Clinical Hemorheology and Microcirculation - Volume 64, issue 4

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

Article Type: Research Article

Abstract: We investigated to what extent a prediction of the ‘ideal’ hematocrit based on individual hemorheological profile with an equation of viscosity is relevant in trained athletes, and how the agreement between theoretical and actual values is modified by changes in training volume and performance. Elite soccer players (national level: 18–32 yr, weight 61–83 kg, body mass index 20.9–25.8 kg/m2 ) were seen twice at one year interval. Hemorheologic parameters were measured with the MT90 viscometer and the Myrenne aggregometer the theoretical bell-shaped curve of hematocrit/viscosity ratio as a function of hematocrit was reconstructed with Quemada’s equation using actual plasma viscosity and red cell rigidity to …predict hematocrit/viscosity at various hematocrit levels. RBC aggregation is correlated at baseline with fat mass (M1 = 0.552 p  < 0.02) and changes in aggregation are related to changes in fat mass (M = 0.652, p  < 0.05; M1 = 0.647, p  < 0.05). Predicted and actual hematocrit are correlated (r  = 0.644, p  < 0.05) but exhibit discrepancies (mean difference –1% range [3.24 to 1.24]) and those discrepancies are inversely correlated to the level of predicted hematocrit (r  = –0.912, p  < 0.01), to systolic blood pressure (r  = –0.626, p  < 0.05), and to the overtraining score (r  = –0.693, p  < 0.05). After one year changes in hematocrit are a close reflect of the change in training volume (r  = –0.877, p  < 0.01) but are not correlated to fitness changes. Therefore in these athletes i) systemic hematocrit is close to its predicted ‘ideal value”, suggesting the accuracy of the prediction; ii) red cell aggregation is correlated to fat mass even in nonobese subjects; iii) hematocrit is lower than predicted by the model when markers of sympathetic tone (systolic blood pressure, overtraining score) are increased; iv) weekly training volume appears the main determinant of the reduction of hematocrit. Show more

Keywords: Exercise, soccer, hematocrit/viscosity ratio, hemorheology, erythrocyte aggregation

DOI: 10.3233/CH-168014

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 799-808, 2016

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

Article Type: Research Article

Abstract: Erythropoietin (EPO) is a major regulator of blood viscosity. Its long lasting action analogue methoxy polyethylene glycol-epoetin-β (MIRCERA® ) seems to be also employed in modern doping. We took the opportunity of a study aiming at developing a detection of recent MIRCERATM injection in the context of doping detection to assess the effects of this EPO analogue on red blood cells (RBC) aggregation. A single dose 200 μg of MIRCERA® was injected to 10 male volunteers and blood samplings were drawn over 24 days. After injection a decrease in mean corpuscular volume at day 2 (p  < 0.01) and day 10 (p  < 0.02), a rise …in reticulocyte count (p  < 0.001) between day 4 and day 17 and a decrease in ferritin a day 5 (p  < 0.05) was observed. Hemoglobin decreased at day 4 (p  < 0.005). Hematocrit was unchanged. There was a dramatic (+67%) increase in RBC aggregation index “M” (from 9.49±1.01 to 17.66±1.8, p  < 0.01). A decrease in systolic blood pressure was observed during the period from day 4 to day 17 (at day 10: –11.90±2.28 mmHg, p  < 0.001; at day 17: –15.80±2.83, p  < 0.001). There was also a decrease in diastolic blood pressure, mean and pulse pressure. Correlations between this decrease in blood pressure and “M” did not reach significance but pulse pressure was positively correlated to “M” (r  = 0.743, p  < 0.05). These data show that the long acting erythropoietin analogue MIRCERA® strongly increases RBC aggregation parallel to a decrease in blood pressure, but a possible causative link between the two events is not clearly evidenced. Show more

Keywords: Blood viscosity, hematocrit, exercise, erythrocyte deformability

DOI: 10.3233/CH-168015

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 809-816, 2016

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

Article Type: Research Article

Abstract: We investigated whether the concept of hematocrit/viscosity (h/η ) ratio explains the “paradox of hematocrit in athletes”, by calculating a “theoretical optimal hematocrit” (i.e., associated with the higher h/η value predicted with Quemada’s equation from plasma viscosity, and erythrocyte rigidity index) before and after exercise. 14 rugby players (19–31 yr; weight 65.8–109.2 kg; height 1.7–1.96 m; BMI 21.7–33.1 kg/m2 ) underwent a standardized submaximal exercise session on cycloergometer corresponding to 225 kjoules over 30 min. The rheologic response to exercise was measured with the MT90 viscometer and the Myrenne aggregometer. After exercise there was an increase in whole blood viscosity (p  < 0.05) …and hematocrit (p  < 0.005) and a decrease in h/η ratio (from 14.7±0.34 to 12.9±0.37, p  < 0.005). There was an increase in viscometric RBC rigidity indexes “Tk” and “k” in 9/14 subjects. Predicted and actual h/η are fairly well correlated (preexercise r  = 0.998, p  < 0.001; postexercise r  = 0.985 p  < 0.001) but actual h/η was lower than predicted (preexercise p  = 0.005; postexercise p  = 0.02). This discrepancy between predicted and measured hematocrit was not correlated to dehydration or plasma viscosity but was correlated to red cell rigidity (r  = 0.774, p  < 0.01) and its exercise-induced change (r  = 0.858, p  < 0.01). This study suggests that h/η , although it is not directly correlated to parameters of exercise performance, is precisely regulated during exercise according to the classic concept of “viscoregulation”, and that the prediction of the theoretical optimal values of h/η and hematocrit by models may help to interpret the actual values of these parameters. However, these models need to be more extendedly tested and improved. Show more

