Clinical Hemorheology and Microcirculation - Volume 14, issue 4
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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: To elucidate the pathophysiologic significance of the mechanical fragility of red blood cells (RBC), we have developed a simple quantitative technique, the impact-force method, for measuring mechanical hemolysis; the method makes use of the instantaneous falling of a metal bar due to gravity. The mechanical hemolysis thus induced was accompanied by cell fragmentation and echinocytosis. The method can be performed under near physiologic conditions. We found that mechanical hemolysis increased with a rise in hematocrit (Hct) value; in particular, the hemolysis rapidly increased above a Hct value of around 50%, thereby suggesting that the mechanical fragility determined by this method…reflects the rheologic characteristics of the RBC suspension, such as cell-cell interactions, as well as membrane stability. Using the impact-force method, we found that the mechanical fragility of rat RBC was greater than that of human RBC, whereas there was little difference between the two species in osmotic fragility. Although osmotic hemolysis was strongly reduced by low concentrations of chlorpromazine, this drug promoted mechanical hemolysis at all concentrations examined. More interestingly, Heinz body-forming RBC from a patient with unstable hemoglobin disease and hemolytic anemia showed a marked increase in mechanical fragility, but a pronounced decrease in osmotic fragility due to dehydration of the cells. This suggests the pathophysiologic importance of the mechanical fragility of RBC, specifically in the pathogenesis of hemolytic disease. It is, therefore, likely that this mechanical fragility test could be of value in various related fields of clinical medicine, as well as hematology.
Abstract: To elucidate the pathogenesis of hemolysis in hereditary spherocytosis (HS), we studied the heterogeneity and deformability of red blood cells (RBCs), before and after splenectomy, in a typical patient with HS. RBC deform ability was measured with our recently developed nickel mesh filter with both 3μm and 5μm pores. HS RBCs showed a marked increase in osmotic fragility with a “tailed” osmotic-fragility curve; consistently, the density distribution of HS RBCs was markedly shifted to heavier cells, with a biphasic profile. HS RBCs, the dense cells in particular, showed a marked impairment in filterability through the 3-μm pore nickel mesh compared…with that through the 5-μm pores. It is, therefore, likely that the impaired deformability of HS RBCs arises from the decrease in the cell surface area to volume ratio and the high mean corpuscular hemoglobin concentration. After splenectomy, the dense microspherocytes disappeared, and there was a marked improvement in RBC filterability through 3-μm pores. This suggests that dense cells were microspherocytes that received splenic conditioning in the walls of splenic sinuses. Correspondingly, splenectomy markedly improved clinical manifestations and ameliorated hemolysis. Thus, the laboratory measurement (i.e., the 3-μm filtration test) reflected the patient's clinical state. The use of both 5- and 3-μm filtration measurements can make a practical contribution to determining the differential diagnosis of hereditary hemolytic anemias. The 3-μm filter is useful in determing the clinical severity and indications for splenectomy in HS.
Abstract: The intrinsic resistance of red blood cell (RBC) is a determining factor of the blood viscosity. Hematocrit (Ht) greater than 60% significantly contributes to an increase in this factor. This study determines the viscosity of the intracellular content of RBC in neonates with and without polycythemia. The viscosity is measured in two neonate groups, according to the absence of illness and their hematocrit values, using capillary tubes with a 0.38 mm diameter at 25° C. The internal viscosity was found to be lower in polycythemic neonates together with lower plasma viscosity and mean corpuscular hemoglobin levels. The relative viscosity was…significantly greater in the polycythemic group. We draw the conclusion, that viscosity changes due to increased hematocrit are compensated by decreases in the plasma and internal viscosities of the red blood cells thus minimizing their effects on tissue blood flow.
Abstract: Activated leukocytes are known to generate reactive oxygen species which may attack other cells in their surroundings. On the other hand, rheological properties of red blood cells (RBC) are affected by oxidant attack. This study was designed to determine the influence of activated leukocytes on RBC rheology in vitro. Activated leukocytes were isolated from the Guinea pigs with an induced E. Coli sepsis and incubated with RBC obtained from normal animals. After two hours of incubation with activated leukocytes, RBC deform ability indices were increased 1.23 ± 0.05 (Mean ± Standart error) times (compared to the control RBC suspensions) while…incubation with leukocytes obtained from healthy animals increased deformability indices 1.12 ± 0.03 times. Thiobarbituric acid reactive substances as a measure of lipid peroxidation were increased 2.95 ± 0.36 times in the RBC suspensions incubated with activated leucocytes, but 1.70 ± 0.10 times in suspensions incubated with normal leukocytes. These results suggest that RBC mechanical properties might be affected by activated leukocytes and possibly an oxidative mechanism plays role in this interaction.
Keywords: Red blood cell deformability, oxidant attack, leukocytes, lipid peroxidation
Abstract: The capacity of red blood cells to deform is of crucial importance for both macro and microcirculation. A satisfying technique for the measurement of this parameter is lacking so far. We have developed and tested in various studies an instrument for automatic measurement of red cell deformability by laser diffractometry. Recently, it appeared that the applicability of the instrument could be extended for measuring another structural hemorheological parameter, red blood cell aggregation. In this communication, a description of the Laser-assisted Optical Rotational Cell Analyser (LORCA) is followed by the general methodology for the measurement of both red blood cell deformability…and aggregation, demonstrating the practical versatility of this instrument in the field of hemorheology.
Abstract: Red blood cell deformability was measured under normal and experimental conditions with the Laser-assisted Optical Rotational Cell Analyser (LORCA). Results were compared to simultaneously performed filtration measurements using the Cell Transit Analyser (CTA). The deformability parameters of the two methods were Elongation Index (EI) and mean Cell Transit Time (CTT), respectively. Aside from instrumental and intra-individual reproducibility, normal values, the effect of sample aging and of changing medium osmolality are reported. Furthermore, the respective sensitivities were determined using red blood cells with slightly impaired deformability. Both heat treatment and incubation in the presence of low concentrations of glutaraldehyde are…used to manipulate the deformability of the entire red cell population. It is concluded that minor defects in red blood cell deformability are detected more easily by the laser technique than by filtration. Even when the absolute differences in EI are small, they can be significant due to the very high reproducibility of the ektacytometric technique. Differentiation between a decreased deformability of the entire RBC population and the presence of a small (i.e., 5% or higher) subpopulation of rigid cells can be achieved with the LORCA by combining the measured EI-values with visual inspection of the diffraction pattern. Finally, no significant correlation was found between the results of both techniques applied to blood from 525 patients with various diseases.