Clinical Hemorheology and Microcirculation - Volume 7, issue 2

Authors: Matrai, A. | Whittington, R.B. | Ernst, E.

Article Type: Research Article

Abstract: Red cell concentration is the main determinant of bulk blood viscosity. the evaluation of other determinants of blood rheology may require elimination of differences due to hematocrit alone. A simple and efficient procedure is described for calculating blood viscosity at a standard hematocrit, based on plasma viscosity, native sample hematocrit and whole blood viscosity at native hematocrit. The method considers individual variations of the viscosity – hematocrit relationship, as well as its dependence on shear rate.

Keywords: blood viscosity, standardized hematocrit

DOI: 10.3233/CH-1987-7210

Citation: Clinical Hemorheology and Microcirculation, vol. 7, no. 2, pp. 261-265, 1987

Authors: Micheli, V. | Pieragalli, D. | Toti, P. | Forconi, S. | Guerrini, M. | Acciavatti, A. | Galigani, C. | Weber, G. | Ricci, C. | DiPerri, T.

Article Type: Other

Abstract: The investigation of erythrocyte deformability changes during cell ageing might give one insight on circulatory behaviour of young and old red blood cells. Erythrocytes of healthy subjects of both sexes had been separated into 3 fractions of increasing age on a Percoll discontinous density gradient and their different age has been tested by pyruvate kinase (PK) and glucose-6-phosphate dehydrogenase (G6PD) activities. Each fraction, free of leucocytes, suspended to 10% haematocrit, was filtered through Nuclepore filters 5 micron diameter; erythrocytes lying on filters were observed by Scanning Electron microscopy. Erythrocyte deformability has shown small decrease from middle aged cells …to old and youngest ones. Show more

Keywords: Erythrocyte life-span, Percoll, G6PD, PK, erythocyte filterability, washed red blood cell filterability

DOI: 10.3233/CH-1987-7211

Citation: Clinical Hemorheology and Microcirculation, vol. 7, no. 2, pp. 267-272, 1987

Authors: Pieragalli, D. | Acciavatti, A. | Galigani, C. | Messa, G.L. | Blardi, P. | Guerrini, M. | Forconi, S. | DiPerri, T.

Article Type: Research Article

Abstract: The existence of changes in blood viscosity and filterability in some diseases supported several methods to wash red cells, hypothesizing that these modifications could be due mainly to red cells. In order to investigate these changes, washed red cells were studied in several diseases. Washed red cells were suspended to 10% haematocrit and filtered through Nucleopore filters 5 micron diameter; this study was meda in healthy subjects and in patients suffering from peripheral obliterative arterial disease, stroke, myocardial infarction and cancers; the same parameter was studied also in arterial and venous blood. The analysis of these data did not show …very significant differences between the healthy donors and each group of patients studied. On the basis of these results we could suppose that the various diseases really did not induce any change of the erythrocyte deformability and that the changes we see in whole blood filterability depends on other blood cells or components. On the contrary we can hypothesize that the washing technique by itself provokes a damage of the erythrocyte membrane; this damage may be so great as to inable us to detect a significant difference among the groups studied. Show more

Keywords: Blood viscosity, whole blood filterability, washed red blood cell filterability

DOI: 10.3233/CH-1987-7212

Citation: Clinical Hemorheology and Microcirculation, vol. 7, no. 2, pp. 273-276, 1987

Authors: Angelkort, B. | Spürk, P. | Gerlach, A. | Kiesewetter, H.

Article Type: Research Article

Abstract: Chronic occlusive arterial disease has been shown to be accompanied by blood hyperviscosity which is associated with increased plasma viscosity, red cell aggregation and red cell rigidity. There exists a linear correlation between fibrinogen and plasma viscosity and the flow behaviour of red cells meshed to each other by fibrinogen. Therapeutical decrease of the fibrinogen level aims at improving blood fluidity and increasing tissue perfusion by raising blood flow velocity in conjunction with an increase in red cell oxygen transport rate. Pharmacological approaches to realize this therapeutical principal are: fibrinolysis (streptokinase, urokinase, in myocardial infarction); defibrinogenation (ancrod, defibrase, in peripheral …vascular disease); anabolics (stanazol in Raynaud’s-Syndrome), lipid lowering drugs (clofibrate analogous in peripheral vascular disease), hemorheologically active drugs (pentoxifylline). Confirmed effects in respect of improvement of blood fluidity and tissue perfusion via fibrinogen reduction are at present only available for defibrinogenation by ancrod and by pentoxifylline. Show more

Keywords: Fibrinogen, blood fluidity, fibrinolysis, defibrinogenation, anabolics, lipid-lowering-drugs, pentoxifylline

DOI: 10.3233/CH-1987-7213

Citation: Clinical Hemorheology and Microcirculation, vol. 7, no. 2, pp. 277-286, 1987

Authors: Miller, B. | Heilmann, L.

Article Type: Research Article

Abstract: 25 patients with breast cancer after primary surgery and 10 patients with metastatic disease were investigated regarding hemorheological parameters such as erythrocyte aggregation, plasma viscosity, hematocrit and fibrinogen during chemotherapy with methotrexate, 5-fluorouracil and cyclophosphamide. Erythrocyte aggregation increased significantly during the first course of chemotherapy and remained elevated thereafter. There were no significant changes regarding the other parameters. The influence of tumor volume was much more important leading to significant differences between the two groups regarding erythrocyte aggregation, plasma viscosity and fibrinogen, while hematocrit and total protein concentration were not different.

