Clinical Hemorheology and Microcirculation - Volume 50, issue 4

Authors: Nemeth, Norbert | Kiss, Ferenc | Magyar, Zsuzsanna | Miszti-Blasius, Kornel | Furka, Istvan

Article Type: Research Article

Abstract: Growing number of clinical and experimental data reflect to the gender differences of hemorheological parameters. However, little is known about the potential hemorheological effect of gonadectomy and consequent changes in sex hormone concentration. Adult, same-aged male and female rats were involved in the study. In control male and female group no surgical intervention was performed. In gonadectomized (GoE) male and female groups bilateral orchidectomy or ovariectomy were completed. Body weight measurement and blood sampling were carried out in the 1st, 2nd and 3rd postoperative months. The GoE females had significant bodyweight augmentation and their plasma estrogen concentration decreased by 40–45% …by the 1st postoperative month, while in males the testosterone level was not detectable after gonadectomy. Leukocyte and platelet counts moderately increased in GoE males. Elongation index values of erythrocytes slightly decreased in both genders after gonadectomy, showing converging values. Erythrocyte aggregation index values of GoE females significantly raised by the 2nd month. It can be concluded that gonadectomy in rats resulted in alteration (dominantly impairment) of blood microrheological parameters, by different manner in males and females. Supposedly decrease in estrogen can cause more expressed hemorheological changes than the cessation of testosterone. Show more

Keywords: Gonadectomy, gender differences, laboratory animals, red blood cell aggregation, red blood cell deformability

DOI: 10.3233/CH-2011-1430

Citation: Clinical Hemorheology and Microcirculation, vol. 50, no. 4, pp. 231-243, 2012

Authors: Bláha, Milan | Rencová, Eva | Langrová, Hana | Lánská, Miriam | Bláha, Vladimír | Studnička, Jan | Rozsíval, Pavel | Malý, Radovan | Fátorová, Ilona | Filip, Stanislav | Dršata, Jakub | Hejsek, Libor | Malý, Jaroslav

Article Type: Research Article

Abstract: To date, rheological treatment is the only chance to control the advanced dry form of age-related macular degeneration and arrest its progression to legal blindness. Rheohaemapheresis can change the main rheological parameters, blood and plasma viscosity, as well as change erythrocyte aggregability, improve erythrocyte flexibility and lead to substantial improvement when other methods of therapy fail. In this study, we describe changes in the levels of rheological efficacy indicators after rheohaemapheresis and their clinical significance in the dry form of age-related macular degeneration (AMD). Seventy-two patients with AMD were randomised; 34 controls, and 38 patients were treated with rheohaemapheresis (separator …Cobe Spectra + Evaflux filter). After the procedures, α2 -macroglobulin levels decreased by approximately 58%, fibrinogen by approximately 65%, IgM by approximately 67%, LDL cholesterol by approximately 71%, apolipoprotein B by approximately 65%, and lipoprotein (a) by approximately 42%. These decreases correspond with a decrease in blood and plasma viscosity (14/12%), clinical improvement (arrest of disease progression, even visual improvement in some cases), and heretofore-unreported improvement (even reattachment) of drusen retinal pigment epithelium detachment. Our modification of rheohaemapheresis is safe (5.4% of patients experienced clinically insignificant side effects). Show more

Keywords: Rheopheresis, rheology, microcirculation, age related macular degeneration

DOI: 10.3233/CH-2011-1431

Citation: Clinical Hemorheology and Microcirculation, vol. 50, no. 4, pp. 245-255, 2012

