Microrheology and light transmission of blood

Schmid‐Schönbein, H.; Volger, E; Hj, Klose

doi:10.1007/bf00586913

Cited by 66 publications

(12 citation statements)

References 15 publications

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“…1 s -1 , respectively), plasma was measured at high shear rate (94 s -1 ). Aggregation of RBCs was determined with a modified Myrenne-Aggregometer (Model MA-1, Myrenne GmbH, Roentgen, Germany) which enables direct digitized data sampling (Schmid-Schönbein et al, 1987;Bauersachs et al, 1989). Measurements of RBC aggregation in this instrument are based on the increased light transmission through an RBC suspension as a result of gaps of cell-free medium which occur when aggregates are formed.…”

Section: Methodsmentioning

confidence: 99%

The anti‐neoplastic drug 5‐fluorouracil produces echinocytosis and affects blood rheology

Baerlocher¹,

Beer²,

Owen³

et al. 1997

Br J Haematol

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Summary. The anti-neoplastic agent 5-fluorouracil (5-FU) in high therapeutic doses can induce angina pectoris and myocardial infarction. The pathophysiological mechanism of this side-effect has not yet been elucidated. We analysed the influence of 5-FU on blood rheology in vitro. Whole blood, blood cell suspensions and plasma were incubated with increasing concentrations of 5-FU (final concentrations 0, 0 . 08, 0 . 4, 2, 10 and 25 mg/ml 5-FU) at 37ЊC. Erythrocyte morphology was analysed after fixation with glutaraldehyde. Viscosity was measured at high and low shear rates (94 and 0 . 1 s -1 ). Erythrocyte aggregation and the cell transit times of erythrocytes through 5 mm pores and polymorphonuclear leucocytes through 8 mm pores were determined. 5-FU induced a dose-dependent formation of echinocytes within minutes and was reversible upon removal of 5-FU, which reflected a preferential intercalation of the drug in the outer hemileaflet of the cell membrane. High shear blood viscosity was increased at the highest 5-FU concentration (148 Ϯ 12%), and at low shear rate a dose-dependent decrease was found (0 mg/ml: 100%, 0 . 08 mg/ml: 87 Ϯ 10%, 0 . 4 mg/ml: 80 Ϯ 19%, 2 mg/ml: 70 Ϯ 15%, 10 mg/ml: 40 Ϯ 19%, 25 mg/ml: 33 Ϯ 5%). Erythrocyte aggregation was decreased by the 5-FU-induced echinocytosis. The transit time of erythrocytes through narrow pores was increased in a dose-dependent manner by 5-FU, whereas the transit time of polymorphonuclear leucocytes was initially decreased at 10 mg/ml and returned to control after 60 min incubation. We conclude that 5-FU interacts with the cell membrane, induces echinocytosis and vesiculation and affects blood rheology in several ways which may contribute to cardiovascular complications.

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Section: Methodsmentioning

confidence: 99%

The anti‐neoplastic drug 5‐fluorouracil produces echinocytosis and affects blood rheology

Baerlocher¹,

Beer²,

Owen³

et al. 1997

Br J Haematol

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“…The registration of this process is called the "syllectogram". The technique was developed several decades ago for reflection of light from blood (6)(7)(8), and for transmission of light through blood (9). A first commercial aggregometer using light transmission with a cone-plate setup was developed by Schmid-Schönbein (10).…”

Section: Introductionmentioning

confidence: 99%

Analysis of Red Blood Cell Aggregation in Cardio-Pulmonary Bypass (CPB) Surgery

Graaff

Boonstra³

et al. 2004

Int J Artif Organs

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“…The rouleaux formation time (T µ ) in our constitutive laws was selected to be 3 seconds for all subjects based on RBC aggregation times measured in experiments in vitro of human blood (Hct = 30-45) using different methods [58,69,70]. We selected the smaller value of RBC aggregation time found in the literature to reduce the impact of non-Newtonian effects without completely suppress them T µ > max T N ewtonian R,LAA ∼ 1 s .…”

Section: Study Limitationsmentioning

confidence: 99%

Non-Newtonian Blood Rheology Impacts Left Atrial Stasis in Patient-Specific Simulations

Gonzalo

García-Villalba

Rossini³

et al. 2021

Preprint

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Atrial fibrillation (AF) is the most common arrhythmia, affecting ~35M people worldwide. The irregular beating of the left atrial (LA) caused by AF impacts the LA hemodynamics increasing the risk of thrombosis and ischemic stroke. Most LA thrombi appear in its appendage (LAA), a narrow sac of varied morphology where blood is prone to stagnate. In the LAA, the combination of slow blood flow and low shear rates (<100 [1/s]) promotes the formation of red blood cell aggregations called rouleaux. Blood experiences a non-Newtonian behavior when rouleaux formed that has not been considered in previous CFD analysis of the LA. We model the anatomy and motion of the LA from 4D-CT images and solve the blood flow inside the LA geometry with our CFD in-house code, which models Non-Newtonian rheology with the shear-hematocrit-dependent Carreau-Yasuda equation. We cover a wide range of non-Newtonian effects considering a small and a large hematocrit, including an additional constitutive relation to account for themrouleaux formation time, and we compare our results with Newtonian simulations. Blood rheology influence in LAA hemostasis is studied in 6 patient-specific anatomies. Two subjects had an LAA thrombus (digitally removed before running the simulations), another had a history of TIAs, and the remaining three had normal atrial function. In our simulations, the shear rate remains below 50 [1/s] in the LAA for all non-Newtonian models considered. This triggers an increase of viscosity that alters the flow behavior in that site, which exhibits different flow patterns than Newtonian simulations. These hemodynamic changes translate into differences in the LAA hemostasis, calculated with the residence time.

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Microrheology and light transmission of blood

Cited by 66 publications

References 15 publications

The anti‐neoplastic drug 5‐fluorouracil produces echinocytosis and affects blood rheology

The anti‐neoplastic drug 5‐fluorouracil produces echinocytosis and affects blood rheology

Analysis of Red Blood Cell Aggregation in Cardio-Pulmonary Bypass (CPB) Surgery

Non-Newtonian Blood Rheology Impacts Left Atrial Stasis in Patient-Specific Simulations

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