Clinical Hemorheology and Microcirculation - Volume 21, issue 3-4

Authors: Turchetti, V. | Bellini, M.A. | Guerrini, M. | Forconi, S.

Article Type: Research Article

Abstract: The aim of our study was to evaluate hemorheological parameters in two groups of patients both suffering from essential hypertension compared with an homologous group of subjects not suffering from hypertension; the 1st group was composed of 16 patients (8 females and 8 males, mean age 65.6 \pm 16.5) suffering from essential hypertension; the 2nd one of 26 patients (8 females and 18 males, mean age 74.3 \pm 11.7) suffering from essential hypertension and cerebral or cardiac ischemia in a chronic phase. The group of controls was composed of 20‘subjects (mean age 50.5 \pm …11.5). In all these subjects we evaluated: blood viscosity, hematocrit, plasmatic fibrinogen, red cell morphology according to Zipursky–Forconi method and blood pressure. Our results show that blood viscosity and fibrinogen were statistically increased relative to controls. Comparison between these groups leads us to observe that blood viscosity and fibrinogen are slightly higher in the first group in a statistically significant way (7.5 \pm 1.1 cPs 10 s^{-1} 1st group, 7.9 \pm 1.05 cPs 10 s^{-1} 2nd group; 362.2 \pm 167.3 mg% 1st group, 384.6 \pm 106.9 mg% 2nd group). Blood pressure was higher in the second group. The study of red cell morphology in all the patients showed a prevalence in the percentage of discocytes, cells which have less deformability compared to bowls. The study demonstrated EMI (Erythrocyte Morphology Index) decreased in a statistically significant way compared to controls (0.70 \pm 0.03 1st group; 0.65 \pm 0.02 2nd group; 1.2 \pm 0.09 control group). In subjects suffering from essential hypertension with end‐organ damage EMI further decreases. So we observed that hypertension is also delineated by the increase in the discocytes percentage which results in reduction of the red cell deformability. In conclusion, when hypertension causes end‐organ damage, the hemorheological alterations, which implicate a worsening in microcirculation, are more evident. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 285-289, 1999

Authors: Wang, X. | Zhao, H. | Zhuang, F.Y. | Stoltz, J. F.

Article Type: Research Article

Abstract: The aim of this work is to study the deformability of red blood cells (RBC) by two laser diffraction methods: the Laser‐assisted Optical Rotational Cell Analyser (LORCA, Mechatronics, Amsterdam, Netherlands) and a Shear Stress Diffractometer (RHEODYN SSD, Myrenne, Roetgen, Germany). Experiments were carried out on 46 healthy human subjects. The elongation index EI of normal and hardened RBCs (obtained by heating blood at 49{}^\circ C or by incubating RBCs in solutions of diamide) was measured. The results showed that the standard deviations of the experimental data for normal RBCs were relatively small, especially at high shear stresses (more than …3.0 Pa), but higher than those reported before. Some correlations between the results given by the two instruments were also found. It should be noted that for hardened RBCs, the standard deviations of the measurements were important compared with the mean values in the two instruments. Show more

Keywords: RBCs deformation, laser diffraction, shear stress

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 291-295, 1999

Authors: Zhao, H. | Wang, X. | Stoltz, J.F.

Article Type: Research Article

Abstract: The aim of this work was to evaluate three optical methods designed to determine erythrocyte aggregation: Erythroaggregometer (EA; Regulest, France), Laser‐assisted Optical Rotational Cell Analyzer (LORCA; Mechatronics, Netherlands) and Fully Automatic Erythrocyte Aggregometer (FAEA; Myrenne, GmbH, Germany). Blood samples were taken from fifty donors (26 males and 24 females). The aggregation of normal red blood cell (RBC) and RBCs suspended in three normo‐ and hyper‐aggregating suspending media was studied. The results revealed some significant correlations between parameters measured by these instruments, in particular, between the indexes of aggregation of EA and LORCA. Further, RBC aggregation of multiple myeloma patients was …also studied and a hyper erythrocyte aggregation state was found by EA and LORCA. Show more

Keywords: Erythrocyte aggregation, laser back‐scattering, multiple myeloma, shear stress

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 297-302, 1999

Authors: Federico, P. | Ragozzino, G. | Del Guercio, M. | Mattera, E. | Del Guercio, R.

