Clinical Hemorheology and Microcirculation - Volume 41, issue 3

Authors: Clevert, D.-A. | Minaifar, N. | Kopp, R. | Stickel, M. | Meimarakis, G. | Sommer, W. | Reiser, M.

Article Type: Research Article

Abstract: Endoleaks following endovascular aneurysm repair (EVAR) are common and present a diagnostic challenge in the follow-up after EVAR. Contrast-enhanced ultrasound (CEUS) with low mechanical index (low MI) is a promising new method for the diagnosis and follow-up of endoleaks. CEUS with SonoVue® allows a more rapid and noninvasive diagnosis, especially in critical patients owing to its bedside availability. This review describes the etiology, classification and importance of different types of endoleaks and compares CEUS findings with computed tomography angiography (CTA), allowing the reader to appreciate the usefulness of CEUS in this clinical situation.

Keywords: Contrast-enhanced ultrasound (CEUS), computed tomography angiography (CTA), abdominal aortic aneurysm (AAA), endovascular aneurysm repair (EVAR), endoleak

DOI: 10.3233/CH-2009-1160

Citation: Clinical Hemorheology and Microcirculation, vol. 41, no. 3, pp. 151-168, 2009

Authors: Babu, N.

Article Type: Research Article

Abstract: The main objective of the present work is to study the influence of cholesterol in hyperglycemic subjects on deformability and shape parameters of erythrocytes. The deformability of erythrocytes in blood samples of diabetic patients with normal cholesterol (group A) and diabetes with hyper cholesterol (group B) concentration are determined by optical hemorheometer and are compared with healthy subjects. The deformability is measured by passing laser light through erythrocyte suspension in physiological saline while filtration of erythrocytes through cellulose micro pore membrane. Blood samples of 5% hematocrit were prepared in physiological saline for control subjects and diabetes mellitus with normal and …hyper cholesterol subjects for deformability measurements. The shape analysis is carried out by shape descriptors based on projected area, perimeter and form factor, as measured by processing of images of erythrocytes. Deformability was reduced in diabetes with normal cholesterol and much reduced significantly in diabetes with hyper cholesterol comparing to healthy subjects was found. The shape descriptor form factor, as determined by processing of erythrocyte images, increases in diabetes with normal cholesterol and further increases in diabetes with hyper cholesterol compare to healthy subjects and shows a pattern similar to filtration time of erythrocyte suspensions through cellulose membranes. This significant decrease in deformability and increase in shape parameters in diabetes with hyper cholesterol may increase the microcirculatory complications compare to diabetes with normal cholesterol. Show more

Keywords: Diabetes mellitus, erythrocyte deformability, cholesterolemia, hyperglycemia

DOI: 10.3233/CH-2009-1165

Citation: Clinical Hemorheology and Microcirculation, vol. 41, no. 3, pp. 169-177, 2009

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

Article Type: Research Article

Abstract: Measurements of red blood cell (RBC) deformability and aggregation can be subject to influence by pre-analytical handling procedures, with the degree of hemoglobin oxygenation having the potential to affect the results. To examine such effects, RBC deformability and aggregation were studied before and after oxygenation or deoxygenation of human blood samples. RBC deformability was assessed using a laser-diffraction ektacytometer having Couette geometry. RBC aggregation was assessed using the same system by monitoring light backscattering after a sudden cessation of high shear; aggregation was also measured by monitoring light transmittance through RBC suspensions. RBC deformability was found to be significantly increased …after equilibrating RBC with ambient air (pO2 : 142.0±3.1 mmHg) compared to the non-oxygenated sample (pO2 : 42.4±1.8 mmHg). In contrast, equilibration with 100% nitrogen resulted in significant impairment in RBC deformability. RBC aggregation parameters were also affected by oxygenation if measured based on light backscattering, but not if measured using light transmittance. It is thus recommended that blood samples be oxygenated by repeated exposure to ambient air prior to the measurement of hemorheological parameters. Show more

Keywords: Erythrocyte deformability, erythrocyte aggregation, oxygenation, deoxygenation

DOI: 10.3233/CH-2009-1168

Citation: Clinical Hemorheology and Microcirculation, vol. 41, no. 3, pp. 179-188, 2009

