La dimensión argumentativa en la entrevista de campo: el espacio biográfico como topo fundamental: Estudio de caso; The Argumentative Dimension in a Field Interview: The Biographical Field as an Essential Setting: Case Study Aráoz, Isabel El objetivo del presente trabajo es abordar la dimensión argumentativa presente en la entrevista de campo a partir de un estudio de caso. La entrevista recupera las experiencias de estudiantes beneficiados con becas económicas que posibilitan la permanencia en el nivel educativo superior universitario y la obtención del título percibido como un medio legítimo de ascenso social. Lo argumentativo se construye, fundamentalmente, como un topo biográfico que certifica la posición y la identidad del sujeto entrevistado por medio de la narración de la propia vida. Tomaremos dos entrevistas como ejemplos representativos de un universo mayor. Para el análisis de los argumentos, que concretizan el topo biográfico, utilizaremos como categorías centrales las nociones de “contradicción, problematización, roles argumentativos, actantes y actores, tipos de argumentos” propuestas por Plantin (2004) como dispositivos básicos de la dimensión argumentativa, junto al concepto de “ley de paso” de Toulmin (1958). Podemos advertir que las entrevistas construyen el espacio de lo social a través de la narración de la experiencia individual. El relato de los entrevistados presenta como estructura básica tres momentos característicos: “desventaja, esfuerzo y recompensa”.; The aim of the following paper is to deal with the argumentative dimension, which is introduced in the field interview of a case study. The interviews collect the experiences of students who have economic benefits (scholarships) that make possible their continuance in the university superior level, and thus the obtaining of the degree as a legal mean of social mobility. The argumentative dimension is built, mainly, as a biography that certifies the position and the identity of the individual interviewed, who tells about his or her own life. We are going to take two interviews as examples that represent a major group. We will also take into account as central categories the notions of “contradiction, approaching, argumentative roles, actors, and types of story lines” to make an analysis that builds the biography. These concepts were proposed by Plantin (2004) as the basic elements of the argumentative dimension. We are also going to bear in mind the concept of the “passing law” posed by Toulmin (1958). These interviews build the social space through the narration of the individual experience. The accounts of the people interviewed present three typical moments which are introduced as the basic structure: “disadvantage, effort and reward”.

Indigenous microorganisms as potential bioremediators for environments contaminated with heavy metals Colin, Veronica Leticia; Villegas, Liliana Beatriz; Abate, Carlos Mauricio Heavy metal pollution is one the most serious environmental problems facing our planet today, and immediate solutions are needed. Heavy metals such as copper (Cu) and chromium (Cr) play an important role as trace elements in biochemical reactions, but these metals are toxic at higher concentrations. In our region, mining and industrial activities have led to large-scale copper contamination in the environment. All organisms have homeostasis mechanisms for this metal, but when these controls fail or are exceeded several toxicological processes can develop.Problems involving Cr contamination are related to the fact that Argentina is an important world producer of leather. A chromium compound is used as a tanning agent, which has resulted in severe contamination near tanneries, with a mix of Cr(III) and Cr(VI). At present, the conventional technologies used to remove heavy metals from the environment involve physicochemical processes, which are costly and require large amounts of energy and specialized equipment. However, microbe-based removal is now considered to be an effective alternative method to the conventional processes and is receiving greater levels of interest for potential uses in bioremediation.This review discusses the toxic effects of Cu and Cr on the environment and on human health, as well as possible approaches for bioremediation of these metals using native microbes from our region.

Θαύματα hagiográficos y αὐτόματα de la Edad de Oro Cavallero, Pablo Adrian A partir del mito de la Edad de Oro y de la producción, en ella, de bienes automáticos, se analizan algunas referencias literarias medievales, seleccionadas del género hagiográfico, en las que se producen lo que habitualmente llamamos "milagros" y que se interpretan como una "cristianización" de los fenómenos asombrosos de los paganos antiguos. En unos y otros se busca una "espontaneidad" de bienes que hacen añorar una etapa perdida.; Starting from the myth of the Golden Age and the production of its automatic holdings, some medieval literary references are analyzed selected from the hagiographic genre. There, what we habitually call miracles appear and are interpreted as a Christianization of the amazing phenomena of the ancient pagans. In each others the spontaneity of those holdings seems to be missing a lost stage.

