Percorrer por autor "Reis, Ana Teresa"
A mostrar 1 - 10 de 21
Resultados por página
Opções de ordenação
- Assessing the in vitro toxicity of airborne (nano)particles to the human respiratory system: from basic to advanced modelsPublication . Bessa, Maria João; Brandão, Fátima; Rosário, Fernanda; Moreira, Luciana; Reis, Ana Teresa; Valdiglesias, Vanessa; Laffon, Blanca; Fraga, Sónia; Teixeira, João PauloSeveral studies have been conducted to address the potential adverse health risks attributed to exposure to nanoscale materials. While in vivo studies are fundamental for identifying the relation-ship between dose and occurrence of adverse effects, in vitro model systems provide important information regarding the mechanism(s) of action at the molecular level. With a special focus on exposure to inhaled (nano)particulate material toxicity assessment, this review provides an over-view of the available human respiratory models and exposure systems for in vitro testing, advan-tages, limitations, and existing investigations using models of different complexity. A brief overview of the human respiratory system, pathway and fate of inhaled (nano)particles is also presented.
- Biocompatibility evaluation of CeO2 nanoparticles to be employed as nanodrugs in brain cancer nanomedicinePublication . Fernández-Bertólez, Natália; Touzani, Assia; Martínez, L.; Reis, Ana Teresa; Fraga, Sónia; Teixeira, João Paulo; Costa, Carla; Pásaro, Eduardo; Laffon, Blanca; Valdiglesias, VanessaCerium dioxide nanoparticles (CeO2NP) have recently gained attention for their unique structure-dependent properties, antioxidant enzyme-like behaviour, ROS scavenging activity and great potential for biomedical applications. In addition to their antioxidant and anti-inflammatory activity, CeO2NP are also known to exhibit anticancer potential, providing an attractive opportunity for use in cancer therapy, as a pharmacological agent and/or in drug/gene delivery systems [1]. Therefore, the main objective of this STSM was to evaluate the cytotoxic and genotoxic effects on human glioblastoma A172 cells exposed for 3, 24 and 48h to CeO2NP (1- 100µg/ml), to verify their safety to be used as possible nanomedicines for brain cancer treatment, specifically glioblastoma [2]. In addition, cell-specific differences in nanoceria effect were evaluated by comparing the results obtained with those observed in human neuronal SH-SY5Y cells exposed under the same experimental conditions. After carrying out the physicochemical characterization and analysing the cellular uptake of the CeO2NP, potential alterations in cell viability (MTT assay) and induction of DNA double-strand breaks (γH2AX assay) caused by the exposure were determined. The possible NP interference with assay methodologies was previously addressed and eliminated when necessary. Results obtained showed that, although there was a significant dose- and time-dependent internalization of NP by both cell types, nanoceria induced scarce cytotoxicity or genotoxicity in both cell lines, being restricted to the highest doses and longer exposure time tested. In general, data obtained suggest a high biocompatibility of CeO2NP under the tested conditions, except for glioblastoma cells exposed for 48h from 25 to 100µg/ml. These results provide a better understanding of the CeO2NP interaction with nervous system cells and their possible adverse effects. However, further studies are necessary to delve into the differential behaviour of these NP depending on the nervous cell type tested.
- Biomarker-validated maternal smoking and environmental tobacco smoke exposure status and its associations with perinatal outcomesPublication . Silva, Ana Inês; Camelo, Alexandra; Madureira, Joana; Reis, Ana Teresa; Barbosa, Fernando; Teixeira, João Paulo; Costa, CarlaTobacco consumption and environmental tobacco smoke (ETS) are associated with an increased risk of multiple adverse perinatal outcomes. Within the framework of the NEOGENE project, the aim of this study was to validate smoking and ETS exposure status among pregnant women, to more precisely ascertain its associations with perinatal outcomes, using urinary cotinine (UC), a biomarker of tobacco smoke exposure. (...)
