Dynamic regulation of cell volume and extracellular ATP of human erythrocytes

Introduction: The peptide mastoparan 7 (MST7) triggered in human erythrocytes (rbcs) the release of ATP and swelling. Since swelling is a well-known inducer of ATP release, and extracellular (ATPe), interacting with P (purinergic) receptors, can affect cell volume (Vr), we explored the dynamic regulation between Vr and ATPe. Methods and Treatments: We made a quantitative assessment of MST7-dependent kinetics of Vr and of [ATPe], both in the absence and presence of blockers of ATP efflux, swelling and P receptors. Results: In rbcs 10 μM MST7 promoted acute, strongly correlated changes in [ATPe] and Vr. Whereas MST7 induced increases of 10% in Vr and 190 nM in [ATPe], blocking swelling in a hyperosmotic medium + MST7 reduced [ATPe] by 40%. Pre-incubation of rbcs with 10 μM of either carbenoxolone or probenecid, two inhibitors of the ATP conduit pannexin 1, reduced [ATPe] by 40-50% and swelling by 40-60%, while in the presence of 80 U/mL apyrase, an ATPe scavenger, cell swelling was prevented. While exposure to 10 μM NF110, a blocker of ATP-P2X receptors mediating sodium influx, reduced [ATPe] by 48%, and swelling by 80%, incubation of cells in sodium free medium reduced swelling by 92%. Analysis and Discussion: Results were analyzed by means of a mathematical model where ATPe kinetics and Vr kinetics were mutually regulated. Model dependent fit to experimental data showed that, upon MST7 exposure, ATP efflux required a fast 1960-fold increase of ATP permeability, mediated by two kinetically different conduits, both of which were activated by swelling and inactivated by time. Both experimental and theoretical results suggest that, following MST7 exposure, ATP is released via two conduits, one of which is mediated by pannexin 1. The accumulated ATPe activates P2X receptors, followed by sodium influx, resulting in cell swelling, which in turn further activates ATP release. Thus swelling and P2X receptors constitute essential components of a positive feedback loop underlying ATP-induced ATP release of rbcs.Instituto de Física de Líquidos y Sistemas Biológico

Dynamic regulation of cell volume and extracellular ATP of human erythrocytes

Introduction: The peptide mastoparan 7 (MST7) triggered in human erythrocytes (rbcs) the release of ATP and swelling. Since swelling is a well-known inducer of ATP release, and extracellular (ATPe), interacting with P (purinergic) receptors, can affect cell volume (Vr), we explored the dynamic regulation between Vr and ATPe. Methods and Treatments: We made a quantitative assessment of MST7-dependent kinetics of Vr and of [ATPe], both in the absence and presence of blockers of ATP efflux, swelling and P receptors. Results: In rbcs 10 μM MST7 promoted acute, strongly correlated changes in [ATPe] and Vr. Whereas MST7 induced increases of 10% in Vr and 190 nM in [ATPe], blocking swelling in a hyperosmotic medium + MST7 reduced [ATPe] by 40%. Pre-incubation of rbcs with 10 μM of either carbenoxolone or probenecid, two inhibitors of the ATP conduit pannexin 1, reduced [ATPe] by 40-50% and swelling by 40-60%, while in the presence of 80 U/mL apyrase, an ATPe scavenger, cell swelling was prevented. While exposure to 10 μM NF110, a blocker of ATP-P2X receptors mediating sodium influx, reduced [ATPe] by 48%, and swelling by 80%, incubation of cells in sodium free medium reduced swelling by 92%. Analysis and Discussion: Results were analyzed by means of a mathematical model where ATPe kinetics and Vr kinetics were mutually regulated. Model dependent fit to experimental data showed that, upon MST7 exposure, ATP efflux required a fast 1960-fold increase of ATP permeability, mediated by two kinetically different conduits, both of which were activated by swelling and inactivated by time. Both experimental and theoretical results suggest that, following MST7 exposure, ATP is released via two conduits, one of which is mediated by pannexin 1. The accumulated ATPe activates P2X receptors, followed by sodium influx, resulting in cell swelling, which in turn further activates ATP release. Thus swelling and P2X receptors constitute essential components of a positive feedback loop underlying ATP-induced ATP release of rbcs.Instituto de Física de Líquidos y Sistemas Biológico

