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

Authors: Pascazio, L. | Regina, G. | Perilli, F. | Caputo, G. | Gigli, A. | Lamberti, P.

Article Type: Research Article

Abstract: 100 patients (pts) receiving CEA (carotid endarterectomy) were evaluated in this study. In some of them postoperative complications were observed, characterized by TIA (transient ischemic attack) and, mostly, by cerebral hyperperfusion. In only two of the pts investigated CEA needed the implantation of a shunt, due to the emergence of intolerance signs at carotid Clamping (C) evaluated by TCD (transcranial Doppler); the preoperative cerebral angiography in the two subjects in question did not show malformations of the circle of Willis. The hyperperfusive phenomenon and the absence of intracranial compensation flows during CEA seemed to be ascribed to a more or …less severe impairment of cerebral reserve. Such impairment of the autoregulatory capacity seems to be crucial to the pathogenesis of hemodynamic stroke. Thus the indication to CEA, in pts with severe carotid disease, should take into account also the cerebral reserve (CR) impairment to prevent both thromboembolic and hemodynamic stroke. The predictive and diagnostic role of TCD turns out to be crucial in assessing and selecting pts candidate to CEA. Show more

Keywords: Carotid endarterectomy, transcranial Doppler, cerebral reserve, hyperperfusion syndrome, carotid disease, hemodynamic stroke

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 395-403, 1999

Authors: Antonova, Nadia | Velcheva, Irena

Article Type: Research Article

Abstract: Whole blood and plasma viscosity were measured of 90 patients with chronic cerebrovascular disease (CVD) and 56 healthy individuals by Couette rotational viscometer Contraves Low Shear 30 at a steady flow. Plasma viscosity was measured with capillary viscometer of Ubbelohde type. Two subgroups of patients were investigated: 23 patients with transient ischemic attacks (TIAs) and 67 patients with chronic cerebral infarctions (CCI). They were compared with two control groups: 56 healthy individuals without risk factors for stroke and 37 randomly selected subjects with risk factors for stroke. It is established significant elevation of plasma viscosity in the patients with cerebral …ischemia. The elevation of blood viscosity was most pronounced at shear rate of 94.5 s^{-1} . This comparison is confirmed by the criterion, using blood rigidity number h defined by the formula of Whittington and Harkness. Conclusion is drawn from our study that chronic ischemic cerebrovascular disorders are characterized with chronic hyperviscosity. Show more

Keywords: Cerebrovascular disease, blood and plasma viscosity, blood rigidity number

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 405-408, 1999

Authors: Battistelli, Sandra | Manasse, Giacomo | Gubbolini, Michele | Landini, Tommaso | Coratti, Andrea

Article Type: Research Article

Abstract: The aim of this study was to investigate the behaviour of circulating ET‐1 in patients with carotid atherosclerosis, before and after carotid thromboendarterectomy (TEA), to test the hypothesis that plasma ET‐1 decreases after removal of atherosclerotic lesion. Plasma immunoreactive ET‐1 levels were determined in 17 patients with symptomatic and/or hemodynamically significant carotid atherosclerosis on the day before TEA, 48 h and 72 h after surgery and, in 11 of them, also after 8 h and 24 h. Compared to controls, ET‐1 levels were significantly higher both before and after TEA; after carotid revascularisation (8 h) ET‐1 increased; then, from the …24th h, ET‐1 gradually decreased and at the 48th h and 72th h the decrease was significant in front of basal values. The increase of plasma ET‐1 in the acute postoperative phase may reflect the degree of surgical stress and manipulation in diseased blood vessels; the following decrease may indicate the improvement of vascular dysfunction in the involved carotid site; the persistence of high ET‐1 levels 72 h after surgery could suggest the presence of residual ischemia in the involved district and/or the involvement of other sites in ET‐1 production. Show more

Keywords: Endothelins, atherosclerosis, carotid endarterectomy

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 409-414, 1999

Authors: Aigbe, A. | Famodu, A.A.

