The role of TNF-αand NFkβin an experimental model of intestinal carcinogenesis with 1,2-dimethyhydrazine

ABSTRACT Purpose: To analyze the potential of tumor necrosis factor-α (TNF-α) and factor nuclear kappa B (NF-κB) as colorectal cancer (CRC) biomarkers in an experimental model of intestinal carcinogenesis with 1,2-dimethyhydrazine (1,2-DMH). Methods: Twenty-four male Wistar rats were divided into two groups: sham and 1,2-DMH. First, 1,2-DMH (20 mg/kg/week) was administered for 15 consecutive weeks. In the 25th week, proctocolectomy was conducted. Histopathological analysis, immunohistochemistry, and gene expression of TNF-α and NF-κB were performed. Statistical analysis was performed using GraphPad Prism. The location of aberrant crypt foci (ACF) was analyzed by Kruskal-Wallis’ test. For analyses with two groups with parametric data, the t-test was used; for non-parametric data, the Mann-Whitney’s test was used. P < 0.05 was considered significant. Results: The number of ACF and macroscopic lesions was significantly higher (p < 0.5) in the 1,2-DMH group compared to the sham group, and most ACF were concentrated in the distal segment of the colon. There was a statistically significant increase (p < 0.5) in protein and gene expression of TNF-α and NF-κB in the 1,2-DMH group compared to the sham group. Conclusions: Our results provide supportive evidence that TNF-α and NF-κB pathways are strongly involved in CRC development in rats and might be used as early biomarkers of CRC pathogenesis in experimental studies

O IMPACTO DA FORMAÇÃO DE BIOFILME NA RECORRÊNCIA DA INFECÇÃO POR CLOSTRIDIOIDES DIFFICILE: UM ESTUDO COMPARATIVO DE CEPAS TOXIGÊNICAS MLST CLADO 2

Introdução/objetivo: Clostridioides difficile é a principal causa de diarreia associada ao uso de antibióticos relacionada a assistência à saúde. Um desafio no tratamento da infecção por C. difficile é a capacidade dessa bactéria em formar biofilmes, um mecanismo de virulência crítico por promover resistência a antibióticos e, consequentemente, maior recorrência da doença. Nesse estudo in vitro, o objetivo foi comparar a capacidade de formação de biofilme de cepas MLST Clado 2: ICC-45 (ribotipo SLO231/UK[CE]821) isolada no Brasil, e duas cepas epidêmicas: NAP1/027/ST01 (LIBA5756), isolada em um surto na Costa Rica e a cepa epidêmica de referência NAP1/027/ST01 (R20291). Além disso, a cepa não toxigênica ATCC700057 foi incluída como controle. Métodos: A capacidade das cepas de formar biofilme foi avaliada por coloração com cristal violeta. Além disso, as amostras foram coradas com Film Tracer biofilm matrix (Invitrogen®) e a espessura da matriz do biofilme foi medida usando microscopia confocal. A arquitetura da matriz foi analisada por Microscopia Eletrônica de Varredura (MEV). A expressão dos genes de virulência (tcdA, tcdB, tcdC, cdtB, spo0A, slpA, cwp66 e cwp84) foi examinada por RT-qPCR. Investigou-se ainda o efeito dos antibióticos Metronidazol (MTZ) e Vancomicina (VAN) no crescimento do biofilme. Resultados: Todas as cepas testadas mostraram capacidade de formar biofilmes moderados (1,13,5). Após 72h, a biomassa do biofilme das cepas epidêmicas NAP1/027/ST01 (LIBA5756 e R20291) foi significativamente maior do que os biofilmes ICC-45 e ATCC 700057, o que foi confirmado por MEV e confocal. As cepas R20291 e LIBA 5756 apresentaram uma expressão mais elevada dos genes tcdA, tcdB, tcdC, cdtA, slpA e spo0A em comparação com a cepa ICC-45. Não foram observadas diferenças significativas na expressão de cdtB, cwp66 e cwp84. Quanto ao efeito dos antibióticos, tanto a VAN quanto o MTZ inibiram a formação de biofilme nas cepas epidêmicas. No entanto, na linhagem ICC-45, as concentrações MIC de VAN e MIC e 4MIC de MTZ não inibiram a formação de biofilme. Conclusão: Os três isolados MLST Clado 2, de diferentes ribotipos, são bactérias formadoras de biofilmes competentes, indicando suas capacidades de induzir a recorrência da infecção por C. difficile, tornando o tratamento desafiador. Esses dados evidenciam a importância da vigilância epidemiológica voltada para a emergência de cepas resistentes e causadoras de recidivas diante de um mundo globalizado

