Clinical Hemorheology and Microcirculation - Volume 19, issue 4

Authors: Mira, Y. | Vayá, A. | Martínez, M. | Villa, P. | Santaolaria, M.L. | Ferrando, F. | Aznar, J.

Article Type: Research Article

Abstract: Deep vein thrombosis (DVT) seems to be related to a hypercoagulation and definite hemorheological alterations, but the importance of these alterations in the development of thrombotic events in the deep vein system has not been established. The present study examines both aspects in a group of 55 patients with DVT; the presence of a hypercoagulable state was assessed by quantifying the prothrombin fragment 1+2 (F1+2) and the thrombin–antithrombin III complex (T–AT), and the main hemorheological parameters were evaluated in the acute state and 6 and 12 months later. The results show marked hemorheological, F1+2, and TAT alterations in the acute …phase. After 12 months the pattern shows a modest improvement, but erythrocyte aggregation, fibrinogen, F1+2 and T–AT remain increased with respect to the control group (8.51{}\pm{} 1.43; 331{}\pm{} 81 mg/dl; 1.33{}\pm{} 0.60 nmol/l; 3.54{}\pm{} 1.71 ng/ml vs. 8.10{}\pm{} 1.40; 230{}\pm{} 38; 0.94{}\pm{} 0.40; 1.56{}\pm{} 0.59, respectively). These data suggest that the thrombotic event could be influenced by the previous rheological situation and hypercoagulable state. Show more

Keywords: Deep vein thrombosis, prothrombin fragment 1+2, thrombin–antithrombin III complexes, hemorheology

Citation: Clinical Hemorheology and Microcirculation, vol. 19, no. 4, pp. 265-270, 1998

Authors: Cook, A.M. | Jones, J.G. | Lane, I.F. | Evans, S.‐A.

Article Type: Research Article

Abstract: Leukocytes are characterised from their influence on the filterability of undiluted blood from patients with PAOD (intermittent claudicants – Fontaine Stage II) and a group of sex and age‐matched controls. Undiluted blood was filtered through 5 \mu m Nuclepore (Hemafil) filters for 300 s, at 711 Pa and room temperature, using a custom‐made constant pressure filtrometer. Four populations of leukocytes are identified in both groups. In the control group, 94.4% of the leukocytes are identified as fast leukocytes with a transit time of 1.8 s. The remaining white cells are recognised as slow flowing leukocytes and subdivided into three …further sub‐populations. The first of these (SL_1 ; 2.8% of total leukocyte count) is characterised by a transit time of 31.7 s, a second population (SL_2 ; 1.5% of total leukocyte count) by a transit time of 145.8 s while the remaining cells are identified as pore blockers (PB) under these conditions. A similar rheological classification is valid in the patients but the sum of the three minor populations is elevated compared to controls (p= 0.001 ) although there is no overall leukocytosis. The only significant difference in flow properties of any blood cells, between the two groups of volunteers, is seen in the major population of leukocytes with an elevated transit time of 2.4 s. Stepwise regression analysis identifies the concentration of fast leukocytes, SL_2 and PB as the major variables affecting blood flow through the filter. It is argued that the higher concentration of SL_{2} and PB probably reflect the increased sensitivity of neutrophils to physical stimuli. Show more

Keywords: Leukocyte filterability, peripheral vascular disease, blood filterability

Citation: Clinical Hemorheology and Microcirculation, vol. 19, no. 4, pp. 271-280, 1998

Authors: Caimi, Gregorio | Lo Presti, Rosalia | Canino, Baldassare | Montana, Maria | Ferrara, Lidia | Oddo, Gaspare | Ventimiglia, Giuseppe | Cerasola, Giovanni

Article Type: Research Article

Abstract: In 24 hypertensives we evaluated, at baseline, the leukocyte filtration parameters (using the St. George’s Filtrometer), polymorphonuclear (PMN) membrane fluidity (with the fluorescent probe 1‐[4‐(trimethylamino)phenyl]‐6‐phenyl‐1,3,5‐hexatriene [TMA‐DPH]) and PMN cytosolic Ca^{2+} content (with the fluorescent probe Fura 2‐AM). In a subgroup of hypertensives (n=17 ) the PMN filtration parameters, PMN membrane fluidity and cytosolic Ca^{2+} content were evaluated after in vitro chemotactic activation (prolonged for 5 and 15 min) with two stimulating agents (4‐phorbol 12‐myristate 13‐acetate [PMA] and N‐formyl‐methionyl‐leucyl‐phenylalanine [fMLP]). It was evident, from the baseline data, that there was a significant difference in the …mononuclear (MN) initial relative flow rate (IRFR), clogging rate (CR) and clogging particles (CP), and in PMN cytosolic Ca^{2+} content. There were, however, no differences in the filtration parameters of unfractionated leukocytes and PMNs or in PMN membrane fluidity. After activation, in normals and in hypertensives, a significant variation in PMN filtration parameters was evident. In normals no variation was present in PMN membrane fluidity or cytosolic Ca^{2+} content after activation. In hypertensives, however, we found an increase solely in PMN cytosolic Ca^{2+} content after fMLP activation. After PMN activation (at 15 min) one parameter (IRFR) of PMN filtration distinguished normal subjects from hypertensives. No difference between the two groups was found in PMN membrane fluidity or PMN cytosolic Ca^{2+} content after PMN activation. Show more

Keywords: Essential hypertension, leukocyte rheology, polymorphonuclear leukocyte activation, membrane fluidity, cytosolic Ca^{2+} content

Citation: Clinical Hemorheology and Microcirculation, vol. 19, no. 4, pp. 281-289, 1998

Authors: Maurice, G. | Wang, X. | Stoltz, J.F.

