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Browsing ESS - SA - Artigos by Author "Almeida, A."
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- Analysis of the use of microcystin-contaminated water in the growth and nutritional quality of the root-vegetable, Daucus carotaPublication . Machado, J.; Azevedo, J.; Freitas, Marisa; Pinto, Edgar; Almeida, A.; Vasconcelos, V.; Campos, A.Toxic cyanobacterial blooms are often observed in freshwaters and may reflect the increased eutrophication of these environments and alterations in climate. Cyanotoxins, such as microcystins (MCs), are an effective threat to many life forms, ranging from plants to humans. Despite the research conducted to date on cyanotoxins, the risks associated to the use of contaminated water in agriculture require further elucidation. To tackle this aim, a research was conducted with the root-vegetable Daucus carota. The specific aims of this work were the following: (i) to evaluate the effects of MC-LR on the plant growth and photosynthesis; (ii) to evaluate the nutritional quality of carrot roots; and (iii) to measure bioaccumulation. To this purpose, young carrots were grown in soil during 1 month in natural conditions and exposed to Mycrocystis aeruginosa aqueous extracts containing environmentally realistic concentrations of MC-LR (10 and 50 MC-LR μg/L). The results showed that MC-LR may decrease root growth after 28 days of exposure to 50 μg/L and increase photosynthetic efficiency. We also observed changes in mineral and vitamin content in carrots as a result of the exposure to contaminated water. Moreover, MC-LR was detected in carrot roots by ELISA at very low concentration 5.23 ± 0.47 ng MC eq./g FW. The soil retained 52.7 % of the toxin potentially available for plants. This result could be attributed to MC-LR adsorption by soil particles or due to microbial degradation of the toxin. We conclude that the prolonged use of MC-LR-contaminated water may affect crop growth, alter the nutritional value of vegetable products, and potentiate contamination.
- Biological effects and bioaccumulation of gold in gilthead seabream (Sparus aurata) – Nano versus ionic formPublication . Barreto, A.; Dias, A. A.; Duarte, B.; Pinto, Edgar; Almeida, A.; Trindade, T.; Soares, A. M. V. M.; Hylland, K.; Loureiro, S.; Oliveira, M.The question of whether gold (Au) is more toxic as nanoparticles or in its ionic form remains unclear and controversial. The present work aimed to clarify the effects of 96 h exposure to 4, 80 and 1600 μg·L−1 of 7 nm gold nanoparticles (AuNPs) – (citrate coated (cAuNPs) or polyvinylpyrrolidone coated (PVP-AuNPs)) – and ionic Au (iAu) on gilthead seabream (Sparus aurata). Effects at different levels of biological organization (behaviour, neurotransmission, biotransformation, oxidative stress/damage and genotoxicity) were assessed. cAuNPs induced oxidative stress and damage (lipid peroxidation increase), even at 4 μg·L−1, and reduced the ability of S. aurata to swim against a water flow at 1600 μg·L−1. Exposure to cAuNPs induced more adverse effects than exposure to PVP-AuNPs. All tested concentrations of Au (nano or ionic form) induced DNA breaks and cytogenetic damage in erythrocytes of S. aurata. Generally, iAu induced significantly more effects in fish than the nano form, probably associated with the significantly higher accumulation in the fish tissues. No fish mortality was observed following exposure to AuNPs, but mortality was observed in the group exposed to 1600 μg·L−1 of iAu.
- Effects of gold nanoparticles in gilthead seabream—A proteomic approachPublication . Barreto, A.; Carvalho, A.; Campos, A.; Osório, H.; Pinto, Edgar; Almeida, A.; Trindade, T.; Soares, A. M. V. M.; Hylland, H.; Loureiro, S.; Oliveira, M.Despite the widespread use of nanoparticles (NPs), there are still major gaps of knowledge regarding the impact of nanomaterials in the environment and aquatic animals. The present work aimed to study the effects of 7 and 40 nm gold nanoparticles (AuNPs) – citrate and polyvinylpyrrolidone (PVP) coated – on the liver proteome of the estuarine/marine fish gilthead seabream (Sparus aurata). After 96 h, exposure to AuNP elicited alterations on the abundance of 26 proteins, when compared to the control group.
- Effects of single and combined exposures of gold (nano versus ionic form) and gemfibrozil in a liver organ culture of Sparus aurataPublication . Barreto, A.; Carvalho, A.; Silva, D.; Pinto, E.; Almeida, A.; Paíga, P.; Correia-Sá, L.; Delerue-Matos, C.; Trindade, T.; Soares, A.M.V.M.; Hylland, K.; Loureiro, S.; Oliveira, M.In vitro methods have gained rising importance in ecotoxicology due to ethical concerns. The aim of this study was to assess the single and combined in vitro effects of gold, as nanoparticle (AuNPs) and ionic (Au+) form, and the pharmaceutical gemfibrozil (GEM). Sparus aurata liver organ culture was exposed to gold (4 to 7200 μg·L−1), GEM (1.5 to 15,000 μg·L−1) and combination 80 μg·L−1 gold +150 μg·L−1 GEM for 24 h. Endpoints related with antioxidant status, peroxidative/genetic damage were assessed. AuNPs caused more effects than Au+, increasing catalase and glutathione reductase activities and damaging DNA and cellular membranes.
