bluuebunny/crossref_metadata_2025 huggingface dataset:
Tomato juice saponin, esculeoside B ameliorates mice experimental dermatitis
Authors: Zhou Jian-Rong , Urata Jun , Shiraishi Takuya , Tanaka Chiaki , Nohara Toshihiro , Yokomizo Kazumi
Published: December 2019

Background: Allergic diseases like atopic dermatitis have recently increased. A naturally occurring glycoside, Esculeoside B, has been identified as a major component in tomato juice from the can. Accordingly, the present study investigated the effects of esculeoside B on experimental dermatitis mice.Results: Oral treatment with 10 mg/kg of esculeoside B on the experimental dermatitis mice for 4 weeks significantly decreased the skin clinical score of 2.0 compared to the control score of 5.0. Furthermore, the scratch frequency of mice treated with esculeoside B was lower compared to the control group. Overall, the administration of esculeoside B significantly inhibited T lymphocyte proliferation and demonstrated a tendency to decrease in IL-4 production. For example, the 121.2 pg/ml in the control group decreased to 96.1 pg/ml. There was also a decrease in serum IgE levels from 928.0 ng/ml in the control group to 687.8 ng/ml.Conclusion: Our study is the first to demonstrate how tomato juice saponin or esculeoside B may ameliorate mice experimental dermatitis by the inhibition of T cell proliferation.Keywords: tomato juice; experimental atopic dermatitis; IgE; cytokine; tomato saponin; esculeoside B
Mango (Mangifera indica Linn) and Anti-Inflammatory Benefits: Versatile Roles in Mitochondrial Bio-Energetics and Exercise Physiology
Authors: Swaroop Anand , Stohs Sidney J. , Bagchi Manashi , Moriyama Hiroyoshi , Bagchi Debasis
Published: December 2019

Background: Mangoes are a popular fruit enjoyed worldwide. The mango is known for its pleasing aroma in addition to its refreshing and soothing taste. Researchers around the globe have demonstrated the diverse beneficial effects of Mangifera indica Linn in human health and disease prevention. Additionally, we should acknowledge how Ayurvedic medicine uses different parts of the mango tree. This branch of medicine has used the leaves, twigs, bark, seeds, flowers, raw and ripe fruits of mango to treat diverse degenerative diseases for thousands of years.Ethnobotany: The mango (Mangifera indica) originally came from India about 4,000 years ago. Since then, the mango has slowly spread across the world. The mango belongs to the family “Anacardiaceae” under the genus “Mangifera” and species “indica”. The mango is also referred to as “Asia’s King of Fruits” or a Royal fruit. The color of the mango fruit varies from green, yellowish green, yellow, yellowish red, orange red and red. The smell and taste of the mango fruit varies based on its state of maturity in addition to place of origin and climate. Different parts of a mango tree and mango fruit are rich in vitamins and antioxidants including vitamins B, C, E and beta-carotene, alkaloids, flavonoids, and polyphenolic compounds which include mangiferin, anthocyanins and anthocyanidins, micronutrients and essential minerals, structurally diverse carbohydrates, dietary fibers, fat, and protein. Health Benefits: Previous and current research demonstrate that the mango fruit and leaf extract, which is enriched in mangiferin and contains structurally diverse chemical constituents, are beneficial. The mango fruit and leaf extract have been shown to boost vitality, vigor, and endurance, leading to extensive application in exercise physiology. Furthermore, these constitutes ameliorate diverse degenerative disease related to metabolic syndrome, bacterial infections, gastrointestinal, and immunomodulatory disorders.Conclusions: Mango and mangiferin exhibit diverse health benefits including energy boosting, exercise performance, and human health.Keywords: Mango (Mangifera indica); mangiferin; vitamins and anthocyanins; anti-inflammatory; endurance, energy homeostasis; exercise
Methods for assessing the contact area of wheel propellers with a support base
Authors: Revenko V. Y.U , Godzhaev Z. A , Rusanov A. V
Published: December 2019

Predicting the level of impact of agricultural machinery on the soil is necessary both at the stages of its design, and when selecting tires for already existing samples. To solve the tasks, the authors assessed the most famous works devoted to the description of the process of interaction of wheeled propulsors of tractors and agricultural machines with a dirt surface. Thirteen of the most famous mathematical models in Russia and abroad, that describe the relationship between the tire size parameters and the size and shape of the contact spot, are analyzed. A technique is proposed for evaluating the accuracy of a particular model, based on an analysis of the comparability of calculation results and the results of measuring the contour area of contact of tires with a rigid supporting surface at specialized test benches. As a result, it was found that the most acceptable is the model of E. Stakevich, which, due to its simplicity and high convergence of the calculated and measured indicators, is used by many researchers for practical calculations, proving their consistency both in the case of diagonal and radial tires. Based on the analysis, as well as on the results of compression of modern tires, a semiempirical model, that relates the dimensional and deformation parameters of the rubbercord sheath to the contact area, is proposed. An integral part of the model is a formula for determining the cross-sectional area of a conventional cylinder (having the same overall dimensions as the tire) with a plane that is separated from its center by the value of the static radius. The model is supplemented by a refinement coefficient taking into account the height of the profile and the degree of deformation of the tire. Its rather high accuracy (the deviation from the results of compression of 74 samples of modern tires does not exceed 5 %) and ease of use greatly simplify the process of assessing the level of impact of agricultural machinery on the soil and selecting the most effective type of wheel propulsors for existing machines.
The temperature state of the engine warmed up in freezing conditions in cold climates
Authors: Kolunin A. V , Bur'yan I. A , Novikov O. V
Published: December 2019

