Red blood cells are known to form aggregates in the form of rouleaux. Meiselman red blood cells in humansand most other mammalshave a tendency to form aggregates with a characteristic facetoface morphology, similar to a stack of coins. The hydrodynamic radius rh of individual samples of dextran, polyvinylpyrrolidone, and polyoxyethylene over a range of molecular weights 15002,000,000 were calculated from their intrinsic viscosities using the einstein viscosity relation and directly measured by quasielastic light scattering. Application of cationic conjugated polymerouter membrane vesicle complexes in inhibiting red blood cell aggregation ping hea endong zhanga,b ruilian qia fengting lva libing liua,b shu wanga,b abeijing national laboratory for molecular sciences, institute of chemistry, chinese academy of. Investigation of blood flow analysis and red blood cell. The natural tendency of the human red blood cells rbc 1. It thus seems likely that these factors could play a role in sickle cell disease.
The book covers basic, clinical, and physiological aspects of this important biophysical phenomenon and integrates these areas with concepts in bioengineering. Kolios a adepartment of physics, ryers on university, toronto, canada. Red blood cells rbcs suspended in plasma form multicellular aggregates under low flow conditions, increasing apparent blood viscosity at low shear rates. Red blood cells harpers illustrated biochemistry, 30e. Erythrocyte aggregation an overview sciencedirect topics. Oguz baskurt is a professor of physiology at koc university school of medicine, istanbul turkey. The hardcover of the red blood cell aggregation by oguz baskurt, bjorn neu, herbert j. Explain why red blood cells are reliant on glucose for energy. The effect of red blood cell aggregation and how it can be. To evaluate differences in erythrocyte deformability in mammals, three species were investigated, whose erythrocytes have a different aggregation property.
Pathological erythrocyte aggregation can stimulate abnormal processes by itself and intensify some abnormalities of blood coagulation. Whole blood viscosity and red blood cell aggregation is in. Unlike water, which exhibits much more newtonian properties, blood moves sluggishly at low speeds and is more liquid at fast speeds. Recent evidence suggests that red blood cell aggregation and the ratio of hematocrit to blood viscosity hvr, an index of the oxygen transport potential of blood, might considerably modulate blood flow dynamics in the microcirculation. Depletionmediated red blood cell aggregation in polymer. Red blood cell aggregation varies widely between species 242, suggesting that it is not essential for the inflammatory process. Rouleaux are stacks of erythrocytes which form because of the unique discoid shape of the cells in vertebrate body. Erythrocytes aggregate in a special way, forming rouleaux. More important than rbc adhesion to endothelial cells as a. The deformability of rbcs allows them to flow in microvessels while transporting oxygen and carbon dioxide. Effect of red blood cell aggregation on tube flow ch. The energy of macromolecular binding to the cell membrane provides the primary aggregating energy. Describe the roles of erythropoietin, thrombopoietin, and other cytokines in the production of red blood cells and platelets.
The model combines electrostatic repulsion due to rbc. The aggregation of red blood cells by macromolecular bridging involves energy balance at the cell surface. Application of cationic conjugated polymer outer membrane. The buckling instability of aggregating red blood cells. Detection and characterization of red blood cell rbc. Red blood cells rbcs have generally been viewed as innocent bystanders in. Physical charaterization of red blood cell aggregation. The hydrodynamic radii of macromolecules and their effect. Red blood cell aggregation crc press book red blood cells in humansand most other mammalshave a tendency to form aggregates with a characteristic facetoface morphology, similar to a stack of coins. Polymerinduced red blood cell rbc aggregation is of current basic science and clinical interest, and a depletionmediated model for this phenomenon has been suggested. Red blood cells have unique mechanical behavior, which can be discussed under the terms erythrocyte deformability and erythrocyte aggregation. Red blood cells, also called erythrocytes, are the most abundant cell type in the blood. Blood viscosity is determined by plasma viscosity, hematocrit volume fraction of red blood cell, which constitute 99.
