Clinical Hemorheology and Microcirculation - Volume 58, issue 2

Authors: Wang, Su | Zhang, Yanyan | Cheng, Yutong | Huang, Ji | Sun, Tao | Liu, Tong | Wang, Qian | Yin, Chengqian | Tao, Ying | Que, Bin | Zhang, Jingmei | Li, Zhizhong | Zhou, Yujie

Article Type: Research Article

Abstract: BACKGROUND: Whether the hematocrit is implicated in the pathogenesis of slow coronary flow (SCF) is not known. METHODS: To evaluate the correlation between the hematocrit and SCF, we studied 367 patients with angiographically near-normal coronary arteries. They were divided into four quartiles based on the hematocrit. The corrected thrombolysis in myocardial infarction frame count (TFC) was used to document velocity of coronary flow. RESULTS: From the first through to the fourth quartile, the percentage of males and those who smoked as well as serum levels of creatinine, uric acid and triglyceride increased (p < 0.001), whereas the age and level …of high-density lipoprotein-cholesterol decreased (p < 0.05). The proportions of SCF in the quartiles increased (55.4, 60.9, 77.2 and 85.7%, respectively, p < 0.001). Multivariate analyses revealed that the corrected TFC for the left anterior descending artery (LAD) (p < 0.001; B = 0.065; 95% confidence interval (CI), 0.038–0.093; beta = 0.199) and the proportion of SCF in the LAD (p < 0.001; B = 1.343; 95% CI 0.704–1.983; beta = 0.174) were correlated with the hematocrit after adjustment for confounding factors. CONCLUSION: The hematocrit is positively correlated with the corrected TFC for the LAD, which suggested that an increase in the hematocrit may contribute to the pathophysiology of SCF. Show more

Keywords: Hematocrit, slow coronary flow, risk factors

DOI: 10.3233/CH-121659

Citation: Clinical Hemorheology and Microcirculation, vol. 58, no. 2, pp. 297-305, 2014

Authors: Lamarre, Yann | Hardy-Dessources, Marie-Dominique | Romana, Marc | Lalanne-Mistrih, Marie-Laure | Waltz, Xavier | Petras, Marie | Doumdo, Lydia | Blanchet-Deverly, Anne | Martino, Jean | Tressières, Benoît | Maillard, Frederic | Tarer, Vanessa | Etienne-Julan, Maryse | Connes, Philippe

Article Type: Research Article

Abstract: Vascular function has been found to be impaired in patients with sickle cell disease (SCD). The present study investigated the determinants of systemic vascular resistance in two main SCD syndromes in children: sickle cell anemia (SCA) and sickle cell-hemoglobin C disease (SCC). Nitric oxide metabolites (NOx), hematological, hemorheological, and hemodynamical parameters were investigated in 61 children with SCA and 49 children with SCC. While mean arterial pressure was not different between SCA and SCC children, systemic vascular resistance (SVR) was greater in SCC children. Although SVR and blood viscosity (ηb) were not correlated in SCC children, the increase of ηb …(+18%) in SCC children compared to SCA children results in a greater mean SVR in this former group. SVR was positively correlated with ηb, hemoglobin (Hb) level and RBC deformability, and negatively with NOx level in SCA children. Multivariate linear regression model showed that both NOx and Hb levels were independently associated with SVR in SCA children. In SCC children, only NOx level was associated with SVR. In conclusion, vascular function of SCC children seems to better cope with higher ηb compared to SCA children. Since the occurrence of vaso-occlusive like complications are less frequent in SCC than in SCA children, this finding suggests a pathophysiological link between the vascular function alteration and these clinical manifestations. In addition, our results suggested that nitric oxide metabolism plays a key role in the regulation of SVR, both in SCA and SCC. Show more

Keywords: Blood rheology, nitric oxide, sickle cell disease, vascular function

DOI: 10.3233/CH-121661

Citation: Clinical Hemorheology and Microcirculation, vol. 58, no. 2, pp. 307-316, 2014

Authors: Ruef, P. | Stadler, A.A. | Poeschl, J.

