Percorrer por data de Publicação, começado por "2014-09"
A mostrar 1 - 10 de 83
Resultados por página
Opções de ordenação
- Indoor microbiological contamination in children day care centres – the ENVIRH studyPublication . Cano, Manuela; Nogueira, Susana; Papoila, Ana Luísa; Aguiar, Fátima; Rosa, Nuno; Mendes, Ana; Teixeira, João Paulo; Proença, Carmo; Neuparth, NunoIn developed countries, after their homes, the children day care center (CDCC) is the place where children spend most of their time, so it is important to understand how environmental factors influence children respiratory health. The aim of ENVIRH (Environment and Health in children day care centres) study is to gather information on indoor environment in CDCC in order to correlate it with both ventilation and children’s health. This paper presents field measurements of indoor microbiological parameters, performed in 19 CDCC during spring and winter and aims to characterize the indoor environment. Bacteria and fungi were collected using a MAS-100 impactor with Trypticase Soy Agar, MacConkey Agar and Malt Extract Agar as culture media for total bacteria, Gram-negative bacteria and fungi, respectively. Concentrations were calculated and fungi were identified. Dust samples were collected on filters using a vacuum cleaner with a DustreamTM collector. Concentration of Der p1 and Der f1 dust mite allergens were assayed separately by ELISA quantitative kit. Most of the CDCC revealed bacterial levels above the reference levels defined by the Portuguese legislation. Nurseries presented lower bacterial concentrations than activity rooms. Indoor fungal concentrations were above outdoor levels in 50% of the studied rooms and the predominant mould genera detected in both seasons were Penicillium and Cladosporium. In spring were obtained higher concentrations of house dust mites in dust with 16% of the rooms surpassing the sensitization threshold.
- Characterization of a Population Concerning Vitamins and Anemia BiomarkersPublication . Mota, Carla; Tavares, Nuno; Torres, Duarte; Santos, Mariana; Castanheira, Isabel; Matos, Ana SofiaFolate, vitamin B12, iron and hemoglobin are essential for metabolic functions. Deficiency of these can cause several known pathologies and, untreated, severe morbidity and death. The objective of this study is to characterize a population, concerning serum levels of folate, B12, iron and hemoglobin, as well as finding evidence of correlations between these parameters and illnesses, mainly cardiovascular, gastrointestinal, neurological and anemia. The laboratorial data collected consists of blood analysis in patients, required by the patients’ doctors, and were retrieved in 2012. The total population consisted of 728 individuals, residing in Lisbon metropolitan area in Portugal. When coming in for examination, the patients were asked routine questions about their age, gender, county of residence, reason for examination and what medication or supplementation they were taking. The population consisted of 140 male patients and 588 female patients, aged from 2 to 95 years of age. There are 329 persons over 60 years old, these are considered elderly patients. Clinical data was submitted to multivariate analysis. The data was screened with Spearman correlation and Kruskal-Wallis analysis of variance to study correlations and variability between groups. To characterize the population, we used cluster analysis with Ward’s linkage method. A positive correlation between iron with, ferritin and transferrin, and with hemoglobin was observed with the Spearman correlation. Kruskal-Wallis analysis of variance showed significant differences between these biomarkers in persons aged 0-29, 30-59 and over 60 years old. Cluster analysis, evidence low folate levels for population in general, and hemoglobin levels below the reference values for 42.8% of study population. Iron and vitamin B12 were within the reference range for most of the population. Low levels of the parameters were registered mainly in cardiovascular, gastrointestinal, neurological diseases and anemia patients.
- Towards a 100% smoke-free Portugal: no more delaysPublication . Ravara, S.B.; Miranda, N.; Calheiros, José M.
