Clinical Hemorheology and Microcirculation - Volume 35, issue 1-2

Authors: Cicha, Iwona | Yilmaz, Atilla | Suzuki, Yoji | Maeda, Nobuji | Daniel, Werner G. | Goppelt-Struebe, Margarete | Garlichs, Christoph D.

Article Type: Research Article

Abstract: Connective tissue growth factor (CTGF) is overexpressed in atherosclerotic blood vessels. To further investigate the role of CTGF in atherosclerosis, we examined whether CTGF is released from platelets by high shear stress, and whether the expression of CTGF along the atherosclerotic lesions depends on local hemodynamic conditions. Human platelets were subjected to 10 dyn/cm2 or 120 dyn/cm2 and analysed by Western blotting. Furthermore, longitudinal sections of 25 carotid plaques were immunohistochemically analysed for the endothelial expression of CTGF. A very low CTGF amount was secreted from platelets at low shear stress (11.4±3.9% of total CTGF in platelets). On …the contrary, high shear stress caused a markedly increased CTGF release from platelets (29±13.8%, p=0.07 vs low shear stress, n=4). Immunohistochemical analyses showed that the mean numbers of CTGF-positive endothelial cells were significantly higher up-stream as compared with down-stream regions of the luminal surface of atherosclerotic vessels (21.3±3.6 vs 13.9±2.8 down-stream, p<0.001). Moreover, in plaques undergoing intimal neovascularization, newly formed vessels accumulated particularly in up-stream parts of the lesions. In conclusion, this study demonstrated that CTGF is released from platelets by high shear stress. Furthermore, disturbed flow along atherosclerotic vessels may induce endothelial CTGF expression and contribute to the progress of atherosclerotic lesions. Show more

Keywords: CTGF, platelets, atherosclerosis, hemodynamics

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 203-206, 2006

Authors: Aloulou, Ikram | Varlet-Marie, Emmanuelle | Mercier, Jacques | Brun, Jean-Frédéric

Article Type: Research Article

Abstract: The metabolic syndrome, which is associated with an high risk for diabetes and atherothrombosis, is associated with hemorheologic abnormalities. These abnormalities seem more and more to be explained by its various symptoms than by insulin resistance which represents theoretically the core of the syndrome. In this study we aimed at defining the specific hemorheologic profile of insulin resistance and hyperinsulinemia by separating a sample of 90 subjects into 4 subgroups according to the clinical score “NCEP-ATPIII” which is the best recognized standardized definition of the syndrome. Results show no significant changes of blood rheology across classes of NCEP score despite …a borderline rank correlation between RBC aggregability “M1” and the score. Whole blood viscosity was mostly correlated to HDL-cholesterol (r=−0.353, p=0.007) and triglycerides (r=0.574, p=0.0001). Plasma viscosity was correlated with total cholesterol (r=0.3359, p=0.02) and with LDL-cholesterol (r=0.357, p=0.03). Red blood cell rigidity “Tk” was negatively correlated to HDL-cholesterol (r=−0.430, p=0.007). Aggregability “M” was correlated to total cholesterol (r=0.356, p=0.01) and “M1” to HDL-cholesterol (r=−0.406, p=0.006). Thus, despite previously described correlations with glucose disposal parameters, the hyperviscosity syndrome of the metabolic syndrome is not proportional to its clinical scoring and is strongly dependent upon the lipid profile. Show more

Keywords: Insulin resistance, insulin sensitivity, minimal model, metabolic syndrome, hemorheology, plasma viscosity, erythrocyte aggregability

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 207-212, 2006

Authors: Yerer, Mükerrem Betül | Aydoğan, Sami | Çomu, Faruk Metin | Arslan, Mustafa | Güneş-Ekinci, Işın | Kurtipek, Omer | Unal, Yusuf

Article Type: Research Article

Abstract: General anesthesia, either with inhalation or through nonvolatile anesthetics, is known to affect the overall cardiovascular function as well as the microcirculatory hemodynamics. In this study, the effects of desfluran anesthesia on the red blood cell deformability of young and old rats are investigated. 33 male rats were used in the study and the rats were divided into two groups according to their age (young and old) comprising of two subgroups in each. First group was the young control (n=5), the second was the young group treated with desfluran (n=7), the third group was the old control (n=7) and the …last group was the old group treated with desfluran (n=7). %6 of desfluran was applied to the rats with inhalation in an adjustable cage for one hour. The elongation indexes of the erythrocytes were measured by a laser diffractometer (Myrenne Rheodyne SSD). Deformability indexes of red blood cells were significantly increased with desfluran in young rats (p=0.042) whereas they were significantly decreased in old rats (p=0.004) with desfluran application compared with their controls. When we compared the young and old control groups, the deformability indexes were significantly higher in old ones (p<0.001). However, there was no significant difference between the old and the young desfluran applied groups. The volatile anesthetic agent desfluran impairs the deformability of erythrocytes in old rats compared to their controls, whereas it has the opposite effects on young ones. This may be due to the alterations in membrane structure with age. These results reveal that the inhalation of anesthetics like desfluran may cause more serious problems in the elder people during the surgery and may influence their hemodynamic parameters. Show more

Keywords: Desflurane, erythrocyte deformability, anesthesia, rat

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 213-216, 2006

Authors: Tatarishvili, J. | Sordia, T. | Mchedlishvili, G.

