Browsing by Author "Costa, Carla"
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- Adequacy of the standardised in vitro mammalian cell Micronucleus (MN) test for nanomaterials genotoxicity testingPublication . Fernández-Bertólez, Natalia; Rodríguez-Fernández, R.; Lema-Arranz, C.; Pásaro, E.; Brandão, Fátima; Teixeira, João Paulo; Costa, Carla; Valdiglesias, Vanessa; Laffon, BlancaAbout adequacy of the standardised in vitro mammalian cell Micronucleus (MN) test for nanomaterials genotoxicity testing.
- Age-related dose deposition of particulate matter in human respiratory tract: findings from a birth cross-sectional study in PortugalPublication . Madureira, Joana; Slezakova, Klara; Costa, Carla; Silva, Ana Inês; Mendes, Ana; Pereira, Maria do Carmo; Teixeira, João PauloIndoor air pollution remains a great global concern. Particulate matter (PM), namely ultrafine particles (aerodynamic diameter smaller than 0.1 μm; UFP), is considered as one of the most health-relevant air pollutant for various subpopulations, one of which is children. Knowledge on the specific dose deposition of PM may provide a critical link for better understanding of the relationship between individual exposure and the respective health effects. Mathematical models have proven to be important tools for analysing PM dose deposition in the respiratory tract providing relevant data for health risk assessment, source apportionment of human lung burdens and control strategies purposes. This work aimed to estimate the deposition dose of different PM sizes at different age categories. Inhalation dosimetry estimations were carried out using the multiple-path particle dosimetry model (MPPD, v3.04). Age specific 5-lobe model with uniform expansion was adopted in the present study
- Are iron oxide nanoparticles safe? Current knowledge and future perspectivesPublication . Valdiglesias, Vanessa; Fernández-Bertólez, Natalia; Kiliç, Gözde; Costa, Carla; Costa, Solange; Fraga, Sonia; Bessa, Maria Joao; Pásaro, Eduardo; Teixeira, João Paulo; Laffon, BlancaDue to their unique physicochemical properties, including superparamagnetism, iron oxide nanoparticles (ION) have a number of interesting applications, especially in the biomedical field, that make them one of the most fascinating nanomaterials. They are used as contrast agents for magnetic resonance imaging, in targeted drug delivery, and for induced hyperthermia cancer treatments. Together with these valuable uses, concerns regarding the onset of unexpected adverse health effects following exposure have been also raised. Nevertheless, despite the numerous ION purposes being explored, currently available information on their potential toxicity is still scarce and controversial data have been reported. Although ION have traditionally been considered as biocompatible - mainly on the basis of viability tests results - influence of nanoparticle surface coating, size, or dose, and of other experimental factors such as treatment time or cell type, has been demonstrated to be important for ION in vitro toxicity manifestation. In vivo studies have shown distribution of ION to different tissues and organs, including brain after passing the blood-brain barrier; nevertheless results from acute toxicity, genotoxicity, immunotoxicity, neurotoxicity and reproductive toxicity investigations in different animal models do not provide a clear overview on ION safety yet, and epidemiological studies are almost inexistent. Much work has still to be done to fully understand how these nanomaterials interact with cellular systems and what, if any, potential adverse health consequences can derive from ION exposure.