A significant part of the territory of Russia is located in the cold climate zone. Negative ambient temperatures are inextricably linked to the temperature of the engine. The temperature range of the engines operated in the conditions of low temperatures of the cold climate is wider relative to the conditions of the middle band. The temperature drop of the engine is accompanied by significant stresses in the structural materials, especially in warm-up conditions. The most common low-temperature mode of operation takes place during heating after a long parking of vehicle without engine start. The temperature condition of the engine largely determines a number of factors within its working process. The completeness of fuel combustion, the consumption of crankcase gases, the viscosity of the operating materials, the conditions of thorns on the surfaces of the parts friction, the presence of condensation processes in the crankcase largely determine the reliability of operation. The activity of temperature changes in warm-up conditions is also considered. This paper describes an experiment consisting in the observation of the change in temperature of the liquids of the two systems. In the experiment, the coolant temperature of the cooling system and the oil temperature of the lubricating system as a criterion for determining the temperature state were chosen.
Optimization of balloon obstruction for simulating equivalent pressure drop in physiological stenoses
Authors: Kolli Kranthi K. , Paul Anup K. , Back Lloyd H. , Effat Mohamed A. , Banerjee Rupak K.
Published: December 2019

The study of hemodynamics in an animal model simulating coronary stenosis has been limited due to the lack of a safe, accurate and reliable technique for creating an artificial stenosis. Creating artificial stenosis using occluders in an open-chest procedure has often caused myocardial infarction (MI) or severe injury to the vessel resulting in high failure rates. To minimize these issues, closed-chest procedures with internal balloon obstruction are often used to create an artificial stenosis. However, the hemodynamics in a blood vessel with internal balloon obstruction versus a physiological stenosis has not been compared. Hence, the aim of this research is to develop a relationship to predict the balloon obstruction equivalent to that of a physiological stenosis. The pressure drop in a balloon obstruction was evaluated and compared with that in a physiological stenosis. It was observed that the flow characteristics in balloon obstructions are more viscous dominated, whereas those in physiological stenoses are momentum dominated. Balloon radius was iteratively varied using a Design of Experiments (DOE) based optimization method to obtain a pressure drop equal to that of a physiological stenosis at mean hyperemic flow rates. A linear relation was obtained to predict equivalent balloon obstruction for a physiological stenosis. Further, the details were verified with our in vivo (animal) study data.
Bivariate and multivariate analyses of the correlations between stability of the erythrocyte membrane, serum lipids and hematological variables
Authors: Bernardino Neto M. , de Avelar, Jr. E.B. , Arantes T.S. , Jordão I.A. , da Costa Huss J.C. , de Souza T.M.T. , de Souza Penha V.A. , da Silva S.C. , de Souza P.C.A. , Tavares M. , Penha-Silva N.
Published: December 2019

The observation that the fluidity must remain within a critical interval, outside which the stability and functionality of the cell tends to decrease, shows that stability, fluidity and function are related and that the measure of erythrocyte stability allows inferences about the fluidity or functionality of these cells. This study determined the biochemical and hematological variables that are directly or indirectly related to erythrocyte stability in a population of 71 volunteers. Data were evaluated by bivariate and multivariate analysis. The erythrocyte stability showed a greater association with hematological variables than the biochemical variables. The RDW stands out for its strong correlation with the stability of erythrocyte membrane, without being heavily influenced by other factors. Regarding the biochemical variables, the erythrocyte stability was more sensitive to LDL-C. Erythrocyte stability was significantly associated with RDW and LDL-C. Thus, the level of LDL-C is a consistent link between stability and functionality, suggesting that a measure of stability could be more one indirect parameter for assessing the risk of degenerative processes associated with high levels of LDL-C.
Shear viscosity and nonlinear behavior of whole blood under large amplitude oscillatory shear
Authors: Sousa P.C. , Carneiro J. , Vaz R. , Cerejo A. , Pinho F.T. , Alves M.A. , Oliveira M.S.N.
Published: December 2019

We investigated experimentally the rheological behavior of whole human blood subjected to large amplitude oscillatory shear under strain control to assess its nonlinear viscoelastic response. In these rheological tests, the shear stress response presented higher harmonic contributions, revealing the nonlinear behavior of human blood that is associated with changes in its internal microstructure. For the rheological conditions investigated, intra-cycle strain-stiffening and intra-cycle shear-thinning behavior of the human blood samples were observed and quantified based on the Lissajous–Bowditch plots. The results demonstrated that the dissipative nature of whole blood is more intense than its elastic component. We also assessed the effect of adding EDTA anticoagulant on the shear viscosity of whole blood subjected to steady shear flow. We found that the use of anticoagulant in appropriate concentrations did not influence the shear viscosity and that blood samples without anticoagulant preserved their rheological characteristics approximately for up to 8 minutes before coagulation became significant.
Microcirculation in hypertensive patients
Authors: Jung F. , Pindur G. , Ohlmann P. , Spitzer G. , Sternitzky R. , Franke R.P. , Leithäuser B. , Wolf S. , Park J.-W.
Published: December 2019

Regardless of the mechanisms that initiate the increase in blood pressure, functional and structural changes in the systemic vasculature are the final result of long-standing hypertension. These changes can occur in the macro- but also in the microvasculature. The supply of the tissues with oxygen, nutrients, and metabolites occurs almost exclusively in the microcirculation (which comprises resistance arterioles, capillaries and venules), and an adequate perfusion via the microcirculatory network is essential for the integrity of tissue and organ function.