¿Herederos de Mayo y la Constitución de 1853? Liberalismo y antiliberalismo en el debate sobre la reforma constitucional de 1949 Martinez Mazzola, Ricardo Hernan El artículo aborda las reconfiguraciones que los discursos peronista y antiperonista experimentaron en el proceso que condujo a la reforma constitucional de 1949. En particular da cuenta del modo en que la posición ante la tradición liberal se convirtió en un parteaguas en el que se expresó, y profundizó, el enfrentamiento político. Reconstruye los argumentos que peronistas, radicales y socialistas sostuvieron en distintas arenas –el Parlamento Nacional, la tribuna pública, la Convención Constituyente- subrayando cómo en ellos se expresaba una profunda disputa acerca de la historia política argentina y del papel que en esa historia, y en particular en la formulación que en la Constitución de 1853, había cumplido la tradición liberal. El artículo concluye mostrando cómo una perspectiva atenta al carácter co-constitutivo de las identidades permite echar luz sobre la significación de la coyuntura de la reforma constitucional en una historia más larga de las tradiciones políticas argentinas.

A novel hybrid promoter responsive to pathophysiological and pharmacological regulation Subang, Maria C.; Fatah, Rewas; Bright, Carly; Blanco, Patricia; Berenstein, Mariana Gisela; Wu, Ying; Podhajcer, Osvaldo Luis; Winyard, Paul G.; Chernajovsky, Yuti; Gould, David The aim of this study was to construct a promoter containing DNA motifs for an endogenous transcription factor associated with inflammation along with motifs for pharmacological regulation factors. We demonstrate in transfected cells that expression of a gene of interest is induced by hypoxic conditions or through pharmacological induction, and also show pharmacological repression. In vivo studies utilised electroporation of plasmid to mouse paws, a delivery method shown to be effective by bioluminescence imaging. For gene therapy, the promoter was used to drive expression of IL-1Ra in a paw inflammation model with therapeutic effect observed which was further enhanced when the promoter was additionally induced with a pharmacological activator. One of the most important observations from this study was that promoter induction by hypoxia or inflammation could be prevented by the pharmacological repressor in the absence of doxycycline. These studies demonstrate that hybrid promoters enable pharmacological adjustment to the pathophysiological level of gene expression and, importantly, that they allow termination of gene expression even in the presence of pathophysiological stimuli.

Retinal changes in an experimental model of early type 2 diabetes in rats characterized by non-fasting hyperglycemia Salido, Ezequiel Martin; de Zavalia, Nuria Maria Asuncion; Schreier, Laura Ester; de Laurentiis, Andrea; Rettori, Valeria; Chianelli, Monica Silvia; Keller Sarmiento, Maria Ines; Arias, Pablo; Rosenstein, Ruth Estela Diabetic retinopathy is a leading cause of acquired blindness in young, but also in elder adults, mostly affected by type 2 diabetes mellitus (T2DM). The aim of this work was to develop an experimental model of early human T2DM in adult rats, and to analyze retinal functional, morphological, and biochemical changes arising during the early stages of the moderate metabolic derangement. For this purpose, animals were divided in four groups: adult male Wistar rats receiving: tap water and citrate buffer i.p. (group 1), tap water with 30% sucrose and citrate buffer i.p. (group 2), tap water and 25 mg/kg i.p streptozotocin (STZ, group 3), or 30% sucrose and STZ (group 4). Fasting and postprandial glycemia, fructosamine and serum insulin levels were assessed. In addition, i.p. glucose and insulin tolerance tests were performed. Retinal function (electroretinogram, ERG) and morphology (optical microscopy), retinal nitric oxide synthase (NOS) activity (using 3H-arginine), lipid peroxidation (thiobarbituric acid reactive substances, TBARS), and TNFα levels (ELISA) were evaluated. At 6 and 12 weeks of treatment, animals which received a sucrose-enriched diet and STZ showed significant differences in most metabolic tests, as compared with the other groups. At 12 weeks of treatment, a significant decrease in the ERG a- and b- wave and oscillatory potential amplitudes, and a significant increase in retinal NOS activity, TBARS, TNFα, glial fibrillary acidic protein in Müller cells, and vascular endothelial growth factor levels were observed. These results indicate that the combination of diet-induced insulin resistance and a slight secretory impairment resulting from a low-dose STZ treatment mimics some features of human T2DM at its initial stages, and provokes significant retinal alterations.

