Clinical Hemorheology and Microcirculation - Volume 12, issue 2

Authors: Evans, S.-A. | Jones, J.G.

Article Type: Research Article

Abstract: Filtration of blood cells through 3 μm and 5 μm Nuclepore membranes has been studied under air and nitrogen. Experimental hypoxia had no effect on the morphological appearance of leukocytes nor their filterability through the 5 μm pores. However the combination of hypoxia and attempted filtration through 3 μm pores caused extensive morphological changes in leukocytes that was characterized by significant pore blocking during filtration. Hence hypoxia alone does not stimulate morphological changes in leukocytes but the combination of hypoxia and slow deformation through narrow pores may well lead to activation of leukocytes in vivo with trapping of red cells …and extensive pore blocking. Show more

DOI: 10.3233/CH-1992-12211

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 2, pp. 255-266, 1992

Authors: Hara, H. | Kitajima, A. | Tamao, Y.

Article Type: Research Article

Abstract: We investigated the effect of a new antiplatelet agent, MCI-9042 ((±)-2-(dimethylamino)-1-[[o-(m-methoxyphenethyl)phenoxy]methyl]ethyl hydrogen succinate) on the deformability of red blood cells (RBC deformability). In the ftltration tests with whole blood and washed red blood cell suspension through Nuclepore ftlter, MCI-9042 improved filterabilities. Furthermore, MCI-9042 inhibited shear stressinduced hemolysis in turbulent flow. These results in the three assessment systems on RBC deform ability indicate that MCI-9042 exhibits an improving effect on the deform ability of red blood cells and the efficacy of MCI-9042 is more potent than that of pentoxifylline. From the studies on the mode of action of MCI-9042 on RBC …deform ability, we found that this compound reduced the membrane microviscosity of red blood cells. It is therefore considered that MCI-9042 directly affects the membrane of red blood cells reducing their membrane microviscosity and consequently improves RBC deform ability. Show more

Keywords: MCI-9042, Red blood cell, Deformability, Membrane microviscosity

DOI: 10.3233/CH-1992-12212

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 2, pp. 267-277, 1992

Authors: Cui, Xizhong | Xu, Longshao

Article Type: Research Article

Abstract: The present work reports the hemorheologic changes and its role in the acute lung injury. The blood viscosity, particularly at low shear rate, increased significantly in the early stage of the lung injury and blood viscosity at 100S−1 increased obviously only from 240 min after oleic acid infusion. The analysis of stepwise regression on O2CT and related parameters at different time suggested that the parameters which had the greatest effect on O2CT changes are blood viscosity at low shear rate, hematocrit and erythrocytes aggregation. Thus, we conclude that the hemorheologic changes play an important role in acute lung injury …and that it is inappropriate that the increase of pulmonary flow resistance was only attributed to the decrease of microvascular radius. Show more

Keywords: Acute lung injury, oleic acid, blood viscosity, erythrocyte aggregation

DOI: 10.3233/CH-1992-12213

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 2, pp. 279-286, 1992

Authors: Mary, A. | Bonne, C. | Modat, G.

Article Type: Research Article

Abstract: An in vitro model was designed to examine the role of ischemialreperfusion and oxygen-derived free radicals on red blood cell (RBC) injury. Normal human RBC suspensions were subjected to various times of hypoxia (1 to 30 min.) followed by various times of reoxygenation (1 to 30 min.). Using a filtration technique, a decrease in RBC deformability was then observed with a maximal effect after 5 min. hypoxial 5 min. reoxygenation. Superoxide anions and hydrogen peroxide could be implicated in this phenomenon, since superoxide dismutase (30 to 300 U/ml) and/or catalase (30 to 300 U/ml) efficiently prevented the membrane rigidity. …This study underlines the role of free radicals on RBC functionality and emphasizes the potential use of free radical scavengers in post-ischemic disorders. Show more

Keywords: Erythrocyte deformability, ischemia, superoxide dismutase, catalase, free radicals

DOI: 10.3233/CH-1992-12214

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 2, pp. 287-296, 1992

Authors: Katoh, Setsushi | Yamamoto, Kazuhiko | Kitao, Manabu

Article Type: Research Article

Abstract: To evaluate fetal erythrocyte functions in the hypoxic environment during delivery, we measured fetal erythrocyte deformability and examined its relationship to various factors affecting it in 102 fullterm, vaginally delivered fetuses. Erythrocyte deformability at delivery was higher in umbilical arterial blood than in umbilical venous blood, and much lower in maternal blood than that in umbilical vessel blood. Erythrocyte deformability was significantly greater in both an asphyxiated group (1-minute Apgar score ≤ 7) and an acidotic group (pH≤ 7.20) than in a normal group (1-minute Apgar score ≤ 8, pH> 7.20, respectively). The PO2 in umbilical arterial blood was …significantly lower than in umbilica1 venous blood. Umbilical blood erythrocyte ATP was significantly higher than that in maternal blood. Erythrocyte deformability in umbilical arterial blood was negatively correlated with umbilical arterial blood PO2 (r=−0.63, n=102, p< 0.001) but positively correlated with erythrocyte ATP level (r= 0.76, n=72, p< 0.001). Umbilical arterial blood erythrocyte ATP was negatively correlated with umbilical arterial blood P02 (r=−0.75, n=72, p< 0.001). These findings suggest that in the hypoxic environment during delivery, fetal erythrocyte deformability is enhanced by the reduced PO2 and the increased erythrocyte ATP levels. Show more

Keywords: Erythrocyte, Deformability, Fetal hypoxia, Delivery, ATP

DOI: 10.3233/CH-1992-12215

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 2, pp. 297-308, 1992

Authors: Caswell, M. | Stuart, J.

Article Type: Research Article

Abstract: Plasma viscosity is used as an alternative to the erythrocyte sedimentation rate (ESR) as a test of the acute-phase response. To determine the effect on these tests of delay between venepuncture and time of testing we have stored plasma and whole blood samples from 39 individuals for 7 days at both 4°C and room temperature (RT). Serial daily testing showed no significant change in the plasma viscosity of separated plasma stored at 4°C or RT or of whole blood stored at 4°C. Whole blood stored at room temperature was stable for 4 days. A closed-tube system was used to determine …the stability of the ESR at 4°C, but there was still a progressive fall in the ESR value over 7 days of storage. This study confirms the validity of plasma viscosity measurements when there is a delay in separation of plasma and/or testing. Show more

Keywords: Rheology, plasma viscosity, erythrocyte sedimentation rate

DOI: 10.3233/CH-1992-12216

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 2, pp. 309-315, 1992

Article Type: Abstract

DOI: 10.3233/CH-1992-12217

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 2, pp. 317-338, 1992

Article Type: Other

DOI: 10.3233/CH-1992-12218

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 2, pp. 339-339, 1992