This review focuses on results from clinical studies in hypertensive patients, which have been performed in close cooperation with different clinical groups over the last three decades. Intravital microscopy was used to study skin microcirculation, microcatheters for the analysis of skeletal muscle microcirculation, the slit lamp for conjunctival microcirculation and the laser scanning ophthalmoscope for the measurement of the retinal capillary network.

The first changes of the normal microcirculation can be found in about 93% of patients with essential hypertension, long before organ dysfunctions become clinically manifest. The earliest disorders were found in skin capillaries and thereafter in the retina and the skeletal muscle. In general, the disorders in the different areas were clearly correlated. While capillary rarefaction occurred mainly in the retina and the conjunctiva bulbi, in skin capillaries morphological changes were rare. A significant decrease of capillary erythrocyte velocities under resting conditions together with a marked damping of the postischemic hyperemia was found, both correlating with the duration of hypertension or WHO stage or the fundus hypertonicus stage. Also the mean oxygen tension in the skeletal muscle was correlated with the state of the disease.

These data show that the microcirculatory disorders in hypertension are systemic and are hallmarks of the long-term complications of hypertension. There is now a large body of evidence that microvascular changes occur very early and may be important in their pathogenesis and progression.
Characterisation of the mechanical behaviour of brain tissue in compression and shear
Authors: Hrapko M. , van Dommelen J.A.W. , Peters G.W.M. , Wismans J.S.H.M.
Published: December 2019

No validated, generally accepted data set on the mechanical properties of brain tissue exists, not even for small strains. Most of the experimental and methodological issues have previously been addressed for linear shear loading. The objective of this work was to obtain a consistent data set for the mechanical response of brain tissue to either compression or shear. Results for these two deformation modes were obtained from the same samples to reduce the effect of inter-sample variation. Since compression tests are not very common, the influence of several experimental conditions for the compression measurements was analysed in detail. Results with and without initial contact of the sample with the loading plate were compared. The influence of a fluid layer surrounding the sample and the effect of friction were examined and were found to play an important role during compression measurements.

To validate the non-linear viscoelastic constitutive model of brain tissue that was developed in Hrapko et al. (Biorheology 43 (2006), 623–636) and has shown to provide a good prediction of the shear response, the model has been implemented in the explicit Finite Element code MADYMO. The model predictions were compared to compression relaxation results up to 15% strain of porcine brain tissue samples. Model simulations with boundary conditions varying within the physical ranges of friction, initial contact and compression rate are used to interpret the compression results.
Breakdown of cell-collagen networks through collagen remodeling
Authors: Iordan Andreea , Duperray Alain , Gérard Anaïs , Grichine Alexeï , Verdier Claude
Published: December 2019

Collagen model tissues, consisting of cells embedded in a collagen matrix at different concentrations (of cells and collagen) were analyzed. Rheological properties were measured and complementary confocal microscopy analysis carried out. An important feature, corresponding to the breakdown of the collagen network (i.e., decrease in network elasticity) was observed at high collagen concentrations, due to the presence of cells. Thanks to confocal microscopy, we showed that cells elongated within the gel and could remodel it, this being a concentration-dependent feature. A careful analysis of the remodeling process showed that cells can attract collagen in their close neighborhood, this being an irreversible process and that migrating cells create collagen-depleted regions behind them.
Plasma expander viscosity effects on red cell-free layer thickness after moderate hemodilution
Authors: Yalcin Ozlem , Wang Qi , Johnson Paul C. , Palmer Andre F. , Cabrales Pedro
Published: December 2019

The objective of the study was to investigate the effects of plasma viscosity after hemodilution on the thickness of the erythrocyte cell free layer (CFL) and on the interface between the flowing column of erythrocytes and the vascular endothelium. The erythrocyte CFL thickness was measured in the rat cremaster muscle preparation. Plasma viscosity was modified in an isovolemic hemodilution, in which the systemic hematocrit (Hctsys) was lowered to 30%. The plasma expanders (PE) of similar nature and different viscosities were generated by glutaraldehyde polymerization of human serum albumin (HSA) at various molar ratios glutaraldehyde to HSA: (i) unpolymerized HSA; (ii) PolyHSA24:1, molar ratio = 24 and (iii) PolyHSA60:1, molar ratio = 60. The HSA viscosities determined at 200 s−1 were 1.1, 4.2 and 6.0 dyn·cm−2, respectively. CFL thickness, vessel diameter and blood flow velocity were measured, while volumetric flow, shear rate and stress were calculated. Hemodilution with PolyHSA60:1 increased plasma viscosity and the blood showed marked shear thinning behavior. CFL thickness decreased as plasma viscosity increased after hemodilution; thus the CFL thickness with HSA and PolyHSA24:1 increased compared to baseline. Conversely, the CFL thickness of PolyHSA60:1 was not different from baseline. Blood flow increased with both PolyHSA's compared to baseline. Wall shear rate and shear stress increased for PolyHSA60:1 compared to HSA and PolyHSA24:1, respectively. In conclusion, PE viscosity determined plasma viscosity after hemodilution and affected erythrocyte column hydrodynamics, changing the velocity profile, CFL thickness, and wall shear stress. This study relates the perfusion caused by PolyHSA60:1 to hemodynamic changes induced by the rheological properties of blood diluted with PolyHSA60:1.
Testicular ischemia-reperfusion may alter micro-rheological parameters in laboratory rats
Authors: Nemeth Norbert , Kiss Ferenc , Klarik Zoltan , Peto Katalin , Vanyolos Erzsebet , Toth Laszlo , Furka Istvan , Miko Iren
Published: December 2019