Article Type: Research Article

Abstract: Objective: The aim of the present study was the analysis of the specific hemorheological disorders during the middle stages of experimental traumatic and hemorrhagic shock. Methods: The following hemorheological properties were investigated: Red Blood Cell (RBC) aggregability, their deformability, and systemic hematocrit. The RBC aggregability was assessed by using the “Georgian technique”. The RBC deformability was determined with the nuclepore membrane filter method of Reid. The hematocrit was measured by blood centrifugation. The results obtained were treated statistically by using the “Two sample T-test”. Results: We found that in the animals with traumatic shock the erythrocyte aggregability index increased by …mean 181%, while in the hemorrhagic group this index on contrary decreased by mean 68% as compared to control group; The RBC deformability underwent a significant decrease during both traumatic and hemorrhagic shock: by a mean of 52% during the first and 62% during the second one. The systemic hematocrit decreased by a mean of 45% during the traumatic shock and by a mean of 50% during the hemorrhagic shock. Conclusion: The data obtained provide evidence that the hemorheological disorders are among the most significant microcirculatory disturbances in the pathogenesis of both the traumatic and the hemorrhagic shock. Show more

Keywords: Traumatic shock, hemorrhage, erythrocyte aggregability

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 217-221, 2006

Authors: Sordia, Tea | Tatarishvili, Jemal | Mchedlishvili, George

Article Type: Research Article

Abstract: Objectives: The aim of the present study was the experimental analysis of blood rheological disorders in the microcirculation during endotoxic shock. Methods: Experiments were carried out on 30 white laboratory rats of both sexes weighing about 200 g. The experimental animals were divided in two groups: the control group and the group undergoing experimental endotoxic shock. The following specific hemorheological properties were investigated in all animals during the experiments: red blood cells (RBC) aggregability, their deformability and the systemic hematocrit. Results: We found that all the investigated hemorheological parameters appreciably changed underconditions of endotoxic shock. The RBC aggregability index was …increased by a mean of 136%. As to the RBC deformability index was found to be decreased by 71%, and the systemic hematocrit lowered by 31%, as compared to the same parameters in the control group. Conclusion: The data obtained provide us with evidence that the hemorheological derangements associated with the development of the heavy microcirculatory disorders during endotoxic shock, are most significant factors. Show more

Keywords: LPS induced endotoxic shock, hemorheological disorders, mesenterial microcirculation in rat experiments

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 223-226, 2006

Authors: Lo Presti, Rosalia | Tozzi Ciancarelli, Maria Giuliana | Hoffmann, Enrico | Incalcaterra, Egle | Canino, Baldassare | Montana, Maria | D'Amico, Teresa | Catania, Anna | Caimi, Gregorio

Article Type: Research Article

Abstract: Acute myocardial infarction (AMI) is associated with an elevated polymorphonuclear leukocyte (PMN) count and a PMN rheological impairment. In this study we evaluated two major rheological aspects (membrane fluidity and cytosolic Ca2+ concentration) in a group of young adults with AMI. We enrolled 41 AMI patients (39 men and 2 women; mean age 41.0±4.0 years), who were examined 5–10 days after AMI (T1) and 12 months later (T2). The membrane fluidity was obtained labelling granulocytes with the fluorescent probe 1-[4-(trimethylamino)phenyl]-6-phenyl-1,3,5-hexatriene (TMA-DPH) and considering the degree of fluorescence polarization, inversely correlated to the membrane lipid fluidity. The cytosolic Ca2+ …content was obtained marking PMN cells with the fluorescent probe Fura-2AM and considering the ratio between the Fura 2-Ca2+ complex and the unchelated Fura 2 fluorescence intensity. Both parameters were evaluated at baseline and after in vitro activation with 4-phorbol 12-myristate 13-acetate (PMA) at the concentration of 4.5 μM, prolonged for 5 and 15 minutes. At T1 the PMN membrane fluidity and cytosolic Ca2+ content in AMI patients were respectively decreased and increased in comparison with control group. At T2 the membrane fluidity was not any more different from control subjects, but there was also a further increase in cytosolic Ca2+ content. In vitro, PMN activation caused no significant variation of these parameters in the control group, while in AMI patients membrane fluidity significantly decreased and cytosolic Ca2+ content increased not only during the initial stage, but also after 12 months. The long-term functional alteration of PMN cells observed in young adults with AMI confirms the role of these cells in the inflammatory response following AMI. In the light of these data, the use of molecules able to modulate granulocyte activity, such as calcium channel blockers or pentoxifylline, should be reconsidered in myocardial infarction, together with the usual pharmacological treatment. Show more

Keywords: Acute myocardial infarction in young people, polymorphonuclear leukocyte membrane fluidity, polymorphonuclear leukocyte Ca$^{2+}$ content

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 227-230, 2006

Authors: Di Massimo, C. | Lo Presti, R. | Corbacelli, C. | Pompei, A. | Scarpelli, P. | De Amicis, D. | Caimi, G. | Tozzi Ciancarelli, M.G.

