Clinical Hemorheology and Microcirculation - Volume 47, issue 3

Authors: Spengler, M.I. | Rasia, M. | Palma, S. | Allemandi, D.

Article Type: Research Article

Abstract: 6-O-alkyl ascorbic acid esters (ASCn ) are amphiphilic molecules that behave as surfactants in aqueous solution. ASCn have shown some physical and rheological properties that suggest a potential utility as drug carriers. The present paper aims to evaluate the effect of ASCn on erythrocyte properties in order to get information regarding the relationship between osmotic fragility, erythrocyte deformability and membrane lipoperoxidation process. The assays were performed at the following concentrations: the critical micelar concentration (CMC), producing 10% hemolysis (CH10 ) and producing 50% hemolysis (CH50 ). We observed that ASCn (ASC8 , ASC10 and ASC12 ), …at concentration nearby CMC, neither affected cell deformability nor produced lipoperoxidation. Nevertheless, at higher concentrations (CH10 and CH50 ), the RBCs incubated with ASCn were affected by a significant and progressive loss of deformability, simultaneously with an increase of osmotic fragility and membrane lipoperoxidation. Show more

Keywords: Amphiphiles, ascorbic acid esters, osmotic fragility, erythrocyte deformability, membrane lipoperoxidation

DOI: 10.3233/CH-2010-1266

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 3, pp. 163-168, 2011

Authors: Dąbrowski, Z. | Dybowicz, A.J. | Marchewka, A. | Teległów, A. | Skotnicki, A. | Zduńczyk, A. | Aleksander, P. | Filar-Mierzwa, K.

Article Type: Research Article

Abstract: The principal aim of the study was to investigate rheological properties of erythrocytes obtained from patients admitted to the clinic, and diagnosed with polycythemia vera. The polycythemia vera diagnosis was based on the WHO criteria for polycythemia vera. Using a laser rheometer SSD Rheometer-Rheodyn, the elongation index of erythrocytes was determined, indicating an increased rigidity of the erythrocytes in this disease compared with the erythrocytes in healthy people. In order to explain (albeit partially) the reason for reduced elasticity, the erythrocytes of patients with polycythemia were studied for the activity of enzymes – glucose-6-phosphate dehydrogenase and acetylcholinesterase membrane enzyme, as …well as the levels of glutathione and malonyldialdehyde. The elevated activities of these enzymes, the glutathione level, and elevated ‰ of reticulocytes, indicated an increased pool of juvenile erythrocyte forms; furthermore, the elevated value of malonyldialdehyde may suggest a lipid peroxidative damage in certain pool of the erythrocyte membrane in blood circulation. Show more

Keywords: Polycythemia, RBC rheology, RBC enzymes, G-6-PD, AChE, GSH, MDA, reticulocytes

DOI: 10.3233/CH-2010-1368

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 3, pp. 169-176, 2011

Authors: Zhao, Wen-Yu | Xiong, Hai-Yun | Yuan, Qing | Zeng, Li | Wang, Li-Ming | Zhu, You-Hua

Article Type: Research Article

Abstract: Addition of hydroxyethyl starch (HES) to UW (University of Wisconsin) solution increases viscosity of the solution and red blood cell (RBC) aggregation. Recently, it was suggested that HES could be replaced by a new colloid, polyethylene glycol (PEG), in UW solution. The aim of this study was to see whether and how PEG affected RBC aggregation, and whether RBC aggregation parameters had any correlation with the molecular weight and concentration of PEG. After giving informed consent and signing consent documents, 12 healthy volunteers were enrolled in the study. Blood samples obtained from these volunteers were mixed with the test solutions …with blood/solutions ratios of 5:1 and 1:1. Human RBC aggregation was investigated with an automatic hemorheological analyzer. Blood viscosity was measured with a cone-plate viscometer. Morphological characters of RBC aggregates were evaluated by light microscopy. It was found that viscosity was not affected by the Colloid-free UW solution. PEG20kDa (1 and 10 g/L) and PEG35kDa (1 g/L) had little effect on RBC aggregation, while PEG20kDa (30 g/L) and PEG35kDa (10 and 30 g/L) had a significant hyperaggregating effect on RBC. In conclusion, PEGs had a potential hyperaggregating effect on human RBC. This effect is correlated with PEG molecular weight and concentration. The use of large molecular weight and high concentration PEG in UW solution accounts for extended and accelerated aggregation of erythrocytes. The use of low concentration PEG35kDa (1 g/L) would be the optimal choice. Show more

