Clinical Hemorheology and Microcirculation - Volume 10, issue 5
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Clinical Hemorheology and Microcirculation, a peer-reviewed international scientific journal, serves as an aid to understanding the flow properties of blood and the relationship to normal and abnormal physiology. The rapidly expanding science of hemorheology concerns blood, its components and the blood vessels with which blood interacts. It includes perihemorheology, i.e., the rheology of fluid and structures in the perivascular and interstitial spaces as well as the lymphatic system. The clinical aspects include pathogenesis, symptomatology and diagnostic methods, and the fields of prophylaxis and therapy in all branches of medicine and surgery, pharmacology and drug research.
The endeavour of the Editors-in-Chief and publishers of
Clinical Hemorheology and Microcirculation is to bring together contributions from those working in various fields related to blood flow all over the world. The editors of
Clinical Hemorheology and Microcirculation are from those countries in Europe, Asia, Australia and America where appreciable work in clinical hemorheology and microcirculation is being carried out. Each editor takes responsibility to decide on the acceptance of a manuscript. He is required to have the manuscript appraised by two referees and may be one of them himself. The executive editorial office, to which the manuscripts have been submitted, is responsible for rapid handling of the reviewing process.
Clinical Hemorheology and Microcirculation accepts original papers, brief communications, mini-reports and letters to the Editors-in-Chief. Review articles, providing general views and new insights into related subjects, are regularly invited by the Editors-in-Chief. Proceedings of international and national conferences on clinical hemorheology (in original form or as abstracts) complete the range of editorial features.
The following professionals and institutions will benefit most from subscribing to
Clinical Hemorheology and Microcirculation: medical practitioners in all fields including hematology, cardiology, geriatrics, angiology, surgery, obstetrics and gynecology, ophthalmology, otology, and neurology. Pharmacologists, clinical laboratories, blood transfusion centres, manufacturing firms producing diagnostic instruments, and the pharmaceutical industry will also benefit.
Important new topics will increasingly claim more pages of
Clinical Hemorheology and Microcirculation: the role of hemorheological and microcirculatory disturbances for epidemiology and prognosis, in particular regarding cardiovascular disorders, as well as its significance in the field of geriatrics. Authors and readers are invited to contact the editors for specific information or to make suggestions.
Abstract: Cardiovascular disease (CVD) is one of the most important factors which affects the life and prognosis of diabetics, especially non insulin-dependent diabetics. Abnormalities in glucose and lipid metabolism could accelerate the atherogenesis, and hemorheological changes might also influence the CVD of diabetics. In this study changes in blood and plasma viscosity, blood viscoelasticity, red cell filterability (RCF) and platelet aggregation were observed in diabetics with CVD, and they were compared to those of diabetics without CVD. In this comparison the age and sex, and the severity of microangiopathy were matched between the groups as well as possible. Blood viscosity, especially…measured at low shear rates, of diabetics with CVD was significantly increased when compared to those without CVD Plasma viscosity also showed an increasing tendency in diabetics with CVD. Blood viscoelasticity was also increased in diabetics with CVD. But RCF showed no significant difference with and without CVD, although a significant decrease of RCF was observed in diabetics with advanced retinopathy compared with the simple retinopathy group. Platelet aggregation showed no significant difference between the groups. In summary the hemorheological abnormalities might play a pathogenetic role in the CVD of diabetics, because, in our study, some of them showed the abnormalities after the age and the severity of microangiopathy were matched. But the possible relations between the hemorheological abnormalities and the other risk factors of CVD in diabetics should be further studied.
Abstract: Aggregation of red cells as a subparameter of flow properties of blood has not been so extensively investigated in the past as other parameters such as red cell deformability. This was in part due to the lack of suitable measuring devices. Today most authors agree that red cell aggregation plays a pathophysiological role in the microcirculation, especially at low shear rates. From the theoretical point of view, disaggregation of red cells should be a suitable therapeutic rationale.
