Browsing by Author "Silva, E."
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- MycoMix and risk assessment: a contribute to improve risk analysisPublication . Alvito, Paula; Assunção, Ricardo; Borges, T.; Dupont, D.; Leal, S.; Loureiro, S.; Louro, H.; Martins, Carla; Nunes, Baltazar; Pinhão, M.; Koroušic Seljak, B.; Silva, M.J.; Silva, E.; Vasco, Elsa; Calhau, Maria AntóniaRisk analysis, is a powerful tool for including science-based knowledge in a systematic approach to food safety problems. The use of risk analysis can promote ongoing improvements in public health and provide a basis for expanding international trade in foods. Within risk analysis, the risk assessment results are quantitative or qualitative expressions of the likelihood of harmful effects associated with exposure to a chemical (WHO, 2010). Human risk assessment of combined exposure to multiple chemicals (chemical mixtures) poses several challenges to scientists, risk assessors and risk managers, namely the complexity of the terminology and problem formulation, the diversity of chemical entities, and the toxicological profiles and exposure patterns in test species and humans (EFSA, 2013). Mycotoxins are natural contaminants produced by fungi and its frequent co-occurrence in food poses a threat to human health, mainly to vulnerable population groups as children. MycoMix is an ongoing national project (2013-15) that explores the toxic effects of mixtures of mycotoxins in infant food and its potential health impact. This project aims to study the occurrence of multiple mycotoxins and toxicity interactions in infant foods and cereals consumed by Portuguese children and try to answer several questions: 1) Are children exposed daily to mycotoxins through food? 2) What are the quality and quantity that characterize this exposure? 3) Can this exposure bring harm to children? Answering these questions will raise novel approaches to: 1) apply new techniques on mycotoxin multiple detection, 2) understand the toxicity responses upon multiple mycotoxin exposures, and 3) implement new methodologies to characterize hazard and risk for children exposure to mycotoxins. A multidisciplinary team has been developing, for the first time in Portugal, i) a liquid chromatography (LC) method coupled with tandem mass-spectrometry (LC-MS/MS) for multimycotoxin detection in infant food developed and applied to study infant food consumed by Portuguese children, ii) cito and genotoxic assays to assess the toxicity of binary mixtures of mycotoxins detected in analyzed infant foods associated with the MIXTOX tool to assess the interactive effects, iii) in vitro methodologies to simulate the digestive and intestinal absorption processes of binary mixtures of mycotoxins, iv) a web-based dietary assessment and diet planning platform, the “OPEN Portugal”, to record infant food consumption data allowing simultaneously the assessment of the nutritional profile of the inquired children, and v) a set of deterministic, probabilistic (@RISK) and cumulative risk assessment approaches that allow the exposure assessment and risk characterization of Portuguese children to multiple mycotoxins in food. An overview of the results obtained within the MycoMix project will be presented, showing the patterns of the exposure of Portuguese infant to multiple mycotoxins as well as the scientific evidence of the toxic effects of mycotoxin mixtures using in vitro models. Hence,MycoMix outputs contribute for hazard identification and characterization as well as to exposure characterization, contributing for risk analysis.
- SCARB2 mutations as modifiers in Gaucher disease: the wrong enzyme at the wrong place?Publication . Coutinho, Maria Francisca; Lacerda, L.; Gaspar, A.; Pinto, E.; Ribeiro, I.; Laranjeira, F.; Ribeiro, H.; Silva, E.; Ferreira, C.; Prata, M.J.; Alves, S.Unlike most lysosomal proteins, β-glucocerebrosidase (GCase), the hydrolase defective in Gaucher disease (GD), is delivered to lysosomes through its interaction with the transmembrane protein LIMP2. A few years ago, mutations in its coding gene, SCARB2, were reported to modify the severity of GD phenotype. The existence of a great variety of GD phenotypes is well-known, with numerous patients who carry identical genotypes presenting remarkable phenotypic variability. Over the years, that variability has been attributed to other genetic, epigenetic and/or environmental factors. Still, there is still much to learn on this subject. Recently, an association between Parkinson's disease (PD) and the presence of mutations in the GBA gene has been demonstrated. Moreover, there are also studies suggesting that genetic variants in the SCARB2 gene may also be risk factors for PD. We analysed the SCARB2 gene in the Portuguese cohort of 91 GD patients, having identified 3 different SCARB2 coding variants. Of those, 2 were known polymorphisms with high prevalence in the normal population (p.M159V and p.V396I) and the third was a novel coding variant, p.T398M, present in heterozigousity in a single patient. Our study demonstrated that, at least for the Portuguese population, genetic variability at SCARB2 does not account much to the GD phenotypic spectrum. Nevertheless, in vitro analyses of the novel p.T398M are envisaged, in order to further characterize the effect of this variant on the levels and sub-cellular location of GCase. The clinical presentation of the patient harbouring this coding variant will also be discussed.
- SCARB2 mutations as modifiers in Gaucher disease: the wrong enzyme at the wrong place?Publication . Coutinho, M.F.; Lacerda, L.; Gaspar, A.; Pinto, E.; Ribeiro, I.; Laranjeira, F.; Ribeiro, H.; Silva, E.; Ferreira, C.; Prata, M.J.; Alves, S.Unlike most lysosomal proteins, β-glucocerebrosidase (GCase), the hydrolase defective in Gaucher disease (GD), is delivered to lysosomes through its interaction with the transmembrane protein LIMP2. A few years ago, mutations in its coding gene, SCARB2, were reported to modify the severity of GD phenotype. The existence of a great variety of GD phenotypes is well-known, with numerous patients who carry identical genotypes presenting remarkable phenotypic variability. Over the years, that variability has been attributed to other genetic, epigenetic and/or environmental factors. Still, there is still much to learn on this subject. Recently, an association between Parkinson's disease (PD) and the presence of mutations in the GBA gene has been demonstrated. Moreover, there are also studies suggesting that genetic variants in the SCARB2 gene may also be risk factors for PD. We analysed the SCARB2 gene in the Portuguese cohort of 91 GD patients, having identified 3 different SCARB2 coding variants. Of those, 2 were known polymorphisms with high prevalence in the normal population (p.M159V and p.V396I) and the third was a novel coding variant, p.T398M, present in heterozigousity in a single patient. Our study demonstrated that, at least for the Portuguese population, genetic variability at SCARB2 does not account much to the GD phenotypic spectrum. Nevertheless, in vitro analyses of the novel p.T398M are envisaged, in order to further characterize the effect of this variant on the levels and sub-cellular location of GCase. The clinical presentation of the patient harbouring this coding variant will also be discussed.