Clinical Hemorheology and Microcirculation - Volume 39, issue 1-4

Authors: Clevert, D.-A. | Minaifar, N. | Weckbach, S. | Jung, E.M. | Stock, K. | Reiser, M. | Staehler, M.

Article Type: Research Article

Abstract: To assess the diagnostic performance of multislice computed tomography (MS-CT) in the classification of atypical or complex cystic renal masses using the Bosniak system in comparison to contrast-enhanced ultrasound (CEUS) and, in unclear cases, to the surgery findings. Thirty-two consecutive patients (14 women, 18 men; age range 39–72 years) with 37 atypical or complex cystic renal masses at MS-CT underwent conventional ultrasound (US) and CEUS. CEUS employed a low-MI technique using 1.6–2.4 ml SonoVue (Bracco, Italy) i.v. and a 2–4 MHz multifrequency transducer (Siemens, Sequoia, Acuson). Fourteen masses were resected, the remaining 23 lesions were followed up for periods …ranging from 3 months to 2 years. Images and digital cine clips of all lesions were evaluated by blinded readers. On the basis of MS-CT appearance the lesions were assigned to the Bosniak classification. Similar criteria modified for US imaging were used to score atypical cysts at CEUS. In the Bosniak classification at MS-CT the lesions were scored as category II (n=15), IIF (n=7), III (n=8) and IV (n=7). At CEUS, masses were classified as Bosniak classification II (n=8), IIF (n=12), III (n=8) or IV (n=9). All type IV and 6/8 type III and 1/8 type IIF lesions were removed surgically. All category IV and 3/8 category III lesions of the surgical group were malignant, the one type IIF lesion was benign. All class II and IIF cysts except one were stable after a follow-up period ranging from 3 months to 2 years. In 7/37 lesions (19%) the MS-CT and CEUS scores were different, while in 30/37 (81%) they were equivalent. CEUS depicted more thin septa than MS-CT, or upgraded wall thickness, resulting in a Bosniak score upgrade from category II to IIF in 5 lesions. Two cystic renal masses could not be clearly assigned by MS-CT but were considered malignant due to the additional information from CEUS, which was confirmed by surgical removal (small cystic renal cancer). CEUS with SonoVue allows an early evaluation of atypical or complex cystic renal masses. It is an additional examination to MS-CT. Due to the dynamic examination, additional information about perfusion of the cystic septa or cystic renal cancer can be gained. Show more

Keywords: Bosniak-classification, contrast enhanced ultrasound, multislice computed tomography

DOI: 10.3233/CH-2008-1083

Citation: Clinical Hemorheology and Microcirculation, vol. 39, no. 1-4, pp. 171-178, 2008

Authors: Connes, Philippe | Hue, Olivier | Tripette, Julien | Hardy-Dessources, Marie-Dominique

Article Type: Research Article

Abstract: Sickle cell trait (SCT) is usually considered a benign disorder compared with sickle cell anemia (SS hemoglobinopathy). However, several authors have reported cases of exercise-related sudden death in this population. Among the mechanisms that could be involved in these fatal complications, vaso-occlusive processes, such as those occurring in SS hemoglobinopathy, may play a role. In sickle cell anemia, these vaso-occlusive processes involve inflammatory and adhesion molecules such as the cell adhesion molecules (CAM family), which play a role in the firm adhesion of reticulocytes and leukocytes to endothelial cells, and the selectins, which play a role in leukocyte and …platelet rolling on the vascular wall. Recent results suggest that adhesion phenomena could be amplified in SCT carriers during exercise compared with non-carriers. Other mechanisms like alterations in blood coagulation and/or hemorheological properties can also favor the occurrence of vaso-occlusive processes. Although few studies have reported coagulation disturbances in SCT carriers at rest, we recently observed no difference between this population and control subjects in response to exercise. In contrast, by studying the behavior of several hemorheological parameters in response to several types of exercise, we detected hemorheological abnormalities in individuals with SCT. These abnormalities included higher red blood cell rigidity and higher blood viscosity in the SCT carriers compared with the non-carriers, particularly during the late recovery period (24 and 48 h after exercise). Therefore, we can suggest that the risks for microvascular complications in SCT carriers in response to exercise could be dependent on alterations in blood rheology and vascular adhesion processes. Show more