Keywords: Erythrocyte aggregation, erythrocyte disaggregation, pathophysiology, drug therapy
Abstract: Increased erythrocyte membrane sialic acid was found to adversely affect cell deformability. Therefore, we studied the erythrocyte sialic acid content and hemorheological parameters in well controlled non-insulin dependent type 2 diabetic patients (17 non-obese and 19 obese). Plasma viscosity was more significantly increased in the obese (p < 0.001) than non-obese (p < 0.05) diabetics. Erythrocyte filterability (IFR µl/sec), measured by gravity methods using 5/µm Nucleopore filters, did not show significant differences between non-obese (31.72±3.94) and obese (32.4±5.4) subjects when compared with controls (28.05±5.29). Erythrocyte sialic acid content (µg/109 cells) was lower in the non-obese (12.62±2.41) than obese (14.08±2.73)…compared to controls (16.17±1.79). In a subset of obese diabetics with fasting plasma free insulin level > 30 mU/L, erythrocyte sialic acid (15.06±3.4/ug/10 cells) correlated inversely with the erythrocyte filtration rate and positively with insulin levels. Insulin levels, on the other hand, correlated positively (p < 0.001) with systolic blood pressure. These results implicate erythrocyte sialic acid in the erythrocyte rheology of hypertensive, obese, type 2 diabetic patients.
Keywords: erythrocyte sialic acid, filterability, hypertension, type 2 diabetes
Abstract: Erythrocyte deformability indexes of 14 male rats exposed to 1 ppm sulfur dioxide (SO2 ) for 24 hours were compared with the values of a control group of 14 male rats. Deformability indexes were found to be increased, suggesting an impaired deform ability, while the volume and hemoglobin contents of erythrocytes were unchanged. In a different set of control and experimental groups resealed erythrocyte membrane ghosts were prepared and the deformability, mean ghost volume and hemoglobin content were studied. No statistically significant differences were found for deformability and mean ghost volumes but the hemoglobin content of the ghosts prepared from…the SO2 treated rats were significantly higher than the control group value. It is postulated that, inhalation of SO2 might impair the deformability of erythrocytes by increasing associations between hemoglobin and membrane proteins.
Keywords: Air pollution, sulfur dioxide, erythrocyte deform ability, erythrocyte membran
Abstract: Haemorheological investigations and plasma fibrinogen estimations have been carried out on blood samples from obstetric patients who were normotensive at the time of testing but subsequently developed hypertension. Pregnancy induced hypertension can be an early indication of impending pre-eclampsic toxaemia (PET) hence the early identification of such patients has the potential to improve ante natal care. Statistically significant differences from the control group in whole blood viscosity and plasma fibrinogen have been found in this study.
Abstract: To assess whether the viscoelastic properties of whole blood might be influenced by age, gender, cigarette smoking and oral contraceptives, we measured viscoelasticity of whole blood and plasma at different shear rates in healthy adult subjects. Thirty-five male and forty female subjects were classified into ten groups and their viscoelastic data were evaluated. Viscoelasticity of whole blood (shear rates 10/s and 50/s), viscosity of plasma (shear rate 10/s), aggregation index, shear resistance and flexibility index of erythrocytes and density hematocrit were measured with an oscillating capillary rheometer and densitymeter. Age was found to increase whole blood elasticity significantly at…low shear rates when young male non- smokers were compared with old non-smokers of both sexes. The intake of oral contraceptives was found to increase whole blood elasticity at high shear rates when young non-smoking men were compared with young non-smoking women who had taken oral contraceptives for at least one year. Concerning shear resistance of aggregated erythrocytes, the values of young non-smoking men were significantly lower than the values of all other groups except the group of young smoking women who had not taken oral contraceptives. Density hematocrit was higher in men than in women. Whole blood and plasma viscosities as well as aggregation and flexibility indices were not significantly different when ten groups were compared by analysis of variance.
Abstract: Erythrocyte deformability for suspensions of washed normal cells was tested by measuring the initial pressure drop during constant volumetric flow through 3-μ m pore size Nuclepore membranes. Filtrations of erythrocytes with the smaller pore size membranes were less sensitive to contaminating leukocytes and independent of leukocyte concentration when less than 100 cells/mm3 at red cell number densities of 3.85 × 105 cells/mm3 . Constant wall shear rate experiments at different erythrocyte fluxes show that the increase of initial pressure drop is nearly linear with the increase of erythrocyte flux over an order of magnitude range in flux. Constant…erythrocyte flux experiments at different wall shear rates suggest viscous shear thinning of erythrocyte suspensions.
