96 research outputs found

    Daily oxygen consumption rhythms of Senegalese sole solea senegalensis (Kaup, 1858) juveniles

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    Senegalese sole is known to be a species with pronounced nocturnal feeding behaviour. However, as for most fish species, there is a lack of knowledge concerning the influence of such biological rhythmon metabolic rate. The aim of this study was to determine whether individual variation in routine and fed metabolic rate was affected by daily light–dark rhythms in juveniles of Senegalese sole. The individual oxygen consumption measurements in Senegalese sole juveniles were determined by flow-through respirometry, at fasted conditions and after the fish were fed a single meal, the meal time started at 0930 h and fish fed ad libitum for 30 min. The measurements were made during 22 h, of which 8 h was in the light and 14 h in the dark, and started immediately after transfer to the respiratory chambers at 1100 h. The results suggest an influence of light–dark cycles in routine metabolism. It was observed that oxygen consumption increased during the dark phase in fasted fish (FAST) but was higher during the light phase in fed fish (FEED). However, when feed is provided during the light phase, juveniles are capable of shifting oxygen consumption rhythms to respond to the energetic demands of digestion and growth. These results suggest that routine metabolism varies according to the species natural habits as Senegalese sole is known to be nocturnal. The findings of this study underline the importance of understanding the biological rhythms of the species under study before metabolic data are interpreted

    Leccinum vulpinum Watling induces DNA damage, decreases cell proliferation and induces apoptosis on the human MCF-7 breast cancer cell line

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    The current work aimed to study the antitumour activity of a phenolic extract of the edible mushroom Leccinum vulpinum Watling, rich essentially in hydroxybenzoic acids. In a first approach, the mushroom extract was tested against cancer cell growth by using four human tumour cell lines. Given the positive results obtained in these initial screening experiments and the evidence of some studies for an inverse relationship between mushroom consumption and breast cancer risk, a detailed study of the bioactivity of the extract was carried out on MCF-7 cells. Once the selected cell line to precede the work was the breast adenocarcinoma cell line, the human breast non-malignant cell line MCF-10A was used as control. Overall, the extract decreased cellular proliferation and induced apoptosis. Furthermore, the results also suggest that the extract causes cellular DNA damage. Data obtained highlight the potential of mushrooms as a source of biologically active compounds, particularly with antitumour activity.IPATIMUP integrates the i3S Research Unit, which is partially supported by FCT, the Portuguese Foundation for Science and Technology. This work is funded by FEDER funds through the Operational Programme for Competitiveness Factors-COMPETE and National Funds through the FCT-Foundation for Science and Technology, under the projects "PEst-C/SAU/LA0003/2013", NORTE-07-0162-FEDER-00018 - Contributos para o reforço da capacidade do IPATIMUP enquanto actor do sistema regional de inovação" and NORTE-07-0162-FEDER-000067 - Reforço e consolidação da capacidade infraestrutural do IPATIMUP para o sistema regional de inovação", both supported by Programa Operacional Regional do Norte (ON.2 – O Novo Norte), through FEDER funds under the Quadro de Referência Estratégico Nacional (QREN). Authors also thank COMPETE/QREN/EU for the financial support to CIMO (strategic project PEst-OE/AGR/UI0690/2014) and L. Barros. The authors also thank QREN for the grant of F.S. Reis (NORTE-07-0124-FEDER-000023) and FCT for the grant of D. Sousa (SFRH/BD/98054/2013), Dr. Maria João Sousa for helping in the harvesting of samples

    Can Suillus granulatus (L.) Roussel be classified as a functional food?