- Caracterização da exposição ao tabaco durante a gravidez e da sua influência em indicadores de saúde neonatal: projeto NeoGenePublication . Madureira, Joana; Silva, Ana Inês; Camelo, Alexandra; Reis, Ana Teresa; Machado, Ana Paula; Ribeiro, Ana Isabel; Teixeira, João Paulo; Costa, CarlaO tabagismo e a exposição ao fumo ambiental do tabaco (ou exposição passiva) estão associados a vários efeitos adversos na saúde, particularmente em períodos de maior suscetibilidade como o período pré-natal. Como condição essencial para o delineamento de estratégias mais adequadas e efetivas de promoção de saúde e prevenção de doença associadas, torna-se essencial caracterizar detalhadamente a exposição ao tabaco no início da vida e conhecer a sua influência em diferentes indicadores de saúde neonatal. Para tal, foi analisada informação individual e clínica de 595 grávidas com mais de 36 semanas de gestação, em consulta no Serviço de Obstetrícia e Ginecologia do Centro Hospitalar de S. João, entre abril de 2017 e julho de 2018. Foram também analisados indicadores de saúde neonatais dos respetivos recém-nascidos por consulta dos seus processos clínicos. Os resultados deste estudo mostram uma prevalência do consumo do tabaco de 27,9% antes da gravidez, valor que diminui para 12,9% ao nascimento, como resultado de uma cessação tabágica de 46,4% durante a gestação. Em termos de exposição passiva ao fumo do tabaco, verificou-se que 31,7% das participantes não fumadoras estavam diariamente expostas, durante mais de uma hora, antes da gravidez, e que houve uma diminuição da exposição ao longo da gravidez (26,3% no terceiro trimestre). A análise da associação entre os indicadores de saúde neonatal e os comportamentos tabágicos apontam para uma diminuição do peso, tamanho e perímetro cefálico ao nascimento entre os recém-nascidos das participantes fumadoras, valores que aumentam nos casos em que há cessação tabágica durante a gravidez
- Co-exposure with CeO2NPs results in an antagonistic effect on the cytotoxicity and genotoxicity of TiO2NP on A549 cellsPublication . Rosário, Fernanda; Vilaça, Cláudia; Costa, Carla; Lopes, Cláudia B.; Estrada, Ana C.; Tavares, Daniela S.; Teixeira, João Paulo; Reis, Ana TeresaObjective: Assess the CYTOTOXIC and GENOTOXIC POTENTIAL resulting from titanium dioxide nanoparticles (TiO2NP) and cerium oxide nanoparticles (CeO2NP) co-exposure in human lung epithelial cell line A549.
- Cytotoxic effects of single and binary mixtures of metal oxide nanoparticles and metal(loid) on A549 human cell line.Publication . Rosário, Fernanda; Bessa, Maria João; Brandão, Fátima; Costa, Carla; Lopes, Cláudia B.; Estrada, Ana Cristina; Tavares, Daniela S.; Teixeira, João Paulo; Reis, Ana TeresaBackground, Motivation and Objective: The need to assess the toxicity resulting from exposure to mixtures of chemicals has been recognized by the WHO and EU, as humans are simultaneously exposed to an array of natural and anthropogenic contaminants. Of particular interest are the potential combined effects resulting from interaction of nanoparticles (NPs) and metals. While the first are the current driving force for emerging contaminants, the latter, as legacy contaminants, remain a concern. Metals show strong affinity to NPs, which can change the uptake and toxicity to the organism of each individual contaminant. Studying the effects on the respiratory tract is of upmost relevance because of its constant contact with xenobiotics, resulting in adverse effects on the lung. Considering the above, the objective of this work was to assess and compare viability, cell cycle, and uptake of A549 cells after exposure to single and binary mixtures of titanium dioxide nanoparticles (TiO2NP), cerium oxide nanoparticles (CeO2NP), arsenic (As) and mercury (Hg). These chemicals were chosen because: 1) TiO2NP are among the most abundantly used NPs; 2) CeO2NP have been used in nanomedicine for its high biocompatibility and cytoprotective effect; and 3) As and Hg due to their non‐biodegradable, persistent, and extremely toxic character. This work intends to support adequate human risk assessment resulting from co-exposure to multiple contaminants.
- Effects of Zinc Oxide Nanoparticle Exposure on Human Glial Cells and Zebrafish EmbryosPublication . Valdiglesias, Vanessa; Alba-González, Anabel; Fernández-Bertólez, Natalia; Touzani, Assia; Ramos-Pan, Lucía; Reis, Ana Teresa; Moreda-Piñeiro, Jorge; Yáñez, Julián; Laffon, Blanca; Folgueira, MónicaZinc oxide nanoparticles (ZnO NPs) are among the most widely used nanomaterials. They have multiple applications in cosmetics, textiles, paints, electronics and, recently, also in biomedicine. This extensive use of ZnO NPs notably increases the probability that both humans and wildlife are subjected to undesirable effects. Despite being among the most studied NPs from a toxicological point of view, much remains unknown about their ecotoxicological effects or how they may affect specific cell types, such as cells of the central nervous system. The main objective of this work was to investigate the effects of ZnO NPs on human glial cells and zebrafish embryo development and to explore the role of the released Zn2+ ions in these effects. The effects on cell viability on human A172 glial cells were assessed with an MTT assay and morphological analysis. The potential acute and developmental toxicity was assessed employing zebrafish (Danio rerio) embryos. To determine the role of Zn2+ ions in the in vitro and in vivo observed effects, we measured their release from ZnO NPs with flame atomic absorption spectrometry. Then, cells and zebrafish embryos were treated with a water-soluble salt (zinc sulfate) at concentrations that equal the number of Zn2+ ions released by the tested concentrations of ZnO NPs. Exposure to ZnO NPs induced morphological alterations and a significant decrease in cell viability depending on the concentration and duration of treatment, even after removing the overestimation due to NP interference. Although there were no signs of acute toxicity in zebrafish embryos, a decrease in hatching was detected after exposure to the highest ZnO NP concentrations tested. The ability of ZnO NPs to release Zn2+ ions into the medium in a concentration-dependent manner was confirmed. Zn2+ ions did not seem entirely responsible for the effects observed in the glial cells, but they were likely responsible for the decrease in zebrafish hatching rate. The results obtained in this work contribute to the knowledge of the toxicological potential of ZnO NPs.