Article Type: Research Article

Abstract: To verify the potential involvement of the age-dependent modifications of EC-SOD activity in the impairment of plasma NO availability with advancing age, 40 healthy men divided into 4 age groups for the purpose of comparison (young: 27.4±1.5 years; middle: 50.8±2.2, years; old: 70.0±1.8 years; very old: 86.1±1.1 years) were enrolled in this study. Plasma samples were used for measurements of the stable end-product nitrite/nitrate (NOx ), as an expression of NO availability, EC-SOD activity, thiobarbituric acid reactive substances (TBARS) as a marker of lipid peroxidation, low density lipoprotein (LDL) copper-mediated oxidation in vitro and total antioxidant capacity (TEAC). Our results …indicated a significant age-related progressive decrease of plasma NOx content and EC-SOD activity and their values were positively correlated (r=0.713, p<0.001). Increased TBARS amount together with reduced lag time for in vitro oxidation of LDL and decreased content of TEAC were observed with advancing age. Finally, EC-SOD values were negatively correlated with plasma TBARS values (r=−0.855, p<0.001). Findings of the present study suggest that the decrease of antioxidant defence strategies play a primary role by compromising NO availability in normally aged individuals, particularly through a progressive decrease of EC-SOD activity. Show more

Keywords: Elderly, nitric oxide, extracellular superoxide dismutase

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 231-237, 2006

Authors: Manetta, Jérôme | Aloulou, Ikram | Varlet-Marie, Emmanuelle | Mercier, Jacques | Brun, Jean-Frédéric

Article Type: Research Article

Abstract: Aging impairs blood rheology while various training protocols improve it. The purpose of this study was to delineate the respective role of aging and endurance training on blood rheology. Thirty-two subjects [16 middle-aged men: 8 cyclists (MAcy) and 8 sedentary men (MAsed) and 16 young men: 8 cyclists (Ycy) and 8 sedentary men (Ysed)] were compared in this study. Results showed higher red blood cell (RBC) rigidity and aggregability (AFFIBIO), lower RBC disaggregability (AFFIBIO) at middle age than at 25 yr, regardless of training status. However there was no age-related difference in whole blood viscosity at either native or corrected …hematocrit, plasma viscosity, hematocrit, and Myrenne aggregation indexes M and M1. Training was associated with a reduced hematocrit in middle age subjects but not in 25 yr old ones. We evidenced no effect of training on red cell rigidity (Dintenfass's Tk index), in whole blood viscosity at either native or corrected hematocrit, and plasma viscosity. Thus, regular cycling at middle age maintains a low hematocrit but does not prevent aging-related increase in red cell rigidity and aggregability. Specific effects of cycling among other sports may explain this specific pattern. Show more

Keywords: Exercise training, hemorheology, aging, viscosity, hematocrit, erythrocyte aggregability, cyclism

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 239-244, 2006

Authors: Silva, A.S. | Saldanha, C. | Martins-Silva, J.

Article Type: Research Article

Abstract: Clinical and experimental studies have shown that the use of phytosterol esters as a food ingredient reduces the plasma concentrations of cholesterol and LDL cholesterol, not affecting the HDL cholesterol levels. Based on the use of phytosterols as a food ingredient, we have conducted a 30-day feeding study with Wistar rats, drinking low-fat milk containing phytosterols, in order to evaluate the plasma cholesterol concentrations and the hemorheological parameters. Throughout the study, clinical observations, body weights and food and milk consumption were measured and at the end of the feeding period, blood samples were collected for biochemical and hemorheological determinations. There …were no clinical changes, alterations in growth, food or milk consumption. In the plasma cholesterol and HDL concentrations there were no significant differences, but LDL levels decreased about 70%. In the hemorheological parameters, significant changes were observed in plasma viscosity and in membrane fluidity in all experimental groups. The blood viscosity and the erythrocyte deformability show significant improvements with the ingestion of the phytosterols enriched milk. With these results we conclude that phytosterols maintain their cholesterol lowering properties when incorporated in milk and can be considered a hypolipemic food component. Show more

Keywords: Phytosterols, cholesterol, LDL-cholesterol, HDL-cholesterol, milk, hemorheology

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 245-250, 2006

Authors: Gonçalves, Sonia | Maria, A. Vasco | Silva, A.S. | Martins-Silva, J. | Saldanha, C.

