616 research outputs found

    Germination response to water availability in populations of Festuca pallescens along a Patagonian rainfall gradient based on hydrotime model parameters

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    Sensitivity to water availability is a key physiological trait for grassland species located in arid and semiarid environments, where successful germination is closely related to rainfall dynamics. Festuca pallescens inhabits diverse environments along a steep precipitation gradient in North Patagonia, thus offering a suitable model for the study of germination behavior in response to water availability. By analyzing germination in nine populations using a hydrotime model approach, we aimed to find within-species variation. Seed population behavior was analyzed under different hydric conditions using hydrotime model parameters (hydrotime, mean base water potential and its standard deviation). We estimated the mean base water potential for F. pallescens (ψb(50) = − 2.79 ± 0.45 MPa), which did not differ significantly between populations. However, the hydrotime parameter (θH) varied markedly, suggesting physiological adaptation to local environments. Higher values of θH were found in populations located at the extremes of the distribution gradient, indicating that germination may be prevented or delayed in conditions that are suboptimal for the species. Since the variation in hydrotime model parameters did not follow a cline, micro-environmental cues may have the greatest influence on the physiological behavior of the species, rather than the macroscale rainfall gradient.Estación Experimental Agropecuaria BarilocheFil: Lopez, Aldana Soledad. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Lopez, Aldana Soledad. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Lopez, Dardo Ruben. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Campo Anexo Villa Dolores; ArgentinaFil: Arana, María Veronica. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Arana, María Veronica. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Battla, Diego. Universidad Nacional de Buenos Aires. Instituto de Investigaciones Fisiológicas y Ecológicas Vinculadas a la Agricultura; ArgentinaFil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Marchelli, Paula. Consejo Nacional de Investigaciones Cientificas y Tecnicas. Instituto de Investigaciones Forestales y Agropecuarias Bariloche; Argentin

    A genomic island in Brucella involved in the adhesion to host cells: identification of a new adhesin and a translocation factor

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    Adhesion to host cells is the first step in the virulence cycle of any pathogen. In Gram-negative bacteria, adhesion is mediated, among other virulence factors such as the lipopolysaccharides, by specific outer-membrane proteins generally termed adhesins that belong to a wide variety of families and have different evolutionary origins. In Brucella, a widespread zoonotic pathogen of animal and human health concern, adhesion is central as it may determine the intracellular fate of the bacterium, an essential stage in its pathogenesis. In the present paper, we further characterised a genomic locus that we have previously reported encodes an adhesin (BigA) with a bacterial immunoglobulin-like domain (BIg-like). We found that this region encodes a second adhesin, which we have named BigB; and PalA, a periplasmic protein necessary for the proper display in the outer membrane of BigA and BigB. Deletion of bigB or palA diminishes the adhesion of the bacterium and overexpression of BigB dramatically increases it. Incubation of cells with the recombinant BIg-like domain of BigB induced important cytoskeletal rearrangements and affected the focal adhesion sites indicating that the adhesin targets cell–cell or cell–matrix proteins. We additionally show that PalA has a periplasmic localisation and is completely necessary for the proper display of BigA and BigB, probably avoiding their aggregation and facilitating their transport to the outer membrane. Our results indicate that this genomic island is entirely devoted to the adhesion of Brucella to host cells.Fil: Lopez, Paula Veronica. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Guaimas, Francisco Fernando. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Czibener, Cecilia. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Biotecnológicas; ArgentinaFil: Ugalde, Juan Esteban. Universidad Nacional de San Martín. Instituto de Investigaciones Biotecnológicas. - Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Parque Centenario. Instituto de Investigaciones Biotecnológicas; Argentin

    Gene expression profile and signaling pathways in MCF-7 breast cancer cells mediated by acyl-CoA synthetase 4 overexpression