- Assessment of DNA damage in a group of professional dancers during a 10-month dancing seasonPublication . Esteves, Filipa; Teixeira, Eduardo; Amorim, Tânia; Costa, Carla; Pereira, Cristiana Costa; Fraga, Sónia; Moraes de Andrade, Vanessa; Teixeira, João Paulo; Costa, SolangeIntroduction: Professional dance is an activity with high artistic and physical demands. Requires physical athletic attributes such as muscular strength, endurance, coordination, agility and swiftness. Regular physical activity brings a lot of positive health-related outcomes. Reduce the risk of numerous health disorders like cardiovascular diseases, cancer, hypertension, diabetes, bone and joint diseases and it is responsible to maintain a numerous psychosocial benefits. However, intensive physical exercise is associated with an increased production of free radicals that may overcome the antioxidant system capacity to maintain homeostasis and may react with different biomolecules, e.g. deoxyribonucleic acid (DNA), inducing oxidative damage that may disturb the cell genomic integrity and cause a lot of diseases. The aim of the present study was to evaluate both DNA damage and oxidative stress in a group of professional dancers before and after a 10-month dancing season
- Assessment of DNA damage in a group of professional dancers during a 10-month dancing seasonPublication . Esteves, Filipa; Teixeira, Eduardo; Amorim, Tânia; Costa, Carla; Pereira, Cristiana Costa; Fraga, Sónia; Moraes de Andrade, Vanessa; Teixeira, João Paulo; Costa, SolangeDespite the numerous health benefits of physical activity, some studies reported that increased intensity and duration may induce oxidative stress in several cellular components including DNA. The aim of this study was to assess the level of basal DNA damage as well as oxidative DNA damage in a group of professional dancers before and after a 10-month dancing season. A group of individuals from general population was also assessed as a control. The alkaline version of the comet assay was the method selected to measure both basal DNA damage and oxidative stress, since this method quantifies both endpoints. In order to measure oxidative stress, the comet assay was coupled with a lesion-specific endonuclease (formamidopyrimidine glycosylase) to detect oxidized purines. The levels of oxidative DNA damage in dancers were significantly increased after the dancing season. Pre-season levels of oxidative DNA damage were lower in dancers than those obtained from the general population, suggesting an adaptation of antioxidant system in dancers. Results of the present biomonitoring study indicate the need for more effective measures to protect ballet dancers from potentially occupational health risks related to regular intensive physical exercise.
- Assessment of genotoxic effects of titanium dioxide nanoparticles on different human cell typesPublication . Fernández-Bertólez, Natalia; Brandao, Fátima; Rosário, Fernanda; Bessa, Maria João; Fraga, Sónia; Pásaro, Eduardo; Teixeira, Joao Paulo; Costa, Carla; Laffon, Blanca; Vanessa, ValdiglesiasThe main objective of the present work was to assess the cellular uptake and potential genotoxicity (micronuclei induction) of TiO2 NPs on four diverse human cell lines.
- Assessment of indoor air exposure among newborns and their mothers: Levels and sources of PM10, PM2.5 and ultrafine particles at 65 home environmentsPublication . Madureira, Joana; Slezakova, Klara; Costa, Carla; Pereira, Maria Carmo; Teixeira, João PauloSignificant efforts have been directed towards addressing the adverse health effects of atmospheric particles, emphasizing the relevance of indoor exposure. Homes represent an indoor environment where human spend the majority of their time. Thus, the objective of this work was to concurrently assess different matrix of indoor particles considering both mass (PM10, PM2.5) and number (N20-1000) concentrations in indoor and outdoor air of homes (n = 65). Real-time measurements (PM10, PM2.5, UFP) were conducted simultaneously during 48 h in dwellings situated in Oporto, Portugal. In 75% of homes, indoor PM2.5 (mean = 53 μg m-3) exceeded limit of 25 μg m-3, for PM10 (mean = 57 μg m-3) 41% of homes demonstrated average levels higher than 50 μg m-3, thus indicating potential risks. Indoor PM10 was mostly (82-99%) composed of PM2.5, both PM were highly correlated (|rs|>0.9655), thus suggesting the similar origin. Indoor PM originated from infiltrations of outdoor emissions; ∼70% of homes exhibited indoor to outdoor (I/O) ratio < 1. On the contrary, UFP indoors (mean = 13.3 × 103 # cm-3) were higher than outdoors (mean = 10.0 × 103 # cm-3). Indoor UFP spatially varied as follows: kitchens > living rooms > bedrooms. UFP indoors were poorly correlated (|rs| = 0.456) with outdoor concentrations, I/O ratios showed that indoor UFP predominantly originated from indoor emission sources (combustions). Therefore, in order to reduce exposure to UFP and protect public health, the primary concerns should be focused on controlling emissions from indoor sources.