Article Type: Research Article

Abstract: BACKGROUND AND OBJECTIVES: In capillaries with diameters less than those of resting RBCs, the cells have to deform to pass through such narrow vessels. Since RBCs of fetuses, neonates and adults differ in their geometrical properties the flow behavior of RBCs with different sizes in uniform tubes with diameters of 3 to 6 μm were studied by means of a micropipette system and a mathematical model. Assumptions in this model include an RBC flow velocity of 1 mm/s, axisymmetric cell shape and a gap between the RBC and the vessel wall that allows sufficient lubrication. The flow resistance depends on …the surface area and volume of RBCs, the plasma viscosity and the vessel diameter. METHODS: Surface area and volume of different RBC populations (20 fetuses, 20 preterm neonates, 10 term neonates and 10 adults) were determined by means of a micropipette system and plasma viscosity was measured using a capillary tube viscometer. The flow behavior of RBCs with different volumes (61, 83 and 127 fl) was studied by direct microscopic observation using a micropipette system. The micropipettes had diameters of 3.5, 4.1, 5.1, and 6.0 μm. The flow velocity of the RBC in the pipettes was 1 mm/s and the calculated and measured cell lengths were compared. RESULTS: Volume and surface area of RBCs were 140 ± 29 fl and 172 ± 20 μm2 , respectively, in the fetuses, decreased with increasing maturity (term neonates: 110 ± 20 fl and 149 ± 18 μm2 ) and reached the lowest values in adults (93 ± 14 fl and 136 ± 12 μm2 ). Plasma viscosities increased with increasing maturity due to rising plasma protein concentrations. The flow model leads to the following conclusions: During the passage of 3- to 6-μm vessels, the large fetal and neonatal RBCs are more elongated than the smaller adult RBCs. The critical vessel diameter, i.e., when the rear of the RBC becomes convex during passage of a narrow capillary, was 4.1 μm for fetal RBCs, 3.6 μm for neonatal RBCs and 3.3 μm adult cells. Suspended in the same medium, fetal and neonatal RBCs require 27% (term neonates) to 100% (fetuses) higher driving pressures than adult RBCs to achieve the necessary elongation for passing through a 4.5-μm capillary. However, the different RBCs require similar driving pressures if the cells are suspended in the corresponding autologous plasma. Cell lengths of the RBCs with different geometry determined during the flow experiments agreed with the predicted values. CONCLUSION: We conclude that the large size of fetal and neonatal RBCs may cause impaired flow in narrow vessels with diameters below the critical values of 3.6 to 4.1 μm. In vessels with diameters above the critical diameter (Dcr ), the disadvantage of the large size of neonatal and fetal RBCs appears to be completely compensated for by the lower plasma viscosity. Show more

Keywords: Capillaries, RBC, neonate, fetus, axisymmetric flow

DOI: 10.3233/CH-121667

Citation: Clinical Hemorheology and Microcirculation, vol. 58, no. 2, pp. 317-331, 2014

Authors: Kianian, Mandana | Kelly, Melanie E.M. | Zhou, Juan | Hung, Orlando | Cerny, Vladimir | Rowden, Geoffrey | Lehmann, Christian

Article Type: Research Article

Abstract: INTRODUCTION: Impairment of the intestinal microcirculation in endotoxemia may cause a deterioration of the mucosal barrier function thus releasing intraluminal bacteria and their toxins into the systemic circulation. In clinical sepsis this mechanism may influence disease severity and outcome. The aim of the study was to investigate the impact of cannabinoid receptor 1 (CB1R) modulation within the intestinal microcirculation with regard to leukocyte activation and capillary perfusion, and on intestinal histology in experimental endotoxemia in rats. METHODS: Endotoxemia was induced by intravenous lipopolysaccharide (LPS) administration. We studied 5 groups of animals: controls (CON), LPS, LPS + CB1R agonist (ACEA, 2.5 …mg/kg), LPS + CB1R antagonist (AM281, 2 mg/kg) and LPS + CB1R agonist (ACEA, 2.5 mg/kg) + CB1R antagonist (AM281, 2 mg/kg). Intestinal intravital microscopy (IVM) was performed two hours following LPS/placebo administration. Intestinal leukocyte adhesion in submucosal venules and functional capillary density (FCD) of the intestinal wall was quantified using IVM. Histological changes were assessed using a standardized injury score. RESULTS: After two hours of endotoxemia, we observed a significant increase of leukocyte adhesion in intestinal submucosal venules. Administration of the CB1R antagonist in endotoxemic animals significantly reduced the number of adhering leukocytes (p < 0.05). The CB1R agonist did not further increase leukocyte adhesion. FCD was significantly improved by the CB1R antagonist (p < 0.05). Administration of the CB1R agonist, ACEA, reversed the beneficial effect of the CB1R antagonist, AM281. CONCLUSIONS: CB1R inhibition significantly improved intestinal microcirculation by reducing leukocyte adhesion and increasing FCD in acute endotoxemia in rats. The data supports the involvement of the CB1R signaling in leukocyte activation during sepsis. Drugs targeting the CB1R may have therapeutic potential in systemic inflammation, such as sepsis. Show more

