Clinical Hemorheology and Microcirculation - Volume 57, issue 1

Authors: Nemeth, Norbert | Kiss, Ferenc | Klarik, Zoltan | Miko, Iren

Article Type: Research Article

Abstract: It is known that red blood cell deformability may show colorful inter-species differences, influenced by inner viscosity, cell membrane viscosity, morphology and surface-volume ratio of the erythrocytes. It is also well-known that the cell volume is changing depending on the micro-environmental osmolarity. These changes can be well observable using osmotic gradient ektacytometry (osmoscan). Interestingly, there is a lack of base and comparative osmoscan data regarding the experimental/laboratory animal species. In this study mouse, rat, canine and porcine blood samples were analyzed using a LoRRca MaxSis Osmoscan ektacytometer. The highest elongation index values were found in mouse, typically above shear stress …of 1 Pa. Some lower values than these were shown in rat and more lower in canine, while the lowest values were detected in porcine, typically above 3–5 Pa. The optimal osmolarity point value, so the measurable maximal EI osmolarity was in a wide range among the species. While the lowest values were detected in canine, the highest ones in porcine and mouse, the rat values were in between. Further analysis and wider comparison of the osmotic gradient ektacytometry may contribute to the better understanding of the erythrocyte micro-rheological properties, their induced changes and inter-species differences. Show more

Keywords: Red blood cell deformability, osmotic gradient ektacytometry, osmoscan, experimental animals, inter-species differences

DOI: 10.3233/CH-2012-1620

Citation: Clinical Hemorheology and Microcirculation, vol. 57, no. 1, pp. 1-8, 2014

Authors: Verger, Emmanuelle | Schoëvaërt, Damien | Carrivain, Pascal | Victor, Jean-Marc | Lapouméroulie, Claudine | Elion, Jacques

Article Type: Research Article

Abstract: The hallmark of sickle cell disease (SCD) is vasoocclusive crisis (VOC). The sickle red blood cells (SS-RBCs) present enhanced adhesion to activated endothelial cells (ECs) as compared to normal RBCs (AA-RBCs) and believed to contribute to VOC. Hydroxycarbamide (HC), the sole drug thus far proven as efficacious at reducing VOC frequency, alters the expression of adhesion proteins both on RBCs and ECs. We investigated the functional effect of HC on the adhesive properties of ECs from the micro- or the macrocirculation (TrHBMEC, HPMEC, and HUVEC). Using a flow chamber, we analyzed RBC dynamics on the treated or untreated EC bed …and firm adhesion in basal and inflammatory conditions. Most significant effects were obtained with ECs from the pulmonary microcirculation (HPMEC). HC treatment of ECs affects both transient interactions and firm adhesion of SS-RBCs to the EC bed. Indeed, first, HC-treatment of ECs decreases the number of firmly adherent SS-RBCs to the adhesion level of AA-RBCs in a VCAM-1 independent manner. Second, HC significantly increases the mean velocity of SS-RBCs and reduces the population of SS-RBCs in contact with the EC bed. These data provide additional evidence that modulation of SS-RBCs/ECs interactions by HC represents an important aspect of its mechanism of action. Show more

Keywords: Sickle cell anemia, endothelial cells, hydroxycarbamide, cell adhesion

DOI: 10.3233/CH-131762

Citation: Clinical Hemorheology and Microcirculation, vol. 57, no. 1, pp. 9-22, 2014

Authors: Montero, David | Walther, Guillaume | Perez-Martin, Antonia | Santamaria, Cristina | Roche, Enrique | Mercier, Charles | Vinet, Agnès

Article Type: Research Article

Abstract: By means of flowmotion analysis, it is mainly accepted that, in normal conditions, insulin specifically increases the activity of microvascular smooth muscle. The objective of this study was to compare this effect in severely obese and normal-weight adolescents. Laser Doppler measurements were used to assess cutaneous blood flux (CBF) and flowmotion in response to transdermal iontophoresis of insulin in 20 severely obese adolescents (SOA) aged 12–17 years (BMI = 33.34 ± 1.07 kg/m2 ), and 16 normal-weight adolescents (BMI = 18.85 ± 0.50 kg/m2 ). Fasting insulin levels were higher in SOA than in normal-weight adolescents (6.25 ± 1.03 vs. …3.11 ± 0.28 μU/ml, P = 0.007). Net insulin-induced increase of CBF did not significantly differ between SOA and normal-weight adolescents (422.41 ± 146.09 vs. 232.36 ± 80.98 %, P = 0.265). A significant impairment of myogenic flowmotion was detected in SOA compared to normal-weight adolescents in response to insulin delivery (5.91 ± 0.35 vs. 8.12 ± 0.63 %, P = 0.003). Severely obese adolescents exhibit decreased myogenic activity in response to insulin, which may be an early step in the development of insulin resistance. Show more

