Microrheology and light transmission of blood

Hj, Klose; Volger, E; Brechtelsbauer, H.; Heinich, L.; Schmid‐Schönbein, H.

doi:10.1007/bf00586912

Cited by 91 publications

(16 citation statements)

References 13 publications

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“…RBC aggregation was measured in Myrenne aggregometer (MA-1 Aggregometer, Myrenne GmbH, Germany) applying the light transmission method of Schmid-Schonbein et al [8,9]. Measurements were performed at room temperature (22 ± 1°C) within 2 h after venepuncture.…”

Section: Rbc Aggregationmentioning

confidence: 99%

Clopidogrel resistance: Role of body mass and concomitant medications

Fehér

Koltai

Alkonyi

et al. 2007

International Journal of Cardiology

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Section: Rbc Aggregationmentioning

confidence: 99%

Clopidogrel resistance: Role of body mass and concomitant medications

Fehér

Koltai

Alkonyi

et al. 2007

International Journal of Cardiology

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“…RBC aggregation was measured in Myrenne aggregometer (MA-1 Aggregometer, Myrenne GmbH, Germany) applying the light transmission method of Schmid-Schonbein et al [16]. In this study the aggregometer was used in low shear (M1) mode.…”

Section: Red Blood Cell (Rbc) Aggregationmentioning

confidence: 99%

The effect of carotid stenting on rheological parameters, free radical production and platelet aggregation

Szekeres

Bagoly

Kövér

et al. 2009

Clinical Hemorheology and Microcirculation

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Introduction: Carotid artery stenting has become a possible treatment of significant carotid stenosis. The risk of stent occlusion and restenosis might be increased by abnormal rheological conditions amplified platelet aggregation and free radical production during the operation.Aims: The aim of our study was to assess the changes in hemorheological parameters, platelet aggregation, and catalase activity after endovascular treatment of carotid stenosis.Methods: 18 patients (11 men, ages 68 ± 9 years and 7 women, ages 62 ± 8 years) suffering from significant carotid stenosis and treated with carotid endovascular intervention were examined. Alteration in hemorheological parameters as well as epinephrine-, ADP-, and collagen-induced platelet aggregation were evaluated. Antioxidant reserve was characterized by the determination of catalase activity. The measurements were carried out directly before and after the procedure and 1, 2, 5 days and 1 month following the intervention. Preceding the operation the patients were administered a maximum dose (300 mg) of clopidogrel.Results: Hematocrit, plasma fibrinogen concentration (PFC) and whole blood-, and plasma viscosity values (WBV and PV) significantly decreased immediately after stenting (p < 0.001). By the fifth day following the intervention the PFC, WBV, PV, red blood cell (RBC) aggregation and ADP-induced platelet aggregation significantly increased (p < 0.0001) compared to values measured postprocedurally. At 1 month follow-up these parameters, except whole blood viscosity, decreased significantly compared to measurements made on the 5th day. On the other hand, catalase activity showed significant elevation by the end of the first month.Conclusion: Hemorheological parameters and platelet aggregation showed specific changes following carotid stenting. Abnormal changes of the rheological conditions and increasing platelet activation are the most pronounced in the first week following stenting, which may lead to early stent occlusion. Oxidative stress production returned to baseline levels only by the end of the first month.

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“…The ratio of apparent viscosities at 0.15 and 94 s −1 was computed and normalized to that of the control solution ( i.e ., RBC without added polymer) to determine inhibition of RBC aggregation; the lower the ratio with respect to unity, the higher is the reduction of the aggregation. RBC aggregation was also quantified using a photometric rheoscope (model MA-1 aggregometer, Myrenne GmbH, Roentgen, Germany), which yields dimensionless indices of aggregation at stasis ( M ) and at a low shear rate of 3 s −1 ( M1 ); both indices decrease with reduced aggregation [31]. Normalized Myrenne aggregation data ( M and M1 ) were obtained by dividing M and M1 by M or M1 for RBC without added polymer.…”

Section: Methodsmentioning

confidence: 99%

Effects of amphiphilic star-shaped poly(ethylene glycol) polymers with a cholic acid core on human red blood cell aggregation

Janvier¹,

Zhu²,

Armstrong³

et al. 2013

Journal of the Mechanical Behavior of Biomedical Materials

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Elevated red blood cell (RBC) aggregation increases low-shear blood viscosity and is closely related to several pathophysiological diseases such as atherosclerosis, thrombosis, diabetes, hypertension, cancer, and hereditary chronic hemolytic conditions. Non-ionic linear polymers such as poly(ethylene glycol) (PEG) and Pluronic F68 have shown inhibitory effects against RBC aggregation. However, hypersensitivity reactions in some individuals, attributed to a diblock component of Pluronic F68, have been reported. Therefore, we investigated the use of an amphiphilic star-shaped PEG polymer based on a cholic acid core as a substitute for Pluronics to reduce RBC aggregation. Cholic acid is a natural bile acid produced in the human liver and therefore should assure biocompatibility. Cholic acid based PEG polymers, termed CA(PEG)4, were synthesized by anionic polymerization. Size exclusion chromatography indicated narrow mass distributions and hydrodynamic radii less than 2 nm were calculated. The effects of CA(PEG)4 on human RBC aggregation and blood viscosity were investigated and compared to linear PEGs by light transmission aggregometry. Results showed optimal reduction of RBC aggregation for molar masses between 10–16 kDa of star-shaped CA(PEG)4 polymers. Cholic acid based PEG polymers affect the rheology of erythrocytes and may find applications as alternatives to linear PEG or Pluronics to improve blood fluidity.

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Microrheology and light transmission of blood

Cited by 91 publications

References 13 publications

Clopidogrel resistance: Role of body mass and concomitant medications

Clopidogrel resistance: Role of body mass and concomitant medications

The effect of carotid stenting on rheological parameters, free radical production and platelet aggregation

Effects of amphiphilic star-shaped poly(ethylene glycol) polymers with a cholic acid core on human red blood cell aggregation

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