Relación entre condiciones habitacionales y mortalidad infantil en la provincia del Chaco (Argentina). Determinación de diferentes escenarios posibles Ponce, Blanca Elizabeth; Fantin, María Alejandra Las condiciones de la vivienda han sido reconocidas como una de las principales determinantes sociales de la salud humana. Las deficiencias en la vivienda y el saneamiento constituyen un determinante reiterado del exceso de mortalidad y una característica sistemáticamente vinculada a los niveles de pobreza, el rezago socioeconómico y la inequidad territorial en América Latina y el Caribe. El presente trabajo tiene como objetivo obtener una clasificación de las áreas programáticas de la provincia del Chaco en función de sus características habitacionales y niveles de mortalidad infantil; mediante el análisis de componentes principales y el análisis de cluster. La provincia del Chaco, se sitúa en el nordeste de la República Argentina e integra la región del Norte Grande Argentino. Geopolíticamente pertenece a un área periférica, con una débil y estacionaria economía, ubicándose entre las provincias más deficitarias.; The housing conditions have been recognized as one of major social determinants of health. The deficiencies in housing and sanitation are a major determinant of excess mortality repeatedly and consistently feature linked to the levels of poverty, socio-economic backwardness and territorial inequality in Latin America and the Caribbean. The present Work aims to obtain a classification of the program areas of the province of Chaco in terms of housing characteristics and levels of child mortality by principal component analysis and cluster analysis.

Fazer cultura: fazer(-se) estado: vernissages e performatividade de estado em Córdoba Blazquez, Gustavo Como assinalam Bourdieu (1994) e Taussig (1992), entre outros, entregarse à tarefa de pensar analiticamente o Estado é expor-se ao perigo de sucumbir a seu encantamento. O brilho, fálico talvez, seu caráter de fetiche e seu “E” maiúsculo têm o poder mágico de fazer com que nos percamos entre suas representações e em seus efeitos encantados e encantadores. Enquanto trabalhadores do Estado, empregados públicos da Ciência e do Saber universitário, também corremos o risco de encantar nossas próprias crenças sobre as formas de organização estatal com os discursos doutos que produzimos, mantendo-as intactas e fora de qualquer crítica. Conscientes destes perigos e com a pretensão talvez também mágica de dar conta do Estado, buscaremos, com o auxílio da Antropologia, desnaturalizar um certo “senso comum intelectual”.; The present article explores processes of State formation and government cultural policies in Córdoba (Argentina) during the first half of the 21st century. Analyzing the cerimonies that attend the inauguration of art exhibits – vernissages – we discuss the performative dimensions of State practices that, in the name of culture, “make the State” through highly esteticized forms which appeal to the senses. In these performances, the State is materialized in two ways. The “magic of the State” occurs when interdependent relationships between agents appears and is institutionalized and also when na attractive image materializes that destined to reinforce this distinction as a resource for the production of hegemony.

Beneficial effects of Neotyphodium tembladerae and Neotyphodium pampeanum on a wild forage grass Iannone, Leopoldo Javier; Pinget, Albertina Daniela; Nagabhyru, P.; Schardl, C. L.; De Battista, J. P. Asexual, vertically transmitted fungal endophytes of the genus Neotyphodium are considered to enhance growth, stress resistance and competitiveness of agronomic grasses, but have been suggested to have neutral or deleterious effects on wild grasses. We studied whether the associations between Bromus auleticus and their endophytes, Neotyphodium pampeanum and Neotyphodium tembladerae, are beneficial for this wild forage grass native to South America. In a greenhouse experiment, 3-month-old endophyte-infected plants (E+) showed enhanced growth relative to their endophyte-free counterparts (E−). In a one-year-long experiment in the field, E+ plants showed higher survival and regrowth rate, and produced more biomass and seeds than E− plants. Only with respect to the seed output did N. tembladerae seem to be detrimental, whereas N. pampeanum did not affect this parameter. No differences were observed with respect to the germination of seeds produced by E+ or E− plants. Loline alkaloids were detected in N. pampeanum-infected plants. Our results show that, similar to results with agronomic grasses, in wild grasses, the symbiosis with Neotyphodium species could be mutualistic.

