Browsing by Issue Date, starting with "2011-06"
Now showing 1 - 10 of 52
Results Per Page
Sort Options
- A rare de novo unbalanced complex rearrangement involving chromosomes 12, 18 and 20 in a child with dysmorphic featuresPublication . Alves, Cristina; Marques, Bárbara; Brito, Filomena; Silva, Marisa; Rodrigues, Rosário; Duarte, Guida; Sousa, Ana Berta; Bicho, Anabela; Correia, HildebertoComplex chromosomal rearrangements (CCRs) are rare structural abnormalities that involve three or more breakpoints located on two or more chromosomes and are often associated with developmental delay, mental retardation and congenital anomalies. Here, we report the case of a rare de novo CCR in a girl who was 9 months old when first reported to us. At 15 months old, her clinical features included marked hypotonia, severe psychomotor delay, progressive postnatal microcephaly, strabismus, depressed nasal root, hands and feet malformations, heart defects, recurrent respiratory infections and bilateral hearing deficit still in study. Conventional cytogenetic analysis revealed an unbalanced complex rearrangement, involving chromosomes 12, 18 and 20, and an apparent loss of material of chromosome 18 resulting from an interstitial deletion. Further molecular cytogenetic studies were performed: whole chromosome painting probes for the involved chromosomes and chromosomal comparative genomic hybridization. These studies revealed that apparently no other chromosomes were involved and confirmed a del(18)(q21.1q22) of approximately 17 Mb on the derivative chromosome 18. The latter chromosome also had material from der(12) to der(20) in its constitution. As most CCRs involving chromosome 18q show rearrangements in the q21, some authors argue that this region might be a breakpoint “hotspot”. On the other hand, cases of single deletions on 18q are predominantly terminal. Interstitial deletions are much rarer, and to our knowledge, this is the first report of a CCR with a del(18)(q21.1q22). The phenotype of patients with deletions within this region, reported so far, seems very similar to the one of our patient, and this may contribute to a better understanding of the genotype–phenotype correlation in this type of structural abnormalities.
- Tuberculosis: new aspects of an old diseasePublication . Jordão, Luísa; Vieira, Otilia V.Tuberculosis is an ancient infectious disease that remains a threat for public health around the world. Although the etiological agent as well as tuberculosis pathogenesis is well known, the molecular mechanisms underlying the host defense to the bacilli remain elusive. In this paper we focus on the innate immunity of this disease reviewing well-established and consensual mechanisms like Mycobacterium tuberculosis interference with phagosomematuration, less consensual mechanism like nitric oxide production, and new mechanisms, such as mycobacteria translocation to the cytosol, autophagy, and apoptosis/necrosis proposed mainly during the last decade.
- Milder phenotype of relatives of index patients can misdiagnose Familial HypercholesterolemiaPublication . Medeiros, A.M.; Alves, A.C.; Bourbon, M.Familial Hypercholesterolemia (FH) is a genetic disorder characterized by high levels of LDLc in plasma, accelerated atherosclerosis and increased risk of premature coronary heart disease (pCHD). FH results from mutations in three genes involved in lipid metabolism: LDLR, APOB, PCSK9. It is known that FH patients’ phenotype is heterogeneous varying with different conditions, as gene and type of mutation. The present study pretends to characterize the biochemical profile of FH patients genetically identified in Portugal. The Portuguese FH Study identified 420 patients: 182 index (60 children, 122 adults) and 238 relatives (56 children, 182 adults) with a genetic defect. Biochemical parameters (total cholesterol (TC), LDLc, HDLc, triglycerides, ApoB, ApoAI) were analyzed with SPSS software using ANOVA tests. TC and LDLc levels are statistically higher in index patients than in relatives identified in cascade screening: index children, TC=315.96±61.51mg/dl and LDLc=239.61±60.43mg/dl vs TC=277.52±66.40mg/dl and LDLc=209.05±53.44mg/dl for relatives children (p=0.002, p=0.014); index adults TC=369.56±78.94mg/dl and LDLc=287.72±78.93mg/dl vs TC=332.93±75.54mg/dl and LDLc=246.26±71.79mg/dl for relatives adults (p<0.001, p=0.001). Although CT and LDLc mean values are above FH criteria a considered number of relatives have both TC and LDLc bellow these values (16%). Only 40% of relatives adults genetically identified are in treatment and 13% have pCHD vs 79% of index adults in treatment and 25% have pCHD. Genetic diagnosis of FH in Portugal allows early identification of FH patients, in particular relatives with mild phenotype that would not be identified by clinical criteria alone, allowing early implementation of therapeutic measures that will reduce their cardiovascular risk.
