35 research outputs found

    Short-course radiotherapy for rectal cancer: real-world evidence in Argentina

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    Latin America; Rectal cancer; Short-course radiotherapyAmérica Latina; Cáncer de recto; Radioterapia de corta duraciónAmèrica Llatina; Càncer de recte; Radioteràpia de curta duradaBackground: Short-course radiotherapy (SCRT) of 25 Gy in five daily fractions is a recommended strategy in the neoadjuvant setting for resectable locally advanced rectal cancer (LARC), as well as in cases of metastatic disease for local control. There is scarce information regarding the use of SCRT for patients who have received nonoperative management. Objectives: To describe the characteristics of patients who received treatment with SCRT for LARC and metastatic rectal cancer, toxicity, and the approach after radiation treatment. Methods: This is a retrospective analysis of all patients who underwent SCRT for rectal cancer at the Alexander Fleming Institute from March 2014 to June 2022. Results: In total, 44 patients were treated with SCRT. The majority were male (29, 66%), with a median age of 59 years (interquartile range 46–73). Most patients had stage IV disease (26, 59.1%), followed by LARC (18, 40.9%). Most lesions were located in the middle rectum (30, 68%). The majority of LARC patients underwent SCRT followed by consolidation chemotherapy (ChT) (16/18, 89%), while most patients with metastatic disease underwent SCRT followed by consolidation ChT (14/26, 53.8%). A clinical complete response (cCR) was documented in 8/44, 18.2% of patients. Most patients with LARC and cCR were managed by a watch and wait approach (5/18, 27.7%). Local recurrence was observed in LARC cases (2/18, 11.1%). Patients who underwent SCRT following consolidation ChT were more likely to have adverse events (AEs) than those undergoing induction ChT following SCRT (11/30, 36.7% versus 3/12, 25%, p = 0.02) Conclusion: In a subgroup of patients diagnosed with LARC and treated with SCRT followed by ChT, surgical treatment could be omitted after they achieved a cCR. Local recurrence was similar to that reported in a previous study. SCRT is a reasonable option for local disease control in stage IV disease, yielding low toxicity rates. Therefore, decisions must be made by a multidisciplinary team. Prospective studies are necessary to reach further conclusions

    A New Paradigm for MAPK: Structural Interactions of hERK1 with Mitochondria in HeLa Cells

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    Extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) are members of the MAPK family and participate in the transduction of stimuli in cellular responses. Their long-term actions are accomplished by promoting the expression of specific genes whereas faster responses are achieved by direct phosphorylation of downstream effectors located throughout the cell. In this study we determined that hERK1 translocates to the mitochondria of HeLa cells upon a proliferative stimulus. In the mitochondrial environment, hERK1 physically associates with (i) at least 5 mitochondrial proteins with functions related to transport (i.e. VDAC1), signalling, and metabolism; (ii) histones H2A and H4; and (iii) other cytosolic proteins. This work indicates for the first time the presence of diverse ERK-complexes in mitochondria and thus provides a new perspective for assessing the functions of ERK1 in the regulation of cellular signalling and trafficking in HeLa cells

    New Algorithm to Determine True Colocalization in Combination with Image Restoration and Time-Lapse Confocal Microscopy to Map Kinases in Mitochondria

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    The subcellular localization and physiological functions of biomolecules are closely related and thus it is crucial to precisely determine the distribution of different molecules inside the intracellular structures. This is frequently accomplished by fluorescence microscopy with well-characterized markers and posterior evaluation of the signal colocalization. Rigorous study of colocalization requires statistical analysis of the data, albeit yet no single technique has been established as a standard method. Indeed, the few methods currently available are only accurate in images with particular characteristics. Here, we introduce a new algorithm to automatically obtain the true colocalization between images that is suitable for a wide variety of biological situations. To proceed, the algorithm contemplates the individual contribution of each pixel's fluorescence intensity in a pair of images to the overall Pearsońs correlation and Manders' overlap coefficients. The accuracy and reliability of the algorithm was validated on both simulated and real images that reflected the characteristics of a range of biological samples. We used this algorithm in combination with image restoration by deconvolution and time-lapse confocal microscopy to address the localization of MEK1 in the mitochondria of different cell lines. Appraising the previously described behavior of Akt1 corroborated the reliability of the combined use of these techniques. Together, the present work provides a novel statistical approach to accurately and reliably determine the colocalization in a variety of biological images

    La política habitacional porteña en la posconvertibilidad. Un análisis de las intervenciones ejecutadas en el hábitat popular y sus efectos en la valorización/desvalorización del suelo urbano