Keywords: Sepsis, endotoxemia, microcirculation, intravital microscopy, intestine, leukocyte adherence, cannabinoid receptor

DOI: 10.3233/CH-131668

Citation: Clinical Hemorheology and Microcirculation, vol. 58, no. 2, pp. 333-342, 2014

Authors: Rennert, Janine | Farkas, Stefan | Georgieva, Martina | Loss, Martin | Dornia, Christian | Jung, Wolfgang | Stroszczynski, Christian | Jung, Ernst-Michael

Article Type: Research Article

Abstract: AIM: Identification of acute and subacute complications following pancreas and renal transplantation using contrast enhanced ultrasound (CEUS) in comparison with Magnetic Resonance Tomography (MRI), Computed Tomography (CT), Digital Subtraction Angiography (DSA) or Ultrasound (US). The study evaluated whether CEUS could confirm the preliminary diagnosis or even provide additional information, relevant for the therapeutic strategy. MATERIAL AND METHODS: Retrospective evaluation of 19 patients (13 male, 6 female, age 26–77 years, mean 53.2 years) following renal transplantation and 10 patients (4 male, 6 female, age 35–56 years, mean 45.7 years) following combined pancreas and renal transplantation. CEUS was used as an additional …diagnostic method when obscure diagnostic findings occurred in US, CT, MRI or DSA. Fundamental B-scan, Color Coded Doppler Sonography (CCDS) and CEUS were performed in all patients by an experienced examiner using a multifrequency convex transducer (1–5 MHz). After a bolus injection of up to 2.4 ml SonoVue® [BRACCO, Italy] digital raw data was stored as cine-loops up to 5 minutes in length. RESULTS: In all patients, the pathological features and suspected diagnostic findings identified in the other imaging modalities could be confirmed using CEUS (100%). In 25 out of 29 patients (86.2%), new clinically relevant findings were detected. In 27 patients, the diagnosis of CEUS was confirmed during surgery (7), DSA (5), follow-up CEUS (13), CT (1) and MRI (1). In 4 patients renal AV-fistulas were found following biopsy, 3 patients showed post-operative allograft arterial stenosis or dissection, 1 patient demonstrated a stenosis of the common iliac artery and 2 patients were diagnosed with post-operative allograft venous thrombosis or stenosis. In 2 patients, a definite diagnosis of a benign lesion following renal transplantation was possible. In 1 patient a malignant lesion was suspected and confirmed following surgery. In 6 patients, normal perfusion of the pancreas and renal parenchyma and the corresponding vessels was diagnosed, in 5 patients the parenchymal perfusion was diminished and 1 patient suffered from pancreatitis. CONCLUSION: These first results show that CEUS can provide additional, clinically relevant informations in patients with acute and subacute complications following pancreas and renal transplantation. Thus, an early application within the diagnostic course seems favorable. Show more

Keywords: Contrast enhanced ultrasound (CEUS), pancreas transplantation, renal transplantation, complications

DOI: 10.3233/CH-131675

Citation: Clinical Hemorheology and Microcirculation, vol. 58, no. 2, pp. 343-352, 2014

Authors: Hsiu, Hsin | Huang, Shih-Min | Chen, Chao-Tsung | Hsu, Wei-Chen | Lin, Fong-Cheng