Article Type: Research Article

Abstract: The authors present analytical and numerical approaches of the deformation of venous and arterial vessels vasa vasorum. An elastic behaviour of the vessel wall is supposed. It is shown that a normal range of intraluminar pressure induces a small deformation in the vasa vasorum in arteries. According to the nonlinear elastic behaviour, a larger deformation is induced in venous vasa vasorum is rapidly obtained. Increased pressure has serious consequences, especially on the flow in vasa vasorum and induces decrease of oxygen transport. This phenomenon could be one of the generating factors of artheriogenesis and ischemia.

Citation: Clinical Hemorheology and Microcirculation, vol. 19, no. 4, pp. 291-298, 1998

Authors: Wen, Zong‐yao | Song, Li‐chuan | Yan, Zong‐yi | Lu, Zhi‐hong | Sun, Da‐gong | Shi, Yan | Chien, Shu

Article Type: Research Article

Abstract: Using the model in which the entire RBC population was nearly synchronously produced following the induction of spherocytic anemia in the rabbit with antibody serum, we determined the changes of RBC osmotic fragility and deformability with aging. The results showed that the osmotic fragility increased with the RBC aging process in a nonlinear manner, being much more profound in the later part of the RBC life span. The RBC deformation index (DI) was measured by an ektacytometry. It is found that the DI decreased with RBC aging in a nonlinear fashion, with increasingly greater changes in the later part of …the RBC life span. The alterations of RBC mechanical properties with aging may be attributable to a number of factors, including changes of RBC size and shape, and the viscoelasticity of the cytoplasm and membrane. Show more

Keywords: Erythrocyte senescence, osmotic fragility, deformability, animal model, red blood cell

Citation: Clinical Hemorheology and Microcirculation, vol. 19, no. 4, pp. 299-306, 1998

Authors: Baskurt, Oguz K. | Meiselman, H.J. | Kayar, Ercument

Article Type: Research Article

Abstract: The analysis of light reflection from or transmission through a blood sample under defined shearing conditions is widely used to assess red blood cell (RBC) aggregation. Different shearing geometries have been used to generate a constant shear rate within the blood sample, including “cone on plate” and Couette systems. In this study, a rotating glass plate, together with a parallel stationary plate, was used to generate a given shear rate at the point of light transmission measurement. The system gave reproducible results and proved to be sensitive to alterations in RBC aggregation. A comparison between different RBC aggregation parameters that …can be calculated using the same light transmission curves (syllectograms) was also made. The index calculated by integrating the area under the syllectogram (M index) was found to be the most appropriate aggregation parameter to be used for comparisons between two groups of blood samples with different aggregation characteristics. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 19, no. 4, pp. 307-314, 1998

Authors: Mchedlishvili, George

Article Type: Research Article

Abstract: Blood flow structuring is a phenomenon of co‐ordinated self‐organization of RBCs in the normal flow in microvessels which actually defines the blood rheological properties in their lumina. Under conditions of undisturbed macrocirculation and normal conductance of microvessels the blood flow structuring is a determining factor of the fluidity of the driven blood. The dynamic structuring of blood flow prevails in advancing of the driven RBCs with plasma in the shear field induced in microvessels. Term “blood flow structuring” was introduced to describe the self‐organised behavior of the RBCs and plasma advancing in the arterio‐venular direction in the rapidly perfused microvessels. …It implies primarily the availability of parietal plasma layer and of RBCs driven in the axial core, the tank treading, deformation and orientation of the red cells, i.e., of their self‐optimizing adaptive behavior which minimizes energy dissipation. Many local hemorheological disturbances in the microvessels are related to intensified RBC aggregation and to the subsequent local accumulation in the microvascular lumina, thus entailing disorders of the blood flow structuring. This, in turn, results in the decrease of flow velocity, to full blood stasis, despite a preserved local arterio‐venous driving pressure gradient. Elevated blood plasma viscosity and considerably curtailed RBC deformability might also entail retardation and even stoppage of the RBC flow in microvessels. The transition of blood flow to blood stasis and again to blood flow represents a synergetic process in the critically underperfused microvascular networks. As to the WBCs and thrombocytes, they are not involved in the normal blood flow structuring in microvessels, but they can largely affect both the blood flow normal structuring and the flow velocity under various pathological conditions. The presented theoretical concept accounts for a wide variety of transition patterns from the normal to the pathological hemorheological phenomena in the microcirculation. Show more

Keywords: Blood flow structuring – phenomenon, determining resistance in microvessels, blood components involved in, factor responsible for its disturbance, RBC aggregation – the principal factor disturbing blood flow in microvessels

Citation: Clinical Hemorheology and Microcirculation, vol. 19, no. 4, pp. 315-325, 1998

Article Type: Research Article

Citation: Clinical Hemorheology and Microcirculation, vol. 19, no. 4, pp. 327-331, 1998