- Carotenoids and α-tocopherol content of some aromatic herbs by ultra-high performance liquid chromatography with diode array detectionPublication . Carvalho-Costa, D.; Albuquerque, T.G.; Costa, H.S.; Reis, A.R.; Castilho, M.C.; Ramos, F.; Machado, A.V.; Sanches-Silva, A.Carotenoids are colorful plant pigments with antioxidant properties that can prevent some forms of cancer and heart disease as well as enhance immune response to infections. Several aromatic herbs, such as Origanum majorana L. (marjoram), Ocimum basilicum L. (basil), Thymus vulgaris (thyme), Artemisia dracunculus L. (tarragon), Origanum vulgare L. (oregano), Mentha piperita L. (peppermint) and Rosmarinus officinalis L. (rosemary) have been examined in order to determine their carotenoids and vitamin E composition. Carotenoids were extracted from aromatic herbs with a mixture of hexane/ethanol, 4:3 (v/v). All samples were subjected to a procedure with and without saponification step. Separation and quantification was performed by Ultra-High Performance Liquid Chromatography with diode array detection (UHPLC-DAD). Chromatographic separation was performed with Acquity UPLC® BEH C18 analytical column (50 mm, 2.1 mm I.D., 1.7 µm particle size) and an Acquity UPLC® BEH C18 guard column (5.0 mm, 2.1 mm I.D., 1.7 µm particle size). Mobile phases were (A) ultrapure water; (B) acetonitrile/methanol (containing 0.05 M ammonium acetate)/dichloromethane (75:20:5, v/v/v). The flow-rate was 0.5 mL/min. In the case of rosemary, lutein, zeaxanthin, α-carotene and α-tocopherol were quantified and saponification decreased the amount of these carotenoids. The analysed aromatic herbs can be considered good sources of carotenoids, although a great variability was found among their content. Due to the putative health benefits of these compounds, their consumption shall be encouraged and promoted.
- Hope for GWAS: Relevant Risk Genes Uncovered from GWAS Statistical NoisePublication . Correia, C.; Diekmann, Y.; Vicente, A.M.; Pereira-Leal, J.B.Hundreds of genetic variants have been associated to common diseases through genome-wide association studies (GWAS), yet there are limits to current approaches in detecting true small effect risk variants against a background of false positive findings. Here we addressed the missing heritability problem, aiming to test whether there are indeed risk variants within GWAS statistical noise and to develop a systematic strategy to retrieve these hidden variants. Employing an integrative approach, which combines protein-protein interactions with association data from GWAS for 6 common diseases, we found that associated-genes at less stringent significance levels (p < 0.1) with any of these diseases are functionally connected beyond noise expectation. This functional coherence was used to identify disease-relevant subnetworks, which were shown to be enriched in known genes, outperforming the selection of top GWAS genes. As a proof of principle, we applied this approach to breast cancer, supporting well-known breast cancer genes, while pinpointing novel susceptibility genes for experimental validation. This study reinforces the idea that GWAS are under-analyzed and that missing heritability is rather hidden. It extends the use of protein networks to reveal this missing heritability, thus leveraging the large investment in GWAS that produced so far little tangible gain.
- Mobile genetic elements associated to antibiotic resistance in Salmonella enterica isolates collected in food-chainPublication . Manageiro, Vera; Gomes-Neves, Eduarda; Correia da Costa, José Manuel; Caniça, ManuelaIn this study, we assessed the presence of IS26 elements in 60 multidrug resistant (R-type ASSuT phenotype) Salmonella enterica isolates collected in slaughtered swine samples in Portugal, investigating its role in the dissemination of antimicrobial resistance among different reservoirs. PCR-mapping allowed us to describe a new genetic organization, in the emergent Salmonella Rissen, including a peptidase C14 caspase catalytic subunit P20 gene between two IS26 elements. Furthermore, we detected the same genetic structures in Salmonella isolates from different serotypes in samples from slaughtered swine, carcasses/meat, and meat handlers, namely a resistance region harboring blaTEM-1 genes also flanked by 2 copies of IS26 elements in Salmonella Typhimurium (n=17) and Salmonella 4,[5],12:i:- variants (n=2). This study highlights that IS26 mobile genetic elements might play an important role in the mobilization of antibiotic resistance genes, which can constitutes a problem in terms of veterinary medicine and public health in general.
