141 results on '"Vasco Branco"'
Search Results
2. Immersive Unit Visualization with Augmented Reality
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Ana Beatriz Marques, Vasco Branco, Rui Costa, and Nina Costa
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Immersive Unit Visualization ,augmented reality ,hybrid space ,immersive analytics ,information design ,data visualization ,Technology ,Science - Abstract
Immersive Unit Visualization is an emergent form of visualization that arose from Immersive Analytics where, unlike traditional visualizations, each data point is represented by an individual visual mark in an immersive virtual environment. This practice has focused almost exclusively on virtual reality, excluding augmented reality (AR). This article develops and tests a prototype of an Immersive Unit Visualization (Floating Companies II) with two AR devices: head-mounted display (HMD) and hand-held display (HHD). Results from the testing sessions with 20 users were analyzed through qualitative research analysis and thematic coding indicating that, while the HHD enabled a first contact with AR visualization on a familiar device, HMD improved the perception of hybrid space by supporting greater stability of virtual content, wider field of view, improved spatial perception, increased sense of immersion, and more realistic simulation, which had an impact on information reading and sense-making. The materialization of abstract quantitative values into concrete reality through its simulation in the real environment and the ludic dimension stand out as important opportunities for this type of visualization. This paper investigates the aspects distinguishing two experiences regarding data visualization in hybrid space, and characterizes ways of seeing information with AR, identifying opportunities to advance information design research.
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- 2023
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3. Thioredoxin Reductase Inhibitors as Potential Antitumors: Mercury Compounds Efficacy in Glioma Cells
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Vanessa Pires, Isabella Bramatti, Michael Aschner, Vasco Branco, and Cristina Carvalho
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glioblastoma ,thioredoxin reductase ,thioredoxin ,thimerosal (thiomersal) ,ethylmercury ,Biology (General) ,QH301-705.5 - Abstract
Glioblastoma multiforme (GBM) is the most aggressive and common form of glioma. GBM, like many other tumors, expresses high levels of redox proteins, such as thioredoxin (Trx) and thioredoxin reductase (TrxR), allowing tumor cells to cope with high levels of reactive oxygen species (ROS) and resist chemotherapy and radiotherapy. Thus, tackling the activity of these enzymes is a strategy to reduce cell viability and proliferation and most importantly achieve tumor cell death. Mercury (Hg) compounds are among the most effective inhibitors of TrxR and Trx due to their high affinity for binding thiols and selenols. Moreover, organomercurials such as thimerosal, have a history of clinical use in humans. Thimerosal effectively crosses the blood–brain barrier (BBB), thus reaching effective concentrations for the treatment of GBM. Therefore, this study evaluated the effects of thimerosal (TmHg) and its metabolite ethylmercury (EtHg) over the mouse glioma cell line (GL261), namely, the inhibition of the thioredoxin system and the occurrence of oxidative cellular stress. The results showed that both TmHg and EtHg increased oxidative events and triggered cell death primarily by apoptosis, leading to a significant reduction in GL261 cell viability. Moreover, the cytotoxicity of TmHg and ETHg in GL261 was significantly higher when compared to temozolomide (TMZ). These results indicate that EtHg and TmHg have the potential to be used in GBM therapy since they strongly reduce the redox capability of tumor cells at exceedingly low exposure levels.
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- 2022
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4. A pilot study to evaluate the serum Alpha-1 acid glycoprotein response in cats suffering from feline chronic gingivostomatitis
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Lisa A. Mestrinho, Rita Rosa, Patrícia Ramalho, Vasco Branco, Leonor Iglésias, Hugo Pissarra, Ana Duarte, and Maria Niza
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Veterinary medicine ,SF600-1100 - Abstract
Abstract Background Feline chronic gingivostomatitis (FCGS) is a multifactorial immune-mediated disease that can lead to chronic pain, anorexia, and weight loss and has substantial health and welfare effects. Currently, the recommended treatment includes dental extractions to decrease the inflammatory stimulation associated with dental plaque. However, complete remission is observed in less than half of the cases, and the majority need comprehensive medical management. This study aimed to evaluate the serum levels of the acute phase protein alpha-1 acid glycoprotein (AGP) in cats with FCGS and to examine whether dental extractions contribute to a significant decrease in the systemic inflammatory response at two postoperative time points. Results AGP serum concentrations in the cats with FCGS were significantly higher at all time points than that in the control groups and were significantly correlated with the global caudal stomatitis score at day 0 but not at day 30 or 60. A significant improvement of some clinical scores, such as perceived comfort and global caudal stomatitis, was observed 60 days after the dental extraction. However, the levels of AGP did not significantly change over time. Conclusions Cats with FCGS were more likely to have a systemic inflammatory response compared with age- and dental disease-matched controls. Dental extractions, in most cases, did not contribute to a significant decrease of AGP both at 30 and 60 days. Therefore, this study reinforces the need to pursue comprehensive medical management after dental extractions to attenuate the systemic inflammatory response as a result of this disease.
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- 2020
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5. Current GBIF occurrence data demonstrates both promise and limitations for potential red listing of spiders
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Vaughn Shirey, Sini Seppälä, Vasco Branco, and Pedro Cardoso
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Araneae ,arthropoda ,conservation ,extent of oc ,Biology (General) ,QH301-705.5 - Abstract
Conservation assessments of hyperdiverse groups of organisms are often challenging and limited by the availability of occurrence data needed to calculate assessment metrics such as extent of occurrence (EOO). Spiders represent one such diverse group and have historically been assessed using primary literature with retrospective georeferencing. Here we demonstrate the differences in estimations of EOO and hypothetical IUCN Red List classifications for two extensive spider datasets comprising 479 species in total. The EOO were estimated and compared using literature-based assessments, Global Biodiversity Information Facility (GBIF)-based assessments and combined data assessments. We found that although few changes to hypothetical IUCN Red List classifications occurred with the addition of GBIF data, some species (3.3%) which could previously not be classified could now be assessed with the addition of GBIF data. In addition, the hypothetical classification changed for others (1.5%). On the other hand, GBIF data alone did not provide enough data for 88.7% of species. These results demonstrate the potential of GBIF data to serve as an additional source of information for conservation assessments, complementing literature data, but not particularly useful on its own as it stands right now for spiders.
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- 2019
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6. Species conservation profiles of spiders (Araneae) endemic to mainland Portugal
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Vasco Branco, Sergio Henriques, Carla Rego, and Pedro Cardoso
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Arachnida ,Arthropoda ,Species distribution mod ,Biology (General) ,QH301-705.5 - Published
- 2019
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7. Narrative Visualization with Augmented Reality
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Ana Beatriz Marques, Vasco Branco, and Rui Costa
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narrative visualization ,augmented reality ,design ,storytelling ,immersive journalism ,interactivity ,Technology ,Science - Abstract
The following study addresses, from a design perspective, narrative visualization using augmented reality (AR) in real physical spaces, and specifically in spaces with no semantic relation with the represented data. We intend to identify the aspects augmented reality adds, as narrative possibilities, to data visualization. Particularly, we seek to identify the aspects augmented reality introduces regarding the three dimensions of narrative visualization—view, focus and sequence. For this purpose, we adopted a comparative analysis of a set of fifty case studies, specifically, narrative visualizations using augmented reality from a journalistic scope, where narrative is a key feature. Despite the strong explanatory character that characterizes the set of analyzed cases, which sometimes limits the user’s agency, there is a strong interactive factor. It was found that augmented reality can expand the narrative possibilities in the three dimensions mentioned—view, focus and sequence—but especially regarding visual strategies where simulation plays an essential role. As a visual strategy, simulation can provide the context for communication or be the object of communication itself, as a replica.
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- 2022
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8. Selenium and Redox Enzyme Activity in Pregnant Women Exposed to Methylmercury
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Vasco Branco, Luís Carvalho, Cássia Barboza, Eduarda Mendes, Afonso Cavaco, and Cristina Carvalho
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selenium ,selenoproteins ,pregnant women ,thioredoxin reductase ,glutathione peroxidase ,thioredoxin ,Therapeutics. Pharmacology ,RM1-950 - Abstract
Selenium (Se) is a micronutrient with essential physiological functions achieved through the production of selenoproteins. Adequate Se intake has health benefits and reduces mercury (Hg) toxicity, which is important due to its neurotoxicity. This study determined the Se status and redox enzyme, including selenoproteins’, activity in pregnant women highly exposed to Hg (between 1 to 54 µg Hg/L blood) via fish consumption. A cross-sectional study enrolling 513 women between the first and third trimester of pregnancy from Madeira, Portugal was conducted, encompassing collection of blood and plasma samples. Samples were analyzed for total Se and Hg levels in whole blood and plasma, and plasma activity of redox-active proteins, such as glutathione peroxidase (GPx), thioredoxin reductase (TrxR) and thioredoxin (Trx). Enzyme activities were related to Se and Hg levels in blood. Se levels in whole blood (65.0 ± 13.1 µg/L) indicated this population had a sub-optimal Se status, which translated to low plasma GPx activity (69.7 ± 28.4 U/L). The activity of TrxR (12.3 ± 5.60 ng/mL) was not affected by the low Se levels. On the other hand, the decrease in Trx activity with an increase in Hg might be a good indicator to prevent fetal susceptibility.
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- 2022
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9. Glutaredoxin: Discovery, redox defense and much more
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Fernando T. Ogata, Vasco Branco, Filipa F. Vale, and Lucia Coppo
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Glutaredoxin ,Redox regulation ,Glutathionylation ,Deglutathionylation ,Iron homeostasis ,Grxs phylogenetics ,Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Glutaredoxin, Grx, is a small protein containing an active site cysteine pair and was discovered in 1976 by Arne Holmgren. The Grx system, comprised of Grx, glutathione, glutathione reductase, and NADPH, was first described as an electron donor for Ribonucleotide Reductase but, from the first discovery in E.coli, the Grx family has impressively grown, particularly in the last two decades. Several isoforms have been described in different organisms (from bacteria to humans) and with different functions.The unique characteristic of Grxs is their ability to catalyse glutathione-dependent redox regulation via glutathionylation, the conjugation of glutathione to a substrate, and its reverse reaction, deglutathionylation. Grxs have also recently been enrolled in iron sulphur cluster formation. These functions have been implied in various physiological and pathological conditions, from immune defense to neurodegeneration and cancer development thus making Grx a possible drug target.This review aims to give an overview on Grxs, starting by a phylogenetic analysis of vertebrate Grxs, followed by an analysis of the mechanisms of action, the specific characteristics of the different human isoforms and a discussion on aspects related to human physiology and diseases.
