Browsing by Issue Date, starting with "2013-07"
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- Diagnóstico da infeção por vírus da hepatite E no INSA, 2000-2012Publication . Ferreira, Carla Manita; Santos, João Almeida; Lourenço, Teresa; Benoliel, Camalavati; Matos, Rita; Martins, Helena Cortes
- Control of cystic fibrosis transmembrane conductance regulator membrane trafficking: not just from the endoplasmic reticulum to the GolgiPublication . Farinha, Carlos; Matos, Paulo; Amaral, MargardiaBiogenesis of cystic fibrosis transmembrane conductance regulator (CFTR) starts with its cotranslational insertion into the membrane of the endoplasmic reticulum (ER) and core glycosylation. These initial events are followed by a complex succession of steps with the main goal of checking the overall quality of CFTR conformation in order to promote its exit from the ER through the secretory pathway. Failure to pass the various checkpoints of the ER quality control targets the most frequent disease-causing mutant protein (F508del-CFTR) for premature degradation. For wild-type CFTR that exits the ER, trafficking through the Golgi is the major site for glycan processing, although nonconventional trafficking pathways have also been described for CFTR. Once CFTR is at the cell surface, its stability is also controlled by multiple protein interactors, including Rab proteins, Rho small GTPases, and PDZ proteins. These regulate not only anterograde trafficking to the cell surface, but also endocytosis and recycling, thus achieving fine and tight modulation of CFTR plasma membrane levels. Exciting recent data have related autophagy and epithelial differentiation to the regulation of CFTR trafficking. Herein, we review the various checkpoints of the complex quality control along the secretory trafficking pathway and the associated pathways that are starting to be explored for the benefit of cystic fibrosis patients.
- Boletim Epidemiológico Observações: Vol. 2, Nº5, jul-set 2013Publication . Instituto Nacional de Saúde Doutor Ricardo JorgeObservações é uma publicação que visa contribuir para o conhecimento da saúde da população, os fatores que a influenciam, a decisão e a intervenção em Saúde Pública, assim como a avaliação do seu impacte na população portuguesa. Através do acesso público e gratuito a resultados científicos gerados por atividades de observação em saúde, monitorização e vigilância epidemiológica, é dada especial atenção à disseminação rápida de informação relevante para a resposta a temas de relevo para a saúde da população portuguesa, tendo como alvo todos os profissionais, investigadores e decisores intervenientes na área da Saúde Pública em Portugal.
- Estudos de especiação de arsénio em arrozPublication . Coelho, Inês; Gueifão, Sandra; Pinto, Tânia; Castanheira, Isabel
- Avaliação da qualidade de águas subterrâneas: estudo de alguns parâmetros físico-químicosPublication . Mansilha, Catarina; Rebelo, Helena
- In vitro culture is the major contributing factor for transgenic vs. non-transgenic proteomic plant differencesPublication . Fonseca, Cátia; Planchon, Sébastien; Serra, Tânia; Chander, Subhash; Saibo, Nelson; Renaut, Jenny; Oliveira, M.Margarida; Batista, RitaThe identification of similarities and differences between genetically modified plants and derived food/feed and their comparators plays a central role in risk assessment strategy. Our main goal was to better understand the relevance of transgene presence, genetic and epigenetic changes promoted by transgene insertion and in vitro culture in the potential unintended effects/differences between transgenic and conventional counterparts. In order to achieve this goal we have used Multiplex fluorescence 2D gel electrophoresis technology coupled with MS to characterize the proteome of three different rice lines (Oryza sativa L. ssp. japonica cv. Nipponbare): a control conventional counterpart, an Agrobacterium-transformed transgenic line (Ta) and a negative segregant (NSb), progeny of a different transgenic line. We have observed that Ta and NSb plant lines grouped together (only 1 differentially regulated spot - fold difference ≥ 1.5), separated from the control (49 spots with fold difference ≥1.5, in both Ta and NSb lines comparing to control line). Since the only feature in common between the tested transgenic and negative segregant lines is that they have both suffered in vitro culture procedures we hypothesised that stress caused by in vitro culture was, in this case, the most relevant factor contributing for the encountered proteomic differences. MS identifications of differentially regulated spots supported our hypothesis, demonstrating that Ta and NSb rice lines present several adjusted metabolic pathways and several proteins with altered expression that were previously associated with plant stress response.