Article Type: Research Article

Abstract: Plant sterols have been reported to decrease plasma concentrations of cholesterol without any side effects. To evaluate the effects on plasma cholesterol concentrations and the hemorheological parameters, we performed a study with hypercholesterolemic patients (n=19) treated with phytosterol-enriched milk (2 g/day). Hypercholesterolemic patients (n=15) of matched age drinking equal type of milk but without phytosterols were used as control group. Concentrations of total cholesterol, HDL-C, LDL-C and hemorheological parameters were measured in the beginning, after 15 and 30 days of milk intake. After 15 days of beverage intake, hypercholesterolemic subjects treated with phytosterol-enriched milk showed a significant decrease in plasma …concentrations of total cholesterol and LDL-C by 9.62% (p<0.05) and 12.20% (p<0.05), respectively. After 30 days, a little increase in the total cholesterol and LDL-C concentrations were observed. In the hypercholesterolemic control group there were nonsignificant changes between plasma concentrations of total cholesterol, HDL-C and LDL-C during the study. The evaluation of plasma viscosity and erythrocyte aggregation shows no changes statistically significant during the study for both groups studied. The results obtained during the study show a positive effect with the phytosterol-enriched milk as plasma cholesterol-lowering as combined treatment for hypercholesterolemia. Show more

Keywords: Hypercholesterolemia, phytosterols, LDL-C, HDL-C, functional food, plasma viscosity, erythrocyte aggregation

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 251-255, 2006

Authors: Kobayashi, Takao | Nakamura, Mashio | Sakuma, Masahito | Yamada, Norikazu | Sakon, Masato | Fujita, Satoru | Seo, Norimasa

Article Type: Research Article

Abstract: Incidence of venous thromboembolism (VTE), which had been considered a relatively rare disease in Japan, has been on the increase in recent years as eating habits have become more similar to those of the West. We have investigated the recent incidence data of perioperative pulmonary thromboembolism (PTE) in Japan and have established guidelines for the prevention of VTE. Recommended thromboprophylaxis is early ambulation for low risk group, elastic stocking (ES) or intermittent pneumatic compression (IPC) for moderate risk group, IPC or low dose unfractionated heparin (LDUH) for high risk group, and LDUH + IPC or LDUH + ES for highest …risk group. The management fee for PTE prophylaxis was established and covered by health insurance in April 2004. Surprisingly, the incidence of perioperative PTE decreased just after this guideline was issued. After accumulation of further evidence and application of pharmacological agents, such as low molecular weight heparin, we will establish the advanced guidelines in the future. Show more

Keywords: Venous thromboembolism, pulmonary thromboembolism, thromboprophylaxis, elastic stocking, intermittent pneumatic compression, heparin

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 257-259, 2006

Authors: Momtselidze, Nana | Mantskava, Maia | Mchedlishvili, George

Article Type: Research Article

Abstract: The aim of the present study was the comparative analysis of the role of specific hemorheological derangements in the pathogenesis of ischemic brain infarcts with and without diabetes mellitus. Blood plasma viscosity, as well as red blood cells (RBC) aggregability were quantitatively investigated in all patients during the study. Both of the above mentioned indices of hemorheological disorders were significantly higher in the patients with brain infarcts and diabetes mellitus as compared to the control and the group of ischemic brain infarcts without diabetes. During the ischemic stroke, blood plasma viscosity was increased by a mean of 9.2 per cent …in the first and by a mean of 17.6 per cent in the second group of patients. As to the erythrocyte aggregability index, it was changed considerably more – by a mean of 113.8 per cent during stroke without diabetes, while in the diabetic patients the RBC aggregability index was found to be increased by a mean of 147.3 per cent. Ischemic brain infarcts in patients with diabetes mellitus were associated with a significant increase of the patients' blood rheological disorders in all the investigated cases. Show more

Keywords: Erythrocyte aggregability, blood plasma viscosity, ischemic brain infarct with and without diabetes mellitus

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 261-264, 2006

Authors: Bolokadze, N. | Lobjanidze, I. | Momtselidze, N. | Shakarishvili, R. | Mchedlishvili, G.

Article Type: Research Article

Abstract: The aim of this work was to perform a comparative investigation of erythrocyte aggregability changes in the peripheral and cerebral circulation during ischemic and hemorrhagic stroke. Subjects of the present study were patients with ischemic brain infarcts (14 patients) and with hemorrhagic stroke (21 patients) from the Intensive Care Unit of the Institute of Neurology and Neurosurgery. The blood samples were obtained from the following blood vessels: the common carotid artery carrying blood to the primarily damaged brain hemisphere, both jugular veins carrying blood from the primarily damaged and the contralateral hemispheres, as well as from the cubital vein to …obtain specimens of the systemically circulating blood. Erythrocyte aggregation was evaluated by using the “Georgian technique”. We found that the RBC aggregation indices increased in both the regional as well as the systemic circulation of the hemorrhagic stroke patients as compared to ischemic stroke patients. The results of the present study demonstrate different changes of erythrocyte aggregation in ischemic and hemorrhagic stroke patients. Therefore, the role of blood rheological properties in their pathogenesis seems also to be different. Show more

