Clinical Hemorheology and Microcirculation - Volume 24, issue 2

Authors: Schnyder, L. | Walter, R. | Rohrer, A. | Contesse, J. | Reinhart, W.H.

Article Type: Research Article

Abstract: The influence of the hormones most involved in glucose homeostasis, C‐peptide, insulin and glucagon on blood viscosity was tested in vitro. Whole blood (adjusted to haematocrit 45%) from healthy volunteers (n=24) and patients with diabetes mellitus (n=17) was incubated with 10−7 –10−10 M C‐peptide, insulin or glucagon. None of these peptide hormones, neither at physiological nor at supraphysiological levels, had an influence on high (94.5 s−1 ) or low (0.1 s−1 ) shear rate viscosity. The small group of diabetic patients had a higher plasma viscosity and increased blood viscosity at 94.5 s−1 , which is in agreement with …earlier studies, but decreased viscosity at low shear rate. We conclude that C‐peptide, insulin and glucagon have no direct effect on blood viscosity in vitro. It is, therefore, unlikely that microvascular disturbances seen with either deficiency or excess of these hormones is due to haemorheological factors. Show more

Keywords: C‐peptide, diabetes, glucagon, insulin, viscosity

Citation: Clinical Hemorheology and Microcirculation, vol. 24, no. 2, pp. 65-74, 2001

Authors: Marton, Zs. | Kesmarky, G. | Vekasi, J. | Cser, A. | Russai, R. | Horvath, B. | Toth, K.

Article Type: Research Article

Abstract: Red blood cell (RBC) aggregation is an important component of whole blood viscosity, especially at low shear rates, and is the major cause of the non‐Newtonian flow properties of normal blood. In different laboratories several methods are used to determine RBC aggregation, therefore the standardization of aggregation measurements is especially important for getting comparable results. Aggregation indices of 62 human blood samples were determined by two different methods; LORCA (Laser‐assisted Optical Rotational Cell Analyzer) and Myrenne aggregometers and related to plasma fibrinogen concentration. Our results show closer correlation values between RBC aggregation and fibrinogen concentration, when RBC aggregation was measured …by LORCA (p<0.001), although correlation could be revealed with Myrenne, when plasma fibrinogen level was less than 4.5 g/l. Correlation coefficient between aggregation indices measured by LORCA and Myrenne aggregometers was also closer below this fibrinogen level. In vitro examination of RBC aggregation in fibrinogen solutions showed that higher fibrinogen concentration results in higher RBC aggregation only up to a certain level similarly to that found in human whole blood samples. Our results show that plasma fibrinogen level has an important, concentration dependent effect on RBC aggregation in human blood, but above a certain level it may not cause further aggregate formation. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 24, no. 2, pp. 75-83, 2001

Authors: Nakano, T. | Wada, Y. | Matsumura, S.

Article Type: Research Article

Abstract: Deformability of red blood cells and the lipid composition of their plasma membranes were studied in ten long‐distance runners, in comparison with ten sedentary matched controls. Mean corpuscular volume and corpuscular hemoglobin concentration did not differ between these groups, while the hemoglobin concentration and hematocrit were lower in the former. Deformability was measured in terms of the erythrocyte suspension filterability through 5 μm microchannels, using an array flow analyzer, and was significantly elevated in athletes. Analysis of the membrane phospholipid composition of red blood cells revealed an increased ratio of phosphatidylcholine to phosphatidylethanolamine and a decreased ratio of cholesterol to …total phospholipids in athletes. The length and saturation levels of fatty acid acyl chains were unchanged. Multiple regression analysis showed clearly that these alterations of membrane lipids correlate with increased deformability and thus favor circulation in the microvasculature in long‐distance runners. Show more

Keywords: Erythrocyte deformability, endurance exercise, membrane lipid, phospholipid

Citation: Clinical Hemorheology and Microcirculation, vol. 24, no. 2, pp. 85-92, 2001