- A first insight into the genotoxicity induced on A549 human cell line by titanium and cerium dioxide nanoparticles co-exposed with arsenic and mercuryPublication . Vilaça, Cláudia; Rosário, Fernanda; Bessa, Maria João; Ribeiro, César; Costa, Carla; Teixeira, João Paulo; Reis, Ana TeresaObjectives: Nanogenotoxicity studies traditionally consider exposure to a single NP. However, potential genotoxicity resulting from exposure to mixtures of NP and other contaminants cannot be neglected; This work will constitute the first insight into the DNA damage induced on A549 cells by exposure to binary mixtures of titanium (TiO2) and cerium (CeO2) dioxide, and highly toxic metals arsenic (As) and mercury (Hg).
- In Vitro Hepatotoxic and Neurotoxic Effects of Titanium and Cerium Dioxide Nanoparticles, Arsenic and Mercury Co-ExposurePublication . Rosário, Fernanda; Costa, Carla; Lopes, Cláudia B.; Estrada, Ana C.; Tavares, Daniela S.; Pereira, Eduarda; Teixeira, João Paulo; Reis, Ana TeresaConsidering the increasing emergence of new contaminants, such as nanomaterials, mixing with legacy contaminants, including metal(loid)s, it becomes imperative to understand the toxic profile resulting from these interactions. This work aimed at assessing and comparing the individual and combined hepatotoxic and neurotoxic potential of titanium dioxide nanoparticles (TiO2NPs 0.75-75 mg/L), cerium oxide nanoparticles (CeO2NPs 0.075-10 μg/L), arsenic (As 0.01-2.5 mg/L), and mercury (Hg 0.5-100 mg/L) on human hepatoma (HepG2) and neuroblastoma (SH-SY5Y) cells. Viability was assessed through WST-1 (24 h) and clonogenic (7 days) assays and it was affected in a dose-, time- and cell-dependent manner. Higher concentrations caused greater toxicity, while prolonged exposure caused inhibition of cell proliferation, even at low concentrations, for both cell lines. Cell cycle progression, explored by flow cytometry 24 h post-exposure, revealed that TiO2NPs, As and Hg but not CeO2NPs, changed the profiles of SH-SY5Y and HepG2 cells in a dose-dependent manner, and that the cell cycle was, overall, more affected by exposure to mixtures. Exposure to binary mixtures revealed either potentiation or antagonistic effects depending on the composition, cell type and time of exposure. These findings prove that joint toxicity of contaminants cannot be disregarded and must be further explored.
- Integrated Use of Bioaccumulation, Genotoxic, and Haematological Endpoints to Assess the Effect of Water Remediation Strategies on Fish Health: A Complementary StudyPublication . Mieiro, Cláudia; Coelho, João; Reis, Ana Teresa; Castro, Diana; Figueira, Paula; Martinho, Filipe; Pardal, Miguel; Pereira, Eduarda; Pacheco, Mário; Lopes, CláudiaBiosorption successfully remediates saline water contaminated with legacy contaminants, but its effects on the health of marine organisms remain unclear. Therefore, our aim was to address this knowledge gap with data on the accumulation ability, as well as the cytogenetic and biochemical effects in turbot (Scophthalmus maximus). To this end, we exposed turbot for seven days to a mixture of remediated metals (Rem treatments: Cd, Hg, and Pb), with and without the presence of nanoparticles (NP), and compared them with the maximum allowable concentrations (MAC treatment) for effluent discharges. We determined the metal accumulation in the blood and kidney and evaluated haematological changes (red blood cell count, haemoglobin, and mean cell haemoglobin (MCH)) and genotoxicity (erythrocytic nuclear abnormalities assay) in the blood. The results showed that remediation with non-living macroalgae significantly reduced the metallic blood and kidney burdens in the Rem treatments. Furthermore, no genotoxic potential occurred in the Rem and MAC treatments in parallel with the reduction in MCH levels in the Rem treatments, which would reflect hematopoietic disturbances in the MAC. Our results validate biosorption remediation as we achieved a considerable reduction in metal loads while maintaining the health status of fish, highlighting the importance of testing water remediation methods in the biota.
- «
- 1 (current)
- 2
- 3
- »