Clinical Hemorheology and Microcirculation - Volume 13, issue 1

Authors: Witte, Siegfried | Stoltz, Jean-François

Article Type: Miscellaneous

DOI: 10.3233/CH-1993-13101

Citation: Clinical Hemorheology and Microcirculation, vol. 13, no. 1, pp. 1-2, 1993

Authors: Stuart, John

Article Type: Research Article

Keywords: Rheology, erythrocyte deformability, sickle cell anemia, drug screening

DOI: 10.3233/CH-1993-13102

Citation: Clinical Hemorheology and Microcirculation, vol. 13, no. 1, pp. 3-11, 1993

Authors: Forconi, S. | Guerrini, M. | Cappelli, R. | Furesi, L. | Battistelli, S. | Sani, P. | Marotta, G. | Trabalzini, L.

Article Type: Research Article

Abstract: This study concerns the effect of intravenous thrombolysis in patients suffering from Peripheral Obliterative Arterial Disease (POAD) at the stage of “Accelerated Limb Ischemia” (ALI). In a previous study on 17 patients, where Streptokinase was employed, there was complete or partial reopening of obstructed vessels in 5 cases and an improvement of clinical conditions in 10 cases. Unfortunately, 6 (35%) patients experienced significant side effects. Subsequently, in 9 POAD patients, we employed rt-PA at the dosage of 100 mg infused i.v. over a period of 4–6 hours. This treatment showed a clinical and instrumental improvement in a high percentage of …patients without any important side effects. The effect of the treatment was examined by means of Doppler ultrasound, strain gauge plethysmography and Transcutaneous oxygen tension (TcPO2). Haemorheological and fibrinolytic parameters were also assessed and no important changes were observed either in blood or plasma viscosity in spite of the reduction of fibrinogen concentration (especially in the Streptokinase group) and the improvement of leg perfusion. Explanation of this aspect was sought through an “in vitro” study: here rt-PA was added to blood samples so as to obtain a more definite fibrinolysis. Before and after the addition of rt-PA, blood and plasma viscosity, fibrinogen, FDP and FDP-E were examined. The results illustrated that the reduction of plasma and blood viscosity was not as significant as the disappearance of fibrinogen might have led us to expect and showed a marked increase of fibrinogenolytic products (FDP and FDP-E). These findings reinforce the working hypothesis stating that fibrino(geno)lytic products can affect plasma and blood viscosity as much as the intact fibrinogen molecule does. So it was concluded that the beneficial results obtained with fibrinolytic agents, in patient with POAD at the ALI stage, are due to the reopening of vessels and not to the rheological effect. Show more

Keywords: thrombolysis, fibrin(ogen) degradation products, blood viscosity

DOI: 10.3233/CH-1993-13103

Citation: Clinical Hemorheology and Microcirculation, vol. 13, no. 1, pp. 13-22, 1993

Authors: Aoshiba, Kazutetsu | Nagai, Atsushi | Konno, Kimio

Article Type: Research Article

Abstract: We measured neutrophil filtrability at different temperatures and pH levels using a filtration method which provided a model system that is regarded to reflect conditions in the microcirculation. Neutrophil filtrability decreased as temperature fell (range: 40 to 4°C), but did not change with pH (range: 6.8 to 7.6). The decreased filtrability induced by cell cooling to 4°C was completely reversed by cell rewarming to 37°C and was also suppressed by the addition of cytochalasin B, which disrupts cellular actin filaments. Thus, neutrophil filtrability may be reduced by hypothermia, this reduction being, in part, to structural changes in cytoskeletal actin organization. …These findings suggest that temperature setting is important in the measurement of neutrophil filtrability. Show more

Keywords: neutrophil, filtrability, temperature, pH

DOI: 10.3233/CH-1993-13104

Citation: Clinical Hemorheology and Microcirculation, vol. 13, no. 1, pp. 23-34, 1993

Authors: Caimi, Gregorio | Contorno, Antonino | Serra, Antonio | Catania, Anna | Lo Presti, Rosalia | Sarno, Antonio | Cerasola, Giovanni

Article Type: Research Article

Abstract: In a group of 22 subjects with essential hypertension we evaluated the red cell filterability and aggregation, the erythrocyte membrane fluidity and red cell membrane transverse fluidity gradient. We also evaluated the total red cell Ca2+ content, the red cell cytosolic free Ca2+ content, the red cell membrane cholesterol/phospholipid ratio and the red cell membrane individual phospholipids. From our results, it is evident that the macrorheological as well as the microrheological determinants discriminate normals from hypertensives. From our data, a significant increase of the total and cytosolic red cell Ca2+ content is evident in hypertension. In hypertensives, the evaluation of …the red cell lipid parameters shows that only the CL/PL ratio plays a discriminant role. The study of correlations between the microrheological determinants and red cell metabolic parameters shows interesting findings. Show more

Keywords: essential hypertension, rheological determinants, total and cytosolic red cell calcium content, erythrocyte membrane lipids

DOI: 10.3233/CH-1993-13105

Citation: Clinical Hemorheology and Microcirculation, vol. 13, no. 1, pp. 35-44, 1993

Authors: Pöschl, J.M.B. | Galanos, C. | Linderkamp, O.