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

DOI: 10.3233/CH-168042

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 817-826, 2016

Authors: Ahmadizad, Sajad | Bassami, Minoo | Hadian, Mohsen | Eslami, Maryam

Article Type: Research Article

Abstract: BACKGROUND: Acute effects of continuous exercise on the markers of blood fluidity have been addressed in different populations and the changes are intensity related. However, the effect of different high intensity interval exercise (HIIE) on these variables is unclear. OBJECTIVE: This study is designed to determine the effects of two different HIIE with different work/rest ratios but the same energy expenditure on the main determinants of blood fluidity. METHODS: Ten overweight men (age, 26.3±1.7 yrs) completed two HIIE protocols on two separate occasions with one week intervening. The two HIIE encompassed performing: 1) 6 intervals …of 2 min activity at 85% of VO2max interspersed by 2 min active recovery at 30% of VO2max (ratio 1 to 1, HIIE1/1 ), and 2) 6 intervals of 30 s activity at 110% of VO2max interspersed by 4 min active recovery at 40% of VO2max (ratio 1 to 8, HIIE1/8 ). Each exercise trial was followed by 30 min rest. Venous blood samples were obtained before exercise, immediately after exercise and after recovery and analyzed for blood and plasma viscosity, fibrinogen and red blood cell indices. RESULTS: The HIIE1/1 protocol led to higher reduction (P  < 0.01) in plasma volume changes compared to HIIE1/8 (9.9% vs 5.7%). Moreover, increases in blood viscosity, plasma viscosity, hematocrit, RBC count and mean arterial blood pressure observed following HIIE1/1 were significantly (P  < 0.05) higher than HIIE1/8 ; whereas, the changes in fibrinogen concentration neither were significant in response to both trials nor were significantly different between two protocols (P  > 0.05). However, the changes in all variables during exercise were transient and returned to the baseline levels after 30 min recovery. CONCLUSIONS: It is concluded that the HIIE protocol with lower intensity and shorter rest intervals (higher work to rest ratio) clearly results in more physiological strain than HIIE with higher intensity but longer rest intervals (lower work to rest ratio) in overweight individuals, and that the work to rest ratio could be as important as exercise intensity when considering the hemorheological variables during HIIE. Show more

Keywords: Interval exercise, exercise intensity, blood viscosity, fibrinogen

DOI: 10.3233/CH-168009

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 827-835, 2016

Authors: Antonova, N. | Tsiberkin, K. | Podtaev, S. | Paskova, V. | Velcheva, I. | Chaushev, N.

Article Type: Research Article

Abstract: The aim of the study is to investigate the changes of the skin blood flow responses to cold stress in patients with diabetes mellitus type 2 through wavelet analysis of the peripheral skin temperature oscillations and to estimate their relationship with the blood viscosity values. The amplitudes of the skin temperature pulsations (ASTP) were monitored by “Microtest” device (“FM-Diagnostics”, Russia); the whole blood viscosity and the shear stresses were measured by Contraves LS30 viscometer (Switzerland) at a steady flow in 9 healthy subjects and in 30 patients with type 2 diabetes mellitus. Power law and Herschel-Bulkley (HB) equations were applied …to describe the blood rheology. Both models include consistency (k ) and flow index (m ), and the HB also gives the yield stress (τ 0 ). The Spearman rank correlations between these parameters and the ASTP in the frequency ranges, corresponding to the myogenic, neurogenic and endothelial mechanisms of the microcirculation tone regulation were calculated. The ASTP values decreased when the blood viscosity increased. The correlation analysis revealed good ASTP–m (r  > 0.5) and ASTP–k (r  < –0.5) relationships in the endothelial range, while the ASTP–τ 0 correlation was weaker (r ≈–0.4). These correlations became lower for the ASTP during the cold stress. The results prompt manifestation of endothelial dysfunction in patients with type 2 diabetes. Show more

Keywords: Diabetes mellitus type 2, skin temperature oscillations, contralateral cold test, microcircular tone regulation, blood viscosity, hemorheological equations

DOI: 10.3233/CH-168000

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 837-844, 2016

Authors: Jovtchev, S. | Alexandrov, S. | Hristova-Avakumova, N. | Miteva, S. | Traikov, L. | Gerasimova, D. | Stoeff, S.