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- 2021
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10. N-Acetylcysteine or Sodium Selenite Prevent the p38-Mediated Production of Proinflammatory Cytokines by Microglia during Exposure to Mercury (II)
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Vasco Branco, Lucia Coppo, Michael Aschner, and Cristina Carvalho
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mercury ,p38 ,microglia ,inflammation ,thioredoxin reductase ,glutathione ,Chemical technology ,TP1-1185 - Abstract
Mercury (Hg) is known for its neurotoxicity and is reported to activate microglia cells at low exposure levels. Since mercury decreases the activity of the glutathione and thioredoxin systems, we hypothesize that Hg would, in turn, disrupt microglia homeostasis by interfering with redox regulation of signaling pathways. Thus, in this work, we analyzed the effect of exposure to Hg2+ on nuclear translocation and activation of NF-kB (p50) and p38 and pro-inflammatory gene transcription (IL-1ß; iNOS, TNF-alpha) considering the interaction of Hg with the glutathione system and thioredoxin systems in microglial cells. N9 (mouse) microglia cells were exposed to different concentrations of Hg2+ and the 24 h EC50 for a reduction in viability was 42.1 ± 3.7 μM. Subsequent experiments showed that at sub-cytotoxic levels of Hg2+, there was a general increase in ROS (≈40%) accompanied by a significant depletion (60–90%) of glutathione (GSH) and thioredoxin reductase (TrxR) activity. Upon 6 h of exposure to Hg2+, p38 (but not p50) accumulated in the nucleus (50% higher than in control), which was accompanied by an increase in its phosphorylation. Transcript levels of both IL1-ß and iNOS were increased over two-fold relative to the control. Furthermore, pre-exposure of cells to the p38 inhibitor SB 239063 hindered the activation of cytokine transcription by Hg2+. These results show that disruption of redox systems by Hg2+ prompts the activation of p38 leading to transcription of pro-inflammatory genes in microglia cells. Treatment of N9 cells with NAC or sodium selenite—which caused an increase in basal GSH and TrxR levels, respectively, prevented the activation of p38 and the transcription of pro-inflammatory cytokines. This result demonstrates the importance of an adequate nutritional status to minimize the toxicity resulting from Hg exposure in human populations at risk.
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- 2022
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11. Synthesis of glutathione as a central aspect of PAH toxicity in liver cells: A comparison between phenanthrene, Benzo[b]Fluoranthene and their mixtures
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Vasco Branco, Beatriz Matos, Carolina Mourato, Mário Diniz, Cristina Carvalho, and Marta Martins
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Polycyclic Aromatic Hydrocarbons ,Glutathione ,Mixtures ,Phenanthrene ,Benzo[b]Fluoranthene ,Nrf2 ,Environmental pollution ,TD172-193.5 ,Environmental sciences ,GE1-350 - Abstract
Polycyclic Aromatic Hydrocarbons (PAH) are a class of organic pollutants normally found as mixtures with effects often hard to predict, which poses a major challenge for risk assessment. In this study, we address the effects of Phenanthrene (Phe), benzo[b]fluoranthene (B[b]F) and their mixtures (2 Phe:1 B[b]F; 1 Phe: 1 B[b]F; 1 Phe: 2 B[b]F) over glutathione (GSH) synthesis and function in HepG2 cells. We analyzed the effects on cellular viability, ROS production, glutathione (GSH) levels, protein-S-glutathionylation (PSSG), the activity of glutathione peroxidase (GPx), glutathione-S-transferases (GST) and glutathione reductase (GR). Transcript (mRNA) levels of glutathione synthesis enzymes - glutathione cysteine ligase catalytical (GCLC) and modifying (GCLM) sub-units and glutathione synthetase (GS) – and Nrf2 translocation to the nucleus were analyzed. Phe showed a higher cytotoxicity (IC50 = 130 µM after 24 h) than B[b]F related to a higher ROS production (up-to 50% for Phe). In agreement, GSH levels were significantly increased (up-to 3-fold) by B[b]F and were accompanied by an increase in the levels of PSSG, which is a mechanism that protect proteins from oxidative damage. The upregulation of GSH was the consequence of Nrf2 signaling activation and increased levels of GCLC, GCLM and GS mRNA observed after exposure to B[b]F, but not during exposure to Phe. Most interestingly, all mixtures showed higher cytotoxicity than individual compounds, but intriguingly it was the 1 Phe: 1B[b]F mixture showing the highest cytotoxicity and ROS production. GSH levels were not significantly upregulated not even in the mixture enriched in B[b]F. These results point to the role of GSH as a central modulator of PAH toxicity and demonstrate the idiosyncratic behavior of PAH mixtures even when considering only two compounds in varying ratios.
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- 2021
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12. Impaired cross-talk between the thioredoxin and glutathione systems is related to ASK-1 mediated apoptosis in neuronal cells exposed to mercury
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Vasco Branco, Lucia Coppo, Susana Solá, Jun Lu, Cecília M.P. Rodrigues, Arne Holmgren, and Cristina Carvalho
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Mercury ,Thioredoxin ,Glutathione ,Glutaredoxin ,ASK- 1 ,Medicine (General) ,R5-920 ,Biology (General) ,QH301-705.5 - Abstract
Mercury (Hg) compounds target both cysteine (Cys) and selenocysteine (Sec) residues in peptides and proteins. Thus, the components of the two major cellular antioxidant systems – glutathione (GSH) and thioredoxin (Trx) systems – are likely targets for mercurials. Hg exposure results in GSH depletion and Trx and thioredoxin reductase (TrxR) are prime targets for mercury. These systems have a wide-range of common functions and interaction between their components has been reported. However, toxic effects over both systems are normally treated as isolated events. To study how the interaction between the glutathione and thioredoxin systems is affected by Hg, human neuroblastoma (SH-SY5Y) cells were exposed to 1 and 5 μM of inorganic mercury (Hg2+), methylmercury (MeHg) or ethylmercury (EtHg) and examined for TrxR, GSH and Grx levels and activities, as well as for Trx redox state. Phosphorylation of apoptosis signalling kinase 1 (ASK1), caspase-3 activity and the number of apoptotic cells were evaluated to investigate the induction of Trx-mediated apoptotic cell death. Additionally, primary cerebellar neurons from mice depleted of mitochondrial Grx2 (mGrx2D) were used to examine the link between Grx activity and Trx function. Results showed that Trx was affected at higher exposure levels than TrxR, especially for EtHg. GSH levels were only significantly affected by exposure to a high concentration of EtHg. Depletion of GSH with buthionine sulfoximine (BSO) severely increased Trx oxidation by Hg. Notably, EtHg-induced oxidation of Trx was significantly enhanced in primary neurons of mGrx2D mice. Our results suggest that GSH/Grx acts as backups for TrxR in neuronal cells to maintain Trx turnover during Hg exposure, thus linking different mechanisms of molecular and cellular toxicity. Finally, Trx oxidation by Hg compounds was associated to apoptotic hallmarks, including increased ASK-1 phosphorylation, caspase-3 activation and increased number of apoptotic cells.
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- 2017
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13. A convergência TV-Web: motivações e modelos
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Jorge Trinidad Ferraz de Abreu and Vasco Branco
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Communication. Mass media ,P87-96 - Abstract
Actualmente, a palavra «convergência» surge com uma frequência crescente na abordagem correlativa de diversos processos comunicacionais. Neste enquadramento, a Web e a Televisão constituem-se como processos comunicacionais nos quais se questiona, de forma efervescente, a sua correlação e eventual convergência. Por outro lado, é também frequente depreender-se que a «futura Televisão Interactiva» resultará deste processo de convergência, no qual se encontram envolvidos diversos agentes, desde as empresas de telecomunicações, companhias de Televisão por cabo e estações de Televisão até aos fornecedores de conteúdos e outras entidades relacionadas com tecnologias dacomunicação.Neste cenário, o presente artigo pretende identificar quais as possíveis formas de convergência entre estes dois media, não descurando quer o valor acrescentado que estas terão que oferecer de forma a garantirem o seu sucesso, quer as limitações que o actual estado da arte tecnológico lhes impõe. Atendendo a estas mesmas limitações, são igualmente propostos alguns modelos comunicacionais, considerados de baixa dependência tecnológica, capazes de promover uma utilização conjunta da Televisão e da Web, contribuindo, simultaneamente, para uma consciencialização pública do poder do novo media daqui resultante.
- Published
- 2013
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14. Temporal clustering of metals in a short sediment core of the Cascais Canyon (Portuguese Margin)
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Mário Mil-Homens, Ana M. Costa, Susana M. Lebreiro, João Canário, Cristina Lopes, Filomena Mouro, Manuela Mateus, Henko de Stigter, Thomas Richter, Vasco Branco, M. Ascensão Trancoso, Zenaida Melo, and Wim Boer
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portuguese margin ,cascais canyon ,sediment ,heavy metals ,cluster analysis ,enrichment factors ,Aquaculture. Fisheries. Angling ,SH1-691 - Abstract
The Cascais Canyon delivers contaminated sediments from the shelf to the deep marine environment. Multi-core PE252-32, located at 2100 m water depth in the canyon, records the latest 300 years of sedimentation. It was dated by 210Pb and analyzed texturally and geochemically for major elements and selected trace metals (Cu, Cr, Hg, Li, Ni, Pb and Zn). Cluster analysis performed on the down-core geochemical data identified four groups of variables related by grain-size, geochemical source and composition. Mercury, Pb and Zn were grouped in a cluster representing the anthropogenic component. Cluster analysis was applied again particularly to the latter cluster relatively to depth, in order to constrain the onset and temporal evolution of anthropogenic contamination. A second clustering, made on the basis of Hg, Pb and Zn, grouped samples by age and degree of anthropogenic contamination. One cluster contained relatively uncontaminated samples older than 1900 AD, and another cluster samples younger than 1900 AD with distinct metal enrichment. Maximum enrichments occurred during the early 1980s, followed by a slight recovery from the mid-1980s to the present. Mercury was the element with the highest enrichment factor (EFHg=5). Despite relatively low accumulation rates at this core location, our results show the importance of the Cascais Canyon as a transport route for contaminated sediments from the Tagus prodelta into the deep regions of the Portuguese Margin.