Ischemia-reperfusion-caused hemorheological alterations have been widely studied but the effect of testicular ischemia-reperfusion has not so far. In this study 14 Sprague-Dawley rats were involved. In the ischemia-reperfusion group under general anaesthesia the left testis was explored by opening the scrotum then the deferent duct and vasculature were clamped for 30 minutes. Testicular microcirculation was monitored by laser Doppler flowmetry. The right testis was untouched. In the control group: only anaesthesia was induced. Blood sampling occurred before and after ischemia, at the 60th minute of reperfusion and on the 1st postoperative day for determining hematological parameters (microcell-counter), erythrocyte deformability (slit-flow ektacytometer) and erythrocyte aggregation (light-transmission aggregometer). After the last blood sampling, testicles were removed for histological examination. Hematological parameter changes reflected inflammatory response. Erythrocyte deformability showed a worsening already at the 60th minute of reperfusion compared to base and control values. By the 1st postoperative day further decrease was observed. Erythrocyte aggregation significantly enhanced with great magnitude versus base and control values (p < 0.001). However, conventional histological examinations did not show marked testicular injury. The experienced changes can attract attention to the testicular ischemia-reperfusion causing significant effects on hemorheological parameters, which can lead to further harmful microcirculatory consequences.
The effect of lead-induced oxidative stress on blood viscosity and rheological properties of erythrocytes in lead exposed humans
Authors: Kasperczyk Aleksandra , Słowińska-Łożyńska Ludmiła , Dobrakowski Michał , Zalejska-Fiolka Jolanta , Kasperczyk Sławomir
Published: December 2019

Lead-induced oxidative stress has been identified as the essential factor in lead poisoning pathogenesis. Therefore, the present study examined the association between occupational lead exposure and blood rheological parameters with respect to malondialdehyde (a lipid peroxidation product), lipofuscin, and glutathione concentrations in erythrocytes. The examined group included 283 healthy male employees of lead-zinc works. In brief, 129 workers were classified as the low-exposure group, while the high-exposure group was composed of 154 workers. The mean blood levels of lead and zinc-protoporphyrin and the mean urine concentrations of delta-aminolevulinic acid were used as exposure markers. The control group consisted of 73 healthy male administrative workers. Whole blood viscosity was elevated in both exposure subgroups compared with the control group. Erythrocyte aggregability increased significantly; although the increase was greater in the low exposure group. Erythrocyte deformability decreased in both subgroups. The levels of malondialdehyde and lipofuscin were significantly elevated, whereas the glutathione content decreased. In conclusion, occupational exposure to lead may induce oxidative stress in erythrocytes. This stress elevates whole blood viscosity and disturbs erythrocyte aggregability and deformability. There is a dose-effect relationship between lead levels and blood rheological parameters.
The role of hemorheological factors in cardiovascular medicine
Authors: Toth A. , Papp J. , Rabai M. , Kenyeres P. , Marton Zs. , Kesmarky G. , Juricskay I. , Meiselman H.J. , Toth K.
Published: December 2019

Cardiovascular diseases (CVD) are the most frequent cause of death throughout the world. The coronary vessel system is a special part of the circulation since there is a continuous change in blood flow, perfusion pressure and shear rate during each cardiac cycle. It is also the place of the narrowest capillaries in the human body, therefore the role of rheological alterations may be of greater importance than in the other parts of the circulatory system. During the past decades, our group has investigated hemorheological parameters (HP) in over 1,000 patients diagnosed with various forms of ischemic heart disease (IHD). In one prospective study, we measured the HP of patients with acute coronary syndrome (ACS). On admission, all examined variables were significantly worse than those of control subjects. During the hospital phase, some of the HP showed further deterioration, and HP remained in the pathologic range during the follow-up period. In another study, we showed that HP are in close correlation with the severity of coronary artery disease. In patients treated with percutaneous coronary intervention, changes in HP were very similar to those observed in subjects with ACS. In a recent study, we analyzed HP in patients undergoing CABG surgery. Our data suggest a hemorheological advantage of off-pump surgery. In another study low Hct/WBV ratio can be regarded as a risk factor of cardiac death in IHD. Our data indicate that rheological parameters are significantly altered in patients with IHD: the extent of the alterations is in excellent correlation with the clinical severity of the disease. Our findings prove that HP play a critical role in the pathogenesis of myocardial ischemia. In recent in vitro and in vivo studies we have investigated the effects of red wine on hemorheological parameters. Our results show that moderate red wine consumption has beneficial effects on hemorheological parameters which may contribute to the French paradox.
Dynamic in vitro hemocompatibility testing of poly(ether imide) membranes functionalized with linear, methylated oligoglycerol and oligo(ethylene glycol)
Authors: Braune Steffen , von Ruesten-Lange Maik , Mrowietz Christof , Lützow Karola , Roch Toralf , Neffe Axel T. , Lendlein Andreas , Jung Friedrich
Published: December 2019

