Clinical Hemorheology and Microcirculation - Volume 12, issue 6

Authors: Witte, Siegfried | Stoltz, Jean-François

Article Type: Other

DOI: 10.3233/CH-1992-12601

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 6, pp. 785-785, 1992

Authors: McMillan, Donald E.

Article Type: Research Article

Abstract: Chronic diabetes mellitus is associated with difficulties that have in common a disturbance of the circulation. A clearly defined hemorheologic burden antedates and is cross-sectionally related to the diabetic circulatory complications, suggesting that blood flow plays a role in damaging diabetic blood vessels. This concept has led to the development of hemorheologic models for both micro- and macroangiopathy. Intensive insulin therapy appears to benefit the diabetic hemorheologic burden, but it has limits that make it unable to normalize blood's flow properties. Other interventions can be identified, based both on drugs and on changes in health habits. They have little or …no effect on blood glucose levels but decrease the hemorheologic burden; fourteen means to improve diabetic blood flow are identified and discussed. Four non-drug managements are already often used in treatment. Ten types of pharmacologic agent have clear potential for reducing or preventing diabetic vascular problems. The strength of evidence for their effects and their possible mechanisms of action are discussed. Establishing a more effective role for these agents in diabetes management will require more sophisticated interventional studies that incorporate modern hemorheologic assessment into their design. Such evaluations are important in examlnlng both established and new drugs if we are to further improve the prognosis for individuals with established diabetes. Show more

Keywords: diabetes mellitus, insulin, fibrinogen, erythrocyte deformability

DOI: 10.3233/CH-1992-12602

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 6, pp. 787-796, 1992

Authors: Stuart, John

Article Type: Research Article

Abstract: Copley (1) reminds us that the science of haemorheology includes study of the vessel wall as well as the components of the blood. This concept is particularly relevant to rheological studies in patients with sickle cell anaemia who exhibit a complex prothrombotic abnormality affecting vasomotor tone and vascular endothelium as well as the plasma and red cells. Such rheological complexity is further compounded by acute-phase changes secondary to cytokine release from ischaemic tissue. Serial longitudinal study of homozygous patients in the asymptomatic steady state has now suggested a fluctuating balance between accumulation and removal of poorly deformable and dense sickle …cells which is associated with sub-clinical episodes of tissue ischaemia. In the prodromal phase of the painful sickle-cell crisis, there is also an accumulation of rheologically compromised dense cells which may be of aetiological significance in relation to the vaso-occlusion that results in established crisis. Show more

Keywords: Sickle cell anaemia, rheology, acute-phase response

DOI: 10.3233/CH-1992-12603

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 6, pp. 797-804, 1992

Authors: Ernst, E.

Article Type: Research Article

Abstract: Prospective epidemiological trials have identied fibrinogen as a major, primary, cardiovascular risk factor. There are, of course, strong associations between fibrinogen and other risk factors, but the risk factor potential of fibrinogen is independent of these. Fibrinogen might also be a secondary risk factor, i.e. a variable with considerable predictive power after a major cardiovascular event. Our knowledge about the variables determining and regulating the highly variable plasma level of fibrinogen in health and disease is still incomplete. The mechanisms involved in the atherogenic action of fibrinogen are probably diverse. Blood coagulation, blood rheology, platelet aggregation, direct effects of fibrinogen …or its metabolites on the vessel wall and the “Copley endoendothelial fibrin lining” may all represent or provide interacting phenomena of importance. It is concluded that fibrinogen is a major, independent cardiovascular risk factor that should be included in the up-dated risk profil. Show more

Keywords: fibrinogen, risk factor, atherogenesis, rheology

DOI: 10.3233/CH-1992-12604

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 6, pp. 805-816, 1992

Authors: Dosquet, C. | Wautier, J.-L.

Article Type: Research Article

Abstract: The blood monocytes adhere to endothelial cells unstimulated and after stimulation by interleukin-1, tumor necrosis factor or other mediators. This process is mediated through specific molecules on both endothelial cells and monocytes. Using specific monoclonal antibodies and molecular cloning several families of molecules involved in leukocyte-endothelial cell interaction have been defined. Leukocyte adhesion molecules include the three β2 integrins (CD11/CD18 molecules), VLA-4 and the L-Selectin. E-Selectin (ELAM-1), P-Selectin (GMP-140) and receptors of the immunoglobulin superfamily (ICAM-1, ICAM-2 and VCAM-1) are expressed on endothelial cells in basal conditions and after activation by cytokines. It has been shown that these adhesive molecules …are involved in blood monocyte adhesion to endothelial cells in vitro. The in vivo expression of these adhesive molecules on the vascular endothelium has been described in acute and chronic inflammatory situations such as Kawasaki syndrome and atherosclerosis. Show more

Keywords: adhesion, atherosclerosis, endothelium, integrin, monocyte, selectin

DOI: 10.3233/CH-1992-12605

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 6, pp. 817-829, 1992

Authors: Liao, Fu-long | Li, Wen | Yin, Xiao-jie

Article Type: Research Article

Abstract: Based on rotational viscometry of clotting, an approach for evaluation of antiplatelet drugs and anticoagulants was explored. Rat platelet rich plasma (PRP) and platelet poor plasma (PPP) were prepared. PRP and PPP were seperately incubated with and without drug (D), namely, PRP, PRP+D, PPP, and PPP+D. Recalcification of the samples were monitored by HAAKE Rotovisco RV20/CV100 at 0.3 s−1 . The inhibition of platelet involvement (IPI) and the inhibition of plasma clotting (IPC) were defined. According to three clotting parameters (tr, dη/dt, τm), six inhibitions (3 IPI, 3 IPC) were obtained for evaluating a drug. The preliminary investigation on heparin, …pentoxifylline, aspirin, notoginseng saponins and alcohol indicated that the approach would be a promising mean for pharmacological and clinical practice. Show more

Keywords: antiplatelet, platelet, anticoagulant, pharmacology, clotting, viscosity

DOI: 10.3233/CH-1992-12606

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 6, pp. 831-839, 1992

Authors: Bauersachs, R. | Wenby, R.B. | Pfafferott, C. | Whittingstall, P. | Meiselman, H.J.

