Synthesis of enantiomeric polyhydroxyalkylpyrrolidines from 1,3-dipolar cycloadducts. Evaluation as inhibitors of a β-galactofuranosidase

Enantiomeric 2,3,4-tris(hydroxyalkyl)-5-phenylpyrrolidines have been synthesized from the major cycloadducts obtained by the 1,3-dipolar cycloaddition of sugar enones with azomethine ylides derived from natural amino acids. Reduction of the ketone carbonyl group of the cycloadducts, which possess a basic structure of bicyclic 6-(menthyloxy)hexahydropyrano[4,3-c]pyrrol-7(6H)one, afforded a number of pyrrolidine-based bicyclic systems. A sequence of reactions, which involved hydrolysis of the menthyloxy substituent, reduction, N-protection, and degradative oxidation, afforded varied pyrrolidine structures having diverse configurations and patterns of substitution; in particular, polyhydroxylated derivatives have been obtained. The unprotected products were isolated as pyrrolidinium trifluoroacetates. Because of the furanose-like nature of the target trihydroxyalkyl pyrrolidines, these molecules have been evaluated as inhibitors of the β-galactofuranosidase from Penicillium fellutanum. The compounds showed practically no inhibitory activity for concentration of pyrrolidines in the range of 0.1–1.6 mM.Fil: Oliveira Udry, Guillermo Alejandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Repetto, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; ArgentinaFil: Vega, Daniel Roberto. Comisión Nacional de Energía Atómica. Centro Atómico Constituyentes. Gerencia de Investigación y Aplicaciones; Argentina. Universidad Nacional de San Martín. Escuela de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Varela, Oscar Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Centro de Investigaciones en Hidratos de Carbono. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Centro de Investigaciones en Hidratos de Carbono; Argentin

Interés de la elaboración de vídeos didácticos como material de prácticas en la asignatura de "Seguridad Química"

El presente trabajo tiene por objeto presentar el proceso seguido en la elaboración de una serie videográfica constituida por tres videos didácticos, que abordan los aspectos fundamentales de los riesgos derivados de la exposición a sustancias químicas y agentes biológicos en un labo - ratorio universitario. dicho material didáctico innovador, se utilizará en los seminarios teóricos de la asignatura seguridad Química, impartida por los profesores del área de toxicología de la universidad de sevilla. los objetivos fundamentales de dichos videos han sido despertar el mayor interés posible y favorecer la asimilación de conceptos básicos en el alumnado de dicha asignatura, haciendo especial hincapié en la correcta y segura manipulación, el adecuado almacenamiento y la correcta eliminación de las sustancias, contribuyendo en definitiva a la prevención de los riesgos derivados de su exposición.The present work aims to illustrate the process followed to elaborate a set of three didactic illustrate the process followed to elaborate a set of three didactic videos, which shows the main aspects of derived risks from the exposure to the chemical substances and biological agents present in a university laboratory. this innovator didactic material will be used in the subject “chemical security” seminaries lectured by the professors from toxicology area in the university of seville. the most important aims of these videos have been to implicate the students in their learning, making easier for them to assimilate the basic concepts of the subject, such as the correct and secure way of manipulate the chemical substances, its appropriate storage and its suitable elimination, contributing to the prevention of the risks derived from their exposure

Direct Determination of Glutathione S-transferase and Glucose-6-phosphate Dehydrogenase Activities in Cells Cultured in Microtitre Plates as Biomarkers for Oxidative Stress

