Clinical Hemorheology and Microcirculation - Volume 44, issue 2

Authors: Salazar Vázquez, B.Y. | Martini, J. | Chávez Negrete, A. | Tsai, A.G. | Forconi, S. | Cabrales, P. | Johnson, P.C. | Intaglietta, M.

Article Type: Review Article

Abstract: Decreasing blood viscosity has been proposed since the advent of hemodilution as a means for increasing perfusion in many pathological conditions, and increased plasma viscosity is associated with the presence of pathological conditions. However, experimental studies show that microvascular functions as represented by functional capillary density in conditions of significantly decreased viscosity is impaired, a problem corrected by increasing plasma and blood viscosity. Blood viscosity, primarily dependent on hematocrit (Hct) is a determinant of peripheral vascular resistance, and therefore blood pressure. In the healthy population Hct presents a variability, which is not reflected by the variability of blood pressure. This …is due to a regulatory process at the level of the endothelium, whereby the increase of Hct (and therefore blood viscosity) leads to increased shear stress and the production of the vasodilator nitric oxide (NO), a finding supported by experimental studies showing that the acute increase of Hct lowers blood pressure. Studies that in the healthy population show that blood pressure and Hct have a weak positive correlation. However, when the effect of blood viscosity is factored out, blood pressure and Hct are negatively and significantly correlated, indicating that as blood viscosity increases, the circulation dilates. Conversely, lower Hct and blood viscosity conditions lead to a constricted circulation, associated with a condition of decreased NO bioavailability, and therefore a pro-inflammatory condition. Show more

Keywords: Microcirculation, blood viscosity, plasma viscosity, blood pressure, vascular resistance, nitric oxide, inflammation

DOI: 10.3233/CH-2010-1261

Citation: Clinical Hemorheology and Microcirculation, vol. 44, no. 2, pp. 75-85, 2010

Authors: Bor-Kucukatay, Melek | Atalay, Habip | Karagenc, Nedim | Erken, Gulten | Kucukatay, Vural

Article Type: Research Article

Abstract: This study aimed to investigate the short term effects of carbon monoxide (CO) poisoning and three kinds of poisoning treatments; namely room air, normobaric and hyperbaric oxygen on hemorheological parameters such as red blood cell (RBC) deformability, aggregation, blood and plasma viscosity. 43 Wistar rats were divided into 5 groups. Poisoning was induced by exposure to 4000 ppm CO (1 h). The poisoning protocol was followed by 3 types of treatments; room air, normobaric 100% oxygen and hyperbaric oxygen for 1 h. RBC deformability and aggregation were determined using an ektacytometer (LORCA) and a cone-plate rotational viscometer was used for …the viscosity measurements. RBC deformability of CO poisoned rats were found to be elevated and the treatments applied, caused decrement of this parameter. A no significant increment tendency was found in erythrocyte aggregation after CO exposure. Although room air and hyperbaric oxygen treatments caused further significant elevations in the amplitude of aggregation, normobaric oxygen therapy induced decrement in this parameter towards control levels. No significant alterations were observed in viscosity values among the groups. The results of this study demonstrate normobaric oxygen therapy as a better choice of treatment after CO poisoning in hemorheological point of view. Show more

Keywords: Carbon monoxide, poisoning, treatment, hemorheology

DOI: 10.3233/CH-2010-1254

Citation: Clinical Hemorheology and Microcirculation, vol. 44, no. 2, pp. 87-96, 2010

Authors: Schacherer, D. | Girlich, C. | Wiest, R. | Büttner, R. | Schölmerich, J. | Feuerbach, S. | Zorger, N. | Hamer, O.W. | Jung, E.M.

Article Type: Research Article

Abstract: Background: At the moment, there is only poor specificity of HCC-detection in tumors smaller than 2 cm in a cirrhotic liver. Thus, efforts have to be made to optimize the distinction between regenerative nodules and HCC. Aims: The aim of our study was to describe the particular perfusion pattern of hepatocellular carcinoma using a specific quantification software. Methods: We evaluated 25 patients with proven hepatocellular carcinoma, who underwent dynamic contrast-enhanced ultrasound (CEUS) using a second generation contrast agent (SonoVue® , Bracco, Germany). Retrospectively, we applied the quantification software Qontrast® (Bracco, Milan, Italy) to obtain contrast-enhanced sonographic perfusion …maps for each lesion. Results: We found a close positive correlation of the perfusion parameters peak, time-to-peak and regional blood volume between the entire tumors, the center (center/total) and the periphery of the tumors (periphery/total), respectively. Moreover, we found significant higher peak values, a significant higher regional blood volume and a trend to lower time-to-peak in the center of the tumors compared to the tumor periphery. Conclusion: These results suggest a better established vascular bed in the center of the tumors. This could be a sonographic marker of HCC in contrast to regenerative nodules. Show more

DOI: 10.3233/CH-2010-1257

Citation: Clinical Hemorheology and Microcirculation, vol. 44, no. 2, pp. 97-105, 2010

Authors: Connes, Philippe | Boucher, John H.