NEOTROPICAL ALIEN MAMMALS: a data set of occurrence and abundance of alien mammals in the Neotropics

Biological invasion is one of the main threats to native biodiversity. For a species to become invasive, it must be voluntarily or involuntarily introduced by humans into a nonnative habitat. Mammals were among first taxa to be introduced worldwide for game, meat, and labor, yet the number of species introduced in the Neotropics remains unknown. In this data set, we make available occurrence and abundance data on mammal species that (1) transposed a geographical barrier and (2) were voluntarily or involuntarily introduced by humans into the Neotropics. Our data set is composed of 73,738 historical and current georeferenced records on alien mammal species of which around 96% correspond to occurrence data on 77 species belonging to eight orders and 26 families. Data cover 26 continental countries in the Neotropics, ranging from Mexico and its frontier regions (southern Florida and coastal-central Florida in the southeast United States) to Argentina, Paraguay, Chile, and Uruguay, and the 13 countries of Caribbean islands. Our data set also includes neotropical species (e.g., Callithrix sp., Myocastor coypus, Nasua nasua) considered alien in particular areas of Neotropics. The most numerous species in terms of records are from Bos sp. (n = 37,782), Sus scrofa (n = 6,730), and Canis familiaris (n = 10,084); 17 species were represented by only one record (e.g., Syncerus caffer, Cervus timorensis, Cervus unicolor, Canis latrans). Primates have the highest number of species in the data set (n = 20 species), partly because of uncertainties regarding taxonomic identification of the genera Callithrix, which includes the species Callithrix aurita, Callithrix flaviceps, Callithrix geoffroyi, Callithrix jacchus, Callithrix kuhlii, Callithrix penicillata, and their hybrids. This unique data set will be a valuable source of information on invasion risk assessments, biodiversity redistribution and conservation-related research. There are no copyright restrictions. Please cite this data paper when using the data in publications. We also request that researchers and teachers inform us on how they are using the data

Brazilian Flora 2020: Leveraging the power of a collaborative scientific network

International audienceThe shortage of reliable primary taxonomic data limits the description of biological taxa and the understanding of biodiversity patterns and processes, complicating biogeographical, ecological, and evolutionary studies. This deficit creates a significant taxonomic impediment to biodiversity research and conservation planning. The taxonomic impediment and the biodiversity crisis are widely recognized, highlighting the urgent need for reliable taxonomic data. Over the past decade, numerous countries worldwide have devoted considerable effort to Target 1 of the Global Strategy for Plant Conservation (GSPC), which called for the preparation of a working list of all known plant species by 2010 and an online world Flora by 2020. Brazil is a megadiverse country, home to more of the world's known plant species than any other country. Despite that, Flora Brasiliensis, concluded in 1906, was the last comprehensive treatment of the Brazilian flora. The lack of accurate estimates of the number of species of algae, fungi, and plants occurring in Brazil contributes to the prevailing taxonomic impediment and delays progress towards the GSPC targets. Over the past 12 years, a legion of taxonomists motivated to meet Target 1 of the GSPC, worked together to gather and integrate knowledge on the algal, plant, and fungal diversity of Brazil. Overall, a team of about 980 taxonomists joined efforts in a highly collaborative project that used cybertaxonomy to prepare an updated Flora of Brazil, showing the power of scientific collaboration to reach ambitious goals. This paper presents an overview of the Brazilian Flora 2020 and provides taxonomic and spatial updates on the algae, fungi, and plants found in one of the world's most biodiverse countries. We further identify collection gaps and summarize future goals that extend beyond 2020. Our results show that Brazil is home to 46,975 native species of algae, fungi, and plants, of which 19,669 are endemic to the country. The data compiled to date suggests that the Atlantic Rainforest might be the most diverse Brazilian domain for all plant groups except gymnosperms, which are most diverse in the Amazon. However, scientific knowledge of Brazilian diversity is still unequally distributed, with the Atlantic Rainforest and the Cerrado being the most intensively sampled and studied biomes in the country. In times of “scientific reductionism”, with botanical and mycological sciences suffering pervasive depreciation in recent decades, the first online Flora of Brazil 2020 significantly enhanced the quality and quantity of taxonomic data available for algae, fungi, and plants from Brazil. This project also made all the information freely available online, providing a firm foundation for future research and for the management, conservation, and sustainable use of the Brazilian funga and flora