3,485 research outputs found

    Cerberus is a feedback inhibitor of Nodal asymmetric signaling in the chick embryo

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    The TGF-beta-related molecule Nodal plays an essential and conserved role in left-right patterning of the vertebrate embryo. Previous reports have shown that the zebrafish and mouse Cerberus-related proteins Charon and Cerberus-like-2 (Cerl-2), respectively, act in the node region to prevent the Nodal signal from crossing to the right side, whereas chick Cerberus (cCer) has an unclear function in the left-side mesoderm. In this study, we investigate the transcriptional regulation and function of cCer in left-right development. By analyzing the enhancer activity of cCer 5' genomic sequences in electroporated chick embryos, we identified a cCer left-side enhancer that contains two FoxH1 and one SMAD binding site. We show that these Nodal-responsive elements are necessary and sufficient for the activation of transcription in the left-side mesoderm. In transgenic mouse embryos, cCer regulatory sequences behave as in chick embryos, suggesting that the cis-regulatory sequences of Cerberus-related genes have diverged during vertebrate evolution. Moreover, our findings from cCer overexpression and knockdown experiments indicate that cCer is a negative-feedback regulator of Nodal asymmetric signaling. We propose that cCer and mouse Cerl-2 have evolved distinct regulatory mechanisms but retained a conserved function in left-right development, which is to restrict Nodal activity to the left side of the embryo.info:eu-repo/semantics/publishedVersio

    Antifungal and antiaflatoxigenic properties of Lactobacillus species

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    Molds play an important role in spoilage of food products. It is estimated that 5 to 10% of the world foods production is lost due to fungal contamination. Further, certain fungal species produce highly toxic metabolites designated as mycotoxins. According to FAO, up to 25% of the worlds food crops have been estimated to be significantly contaminated with mycotoxins. Among all known mycotoxins, aflatoxins are the most relevant ones because they are carcinogenic. Biopreservation, defined as the control of one organism by another, has received much attention by researchers in recent years. In this field, lactic acid bacteria (LAB) are of great interest to be used as natural biopreservatives of food and feed since they have extensive probiotic properties and have been traditionally used in fermentation processes. The aim of this work is to demonstrate the potential of Lactobacillus species to control the occurrence of aflatoxigenic fungi and aflatoxins in agricultural commodities. For that several aflatoxigenic species such as Aspergillus flavus, A. parasiticus, A. nomius, A. tamari, A. arachidicola, and A. minisclerotigenes were inoculated in triplicate in MEA supplemented with 10% of sterile supernatants of different Lactobacillus species obtained from liquid MRS cultures. Supernatants of most active strains inactivated with heat, proteases and NaOH (for pH neutralization) were also tested and compared with untreated ones. The fungal radial growth and the aflatoxin concentration produced in each plate were recorded and compared. L. casei and L. plantarum supernatants were found to be most active. Growth of Aspergillus flavus in MEA after 7 days was reduced approx. by 31% and 25%, respectively for each bacteria. Aflatoxins B1 and B2 production were inhibited approx. by 97 and 87%, respectively. The antifungal and antiaflatoxigenic activity of those strains was reverted when supernatants were treated with proteolytic enzymes or their pH adjusted to 7

    Mycotoxins in food and mitigation of its effects

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    Book of Abstracts of CEB Annual Meeting 2017[Excerpt] Mycotoxins are toxic compounds mainly produced by fungi of the genera Aspergillus, Fusarium and Penicillium. These toxins are frequently detected in many food commodities including cereals, fruit and vegetables, even after processing [1]. Since the same fungus may produce more than one toxin and the same toxin may be produced by different fungi, mycotoxins often occur as a mixture. Their ubiquitous presence represents a challenge to the health of humans, animals and the environment. Hundreds of compounds are listed as possible mycotoxins; however, only a few occur at levels that may are really challenging. The main focus of AMG is to study and develop integrated and innovative methods, supported in fundamental and applied research, for the mitigation of the occurrence of mycotoxins in food and feed, promoting complex system understanding and knowledge gaps identification. [...]info:eu-repo/semantics/publishedVersio

