Insights into gliadin supramolecular organization at digestive pH 3.0

Herrera MG, Vazquez DS, Sreij R, et al. Insights into gliadin supramolecular organization at digestive pH 3.0. COLLOIDS AND SURFACES B-BIOINTERFACES. 2018;165:363-370.Alpha-gliadin is a highly immunogenic protein from wheat, which is associated with many human diseases, like celiac disease and non-celiac gluten sensitivity. Because of that, gliadin solution is subject to intense biomedical research. However, the physicochemical nature of the employed gliadin solution at physiological pH is not understood. Herein, we present a supramolecular evaluation of the alpha-gliadin protein in water at pH 3.0 by dynamic light scattering (DLS), cryo-transmission electron microscopy (cryoTEM) and small-angle-.X-ray scattering (SAXS). We report that at 0.5 wt% concentration (0.1 mg/ml), gliadin is already a colloidal polydisperse system with an average hydrodynamic radius of 30 +/- 10 nm. By cryo-TEM, we detected mainly large clusters. However, it was possible to visualise for the first time prolate oligomers of around 68 nm and 103 nm, minor and major axis, respectively. SAXS experiments support the existence of prolate/rod-like structures. At 1.5 wt% concentration gliadin dimers, small oligomers and large clusters coexist. The radius of gyration (R-g1) of gliadin dimer is 5.72 +/- 0.23 nm with a dimer cross-section (R-c) of 1.63 nm, and an average length of around 19 nm, this suggests that gliadin dimers are formed longitudinally. Finally, our alpha-gliadin 3D model, obtained by ab initio prediction and analysed by molecular dynamics (MD), predicts that two surfaces prone to aggregation are exposed to the solvent, at the C-terminus. We hypothesise that this region may be involved in the dimerisation process of alpha-gliadin. (C) 2018 Elsevier B.V. All rights reserved

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Wave instabilities in an anisotropic magnetized space plasma

We study wave instability in an collisionless, rarefied hot plasma (e.g. solar wind or corona). We consider the anisotropy produced by the magnetic field, when the thermal gas pressures across and along the field become unequal. We apply the 16-moment transport equations (obtained from the Boltzmann-Vlasov kinetic equation) including the anisotropic thermal fluxes. The general dispersion relation for the incompressible wave modes is derived. It is shown that a new, more complex wave spectrum with stable and unstable behavior is possible, in contrast to the classic fire-hose modes obtained in terms of the 13-moment integrated equations.Comment: 5 pages, length reduced to that of a Research Note, A&A (in press

Characterization of visual object representations in rat primary visual cortex

For most animal species, quick and reliable identification of visual objects is critical for survival. This applies also to rodents, which, in recent years, have become increasingly popular models of visual functions. For this reason in this work we analyzed how various properties of visual objects are represented in rat primary visual cortex (V1). The analysis has been carried out through supervised (classification) and unsupervised (clustering) learning methods. We assessed quantitatively the discrimination capabilities of V1 neurons by demonstrating how photometric properties (luminosity and object position in the scene) can be derived directly from the neuronal responses

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Neuroimaging Evidence of Major Morpho-Anatomical and Functional Abnormalities in the BTBR T+TF/J Mouse Model of Autism

BTBR T+tf/J (BTBR) mice display prominent behavioural deficits analogous to the defining symptoms of autism, a feature that has prompted a widespread use of the model in preclinical autism research. Because neuro-behavioural traits are described with respect to reference populations, multiple investigators have examined and described the behaviour of BTBR mice against that exhibited by C57BL/6J (B6), a mouse line characterised by high sociability and low self-grooming. In an attempt to probe the translational relevance of this comparison for autism research, we used Magnetic Resonance Imaging (MRI) to map in both strain multiple morpho-anatomical and functional neuroimaging readouts that have been extensively used in patient populations. Diffusion tensor tractography confirmed previous reports of callosal agenesis and lack of hippocampal commissure in BTBR mice, and revealed a concomitant rostro-caudal reorganisation of major cortical white matter bundles. Intact inter-hemispheric tracts were found in the anterior commissure, ventro-medial thalamus, and in a strain-specific white matter formation located above the third ventricle. BTBR also exhibited decreased fronto-cortical, occipital and thalamic gray matter volume and widespread reductions in cortical thickness with respect to control B6 mice. Foci of increased gray matter volume and thickness were observed in the medial prefrontal and insular cortex. Mapping of resting-state brain activity using cerebral blood volume weighted fMRI revealed reduced cortico-thalamic function together with foci of increased activity in the hypothalamus and dorsal hippocampus of BTBR mice. Collectively, our results show pronounced functional and structural abnormalities in the brain of BTBR mice with respect to control B6 mice. The large and widespread white and gray matter abnormalities observed do not appear to be representative of the neuroanatomical alterations typically observed in autistic patients. The presence of reduced fronto-cortical metabolism is of potential translational relevance, as this feature recapitulates previously-reported clinical observations

The effect of air pollution on children's health: A comparative study between La Plata and Bahía Blanca, Buenos Aires province, Argentina

