Clinical Hemorheology and Microcirculation - Volume 64, issue 4

Authors: Priezzhev, A. | Lee, K.

Article Type: Research Article

Abstract: Laser trapping and manipulation of blood cells without mechanical contact have become feasible with implication of laser tweezers. They open up new horizons for the hemorheologic researches, offer new possibilities for studying live cells interactions on individual cell level under the influence of different endogenous and exogenous factors. The operation principle of laser tweezers is based on the property of strongly focused laser beam to act on a dielectric microparticle located in the vicinity of the beam waist with a force that drives the particle to the equilibrium location and holds it there. If the beam waist position is manipulated, …so is the position of the particle. The displacement of the particle from the equilibrium position by external forces can be calibrated so that these forces can be precisely measured in the range ca. 0.1–100 pN. This is the range of forces of elastic deformation of blood cells and of their interaction with each other and with vessel walls. Being able to measure these forces without mechanical contact allows for studying on single cell level the mechanisms of interactions that was impossible earlier. Here we discuss the basic features of these techniques and give some examples of challenging hemorheologic studies. Show more

Keywords: Red blood cell, interaction, aggregation, critical shear stress, temperature, shearing-geometry, single-cell level measurements, optical tweezers, microfluidic flow

DOI: 10.3233/CH-168030

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 587-592, 2016

Authors: Brun, Jean-Frédéric | Varlet-Marie, Emmanuelle | Fédou, Christine | Raynaud de Mauverger, Eric

Article Type: Research Article

Abstract: Equations of blood viscosity provide a prediction of the ‘optimal’ hematocrit’ (hct) as the hct resulting in the highest value of the bell-shaped curve of hematocrit/viscosity ratio h/η. We investigated if overweight and obesity have an influence on these parameters. We compared 32 normal weight subjects, 40 overweight (BMI 25–30) and 38 obese subjects. There was no difference in the theoretical curve of h/η. The actual h/η is the same in the 3 groups but is always higher than the theoretical h/η in all groups. The actual h/η is lower in overweight than controls (p  = 0.011). Modeling yields the same value …of theoretical optimal hct across BMI classes. The 3 groups have the same values of actual hct, but actual is significantly lower than optimal in all cases (p  < 0.001). Hematocrit is lower than predicted due to a discrepancy between predicted and actual h/η which is due to the inter-subject variability of RBC rigidity ...   The discrepancy between optimal and actual h/η is negatively correlated to RBC rigidity indexes even if the model uses a fixed value of these indexes. Thus keeping in mind that the optimal hct should not be the same in the various parts of the vascular bed, its theoretical prediction with Quemada's equation appears to predict a value higher than actual hematocrit but well correlated to it, and the agreement between optimal and actual hct is dependent on RBC flexibility. This leads to think that the body sets hematocrit below its ideal value in sedentary subjects in order to cope with the need of increasing blood viscosity factors in case of exercise without impairing O2 supply to tissues. Show more

Keywords: Blood viscosity, hematocrit, exercise, erythrocyte deformability, obesity

DOI: 10.3233/CH-168013

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 593-601, 2016

Authors: Varlet-Marie, Emmanuelle | Joré, Céline | Brun, Jean-Frédéric

Article Type: Research Article

Abstract: Bioelectrical impedancemetry (BIA) has been used to evaluate hematocrit and red cell aggregability in vitro but whole body impedance measurements are also correlated to some hemorheologic factors, suggesting a relationship between viscosity factors and electric properties of blood. We repeatedly reported correlations with whole body BIA and hematocrit, whole blood viscosity and plasma viscosity, red cell rigidity and RBC aggregation. The SBIA Inbody 770 modelizes body as 5 cylinders and measures impedance at 1, 5, 50, 250, 500, and 1000 kHz. With the SBIA we found that hematocrit is best correlated to leg reactance at 50 kHz but also to leg …impedance at 1 and 5 kHz and trunk reactance. RBC aggregation “M” is best correlated to arm reactance at 5 kHz but also to most measurements of segmental impedance (28 correlations found). RBC aggregation “M1” is best correlated to arm reactance at 5 kHz and to 19 other impedance measurements. A predictive equation for “M” from the mean between the two arm reactances at 5 kHz (maXc5) is found: M = 2.1845maXc5-23.958 (r  = 0.665, p  < 0.001) that provides a satisfactory Bland-Altman plot (mean difference: 0.000524 range [–1.6;+1.6]. This study suggests that previously reported correlations between BIA and viscosity factors were not spurious, and that in a narrow cylinder such as the arm the structure of circulating blood (hematocrit, red cell aggregation) may influence the passage of an electric current by increasing reactance. Show more

