Browsing by Author "Santos, Catarina"
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- Analog electronic teaching – a new approach for bipolar transistorsPublication . Felgueiras, Carlos; Santos, Catarina; Alves, Gustavo R.; Fidalgo, André; Pertry, Clovis; Schlichting, Luisa) This work was based in a single individual sample; b) Learning Support Means (LSM) received poor acceptance; c) Other Alternative Support Means are under development; d) For these, a broader test sample was used; e) Preliminary results from this test are encouraging to further pursue this work
- Combined germline and tumor mutation signature testing identifies new families with NTHL1 tumor syndromePublication . Pinto, Carla; Guerra, Joana; Pinheiro, Manuela; Escudeiro, Carla; Santos, Catarina; Pinto, Pedro; Porto, Miguel; Bartosch, Carla; Silva, João; Peixoto, Ana; Teixeira, Manuel R.NTHL1 tumor syndrome is an autosomal recessive rare disease caused by biallelic inactivating variants in the NTHL1 gene and which presents a broad tumor spectrum. To contribute to the characterization of the phenotype of this syndrome, we studied 467 index patients by KASP assay or next-generation sequencing, including 228 patients with colorectal polyposis and 239 patients with familial/personal history of multiple tumors (excluding multiple breast/ovarian/polyposis). Three NTHL1 tumor syndrome families were identified in the group of patients with polyposis and none in patients with familial/personal history of multiple tumors. Altogether, we identified nine affected patients with polyposis (two of them diagnosed after initiating colorectal cancer surveillance) with biallelic pathogenic or likely pathogenic NTHL1 variants, as well as two index patients with one pathogenic or likely pathogenic NTHL1 variant in concomitance with a missense variant of uncertain significance. Here we identified a novel inframe deletion classified as likely pathogenic using the ACMG criteria, supported also by tumor mutational signature analysis. Our findings indicate that the NTHL1 tumor syndrome is a multi-tumor syndrome strongly associated with polyposis and not with multiple tumors without polyposis.
- Culture-dependent characterization of cyanobacterial diversity in the intertidal zones of the Portuguese coast: A polyphasic studyPublication . Brito, Ângela; Ramos, Vitor; Seabra, Rui; Santos, Arlete; Santos, Catarina; Lopo, Miguel; Ferreira, Sérgio; Martins, António; Mota, Rita; Frazão, Bárbara; Martins, Rosario; Vasconcelos, Vítor; Tamagnini, PaulaCyanobacteria are important primary producers, and many are able to fix atmospheric nitrogen playing a key role in the marine environment. However, not much is known about the diversity of cyanobacteria in Portuguese marine waters. This paper describes the diversity of 60 strains isolated from benthic habitats in 9 sites (intertidal zones) on the Portuguese South and West coasts. The strains were characterized by a morphological study (light and electron microscopy) and by a molecular characterization (partial 16S rRNA, nifH, nifK, mcyA, mcyE/ndaF, sxtI genes). The morphological analyses revealed 35 morphotypes (15 genera and 16 species) belonging to 4 cyanobacterial Orders/Subsections. The dominant groups among the isolates were the Oscillatoriales. There is a broad congruence between morphological and molecular assignments. The 16S rRNA gene sequences of 9 strains have less than 97% similarity compared to the sequences in the databases, revealing novel cyanobacterial diversity. Phylogenetic analysis, based on partial 16S rRNA gene sequences showed at least 12 clusters. One-third of the isolates are potential N2-fixers, as they exhibit heterocysts or the presence of nif genes was demonstrated by PCR. Additionally, no conventional freshwater toxins genes were detected by PCR screening.