Article Type: Research Article

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 303-305, 1999

Authors: Lugarà, P.M.

Article Type: Research Article

Abstract: The optical oxymetry methods based on light transmission or diffuse reflectance of living tissues are discussed. The experimental techniques now under test are highlighted.

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 307-310, 1999

Authors: Cicco, G.

Article Type: Research Article

Abstract: In order to evaluate the oxygen saturation of hemoglobin in living tissues we use a new experimental instrument: the optical oximeter (LOX). The LOX uses 2 LEDs, like the pulse oximeter (PO). One LED operates at 670 nm (Hb absorption), the other one operates at 830 nm, i.e., near the isosbestic point for which Hb and HbO_2 show the same extinction. The oxygen saturation of Hb can be expressed as a linear function of the ratio of the absorption coefficients at the wavelengths of the 2 LEDs. Indeed the LOX is based on diffused reflectance measurements and not …on light transmission such as the POs. We studied in standard conditions 10 healthy volunteer subjects (6 M, 4 F aged 40 \pm 4 years) non smokers. We used TO (Combi Sensor) at the subclavicular standard area and at the right ankle, PO with the probe always at 2nd finger of the right hand and LOX at right wrist and at right ankle. We obtained a significant relationship between values of TO, PO and LOX (p<{} 0.01). Our preliminary data suggest that this could be a new methodology to evaluate tissular oxygenation, also exploring living tissues several centimeters deep. Show more

Keywords: Tissue oxygenation, microcirculation, optical oximetry

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 311-314, 1999

Authors: Cicco, G. | Vicenti, P. | Stingi, G.D. | Tarallo, M.S. | Pirrelli, A.

Article Type: Research Article

Abstract: During essential and secondary arterial hypertension it is possible to observe changes in microcirculation perfusion associated with a reduction in tissue oxygenation due in part to hemorheological changes such as an increase in blood viscosity or the formation of the red blood cell “rouleaux” which favour an increase in peripheral resistance and can cause or worsen arterial hypertension. We studied 21 healthy subjects (11 male and 10 female aged 42{}\pm{} 4) and 26 hypertensive subjects (14 male and 12 female aged 49{}\pm{} 3). The patients were non smokers and non suffering from respiratory or haemathological pathologies. They …were not undergoing antihypertensive or vasodilatory pharmaceutical treatment. The patients suffered from mild hypertension (II WHO) with Peripheral Occlusive Arterial Disease (POAD II “a” acc. to Leriche–Fontaine class.). The patients showed an increase in cholesterolaemia (6.42{}\pm{} 0.81 mmol/l) and trygliceridaemia (2.73{}\pm{} 0.09 mmol/l) at an average level. The patients were studied in standard conditions with a constant temperature of 22{}^\circ C. We measured SBP, DBP, MBP, and the HR. We also measured the elongation index (EI) (with shear stress range 0.30 to 30 pascals) using LORCA, acc. to Hardeman method (1994), in order to study the erythrocyte deformability and aggregation kinetics in dynamic condition. To evaluate deformability in static conditions we calculated the Erythrocyte Morphologic Index (EMI), acc. to Forconi method, via the bowl/discocyte ratio (for 100 red blood cells fixed in glutaraldehyde at 0.3% and observed with an optical microscope under immersion in glycerol). Peripheral oxygenation was taken transcutaneously (TcpO_{2} ). To establish the level of vascular disease we used the Regional Perfusion Index (RPI{}={} TcpO_{2} foot/ TcpO_{2} subclavean) and doppler guided Winsor Index (WI). The Student “t ” test and linear regression were used for the statistical analysis. Our data confirm a reduction in peripheral tissue oxygenation in hypertensives especially if suffering from vascular disease which correlates significantly (p<{} 0.01) with a reduction in red blood cell deformability. This itself can increase peripheral resistances and favour the onset of hemorheological complications, at a cerebral‐vascular level, which are frequent in hypertensives. Show more