Article Type: Research Article

Abstract: Walking can help improve the recovery after stroke. The present study used skin-surface laser-Doppler flowmetry (LDF) measurements and beat-to-beat waveform analysis with the aim of discriminating the microcirculatory blood flow (MBF) characteristics in stroke subjects subdivided into two groups according to their walking ability. Five-minute LDF measurements were performed in the following groups: Group A (cannot walk independently; n = 17), Group B (can walk independently; n = 11), and Group C (healthy controls; n = 17). The pulse width (PW) and foot delay time (FDT) and their coefficients of variation (PWCV and FDTCV, respectively) were calculated for the beat-to-beat …LDF waveform. The FDT in Group A and the blood-pressure-normalized PW in Group C were significantly longer than the corresponding values in the other groups, and PWCV and FDTCV were significantly larger in Group C than in Group A. To our knowledge this is the first study demonstrating the feasibility of using a beat-to-beat LDF waveform index to discriminate between stroke subjects with different walking abilities and between stroke and normal subjects. It provides a noninvasive and real-time method for discriminating MBF characteristics, and thus could aid the development of an index for the early detection of stroke or for evaluating the recovery condition in stroke patients. Show more

Keywords: Stroke, laser Doppler, beat-to-beat

DOI: 10.3233/CH-131679

Citation: Clinical Hemorheology and Microcirculation, vol. 58, no. 2, pp. 353-362, 2014

Authors: Wei, Xi | Li, Ying | Zhang, Sheng | Xin, Xiao J. | Zhu, Lei | Gao, Ming

Article Type: Research Article

Abstract: OBJECTIVE: To explore the role of contrast-enhanced ultrasound (CEUS) in the early evaluation of microvacularization in patients with aggressive B-cell lymphoma treated by R-CHOP. MATERIALS AND METHODS: Fifty-two patients with aggressive B-cell lymphoma underwent combined rituximab-CHOP treatment (CHOP: cyclophosphamide, hydroxydaunomycin, vincristine, prednisonetreatment). Before the treatment and after the first two cycles of R-CHOP, CEUS was performed to assess the microvascularization of tumors. In addition, PET/CT examination was also included in this study before and after the treatment. Ideal cut-off value of CEUS parameters was calculated using receiver-operating characteristic (ROC) curve analysis to predict the treatment outcome. The response to treatment, …progression-free survival (PFS) and overall survival (OS) were then compared according to PET/CT and CEUS results. The correlation between CEUS parameters and PET/CT results was investigated based on these analyses. RESULTS: All patients were non-Hodgkin lymphomas (NHL) with CD20 positive. The variations of CEUS parameters (peak intensity and mean intensity) at the mid-term of R-CHOP treatment significantly associated with results of treatment response (P < 0.001), and were also positive correlation with PET/CT results (P = 0.001). The CEUS positive or negative results were determined by cut-off points of peak intensity and mean intensity (4.70 and 4.15dB). The median time of clinical follow-up was 35.4 months. Kaplan-Meier survival analysis demonstrated that PET/CT and CEUS were both good predictors for PFS and OS rate in these patients. CONCLUSION: As a microvascular imaging modality, CEUS could be a feasible tool to predict the survival rate of patients with aggressive B-cell lymphoma after R-CHOP treatment. Show more

Keywords: Aggressive B-cell lymphoma, CEUS, microvascularization, PET/CT, R-CHOP treatment

DOI: 10.3233/CH-131773

Citation: Clinical Hemorheology and Microcirculation, vol. 58, no. 2, pp. 363-376, 2014

Authors: Vayá, Amparo | Sarnago, Ana | Suescun, Marta | Camara, Rosa | Laiz, Begoña

Article Type: Other

DOI: 10.3233/CH-141853

Citation: Clinical Hemorheology and Microcirculation, vol. 58, no. 2, pp. 377-379, 2014

Authors: Fuster, Óscar | Vayá, Amparo | Giménez, Cristina | Todolí, José | Hernández, José L. | Laiz, Begoña

Article Type: Other

DOI: 10.3233/CH-141864

Citation: Clinical Hemorheology and Microcirculation, vol. 58, no. 2, pp. 381-384, 2014