Authors: Nam, Jeong-Hun | Xue, Shubin | Lim, Hyunjung | Shin, Sehyun

Article Type: Research Article

Abstract: In vivo red blood cell aggregation will vary under pulsatile flow but few studies have been reported due to various difficulties in generating physiological flow conditions and detecting RBC aggregation. The present study developed a microfluidic system that generates cyclic pulsatile flow through a microchannel. Backscattered light signals from human blood were recorded over time and analyzed for RBC aggregation in pulsatile flow. Four different blood samples (control, normal RBCs in PBS, hardened RBCs in autologous plasma, and hardened RBCs in PBS) were examined. In a cyclic pulsatile flow condition, light intensity-time curve for the control and hardened RBCs in …plasma exhibited apparent critical shear stresses that were similar to the respective values measured at a single pulse flow condition. During entire cycles of pulsatile flow, the measured critical shear stress remained nearly constant. We conclude that the critical shear stress can be observed in cyclic pulsatile flow and would be an important index to represent in-vivo pulsatile blood flow rheology. Show more

Keywords: RBC, aggregation, critical shear stress, in-vivo, pulsatile flow

DOI: 10.3233/CH-2011-1434

Citation: Clinical Hemorheology and Microcirculation, vol. 50, no. 4, pp. 257-266, 2012

Authors: Li, Yu-Juan | Han, Dong | Xu, Xiang-Shun | Liu, Yu-Ying | Sun, Kai | Fan, Jing-Yu | Qian, Rui-Qin | Han, Jing-Yan

Article Type: Research Article

Abstract: This study intended to examine the effect of 3,4-dihydroxyphenyl lactic acid (DLA), a major ingredient of Salvia miltiorrhiza, on lipopolysaccahride (LPS) -induced mouse cerebral cortical microcirculatory disturbance. Velocity of red blood cells in, and albumin leakage from venules, and the numbers of leukocytes rolling on, and adherent to the venular wall were determined by an up-right microscope after LPS (5 mg/kg/h) infusion with or without administration of DLA (5 mg/kg/h). Expression of adhesion molecules CD11b/CD18 and L-selectin on neutrophils, plasma concentration of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6) were evaluated by flow cytometry. Concentration of TNF-α in supernatants of …LPS-stimulated mononuclear cells was evaluated in vitro by flow cytometry as well. LPS exposure significantly increased the number of rolling and adherent leukocytes as well as albumin leakage, and decreased the velocity of red blood cells in venules. In addition, LPS stimulation apparently increased the expression of CD11b/CD18 on neutrophils, the concentration of plasma TNF-α, and the production of TNF-α from mononuclear cells. Treatment with DLA significantly ameliorated LPS-induced insults in mice, including cerebral microcirculatory disturbance, the expression of CD11b/CD18 on neutrophils, and the increased concentration of plasma TNF-α and the production of TNF-α from mononuclear cells. Show more

Keywords: Brain, lipopolysacchride, TNF-α, vascular permeability, intravital microscopy

DOI: 10.3233/CH-2011-1435

Citation: Clinical Hemorheology and Microcirculation, vol. 50, no. 4, pp. 267-278, 2012

Authors: Vendégh, Zsolt | Melly, András | Tóth, Balázs | Wolf, Konrad | Farkas, Tamás | Kádas, István | Hamar, János

Article Type: Research Article

Abstract: The developing callus requires sufficient oxygen and substrate supply. Despite the importance of these processes, we have limited understanding of regulation of the callus microcirculation. We aimed to assess the role of vasoactive substances in the microcirculation of the callus in a gap osteotomy model in the rabbit detected by laser-Doppler flowmetry. The reactions were elicited with locally applied vasoactive substances: epinephrine (E), calcitonine-gene related protein (CGRP), substance P (SP), sodium nitroprusside (SNP) and Ebrantil (Ebr) on the 10th and 15th postoperative days. Changes of the circulatory parameters were compared to changes in the ipsilateral femoral bone marrow. Perfusion pressure, …maximal change of the blood flow and 50% recovery time (50RT) of the flow reactions and peripheral micro vascular resistance (MVR) was calculated. Systemic blood pressure (BP) was measured directly with an arterial catheter. Reactive neurovascular structures, sensitive to neuropeptides and vasoactive substances, appear at a very early stage of callus formation. On the 10th postoperative day, 2/3 of the blood flow velocity of the intact tibia has already returned, and the values are higher on the 15th postoperative day than those of the intact tibia. The basal blood flow velocities (prior to administration of any substance) are significantly higher on the 15th postoperative day than on the 10th. Show more

