Clinical Hemorheology and Microcirculation - Volume 4, issue 2-3

Authors: Coccheri, S. | Palareti, G.

Article Type: Research Article

Abstract: Hemorheologic changes may be primary, associated, or secondary, in relation to arterial disease and ischaemic damage. Therefore the significance of the hemorheologic changes in the pathophysiology of POAD, also in view of a therapeutic approach, needs careful assessment in each patient. Goals of the “hemorheologic” treatments in POAD are: 1) to induce a moderate lowering of peripheral resistance even when the vasodilatory reserve has been exhausted; 2) to improve blood flow in the microcirculation; 3) possibly, to increase blood flow in the newly formed collateral vessels. Some therapeutic measures dramatically altering blood rheology have been reported as effective in critical …phases of POAD, thus proving that lowering of blood viscosity improves blood flow and clinical conditions in certain groups of patients. Recent trials with “hemorheologic” drugs, mostly acting on blood filterability, suggest that some of them may indeed be effective in improving the walking ability of patients with intermittent claudication. However, the relation between hemorheologic and therapeutic effects of these drugs is not yet established. It is suggested that these drugs may be especially effective in a number of “good responders”, whose identification is however still doubtful. Show more

Keywords: Obliterative arterial diseases, pathophysiology, Haemorheology, Haemorheologic drugs

DOI: 10.3233/CH-1984-42-310

Citation: Clinical Hemorheology and Microcirculation, vol. 4, no. 2-3, pp. 177-191, 1984

Authors: Stuart, J.

Article Type: Research Article

Abstract: Rheological methods have much to contribute to better understanding of the microvascular changes that characterise the asymptomatic steady state and the painful vaso-occlusive crisis of sickle-cell anaemia. Loss of deformability of the reversibly sickled cell, rather than an increase in the number of irreversibly sickled cells or in plasma viscosity, is probably the important rheological change at the onset of vaso-occlusive crisis and can be measured using positive-pressure or initial-flow-rate filtration methods. These bulk filtration methods can also be used for in vitro screening of new anti-sickling compounds and to provide an objective end point, during clinical trials of …these compounds, of the resolution of crisis. Show more

Keywords: Rheology, Sickle, Erythrocyte deformability

DOI: 10.3233/CH-1984-42-311

Citation: Clinical Hemorheology and Microcirculation, vol. 4, no. 2-3, pp. 193-207, 1984

Authors: Volger, E.

Article Type: Research Article

Abstract: The flow property of blood is one of the two major determinants of flow resistance, but it has not gained as much attention as the vascular component in haemodynamic investigations on ischaemic heart disease. Recent observations in some patients with typical angina pectoris but normal coronary arteriogram shed new light on this problem, since it became evident that merely severe rheological abnormalities can cause impaired coronary perfusion, while improvement of blood fluidity by plasmapheresis or haemodilution clearly increases coronary blood flow and coronary reserve. This, however, means that in coronary artery or small vessel diseases with already reduced flow forces …and restricted coronary reserve, rheological factors would be more relevant than it was expected until now. The more the vasomotor reserve is recruited the more likely are microcirculatory disturbances with clinical signs caused by pathologically altered viscosity factors. It is therefore of clinical interest that in most patients with common coronary artery disease the haemorheological parameters differ from normal. This is also true for non inflammatory and inflammatory small vessel diseases, where the changes are even more pronounced. Although rheological abnormalities can be determined in ischaemic heart disease it is not possible to forecast effects on coronary microcirculation as long as we have no data on the myocardial microhaemodynamic. Show more

Keywords: Ischaemic heart disease, small vessel disease, plasma viscosity, red cell filtrability, red cell aggregation

DOI: 10.3233/CH-1984-42-312

Citation: Clinical Hemorheology and Microcirculation, vol. 4, no. 2-3, pp. 209-221, 1984

Authors: Dintenfass, L. | Fu-lung, Liao | Francis, Donna | Willard, A.

