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

A tale of two community networks program centers: Operationalizing and assessing CBPR principles and evaluating partnership outcomes

BACKGROUND: Community Networks Program (CNP) centers are required to use a community-based participatory research (CBPR) approach within their specific priority communities. Not all communities are the same and unique contextual factors and collaborators’ priorities shape each CBPR partnership. There are also established CBPR and community engagement (CE) principles shown to lead to quality CBPR in any community. However, operationalizing and assessing CBPR principles and partnership outcomes to understand the conditions and processes in CBPR that lead to achieving program and project level goals is relatively new in the science of CBPR. OBJECTIVES: We sought to describe the development of surveys on adherence to and implementation of CBPR/CE principles at two CNP centers and examine commonalities and differences in program- versus project-level CBPR evaluation. METHODS: A case study about the development and application of CBPR/CE principles for the Missouri CNP, Program for the Elimination of Cancer Disparities, and Minnesota CNP, Padres Informados/Jovenes Preparados, surveys was conducted to compare project versus program operationalization of principles. Survey participant demographics were provided by CNP. Specific domains found in CBPR/CE principles were identified and organized under an existing framework to establish a common ground. Operational definitions and the number of survey items were provided for each domain by CNP. CONCLUSION: There are distinct differences in operational definitions of CBPR/CE principles at the program and project levels of evaluation. However, commonalities support further research to develop standards for CBPR evaluation across partnerships and at the program and project levels

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

Antifungal chalcones and new caffeic acid esters from Zuccagnia punctata acting against soybean infecting fungi

Schmeda-Hirschmann, G. Laboratorio de Química de Productos Naturales, Instituto de Química de Recursos Naturales.The crude methanolic extract of Zuccagnia punctata was active toward the fungal pathogens of soybean Phomopsis longicolla and Colletotrichum truncatum. Assay guided fractionation led to the isolation of two chalcones, one flavanone and a new caffeoyl ester derivative as the compounds responsible for the antifungal activity. Another new caffeoyl ester derivative was isolated from the antifungal chloroform extract but proved to be inactive against the soybean infecting fungi up to 50 g/m

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

Racism and Its Harmful Effects on Nondominant Racial–Ethnic Youth and Youth-Serving Providers: A Call to Action for Organizational Change: The Society for Adolescent Health and Medicine

© 2018 Racism can exert negative effects on the self-concepts, health and well-being, and life trajectories of both nondominant racial–ethnic (NDRE) youth and youth-serving providers. In the face of growing nationalism, ethnocentrism, xenophobia, and overt expressions of racism, the Society for Adolescent Health and Medicine recognizes the critically important need to address the issue of racism and its impact on both NDRE youth and youth-serving providers. Organizations involved in clinical care delivery and health professions training and education must recognize the deleterious effects of racism on health and well-being, take strong positions against discriminatory policies, practices, and events, and take action to promote safe and affirming environments. The positions presented in this paper provide a comprehensive set of recommendations to promote routine clinical assessment of youth experiences of racism and its potential impact on self-concept, health and well-being, and for effective interventions when affected youth are identified. The positions also reflect the concerns of NDRE providers, trainees, and students potentially impacted by racism, chronic minority stress, and vicarious trauma and the imperative to create safe and affirming work and learning environments across all levels of practice, training, and education in the health professions. In this position paper, Society for Adolescent Health and Medicine affirms its commitment to foundational moral and ethical principles of justice, equity, and respect for humanity; acknowledges racism in its myriad forms; defines strategies to best promote resiliency and support the health and well-being of NDRE youth, providers, trainees, and students; and provides recommendations on the ways to best effect systemic change