- Insights into corrosion behaviour of uncoated Mg alloys for biomedical applications in different aqueous mediaPublication . Neves, C. S.; Sousa, L.; Freitas, M. A.; Costa, C.; Teixeira, J. P.; Fraga, S.; Pinto, Edgar; Almeida, A.; Scharnagl, N.; Zheludkevich, M. L.; Ferreira, M. G. S.; Tedim, J.MgCa and MgGd series of alloys are often reported as promising candidates for biomedical applications. In the present study, cytotoxicity and corrosion behavior of Mg1Ca and Mg10Gd alloys in different electrolytes (NaCl, PBS, MEM) have been investigated in order to make a direct comparison and understand the mechanisms behind their performance. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) were employed to analyze corrosion processes depending on media composition, whereas X-Ray diffraction (XRD) and scanning electron microscopy (SEM) were used to evaluate crystalline structure, phase composition and surface morphology of the corroded substrates after immersion in the different electrolytes. Moreover, cytotoxicity of the Mg alloys was assessed using the WST-1 reduction and lactate dehydrogenase (LDH) release assays in L929 mouse fibroblasts. The electrochemical results showed that Mg1Ca has a lower degradation rate when compared to Mg10Gd, due to the lower microgalvanic effects and the presence of Ca as an alloying element. Furthermore, the corrosion activity is reduced in MEM, for both alloys, when compared to NaCl and PBS. The cytotoxicity assays revealed that Mg10Gd was cytotoxic in all the conditions tested, while the toxicity of Mg1Ca was low. Overall, these findings show that Mg1Ca alloy presents a higher corrosion resistance and biocompatibility and is a promising material to be used in biomedical implants.
- Noncompliance to iodine supplementation recommendation is a risk factor for iodine insufficiency in portuguese pregnant women: results from the IoMum cohortPublication . Matta Coelho, C.; Guimarães, J.; Bracchi, I.; Xavier Moreira, N.; Pinheiro, C.; Ferreira, P.; Pestana, D.; Barreiros Mota, I.; Cortez, A.; Prucha, C.; Martins, C.; Pinto, E.; Almeida, A.; Delerue‑Matos, C.; C. Dias, C.; Moreira‑Rosário, A.; F. Ribeiro de Azevedo, L.; Cruz Fernandes, V.; Ramalho, C.; Calhau, C.; ‑L. Brantsæter, A.; Costa Leite, J.; Keating, E.After a recommendation for iodine supplementation in pregnancy has been issued in 2013 in Portugal, there were no studies covering iodine status in pregnancy in the country. The aim of this study was to assess iodine status in pregnant women in Porto region and its association with iodine supplementation. A cross-sectional study was conducted at Centro Hospitalar Universitário São João, Porto, from April 2018 to April 2019. Pregnant women attending the 1st trimester ultrasound scan were invited to participate. Exclusion criteria were levothyroxine use, gestational age<10 and≥14 weeks, non-evolutive pregnancy at recruitment and non-signing of informed consent. Urinary iodine concentration (UIC) was measured in random spot urine by inductively coupled plasma-mass spectrometry. Median UIC was 104 μg/L (IQR 62–189) in the overall population (n=481) of which 19% had UIC<50 µg/L. Forty three percent (n=206) were not taking an iodine-containing supplement (ICS) and median UIC values were 146 µg/L (IQR 81–260) and 74 µg/L (IQR 42–113) in ICS users and non-users, respectively (p<0.001). Not using an ICS was an independent risk factor for iodine insufciency [adjusted OR (95% CI)=6.00 (2.74, 13.16); p<0.001]. Iodised salt use was associated with increased median iodine-to-creatinine ratio (p<0.014). A low compliance to iodine supplementation recommendation in pregnancy accounted for a mild-to-moderately iodine defciency. Our results evidence the need to support iodine supplementation among pregnant women in countries with low household coverage of iodised salt.
- Trace element imbalances in patients undergoing chronic hemodialysis therapy - Report of an observational study in a cohort of Portuguese patientsPublication . Almeida, A.; Gajewska, K.; Duro, M.; Costa, F.; Pinto, EdgarPatients with end-stage renal disease undergoing hemodialysis therapy are at risk of developing deficiencies of essential trace elements and/or overload of toxic trace elements, both of which may significantly affect their clinical status of. Those imbalances may result from the disease itself but also from the quality of the therapeutic process, namely the hemodialysis process, which has greatly evolved in the last decades. Thus, old observations that have been assumed as very well-proven have been recently questioned. In this case-control study we evaluate the current trace elements status in a group of Portuguese patients under hemodialysis therapy.