Browsing by Author "Silva, M"
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- Adenocarcinoma do reto: uma análise retrospetiva dos anos 2005-06Publication . Fernandes, M; Silva, M; Carvalho, C
- Apresentação rara de um tumor torácicoPublication . Bento, L; Melo, R; Liberato, H; Pires, E; Silva, M; Almeida, A; Beptista, M; Santos, S; Rodrigues, F
- Biomarkers and genetic modulators of cerebral vasculopathy in sub-Saharan ancestry children with sickle cell anemiaPublication . Silva, M; Vargas, S; Coelho, A; Ferreira, E; Mendonça, J; Vieira, L; Maia, R; Dias, A; Ferreira, T, et al.We investigated biomarkers and genetic modulators of the cerebral vasculopathy (CV) subphenotype in pediatric sickle cell anemia (SCA) patients of sub-Saharan African ancestry. We found that one VCAM1 promoter haplotype (haplotype 7) and VCAM1 single nucleotide variant rs1409419_T were associated with stroke events, stroke risk, as measured by time-averaged mean of maximum velocity in the middle cerebral artery, and with high serum levels of the hemolysis biomarker lactate dehydrogenase. Furthermore, VCAM-1 ligand coding gene ITGA4 variants rs113276800_A and rs3770138_T showed a positive association with stroke events. An additional positive relationship between a genetic variant and stroke risk was observed for ENPP1 rs1044498_A. Conversely, NOS3 variants were negatively associated with silent cerebral infarct events (VNTR 4b_allele and haplotype V) and CV globally (haplotype VII). The -alpha3.7kb-thal deletion did not show association with CV. However, it was associated with higher red blood cell and neutrophil counts, and lower mean corpuscular volume, mean corpuscular hemoglobin and red cell distribution width. Our results underline the importance of genetic modulators of the CV sub-phenotype and their potential as SCA therapeutic targets. We also propose that a biomarker panel comprising biochemical, hematological, imaging and genetic data would be instrumental for CV prediction, and prevention.
- Cancro gástrico: doença loco-regionalPublication . Vergueiro, MJ; Silva, M; Fiúza, T
- Endoscopic bilio-duodenal bypass: outcomes of primary and revision efficacy of combined metallic stents in malignant duodenal and biliary obstructions.Publication . Canena, J; Coimbra, J; Carvalho, D; Rodrigues, C; Silva, M; Costa, M; Horta, D; Dias, A; Seves, I; Ramos, G; Ricardo, L; Coutinho, A; Romão, C; Veiga, PBACKGROUND: Self-expandable metal stents (SEMSs) can be used for palliation of combined malignant biliary and duodenal obstructions. However, the results of the concomitant stent placement for the duration of the patients' lives, as well as the need for and efficacy of endoscopic revision, are unclear. AIM: This study evaluated the clinical effectiveness of SEMS placement for combined biliary and duodenal obstructions throughout the patients' lives and the need for endoscopic revision. METHODS: This study is a retrospective multicenter study of 50 consecutive patients who underwent simultaneous or sequential SEMS placement for malignant biliary and duodenal obstructions. The data were collected to analyze the sustained relief of obstructive symptoms until the patients' death and the efficacy of endoscopic revision, as well as stent patency, adverse events, survival and prognostic factors for stent patency. RESULTS: Technical and immediate clinical success was achieved in all of the patients. Duodenal stricture occurred before the papilla in 35 patients (70 %), involved the papilla in 11 patients (22 %) and was observed distal to the papilla in four patients (8 %). Initial biliary stenting was performed endoscopically in 42 patients (84 %) and percutaneously in eight patients. After combined stenting, 30 patients (60 %) required no additional intervention until the time of their death. The remaining 20 patients were successfully treated using endoscopic stent reinsertion: nine patients needed biliary revision, three patients needed duodenal restenting and eight patients needed both biliary and duodenal reinsertion. The median duodenal stent patency and median biliary stent patency were 34 and 27 weeks, respectively. The median survival after combined stent placement was 18 weeks. A Cox multivariate analysis showed that duodenal stent obstruction after combined stenting was a risk factor for biliary stent obstruction (hazard ratio 6.85; 95 % confidence interval 1.43-198.98; P = 0.025). CONCLUSIONS: Endoscopic bilio-duodenal bypass is clinically effective, and the majority of the patients need no additional intervention until their death. Endoscopic revision is feasible and has a high success rate.