Keywords: Segmental bioelectrical impedance, hematocrit, myrenne aggregometer, red blood cell aggregation, electrical conductance, light transmission

DOI: 10.3233/CH-168041

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 603-611, 2016

Authors: Stoltz, J.-F. | Bensoussan, D. | De Isla, N. | Zhang, L. | Han, Z. | Magdalou, J. | Huselstein, C. | Ye, J.S. | Leballe, B. | Decot, V. | Reppel, L.

Article Type: Research Article

Abstract: Most human tissues do not regenerate spontaneously, which is why “cell therapy” are promising alternative treatments. The Principe is simple: patients’ or donors’ cells are collected and introduced into the injured tissues or organs directly or in a porous 3D material, with or without modification of their properties. This concept of regenerative medicine is an emerging field which can be defined as “the way to improve health and quality of life by restoring, maintaining, or enhancing tissue and organ functions ”. There is an extraordinarily wide range of opportunities for clinical applications: artheropathies, diabetes, cartilage defects, bone repair, …burns, livers or bladder regeneration, organs reconstruction (lung, heart, liver ...) neurodegenerative disorders, sepsis ...   Different stem cells (SC) with different potential can be used and characterised (totipotent, mesenchymal of different origins, especially those present in tissues...). Today it is undeniable that cells like bone marrow, adipose tissue or Wharton Jelly stem cells, are of potential interest for clinical applications because they are easily separated and prepared and no ethical problems are involved in their use. In this paper some potential clinical applications in the vascular field are considered: peripheral arteriopathy in diabetic patients, cardiac insufficiency, traitment of erectile dysfunction, or organ regeneration with liver as example. But the regeneration of tissue or organ is and will remain a challenge for the future development of cell therapy. Many problems remain to be solved that could lead to the development of innovative strategies to facilitate cell differentiation, increase the yield of cells and ensure a standardised product, overcome the risks of teratogenic effects and/or immune reactions, enable grafting via direct cell or biotissue transplantation and avoid legal issues involved in national regulations. Show more

DOI: 10.3233/CH-168036

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 613-633, 2016

Authors: Tikhomirova, Irina | Petrochenko, Elena | Malysheva, Yulia | Ryabov, Mihail | Kislov, Nikolay

Article Type: Research Article

Abstract: Cancer progression is associated with activation of blood coagulation. Blood coagulation process, platelet hemostasis and hemorheological properties were evaluated in patients with solid tumors (n  = 27) before and after surgery and in healthy control (n  = 20). The main features of blood coagulation process in cancer patients were elevated intensity and shortened period of contact phase of coagulation and inhibited fibrinolysis stage. Such prothrombotic state was fixed before surgery as well as in early postoperative period in spite of preventing thromboprophylactic treatment. Platelets depletion within the high level of spontaneous and ADP-induced platelet aggregation was fixed in cancer. The main cause …of blood viscosity decrease in cancer patients was dramatic fall of Hct, because blood viscosity adjusted by Hct 40% was increased owing to the rise of plasma viscosity and substantially worsened RBC microrheological properties. The results of our study indicated close correlation between hemorheological and hemostasis parameters; these interrelations were more numerous and strong in cancer. In cancer patients the combination of a high aggregation activity of platelets, reduced number of erythrocytes (Hct), an increase of RBC aggregation and plasma viscosity caused impairment of blood oxygen transportation efficacy that provoke hypoxia in the microcirculation favoring thrombosis, settlement of tumor and metastasis. Show more