Keywords: Erythrocyte aggregation, ischemic stroke, hemorrhagic stroke

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 265-267, 2006

Authors: Bianciardi, Giorgio | Tanganelli, Italo | Totagiancaspro, Dorotea | Brogi, Marco | Carducci, Antonietta | De Santi, Maria Margherita

Article Type: Research Article

Abstract: Fractal dimension of pericellular membrane of monocytes was evaluated in diabetic patients and in control subjects. Monocytes were collected from normal healthy volunteers (n=6) and from diabetic (type 1 and type 2) patients (n=9). Monocytes from healthy volunteers were also stimulated in vitro with the ionophore A23187 or with the oligopeptide FMLP. Monocytes, obtained by Ficoll-Hypaque, were examined with a Philips 300 transmission electron microscope. The cell contour was extracted, resized to a standard dimension and converted to a single pixel outline. Box-counting method was then applied to determine the fractal dimension. Fractal dimensions of monocytes appeared statistically increased in …diabetic patients (type 1 and type 2), compared with sex- and age-matched controls (p<0.01, p<0.01). The mechanism underlying the observed increased complexity of pericellular membrane may be explained by the in vivo activation of the circulating monocyte in diabetes. In effect, fractal analysis of stimulated in vitro monocytes showed a significant increase of complexity of pericellular membrane, compared with their controls (p<0.001). Our approach was able to assess and quantitatively evaluate in diabetic patients morphological modifications of the monocyte linked to its activation, offering new parameters useful to follow the effects of therapeutical procedures. Show more

Keywords: Fractals, morphometry, monocytes, diabetes

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 269-272, 2006

Authors: Fornal, Maria | Lekka, Małgorzata | Pyka-Fościak, Grażyna | Lebed, Kateryna | Grodzicki, Tomasz | Wizner, Barbara | Styczeń, Jan

Article Type: Research Article

Abstract: The mechanical properties of erythrocyte membrane have been studied using an atomic force microscope. Measurements were carried out on blood samples taken from 7 diabetes mellitus patients and 8 healthy individuals. For each blood sample a distribution of a Young's modulus was constructed. It has been found that both the mean value and the width of the distribution in diabetic patients exceed the corresponding results for healthy persons by a factor greater than 3. The high sensitivity of the atomic force microscopy and the ability to measure the full distribution of the erythrocyte membrane Young's modulus makes it a unique, …powerful and promising tool in studies of the membrane stiffness of red blood cells. Show more

Keywords: Atomic force microscopy, erythrocyte deformability, erythrocyte stiffness, diabetes mellitus

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 273-276, 2006

Authors: Riquelme, Bibiana | Foresto, Patricia | D'Arrigo, Mabel | Filippini, Fernando | Valverde, Juana

Article Type: Research Article

Abstract: Hypertension (HTA) and dyslipidemia (DLP) represent major risk factors for cardiovascular and cerebral-vascular ischemic disease. The mechanisms through which they can induce vascular damage are both metabolic and mechanical. Hemorheological alterations in HTA are result of changes affecting both red cell intrinsic structure and their interactions with the plasmatic components. Several hemorheological determinants (biochemical, ionic, metabolic and rheologic) could influence and produce an impaired erythrocyte deformability determining an increased flow resistance in the microcirculation. The “Erythrodeformeter” allows obtaining the stationary and dynamical linear parameters of erythrocyte membrane by laser diffractometry. Stationary and oscillatory shear-induced elongation of cells leads to an …elliptical diffraction pattern, its geometric characteristics being directly related to those of deformed RBC. Erythrocyte stationary parameters (Deformability Index, surface viscosity and elastic modulus) were obtained in stationary regime. Complex viscoelastic parameters (dynamic elasticity, dynamic loss, viscous and elastic components of the complex viscosity) were obtained when operating in oscillating mode. The diffractometric method is sensitive to detect pathological or induced alterations on RBC membrane, which can affect blood flow in vivo. The rheological parameters obtained give important information about the erythrocyte membrane and allow to detect and characterize erythrocyte alterations in vascular pathologies. Show more

Keywords: Diffractometry, erythrocyte viscoelastic properties, hemorheology, hypertension

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 277-281, 2006

Authors: Travagli, Valter | Zanardi, Iacopo | Boschi, Letizia | Turchetti, Vera | Forconi, Sandro

Article Type: Research Article

Abstract: Clinical measurement of blood viscosity is an important parameter in the diagnosis of different diseases (e.g., diabetes, hypertension, cardiovascular diseases). The significance of blood viscosity in the microcirculatory flow is also of great importance. Thus, a simple and accurate evaluation of hemorheological properties could be an important challenge in clinical practice. Nowadays, validated measurements of plasma viscosity are commonly carried out with rotational viscometers by means of the various geometric configurations. However, red blood cells deform under mechanical force and this aspect could lead to an artificial variation in the apparent viscosity. In this work, an evaluation of a new …technique for the viscosity determination is focused. In particular, a torsional oscillation viscometer was adopted (VM10AL, CBC Europe) in the presence and in the absence of stirring conditions at thermostated conditions. The profile of the rheological behaviour as a function of time was recorded and compared with that obtained using a cone-plate rotational viscometer (AR300, TA Instrument). Show more

Keywords: Blood viscosity, torsional oscillation viscometer

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 283-289, 2006

Authors: Athanassiou, G. | Moutzouri, A. | Kourakli, A. | Zoumbos, N.