Keywords: Polyethylene glycol, erythrocyte aggregation, hemorheology, UW

DOI: 10.3233/CH-2010-1379

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 3, pp. 177-185, 2011

Authors: You, Yun | Liu, Weihong | Li, Yujie | Zhang, Yi | Li, Defeng | Li, Wen | Yin, Xiaojie | Liao, Fulong | Zhu, Xiaoxin | Liu, Chifeng

Article Type: Research Article

Abstract: This work is to investigate the joint effect of extract from Shenlian (SL, the Chinese abbreviation for Radix Salviae miltiorrhizae and Andrographis paniculata) and swimming on atherosclerosis prevention and treatment. Atherosclerotic rat model was established by combining low shear stress by partial ligation of common carotid artery with afterwards feeding of a hyperlipotic diet. Sprague-Dawley rats after partial ligation of common carotid artery were allotted to a 3 × 3 factorial design with three levels of swimming (0, 1, and 2 hr per day) and three levels of SL extract (0, 2.56, and 5.12 g/kg once daily p.o.) for a …total of 9 treatment groups. Then, the feeding of the hyperlipotic diet and the intervention of swimming and SL started at the same time, and lasted for 8 weeks. By the end, blood samples were collected to determine blood viscosity, hematocrit, blood lipids, MCP-1, NF-κB and NO levels. The common carotid arteries of the rats were harvested to investigate pathological changes. The animal model showed early sign of atherosclerosis according to the pathological findings. Joint effects of SL extract and swimming on preventing atherosclerosis appeared significantly: The combination of 1 hour swimming with 2.56 g/kg SL extract showed to be effective for lowering hematocrit, blood viscosity (at 10 s−1 and 200 s−1 ) and low-density-lipoprotein (p < 0.001). Combined treatment of 2.56 g/kg SL extract with 2 hr swimming led to a synergistic decrease in serum level of MCP-1. As a single factor, SL extract (2.56 g/kg) alone could decrease serum levels of NF-κB significantly (p = 0.003). Swimming alone could decrease cholesterol, triacylglycerols level and increase high-density-lipoprotein. The study demonstrates the combined therapy of oral SL extract with swimming on inhibiting inflammatory factors, improving hemorheological parameters and lipoproteins in rat model of atherosclerosis. It highlights the promising effects of the drugs and shear stress of blood flow, the biomechenopharmacological means, for prevention of atherosclerosis. Show more

Keywords: Atherosclerosis, exercise, shear stress, Radix Salviae miltiorrhizae, Andrographis paniculata

DOI: 10.3233/CH-2010-1380

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 3, pp. 187-198, 2011

Authors: Du, Yuan | Yao, Weijuan | Qian, Yeyong | Han, Mengxia | Wen, Zongyao | Ma, Lulin

Article Type: Research Article

Abstract: Living-donor renal transplantation is the preferred treatment for patients with end stage renal disease since it affords earlier transplantation and better graft for long term survival. The aim of the present study was to explore the hemorheological changes in patients undergone living-donor renal transplantation. We investigated the dynamic changes in the hemorheological properties of blood taken from the patients before renal transplantation and at 1 week, 2 week, 3 week and >1 month after the operation. As compared with pre-operation, the whole blood viscosity at different shear rates decreased significantly; the erythrocyte aggregation index decreased; the erythrocyte deformation index (DI) …and integrated deformation index (IDI) had a remarkable improvement; the erythrocyte electrophoresis rate was rasied. We also found that the osmotic fragility of RBCs at 145 mOsm/kg was greatly decreased after renal transplantation. Importantly, the ratio of erythrocyte membrane protein 4.1 a to 4.1 b decreased, which may explain the changes in DI, IDI, and osmotic fragility. Our results suggest that these hemorheological changes may greatly improve the organ microcirculation, which would play a critical role in reduce the ischemia-reperfusion injury in the graft. Show more

Keywords: Living-donor renal transplantation, Hemorheology, Erythrocyte membrane protein

