Clinical Hemorheology and Microcirculation - Volume 5, 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: Using two different technical approaches (modified Reid and Dormandy and initial filtration flow rate methods), the RBC deformability has been determined under various conditions, in order to estimate the role of the membrane. On normal human RBCs, the rigidity index (IR) is the same for the whole cell as for the membranes. The thermal variations of IR (between 5 and 40°C) are the same for the whole cells as for the ghosts. Moreover they show the same low temperature transition as the one presented by natural and artificial lipid bilayers. Using RBC from various species of mammals, the filtration…indices of the intact cells and of the ghosts are only correlated with the membrane cholesterol/phospholipids ratio. Therefore, we think that, in the above mentioned conditions, the RBC deformability is mainly controlled by its membrane composition and organization.
Abstract: The hemorheological parameters: whole blood viscoelasticity, plasma viscosity and hematocrit were measured in 60 patients with completed stroke. These values are significantly higher than those of 90 healthy subjects. 16 patients with completed stroke with different treatments were investigated in a controlled study. The group with daily infusion of Ginkgo biloba extract added to low molecular weight dextran solution showed a significant decrease in the viscoelastic parameters of blood after 5 and 10 days after the beginning of treatment, whereas in the control group, treated with low molecular dextran only, no significant changes in blood viscoelasticity could be observed.
Abstract: The effects of the 24-h insulin treatment using an artificial pancreas on red blood cell filterability (VRBC) were studied in two groups of insulin-dependent diabetics with different degrees of metabolic control. RBC filterability significantly improved in the group with better metabolic control, but was reduced in the group with poor control. In the latter group, the initial plasma lactate levels were slightly abnormal and did not significantly change following the treatment. Significantly increased MCHC and decreased VRBC were found after an in vitro addition of lactate, and it was further observed that the correction of RBC filterability obtained by…insulin was abolished with the addition of lactate. These results suggest that insulin correction of RBC filterability by the treatment using the artificial pancreas will be less effective in those insulin-dependent diabetics who also exhibit marked disturbances in intermediary metabolism.
Keywords: Red cell filterability, Insulin action, Artificial pancreas, Lactate, Hyperosmolarity
Abstract: A study of the relationship between erythrocyte mean cell volume (MCV) and erythrocyte elongation (EI max) in the Ektacytometer has been made in healthy controls , arterial disease , renal disease , diabetes mellitus , Raynaud’s phenomenon , and liver disease . There was a significant correlation between MCV and EI max in the 58 healthy controls (r = 0.574, p < 0.001) and in each of the clinical groups, with the exception of liver disease in which abnormal erythrocyte morphology independently influenced EI max. Correction of EI max for MCV, using a regression line, increases the specificity of erythrocyte…elongation measurements for a loss of erythrocyte deformability.
Abstract: Ultrasonication for 10 s in 1% w/v aqueous sodium dodecyl sulphate has been used to clean polycarbonate membranes, either singly or in batches, thus allowing their repeated use for measurement of erythrocyte filterability. Ultrasonication effectively prevented carry-over when normal and rheologically abnormal cells were filtered alternately and membranes used up to 60 times showed no morphological deterioration on scanning electron microscopy. Ultrasonicated membranes can be stored, for subsequent reuse, in filtered buffer or in the dry state. Reuse of polycarbonate membranes in filtration studies offers considerable advantages in relation to improved precision, quality assurance, and lower cost.
Abstract: Initial-flow-rate filtration of erythrocytes was studied using a Hemorheometre fitted with straight-channel polycarbonate and tortuous-channel silver membranes of both 3 and 5 μm pore diameter. Erythrocyte filtration through straight-channel 3 μm pores was sensitive to in vitro manipulation of erythrocyte mean cell volume (MCV) and correlated with patients’ MCV in four clinical groups; 3 μm pore filtration was also sensitive to laboratory temperature even within the range 20–25°C. Rheological studies using 3 μm pores therefore require strict observance of buffer pH and osmolality, which affect MCV, and also filtration temperature. Filtration through 5 μm pores was less dependent on MCV…in vitro, and in the clinical groups, but was sensitive to in vitro increase in mean cell haemoglobin concentration (MCHC). Use of both 3 and 5 μm diameter pores in filtration studies will increase test sensitivity to different determinants of erythrocyte deformability.
Keywords: Rheology, Erythrocyte deformability, Erythrocyte indices
Abstract: In ischaemic heart disease, it is not easy to define whether hemorheological disturbances are primitive or secondary to myocardial ischemia. We report results from 14 patients aged 48 to 75 admitted to the coronary care unit (CCU) with myocardial pre-infarction syndrome (MPIS) defined as a persistant typical angina resistant to NTG and accompanied by specific ECG changes. Venous blood samples were taken on admission to the CCU for measurement of hematocrit (Hc), whole blood viscosity (BV), plasma viscosity (PV), and whole blood filterability (Fi). Six patients improved subsequently and were discharged without myocardial infarction (NMI patients), while the other 8…developed documented MI 12 hours to 4 days after admission (MI patients) with significantly higher BV at any shear rate and at patients hematocrits as well as at corrected hematocrit (p < 0.01), higher PV (p < 0.01). Hc was higher and Fi lower in MI patients although not significantly so. The results suggest that hemorheological changes play a major role in triggering or worsening hemodynamic events leading to MI.
Abstract: Erythrocyte deformability was studied by 5 μm pore filtration (initial-flow-rate and positive-pressure methods) and by viscometric and Ektacytometric techniques in 30 patients with liver disease compared with 30 matched controls. All of the rheological techniques demonstrated abnormal erythrocyte deformability in the patient group, with a left shift of the Ektacytometer Osmoscan curve correlating significantly with degree of liver failure. Abnormal erythrocyte morphology (codocytes, acanthocytes, and an increase in mean cell diameter), rather than an increase in mean cell volume, was a major determinant of abnormal erythrocyte deformability.