Article Type: Research Article

Abstract: Sickle cell disease is characterized by vaso-occlusive episodes, mainly in the small vessels, resulting in tissue ischemia, multi-organ failure, and, occasionally, death. Hydroxyurea (HU) is an agent with important and effective role in the treatment of patients suffering from this disease. The purpose of this study was to estimate the effect of HU on the deformability of the red blood cell's membrane (RBCM) in an effort to possibly improve the rheological properties of the RBCs of patients with sickle cell anemia (SCA), as well as to investigate the mechanical and rheological properties of these cells using micropipette and filtration techniques. …The rigidity index, IR, which is a measure of cell rigidity and the elastic shear modulus, μ, which is a measure of cell's membrane deformability (CMd), of the RBCs from normal subjects, used as normal controls, were found significantly lower as compared to those of patients with SCA, regardless the treatment with HU. Patients under treatment with HU exhibited values better than those of untreated patients, in both, IR as well as μ, although still worse than the values of normal controls. Show more

Keywords: Red blood cell deformability, filterability, sickle cell disease, micropipette

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 291-295, 2006

Authors: Aydoğan, Sami | Yerer, Mükerrem Betül | Çomu, Faruk Metin | Arslan, Mustafa | Güneş-Ekinci, Işın | Unal, Yusuf | Kurtipek, Omer

Article Type: Research Article

Abstract: Alterations in blood rheology under the influence of anesthesia have been observed and discussed among the responsible factors for the deterioration of tissue and organ perfusion related to anesthetic procedures. Sevoflurane is one of the volatil anesthetics which is being used very common in surgery. In this study, the effects of sevoflurane anesthesia were investigated in different age groups of rats. 22 male rats were used in the study and the rats were divided into two groups according to their age (young and old) comprising of two subgroups in each. First group was the young control (n=5), the second was …the young group treated with sevoflurane (n=5), the third group was the old control (n=7) and the last group was the old group treated with sevoflurane (n=5). %2 of sevoflurane was applied to the rats with inhalation in a adjustable cage for one hour. The deformability indexes of the erythrocytes were measured by a laser diffractometer (Myrenne Rheodyne SSD). Deformability indexes of red blood cells were significantly decreased with sevoflurane in old rats (p=0.028) whereas it had not any significant effect in young group compared with their controls. When we compared the young and old control groups, the deformability indexes were significantly higher in old ones (p<0.001). However, there were not any significant difference between the old and the young sevoflurane applied groups. A volatil anesthetic agent sevoflurane has impaired the deformability of erythrocytes in old rats compared to their controls, whereas it had not any significant effect in young ones which may be due to the flexibility of the young erythrocytes leading them to tolerate to the environmental changes. These results reveal that the inhalation anesthetics like sevoflurane may cause more serious problems in the elder people and their hemodynamic parameters should be checked more seriously during the surgery. Show more

Keywords: Sevoflurane, erythrocyte deformability, anesthesia, rat

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 297-300, 2006

Authors: Musielak, Malgorzata | Kościelak, Jerzy

Article Type: Research Article

Abstract: Human fibrinogen (TF) has been separated into two fractions: F1 – homodimers with respect to the γ chain, and F2 – heterodimers composed of γA and γ′ polypeptides. Their rouleaux-inducing properties were as follows: (1) both, at the same concentration of 0.8%, were less effective than TF; (2) F1 produced larger rouleaux even under static conditions of a hemocytometer where F2 was silent; (3) F2 induced the process when a suspension was gently sheared between microscopic slides. Since the synthetic peptide γ′(414–427) inhibited the rouleau formation in a mixture with F2, the C-terminal amino acids of the γ′ polypeptide …probably bind the molecule to the cell. The inhibition was feebly visible in the native ratio of F1/F2, implicating a compensatory effect of F1. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 301-303, 2006

Authors: Startseva, Julia | Sulimova, Natali | Cherkassov, Vladimir | Kon, Kat | Lysov, Andrej

Article Type: Research Article

Abstract: We have made the diagnosis of transcapillary flow disturbances in the lungs of lung cancer patients with the available noninvasive method of videobiomicroscopy of eye conjunctiva with further morphometric processing of obtained data using PC. 77 patients with lung cancer have been studied. Using videobiomicroscopy we calculated the size of venous capillary sacculations, the square of capillary glomerules (Sg ), the amplitude (A), the ‘length’ of the twisted part of a microvessel (Lt ), the amplitude-length coefficient (Ca ), the frequency-length coefficient (Cf ), the size of venous capillaries (V), intravascular conglomeration of aggregated erythrocytes (conglomerate), RBC aggregation coefficient (Cs …) and the degree of sludge. To evaluate the data obtained, a comparative morphologic investigation of histologic samples taken from the intact areas of the lung parenchyma has been carried out. We diagnosed moderate or determined disturbances in the capillary flow that were confirmed by microscopy. Show more