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    El documento que se presenta a continuación nuclea resultados de investigación construidos de manera colectiva por investigadores del Área de Estudios Urbanos (AEU) del Instituto de Investigaciones Gino Germani (IIGG) interesados por la producción social del hábitat y las políticas públicas que tienen por escenario la Ciudad de Buenos Aires (CABA).A partir del año 2003, la progresiva recuperación económica que mostró el país (en términos de salarios y niveles de empleo), impactó en la Ciudad de Buenos Aires ?entre otros aspectos- en un crecimiento inédito de la rama de la construcción y ?específicamente- de la edificación residencial. No obstante, esta mejora no repercutió en la situación habitacional de gran parte de los hogares porteños en situación de pobreza. A raíz de los incrementos en los precios del suelo y los inmuebles, una porción significativa de la población encontró dificultades para acceder a una vivienda a través del mercado inmobiliario formal y los procesos de producción social del hábitat se expandieron.En este marco, este documento se propone abordar las políticas habitacionales orientadas al hábitat popular implementadas desde el año 2003, a partir del análisis de una serie de intervenciones estatales específicas. A partir del análisis de las tipologías de hábitat objeto de las políticas y sus localizaciones, se indaga la dinámica de valorización/desvalorización del suelo en la Ciudad de Buenos Aires.Para ello, primeramente, se realizará una caracterización de la dinámica demográfica y la evolución del déficit habitacional en la ciudad y específicamente en tres comunas de la urbe, la Comuna n°1, Comuna n° 4 y Comuna n°8. Luego, se analizarán las políticas desplegadas sobre diferentes tipologías de hábitat popular y, posteriormente, se analizará la dinámica urbana que despliegan en el territorio, a partir de un estudio que abarca diferentes casos (Villa 31, Villa 19-Barrio INTA, el Asentamiento Rodrigo Bueno, los conjuntos habitacionales construidos a partir de 2003 en Villa Lugano y los conjuntos construidos por autogestión en el barrio de La Boca ). Por último, se ensayarán algunas conclusiones en las que se analiza la localización como una variable de peso en las características que asume la intervención estatalFil: Raspall Galli, Tomás Francisco. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; ArgentinaFil: Zapata, María Cecilia. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Di Virgilio, Maria Mercedes. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; ArgentinaFil: Rodriguez, Maria Carla. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Arqueros Mejica, Maria Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; ArgentinaFil: Rodriguez, Maria Florencia. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; ArgentinaFil: Vitale, Pablo Julián. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Von lucken, Marianne. Universidad de Buenos Aires. Facultad de Ciencias Sociales. Instituto de Investigaciones "Gino Germani"; Argentin

    Reversal of Synapse Degeneration by Restoring Wnt Signaling in the Adult Hippocampus

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    Synapse degeneration occurs early in neurodegenerative diseases and correlates strongly with cognitive decline in Alzheimer's disease (AD). The molecular mechanisms that trigger synapse vulnerability and those that promote synapse regeneration after substantial synaptic failure remain poorly understood. Increasing evidence suggests a link between a deficiency in Wnt signaling and AD. The secreted Wnt antagonist Dickkopf-1 (Dkk1), which is elevated in AD, contributes to amyloid-β-mediated synaptic failure. However, the impact of Dkk1 at the circuit level and the mechanism by which synapses disassemble have not yet been explored. Using a transgenic mouse model that inducibly expresses Dkk1 in the hippocampus, we demonstrate that Dkk1 triggers synapse loss, impairs long-term potentiation, enhances long-term depression, and induces learning and memory deficits. We decipher the mechanism involved in synapse loss induced by Dkk1 as it can be prevented by combined inhibition of the Gsk3 and RhoA-Rock pathways. Notably, after loss of synaptic connectivity, reactivation of the Wnt pathway by cessation of Dkk1 expression completely restores synapse number, synaptic plasticity, and long-term memory. These findings demonstrate the remarkable capacity of adult neurons to regenerate functional circuits and highlight Wnt signaling as a targetable pathway for neuronal circuit recovery after synapse degeneration