- Nutritional safety of commercial bakery products manufactured in PortugalPublication . Albuquerque, T.G.; Oliveira, M.B.; Sanches-Silva, A.; Bento, A.C.; Costa, H.S.Introduction: Bakery products are a wide group of ready-to-eat processed foods, highly consumed, especially by young people. These foods mainly present poor nutritional quality, namely due to its high content in saturated fat, salt and sugar. In the past years, food industry has made efforts to develop food products that at the same time meet the consumers demand and contribute to a healthier diet. However, the information concerning their nutritional quality is usually scarce and incomplete. Aim: To evaluate nutritional safety of thirty commercial bakery products available in the Portuguese market, considering its total fat content, salt content and fatty acids profile (including trans fatty acids). Moreover, commercial and supermarket brands for each product were included in the study in order to assess a possible effect of price on the nutritional quality of foods. Materials and methods: Thirty samples of the most common industrial bakery products sold in Portugal were analyzed for their total fat, salt and fatty acids composition. In order to assure the representativeness of samples, bakery products were collected randomly, in the major supermarkets chains from the Portuguese market. Total fat determination was performed by acid hydrolysis method followed by Soxhlet’s extraction with petroleum ether. The salt content was determined by Charpentier Volhard’s titration. Preparation of fatty acids methyl esters was carried out by a combined method of methylation and transesterification, followed by gas chromatography analysis coupled with a mass detector. Results of the present study are expressed as g/100 g of edible portion. Results and discussion: Our results showed that bakery products have high total fat contents, varying between 10.2 ± 0.0 and 27.7 ± 1.0 g/100 g of edible portion. With respect to salt content, the values ranged from 0.244 ± 0.0 to 2.07 ± 0.1 g/100 g. In our study, the most abundant saturated fatty acids found in the analysed samples was palmitic acid (C16:0), which is also one of the most common fatty acids in foodstuffs. Considerable differences in total fat and salt contents were found between commercial and supermarket brands. Conclusions: In summary, this study demonstrated that bakery products commercialized in Portugal are considerable sources of fat and salt. Nevertheless, more studies are needed to cover a wider range of bakery products and other processed foods.
- Estudo para avaliar o grau de conhecimento dos consumidores sobre embalagens plásticasPublication . Carvalho-Costa, D.; Costa, H.S.; Reis, A.R.; Albuquerque, T.G.; Castilho, M.C.; Ramos, F.; Machado, A.V.; Sanches-Silva, A.Actualmente, a grande maioria dos alimentos disponíveis nos supermercados encontram-se embalados. As embalagens podem ser muito variadas, quer no que respeita à permeabilidade ao oxigénio ou ao vapor de água, ao tipo de material/materiais, como à resistência. A escolha das mesmas deve ser sempre realizada de acordo com o tipo de alimento a que se destina. Foi realizado um estudo baseado num inquérito por questionário para avaliar o grau de conhecimento dos consumidores sobre as embalagens, principalmente as plásticas, incidindo em temas como a preocupação com a reciclagem ou a utilização das embalagens de acordo com as indicações do fabricante Dado o interesse crescente nos novos tipos de embalagens como as embalagens ativas, que interagem com o alimento embalado com o objetivo de prolongar o tempo de conservação ou de manter/melhorar o estado do alimento embalado, e as embalagens inteligentes que monitorizam o estado de conservação dos alimentos ou do ambiente que os envolve, estas também foram incluídas no estudo. O estudo foi aplicado a cerca de 200 indivíduos, na sua maioria jovens adultos. Verificou-se que cerca de 60% dos inquiridos não tinha conhecimento da existência de embalagens activas nem de embalagens inteligentes, mas aproximadamente 90% dos mesmos estaria disposto a adquirir alimentos nestas embalagens. Cerca de 55% dos inquiridos afirma cumprir as indicações do fabricante aquando da utilização de recipientes de plástico, conhecendo os riscos derivados da má utilização deste tipo de materiais. Aproximadamente 40% dos inquiridos recicla sempre as embalagens de plástico, enquanto cerca de 20% raramente o faz. A análise dos resultados teve em linha de conta a faixa etária e o nível de escolaridade dos inquiridos. Os resultados indicam a necessidade de consciencializar a população para os perigos relacionados com o uso indevido das embalagens, a importância da reciclagem bem como para os benefícios/riscos dos novos tipos de embalagens.