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- 2010
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15. Exposure of human glioblastoma cells to thimerosal inhibits the thioredoxin system and decreases tumor growth-related factors
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Isabella, Bramatti, primary, Michael, Aschner, additional, Vasco, Branco, additional, and Cristina, Carvalho, additional
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- 2024
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16. Data Visualization in Hybrid Space—Constraints and Opportunities for Design
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Nina Costa, Vasco Branco, Ana Beatriz Antunes Marques, and Rui Costa
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Immersive analytics ,Data visualization ,Augmented reality - Abstract
It is intended to investigate the hybrid space, as a determining attribute of the experience and interaction with augmented reality systems, to assess the potential and limitations of this space for information design, specifically in the context of data visualization. This paper presents a study which focused on the use of augmented reality in data visualization, in cases where there is no direct semantic relation between the virtual content and the real setting where the visualization will be displayed. For this study, a practice-based methodology was adopted, supported by the development, implementation and testing of a prototype of an augmented reality application for mobile devices. This prototype, which allows to visualize data related to design companies in Portugal, was assessed in real context. The data collected in this process sparked a reflection on the achieved results, but also on the challenges inherent to the application of this technology in the design of data visualizations. published
- Published
- 2022
17. Mapping Ecosystems Through Design—Reflections of the DesignOBS Project
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Nina Costa, Rui Costa, Afonso Borges, Vasco Branco, António Modesto, Raul Cunca, and Ana Catarina Silva
- Published
- 2022
18. Cysteine redox post-translational modifications: the missing link between redox-signalling and mitochondrial dynamics and function in Parkinson’s disease?
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Daria Alexandrovna Kovalchuk, Sandra I. Anjo, Maria João Nunes, Vasco Branco, Fabiana Santos, Inês Caria, Margarida Castro-Caldas, Elsa Rodrigues, Bruno Manadas, Rita C. Guedes, Maria João Gama, and Andreia N. Carvalho
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Physiology (medical) ,Biochemistry - Published
- 2023
19. Interaction of Polycyclic Aromatic Hydrocarbon compounds in fish primary hepatocytes: From molecular mechanisms to genotoxic effects
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Isabella Bramatti, Beatriz Matos, Neusa Figueiredo, Pedro Pousão-Ferreira, Vasco Branco, and Marta Martins
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History ,Environmental Engineering ,Polymers and Plastics ,Swine ,Fishes ,Pollution ,Industrial and Manufacturing Engineering ,Cytochrome P-450 CYP1A1 ,Hepatocytes ,Carcinogens ,Environmental Chemistry ,Animals ,Female ,Environmental Pollutants ,RNA, Messenger ,Business and International Management ,Polycyclic Aromatic Hydrocarbons ,Waste Management and Disposal ,DNA Damage - Abstract
Polycyclic Aromatic Hydrocarbons (PAHs) are persistent pollutants normally found in the environment as complex mixtures. Although several individual PAHs are classified as mutagenic and carcinogenic pollutants, the interaction effects between compounds in a mixture may trigger different toxicological mechanisms and, consequently, yield different effects to organisms which are not accounted for in risk assessment guidelines. Given the ubiquity of PAHs, understanding the mechanistic features of their mixtures is a pressing research need. Therefore, the present work aimed to disclose the interaction effects of three PAHs with different carcinogenic potential and chemical structure, in primary hepatocyte cells of gilt-headed seabreams (Sparus aurata). Hepatocytes were exposed to Phenanthrene (Phe), Benzo[a]pyrene (B[a]P) and Benzo[b]fluoranthene (B[b]F) and their mixtures at different proportions and several cellular responses were analyzed: cellular viability, CYP1A1 activity (EROD assay) and protein expression level (Western blot); transcript (mRNA) levels of CYP1A1, EPXH1 and GST-3 (qRT-PCR); genotoxic effects (DNA strand breakage) by the Comet assay. Results show that B[a]P induced CYP1A1 gene and protein expression increasing its activity and, therefore, increasing the production of metabolites that trigger genotoxic DNA damage (%). Most importantly, mixtures containing Phe and B[a]P increased even further CYP1A1 mRNA levels and DNA damage (up to 70 %) which suggests that, although Phe is considered a non-carcinogenic PAH, it potentiates CYP1A1 synthesis induced by B[a]P, increasing its genotoxicity. These findings indicate that the upregulation of CYP1A1 by carcinogenic PAHs will not weaken even when in mixtures with non-carcinogenic PAHs. On contrary, non-carcinogenic PAHs may potentiate the genotoxic effect of carcinogenic PAH and therefore mixture composition should be taken in account when assessing PAH toxicity. In fact, our results point to the need of redefining Environmental Risk Assessment protocols for mixtures of carcinogenic pollutants.
- Published
- 2022
20. 2BeOn - Interactive Television Supporting Interpersonal Communication.
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Jorge Ferraz de Abreu, Pedro Almeida 0002, and Vasco Branco
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- 2001
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21. Infusing data literacy in design education: maturing a distributed design observation approach in Portugal
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Ana Catarina Silva, Vasco Branco, Raul Cunca, Afonso Borges, António Modesto, Rui M. Costa, and Nina Rosa do Amaral Costa
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Design education ,Data literacy ,Information design ,Participatory approach ,Mathematics education ,Design companies ,Sociology - Abstract
The production of data about design is important to create new knowledge about the discipline and support the development of better public policies. In Portugal, the DesignOBS project is developing these tasks, gathering information about the ecosystem. Databases are very important instruments to understand the discipline to systematically innovate. In this paper, we want to go further and address its literacy. Starting from the assumption that design is an activity of cultural mediation, its role in data interpretation could promote more participatory discussions about the discipline, and ultimately enrich the ecosystem; but data literacy in design is still at its infancy. To address this challenge, the present paper describes a hands-on approach to infuse data literacy in an educational design con- text, to support novice designers navigating a database about design companies. The study adopts a longitudinal case study approach and follows fifteen students from a design master course during the period of one semester. This research is an additional step for the maturation of the process to develop a design observatory in Portugal. It resulted in a set of data-focused infographics about design companies, richer datasets and levered the transformation of the student’s perception of their potential role in the context of data. This study contributes to ongoing discussions at the intersection of data literacy and design, still in an early stage. Moreover, it advances design research by reflecting on the value of adopting designerly approaches to create new materials, diffuse information about the design ecosystem and promote more participatory reflections about the discipline. This article is a result of the project Design Obs. Para um Observatório de Design em Portugal: Modelos, Instrumentos, Representação e Estratégias, (Towards a design Obser- vatory in Portugal: models, instruments representation and strategies) supported by Lisbon Regional Operational Programme (LISBOA 2020) and the Competitiveness and Internationalisation Oper- ational Programme (POCI-01-0145-FEDER-032445), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and FCT – Fundação para a Ciência e a Tecnologia (Foundation for Science and Technology). published
- Published
- 2022
22. Thioredoxin, Glutathione and Related Molecules in Tumors of the Nervous System
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Vasco Branco, Maria Alexandra Brito, Cristina Carvalho, and José Pimentel
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Thioredoxin-Disulfide Reductase ,Thioredoxin reductase ,Brain tumor ,Biochemistry ,Metastasis ,03 medical and health sciences ,chemistry.chemical_compound ,Thioredoxins ,0302 clinical medicine ,Neoplasms ,Glioma ,Glutaredoxin ,Drug Discovery ,medicine ,Humans ,030304 developmental biology ,Pharmacology ,0303 health sciences ,business.industry ,Melanoma ,Organic Chemistry ,Glutathione ,medicine.disease ,chemistry ,030220 oncology & carcinogenesis ,Cancer research ,Molecular Medicine ,Thioredoxin ,business ,Oxidation-Reduction - Abstract
Background:Central Nervous System (CNS) tumors have a poor survival prognosis due to their invasive and heterogeneous nature, in addition to the resistance to multiple treatments.Objective:In this paper, the main aspects of brain tumor biology and pathogenesis are reviewed both for primary tumors of the brain, (i.e., gliomas) and for metastasis from other malignant tumors, namely lung cancer, breast cancer and malignant melanoma which account for a high percentage of overall malignant brain tumors. We review the role of antioxidant systems, namely the thioredoxin and glutathione systems, in the genesis and/or progression of brain tumors.Methods:Although overexpression of Thioredoxin Reductase (TrxR) and Thioredoxin (Trx) is often linked to increased malignancy rate of brain tumors, and higher expression of Glutathione (GSH) and Glutathione S-Transferases (GST) are associated to resistance to therapy, several knowledge gaps still exist regarding for example, the role of Peroxiredoxins (Prx), and Glutaredoxins (Grx).Conclusion:Due to their central role in redox homeostasis and ROS scavenging, redox systems are potential targets for new antitumorals and examples of innovative therapeutics aiming at improving success rates in brain tumor treatment are discussed.
