Browsing by Issue Date, starting with "2019-06-26"
Now showing 1 - 6 of 6
Results Per Page
Sort Options
- Chemical Composition, Nutritional Value, and Safety of Cooked Female Chaceon Maritae from Namibe (Angola)Publication . Mandume, Celso Manuel Cristovão; Bandarra, Narcisa M.; Raimundo, Joana; Lourenço, Helena Maria; Gonçalves, Susana; Ventura, Marta; Delgado, Inês; Rego, Andreia; Motta, Carla; Castanheira, Isabel; Nunes, Maria Leonor; Duarte, Maria PaulaDespite being highly appreciated and consumed, the nutritional value of Chaceon maritae from Namibe (Angola) had never been studied. In the present work, edible tissues (muscle, ovaries, and hepatopancreas) of boiled female C. maritae caught o Namibe coast in two distinct seasons were analyzed in terms of proximate chemical composition (fat, ash, protein, and moisture), fatty acid and amino acid profiles, cholesterol, essential minerals (macro and trace) and toxic elements. Results showed that, in both seasons, C. maritae muscle was a valuable source of protein, essential amino acids, polyunsaturated fatty acids, and essential elements, especially zinc, selenium, iodine, and copper. Ovaries and hepatopancreas are also good sources of protein, but were richer in fat, particularly when caught in October. Ovarian fat is rich in polyunsaturated fatty acids and that of hepatopancreas has higher values of monounsaturated and saturated fatty acids. Hepatopancreas and ovaries are also good sources of copper and, especially ovaries, of zinc. Moreover, in both seasons, all the edible tissues of C. maritae analyzed presented very low contents of heavy metals (mercury, cadmium, lead, and arsenic).
- Exposure assessment of Portuguese population to multiple mycotoxins: the human biomonitoring approachPublication . Martins, Carla; Vidal, A.; De Boevre, M.; De Saeger, S.; Nunes, C.; Torres, D.; Goios, A.; Lopes, C.; Assunção, R; Alvito, P.Mycotoxins constitute a relevant group of food contaminants with several associated health outcomes such as estrogenic, immunotoxic, nephrotoxic and teratogenic effects. Although scarce data are available in Portugal, human biomonitoring studies have been globally developed to assess the exposure to mycotoxins at individual level. In order to overcome this lack of data, the present study concerned the analysis of mycotoxins in 24h urine and first-morning urine paired samples from 94 participants enrolled within the scope of the National Food, Nutrition, and Physical Activity Survey of the Portuguese General Population (2015–2016). Following a salt assisted matrix extraction, urine samples were analysed by liquid chromatography–mass spectrometry for the simultaneous determination of 37 urinary mycotoxins’ biomarkers and data obtained used to estimate the probable daily intake as well as the risk characterization applying the Hazard Quotient approach. Results revealed the exposure of Portuguese population to zearalenone, deoxynivalenol, ochratoxin A, alternariol, citrinin and fumonisin B1 through the quantification in 24h urine and first-morning urine paired samples. Risk characterization data revealed a potential concern to some reported mycotoxins since the reference intake values were exceeded by some of the considered participants. Alternariol was identified for the first time in urine samples from a European country; however, risk characterization was not performed due to lack of reference intake value. These results confirmed mycotoxins as part of the human exposome of the Portuguese population reinforcing the need for further studies regarding the determinants of exposure.
- In vitro exposure to the next-generation plasticizer diisononyl cyclohexane-1,2-dicarboxylate (DINCH): cytotoxicity and genotoxicity assessment in human cellsPublication . Vasconcelos, Ana Luísa; Silva, Maria João; Louro, HenriquetaPlasticizers are currently present in many consumer products, particularly food packaging, children's toys, and medical devices. There are concerns regarding potential leaching to environment or food, thus increasing the risk of human exposure by inhalation, ingestion and/or dermal absorption potentially leading to adverse health consequences. Hexamoll diisononyl cyclohexane-1,2-dicarboxylate (Hexamoll® DINCH®), a non-phthalate plasticizer, has been used as a safer alternative to hazardous phthalates. In contrast to phthalates, evidence indicates that DINCH did not produce endocrine disruption, reproductive dysfunctions, genotoxicity or mutagenicity. However, there are limited data available regarding safety assessment, especially with respect to genotoxicity in human cells. The aim of this study was to assess DINCH cytotoxic and genotoxic effects in human liver and kidney cell lines following several exposure periods. For this purpose, the MTT cell viability, micronucleus, conventional and formamidopyrimidine DNA glycosylase (FPG)-modified comet assays were employed to detect cell death and genotoxicity, respectively. Data demonstrated that DINCH induced cytotoxicity in kidney cells exposed for 48hr, but not in liver cells. No marked chromosomal damage was noted after short-term or longer following treatment of both cell lines. However, DINCH produced oxidative DNA damage in liver cells exposed for 3 h, which decreased after a more prolonged incubation period. The occurrence of oxidative lesions, even transiently, indicates that mutation fixation may occur leading to adverse effects in liver. Therefore, these findings suggest that DINCH may be hazardous to humans and that further investigation is necessary to warrant its safety.
