Percorrer por autor "Duarte, Elsa"
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- Bioaccessibility assessment of patulin and ochratoxin A in cereal and fruit based baby foods using a harmonized in vitro digestion model: contribution for the risk assessment of chemical mixturesPublication . Assunção, Ricardo; Martins, Carla; Duarte, Elsa; Alvito, PaulaPeople, animals and the environment can be exposed to multiple chemicals at once from a variety of sources, but current risk assessment is usually carried out on one chemical substance at a time. Mycotoxins are fungal natural contaminants commonly found in a variety of foods including baby foods and have been found in cereal and fruit based baby foods. In human health risk assessment, ingestion of food is considered a major route of exposure to many contaminants including mycotoxins, although the total amount of an ingested contaminant (external dose) does not always reflect the amount that is available to the body (internal dose). The amount of mycotoxin resisting to the digestion process and potentially absorbable by the systemic circulation is only a smaller part of that ingested. In vitro digestion models become useful for evaluating mycotoxins bioaccessibility during the intestinal transit and can be intended as a valuable tool for the assessment of mycotoxin bioavailability in food. Trichothecenes, Ochratoxin A (OTA) and Patulin (PAT) are the best known enteropathogenic mycotoxins able to alter functions of the intestine. OTA and PAT were previously detected in cereal and fruit based baby food. This study aimed to evaluate the bioaccessibility of the mycotoxins OTA and PAT in cereal and fruit based baby food and the possible interactions that could happen when these mycotoxins co-occur. A standardized static in vitro digestion method was used to assess the bioaccessibility of OTA and PAT in three different cereal and fruit based baby foods, previously checked not to be contaminated with these mycotoxins and artificially contaminated to 1 µg/kg of OTA and 20 µg/kg of PAT. Mycotoxins quantification was performed by HPLC-FLD for OTA and HPLC-UV for PAT. Preliminary results showed that PAT presented bioaccessibility values ranging from 42 % to 65 %. Bioaccessibility assays for OTA and the mixture of OTA and PAT are under process. This study will provide new information related with the bioaccessibility of mycotoxins in baby foods and the results will offer a more comprehensive picture of what occurs during the digestion of food contaminants in the gastrointestinal tract and subsequently contributes to provide a more accurate risk assessment of single and multiple food contaminants.
- Determinants of the Sympatric Host-Pathogen Relationship in TuberculosisPublication . David, Susana; Mateus, A.R.A.; Duarte, Elsa; Albuquerque, José Maria; Portugal, Clara; Sancho, Luísa; Lavinha, João; Gonçalves, GuilhermeMajor contributions from pathogen genome analysis and host genetics have equated the possibility of Mycobacterium tuberculosis co-evolution with its human host leading to more stable sympatric host–pathogen relationships. However, the attribution to either sympatric or allopatric categories depends on the resolution or grain of genotypic haracterization. We explored the influence on the sympatric host-pathogen relationship of clinical (HIV infection and multidrug-resistant tuberculosis [MDRTB]) and demographic (gender and age) factors in regards to the genotypic grain by using spacer oligonucleotide typing (spoligotyping) for classification of M. tuberculosis strains within the Euro-American lineage. We analyzed a total of 547 tuberculosis (TB) cases, from six year consecutive sampling in a setting with high TB-HIV coinfection (32.0%). Of these, 62.0% were caused by major circulating pathogen genotypes. The sympatric relationship was defined according to spoligotype in comparison to the international spoligotype database SpolDB4. While no significant association with Euro-American lineage was observed with any of the factors analyzed, increasing the resolution with spoligotyping evidenced a significant association of MDRTB with sympatric strains, regardless of the HIV status. Furthermore, distribution curves of theprevalence of sympatric and allopatric TB in relation to patients’ age showed an accentuation of the relevance of the age of onset in the allopatric relationship, as reflected in the trimodal distribution. On the contrary, sympatric TB was characterized by the tendency towards a typical (standard) distribution curve. Our results suggest that within the EuroAmerican lineage a greater degree of genotyping fine-tuning is necessary in modeling the biological processes behind the host-pathogen interplay. Furthermore, prevalence distribution of sympatric TB to age was suggestive of host genetic determinisms driven by more common variants