ATPe Dynamics in Protozoan Parasites: Adapt or Perish

In most animals, transient increases of extracellular ATP (ATPe) are used for physiological signaling or as a danger signal in pathological conditions. ATPe dynamics are controlled by ATP release from viable cells and cell lysis, ATPe degradation and interconversion by ecto-nucleotidases, and interaction of ATPe and byproducts with cell surface purinergic receptors and purine salvage mechanisms. Infection by protozoan parasites may alter at least one of the mechanisms controlling ATPe concentration. Protozoan parasites display their own set of proteins directly altering ATPe dynamics, or control the activity of host proteins. Parasite dependent activation of ATPe conduits of the host may promote infection and systemic responses that are beneficial or detrimental to the parasite. For instance, activation of organic solute permeability at the host membrane can support the elevated metabolism of the parasite. On the other hand ecto-nucleotidases of protozoan parasites, by promoting ATPe degradation and purine/pyrimidine salvage, may be involved in parasite growth, infectivity, and virulence. In this review, we will describe the complex dynamics of ATPe regulation in the context of protozoan parasite–host interactions. Particular focus will be given to features of parasite membrane proteins strongly controlling ATPe dynamics. This includes evolutionary, genetic and cellular mechanisms, as well as structural-functional relationships.Instituto de Investigaciones Bioquímicas de La Plat

Combinations of single-top-quark production cross-section measurements and vertical bar f(LV)V(tb)vertical bar determinations at root s=7 and 8 TeV with the ATLAS and CMS experiments

This paper presents the combinations of single-top-quark production cross-section measurements by the ATLAS and CMS Collaborations, using data from LHC proton-proton collisions at = 7 and 8 TeV corresponding to integrated luminosities of 1.17 to 5.1 fb(-1) at = 7 TeV and 12.2 to 20.3 fb(-1) at = 8 TeV. These combinations are performed per centre-of-mass energy and for each production mode: t-channel, tW, and s-channel. The combined t-channel cross-sections are 67.5 +/- 5.7 pb and 87.7 +/- 5.8 pb at = 7 and 8 TeV respectively. The combined tW cross-sections are 16.3 +/- 4.1 pb and 23.1 +/- 3.6 pb at = 7 and 8 TeV respectively. For the s-channel cross-section, the combination yields 4.9 +/- 1.4 pb at = 8 TeV. The square of the magnitude of the CKM matrix element V-tb multiplied by a form factor f(LV) is determined for each production mode and centre-of-mass energy, using the ratio of the measured cross-section to its theoretical prediction. It is assumed that the top-quark-related CKM matrix elements obey the relation |V-td|, |V-ts| << |V-tb|. All the |f(LV)V(tb)|(2) determinations, extracted from individual ratios at = 7 and 8 TeV, are combined, resulting in |f(LV)V(tb)| = 1.02 +/- 0.04 (meas.) +/- 0.02 (theo.). All combined measurements are consistent with their corresponding Standard Model predictions.Peer reviewe

La renovación de la palabra en el bicentenario de la Argentina : los colores de la mirada lingüística

El libro reúne trabajos en los que se exponen resultados de investigaciones presentadas por investigadores de Argentina, Chile, Brasil, España, Italia y Alemania en el XII Congreso de la Sociedad Argentina de Lingüística (SAL), Bicentenario: la renovación de la palabra, realizado en Mendoza, Argentina, entre el 6 y el 9 de abril de 2010. Las temáticas abordadas en los 167 capítulos muestran las grandes líneas de investigación que se desarrollan fundamentalmente en nuestro país, pero también en los otros países mencionados arriba, y señalan además las áreas que recién se inician, con poca tradición en nuestro país y que deberían fomentarse. Los trabajos aquí publicados se enmarcan dentro de las siguientes disciplinas y/o campos de investigación: Fonología, Sintaxis, Semántica y Pragmática, Lingüística Cognitiva, Análisis del Discurso, Psicolingüística, Adquisición de la Lengua, Sociolingüística y Dialectología, Didáctica de la lengua, Lingüística Aplicada, Lingüística Computacional, Historia de la Lengua y la Lingüística, Lenguas Aborígenes, Filosofía del Lenguaje, Lexicología y Terminología

Estudio de las competencias en el grado de Enfermería del National University College de Puerto Rico desde la perspectiva de los alumnos, docentes y empleadores