Linear, side-chain methylated oligoglycerols (OGMe) were recently reported as potential surface passivating molecules for improving the protein resistance of cardiovascular application relevant poly(ether imide) (PEI) membranes. A previously reported in vitro screening under static test conditions allowed an end-point evaluation of the adhesion and activation of adherent thrombocytes performed on the material surfaces and revealed similar levels of thrombogenicity on PEI membranes, functionalized with OGMe and oligo(ethylene glycol) (OEG) of similar molecular weight (Mn = 1,300 g·mol−1 - 1,800 g·mol−1). In the present study, we investigated the hemocompatibility of these materials in a dynamic closed loop system, in order to study time-dependent thrombocyte material interactions also of the circulating thrombocytes by mimicking in vivo relevant flow conditions in a dynamic test system with multiple material contacts. Activation and aggregation of circulating thrombocytes as well as complement activation and plasmatic coagulation were evaluated after 40 circulations of thrombocyte rich plasma in the closed loop system. The results of the dynamic tests revealed no differences between the OGMe and OEG functionalized PEI membranes. Furthermore, no differences were observed between the latter and a PEI membrane treated under the conditions of functionalization at pH 11 (PEI-pH11) without an oligoether being present. Blood plasma protein adsorption, as well as activation, and adherence of circulating thrombocytes occurred in a comparable, but minor manner on all investigated PEI membranes. From this we conclude that the OGMe and OEG surface functionalization did not lead to an improvement of the already good hemocompatibility of the PEI-pH11 membrane.
Hypoxia/reoxygenation stress increases markers of vaso-occlusive crisis in sickle SAD mice
Authors: Aufradet Emeline , DeSouza Geneviève , Bourgeaux Vanessa , Bessaad Amine , Campion Yannick , Canet-Soulas Emmanuelle , Pialoux Vincent , Chirico Erica N. , Chevrier Anne-Marie , Godfrin Yann , Martin Cyril
Published: December 2019

In sickle cell disease, the factors involved in vasoocclusive crisis (VOC) include the sickling of red blood cells (RBC), abnormal blood rheology, inflammation, vascular adhesion, oxidative stress, coagulation, and vascular tone modulation. The aim of this study was to further characterize the molecular response of some factors involved in VOC by inducing a hypoxia/reoxygenation stress in sickle SAD mice. Results show that a hypoxia/reoxygenation stress in SAD mice can induce: (i) a decrease in reticulocytes count, and mean corpuscular volume along with an increase in lactate dehydrogenase (p = 0.07) and sickled cell proportion; (ii) a significant increase in lung VCAM-1, ICAM-1, IL-1β, ET-1, eNOS, and TF mRNA associated with an increase in VCAM-1 expression on lung endothelium; (iii) a rise in cardiac oxidative stress with increased lipid oxidation and decreased anti-oxidant enzyme activities, and (iv) an increase in plasma TNF-α and IL-6 and a decrease in plasma ET-1. In SAD mice, hypoxia/reoxygenation stress induces hemolysis that, together with oxidative stress, inflammation, vascular adhesion, and coagulation, may induce vascular occlusion and consequently RBC sickling. The present results give the kinetics of VOC molecular markers in SAD mice which may aid in testing the efficiency of new therapeutic processes against VOC.
Shear stress and flow dynamics of the femoral vein among obese patients who qualify for bariatric surgery
Authors: Wiewiora Maciej , Piecuch Jerzy , Glűck Marek , Slowinska-Lozynska Ludmila , Sosada Krystyn
Published: December 2019

The aim of this study was to evaluate the effects of obesity on wall shear stress and its relationship to erythrocyte aggregation. We studied 35 morbidly obese patients who were qualified for bariatric surgery. The control group consisted of 20 non-obese people. Blood rheological measurements were performed using the Laser-assisted Optical Rotational Cell Analyzer (Mechatronics, the Netherlands) and a cone-plate viscometer (Brookfield DV-II). The venous flow dynamics were assessed using a duplex ultrasound. The shear rate was estimated from the measured blood flow velocity and the diameter of the femoral vein. Venous wall shear stress was calculated from the whole blood viscosity and the shear rate. The shear rate (P < 0.005) and the venous wall shear stress (P < 0.05) were significantly lower in obese patients compared with the controls. The aggregation index (P < 0.001), syllectogram amplitude – AMP (P < 0.05) and Tslow (P < 0.001) were significantly higher in the obese patients; the aggregation half-time (P < 0.001) and Tfast (P < 0.001) were decreased compared with the control group. Multivariate regression analyses found waist circumference (β −0.31, P < 0.05), thigh circumference (β 0.33, P < 0.05) and Tslow (β −0.47, P < 0.005) to be variables that independently influenced the shear rate. Nevertheless, the AMP (β 0.34, P < 0.05) and Tslow (β −0.47, P < 0.01) were independent predictors that influenced the wall shear stress. This study indicates that there is a relationship between wall shear stress in the femoral vein and the rheological impairment of the RBC among obese patients, but further studies are necessary to confirm this suggestion.
RDW in patients with systemic lupus erythematosus. Influence of anaemia and inflammatory markers
Authors: Vayá Amparo , Alis Rafael , Hernández Jose-Luis , Calvo Javier , Micó Luisa , Romagnoli Marco , Ricart Jose M.
Published: December 2019

