Clinical Hemorheology and Microcirculation - Volume 8, issue 1
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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: Studies were carried out to evaluate the effects of different methylxanthines on the erythrocyte deformability (E.D.) using two techniques of filtration through polycarbonate 5 µm pore diameter. 1. Initial flow rate filtration. 2. Initial pressure rate filtration induced at constant flow. Correlation assays between structure and effects of these methylxanthines on the E.D. are discussed. Initial flow rate filtration. Initial pressure rate filtration induced at constant flow.
Abstract: Resorption of subcutaneously administered insulin is known to be under dependence of various factors, including changes in local blood flow. This study was undertaken in order to determine whether hemorheologic disturbances may also modify it. Fourteen insulin-dependent diabetics (4 females and 10 males, age 24 to 70 yr) received subcutaneously 10 units of porcine monocomponent insulin (Actrapid MC, Novo) and blood increases in both total and free insulinemia were measured over 2 hours. Rheological parameters studied during the test were: Ca) blood filterability (according to Reid et al) and (b) washed erythrocyte filterability. In six patients who had lowered blood…filterability, the increase in total insulinemia was significantly impaired. Therefore, among various other factors, blood rheology might play a role in insulin resorption kinetics, possibility by modulating blood flow in subcutaneous microvessels.
Abstract: Abnormal rheological properties of red cells are important in a wide range of microvascular diseases. A beneficial effect of beta-blocking drugs has been noted in the secondary prevention of myocardial infarction. We therefore investigated the influence of these drugs on red cell rheology. Erythrocyte filtrability was significantly increased after incubation with Metoprolol, there was no effect, however, after incubation with Propranolol or Timolol. The exact mechanism of this effect is still unknown. Differences regarding cardioselectivity do not seem to be involved. Lipophilic agents, however, induce changes within the erythrocyte membrane leading to a constant cell volume.
Keywords: Hemorheological properties, Effect of Beta-Blocking agents
Abstract: Erythrocyte-endothelial interaction has been postulated as a potential etiologic factor of vascular pathology in diabetes mellitus. To examine this hypothesis, red cells from diabetics with a wide range of vascular disease were allowed to contact cultured endothelial monolayers and then were subjected to shear stresses calculated to be in the physiological range for capillaries, venules and arterioles to assess whether erythrocyte-endothelial binding is sustained in conditions simulating in vivo flow. Diabetic red cells, like control cells, do not demonstrate adherence to cultured endothelium under conditions which resemble in vivo flow dynamics in venous,capillary or arterial regions of the…circulation. This suggests that erythrocyte-endothelial adherence is not likely to be the primary factor in initiation of vessel wall degeneration.
Abstract: Sixteen arteritic patients at stage II, III and IV according to Fontaine, were treated by isovolemic hemodilution. The procedure consisted of the daily withdrawal of 500 ml of blood, which is replaced by 250 ml of a 4% solution of human albumin and 250 ml of Dextran 40. The procedure was applied, on average, for three days in succession until the patient’s hematocrit reached 0.30. The therapy was carried out over a total of 8 weeks, with fortnightly hemodilution sessions. Improvement was observed in clinical factors: a 100% increase in treadmill performance, disappearance of decubitus pain and wound healings. The…following biological parameters were studied: plasma albumin and fibrinogen levels, plasma and blood viscosity, red blood cells aggregation index, platelet aggregation, plasma β -thromboglobulin level, platelet MDA and nucleotides concentrations. The results revealed that by the 56th day of treatment, 8 patients had improved, 4 remained stationary and 4 were deteriorated, regardless of etiology or stage of arteritis. With regard to biological parameters (which before IHD, were always impaired), they improved after the first IHD procedure, then returned after two months of IHD Trial to levels some half-way between the values measured before HID and normal values. Physiopathological implications of these clinical and biological results are discussed.
Keywords: Isovolemic hemodilution, arteriopathy, human albumin, hemorheology, platelet activation, Dextran
Abstract: Fourteen patients suffering from reflex atrophy stage II were investigated for blood rheology. Blood and plasma viscosity, hematocrit, blood cell filterability, red cell aggregation, leukocyte count, serum electrophoresis, erythrocyte sedimentation rate (ESR) and plasma fibrinogen levels were measured. The cross-sectional comparison shows that, compared to matched controls, plasma viscosity, red cell aggregation and ESR were significantly higher, while blood cell filterability and gamma globulin fractions were lower in patients. In a subsequent longitudinal study five patients were studied while receiving hydroelectric treatment. During therapy a progressive normalization of plasma viscosity and blood cell filterability readings, paralleled by clinical improvement could…be observed. It is suggested, that blood rheology is impaired in reflex atrophy stage II, possibly due to an imbalance of autonomous nervous control, and that this hemorheological deficit might contribute to the disruption of the microcirculation in this disease.