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    The present work outlines a detailed chemical characterization of Suillus granulatus species, besides the antioxidant and antimicrobial properties of their methanolic extracts. The study was carried out with samples drawn from Portugal and Serbia in order to prove that though mushrooms are strongly influenced by the environment in which they develop, they have a specific chemical profile that can be typical of their genus/species. The studied species proved to be healthy foods, low in fat and rich in protein and carbohydrates, with mannitol and trehalose being the main free sugars detected. They also proved to be a source of organic and phenolic acids, as well as mono- and polyunsaturated fatty acids and tocopherols. The Serbian samples revealed higher antioxidant and antimicrobial potential. Accordingly, we find that the S. granulatus species is likely to be considered a functional food, since it is a source of nutraceutical and biologically active compounds.The authors are grateful to Foundation for Science and Technology (FCT, Portugal) and COMPETE/QREN/EU for the financial support of the CIMO strategic project PEst-OE/AGR/UI0690/2011 and of the contract of L. Barros. The authors also thank to the Serbian Ministry of Education, Science and Technological Development for financial support (grant number 173032). The authors thank Dr. Maria João Sousa for the harvest of the Portuguese samples

    Microfluidic-assisted electrospinning, an alternative to coaxial, as a controlled dual drug release system to treat inflammatory arthritic diseases

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    Inflammatory arthritic diseases are characterized by a persistent inflammation of the synovial tissues where tumor necrosis factor alpha (TNFα) and interleukin-6 (IL-6) pro-inflammatory cytokines are over-expressed, leading to progressive musculoskeletal disability. Methotrexate (MTX), a disease-modifying-anti-rheumatic drug (DMARD) commonly applied in their treatment, can be used in combination with biological-DMARDs as anti-TNFα antibody to improve the treatments efficacy. However, their systemic administration comes with severe side-effects and limited therapeutic efficacy due to their off-target distribution and short half-life. To overcome such limitations, encapsulation of clinically relevant concentrations of MTX and anti-TNFα antibody into polycaprolactone (PCL) or poly(vinyl-alcohol) (PVA) microfluidic-assisted or coaxial electrospun fibrous meshes is proposed as local controlled dual drug release systems. Release studies show that microfluidic-assisted electrospinning meshes encapsulating both drugs achieved higher concentrations than coaxials. Biological assays using human articular chondrocytes (hACs) and monocytic cells (THP-1 cell line) demonstrate that fibrous meshes encapsulating the drugs are non-toxic. The systems' efficacy is proved by a significant decrease of TNFα and IL-6 concentrations in conditioned medium of lipopolysaccharide (LPS)-stimulated THP-1 cells, especially in the presence of microfluidic-assisted electrospun meshes, when compared with THP-1 conditioned medium (59.5% and 83.9% less, respectively). Therefore, microfluidic-assisted electrospinning fibrous meshes with encapsulating drugs represent an alternative to coaxial, as a local therapy for inflammatory arthritis diseases.This work was supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement, for the Ph.D grant of Catarina Silva (UMINHO/BD/33/2016; NORTE-08-5369-FSE-000012), and by the Portuguese Science and Technology Foundation (FCT) for the cells project Cells4_ID (PTDC/BTM-SAL/28882/2017)

    Preparation of robust polyamide microcapsules by interfacial polycondensation of p-phenylenediamine and sebacoyl chloride and plasticization with oleic acid

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    Microcapsules produced by interfacial polycondensation of p-phenylenediamine (PPD) and sebacoyl chloride (SC) were studied. The products were characterized in terms of morphology, mean diameter and effectiveness of dodecane encapsulation. The use of Tween 20 as dispersion stabilizer, in comparison with polyvinyl alcohol (PVA), reduced considerably the mean diameter of the microcapsules and originated smoother wall surfaces. When compared to ethylenediamine (EDA), microcapsules produced with PPD monomer were more rigid and brittle, prone to fracture during processing and ineffective retention of the core liquid. The use of diethylenetriamine (DETA) cross-linker in combination with PPD did not decrease capsule fragility. On the other hand, addition of a small fraction of oleic acid to the organic phase remarkably improved wall toughness and lead to successful encapsulation of the core-oil. Oleic acid is believed to act as a plasticizer. Its incorporation in the polymeric wall was demonstrated by FTIR and (1)H-NMR.This work was funded by FEDER funds through the Operational Programme for Competitiveness Factors (COMPETE), ON.2 – O Novo Norte – North Portugal Regional Operational Programme and National Funds through Foundation for Science and Technology (FCT) under the projects: PEst-C/EQB/UI0511, NORTE-07-0124-FEDER-000026 – RL1_ Energy and PTDC/CTM-NAN/119979/2010. The Bruker Avance III 400 spectrometer is part of the National NMR network and was purchased under the framework of the National Programme for Scientific Reequipment, REDE/1517/RMN/2005, with funds from POCI 2010 (FEDER) and (FCT). Joana R. Góis acknowledges FCT-MCTES for her PhD scholarship (SFRH/BD/69635/2010)