Keywords: breast cancer, chemotherapy, hemorheology

DOI: 10.3233/CH-1987-7214

Citation: Clinical Hemorheology and Microcirculation, vol. 7, no. 2, pp. 287-293, 1987

Authors: Mills, P. | Snabre, P.

Article Type: Research Article

Abstract: Particle migration induced by rheological mechanisms in a flowing suspension is studied. Most of this paper is devoted to calculate the migration force due to aggregation of the particles which form the bulk suspension. The last section deals with the effect of particles deformability on the margination phenomena. The mechanism of white blood cell margination and the following steps leading to emigration can be fully understood owing to our theoretical model. Theory is compared to experimental data obtained by P. GAEHTGENS and his group in blood perfused glass capillaries in which white blood cells adhesion does not occur.

Keywords: Suspension, particle migration, aggregation, white blood cells

DOI: 10.3233/CH-1987-7215

Citation: Clinical Hemorheology and Microcirculation, vol. 7, no. 2, pp. 295-304, 1987

Authors: Bodis, J. | Bogar, L. | Zambo, K. | Nemessanyi, Z. | Tekeres, M. | Csaba, I. | Matrai, A.

Article Type: Research Article

Abstract: Deteriorated blood rheology has been demonstrated in obstetric diseases with decreased placental perfusion. Many of the patients investigated in these studies suffered from conditions associated with hemorheological abnormalities, such as diabetes or pre-eclampsy. Therefore it is difficult to establish the pathogenetic role of blood rheology in fetal growth retardation. In the present study placental perfusion and whole blood viscosity were measured in 26 pregnant women with intrauterine fetal growth retardation, without pre-eclampsy or other disease of the mother. These patients were compared to 20 controls with normal, uncomplicated pregnancy. Significantly higher whole blood viscosity accompanied with deteriorated placental perfusion was …found in the patient’s group. Results suggest a pathogenetic role of hyperviscostiy in cases of intrauterine growth retardation without pre-eclampsy. Show more

Keywords: blood viscosity, intrauterine growth retardation, placental perfusion

DOI: 10.3233/CH-1987-7216

Citation: Clinical Hemorheology and Microcirculation, vol. 7, no. 2, pp. 305-310, 1987

Authors: Tooke, J.E. | Milligan, D.W.

Article Type: Research Article

Abstract: The technique of television microscopy has been applied to study human nailfold capillary blood flow in a variety of conditions that result in changes in blood rheological behaviour. The most striking changes were observed in leukaemia: in the presence of high total leucocyte counts stationary capillaries were frequently observed. A highly significant improvement in capillary flow velocity followed cytoreduction therapy. In contrast capillary flow velocity was normal at rest in patients with polycythaemia and was not altered following isovolaemic haemodilution. In patients with Waldenström’s macroglobulinaemia capillary flow tended to be lower than age matched control subjects but few stationary capillaries …were observed. Plasmapheresis in two subjects resulted in an improvement in capillary flow. These results emphasize the need to take into account the autoregulatory capacity of the microvasculature when extrapolating from the viscometer to the in vivo state. Show more

Keywords: capillary, viscosity, leukaemia, polycythaemia

DOI: 10.3233/CH-1987-7217

Citation: Clinical Hemorheology and Microcirculation, vol. 7, no. 2, pp. 311-319, 1987

Authors: Judkiewicz, L. | Ciszewski, R. | Bartosz, G.

Article Type: Research Article

Abstract: A new method of estimation of mechanical properties of erythrocytes is presented, based on the measurement of red cell susceptibility to centrifugal packing. Blood is spun in a microhematocrit centrifuge run at a voltage lowered to provide a rotation speed corresponding to 200 × g and apparent hematocrit is measured after 15-min centrifugation (Ha15 ). Then the centrifuge is run at a standard speed and the final hematocrit is read (Hk). The difference between these two values, denoted as Erythrocyte Packing Difference (EPD) is a measure of red cell susceptibility to centrifugal packing. EPD is independent of hematocrit in a …broad range of hematocrit values. A survey of a population of 489 healthy donors points to a significant sex difference in EPD which amounted to 10% ± 2% for males and 8.5% ± 2.5% for females. A decreased EPD was found in diabetes. EPD changes under conditions affecting red cell deformability. This simple and easily standarizable method of estimation of mechanical properties of unmanipulated erythrocytes is recommended for routine use. Show more

Keywords: Erythrocyte, Mechanical properties, Deformability, Diabetes

DOI: 10.3233/CH-1987-7218

Citation: Clinical Hemorheology and Microcirculation, vol. 7, no. 2, pp. 321-329, 1987

Authors: Ernst, E. | Heider, E. | Schmid, T. | Matrai, A.

Article Type: Research Article

Abstract: Hemoconcentration was induced by administration of oral Furosemide in a group of healthy athletes. Before and after this treatment a variety of hemorheological variables was measured. Simultaneously the time needed to reach the anaerobic threshold during a standardized ergometer test was recorded. The results show that the changes in blood rheology correlate with the changes in threshold – the more hemoconcentration, the more prolongation of the time to reach the threshold. This suggests that athletes may benefit in terms of performance by hemoconcentration. The findings support the hypothesis that the optimal hematocrit for oxygen transport rate is higher than normal …when average shear stress in the circulation is high such as in athletes. Conversely it may be lower than normal when shear stress is low like distal to a stenosis in occlusive arterial diseases. Show more

Keywords: hemorheology, hemoconcentration, physical performance, optimal hematocrit

DOI: 10.3233/CH-1987-7219

Citation: Clinical Hemorheology and Microcirculation, vol. 7, no. 2, pp. 331-337, 1987