Red blood cell distribution width (RDW) is a routine parameter that reflects size variations in erythrocytes. High RDW has been associated with cardiovascular events and inflammatory diseases. However, no studies evaluating the association of RDW with systemic lupus erythematosus (SLE) have been published. We aimed to explore the association of RDW with inflammatory markers in SLE. As SLE is often associated with anaemia, we considered this factor in order to know whether RDW is related with inflammation, anaemia or both in SLE. The study included 105 SLE patients (7 men, 98 women; aged 15–73 years) and 105 controls (9 men, 96 women; aged 18–71 years). Patients were divided according to anaemia status (26 with, 79 without). Biochemical, hematological and inflammatory parameters (C-reactive protein (CRP), fibrinogen and erythrocyte aggregation (EA1)) were analyzed. SLE patients showed increased RDW, CRP and EA1 (p < 0.001), and decreased hemoglobin levels (p < 0.001) when compared with controls. RDW was higher in SLE patients with anaemia (a-SLE) as compared with those without anaemia (na-SLE) (p < 0.01) or controls (p < 0.001). CRP in a-SLE was higher than in controls (p < 0.01) but lower than in na-SLE (p < 0.05). In na-SLE RDW correlated directly with fibrinogen and CRP (p < 0.001), but not in a-SLE. Our results indicate that SLE patients show higher RDW irrespectively of anaemia status, and that RDW is influenced by both anaemia and inflammation, but the influence of anaemia is stronger.
The effect of ischemia-reperfusion injury on measures of vascular function
Authors: Alhejily Wesam , Aleksi Alda , Martin Billie-Jean , Anderson Todd J.
Published: December 2019

BACKGROUND: Ischemia-reperfusion injury results in conduit vessel endothelial dysfunction as assessed by flow-mediated dilatation (FMD). The effect on the potentially more important microvascular circulation has not been well studied. The objective of our study was to assess the effect of ischemia-reperfusion injury on microvascular function including peripheral arterial tonometry (PAT) hyperemic index. METHODS: 45 healthy volunteers free of cardiovascular disease were recruited (mean age 35 ± 14 yrs, 29 men). Using ultrasound, the flow-mediated dilation (FMD) and hyperemic velocity (VTI) of the brachial artery were measured following a 5-minute forearm cuff occlusion. Simultaneously, the PAT hyperemic index was measured. Ischemia was then induced by a 15-minute upper arm occlusion and within 15 minutes of recovery the vascular measures were repeated. RESULTS: Ischemia caused a significant reduction in FMD (7.9 ± 4.0 to 4.7 ± 3.5, p = 0.0001). The hyperemic VTI, a measure of microvascular function, was unaffected following ischemia-reperfusion (92 ± 30 vs. 97 ± 37 cm, p = 0.236). Finally, PAT index was also unchanged by the intervention (2.07 ± 0.8 vs. 2.04 ± 0.7, p = 0.742). CONCLUSIONS AND DISCUSSIONS: Ischemia-reperfusion caused conduit and not resistance vessel endothelial dysfunction. The PAT-index was unchanged suggesting that this measure is more closely aligned with resistance than conduit vessel function. This has implications for its use as a measure of vascular function in clinical research.
Is there a relationship between the hematocrit-to-viscosity ratio and microvascular oxygenation in brain and muscle?
Authors: Waltz Xavier , Hardy-Dessources Marie-Dominique , Lemonne Nathalie , Mougenel Danièle , Lalanne-Mistrih Marie-Laure , Lamarre Yann , Tarer Vanessa , Tressières Benoit , Etienne-Julan Maryse , Hue Olivier , Connes Philippe
Published: December 2019

The hematocrit-to-viscosity ratio (HVR) has been widely used has an estimate of red blood cell (RBC) oxygen transport effectiveness into the microvasculature or as an oxygen delivery index. However, no study investigated the possibility of HVR to truly reflect RBC oxygen transport effectiveness or to be an oxygen delivery index. We measured blood viscosity at high shear rate (225 s−1), hematocrit, HVR, as well as the microvascular oxyhemoglobin saturation (TOI; tissue oxygen index) by spatial resolved near-infrared spectroscopy (NIRS) at cerebral and muscle levels in three population known to have various degrees of hemorheological abnormalities: healthy subjects (AA), patients with sickle cell SC disease (SC) characterized by moderate anemia and patients with sickle cell anemia (SS) marked by severe anemia. At both the cerebral and muscle level, HVR was positively correlated with TOI (r = 0.28; p = 0.03 and r = 0.38; p = 0.003, at the cerebral and muscle level, respectively). These findings suggest that HVR probably play a key role in blood flow and hemodynamic regulation in the microvasculature, hence modulating the amount of oxygen available for tissues. Nevertheless, the strengths of the associations are weak (R2 < 0.50), suggesting that other determinants modulate microvascular blood flow and oxygenation, such as vascular geometry and vasomotor reserve.
Physostigmine reverses disturbances of the intestinal microcirculation during experimental endotoxemia
Authors: Zhou Juan , Pavlovic Dragan , Rüb Johanna , Masur Stefan , Spassov Alexander , Whynot Sara , Hung Orlando , Kern Hartmut , Saleh Abdo Islam , Shukla Romesh , Cerny Vladimir , Lehmann Christian
Published: December 2019