Article Type: Research Article

Abstract: Abnormal hemorheology has been proposed previously as a possible genesis of exercise-induced hypoxemia (EIH) in humans. This study, in support of the hemorheological hypothesis, aims at determining if red blood cell shape changes might be related to EIH. Three groups of subjects: one without EIH (n=5); one developing mild-EIH (n=7); and, one with moderate EIH (n=5). Each group performed a progressive and maximal exercise test on cycle-ergometer. We evaluated the percent of stomatocytes, echinocytes and schizocytes in blood smears prepared from phlebotomy samples taken at rest and at maximal exercise. The percent of schizocytes or stomatocytes was not different between …the three EIH groups at rest; and, exercise produced no change from the resting values of those cell types. The percent of echinocytes was not different between the three EIH groups at rest, however, exercise significantly increased the percent of echinocytes from the resting value of both the mild- and moderate-EIH groups, while the non-EIH group remained unchanged. We suggested that the rigidity of echinocytes could have contributed to the genesis of EIH. Show more

Keywords: Echinocytes, exercise, hypoxemic athletes

DOI: 10.3233/CH-2010-1258

Citation: Clinical Hemorheology and Microcirculation, vol. 44, no. 2, pp. 107-114, 2010

Authors: Muravyov, A.V. | Cheporov, S.V. | Kislov, N.V. | Bulaeva, S.V. | Maimistova, A.A.

Article Type: Research Article

Abstract: The aim of our study was to compare hemorheological consequences of hemotransfusion and recombinant human erythropoetin treatment in anemic cancer patients. Forty anemic patients with solid nonmyeloid malignancies were enrolled in this prospective, open-label study. Both prior to and following treatment (epoetin beta, 10,000 units subcutaneously thrice weekly, for four weeks and transfusion of 400 ml of erythrocyte mass) hemorheological measurements including blood and plasma viscosity, hematocrit (Hct), hemoglobin, red blood cell aggregation (RBCA) and deformability were completed. It was found an increase of Hb from 76.07±3.68 g/l to 87.86±4.26 g/l after the transfusion. It was accompanied by Hct rise …by 25% (from 23.67±1.85 to 29.50±1.96%, p<0.05). Under these conditions the whole blood viscosity (BV) was increased by 19% (p<0.05). Plasma viscosity did not change markedly. Therefore the main cause of the whole blood viscosity rise was an increase of Hct. After erythrocyte mass transfusion there were some increases of red cell deformability and aggregation (by 7%, p>0.05). Under these conditions the Hct/BV ratio as an index of oxygen transport efficiency was changed after transfusion only slightly. While after four weeks of epoetin treatment the hematocrit/viscosity ratio was raised by 14% (p<0.05), in spite of the high blood viscosity. In addition RBCA decreased (p<0.01) and their deformability was increased by 14% (p<0.05). In vitro microrheological data permit to suggest that epoetin has a direct effect on the microrheological properties of red cells due to activation of the cellular signal transduction system including the tyrosine kinases and phosphatases. Thus, Epoetin beta administered s.c. thrice weekly, during four weeks, increased hemoglobin levels, improved hemorheological profile and especially its microrheological part as well as the blood transport capacity in anemic cancer patients who were receiving chemotherapy and its hemorheological effect was more positive than under hemotransfusion. Show more

Keywords: Anemia, cancer, epoetin, hemotransfusion, red blood cells, hemoglobin, hematocrit, blood viscosity, aggregation and deformability, tyrosine kinase and phosphatase

DOI: 10.3233/CH-2010-1259

Citation: Clinical Hemorheology and Microcirculation, vol. 44, no. 2, pp. 115-123, 2010

Authors: Arató, E. | Kürthy, M. | Sínay, L. | Kasza, G. | Menyhei, G. | Hardi, P. | Masoud, S. | Ripp, K. | Szilágyi, K. | Takács, I. | Miklós, Z. | Bátor, A. | Lantos, J. | Kollár, L. | Rőth, E. | Jancsó, G.

