Clinical Hemorheology and Microcirculation - Volume 6, issue 6

Article Type: Editorial

DOI: 10.3233/CH-1986-6619

Citation: Clinical Hemorheology and Microcirculation, vol. 6, no. 6, pp. I-III, 1986

Authors: Witte, Siegfried | Copley, Alfred L.

Article Type: Editorial

DOI: 10.3233/CH-1986-6601

Citation: Clinical Hemorheology and Microcirculation, vol. 6, no. 6, pp. 491-499, 1986

Authors: Bareford, D. | Lucas, G.S. | Stone, P.C.W. | Caldwell, N.M. | McGonigle, R. | Stuart, J.

Article Type: Research Article

Abstract: Erythrocyte deformability was studied by filtration through silver membranes (nominal 5 µm diameter channels) and by laser diffractometry (Ektacytometer) in 30 non-dialysed patients with chronic renal failure (CRF) compared with 30 matched healthy controls. Patients with CRF showed impaired erythrocyte filterability, which correlated with the degree of renal failure, and a left shift of the Ektacytometer osmotic deformability profile in favour of lower osmolality. Subsequent analysis of 20 patients undergoing regular haemodialysis and 23 patients undergoing continuous ambulatory peritoneal dialysis showed, compared with matched controls, a complete or partial correction of the rheological abnormality. Impaired deformability may contribute to the …shortened erythrocyte survival of patients with CRF. Show more

Keywords: Erythrocyte deformability, Rheology, Hemodialysis, Peritoneal dialysis

DOI: 10.3233/CH-1986-6602

Citation: Clinical Hemorheology and Microcirculation, vol. 6, no. 6, pp. 501-510, 1986

Authors: Guerciolini, R. | Merante, F. | Gresele, P. | Grasselli, S. | Susani, L. | Nenci, G.G.

Article Type: Research Article

Abstract: The effect of some plasma expanders (dextran 40, polygeline, succinyl-gelatin) currently used for normovolernic hemodilution (NHD) and of isotonic saline on erythrocyte deformability was tested by a whole blood filtration technique in vitro and ex vivo after NHD. Dextran 40 resulted able to improve erythrocyte filtrability ex vivo but not in vitro . Gelatine derivatives did not change ex vivo and worsened in vitro erythrocyte filtration rate. Hyperosmolarity was a major determinant of the negative influence exerted by plasma expanders on erythrocyte flexibility in vitro .

Keywords: Erythrocyte deformability, erythrocyte filtrability, normovolemic hemodilution, plasma expanders, whole blood filtration

DOI: 10.3233/CH-1986-6603

Citation: Clinical Hemorheology and Microcirculation, vol. 6, no. 6, pp. 511-521, 1986

Authors: García Rosasco, M. | Porta, P.E. | Rasia, R.J.

Article Type: Research Article

Abstract: A comparison has been made between the new laser diffraction technique and the well known method of erythrocyte filterability for the determination of erythrocyte deformability. A hyperbolic correlation has been found between deformation index and filtration time. This correlation becomes linear by inversing the deformation index. Our results demonstrate that filterability (filtration time method) selects the more deformable cells from the whole population. In this way, statistic tests have demonstrated that filtered cells are more deformable than cells retained above the filter at 95% confidence level.

Keywords: Laser diffractometry, Rheology, Erythrocyte deformability, Filterability

DOI: 10.3233/CH-1986-6604

Citation: Clinical Hemorheology and Microcirculation, vol. 6, no. 6, pp. 523-528, 1986

Authors: Carr, M.E. | Gabriel, D.A.

Article Type: Research Article

Abstract: Decreased perfusion of the microcirculation underlies the pathophysiology of cryoglobulinemia. Reduced temperature initiates cryoaggregate assembly. Perfusion of the microcirculation is diminished with increasing size of the cryoaggregate. Flow properties of both cryoglobulinemic plasma and solutions of highly purified cryoglobulin derived from a patient with Waldenstrom’s macroglobulinemia are highly dependent on both temperature and shear rate. At low temperature, cryoaggregates can be disrupted by low shear. However, at low temperature and shear rates above 200 sec−1 , shear dependent increases in viscosity occurs. Both fibrinogen and D-penicillamine inhibit cryoaggregate formation. The role of cryoaggregation in microcirculation ischemia is presented.

Keywords: Cryoglobulin, plasma viscosity, Rheology

DOI: 10.3233/CH-1986-6605

Citation: Clinical Hemorheology and Microcirculation, vol. 6, no. 6, pp. 529-540, 1986

Authors: Bernasconi, C. | Ferraresi, I. | Agostoni, A.