Article Type: Research Article

Abstract: BACKGROUND: Different colloids are used as a part of solutions for fluid resuscitation and organ preservation: hydroxyethyl starches (HES), dextran (Dx), polyethylene glycols (PEG), polyvinyl pyrrolidone (PVP). Some of the problems associated with their application are addressed to alteration in erythrocyte (ERY) rheology. OBJECTIVE: We intended to estimate in vitro and compare the aggregation power (AP) of these molecules related to ERY interactions. METHODS: Washed human ERY are used during the study. The zeta sedimentation technique is used to quantify the cell aggregation. Zeta sedimentation ratio (ZSR) based indices (AI) are calculated. The hydrodynamic …radius (Rh ) of the polymer molecules is determined using viscometry. RESULTS: For all polymers tested a linear range in the relationship AI – concentration was found. The slope of the calculated line was interpreted as measure of the molecule’s AP. The following ranking was obtained: PEG >PVP >DX >HES. Within the same chemical type of polymer, increasing Rh of the molecules leads to elevated AI. Comparison of the AP of molecules with similar Rh reveals a significant dependence on their chemical nature. CONCLUSIONS: Our results show that molecule’s AP is significantly dependent on their chemical nature – i.e. not only molecular size does matter. Show more

Keywords: Erythrocyte, aggregation, polymer, Zeta sedimentation ratio, hydrodynamic radius

DOI: 10.3233/CH-168019

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 845-851, 2016

Authors: Lee, K. | Priezzhev, A. | Shin, S. | Yaya, F. | Meglinski, I.

Article Type: Research Article

Abstract: BACKGROUND: The novel measure of the red blood cells (RBC) aggregation (RBC-A) – the critical (minimum) shear stress (CSS) to prevent the cells from aggregation was found to be a promising clinically significant parameter. However, the absolute values of this parameter were found to change significantly depending on the shearing geometry (cup-and-bob, cone-plate or microchannel-flow) and have different temperature dependences along with it. The direct confirmation of these dependences aimed to find out the correct values is still pending. OBJECTIVE: In this work, we aim to assess the absolute values of CSS at different temperatures. METHODS: …The single cell level measurements of CSS were performed using optical tweezers. The measurements were carried out in heavily diluted suspensions of RBCs in plasma. RESULTS: The temperature dependent changes in CSS were measured at the points (22 and 38°C), in which the cup-and-bob and cone-plate systems yielded about 1.5-fold different values, while the microchannel-flow system yielded a constant value. The single cell CSS were found to be 362±157 mPa (22°C) and 312±57 mPa (38°C). CONCLUSIONS: Our results prove that the microfluidic-flow approach is reflecting the RBC-A correctly. While the CSS values measured with other systems show the temperature dependent effect of the shearing geometry. Show more

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

DOI: 10.3233/CH-168020

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 853-857, 2016

Authors: Silva, Marisa | Vargas, Sofia | Coelho, Andreia | Dias, Alexandra | Ferreira, Teresa | Morais, Anabela | Maia, Raquel | Kjöllerström, Paula | Lavinha, João | Faustino, Paula

Article Type: Research Article

Abstract: Sickle cell anemia (SCA) is an autosomal recessive disease caused by the HBB:c.20A>T mutation that leads to hemoglobin S synthesis. The disease presents with high clinical heterogeneity characterized by chronic hemolysis, recurrent episodes of vaso-oclusion and infection. This work aimed to characterize by in silico studies some genetic modulators of severe hemolysis and stroke risk in children with SCA, and understand their consequences at the hemorheological level. Association studies were performed between hemolysis biomarkers as well as the degree of cerebral vasculopathy and the inheritance of several polymorphic regions in genes related with vascular cell adhesion and vascular …tonus in pediatric SCA patients. In silico tools (e.g. MatInspector ) were applied to investigate the main variant consequences. Variants in vascular adhesion molecule-1 (VCAM1 ) gene promoter and endothelial nitric oxide synthase (NOS3 ) gene were significantly associated with higher degree of hemolysis and stroke events. They potentially modify transcription factor binding sites (e.g. VCAM1 rs1409419_T allele may lead to an EVI1 gain) or disturb the corresponding protein structure/function. Our findings emphasize the relevance of genetic variation in modulating the disease severity due to their effect on gene expression or modification of protein biological activities related with sickled erythrocyte/endothelial interactions and consequent hemorheological abnormalities. Show more

Keywords: Sickle cell anemia, VCAM1, NOS3, genetic modulators, in silico analysis

DOI: 10.3233/CH-168048

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 859-866, 2016

Authors: Krüger-Genge, A. | Fuhrmann, R. | Jung, F. | Franke, R.P.