- Ultra-high Pressure LC Method to Determine Astaxanthin in Shrimp By-Products and Migration Evaluation from an Active Plastic Film Produced with Shrimp Waste to Fatty Food SimulantsPublication . Sanches-Silva, A.; Ribeiro, T.; Paseiro, P.; Sendón, R.; Rodriguéz- Bernaldo de Quirós, A.; López-Cervantes, J.; Sánchez-Machado, D.I.; Soto-Valdez, H.; Angulo, I.; Aurrekoetxea, G.; Costa, H.S.Carotenoids have antioxidant properties allowing protection of tissues from oxidative damages and they are also beneficial in cardiovascular, immune, inflammatory and neurodegenerative diseases. Astaxanthin (3,3’-dihydroxy-β-β´-carotene-4-4´-dione) is a carotenoid classified as xanthophyl and it is one of the major carotenoids in crustaceans. The project ‘Preparation of active packaging with antioxidant and antimicrobial activity based on astaxanthin and chitosan’ aims to develop a methodology for the incorporation of compounds obtained from shrimp waste in plastic matrices for the development of an active packaging with antimicrobial and antioxidant properties. In the frame of this project, shrimp by-products were fermented and the silage was centrifuged. Three fractions were obtained and the upper phase, corresponding to the lipid fraction, was further analysed to determine astaxanthin content. The aim of the present work was to optimize a method to determine astaxanthin as well as seven other carotenoids and two vitamins (A and E) by ultra-high pressure liquid chromatography (Ultra Performance Liquid Chromatography, UPLC) with diode array detection (DAD) method in shrimp by-products. The chromatographic separation is achieved using a vanguard pre-column (UPLCÒ BEH, 1.7 µm particle size) and a column (UPLCÒ BEH, 2.1 x 50 mm, 1.7 µm particle size) at 20 °C. The mobile phase is a gradient of A (dichoromethane/methanol with ammonium acetate/acetonitrile 5:20:75 (v/v)) and B (ultrapure water) with a flow rate of 0.5 mL/min. The optimized UPLC method allows excellent peaks separation. Shrimp by-products (lipid fraction of shrimp waste, head and shell of cooked and raw shrimp) have been analysed. Moreover, low density polyethylene plastic films produced by extrusion with different amount of the lipid fraction of shrimp waste were prepared and tested regarding migration into fatty food simulants. Migration tests were carried out with isooctane and ethanol 95% (v/v), both alternative fatty food simulants. No migration was detected at the conditions tested, which are conventionally considered the most severe when the food contact material is intended for use at room temperature.
- Influence of APOE genotype in the phenotype of clinical diagnosed Portuguese FH patientsPublication . Medeiros, A.M.; Santos, T.; Alves, A.C.; Bourbon, M.APOE gene is polymorphic, comprises three frequent alleles (e2, e3, e4) which create six different genotypes and six protein isoforms with different affinity to LDLR. Isoform E2 has less affinity to receptor while isoform E4 have much efficient bond and compete with apoB. The present study pretends to evaluate the distribution of APOE alleles/genotype of index patients with clinical diagnosis of Familial Hypercholesterolemia (FH) and investigate if a specific allele/genotype is cause of hypercholesterolemia. APOE genotyping was performed using SnaPShot Multiplex System after PCR amplification. Biochemical parameters were determined by routine methods and results were analyzed with SPSS software using t- test. For this analysis, children and adults were divided according to their genetic diagnosis. Total of 353 patients were analyzed: 140 patients with mutation in LDLR, APOB or PCSK9 (44 children (G1), 96 adults (G2)) and 213 without a detectable mutation (70 children (G3), 143 adults (G4). Distribution of 6 genotypes (E2/E2, E2/E3, E2/E4, E3/E3, E3/E4, E4/E4) was as following: G1, 0%, 2.3%, 4.5%, 68.2%, 20.5%, 4.5%; G2, 1.0%, 1.0%, 4.2%, 62.5%, 28.1%, 3.1%; G3, 0%, 1.4%, 5.7%, 55.7%, 35.7%, 1.4%; G4, 0%, 1.4%, 5.6%, 63.5%, 25.9%, 3.5%. Statistical analysis revealed that presence of at least one e4 is associated with high levels of LDLc in G3/G4 patients (LDLcG3=182.96±49.46mg/dl, (e4/eX, X=2,3,4) vs LDLcG3=152.65±60.60mg/dl (eY/eZ, Y,Z=2,3), p=0.025; LDLcG4=227.69±43.17mg/dl, (e4/eX, X=2,3,4) vs LDLcG4=179.70±64.78mg/dl (eY/eZ, Y,Z=2,3), p<0.001)) but not in G1/G2 patients (p=0.100, p=0.832). Presence of e4 can be the cause of hypercholesterolemia presented by patients without genetic diagnosis of FH.
