cycle period, although smaller than the variation between non-siblings. The additional variance between non-siblings likely arises from the variable environments and/or developmental programs experienced in different host cells.

Sign in / Sign up

Export Citation Format

Share Document