Article Type: Research Article

Abstract: The Slit-Capillary PhotoViscometer allows a study of kinetics and morphology of aggregation of red cells. Micro and macro photography are carried out either during flow, or more frequently during stasis at 15 sec and 30 sec intervals. Colour slides are analyzed by stereological methods. Hereby three morphological indices are introduced based on the standard stereological parameters of Zeiss Videomat 2. Results for a specific stasis time can be compared using either Students t-test or by comparison of slopes and elevations of linear regressions linking various parameters and stasis time. Blood samples examined included a selection obtained from different patients, as …also a series of reconstituted suspensions at standard haematocrit of 30% but differing concentrations of albumin, fibrinogen, paraproteins, etc. Statistically significant differences have been observed using these parameters, both in kinetics and in morphology of blood samples. Show more

Keywords: slit-capillary, aggregation of red cells, kinetics of aggregation, morphology of aggregation, stereological parameters, indices of morphology

DOI: 10.3233/CH-1984-42-313

Citation: Clinical Hemorheology and Microcirculation, vol. 4, no. 2-3, pp. 223-236, 1984

Authors: Friederichs, E. | Germs, J. | Lakomek, M. | Winkler, H. | Tillmann, W.

Article Type: Research Article

Abstract: In vitro measurements with a transparent rheophotometer were carried out to study the spontaneous aggregation of red cells of 208 blood samples obtained from 132 children with different infectious diseases. The mean evaluation of aggregate formation in stasis (MEA) as well as of the erythrocyte sedimentation rate (ESR) was correlated with the concentration of most of the acute phase proteins of the plasma. The aggregate formation of erythrocytes (MEA) was more sensitively influenced by an increased concentration of the most important acute phase proteins than the erythrocyte sedimentation rate (ESR). A distinct correlation of red cell aggregation and the fibrinogen …concentration was found. We suggest, that the measurement of red cell aggregation is an appropriate method to describe the increase in the concentrations of the most important acute phase proteins, especially fibrinogen, during infectious diseases. Show more

Keywords: erythrocyte aggregation, acute phase proteins, infectious diseases

DOI: 10.3233/CH-1984-42-314

Citation: Clinical Hemorheology and Microcirculation, vol. 4, no. 2-3, pp. 237-244, 1984

Authors: Adjizian, J.C. | Pignon, B. | Poynard, A. | Ostermann, G. | Potron, G.

Article Type: Research Article

Abstract: The laser light scattered by erythrocytes subjected to a well defined shear stress can be analysed with the Ektacytometer to obtain information regarding the changes in all shape due to fluid shear. We used this technique for measuring cell deformation in different clinical status: diabetes, liver disease, geriatric population, arterial hypertension, and other clinical vascular disease. The results were compared to other biological parametes as: rheological parameters with a Couette viscometer, erythrocyte filtrability; coagulation and fibrinolytic parameters, tested as an index of a potent endothelial lesion. No reduced cell deformability was noted in clinical status at 290 mOs. However, by …modifying the osmotic strength of the suspending medium we can demonstrate the influence of S/V ratio and the internal viscosity upon erythrocyte deformability. Show more

Keywords: Ektacytometer, Laser diffractometry, Osmotic strength

DOI: 10.3233/CH-1984-42-315

Citation: Clinical Hemorheology and Microcirculation, vol. 4, no. 2-3, pp. 245-254, 1984

Authors: Clark, Peter A. | Willars, Elizabeth J. | Oughton, James | Barnes, Adrian J.

Article Type: Research Article

Abstract: A comparatively simple method is described for examining the clinical importance of red cell deformability in large numbers of patients. Using glass micropipettes in a thermostatically controlled unit, individual cells may be studied either in their native plasma or in buffer at varying pH, temperature and gas tensions. An apparatus has been produced which can make micro pipettes under reasonably controlled conditions of shape, diameter and length, with acceptable levels of production time and quality.