Keywords: Hemoglobin S, red blood cell deformability, coagulation, selectins, cell adhesion molecules

DOI: 10.3233/CH-2008-1078

Citation: Clinical Hemorheology and Microcirculation, vol. 39, no. 1-4, pp. 179-184, 2008

Authors: Leone, Maria Cristina | Gori, Tommaso | Fineschi, Massimo

Article Type: Research Article

Abstract: The coronary slow flow phenomenon (CSFP) is an angiographic finding that is characterised by delayed progression of the contrast medium during coronary angiography. The mechanism of this phenomenon remains unknown. In the present paper, we revise the current evidence regarding this phenomenon and discuss recent findings from our group reporting increased resting resistances in patients with the CSFP. We report that these patients had preserved blood flow responses to the intracoronary infusion of the vasodilator papaverine, demonstrating that the CSFP is not necessarily associated with an abnormal coronary flow reserve. Based on these findings and on the review of …the current literature, we concur with the concept proposed by Beltrame et al. that the CSFP should be considered a separate clinical entity. Further studies are necessary to describe the clinical characteristics, including the prognosis, of these patients and to identify potential treatments. Show more

Keywords: Ischemia, slow flow, microvasculature

DOI: 10.3233/CH-2008-1079

Citation: Clinical Hemorheology and Microcirculation, vol. 39, no. 1-4, pp. 185-190, 2008

Authors: Gori, Tommaso | Di Stolfo, Giuseppe | Dragoni, Saverio | Lisi, Monica | Leone, Maria Cristina | Forconi, Sandro | Parker, John D.

Article Type: Research Article

Abstract: Nitroglycerin (GTN) has been shown, in both human and animal studies, to induce a protective phenotype that limits tissue damage after ischemia and reperfusion. This phenomenon is similar to ischemic preconditioning, and several reports suggest that also the molecular pathways involved in this protective effect of nitrates are the same that determine ischemic preconditioning. Our group conducted a series of studies aimed at investigating, using a human model of endothelial IR injury, the mechanism of nitrate-induced preconditioning and particularly the role of reactive oxygen species formation and of the opening of mitochondrial permeability transition pores. Our data demonstrate that …GTN protects the endothelium against postischemic endothelial dysfunction in a mechanism that is mediated by oxygen free radical release and opening of mitochondrial permeability transition pores. In contrast, the protective effect of pentaerithrityl tetranitrate appears to be independent of these mechanisms, and it seems to be mediated by induction of antioxidant genes. Finally, isosorbide mononitrate seems to be devoid of a significant protective effect. These data are summarized and discussed in the present paper. Show more

Keywords: Endothelium, ischemia, reperfusion

DOI: 10.3233/CH-2008-1081

Citation: Clinical Hemorheology and Microcirculation, vol. 39, no. 1-4, pp. 191-196, 2008

Authors: Grotti, S. | Gori, T.

Article Type: Research Article

Abstract: Pathophysiological studies have clearly demonstrated that the relationship between endothelial (dys)function and tissue ischemia is bidirectional: while it is well accepted that endothelial dysfunction has a key role in the progression and the instabilization of coronary atherosclerosis, it is also well known that the endothelium is particularly sensitive to ischemia and reperfusion injury, and that this damage is an important component in determining the size of the infarction. Therefore, protecting the endothelium from ischemia has potentially important clinical implications. In this scenario, a particularly important role is played by reactive oxygen species: these elusive mediators are involved in determining the …endothelial toxic effect of risk factors, are involved in reperfusion injury, but, most importantly, also have a role in endothelial preconditioning, a protective process that is characterized by a reduced sensitivity to ischemia and reperfusion. The present paper reports considerations regarding these phenomena as discussed in a lecture at the recent Conference of the European Society of Clinical Hemorheology and Microcirculation held in Dresden, Germany. Show more

Keywords: Oxygen free radicals, ischemia, reperfusion, endothelium, endothelial dysfunction, nitric oxide, ischemic preconditioning

DOI: 10.3233/CH-2008-1082

Citation: Clinical Hemorheology and Microcirculation, vol. 39, no. 1-4, pp. 197-203, 2008

Authors: Fink, J. | Fuhrmann, R. | Scharnweber, T. | Franke, R.P.