The enzymes glutathione S,-transferase (GST) and glucose-6-phosphate dehydrogenase (G-6PDH) are implicated in the defence against oxidative stress. GST is mainly involved in the conjugation of electrophilic compounds with glutathione (GSH), although some of its isoenzymes display peroxidase activity. G-6PDH and glutathione reductase regenerate NADPH and GSH, respectively, to restore the reduced intracellular redox .status following oxidative stress. Enzymatic assays for GST and G-6PDH were adapted and optimised to permit the direct in vitro determination of the effects of toxicants which induce oxidative stress in cells on microtitre plates, thereby avoiding the need to prepare cell-free extracts. To optimise the conditions of the enzymatic assays, GST activity was measured at substrate concentrations of 1-3mM GSH and 1-3mM 1-chloro-2,4-dinitrobenzenew, hile G-6PDH activity was measured at 7.5-37.5mM glucose-6-phosphate and 55-275mM NADP. Both enzymatic activities were directly proportional to cell number up to a density of 1 x 105 cellsiwell. The effects on GST and G-6PDH activities of three toxicants which induce oxidative stress - paraquat, iron (11) chloride and iron (111) chloride - were compared in cultured Vero cells to validate the new assays. Specific GST activity increased to 145% and 171% compared to the controls in cells treated with 5mM paraquat and 5mM iron (11) chloride, respectively, but was inhibited after exposure to 25mM iron (111) chloride. Specific G-6PDH activity increased to 136% compared to the control after exposure to 5mM paraquat, but was inhibited in cells exposed to 5mM iron (11) chloride and 25mM iron (111) chlorid

Direct Determination of Glutathione Reductase in Cells Cultured in Microtitre Plates as a Biomarker for Oxidative Stress

A new method was developed for the direct determination of glutathione reductase (GOR) activity in Vero cells cultured in microtitre plates, avoiding cell-free extract preparation. The cells in each well were washed twice with phosphate-buffered saline, lysed with Triton X-100, and assayed in 0.1M potassium phosphate, pH 7.0. After subtracting oxidase activity, which increased with NADPH concentration, the net GOR activity was similar at different oxidised glutathione (GSSG) and NADPH concentrations, thus confirming enzyme saturation. The optimised GOR assay used 2.5mM GSSG and 0.12mM NADPH; 5mM EDTA was also added to prevent the enzyme from redox inactivation. The GOR activity was directly proportional to the number of cells per well for a wide range of cell densities, thus supporting the assay's validity for use with cultured cells. The effects on GORactivity of three chemicals which induce oxidative stress, namely, paraquat, iron (11) chloride and iron (111) chloride, were examined to validate the assay under experimental conditions. The specific enzymatic activity increased to 357% of untreated control activity in 5mM paraquat-treated cells, and to 407% of control activity in cells exposed to 7.5mM iron (11) chloride. By contrast, activity decreased to 56% of control activity in cells exposed to 5mM iron (111) chloride. In conclusion, the changes in GOR activity detected in Vero cells confirm that the new assay is suitable for routine in vitro screening of toxicants capable of inducing oxidative stress

Media and Journalism in Argentina: Politics, Money and Technology

Argentina has a robust media structure. There are many newspapers throughout the country. Radio and television have nation wide coverage through a system that privileges licenses to the private commercial sector. State radio stations and television channels also have a nationwide presence, but with very small audiences. In 2005, non-profit community radio and television was authorized to broadcast. Access to communication services has high penetration rates. Pay-TV (cable and satellite) has maintained a wide penetration since the 1990s and currently reaches 70% of households. News programming holds a relevant place. Mobile telephony, which developed in the 1990s, is used by the entire population. It is the main access route to the internet, especially in popular sectors. The penetration of internet services in households is lower than that of mobile telephony. Only in recent years has the introduction of fiber optic to home begun to take shape, although for now itis only available in some large urban centers. Regarding the market structure, one of the characteristics of the media system in Argentina is the high concentration of ownership. The Clarín Group is the mainplayer in the communication system, with dominant positions (first or second largest player in each market) in print media, radio, open and paid television, fixed and mobile telephony, and home internet distribution. It is an unprecedented case, even at the level of Latin America, of dominance in content production markets and content distribution at the same time. Historically, Argentina has shown significant development in its cultural industries, especially when compared to the region. The media has had high rates of consumption. However, in recent years, analog media has lost importance. This situation is more evident in the print press and is beginning to impact television and radio. On the other hand, digital media, especially information distribution through platforms, is gaining space.Fil: Mastrini, Guillermo Néstor. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Repetto, Carla Belén. Universidad Nacional de Quilmes; ArgentinaFil: Espada, Agustín Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de Quilmes; ArgentinaFil: Razetto, Martín. Universidad Nacional de Quilmes; Argentin