Resumen: El trabajo que presentamos está relacionado con el estudio de las competencias genéricas y específicas desde la perspectiva europea (Proyecto Tuning Europa), la visión latinoamericana (Proyecto Tuning América Latina) y los requerimientos establecidos por la Accreditation Commission for Education in Nursing, así como de otras investigaciones actuales sobre competencias en Enfermería. Para realizar esta investigación, utilizamos una metodología ex post facto de tipo comparativo-causal, planteamos como objetivo de investigación determinar el grado de importancia que deben tener las competencias del grado profesional de Enfermería desde la opinión del alumnado, el profesorado y los empleadores y si dicha opinión muestra o no diferencias estadísticamente significativas. Elegimos una muestra en la que están representados los 3 agentes, elaborando 3 escalas en formato Likert. Cada una de las escalas está conformada por 22 competencias valoradas con 5 categorías de respuesta. Algunas de las conclusiones a las que llegamos con este trabajo son la combinación de criterios entre los alumnos, docentes y empleadores para poder establecer un compromiso para mejorar los planes de estudios del grado de Enfermería y su adecuación al ámbito laboral. Abstract: The work presented is related to the study of generic and specific competences from the European perspective (Tuning Project), the Latin American vision through (Tuning Latin America Project) and the requirements established by the Accreditation Commission for Education in Nursing, as well as, other current research on nursing skills. To carry out this research, we have used an ex post facto methodology, exactly a comparative-causal study, establishing as the main research objective the degree of importance that competences should have in the Nursing program from the students, faculty members and employers point of view, and if their opinions shows or not statistically significant differences. For the study, we chose a sample in which the 3 agents are represented and 3 Likert scales were designed. Each scale is comprised of 22 competencies which have been valued with 5 categories of response. Some conclusions of this study are the combination of criteria among the students, teachers and employers, in order to establish a commitment to improve the curriculum of the degree of Nursing and its adaptation to the workplace. Palabras clave: Competencias, Enfermería, Tuning, Alumnado, Docentes, Empleadores, Keywords: Competencies, Nursing, Tuning, Students, Teachers, Employer

Physico-mechanical characterization and interactions with excipients of D-003, a mixture of fatty acids isolated from sugar cane wax

El D-003 es un nuevo producto que consiste en una mezcla de ácidos grasos de elevado peso molecular (desde C24:0 hasta C36:0), donde cada uno de ellos está en una proporción reproducible. Este producto presenta efectos antiplaquetarios y como reductor del colesterol. Como parte de los estudios de formulación del D-003 fueron llevadas a cabo la caracterización físico-mecánica y su interacción con excipientes para tabletas. El presente estudio utilizó la calorimetría diferencial de barrido (CDB) y la termogravimetría (TG) con el objetivo de evaluar la estabilidad térmica y las transiciones características del D-003 en presencia de diversos excipientes. Fueron medidas otras propiedades, tales como el ángulo de contacto, solubilidad, humectabilidad, distribución del tamaño de partículas, propiedades de fluido, densidades por asentamiento, por vertido y de alta presión, así como la reducción de volumen bajo compresión. Estos estudios, según nuestro conocimiento, no han sido previamente reportados para estos ácidos. Los estudios por CDB demostraron que no hubo interacción química o física entre el D-003 y los excipientes investigados. También, los análisis termogravimétricos probaron la elevada estabilidad térmica del D-003, el cual es estable y funde sin descomposición hasta temperaturas tan elevadas como 220 °C. Los lotes industriales estudiados mostraron adecuada pureza y distribución uniforme del tamaño de partícula, buenas propiedades de fluido, compresibilidad y cohesión, lo cual sustenta que sea un polvo apropiado para la elaboración de tabletas revestidas como forma terminada. Sin embargo, la muy baja solubilidad del D-003 en la mayoría de los disolventes, especialmente en agua, es el aspecto más crítico para el desarrollo la forma terminada, lo cual es importante para decidir la formulación del revestimiento.D-003 is a new product consisting of a mixture of fatty acids of very high molecular weight (from C24:0 to C36:0) in a reproducible proportion each, with cholesterol-lowering, and antiplatelet effects. As part of the formulation studies of D-003 a physico-mechanical characterization and its interaction with tablet excipients were carried out. The present study used differential scanning calorimetry (DSC) and thermogravimetry (TG) in order to evaluate the characteristic transitions and thermal stability of D- 003 in presence of several excipients. Other properties, such as the angle of contact, solubility, wettability, particle size distribution, flow properties, tapped, bulk and at high pressure densities, as well as volume reduction under compression were measured. These studies, to our knowledge, have not been previously reported to these fatty acids. DSC studies demonstrated that there was no chemical or physical interaction between D-003 and the investigated excipients. Also, thermogravimetric analysis proved the high thermal stability of D-003, which melts without decomposition and is stable at temperatures as high as 220 °C. Industrial batches of D-003 showed adequate purity and uniform particle size distribution, good flow properties, compressibility and compactability, which support a suitable powder for manufacturing film-coated tablets as finished forms. Nevertheless, the very low solubility of D-003 in most solvents, especially in water, is the most critical aspect for developing the finished form, being relevant to decide the coating formulation.Colegio de Farmacéuticos de la Provincia de Buenos Aire