Keywords: Flowmotion, insulin action, microcirculation, severe obesity, adolescents

DOI: 10.3233/CH-131769

Citation: Clinical Hemorheology and Microcirculation, vol. 57, no. 1, pp. 23-32, 2014

Authors: Alkhatib, Ahmad | Klonizakis, Markos

Article Type: Research Article

Abstract: This study tested the potential risk-reduction benefits of Mediterranean Diet (MD) and regular exercise training on microvascular activity and cardiorespiratory capacity in postmenopausal women. Fifteen sedentary postmenopausal participants (age = 54.6 ± 3.6) were randomised into either exercise training or exercise combined with following MD for eight-weeks, and were assessed for their cardiorespiratory capacity, and upper- and lower-limb endothelial cutaneous vascular conductance (CVC) test using Laser Doppler Fluximetry (LDF), coupled with measuring endothelium-dependent Acetylcholine Chloride (Ach) and -dependent Sodium Nitropurruside (SNP) vasodilators. Exercise training improved cardiorespiratory capacity as indicated by ventilatory threshold (11.5 ± 2.1 vs. 14.0 ± 3.0 ml·kg−1 …·min−1 , p < 0.05) and improved the microcirculatory perfusion results of CVC for both vasodilators Ach (p < 0.001, d = 0.65) and SNP (p = 0.003, d = 0.53) in the lower-limb and ACh (p = 0.01, d = 0.41) and SNP (p = 0.03, d = 0.48) in the upper-limb, all (p < 0.05). However, combining exercise with MD showed a stronger improvement in Ach (p = 0.02, d = 0.36) of the lower limb, than in exercise alone group. The results suggest that regular moderate exercise improves microcirculatory vascular function and increases exercise tolerance, both are responsible for reducing cardiovascular risk in postmenopausal women. However, combining MD with exercise suggests additional microvascular vasodialiatory improvement, suggesting an effective strategy for further cardiovascular risk-reduction in this high-risk group. Show more

Keywords: Menopause, cardiorespiratory capacity, endothelial function, microcirculation, nutrition

DOI: 10.3233/CH-131770

Citation: Clinical Hemorheology and Microcirculation, vol. 57, no. 1, pp. 33-47, 2014

Authors: Reinhart, W.H. | Cagienard, F. | Schulzki, T. | Venzin, R.M.

Article Type: Research Article

Abstract: We investigated the influence of the passage of a hemodialysis filter on red blood cells (RBCs), platelets, and hemorheological parameters. After one hour of hemodialysis, blood was drawn from 15 patients immediately ahead and behind the dialysis filter. RBCs were fixed for morphological analysis. Blood viscosity was measured with a Couette viscometer (LS-30, Contraves), RBC aggregation with a Myrenne aggregometer, platelet aggregation in flowing whole blood and in platelet rich plasma. The passage of the hemodialysis filter increased the hematocrit from 34.0 ± 3.8 to 44.6 ± 8.7% (p < 0.01). Discocytes decreased from 73 ± 9 to 60 ± …15%, while echinocytes/knizocytes were more abundant 24 ± 9% and 38 ± 15%, respectively, p < 0.01). Blood viscosity increased from 3.77 ± 0.52 to 6.75 ± 2.21 mPa.s (p < 0.01). The RBC aggregation index decreased from 25.8 ± 5.0 to 20.9 ± 5.6 (p < 0.05). These changes were less pronounced when the blood flow rate was reduced from 350 to 100 ml/min. Platelet aggregation was slightly increased in flowing whole blood, but decreased in platelet rich plasma. At the end of hemodialysis, a small increase in abnormally shaped RBCs, hematocrit, and whole blood viscosity persisted; platelet aggregation in flowing whole blood was reduced in all patients. We conclude that the passage of a hemodialysis filter induced RBC shape changes, increased the hematocrit, whole blood and plasma viscosity, decreased RBC aggregation, and affected platelet aggregation. Show more

