In vitro and ex vivo effect of hyaluronic acid on erythrocyte flow properties

<p>Abstract</p> <p>Background</p> <p>Hyaluronic acid (HA) is present in many tissues; its presence in serum may be related to certain inflammatory conditions, tissue damage, sepsis, liver malfunction and some malignancies. In the present work, our goal was to investigate the significance of hyaluronic acid effect on erythrocyte flow properties. Therefore we performed <it>in vitro </it>experiments incubating red blood cells (RBCs) with several HA concentrations. Afterwards, in order to corroborate the pathophysiological significance of the results obtained, we replicated the <it>in vitro </it>experiment with <it>ex vivo </it>RBCs from diagnosed rheumatoid arthritis (RA) patients, a serum HA-increasing pathology.</p> <p>Methods</p> <p>Erythrocyte deformability (by filtration through nucleopore membranes) and erythrocyte aggregability (EA) were tested on blood from healthy donors additioned with purified HA. EA was measured by transmitted light and analyzed with a mathematical model yielding two parameters, the aggregation rate and the size of the aggregates. Conformational changes of cytoskeleton proteins were estimated by electron paramagnetic resonance spectroscopy (EPR).</p> <p>Results</p> <p><it>In vitro</it>, erythrocytes treated with HA showed increased rigidity index (RI) and reduced aggregability, situation strongly related to the rigidization of the membrane cytoskeleton triggered by HA, as shown by EPR results. Also, a significant correlation (r: 0.77, p < 0.00001) was found between RI and serum HA in RA patients.</p> <p>Conclusions</p> <p>Our results lead us to postulate the hypothesis that HA interacts with the erythrocyte surface leading to modifications in erythrocyte rheological and flow properties, both <it>ex vivo </it>and <it>in vitro</it>.</p

Upcycling of composite materials waste into geopolymer-based mortars for applications in the building sector

The possibility to use quartz-composite industrial swarfs as aggregate component in geopolymer-based mortars, to produce materials for upcycling applications, was evaluated. Two different composites (A-type: 90&nbsp;wt.% quartz, 10&nbsp;wt.% unsaturated polyester resin; B-type: 60&nbsp;wt.% quartz, 40&nbsp;wt.% acrylic resin) were ground to the grainsize&nbsp;&lt;&nbsp;2&nbsp;mm, then mixed with metakaolin and potassium silicate (K2SiO3), with the aim to obtain samples with high waste content. The samples produced, with 60–70–80&nbsp;wt.% waste, show low water absorption, isolated porosity, and good textural relations among components. Mechanical tests indicated very good results at 7 and 28&nbsp;days, with best data obtained for A-type 70&nbsp;wt.% waste-bearing sample showing values of 7.5&nbsp;MPa for flexural strength and 62.5&nbsp;MPa for compressive strength. The study revealed that quartz-composite waste, usually destined to landfill, could be effectively recycled using geopolymeric binders, postponing therefore their end-of-life. The new materials are very promising for applications in the building sector, e.g., as tiles, slabs or even structural panels and bricks

Geopolymers-based application for the up-cycling utilization of construction and demolition waste from the 2016 central Italy earthquakes

The 2016 seismic sequence in central Italy produced huge amounts of rubble. The need to recycle construction and demolition waste (CDW) to facilitate reconstruction process is therefore a problem of highest concern for quantities involved. In addition, CDW from rubble is very difficult to recycle being an extremely heterogeneous material. In this study, in order to produce mortars, the complete replacement of natural aggregate was investigated using the finest as-received CDW (0–8 mm) produced by local plants that managed the 2016 earthquake rubble. Results revealed that samples containing 60 wt.% CDW, metakaolin as precursor and K-silicate as alkaline reagent, have mechanical properties up to 28.7 MPa and mostly in the range of structural ordinary cementitious materials, suggesting that even the CDW fine fractions could be used in the production of upcycling mortar