Measurement of prompt photon production in sNN=8.16 TeV p + Pb collisions with ATLAS

The inclusive production rates of isolated, prompt photons in p+Pb collisions at s=8.16 TeV are studied with the ATLAS detector at the Large Hadron Collider using a dataset with an integrated luminosity of 165 nb recorded in 2016. The cross-section and nuclear modification factor R are measured as a function of photon transverse energy from 20 GeV to 550 GeV and in three nucleon-nucleon centre-of-mass pseudorapidity regions, (−2.83,−2.02), (−1.84,0.91), and (1.09,1.90). The cross-section and R values are compared with the results of a next-to-leading-order perturbative QCD calculation, with and without nuclear parton distribution function modifications, and with expectations based on a model of the energy loss of partons prior to the hard scattering. The data disfavour a large amount of energy loss and provide new constraints on the parton densities in nuclei

Measurement of the W boson polarisation in t(t)over-bar events from pp collisions at root s = 8 TeV in the lepton + jets channel with ATLAS (vol 77, pg 264, 2018)

This change does not have any impact on the measured helicity fractions, but it changes the obtained limits on the anomalous couplings

Measurements of the Total and Differential Higgs Boson Production Cross Sections Combining the H??????? and H???ZZ*???4??? Decay Channels at s\sqrt{s}=8??????TeV with the ATLAS Detector

Measurements of the total and differential cross sections of Higgs boson production are performed using 20.3~fb$^{-1}$ of $pp$ collisions produced by the Large Hadron Collider at a center-of-mass energy of $\sqrt{s} = 8$ TeV and recorded by the ATLAS detector. Cross sections are obtained from measured $H \rightarrow \gamma \gamma$ and $H \rightarrow ZZ ^{*}\rightarrow 4\ell$ event yields, which are combined accounting for detector efficiencies, fiducial acceptances and branching fractions. Differential cross sections are reported as a function of Higgs boson transverse momentum, Higgs boson rapidity, number of jets in the event, and transverse momentum of the leading jet. The total production cross section is determined to be $\sigma_{pp \to H} = 33.0 \pm 5.3 \, ({\rm stat}) \pm 1.6 \, ({\rm sys}) \mathrm{pb}$. The measurements are compared to state-of-the-art predictions.Measurements of the total and differential cross sections of Higgs boson production are performed using 20.3  fb-1 of pp collisions produced by the Large Hadron Collider at a center-of-mass energy of s=8  TeV and recorded by the ATLAS detector. Cross sections are obtained from measured H→γγ and H→ZZ*→4ℓ event yields, which are combined accounting for detector efficiencies, fiducial acceptances, and branching fractions. Differential cross sections are reported as a function of Higgs boson transverse momentum, Higgs boson rapidity, number of jets in the event, and transverse momentum of the leading jet. The total production cross section is determined to be σpp→H=33.0±5.3 (stat)±1.6 (syst)  pb. The measurements are compared to state-of-the-art predictions.Measurements of the total and differential cross sections of Higgs boson production are performed using 20.3 fb$^{-1}$ of $pp$ collisions produced by the Large Hadron Collider at a center-of-mass energy of $\sqrt{s} = 8$ TeV and recorded by the ATLAS detector. Cross sections are obtained from measured $H \rightarrow \gamma \gamma$ and $H \rightarrow ZZ ^{*}\rightarrow 4\ell$ event yields, which are combined accounting for detector efficiencies, fiducial acceptances and branching fractions. Differential cross sections are reported as a function of Higgs boson transverse momentum, Higgs boson rapidity, number of jets in the event, and transverse momentum of the leading jet. The total production cross section is determined to be $\sigma_{pp \to H} = 33.0 \pm 5.3 \, ({\rm stat}) \pm 1.6 \, ({\rm sys}) \mathrm{pb}$. The measurements are compared to state-of-the-art predictions