Intestinal microcirculatory disturbances play an important role in the pathophysiology of sepsis. A neural anti-inflammatory pathway has been suggested as a potential target for therapy that may dampen systemic inflammation. The aim of this study is to investigate the effects of physostigmine, a cholinesterase inhibitor, on the intestinal microcirculation and vascular contractility in experimental endotoxemia. Endotoxemia was induced in Lewis rats by intravenous lipopolysaccharide (LPS) administration. Animals were treated with either physostigmine or saline (control) following LPS challenge. The intestinal microcirculation, including leukocyte-endothelial interaction, functional capillary density (FCD) and non-perfused capillary density (NCD), was examined by intravital microscopy (IVM) 2 hours after LPS administration. The impact of physostigmine on vascular contractility of rat aortic rings was examined by in vitro myography. Physostigmine significantly reduced the number of adhering leukocytes in intestinal submucosal venules (V1 venules: −61%, V3 venules: −36%) of LPS animals. FCD was significantly increased by physostigmine treatment (circular muscle layer: +180%, longitudinal muscle layer: +162%, mucosa: +149%). Low concentrations of physostigmine produced significant contraction of aortic ring preparations, whereas high concentrations produced relaxation. In conclusion, physostigmine treatment significantly improved the intestinal microcirculation in experimental endotoxemia by reducing leukocyte adhesion and increasing FCD.
Red blood cell distribution width and erythrocyte deformability in patients with acute myocardial infarction
Authors: Vayá Amparo , Rivera Leonor , de la Espriella Rafael , Sanchez Fernando , Suescun Marta , Hernandez José Luis , Fácila Lorenzo
Published: December 2019

Increased RDW has been found to be a marker of adverse outcomes in cardiovascular disease (CVD), although the exact mechanism remains unclear. Recently, several authors have found that higher RDW is associated with decreased erythrocyte deformability, which can impair blood flow through microcirculation, a fact which may explain the increased risk for CVD events associated with elevated RDW. The aim of the present study was to investigate the association between RDW and erythrocyte deformability in patients with acute myocardial infarction (AMI). The study group comprised 60 AMI patients and 72 gender- and age-matched controls, in whom erythrocyte deformability was determined by means of the elongation index (EI) in a Rheodyn SSD, along with haematological, biochemical and inflammatory parameters. Patients showed higher RDW (p = 0.012) and lower EI (p < 0.05) than controls. When anaemic patients were removed from the study, AMI showed still lower EI than controls (p < 0.05), but no differences in RDW were observed (p = 0.141). RDW correlated inversely with haematimetric indices (p < 0.001), but not with inflammatory and biochemical parameters (p > 0.05). EI correlated inversely with Hb, MCHC (p < 0.001) and directly with MCV (p < 0.05). EI also correlated inversely with glucose (p < 0.05) and directly with HDL-cholesterol (p < 0.05). The multivariate regression model showed that only MCV and Hb were independent predictors of RDW (beta coefficients: −0.383, −0.208; p < 0.001, p = 0.050, respectively). In addition, MCV, MCHC and hyperlipidaemia were independent predictors of EI (beta coefficients: 0.366, −0.533, −0.192; p < 0.001, p < 0.001, p = 0.019 respectively). In AMI patients, increased RDW is not related with EI, so this mechanism does not seem to be responsible for an increased CDV risk in these patients.
Culture surface influence on T-cell phenotype and function
Authors: Hashimdeen Shaikh Shimaz , Römhild Andy , Schmueck Michael , Kratz Karl , Lendlein Andreas , Kurtz Andreas , Reinke Petra
Published: December 2019

When dealing with T lymphocyte culture there is currently very less information available about the interaction between T-cells and the culture system. In this study we look at the influence of the culture chamber on T-cell proliferation in two main aspects of the culture system, namely: culture chamber material and geometry. The study was carried out using unique polymeric closed cell culture inserts, which were processed via injection moulding from polystyrene (PS), polycarbonate (PC), polyetherurethane (PEU), polystyrene-co-acrylonitrile (PSAN) and polyetherimide (PEI). Furthermore culture chamber geometry was studied using commercially available 24, 12 and 6-well plates prepared from tissue culture plastic (TCP). For T lymphocyte stimulation two methods were used involving either EBV peptide pools or MACS iBead particles depending on the experiment performed. Culture was done with 1645 RPMI medium supplemented with foetal calf serum, penicillin, streptomycin and rhIL-2. We found four materials out of five we tested (PS, PC, PSAN and PEI) exhibited similar fold expansions with minimal influence on proportions of CD4 and CD8, while PEU had a negative influence on T cell growth along with adversely affected CD4/CD8 proportions. Changes in the geometry of TCP had no effect on T cell growth or maturation rather the size of geometry seems to have more influence on proliferation. T-cells appear to prefer smaller geometries during initial stages of culture while towards the end of the culture size becomes less significant to cell proliferation. The parameters tested in this study have significant influences on T-cell growth and are necessary to consider when designing and constructing expansion systems for antigen specific T lymphocytes. This is important when culturing T-cells for immunotherapeutic applications where antigen specificity, T-cell maturation and function should remain unaffected during culture.
Dark chocolate and vascular function in patients with peripheral artery disease: A randomized, controlled cross-over trial
Authors: Hammer Alexandra , Koppensteiner Renate , Steiner Sabine , Niessner Alexander , Goliasch Georg , Gschwandtner Michael , Hoke Matthias
Published: December 2019

