Clinical Hemorheology and Microcirculation - Volume 31, issue 1

Authors: Szapary, L. | Horvath, B. | Marton, Zs. | Alexy, T. | Demeter, N. | Szots, M. | Klabuzai, A. | Kesmarky, G. | Juricskay, I. | Gaal, V. | Czopf, J. | Toth, K.

Article Type: Research Article

Abstract: Hemorheological disturbances may occur in more than 40% of patients with ischemic cerebrovascular diseases. In this study the changes of rheological factors – hematocrit, plasma fibrinogen concentration, whole blood and plasma viscosity, red blood cell aggregation and deformability were investigated in 297 patients (173 males, 124 females, mean age 60±11 years) with transient ischemic attack or chronic phase (>3 months after onset) ischemic stroke, and in 73 healthy volunteers (35 males, 38 females, mean age 38±7 years). Hematocrit, plasma and whole blood viscosity were significantly (p<0.0001) elevated in cerebrovascular patients compared to controls. Plasma fibrinogen concentration (p<0.001), red blood cell …aggregation (p<0.05) and deformability (p<0.01) were also impaired in stroke patients. Hemorheological disturbances were dominant in stroke patients with diabetes, hyperlipidemia and smoking habits. Hematocrit, plasma viscosity and red blood cell aggregation showed a significant (p<0.025–0.001) correlation with the severity of carotid artery stenosis. We could not find any characteristic distribution of rheological parameters among the three subtypes of brain ischemia. Our results show that all of the measured rheological parameters are significantly impaired in chronic ischemic cerebrovascular disorders, especially in diabetic, smoking and alcoholic patients. They correlate with the severity of the carotid artery stenosis, but there is no association with the type of ischemic stroke. Show more

Citation: Clinical Hemorheology and Microcirculation, vol. 31, no. 1, pp. 1-9, 2004

Authors: Cheng, Xuefeng | Mao, Jian‐min | Xu, Xiaorong | Elmandjra, Mohamed | Bush, Robin | Christenson, Linda | O'keefe, Bill | Bry, John

Article Type: Research Article

Abstract: We measured tissue oxygen saturation (StO2 ) changes during a post‐occlusive reactive hyperemia (PORH) test on lower extremities of peripheral vascular disease (PVD) patients and healthy controls. The StO2 changes were measured by the near‐infrared tissue oximeter prototyped by ViOptix Inc. We found that PVD indicators may include the post‐occlusive StO2 reperfusion rate, the time duration of the reperfusion phase in a PORH test, and the StO2 dispersion rate in reactive hyperemia. We suggest critical values of these indicators for PVD assessments.

Citation: Clinical Hemorheology and Microcirculation, vol. 31, no. 1, pp. 11-21, 2004

Authors: Baskurt, Oguz K. | Meiselman, Herbert J.

Article Type: Research Article

Abstract: Ektacytometry is frequently used to study red blood cell (RBC) deformability. This method is capable of measuring RBC deformation under a wide range of shear stresses, and the results are usually presented as shear stress–elongation index curves. These curves are very useful for detailed analyses of RBC mechanical behavior under various shearing conditions, yet may not be appropriate for clinical and experimental studies where a global parameter of deformability is satisfactory. That is, presenting data at a selected shear stress may not always be appropriate, since the selected stress level may not accurately reflect variations of the whole curve. We …have thus compared two approaches to calculate parameters that represent the entire shear stress–elongation index curve; data were obtained using a commercial laser diffraction ektacytometer (LORCA) and compared in terms of their power to detect a difference between groups. Usage of these parameters (i.e., shear stress at half maximal deformation and maximal deformation) appears to offer a simplified approach to data presentation and interpretation in clinical and experimental hemorheological studies. Show more

Keywords: Ektacytometry, erythrocyte deformability, Lineweaver–Burke plot, elongation index

Citation: Clinical Hemorheology and Microcirculation, vol. 31, no. 1, pp. 23-30, 2004

Authors: Satomura, Yasuhiko | Seki, Junji | Ooi, Yasuhiro | Yanagida, Toshio | Seiyama, Akitoshi