- Published
- 2020
23. Perdas por Imparidade em dívidas a receber e Manipulação de Resultados: o comportamento das Empresas Portuguesas durante a Crise Financeira
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Sara Cristina Vasco Branco and Faculdade de Economia
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Economia e gestão ,Economics and Business ,Economia e gestão [Ciências sociais] ,Economics and Business [Social sciences] - Published
- 2021
24. Contributos para um Sistema de Anotações no Contexto da Comunicação Científica
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Sandra Cruz, Vasco Branco, and Francisco Providência
- Published
- 2021
25. Representação e literacia dos dados: o caso das empresas de design em Portugal
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Ana Catarina Silva, Raul Cunca, Vasco Branco, Afonso Borges, Rui M. Costa, Nina Rosa do Amaral Costa, and António Modesto
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Educação em design ,Literacia dos dados ,Empresas de design em Portugal ,Design de informação - Abstract
Este estudo resulta de um exercício desenvolvido dentro do âmbito do projeto nacional “Para um observatório de design em Portugal: modelos, instrumentos, representações, estratégias”, com 15 alunos de mestrado da Universidade de Aveiro. Objetivou mapear dados económicos e financeiros sobre 1200 empresas de design em Portugal e capacitar jovens designers na interpretação e representação de dados. Durante um semestre, os alunos categorizaram, curaram, densificaram e mapearam a informação sobre essas empresas. Usaram essa informação para desenvolver uma infografia, com abstrações e metáforas, constituindo a sua primeira experiência de manuseamento e comunicação de dados. Os resultados preliminares indicam uma emancipação importante por parte dos alunos, que demonstraram interesse e capacidade crítica, na interpretação dos dados. Este estudo constitui mais um passo rumo à consolidação de uma abordagem participativa e distribuída de observação, essencial para a construção de um observatório de design em Portugal. Este artigo é resultado do projeto Design Obs. Para um Observatório do Design em Portugal: modelos, instrumentos, representação e estratégias, apoiado pelo Programa Operacional Regional de Lisboa (LISBOA 2020) e pelo Programa Operacional de Competitividade e Internacionalização (POCI-01-0145-FEDER-032445), no âmbito do Partnership Agreement PORTUGAL 2020, através do Fundo Europeu de Desenvolvimento Regional (FEDER) e da FCT - Fundação para a Ciência e Tecnologia. published
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- 2021
26. Neurotoxicity of mercury: an old issue with contemporary significance
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Michael Aschner, Vasco Branco, and Cristina Carvalho
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Mechanism (biology) ,business.industry ,Glutamate receptor ,Neurotoxicity ,Excitotoxicity ,chemistry.chemical_element ,medicine.disease ,medicine.disease_cause ,Article ,Mercury (element) ,Ethylmercury ,chemistry.chemical_compound ,chemistry ,Toxicity ,medicine ,business ,Neuroscience ,Methylmercury - Abstract
Mercury exerts a variety of toxic effects, depending on the specific compound and route of exposure. However, neurotoxicity in virtue of its consequence to health causes the greatest concern for toxicologists. This is particularly true regarding fetal development, where neurotoxic effects are much more severe than in adults, and the toxicity threshold is lower. Here, we review the major concepts regarding the neurotoxicity of mercury compounds (mercury vapor; methylmercury and ethylmercury), from exposure routes to toxicokinetic particularities leading to brain deposition and the development of neurotoxic effects. Albeit research on the neurotoxicity of mercury compounds has significantly advanced from the second half of the twentieth century onwards, several grey areas regarding the mechanism of toxicity still exist. Thus, we emphasize research advances during the last two decades concerning the molecular interactions of mercury which cause neurotoxic effects. Highlights include the disruption of glutamate signaling and excitotoxicity resulting from exposure to mercury and the interaction with redox active residues such as cysteines and selenocysteines which are the premise accounting for the disruption of redox homeostasis caused by mercurials. We also address how immunotoxic effects at the CNS, namely microglia and astrocyte activation modulate developmental neurotoxicity, a major topic in contemporary research.
- Published
- 2021
27. Glutaredoxin: Discovery, redox defense and much more
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Filipa F. Vale, Lucia Coppo, Vasco Branco, Fernando T. Ogata, and Repositório da Universidade de Lisboa
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0301 basic medicine ,Gene isoform ,Medicine (General) ,QH301-705.5 ,Clinical Biochemistry ,Glutathione reductase ,Glutaredoxin ,Grxs phylogenetics ,Biochemistry ,Redox ,Catalysis ,03 medical and health sciences ,chemistry.chemical_compound ,R5-920 ,0302 clinical medicine ,Iron homeostasis ,medicine ,Humans ,Biology (General) ,Glutaredoxins ,Phylogeny ,Glutathionylation ,biology ,Organic Chemistry ,Neurodegeneration ,Glutathione ,medicine.disease ,biology.organism_classification ,030104 developmental biology ,Ribonucleotide reductase ,chemistry ,Redox regulation ,Deglutathionylation ,Oxidation-Reduction ,030217 neurology & neurosurgery ,Bacteria - Abstract
Glutaredoxin, Grx, is a small protein containing an active site cysteine pair and was discovered in 1976 by Arne Holmgren. The Grx system, comprised of Grx, glutathione, glutathione reductase, and NADPH, was first described as an electron donor for Ribonucleotide Reductase but, from the first discovery in E.coli, the Grx family has impressively grown, particularly in the last two decades. Several isoforms have been described in different organisms (from bacteria to humans) and with different functions. The unique characteristic of Grxs is their ability to catalyse glutathione-dependent redox regulation via glutathionylation, the conjugation of glutathione to a substrate, and its reverse reaction, deglutathionylation. Grxs have also recently been enrolled in iron sulphur cluster formation. These functions have been implied in various physiological and pathological conditions, from immune defense to neurodegeneration and cancer development thus making Grx a possible drug target. This review aims to give an overview on Grxs, starting by a phylogenetic analysis of vertebrate Grxs, followed by an analysis of the mechanisms of action, the specific characteristics of the different human isoforms and a discussion on aspects related to human physiology and diseases., LC, FTO and VB would like to dedicate this work to the memory of Professor Arne Holmgren, discoverer of glutaredoxin, a reference in redox research, a great mentor and storyteller. It was a privilege to work and learn from him. The authors want to thank also all the excellent scientists with whom Arne worked for their contribution to increases the knowledge about glutaredoxins. The authors thank Dr Colin Miller for proofreading the manuscript. LC was supported by the Swedish Cancer Society (961), the Swedish Research Council Medicine (13X-3529) and a grant from the Swedish Fulbright Commission (2020). VB and FFV are supported by iMed.ULisboa’s strategic project (UIDP/04138/2020; UIDB/04138/2020), financed by national funds from Fundação para a Ciência e Tecnologia, Portugal (FCT; www.fct.pt). VB is financed by national funds via Fundação para a Ciência e Tecnologia through Norma Transitória - DL57/2016/CP1376/CT002. FFV is financed by Fundação para a Ciência e Tecnologia through Assistant Researcher grant CEECIND/03023/2017.
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- 2021
28. Design infrastructures: proposing alternative strategies for countries with a lower maturation of design culture
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Raul Cunca, Nina Rosa do Amaral Costa, Afonso Borges, António Modesto, Rui Costa, Ana Vieira Silva, and Vasco Branco
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Knowledge management ,Design networks ,business.industry ,Association (object-oriented programming) ,Infrastructuring ,Design schools ,language.human_language ,Test (assessment) ,language ,Key (cryptography) ,Portuguese ,business ,Design culture ,Design observation - Abstract
In Europe, Design Centers and Associations are considered as key infrastructures to efficiently promote and represent the discipline. However, in some countries with a lower maturation of Design culture – such as the case of Portugal - there are no official actors fully dedicated to these activities. Previous research indicated Design schools as a potential alternative infrastructure to promote and represent Design, but further research is needed to understand what they can learn/adapt from the activities currently undertaken by Centers and Associations. This paper maps the European landscape looking in particular at BEDA (Bureaux of European Design Association) members. Based on these insights and recent infrastructuring literature, it develops adapted strategies for observation activities to test with Design schools in the Portuguese territory. The results obtained are a first step to bring countries with lower maturation of design culture under the EU Design Ecosystem radar. Project Design Obs. Towards a design Observatory in Portugal: models, instruments, representation and strategies supported by Lisbon Regional Operational Program (LISBOA 2020) and the Competitiveness and Internationalization Operational Program (POCI-01-0145-FEDER-032445), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and FCT – Foundation for Science and Technology. in publication
- Published
- 2021
29. Mapping the Research Thread of PhDs in Design: A PhD Citation Analysis of the Portuguese Doctorates
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Rui M. Costa, Vasco Branco, António Modesto, Nina Rosa do Amaral Costa, Afonso Borges, Raul Cunca, and Ana Catarina Silva
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Research design ,Citation network ,Thread (network protocol) ,language.human_language ,Doctoral research ,Design doctorates ,Work (electrical) ,Citation analysis ,Mathematics education ,language ,Sociology ,Portuguese ,PhD research ,Citation - Abstract
The present study undertaken within the DesignOBS project, is based on 172 PhD theses in Design submitted to the Portuguese National Design Schools between 2005 and 2019. It focuses in particular on the extraction and analysis of 522 PhD citations appended to design doctoral work. The analysis is used to observe school impact, explore the weight of previous design-focused and non-design doctoral work to develop PhD research in Design in the country. The results reveal few connections between doctorates and few overlaps in- between as well as outside design schools thus indicating poor continuity and reproducibility of domestic doctoral work, little tradition of PhD citation, and an important weight of non-design schools. A network-based visualisation of the connections between PhDs in Design within PhD thesis, by use of a citation analysis method, enabled to draw reflections on the status of domestic doctoral research in Portugal and provides an empirical approach to explore the reproducibility of this type of research which may be used in other countries. Project Design Obs. Towards a design Observatory in Portugal: models, instruments, representation and strategies supported by Lisbon Regional Operational Program (LISBOA 2020) and the Competitiveness and Internationalization Operational Program (POCI-01-0145-FEDER-032445), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (ERDF) and FCT – Foundation for Science and Technology. published
- Published
- 2021
30. Minard revisited: exploring augmented reality in information design
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Ana Beatriz Marques, Vasco Branco, and Rui M. Costa
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Design ,Computer science ,Human–computer interaction ,Information ,Augmented reality systems ,Virtuality (gaming) ,Augmented reality ,Narrative ,Representation (arts) ,Information design ,Cultural mediation ,Multimodality - Abstract
This study intends to test and confirm the interest and viability of incorporating augmented reality (AR) technologies in cultural mediation driven by information design, focusing on narrative representation. It is specifically intended to explore semantic relations between reality and virtuality in augmented narratives, ie. expanded narratives through the multimodality enhanced by the use of interactive processes based in augmented reality systems. Departing from Charles Minard’s Figurative Map (1869), three experiments were conducted, in order to reinterpret the program embodied in that artefact, testing several hypotheses in which, through augmented reality, the combination of different modes and media configures different semantic relations between real and virtual. The action-reflection approach undertaken with Figurative Map experiments enabled us to observe and openly systematize different augmented reality functions regarding the physical instance, which can potentially expand traditional forms of information design. Although they are not entirely extrapolatable, the proposal of virtual functions regarding reality were repurposed and adapted from the illustration field, specifically from the semantic relation between text and image. It is acknowledged that this is an open model to be reconsidered and reformulated through several action-reflection iterations and fostered through the narrative study. published
- Published
- 2021
31. Mitigating the Ephemeral Character of Design Exhibitions
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Helena Barbosa and Vasco Branco
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Exhibition ,Architectural engineering ,Character (computing) ,Interpretation (philosophy) ,Ephemeral key ,language ,Citizen journalism ,Sociology ,Hermeneutics ,Product (category theory) ,Portuguese ,language.human_language - Abstract
This paper presents the project “CIDEX.PT-Interpretation Centre for Design: the northern region in Portuguese design Exhibitions” aiming to research, analyze, interpret and assess the importance of exhibitions as vehicles for the development of a territory through promoting Design and the artifacts conceived and/or produced therein. The methodological approach includes research in documents and archives, the interpretation of which highlights the hermeneutics underlying the artifacts, cross-referenced by the participatory contribution of the memories collected locally. A model is used - already tested for the research and teaching of Design, emphasizing relationships between authorship, programme and technology in the design of a product - showing different layers of the designer's activity in interaction with companies at a given historical moment. The contributions of this paper are based on the methodological proposal for the study of design exhibitions emphasizing its role in the construction of the discourse of the History of Design.