Article Type: Research Article

Abstract: Hypertension is the most significant cardiovascular risk factor to emerge in developing countries. 64 hypertensives (40 old hypertensives and 18 newly diagnosed hypertensives) and 40 age and sex matched normotensives controls were studied. Plasma fibrinogen concentration (PFC), euglobulin lysis time (ELT) and relative plasma viscosity (RPV) and relative whole blood viscosity (RWBV) were estimated. The PFC, RPV, RWBV and ELT were significantly higher in new and old hypertensives (P<{} 0.005), respectively, compared with controls. while the RPV was significantly higher (P<{} 0.005) in new hypertensives than old hypertensives. The significantly higher PFC, RPV and ELT in new hypertensives …correspond to higher BP in the new hypertensives than old hypertensives. There were consistence significance levels in PFC, RPV and ELT in both female hypertensives and controls (P<{} 0.005), respectively, with higher BP in male than female. Though there were no significant mean differences between the hypertensive patients in the first two years of the disease, there were cumulative consistent increase in fibrinogen levels and euglobulin lysis time from two years; while RPV shows inconsistence variation until the 5th year. We conclude that a defective rheology and fibrin‐clearing mechanism may contribute to aetiology of vascular complications in hypertensive patients especially in the long term. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 415-420, 1999

Authors: Passavanti, G. | Cicco, G. | Baldassarre, G. | Vicenti, P. | Soleti, F. | Stingi, G.D. | Carbonara, M.C. | Coratelli, P. | Pirrelli, A.

Article Type: Research Article

Abstract: We studied the effect of some dialytic membrane on tissular oxygenation (TO) and erythrocyte deformability (ED). Sixteen patients (10 M and 6 F, aged 59 \pm 12 years) have been submitted to bicarbonate dialysis (BD) and subdivided into four groups (GR) of 4 patients each: GR 1 (hemophan membrane, 35 BD), GR 2 (polyacrylonitrile, PAN AN 69, 42 BD), GR 3 (polysulphone, 38 BD) and GR 4 (polycarbonate, 37 BD). The TO has been detected with the transcutaneous oxygen pressure (Tc pO_{2 } ) using a transcutaneous oxymeter and the ED has been evaluated with the EMI …(Erythrocyte Morphometric Index), which results from the ratio between deformable erythrocytes (bowl shape) and rigid erythrocytes (discocyte shape), for every 100 red cells fixed in vitro with 0.3% glutaraldehyde. The ED was also evaluated using a laser instrument: Laser Optical Rotational Cell Analyser. During BD was observed a significant decrease of Tc pO_{2 } in the 1st hour only in the 1st and 2nd GR and, in contrast with results obtained in the 3rd and 4th GR, in the same GRs the EMI showed a significant reduction of ED at the end of BD. Finally the LORCA results, showing a significant decrease of ED only in the 1st and 2nd GR, confirmed the data obtained with EMI. In conclusion, our study has suggested that hemophan and PAN AN 69 are less biocompatible than polysulphone and polycarbonate membranes according to effects on ED and TO. Show more

Keywords: Dialysis membranes, biocompatibility, oxymetry, transcutaneous oxymetry, erythrocyte deformability

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 421-424, 1999

Authors: Izzo, P. | Spagnuolo, A. | Manicone, A. | Nazzaro, P. | Lauta, V.M.

Article Type: Research Article

Abstract: In this study we report results regarding erythrocytes deformability in congenital dyserythropoietic anemia type II (HEMPAS) by the use of LORCA (Laser‐assisted Optical Rotational Cell Analyzer). The reduced erythrocytes deformability observed in seven case of CDA II is caused by changes in the structure of glycoproteins due to the incomplete glycosylation of erythrocytic and erythroblastic membrane. Erythrocytes deformbility (EI) was shown to be inversely related with mean corpuscular volume (MCV) and mean haemoglobin concentration (MCH).

Keywords: Dyserythropioietic anaemia, LORCA, erythrocytes deformability

Citation: Clinical Hemorheology and Microcirculation, vol. 21, no. 3-4, pp. 425-430, 1999