Keywords: Aggregation, blood viscosity, echinocytes, erythrocytes, hemorheology, platelet aggregation

DOI: 10.3233/CH-131771

Citation: Clinical Hemorheology and Microcirculation, vol. 57, no. 1, pp. 49-62, 2014

Authors: Lamarre, Yann | Romana, Marc | Lemonne, Nathalie | Hardy-Dessources, Marie-Dominique | Tarer, Vanessa | Mougenel, Danielle | Waltz, Xavier | Tressières, Benoît | Lalanne-Mistrih, Marie-Laure | Etienne-Julan, Maryse | Connes, Philippe

Article Type: Research Article

Abstract: While chronic hemolysis has been suspected to be involved in the development of glomerulopathy in patients with sickle cell anemia (SCA), no study focused on the implications of blood rheology. Ninety-six adults with SCA at steady state were included in the present cross-sectional study. Three categories were defined: normo-albuminuria (NORMO, n = 41), micro-albuminuria (MICRO, n = 23) and macro-albuminuria (MACRO, n = 32). Blood was sampled to measure hematological and hemorheological parameters, and genomic DNA extraction was performed to detect the presence of α-thalassemia. The prevalence of α-thalassemia was lower in the MACRO group compared with the two other …groups. Anemia was more severe in the MACRO compared with the NORMO group leading the former group to exhibit decreased blood viscosity. Red blood cell deformability was lower and red blood cell aggregates strength was greater in the MACRO compared to the two other groups, and this was directly attributed to the lower frequency of α-thalassemia in the former group. Our results show the protective role of α-thalassemia against the development of sickle cell glomerulopathy, and strongly suggest that this protection is mediated through the decrease of anemia, the increase of RBC deformability and the lowering of the RBC aggregates strength. Show more

Keywords: Sickle cell anemia, glomerulopathy, hemorheology, hemolysis

DOI: 10.3233/CH-131772

Citation: Clinical Hemorheology and Microcirculation, vol. 57, no. 1, pp. 63-72, 2014

Authors: Gyawali, Prajwal | Richards, Ross S. | Hughes, Diane L. | Tinley, Paul

Article Type: Research Article

Abstract: Erythrocyte aggregation has been consistently associated with insulin resistance, central obesity and hypertension in the literature. Oxidative stress and chronic inflammation are almost always present in metabolic syndrome (MetS). Prooxidants and adipocytokines generated in MetS alter erythrocyte morphology, decrease erythrocyte deformability and increase whole blood viscosity (WBV). Increased WBV has been attributed to erythrocyte aggregation which in turn is greatly influenced by other rheological parameters, including its membrane surface charge and plasma fibrinogen concentration. The interplay of hemorheological factors, oxidative stress and inflammation has a detrimental effect in MetS due to the gross disturbance in microcirculation. The hemodynamic aspect of …MetS needs further research and exploration. Show more

Keywords: Aggregation, hemorheology, diabetes, obesity, dyslipidemia, hypertension

DOI: 10.3233/CH-131792

Citation: Clinical Hemorheology and Microcirculation, vol. 57, no. 1, pp. 73-83, 2014

Authors: Li, Rulin | Chen, Xuyang

Article Type: Research Article

Abstract: BACKGROUND: This study examines the relationship between circulating advanced glycated end products (AGEs) level and erythrocyte osmotic fragility in smokers. METHODS: Forty-eight smokers (aged 45 ± 5 years) and fifty healthy nonsmokers (aged 42 ± 6 years) were selected in this study. All subjects were analysed according to serum AGEs, osmotic fragility (H50, the NaCL concentration producing 50% hemolysis), malondialdehyde (MDA) and advanced oxidation protein products (AOPP). RESULTS: The data show that the serum AGEs, H50, MDA and AOPP levels were significantly higher for smokers than that of nonsmokers (p < 0.01). The serum AGEs correlated with H50 in smokers …(r = 0.7703, p < 0.01). MDA levels correlated with H50 in smokers (r = 0.7584, p < 0.01). CONCLUSIONS: This study demonstrated that serum AGEs and MDA levels positively correlated with osmotic fragility in smokers. Show more

Keywords: Advanced glycated end products, osmotic fragility, cigarette smoker

DOI: 10.3233/CH-131801

Citation: Clinical Hemorheology and Microcirculation, vol. 57, no. 1, pp. 85-92, 2014