- Published
- 2021
32. A pilot study to evaluate the serum Alpha-1 acid glycoprotein response in cats suffering from feline chronic gingivostomatitis
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Hugo Pissarra, Lisa A Mestrinho, Patrícia Ramalho, Vasco Branco, Ana Rita C. Duarte, Leonor V Iglésias, Rita Mourão Rosa, and Maria M. R. E. Niza
- Subjects
Male ,medicine.medical_specialty ,040301 veterinary sciences ,medicine.medical_treatment ,Pilot Projects ,Anorexia ,Disease ,Cat Diseases ,Dental plaque ,Gastroenterology ,0403 veterinary science ,03 medical and health sciences ,Weight loss ,Internal medicine ,Animals ,Medicine ,030304 developmental biology ,Stomatitis ,0303 health sciences ,lcsh:Veterinary medicine ,CATS ,General Veterinary ,business.industry ,Chronic pain ,Acute-phase protein ,Orosomucoid ,04 agricultural and veterinary sciences ,General Medicine ,medicine.disease ,Gingivitis ,Dental extraction ,Chronic Disease ,Tooth Extraction ,Cats ,lcsh:SF600-1100 ,Female ,medicine.symptom ,business ,Research Article - Abstract
Background Feline chronic gingivostomatitis (FCGS) is a multifactorial immune-mediated disease that can lead to chronic pain, anorexia, and weight loss and has substantial health and welfare effects. Currently, the recommended treatment includes dental extractions to decrease the inflammatory stimulation associated with dental plaque. However, complete remission is observed in less than half of the cases, and the majority need comprehensive medical management. This study aimed to evaluate the serum levels of the acute phase protein alpha-1 acid glycoprotein (AGP) in cats with FCGS and to examine whether dental extractions contribute to a significant decrease in the systemic inflammatory response at two postoperative time points. Results AGP serum concentrations in the cats with FCGS were significantly higher at all time points than that in the control groups and were significantly correlated with the global caudal stomatitis score at day 0 but not at day 30 or 60. A significant improvement of some clinical scores, such as perceived comfort and global caudal stomatitis, was observed 60 days after the dental extraction. However, the levels of AGP did not significantly change over time. Conclusions Cats with FCGS were more likely to have a systemic inflammatory response compared with age- and dental disease-matched controls. Dental extractions, in most cases, did not contribute to a significant decrease of AGP both at 30 and 60 days. Therefore, this study reinforces the need to pursue comprehensive medical management after dental extractions to attenuate the systemic inflammatory response as a result of this disease.
- Published
- 2020
33. Towards a design observatory: the case of scholarly design research in Portugal
- Author
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António Modesto, Raul Cunca, Rui Carlos Costa, Catarina Silva, Vasco Branco, Afonso Borges, and Nina Rosa do Amaral Costa
- Subjects
Research design ,Engineering ,Process management ,Design ,Process (engineering) ,0211 other engineering and technologies ,02 engineering and technology ,Design research ,Observatory ,0502 economics and business ,021106 design practice & management ,business.industry ,05 social sciences ,Perspective (graphical) ,Citizen journalism ,General Medicine ,language.human_language ,Test (assessment) ,Design doctorates ,Design education ,language ,Portuguese ,business ,Design guidelines ,050203 business & management - Abstract
Submitted by Rui Costa (ruicosta@ua.pt) on 2020-06-12T17:15:47Z No. of bitstreams: 1 TOWARDS A DESIGN OBSERVATORY_ InternationalDesignConference2020.pdf: 500409 bytes, checksum: 295715e0f63cf3164a253ad5b768b6f0 (MD5) Approved for entry into archive by Rita Gonçalves (ritaisabel@ua.pt) on 2020-06-15T17:14:45Z (GMT) No. of bitstreams: 1 TOWARDS A DESIGN OBSERVATORY_ InternationalDesignConference2020.pdf: 500409 bytes, checksum: 295715e0f63cf3164a253ad5b768b6f0 (MD5) Made available in DSpace on 2020-06-15T17:14:45Z (GMT). No. of bitstreams: 1 TOWARDS A DESIGN OBSERVATORY_ InternationalDesignConference2020.pdf: 500409 bytes, checksum: 295715e0f63cf3164a253ad5b768b6f0 (MD5) Previous issue date: 2020-05 published
- Published
- 2020
34. In Vitro Assessment of the Efficacy of a Macrocyclic Chelator in Reversing Methylmercury Toxicity
- Author
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MF Cabral, Judite Costa, Margarida Castro-Caldas, Paula Nobre, Vasco Branco, Cristina Carvalho, DCV - Departamento de Ciências da Vida, and UCIBIO - Applied Molecular Biosciences Unit
- Subjects
Programmed cell death ,Macrocyclic Compounds ,Thioredoxin-Disulfide Reductase ,DTNB ,Thioredoxin reductase ,Health, Toxicology and Mutagenesis ,Pharmacology ,Clinical toxicology ,Chelators ,Article ,03 medical and health sciences ,Thioredoxins ,0302 clinical medicine ,SDG 3 - Good Health and Well-being ,In vivo ,Cell Line, Tumor ,clinical toxicology ,Humans ,Thioredoxin ,Chelating Agents ,030304 developmental biology ,chemistry.chemical_classification ,Aza Compounds ,0303 health sciences ,Chemistry ,Public Health, Environmental and Occupational Health ,Methylmercury ,methylmercury ,thioredoxin reductase ,thioredoxin ,Methylmercury Compounds ,In vitro ,3. Good health ,Enzyme ,Toxicity ,chelators ,030217 neurology & neurosurgery - Abstract
Methylmercury (MeHg) is a highly neurotoxic compound to which human populations are exposed via fish consumption. Once in cells, MeHg actively binds thiols and selenols, interfering with the activity of redox enzymes such as thioredoxin (Trx) and the selenoenzyme thioredoxin reductase (TrxR) which integrate the thioredoxin system. In fact, it has been shown that inhibition of this system by MeHg is a critical step in the unfolding of cell death. Current clinical approaches to mitigate the toxicity of MeHg rely on the use of chelators, such as meso-2,3-dimercaptosuccinic acid (DMSA) which largely replaced British anti-Lewisite or 2,3-dimercapto-1-propanol (BAL) as the prime choice. However, therapeutic efficacy is limited and therefore new therapeutic options are necessary. In this work, we evaluated the efficacy of a macrocyclic chelator, 1-thia-4,7,10,13-tetraazacyclopentadecane ([15]aneN4S), in preventing MeHg toxicity, namely by looking at the effects over relevant molecular targets, i.e., the thioredoxin system, using both purified enzyme solutions and cell experiments with human neuroblastoma cells (SH-SY5Y). Results showed that [15]aneN4S had a similar efficacy to DMSA and BAL in reversing the inhibition of MeHg over purified TrxR and Trx by looking at both the 5,5&prime, dithiobis(2-nitrobenzoic acid) (DTNB) reduction assay and insulin reduction capability. In experiments with cells, none of the chelating agents could reverse the inhibition of TrxR by MeHg, which corroborates the high affinity of MeHg to the selenol in TrxR active site. [15]aneN4S and BAL, unlike DMSA, could prevent inhibition of Trx, which allows the maintenance of downstream functions, although BAL showed higher toxicity to cells. Overall these findings highlight the potential of using [15]aneN4S in the treatment of MeHg poisoning and encourage further studies, namely in vivo.
- Published
- 2019
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35. Tax on companies and European fiscal integration: The Portuguese corporation tax
- Author
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Guimarães, Vasco Branco
- Subjects
ComputingMilieux_GENERAL ,corporate tax ,Portugal ,ComputingMilieux_LEGALASPECTSOFCOMPUTING - Abstract
The paper aims to review and update readers on the existing tax regime of corporate entities in Portugal by giving an expanation on the structure of the tax and it ´s main features. It also situates the tax regime within the European trends and existing issues of integration., Studi Tributari Europei, Vol 8 (2018)
- Published
- 2019
- Full Text
- View/download PDF
36. Design as Cultural Mediation between Matter and What Matters
- Author
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Vasco Branco and Francisco Providência
- Subjects
Research design ,business.industry ,05 social sciences ,0211 other engineering and technologies ,02 engineering and technology ,Public relations ,Computer Graphics and Computer-Aided Design ,Arts and Humanities (miscellaneous) ,0502 economics and business ,Join (sigma algebra) ,050211 marketing ,Sociology ,business ,Cultural mediation ,021106 design practice & management - Abstract
This paper aims to join the 20-year celebration of The Design Journal since we consider it both an excellent means for dissemination of design research, as well as a powerful amplifier of the diver...
