INSA - Artigos em revistas internacionais
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Browsing INSA - Artigos em revistas internacionais by Field of Science and Technology (FOS) "Ciências Naturais"
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- Challenges of the Application of In Vitro Digestion for Nanomaterials Safety AssessmentPublication . Vital, Nádia; Gramacho, Ana Catarina; Silva, Mafalda; Cardoso, Maria; Alvito, Paula; Kranendonk, Michel; Silva, Maria Joao; Louro, HenriquetaConsidering the increase in the production and use of nanomaterials (NM) in food/feed and food contact materials, novel strategies for efficient and sustainable hazard characterization, especially in the early stages of NM development, have been proposed. Some of these strategies encompass the utilization of in vitro simulated digestion prior to cytotoxic and genotoxic assessment. This entails exposing NM to fluids that replicate the three successive phases of digestion: oral, gastric, and intestinal. Subsequently, the resulting digestion products are added to models of intestinal cells to conduct toxicological assays, analyzing multiple endpoints. Nonetheless, exposure of intestinal cells to the digested products may induce cytotoxicity effects, thereby posing a challenge to this strategy. The aim of this work was to describe the challenges encountered with the in vitro digestion INFOGEST 2.0 protocol when using the digestion product in toxicological studies of NM, and the adjustments implemented to enable its use in subsequent in vitro biological assays with intestinal cell models. The adaptation of the digestion fluids, in particular the reduction of the final bile concentration, resulted in a reduced toxic impact of digestion products.
- Exploring flagellar contributions to motility and virulence in Arcobacter butzleriPublication . Santos, Raquel; Mateus, Cristiana; Oleastro, Mónica; Ferreira, SusanaFlagella is a well-known bacterial structure crucial for motility, which also plays pivotal roles in pathogenesis. Arcobacter butzleri, an enteropathogen, possesses a distinctive polar flagellum whose functional aspects remain largely unexplored. Upon investigating the factors influencing A. butzleri motility, we uncovered that environmental conditions like temperature, oxygen levels, and nutrient availability play a significant role. Furthermore, compounds that are found in human gut, such as short-chain fatty acids, mucins and bile salts, have a role in modulating the motility, and in turn, the pathogenicity of A. butzleri. Further investigation demonstrated that A. butzleri ΔflaA mutant showed a reduction in motility with a close to null average velocity, as well as a reduction on biofilm formation. In addition, compared with the wild-type, the ΔflaA mutant showed a decreased ability to invade Caco-2 cells and to adhere to mucins. Taken together, our findings support the role of environmental conditions and gut host associated compounds influencing key physiological aspects of the gastrointestinal pathogen A. butzleri, such as motility, and support the role of the flagellum on bacterial virulence.
- Hazard characterization of the mycotoxins enniatins and beauvericin to identify data gaps and improve risk assessment for human healthPublication . Behr, Anne-Cathrin; Fæste, Christiane Kruse; Azqueta, Amaya; Tavares, Ana M.; Spyropoulou, Anastasia; Solhaug, Anita; Olsen, Ann-Karin; Vettorazzi, Ariane; Mertens, Birgit; Zegura, Bojana; Streel, Camille; Ndiaye, Dieynaba; Spilioti, Eliana; Dubreil, Estelle; Buratti, Franca Maria; Crudo, Francesco; Eriksen, Gunnar Sundstøl; Snapkow, Igor; Teixeira, João Paulo; Rasinger, Josef D.; Sanders, Julie; Machera, Kyriaki; Ivanova, Lada; Gaté, Laurent; Le Hegarat, Ludovic; Novak, Matjaz; Smith, Nicola M.; Tait, Sabrina; Fraga, Sónia; Hager, Sonja; Marko, Doris; Braeuning, Albert; Louro, Henriqueta; Silva, Maria João; Dirven, Hubert; Dietrich, JessicaEnniatins (ENNs) and beauvericin (BEA) are cyclic hexadepsipeptide fungal metabolites which have demonstrated antibiotic, antimycotic, and insecticidal activities. The substantial toxic potentials of these mycotoxins are associated with their ionophoric molecular properties and relatively high lipophilicities. ENNs occur extensively in grain and grain-derived products and are considered a food safety issue by the European Food Safety Authority (EFSA). The tolerable daily intake and maximum levels for ENNs in humans and animals remain unestablished due to key toxicological and toxicokinetic data gaps, preventing full risk assessment. Aiming to find critical data gaps impeding hazard characterization and risk evaluation, this review presents a comprehensive summary of the existing information from in vitro and in vivo studies on toxicokinetic characteristics and cytotoxic, genotoxic, immunotoxic, endocrine, reproductive and developmental effects of the most prevalent ENN analogues (ENN A, A1, B, B1) and BEA. The missing information identified showed that additional studies on ENNs and BEA have to be performed before sufficient data for an in-depth hazard characterisation of these mycotoxins become available.
