Clinical Hemorheology and Microcirculation - Volume 26, issue 1

Authors: Singh, Megha | Stoltz, J.F.

Article Type: Research Article

Abstract: Erythrocyte aggregation and elongation index (EI) (deformability) are measured at temperatures ranging from 5°C to 37°C by aggregometer MA1, and diffractometer Rheodyne SSD and the LORCA, respectively. The test samples are prepared from blood obtained from healthy subjects in test tubes containing EDTA as an anticoagulant and prior to measurement are placed in a water bath for 30 min, maintained at respective temperatures. The aggregation process is given in terms of primary aggregation time and indices of aggregation. These show significant to highly significant changes with the increase of temperature compared to that at 5°C. The EI increases with the …increase of shear stress but shows significant decrease with the decrease of temperature. Show more

Keywords: Erythrocyte aggregation, deformability, low temperature

Citation: Clinical Hemorheology and Microcirculation, vol. 26, no. 1, pp. 1-7, 2002

Authors: Tamer, Sule | Cefle, Kivanc | Palanduz, Sukru | Vatansever, Sezai

Article Type: Research Article

Abstract: We analyzed rheologic parameters, including erythrocyte rigidity (ER), whole blood and plasma viscosity, erythrocyte and platelet count, hemoglobin, hematocrit, mean corpuscular volume (MCV), fibrinogen, erythrocyte sedimentation rate (ESR), cholesterol, triglyceride, high‐density lipoprotein (HDL), low‐density lipoprotein (LDL), very‐low density lipoprotein (VLDL), and gamma globulin levels in 18 patients with chronic liver disease and 20 healthy volunteers. Fifteen patients had cryptogenic cirrhosis while 3 had chronic active hepatitis. ER and MCV was significantly higher in the patient group than the control group while whole blood and plasma viscosities were significantly lower. There were significant correlations between ER and blood and plasma viscosity, …ER and MCV, plasma and blood viscosity, HDL and plasma viscosity and a negative correlation between ER and ESR. Our results demonstrate that erythrocytes become more rigid in chronic liver disease. We suggest that erythrocytes with increased rigidity can impair hepatic microvascular circulation and thus contribute to liver dysfunction. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 26, no. 1, pp. 9-14, 2002

Authors: Ohnishi, Yoshihiko | Hu, Qing‐Hua | Yamaguchi, Saburo | Kuro, Masakazu | Niimi, Hideyuki

Article Type: Research Article

Abstract: Cerebral microcirculatory changes in rat with a cardiopulmonary bypass (CPB) at normothermia was investigated in relation to cerebrovascular disorders caused by surgical operation with CPB. The mean arterial pressure was changed from 50 to 200 mmHg by changing the pump flow‐rate. A non‐pulsatile flow model was developed by stopping the cardiac beat using a fibrillator. The pial microcirculation was visualized using fluorescence‐labeled red cells and dextran, and was directly observed under a fluorescence videomicroscope during CPB. Based on the recorded videoimages, the arteriolar diameter and red cell velocity were measured, in which single arterioles with approximately 40 μm diameter were …selected among the pial arterioles. It was shown that when the arterial pressure was changed: (1) arteriolar vasodilation or constriction appeared during pulsatile flow but it disappeared during non‐pulsatile flow, and (2) the arteriolar red cell velocity increased or decreased linearly during non‐pulsatile flow as well as pulsatile flow. The flow‐rate was almost constant at a large range of the mean arterial pressure from 60 to 160 mmHg during pulsatile flow (autoregulation), but it increased or decreased during non‐pulsatile flow with an increase or decrease in mean arterial pressure, respectively. It was suggested that pulsativity might be responsible for cerebral autoregulation. Show more

Keywords: Autoregulation, cardiopulmonary bypass, intravital microscopy, pial microcirculation

Citation: Clinical Hemorheology and Microcirculation, vol. 26, no. 1, pp. 15-26, 2002

Authors: Hacioglu, Gulay | Yalcin, Ozlem | Bor‐Kucukatay, Melek | Ozkaya, Gul | Baskurt, Oguz K.

Article Type: Research Article

Abstract: Red blood cell (RBC) properties were proposed to play role in the development of hypertension (HT). This study aimed at investigating the alterations of RBC deformability and aggregation, in various models of HT in rats. The following four models of HT were developed in rats: one kidney‐one clip HT (1K‐1C HT), two kidney‐one clip HT (2K‐1C HT), deoxycorticosterone acetate (DOCA) induced HT (15 mg/kg, 2 times/week, sc) and N‐nitro L‐arginine methyl ester (L‐NAME) induced HT (50 mg/kg/day, 10 weeks, ip). The blood samples were obtained from abdominal aorta, under ether anesthesia, after a period of 10 weeks of increased blood …pressure. RBC deformability was determined by ektacytometry. RBC aggregation was measured in autologous plasma and 0.5% dextran 500, using a photometric rheoscope. Plasma fibrinogen concentration was determined by Clauss method. The mean blood pressure in all four HT models were about 140 mmHg, on the day of sampling, compared to ∼110 mmHg in the control group. RBC deformability was found to be significantly decreased in the L‐NAME model of HT. RBC aggregation in autologous plasma was significantly higher than control in 2K‐1C, L‐NAME and DOCA models, DOCA HT model being the most effective in altering the RBC aggregation. Plasma fibrinogen values were found to be higher than control in 2K‐1C and L‐NAME HT models, but not in DOCA HT. These results confirm that RBC rheological properties might be altered in HT. It can also be suggested that these alternations may not simply be the result of the vascular effects of HT, but may play role in the development of HT, as the alterations in different HT models were not the same, although the length and magnitude of increased blood pressure were similar. Show more

Keywords: Hypertension, erythrocyte aggregation, deformability, rat

Citation: Clinical Hemorheology and Microcirculation, vol. 26, no. 1, pp. 27-32, 2002

Authors: Ornstein, Deborah L. | Zacharski, Leo R.