- Phenotype and genotype in 101 males with X-linked creatine transporter deficiencyPublication . van de Kamp, J.M.; Betsalel, O.T.; Mercimek-Mahmutoglu, S.; Abulhoul, L.; Grünewald, S.; Anselm, I.; Azzouz, H.; Bratkovic, D.; de Brouwer, A.; Hamel, B.; Kleefstra, T.; Yntema, H.; Campistol, J.; Vilaseca, M.A.; Cheillan, D.; D'Hooghe, M.; Diogo, L.; Garcia, P.; Valongo, C.; Fonseca, M.; Frints, S.; Wilcken, B.; von der Haar, S.; Meijers-Heijboer, H.E.; Hofstede, F.; Johnson, D.; Kant, S.G.; Lion-Francois, L.; Pitelet, G.; Longo, N.; Maat-Kievit, J.A.; Monteiro, J.P.; Munnich, A.; Muntau, A.C.; Nassogne, M.C.; Osaka, H.; Ounap, K.; Pinard, J.M.; Quijano-Roy, S.; Poggenburg, I.; Poplawski, N.; Abdul-Rahman, O.; Ribes, A.; Arias, A.; Yaplito-Lee, J.; Schulze, A.; Schwartz, C.E.; Schwenger, S.; Soares, G.; Sznajer, Y.; Valayannopoulos, V.; Van Esch, H.; Waltz, S.; Wamelink, M.M.; Pouwels, P.J.; Errami, A.; van der Knaap, M.S.; Jakobs, C.; Mancini, G.M.; Salomons, G.S.BACKGROUND: Creatine transporter deficiency is a monogenic cause of X-linked intellectual disability. Since its first description in 2001 several case reports have been published but an overview of phenotype, genotype and phenotype--genotype correlation has been lacking. METHODS: We performed a retrospective study of clinical, biochemical and molecular genetic data of 101 males with X-linked creatine transporter deficiency from 85 families with a pathogenic mutation in the creatine transporter gene (SLC6A8). RESULTS AND CONCLUSIONS: Most patients developed moderate to severe intellectual disability; mild intellectual disability was rare in adult patients. Speech language development was especially delayed but almost a third of the patients were able to speak in sentences. Besides behavioural problems and seizures, mild to moderate motor dysfunction, including extrapyramidal movement abnormalities, and gastrointestinal problems were frequent clinical features. Urinary creatine to creatinine ratio proved to be a reliable screening method besides MR spectroscopy, molecular genetic testing and creatine uptake studies, allowing definition of diagnostic guidelines. A third of patients had a de novo mutation in the SLC6A8 gene. Mothers with an affected son with a de novo mutation should be counselled about a recurrence risk in further pregnancies due to the possibility of low level somatic or germline mosaicism. Missense mutations with residual activity might be associated with a milder phenotype and large deletions extending beyond the 3' end of the SLC6A8 gene with a more severe phenotype. Evaluation of the biochemical phenotype revealed unexpected high creatine levels in cerebrospinal fluid suggesting that the brain is able to synthesise creatine and that the cerebral creatine deficiency is caused by a defect in the reuptake of creatine within the neurones
- Use of the NucliSENS EasyQ HPV Assay in the Management of Cervical Intraepithelial NeoplasiaPublication . Oliveira, Ana; Verdasca, Nuno; Pista, ÂngelaPersistent infection by high-risk human papillomavirus is a necessary cause for cervical cancer. DNA-based human papillomavirus (HPV) assays show high sensitivity but poor specificity in detecting high-grade cervical lesions. Assays detecting mRNA of the oncoproteins E6 and E7 show higher specificity but lack either detection of all high-risk genotypes or the ability to specify the detected genotypes. The aim of this study was to evaluate the clinical performance of the NucliSENS EasyQ HPV assay in comparison with the Hybrid Capture 2 test (HC2) and the CLART Human Papillomavirus 2 assay (CLART), using a clinical cut-off of cervical intraepithelial neoplasia grade 2 or worse. In the 554 studied women, the lowest HPV positivity rate was detected for NucliSENS EasyQ HPV assay (55.1%), while HC2 and CLART showed similar results (HC2: 77.4%; CLART: 78.0%). In comparison with the other tests, the NucliSENS EasyQ HPV assay showed a lower clinical sensitivity (79.3% vs. 96.4% for HC2 and 95.9% for CLART) but a higher clinical specificity (72.6% vs. 42.8% for HC2 and 42.5% for CLART). Detection of E6/E7 mRNA transcripts may provide a higher specificity for cervical intraepithelial neoplasia grade 2 lesions or worse, since the oncogenic potential of HPV infection depends on the over-expression of these two oncoproteins.
- Comparative study on effects of two different types of titanium dioxide nanoparticles on human neuronal cellsPublication . Valdiglesias, V.; Costa, C.; Sharma, V.; Kiliç, G.; Pásaro, E.; Teixeira, João Paulo; Dhawan, A.; Laffon, B.Titanium dioxide (TiO2) are among most frequently used nanoparticles (NPs). They are present in a variety of consumer products, including food industry in which they are employed as an additive. The potential toxic effects of these NPs on mammal cells have been extensively studied. However, studies regarding neurotoxicity and specific effects on neuronal systems are very scarce and, to our knowledge, no studies on human neuronal cells have been reported so far. Therefore, the main objective of this work was to investigate the effects of two types of TiO₂ NPs, with different crystalline structure, on human SHSY5Y neuronal cells. After NPs characterization, a battery of assays was performed to evaluate the viability, cytotoxicity, genotoxicity and oxidative damage in TiO₂ NP-exposed SHSY5Y cells. Results obtained showed that the behaviour of both types of NPs resulted quite comparable. They did not reduce the viability of neuronal cells but were effectively internalized by the cells and induced dose-dependent cell cycle alterations, apoptosis by intrinsic pathway, and genotoxicity not related with double strand break production. Furthermore, all these effects were not associated with oxidative damage production and, consequently, further investigations on the specific mechanisms underlying the effects observed in this study are required.