Modelling the effect of temperature and water activity of Aspergillus flavus isolates from corn Astoreca, Andrea Luciana; Vaamonde, Graciela; Dalcero, Ana Maria; Ramos, A. J.; Marin, S. The aim of this study was to model the effects of temperature (10–40 °C) and aw (0.80–0.98), in two media (Czapek yeast agar: CYA; corn extract medium: CEM) on the growth rates and growth boundaries (growth–no growth interface) of three strains of A. flavus isolated from corn in Argentina. Both kinetic and probability models were applied to colony growth data. The growth rates obtained in CYA were significantly (p < 0.05) greater than those obtained in CEM medium. No significant differences (p < 0.05) were observed among the three isolates. The growth rate data showed a good fit to the Rosso cardinal models combined with the gamma-concept with R2 = 0.98–0.99 and RMSE = 0.60–0.78, depending on media and isolates. The probability model allowed prediction of safe storage (p of growth < 0.01) for one month for moist maize (e.g. 0.90 aw) provided temperature is under 15 °C, or for dry maize (e.g. 0.80 aw) provided temperature is under 27 °C. Storage at < 0.77 aw would be safe regardless of the storage temperature. Probability models allow evaluation of the risk of fungal contamination in the process of storage, so the results obtained in this study may be useful for application in systems of food safety management.

Characterization of full-length HIV-1 CRF17_BF genomes and comparison to the prototype CRF12_BF strains Aulicino, Paula; Gómez Carrillo, Manuel; Bello, Gonzalo; Rocco, Carlos; Mangano, Andrea María Mercedes; Carr, Jean; Sen, Luisa; Foley, Brian The aim of this work is to characterize the full-length intersubtype recombinant structure of the HIV-1 Circulating Recombinant Form CRF17_BF. A single genome of CRF17_BF was originally described in 2001 as being largely similar to CRF12_BF. Since then, more genomes of CRF17_BF have been sequenced but not adequately described in publications. Here we describe CRF17_BF as a genuine CRF, and analyze its recombination pattern based on bootscan analyses, subtype signature patterns, and phylogenetic reconstruction of subtype-delimited segments. We show that CRF17_BF can be distinguished from CRF12_BF in several regions of the genome, including vpu, pol, env and nef. A complete and accurate characterization and description of recombination breakpoints in CRFs is required for a proper surveillance of HIV-1 genotypes, and important for epidemiological purposes.

Operations research techniques for scheduling chile's second division soccer league Duran, Guillermo Alfredo; Guajardo, Mario; Wolf Yadlin, Rodrigo In this paper, we use operations research (OR) techniques to schedule the Second Division of the Chilean professional soccer league. The solution must satisfy a series of conditions requested by league officials. Because the teams generally travel long distances by bus, geographical restrictions are particularly important. We specify the scheduling problem and solve it using an integer linear programming (ILP) model that defines when and where each match is played, subject to constraints. For the most difficult instances, we formulate a second ILP model that generates home-away patterns and assigns them to the teams; we then run the model, which determines the match schedule. Chilean league officials have successfully used the models to schedule all five Second Division tournaments between 2007 and 2010, replacing the random scheduling methodology that they used previously. Since 2007, the two formulations have been adapted to various formats with which the Second Division has experimented; these include a quadruple round robin and a two-phase tournament with zonal and national phases. The application we present is one of a number of such projects that the authors and their colleagues developed over the past few years, and it represents an expansion of the use of OR techniques for managing tasks in Chilean soccer.

