scholarly journals An Investigation on the Aggregation and Rheodynamics of Human Red Blood Cells Using High Performance Computations

Scientifica ◽  
2017 ◽  
Vol 2017 ◽  
pp. 1-10 ◽  
Author(s):  
Dong Xu ◽  
Chunning Ji ◽  
Eldad Avital ◽  
Efstathios Kaliviotis ◽  
Ante Munjiza ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Blood Cells ◽  
High Performance ◽  
Large Scale ◽  
Experimental Studies ◽  
Computational Technique ◽  
Human Red Blood Cells ◽  
Lower Shear ◽  
High Shear Rates ◽  
Lower Shear Rate

Studies on the haemodynamics of human circulation are clinically and scientifically important. In order to investigate the effect of deformation and aggregation of red blood cells (RBCs) in blood flow, a computational technique has been developed by coupling the interaction between the fluid and the deformable RBCs. Parallelization was carried out for the coupled code and a high speedup was achieved based on a spatial decomposition. In order to verify the code’s capability of simulating RBC deformation and transport, simulations were carried out for a spherical capsule in a microchannel and multiple RBC transport in a Poiseuille flow. RBC transport in a confined tube was also carried out to simulate the peristaltic effects of microvessels. Relatively large-scale simulations were carried out of the motion of 49,512 RBCs in shear flows, which yielded a hematocrit of 45%. The large-scale feature of the simulation has enabled a macroscale verification and investigation of the overall characteristics of RBC aggregations to be carried out. The results are in excellent agreement with experimental studies and, more specifically, both the experimental and simulation results show uniform RBC distributions under high shear rates (60–100/s) whereas large aggregations were observed under a lower shear rate of 10/s.

Ex vivo large-scale generation of human red blood cells from cord blood CD34+ cells by co-culturing with macrophages

2008 ◽  
Vol 87 (4) ◽  
pp. 339-350 ◽  
Author(s):  
Akihito Fujimi ◽  
Takuya Matsunaga ◽  
Masayoshi Kobune ◽  
Yutaka Kawano ◽  
Taiko Nagaya ◽  
...  
Keyword(s):  
Cord Blood ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Large Scale ◽  
Ex Vivo ◽  
Human Red Blood Cells ◽  
Cd34 Cells ◽  
Cord Blood Cd34

scholarly journals Elevated intracellular Ca2+ reveals a functional membrane nucleotide pool in intact human red blood cells

2011 ◽  
Vol 138 (4) ◽  
pp. 381-391 ◽  
Author(s):  
Teresa Tiffert ◽  
Virgilio L. Lew
Keyword(s):  
Atpase Activity ◽  
Red Blood Cells ◽  
Blood Cells ◽  
High Performance ◽  
Enzyme System ◽  
Membrane Surface ◽  
Nucleotide Metabolism ◽  
Human Red Blood Cells ◽  
Cell Extracts ◽  
Functional Membrane

Elevated intracellular calcium generates rapid, profound, and irreversible changes in the nucleotide metabolism of human red blood cells (RBCs), triggered by the adenosine triphosphatase (ATPase) activity of the powerful plasma membrane calcium pump (PMCA). In the absence of glycolytic substrates, Ca2+-induced nucleotide changes are thought to be determined by the interaction between PMCA ATPase, adenylate kinase, and AMP-deaminase enzymes, but the extent to which this three-enzyme system can account for the Ca2+-induced effects has not been investigated in detail before. Such a study requires the formulation of a model incorporating the known kinetics of the three-enzyme system and a direct comparison between its predictions and precise measurements of the Ca2+-induced nucleotide changes, a precision not available from earlier studies. Using state-of-the-art high-performance liquid chromatography, we measured the changes in the RBC contents of ATP, ADP, AMP, and IMP during the first 35 min after ionophore-induced pump-saturating Ca2+ loads in the absence of glycolytic substrates. Comparison between measured and model-predicted changes revealed that for good fits it was necessary to assume mean ATPase Vmax values much higher than those ever measured by PMCA-mediated Ca2+ extrusion. These results suggest that the local nucleotide concentrations generated by ATPase activity at the inner membrane surface differed substantially from those measured in bulk cell extracts, supporting previous evidence for the existence of a submembrane microdomain with a distinct nucleotide metabolism.

scholarly journals Large Scale Purification and Characterisation of Porcine Factor VIII for Clinical Use

1977 ◽  
Author(s):  
Helen Lee ◽  
S.I. Chavin ◽  
Rita E. Blewitt ◽  
D. E. G. Austen
Keyword(s):  
Factor Viii ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Large Scale ◽  
Gel Filtration ◽  
Cross Reactivity ◽  
Value Analysis ◽  
Human Red Blood Cells ◽  
Human Factor Viii ◽  
Haemagglutinating Activity

Animal factor VIII can be useful in the treatment of haemophilic patients with high titres of human factor VIII antibody when the antibody shows low cross-reactivity towards animal factor VIII. The use of currently available preparations of animal factor VIII is associated with rigor, anaphylaxis and transient thrombocytopaenia, which limit their therapeutic value. Analysis of some of these preparations has shown low IgM and high IgG concentrations and haemagglutinating activity against a panel of human red blood cells. It has been demonstrated that purified porcine IgG and IgN agglutinate human red blood cells, while IgM is also complement fixing.A large scale purification procedure has been developed for producing porcine factor VIII from platelet-poor plasma. It involves various precipitations followed by gel filtration through Sepharose 4B-CL on a KS sectional column. The pooled void-volume fractions are concentrated by using the Pellicon cassette system, giving a final yield of approximately 20% of the starting plasma. Porcine factor VIII prepared by this method is stable. Its greatly reduced fibrinogen content facilitates final filtration and prevents the accumulation of fibrinogen in patients treated with high doses. Non-specific haemagglutinins which may have contributed to some of the post-transfusion reactions have been removed. Specific activities of at least 50 U/mg of protein are obtained, and doses greater than 10,000 units can be given in 10 ml.

scholarly journals Large‐Scale Ex Vivo Generation of Human Red Blood Cells from Cord Blood CD34 + Cells

2017 ◽  
Vol 6 (8) ◽  
pp. 1698-1709 ◽  
Author(s):  
Yu Zhang ◽  
Chen Wang ◽  
Lan Wang ◽  
Bin Shen ◽  
Xin Guan ◽  
...  
Keyword(s):  
Cord Blood ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Large Scale ◽  
Ex Vivo ◽  
Human Red Blood Cells ◽  
Cd34 Cells ◽  
Cord Blood Cd34
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