Article Type: Research Article

Abstract: The endothelialization of cardiovascular prostheses is known to improve their haemocompatibility. As such body-foreign materials often do not endothelialize spontaneously. A lot of in vitro studies are ongoing how endothelialization of biomaterials can be improved. In this study the influence of different components of a tissue-typical extracellular matrix (ECM) like laminin, fibronectin or gelatin on the formation of an endothelial cell monolayer and on the shear resistance of adherent cells on these substrates was studied. The study revealed that the density of human venous endothelial cells (HUVEC) monolayers differed markedly between cells grown on a natural ECM and …cells grown on singularized components of an ECM (p  < 0.001). Only HUVEC grown on laminin showed similar densities and a stress fiber pattern comparable to HUVEC grown on the ECM. HUVEC grown on gelatin- or fibronectin-coated coverslips were less firmly attached to the substrate; frequently individual HUVEC and even groups of cells detached. Concluding it seems that coating of implants with laminin supports the formation of shear resistant endothelial cell (EC) monolayer - superior to other ECM components. Show more

Keywords: HUVEC, extracellular matrix, laminin, fibronectin, gelatin

DOI: 10.3233/CH-168051

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 867-874, 2016

Authors: Rozanovic, Martin | Csontos, Csaba | Bogár, Lajos | Szélig, Lívia | Bocskai, Tímea | Kovács, Patrícia | Matancic, Marianna | Miseta, Attila | Loibl, Csaba

Article Type: Research Article

Abstract: BACKGROUND: In polytrauma and burn injury Systemic Inflammatory Response Syndrome (SIRS) develops. SIRS is presented in many hospitalized patients, including those who never develop infection or sepsis. Both in SIRS and sepsis the leukocyte activation occurs. In acute phase reaction leukocytes’ upward flotation i.e. leukocyte antisedimentation rate (LAR) can indicate infectious origin. OBJECTIVE: To evaluate the predictive power of LAR, serum C-reactive protein (CRP) and procalcitonin (PCT) levels regarding mortality risk and development of septic complications. METHODS: In a prospective, observational study, 36 patients were followed for 5 days (T1-T5) after admission to a critical …care unit immediately with severe polytrauma or burn injury. Eleven patients developed septic complications, their LAR, CRP and PCT levels were analyzed before and after 3 days of sepsis was declared. RESULTS: Ten patients died due to septic complications. In survivors LAR at T1 (p  < 0.001) and T2 (p  < 0.001) as well as CRP at T1 (p  < 0.05) were significantly higher compared to controls and non survivors. In septic patients LAR (p  < 0.05) and CRP (p  < 0.05) showed a significant drop one day before sepsis was declared. PCT levels failed to predict this. CONCLUSIONS: Drop in LAR and CRP levels may be warning signs regarding the onset of septic complications after severe polytrauma and burn injury. Show more

Keywords: Mechanical and heat trauma, inflammatory response, leukocyte antisedimentation rate, C-reactive protein, procalcitonin

DOI: 10.3233/CH-168024

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 875-885, 2016

Authors: Paprottka, Karolin J. | Waggershauser, Tobias | Rübenthaler, Johannes | Paprottka, Felix J. | Clevert, Dirk A. | Reiser, Maximilian F. | Paprottka, Philipp M.

Article Type: Research Article

Abstract: OBJECTIVE: To evaluate various embolization particles on their physical properties with special regard on morphological variability and elasticity. METHODS: 8 embolization particles (EmboCept® , Contour SE® Microspheres, Embosphere® Micorspheres 400 μm, 500 μm, 1300 μm, Embozene® Microspheres, DC Beads® , Embozene Tandem® ) were evaluated and graduated from 1–6 microscopically due to morphologic changes in vitro before, during and after their catheter passage by 4 blinded reviewers. To facilitate comparison, microscopic images were provided with a scale. RESULTS: All tested particles showed a homogenous shape and morphology before passage through the …simulation catheter. During the passage all particles were elastically deformable, where necessary. After the catheter passage no loss of basic shape was seen. Changes in size were found in 5/8 particles. Grading of morphologic changes varied between mean value of 1.0 and 3.0. No complete destruction or loss of function was seen. CONCLUSION: All tested embolization particles are, regarding their morphological properties in sense of homogenous shape and deformation after catheter passage, a safe treatment option. Tested in vitro no less of functionality regarding physical properties should be expected. Show more

Keywords: Embolization particles, physical properties, morphology, elasticity, catheter passage