    Modulation of butyrate-degrading methanogenic communities by conductive materials

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    Butyrate is a volatile fatty acid commonly present in anaerobic bioreactors. Previous research showed that methane production (MP) rates from butyrate, by lake sediment microbiomes, doubled by addition of carbon nanotubes, which was accompanied by changes in the microbial community composition, with enrichment of typical fatty-acid degrading bacteria (Syntrophomonas spp.), well known to exchange electrons with methanogens via hydrogen or formate formation1. But the authors suggested that electrons exchange via conductive materials (CM) may take place instead. In our study, anaerobic butyrate-degrading enrichment cultures were developed with other CM, namely activated carbon (AC) and magnetite (Mag) at 0.5 g/L. MP started earlier in AC enrichment and complete degradation was achieved faster in Mag enrichment. Syntrophomonas spp. were enriched in all cultures (representing 60 to 80 % of the total bacterial community), but hydrogenotrophic methanogens were highly stimulated by AC (78 % of Methanomicrobiales), while the methanogenic community of Mag culture was more diverse in acetoclastic methanogens (43% of Methanosarcina and Methanosaeta). It is still unclear if the improvement on butyrate degradation is associated to the role of CM in interspecies electron transfer, but it is undoubtful that they differentially modulate the methanogenic communities towards faster MP.info:eu-repo/semantics/publishedVersio

    Nutritional, antioxidant and antitumour properties of Leccinum vulpinum Watling

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    Mushrooms are widely appreciated all over the world for their nutritional [1] and bioactive properties [2, 3]. This work characterizes Leccinum vulpinum Watling, an edible mushroom harvested in Bragan<;:a's outskirts (Northeastern Portugal), a region with a great mycological biodiversity. The samples were chemically characterized regarding their content in nutrients and non-nutrients. Furthermore, the antioxidant and antitumour properties of the methanolic extract were evaluated. The nutritional value was assessed through the composition in macronutrients following standard procedures; the individual profiles in sugars, fatty acids, tocopherols, phenolic and organic acids were evaluated through chromatographic techniques. The antioxidant capacity was evaluated though the reducing power, radical-scavenging activity and lipid peroxidation inhibition of the samples. The screening for tumour cell growth inhibitory activity was carried out in four human tumour cell lines: AGS (gastric adenocarcinoma), MCF-7 (breast adenocarcinoma), NCI-H460 (non-small cell lung cancer) and HCT-15 (colorectal adenocarcinoma). The activity of the extract was further studied in the most sensitive cells (HCT-15), particularly regarding its effects on the cell cycle profile (by flow cytometry). L. vulpinum species may be considered a healthy food, with a great nutritional value, being a source of nutraceuticals (e.g., mono- and polyunsaturated fatty acids, and vitamins) and other bioactive compounds (e.g., phenolic acids). This species also showed antioxidant activity. Concerning the antitumour properties, L. vulpinum inhibited the growth of the tested cell lines. Additionally, treatment of HCT-15 cells (the most sensitive cell line) with 77.2 flg/mL of this extract caused a statistically significant increase in the S phase and a decrease in the G2/M phase of the cell cycle

    Behavioural stress responses predict environmental perception in European sea bass (Dicentrarchus labrax)