Keywords: Hemorheology, hypertension, lipoidoproteinosis, vasculopathy

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 315-319, 1999

Authors: Kowal, Piotr

Article Type: Research Article

Abstract: In a group of 36 patients with acute ischemic stroke, the study of influence of arterial hypertension on the red cells and fibrinogen interaction was carried out by the aspect of fibrinogen molecules contribution to this phenomenon, respecting the role of other plasma biochemical factors. Patients were divided into two clinical groups: with and without arterial hypertension. In the blood samples with stable haematocrit ratio the following rheological properties were estimated: plasma viscosity, yield shear stress (YSS), fibrinogen level and parameter R (the difference between twice measurements of fibrinogen concentration). There were also measured the levels of albumin, IgG, IgA, …IgM, cholesterol, HDL and LDL. The value of parameter R in patients with arterial hypertension was lower than the group without accompanying disease (statistical significance was indicated for 80% and 60% of plasma dilution). The first group of patients was also characterized by significant increase of IgA level (in comparison with the control group), whereas the red cells and fibrinogen interaction measured as a value of YSS was similar in both analyzed clinical groups. This study indicated a specific character some of hemorehological changes in relation to a certain vascular pathology. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 321-324, 1999

Authors: Chmiel, Bogdan | Olszowy, Zofia | Turczynski, Boleslaw | Kusmierski, Stanislaw

Article Type: Research Article

Abstract: Although blood pressure is in most cases determined genetically, environmental factors such as obesity or alcohol consumption are implicated in the development of hypertension. On the other hand it is well known that alcohol drinking and hypertension are associated with reduction of red blood cells deformability. Aim: To compare the effect of ethanol on arterial pressure and red cell deformability in well controlled experimental conditions. Methods: Five healthy volunteers, men with age range between 26–38 underwent ethanol consumption 1.0 g per kg of body weight during 10 min period. Before and 90 min, 3 h and 5 h …after ethanol consumption arterial pressure, heart rate, blood morphology, alcohol and acetaldehyde blood level and deformability index by Rheodyn SSD were measured. Results: After ethanol consumption rise in ethanol and acetaldehyde blood levels and no changes in blood pressure, but significant increase in heart rate were observed. Elongation index of red blood cells at low shear rates has not been changed. At shear stresses of 12.0, 30.0 and 60 Pa significant increase in elongation index of erythrocytes after 1.5 hour of ethanol intake had occurred. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 325-328, 1999

Authors: Le Devehat, C. | Khodabandehlou, T. | Vimeux, M.

Article Type: Research Article

Abstract: The present study was designed to investigate whether the Veno‐Arteriolar Reflex (VAR) mediated via a local nervous reflex mechanism may be used as a microvascular approach to predict the effect of vasoactive drugs in diabetic patients. The vasoactive drug we studied here was Buflomedil. The effect of a single infusion of 400 mg of Buflomedil was examined on VAR and on transcutaneous oxygen pressure (TcPO_2 ). Investigations were performed in 42 diabetic patients. The VAR was assessed on dorsal foot and dorsal big toe by measuring changes in skin blood flux induced by lowering the leg. TcPO_2 …was measured on dorsal foot. Before Buflomedil infusion, patients were characterized by a loss of the VAR in comparison to healthy volunteers. The loss of the VAR was associated to significant decreases in TcPO_2 values. Buflomedil infusion led to significant increases in VAR at the two sites of measurement and also in TcPO_2 values. These findings indicate that the VAR can be used as a sensitive microvascular test, as it allows to detect the effect of Buflomedil. Furthermore, our findings demonstrate that the Buflomedil‐induced improvement in VAR is identical in the two diabetic groups with or without complications. This result emphasizes the benefit of Buflomedil not only in diabetics with microangiopathy or those suffering from a peripheral vascular disease for reducing pain or healing trophic lesions, but also in those patients without any clinically detectable macro‐ or microangiopathy in order to prevent or to reduce as long as possible the risk of developing diabetes related complications by the normalization of functional microangiopathy. Show more

Keywords: Diabetes, venoarteriolar reflex, transcutaneous oxygen pressure, Buflomedil

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 329-334, 1999