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    Aim: Breast cancer comprises a heterogeneous group of diseases that vary in morphology, biology, behavior and response to therapy. Previous studies have identified an acyl-CoA synthetase 4 (ACSL4) gene-expression pattern correlated with very aggressive tumors. In particular, we have used the tetracycline Tet-Off system to stably transfect non-aggressive breast cancer MCF-7 cells and developed a stable line overexpressing ACSL4 (MCF-7 Tet-Off/ACSL4). As a result, we have proven that cell transfection solely with ACSL4 cDNA renders a highly aggressive phenotype in vitro and results in the development of growing tumors when injected into nude mice. Nevertheless, and in spite of widespread consensus on the role of ACSL4 in mediating an aggressive phenotype in breast cancer, the early steps through which ACSL4 increases tumor growth and progression have been scarcely described and need further elucidation. For this reason, the goal of this work was to study the gene expression profile and the signaling pathways triggered by ACSL4 overexpression in the mechanism that leads to an aggressive phenotype in breast cancer. Methods: We have performed a massive in-depth mRNA sequencing approach and a reverse-phase protein array using MCF-7 Tet-Off/ACSL4 cells as a model to identify gene expression and functional proteomic signatures specific to ACSL4 overexpression. Results and Conclusion: The sole expression of ACSL4 displays a distinctive transcriptome and functional proteomic profile. Furthermore, gene networks most significantly upregulated in breast cancer cells overexpressing ACSL4 are associated to the regulation of embryonic and tissue development, cellular movement and DNA replication and repair. In conclusion, ACSL4 is an upstream regulator of tumorigenic pathways. Because an aggressive tumor phenotype appears in the early stages of metastatic progression, the previously unknown mediators of ACSL4 might.Fil: Castillo, Ana Fernanda. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquimica; ArgentinaFil: Orlando, Ulises Daniel. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquimica; ArgentinaFil: Lopez, Paula Veronica. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquimica; ArgentinaFil: Solano, Angela Rosario. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquimica; ArgentinaFil: Maloberti, Paula Mariana. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquimica; ArgentinaFil: Podesta, Ernesto Jorge. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Biomédicas; Argentina. Universidad de Buenos Aires. Facultad de Medicina. Departamento de Bioquimica; Argentin

    Pigments and paints in Antofagasta de la sierra. compositional analysis of minerals and ceramic surfaces (province of Catamarca, Argentina)

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    Se presentan los resultados obtenidos sobre el estudio composicional de pinturas y engobes aplicados sobre cerámica arqueológica de distintos estilos recuperada en Punta de la Peña, Peñas Coloradas y Paicuqui, localidades arqueológicas de la microrregión de Antofagasta de la Sierra (Provincia de Catamarca, Argentina). Se evalúa la variabilidad de minerales empleados tanto en piezas de producción local como en recipientes de procedencia alóctona. Además, se detectó que en Paicuqui afloran depósitos de minerales colorantes de distintas tonalidades y se recuperaron también evidencias de procesamiento de pigmentos. A través de análisis por Difracción de Rayos X y Microespectroscopía Raman se caracteriza la composición de estas materias primas y se discute su posible uso en la cerámica estudiada. La información generada contribuye, por un lado, al conocimiento de las prácticas locales de producción, circulación y consumo de alfarería y de saberes para su elaboración que se desarrollaron en la región en el rango cronológico ca. 1000-1500 DC y, además, conforma el principio de una base de datos necesaria para la referencia de fuentes de pigmentos, escasamente registrados en el Noroeste Argentino.The results of compositional studies of paints and slips applied on archaeological ceramics of different styles recovered at Punta de la Peña, Peñas Coloradas and Paicuqui, archaeological sites of Antofagasta de la Sierra microrregion (Catamarca Province, Argentina), are presented and discussed. The variability of minerals used in local, as well as, in foreign pieces is evaluated. Furthermore, pigment deposits of diverse colors and also evidences of pigment processing were found. These materials were characterized by X-ray diffraction and Raman microspectroscopy and their possible appli cation in the fabrication of the studied ceramics is discussed. This information may contribute to the knowledge of the local pottery production, circulation ways and use, and of the elaboration techniques developed in this region during the chronological range ca. 1000-1500 AD. Also, may serve as the start of an empirical reference database of raw materials sources, which are scarcely registered in Argentine Northwest.Fil: Puente, Veronica. Universidad Nacional de Mar del Plata. Facultad de Humanidades. Departamento de Historia. Laboratorio de Arqueología Regional Bonaerense; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; ArgentinaFil: Desimone, Paula Mariela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones en Ciencia y Tecnología de Materiales. Universidad Nacional de Mar del Plata. Facultad de Ingeniería. Instituto de Investigaciones en Ciencia y Tecnología de Materiales; ArgentinaFil: Porto Lopez, Jose Manuel. Universidad Nacional de Mar del Plata. Facultad de Humanidades. Departamento de Historia. Laboratorio de Arqueología Regional Bonaerense; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata; Argentin

    Survival trends of patients with oral and oropharyngeal cancer treated at a cancer center in Sa˜o Paulo, Brazil