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    Individual variation in the response to environmental challenges depends partly on innate reaction norms, partly on experience-based cognitive/emotional evaluations that individuals make of the situation. The goal of this study was to investigate whether pre-existing differences in behaviour predict the outcome of such assessment of environmental cues, using a conditioned place preference/avoidance (CPP/CPA) paradigm. A comparative vertebrate model (European sea bass, Dicentrarchus labrax) was used, and ninety juvenile individuals were initially screened for behavioural reactivity using a net restraining test. Thereafter each individual was tested in a choice tank using net chasing as aversive stimulus or exposure to familiar conspecifics as appetitive stimulus in the preferred or non preferred side respectively (called hereafter stimulation side). Locomotor behaviour (i.e. time spent, distance travelled and swimming speed in each tank side) of each individual was recorded and analysed with video software. The results showed that fish which were previously exposed to appetitive stimulus increased significantly the time spent on the stimulation side, while aversive stimulus led to a strong decrease in time spent on the stimulation side. Moreover, this study showed clearly that proactive fish were characterised by a stronger preference for the social stimulus and when placed in a putative aversive environment showed a lower physiological stress responses than reactive fish. In conclusion, this study showed for the first time in sea bass, that the CPP/CPA paradigm can be used to assess the valence (positive vs. negative) that fish attribute to different stimuli and that individual behavioural traits is predictive of how stimuli are perceived and thus of the magnitude of preference or avoidance behaviour.European Commission [265957]; Portuguese Fundacao para a Ciencia e Tecnologia (FCT) [FRH/BPD/72952/2010]; FCT [SFRH/BD/80029/2011

    Can we predict personality in fish? searching for consistency over time and across contexts

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    The interest in animal personality, broadly defined as consistency of individual behavioural traits over time and across contexts, has increased dramatically over the last years. Individual differences in behaviour are no longer recognised as noise around a mean but rather as adaptive variation and thus, essentially, raw material for evolution. Animal personality has been considered evolutionary conserved and has been shown to be present in all vertebrates including fish. Despite the importance of evolutionary and comparative aspects in this field, few studies have actually documented consistency across situations in fish. In addition, most studies are done with individually housed fish which may pose additional challenges when interpreting data from social species. Here, we investigate, for the first time in fish, whether individual differences in behavioural responses to a variety of challenges are consistent over time and across contexts using both individual and grouped-based tests. Twenty-four juveniles of Gilthead seabream Sparus aurata were subjected to three individual-based tests: feed intake recovery in a novel environment, novel object and restraining and to two group-based tests: risk-taking and hypoxia. Each test was repeated twice to assess consistency of behavioural responses over time. Risk taking and escape behaviours during restraining were shown to be significantly consistent over time. In addition, consistency across contexts was also observed: individuals that took longer to recover feed intake after transfer into a novel environment exhibited higher escape attempts during a restraining test and escaped faster from hypoxia conditions. These results highlight the possibility to predict behaviour in groups from individual personality traits.European Commission [265957 COPEWELL]; European Social Fund of Andalusia; Foundation for Science and Technology, Portugal [SFRH/BPD/77210/2011]info:eu-repo/semantics/publishedVersio

    Advancing the use of molecular methods for routine freshwater macroinvertebrate biomonitoring : the need for calibration experiments

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    Over the last decade, steady advancements have been made in the use of DNA-based methods for detection of species in a wide range of ecosystems. This progress has culminated in molecular monitoring methods being employed for the detection of several species for enforceable management purposes of endangered, invasive, and illegally harvested species worldwide. However, the routine application of DNA-based methods to monitor whole communities (typically a metabarcoding approach) in order to assess the status of ecosystems continues to be limited. In aquatic ecosystems, the limited use is particularly true for macroinvertebrate communities. As part of the DNAqua-Net consortium, a structured discussion was initiated with the aim to identify potential molecular methods for freshwater macroinvertebrate community assessment and identify important knowledge gaps for their routine application. We focus on three complementary DNA sources that can be metabarcoded: 1) DNA from homogenised samples (bulk DNA), 2) DNA extracted from sample preservative (fixative DNA), and 3) environmental DNA (eDNA) from water or sediment. We provide a brief overview of metabarcoding macroinvertebrate communities from each DNA source and identify challenges for their application to routine monitoring. To advance the utilisation of DNA-based monitoring for macroinvertebrates, we propose an experimental design template for a series of methodological calibration tests. The template compares sources of DNA with the goal of identifying the effects of molecular processing steps on precision and accuracy. Furthermore, the same samples will be morphologically analysed, which will enable the benchmarking of molecular to traditional processing approaches. In doing so we hope to highlight pathways for the development of DNA-based methods for the monitoring of freshwater macroinvertebrates
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