Clinical Hemorheology and Microcirculation - Volume 12, issue 1

Authors: oude Egbrink, Mirjam G.A. | Tangelder, Geert Jan | Slaaf, Dick W. | Reneman, Robert S.

Article Type: Research Article

Abstract: Intravital videomicroscopy was used to investigate interactions between blood platelets, vascular cells and leukocytes at a site of vessel wall injury in rabbit mesenteric venules (diameter 21–40 μm). A thromboembolic reaction was evoked by puncture of the wall with a glass micropipet (tip 6–8 μm); in all vessels a thrombus was formed, while in most vessels emboli were produced as well. Leukocyte rolling, i.e. their movement along the wall at a clearly lower velocity than the other blood cells flow, was quantitated simultaneously in vessel segments upstream and downstream of a thrombus. In venules without embolization the degree of leukoycte …rolling was not different upstream and downstream of the thrombus, indicating that fluid dynamic changes induced by the thrombus do not influence leukocyte rolling. In venules, in which emboli were produced, leukocyte rolling decreased significantly from upstream to downstream of the thrombus during embolization (median decrease: 45%; p≤0.001). This decrease in leukocyte rolling still existed after embolization had stopped (50%; p≤0.01), indicating that it cannot be explained by inclusion of leukocytes in emboli. Inhibition of prostaglandin formation with aspirin (100 mg/kg) significantly diminished the influence of the thromboembolic reaction on leukocyte rolling (p≤0.05), but blockade of TXA2 -receptors with sulotroban (30 mg/kg) had no effect. The findings suggest that substances, produced by activated blood platelets and/or damaged vascular cells, diminish leukocyte rolling. The identity of the substances is not yet clear, but prostaglandins, other than TXA2 , are probably involved. Show more

Keywords: Platelets, leukocytes, vessel wall injury, thromboembolic reaction, microcirculation, rabbit

DOI: 10.3233/CH-1992-12111

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 1, pp. 59-65, 1992

Authors: Fossat, C. | Sainty, D. | Stoppa, A.M. | David, M. | Maraninchi, D. | Juhan-Vague, I.

Article Type: Research Article

Abstract: Cytokine produce important effects on polymorphonuclear (PMN) functions. We have studied PMN functions in patients with acute inflammatory syndrome with endogenous production of cytokines due to myocardial infarction (MI) at D1 and D3 and in patients suffering from neoplasia submitted to different in vivo cytokines administration: Interleukine 2 (IL-2), Interferon gamma (IFN-G), association IL-2/IFN-G, Granulocyte-colony stimulating factor (G-CSF) before (D0) and at the end of treatment (D36). In MI, leukocyte count increased on the first day and decreased at 03 certainly due to plugging and local destruction. Leukocyte activation occured at 01 and was more pronounced at D3. The …in vivo administration of cytokines had contradictory effects: – IL-2 had a significant inhibitory effect on directed chemotaxis at the end of treatment (D36), while the other functions were not modified. – INF-G had no effect. – This inhibitory effect of IL-2 was not observed when IFN-G was administrated together with IL-2. – G-CSF induced the most important activation of PMN. Show more

Keywords: Polymorphonuclear functions, Cytokines

DOI: 10.3233/CH-1992-12112

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 1, pp. 67-82, 1992

Authors: Nolte, Dirk | Lehr, Hans Anton | Menger, Michael D. | Messmer, Konrad

Article Type: Research Article

Abstract: Ischemia-reperfusion is associated with activation of leukocytes which accumulate in the postischemic tissue, adhere to the microvascular endothelium, emigrate into the perivascular space and contribute to postischemic reperfusion injury through the release of cytotoxic enzymes as well as generation of oxygen free radicals. In the following we have summarized the results of four studies in which the effects of different pharmacological agents on leukocyte-endothelium interaction after ischemia-reperfusion were tested. A 4h ischemia was induced to a thin striated muscle contained in the dorsal skin fold chamber preparation of awake hamsters. Using intravital fluorescence microscopy and a computer-assisted microcirculation analysis system, …red cell velocity, vessel diameter, and leukocyte-endothelium interaction were analyzed in postcapillary venules. Drugs under investigation were infused intravenously prior to and during the early phase of reperfusion. Animals received either adenosine (110 μg kg−1 min−1 ), buflomedil (3 mg kg−1 body weight), the selective leukotriene synthesis inhibitor MK-886 (20 μmol kg−1 h−1 ), or dextran 70 (5 mg kg−1 body weight). In saline-treated control animals, a drastic increase of leukocyte sticking and rolling along the endothelium was observed in the early phase of reperfusion. In animals treated with adenosine, buflomedil, MK-886 or dextran 70 postischemic leukocyte-endothelium interaction was markedly reduced. Our results indicate a protective pharmacological potential of adenosine, buflomedil, MK-886 and dextran 70 on postischemic leukocyte adhesion to the endothelium of postcapillary venules. Show more