Article Type: Research Article

Abstract: A technique called optical coherence tomography (OCT) was applied to in vivo observation of microcirculation in the rat cerebral cortex. The OCT system used in this study provided cross‐sectional images of the cerebral cortical tissue up to about 1 mm depth with longitudinal resolution up to 8 μm. It could visualize cross‐sectional structure of the dura, arachnoid membrane, cortical tissue, and pial microvessels through the cranial window. Pial microvessels with diameter larger than several 10 μm could be detected to observe their cross‐sectional shape, while the microvessels within the cortical tissue with smaller diameter were not discernible. The OCT observation …revealed that the pial microvessels showed different spatial configurations depending on the cerebral preparations with intact dura and without dura. Stimulus responses of the somatosensory cortices were also different among the preparation methods; Delayed swelling of the cortical surface appeared in the somatosensory cortex following the electrical stimulation of the hind paw in the case of dura removal, which was restricted to a thin surface layer with less than several 10 μm. It is considered to reflect the reactive hyperemia accompanying the neuronal activation. Doppler frequency shift due to the blood flow was detected in pial arterioles. This phenomenon is promising to provide the velocity profile within microvessels and may be applicable to the functional imaging of the brain. Show more

Keywords: Optical coherence tomography (OCT), somatosensory cortex, neuronal activation, reactive hyperemia, Doppler effect

Citation: Clinical Hemorheology and Microcirculation, vol. 31, no. 1, pp. 31-40, 2004

Authors: Caimi, G. | Hoffmann, E. | Canino, B. | Montana, M. | Dispensa, F. | Incalcaterra, E. | Casciolo, M.F. | Catania, A. | Lo Presti, R.

Article Type: Research Article

Abstract: Our aim was to examine two aspects of polymorphonuclear leukocyte (PMN) rheology (membrane fluidity and cytosolic Ca2+ content), at baseline and after in vitro activation, in a group of young adults with acute myocardial infarction (AMI) at the initial stage and after 12 months. We enrolled 21 AMI subjects aged ≤45 years (mean age 41.1±3.5 years) and evaluated PMN membrane fluidity, labelling intact PMN cells with the fluorescent probe 1,4‐(trimethylamino)‐phenyl‐4‐phenylhexatriene and the PMN cytosolic Ca2+ content marking PMN cells with the fluorescent probe Fura 2‐AM, at baseline and after in vitro activation with 4‐phorbol 12‐myristate 13‐acetate (PMA) and …N‐formyl‐methionyl‐leucyl‐phenylalanine (fMLP). During the initial stage PMN membrane fluidity and cytosolic Ca2+ content did not distinguish AMI patients from control subjects; after 12 months, when compared with the initial stage, PMN cytosolic Ca2+ content was significantly increased. In vitro PMN activation with PMA and fMLP caused no variation of the two PMN parameters in control subjects, while in AMI patients membrane fluidity decreased and cytosolic Ca2+ content increased; the same behaviour pattern was observed after 12 months. The constant functional alteration of PMN cells in young AMI patients highlights the role of activated leukocytes as a component of the inflammatory reaction that follows ischemia. Show more

Keywords: Acute myocardial infarction in young people, polymorphonuclear leukocyte membrane fluidity, polymorphonuclear leukocyte Ca$^{2+}$ content, polymorphonuclear leukocyte activation

Citation: Clinical Hemorheology and Microcirculation, vol. 31, no. 1, pp. 41-47, 2004

Authors: Heilmann, L. | Rath, W. | Pollow, K.

Article Type: Research Article

Abstract: The objective of this study was to determine the differences of hemorheological parameters in association to haematological tests in patients with severe preeclampsia (blood pressure (diastolic) > 100 mm Hg, blood pressure (systolic) > 180 mm Hg and proteinuria > 3 g/24 h). Blood samples of 45 primigravidas by hospital admission were studied. The control group were 45 pregnant women – age and weight matched – with normal blood pressure and without obstetric complications. We measured red cell aggregation (stasis, low shear), red cell elongation with the ectacytometer, blood cell indices (Hct, Hbg, MCV, MCHC, reticulocytes, white cells, platelets), fibrinogen …haptoglobin and factor VIIIR:Ag, cholesterol and triclycerides. In comparison between patients with severe preeclampsia and normal pregnant women we found statistically elevated values of hematocrit, hemoglobin, red cell aggregation (stasis, low shear rate), MVC and factor VIIIR:Ag. Non‐significant changes were observed in values of plasma viscosity, white cells, platelets, haptoglobin, MCHC, reticulocytes, triglycerides and cholesterol. The red cell deformability measured as cell elongation was statistically reduced by high shear stress application in patients with severe preeclampsia. Our results suggest that hemorheological parameters play an important role in severe preeclampsia, especially at microcirculatory regions with high shear stress such as intervillous space of placenta. Show more

Keywords: Preeclampsia, red cell aggregation, erythrocyte deformability, macromolecules, triglycerides

Citation: Clinical Hemorheology and Microcirculation, vol. 31, no. 1, pp. 49-58, 2004

Authors: Molsiri, K. | Khemapech, S. | Patumraj, S. | Siriviriyakul, P.