Authors: Kaibara, Manabu | Watanabe, Takaya | Ooka, Fumiko | Liang, Shan‐Guang | Aisaka, Kohzo | Okinaga, Shoichi

Article Type: Research Article

Abstract: Fifteen cases of endometrial cancer were administered daily doses of 600 mg of MPA after surgery to prevent the recurrence of cancer. The initiation times of coagulation (time necessary for fibrin network formation) were measured with a highly sensitive damped oscillation rheometer and compared with those of 15 control patients who were not administered MPA. Biochemical studies of blood coagulation and fibrinolysis were also done. The initiation times of coagulation were 19.0±1.8 minutes (min mean ± standard deviation) after 3–6 months and 16.0±2.0 min after 9–12 months of MPA administration, both times being significantly shorter compared with the controls (24.0±2.5 …min). Hematocrit values, platelet counts and fibrinogen levels were similar between the two groups. Activated partial thromboplastin time (APTT) was significantly decreased and antithrombin III activity (AT III), thrombin–antithrombin complex (TAT), plasminogen level, plasmin–α2 plasmin inhibitor complex level (PIC) and the fibrin degradation product level (FDP) were significantly increased in the MPA group compared with the control group. Accelerated coagulation of blood was definitely induced by high‐dose MPA but antithrombin and fibrinolytic activities were also induced, and, thus, thromboembolic complications were prevented. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 24, no. 2, pp. 93-99, 2001

Authors: Franke, R.‐P. | Reuter, P. | Mrowietz, C. | Bach, R. | Jung, F.

Article Type: Research Article

Abstract: Does a NO‐donor (Corvaton® , Aventis, France) attenuate the adherence and the aggregation of platelets in a closed‐loop perfusion modell with or without the implantation of coronary stents? SIN‐1, the active metabolite of molsidomine, exerted a strong influence on the interaction of platelets with the surfaces of stents. When SIN‐1 was added the adherence of platelets to the surfaces of stents was markedly reduced. The sites were most of the platelets adhered to, also changed. More platelets adhered to the stent backbone and less to the free modular stent parts. The localisation of adherent platelets could easily be shown by …light microscopy. The aggregation of platelets, accompanied by a spheroidic shape change, could be demonstrated by scanning electron microscopy on the addition of an NO‐donor, not only a reduction of platelet adherence was realised but also the reduction of platelet aggregation. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 24, no. 2, pp. 101-109, 2001

Authors: Vayá, Amparo | Martínez, Marcial | Fernández, Angeles | Ripoll, Francisco | Moscardó, Federico | Mira, Yolanda | Aznar, Justo

Article Type: Research Article

Abstract: The effect of acenocoumarol on hemorheological variables was measured in 35 non‐valvular chronic atrial fibrillation patients before starting oral anticoagulant therapy (basal) and one and two months after beginning treatment (INR‐2,3). Fibrinogen increased significantly from the basal situation: 332±99 mg/dl to 386±96 mg/dl in the second month (p<0.05). However, this small increase in fibrinogen is not large enough to mediate other rheological changes, and whole blood filterability, blood viscosity, plasma viscosity and erythrocyte deformability and aggregability remained unchanged after treatment. These results suggest that acenocoumarol does not affect rheological parameters and can therefore be used as a “neutral drug” for …rheological studies in cardiovascular patients under oral anticoagulant therapy. Show more

Keywords: Acenocoumarol, hemorheology, artrial fibrillation

Citation: Clinical Hemorheology and Microcirculation, vol. 24, no. 2, pp. 111-115, 2001

Authors: Mchedlishvili, George

Article Type: Miscellaneous

Citation: Clinical Hemorheology and Microcirculation, vol. 24, no. 2, pp. 117-118, 2001

Authors: Schuff‐Werner Holdt‐Lehmann, Peter Birgit

Article Type: Research Article

Citation: Clinical Hemorheology and Microcirculation, vol. 24, no. 2, pp. 119-146, 2001