- HBM4EU chromates study: the Portuguese integrated and harmonized study on exposure to hexavalent chromium and related early effects.Publication . Viegas, Susana; Martins, Carla; Ribeiro, Edna; Ladeira, Carina; Pinhal, Hermínia; Nogueira, Ana; Santos, Sílvia; Tavares, Ana; Gomes, Bruno Costa; Afonso, Catarina Maia; Louro, Henriqueta; Silva, Maria JoaoIn the scope of the European Union (EU) human biomonitoring initiative, a multicentric study on different occupational settings from several European countries was performed, to provide information on occupational exposure to hexavalent chromium [Cr(VI)], a known lung carcinogen. Biomonitoring approaches were used to obtain exposure data to support the implementation of new risk management measures and policy actions at the national and European levels. This work describes the Portuguese contribution to the study, which aimed to assess workers' exposure to Cr, by using exposure biomarkers (urinary chromium [U-Cr]), and industrial hygiene samples (air and hand wipes) and to link exposure to potential long-term health effects by using effect biomarkers. Exposure determinants influencing exposure were explored from the contextual information and human biomonitoring data. The ultimate goal of the study was to appraise the risk management measures contributing to minimize exposure and protect workers' health. Several occupational settings and activities were considered, including plating, welding, and painting. A control group from the Portuguese general population was also included. Data on age, sex, and smoking habits from both groups were considered in the statistical analysis. Information on the risk management measures available for workers was collected and used to identify the ones that mainly contributed to reduce exposure. Environmental monitoring and human biomonitoring revealed that painters were the highest exposed group. The use of respiratory protection equipment showed an influence on total U-Cr levels for workers involved in painting activities. Concerning early health effects, the painters presented also a significantly higher level of DNA and chromosomal damage in peripheral blood cells, as compared to the control group, suggesting a plausible association between exposure to Cr(VI) and early genotoxic effects. The results showed that workers are exposed to Cr(VI) in those occupational settings. These findings point to the need to improve the prevention and risk management measures and the implementation and enforcement of new regulatory actions at the national level.
- New approach methodologies to enhance human health risk assessment of immunotoxic properties of chemicals - a PARC (Partnership for the Assessment of Risk from Chemicals) projectPublication . Snapkow, Igor; Smith, Nicola M.; Arnesdotter, Emma; Beekmann, Karsten; Blanc, Etienne B.; Braeuning, Albert; Corsini, Emanuela; Sollner Dolenc, Marija; Duivenvoorde, Loes P.M.; Sundstøl Eriksen, Gunnar; Franko, Nina; Galbiati, Valentina; Gostner, Johanna M.; Grova, Nathalie; Gutleb, Arno C.; Hargitai, Rita; Janssen, Aafke W.F.; Krapf, Solveig A.; Lindeman, Birgitte; Lumniczky, Katalin; Maddalon, Ambra; Mollerup, Steen; Parráková, Lucia; Pierzchalski, Arkadiusz; Pieters, Raymond H.H.; Silva, Maria Joao; Solhaug, Anita; Staal, Yvonne C.M.; Straumfors, Anne; Szatmári, Tünde; Turner, Jonathan D.; Vandebriel, Rob J.; Zenclussen, Ana Claudia; Barouki, RobertAs a complex system governing and interconnecting numerous functions within the human body, the immune system is unsurprisingly susceptible to the impact of toxic chemicals. Toxicants can influence the immune system through a multitude of mechanisms, resulting in immunosuppression, hypersensitivity, increased risk of autoimmune diseases and cancer development. At present, the regulatory assessment of the immunotoxicity of chemicals relies heavily on rodent models and a limited number of Organisation for Economic Co-operation and Development (OECD) test guidelines, which only capture a fraction of potential toxic properties. Due to this limitation, various authorities, including the World Health Organization and the European Food Safety Authority have highlighted the need for the development of novel approaches without the use of animals for immunotoxicity testing of chemicals. In this paper, we present a concise overview of ongoing efforts dedicated to developing and standardizing methodologies for a comprehensive characterization of the immunotoxic effects of chemicals, which are performed under the EU-funded Partnership for the Assessment of Risk from Chemicals (PARC).