Abstract: The St. George’s Filtrometer was designed to differentiate between the two major factors effecting blood filterability: red cell transit and filter clogging. Using this method, blood filterability was studied in 20 patients suffering from intermittent claudication. Pentoxifylline (RentylinR ) improved filterability of blood cell suspensions of standardized red and white cell counts. A statistically significant but small (5%) increase of red cell deformability accompanied with an apparently more significant (36%) decrease of filter clogging was found. This seems to reflect qualitative change of leucocytes. It is suggested, that besides improving intrinsic red cell deformability, Pentoxyfilline might have an other, possibly…important pharmacological action in peripheral vascular disease.
Abstract: In epidemiological studies, residents of a fishing village had lower whole blood viscosity and higher red blood cell (RBC) filterability than residents of a farming village. Daily administration of either fish oil concentrate containing 1.4 g EPA or 3.6 g EPA-ethylester (EPA-E) to 7 normal volunteers for 4 weeks resulted in a reduction in whole blood viscosity. EPA-E administration was found to increase RBC-filterability. In clinical studies, we treated 40 male patients suffering from diabetes mellitus (15 patients), hyperlipidemia (12 patients), ischemic heart disease (11 patients) and other diseases (2 patients) with 2.7 g EPA-E for 16 weeks. Whole blood…viscosity decreased and RBC-filterability increased in 8–16 weeks. It seems that an increase in EPA content in RBC-membrane increases membrane fluidity, and hence RBC-filterability, on which blood viscosity is partially dependent.
Keywords: eicosapentaenoic acid, blood viscosity, RBC-filterability, epidemiology, fish oil
Abstract: Red cell deformability was measured in 13 patients with stable angina controlled by beta-adrenoceptor antagonists and 13 controls. Filtration of leucocyte-poor blood was carried out by a modification of the Reid-Dormandy method at 37°C. No difference was found between the flow rates for blood anticoagulated with heparin, defibrinated blood or washed cells resuspended in serum when the two groups were compared. There is no evidence for impaired red cell deformability in these patients with stable angina.
Abstract: Using the spin-label method, we have compared the physical state of the human platelet membrane before and after thrombin-induced aggregation. In its resting state this membrane is rigid and highly organized. After aggregation, its ordering decreases. This phenomenon is dose dependent and reaches its maximum with about 0.5 U/ml of thrombin for 3.109 platelets per ml. Preliminary results obtained on genetic diseases (Glanzman thrombasthenia and Gray platelets syndrome) indicate that this change is independent from the aggregation phenomenon itself. In thromboembolic states (thrombocytemia, diabetes) the membrane molecular structure of platelets at rest seems to be similar to that of…activated normal platelets.
Abstract: Concepts originally introduced in 1970 (1), concerning the rotational “viscosity vectors”, are further developed: as is the concept of “effective molecular mass” (for viscosity). This is used first to calculate “molar” viscosities at three temperatures for a sucrose concentration of 60% in water. These differ from published experimental values by about 1%. Adjustments of the “effective” molecular mass to give agreement at all concentrations up to 60%, are made on a geometrical empirical basis. A tentative viscosity-concentration table is presented for 20°, 25° and 37°C., for concentrations of 20, 40 and 60% w/w. Finally, a few significant plasma…and whole-blood viscosity-values are chosen to illustrate how the field of clinical results can be mapped against an aqueous-sucrose background.
Keywords: Viscosity, sucrose, water, ranges in haemorheology
Abstract: Under specific hemorheologic and hemostasiologic conditions (Pcath 1200 mmHg, hematocrit value lesser than 30%, adequate heparinisation) it is possible to archieve a sufficient flow rate through the narrow lumen (0.5 mmØ) of the dilatation catheter (DC) during PTCA to exert a myocardial protective effect of the myocardium distal to the balloon. This prevents hemodynamic deterioration and should permit longer duration of balloon inflation.
Keywords: Percutaneous transluminal coronary angioplasty, in vitro and in vivo studies, intracoronary perfusion, myocardial protective effect
Abstract: At atmospheric pO2 and at 25°C the red blood cell rigidity is highly increased in sickle cell syndromes (SS and AS) and in β thalassemia (minor and intermedia). The initial filtration flow rate of RBCs was evaluated with the hemorheometre. The individual transit time of cells passing through 5 μ pores was measured with a new apparatus the “cell transit time analyser” which permitted the study of up to 1000 cells in one minute. This method showed the heterogeneity of normal and sickle cell.s at atmospheric pO2 .
Keywords: Deformability, Hemoglobinopathy, transit time, Red Blood Cells
Abstract: The aim of this study is to compare 3 methods allowing to assess R.B.C. Aggregation: steady viscometry, unsteady viscometry ana light reflectometry. This comparison was performed on blood samples drawn from forty insulino-dependent diabetics. We found strong correlations between the parameters measured by the three techniques. These correlations are most likely explained by the existence of a common underlying parameter influencing the three types of measurements: the adhesive energy per unit area. Moreover, we attempted to know whether the measured viscometric or light reflectometric parameters are good diagnosis (or prognosis) instruments. For that we compared the number of diabetics…having an abnormal value of the different aggregometric parameters. The thixotropy index, measured by unsteady viscometry, and the disagregation shear stress reached by light reflectometry detected the largest number of pathological cases. The steady viscometric data were then discussed with regard to the conditions of appearance of a plasma layer near the viscometer walls.