Flavonoid-rich dark chocolate has positive effects on vascular function in healthy subjects and in patients at risk of atherosclerosis. The impact of dark chocolate on endothelial and microvascular function in patients with symptomatic peripheral artery disease (PAD) has not been investigated so far. In an investigator blinded, randomized, controlled, cross-over trial we assessed the effect of flavonoid-rich dark chocolate and cocoa-free control chocolate on flow-mediated dilatation (FMD) of the brachial artery and on microvascular function (assessed by Laser Doppler fluxmetry) in 21 patients with symptomatic (Fontaine stage II) PAD. Measurements were done in each patient on 2 single days, with an interval of 7 days, at baseline and at 2 hours after ingestion of 50 g dark chocolate or 50 g white chocolate, respectively. FMD remained unchanged after intake of dark chocolate (baseline and 2 hours after ingestion, %: 5.1 [IQR 4.4 to 7.3] and 5.5 [IQR 3.9 to 10.4]; p = 0.57, and after intake of white chocolate (baseline and 2 hours after ingestion, %: 6.4 [IQR 4.5 to 11.4] and 4.4 [IQR 2.6 to 8.7]; p = 0.14. Similarly, microcirculatory parameters were not significantly altered after intake of any chocolate compared with the respective baseline values. In conclusion, a single consumption of 50 g dark chocolate has no effect on endothelial and microvascular function in patients with symptomatic PAD.
Angiogenically stimulated alternative monocytes maintain their pro-angiogenic and non-inflammatory phenotype in long-term co-cultures with HUVEC
Authors: Krüger Anne , Mayer Anke , Roch Toralf , Schulz Christian , Lendlein Andreas , Jung Friedrich
Published: December 2019

Angiogenically stimulated alternative monocytes (aMO2) could be established as cellular release system accelerating the endothelialization of polymers rendering their surfaces hemocompatibility in a short-term study. However, for their clinical application it is essential that aMO2 do not switch back to the MO1 state sustaining their capability as cellular release system over an extended period of time. We explored whether aMO2 can maintain their differentiation state over 21 days in a mono- and in a co-culture with HUVEC. In comparison, the influence of recombinant VEGF-A165 on the endothelialization of biomaterials was assessed including endothelial cell (HUVEC) density, organisation of the endothelial cytoskeleton, cytokine secretion profile and release of prostacyclin, thromboxane A2 and matrix metalloproteinases. In mono-culture aMO2 secreted high amounts of VEGF and other growth factors/cytokines. Co-cultured with HUVEC, aMO2 accelerated the formation of a confluent HUVEC monolayer. Furthermore, no pro-inflammatory cytokines were found, neither in aMO2-mono, nor in co-cultures with HUVEC indicating that the majority of the aMO2 remained stable in their aMO2 state during the 21 days of cultivation. In contrast, the addition of recombinant VEGF-A165 instead of the co-culture with aMO2 resulted in the formation of stress fibres, dissociated marginal filament bands, and a detachment of HUVEC. In addition, the profile of bioactive agents of HUVEC (e.g. prostacyclin, thromboxane A2, matrix metalloproteinases, IFN-γ and TNF-α) was influenced by the VEGF-A165 treatment inducing the detachment of HUVEC. In conclusion, in co-culture with HUVEC aMO2 remained stable in their type 2 state over 21 days confirming the suitability of aMO2 as biological release system for the endothelialization of biomaterial surfaces with constant release of angiogenic factors but without secretion of pro-inflammatory cytokines over three weeks. Therefore, this endothelialization approach seems to be appropriate to improve the hemocompatibility of cardiovascular implant materials in vitro, and proved to be superior to the use of recombinant VEGF-A165.
Isolation of equine endothelial cells and life cell angiogenesis assay
Authors: Dietze Kathrin , Slosarek Ilka , Fuhrmann-Selter Tania , Hopperdietzel Carsten , Plendl Johanna , Kaessmeyer Sabine
Published: December 2019

Arterial or venous thromboses are frequent clinical complications with the risk of fatal progression. Recent studies suggest the disruption of angiogenesis in the course of thrombus resolution as the underlying pathomechanism. Very similar to the situation in human patients, equine vessels have been described to be particularly susceptible to thrombosis. In contrast to humans, equine donors are readily available to obtain organs and tissues for isolation of endothelial cells. Objective of this study was to isolate equine endothelial cells and develop an angiogenesis assay from primary cultures. Macrovascular endothelial cells were obtained from jugular veins and carotid arteries of nine horses, one of which suffered from inflammatory processes. After enzymatic isolation, the cells were incubated in different selective primary media. Phenotypic identification of endothelial cells was accomplished by morphology and positive staining to von Willebrand factor. The reliable, inexpensive, and standardized combination of methods presented here resulted in pure endothelial cultures for angiogenesis assays that can be used in any cell culture laboratory. Inverted phase microscopy and life cell imaging was used to characterize the stages of the angiogenic cascade of the endothelial cells. Life cell imaging gave new insights into the in vitro formation of capillary like structures including exocytosis of microparticles from endothelial cells before integration into the three-dimensional structure. We hypothesize that a specific population of endothelial cells showing a highly active migration pattern in life cell imaging might play a role in the resolution of thrombosis.