- Scientific opinion on the extension of uses of quillaia extract (E 999) as a food additivePublication . Castle, Laurence; Andreassen, Monica; Aquilina, Gabriele; Bastos, Maria Lourdes; Boon, Polly; Fallico, Biagio; FitzGerald, Reginald; Frutos Fernandez, Maria Jose; Grasl-Kraupp, Bettina; Gundert-Remy, Ursula; Gürtler, Rainer; Houdeau, Eric; Kurek, Marcin; Louro, Henriqueta; Morales, Patricia; Passamonti, Sabina; Barat Baviera, José Manuel; Leblanc, Jean-Charles; Tard, Alexandra; Vermeiren, Sam; Zakidou, Panagiota; Ruggeri, Laura; EFSA Panel on Food Additives and Flavourings (FAF)The EFSA Panel on Food Additives and Flavourings (FAF Panel) evaluated the safety of the extension of uses of quillaia extract (E 999) as a food additive in food supplements supplied in a solid or liquid form, excluding food supplements for infants and young children. Quillaia extract (E 999) was re-evaluated in 2019 by the EFSA FAF Panel, which derived an acceptable daily intake (ADI) of 3 mg saponins/kg bw per day for E 999, while in 2024 a follow-up of the re-evaluation was published by the FAF Panel, recommending some modifications of the existing EU specifications for quillaia extract (E 999). Currently, quillaia extract (E 999) is authorised in two food categories (FCs) i.e. FC 4.1.4 'Flavoured drinks' and FC 14.2.3 'Cider and perry' (excluding ). A 'food supplements consumers only' scenario was calculated for this opinion considering the proposed extension of uses, together with the current authorised uses at both the maximum permitted level (MPLs) and the typical reported use levels of quillaia extract (E 999) at the time of the 2019 re-evaluation. The Panel concluded that the exposure estimates using the typical reported use levels for the currently authorised food categories and considering the proposed extension of uses for E 999 in FC 17.1 'Food supplements supplied in a solid form, excluding food supplement for infants and young children' and FC 17.2 'Food supplements supplied in a liquid form, excluding food supplement for infants and young children', if authorised, would not result in an exceedance of the ADI in any population group.
- Screening and in silico characterization of prophages in Helicobacter pylori clinical strainsPublication . Ferreira, Rute; Pinto, Graça; Presa, Eva; Oleastro, Mónica; Silva, Catarina; Vieira, Luís; Sousa, Claúdia; Pires, Diana; Figueiredo, Ceu; Melo, LuísThe increase of antibiotic resistance calls for alternatives to control Helicobacter pylori, a Gram-negative bacterium associated with various gastric diseases. Bacteriophages (phages) can be highly effective in the treatment of pathogenic bacteria. Here, we developed a method to identify prophages in H. pylori genomes aiming at their future use in therapy. A polymerase chain reaction (PCR)-based technique tested five primer pairs on 74 clinical H. pylori strains. After the PCR screening, 14 strains most likely to carry prophages were fully sequenced. After that, a more holistic approach was taken by studying the complete genome of the strains. This study allowed us to identify 12 intact prophage sequences, which were then characterized concerning their morphology, virulence, and antibiotic-resistance genes. To understand the variability of prophages, a phylogenetic analysis using the sequences of all H. pylori phages reported to date was performed. Overall, we increased the efficiency of identifying complete prophages to 54.1 %. Genes with homology to potential virulence factors were identified in some new prophages. Phylogenetic analysis revealed a close relationship among H. pylori-phages, although there are phages with different geographical origins. This study provides a deeper understanding of H. pylori-phages, providing valuable insights into their potential use in therapy.