Keywords: reflex atrophy, hemorheology, physical therapy, electric current
Abstract: To determine whether or not viscosity reduction would improve flow past a significant stenosis in a major artery an in vitro perfusion apparatus with 12 variable sized stenoses was used with whole blood at three different viscosity levels. A 36% reduction of the viscosity of whole blood by the addition of normal saline did not alter either the pressure flow relationships or the resistance to blood flow across any of the 12 stenoses ranging from 50% to 97%. We conclude that although change in viscosity may improve perfusion through the microcirculation it does not alter perfusion across a discrete arterial…stenosis.
Abstract: Different methodologies and heterogeneous patient groups have led to conflicting results with respect to erythrocyte deformability in diabetes mellitus. Therefore we studied erythrocyte deformability by means of viscosity measurements in insulin dependent diabetics without major vascular complications and its relationship with metabolic control. Viscosity measurements of red cells suspended in a non-aggregating physiological medium were performed with a Contraves Low Shear 30 viscosimeter at low (0.945s−1 ) and high (128.5s−1 ) shear rate. Erythrocyte viscosity in the diabetic group was normal at high shear rate but significantly increased at low shear rate. This increased low shear rate viscosity was observed…only in patients with bad metabolic control. Two important conclusions can be derived from our results: 1) detecting abnormal erythrocyte rheology in diabetes depends upon experimental conditions and 2) in insulin dependent diabetics without vascular complications erythrocyte flow properties depend on the metabolic status. detecting abnormal erythrocyte rheology in diabetes depends upon experimental conditions and in insulin dependent diabetics without vascular complications erythrocyte flow properties depend on the metabolic status.
Abstract: An assessment of the impact of transfusing blood on the hemorheological data of patients is reported when submitted to vascular or plastic surgery. Autotransfusion and hemodilution are discussed as a challenge to the homologous transfusion. The rheological study is performed with a Couette viscometer. Unsteady flow measurements related to blood thixotropy and measurements in steady state flow conditions related to the shearthinning property of blood are reported. Pre and postoperative results are discussed taking into account the surgical procedure, the intraoperative blood and fluid requirements. The main conclusion of the study is that for the six cases here reported, from…a rheological standpoint, the immediat post-operative state is quite good irrespective of the method of transfusion.
Keywords: Viscometry, blood transfusion, vascular and plastic surgery
Abstract: A 54 year old man presented with typical claudication due to occluded superficial femoral arteries of both legs. On the right side there was a short occlusion without visible col laterals in the angiogram. On the left side there was a long occlusion with numerous narrow col laterals. Before hemodilution the walking distance was limited by ischemic pain in the left leg. After hemodilution walking distance increased but was then limited by pain in the right leg. It is concluded that the different hemodynamic situations respond differently to hemodilution. Possibly this form of treatment is effective…only when average shear stresses are low in the flow limiting segment.
Abstract: In order to determine accuracy and precision of the oscillatory capillary rheometer (OCR-D), two Newtonian (water, ethyleneglycol) fluids and a Non-Newtonian (aqueous solution of polyacrylamides) fluid were used. In addition, the ranges of normal and pathological plasma viscosity (1.07–4.61 mPas) and of whole blood viscoelasticity (2.94–12.32 mPas for the viscous and 0–6.46 mPas for the elastic component) were determined in order to select the ranges of viscoelastic parameters for control materials of clinical interest. Mixtures of water and ethyleneglycol were examined to prove their suitability as control samples for plasma viscosity: mixtures in a ratio of 1 to 0.5 and…1 to 4 (v/v) are recommended. To control the measurement of viscoelastic parameters of whole blood, the Non-Newtonian fluid (PAA) and a commercially available red blood cell test suspension (Dia-HT2) were investigated for their precision parameters. For quality control of the viscous component both solutions are required, whereas PAA may also serve for control of the elastic component, Dia-HT2 is not appropriate due to very low elastic responses.
Abstract: Valinomycin, a K+ ionophore, was used in vitro to induce loss of K+ and water from the erythrocytes of 20 patients with homozygous sickle cell anaemia. The resulting loss of filterability, through pores of 5 µm diameter, of these dehydrated sickle cells was significantly improved by the presence of oxpentifylline (1.0 and 10 µmol/l), cetiedil citrate (0.1 and 1.0 µmol/l), or the two drugs in combination (each at 0.1 and 1.0 µmol/l). Thus pharmacological concentrations of these drugs, which act by altering cation flux across erythrocyte membranes, can improve the hydration and deformability of sickle cells.
Keywords: Rheology, Erythrocyte deformability, Ion transport
Abstract: Central hemodynamics and rheological properties of blood were studied in 15 healthy controls and 28 primary hypertensive patients (WHO 1–2) of both sexes. Hemorheological parameters: whole blood viscosity (η B ), plasma viscosity (η p ), hematocrit (HCT) and red blood cell filterability index (FI) were measured in venous blood sampled just prior to hemodynamic investigation. Plasma volume, systolic and diastolic blood pressure and cardiac output were estimated and indices: plasma volume index (PVI), blood volume index (BVI), cardiac index (CI), stroke volume index (SVI), total peripheral resistance index (TPRI) and aortic rigidity index (ARI) were calculated.
Keywords: hypertension, hemodynamics, hemorheology, blood viscosity, red blood cell deformability