Affirmative cue words in task-oriented dialogue Gravano, Agustin; Hirschberg, Julia; B?nu?, Stefan We present a series of studies of affirmative cue words-a family of cue words such as "okay" or "alright" that speakers use frequently in conversation. These words pose a challenge for spoken dialogue systems because of their ambiguity: They may be used for agreeing with what the interlocutor has said, indicating continued attention, or for cueing the start of a new topic, among other meanings. We describe differences in the acoustic/prosodic realization of such functions in a corpus of spontaneous, task-oriented dialogues in Standard American English. These results are important both for interpretation and for production in spoken language applications. We also assess the predictive power of computational methods for the automatic disambiguation of these words. We find that contextual information and final intonation figure as the most salient cues to automatic disambiguation. © 2012 Association for Computational Linguistics.

Anatomía de leño de Maytenus vitis-idaea y M. viscifolia (Celastraceae) Giménez, María Juliana; Calatayu, Federico; Figueroa, María Eugenia; Diaz Zirpolo, Jose Antonio Es objetivo del trabajo describir el leño de Maytenus vitis-idaea Griseb. y M. viscifolia Griseb.(Celastraceae) y determinar rasgos ecoanatómicos. Las muestras fueron recolectadas del bosque natural en la localidad Guampacha, Sierras de Guasayán, Santiago del Estero, Argentina (distrito chaqueño serrano). Cinco individuos de cada especie fueron seleccionados al azar, obteniéndose una rodaja a 0.3 m. En las descripciones del leño se usó la terminología del Comité de Nomenclatura de IAWA. Los rasgos fundamentales del leño de Maytenus se resumen en: poros pequeños, numerosos, vasos pequeños,miembros de vasos cortos y anillos de crecimiento angostos. El leño de las dos especies estudiadas se caracteriza por presentar porosidad difusa a semicircular, anillos de crecimiento tipo 5b; poros numerosos y pequeños, parénquima axial de distribución apotraqueal en bandas discontinuas de una sola hilera de células, con tendencia a reticulado; escaso paratraqueal unilateral y difuso en agregados,radios heterogéneos; presencia de fibrotraqueidas. Las principales diferencias anatómicas radican en el tipo de poros, fundamentalmente solitarios en M. vitis-idaea y la presencia de radios de mayor longitud en M. viscifolia. Ambas maderas presentan rasgos xerofiticos notorios.; Wood anatomy of Maytenus vitis-idaea. y M. viscifolia (Celastraceae). Is objective of this study to describe the wood anatomy of Maytenus vitis-idaea Griseb. and M. viscifolia Griseb. (Celastraceae) and to determine ecoanatomy features. The samples were collected from natural forest in Guampacha, Guasayán, Santiago del Estero, Argentina (Chaco Serrano district). Five individuals were randomly selected; being obtained a track to 0.3 m. IAWA Committee on Nomenclature terminology was used in wood descriptions. Xylem features of Maytenus be summarized as: numerous small pores, short vessel members and growth rings narrow. The wood of the two species were characterized by diffuse to semi-circular porosity, growth rings type 5b, numerous small pores, apotracheal axial parenchyma in discontinuous bands, with a tendency to cross-linked, low paratracheal unilateral and diffuse in aggregates, heterogeneous rays, fibrotracheids present. The main anatomical difference is the predominance of solitary pores in M. vitis-idaea and longest rays in M. viscifolia. Both woods present conspicuous xerophytic features.

Carboniferous atomodesmids (Mollusca: Bivalvia) from central Patagonia, Argentina Gonzalez, Carlos Roberto; Waterhouse, J. B. A group of bivalves from the Carboniferous rocks of central Patagonia show some resemblances with the Permian family Atomodesmidae. These specimens are known from fragmentary material; some may be in the early stages of the atomodesmids, and kolymiids, and are provisionally assigned to that genus. Four distinct forms are revised; they are Atomodesma amleri n. sp., Aphanaia? sp. indet., Aphanaia precursa n. sp., and Kolymia? sp. indet.