- Published
- 2017
37. Redox Signaling Mediated by Thioredoxin and Glutathione Systems in the Central Nervous System
- Author
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Arne Holmgren, Jun Wang, Jun Lu, Cristina Carvalho, Vasco Branco, Lili Zou, Xu Zhang, and Xiaoyuan Ren
- Subjects
Central Nervous System ,0301 basic medicine ,Cell signaling ,Antioxidant ,Physiology ,medicine.medical_treatment ,Clinical Biochemistry ,Biology ,medicine.disease_cause ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Thioredoxins ,Glutaredoxin ,medicine ,Humans ,Review Articles ,Molecular Biology ,Reactive nitrogen species ,General Environmental Science ,chemistry.chemical_classification ,Reactive oxygen species ,Cell Biology ,Glutathione ,Reactive Nitrogen Species ,Cell biology ,030104 developmental biology ,chemistry ,General Earth and Planetary Sciences ,Thioredoxin ,Reactive Oxygen Species ,Oxidation-Reduction ,Oxidative stress ,Signal Transduction - Abstract
The thioredoxin (Trx) and glutathione (GSH) systems play important roles in maintaining the redox balance in the brain, a tissue that is prone to oxidative stress due to its high-energy demand. These two disulfide reductase systems are active in various areas of the brain and are considered to be critical antioxidant systems in the central nervous system (CNS). Various neuronal disorders have been characterized to have imbalanced redox homeostasis. Recent Advances: In addition to their detrimental effects, recent studies have highlighted that reactive oxygen species/reactive nitrogen species (ROS/RNS) act as critical signaling molecules by modifying thiols in proteins. The Trx and GSH systems, which reversibly regulate thiol modifications, regulate redox signaling involved in various biological events in the CNS.In this review, we focus on the following: (i) how ROS/RNS are produced and mediate signaling in CNS; (ii) how Trx and GSH systems regulate redox signaling by catalyzing reversible thiol modifications; (iii) how dysfunction of the Trx and GSH systems causes alterations of cellular redox signaling in human neuronal diseases; and (iv) the effects of certain small molecules that target thiol-based signaling pathways in the CNS.Further study on the roles of thiol-dependent redox systems in the CNS will improve our understanding of the pathogenesis of many human neuronal disorders and also help to develop novel protective and therapeutic strategies against neuronal diseases. Antioxid. Redox Signal. 27, 989-1010.
- Published
- 2017
38. Impaired cross-talk between the thioredoxin and glutathione systems is related to ASK-1 mediated apoptosis in neuronal cells exposed to mercury
- Author
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Jun Lu, Cristina Carvalho, Susana Solá, Cecília M. P. Rodrigues, Vasco Branco, Lucia Coppo, and Arne Holmgren
- Subjects
0301 basic medicine ,Antioxidant ,animal structures ,medicine.medical_treatment ,Thioredoxin reductase ,Clinical Biochemistry ,Glutaredoxin ,Apoptosis ,MAP Kinase Kinase Kinase 5 ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,Thioredoxins ,Cell Line, Tumor ,medicine ,Animals ,Humans ,ASK1 ,Buthionine sulfoximine ,Thioredoxin ,lcsh:QH301-705.5 ,Cells, Cultured ,Neurons ,lcsh:R5-920 ,Mercury Compounds ,Organic Chemistry ,Glutathione ,Mercury ,3. Good health ,Cell biology ,030104 developmental biology ,chemistry ,lcsh:Biology (General) ,Mercury Poisoning ,ASK- 1 ,lcsh:Medicine (General) ,Signal Transduction ,Research Paper - Abstract
Mercury (Hg) compounds target both cysteine (Cys) and selenocysteine (Sec) residues in peptides and proteins. Thus, the components of the two major cellular antioxidant systems – glutathione (GSH) and thioredoxin (Trx) systems – are likely targets for mercurials. Hg exposure results in GSH depletion and Trx and thioredoxin reductase (TrxR) are prime targets for mercury. These systems have a wide-range of common functions and interaction between their components has been reported. However, toxic effects over both systems are normally treated as isolated events. To study how the interaction between the glutathione and thioredoxin systems is affected by Hg, human neuroblastoma (SH-SY5Y) cells were exposed to 1 and 5 μM of inorganic mercury (Hg2+), methylmercury (MeHg) or ethylmercury (EtHg) and examined for TrxR, GSH and Grx levels and activities, as well as for Trx redox state. Phosphorylation of apoptosis signalling kinase 1 (ASK1), caspase-3 activity and the number of apoptotic cells were evaluated to investigate the induction of Trx-mediated apoptotic cell death. Additionally, primary cerebellar neurons from mice depleted of mitochondrial Grx2 (mGrx2D) were used to examine the link between Grx activity and Trx function. Results showed that Trx was affected at higher exposure levels than TrxR, especially for EtHg. GSH levels were only significantly affected by exposure to a high concentration of EtHg. Depletion of GSH with buthionine sulfoximine (BSO) severely increased Trx oxidation by Hg. Notably, EtHg-induced oxidation of Trx was significantly enhanced in primary neurons of mGrx2D mice. Our results suggest that GSH/Grx acts as backups for TrxR in neuronal cells to maintain Trx turnover during Hg exposure, thus linking different mechanisms of molecular and cellular toxicity. Finally, Trx oxidation by Hg compounds was associated to apoptotic hallmarks, including increased ASK-1 phosphorylation, caspase-3 activation and increased number of apoptotic cells., Graphical abstract fx1, Highlights • Trx is functional even when TrxR is inhibited by Hg compounds. • Depletion of GSH with BSO increases oxidation of Trx by Hg compounds. • Mice neurons lacking mitochondrial Grx2 show increased oxidation of Trx2 by Hg. • GSH/Grx act as a backup for TrxR during Hg exposure. • Oxidation of Trx by Hg leads to activation of ASK-1 and apoptotic cell death.
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- 2017
39. The 2BeOn system - A multimedia workbench for telework and interactive television research.
- Author
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Jorge Ferraz de Abreu, Pedro Almeida 0002, Vasco Branco, and óscar Mealha
- Published
- 2001
40. Design research for the development of a Medical Emergency Ambulance. Design as a symbolic qualifier in the design of complex systems/products
- Author
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Vasco Branco and Augusto de Sousa Coelho
- Subjects
Research design ,Engineering ,Arts and Humanities (miscellaneous) ,Product design ,business.industry ,medicine ,Complex system ,Medical emergency ,business ,medicine.disease ,Computer Graphics and Computer-Aided Design - Abstract
This research made it possible to launch a cooperation program between the University, the Industry and the National Institute of Medical Emergency of Portugal (INEM), to design a new medical emerg...
- Published
- 2017
41. Diphenyl diselenide protects against methylmercury-induced inhibition of thioredoxin reductase and glutathione peroxidase in human neuroblastoma cells: a comparison with ebselen
- Author
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João Rocha, Daiane Francine Meinerz, Cristina Carvalho, Michael Aschner, and Vasco Branco
- Subjects
0301 basic medicine ,chemistry.chemical_classification ,Antioxidant ,Chemistry ,Ebselen ,medicine.medical_treatment ,Glutathione peroxidase ,Thioredoxin reductase ,Pharmacology ,Toxicology ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,Downregulation and upregulation ,Biochemistry ,Toxicity ,medicine ,Diphenyl diselenide ,Toxicant - Abstract
Exposure to methylmercury (MeHg), an important environmental toxicant, may lead to serious health risks, damaging various organs and predominantly affecting the brain function. The toxicity of MeHg can be related to the inhibition of important selenoenzymes, such as glutathione peroxidase (GPx) and thioredoxin reductase (TrxR). Experimental studies have shown that selenocompounds play an important role as cellular detoxifiers and protective agents against the harmful effects of mercury. The present study investigated the mechanisms by which diphenyl diselenide [(PhSe)2 ] and ebselen interfered with the interaction of mercury (MeHg) and selenoenzymes (TrxR and GPx) in an in vitro experimental model of cultured human neuroblastoma cells (SH-SY5Y). Our results established that (PhSe)2 and ebselen increased the activity and expression of TrxR. In contrast, MeHg inhibited TrxR activity even at low doses (0.5 μm). Coexposure to selenocompounds and MeHg showed a protective effect of (PhSe)2 on both the activity and expression of TrxR. When selenoenzyme GPx was evaluated, selenocompounds did not alter its activity or expression significantly, whereas MeHg inhibited the activity of GPx (from 1 μm). Among the selenocompounds only (PhSe)2 significantly protected against the effects of MeHg on GPx activity. Taken together, these results indicate a potential use for ebselen and (PhSe)2 against MeHg toxicity. Furthermore, for the first time, we have demonstrated that (PhSe)2 caused a more pronounced upregulation of TrxR than ebselen in neuroblastoma cells, likely reflecting an important molecular mechanism involved in the antioxidant properties of this compound. Copyright © 2017 John Wiley & Sons, Ltd.
- Published
- 2017
42. Biomarkers of mercury toxicity: Past, present, and future trends
- Author
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Cristina Carvalho, Michael Aschner, Vasco Branco, João Rocha, Sam Caito, and Marcelo Farina
- Subjects
0301 basic medicine ,Health, Toxicology and Mutagenesis ,chemistry.chemical_element ,010501 environmental sciences ,Toxicology ,Risk Assessment ,01 natural sciences ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Ethylmercury ,Environmental health ,Animals ,Humans ,Adverse effect ,Methylmercury ,0105 earth and related environmental sciences ,Mercury Compounds ,Environmental Exposure ,Mercury ,Environmental exposure ,Methylmercury Compounds ,Mercury (element) ,030104 developmental biology ,chemistry ,Environmental chemistry ,Toxicity ,Environmental Pollutants ,Biomarkers of exposure assessment ,Risk assessment ,Biomarkers - Abstract
Mercury (Hg) toxicity continues to represent a global health concern. Given that human populations are mostly exposed to low chronic levels of mercurial compounds (methylmercury through fish, mercury vapor from dental amalgams, and ethylmercury from vaccines), the need for more sensitive and refined tools to assess the effects and/or susceptibility to adverse metal-mediated health risks remains. Traditional biomarkers, such as hair or blood Hg levels, are practical and provide a reliable measure of exposure, but given intra-population variability, it is difficult to establish accurate cause-effect relationships. It is therefore important to identify and validate biomarkers that are predictive of early adverse effects prior to adverse health outcomes becoming irreversible. This review describes the predominant biomarkers used by toxicologists and epidemiologists to evaluate exposure, effect and susceptibility to Hg compounds, weighing on their advantages and disadvantages. Most importantly, and in light of recent findings on the molecular mechanisms underlying Hg-mediated toxicity, potential novel biomarkers that might be predictive of toxic effect are presented, and the applicability of these parameters in risk assessment is examined.