Authors: Chwała, Maciej | Spannbauer, Anna | Teległów, Aneta | Cencora, Andrzej | Marchewka, Anna | Hardeman, Max R. | Dąbrowski, Zbigniew

Article Type: Research Article

Abstract: Rheological studies concerning aggregation and elongation of erythrocytes were carried out in 21 patients (mean age 56 years) with chronic venous disease (CVD) and 10 (mean age 45 years) healthy control subjects, with the use of a LORCA device. Higher values of parameters characterizing both erythrocyte elongation (EI) and aggregation (γthr ) in non-control patients than in the control group were found. These values differed significantly ranging from 1.13 to 8.23 Pa for the shear stress and γthr in patients – 432.14, in relation to the control group – 166.5. It was proposed, that the increase in deformability may …constitute a compensatory mechanism in subjects with chronic venous disease, due to increased resistance in their microcirculation. Show more

Keywords: Chronic venous disease (CVD), chronic venous insufficiency (CVI), erythrocyte elongation, erythrocyte aggregation, rheology

DOI: 10.3233/CH-2009-1171

Citation: Clinical Hemorheology and Microcirculation, vol. 41, no. 3, pp. 189-195, 2009

Authors: Shin, Sehyun | Yang, Yijie | Suh, Jang-Soo

Article Type: Research Article

Abstract: In the analysis of red blood cell (RBC) aggregation using optical detection, various shearing methods have been used to disperse RBCs in confined geometries. This study investigated RBC aggregation measurement in a microchip-stirring system by analysis of light transmission. A stirring-aided disaggregation mechanism in a microchip, consisting of a flat-cylindrical test chamber (D=4 mm, H=0.3 mm) and a magnetic stirrer (d=0.14 mm, l=2.2 mm), was used to generate a given shear which was large enough to disperse RBC aggregates, but not large enough to cause any mechanical hemolysis of cells. After stirring for 10 s followed by an abrupt halt …of the stirring, the intensity of the light transmitted through a microchip was measured with respect to time and analyzed. A comparative study was conducted with varying test chamber height and hematocrit. The AI and t1/2 as typical aggregation indices obtained by analysis of transmitted light, which showed a good reproducibility (coefficient of variation (CV)<2.8%, n=10), also were found to be nearly independent of the chamber dimensions (CV<3.4%). The present aggregometry also showed the similar results of aggregation indices with varying hematocrits compared to those obtained using a laser-assisted optical rotational cell analyzer (LORCA). The essential feature of the present design is the adoption of a disposable microchip requiring a minimum blood sample volume as small as 6 μl, which enables it to be used easily in a clinical setting. Show more

Keywords: Aggregometer, erythrocyte aggregation, hematocrit, light transmission, microchip stirring system

DOI: 10.3233/CH-2009-1172

Citation: Clinical Hemorheology and Microcirculation, vol. 41, no. 3, pp. 197-207, 2009

Authors: Hopps, Eugenia | Presti, Rosalia Lo | Caimi, Gregorio

Article Type: Review Article

Abstract: This review shows how polymorphonuclear leukocytes (PMNs) play a pivotal role in the development of the organ injury that is associated with arterial hypertension. Elevated white blood cell count and higher levels of PMNs activation are risk factors for arterial hypertension and cardiovascular disease. Spontaneously activated PMNs release proinflammatory factors and reactive oxygen species, which have negative effects on vascular tone and on their adhesion to the endothelium. The oxidative stress in hypertensive PMNs is revealed by increased NADPH-oxidase production and lipid peroxidation and by decreased cytosolic and mitochondrial superoxide dismutase concentrations. The overexpression of adhesion molecules, such as β2 …-integrin, promotes PMNs rolling and leukocyte–endothelium interactions too. All these events underline how polymorphonuclear leukocytes may contribute to the vascular damage accompaining arterial hypertension. Show more

Keywords: Polymorphonuclear leukocytes, hypertension, oxidative stress, adhesion molecules

DOI: 10.3233/CH-2009-1173

Citation: Clinical Hemorheology and Microcirculation, vol. 41, no. 3, pp. 209-218, 2009