Browsing by Issue Date, starting with "2010-12"
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- Fragile X Syndrome: Genetic BackgroudsPublication . Loureiro, Joana; Marques, Isabel; Oliveira, Bárbara; Amorim, António; Santos, Rosário; Jorge, PaulaFragile X Syndrome (FXS) is the most frequent hereditary form of mental retardation, caused by an expansion of polymorphic [CGG] repeats in the 5’UTR region of the FMR1 gene; the molecular mechanism of this expansion is, however, still unknown. Based on [CGG] triplet number, three allele classes can be distinguished: normal sized-alleles (5-50 repeats); pre-mutation alleles (50-200 repeats) and the full mutation where alleles have an expansion of over 200 CGG repeats. Previous studies using Short Tandem Repeat (STR) haplotypes of mutant chromosomes in diverse populations revealed founder effects based on linkage disequilibrium between CGG repeats and flanking molecular markers.
- Relatório REVIVE 2010 - Culicídeos (excerto) : Programa Nacional de Vigilância de Vectores CulicídeosPublication . Centro de Estudos de Vetores e Doenças Infecciosas Doutor Francisco Cambournac; Alves, Maria João; Osório, Hugo; Zé-Zé, Líbia; Amaro, Fátima
- Estudo molecular de Epilepsia Mioclónica Progressiva de Unverritch -LundborgPublication . Pinto, Eugénia; Amaral, Olga; Santos, ManuelThe Progressive Myoclonus Epilepsies (PME) are associated to an heterogeneous group of rare metabolic diseases. They are clinically marked by myoclonic, tonic-clonic episodes and progressive neurological decline, with ataxia and dementia. One of the major causes of PME is the Unverricht- Lundborg disease (EPM1, MIM 254800), an autosomal recessive disorder, caused by loss of function mutations in the cystatin B gene (CSTB). The onset of the symptoms is around the age of 10 yr. and is marked by convulsions. The EPM1 diagnostic is done through a differential diagnostic, first at a clinical level, and being confirmed at a genetic level. The main objective of this work is the implementation of the genetic study and applied research in EPM1. Since EPM1 is a rare disease without laboratory diagnostic in Portugal its real impact at the level of public health is unknown, the methods developed in this thesis will give the possibility of confirming/excluding clinical suspicion of EPM1, and allow the characterization of the patients. The results obtained have permitted the initiation of the study of CSTB, in instances where there was a suspicion of EPM1. It became possible to confirm a case of a patient suspect of having the EPM1, as well as making the evaluation of some polymorphisms present in our population. The new mutation, found and characterized in this work, is a point mutation, apparently silent (p.Q22Q), which alters the normal splicing pattern resulting in partial retention of the intronic sequence and subsequently leading to loss of function. These results show the need for making a non directional approach, doing a comprehensive study of the CSTB gene and complementing the gDNA study with the cDNA one. The study of this disease at the molecular biology level, may contribute to the evaluation and characterization of this pathology as far as its mutations and, at same time, it may contribute for a better understanding of its pathophysiology.
- Coinfections of Rickettsia slovaca and Rickettsia helvetica with Borrelia lusitaniae in ticks collected in a Safari Park, PortugalPublication . Milhano, Natacha; Carvalho, Isabel Lopes de; Alves, Ana Sofia; Arroube, Sofia; Soares, Jorge; Rodriguez, Pablo; Carolino, Manuela; Núncio, Maria Sofia; Piesman, Joseph; Sousa, Rita deBorrelia and Rickettsia bacteria are the most important tick-borne agents causing disease in Portugal. Identification and characterization of these circulating agents, mainly in recreational areas, is crucial for the development of preventive measures in response to the gradually increasing exposure of humans to tick vectors. A total of 677 questing ticks including Dermacentor marginatus, Rhipicephalus sanguineus, Ixodes ricinus, Hyalomma lusitanicum, H. marginatum, and Haemaphysalis punctata were collected in a Safari Park in Alentejo, Portugal, to investigate the prevalences of infection and characterize Borrelia and Rickettsia species. From a total of 371 ticks tested by PCR for Borrelia burgdorferi sensu lato (s.l.), of which 247 were tested for Rickettsia, an infection prevalence of 18.3% was found for B. lusitaniae and 55.1% for Rickettsia spp. Sequence analysis of positive amplicons identified the presence of B. lusitaniae (18.3%), R. monacensis strain IRS3 (51.7%), and R. helvetica (48.3%) in I. ricinus. R. slovaca (41.5%), R. raoultii (58.5%), and also B. lusitaniae (21%) were identified in D. marginatus ticks. One (5.9%) H. lusitanicum was infected with B. lusitaniae, and R. massiliae was found in one Rhipicephalus sanguineus. Coinfection was found in 7 (20%) I. ricinus and 34 (23.3%) D. marginatus ticks. We report, for the first time, simultaneous infection with R. helvetica and B. lusitaniae and also R. slovaca, the agent of TIBOLA/DEBONEL, with B. lusitaniae. Additionally, 6 isolates of B. lusitaniae were established, and isolates of Rickettsia were also obtained for the detected species using tick macerates cultured in mammalian and mosquito cell lines. This report describes the detection and isolation of tick-borne agents from a Portuguese Safari Park, highlighting the increased likelihood of infection with multiple agents to potential visitors or staff.
