376 research outputs found

    In vitro screening of cytotoxic activity of euphol from Euphorbia tirucalli on a large panel of human cancer-derived cell lines

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    A large number of classic antineoplastic agents are derived from plants. Euphorbia tirucalli L. (Euphorbiaceae) is a subtropical and tropical plant, used in Brazilian folk medicine against many diseases, including cancer, yet little is known about its true anticancer properties. The present study evaluated the antitumor effect of the tetracyclic triterpene alcohol, euphol, the main constituent of E. tirucalli in a panel of 73 human cancer lines from 15 tumor types. The biological effect of euphol in pancreatic cells was also assessed. The combination index was further used to explore euphol interactions with standard drugs. Euphol showed a cytotoxicity effect against several cancer cell lines (IC50 range, 1.41-38.89 µM), particularly in esophageal squamous cell (11.08 µM) and pancreatic carcinoma cells (6.84 µM), followed by prostate, melanoma, and colon cancer. Cytotoxicity effects were seen in all cancer cell lines, with more than half deemed highly sensitive. Euphol inhibited proliferation, motility and colony formation in pancreatic cancer cells. Importantly, euphol exhibited synergistic interactions with gemcitabine and paclitaxel in pancreatic and esophageal cell lines, respectively. To the best of our knowledge, this study constitutes the largest in vitro screening of euphol efficacy on cancer cell lines and revealed its in vitro anti-cancer properties, particularly in pancreatic and esophageal cell lines, suggesting that euphol, either as a single agent or in combination with conventional chemotherapy, is a potential anti-cancer drug.Amazônia Fitomedicamentos Ltda. (grant no. FITO 05/2012) and Barretos Cancer Hospital, all from Brazilinfo:eu-repo/semantics/publishedVersio

    Education 4.0: Robotics Projects to Encourage 21st Century Skills

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    Education 4.0 is defined as a student-centered learning model that prepares young for the challenges of the 21st Century, how to deal with emerging technological resources and processes. This case study aimed to encourage 21st Century skills and competencies seen as relevant to Education 4.0, such as teamwork, communication, autonomy, creativity, and innovation. In this study, we analyzed the feedbacks collected to identify which skills were encouraged in undergraduate and graduate students during one semester of the Mobile Robotics discipline, using Project-Based Learning (PBL). Students carried out projects and answered a self-assessment questionnaire about their skills. The qualitative analysis of the case study followed the procedures of the Grounded Theory method. The results indicated that learning based on robotics projects could encourage teamwork, communication, and organization skills

    Chromosomal painting and ZW sex chromosomes differentiation in Characidium (Characiformes, Crenuchidae)

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    <p>Abstract</p> <p>Background</p> <p>The <it>Characidium </it>(a Neotropical fish group) have a conserved diploid number (2n = 50), but show remarkable differences among species and populations in relation to sex chromosome systems and location of nucleolus organizer regions (NOR). In this study, we isolated a W-specific probe for the <it>Characidium </it>and characterized six <it>Characidium </it>species/populations using cytogenetic procedures. We analyzed the origin and differentiation of sex and NOR-bearing chromosomes by chromosome painting in populations of <it>Characidium </it>to reveal their evolution, phylogeny, and biogeography.</p> <p>Results</p> <p>A W-specific probe for efficient chromosome painting was isolated by microdissection and degenerate oligonucleotide primed-polymerase chain reaction (DOP-PCR) amplification of W chromosomes from <it>C. gomesi</it>. The W probe generated weak signals dispersed on the proto sex chromosomes in <it>C. zebra</it>, dispersed signals in both W and Z chromosomes in <it>C. lauroi </it>and, in <it>C. gomesi </it>populations revealed a proximal site on the long arms of the Z chromosome and the entire W chromosome. All populations showed small terminal W probe sites in some autosomes. The 18S rDNA revealed distinctive patterns for each analyzed species/population with regard to proto sex chromosome, sex chromosome pair, and autosome location.</p> <p>Conclusions</p> <p>The results from dual-color fluorescence <it>in situ </it>hybridization (dual-color FISH) using W and 18S rDNA probes allowed us to infer the putative evolutionary pathways for the differentiation of sex chromosomes and NORs, from structural rearrangements in a sex proto-chromosome, followed by gene erosion and heterochromatin amplification, morphological differentiation of the sex chromosomal pair, and NOR transposition, giving rise to the distinctive patterns observed among species/populations of <it>Characidium</it>. Biogeographic isolation and differentiation of sex chromosomes seem to have played a major role in the speciation process in this group of fish.</p

    Molecular Characterization of the Schistosoma mansoni Zinc Finger Protein SmZF1 as a Transcription Factor

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    Schistosomes are parasites that exhibit a complex life cycle during which they progress through many morphological and physiological transformations. These transformations are likely accompanied by alterations in gene expression, making genetic regulation important for parasite development. Here we describe a Schistosoma mansoni protein (SmZF1) that may act as a parasite transcription factor. These factors are key proteins for gene regulation. We have previously demonstrated that SmZF1 is able to bind DNA and that its mRNA is present at different stages during the parasite life cycle. In this study we aimed to define if this protein can function as a transcription factor in S. mansoni. SmZF1 was detected in the nucleus of adult male worms, cercariae and schistosomula cells. It was not, however, observed in female cells, suggesting it to be gender specific. We used mammalian cells expressing recombinant SmZF1 to analyze if SmZF1 protein is able to activate/repress gene transcription and demonstrated that it increased the expression of a reporter gene by two-fold. The results obtained confirm SmZF1 as a S. mansoni transcription factor