Article Type: Research Article

Abstract: Lipid A is responsible for the endotoxic activities. The effect of different lipid A concentrations and incubation times on red blood cell (RBC) deformation was studied by means of a rheoscope. Lipid A concentrations of 10 and 100 μg/ml decreased RBC deformability by 41% and 46%, respectively, after 20 min of incubation. After 1 h, RBC deformability nearly reached preincubation values. Lipid A binding to RBC membranes (passive hemolysis test) was similar after 30 and 60 min incubation. This suggests that lipid A binding to RBC membrane does not change during this time, but that lipid A is inserted into …the membrane, thereby improving RBC deformability. Show more

Keywords: Lipid A, red blood cell deformability

DOI: 10.3233/CH-1993-13106

Citation: Clinical Hemorheology and Microcirculation, vol. 13, no. 1, pp. 45-48, 1993

Authors: Dikmenoglu, N. | Akbas, A. | Atakan, N. | Dundar, S. | Baskurt, O.K.

Article Type: Research Article

Abstract: Erythrocyte filterability and aggregation were measured in two separate groups of psoriasis patients, one treated with cyclosporin-A (CsA; 2 mg/kg daily) and the second with topical preparations only. Erythrocyte deformability indexes were significantly higher in both groups of patients in comparison with a healthy control group. Erythrocyte aggregation indexes were decreased significantly in psoriasis patients, however the indexes in the group treated with CsA were closer to the control values. These findings can be explained on the basis of biochemical changes in red blood cells observed in psoriasis patients, but the pathophysiological significance of hemorheological alterations remains unclear.

Keywords: Psoriasis, cyclosporin-A, erythrocyte deformability, erythrocyte aggregation

DOI: 10.3233/CH-1993-13107

Citation: Clinical Hemorheology and Microcirculation, vol. 13, no. 1, pp. 49-54, 1993

Authors: Lakomek, M. | Friederichs, E. | Winkler, H. | Tillmann, W. | Schröter, W.

Article Type: Research Article

Abstract: The deformability of erythrocytes from 30 healthy controls and from 10 patients with pyruvate kinase (PK) deficiency in different states of red blood cell (RBC) maturation has been determined by cell filtration through polycarbonate sieves. The deformability of the whole RBC population from patients with a mild clinical course was with a flow rate of 16–20 μl/sec markedly decreased, compared to the controls (54 ± 4μl/sec). Red blood cells from patients with severe degree of hemolysis showed even lower flow rates (4–8μl/sec) depending on the counts of reticulocytes. Separation of the different RBC-fractions was obtained by density gradient centrifugation. …Normal “young” erythrocytes are more deformable than “old” erythrocytes showing in filtration experiments flow rates between 60–65 μl/sec, compared to the old cells, which exhibited a velocity of 40–45 μl/sec. Flow rates of the reticulocytes from all patients, independent from their clinical condition, had a value of 5–10 μl/sec. The flow rates of their “old” cells, however, very well agree with the degree of hemolysis. In case of mild clinical course the flow rates of the “old” cells were 15–45μl/sec whereas in case of severe disease the flow rates were even more decreased (5–15μl/sec). The filtration rate of the whole red blood cell population apparently can be regarded as the sum of the filtration rates of the single fractions and the low total filtration rate of cells from patients with PK deficiency is caused mainly by the rigidity of reticulocytes present in their whole blood. The results of these rheological investigations support earlier kinetic and electrophoretic studies with enzymes from patients suffering from PK deficiency, where could be demonstrated that reticulocytes from normal controls and from patients with PK deficiency showed no deviating behaviour, whereas the erythrocytes do deviate, thus suggesting a perturbation of their maturation process. Show more

Keywords: Pyruvate kinase deficiency, cell separation, red blood cell deformability, energy metabolism

DOI: 10.3233/CH-1993-13108

Citation: Clinical Hemorheology and Microcirculation, vol. 13, no. 1, pp. 55-65, 1993

Authors: Böhler, Thomas | Leo, Albrecht | Schärer, Karl | Linderkamp, Otwin

Article Type: Research Article

Abstract: Red blood cell (RBC) deformability was studied by means of a rheoscope and RBC membrane rigidity (i.e. membrane extensional elastic modulus, μe ) was measured by using a flow channel in seven children and adolescents (9 to 17 years) with chronic renal failure undergoing regular hemodialysis. μe was 6.34±1.28x10−6 N/m in the uremic patients and 4.48±0.55×10−6 N/m in a control group of six healthy children (P<0.001). RBC deformation in the rheoscope (shear stress of 0.7 Pa) was 0.14±0.03 in the uremic patients and 0.19±0.02 in the controls (p<0.01). At a shear stress of 3 Pa, there was …no significant difference between the patients and the controls. These results indicate that chronic renal failure is associated with increased RBC membrane rigidity and decreased RBC deformability at low shear. Show more

Keywords: Erythrocytes, erythrocyte deformablity, hemodialysis, renal failure

DOI: 10.3233/CH-1993-13109

Citation: Clinical Hemorheology and Microcirculation, vol. 13, no. 1, pp. 67-72, 1993

Authors: Evans, S.-A. | Jones, J.G. | Wardrop, C.A.J. | Lane, I.

Article Type: Research Article

Abstract: The initial flow rate of diluted blood, from patients with intermittent claudication, can be used to calculate the average flow properties of a combined population of lymphocytes and granulocytes. The transit time for the flowing leukocytes, calculated in this way, is close to that determined from the flow rate of suspensions of unfractionated leukocytes. The isolation and purification of leukocytes is therefore not a prerequisite to the investigation of their filterability in this group of patients. The number and transit time for flowing leukocytes is higher in the patient group compared to normals, and the variation in the rate of …flow of diluted blood through 5 μm membranes is attributable to differences in both the concentration and the flow properties of the participating leukocytes. Small variations in red cell transit time or platelet count are not reflected in the measured flow rate of diluted blood. Show more

Keywords: Leukocytes, deformability, peripheral vascular disease

DOI: 10.3233/CH-1993-13110

Citation: Clinical Hemorheology and Microcirculation, vol. 13, no. 1, pp. 73-81, 1993