Keywords: Micropipette, hemorheology, erythrocyte deformability

DOI: 10.3233/CH-1984-42-316

Citation: Clinical Hemorheology and Microcirculation, vol. 4, no. 2-3, pp. 255-262, 1984

Authors: Seiffge, D.

Article Type: Research Article

Abstract: Single erythrocyte passage time, flow curve in the Filtrometer, and Nuclepore filtration rate have been examined under different experimental conditions, which are supposed to simulate pathophysiological situations of diminished microvascular perfusion. The following methods have been used: 1. Nuclepore filtration test; 2. Filtrometer MF 4 (employing Nuclepore filters); 3. Single Erythrocyte Rigidometer (SER). To change RBC “deformability”, the cell suspensions have been treated with: 1. lactic acid (e.c. 0.1%); 2. 4h ageing in buffer; 3. CaCl2 (5 mmol/l); 4. adrenalin (0.1 and 0.316 mmol/l); 5. PGI2 (100 and 1000 ng/ml), and 6. PGE2 (0.3 ng/ml). The mean …passage time in the SER has been found to be significantly extended by all stress models applied, except for a non-measurable flow of RBC (e.g. occlusion) by the much too severe first stress model. In contrast, Nuclepore filtration test showed no effect on RBC deformability incubated with catecholamines and prostaglandins. Show more

Keywords: RBC Deformability, RBC Stress Models, Nuclepore Filtration, Filtrometer, Single Erythrocyte Rigidometer

DOI: 10.3233/CH-1984-42-317

Citation: Clinical Hemorheology and Microcirculation, vol. 4, no. 2-3, pp. 263-273, 1984

Authors: Isogai, Y. | Yokose, T. | Maeda, T. | Akiyama, M. | Onogi, S. | Masuda, T. | Iwamoto, S. | Ohmachi, T.

Article Type: Research Article

Abstract: The OP-Rheometer was developed to measure blood viscosity at lower shear rate (0.2–40 sec−1 ) and viscoelasticity at 0.1–3.0Hz in the context of clinical medicine. The system consists of a mechanical unit, a control unit, a data processing unit and a printer. The dynamic or constant flow data are automatically printed out. One of the features of this rheometer was a pair of magnetic bearings which supported an outer cylinder (blood sample container) connected to the torsion wire assembly. In clinical application, viscoelasticity of blood in diabetics showed higher level than that of normal subjects.

Keywords: viscoelasticity, OP-Rheometer, diabetes, rigidity modulus, loss modulus

DOI: 10.3233/CH-1984-42-318

Citation: Clinical Hemorheology and Microcirculation, vol. 4, no. 2-3, pp. 275-283, 1984

Authors: Whittington, R.B. | Matrai, A. | Nicol, C.G.

Article Type: Research Article

Abstract: Recently, Whittington and Harkness (1) showed how whole-blood viscosities, as measured in a concentric-cylinder apparatus, could, in principle, be inferred from capillary-tube measurements made at rates of shear up to 1,000 times those in the rotary machine. Two invariant parameters, “A” and “β ” were postulated. “A” is the relative whole-blood viscosity at unit rate of shear and 1% haematocrit; and “β ” is the shear-sensitivity exponent. The ability of these parameters to discriminate between normal, hyperproteinaemic and sickle-cell bloods will now be demonstrated. It will be suggested that A and β may also be more useful indicators of …haemorheo1ogica1 reaction to surgery and drug-therapy than the data arising from whole-blood viscometry as usually presented. Hitherto, this art has generally implied the measurement of viscosity at selected constant shear-rates, often with a “correction” to an arbitrary haematocrit value. The new approach is to presume that A and β are constant characteristics of the blood-sample, quite independent of the haematocrit at withdrawal, and of the stresses imposed upon the blood during measurement. Show more

Keywords: Viscosity, haematocrit, shear, characteristic parameters

DOI: 10.3233/CH-1984-42-319

Citation: Clinical Hemorheology and Microcirculation, vol. 4, no. 2-3, pp. 285-293, 1984