- RNA structure-function analysis of regulatory regions of p53 mRNAPublication . Pereira, Bruna F.; López-Iniesta, Maria; Lacerda, Rafaela; Romão, Luísa; Candeias, Marco M.At least half of all tumors exhibit mutations in the tumor suppressor p53 gene. Indeed, the fact that p53 is frequently mutated in cancer led to its identification as an oncogene, when first described in 1979. Later, it was classified as a tumor suppressor, due to the clarification of its wild-type role in maintaining genome integrity and preventing malignant transformation. The p53 gene can encode for many p53 isoforms, by alternative splicing, alternative promoters and internal translation initiation mechanisms. While full-length p53 (FL-p53) protein works as a tumor suppressor by regulating many biological processes such as cell cycle, apoptosis, senescence and DNA repair, shorter p53 protein isoforms seem to play different roles in the cell. Recently, we have shown that the most common p53 mutations induce the expression of shorter p53 isoforms. Furthermore, we found that shorter p53 isoforms are implicated in cancer progression as they promote enhanced cell survival, proliferation, adhesion and formation of invasive cell structures. Here, with a bicistronic system containing two reporter genes (Renilla luciferase and firefly luciferase), we show that expression of shorter p53 isoforms is mediated by a non-canonical translation initiation mechanism regulated by an Internal Ribosome Entry Site (IRES) in the p53 mRNA. By investigating the effect of common p53 missense mutations on the function of this new IRES, through bioluminescence assays and Western blot analysis, we show that some p53 cancer mutations have a preponderant role in IRES-mediated translation induction of shorter p53 isoforms. With the obtained results we identified a new mechanism by which p53 cancer mutations promote tumorigenesis, which may lead to new understandings of the onset and progression of some types of tumors as well as to the development of new cancer therapies.
- Epidemiology of congenital cerebral anomalies in Europe: a multicentre, population-based EUROCAT studyPublication . Morris, Joan K.; Wellesley, Diana G.; Barisic, Ingeborg; Addor, Marie-Claude; Bergman, Jorieke E.H.; Braz, Paula; Cavero-Carbonell, Clara; Draper, Elizabeth S.; Gatt, Miriam; Haeusler, Martin; Klungsoyr, Kari; Kurinczuk, Jennifer J.; Lelong, Natalie; Luyt, Karen; Lynch, Catherine; O’Mahony, Mary T.; Mokoroa, Olatz; Nelen, Vera; Neville, Amanda J.; Pierini, Anna; Randrianaivo, Hanitra; Rankin, Judith; Rissmann, Anke; Rouget, Florence; Schaub, Bruno; Tucker, David F.; Verellen-Dumoulin, Christine; Wiesel, Awi; Zymak-Zakutnia, Natalia; Lanzoni, Monica; Garne, EsterObjectives: To describe the epidemiology and geographical differences in prevalence of congenital cerebral anomalies in Europe. Design and setting: Congenital cerebral anomalies (International Classification of Diseases, 10th Revision code Q04) recorded in 29 population-based EUROCAT registries conducting surveillance of 1.7 million births per annum (29% of all European births). Participants: All birth outcomes (live births, fetal deaths from 20 weeks gestation and terminations of pregnancy after prenatal diagnosis of a fetal anomaly (TOPFA)) from 2005 to 2014. Main outcome measures: Prevalence, proportion of associated non-cerebral anomalies, prenatal detection rate. Results: 4927 cases with congenital cerebral anomalies were identified; a prevalence (adjusted for under-reporting) of 9.8 (95% CI: 8.5 to 11.2) per 10 000 births. There was a sixfold difference in prevalence across the registries. Registries with higher proportions of prenatal diagnoses had higher prevalence. Overall, 55% of all cases were liveborn, 3% were fetal deaths and 41% resulted in TOPFA. Forty-eight per cent of all cases were an isolated cerebral anomaly, 25% had associated non-cerebral anomalies and 27% were chromosomal or part of a syndrome (genetic or teratogenic). The prevalence excluding genetic or chromosomal conditions increased by 2.4% per annum (95% CI: 1.3% to 3.5%), with the increases occurring only for congenital malformations of the corpus callosum (3.0% per annum) and 'other reduction deformities of the brain' (2.8% per annum). Conclusions: Only half of the cases were isolated cerebral anomalies. Improved prenatal and postnatal diagnosis may account for the increase in prevalence of congenital cerebral anomalies from 2005 to 2014. However, major differences in prevalence remain between regions.
- Multi-Network approach to predict new proteins involved in NMDPublication . Nogueira, Gonçalo; Pinto, Francisco; Romão, LuísaThe mechanism of nonsense-mediated decay (NMD) selectively degrades mRNAs carrying a premature translation-termination codon and regulates the abundance of a large number of physiological mRNAs that encode full-length proteins. Although this complex process has been extensively studied along the years, the interactions and connectivity among NMD players is not completely understood. Additionally, some NMD mechanistical aspects suggest missing roles that can be played by proteins still not reported as involved in this pathway. To tackle this hypothesis, we developed a bioinformatic network-based approach to predict new proteins involved in NMD. Our approach consists in performing several queries to different types of publicly available data, in order to explore the ability of proteins to bridge related processes, while integrating data regarding protein-protein interactions, co-expression and co-regulation. We found that known NMD-factors have physical, regulatory and co-expression interaction signatures with related processes (mRNA translation, mRNA splicing, mRNA degradation and mRNA transport), which can be used to distinguish them from other proteins. We computed a scoring algorithm to rank NMD-neighbors according to the similarity to these signatures, generating a list of NMD candidates, that we aim to validate experimentally. Interestingly, some candidates were recently studied in NMD context and showed promising results. Furthermore, a cross-validation analysis indicated the robustness of the predictions provided by our method. On the road to developing a tool to apply this approach to other biological processes, we observed good cross-validations results for other RNA-related processes, suggesting this method’s usefulness in the RNA research area.