DOI: 10.3233/CH-2010-1381

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 3, pp. 199-209, 2011

Authors: Lim, Hyunjung | Nam, Jeonghun | Xue, Shubin | Shin, Sehyun

Article Type: Research Article

Abstract: Even though blood coagulation can be tested by various methods and techniques, the effect of RBC aggregation on blood coagulation is not fully understood. The present study monitored clot formation in a microchip-based light transmission aggregometer. Citrated blood samples with and without the addition of calcium ion solution were initially disaggregated by rotating a stirrer in the microchip. After abrupt stop of the rotating stirrer, the transmitted light intensity over time was recorded. The syllectogram (light intensity vs. time graph) manifested a rapid increase that is associated with RBC aggregation followed by a decrease that is associated with blood coagulation. …The time to reach the peak point was used as a new index of coagulation time (CT) and ranged from 200 to 500 seconds in the present measurements. The CT was inversely proportional to the concentration of fibrinogen, which enhances RBC aggregation. In addition, the CT was inversely proportional to the hematocrit, which is similar to the case of the prothrombin time (PT), as measured by a commercial coagulometer. Thus, we carefully concluded that RBC aggregation should be considered in tests of blood coagulation. Show more

Keywords: RBC aggregation, Coagulation, Fibrinogen, Hematocrit

DOI: 10.3233/CH-2010-1382

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 3, pp. 211-218, 2011

Authors: El-Sayed, Mahmoud S. | Ali, Nagia | Omar, Ayad Abuelgasem

Article Type: Research Article

Abstract: The aim of the present study was ascertain the effects posture and exercise modality on the main determinants of blood rheology. Thirteen subjects performed two exercise trials, in random order, at approximately 70% VO2 max for 45-min. One trial was performed on a motorized treadmill at an intensity corresponding to 70% VO2 max, while the other was performed on a stationary pike at an intensity corresponding to 70% VO2 max. In the cycling trial subjects stood for 30-min, followed by sitting for 30-min then cycled for 30-min at 70% VO2 max. In the treadmill trial, subjects …sat for 30-min followed by standing for 30-min then ran on the treadmill for 30-min at 70% VO2 max. Variations of body postures prior to exercise were associated with opposite changes in plasma volume, plasma viscosity and plasma fibrinogen. When post exercise raw data were not adjusted for plasma volume changes, a significant increase (p < 0.05) in plasma viscosity and plasma fibrinogen was found with no difference between the cycling and running trials. However, the increase in plasma viscosity and fibrinogen were no longer apparent when the raw data post exercises were adjusted for plasma volume changes. Changing body posture from standing to sitting and vice versa were associated with opposite changes in plasma volume and mirrored the changes in plasma viscosity and fibrinogen. In addition, ergometer-specific vigorous exercises at the same relative intensity, irrespective of its modality, transiently increased plasma viscosity and plasma fibrinogen mainly due to exercise-associated haemoconcentration. Show more

Keywords: Exercise, cycling, running, plasma viscosity, plasma fibrinogen, plasma volume

DOI: 10.3233/CH-2010-1383

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 3, pp. 219-228, 2011

Authors: Stadnick, H. | Onell, R. | Acker, J.P. | Holovati, J.L.

Article Type: Research Article

Abstract: In recent years, linear data transformation has become an accepted method to simplify the analysis of red blood cell (RBC) deformability curves obtained by ektacytometry. In this study, we introduce the Eadie-Hofstee transformation as an alternative linearization method for the analysis of RBC deformability. RBCs were treated with hydrogen peroxide (H2 O2 ), tert-butyl-hydroperoxide (t-BuOOH), or methyl β-cyclodextrin (MβCD) and analyzed via ektacytometry (LORCA). RBC hemopathological clinical isolates (hereditary spherocytosis and α-thalassemia) were also analyzed by LORCA. Following ektacytometry, Eadie-Hofstee linearization was performed to obtain the maximum deformability (EImax ) and shear stress at half maximal deformation (KEI ) parameters. …Significant changes in deformability parameters were observed with all agents tested. For H2 O2 and t-BuOOH, the KEI values increased significantly accompanied by marginal changes in EImax , while treatment with MβCD resulted in a dose dependant decrease in EImax . Contrasting deformability profiles were also observed in the two hematological disorders tested. In this study we have demonstrated the ability of Eadie-Hofstee linearization to detect and resolve changes in RBC deformability induced in vitro as well as deformability changes associated with in vivo hematological disorders. This technique shows promise in basic research, blood bank and clinical hematology settings. Show more

Keywords: Erythrocyte, Red blood cell, Deformability, Ektacytometry, Hematology

DOI: 10.3233/CH-2010-1384

Citation: Clinical Hemorheology and Microcirculation, vol. 47, no. 3, pp. 229-239, 2011