Browsing by Issue Date, starting with "2008-09"
Now showing 1 - 5 of 5
Results Per Page
Sort Options
- Molecular characterization of Portuguese patients with pathologies related to the lysosomal multienzymatic complex: Sialidosis and GalactosialidosisPublication . Coutinho, Maria Francisca; Lacerda, Lúcia; Prata, Maria João; Ribeiro, Helena; Alves, SandraBackgroung/ Objectives: The functional activity of lysosomal enzymes sialidase, -galactosidase, and N-acetylaminogalacto-6-sulfate in the cell depends on their association in a multienzyme complex with lysosomal carboxipeptidase, cathepsin A. Genetic mutations in any of this complex components results in their functional deficiency causing severe lysosomal storage disorders. Here we study the molecular defects underlying sialidosis (mutaions in sialidase; gene NEU1) and galactosialidosis (mutations in cathepsin A; gene PPGB) in the Portuguese population. Methods: Using gDNA extracted from patient’s fibroblasts, we performed a molecular study of the PPGB and NEU1 genes in the known Portuguese patients with galactosialidosis and sialidosis, respectively. The expression of both genes was determined by qRT-PCR. The effect of each mutation was also analysed at protein levels, through different in silico procedures. Results and Conclusions: On the PPGB gene, we identified two predictably deleterious missense mutations (c.394 G>A -Zhou et al, 1996- and c.254 G>T) and two deletions (c.228-229DelC and c.1075-1076DelT), both of them giving origin to transcripts that lead to the synthesis of truncated non-functional proteins. On the NEU1 gene, we found two novel missense mutations associated to a severe form of the disease (c.700 G>A and c.599 C>T), which, at protein levels, lead to the substitution of two aminoacids localized in a surface region of the molecule, already proposed to be involved in the interface of sialidase binding with cathepsin A (Lukong, 2000). Knowledge about these findings is important to allow carrier detection and molecular diagnostics as well as to understand the genetics of LMC.
- Characterization of influenza A/Fujian/411/2002(H3N2)-like viruses isolated in Portugal between 2003 and 2005Publication . Pechirra, Pedro; Gonçalves, Paulo; Arraiolos, Ana; Coelho, Anabela; Rebelo-de-Andrade, HelenaIn Portugal, influenza surveillance is achieved through the National Influenza Surveillance Programme (NISP), in close collaboration with other European and global surveillance networks. The NISP integrates epidemiological, clinical and virological data based on the information collected by a Network of Sentinel Medical Practitioners and by a network of Emergency Units of Hospitals and Health Care Centres. In this study, genetic and antigenic characterization of influenza A viruses of the A/Fujian/411/2002 lineage, isolated during the 2003/2004 and 2004/2005 influenza winter seasons, in the context of the NISP, are described. Antigenic analysis of A/ Fujian/411/2002-like viruses, first detected and isolated during the 2003/2004 winter season, revealed a close similarity with the reference strains A/Kumamoto/102/2002 and A/Wyoming/ 3/2003. Genetic analysis confirmed this similarity and revealed two different phylogenetic branches. The 2004/2005 influenza A(H3) isolates formed, both antigenic and genetically, a more homogeneous group and were closely related to A/Oslo/807/2004 and A/California/7/2004. During this season, the characterization of the influenza viral strains has shown continuous evolution to variants close related to A/Oslo/807/2004. The majority of amino acid substitutions detected in the haemagglutinin occurred at antigenic sites. This study reflects the contribution of individual countries for the surveillance and knowledge of the molecular epidemiology of the infection, essential for a concerted action towards the global monitoring of the disease. It also reflects the importance of constant monitoring of genetic and antigenic characteristics of circulating influenza strains, which will certainly be a major contribution to the formulation of influenza vaccines.
- Portuguese study of familial dilated cardiomyopathy: the FATIMA studyPublication . Martins, E.; Silva-Cardoso, J.; Bicho, M.; Bourbon, M.; Ceia, F.; Rebocho, M.J.; Moura, B.; Fonseca, C.; Correia, M.J.; Brito, D.; Perdigão, C.; Madeira, H.; Abreu-Lima, C.Dilated cardiomyopathy (DCM) is a myocardial disease, characterized by ventricular dilatation and impaired systolic function, that in more than 30% of cases has a familial or genetic origin. Given its age-dependent penetrance, DCM frequently manifests in adults by signs or symptoms of heart failure, arrhythmias or sudden death. The predominant mode of inheritance is autosomal dominant, and in these cases mutations are identified in genes coding for cytoskeletal, sarcomeric or nuclear envelope proteins. To date, most studies aimed at molecular diagnosis of DCM have been in selected families, or in larger groups of patients, but screening for mutations in a limited number of genes. Consequently, the epidemiology of mutations in familial DCM remains unknown. There is thus a need for multicenter studies, involving screening for a wide range of mutations in several families and in cases of idiopathic DCM. The present article describes the methodology of a multicenter study, aimed at clinical and molecular characterization of familial DCM patients in the Portuguese population.
- Cyanobacterial blooms in natural waters in southern Portugal: a water management perspectivePublication . Galvão, Helena M.; Reis, Margarida P.; Valério, Elisabete; Domingues, Rita B.; Costa, Cristina; Lourenço, Dulce; Condinho, Sílvia; Miguel, Rute; Barbosa, Ana; Gago, Conceição; Faria, Natália; Paulino, Sérgio; Pereira, PauloThis synthesis of 3 studies from 2 regions of southern Portugal (Alentejo and Algarve) was part of a workshop focusing on cyanobacteria held at the SAME 10. The first study monitored impacts of the large Alqueva dam on the Guadiana estuary since 1996, revealing changes in sediment load, nutrient regime and phytoplankton succession. Prior to dam construction, dense cyanobacterial blooms occurred in the upper estuary during summer and fall. After dam construction, chlorophyll concentration, phytoplankton diversity and abundances of cyanobacteria decreased, contrary to predictions. Mycrocystins remained at low levels in the seston and undetectable in water samples, except during summer 2003 when the particulate fraction contained 1 µg l–1, while chlorophyll concentrations and abundances of potentially toxic cyanobacteria remained low. Algarve reservoirs studied since 2001 revealed differences in phytoplankton dynamics. In the western mesotrophic reservoirs (Bravura and Funcho), 40 to 50% of surface samples contained cyanobacterial concentrations of ≥2000 cells ml–1, while over 80% of samples from the eastern oligotrophic reservoirs (Odeleite and Beliche) exceeded this value. Spring blooms were dominated by Oscillatoriales in Odeleite and Beliche and by Chroococcales in Bravura and Funcho. Bloom composition seemed to depend on water temperature and management strategies, while toxin concentrations reflected the increased biomass of toxic species. Finally, phytoplankton communities and microcystin production in 5 Alentejo freshwater reservoirs were studied from May to December 2005 and April to July 2006. Cyanobacterial blooms occurred, with varying intensities, not only during summer but also occasionally in winter. Microcystins were detected in 23% of the samples (n = 51), but without correlation with cyanobacterial biomass. Although Microcystis aeruginosa seemed to be the major producer of microcystins, other potentially toxic species were found. In summary, the varying pattern of cyanobacterial bloom occurrence and toxicity requires a systematic approach to monitoring programs for adequate risk assessment.
- Centro de Saúde Doutor Gonçalves Ferreira - PortoPublication . Instituto Nacional de Saúde Doutor Ricardo Jorge, IPMonografia comemorativa da inauguração das novas instalações.