- Published
- 2017
43. Risk assessment of methylmercury in pregnant women and newborns in the island of Madeira (Portugal) using exposure biomarkers and food-frequency questionnaires
- Author
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Afonso Cavaco, Tiago Caetano, Cristina Carvalho, and Vasco Branco
- Subjects
Adult ,Health, Toxicology and Mutagenesis ,Population ,Food Contamination ,010501 environmental sciences ,Toxicology ,01 natural sciences ,Umbilical cord ,Diet Surveys ,Risk Assessment ,03 medical and health sciences ,chemistry.chemical_compound ,Young Adult ,0302 clinical medicine ,Predatory fish ,Pregnancy ,Environmental health ,Food choice ,medicine ,Humans ,030212 general & internal medicine ,education ,Methylmercury ,0105 earth and related environmental sciences ,Exposure assessment ,education.field_of_study ,Portugal ,business.industry ,Infant, Newborn ,Environmental Exposure ,Mercury ,Methylmercury Compounds ,Middle Aged ,medicine.anatomical_structure ,chemistry ,Maternal Exposure ,Cord blood ,Female ,business ,Risk assessment ,Biomarkers ,Water Pollutants, Chemical ,Environmental Monitoring - Abstract
Methylmercury (MeHg) is a contaminant present in fish which exerts a severe impact on health predominantly exhibiting neurotoxicity that might irreversibly affect fetal neurodevelopment. Fish consumption in Portugal is the third highest in the world, particularly high in regions with fishing tradition such as the Madeira Archipelago. Therefore, this study aimed at assessing the risk of exposure to MeHg in a population of pregnant women residing in Madeira. Blood samples from pregnant women (533) and umbilical cord (194) were collected from volunteer participants collected at primary health services in Madeira (Portugal) and analyzed for total mercury (HgT) level. A food-frequency questionnaire was used to estimate exposure and indices of risk while HgT in blood were correlated with estimated exposure. Analysis of HgT levels in blood indicated that 30% of pregnant women surpassed the maximum safe level of 10 µg/L recommended by the WHO, which was derived from the consumption of predatory fish, rich in MeHg. In addition, HgT levels in cord blood were 1.3 fold higher than in maternal blood, indicating the high risk of exposure to MeHg in this population. It is thus important to provide nutritional advice concerning fish consumption as a food choice in order to reduce fetal exposure and potential neurologic damage.
- Published
- 2019
44. Marine Fish Primary Hepatocyte Isolation and Culture: New Insights to Enzymatic Dissociation Pancreatin Digestion
- Author
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Beatriz Matos, Mário Diniz, Neusa Figueiredo, Vasco Branco, and Marta Martins
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Health, Toxicology and Mutagenesis ,Cell Culture Techniques ,lcsh:Medicine ,in vitro assays ,Dissociative Disorders ,010501 environmental sciences ,01 natural sciences ,Article ,03 medical and health sciences ,chemistry.chemical_compound ,Sparus aurata ,In vivo ,Lactate dehydrogenase ,Cytochrome P-450 CYP1A1 ,medicine ,Animals ,Viability assay ,primary hepatocytes ,030304 developmental biology ,0105 earth and related environmental sciences ,0303 health sciences ,lcsh:R ,Public Health, Environmental and Occupational Health ,Molecular biology ,Sea Bream ,medicine.anatomical_structure ,Liver ,chemistry ,Cell culture ,Hepatocyte ,Pancreatin ,Flatfishes ,Hepatocytes ,Collagenase ,Digestion ,Immortalised cell line ,medicine.drug - Abstract
Primary cell cultures from wild organisms have been gaining relevance in ecotoxicology as they are considered more sensitive than immortalized cell lines and retain the biochemical pathways found in vivo. In this study, the efficacy of two methods for primary hepatocyte cell isolation was compared using liver from two marine fish (Sparus aurata and Psetta maxima): (i) two-step collagenase perfusion and (ii) pancreatin digestion with modifications. Cell cultures were incubated in L-15 medium at 17 ± 1 °C and monitored for up to six days for cell viability and function using the trypan blue exclusion test, MTT test, lactate dehydrogenase (LDH) activity, and ethoxyresorufin O-deethylase (EROD) activity after Benzo[a]Pyrene exposure. The results showed significant differences between the number of viable cells (p <, 0.05), the highest number being obtained for the pancreatin digestion method (average = 4.5 ± 1.9 × 107 cells). Moreover, the hepatocytes showed solid adherence to the culture plate and the rounded shape, changing into a triangular/polygonal shape. The cell viability and function obtained by pancreatin digestion were maintained for five days, and the EROD induction after exposure to the B[a]P showed that cells were metabolically active. This study shows that the optimized pancreatin digestion method is a valid, cost-effective, and simple alternative to the standard perfusion method for the isolation of primary hepatocytes from fish and is suitable for ecotoxicological studies involving marine pollutants, such as PAHs.
- Published
- 2021
45. Synthesis of glutathione as a central aspect of PAH toxicity in liver cells: A comparison between phenanthrene, Benzo[b]Fluoranthene and their mixtures
- Author
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Mário Diniz, Cristina Carvalho, Beatriz Matos, Marta Martins, Carolina Mourato, Vasco Branco, MARE - Centro de Ciências do Mar e do Ambiente, DCEA - Departamento de Ciências e Engenharia do Ambiente, DQ - Departamento de Química, and UCIBIO - Applied Molecular Biosciences Unit
- Subjects
Cell Survival ,Health, Toxicology and Mutagenesis ,Glutathione reductase ,0211 other engineering and technologies ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Nrf2 ,Environmental pollution ,chemistry.chemical_compound ,SDG 3 - Good Health and Well-being ,Cell Line, Tumor ,Phenanthrene ,Humans ,GE1-350 ,Polycyclic Aromatic Hydrocarbons ,Benzo(b)fluoranthene ,0105 earth and related environmental sciences ,chemistry.chemical_classification ,Fluorenes ,021110 strategic, defence & security studies ,GCLM ,Glutathione peroxidase ,Public Health, Environmental and Occupational Health ,General Medicine ,Glutathione ,Phenanthrenes ,Benzo[b]Fluoranthene ,Pollution ,Molecular biology ,Glutathione synthetase ,Environmental sciences ,Oxidative Stress ,GCLC ,TD172-193.5 ,chemistry ,Mixtures ,Hepatocytes ,Environmental Pollutants ,Cysteine - Abstract
FCT 2020.09005 DL57/2016/CP1376/CT002 Polycyclic Aromatic Hydrocarbons (PAH) are a class of organic pollutants normally found as mixtures with effects often hard to predict, which poses a major challenge for risk assessment. In this study, we address the effects of Phenanthrene (Phe), benzo[b]fluoranthene (B[b]F) and their mixtures (2 Phe:1 B[b]F; 1 Phe: 1 B[b]F; 1 Phe: 2 B[b]F) over glutathione (GSH) synthesis and function in HepG2 cells. We analyzed the effects on cellular viability, ROS production, glutathione (GSH) levels, protein-S-glutathionylation (PSSG), the activity of glutathione peroxidase (GPx), glutathione-S-transferases (GST) and glutathione reductase (GR). Transcript (mRNA) levels of glutathione synthesis enzymes - glutathione cysteine ligase catalytical (GCLC) and modifying (GCLM) sub-units and glutathione synthetase (GS) – and Nrf2 translocation to the nucleus were analyzed. Phe showed a higher cytotoxicity (IC50 = 130 µM after 24 h) than B[b]F related to a higher ROS production (up-to 50% for Phe). In agreement, GSH levels were significantly increased (up-to 3-fold) by B[b]F and were accompanied by an increase in the levels of PSSG, which is a mechanism that protect proteins from oxidative damage. The upregulation of GSH was the consequence of Nrf2 signaling activation and increased levels of GCLC, GCLM and GS mRNA observed after exposure to B[b]F, but not during exposure to Phe. Most interestingly, all mixtures showed higher cytotoxicity than individual compounds, but intriguingly it was the 1 Phe: 1B[b]F mixture showing the highest cytotoxicity and ROS production. GSH levels were not significantly upregulated not even in the mixture enriched in B[b]F. These results point to the role of GSH as a central modulator of PAH toxicity and demonstrate the idiosyncratic behavior of PAH mixtures even when considering only two compounds in varying ratios. publishersversion published
- Published
- 2021
46. The thioredoxin system as a target for mercury compounds
- Author
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Vasco Branco and Cristina Carvalho
- Subjects
0301 basic medicine ,Programmed cell death ,Thioredoxin-Disulfide Reductase ,Thioredoxin reductase ,Biophysics ,chemistry.chemical_element ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Thioredoxins ,Glutaredoxin ,Animals ,Humans ,Molecular Biology ,Cell Proliferation ,Mercury Compounds ,Glutathione ,Mercury (element) ,030104 developmental biology ,chemistry ,Toxicity ,Thioredoxin ,030217 neurology & neurosurgery ,Selenium - Abstract
Background Mercury interaction with selenium in vivo has been recognized for >50 years. Several researchers attempted to use selenium to mitigate the detrimental effects of mercurial compounds but the results were controversial. Selenium pools in living organisms are quite low and the high affinity of mercury to bind selenols pointed out selenoproteins as possible targets of toxicity. Such was the case of the selenoenzyme thioredoxin reductase (TrxR) which is an integrant part of the thioredoxin system. Given the important role of this redox system for cellular functioning and the high affinity of mercury for TrxR's active site, this interaction can be key to understand the mechanism by which Hg causes cell death. Scope of the review This review discusses the current state of knowledge concerning the interaction between mercury compounds and the thioredoxin system, its implications for the development of toxicity and the effects of selenium co-exposure. Major conclusions The mechanism of toxicity of mercurials is a complex chain of events starting with inhibition of the selenoenzyme, TrxR. Selenium supplementation protects TrxR from the toxicity of inorganic forms of mercury (i.e., Hg(II)) to a certain extent, but not from methylmercury. When TrxR is inhibited, thioredoxin is reduced by alternative mechanisms involving glutathione and glutaredoxin and only when this pathway is hampered does cell death occur. General significance Understanding the molecular mechanism of mercury toxicity and the mechanisms of enzymatic compensation allows the design of mitigation strategies and, since TxrR and Trx exist in the plasma, puts forward the possibility for future use of changes in activity/expression of these enzymes as biomarkers of mercury toxicity, thus refining the risk assessment process.
