Browsing by Author "Oliveira, Beatriz"
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- Bringing hope to improve treatment in pancreatic ductal adenocarcinoma - a new tool for molecular profiling of KRAS mutations in tumor and plasma samplesPublication . Bravo, Ana Catarina; Morão, Bárbara; Luz, André; Dourado, Rúben; Oliveira, Beatriz; Guedes, Ana; Moreira-Barbosa, Catarina; Fidalgo, Catarina; Mascarenhas-Lemos, Luís; Costa-Santos, Maria Pia; Maio, Rui; Paulino, Jorge; Baptista, Pedro Viana; Fernandes, Alexandra R.; Cravo, MaríliaBackground/Objectives: Pancreatic ductal adenocarcinoma (PDAC) incidence is rising, and prognosis remains poor due to late diagnosis and limited effective therapies. Currently, patients are treated based on TNM staging, without molecular tumor characterization. This study aimed to validate a technique that combines the amplification refractory mutation system (ARMS) with high-resolution melting analysis (HRMA) for detecting mutations in codon 12 of KRAS in tumor and plasma, and to assess its prognostic value. Methods: Prospective study including patients with newly diagnosed PDAC with tumor and plasma samples collected before treatment. Mutations in codon 12 of KRAS (G12D, G12V, G12C, and G12R) were detected using ARMS–HRMA and compared to Sanger sequencing (SS). Univariate and multivariate analyses were used to evaluate the prognostic significance of these mutations. Results: A total of 88 patients, 93% with ECOG-PS 0–1, 57% with resectable disease. ARMS–HRMA technique showed a higher sensitivity than SS, both in tumor and plasma (77% vs. 51%; 25 vs. 0%, respectively). The most frequent mutation was G12D (n = 32, 36%), followed by G12V (n = 22, 25%). On multivariate analysis, patients with G12D and/or G12C mutations, either in tumor or plasma, had lower PFS (HR 1.792, 95% CI 1.061–3.028, p = 0.029; HR 2.081, 95% CI 1.014–4.272, p = 0.046, respectively) and lower OS (HR 1.757, 95% CI 1.013–3.049, p = 0.045; HR 2.229, 95% CI 1.082–4.594, p = 0.030, respectively). Conclusions: ARMS–HRMA is a rapid and cost-effective method for detecting KRAS mutations in PDAC patients, offering the potential for stratifying prognosis and guiding treatment decisions. The presence of G12D and G12C mutations in both tumor and plasma is associated with a poorer prognosis.
- Dietary inclusion of blood hydrolysates affects muscle growth in European seabass (Dicentrarchus labrax)Publication . Velasco, Cristina; Resende, Daniela; Oliveira, Beatriz; Canada, Paula; Pereira, Miguel; Pereira, Carlos; Pintado, Manuela; Valente, Luisa M. P.Dietary supplementation with hydrolysates has been suggested to influence muscle protein synthesis and fish growth. This study assessed the impact of including 3% swine blood hydrolysates (BH) in a plant-based diet on muscle cellularity and the expression of molecular markers related to muscle fibre proliferation and hypertrophic growth of European seabass. Three BH fractions were obtained by two different processes, autohydrolysis (AH-H) and enzymatic hydrolysis followed by micro- (RMF-H) and nanofiltration (RNF-H). Each BH was added to a commercial-based diet, where 50% of fishmeal was replaced by vegetable proteins (negative control, NC). A fishmeal-based diet was used as positive control, PC. The diets were fed to juveniles (12 g) during 74 days. The RMF group showed down-regulation of myod1 and fgf4, essential to myoblast proliferation and differentiation, and upregulation of mafbx, responsible for protein breakdown, resulting in impairment of muscle hyperplasic growth and the lowest muscle fibres number. However, compensatory growth mechanisms were observed through capn1 downregulation and mymk upregulation, suggesting decreased muscle proteolysis and increased myoblast fusion. Despite this, the compensatory mechanisms were insufficient as RMF group had the worst growth. RNF group had a final weight similar to the NC, but downregulation of fgf4, fgf6 and capn1 may compromise growth potential at long term. The expression of these genes in the AH group was similar to that in the FM-based diet. Despite not having demonstrated growth promotion ability, BH affect muscle growth and cellularity factors, prompting further research on commercial-sized fish to reveal their impact on important commercial traits.
- Physical processing or supplementation of feeds with phytogenic compounds, alginate oligosaccharide or nucleotides as methods to improve the utilization of Gracilaria gracilis by juvenile European seabass (Dicentrarchus labrax)Publication . Valente, Luisa M.P.; Batista, Sónia; Ribeiro, Catarina; Pereira, Ricardo; Oliveira, Beatriz; Garrido, Inês; Baião, Luís F.; Tulli, Francesa; Messina, Maria; Pierre, Ronan; Abreu, Helena; Pintado, Manuela; Kiron, ViswanathThis study assessed both the effectiveness of a physical-mechanical rupture method and the ability of feed additives (phytogenic compounds, alginate oligosaccharide and nucleotides) to enhance the utilization of G. gracilis by European seabass. A commercial-based diet was used as control diet (CTRL) and compared with five isoproteic (53.5% Dry matter, DM) and isolipidic (14.9% DM) diets containing 8% of G. gracilis. This seaweed was either unprocessed (diet GRA) or subjected to physical processing (diet GRAP). The three additive-containing diets were formulated by supplementing the GRA diet with either 0.02% phytogenic compounds (PHY), 2.5% oligo-alginate (OAS) or 0.08% free nucleotides (NUC). Triplicate groups of nineteen fish (29.7 ± 0.02 g) were distributed by 50 L tanks (11.3 kg m−3) and fed the experimental diets to satiety during 106 days. By the end of the trial, growth performance and nutrient utilization (specific growth ratio, feed conversion ratio, apparent digestibility coefficients, nutrient balance, intestinal brush border membrane enzyme activities and plasma metabolic parameters), gut histomorphology, antioxidant and immunological status of fish were evaluated. The ability of fish to digest seaweed-rich diets was largely improved by the technological processing of G. gracilis, albeit nil effect on fish specific growth rate (1.0 in all groups). This major achievement was associated with increased ability of GRAP to digest protein (84 vs 68% in GRA) and energy (64 vs 38% in GRA). The use of feed additives in Gracilaria-rich diets was less efficacious in improving European sea bass nutrient and energy ADCs, but have still improved the overall digestibility of those diets. Fish fed alginate oligosaccharide was mainly associated with increased activity of anterior intestine enzymes, particularly intestinal alkaline phosphatase (IAP; 174.4 vs 104.7–120.6 μm min−1 g−1 in Gracilaria-rich diets). Moreover, the algae technological processing and both the nucleotides and the alginate oligosaccharide seem to have positively affected the intestinal villus width compared to the negative impact seen in fish fed GRA. The tested additives had limited impact on oxidative stress, although glutathione peroxidase (GPx; 2.1 μmol min−1 mg protein−1) and catalase (CAT; 35 μmol min−1 mg protein−1) activities were lowest in fish fed NUC and PHY, respectively. It can be concluded that the physical processing of Gracilaria sp. or the addition of either oligo-alginate or nucleotides can effectively increase the nutritional value of this seaweed for European seabass diets.