Keywords: Lung cancer, capillary flow, videobiomicroscopy

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 305-306, 2006

Authors: Mantskava, Maia | Momtselidze, Nana | Pargalava, Nugzar | Mchedlishvili, George

Article Type: Research Article

Abstract: The aim of the present study was to evaluate blood rheological disorders, in particular RBC enhanced aggregation, and compare changes in these parameters in patients with type 1 and 2 diabetes mellitus. For evaluation of RBC aggregability in the present study we applied the “Georgian technique”, which was developed and applied for several years in our laboratory. Its advantage is that it is a direct and quantitative method. In all the investigated patients, diabetes mellitus was complicated with the foot gangrenes. The patients were divided into two groups: (a) with type 1 and (b) with type 2 diabetes mellitus. We …matched the RBC aggregability indices in both groups of diabetic patients and compared the obtained results with those in the healthy control group. We found that rheological disorders were considerably pronounced. The RBC aggregability index increased by 62 percent (p<0.001) in type 1 and by 57 percent (p<0.001) in type 2 diabetic patients as compared to the control group. However, there were insignificant differences of the RBC aggregability changes between the two groups of patients. Therefore we conclude that blood rheological disorders are similar in both types of diabetes mellitus. The disturbed blood fluidity related to the increased RBC aggregability in the microcirculation promotes, in particular, the development of legs gangrene in both types of diabetes mellitus. Show more

Keywords: Blood rheological disorders, the erythrocyte aggregability index, 1st types and 2nd types of diabetes mellitus

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 307-310, 2006

Authors: Pérez, S.M. | Riquelme, B. | Acosta, I. | Valverde, J. | Milani, A.

Article Type: Research Article

Abstract: β-thalassaemia is a hereditary hemolytic disease, in which each clinic phenotype encompasses a heterogenic group of genetic alterations resulting in β-globin chain synthesis decrease or absence in red blood cells. Studies on β-thalassaemia carriers suggest the existence of decreased red cell deformability. The erythrocyte deformability in the blood stream is a well-known fact regarding blood circulation efficiency. Red blood cells may be considered to be viscoelastic and their behavior may be described according to complex viscoelastic parameters when they undergo oscillatory stresses. This dynamic behavior is physiologically important due to the in vivo pulsatile blood flow. The aim of the …present work was to evaluate complex erythrocyte viscoelastic parameters in patients suffering from heterozygous β-thalassaemia in comparison with healthy individuals. Our results reveal that even though thalassaemia erythrocytes show a decreased deformability in the stationary state, in a dynamic state, hemorheological alterations are only evident at low oscillatory frequencies, i.e., at lower frequencies in contrast with the normal heart rate (60 cycles/min = 1 Hz), producing no significant alterations at increased heart rate. Show more

Keywords: β-thalassaemia minor, erythrocyte rheology, dynamic viscoelasticity

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 311-316, 2006

Authors: Ahmadizad, Sajad | El-Sayed, Mahmoud S. | MacLaren, Donald P.M.

Article Type: Research Article

Abstract: To examine the effects of drinking an amount of water equal to weight loss on the responses of blood rheological variables, eleven healthy male subjects performed three resistance exercise trials. The aim of the first session was to determine the amount of weight loss following a resistance exercise trial at 80% of one repletion maximum (1RM). In the second and third sessions subjects performed the same resistance exercise protocol without and with drinking an amount of water equal to that recorded for body weight loss. Three venous blood samples were taken before exercise, immediately after exercise, and at the end …of 30-min recovery and were analysed for haematocrit (Hct), haemoglobin (Hb), blood cells count and the main determinant of blood rheology. Haematocrit, plasma viscosity, fibrinogen, albumin, and total protein were significantly increased in response to resistance exercise and returned to pre-exercise level following 30-min of recovery. The changes in blood rheological variables in response to resistance exercise occurred similarly in both control and water trials with no significant difference being observed between trials. Plasma volume loss through sweating and respiratory tract during resistance exercise could have contributed to the decrease in plasma volume, though, this contribution was negligible. Therefore, it is concluded that the increases in blood rheological variables in response to resistance exercise are mainly due to plasma shifts from intravascular space to extravascular spaces rather than plasma volume loss through sweating and respiratory tract. Show more

Keywords: Water intake, resistance exercise, fibrinogen, plasma viscosity, haemoconcentration