Known as rouleaux, these aggregates are a normally occurring phenomenon and have a major impact on blood rheology. His research is focused on the role of hemorheological factors in in vivo flow dynamics of blood, and he has conducted research on the mechanisms of red blood cell aggregation and hemorheological instrumentation. Red blood cells because no rbc aggregation occurs in phosphate buffered saline pbs 21, but blood plasma proteins strongly affect rbc aggregation, the experiments were conducted in. Fibrinogen increases blood viscosity and promotes red blood cell aggregation, which may help leukocytes to marginate and start rolling 241. Rheology of red blood cell aggregation by computer. Describe the enzyme systems that protect heme iron from oxidation and reduce methemoglobin. Erythrocyte aggregation is the reversible clumping of red blood cells rbcs under low shear forces or at stasis. Highly sensitive detection of red blood cell aggregation.
In vivo hemodynamics and red blood cell aggregation ch. Enhanced rbc aggregation is well known to increase blood viscosity measured in rotational viscometers. This aggregation process is believed to be reversible, but there is still no full understanding on the binding mechanism. Red blood cell aggregation, aggregate strength and oxygen. Polymerinduced red blood cell rbc aggregation is of current basic science and clinical interest, and a depletionmediated model for this phenomenon has. Once it gets moving and builds momentum, it flows fast. The primary function of red blood cells is to transport oxygen to body cells and deliver carbon dioxide to the lungs.
Red blood cells in humansand most other mammalshave a tendency to form aggregates with a characteristic facetoface morphology, simi. Other major blood components include plasma, white blood cells, and platelets. Influence of red blood cell aggregation on perfusion of an. An approach is thus described for calculating the interaction energy between rbc in polymer solutions.
Changes in the microstruture of blood caused by the red blood cell aggregation phenomenon affect the mechanical properties of the fluid. The effects of nonionic polymers on human red blood cell rbc aggregation were investigated. Erythrocyte aggregation is the reversible clumping of red blood cells rbcs under low shear. Journal of medical and biological engineering, 345. Detection and characterization of red blood cell rbc aggregation with photoacoustics eno hysi a, ratan k. Red blood cell deformability and aggregation behaviour in. Plasma proteins such as fibrinogen induce the aggregation of red blood cells rbc into rouleaux, which are responsible for the pronounced shear thinning behavior of blood. The influence of red blood cell rbc aggregation on blood flow in vivo has been under debate since early 1900s, yet a full understanding has still has not been reached. Effect of red blood cell aggregation on in vitro blood rheology ch. Red blood cell aggregation by oguz baskurt, bjorn neu. The aggregation of human red blood cells rbc is a dominant factor of the in vitro rheological properties of blood. Mutual interaction of red blood cells influenced by. Red blood cells and relation to thrombosis intechopen.
In general the role of the cellular factors for the aggregation was masked increasing the aggregating force between rbc. The aggregation of red blood cells rbc induced by the interactions between rbcs is a dominant factor of the in vitro rheological properties of blood, and existing models of blood. Red blood cell rbc aggregates can influence microcirculation 1, especially in pathological conditions 2. Depletionmediated red blood cell aggregation in polymer solutions. The test is usually part of a complete blood count cbc test that measures all the components in. We compared red blood cell aggregation characteristics, blood viscosity and hvr at different shear rates between sickle cell anemia and sickle cell hemoglobin c. Impact of red blood cell transfusion on platelet aggregation and inflammatory response in anemic coronary and noncoronary patients the transfusion2 study impact of transfusion of red blood cell on platelet activation and aggregation studied with flow cytometry use and light transmission aggregometry. Rheology of red blood cell aggregation by computer simulation. Activated platelets can directly interact with erythrocytes 3 or affect erythrocytes with. Red blood cell aggregation oguz k baskurt, bjorn neu. It has previously been unclear, however, if rbc aggregation affects microvascular perfusion.