- O enfermeiro: um cuidador culturalmente competentePublication . Silva, M; Marques, SAssistimos na atualidade a uma globalização em que as migrações constituem uma realidade patente e que carece de uma preocupação real em termos de pensamento de enfermagem. Para responder a estas novas alterações populacionais o enfermeiro especialista na área de saúde infantil e pediátrica deve estar sensível à necessidade de desenvolver competências que lhe permitam cuidar de formar personalizada à criança/jovem e família culturalmente diferente. Portugal não foge a esta realidade de dimensões mundiais, inicialmente um país de emigrantes, tornou-se no momento, num país recetor de múltiplos grupos migratórios. Cuidar de uma criança/Jovem e família culturalmente diferente constitui um enorme desafio para o enfermeiro, sendo necessário adquirir competências que o tornem culturalmente competente. Este deve possuir um conjunto de técnicas e atitudes que lhe permitam compreender as caraterísticas culturais dos clientes, famílias e comunidade de forma a conseguir uma intervenção eficaz a todos os níveis de prevenção. Este artigo pretende aprofundar conhecimentos sobre a temática da multiculturalidade e perceber a importância do enfermeiro especialista enquanto cuidador culturalmente competente.
- Genetic modulators of fetal hemoglobin expression and ischemic stroke occurrence in African descendant children with sickle cell anemiaPublication . Nicolau, M; Vargas, S; Silva, M; Coelho, A; Ferreira, E; Mendonça, J; Alexandra, D, et al.Sickle cell anemia (SCA) is an autosomal recessive monogenic disease with significant clinical variability. Cerebrovascular disease, particularly ischemic stroke, is one of the most severe complications of SCA in children. This study aimed to investigate the influence of genetic variants on the levels of fetal hemoglobin (Hb F) and biochemical parameters related with chronic hemolysis, as well as on ischemic stroke risk, in ninety-one unrelated SCA patients, children of sub-Saharan progenitors. Our results show that a higher Hb F level has an inverse relationship with the occurrence of stroke, since the group of patients who suffered stroke presents a significantly lower mean Hb F level (5.34 ± 4.57% versus 9.36 ± 6.48%; p = 0.024). Furthermore, the co-inheritance of alpha-thalassemia improves the chronic hemolytic pattern, evidenced by a decreased reticulocyte count (8.61 ± 3.58% versus 12.85 ± 4.71%; p < 0.001). In addition, our findings have confirmed the importance of HBG2 and BCL11A loci in the regulation of Hb F expression in sub-Saharan African SCA patients, as rs7482144_A, rs11886868_C, and rs4671393_A alleles are significantly associated with a considerable increase in Hb F levels (p = 0.019, p = 0.026, and p = 0.028, respectively). Concerning KLF1, twelve different variants were identified, two of them novel. Seventy-three patients (80.2%) presented at least one variant in this gene. However, no correlation was observed between the presence of these variants and Hb F level, severity of hemolysis, or stroke occurrence, which is consistent with their in silico-predicted minor functional consequences. Thus, we conclude that the prevalence of functional KLF1 variants in a sub-Saharan African background does not seem to be relevant to SCA clinical modulation.
- Hemorheological alterations in sickle cell anemia and their clinical consequences: the role of genetic modulators.Publication . Silva, M; Vargas, S; Coelho, A; Dias, A; Ferreira, T; Morais, A; Maia, R; Kjöllerström, P; Lavinha, J; Faustino, PSickle cell anemia (SCA) is an autosomal recessive disease caused by the HBB:c.20A>T mutation that leads to hemoglobin S synthesis. The disease presents with high clinical heterogeneity characterized by chronic hemolysis, recurrent episodes of vaso-oclusion and infection. This work aimed to characterize by in silico studies some genetic modulators of severe hemolysis and stroke risk in children with SCA, and understand their consequences at the hemorheological level.Association studies were performed between hemolysis biomarkers as well as the degree of cerebral vasculopathy and the inheritance of several polymorphic regions in genes related with vascular cell adhesion and vascular tonus in pediatric SCA patients. In silico tools (e.g. MatInspector) were applied to investigate the main variant consequences.Variants in vascular adhesion molecule-1 (VCAM1) gene promoter and endothelial nitric oxide synthase (NOS3) gene were significantly associated with higher degree of hemolysis and stroke events. They potentially modify transcription factor binding sites (e.g. VCAM1 rs1409419_T allele may lead to an EVI1 gain) or disturb the corresponding protein structure/function. Our findings emphasize the relevance of genetic variation in modulating the disease severity due to their effect on gene expression or modification of protein biological activities related with sickled erythrocyte/endothelial interactions and consequent hemorheological abnormalities.