    Tumor Cell Phenotype Is Sustained by Selective MAPK Oxidation in Mitochondria

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    Mitochondria are major cellular sources of hydrogen peroxide (H2O2), the production of which is modulated by oxygen availability and the mitochondrial energy state. An increase of steady-state cell H2O2 concentration is able to control the transition from proliferating to quiescent phenotypes and to signal the end of proliferation; in tumor cells thereby, low H2O2 due to defective mitochondrial metabolism can contribute to sustain proliferation. Mitogen-activated protein kinases (MAPKs) orchestrate signal transduction and recent data indicate that are present in mitochondria and regulated by the redox state. On these bases, we investigated the mechanistic connection of tumor mitochondrial dysfunction, H2O2 yield, and activation of MAPKs in LP07 murine tumor cells with confocal microscopy, in vivo imaging and directed mutagenesis. Two redox conditions were examined: low 1 µM H2O2 increased cell proliferation in ERK1/2-dependent manner whereas high 50 µM H2O2 arrested cell cycle by p38 and JNK1/2 activation. Regarding the experimental conditions as a three-compartment model (mitochondria, cytosol, and nuclei), the different responses depended on MAPKs preferential traffic to mitochondria, where a selective activation of either ERK1/2 or p38-JNK1/2 by co-localized upstream kinases (MAPKKs) facilitated their further passage to nuclei. As assessed by mass spectra, MAPKs activation and efficient binding to cognate MAPKKs resulted from oxidation of conserved ERK1/2 or p38-JNK1/2 cysteine domains to sulfinic and sulfonic acids at a definite H2O2 level. Like this, high H2O2 or directed mutation of redox-sensitive ERK2 Cys214 impeded binding to MEK1/2, caused ERK2 retention in mitochondria and restricted shuttle to nuclei. It is surmised that selective cysteine oxidations adjust the electrostatic forces that participate in a particular MAPK-MAPKK interaction. Considering that tumor mitochondria are dysfunctional, their inability to increase H2O2 yield should disrupt synchronized MAPK oxidations and the regulation of cell cycle leading cells to remain in a proliferating phenotype

    A Mitochondrial Kinase Complex Is Essential to Mediate an ERK1/2-Dependent Phosphorylation of a Key Regulatory Protein in Steroid Biosynthesis

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    ERK1/2 is known to be involved in hormone-stimulated steroid synthesis, but its exact roles and the underlying mechanisms remain elusive. Both ERK1/2 phosphorylation and steroidogenesis may be triggered by cAMP/cAMP-dependent protein kinase (PKA)-dependent and-independent mechanisms; however, ERK1/2 activation by cAMP results in a maximal steroidogenic rate, whereas canonical activation by epidermal growth factor (EGF) does not. We demonstrate herein by Western blot analysis and confocal studies that temporal mitochondrial ERK1/2 activation is obligatory for PKA-mediated steroidogenesis in the Leydig-transformed MA-10 cell line. PKA activity leads to the phosphorylation of a constitutive mitochondrial MEK1/2 pool with a lower effect in cytosolic MEKs, while EGF allows predominant cytosolic MEK activation and nuclear pERK1/2 localization. These results would explain why PKA favors a more durable ERK1/2 activation in mitochondria than does EGF. By means of ex vivo experiments, we showed that mitochondrial maximal steroidogenesis occurred as a result of the mutual action of steroidogenic acute regulatory (StAR) protein –a key regulatory component in steroid biosynthesis-, active ERK1/2 and PKA. Our results indicate that there is an interaction between mitochondrial StAR and ERK1/2, involving a D domain with sequential basic-hydrophobic motifs similar to ERK substrates. As a result of this binding and only in the presence of cholesterol, ERK1/2 phosphorylates StAR at Ser232. Directed mutagenesis of Ser232 to a non-phosphorylable amino acid such as Ala (StAR S232A) inhibited in vitro StAR phosphorylation by active ERK1/2. Transient transfection of MA-10 cells with StAR S232A markedly reduced the yield of progesterone production. In summary, here we show that StAR is a novel substrate of ERK1/2, and that mitochondrial ERK1/2 is part of a multimeric protein kinase complex that regulates cholesterol transport. The role of MAPKs in mitochondrial function is underlined

    Escuela secundaria posible

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    REPENSAR LA EDUCACIÓN SECUNDARIA Colección de infografías II Parte Seguimiento de medios de comunicación 2017-2019Fil: Ferreyra, Horacio Ademar. Universidad Católica de Córdoba. Facultad de Educación; ArgentinaFil: Di Francesco, Adriana Carlota. Universidad Católica de Córdoba. Facultad de Educación; ArgentinaFil: Equipo de investigación en educación de adolescentes y jóvenes. Unidad Asociada CONICET. Universidad Católica de Córdoba. Facultad de Educación; Argentina

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

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    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

    Python feature engineering cookbook: over 70 recipes for creating, engineering, and transforming features to build machine learning models

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    Feature engineering is invaluable for developing and enriching your machine learning models. In this book, you will work with the best Python tools to streamline your feature engineering pipelines, feature engineering techniques and simplify and improve the quality of your code
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