260 research outputs found

    As concepçÔes evolutivas de Darwin sobre a expressão das emoçÔes no homem e nos animais

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    Charles Darwin’s most known work is the Origin of species. However in such book, he did not deal with man. So he did in two other books: The descent of man and The expression of emotions in man and animals. This article aims to discuss some evolutionary conceptions present in these two works, as well as its background. This study led to the conclusion that although Darwin considered natural selection as being an important way of modification concerning the expression of emotions in man and animals, he stressed the role of the inheritance of acquired characteristics by use and disuse in relation to this subjectO trabalho mais conhecido de Charles Darwin Ă© o Origem das espĂ©cies (1859). No entanto, nesta obra ele nĂŁo lidou com o homem. Ele fez isso em duas outras obras: The descent of man (1871) e The expression of emotions in man and animals (1872). O objetivo deste artigo Ă© discutir algumas concepçÔes evolutivas presentes nessas duas obras bem como alguns de seus antecedentes. Este estudo levou Ă  conclusĂŁo de que embora Darwin considerasse a seleção natural como um importante meio de modificação em relação Ă  expressĂŁo das emoçÔes no homem e nos animais, enfatizou o papel da herança de caracteres adquiridos pelo uso e desuso em relação a este assunto

    Estimating the global conservation status of more than 15,000 Amazonian tree species

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    Estimates of extinction risk for Amazonian plant and animal species are rare and not often incorporated into land-use policy and conservation planning. We overlay spatial distribution models with historical and projected deforestation to show that at least 36% and up to 57% of all Amazonian tree species are likely to qualify as globally threatened under International Union for Conservation of Nature (IUCN) Red List criteria. If confirmed, these results would increase the number of threatened plant species on Earth by 22%. We show that the trends observed in Amazonia apply to trees throughout the tropics, and we predict thatmost of the world’s >40,000 tropical tree species now qualify as globally threatened. A gap analysis suggests that existing Amazonian protected areas and indigenous territories will protect viable populations of most threatened species if these areas suffer no further degradation, highlighting the key roles that protected areas, indigenous peoples, and improved governance can play in preventing large-scale extinctions in the tropics in this century

    miR-22 and miR-205 Drive Tumor Aggressiveness of Mucoepidermoid Carcinomas of Salivary Glands

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    Publisher Copyright: Copyright © 2022 Naakka, Barros-Filho, Adnan-Awad, Al-Samadi, Marchi, Kuasne, Korelin, Suleymanova, Brown, Scapulatempo-Neto, Lourenço, Castilho, Kowalski, MĂ€kitie, AraĂșjo, Leivo, Rogatto, Salo and Passador-Santos.Objectives: To integrate mRNA and miRNA expression profiles of mucoepidermoid carcinomas (MECs) and normal salivary gland (NSGs) tissue samples and identify potential drivers. Material and Methods: Gene and miRNA expression arrays were performed in 35 MECs and six NSGs. Results: We found 46 differentially expressed (DE) miRNAs and 3,162 DE mRNAs. Supervised hierarchical clustering analysis of the DE transcripts revealed two clusters in both miRNA and mRNA profiles, which distinguished MEC from NSG samples. The integrative miRNA-mRNA analysis revealed a network comprising 696 negatively correlated interactions (44 miRNAs and 444 mRNAs) involving cell signaling, cell cycle, and cancer-related pathways. Increased expression levels of miR-205-5p and miR-224-5p and decreased expression levels of miR-139-3p, miR-145-3p, miR-148a-3p, miR-186-5p, miR-338-3p, miR-363-3p, and miR-4324 were significantly related to worse overall survival in MEC patients. Two overexpressed miRNAs in MEC (miR-22 and miR-205) were selected for inhibition by the CRISPR-Cas9 method. Cell viability, migration, and invasion assays were performed using an intermediate grade MEC cell line. Knockout of miR-205 reduced cell viability and enhanced ZEB2 expression, while miR-22 knockout reduced cell migration and invasion and enhanced ESR1 expression. Our results indicate a distinct transcriptomic profile of MEC compared to NSG, and the integrative analysis highlighted miRNA-mRNA interactions involving cancer-related pathways, including PTEN and PI3K/AKT. Conclusion: The in vitro functional studies revealed that miR-22 and miR-205 deficiencies reduced the viability, migration, and invasion of the MEC cells suggesting they are potential oncogenic drivers in MEC.Peer reviewe

    CD24 + Liver Tumor-Initiating Cells Drive Self-Renewal and Tumor Initiation through STAT3-Mediated NANOG Regulation

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    Tumor-initiating cells (T-ICs) are a subpopulation of chemoresistant tumor cells that have been shown to cause tumor recurrence upon chemotherapy. Identification of T-ICs and their related pathways are therefore priorities for the development of new therapeutic paradigms. We established chemoresistant hepatocellular carcinoma (HCC) xenograft tumors in immunocompromised mice in which an enriched T-IC population was capable of tumor initiation and self-renewal. With this model, we found CD24 to be upregulated in residual chemoresistant tumors when compared with bulk tumor upon cisplatin treatment. CD24 + HCC cells were found to be critical for the maintenance, self-renewal, differentiation, and metastasis of tumors and to significantly impact patients' clinical outcome. With a lentiviral-based knockdown approach, CD24 was found to be a functional liver T-IC marker that drives T-IC genesis through STAT3-mediated NANOG regulation. Our findings point to a CD24 cascade in liver T-ICs that may provide an attractive therapeutic target for HCC patients. © 2011 Elsevier Inc.postprin
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