    Rice in vitro digestion: application of INFOGEST harmonized protocol for glycemic index determination and starch morphological study

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    Starch is the main sugar source present in staple foods. Understanding starch hydrolysis during digestion and the resulting glucose release can be important to strategically modulate starch digestion and glucose absorption. In vitro digestion methodologies are fundamental to evaluate starch hydrolysis length and rate, but the lack of uniformity between protocols prevent the comparison of results. In this context, three different Carolino rice varieties (i.e., Carolino whiteCw, Carolino brownCb and Carolino Ariete brownCAb) were submitted to the INFOGEST harmonized in vitro digestion protocol for the evaluation of starch hydrolysis and subsequent glycemic index (GI) determination, and starch granules morphological study. Samples of Carolino rice presented total starch percentages between 64.52 (for Cb) to 71.52% (for Cw) with low amylose content (16.1919.95%, varying in the following order Cb<CabCw). During digestion, between 39.43 (for CAb) to 44.48% (for Cb) of starch was hydrolyzed, classifying samples as medium GI foods (61.7369.17). Starch hydrolysis was accompanied by a decrease of starch granules dimensions. For all samples, area decrease was higher than 59%, perimeter decrease was higher than 37%, feret diameter decrease was higher than 39% and minimum feret diameter decrease was higher than 32%. This work provides new insights to describe, both qualitatively and quantitatively, the fate of rice during digestion, and allowed establishing a comparative basis for the development of rice-based recipes with a lower GI.Daniel A. Madalena acknowledge the Foundation for Science and Technology (FCT) for his fellowship (SFRH/BD/129127/2017). This work was supported by Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte. The authors would also like to thank the investment project n8 017931 – Development of rice products with low glycemic index- co-funded by Fundo Europeu de Desenvolvimento Regional (FEDER) through Programa Operacional Competitividade e Internacionalizac¸a˜o (COMPETE 2020) (POCI-01- 0247-FEDER-017931).info:eu-repo/semantics/publishedVersio

    Morphostructure of the S. Vicente Canyon, Marquês de Pombal Fault and Pereira de Sousa Fault (SW Iberia margin)

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    The S. Vicent Canyon (SVC), Marquês de Pombal Fault (MPF) and Pereira de Sousa Fault (PSF) are located along the SW Iberian margin. The SVC appears to be controlled by the S. Vicent Fault (SVF), a steep NE-SW striking fault that outcrops along the southeast flank of the canyon. To better understand the SVC, MPF and PSF structures and the Meso-Cenozoic morphostructural evolution of this sector it is important to identify the main tectonic phases from the Mesozoic up to Plio-Quaternary. To attain this objective, the main regional structures were mapped using 2D seismic lines and multibeam swath bathymetry data, allowing the mapping of the northern prolongation of PSF and the identification of faults that do not reach the sea floor

    Developmental expression of Shisa-2 in Xenopus laevis

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    Shisa is an antagonist of Wnt and FGF signaling, that functions cell autonomously in the endoplasmic reticulum (ER) to inhibit the post-translational maturation of Wnt and FGF receptors. In this paper we report the isolation of a second Xenopus shisa gene (Xshisa-2). Xenopus Shisa-2shows 30.7% identity to Xshisa. RT-PCR analysis indicated that Xshisa-2 mRNA is present throughout early development and shows an increased expression during neurula and tailbud stages. At neurula stages Xenopus shisa-2 is initially expressed in the presomitic paraxial mesoderm and later in the developing somites. The expression profiles and pattern of Xshisa and Xshisa-2 differ significantly. During gastrulation only Xshisa mRNA is present in the Spemann-Mangold organizer and later on becomes restricted to the neuroectoderm and the prechordal plate

    Lipid-based nanostructures as strategies to enhance curcumins bioavailability: effect of carrier oil physical state

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    This study was supported by the Portuguese Foundation for Science and Technology (FCT) under the scope of the Project PTDC/AGR-TEC/5215/2014, the strategic funding of UID/BIO/04469/2019 unit and BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