- Assessment of indoor air exposure at residential homes: Inhalation dose and lung deposition of PM10, PM2.5 and ultrafine particles among newborn children and their mothersPublication . Madureira, Joana; Slezakova, Klara; Silva, Ana Inês; Lage, Bruna; Mendes, Ana; Aguiar, Lívia; Pereira, Maria Carmo; Teixeira, João Paulo; Costa, CarlaAccurate assessment of particulate matter (PM) dose and respiratory deposition is essential to better understand the risks of exposure to PM and, consequently, to develop the respective risk-control strategies. In homes, this is especially relevant in regards to ultrafine particles (UFP; <0.1 μm) which origin in these environments is mostly due to indoor sources. Thus, this study aimed to estimate inhalation doses for different PM mass/number size fractions (i.e., PM10, PM2.5 and UFP) in indoor air of residential homes and to quantify the deposition (total, regional and lobar) in human respiratory tract for both newborn children and mothers. Indoor real-time measurements of PM10, PM2.5 and UFP were conducted in 65 residential homes situated in Oporto metropolitan area (Portugal). Inhalation doses were estimated based on the physical characteristics of individual subjects and their activity patterns. The multi-path particle dosimetry model was used to quantify age-specific depositions in human respiratory tract. The results showed that 3-month old infants exhibited 4-fold higher inhalation doses than their mothers. PM10 were primarily deposited in the head region (87%), while PM2.5 and UFP depositions mainly occurred in the pulmonary area (39% and 43%, respectively). Subject age affected the pulmonary region and the total lung deposition; higher deposition being observed among the newborns. Similarly, lower lobes (left lobe: 37% and right lobe: 30%) received higher PM deposition than upper and middle lobes; right lobes lung are prone to be more susceptible to respiratory problems, since asymmetric deposition was observed. Considering that PM-related diseases occur at specific sites of respiratory system, quantification of site-specific particle deposition should be predicted in order to better evidence the respective health outcomes resulting from inhaled PM.
- Assessment of oxidative damage induced by iron oxide nanoparticles on different nervous system cellsPublication . Fernández-Bertólez, Natalia; Costa, Carla; Bessa, Maria João; Park, Magriet; Carriere, Marie; Dussert, Fanny; Teixeira, João Paulo; Pásaro, Eduardo; Laffon, Blanca; Valdiglesias, VanessaIron oxide nanoparticles (ION) have received much attention for their utility in biomedical applications, such as magnetic resonance imaging, drug delivery and hyperthermia, but concerns regarding their potential harmful effects are also growing. Even though ION may induce different toxic effects in a wide variety of cell types and animal systems, there is a notable lack of toxicological data on the human nervous system, particularly important given the increasing number of applications on this specific system. An important mechanism of nanotoxicity is reactive oxygen species (ROS) generation and oxidative stress. On this basis, the main objective of this work was to assess the oxidative potential of silica-coated (S-ION) and oleic acid-coated (O-ION) ION on human SH-SY5Y neuronal and A172 glial cells. To this aim, ability of ION to generate ROS (both in the absence and presence of cells) was determined, and consequences of oxidative potential were assessed (i) on DNA by means of the 8-oxo-7,8-dihydroguanine DNA glycosylase (OGG1)-modified comet assay, and (ii) on antioxidant reserves by analyzing ratio of reduced glutathione (GSH) to oxidized glutathione (GSSG). Conditions tested included a range of concentrations, two exposure times (3 and 24 h), and absence and presence of serum in the cell culture media. Results confirmed that, even though ION were not able to produce ROS in acellular environments, ROS formation was increased in the neuronal and glial cells by ION exposure, and was parallel to induction of oxidative DNA damage and, only in the case of neuronal cells treated with S-ION, to decreases in the GSH/GSSG ratio. Present findings suggest the production of oxidative stress as a potential action mechanism leading to the previously reported cellular effects, and indicate that ION may pose a health risk to human nervous system cells by generating oxidative stress, and thus should be used with caution.
- Avaliação de dano genético em agricultores: agricultura biológica e tradicionalPublication . Costa, Carla; Silva, Susana; Costa, Solange; Teixeira, João Paulo