Article Type: Research Article

Abstract: Red blood cell (RBC) deformability remains a central issue in clinical hemorheology and thus we have developed a simple quantitative approach to determine this cellular mechanical property. The method is based upon the analysis of light transmission (LT)-shear rate relations for RBC suspended in various media. LT measurements are performed with a small (0.025 ml) sample of RBC suspension via a computerized Myrenne cone-plate shearing system; LT values are measured at eight shear rates from 5 to 500 s−1 using specially developed software. With appropriate combinations of hematocrit and suspending media viscosity, linear relations (r>0.997) between LT and log …(shear rate) are obtained for cells in non-aggregating media. LT-shear rate relations are markedly affected by cell rigidity, such that LT decreases for less deformable RBC (i.e., dense or heat treated cells). Simplification of the procedure is possible by testing RBC in aggregating media (e.g., plasma) and measuring LT at 500 s−1 (LT500 ) to completely disperse aggregates; LT500 values in both non-aggregating and aggregating media are lower for less deformable cells. The method is sensitive, reproducible (CV < 2%) and can be performed in less than three minutes; LT500 values can be obtained within seconds and for RBC in plasma are available during routine aggregation measurements. The methods thus appears to be relevant to clinical studies of erythrocyte deformability. Show more

Keywords: Erythrocyte deformability, light transmission, RBC deformation, shear forces

DOI: 10.3233/CH-1992-12607

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 6, pp. 841-856, 1992

Authors: Maeda, T. | Fisher, A.C. | Nash, G.B.

Article Type: Research Article

Abstract: Interaction between platelets and granulocytes may contribute to ischaemic and inflammatory disorders. We have used a recently developed granulocyte aggregation assay, in which isolated granulocytes and platelet-rich plasma (PRP) are mixed, to test the ability of a range of pharmacological agents to inhibit this interaction. A stable prostacyclin analogue (Iloprost) could completely inhibit platelet-induced granulocyte aggregation if the whole blood was treated immediately following withdrawal, but not if the agent was added to granulocytes or PRP after isolation. A surfactant (Poloxamer 188) added to the whole blood, either increased aggregation or had no effect, depending on the source of the …compound under test. Naftidrofuryl oxalate and pentoxifylline tended to reduce aggregation, but these effects were not statistically significant. It appears that agents which can inhibit platelet activation may reduce adhesion to granulocytes, but are unable to reverse the interaction after the platelets have been stimulated. Show more

Keywords: Leukocytes, Platelets, Aggregation, Drugs

DOI: 10.3233/CH-1992-12608

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 6, pp. 857-865, 1992

Authors: Al-Zahrani, H. | Lowe, G.D.O. | Douglas, J.T. | Cuschieri, R. | Pollock, J.G. | Smith, W.C.S.

Article Type: Research Article

Abstract: Copley hypothesised the existence of an endoendotnelial fibrin lining of blood vessels; while the Rokitansky-Duguid hypothesis suggests that ongoing fibrin formation on the arterial wall contributes to atherosclerosis. We assessed in vivo fibrin turnover by measurement of plasma levels of cross-linked fibrin degradation products (D-dimer antigen) using a sensitiveimmunoassay, in 68 patients with extensive atherosclerosis (chronic peripheral arterial disease) compared to 239 controls (a random population sample in the same area). Plasma D-dimer levels were significantly higher in patients than controls (p<0.01) and correlated with clinical severity. We suggest that the plasma D-dimer level may be a useful index of …intravascular fibrin turnover and of the ongoing contribution of thrombosis to arterial disease. Show more

DOI: 10.3233/CH-1992-12609

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 6, pp. 867-872, 1992

Authors: Ziegler, O. | Candiloros, H. | Derriennic, X. | Muller, S. | Donner, M. | Stoltz, J.F. | Drouin, P.

Article Type: Research Article

Abstract: The role of either plasmatic or cellular factors in the erythrocyte aggregation has been quantitatively examined in type I diabetes mellitus by studying the variations in the light backscattered by an aggregating blood suspension. The erythrocyte aggregation parameters measured on cells from diabetic patients resuspended in autologous plasma were significantly impaired when compared to the values observed on erythrocytes from healthy controls resuspended in their own plasma. Aggregation was significantly lower when erythrocytes from diabetic patients were resuspended in normal plasma Conversely, it was noted a significantly higher aggregation when normal erythrocytes were resuspended in plasma from diabetic patients as …compared to normal plasma. Similar cross-match experiments showed that erythrocyte membrane lipid fluidity is not affected by resuspension of red cells in different plasmas. These results underly the major role of plasmatic factors in erythrocyte hyperaggregation in type I diabetes mellitus. Show more

Keywords: Type I diabetes mellitus, Erythrocyte aggregation, Plasma proteins, Membrane

DOI: 10.3233/CH-1992-12610

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 6, pp. 873-881, 1992