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    OBJECTIVE: We aimed to estimate the overall survival (OS) and conditional survival (CS) in patients diagnosed with oral and oropharyngeal squamous cell carcinoma (SCC) and to determine their survival trends. METHODS: The study included all consecutive patients treated at the A.C. Camargo Cancer Center for oral or oropharyngeal SCC between 2001 and 2012. Data were obtained from the Hospital Cancer Registry. OS and CS were analyzed using the Kaplan-Meier method to evaluate the probability of survival with Cox predictor models. RESULTS: Data of 505 oral and 380 oropharyngeal SCC patients obtained in 2001–2006 and 2007–2012 were analyzed. Most of the oral SCC (59%) and oropharyngeal SCC (90%) patients had stages III–IV SCC. The 5-year OS for patients with oral SCC was 51.7%, with no significant difference between the first and second periods. The CS rates in 2007–2012 were 65% after the first year and 86% up to the fifth year. For oropharyngeal SCC, the 5-year OS rate was 45.0% in the first period. The survival rate increased to 49.1% from 2007 to 2012, with a reduction in the risk of death (HR=0.69;0.52–09.2). The CS estimates from 2007 to 2012 were 59% after the first year and 75% up to the fifth year. CONCLUSION: Survival across the two time periods remained stable for oral SCC but showed a significant increase for oropharyngeal SCC, possibly because of improvements in the patients’ response to radiotherapy, such as intensity-modulated radiation therapy, and the use of more accurate diagnostic imaging approaches

    Coirón blanco: primeros pasos en la domesticación de una especie clave de los pastizales patagónicos

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    Los pastizales naturales son el principal componente forrajero en Patagonia Norte. La ganadería extensiva con suplementación en períodos críticos, la baja cobertura vegetal del suelo y el efecto del viento aumentan el riesgo de degradación de los pastizales. La domesticación para el cultivo de especies forrajeras nativas permitiría la mejora de la productividad y la recuperación de pastizales con diferentes niveles de degradación.Estación Experimental Agropecuaria BarilocheFil: Lopez, Aldana Soledad. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; ArgentinaFil: Siffredi, Guillermo Lorenzo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área de Recursos Naturales; ArgentinaFil: Azpilicueta, María Marta. Instituto Nacional de Tecnología Agropecuaria (INTA). Estacion Experimental Agropecuaria Bariloche. Área Sistemas Forestales. Grupo de Genética Ecológica y Mejoramiento Forestal; ArgentinaFil: Arana, María Verónica.Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche, Instituto de Investigaciones Forestales y Agropecuarias Bariloche; ArgentinaFil: Caballé, Gonzalo. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Grupo Ecología Forestal; ArgentinaFil: López, Dardo Ruben. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Campo Anexo Villa Dolores; ArgentinaFil: Marchelli, Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentin

    SOX9 Triggers Different Epithelial to Mesenchymal Transition States to Promote Pancreatic Cancer Progression.

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    BACKGROUND Pancreatic ductal adenocarcinoma (PDAC) is one of the most lethal cancers mainly due to spatial obstacles to complete resection, early metastasis and therapy resistance. The molecular events accompanying PDAC progression remain poorly understood. SOX9 is required for maintaining the pancreatic ductal identity and it is involved in the initiation of pancreatic cancer. In addition, SOX9 is a transcription factor linked to stem cell activity and is commonly overexpressed in solid cancers. It cooperates with Snail/Slug to induce epithelial-mesenchymal transition (EMT) during neural development and in diseases such as organ fibrosis or different types of cancer. METHODS We investigated the roles of SOX9 in pancreatic tumor cell plasticity, metastatic dissemination and chemoresistance using pancreatic cancer cell lines as well as mouse embryo fibroblasts. In addition, we characterized the clinical relevance of SOX9 in pancreatic cancer using human biopsies. RESULTS Gain- and loss-of-function of SOX9 in PDAC cells revealed that high levels of SOX9 increased migration and invasion, and promoted EMT and metastatic dissemination, whilst SOX9 silencing resulted in metastasis inhibition, along with a phenotypic reversion to epithelial features and loss of stemness potential. In both contexts, EMT factors were not altered. Moreover, high levels of SOX9 promoted resistance to gemcitabine. In contrast, overexpression of SOX9 was sufficient to promote metastatic potential in K-Ras transformed MEFs, triggering EMT associated with Snail/Slug activity. In clinical samples, SOX9 expression was analyzed in 198 PDAC cases by immunohistochemistry and in 53 patient derived xenografts (PDXs). SOX9 was overexpressed in primary adenocarcinomas and particularly in metastases. Notably, SOX9 expression correlated with high vimentin and low E-cadherin expression. CONCLUSIONS Our results indicate that SOX9 facilitates PDAC progression and metastasis by triggering stemness and EMT

    Herramienta para analizar la relación entre la toma de decisiones y el mantenimiento de los servicios ecosistémicos: Estudio de caso en bosque nativo de ñire de patagonia norte.