Keywords: Hemorheology, blood coagulation, platelet hemostasis, cancer, surgery

DOI: 10.3233/CH-168037

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 635-644, 2016

Authors: das Graças Coelho de Souza, Maria | Kraemer-Aguiar, Luiz Guilherme | Bouskela, Eliete

Article Type: Research Article

Abstract: Obesity is a crescent epidemic in the world, affecting more than half a billion of adults worldwide. Obesity is associated to main cardiovascular risk factors, such as insulin resistance, type 2 diabetes mellitus, high blood pressure and dyslipidemia. The excessive adiposity causes a dysregulation of adipokines secretion by adipose tissue, upregulating the expression of pro-inflammatory adipokines and downregulating the anti-inflammatory ones. This scenario contributes for the appearance of atherosclerosis. Since endothelium dysfunction is considered the earliest known marker of the atherosclerotic process, several methods to assess precociously the manifestations of endothelial dysfunction in microvessels, such as venous occlusion plethysmography, laser …Doppler flowmetry and nailfold videocapillaroscopy, have been developed. Clinical and experimental studies have shown an impairment of microvascular function, capillary rarefaction and increase in inflammatory status in obesity and the introduction of lifestyle modifications, mainly physical activity and diet, constitute effective interventions to restore microvascular function in obesity. Show more

Keywords: Obesity, adipokines, inflammation, endothelial dysfunction, microvascular function assessment, cardiovascular risk

DOI: 10.3233/CH-168018

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 645-654, 2016

Authors: Lehmann, Christian | Fisher, Nicholas B. | Tugwell, Barna | Szczesniak, Anna | Kelly, Mel | Zhou, Juan

Article Type: Research Article

Abstract: BACKGROUND: Destruction of the insulin-producing beta cells in type 1 diabetes (T1D) is induced by invasion of immune cells causing pancreatic inflammation. Cannabidiol (CBD), a phytocannabinoid, derived from the plant, Cannabis sativa, was shown to lower the incidence of diabetes in non-obese diabetic (NOD) mice, an animal model of spontaneous T1D development. OBJECTIVE: The goal of this study was to investigate the impact of experimental CBD treatment on early pancreatic inflammation in T1D by intravital microscopy (IVM) in NOD mice. METHODS: Seven-week-old female NOD mice were prophylactically administered daily 5 mg/kg CBD or control vehicle …i.p. five times weekly for ten weeks. Animals underwent IVM following confirmation of T1D diagnosis by blood glucose testing. Leukocyte activation and functional capillary density (FCD) were quantified via IVM. RESULTS: CBD-treated NOD mice developed T1D later and showed significantly reduced leukocyte activation and increased FCD in the pancreatic microcirculation. CONCLUSIONS: Experimental CBD treatment reduced markers of inflammation in the microcirculation of the pancreas studied by intravital microscopy. Show more

Keywords: Type 1 diabetes, inflammation, intravital microscopy, leukocyte adherence, functional capillary density, cytokines, adhesion molecules

DOI: 10.3233/CH-168021

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 655-662, 2016

Authors: Lenasi, Helena | Klonizakis, Markos

Article Type: Research Article

Abstract: Diabetes mellitus (DM) is associated with cardiovascular complications. Impairment of glycemic control induces noxious glycations, an increase in oxydative stress and dearangement of various metabolic pathways. DM leads to dysfunction of micro- and macrovessels, connected to metabolic, endothelial and autonomic nervous system. Thus, assessing vascular reactivity might be one of the clinical tools to evaluate the impact of harmful effects of DM and potential benefit of treatment; skin and skeletal muscle microcirculation have usually been tested. Physical exercise improves vascular dysfunction through various mechanisms, and is regarded as an additional effective treatment strategy of DM as it positively impacts glycemic …control, improves insulin sensitivity and glucose uptake in the target tissues, thus affecting glucose and lipid metabolism, and increases the endothelium dependent vasodilation. Yet, not all patients respond in the same way so titrating the exercise type individualy would be desirable. Resistance training has, apart from aerobic one, been shown to positively correlate to glycemic control, and improve vascular reactivity. It has been prescribed in various forms or in combination with aerobic training. This review would assess the impact of different modes of exercise, the mechanisms involved, and its potential positive and negative effects on treating patients with Type I and Type II DM, focusing on the recent literature. Show more

