449 research outputs found

    Cholangiocarcinoma: from molecular biology to treatment

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    Cholangiocarcinoma is a rare tumor originating in the bile ducts, which, according to their anatomical location, is classified as intrahepatic, extrahepatic and hilar. Nevertheless, incidence rates have increased markedly in recent decades. With respect to tumor biology, several genetic alterations correlated with resistance to chemotherapy and radiotherapy have been identified. Here, we highlight changes in KRAS and TP53 genes that are normally associated with a more aggressive phenotype. Also IL-6 and some proteins of the BCL-2 family appear to be involved in the resistance that the cholangiocarcinoma presents toward conventional therapies. With regard to diagnosis, tumor markers most commonly used are CEA and CA 19-9, and although its use isolated appears controversial, their combined value has been increasingly advocated. In imaging terms, various methods are needed, such as abdominal ultrasound, computed tomography and cholangiopancreatography. Regarding therapy, surgical modalities are the only ones that offer chance of cure; however, due to late diagnosis, most patients cannot take advantage of them. Thus, the majority of patients are directed to other therapeutic modalities like chemotherapy, which, in this context, assumes a purely palliative role. Thus, it becomes urgent to investigate new therapeutic options for this highly aggressive type of tumor

    Influence of P53 on the radiotherapy response of hepatocellular carcinoma

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    Hepatocellular carcinoma (HCC) is one of the most common cancers worldwide, and it has a poor prognosis and few therapeutic options. Radiotherapy is one of the most effective forms of cancer treatment, and P53 protein is one of the key molecules determining how a cell responds to radiotherapy. The aim of this study was to determine the therapeutic efficacy of iodine-131 in three human HCC cell lines

    The EMBLA survey - metal-poor stars in the Galactic bulge

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    Cosmological models predict the oldest stars in the Galaxy should be found closest to the centre of the potential well, in the bulge. The Extremely Metal-poor BuLge stars with AAOmega survey (EMBLA) successfully searched for these old, metal-poor stars by making use of the distinctive SkyMapper photometric filters to discover candidate metal-poor stars in the bulge. Their metal-poor nature was then confirmed using the AAOmega spectrograph on the Anglo-Australian Telescope. Here we present an abundance analysis of 10 bulge stars with −2.8 < [Fe/H] < −1.7 from MIKE/Magellan observations, in total determining the abundances of 22 elements. Combining these results with our previous high-resolution data taken as part of the Gaia-ESO Survey, we have started to put together a picture of the chemical and kinematic nature of the most metal-poor stars in the bulge. The currently available kinematic data are consistent with the stars belonging to the bulge, although more accurate measurements are needed to constrain the stars’ orbits. The chemistry of these bulge stars deviates from that found in halo stars of the same metallicity. Two notable differences are the absence of carbon-enhanced metal-poor bulge stars, and the α element abundances exhibit a large intrinsic scatter and include stars which are underabundant in these typically enhanced elements.LMH and MA have been supported by the Australian Research Council (grant FL110100012). ARC acknowledges support from the European Union FP7 programme through ERC grant number 320360. DY is supported through an Australian Research Council Future Fellowship (FT140100554). Research on metal-poor stars with SkyMapper is supported through Australian Research Council Discovery Projects grants DP120101237 and DP150103294 (PI: Da Costa). This publication makes use of data products from the Two Micron All Sky Survey, which is a joint project of the University of Massachusetts and the Infrared Processing and Analysis Center/California Institute of Technology, funded by the National Aeronautics and Space Administration and the National Science Foundation. This paper includes data gathered with the 6.5 metre Magellan Telescopes located at Las Campanas Observatory, Chile.This is the final version of the article. It first appeared from Oxford University Press via http://dx.doi.org/10.1093/mnras/stw100

    Using the Juvenile Arthritis Disease Activity Score based on erythrocyte sedimentation rate or C-reactive protein level: results from the Portuguese register

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    Our aims were to evaluate the correlation between Juvenile Arthritis Disease Activity Score 27-joint reduced count (JADAS27) with erythrocyte sedimentation rate (ESR) and JADAS27 with C-reactive protein (CRP) scores and to test the agreement of both scores on classifying each disease activity state. We also aimed at verifying the correlation of the 2 scores across juvenile idiopathic arthritis (JIA) categories and to check the correlation between JADAS27-ESR and clinical JADAS27 (JADAS27 without ESR)

    An optically stimulated superconducting-like phase in K3C60 far above equilibrium Tc

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    The control of non-equilibrium phenomena in complex solids is an important research frontier, encompassing new effects like light induced superconductivity. Here, we show that coherent optical excitation of molecular vibrations in the organic conductor K3C60 can induce a non-equilibrium state with the optical properties of a superconductor. A transient gap in the real part of the optical conductivity and a low-frequency divergence of the imaginary part are measured for base temperatures far above equilibrium Tc=20 K. These findings underscore the role of coherent light fields in inducing emergent order.Comment: 40 pages, 23 figure

    Exercise and cognitive function: a hypothesis for the association of type II diabetes mellitus and Alzheimer's disease from an evolutionary perspective

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    The association of type II diabetes mellitus (DM2) with Alzheimer's disease (AD) has received considerable attention in recent years. In the present paper, a hypothesis for this association from an evolutionary perspective, with emphasis on the close interplay between exercise and cognitive function, will be advanced in order to provide a biological rationale for the notion that the fundamental metabolic features of DM2 act in the brain over a protracted time span to induce the neuropathological characteristics of Alzheimer's disease thereby producing cognitive impairment. It is hoped that this hypothesis puts the association of DM2 and AD on firm conceptual grounds from a biological perspective and offers directions for further research

    Trophic Relationships and Habitat Preferences of Delphinids from the Southeastern Brazilian Coast Determined by Carbon and Nitrogen Stable Isotope Composition

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    To investigate the foraging habitats of delphinids in southeastern Brazil, we analyzed stable carbon (δ13C) and nitrogen (δ15N) isotopes in muscle samples of the following 10 delphinid species: Sotalia guianensis, Stenella frontalis, Tursiops truncatus, Steno bredanensis, Pseudorca crassidens, Delphinus sp., Lagenodelphis hosei, Stenella attenuata, Stenella longirostris and Grampus griseus. We also compared the δ13C and δ15N values among four populations of S. guianensis. Variation in carbon isotope results from coast to ocean indicated that there was a significant decrease in δ13C values from estuarine dolphins to oceanic species. S. guianensis from Guanabara Bay had the highest mean δ13C value, while oceanic species showed significantly lower δ13C values. The highest δ15N values were observed for P. crassidens and T. truncatus, suggesting that these species occupy the highest trophic position among the delphinids studied here. The oceanic species S. attenuata, G. griseus and L. hosei had the lowest δ15N values. Stable isotope analysis showed that the three populations of S. guianensis in coastal bays had different δ13C values, but similar δ15N results. Guiana dolphins from Sepetiba and Ilha Grande bays had different foraging habitat, with specimens from Ilha Grande showing more negative δ13C values. This study provides further information on the feeding ecology of delphinids occurring in southeastern Brazil, with evidence of distinctive foraging habitats and the occupation of different ecological niches by these species in the study area.Peer reviewe
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