DOI: 10.3233/CH-168002

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 887-898, 2016

Authors: Roch, Toralf | Kratz, Karl | Ma, Nan | Lendlein, Andreas

Article Type: Research Article

Abstract: Although frequently used as implants materials, both polydimethylsiloxane (PDMS) and polytetrafluoroethylene (PTFE) are often associated with adverse effects including foreign body responses. Dendritic cells (DC) are crucial for the initiation of immune reactions and could also play a role in foreign body associated inflammations. Therefore, the interaction of DC with PDMS and PTFE was investigated regarding their capacity to induce undesired cell activation. Medical grade PDMS and PTFE films were embedded into polystyrene PS inserts via injection molding to prevent the DC from migrating below the substrate and thereby, interacting not only with the test sample but also with the …culture vessel material. The viability, the expression of co-stimulatory molecules, and the cytokine/chemokine profiles were determined after 24 hours incubation of the DC with PDMS or PTFE. Blank PS inserts and tissue culture polystyrene (TCP) served as reference materials. The viability of DC was not substantially influenced after incubation with PDMS and PTFE. However, both polymers induced DC activation indicated by the upregulation of co-stimulatory molecules. The release profiles of 14 soluble inflammatory mediators showed substantial differences between PDMS, PTFE, PS, and TCP. This study showed the potential of PTFE and PDMS to activate primary human dendritic cells, which could be an explanation for the often observed inflammatory events associated with the implantation of these polymers. Show more

Keywords: Biomaterials, dendritic cells, polydimethylsiloxane, polytetrafluoroethylene, cell culture devices

DOI: 10.3233/CH-168033

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 899-910, 2016

Authors: Ahmadizad, Sajad | Nouri-Habashi, Akbar | Rahmani, Hiwa | Maleki, Majid | Naderi, Nasim | Lotfian, Sara | Salimian, Morteza

Article Type: Research Article

Abstract: BACKGROUND: The effects of high intensity interval training (HIIT) on inflammatory markers and endothelial function have been extensively shown. However, the acute effect of HIIT on platelet activation and function in patients with recent revascularization is unclear. OBJECTIVE: The purpose of present study was to compare the responses of platelet activation (CD62P) and function (platelet aggregation) to high intensity interval exercise (HIIE) and moderate continuous exercise (MCE) in coronary artery bypass grafting (CABG) and percutaneous coronary interventions (PCI) patients. METHODS: Thirty patients who had CABG or PCI were randomly divided into HIIE, MCE and control …groups. After determining the VO2peak , subjects in the MCE group carried out 30 min of continuous exercise at 60% of VO2peak , whereas, the subjects in HIIE group performed an interval protocol consisted of 8 repetitions of 2 min activity (running on treadmill) at 90% of VO2peak interspersed by 2 min of active recovery between repetitions at 30% of VO2peak .  Subjects in control group were seated and had no activity for the same period of time. Two blood samples were collected before and immediately after exercise and were analyzed for markers of platelet activation and function. RESULTS: Data analyzes revealed that increases in platelet aggregation induced by ADP and corrected for increases in platelet count in response to MCE trial was significantly lower than HIIE group (P  < 0.05). In addition, responses of CD62P to MCE trial was significantly lower compared to HIIE group (P  < 0.05). Changes in plateletcrit and platelet distribution width were significantly different among the three trials where the PCT and PDW following the HIIE were higher than MCE. Platelet count increased significantly (P  < 0.05) by 13% following HIIE trial. CONCLUSIONS: Based on the findings of the present study it could be concluded that the risk of exercise-induced thrombosis is higher during HIIE than MCE in patients with recent revascularization. Show more

Keywords: Interval exercise, acute exercise, platelet aggregation, p-selectin, CD62P

DOI: 10.3233/CH-168010

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 911-919, 2016

Authors: Basarab, M.A. | Basarab, D.A. | Konnova, N.S. | Matsievskiy, D.D. | Matveev, V.A.

Article Type: Research Article

Abstract: OBJECTIVE: The aim of this work was to develop a novel technique for digital processing of Doppler ultrasound blood flow sensor data from noisy blood flow velocity waveforms. METHODS: To evaluate the fluctuating blood flow parameters, various nonlinear dynamics methods and algorithms are often being used. Here, for identification of chaotic and noise components in a fluctuating coronary blood flow, for the first time the Allan variance technique was used. Analysis of different types of noises (White, Brownian, Flicker) was carried out and their strong correlation with fractality of time series (the Hurst exponent) was revealed. …RESULTS: Based on a specialized software realizing the developed technique, numerical experiments with real clinical data were carried out. Recommendations for identification of noisy patterns of coronary blood flow in normal and pathological states were developed. CONCLUSION: The methodology gives us the possibility for the more detailed quantitative and qualitative analysis of a noisy fluctuating blood flow data. Show more

Keywords: Blood flow, Doppler flowmetry, Allan variance, Hurst exponent, nonlinear dynamics, Alavar

DOI: 10.3233/CH-168011

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 921-930, 2016

Authors: Kumar, Reddi K. | Basu, Sayantani | Lemke, Horst-Dieter | Jankowski, Joachim | Kratz, Karl | Lendlein, Andreas | Tetali, Sarada D.