Keywords: Laser-doppler flowmetry, neuropeptides, vasoactive substances, interfragmentary callus, gap osteotomy, callus microcirculation

DOI: 10.3233/CH-2011-1436

Citation: Clinical Hemorheology and Microcirculation, vol. 50, no. 4, pp. 279-291, 2012

Authors: Fadini, Gian Paolo | Grego, Franco | Menegolo, Mirko | Agostini, Carlo | Avogaro, Angelo

Article Type: Research Article

Abstract: Ischemic recruitment of endothelial progenitor cells (EPCs) in involved in compensatory angiogenic in animal models, but this still needs to be substantiated in humans. We enrolled 12 patients, who underwent surgical correction of abdominal aortic aneurysm without atherosclerosis of leg arteries (n = 4) or lower limb atherosclerosis obliterans (AO; n = 8). We measured VEGF, SDF-1, lactate and CD34+ KDR+ EPCs in the arterial and venous circulation of lower limbs. We found that, irrespectively of AO stage and lactate production, there was no consistent arterio-venous gradient of EPC, VEGF and SDF-1. Notably, in 4/8 patients, EPCs were …more abundant in the vein than in the artery. EPC gradient was directly correlated with VEGF gradient and inversely correlated with SDF-1 gradient. In conclusion, we failed to show any consistent gradient of EPCs across ischemic limbs in relation to severity of atherosclerosis obliterans, but we speculatively suggest that a bidirectional traffic of EPCs in and out the ischemic tissue might be regulated by VEGF and SDF-1. Show more

DOI: 10.3233/CH-2011-1437

Citation: Clinical Hemorheology and Microcirculation, vol. 50, no. 4, pp. 293-300, 2012

Authors: Sandhagen, Bo | Lind, Lars

Article Type: Research Article

Abstract: It has previously been shown that a high hemoglobin value, a major determinant of whole blood viscosity (WBV), predicts cardiovascular events. One putative mechanism might be an impaired endothelial function. Erythrocyte deformability is another rheologic feature of the erythrocyte being of importance for the flow properties of the blood, especially in the capillaries. The present study evaluates the relationships between blood viscosity, erythrocyte deformability assessed as erythrocyte fluidity (EF), coronary risk and endothelial vasodilatory function. In the population-based PIVUS study (1016 subjects aged 70); endothelium-dependent vasodilation (EDV) was evaluated by the invasive forearm technique with acetylcholine given in the brachial …artery and the brachial artery ultrasound technique with measurement of flow-mediated dilatation (FMD). WBV, plasma viscosity (PV) and EF were measured in a random sample of 573 subjects. WBV and PV were positively and EF negatively related to Framingham risk score. EDV was inversely related to both whole blood and plasma viscosity. FMD was not related to any rheologic variable. In multiple regression analyses WBV and EF were significantly related to EDV independently of gender, hypertension, smoking, hypercholesterolemia, obesity and diabetes. Acetylcholine-induced vasodilation in the forearm, but not FMD, was negatively related to whole blood viscosity and positively related to EF independently of traditional risk factors in elderly subjects, indicating a pathophysiological link between impaired hemorheology and coronary risk. Show more

Keywords: Blood viscosity, endothelium, erythrocyte deformability, coronary risk, vasodilation

DOI: 10.3233/CH-2011-1505

Citation: Clinical Hemorheology and Microcirculation, vol. 50, no. 4, pp. 301-311, 2012

Article Type: Other

Citation: Clinical Hemorheology and Microcirculation, vol. 50, no. 4, pp. 313-317, 2012