- Antioxidant capacity, phenolic content and total flavonoids of orange juicePublication . Raposo, C.A.; Albuquerque, T.G.; Oom, M.; Sanches-Silva, A.; Costa, H.S.Nowadays, the search for healthier dietary food choices has increased the demand for fresh and nutritive products. Several epidemiological studies indicate that fruits, vegetables and less processed food ensure a higher protection against diseases caused by oxidative stress. Citrus juices attract attention as a result of their health-related properties, due to the presence of natural antioxidants. Orange juice, in particular, is one of the most consumed juices worldwide and it is an important source of flavonoids and phenolic compounds. As a result of the development of new technologies and the improvement of traditional industrial processing, there is a wide range of new commercial juices promoted by strong marketing strategies. In fact, it is important to evaluate whether these processed products maintain similar properties to a freshly squeezed juice. The main objective of the present work was to evaluate the antioxidant activity of six samples of orange juice: one nectar, three concentrated juices, and two freshly squeezed juices (filtrated and non-filtrated). The oranges and orange juices were acquired in local supermarkets, and the antioxidant activity was determined comparing three different methods: 2,2-diphenyl-1-picrylhydrazyl (DPPH●), Folin-Ciocalteu method (applied to determine total phenolics, using gallic acid as standard) and total flavonoids assay (using epicatechin as standard). All the analyses were performed at least in duplicate. For DDPH● assay, the EC50 value (inversely proportional to antioxidant activity) was higher for the nectar (13.8 ± 0.33 mg/mL), followed by freshly squeezed juices (12.6 ± 0.59 and 12.3 ± 0.22 mg/mL, filtrated and non-filtrated, respectively) and concentrated juice (9.01 ± 0.03 mg/mL). The highest value for total phenolics was found in concentrated juices (0.208 ± 0.04 mg/mL), whereas the lowest corresponds to the orange nectar (0.134 ± 0.00 mg/mL). With respect to total flavonoids content, the values varied between 0.099 ± 0.00 and 0.158 ± 0.01 mg/mL, for nectar and concentrated juices, respectively. Our results indicated that orange juice can be considered a good source of natural antioxidants, including flavonoids and phenolic compounds. The methods for antioxidant activity evaluation showed that orange nectar had the lowest antioxidant capacity, whereas the concentrated juices presented the highest. There is no evidence that filtration of the freshly squeezed juice produced considerable variations. Although the industrial processing of orange juice may cause losses of vitamin C, it is a common practice of food industry to add L-ascorbic acid at the end of the processing. In fact, commercial concentrated juices revealed higher values of antioxidant activity, flavonoids and phenolic compounds, than the freshly squeezed juices.
- Determinação de macronutrientes em três variedades de casca, farelo e grão de arroz portuguêsPublication . Delgado, Inês; Rego, Andreia; André, Catarina; Castanheira, IsabelIntrodução: Os macronutrientes são nutrientes que fornecem calorias e energia. Estes são essenciais para o crescimento, para o metabolismo e para outras funções corporais. Entende-se por humidade a perda de peso sofrida pela amostra quando seca a 100 – 105ºC até peso constante. Entende-se por cinza o resíduo calcinado obtido submetendo a amostra a uma temperatura de 525 ºC no caso de cereais numa mufla. Entende-se por gordura bruta a fração da amostra extraída por um solvente orgânico num sistema de extração Soxhlet. A proteína neste estudo é determinada pelo método de Kjeldahl. A qualidade nutricional da proteína é determinada pela proporção dos aminoácidos essenciais ao ser humano, sendo que existem dez aminoácidos que são estritamente essenciais ao ser humano: lisina, isoleucina, leucina, fenilalanina, tirosina, treonina, triptofano, valina, histidina e metionina.