Article Type: Research Article

Abstract: The aim of this study was to understand the mechanisms of interaction of monocytes/macrophages and foreign body giant cell (FBGC) with implant materials, with respect to the roughness and the solubility of calcium phosphate based coatings. Anderson et al. (Bone Engineering, J.E. Davies, ed., Toronto, 2000, pp. 81–93) showed that the presence of FBGC's and monocytes/macrophages influenced the strength of the implant-tissue integration and that more monocytes/macrophages rested on smooth surfaces compared to rough surfaces. We seeded human bone marrow cells on uncoated ultrasmooth polished TiAl6V4 samples as well as on coated TiAl6V4 discs of the same diameter with two …different calcium phosphates coatings, monetite (DCP) and hydroxyapatite (OHAp), both with rougher surfaces. On uncoated ultrasmooth polished TiAl6V4 discs (UUTi, diameter 16 mm, thickness 2 mm) and on TiAl6V4 discs of same diameter coated with OHAP or DCPA, human bone marrow cells (HMBC) were seeded and cultivated under standard culture conditions for 90 days without addition of inducing substances like ascorbic acid, Na-β-glycerophosphate or dexamethasone. The roughnesses of the virgin samples were assessed with atomic force microscopy and light profilometry. After 90 days of cultivation a fraction of the samples, with cells and extracellular matrix, were stained with hematoxylin eosin (HE) and examined in light microscopy. Ra roughness values of virgin uncoated TiAl6V4 samples were 0.001 μm, of DCP coated discs 4 μm and of OHAp coated discs 3 μm. The examination of HE stained samples showed a high number of FBGC and monocytes/macrophages on the UUTi samples. On the DCP coated samples there were less FBGC and monocytes/macrophages and on the OHAp coated samples we could not find any FBGC and monocytes/macrophages. The extracellular matrix (ECM) we found on the UUTi samples was finer and thinner than on the coated samples. The ECM was vastly spread and not dense on the UUTi samples in contrast to the calcium phosphate coated samples, where the ECM was much thicker and stronger. The ultrasmooth surface of the uncoated TiAl6V4 samples, a material which is accepted to be biocompatible, evidently induced the differentiation of cells of the monocytic lineage and the formation of FBGC out of the cell populations present in the human bone marrow. Show more

Keywords: Calcium phosphate, monocytes, macrophages, foreign body giant cells, stimulation

DOI: 10.3233/CH-2008-1090

Citation: Clinical Hemorheology and Microcirculation, vol. 39, no. 1-4, pp. 205-212, 2008

Authors: Fornal, M. | Korbut, R.A. | Lekka, M. | Pyka-Fościak, G. | Wizner, B. | Styczen, J. | Grodzicki, T.

Article Type: Research Article

Abstract: Rheological properties of erythrocytes from patients with high risk of cardiovascular disease (CVD) were analyzed in relation to individual patient risk factors as well as to the medication. Additionally, comparative statistical analysis was performed considering plasma concentration of the selected mediators of vascular endothelium: 6-keto-prostaglandin F1α (PGF1α ), sVCAM-1 and E-selectin adhesion molecules and interleukin-6 (IL-6). It was found that antihypertensive therapy with angiotensin-converting enzyme inhibitor (ACEI) is accompanied by improvement of RBC rheology: the increase of deformability and the decrease of aggregability. This improvement is probably mediated by endothelial prostacyclin and nitric oxide which are generated by ACEI. …A correlation was observed between RBC deformability/aggregability and the patient's hematocrit level, what implicates that the hematocrit level should be explicitly taken into consideration when investigating rheological properties of erythrocytes. A strong relationship was also found between the plasma concentration of sVCAM-1 and patient's age. Show more

Keywords: Erythrocyte deformability, erythrocyte aggregability, hypertension, ACEI, CVD risk

DOI: 10.3233/CH-2008-1084

Citation: Clinical Hemorheology and Microcirculation, vol. 39, no. 1-4, pp. 213-219, 2008

Authors: Hiebl, B. | Fuhrmann, R. | Franke, R.P.