- Kalirin: a novel genetic risk factor for ischemic strokePublication . Krug, T; Manso, H; Gouveia, L; Sobral, J; Xavier, J; Albergaria, I; Gaspar, G; Correia, M; Viana-Baptista, M; Simões, R; Pinto, A; Taipa, R; Ferreira, C; Fontes, J; Silva, M; Gabriel, J; Matos, I; Lopes, G; Ferro, J; Vicente, A; Oliveira, SCerebrovascular and cardiovascular diseases are the leading causes of death and disability worldwide. They are complex disorders resulting from the interplay of genetic and environmental factors, and may share several susceptibility genes. Several recent studies have implicated variants of the Kalirin (KALRN) gene with susceptibility to cardiovascular and metabolic phenotypes, but no studies have yet been performed in stroke patients. KALRN is involved, among others, in the inhibition of inducible nitric oxide synthase, in the regulation of ischemic signal transduction, and in neuronal morphogenesis, plasticity, and stability. The goal of the present study was to determine whether SNPs in the KALRN region on 3q13, which includes the Ropporin gene (ROPN1), predispose to ischemic stroke (IS) in a cohort of Portuguese patients and controls. We genotyped 34 tagging SNPs in the KALRN and ROPN1 chromosomal region on 565 IS patients and 517 unrelated controls, and performed genotype imputation for 405 markers on chromosome 3. We tested the single-marker association of these SNPs with IS. One SNP (rs4499545) in the ROPN1-KALRN intergenic region and two SNPs in KALRN (rs17286604 and rs11712619) showed significant (P < 0.05) allelic and genotypic (unadjusted and adjusted for hypertension, diabetes, and ever smoking) association with IS risk. Thirty-two imputed SNPs also showed an association at P < 0.05, and actual genotyping of three of these polymorphisms (rs7620580, rs6438833, and rs11712039) validated their association. Furthermore, rs11712039 was associated with IS (0.001 < P < 0.01) in a recent well-powered genomewide association study (Ikram et al. 2009). These studies suggest that variants in the KALRN gene region constitute risk factors for stroke and that KALRN may represent a common risk factor for vascular diseases.
- Mitochondrial haplogroup H1 is protective for ischemic stroke in Portuguese patients.Publication . Rosa, A; Fonseca, B; Krug, T; Manso, H; Gouveia, L; Albergaria, I; Gaspar, G; Correia, M; Viana-Baptista, M; Simões, R; Pinto, A; Taipa, R; Ferreira, C; Fontes, J; Silva, M; Gabriel, J; Matos, I; Lopes, G; Ferro, J; Vicente, A; Oliveira, SBACKGROUND: The genetic contribution to stroke is well established but it has proven difficult to identify the genes and the disease-associated alleles mediating this effect, possibly because only nuclear genes have been intensely investigated so far. Mitochondrial DNA (mtDNA) has been implicated in several disorders having stroke as one of its clinical manifestations. The aim of this case-control study was to assess the contribution of mtDNA polymorphisms and haplogroups to ischemic stroke risk. METHODS: We genotyped 19 mtDNA single nucleotide polymorphisms (SNPs) defining the major European haplogroups in 534 ischemic stroke patients and 499 controls collected in Portugal, and tested their allelic and haplogroup association with ischemic stroke risk. RESULTS: Haplogroup H1 was found to be significantly less frequent in stroke patients than in controls (OR = 0.61, 95% CI = 0.45-0.83, p = 0.001), when comparing each clade against all other haplogroups pooled together. Conversely, the pre-HV/HV and U mtDNA lineages emerge as potential genetic factors conferring risk for stroke (OR = 3.14, 95% CI = 1.41-7.01, p = 0.003, and OR = 2.87, 95% CI = 1.13-7.28, p = 0.021, respectively). SNPs m.3010G>A, m.7028C>T and m.11719G>A strongly influence ischemic stroke risk, their allelic state in haplogroup H1 corroborating its protective effect. CONCLUSION: Our data suggests that mitochondrial haplogroup H1 has an impact on ischemic stroke risk in a Portuguese sample.