Evaluación de fungicidas curasemillas en garbanzo en Tucumán, R. Argentina de Lisi, Vicente; Gonzalez, Victoria Anahí; Reznikov, Sebastian; Stagnetto, Pablo; Ploper, Leonardo Daniel El garbanzo (Cicer arietinum L.) es una leguminosa invernal cuyo cultivo comenzó a realizarse en la Argentina durante la etapa colonial y que en 2010 ocupó alrededor de 40.000 hectáreas. En 2011 se incrementó a 80.000 hectáreas a nivel nacional de las cuales 25.000 hectáreas se sembraron en Tucumán y zonas de influencia (sudeste de Catamarca y oeste de Santiago del Estero). Uno de los principales problemas sanitarios del cultivo de garbanzo es la enfermedad llamada fusariosis, causada por el hongo Fusarium oxysporum. Desde hace tres campañas agrícolas se viene observando, en la zona de producción de garbanzo de Tucumán y áreas de influencia, la presencia de rodales de plantas marchitas, con elevada incidencia de marchitamiento por Fusarium sp. Una de las alternativas para prevenir la ocurrencia o disminuir la incidencia de esta patología en las primeras etapas del cultivo es el uso de fungicidas curasemillas. El objetivo del presente trabajo fue valorar el efecto de la aplicación de diferentes curasemillas de origen químico, en condiciones controladas y a campo, para mejorar la emergencia radicular de plantas de garbanzo, en lotes que habían mostrado una alta incidencia de marchitamiento por fusariosis en garbanzo. Los resultados mostraron que el uso de curasemillas en el cultivo de garbanzo incrementó el porcentaje de emergencia radicular, lo que se vio reflejado en los ensayos realizados a campo y en condiciones controladas. Se observó un mejor comportamiento de los tratamientos que contenían ingredientes activos del grupo de los bencimidazoles (pero no en todos los casos). En el ensayo a campo, el tratamiento que mejores resultados mostró fue el que combinó Cruiser Plus + Rizocarb 50.

Peculiar anisotropic stationary spherically symmetric solution of Einstein equations Gallo, Emanuel; Moreschi, Osvaldo Mario Motivated by studies on gravitational lenses, we present an exact solution of the field equations of general relativity, which is static and spherically symmetric, has no mass but has a nonvanishing spacelike components of the stressenergymomentum tensor. In spite of its strange nature, this solution has nontrivial descriptions of gravitational effects. We show that the main aspects found in the dark matter phenomena can be satisfactorily described by this geometry. We comment on the relevance it could have to consider nonvanishing spacelike components of the stressenergymomentum tensor ascribed to dark matter. © 2012 World Scientific Publishing Company.

Estimación de la Incidencia de Cáncer de Tiroides en Capital Federal y el Gran Buenos Aires (período 2003-2011) Faure, E. N.; Soutelo, Maria Jimena; Faraj, G.; Lufti, Ruben Julio; Juvenal, Guillermo Juan La incidencia del cáncer de tiroides ha aumentado significativamente en las últimas décadas en el resto del mundo. En Argentina no existe un registro nacional de cáncer por lo que la incidencia del mismo no puede establecerse. Por lo tanto, nuestro objetivo fue estimar la incidencia de cáncer de tiroides en la población de la Ciudad Autónoma de Buenos aires y Gran Buenos Aires así como la relación por género y la histología en el período de 2003 hasta 2011. Asumiendo que la población de afiliados a la Obra Social de la Policía Federal Argentina es representativa de los habitantes de Buenos Aires y el conurbano calculamos que la incidencia es de 6,51 casos/100.000 habitantes/año, con un incremento en 25 años mayor al doble, con predominio del carcinoma papilar frente al folicular.; Thyroid cancer incidence has significantly risen worldwide in the last decades. In Argentina, there is no national cancer registry; therefore its incidence can not be established. The objective of this study was to estimate the incidence of thyroid cancer in the population of Buenos Aires City and suburbs, and the relationship between gender and histology over the period 2003-2011. Assuming that the population affiliated to the Social Security of the Argentine Federal Police is representative of the inhabitants of Buenos Aires City and suburbs, we estimate an incidence of 6.51 cases/100,000 population/year, with an increasing incidence of almost double from 1981-1986 to 2003-2011. An increase in papillary thyroid cancer was mainly responsible for this rising trend. Incidence rates were higher for females (11.76/100,000 women) compared to those for males (2.65/100,000 men). Among men and women of all ages, the highest rate of incidence was for tumor size < 1 cm.Thyroid cancer incidence has significantly risen worldwide in the last decades. In Argentina, there is no national cancer registry; therefore its incidence can not be established. The objective of this study was to estimate the incidence of thyroid cancer in the population of Buenos Aires City and suburbs, and the relationship between gender and histology over the period 2003-2011. Assuming that the population affiliated to the Social Security of the Argentine Federal Police is representative of the inhabitants of Buenos Aires City and suburbs, we estimate an incidence of 6.51 cases/100,000 population/year, with an increasing incidence of almost double from 1981-1986 to 2003-2011. An increase in papillary thyroid cancer was mainly responsible for this rising trend. Incidence rates were higher for females (11.76/100,000 women) compared to those for males (2.65/100,000 men). Among men and women of all ages, the highest rate of incidence was for tumor size < 1 cm.