Article Type: Research Article

Abstract: Accumulated uremic toxins like indoxyl sulphate, hippuric acid and p-cresyl sulphates in renal failure patients stimulate proinflammatory effects, and consequently kidney and cardiovascular diseases. Low clearance rate of these uremic toxins from the blood of uremic patients by conventional techniques like hemodialysis is due to their strong covalent albumin binding (greater than 95%) and hydrophobic nature, which led to alternatives like usage of hydrophobic adsorber’s in removing these toxins from the plasma of kidney patients. Polymers like polyethylene, polyurethane, polymethylmethacrylate, cellophane and polytetrafluoroethylene were already in use as substitutes for metal devices as dialysis membranes. Among new synthetic polymers, one …such ideal adsorber material are highly porous microparticles of poly(ether imide) (PEI) with diameters in the range from 50–180μ m and a porosity around 88±2% prepared by a spraying and coagulation process. It is essential to make sure that these synthetic polymers should not evoke any inflammatory or apoptotic response during dialysis. Therefore in our study we evaluated in vitro effect of PEI microparticle extracts in human aortic endothelial cells (HEACs) concerning toxicity, inflammation and apoptosis. No cell toxicity was observed when HAECs were treated with PEI extracts and inflammatory/apoptotic markers were not upregulated in presence of PEI extracts. Our results ensure biocompatibility of PEI particles and further hemocompatibility of particles will be tested. Show more

Keywords: Poly(ether imide) (PEI), biomaterial, inflammation, apoptosis, medical devices, Tumor necrosis factor-alpha(TNF-α)

DOI: 10.3233/CH-168046

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 931-940, 2016

Authors: Tzoneva, Rumiana | Uzunova, Veselina | Apostolova, Sonia | Krüger-Genge, Anne | Neffe, Axel. T. | Jung, Friedrich | Lendlein, Andreas

Article Type: Research Article

Abstract: Angiogenesis is one of the key processes during development, wound healing and tumor formation. Prerequisite for its existence is the presence of endogenous electrical fields (EFs) generated by active ion transport across polarized epithelia and endothelia, and appearance of the transcellular potentials. During angiogenesis cellular factor as endothelial growth factor (VEGF), synthesis of adhesive proteins and membrane metalloproteinases (MMPs) govern the angiogenic response to different external stimuli as biomaterials interactions and/or exogenous EF. Gelatin-based hydrogels with elasticities comparable to human tissues have shown to influence cell behavior as well as cell attachment, protein synthesis, VEGF and MMP’s production after the …application of EF. Gelatin-based matrices with 3 (G10_LNCO3), 5 (G10_LNCO5), and 8 (G10_LNCO8) fold excess of isocyanate groups per mol of amine groups present in gelatin were used. Human umbilical endothelial cells (HUVEC) (Lonza Basel, Switzerland) and highly invasive breast cancer MDA-MB-231 cells (ATCC®HTB-26TM ) were used. For an estimation of the amount of VEGF released from cells a commercially available VEGF ELISA (Thermo Fisher Scientific, Germany) kit was used. Fibronectin (FN) enzyme immunoassay (EIA) was used to analyze the secreted amount of FN by cells seeded on the materials. Secreted MMPs were analyzed by zymography. Gelatin-based hydrogels attracted HUVEC adhesion and diminished the adhesion of MDA-MB-231 cells. The applied direct current (DC) EF induced an almost 5–fold increase in VEGF production by HUVEC seeded on gelatin-based hydrogels, while in contrast, the applied EF decreased the production of VEGF by cancer cells. FN synthesis was elevated in HUVEC cells seeded on gelatin-based materials in comparison to FN synthesis by cancer cells. HUVEC seeded on gelatin hydrogels showed an expression mainly of MMP-2. The application of EF increased the production of MMP-2 in HUVEC seeded on gelatin materials. In contrast, for MDA-MB-231 the production of MMPs on gelatin materials was lower compared to control materials. With the application of EF the levels of MMP-9 decreased but MMP-2 expression raised significantly for gelatin materials. Overall, the results showed that studied gelatin materials suppressed attachment of cancerous cells, as well as suppressed their angiogenic potential revealed by decreased VEGF and MMP production. Thus, this study approved gelatin-based hydrogels with proper elasticity characteristics and different degradation behavior as useful matrices for use in vascular tissue regeneration or in restriction of tumor growth after tumor resection. Show more

Keywords: Angiogenesis, gelatin hydrogels, VEGF production, FN synthesis, MMPs expression

DOI: 10.3233/CH-168040

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 941-949, 2016

Authors: Duarte, Catarina | Napoleão, Patrícia | Freitas, Teresa | Saldanha, Carlota