Article Type: Research Article

Abstract: The effects of genistein on coronary endothelial dysfunction in bilateral ovariectomized rats were examined. Female Wistar rats were subjected to a bilateral ovariectomy (OVX rat). The animals were divided into three groups: sham treated with vehicle (DMSO 100 μl/day, Sham‐DMSO), OVX treated with vehicle (DMSO 100 μl/day, OVX‐DMSO), and OVX treated with genistein (0.25 mg/kgBW/day, OVX‐genistein). Mean arterial pressure (MAP), heart rate (HR), body weight (BW), uterine weight and plasma E2 were monitored at 4‐ and 10‐week after the treatment. We investigated the endothelium‐dependent and ‐independent vasorelaxation by using acetylcholine (Ach 10−5 M) and sodium nitroprusside (SNP 10−7 …M), respectively. The experimental results indicated that the uterine weights of all OVX rats were significantly decreased as compared to the sham groups. HR and MAP of both OVX‐DMSO and OVX‐genistein on 4 and 10 weeks were no significantly increased as compared to the Sham groups. The present coronary vasodilatation responses demonstrated only the significant decrement of endothelium‐dependent, not for endothelium‐independent, in OVX rats. The treatment of genistein could significantly attenuate this abnormality (% changes of vessel diameter obtained after Ach 10−6 M: Sham‐DMSO10‐wk =10.96±1.2%, OVX‐DMSO10‐wk =3.2±0.77%, OVX‐genistein10‐wk =11.45±1.85%), (% changes of vessels diameter obtained after SNP 10−7 M: Sham‐DMSO10‐wk =16.05±2.82%, OVX‐DMSO10‐wk =12.73±2.72%, OVX‐genistein10‐wk =16.4±4.71%) (p<0.05). However, the lipid profiles monitored from all groups of 4 and 10 weeks did not demonstrate any significant changes. Therefore, it implied that endothelial dysfunction was not primarily cause by the lipid profiles changing in ovariectomized rats. Moreover, such effects of estrogen lacking on coronary endothelial‐dependent vasodilatation could be attenuated by genistein supplementation. The present findings suggest that genistein might be used as an therapeutic agent for preventing the menopausal vascular complications. Show more

Keywords: Genistein, coronary endothelial dysfunction, ovariectomized rat

Citation: Clinical Hemorheology and Microcirculation, vol. 31, no. 1, pp. 59-66, 2004

Authors: Boisseau, M.R. | de La Giclais, B.

Article Type: Research Article

Abstract: Disturbances in haemodynamic, biochemical and enzymatic factors have been observed in chronic venous diseases (CVD). These changes lead to the development of varices, telangiectasies and skin disorders. They affect vessels, blood, skin tissues and cells. It is now possible to describe their time course and interdependance of these changes. Orthostatism pressure on vein wall may lead to fluid leakage and oedema, these resulting in vein enlargement. These processes may be further influenced by genetic or acquired risk factors. Skin microvessels suffer more from hypoxia than from hypertension. Indeed, hypoxia affects not only endothelial cells, but also red and white blood …cells and modifies particularly, but not exclusively, TGF‐β1 production. This substance is, an important modulator of zinc dependent‐metallo‐proteinases and their tissue inhibitor of metallo‐proteinases (TIMP) in the skin. Imbalance in this enzymatic system seems to lead either to sclerosis or ulcer. Of course, other biochemical events (also in this review) play a role in vessel wall and skin deterioration in CVD. The aim of the present review is to assess the role of pathophysiological factors in CVD and the influence of different therapies, including the venotropic agent calcium dobesilate, on some of these haemodynamic or biochemical aspects. Show more

Keywords: Chronic venous disease, transforming growth factor‐beta‐1/tissue inhibitor of metallo‐proteinases balance, clinical sign and symptoms, calcium dobesilate

Citation: Clinical Hemorheology and Microcirculation, vol. 31, no. 1, pp. 67-74, 2004