Clinical Hemorheology and Microcirculation - Volume 25, issue 2

Article Type: Other

Citation: Clinical Hemorheology and Microcirculation, vol. 25, no. 2, pp. 41-41, 2001

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

Article Type: Research Article

Abstract: The rheological properties of blood play an important role in the regulation of blood flow resistance in vessels. Numerous data show evidence for an impaired hemorheological characteristic in diabetes mellitus. The aim of this study was to investigate whether chronic severe leg ischaemia in diabetes may be associated with further hemorheologic impairment. To do this, whole blood viscosity, erythrocyte aggregation/disaggregation, plasma viscosity and proteins were measured in 32 healthy control subjects, in 32 diabetic patients without micro‐ and macroangiopathy, in 21 diabetic patients with chronic tissue hypoxia of lower limbs and in 23 diabetic patients with severe leg ischaemia. The …diabetic patients with leg hypoxia and leg ischaemia were selected according to their value of transcutaneous oxygen pressure (TcPO2 ) measured on dorsal side of the foot in supine position. The TcPO2 value was within 10–30 mmHg or less than 10 mmHg in patients with chronic hypoxia and severe ischaemia, respectively. Results in diabetic patients without micro‐ and macroangiopathy showed an increased erythrocyte aggregation associated with an increased fibrinogen level while albumin levels were decreased. Both diabetic patients with chronic hypoxia and those with severe ischaemia exhibited similarly more aggravated hemorheological disturbances including an increased whole blood viscosity at low shear rate, an increased erythrocyte hyperaggregation, increased plasma viscosity, increased fibrinogen level, decreased albumin level and decreased hematocrit. In conclusion, the hemorheological disturbances are present even in diabetic patients without clinically detectable micro‐ and/or macroangiopathy. The fact that the extent of disturbances was similar in the two later diabetic groups, emphasizes that the hemorheological disturbances are not the consequences of chronic hypoxia and/or severe ischaemia but are likely among factors promoting the maldistribution of blood flow in nutritive capillaries as evidenced by decreased TcPO2 in patients with chronic leg hypoxia or severe leg ischaemia. Show more

Keywords: Diabetes, hemorheology, ischemia

Citation: Clinical Hemorheology and Microcirculation, vol. 25, no. 2, pp. 43-48, 2001

Authors: Wautier, Jean‐Luc | Wautier, Marie‐Paule

Article Type: Research Article

Abstract: The diabetic vasculopathy is one of the major complications responsible for the high incidence of arteriopathy, coronary ischemia and renal failure. Several hypothesis have been formulated to explain the vascular abnormalities. We recently showed that advanced glycation end products (AGE) have a pivotal role in the genesis of vascular dysfunction. AGE bind to a receptor (RAGE) present on endothelial cells. AGE binding to RAGE produced an oxidant stress and diminished vascular barrier function, increased vascular permeability, enhanced the expression of vascular cell adhesion molecule 1 (VCAM‐1). VCAM‐1 expression on endothelial cell and increased expression of CD11 b CD18 on …monocytes may facilitate monocyte emigration and can represent one of the initial steps of vascular alteration. In diabetic animals or in ApoE null diabetic mice which developed atherosclerosis, the infusion of recombinant RAGE prepared in insect cells was studied. Recombinant RAGE administration corrected vascular hyperpermeability and prevented the development of atherosclerosis in the animals. Show more

Keywords: Advanced glycation end products, monocytes, endothelial cell, adhesion molecules, diabetic angiopathy

Citation: Clinical Hemorheology and Microcirculation, vol. 25, no. 2, pp. 49-53, 2001

Authors: Wiernsperger, Nicolas F.

Article Type: Research Article

Abstract: In sharp contrast to vasodilatation, vasoconstriction is not subjected to great consideration in vascular physiological and pharmacological investigations in diabetes. However, vasoconstriction is a main regulatory process in smaller vessels, in particular in the small arterioles. Here it is linked to maintenance of local blood pressure and avoids capillary hyperperfusion/hypertension. This highlights the importance of constrictor processes in the microvascular bed as opposed to larger vessels. It is manifested by a series of phenomena such as precapillary vasomotion, venoarteriolar reflex and myogenic response. Animal and human studies indeed reported defects in small vessel constrictor reactivity in diabetes but also evidence …for disturbances already present in nondiabetic, insulin resistant states. This abnormality is present whether humoral, neuronal or physical stimuli are used for test. This article overviews the adequate literature and discusses both vascular and metabolic implications induced by defective vasoconstriction. Show more

Keywords: Microcirculation, vasoconstriction, diabetes, insulin‐resistance

Citation: Clinical Hemorheology and Microcirculation, vol. 25, no. 2, pp. 55-62, 2001

Authors: Evans, Shelley‐Ann | , Rachel | Rainger, G.Ed.

Article Type: Research Article

Abstract: The effect of increased adhesiveness and decreased deformability of leukocytes following activation can have a profound effect on flow through the microcirculation. Measurement of leukocyte deformability is therefore an important tool in the study of the pathology of vascular diseases. Although much work has been done on the rheological properties of lymphocytes and granulocytes, there is little information available on the larger mononuclear cells, the monocytes. To investigate monocyte rheology, attempts were made to purifiy monocytes by a variety of methods. Purified monocytes were then filtered through 5 μm polycarbonate filters, with flow profiles (change in volume with time) recorded …over 300 seconds. The profiles were analysed by least squares fitting to an appropriate mathematical model. Analysis of filtration data demonstrated 3 distinct sub‐populations of monocytes with differing rheological properties. Other workers have characterised monocytes into defined subsets on the basis of their size, phagocytic ability or expression of cell surface markers. The definition of monocytes into defined rheological subsets is a new and useful addition to these studies. Show more

Keywords: Monocytes, heterogeneity, rheology, leukocyte, isolation

Citation: Clinical Hemorheology and Microcirculation, vol. 25, no. 2, pp. 63-73, 2001

Authors: Wen, Zongyao | Xie, Lide | Yan, Zongyi | Yao, Weijuan | Chen, Kai | Ka, Weibo | Chien, Shu

Article Type: Research Article

Abstract: A high‐dose (7 Gy) whole‐body 60 Co irradiation for a short period caused disturbances of hematopoietic function. A decrease in the hematocrit of the circulating blood lasted for about 15 days, thus forming an anemic animal model. We studied the influence of high‐dose 60 Co irradiation on hemorheologic parameters: percentage of reticulocytes, RBC deformability, sedimentation rate and plasma fibrinogen concentration in the rabbit. It was found that the plasma fibrinogen concentration increased to twice more than control level and that percentage of reticulocytes in circulation disappeared immediately after irradiation. The deformation index of RBCs in shear flow decreased from a …value of 58% down to a value of 42% in the first two weeks and gradually returned to control levels about 40 days after 60 Co irradiation. Our results showed that a short period of high‐dose 60 Co irradiation caused severe and relatively long‐lasting damage of hematopoietic system in animals' body. Show more

Keywords: $^{60}$Co irradiation, rabbit, hemorheological characteristics

Citation: Clinical Hemorheology and Microcirculation, vol. 25, no. 2, pp. 75-81, 2001