We present the results of a study of outdoor air quality in two comparable regions of Buenos Aires province (Argentina); La Plata and Bahía Blanca, developed jointly by researchers of the National University in both cities, and of the Hospital of Bahía Blanca, between 2009 and 2011. Both regions are characterized by a large petrochemical complex and a village with outstanding traffic. In this study, we measure levels of volatile organic compounds (VOCs), particulate matter suspended in air (PM) in air outdoor and affectation of respiratory system in children between 6 and 12 years. Also, analysis of the effect of the air pollution exposure was made through the calculation of potentially increased life time cancer risk (LCR) in children. In both regions, including three areas: urban, industrial and residential (reference area), 20 VOCs were sampled by passive monitoring (3M 3500), and determined by GC/FID, comprising n-alkanes, cycloalkanes, aromatics, chlorinated compounds, terpenoids and ketones; particulate matter (PM10) was token using a low flow sampler MiniVol TAS, and spirometry were performed, using a portable spirometer. The collected data show higher levels of PM10 in Bahía Blanca, both in the industrial zone and urban areas, the industrial area of Bahía Blanca with very bad air quality, associable with a 5% increase in mortality. The levels of total VOCs found in the residential area for both regions are comparable. Spirometry parameters of children living in an industrial area evidence respiratory disease with respect to urban and residential areas.Facultad de Ciencias ExactasFacultad de Ingenierí

Presencia de enfermedades en majadas caprinas de las quebradas áridas de Jujuy y Salta

Una encuesta transversal ad hoc se llevó a cabo en 40 unidades productoras familiares (UPF) de las áridas en las provincias de Jujuy y Salta, con el objetivo de describir la presencia de enfermedades en sus majadas caprinas. Se recabaron datos del manejo general y sanitario en particular. Se procesaron sueros para el diagnóstico de brucelosis por las pruebas tamiz del antígeno bufferado en placa (BPA) y confirmadas por polarización fluorecente (FPA), para paratuberculosis (PTBC), artritis-encefalitis (CAEV), chlamydiosis, herpesvirus caprino tipo 1 (CaHV-1), fiebre Q y toxoplasmosis se utilizó ELISA indirecto y para leptospirosis microaglutinación. Se determinaron los valores de Cu2+, Zn2+, Mg2+ y Ca2+ sérico por espectofotómetría de absorción atómica. En heces, se realizó el recuento de huevos de helmintos por gramo (hpg) y la diferenciación de géneros por coprocultivo.Las UPF tuvieron en promedio 91,4±75 caprinos (sin contar cabritos), siendo el 80,9% cabras madres. La cría fue extensiva con encierre nocturno y la alimentación de la majada se basó mayormente en el pastoreo de los cerros y de cultivos y rastrojos. La parición se concentró en dos períodos, uno principal en abril-julio y una segunda parición de menor número de cabras ubicada en octubre-diciembre. El 92,3% de los productores desparasitaba en forma rutinaria toda la majada con ivermectina, albendazole o closantel y el 71,8 % trataba los piojos. En un 61,5% de las UPF se inyectaba mineralizantes-vitamínicos a toda la majada y en solo un 15,4% se vacunaba contra enfermedades clostridiales. El promedio de la tasa de mortalidad anual por majada fue del 14,2±11%. En el 86,4% de las UPF se registró la ocurrencia de abortos, y de estos el 42,9% presentó retención de placenta. El promedio intramajada de abortos comunicados fue del 8,6±8,5%. El 75% de las UPF declaró tener ectima contagioso, aunque solo el 22% dijo que era grave. Se registraron un 30,4% cuadros de muertes agudas probablemente por infecciones clostridiales. En el 72,7% de las UPF se registraron problemas de mastitis. El porcentaje de UPF con seroprevalencia positiva a brucelosis, leptospirosis, paratuberculosis, toxoplasmosis, clamidiosis, CpHV-1, CAEV y fiebre Q fue respectivamente de 0%, 25%, 50%, 42,8%, 88,8%, 85,7%, 12,5% y 0%. Las UPF destacaron la importancia de los piojos (Linognathus spp.: 87%). Los promedios de los hpg fueron en abril-mayo, julio-agosto y septiembre-noviembre respectivamente de 407, 332 y 59 con Haemonchus y en menor medida Trichostrongylus como nematodes predominantes. En el 76% de las UPF se diagnosticó Fasciolosis. El 30,8% de las UPF describió la presencia a la faena de quistes hidatídicos. En un 31% de las majadas se describió bocio. Los promedios por UPF de cobre, zinc, magnesio y calcio séricos fueron respectivamente 0,48 ±0,10 ppm, 0,73±0,16 ppm, 2,4±0,47mg/d y 7,25±2,25 mg/dl. Se describieron casos de timpanismo espumoso (43,5%), muertes (36%) atribuidas por los propietarios a la ingesta de ñusco, mio mio y sunchillo y un 38,1% de las UPF dijeron padecer casos de intoxicación con cegadera (Heterophyllaea pustulata). Un 66,7% de los propietarios declararon tener problemas de pérdidas de animales en el monte a causa mayormente de pumas. Estos primeros resultados en cuanto a mortandad y presencia de enfermedades y zoonosis, muestran la importancia de llevar a cabo estudios más específicos respecto de la salud de las majadas para incrementar la producción y el bienestar general de las familias productoras.Fil: Suarez, V. H.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Dodero, Ana Mariela. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Nievas, J. D.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Martinez, G. M.. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Salta-Jujuy. Estación Experimental Agropecuaria Salta; ArgentinaFil: Bertoni, E. A.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Salatin, A. O.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Viñabal, A. E.. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Grossberger, G.. No especifíca;Fil: Brihuega, Bibiana. Instituto Nacional de Tecnología Agropecuaria. Centro de Investigación en Ciencias Veterinarias y Agronómicas; ArgentinaFil: Romera, Sonia. Instituto Nacional de Tecnología Agropecuaria; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pinto, G.. Instituto Nacional de Tecnología Agropecuaria; Argentin