Article Type: Research Article

Abstract: A method has been developed for studying blood viscosity at shear rates from 4·10−2 to 7·102 sec−1 i.e., in the shear range in which the influence of shear rate on viscosity is greatest. Blood viscosity is expressed by the two regression coefficients of a power regression, according to the equation: η = a · D b in which η is viscosity, D is the shear rate, a and b are the two regression coefficients, which are independent of the shear rate. …We found that the power regression gives a good fit of the experimental data over a wide range of hematocrit. We also found significant correlations between the two regression coefficients and hematocrit and plasma viscosity, thus making it possible to correct the two regression coefficients for standard hematocrit and standard plasma viscosity. This method is simple, highly reproducible, and can easily be automatically performed by using a computer. Show more

Keywords: blood viscosity, plasma viscosity

DOI: 10.3233/CH-1986-6606

Citation: Clinical Hemorheology and Microcirculation, vol. 6, no. 6, pp. 541-551, 1986

Authors: Parker, M.C. | Hynd, J.W. | Dormandy, J.A.

Article Type: Research Article

Abstract: To test the hypothesis that lowering the haemoglobin concentration pre-operatively improves wound healing 52 Wistar rats were randomly allocated into two groups: group ‘A’ were haemodiluted pre-operatively by ten per cent of their blood volume; group ‘B’ were untreated controls. All rats were subject to laparotomy and one leg rendered ischaemic. Two 2 centimetre long full thickness skin incisions were made in each leg and sutured. At seven days the wound strengths were measured by tensometry and quantitative wound collagen content was performed. A second experiment was performed employing 28 rats allocated into two similar groups. In this experiment the …study group were repeatedly diluted on alternate post-operative days whereas controls were sham diluted. The experiments were otherwise identical. Compared with controls, haemodilution did not improve wound strength in non-ischaemic limbs but did improve wound strenth in ischaemic limbs in experiment two (p ⩽ 0.001). Show more

Keywords: Haemodilution, ischaemia, wound healing

DOI: 10.3233/CH-1986-6607

Citation: Clinical Hemorheology and Microcirculation, vol. 6, no. 6, pp. 553-560, 1986

Authors: Ernst, E. | Schmidt-Pauly, E. | Mühlig, P. | Matrai, A.

Article Type: Research Article

Abstract: Eleven patients suffering from pressure sores were compared to eleven matched controls, free of this complication. Blood rheology was quantified by means of blood viscosity, plasma viscosity, hematocrit, total white blood cell count, blood cell filterability and red cell aggregation. Results show that native blood viscosity is reduced in pressure sore patients due to significantly lower hematocrit levels. The total white cell count is significantly elevated in this group. Other rheological parameters reveal no significant difference compared to controls. It is concluded that bulk blood viscosity seems not to contribute to the malfunction of the skin microcirculation in pressure sores. …However, white cells might play an unrecognized role, which merits further investigation. Show more

Keywords: hemorheology, pressure sores, microcirculation, leukocytes, skin

DOI: 10.3233/CH-1986-6608

Citation: Clinical Hemorheology and Microcirculation, vol. 6, no. 6, pp. 561-566, 1986

Authors: Longhini, Erminio | Agosti, Roberto | Cherubini, Paola | Clivati, Alberto | Farini, Paola | Marazzini, Luigi

Article Type: Research Article

Abstract: Haemorheologic investigations were performed on 25 essential and 8 secondary hypertensive patients as well as in 8 normotensive subjects with positive family history for essential hypertension. 20 normal subjects also entered this study as control group. Whole blood viscosity was increased in all hypertensive patients both at low and high shear rates. The increase of erythrocyte aggregation was more significant in essential than in secondary hypertensives in respect to normal subjects. On the contrary, blood filterability was reduced in all hypertensive patients. After challenge with furosemide, employed as a blocker of red cell membrane Na/K cotransport system, filterability index appeared …to be reduced in secondary hypertensives and not significantly decreased in essential hypertensive patients. Normotensive subjects with positive family history for essential hypertension showed a decreased blood filterability, poorly influenced by challenge with furosemide. These findings support the hypothesis that Na/K cotransport system is genetically impaired in essential hypertensive patients and in normotensives with positive family history for essential hypertension. Show more

Keywords: filterability, red blood cell, cation fluxes, hypertension

DOI: 10.3233/CH-1986-6609

Citation: Clinical Hemorheology and Microcirculation, vol. 6, no. 6, pp. 567-576, 1986