    Anti-aflatoxigenic effect of organic acids produced by Lactobacillus plantarum

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    ICFC 2017 - International Conference on Food Contaminants (Book of Abstracts)Molds play an important role in food spoilage, being estimated that 5 to 10% of the world food’s production is lost due to fungal contamination. Further, certain fungal species produce highly toxic metabolites, designated as mycotoxins. Biopreservation, de fined as the control of one organism by another, has received much attention in recent years. Also, some strains of lactic acid bacteria (LAB) that demonstrated antifungal and antimycotoxin properties gained interest to be used as natural biopreservatives. In this work, it is shown that the cell free supernatant (CFS) of Lactobacillus plantarum UM55 inhibited the growth of aflatoxigenic fungi, Aspergillus flavus , by 32% and the production of aflatoxins (AFs) by 91%. These inhibitions were lost when the CFS pH was neutralized. Additionally, it was observed an increase of the inhibitions with increasing concentration of CFS. Other aflatoxigenic strains, such as A. parasiticus , A. arachidicola , A. nomius and A. minisclerotigenes were inhibited by the CFS of the bacterium in different extents. Organic acids present in CFS were quantified, with main differences between CFS and control found in the levels of lactic acid, phenyllactic acid (PLA), hydroxyphenyllactic acid (OH - PLA) and indole lactic acid (ILA). When t ested, individually against A. flavus , all the compounds were able to inhibit fungal growth and AFs production. PLA showed the stronger effects and the 90% inhibitory concentration (IC90) for fungal growth and AFs was of 11.9 and 0.87 mg/mL, respectively. AFLs IC90 for ILA, OH - PLA and lactic acid were of 1.47, 1.80, and 3.92 mg/mL, respectively. Inhibitory effects of L. plantarum UM55 seems to be related to the production of lactic acid, PLA, OH-PLA and ILASFRH/BD/103245/2014 from the Portuguese Foundation for Science and Technology (FCT). Luís Abrunhosa was supported by grant UMINHO/BPD/51/2015 from project UID/BIO/04469/2013 financed by FCT/MEC (OE). This study was supported by FCT under the s cope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684); of BioTecNorte operation (NORTE-01-0145-FEDER-000004) funded by European Regional Development Fund under the scope of Norte2020 -Programa Operacional Regional do Norte; and under the scope of the projects RECI/BBB-EBI/0179/2012 (FCOMP - 01 - 0124 - FEDER - 027462)info:eu-repo/semantics/publishedVersio

    Consenso Técnico para a determinação do status da proteína HER2 por imunocitoquímica em carcinoma da mama

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    A determinação do status da proteína HER2 por imunocitoquímica é uma metodologia fundamental para o diagnóstico, prognóstico e indicação terapêutica no carcinoma da mama, nomeadamente para o encaminhamento terapêutico com Herceptin®/trastuzumab. O estabelecimento desta terapêutica nas vertentes adjuvante ou neoadjuvante, e até em doença metastática, tem vindo a acentuar a importância da determinação do referido status de modo a melhor responder às necessidades dos doentes. Sendo a imunocitoquímica o método validado para determinação do status HER2 em carcinoma da mama, é de extrema importância definir linhas de orientação para a sua correta performance como tem sido estabelecido em diversos países em todo o mundo. A área científica de Anatomia Patológica, Citológica e Tanatológica da Escola Superior de Tecnologia da Saúde de Lisboa (APCT-ESTeSL) e a Associação Portuguesa de Técnicos de Anatomia Patológica (APTAP) reuniram um painel de especialistas para a construção e estabelecimento de linhas de orientação técnica para a determinação do status HER2 em carcinoma da mama para a realidade portuguesa. Pretende-se com este consenso criar linhas de orientação técnicas para a construção, validação e manutenção do teste imunocitoquímico para determinação do status HER2 em carcinoma da mama, no que diz respeito à realidade portuguesa. Todas as orientações aqui descritas têm em conta o estado da arte atual no que diz respeito à determinação do status HER2 por imunocitoquímica em carcinoma da mama, bem como a experiência pessoal e académica de cada um dos membros do painel de especialistas que a subscrevem
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