Pollution detection in the atmosphere of the Neuquén city by biomass burning from 18th to 22nd February 2015

El humo provocado por una importante quema de biomasa en la provincia de Chubut,cerca del Parque Nacional Los Alerces, en febrero de 2015, fue trasportado por efecto de los vientos a diferentes zonas de la Patagonia. En este trabajo se presenta la detección de este evento sobre la ciudad de Neuquén por la estación de monitoreo atmosférico instalada en el Aeropuerto Internacional de Neuquén por CITEDEF y operada por personal del Servicio Meteorológico Nacional. Las mediciones realizadas con el sistema lidar muestra las alturas de las distintas capas de aerosoles y el fotómetro solar de la red AERONET/NASA (Aerosol Robotic Network) detectó valores altos de espesor óptico de aerosoles. Las imágenes satelitales muestran que el humo llegó a la ciudad el 18 de febrero quedando en suspensión por varios días.The smoke caused by an important biomass burning in the province of Chubut, near Los Alerces National Park, in February 2015, was transported by the effect of winds to different areas of Patagonia. This paper presents the detection of this event over the city of Neuquén by the atmospheric monitoring station installed at the Neuquén International Airport by CITEDEF and operated by staff of the National Meteorological Service. The measurements made with the lidar system show the heights of the different aerosol layers and the AERONET/NASA (AErosol RObotic NETwork) solar photometer detected high values of aerosol optical thickness. The satellite images show that the smoke arrived in the city on February 18, staying in suspension for several days.Fil: Otero, Lidia Ana. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Ministerio de Defensa. Ejército Argentino. Instituto de Enseñanza Superior del Ejército. Escuela Superior Técnica; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Ristori, Pablo Roberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; ArgentinaFil: Sambueza, Sandra. Ministerio de Defensa. Secretaria de Planeamiento. Servicio Meteorológico Nacional; ArgentinaFil: Brusca de Giorgio, Silvina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Herrera, Milagros Estefanía. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones Científicas y Técnicas para la Defensa. Centro de Investigación en Láseres y Aplicaciones; ArgentinaFil: Bali, Juan Lucas. Ministerio de Defensa. Instituto de Investigaciones Científicas y Técnicas para la Defensa; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Pereyra, Andrea Fabiana. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Martorella, Evangelina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: D'elia, Raul Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Fierro, Victor Eduardo. Ministerio de Defensa. Ejército Argentino. Instituto de Enseñanza Superior del Ejército. Escuela Superior Técnica; ArgentinaFil: Franchi, Guillermo Javier. Ministerio de Defensa. Ejército Argentino. Instituto de Enseñanza Superior del Ejército. Escuela Superior Técnica; ArgentinaFil: Repetto, Carla Irene. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; ArgentinaFil: Vilar, Osvaldo Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Salvador, Jacobo Omar. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentina. Universidad Nacional de la Patagonia Austral. Unidad Académica Río Gallegos; ArgentinaFil: Raponi, Marcelo Martín. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Unidad de Investigación y Desarrollo Estratégico para la Defensa. Ministerio de Defensa. Unidad de Investigación y Desarrollo Estratégico para la Defensa; ArgentinaFil: Quel, Eduardo Jaime. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Ministerio de Defensa. Ejército Argentino. Instituto de Enseñanza Superior del Ejército. Escuela Superior Técnica; Argentina. Universidad Tecnológica Nacional. Facultad Regional Buenos Aires; Argentin

Daily Gain, Feed Conversion, and Rumen Fermentation in Finishing Steers Fed a Total Mixed Ration Supplemented with a Blend of Essential Oils, Tannins, and Bioflavonoids or Monensin