Erythrocyte aggregation in rheumatoid arthritis: cell and plasma factor’s role

ncrease in erythrocyte aggregation (EA) is pathognomonic for rheumatoid arthritis (RA), and its estimation through erythrocyte sedimentation rate (ESR) is part of DAS 28-4 activity diagnosis, with low correlation with EA and that does not discriminate the contribution of cell factors that increase aggregation. Objective: To analyse cell and plasma factors that might be involved in EA increase, to understand how RA affects blood components, thus modifying blood fluid behavior. Methodology: One hundred women presenting active RA were compared with age-matched controls (C). EA was measured by transmitted light, obtaining two parameters: 2k2n0, characterizing the aggregation process kinetics and s0/n0, estimating aggregates size. Cell factors assays: erythrocyte deformability, by filtration through nucleopore membranes, cell shape, by microscopy, and membrane fluidity by EPR. Plasma: total proteins and CRP, albumin, fibrinogen (Fb), by gravimetry, and IgG and IgM by single radial immuno-diffusion. Results: AR and C (x ± SE). 2k2n0: 31.83 ± 2.84, 23.75 ± 1.91; s0/n0: 0.92 ± 0.05, 0.87 ± 0.04. Rigidity index (RI): 14.79 ± 4.71, 6.92 ± 1.31. Morphological index: 0.28 ± 0.03, 0.30 ± 0.05, n.s. Fb (mg/dl): 382 ± 80, 299 ± 70. IgG (mg/dl): 1580 ± 219, 1296 ± 158; IgM (mg/dl) 233 ± 28, 183 ± 23; albumin (g/dl) 3.84 ± 0.44, 3.77 ± 0.51 n.s. p < 0.05 accepted. Correlations: 2k2n0 vs. Fb r = 0.66; s0/n0 vs. Fb r = 0.51; 2k2n0 vs. Igs r = 0.65; s0/n0 vs. Igs r = 0.56. 2k2n0 vs. RI r = -0.59; s0/n0 vs. RI = -0.52, p < 0.05. Conclusions: Plasma factors, Igs and Fb increased aggregation, since RI is altered, this reduces the process efficiency regarding aggregation. Patients with active RA present an increased EA, with values modifications associated with the activity index DAS 28-4, thus becoming an RA activity indicator.Fil: Luquita, A.. Universidad Nacional de Rosario; ArgentinaFil: Urli, L.. Universidad Nacional de Rosario; ArgentinaFil: Svetaz, M. J.. Universidad Nacional de Rosario; ArgentinaFil: Gennaro, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Volpintesta, R.. Universidad Nacional de Rosario; ArgentinaFil: Palatnik, S.. Universidad Nacional de Rosario; ArgentinaFil: Rasia, M.. Universidad Nacional de Rosario; Argentin

Haemorheological variables as a rheumatoid arthritis activity indicator

Objective: To investigate if blood hyperviscosity in RA patients is due to a reduced erythrocyte deformability and, therefore, turning it into a reliable activity indicator, as well as a therapy follow-up marker for this pathology. Methods: (1) The haemorheological profile consisting of erythrocyte deformability, blood and plasma viscosity, and erythrocyte membrane fluidity was determined in 24 AR patients and 17 healthy controls. (2) A 4 year follow-up was carried on in 16 patients monitoring blood viscosity, erythrocyte deformability and biochemical variables in relation to clinical assessment of disease activity (Disease Activity Score “DAS 28-4”). Results: Erythrocyte deformability and membrane fluidity were impaired in RA patients compared to controls (p<0.001). Blood viscosity was significantly increased and correlated with the cell rigidity index (r=0.85, p<0.0000) in RA patients. The follow-up showed a good correlation between haemorheological parameters and DAS 28-4 during disease evolution. Conclusion: our results support the hypothesis that in RA, blood hyperviscosity is determined by deformability loss, which in turn is due to a membrane rigidization. This could evidenced that a widespread cell membrane damage is expressed through an impaired erythrocyte deformability, turning haemorheological parameters into reliable tools to study disease evolution. The follow-up study enabled us to confirm that erythrocyte deformability is an efficient indicator of rheumatoid arthritis activity.Fil: Luquita, A.. Universidad Nacional de Rosario; ArgentinaFil: Urli, L.. Universidad Nacional de Rosario; ArgentinaFil: Dominighini, A.. Universidad Nacional de Rosario; ArgentinaFil: Svetaz, M. J.. Universidad Nacional de Rosario; ArgentinaFil: Gennaro, Ana Maria. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe. Instituto de Desarrollo Tecnológico para la Industria Química. Universidad Nacional del Litoral. Instituto de Desarrollo Tecnológico para la Industria Química; ArgentinaFil: Volpintesta, R.. Universidad Nacional de Rosario; ArgentinaFil: Palatnik, S.. Universidad Nacional de Rosario; ArgentinaFil: Rasia, M.. Universidad Nacional de Rosario; Argentin