Browsing by Author "Alves, S."
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- Avaliação da hiperalgesia em relação com a administração peri-operatória de opióidesPublication . Brás, A.; Carvalho, A.; Carvalho, C.; Carvalho, M.; Dias, J.; Duarte, A.; Mendes, D.; Mendes, T.; Mesquita, M.; Pinto, A.; Santos, A.; Alves, S.; Amorim, P.
- Cistinúria – Revisão da literatura e investigação das suas bases genéticas em 4 doentesPublication . Lopes, A.; Barbosa, M.; Mota, C.; Alves, S.; Martins, E.; Mota, M.C.; Quelhas, D.; Lacerda, L.; Cardoso, M.L.Introdução: Classicamente, e com base na apresentação fenotípica, os doentes com cistinúria classificavam-se em tipo I e tipo não I. Mais recentemente e com base nos aspectos genéticos da doença podemos identificar: o tipo A, causada por mutações no gene SLC3A1, o tipo B, causada por mutações no gene SLC7A9 Objectivos e metodologia: O objectivo deste trabalho foi rever o estado actual do conhecimento no que se refere ao diagnóstico, incidência/prevalência, classificação bioquímica, aspectos genéticos e tratamento desta patologia e caracterizar a nível molecular quatro casos com diagnóstico clínico e/ou bioquímico de cistinúria através da sequenciação dos genes SLC3A1 e SLC7A9. Resultados: No gene SLC3A1 foram detectadas cinco mutações, duas das quais são novas (c.1597T>A e c.611-2A>C) e três previamente descritas na literatura (c.647C>T; c.1190A>G e c.2019C>G). A sequenciação do gene SLC7A9 revelou a presença de uma mutação previamente descrita (c.614_615insA). Foi possível classificar três doentes tipo A (um homozigoto e dois heterozigotos compostos) e um doente como heterozigoto tipo B, o que está de acordo com a excreção urinária de cistina observada. Conclusões: A caracterização genotípica dos doentes cistinúricos contribui para o esclarecimento da patofisiologia da doença, permite efectuar a confirmação do diagnóstico clínico e bioquímicoe oferecer o aconselhamento genético aos familiares em risco. Os autores salientam a importância de uma abordagem multidisciplinar na estratégia de seguimento destes doentes. ABSTRACT Introduction: Classically, based on the phenotype, two types of cystinuria were identifi ed and classifi ed as type I and non-type I. More recently a new classification was proposed based on molecular genetics: cystinuria type A (caused by mutations on SLC3A1 gene), type B (involving mutations on SLC7A9 gene) and type AB if there is a digenic inheritance (SLC3A1 and SLC7A9). Objective and methodology: We reviewed the state of the art on the diagnosis, incidence/prevalence, biochemical classification, genetic data and treatment of cystinuria. Furthermore we characterized four patients with cystinuria at molecular level by sequencing SLC3A1 and SLC7A9 genes. Results: On SLC3A1 we detect five mutations, two of them (c.1597T>A and c.611-2A>C) are novel and three (c.647C>T; c.1190A>G and c.2019C>G) were been previously reported in literature. Sequencing of SLC7A9 gene showed one (c.614_615insA) previously published mutation. It was possible to classify three type A patients (one homozygote and two compound heterozygotes) and one patient as heterozygous type B, which is consistent with the observed urinary excretion of cystine. Conclusions: Genotypic characterization of patients with cystinuria contributes to the understanding of the pathophysiology, confirms the clinical and biochemical diagnosis and provides genetic counseling to relatives at risk. The authors underline the need of a multidisciplinary team approach in the follow-up of these patients.
- Correction of a Splicing Mutation Affecting an Unverricht-Lundborg Disease Patient by Antisense TherapyPublication . Matos, L.; Duarte, A.; Ribeiro, D.; Chaves, J.; Amaral, O.; Alves, S.Unverricht-Lundborg disease (ULD) is a common form of progressive myoclonic epilepsy caused by mutations in the cystatin B gene (CSTB) that encodes an inhibitor of several lysosomal cathepsins. Presently, only pharmacological treatment and psychosocial support are available for ULD patients. To overcome the pathogenic effect of the ULD splicing mutation c.66G>A (exon 1), we investigated whether an antisense oligonucleotide therapeutic strategy could correct the defect in patient cells. A specific locked nucleic acid (LNA) antisense oligonucleotide was designed to block a cryptic 5'ss in intron 1. Overall, this approach allowed the restoration of the normal splicing pattern. Furthermore, the recovery was both sequence and dose-specific. In general, this work provides a proof of principle on the correction of a CSTB gene defect causing ULD through a mutation-specific antisense therapy. It adds evidence to the feasibility of this approach, joining the many studies that are paving the way for translating antisense technology into the clinical practice. The insights detailed herein make mutation-based therapy a clear candidate for personalized treatment of ULD patients, encouraging similar investigations into other genetic diseases.
- The Diagnosing Challenge of a Positive ANCA Vasculitis in the Paediatric AgePublication . Preto, C.; Silva, A.; Alves, S.; Guedes, M.; Matos, P.; Mota, C.; Rocha, P.; Fernandes, P.ANCA-positive systemic vasculitides, rare in paediatric age, present multiorganic involvement. A female teenager presented with a history of subglottic stenosis diagnosed at the age of 12. From the investigation carried out, we highlight hematoproteinuria and negative ANCAs. At 15 years old, she was admitted for gastrointestinal symptoms and respiratory distress. She presented poor peripheral perfusion, pulmonary haemorrhage, respiratory failure, and severe renal insufficiency. She was started mechanical ventilation and emergency haemodialysis. The immunological study revealed ANCA MPO positive. A presumptive diagnosis of ANCA-positive vasculitis was made, and she was started corticotherapy, cyclophosphamide, and plasmapheresis. A renal biopsy, performed later, showed crescentic glomerulonephritis with chronicity signs. Positive ANCA vasculitis may progress slowly or suddenly. The diagnosis was confirmed by a biopsy; however, we can make a presumptive diagnosis based on clinical findings and in a positive ANCA test in order to start an early treatment and decrease the associated morbimortality.