Keywords: Diabetes, exercise, aerobic training, resistance training, high intensity interval training, microcirculation, laser Doppler fluxmetry

DOI: 10.3233/CH-168022

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 663-678, 2016

Authors: Carelli-Alinovi, Cristiana | Dinarelli, Simone | Girasole, Marco | Misiti, Francesco

Article Type: Research Article

Abstract: Our attention is focused on the study of a new model based on the red blood cell (RBC) and on its interaction with amyloid beta peptide 1-42 (Aβ). RBC are highly deformable to assist blood flow in the microcirculation. For this reasons RBC abnormalities could contribute to Alzheimer’s disease (AD) by obstructing oxygen delivery to brain, causing hypoxia. In our work, considering that RBC membrane contains, among blood elements, higher acetylcholinesterase (AChE) levels, we can assume that in blood occurs a mechanism similar to the one which occurs at the neuronal level leading to an increase of Aβ toxicity mediated …by its binding with AChE, located on the RBC external face. Furthermore, since mechanical properties of RBC membrane are regulated by a number of molecular components of signalling and/or regulatory pathways, of these, particular interest has been addressed toward Nitric Oxide (NO) metabolism, due to its dependence to AChE. Show more

Keywords: Amyloid beta peptide, red blood cell, nitric oxide synthase, acetylcholinesterase, NO metabolites, Alzheimer disease

DOI: 10.3233/CH-168047

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 679-687, 2016

Authors: Pfister, Karin | Kasprzak, Piotr M. | Jung, Ernst M. | Müller-Wille, René | Wohlgemuth, Walter | Kopp, Reinhard | Schierling, Wilma

Article Type: Research Article

Abstract: PURPOSE: To evaluate the organ microvascularization after operative versus endovascular treatment of visceral artery aneurysms (VAAs) by contrast-enhanced ultrasound (CEUS) and colour-coded duplex sonography (CCDS). METHOD AND MATERIALS : Between April 1995 to January 2016, 168 patients (78 males, 90 females; median age: 62 years) were diagnosed with VAAs at our hospital site. 60/168 patients (36%) fulfilled treatment criteria and had either open (29/60, 48%) or endovascular (31/60, 52%) aneurysm repair. Patients’ characteristics and presentations were consecutively reviewed. Technical success and organ microvascularization were determined by CCDS/CEUS and correlated to computed tomography angiography (CTA) or magnetic resonance imaging …(MRI). RESULTS: 18/60 patients (30%) presented with acute bleeding. 16/18 emergency patients (89%) were treated by endovascular means. After emergency treatment, two patients showed segmental liver malperfusion by CEUS and CTA. One small bowel resection had to be performed. 42/60 patients (70%) were electively treated. 27/42 patients (64%) had open and 15/42 (36%) endovascular aneurysm repair. There were no liver or bowel infarctions after elective treatment of hepatic or mesenteric artery aneurysms (n  = 13) in CCDS/CEUS and in CTA. Treatment of patients with splenic or renal artery aneurysms led to partial or complete organ loss in 42% (8/19) after operative and in 50% (5/10) after endovascular treatment (p  < 0.05). CONCLUSION: The endovascular approach is the preferred therapeutic option in emergency to control bleeding. In contrast to hepatic or mesenteric procedures, patients for elective splenic or renal artery aneurysm repair have to be evaluated very carefully because of a high rate of partial or complete organ loss demonstrated by CEUS – either after open or endovascular aneurysm repair. Show more

Keywords: Visceral artery aneurysms, open repair, endovascular treatment, contrast-enhanced ultrasound, organ microvascularization

DOI: 10.3233/CH-168003

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 689-698, 2016