Article Type: Research Article

Abstract: INTRODUCTION: Acetylcholinesterase (AChE) is located on outer surface of erythrocyte membrane. Gender-related differences in erythrocyte AChE enzyme activity had been verified in young adults. It is also known that binding of acetylcholine (ACh) with AChE on erythrocyte membrane initiates a signal transduction mechanism that stimulates nitric oxide (NO) efflux. AIMS: This ex vivo study was done to compare the amount of NO efflux obtained from erythrocytes of healthy donors in males and females. METHODS: We included 66 gender age-matched healthy donors (40–60 years old). We performed quantification of erythrocyte NO efflux from erythrocytes and …of the membrane AChE enzyme activity. RESULTS: There are no significant differences in NO efflux from erythrocytes between men and women. Regarding AChE enzyme activity values, in this range of age, no differences between genders were obtained. However, the values of AChE enzyme activity in the third quartile of NO efflux values were significantly higher (p  < 0.05) in women than in men. CONCLUSIONS: The efflux of NO from erythrocyte of healthy humans did not change with gender. For the same range of values of NO efflux from erythrocytes, in both gender, it was verified higher values of AChE enzyme activity in women. Show more

Keywords: Gender, erythrocyte, nitric oxide, acetylcholinesterase

DOI: 10.3233/CH-168023

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 951-955, 2016

Authors: Aguiar, Laura | Matos, Andreia | Gil, Ângela | Afonso, Conceição | Almeida, Salomé | Braga, Lígia | Lavinha, João | Kjollerstrom, Paula | Faustino, Paula | Bicho, Manuel | Inácio, Ângela

Article Type: Research Article

Abstract: BACKGROUND: Sickle cell anemia (SCA) is an inherited blood disorder. SCA patients present clinical and hematologic variability that cannot be only explained by the single mutation in the beta-globin gene. Others genetic modifiers and environmental effects are important for the clinical phenotype. SCA patients present arginine deficiency that contributes to a lower nitric oxide (NO) bioactivity. OBJECTIVE: The aim of this work is to determine the association between hematological and biochemical parameters and genetic variants from eNOS gene, in pediatric SCA patients. METHODS: 26 pediatric SCA patients were genotyped using polymerase chain reaction (PCR) …and restriction fragment length polymorphism (RFLP) techniques in three important eNOS gene polymorphisms - rs2070744, rs1799983 and intron 4 VNTR. RESULTS: Results from this study show a significant statistical association between some parameters and genetic variants: an increased reticulocyte count and high serum lactate dehydrogenase levels were associated with both the rs2070744_TT and the rs1799983_GG genotypes at eNOS gene and high levels of neutrophils were associated with the eNOS4a allele at intron 4 VNTR. CONCLUSIONS: Our results reinforce the importance of NO bioactivity in SCA. We presume that NO, and its precursors might be used as therapy to improve the quality of life of SCA patients. Show more

Keywords: Sickle cell anemia, genetic modifiers, nitric oxide

DOI: 10.3233/CH-168008

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 957-963, 2016

Authors: Napoleão, Patrícia | Potapova, Ekaterina | Moleirinho, Sara | Saldanha, Carlota | Messias, António

Article Type: Research Article

Abstract: AIM: Soluble CD40 ligand (sCD40L) has been considered as a marker of thrombosis and inflammation in several diseases, including sepsis. Recent studies challenge this view and point to a role of sCD40L in vascular and endothelial function. An indication of that association in sepsis has not been obtained so far. Therefore, herein we evaluated association between sCD40L and markers of hemorheology and inflammation on context of septic shock. METHODS: Time-changes of sCD40L levels over 72 hours of Intensive Care Unit (ICU) internment were assessed in 22 patients with septic shock and compared with 36 healthy volunteers. Association of sCD40L …levels with erythrocyte deformability and aggregation (as markers of hemorheology), plasma concentrations of haemoglobin (Hb, as markers of endothelial function) and white blood cells (WBC) count (as marker of low-grade inflammation) were assessed in patients with septic shock. RESULTS: At ICU admission, sCD40L concentrations in patients with septic shock were lower (p  = 0.024) than levels of healthy volunteers. However, sCD40L did not change over 72 hours of internment (F = 2.1, p  = 0.137). Soluble CD40L levels in patients with septic shock at ICU admission correlate with concentrations of Hb (r  = 0.61, p  = 0.00) and WBC count (r  = 0.63, p  = 0.00), but not to erythrocyte deformability (r ≥0.157, p ≤0.235) and aggregation (r ≥–0.109, p ≤0.192). CONCLUSIONS: These results seem to highlight a possible association of sCD40L to endothelial function and inflammation in septic shock context. Show more