Article Type: Research Article

Abstract: Monocytes are broadly discussed in the literature as cells, which can get properties of endothelial progenitor cells after angiogenic stimulation. Angiogenically stimulated monocytes can be used to promote implant vascularisation. A necessity therefore is that these cells can be stored and used after storage without a loose of their characteristic phenotype. In this study we tested, if freshly thawed cryopreserved human monocytes are positive for the mo/macrophage markers CD14 and CD68 and the endothelial marker CD31 after thawing and following angiogenic stimulation in a VEGF-A165 enriched (10 ng/ml) angiogenic medium. Thereby the monocytes were tested before and after differentiation …towards macrophages. The results revealed that freshly thawed human CD14 positive monocytes are positive for CD14, CD68 and CD31 after angiogenic stimulation. This CD specification was much more intense in the differentiated cells. The differentiation step also resulted in an increased cell count. Both results can be attributed to the method of differentiation, were cell culture bags were used instead of common cell culture dishes. Additionally the differentiation medium (X-VIVO 10+10% FCS) was specifically adapted to the requirements of monocytes/macrophages. The study showed that human CD14 positive monocytes can be thawed after cryopreservation without loss of their monocytes/macrophage phenotype and without loss of their ability to get angiogenically stimulated. To enhance the efficiency of both steps (thawing, angiogenic stimulation) it can be useful to differentiate the thawed cells in cell culture bags by the use of X-VIVO 10 (+10% FCS) before angiogenic stimulation. Show more

Keywords: VEGF, monocyte, macrophage, CD14, CD68, CD31

DOI: 10.3233/CH-2008-1086

Citation: Clinical Hemorheology and Microcirculation, vol. 39, no. 1-4, pp. 221-228, 2008

Authors: Jovtchev, S. | Stoeff, S. | Arnold, K. | Zschörnig, O.

Article Type: Research Article

Abstract: Covalent binding of poly(ethylene glycol), abbreviated as PEG, to red blood cells (RBC) surface leads to masking of the RBC blood group determinants and the PEG layer on the cell surface sterically hinders RBC–RBC and RBC–plasma protein interactions. We cross-linked linear mPEG-SPA of various molecular mass (2000, 5000, 20000) to washed human RBC under varying incubation ratios polymer to RBC. The electrophoretic mobility (EM) of the modified RBC decreases with increasing of chain length and concentration of PEG up to 50%. It may reflect the alteration in the surface layer thickness and friction. The aggregation behaviour of the pegylated RBC …was studied with the Zeta sedimentation technique modifying the cell–cell interactions pressing them toward each other under centrifugal forces of various magnitudes. As a rule at low centrifugation forces the increase in chain length and concentration of PEG linked to RBC surface reduces the dextran-induced aggregation probably via elevation of the steric repulsion, which counteracts the depletion force generated by the free polymer. This effect was reversed to some extent by elevation of free dextran concentration and centrifugation forces. If cell–cell polymer bridging starts playing a role under these conditions requires further experimental and theoretical investigations. Show more

Keywords: Pegylated red blood cells, aggregation, dextran, Zeta sedimentation ratio

DOI: 10.3233/CH-2008-1085

Citation: Clinical Hemorheology and Microcirculation, vol. 39, no. 1-4, pp. 229-233, 2008

Authors: Kaliviotis, Efstathios | Yianneskis, Michael

Article Type: Research Article

Abstract: Red blood cell aggregation affects the flow of blood at low shear rates; not only the behaviour of the fluid deviates from its Newtonian characteristics, but, depending on the shearing history of the flow, the non-Newtonian characteristics may be influenced. It is not clear how the time and flow-dependent characteristics of the microstructural network developed in blood affect its mechanical properties. The present study aims to improve understanding of the effect of dynamic flow conditions on microstructural characteristics and consequently on the mechanical properties of the fluid. Viscosity measurements on blood samples from healthy volunteers (H=0.45) were taken with a …double-walled Couette rheometric cell, under unsteady and quasi-unsteady flow conditions. The aggregation extent index Aα , and the microstructural integrity index AI were assessed with an optical shearing system and image analysis. Results showed that energy losses in Couette geometries may depend on the structural integrity of the developed RBC network. Show more

Keywords: RBC aggregation, shear rate variation with time, microstructural integrity

DOI: 10.3233/CH-2008-1087

Citation: Clinical Hemorheology and Microcirculation, vol. 39, no. 1-4, pp. 235-242, 2008