- Investigação em saúde pública: precisa-se!Publication . Pereira Miguel, José
- Complete sequencing by Pyrosequencing of APOB gene of patients with clinical diagnosis of Familial HypercholesterolaemiaPublication . Alves, A.C.; Bourbon, M.Familial hypercholesterolemia (FH) is a monogenic condition caused in most cases by mutations in LDLR gene, but mutations in APOB and PCSK9 genes are also cause of FH. These 3 genes are currently studied in the “Portuguese FH Study”. From the 404 families with a clinical diagnosis of FH studied, only 48% of these have a detectable mutation in the 3 genes mention above so, other mutations in these genes or other gene defects must exist to explain the cause of hypercholesterolemia in the remaining families. The main aim of this project was the whole sequencing of APOB gene, in 65 index patients with clinical diagnosis of FH, without mutations in LDLR gene or in fragments of exon 26 and 29 of APOB gene, by pyrosequencing, in order to identify the genetic cause of the hypercholesterolemia in these patients. A pool of the 65 DNAs was sequenced by pyrosequecing method and a total of 227688 nucleotide reads were obtained, corresponding to a mean coverage of 35x/fragment/individual. The results obtained included the detection of 87 alterations, being 27 previously described SNPs. All patients were re-sequenced for the fragments containing exons 26 and 29 alterations identified by this method. From the 26 alterations detected in these exons, only 12 were found and four of these had not been previously described. After family studies only one alteration did not co-segregate in the family, providing further evidence that 3 of the alterations found can be mutations causing disease but, functional studies are required to prove pathogenicity. Pyrosequencing allows the rapid sequencing of a large number of individuals, but apart from its high cost, it has some limitations and requires an improvement of technique.
- Childhood Obesity Surveillance Initiative- COSI Portugal 2008Publication . Rito, Ana IsabelA obesidade infantil apresenta-se como um dos mais sérios problemas de saúde pública, quer no espaço Europeu, quer no resto do mundo. A taxa de crescimento desta doença tem-se mantido constante, acrescentando 400,000 crianças por ano, aos já existentes 45 milhões de crianças com excesso de peso. A Organização Mundial da Saúde (OMS), no seguimento da aprovação da Carta Europeia de Luta Contra a Obesidade1, lançou uma iniciativa a pedido dos Estados-Membros da Região Europeia com a intenção de instalar um sistema de vigilância da obesidade infantil. O WHO - European Childhood Obesity Surveillance Initiative, constitui o primeiro Sistema Europeu de Vigilância Nutricional Infantil. Portugal assumiu a coordenação Europeia desta iniciativa e a nível nacional este estudo denomina-se “COSI – Portugal". Sendo Portugal um dos países com maior prevalência de obesidade infantil com a morbilidade e mortalidade associada e ainda os elevados custos que a determinam, o combate a esta doença e a sua prevenção constituem-se como uma prioridade política, nomeadamente do Ministério da Saúde. Neste contexto, houve a necessidade de se estabelecer a implementação de um sistema de vigilância simples, padronizado, harmonizado e sustentável constituindo uma medida claramente importante para corrigir a lacuna que existe na obtenção de informação sobre o estado nutricional e avaliação e monitorização da prevalência de obesidade em crianças, permitindo também identificar grupos em risco. O COSI Portugal tem como principal objectivo criar uma rede de informação sistemática (a cada 2 