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 317-327, 2006

Authors: Varlet-Marie, Emmanuelle | Mercier, Jacques | Brun, Jean-Frédéric

Article Type: Research Article

Abstract: There is a lack of consensus about the biological diagnosis of the overtraining syndrome (OTS). Recently, efforts have been made to standardize its clinical diagnosis (e.g., standardized questionnaires like that of the French consensus group on overtraining of the Société Française de Médecine du Sport–SFMS). We previously reported that the early signs of overtraining (= “overreaching”) in elite sportsmen are associated with a hemorheologic pattern (raised hematocrit and plasma viscosity ηp ) that suggests some degree of reversal of the “autohemodilution” which characterizes fitness, and that the feeling of heavy legs in overtrained athletes is related to higher ηp …and higher red cell aggregation. We thus investigated on a sample of 48 athletes (age 24±1 yr), referred for possible diagnosis of overtraining to what extent plasma viscosity is a predictor of OTS. From those 48 athletes 10 had a value of ηp in the highest quartile (ηp >1.44 pPa.s) and 8 of them had a diagnosis of overreaching, while in the 38 whose ηp was <1.44 mPa.s there were 20 cases of overreachings. Overt cases of OTS were found in 1 subject of the highest quintile and two in the lowest. Thus the predictive value of ηp for early stages (overreaching) or chronicized stages (overtraining syndrome) is as follows: (a) prediction of overreaching: sensitivity 28.57%; specificity 90%; positive predictive value 80%; negative predictive value 47.37%; (b) prediction of chronicized overtraining: sensitivity 2.70%; specificity 18.18%; positive predictive value; 10.00%; negative predictive value 5.26%. These results show that ηp is a rather specific, although poorly sensitive predictor of overreaching but has no interest in the diagnosis of the overtraining syndrome itself. Show more

Keywords: Overtraining, overreaching, plasma viscosity, hemorheology

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 329-332, 2006

Authors: Aloulou, Ikram | Varlet-Marie, Emmanuelle | Mercier, Jacques | Brun, Jean-Frederic

Article Type: Research Article

Abstract: Hemorheologic effects of exercise training (“hemorheologic fitness”) are very different according to the mode and the intensity of this training. We previously reported that low intensity endurance training in sedentary patients suffering from the metabolic syndrome sumultaneously improved blood rheology, body composition and lipid oxidation at exercise. We aimed at analyzing the link among these improvements in 24 patients submitted to a 2 months targeted training designed for increasing exercise lipid oxidation. Variations of whole blood viscosity at high shear rate (ηb 1000 s−1 ) were explained here by two statistically independent determinants: hematocrit and red cell rigidity. ηb …decreased in 16 subjects, but increased in 8, due to a rise in hematocrit. Changes in RBC rigidity appeared to reflect weight loss and decrease in LDL cholesterol. Plasma viscosity was related to cholesterol and its training-induced changes are related to those of VO2 max  but not to lipid oxidation. Red cell aggregability (Myrenne) reflected both the circulating lipids (Chol, HDL and LDL) and the ability to oxidize lipids at exercise. Factors associated to a post-training decrease in aggregability (M1) were weight loss and more precisely decrease in fat mass, improvement in lipid oxidation, rise in HDL-Chol, and decrease in fibrinogen. On the whole the major determinant of hemorheologic improvement was an increase in cardiorespiratory fitness (VO2 max  ), correlated with a decrease in plasma viscosity, rather than an improvement in lipid metabolism, although RBC aggregability and deformability exhibited clear relationships with lipid metabolism. For which reason Hct increased in 30% of the patients during this kind of training remains unclear. Show more

Keywords: Blood viscosity, plasma viscosity, hemorheology, erythrocyte deformability, erythrocyte aggregability, insulin sensitivity, insulin resistance, minimal model

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 333-339, 2006

Authors: Carvalho, F.A. | Maria, A.V. | Braz Nogueira, J.M. | Guerra, J. | Martins-Silva, J. | Saldanha, C.

Article Type: Research Article

Abstract: We stimulated human erythrocytes obtained from patients with hypercholesterolemia (HC; n=42), renal transplantation (RT; n=18) and hypertension (HT; n=10) with acetylcholine (ACh 10 μM) and measured the amperometric NO production, comparing with the NO levels achieved on erythrocytes of healthy persons (n=27). We also measured the hemoglobin, hematocrit, erythrocyte aggregation, erythrocyte deformability, plasma viscosity and fibrinogen concentration from human blood samples. The erythrocytes NO levels were of 2.5±0.7 nM (P=0.038, HC), 2.4±1.1 nM (RT) and 2.2±0.8 nM (HT) against the 2.0±0.8 nM for the control groups. For each group and at each shear stress value, the erythrocytes deformability decreases with …the increase of the NO concentration after ACh stimulation. We observed a significant increase of the control values on the erythrocyte aggregation results on each patient group. Besides the lower erythrocyte deformability obtained on HC, RT and HT blood samples, the erythrocytes produced higher NO levels after ACh stimulation than the healthy ones. The power of erythrocyte hemorheological behaviour could be compensated by the NO production at the presence of acetylcholine. We can hypothesises that cholinergic drugs could be used as co-adjuvants of specific therapeutics compounds on these studied diseases. Show more

Keywords: Nitric oxide, hemorheology, acetylcholine, hypertension, hypercholesterolemia, renal transplantation

Citation: Clinical Hemorheology and Microcirculation, vol. 35, no. 1-2, pp. 341-347, 2006