Keywords: Sepsis, sCD40L, haemoglobin, inflammation, hemorheology

DOI: 10.3233/CH-168026

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 965-970, 2016

Authors: Napoleão, Patrícia | Freitas, Teresa | Saldanha, Carlota

Article Type: Research Article

Abstract: AIMS: Oxidized low density lipoprotein (ox-LDL) has been reported as an inhibitor of nitric oxide (NO)-mediated dilatation in microcirculation. Oxidized LDL effect on NO metabolism of erythrocytes is not known. Therefore, this study aims to evaluate the effect of ox-LDL on erythrocytes NO metabolism. METHODS: The effect of different concentrations of human purified ox-LDL (25, 50 and 100 μg/mL) on NO metabolism was evaluated on blood of healthy subjects. RESULTS: An inhibitory effect of higher concentrations of ox-LDL on erythrocyte NO efflux levels was verified. Concentrations of NO efflux from erythrocytes were lower as consequence …of treatments with 50 μg/mL ox-LDL treatment (1.6±0.27 nM) and 100 μg/mL ox-LDL treatment (1.3±0.22 nM) than control (1.9±0.28 nM). Opposite, ox-LDL incubation has a positive effect on GSNO content of erythrocytes. That effect is proportional to concentrations of ox-LDL treatments (10.8±1.4 nM for 25 μg/mL, 12.9±1.5 nM for 50 μg/mL and 12.1±1.9 nM for 100 μg/mL) and is significant relative to control (8.56±0.76 μM) and ACh (8.9±0.52 μM) aliquots. CONCLUSIONS: Presence of oxidized LDL in erythrocyte NO metabolism induces a decrease of NO efflux amount and an increase on intra-erythrocyte GSNO concentrations. These results suggest a role of ox-LDL in mobilization of NO between NO derivatives molecules in dependence of oxidized LDL concentration. An anti - reactive nitrogene role can be attributed to ox-LDL for its contribution in the erythrocyte scavenged ability for nitric oxide. Show more

Keywords: Oxidized LDL, erythrocyte, nitric oxide, S-nitrosoglutathione

DOI: 10.3233/CH-168025

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 971-975, 2016

Authors: Melinda, Vass | Ágnes, Diószegi | Norbert, Németh | Viktória, Sógor | Sándor, Baráth | Eszter, Szalai | László, Módis | Soltész, Pál

Article Type: Research Article

Abstract: Rheopheresis is an extracorporal selective double-filtration procedure. In the first part of the treatment the blood is passes through the plasma filter, which separates blood cells from the plasma. Then the plasma flow to a second filter called MONET (Membranefiltration Optimised Novel Extracorporal Treatment). The MONET filter retains high molecular weight proteins such LDL, Lp(a), fibrinogen, α2 macroglobulin, vWF and IgM. Hereby the whole blood and plasma viscosity decrease, improves microcirculation, and has a positive effect on lipid profile as well. Accorging to ASFA recommendation rheopheresis is a first line treatment in age-related dry macular degeneration and in sudden …sensorineural hearing loss. There are other clinical situations in which rheopheresis has been used effectivly. But only few data are available and large clinical trials have not been done in these diseases. In this paper we describe a case history and laboratory findings of a patient who suffers from age related dry macular degeneration and was successfully treated by rheopheresis. Show more

Keywords: Rheopheresis, microcirculation, age-related dry macular degeneration, anti-inflammatory effect, haemorheological parameters

DOI: 10.3233/CH-168004

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 977-987, 2016

Authors: Esteves, Rita | Freitas, Teresa | Teixeira, Pedro | Napoleão, Patrícia | Neves, Carlos | Saldanha, Carlota

Article Type: Research Article

Abstract: BACKGROUND: Glaucoma is an optic neuropathy associated with vascular dysregulation and increased intra-ocular pressure (IOP). Timolol is used as treatment for reducing IOP, by limiting aqueous humour production. Increased NOS expression as well as decreased levels of nitric oxide (NO) metabolites, and high activity of erythrocyte acetylcholinesterase (AChE) were observed in primary open angle glaucoma patients. OBJECTIVE: This ex vivo study aims to evaluate timolol effect in NO efflux and its derivatives in glaucoma patient’s erythrocytes. METHODS: Venous blood from 15 glaucoma patients was collected. Erythrocyte suspensions were incubated with the AChE modulators acetylcholine …(ACh) and timolol at 10 μM. Erythrocyte NO efflux and S-nitrosoglutathione (GSNO) concentration were measured. RESULTS: No significant differences were obtained in erythrocyte NO efflux and GSNO concentration in response to ACh or timolol when compared with the untreated erythrocytes of glaucoma patients. When comparing the same incubation conditions for erythrocyte suspensions between glaucoma patients and healthy subjects, those from glaucoma patients showed higher NO efflux in presence and absence of timolol, and higher values of GSNO in the presence of timolol. CONCLUSIONS: We demonstrated that erythrocytes from glaucoma patients have similar availability to release NO both in absence and presence of timolol, and have higher GSNO values in presence of timolol. Show more

Keywords: Glaucoma, erythocyte, nitric oxide, GSNO, ACh, timolol

DOI: 10.3233/CH-168049

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 989-994, 2016

Article Type: Other

Citation: Clinical Hemorheology and Microcirculation, vol. 64, no. 4, pp. 995-1010, 2016