    Multivariate characterization of bean varieties according to yield production, mineral and phenolic contents

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    The contents of mineral nutrients (Fe, Ca, Cu, Mn, Mg, and Zn) and phenolic compounds (total phenols and tannins) of sixteen bean cultivars grown under controlled conditions have been quantified. Data obtained from chemical determinations and bean yields were evaluated by multivariate methods, principal components, hierarchical cluster and canonical correlation analysis. Three groups of cultivars were recognized and mineral nutrients Fe, Zn, Cu, and Mn as well as bean yields were the most relevant factors for their discrimination. Potential bean varieties for biofortification programs or direct use in fortified food were identified mainly in cluster I, in which a number of cultivars conciliate good yields and high mineral contents, such as Aporé (Fe and Mg), Bambuí (Zn), and Valente (Fe and Cu). The use of canonical correlation analysis allowed for the detection of significant relationships between bean yield, tannins, and Mg, Zn, and Mn metals

    Wild dogs at stake: deforestation threatens the only Amazon endemic canid, the short-eared dog (Atelocynus microtis)

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    The persistent high deforestation rate and fragmentation of the Amazon forests are the main threats to their biodiversity. To anticipate and mitigate these threats, it is important to understand and predict how species respond to the rapidly changing landscape. The short-eared dog Atelocynus microtis is the only Amazon-endemic canid and one of the most understudied wild dogs worldwide. We investigated short-eared dog habitat associations on two spatial scales. First, we used the largest record database ever compiled for short-eared dogs in combination with species distribution models to map species habitat suitability, estimate its distribution range and predict shifts in species distribution in response to predicted deforestation across the entire Amazon (regional scale). Second, we used systematic camera trap surveys and occupancy models to investigate how forest cover and forest fragmentation affect the space use of this species in the Southern Brazilian Amazon (local scale). Species distribution models suggested that the short-eared dog potentially occurs over an extensive and continuous area, through most of the Amazon region south of the Amazon River. However, approximately 30% of the short-eared dog's current distribution is expected to be lost or suffer sharp declines in habitat suitability by 2027 (within three generations) due to forest loss. This proportion might reach 40% of the species distribution in unprotected areas and exceed 60% in some interfluves (i.e. portions of land separated by large rivers) of the Amazon basin. Our local-scale analysis indicated that the presence of forest positively affected short-eared dog space use, while the density of forest edges had a negative effect. Beyond shedding light on the ecology of the short-eared dog and refining its distribution range, our results stress that forest loss poses a serious threat to the conservation of the species in a short time frame. Hence, we propose a re-assessment of the short-eared dog's current IUCN Red List status (Near Threatened) based on findings presented here. Our study exemplifies how data can be integrated across sources and modelling procedures to improve our knowledge of relatively understudied species

    Use of Wild Type or Recombinant Lactic Acid Bacteria as an Alternative Treatment for Gastrointestinal Inflammatory Diseases: A Focus on Inflammatory Bowel Diseases and Mucositis

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    The human gastrointestinal tract (GIT) is highly colonized by bacterial communities, which live in a symbiotic relationship with the host in normal conditions. It has been shown that a dysfunctional interaction between the intestinal microbiota and the host immune system, known as dysbiosis, is a very important factor responsible for the development of different inflammatory conditions of the GIT, such as the idiopathic inflammatory bowel diseases (IBD), a complex and multifactorial disorder of the GIT. Dysbiosis has also been implicated in the pathogenesis of other GIT inflammatory diseases such as mucositis usually caused as an adverse effect of chemotherapy. As both diseases have become a great clinical problem, many research groups have been focusing on developing new strategies for the treatment of IBD and mucositis. In this review, we show that lactic acid bacteria (LAB) have been capable in preventing and treating both disorders in animal models, suggesting they may be ready for clinical trials. In addition, we present the most current studies on the use of wild type or genetically engineered LAB strains designed to express anti-inflammatory proteins as a promising strategy in the treatment of IBD and mucositis

    Human consumption of meat from roadkilled animals in the Southwestern Amazon

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    The harvest of meat from wild animals is essential for the nutrition of many human populations in the Neotropics. Specific techniques are used to access wild meat, but collecting meat from road killed animals, or purposely run over animals to kill and consume the meat have not been documented so far. In this study we interviewed four residents of the state of Rondônia who claimed to consume roadkilled animals. Respondents cited only medium and large mammals (10 species in total) as the group from which wild meat is harvested, with one respondent claiming to intentionally run over the animals. The interviewees analyse the smell/putrefaction, swelling and exposure of viscera as criteria for not collecting the meat. The meat from roadkilled animals may pose a risk to the health of humans who consume it due to the foodborne diseases it may spread after the decomposition process. In addition, the practice of running over animals for consumption of their meat can cause potential impacts to the fauna and humans since it can reduce animal numbers and also cause serious accidents. Further investigations are needed to clarify whether this is widespread phenomenon occurring in other places of the Amazon and of the Neotropics
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