Keywords: erythrocyte filterability, WBC effects, red cell flux, shear thinning
Abstract: The effects of hypertonic glycerol solution on erythrocyte (RBC) aggregability were examined in 8 patients with cerebral infarction confirmed by computed tomography scans. Each patient was administered intravenously with 500 ml of 10% glycerol in 5% fructose saline (glycerol solution) over a period of 3 h on the first day, and then with 500 ml of 5% fructose saline without glycerol (control solution) over 3 h on the next day. Venous blood was sampled from the antecubital vein before and after administration of each solution and analyzed with a whole blood RBC aggregometer. The RBC aggregation rate before the glycerol…solution (0.160±0.029/s, mean±SD) was higher than the value for normal volunteers reported previously. After the glycerol administration, the RBC aggregation rate showed a significant decrease to 0.147±0.030/s (p<0.05). On the other hand, the RBC aggregation rate (0.149±0.026/s) did not change significantly after infusion of the control solution (0.155±0.031/s). These data indicate that hypertonic glycerol solution can reduce the RBC hyperaggregability in patients with cerebral infarction. Analysis of the venous blood constituents revealed that these changes could not be attributed to changes in the hematocrit or fibrinogen concentration.
Abstract: In order to determine the analytical precision and physiological fluctuation of a battery of blood tests (hematocrit, blood viscosity, plasma viscosity, blood filterability, red cell aggregation and blood cell counts) 15 volunteers were tested at fortnightly intervals for 16 weeks in the absence of overt disease. The results indicate that accuracy of rheological tests is satisfactory (analytical variation 0.6–9.3%). The physiological variation not only depends on the variable tested, but apparently also on the individual. Plasma and blood viscosity are promising tests as they can be measured accurately and show little physiological variation.
Abstract: Piracetam has been reported to have a protective rheological effect on sickle cells. When sickle cells were subjected to cyclical oxygenation-deoxygenation for 15 hours in Ca2+ -containing buffer, there was a loss of cell filterability through pores of 5 µm diameter and an increase in mean cell haemoglobin concentration and percentage irreversibly sickled cells. These changes were consistent with entry of Ca2+ , activation of the Gardos channel in the sickle cell membrane, and loss of cell K+ and water. Piracetam at 100 mmol/l had a significant protective rheological effect. When sickle cells containing 86 Rb were loaded with…Ca2+ using the Ca2+ -ionophore A23187, however, the consequential efflux of K+ (86 Rb) through the Gardos channel was not inhibited by 10 or 100 mmol/l piracetam. The action of piracetam in preventing dehydration of sickle cells would not therefore seem to be due to inhibition of the Gardos channel.
Abstract: Blood rheology measurements (whole blood viscosity, plasma viscosity, hematocrit and fibrinogen) and fibrinolytic and metabolic tests (plasma fibrinolytic activity, C-peptide, total cholesterol, triglycerides) were performed in 40 obese subjects before and after one year of hypocaloric diet. Our data show a slight decrease after weight loss of whole blood viscosity at 0.1 sec−1 but not at 1.3 and 94.5 sec−1 . Hypocaloric diet did not affect plasma viscosity, plasma fibrinogen or plasma fibrinolytic activity despite a significant lowering of body mass index and C-peptide. We conclude that in obesity there are metabolic, coagulation, fibrinolytic, and rheological changes…that persist after weight loss.
Abstract: 30 patients undergoing elective aortic surgery had intraoperative autologous blood transfusion, 15 with the Solcotrans device and 15 with the Haemonetics Cell Saver system Markers of red cell damage and alteration of red cell parameters and biochemistry were studied. Using the St Georges Filtrometer, the filterability of preoperative red cells was compared to that of red cells that had undergone salvage. The indices of filtration measured were the red cell transit time (RCTT) and the number of clogging particles (CP). Various other parameters of red cell damage or known to affect red cell filterability were assessed. There was no…difference between the pre-operative and the salvaged red cell transit times with either autotransfusion device. However, for both devices, there were significantly more clogging particles in the salvaged samples than in the preoperative samples indicating the presence of a subpopulation of rigid cells. This is probably due to an increase in the MVC of damaged cells salvaged with the Solcotrans device, and a relative increase in the MCHC of damaged cells salvaged with the Cell Saver. A comparison of the results obtained for each device, shows that cell washing confers no advantage with respect to the filterability of autotransfused red cells, for differing reasons.