Article Type: Research Article

Abstract: Introduction: The challenge against reperfusion injury and tissue oxidative stress, especially in vascular surgical interventions has an essential importance to reach the optimal clinical result. Numerous experimental attempts have proved the positive antioxidant effect of vitamin E in both chronic and acute phase models. In our study we monitored the effect of continuous preoperative treatment with vitamin E, on oxidative stress and tissue inflammation reactions developed after reconstructive operations. Patients and methods: 32 patients have been involved in a randomized, prospective study, all suffering from AFS occlusion proved by angiography, and all undergone supragenual reconstruction. Duration of ischemia and …amount of tissues under vascular clamping were almost the same in all patients. In the group treated with E-vitamin, we administered 1×200 mg of vitamin E p/o from the preoperative day till the 7th post operative day. Patients of the second group did not receive vitamin E. Materials and methods: Peripheral blood samples were collected immediately before operation and at the end of the second reperfusion hour (early reperfusion period). Late reperfusion period has been monitored by analyzing blood samples taken at 24th hour and 7th day next to the operative ischemia. Among oxidative stress parameters, direct measurement of reactive oxygen intermediator (ROI) and determination of antioxidant state (GSH, Total-SH group, SOD) have been performed. Malondialdehyde was chosen as marker for lipidperoxidation. Inflammation reactions were monitored up on expression of adhesion molecules (CD11a and CD18). We also controlled the oscillation of myeloperoxidase (MPO) activity. Results: Our study has proved that preoperative (from the preoperative day till the 7th post operative day) administration of 200 mg vitamin E could reduce the level of oxidative stress developed after ischemic-reperfusion insult (lipidproxidation, antioxidant enzymes). According to our results, the prooxidant-antioxidant imbalance also diminished in the group with E-vitamin treatment. We proved that elective administration of vitamin E could decrease the WBC activity (MPO activity, free radicals production, expression of adhesion molecules) and its consequential local inflammation process, during early reperfusion. Show more

Keywords: Vitamin E, oxidative stress, reperfusion injury, leukocyte activity, PAD

DOI: 10.3233/CH-2010-1260

Citation: Clinical Hemorheology and Microcirculation, vol. 44, no. 2, pp. 125-136, 2010

Authors: Wenzel, Folker | Gruber, Wolfgang | Giers, Günther

Article Type: Research Article

Abstract: Thrombocytopenia is commonly observed during interferon-α (IFN-α) therapy in patients with chronic hepatitis C. Since thrombopoietin (TPO) is the main regulator of thrombopoiesis, thrombocytopenia may partially be due to a reduced TPO generation. Because of the developments of the second generation of TPO mimetic drugs patients with reduced TPO levels should be identified possibly having a benefit by medicinal stimulation of thrombopoiesis. Therefore, platelet count and serum TPO concentration of patients receiving an interferon-α therapy were determined. Twelve patients treated with IFN-α (daily 10×106 IU s.c. for four weeks) in cause of chronic hepatitis C were examined during …the first month of therapy. Serum TPO concentration significantly decreased from 80.8±48.0 to 34.6±24.5 pg/ml (p<0.05, Mann–Whitney test), and platelet count declined from 214,417±48,292 to 151,333±44,726 platelets/μl. During the following three weeks platelet count remained at a low level, while serum TPO increased to normal range. In conclusion, an interferon treatment causes reduced serum TPO level during the first week of therapy accompanied by decreased platelet count. The reduction in TPO synthesis contributes to the development of thrombocytopenia in patients during interferon therapy. Show more

Keywords: Thrombopoietin, interferon therapy, chronic hepatitis C, blood platelet count, serum TPO concentration, regulation of TPO concentration

DOI: 10.3233/CH-2010-1262

Citation: Clinical Hemorheology and Microcirculation, vol. 44, no. 2, pp. 137-144, 2010

Authors: Li, Guolin | He, Hong | Yan, Han | Zhao, Qiong | Yin, Dazhong

Article Type: Research Article

Abstract: Background: The structural and biochemical changes to erythrocytes during storage, called ‘storage lesion’, are important factors that contribute to decreases in the efficacy and safety of blood transfusions. However, the biochemical mechanisms are only partly understood. Study design and methods: Fresh whole blood in citrate phosphate dextrose anticoagulant was preserved in storage bags at 1–4°C for over 20 days. Aliquots of stored blood were withdrawn for analysis at the 1st, 5th, 10th, 15th and 20th day of storage. Whole blood viscosity, plasma reactive carbonyl species, erythrocyte membrane protein carbonylation, protein (tryptophan) fluorescence and the contents of thiols were quantified …concurrently. Results: There were significant increases in blood viscosity and plasma reactive carbonyl species level during storage. There were significant time-dependent increases in membrane protein carbonylation, increases in protein (tryptophan) fluorescence and a decrease in the content of thiols. Conclusion: Reactive carbonyl species, by attacking the amino and/or sulfhydryl groups of erythrocyte membrane proteins, induce a series of structural alterations in erythrocytes. These lead to an increase in blood viscosity and reduce the efficacy and safety of storage and transfusion. Show more

Keywords: Blood storage, reactive carbonyl species (RCS), carbonyl stress, viscosity, protein carbonylation, storage lesion

DOI: 10.3233/CH-2010-1263

Citation: Clinical Hemorheology and Microcirculation, vol. 44, no. 2, pp. 145-154, 2010