anos) comparável entre os países da Europa, sobre as características do estado nutricional infantil de crianças dos 6 aos 10 anos. No primeiro ano de avaliação (2007/2008) participaram 13 países dos 22 inscritos. Em Portugal este projecto foi articulado com as Administrações Regionais de Saúde do Norte, Centro, Lisboa e Vale do Tejo, Algarve, Alentejo e com as Direcções Regionais de Saúde dos Açores e da Madeira. De acordo com a listagem oficial das escolas do 1º ciclo do Ensino Básico (2007/2008) do Ministério de Educação, foi seleccionada uma amostra representativa nacional. O estudo em questão baseia-se no modelo da epidemiologia descritiva do tipo transversal, tendo sido avaliadas 3765 crianças dos 6 aos 8 anos (média de idades: 7,0 anos ± 0,7) do 1ºano e 2º ano de 181 escolas. A metodologia aplicada seguiu o protocolo comum a todos os países participantes. As crianças foram avaliadas através de parâmetros antropométricos (peso e estatura) por 74 examinadores que receberam o mesmo treino de uniformização e qualidade de procedimentos. Para a classificação do estado nutricional foram utilizados os 3 critérios internacionalmente reconhecidos (IOTF2, CDC3 e OMS4). Foram ainda aplicados mais dois questionários compreendo variáveis relativas à família e ao ambiente escolar. É de notar que a participação neste estudo foi superior a 80% dos inicialmente inscritos, designadamente 95,8% de escolas; 81,9% de crianças e 83,8% de famílias. Principais Resultados • A prevalência de baixo peso das 3765 crianças portuguesas dos 6 aos 8 anos de idade das 181 escolas do 1.º ciclo do Ensino Básico das sete Regiões de Portugal participantes do estudo foi de 2,1% (IMC
- Update of the biochemical and molecular results of Portuguese patients with Familial Combined HyperlipidaemiaPublication . Santos, T.; Rato, Q.; Gaspar, I.M.; Rico, M.T.; Silva, J.M.; Bourbon, M.FCHL is a complex disorder with a highly atherogenic profile. The aim of this study is the biochemical/molecular characterization of FCHL patients. Molecular study of LPL, APOAIV, APOAV, APOCIII and USF1 (s1,s2) was performed in 35 index patients by PCR amplification and sequencing. Total cholesterol (TC), HDL-c, sdLDL, triglycerides (TG), apoB and apoCIII were measured in automated analysers. sdLDL was also analysed by electrophoresis with Lipoprint®. ApoAIV and ApoAV were measured by ELISA. For all patients, biochemical characterization of apolipoproteins and sdLDL before treatment was not possible to determine. Prior to medication the levels of TC (305±62mg/dL) and TG (380±269mg/dL) were high but HDL-c was normal (44±11mg/dL). Even under medication these patients presented high levels of CT (205±58mg/dL), TG (233±109mg/dL) and ApoCIII (15±4mg/dL) and normal levels of HDL-c (44±9mg/dL). ApoAIV (17±10mg/dL), ApoAV (156±140ng/mL) and ApoB (89±41mg/dL) levels were within normal range in majority of cases. Lipoprint® analysis of 8 patients under medication revealed an atherogenic pattern. Two new alterations were found. One patient with TC=271mg/dl and TG=275mg/dL carried APOAIV Q359_E362 (values without medication). Another patient with TC=419mg/dL and TG=1095mg/dL presented APOAV D332fsX336 and, even under medication, had high sdLDL (39 mg/dL, cut-off value 35mg/dl) and an atherogenic pattern with Lipoprint® analysis (pattern B). Some patients had a novel alteration APOCIII 3269C>A that was proven later that was a polymorphism. Patients with FCHL have increased cardiovascular risk that can be prevented with an early genetic identification and an extensive biochemical characterization that can be important to evaluate the efficacy of treatment.