Clinical Hemorheology and Microcirculation - Volume 5, issue 6

Authors: McMillan, D.E. | Utterback, N.G. | Lee, M.M.

Article Type: Research Article

Abstract: Increased low shear rate blood viscosity in diabetes, linked in previous studies to elevated blood thixotropy, has been further examined by comparing erythrocytes from diabetic subjects with those from age- and sex-matched nondiabetic subjects. The red cells were resuspended at 0.60 hematocrit in phosphate-buffered saline containing sufficient 100–200,000 Dalton dextran to produce minimal erythrocyte aggregation. Diabetic erythrocytes were found to sediment at a rate not significantly higher than nondiabetic erythrocytes in this medium. Diabetic erythrocyte suspensions were 16% more viscous than those of nondiabetic erythrocytes at low shear rate, but their viscosity averaged only 3–4% higher at high shear rate. …The increased viscosity was found to be related to current fasting glucose level but not to erythrocyte glycosylated hemoglobin content. Flow onset and cessation shear stress patterns were examined to assess RBC suspension viscoelasticity and thixotropy at shear rates below 30 inverse seconds. The apparent elastic modulus of diabetic erythrocyte suspensions was found to be elevated at shear onset but did not differ at cessation. Flow onset thixotropy was found to parallel steady shear stress in diabetic and nondiabetic suspensions. Thixotropic (flow initiation) work increased more rapidly than shear rate for both diabetic and nondiabetic erythrocytes. When examined in relation to published studies of diabetic blood flow properties, these observations support the conclusion that diabetic erythrocyte deformation as flow begins consumes more energy than that of nondiabetic erythrocytes. Show more

Keywords: Diabetes mellitus, blood viscosity, blood thixotropy, erythrocyte deformability, erythrocyte aggregation, insulin

DOI: 10.3233/CH-1985-5610

Citation: Clinical Hemorheology and Microcirculation, vol. 5, no. 6, pp. 937-948, 1985

Authors: De Cree, J. | Geukens, H. | Leempoels, J. | Verhaegen, H.

Article Type: Research Article

Abstract: Blood cell (BC) filtration in platelet rich plasma (PRP) or platelet poor plasma (PPP) was equally decreased in patients with acute myocardial infarction. Cross-exchange experiments showed plasma of patients with acute myocardial infarction to be responsible for the impairment of Be filtration. In a double-blind placebo-controlled study 2 groups of 30 patients with acute myocardial infarction received an acute oral dose of 60 mg of ketanserin, a 5-hydroxytryptamine (5-HT, serotonin) receptor antagonist, at 5-HT2 receptors, or placebo. Ketanserin treatment significantly improved BC filtration in PRP, whereas placebo had no effect. In a subsequent study ketanserin also significantly improved …BC filtration in PPP in patients with acute myocardial infarction. Filtration of plasma improved after ketanserin treatment in PRP, but not in PPP. Cross-exchange experiments showed the ketanserin-induced improvement of Be filtration in PRP and PPP to be also plasmadependent. The possible role of serotonin on red blood cell (RBC) deformability and the interaction with platelet activation is discussed. Show more

Keywords: Ketanserin, 5-HT2 Receptor Antagonist, RBC Filtration, Acute Myocardial Infarction, RBC Deformability, Platelet Activation

DOI: 10.3233/CH-1985-5611

Citation: Clinical Hemorheology and Microcirculation, vol. 5, no. 6, pp. 949-957, 1985

Authors: Irwin, S.T. | McGuigan, J.A. | Rocks, M.J. | Morris, T.C.M. | Merret, J.D. | O’Reilly, J.G.

Article Type: Research Article

Abstract: Impaired red cell filterability has been demonstrated in peripheral vascular disease. We have analysed the causes of impaired red cell filterability (using a simple filtration technique). The number of residual white cells in the filtered sample is critical. There was no evidence of white cell retention in the filter. The residual white cell count in the filtered samples was related to the plasma viscosity. The presence of a plasma factor, probably an acute phase reactant, makes the white cells more difficult to remove from whole blood by a standard technique. The white cells are more difficult to remove in patients …with severe ischaemia and this therefore delays filtration of blood in these patients. Show more

Keywords: Red cell filterability, leucocytes, ischaemia

DOI: 10.3233/CH-1985-5612

Citation: Clinical Hemorheology and Microcirculation, vol. 5, no. 6, pp. 959-963, 1985

Authors: Stoltz, J.F. | Penin, F. | Voisin, Ph. | Gaillard, S. | Donner, M. | Streiff, F.

Article Type: Research Article

Abstract: Blood viscosity, and a certain number of platelet parameters have been studied on 36 patients, aged between 56 and 90 (average age 79 years), who had suffered a cerebral vascular accident. Measurements were carried out less than 24 hours after the stroke. The results of this study show significant plasma hyperviscosity as well as an increase in fibrinogen level. Platelet hyperaggregability is demonstrated at low ADP levels in all the patients, but at the highest ADP level (2.64 µM) only hypertensive patients reveal an increase in this parameter. The β thromboglobulin level, which is a platelet …activation indicator, is higher in patients than in controls, but the effect of age on this parameter is well known. The MDA platelet level, which is related to prostaglandin biosynthesis, remains within normal values. Show more

Keywords: Stroke, hyperviscosity, βTG, platelet MDA, Platelet aggregability

DOI: 10.3233/CH-1985-5613

Citation: Clinical Hemorheology and Microcirculation, vol. 5, no. 6, pp. 965-973, 1985

Authors: Dormandy, J. | Flute, P. | Matrai, A. | Bogar, L. | Mikita, J. | Lowe, G.D.O. | Anderson, J. | Chien, S. | Schmalzer, E. | Herschenfeld, A.

Article Type: Research Article

Abstract: A new commercially available blood filtration apparatus is described, which can be used with whole blood, red cell or white cell suspensions. The apparatus is interfaced to a computer which automatically analyses sequential flow rates and thus distinguishes between cell transit time and pore clogging rate. A series of validation experiments carried out in three different laboratories by the authors show that results are comparable and reproducible. The apparatus is sensitive to detecting small subpopulations of hardened cells or small changes in the filterability of all the cells.

Keywords: Erythrocyte deformability, Blood cell filtration

DOI: 10.3233/CH-1985-5614

Citation: Clinical Hemorheology and Microcirculation, vol. 5, no. 6, pp. 975-983, 1985