- Plant natural variability may affect safety assessment dataPublication . Batista, Rita; Oliveira, MargaridaBefore market introduction, genetic engineered (GE) food products, like any other novel food product, are subjected to extensive assessment of their potential effects on human health. In recent years, a number of profiling technologies have been explored aiming to increase the probability of detecting any unpredictable unintended effect and, consequently improving the efficiency of GE food safety assessment. These techniques still present limitations associated with the interpretation of the observed differences with respect to their biological relevance and toxicological significance. In order to address this issue, in this study, we have performed 2D-gel electrophoresis of five different ears of five different MON810 maize plants and of other five of the non-transgenic near-isogenic line. We have also performed 2D-gel electrophoresis of the pool of the five protein extractions of MON810 and control lines. We have notice that, in this example, the exclusive use of data from 2D-electrophoresed pooled samples, to compare these two lines, would be insufficient for an adequate safety evaluation. We conclude that, when using ‘‘omics” technologies, it is extremely important to eliminate all potential differences due to factors not related to the ones under study, and to understand the role of natural plant-to-plant variability in the encountered differences.
- ADELIA–Acidentes Domésticos e de Lazer: Informação Adequada : relatório 2006-2008Publication . Contreiras, Teresa; Rodrigues, Emanuel; Nunes, BaltazarO sistema ADELIA, criado em 2000, é coordenado pelo Departamento de Epidemiologia deste Instituto e visa determinar frequências e tendências dos ADL, as características das vítimas, das situações e dos agentes envolvidos, e identificar situações de risco e produtos perigosos com vista a apoiar a definição de políticas de prevenção baseadas na evidência. Da análise descritiva dos dados recolhidos durante os anos de 2006 a 2008, destaca-se: A distribuição percentual dos ADL por sexo em cada um dos grupos etários mostra que a % de ADL é mais elevada até ao grupo etário 35-44 anos nos homens e a partir deste grupo etário os ADL são mais frequentes nas mulheres Salienta-se como tipo de lesão mais frequente a "concussão, contusão e hematoma". O mecanismo de lesão mais referido foi a "Queda", tendo revelado um acréscimo entre 2006 e 2008 de 7,8%. Este mecanismo foi, também, o mais prevalente em todos os grupos etários. Cerca de 4,4% (2008) dos ADL têm como consequência "Internamento". Destes o grupo etário acima dos 75 anos apresenta o maior valor percentual: 10,8% (2006), 11,1% (2007) e 12,5 %(2008). O sistema ADELIA assenta na adesão voluntária dos participantes.
- Fragile X Mental Retardation Protein: broadening the possibilities for studying Fragile X SyndromePublication . Oliveira, Bárbara; Marques, Isabel; Loureiro, Joana; Santos, Rosário; Jorge, PaulaThe presence of chromosomal fragility in locus FRAXA, located at Xq27.3, is directly related with Fragile X Syndrome (FXS), where the main symptoms include intellectual and emotional disabilities. The main cause of this monogenic disorder is the transcriptional silencing of the FMR1 gene, due to an expansion of more than 200 CGG repeats, found in the 5’-untranslated region, and its consequent hypermethylation which extends to the promoter region. The diagnostic complexity of FXS is proportional to the heterogeneity underlying this disease. In situations that strongly suggest a clinical diagnosis of FXS, but in which the repetitive region is not expanded, studying the presence of the encoded protein has proved to be very helpful as a complement to the molecular diagnosis. The Fragile X Mental Retardation Protein (FMRP), a selective RNA-binding protein that negatively regulates local protein synthesis in neuronal dendrites, may be detected applying specific antibodies either by immunocytochemistry or Western Blot analysis. The aim of the present work was to optimize such techniques, so as to complement the routine molecular procedures employed in prenatal and postnatal FXS diagnosis. In order to test the efficacy of the procedure, different types of biological samples were used, namely leukocytes from peripheral blood, human brain tissue, cultured amniocytes and chorionic villi. Additionally, slide preparation and detection method for immunocytochemistry, as well as protein isolation for Western Blot, were optimized resorting to several approaches. Both immunocytochemistry and Western Blot techniques allowed the detection of FMRP and were equally suitable. The advantages and disadvantages of the implementation of these techniques in terms of laboratory workflow and specimen type as well as in diagnostic and research context are discussed herein.