This study investigated the effects of adding a blend of essential oils, tannins, bioflavonoids (ANAVRIN®, VetosEurope, Lugano, Switzerland), monensin, and their combination on the daily gain, feed conversion, and rumen fermentation of finishing steers fed a total mixed ration (TMR). Thirty finishing steers (441 kg body weight, 34.3 months old) consuming a TMR were blocked by BW and randomly assigned to three treatments according to the addition of (1) EOTB (ANAVRIN® at 0.35 g/100 kg body weight), (2) MON (monensin at 0.033 g/kg dry matter), and (3) EOTB + MON (at the same dose as in (1) and (2). A 60-day feeding trial was conducted, including a 19-day adaptation period. Data collected included daily dry matter intake (DMI), average daily gain (ADG), feed conversion ratio (FCR), and rumen fermentation parameters (pH, NH3-N, and volatile fatty acid (VFA) concentrations). EOTB resulted in higher DMI compared to EOTB + MON, while no significant differences were observed in ADG or FCR. The ruminal pH and NH3-N concentrations were similar among treatments, but there were interactions among treatment × hour for VFAs. The EOTB + MON led to a more stable VFA concentration in rumen suggesting possible complementary supplementation effects. However, more studies are needed to confirm this and to go deeper into the underlying mechanism of action

Toxicological interest of Microcystins

Las Microcistinas (MCs) son toxinas de estructura heptapeptídica producidas por floraciones de cianobacterias tóxicas de aguas superficiales eutróficas. Las MCs al igual que la nodularina son hepatotóxicas en humanos, aunque también dan lugar a alteraciones gastrointestinales, reacciones alérgicas o irritación y sintomatología similar a la neumonía. El principal riesgo tóxico deriva de su actividad promotora tumoral, y capacidad genotóxica. Diversos estudios epidemiológicos sugieren una mayor incidencia de cáncer de hígado en zonas cuya población está expuesta de forma prolongada a MCs, por consumo de aguas de bebida contaminadas, advirtiéndose la necesidad de conocer otras posibles fuentes de exposición humana, tales como alimentos. La Organización Mundial de la Salud ha adoptado (WHO, 1998) un valor guía provisional de 1,0 μg/L de MCLR en aguas de bebida, comprendiendo tanto las MCs intra como las extracelulares. En la Reglamentación técnico-sanitaria vigente en España para el abastecimiento y control de la calidad de las aguas potables de consumo público (RD 1138/1990 de 14 de Septiembre) no se hace referencia a la determinación y control de MCs; sin embargo en el nuevo proyecto de reglamentación, anexo D, que hace referencia a las sustancias tóxicas, se fija una concentración máxima admisible de MCs de 1 μg/L en el caso de aguas eutróficas. En esta revisión se consideran los efectos tóxicos agudos, crónicos y el mecanismo de acción de las Microcistinas.Microcystins (MCs) are toxins of heptapeptidic structure produced by the bloom of toxic cyanobacteria in surface eutrophic waters. MCs, just like nodularine, are hepatotoxic in humans, but they also cause gastrointestinal alterations, allergic reactions, irritation and neumonia-like symptomatology. The main toxic risk derives from their tumor-promoting activity and genotoxic capacities. Several epidemiological studies suggest an increased incidence of liver cancer in populations chronically exposed to MCs. The main source is contaminated drinking water, but other sources of human exposure, such as food, should be investigated. The World Health Organization adopted (WHO, 1998) a provisional guide value of 1,0 μg/L of MC-LR in drinking water, including intra- and extracellular MCs. In the present Spanish legislation regarding quality control of drinking water (RD 1138/1990 of 14 September), the determination and control of MCs are not included; however, in the draft of the new legislation, annex D, concerning toxic chemicals, a maximum tolerable concentration of 1 μg/L is fixed for MCs in eutrophic waters. Acute and chronic effects and the mechanism of action of MCs are considered in this review