Keywords: Microcirculation, ischemia-reperfusion, leukocyte, endothelium, drug action

DOI: 10.3233/CH-1992-12113

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 1, pp. 83-91, 1992

Authors: Ley, K.

Article Type: Research Article

Keywords: Leukocyte, Adhesion, Rheology

DOI: 10.3233/CH-1992-12114

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 1, pp. 93-108, 1992

Authors: Carter, C. | Fisher, T.C. | Hamai, H. | Johnson, C.S. | Meiselman, H.J. | Nash, G.B. | Stuart, J.

Article Type: Research Article

Keywords: Poloxamer 188, Surfactant, Blood rheology, Erythrocytes

DOI: 10.3233/CH-1992-12115

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 1, pp. 109-120, 1992

Authors: Forman, Mervyn B. | Ingram, David A. | Murray, John J.

Article Type: Research Article

Abstract: Perfluorochemicals are substances with a small particle size, low viscosity, and high oxygen-carrying capacity. We have investigated the role of one perfluorochemical, Fluosol, an emulsion of two perfluorocarbons, a detergent [Pluronic F-68], and phospholipids on myocardial reperfusion injury in the closed-chest canine model. Intracoronary and intravenous Fluosol infused in the peri-reperfusion period significantly reduced infarct size and improved ventricular function up to two weeks after reperfusion. Fluosol attenuates neutrophil infiltration into the reperfused bed, preserves endothelial cell structure, and reduces neutrophil plugging of capillaries. Endothelium-dependent relaxation of large and small vessels was maintained 1 hour after reperfusion in Fluosol animals. …Ex vivo studies showed apparent suppression of neutrophil chemotaxis and lysozyme degranulation. Unstimulated neutrophils manifested enhanced superoxide anion production within 5 minutes of incubation even with low concentrations of Fluosol, and this effect was almost entirely due to Pluronic F-68. Neutrophil stimulation was prevented by cytochalasin B, an inhibitor of phagocytosis. Perfluorochemicals may offer a novel therapy to enhance myocardial salvage after successful reperfusion. The mechanism appears to be due to “deactivation” of neutrophils peripherally, thereby reducing their cytotoxic potential in the reperfused myocardium. Show more

Keywords: perfluorochemical, neutrophil, myocardial reperfusion injury, endothelium, pluronic, complement

DOI: 10.3233/CH-1992-12116

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 1, pp. 121-140, 1992

Authors: Lowe, Kenneth C.

Article Type: Research Article

Abstract: Perfluorochemicals (PFCs) are valuable in medicine, primarily as 02-carrying perfusates and tissue imaging agents. Their basic properties are described, including the need for emulsification before intravascular use. The formulation and assessment of PFC emulsions and their components in man and other species are discussed. Attention is focussed on the use of the commercial emulsion, Fluosol™ during clinical coronary angioplasty. Potential applications for PFCs in cancer therapy, ophthalmology, and the treatment of blood and respiratory disorders are also outlined.

Keywords: Perfluorochemicals, blood substitutes, biocompatibility, biomedical applications

DOI: 10.3233/CH-1992-12117

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 1, pp. 141-156, 1992

Article Type: Other

DOI: 10.3233/CH-1992-12118

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 1, pp. 157-159, 1992

Article Type: Other

DOI: 10.3233/CH-1992-12119

Citation: Clinical Hemorheology and Microcirculation, vol. 12, no. 1, pp. 161-161, 1992