Browsing by Author "Costa, Helena"
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- Key Metrological Issues for the estimation of Dietary Intakes of Manganese and Copper from Portuguese Total Diet StudyPublication . Ventura, Marta; Coelho, Inês; Gueifão, Sandra; Moreira, Tiago; Costa, Helena; Castanheira, IsabelManganese and Copper are two essential micronutrients required for several vital functions. Recently EFSA reviewed adequate intake values for these nutrients. AIs of 1.6 mg/day for copper, and 3 mg/day for manganese were established for adults. This work aims at evaluating the contents of Mn and Cu in foods collect during the Portuguese Total Diet Study (TDS). One thousand one hundred and fifty two foods were prepared as consumed and analysed in ninety six pooled laboratory samples. Samples were digested with nitric acid and hydrogen peroxide in a microwave assisted digestion and analysed by Inductively Coupled Plasma Mass Spectrometry (ICP-MS). Analytical procedures were carried out under rigorous metrological control and traceable to SI units. The following food groups were analysed: dairy products, meat, fish, cereals, pulses, bread, potatoes and juices. The lowest amounts of Mn and Cu were found in milk with 27 ± 0.9 μg/kg and 42 ± 4.5 μg/kg, respectively. The highest concentration of Mn was present in pulses 12541 ± 237 μg/kg while the maximum value of Cu was observed in cereals 2451 ± 52 μg/kg. The assessment of different food groups to overall AIs was based on combination of analytical data with consumption data from national food survey. Our results, showed that a diet including only these food groups is not sufficient to suppress the AIs of Mn or Cu for Portuguese adult population. Metrological tools were crucial to guarantee consistency conclusions.
- Molecular Variants of Human Papillomavirus Type 16 and 18 and Risk for Cervical Neoplasia in PortugalPublication . Pista, Angela; Oliveira, Ana; Barateiro, Andreia; Costa, Helena; Verdasca, Nuno; Paixão, TeresaPersistent high-risk human papillomavirus (HPV) infection is considered as the central cause of invasive cervical cancer. Specific HPV 16 and 18 sequence variations were associated with an increased risk for progression. The purpose of this study was to analyze intratypic variations of HPV 16 and 18 within the E6 gene, MY09/11 and LCR regions, and to evaluate the risk of these variants for cervical neoplasia among Portuguese women. Cervical samples from 187 HPV 16-positive and 41 HPV 18-positive women with normal epithelium, cervical intraepithelial neoplasia, or invasive cervical cancer were amplified by type-specific PCR, followed by sequence and phylogenetic analysis. Sixteen new HPV 16 and 18 patterns are described in this paper. European HPV 16 variants were the most frequent (74.3%), particularly Ep-T350 (44.4%), followed by African (16.1%), and Asian-American (9.6%). Non- European HPV 16 variants were more frequent in pre-invasive lesions than in normal tissue and low-grade lesions. However, when analyzed separately, only African variants were associated significantly with an increased risk for cervical cancer. For HPV 18, the AsAi variant showed a trend, which was not statistically significant to an enhanced oncogenicity. European variants seemed to be significantly associated with a lower risk for cervical cancer development. The distribution of HPV 16 and 18 variants was not related to age or race among women living in the same geographical region. Knowledge of variants will be important for risk determination as well as for designing primers or probes for HPV detection methods, and for appropriate cervical cancer prevention strategies.