Amplificación del oncogén Her-2/neu en el carcinoma mamario Cánepa, Mariana Clara; Denninghoff, Valeria Cecilia; Perazzo, Florencia; Paesani, Fernando; Nieto, Silvana; Garcia, Alejandro; Avagnina, Alejandra; Elsner, Boris La determinación del estado de amplificación génica del Her-2/neu es crucial en el cáncer de mama porque permite seleccionar pacientes que se beneficiarían del tratamiento con trastuzumab. El trastuzumab es un anticuerpo monoclonal diseñado específicamente para reconocer y unirse a la proteína HER2. Según trabajos clínicos publicados, reduce un 50% el riesgo de recurrencia del cáncer en estadio temprano (utilizado en adyuvancia durante el lapso de un año)1 y reduce un 20% el riesgo relativo de muerte en pacientes con cáncer de mama metastásico (asociado a quimioterapia vs. quimioterapia solamente)2 . La amplificación del oncogen Her-2/neu determina que cada copia del gen puede ser transcripta y traducida llevando a una sobreproducción de ARNm y de la proteína correspondiente. La célula normal que expresa HER2 posee amplificación del gen Her-2/neu y alrededor de 50 000 copias de la proteína en la membrana celular3 . Las células tumorales pueden tener un incremento en el número de receptores a nivel de la membrana citoplasmática de hasta 20 veces sobre el valor normal, conduciendo a la célula a un crecimiento descontrolado.

Polyaniline nanofibers: Acute toxicity and teratogenic effect on Rhinella arenarum embryos Yslas, Edith Inés; Ibarra, Luis Exequiel; Peralta, Damian Oscar; Barbero, César Alfredo; Rivarola, Viviana; Bertuzzi, Mabel Lucia The fate and effect of nanomaterials in the environment is of paramount importance towards the technological application of the materials. This work shows the ecotoxicological potential of polyaniline (PANI) nanofibers in the larvae Rhinella arenarum by means of AMPHITOX test. Acute toxicity of PANI nanofibers towards embryos of the common South American toad R. arenarum (Anura: bufonidae) was evaluated in the premetamorphosis (stage 25) larvae. The exposure of R. arenarum larvae to at dose of 150, 250 and 400mgL-1 resulted in 100% viability within 96h exposure. The embryos at 2-4 blastomers stage (early life stage teratogenic test) revealed that embryos were not killed and no teratogenic effects were observed when embryos were incubated with PANI nanofibers (150 and 250mgL-1), while only a growth retardation of embryos was induced at levels of 250mg PANI nanofibersL-1. On the other hand, at 400mgL-1 concentration, a reduction in the body length of larvae and tail malformation was observed. This results suggest that a concentration-dependent toxicity is operative, typified by phenotypes that had abnormal body axes. The presence of PANI nanofibers in gut contents and its excretion by larval stages of R. arenarum was confirmed by UV-visible spectroscopy.