- Eficácia e segurança de medicamentos oftálmicos na conjuntivite alérgica e síndrome do olho secoPublication . Santos, Catarina; Jesus, ÂngeloA conjuntivite alérgica e a síndrome do olho seco são as duas patologias oculares em que é permitida a automedicação e embora raramente provoquem perda visual permanente ou dano estrutural da córnea, apresentam um grande impacto na qualidade de vida dos pacientes. Por isso, os medicamentos não sujeitos a receita médica são frequentemente recomendados como tratamento de primeira linha que, sempre que possível, deve ser combinado com a adopção de medidas não farmacológicas. Rever a evidência disponível sobre a eficácia e segurança dos MNSRM que apresentam como indicação terapêutica o tratamento da conjuntivite alérgica e da síndrome do olho seco e criar um referencial de actuação relativo ao aconselhamento farmacoterapêutico destas duas patologias oculares. Efectuou-se uma revisão sistemática através de uma pesquisa bibliográfica em diversas bases de dados científicas internacionais, seguindo critérios de inclusão específicos. Os estudos seleccionados foram avaliados de acordo com a classificação de Oxford Centre for Evidence-Based Medicine. Os MNSRM utilizados na conjuntivite alérgica apresentaram eficácia clínica comprovada por resultados estatisticamente significativos em comparação com o placebo no tratamento desta patologia. Estas substâncias activas exibiram um perfil de segurança bem estabelecido e similar ao placebo. As lágrimas artificiais não sujeitas a receita médica (carbómero, hipromelose e álcool polivinílico) mostraram resultados satisfatórios no alívio sintomático da síndrome do olho seco em relação ao placebo, contudo não impedem a progressão da doença. As conclusões deste projecto de investigação devem ter em consideração o reduzido número de estudos analisados e a variação entre os protocolos de actuação e população dos ensaios clínicos.
- Frequency of CDH1, CTNNA1 and CTNND1 germline variants in families with diffuse and mixed gastric cancerPublication . Guerra, Joana; Pinto, Carla; Pinto, Pedro; Pinheiro, Manuela; Santos, Catarina; Peixoto, Ana; Escudeiro, Carla; Barbosa, Ana; Porto, Miguel; Francisco, Inês; Lopes, Paula; Isidoro, Ana Raquel; Cunha, Ana Luísa; Albuquerque, Cristina; Claro, Isabel; Oliveira, Carla; Silva, João; Teixeira, Manuel R.Hereditary diffuse gastric cancer (HDGC) is caused by germline pathogenic variants in the CDH1 and CTNNA1 genes and is characterized by a high prevalence of diffuse gastric cancer and lobular breast cancer. We aimed to evaluate the contribution of CTNNA1 and CTNND1 germline variants to HDGC, as well as to compare the frequencies of CDH1 and CTNNA1 (and eventually CTNND1) germline variants between patients with diffuse and mixed gastric carcinomas. In this study, we report a deleterious CTNNA1 germline variant and four CDH1 pathogenic variants in patients with criteria for genetic testing. None of the cases with mixed gastric cancer carried pathogenic variants in either the CDH1 or the CTNNA1 genes, so there is no evidence to use this tumor type in testing criteria.
- Validation of a single-extraction procedure for sequential analysis of vitamin E, cholesterol, fatty acids, and total fat in seafoodPublication . Cruz, Rebeca; Casal, Susana; Mendes, Eulália; Costa, Ana; Santos, Catarina; Morais, SimoneFood lipid major components are usually analyzed by individual methodologies using diverse extractive procedures for each class. A simple and fast extractive procedure was devised for the sequential analysis of vitamin E, cholesterol, fatty acids, and total fat estimation in seafood, reducing analyses time and organic solvent consumption. Several liquid/liquid-based extractive methodologies using chlorinated and non-chlorinated organic solvents were tested. The extract obtained is used for vitamin E quantification (normal-phase HPLC with fluorescence detection), total cholesterol (normal-phase HPLC with UV detection), fatty acid profile, and total fat estimation (GC-FID), all accomplished in <40 min. The final methodology presents an adequate linearity range and sensitivity for tocopherol and cholesterol, with intra- and inter-day precisions (RSD) from 3 to 11 % for all the components. The developed methodology was applied to diverse seafood samples with positive outcomes, making it a very attractive technique for routine analyses in standard equipped laboratories in the food quality control field.