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    La toma de decisiones sobre el manejo de los sistemas socio-ecológicos que producen Servicios Ecosistémicos (SE) son complejas por los plazos, las interacciones de los factores intervinientes, y las percepciones de los actores. Este trabajo tiene como objetivo proponer una metodología que permita integrar los conocimientos sobre los procesos de cambio de los ecosistemas y los de toma de decisión, resaltando el rol de los SE. Mediante un taller de expertos, y basándonos en información preexistente y cálculos ad hoc, se integraron tres propuestas metodológicas: (1) los Modelos de Estados y Transiciones, que modelan el comportamiento del ecosistema, sus caminos de degradación y recuperación; (2) la definición y cuantificación de los SE provistos por cada uno de los estados del ecosistema, considerando los SE finales, los beneficios y el valor monetario de los mismos y (3) los modelos de Toma de Decisiones basado en estadística bayesiana, que considera los objetivos finales mediante una matriz de valoración; los objetivos intermedios, y las decisiones de manejo posibles que impactan sobre estos. La propuesta se ejemplifica con bosques de Nothofagus antárctica de Patagonia norte.Decision making about the management of socio-ecological systems that produce Ecosystem Services (ES) are complicated by the terms, number of factors involved in the processes and their interactions, and perceptions of the actors. This paper aims to propose a methodology to integrate knowledge about the processes of ecosystem change and decision making, highlighting the role of SE. Through a workshop of experts, and based on existing information and calculations ad hoc three methodological proposals were integrated: (1) Models States and Transitions, modelling ecosystem behaviour, its ways of degradation and recovery; (2) the definition and quantification of the ES provided by each of the states of the ecosystem, considering the final ES end, benefits and monetary value and (3) A Decision Making Models, based on Bayesian networks which considers the final objectives through a matrix of values; intermediate objectives and possible management decisions that impact on them. The proposal is exemplified by Nothofagus antarctica forests of northern Patagonia.EEA Santa CruzFil: Rusch, Verónica Elena. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Área Forestal. Grupo de Ecología Forestal; Argentina.Fil: Goijman, Andrea Paula. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Recursos Biológicos; Argentina.Fil: Peri, Pablo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Santa Cruz; Argentina.Fil: Peri, Pablo Luis. Universidad Nacional de la Patagonia Austral; Argentina.Fil: Peri, Pablo Luis. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Lopez, Dardo Ruben. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Manfredi. Campo Anexo Villa Dolores; Argentina.Fil: Lopez, Dardo Ruben. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina.Fil: Claps, Leonardo Luis. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina.Fil: Sarasola, Mauro Miguel. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche; Argentina.Fil: Cardozo, Andrea. Instituto Nacional de Tecnología Agropecuaria (INTA). Estación Experimental Agropecuaria Bariloche. Agencia de Extensión Rural El Bolsón; Argentina.Fil: Rusch, Graciela Mónica. Norwegian Institute for Nature Research (NINA). Trondheim; Norueg

    Lipid-coated ruthenium dendrimer conjugated with doxorubicin in anti-cancer drug delivery: Introducing protocols

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    One of the major limitations for the treatment of many diseases is an inability of drugs to cross the cell membrane barrier. Different kinds of carriers are being investigated to improve drug bioavailability. Among them, lipid or polymer-based systems are of special interest due to their biocompatibility. In our study, we combined dendritic and liposomal carriers and analysed the biochemical and biophysical properties of these formulations. Two preparation methods of Liposomal Locked-in Dendrimers (LLDs) systems have been established and compared. Carbosilane ruthenium metallodendrimer was complexed with an anti-cancer drug (doxorubicin) and locked in a liposomal structure, using both techniques. The LLDs systems formed by hydrophilic locking had more efficient transfection profiles and interacted with the erythrocyte membrane better than systems using the hydrophobic method. The results indicate these systems have improved transfection properties when compared to noncomplexed components. The coating of dendrimers with lipids significantly reduced their hemotoxicity and cytotoxicity. The nanometric size, low polydispersity index and reduced positive zeta potential of such complexes made them attractive for future application in drug delivery. The formulations prepared by the hydrophobic locking protocol were not effective and will not be considered furthermore as prospective drug delivery systems. In contrast, the formulations formed by the hydrophilic loading method have shown promising results where the cytotoxicity of LLD systems with doxorubicin was more effective against cancer than normal cells
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