- Published
- 2018
47. Microplastics increase mercury bioconcentration in gills and bioaccumulation in the liver, and cause oxidative stress and damage in Dicentrarchus labrax juveniles
- Author
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Cristina Carvalho, Luis R. Vieira, Luís Gabriel Antão Barboza, Lúcia Guilhermino, and Vasco Branco
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Gill ,Gills ,Microplastics ,010504 meteorology & atmospheric sciences ,chemistry.chemical_element ,lcsh:Medicine ,Bioconcentration ,010501 environmental sciences ,medicine.disease_cause ,01 natural sciences ,Article ,medicine ,Animals ,14. Life underwater ,lcsh:Science ,0105 earth and related environmental sciences ,Pollutant ,Glutathione Peroxidase ,Multidisciplinary ,lcsh:R ,Mercury ,Catalase ,Mercury (element) ,Oxidative Stress ,Glutathione Reductase ,chemistry ,Liver ,13. Climate action ,Environmental chemistry ,Bioaccumulation ,Toxicity ,lcsh:Q ,Bass ,Lipid Peroxidation ,Plastics ,Oxidative stress ,Environmental Monitoring - Abstract
The presence of microplastics and several other pollutants in the marine environment is of growing concern. However, the knowledge on the toxicity of mixtures containing microplastics and other contaminants to marine species is still scarce. The main goals of this study were to investigate the oxidative stress and lipid oxidative damage potentially induced by 96 h of exposure to mercury (0.010 and 0.016 mg/L), microplastics (0.26 and 0.69 mg/L), and mixtures of the two substances (same concentrations, full factorial) in the gills and liver of D. labrax juveniles, and the possible influence of microplastics on mercury bioconcentration (gills) and bioaccumulation (liver). The results indicate that the presence of microplastics in the water increased the concentration of mercury in gills and liver of D. labrax juveniles. Microplastics and mercury, alone and in mixtures, caused oxidative stress in both organs. Based on the total induction of antioxidant enzymatic activity, the type of toxicological interaction in fish exposed to the mixture containing the lowest concentration of the two substances was addition in gills, and addition or synergism in the liver. These results stress the need to further address the role of microplastics in the bioconcentration, bioaccumulation, and toxicity of other environmental contaminants in different species.
- Published
- 2018
48. Effects of microplastics and mercury in the freshwater bivalve Corbicula fluminea (Müller, 1774): Filtration rate, biochemical biomarkers and mercury bioconcentration
- Author
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Luís Gabriel Antão Barboza, Cristina Carvalho, Vasco Branco, Lúcia Guilhermino, Patrícia Oliveira, and Neusa Figueiredo
- Subjects
Gills ,Microplastics ,Freshwater bivalve ,Health, Toxicology and Mutagenesis ,Glutathione reductase ,0211 other engineering and technologies ,chemistry.chemical_element ,Bioconcentration ,Fresh Water ,02 engineering and technology ,010501 environmental sciences ,01 natural sciences ,Bioassay ,Animals ,Corbicula fluminea ,Corbicula ,0105 earth and related environmental sciences ,Glutathione Transferase ,chemistry.chemical_classification ,021110 strategic, defence & security studies ,Glutathione Peroxidase ,biology ,Glutathione peroxidase ,Public Health, Environmental and Occupational Health ,General Medicine ,Mercury ,biology.organism_classification ,Catalase ,Pollution ,Mercury (element) ,Oxidative Stress ,Glutathione Reductase ,chemistry ,Environmental chemistry ,Biological Assay ,Lipid Peroxidation ,Plastics ,Biomarkers ,Filtration ,Water Pollutants, Chemical - Abstract
The main objectives of this study were to investigate the effects of a mixture of microplastics and mercury on Corbicula fluminea, the post-exposure recovery, and the potential of microplastics to influence the bioconcentration of mercury by this species. Bivalves were collected in the field and acclimated to laboratory conditions for 14 days. Then, a 14-day bioassay was carried out. Bivalves were exposed for 8 days to clean medium (control), microplastics (0.13 mg/L), mercury (30 µg/L) and to a mixture (same concentrations) of both substances. The post-exposure recovery was investigated through 6 additional days in clean medium. After 8 and 14 days, the following endpoints were analysed: the post-exposure filtration rate (FR); the activity of cholinesterase enzymes (ChE), NADP-dependent isocitrate dehydrogenase (IDH), octopine dehydrogenase, catalase, glutathione reductase, glutathione peroxidase and glutathione S-transferases (GST), and the levels of lipid peroxidation (LPO). After 8 days of exposure to mercury, the bioconcentration factors (BCF) were 55 in bivalves exposed to the metal alone and 25 in bivalves exposed to the mixture. Thus, microplastics reduced the bioconcentration of mercury by C. fluminea. Bivalves exposed to microplastics, mercury or to the mixture had significantly (p ≤ 0.05) decreased FR and increased LPO levels, indicating fitness reduction and lipid oxidative damage. In addition, bivalves exposed to microplastics alone had significant (p ≤ 0.05) reduction of adductor muscle ChE activity, indicating neurotoxicity. Moreover, bivalves exposed to mercury alone had significantly (p ≤ 0.05) inhibited IDH activity, suggesting alterations in cellular energy production. Antagonism between microplastics and mercury in FR, ChE activity, GST activity and LPO levels was found. Six days of post-exposure recovery in clean medium was not enough to totally reverse the toxic effects induced by the substances nor to eliminate completely the mercury from the bivalve’s body. These findings have implications to animal, ecosystem and human health.
- Published
- 2018
49. O Imposto sobre o Valor Acrescentado europeu e o processo de reforma tributária brasileira
- Author
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Guimarães, Vasco Branco
- Subjects
Sistema tributário, aspectos constitucionais ,Imposto sobre o valor adicionado (IVA) ,Imposto sobre circulação de mercadorias e serviços (ICMS) ,Imposto de consumo, Brasil ,Princípio constitucional ,Imposto sobre o valor acrescido ,Taxa sobre o valor acrescentado ,Imposto sobre o valor adicional (IVA) ,Taxa sobre o valor ajustado ,Sistema tributário nacional ,Imposto sobre circulação de mercadorias e serviços de transporte e comunicação (ICMS) ,Imposto sobre o valor agregado ,Taxa sobre o valor agregado ,ICMS ,Imposto de consumo, Europa - Abstract
Submitted by Iury Batista (iurys@stj.jus.br) on 2018-10-25T19:38:37Z No. of bitstreams: 2 iva_europeu_processo_guimaraes.pdf: 628934 bytes, checksum: fa3be1490703d41cd23d906c0d95cbab (MD5) license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) Approved for entry into archive by Patrícia Rabello (rabello@stj.jus.br) on 2018-10-26T18:13:39Z (GMT) No. of bitstreams: 2 license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) iva_europeu_processo_guimaraes.pdf: 628934 bytes, checksum: fa3be1490703d41cd23d906c0d95cbab (MD5) Made available in DSpace on 2018-10-26T18:13:39Z (GMT). No. of bitstreams: 2 license.txt: 1239 bytes, checksum: c9b4c351324448672315a00808efb725 (MD5) iva_europeu_processo_guimaraes.pdf: 628934 bytes, checksum: fa3be1490703d41cd23d906c0d95cbab (MD5) Previous issue date: 2018
- Published
- 2018
50. Toxicological effects of thiomersal and ethylmercury: Inhibition of the thioredoxin system and NADP+-dependent dehydrogenases of the pentose phosphate pathway
- Author
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Jun Lu, Arne Holmgren, Vasco Branco, Cristina Carvalho, and Juan Rodrigues
- Subjects
Pharmacology ,chemistry.chemical_classification ,Dose-Response Relationship, Drug ,Cell Survival ,Thimerosal ,Metabolite ,NADPH Dehydrogenase ,Dehydrogenase ,Hep G2 Cells ,Pentose phosphate pathway ,Toxicology ,Pentose Phosphate Pathway ,Ethylmercury ,chemistry.chemical_compound ,Thioredoxins ,Enzyme ,chemistry ,Biochemistry ,Humans ,Thiomersal ,Thioredoxin ,Ethylmercury Compounds - Abstract
Mercury (Hg) is a strong toxicant affecting mainly the central nervous, renal, cardiovascular and immune systems. Thiomersal (TM) is still in use in medical practice as a topical antiseptic and as a preservative in multiple dose vaccines, routinely given to young children in some developing countries, while other forms of mercury such as methylmercury represent an environmental and food hazard. The aim of the present study was to determine the effects of thiomersal (TM) and its breakdown product ethylmercury (EtHg) on the thioredoxin system and NADP(+)-dependent dehydrogenases of the pentose phosphate pathway. Results show that TM and EtHg inhibited the thioredoxin system enzymes in purified suspensions, being EtHg comparable to methylmercury (MeHg). Also, treatment of neuroblastoma and liver cells with TM or EtHg decreased cell viability (GI50: 1.5 to 20μM) and caused a significant (p0.05) decrease in the overall activities of thioredoxin (Trx) and thioredoxin reductase (TrxR) in a concentration- and time-dependent manner in cell lysates. Compared to control, the activities of Trx and TrxR in neuroblastoma cells after EtHg incubation were reduced up to 60% and 80% respectively, whereas in hepatoma cells the reduction was almost 100%. In addition, the activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase were also significantly inhibited by all mercurials, with inhibition intensity of Hg(2+)MeHg≈EtHgTM (p0.05). Cell incubation with sodium selenite alleviated the inhibitory effects on TrxR and glucose-6-phosphate dehydrogenase. Thus, the molecular mechanism of toxicity of TM and especially of its metabolite EtHg encompasses the blockage of the electrons from NADPH via the thioredoxin system.
- Published
- 2015
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