Browsing by Author "Rodrigues, Marta"
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- Comparison of different histological indexes in the assessment of UC activity and their accuracy regarding endoscopic outcomes and faecal calprotectin levelsPublication . Magro, Fernando; Lopes, Joanne; Borralho, Paula; Lopes, Susana; Coelho, Rosa; Cotter, Jose; de Castro, Francisca Dias; Sousa, Helena Tavares; Salgado, Marta; Andrade, Patricia; Vieira, Ana Isabel; Figueiredo, Pedro; Caldeira, Paulo; Sousa, A.; Duarte, Maria A.; Avila, Filipa; Silva, Joao; Moleiro, Joana; Mendes, Sofia; Giestas, Silvia; Ministro, Paula; Sousa, Paula; Goncalves, Raquel; Goncalves, Bruno; Oliveira, Ana; Rosa, Isadora; Rodrigues, Marta; Chagas, Cristina; Dias, Claudia Camila; Afonso, Joana; Geboes, Karel; Carneiro, FatimaObjective Histological remission is being increasingly acknowledged as a therapeutic endpoint in patients with UC. The work hereafter described aimed to evaluate the concordance between three histological classification systems-Geboes Score (GS), Nancy Index (NI) and RobartsHistopathologyIndex (RHI), as well as to evaluate their association with the endoscopic outcomes and the faecal calprotectin (FC) levels. Design Biopsy samples from 377 patients with UC were blindly evaluated using GS, NI and RHI. The results were compared with the patients' Mayo Endoscopic Score and FC levels. Result GS, NI and RHI have a good concordance concerning the distinction between patients in histological remission or activity. RHI was particularly close to NI, with 100% of all patients classified as being in remission with NI being identified as such with RHI and 100% of all patients classified as having activity with RHI being identified as such with NI. These scores could also predict the Mayo Endoscopic Score and the FC levels, with their sensitivity and specificity levels depending on the chosen cut-offs. Moreover, higher FC levels were statistically associated with the presence of neutrophils in the epithelium, as well as with ulceration or erosion of the intestinal mucosa. Conclusions GS, NI and RHI histopathological scoring systems are comparable in what concerns patients' stratification into histological remission/activity. Additionally, FC levels are increased when neutrophils are present in the epithelium and the intestinal mucosa has erosions or ulcers. The presence of neutrophils in the epithelium is, indeed, the main marker of histological activity.
- Effects of climate change and anthropogenic pressures in the water quality of a coastal lagoon (Ria Formosa, Portugal)Publication . Rodrigues, Marta; Rosa, Alexandra; Cravo, Alexandra; Jacob, J.; Fortunato, André B.Understanding how climatic and anthropogenic drivers will influence coastal lagoons is fundamental to guarantee their preservation and sustainability. The Ria Formosa (coastal lagoon, South coast of Portugal) is a very important ecosystem that supports diverse economic activities in the region. The 3D coupled hydrodynamic-biogeochemical model SCHISM was validated and used to assess the influence of climate change and anthropogenic pressures on the water quality of the Ria Formosa. Five scenarios were simulated: reference scenario (S0), mean sea level rise (SLR) of 0.5 m (S1), increase of the air temperature of 1.68 °C (S2), increase of the outflow from the wastewater treatment plants (WWTP) by 50% (S3) and a combined scenario (S4). Results suggest that SLR of 0.5 m promotes an increase of 0.5-3 in the salinity near the area of influence of the WWTP. SLR decreases the inorganic nutrient concentrations in these areas by about 40-60%, due to an increase of the dilution. In contrast, the increase of the outflow from the WWTP by 50% increases the nutrients concentrations by about 20-40%. The increase of the air temperature alone by 1.68 °C increases the water temperature by 0-1 °C. The combined scenario suggests antagonist effects in the nutrient concentrations. Overall, the trophic index (TRIX) of the lagoon calculated for the scenarios exhibits only minor differences relative to the reference scenario, except in some areas near the WWTP discharges. In these areas, TRIX tends to increase with the increase of the outflow from the WWTP in scenario S3. These results provide further insight into the response of coastal lagoons, and the Ria Formosa in particular, to future changes and contribute to support their management.
- Isolation and characterization of a stress-inducible Dunaliella salina Lcy-β gene encoding a functional lycopene β-cyclasePublication . Ramos, Ana; Coesel, Sacha; Marques, Ana; Rodrigues, Marta; Baumgartner, Alexandra; Noronha, João; Rauter, Amélia; Brenig, Bertram; Varela, J.The halotolerant green alga Dunaliella salina accumulates large amounts of β-carotene when exposed to various stress conditions. Although several studies concerning accumulation and biotechnological production of β-carotene have been published, the molecular basis and regulation of the genes involved in carotenoid biosynthesis in D. salina are still poorly known. In this paper, we report the isolation and regulation of the lycopene β-cyclase (Lcy-β) gene by abiotic stress. The function of this gene was determined by heterologous genetic complementation in E. coli. Gene expression and physiological analyses revealed that D. salina Lcy-β steady-state transcript and carotenoid levels were up-regulated in response to all stress conditions tested (salt, light and nutrient depletion). The results presented here suggest that nutrient availability is a key factor influencing carotenogenesis as well as carotenoid biosynthesis-related gene expression in D. salina.
- Temporal assessment of the water quality along an urban estuary (Tagus estuary, Portugal)Publication . Rodrigues, Marta; Cravo, Alexandra; Freire, Paula; Rosa, Alexandra; Santos, DanielaUnderstanding the natural dynamics of estuaries and their response to changes in the human-related or climatic drivers is fundamental to guarantee their environmental quality. This study aims to contribute to a better understanding of the water quality dynamics in an urban estuary, the Tagus estuary (Portugal), across different temporal scales. This estuary supports diverse uses and activities and its ecological value is well recognized. Three field campaigns were performed covering distinct seasons (Spring, Summer and Autumn - 2018). Physical, chemical and biological data were measured along the estuary. The acquired data was then integrated into a set of indicators and compared with historical data, to assess the long-term evolution of the water quality in the estuary. Results showed marked spatial gradients, typically with larger concentrations of chlorophyll a, nitrate and silicate upstream. Silicate and nitrate presented a conservative behavior. Ammonium and phosphate were not conservative, which suggests an anthropogenic pressure along the estuary. Seasonally, the highest nutrients and suspended solids concentrations were found in Autumn, after a period of rainfall, pointing out to the relevance of land runoff for material supply into the estuary. These conditions were favorable for phytoplankton development upstream, once chlorophyll a was maximum during this campaign (24 mu g/L in the upper estuary). Regarding the nutrients classification, results suggest that the upper estuary is at risk with a "Medium" status. The middle and downstream areas presented a "High" status, with the exception of the middle-right margin that is also at risk ("Medium" status). The assessment of the historical data suggests that high loads of nutrients have been reaching the Tagus estuary over time, with a decreasing trend in recent years. The trophic index (TRIX) suggests a "Moderate" trophic status in the middle and upstream areas of the estuary. As for nutrients, a "Poor" classification was obtained in the middle-right margin of the estuary, mainly due to ammonium concentrations, confirming an intensification of anthropogenic pressure at this site. Similarly to the nutrients status, TRIX suggests some improvement of the water quality in the Tagus estuary in recent years compared to the 1980s. These results provide further insight regarding the water quality dynamics in the Tagus estuary and are useful to support management.