- Óbitos por gripe pandémica A (H1N1) 2009 em Portugal Período de Abril de 2009 a Março de 2010Publication . Froes, Filipe; Diniz, António; Falcão, Isabel; Nunes, Baltazar; Catarino, JuditeProcedeu-se à análise dos 124 óbitos notificados em Portugal por gripe pandémica A (H1N1) 2009 no período de Abril de 2009 a Março de 2010. A taxa de mortalidade estimada foi de 1,17/100.000 habitantes. Cerca de 60% dos falecidos eram do sexo masculino, a idade média foi de 47,6 anos e 66,7% apresentavam, pelo menos, um factor de risco para doença grave. As doenças pulmonar e cardíaca crónicas foram os factores de risco mais prevalentes, identificados em 24,7% e 20,7% dos casos, respectivamente. Mais de ¾ dos doentes foram internados em Unidades de Cuidados Intensivos (UCI). A pneumonia viral primária foi a principal causa de morte, diagnosticada em 79,7% dos doentes. Constatou-se haver diferença estatisticamente significativa em relação à distribuição da causa de morte nos grupos dos indivíduos com e sem factores de risco (p=0.048). Estimaram-se em 2 853 os anos potenciais de vida perdidos, o que equivale a 30,8 anos por 100.000 habitantes. Os valores encontrados são comparáveis, na generalidade, com os encontrados noutros países com o mesmo nível de desenvolvimento. Em futuras circunstâncias semelhantes deverá ser equacionada a notificação obrigatória dos casos de maior gravidade.
- Schistosoma haematobium: identification of new estrogenic molecules with estradiol antagonistic activity and ability to inactivate estrogen receptor in mammalian cellsPublication . Botelho, Mónica Catarina; Soares, Raquel; Vale, Nuno; Ribeiro, Ricardo; Camilo, Vânia; Almeida, Raquel; Medeiros, Rui; Gomes, Paula; Machado, José Carlos; Costa, José Manuel Correia daWe have previously identified the expression of an estradiol (E2)-related molecule by Schistosoma haematobium total antigen (Sh). We now show that this molecule has an antagonistic effect of estradiol in vitro. Our results are consistent with the existence of an estrogenic molecule that antagonizes the activity of estradiol. We found evidence for this molecule as we identified and characterized by mass spectrometry new estrogenic molecules previously unknown, present in schistosome worm extracts and sera of Schistosoma-infected individuals. We also show that Sh is able to interact in vitro with estrogen receptor (ER), explaining how host endocrine system can favor the establishment of schistosomes. These findings highlight the exploitation of the host endocrine system by schistosomes and represent an additional regulatory component of schistosome development that defines a novel paradigm enabling host–parasite interactions. The identification of these molecules opens new ways for the development of alternative drugs to treat schistosomiasis.
- Quality control materials development for proximate composition determination in baby foods to enhance the Portuguese food composition database: Packaging conditionsPublication . Castanheira, I.; António, C.; Mota, C.; André, C.; Sanches-Silva, A.Food matrix reference materials play an important role in the quality of data used in food composition databanks concerning the precision, trueness and accuracy of analytical values. In this work the feasibility studies according to ISO 34 (ISO, 2000) of two commercial baby foods (ready-to-eat baby soup and milk-based powdered infant formula) were evaluated to check for their suitability as quality control materials for the analysis of moisture, protein, fat, ash and acidity. The suitability of plastic packaging materials to guarantee the reference materials’ characteristics is discussed. Official methods of analysis were used to evaluate the homogeneity and to monitor short-term and long-term stability studies. ANOVA was carried out to confirm homogeneity within and between samples. ISO 34 method was applied to monitor stability at different temperatures. The coefficients of variation obtained between sachets for milk-based powdered infant formula were less than 4.4% for moisture and 0.5% for fat. The stability data over 8.5 months storage period at 20 8C, 5 8C and 20 8C and 70 8C indicate that both materials are stable depending on the parameter studied and temperature. According to results, quality control materials (QCMs) prepared in agreement with ISO 34 requirements are a valuable tool in food composition analysis.