Article Type: Research Article

Abstract: Heparin and heparin‐like compounds appear to possess anticancer properties apart from their anticoagulant activities. This paper reviews recent data on heparins in experimental models of tumor growth and metastasis and discusses various mechanisms by which heparins may inhibit cancer progression. The growing body of evidence supporting the antineoplastic activity of heparins provides the rationale for their widespread testing in cancer patients for the purpose of improving cancer‐related survival. Their improved safety, convenience and ease of outpatient administration compared to unfractionated heparin, as well as the suggestion of superior anticancer activity, make the low molecular weight heparins the preferred agents to …test in prospective cancer trials. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 26, no. 1, pp. 33-40, 2002

Authors: Vayá, Amparo | Mira, Yolanda | Martínez, Marcial | Villa, Piedad | Ferrando, Fernando | Estellés, Amparo | Corella, Dolores | Aznar, Justo

Article Type: Research Article

Abstract: Hypercoagulable states due either to inherited or acquired thrombotic risk factors are only present in approximately half of cases of DVT, but the causes in the other half, remain unknown. The importance of biological risk factors such as hyperlipidemia, hypofibrinolysis and hemorheological alterations in the pathogenesis of DVT has not been well established. In order to ascertain whether the above mentioned biological factors are associated with DVT and could constitute independent risk factors, we carried out a case‐control study in 109 first DVT patients in whom inherited or acquired thrombophilic risk factors had been ruled out and 121 healthy controls …age (42±15 years) and sex matched. From all the biological variables analyzed (cholesterol, triglycerides, glucose, fibrinogen, erythrocyte aggregation, hematocrit, plasma viscosity and PAI‐1) only fibrinogen concentration reached a statistically significant difference on the comparison of means (290±73 mg/dl in cases vs 268±58 mg/dl in controls, p<0.05). After this continuous variables were dichotomized according to our reference values, the percentage of cases with cholesterolemia >220 mg/dl, hematocrit >45% and fibrinogen >300 mg/dl was higher in cases than in controls: 38% vs 22%; p<0.01; 43% vs 27%; p<0.05; 36% vs 23%; p<0.05, respectively. The percentage of cases with PAI‐1 values >30 ng/ml, 37% vs 25% was borderline significant; p=0.055. Multivariate logistic regression analysis showed that cholesterolemia >220 mg/dl and fibrinogen >300 mg/dl constitute independent predictors of venous thrombotic risk. The adjusted OR's were 2.03 (95% CI; 1.12–3.70) for cholesterolemia and 1.94 (95% CI; 1.07–3.55) for fibrinogen. When these two variables combined DVT risk rose about fourfold (3.96; p<0.05). Our results suggest that hypercholesterolemia and hyperfibrinogenemia should be added to the list of known DVT risk factors and we recommend adopting measures to decrease these variables in the population with a high risk of DVT. Show more

Keywords: Deep vein thrombosis, lipids, rheology, fibrinolysis

Citation: Clinical Hemorheology and Microcirculation, vol. 26, no. 1, pp. 41-53, 2002

Authors: von Tempelhoff, Georg‐Friedrich | Schönmann, Nicole | Heilmann, Lothar | Pollow, Kunhard | Hommel, Gerhard

Article Type: Research Article

Abstract: Tumor growth leads to tissue hypoxia and tissue hypoxia, in turn, is a strong stimulus for expression of genes encoding factors that promote tumor growth. Likewise, hypoxia is a key condition within the vicious cycle of autogenous neoplastic dissemination. A marker of the presence of tissue hypoxia may be the presence of high blood viscosity, which is found in a number of neoplastic diseases including gynecological cancer. At the time of diagnosis of breast cancer, patients dying of this disease had had significantly higher initial pv (1.40±0.18 mPa s; p<0.0001) when compared to patients not dying of cancer (1.30±0.10 mPa s). In …multivariate proportional hazard regression analysis, next to tumor size (p=0.03) and nodal status (p=0.004), pv was found an independent prognostic marker for overall survival of breast cancer patients (RR=130.2; 95% CI: 11.6–1,460.6; p<0.0001). An optimized preoperative cut‐off value above 1.40 mPa s was significantly associated with poor outcome (log‐rank‐test) in the Kaplan–Meier survival‐estimates, even in node‐negative breast cancer (n=153; 54.6%). The most likely explanation for these findings is that increased fibrinogen/fibrin turnover and breakdown products characteristically associated with tumor‐cell dissemination contribute to the increased plasma viscosity while the hematocrit, leukocyte count, and platelet count contributed little to the increased blood viscosity in patients with breast cancer. These findings may constitute an approach for new strategies in cancer therapy since it might be possible that reduction of plasma viscosity by treatment improves responsiveness to radio/chemotherapy and thus survival of patients. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 26, no. 1, pp. 55-61, 2002