- Exposição precoce a contaminantes alimentares e avaliação de risco-beneficio de alimentos: dois desafios da nova décadaPublication . Alvito, Paula; Duarte, Elsa; Ferreira, M.; Nunes, C.; Pires, S.; Martins, Carla; Assunção, R.As escolhas alimentares influenciam diretamente a dieta bem como o aporte diário de nutrientes. A sensibilização e a capacitação dos cidadãos para escolhas alimentares mais saudáveis é também determinante para uma estratégia para a promoção da alimentação saudável. Os alimentos pelos quais optamos apresentam compostos com efeitos benéficos, no entanto, alguns podem apresentar potencial efeito negativo para a saúde, como por exemplo, os contaminantes alimentares. A avaliação de risco-benefício (RBA) de alimentos estima os benefícios e riscos para os seres humanos decorrentes da ingestão de um alimento, um componente alimentar ou uma dieta específica, e integra-os utilizando ferramentas que permitam essa comparação. O projeto internacional RiskBenefit4EU, financiado pela EFSA (https://riskbenefit4eu.wordpress.com/), pretende, ao integrar as perspetivas microbiológicas, toxicológicas e nutricionais, contribuir para o desenvolvimento, na Europa e em Portugal, de uma nova cultura no âmbito da segurança alimentar e nutrição, sugerindo linhas de orientação para a realização de uma alimentação mais segura e saudável. A exposição a contaminantes químicos nos primeiros 1000 dias de vida tem sido associada a alterações de saúde, constituindo também um domínio emergente de investigação. A exposição precoce a contaminantes ocorre durante a gestação pela transferência de substâncias tóxicas da dieta materna para o feto através da placenta e, posteriormente, durante a lactação, através do leite materno. As micotoxinas, contaminantes químicos presentes nos alimentos, são compostos tóxicos com efeitos carcinogénicos, nefrotóxicos, hepatotóxicos e imunossupressores. Estudos recentes evidenciaram que as crianças portuguesas até aos 3 anos estão expostas a múltiplas micotoxinas através da alimentação, o que constitui um risco potencial para a sua saúde (https://www.youtube.com/watch?v=CsKaz3mt2J4). Neste contexto, é pertinente questionar qual o impacto de uma exposição precoce a micotoxinas na saúde da criança e do futuro adulto. O projeto nacional earlyMYCO, financiado pela FCT, pretende assim responder a questões como: estarão as grávidas e lactentes até aos 6 meses de idade expostos a micotoxinas? Esta exposição representa um risco para a sua saúde? Nesta comunicação pretende-se apresentar e discutir dois projetos complementares a decorrer no Departamento de Alimentação e Nutrição, do INSA, e que constituem dois desafios atuais relacionados com as escolhas alimentares.
- Genetic variants in the IFNGR2 locus associated with severe chronic Q feverPublication . David, Susana; Castro, Liliana; Duarte, Elsa; Gaspar, Ulisses; Rodrigues, Maria Rosário da Costa; Cueto-Rojo, Maria Vanessa; Mendonça, Joana; Ferrão, José; Machado, Miguel; Poças, José; Lavinha, João; Vieira, Luís; Santos, Ana Sofia; ElsevierQ fever is a highly contagious zoonosis capable of causing large outbreaks of important health and economic consequences. Host genetic factors are believed to influence the development of severe chronic Q fever following the infection by the etiological agent, Coxiella burnetii. Targetted next generation sequencing (NGS) was performed in a case-control genetic association study on 53 confirmed Q fever cases, including 38 compatible with acute and 15 with chronic disease, and 29 samples from the general Portuguese population. Four SNPs in the IFNGR2 locus, rs78407108 G > A, rs17879956 C > T, rs7277167 C > T, and rs9974603 C > A, showed a statistically significant association to chronic Q fever, resisting the Bonferroni correction. These belonged to haplotypes significantly associated with chronic Q fever. The individual SNPs are referenced in the GTEx database as possible eQTLs. Given the direct bearing of IFNGR2 on IFN-γ signaling, the possible involvement of the associated variants with higher IFNGR2 expression could be in line with observations suggesting that IFN-γ production in chronic Q fever patients is significantly higher than in healthy controls. Further investigations are required to clarify the role of IFNGR2 signaling in association with chronic Q fever.