Sapientia
Repositório Científico da UAlg
Entradas recentes
Dietary supplementation with algae-based ingredients modulates antioxidant defenses and immune response in sea urchin Paracentrotus lividus following a Vibrio parahaemolyticus challenge
Publication . Rodrigues, Ana Filipa; Lourenço, S.; Gomes, Ana Sofia; Vaz, M.; Cardoso, H.; Violante, A. P.; Baptista, T.
Functional diets are increasingly recognized as an important strategy to enhance health and production performance in sea urchin aquaculture. This study evaluates the effects of diets containing algae-based ingredients with different carotenoid pigment profiles on the immune and antioxidant systems of the sea urchin Paracentrotus lividus. During a 60-day nutritional trial, sea urchins were fed one of three diets that differed in both ingredient matrix and pigment profile: 1) a base diet formulated without algae and low in carotenoid pigments; 2) a formulated pumpkin/algal diet supplemented with Nannochloropsis sp. and high in β-carotene (nanno diet); and 3) a kelp diet based on Saccorhiza polyschides containing a mixture of carotenoid pigments and representing the natural diet of P. lividus. The effects of diets on oxidative stress response were assessed by quantifying catalase (CAT) and superoxide dismutase (SOD) activities and lipid peroxidation (LPO). The effect of diets on the short-term immune response was assessed using a time-course challenge with Vibrio parahaemolyticus at the end of the feeding trial. Sea urchins fed the kelp diet showed the strongest antioxidant defenses, while sea urchins fed the base diet presented higher LPO. After the pathogen challenge, total coelomocyte density was not significantly affected by diet. However, significant diet-dependent changes were observed in specific coelomocyte populations, including colorless granulocytes, red granulocytes and vibratile cells. Sea urchins fed the kelp diet exhibited a more pronounced immune activation, characterized by higher concentrations of lysozyme. In conclusion, supplementing diets with algae rich in carotenoids and other bioactive compounds may enhance sea urchin immune defenses against pathogens and improve resistance to oxidant stress. These findings support the development of functional diets for sea urchin aquaculture aimed at promoting health and resilience under culture conditions.
Levodopa and melanoma: practical recommendations for Parkinson's disease—international Parkinson and movement disorder society scientific issues committee viewpoint
Publication . Sciacca, Giorgia; Elsayed, Inas; Perez‐Lloret, Santiago; Outeiro, Tiago; Unni, Vivek K.; Kordower, Jeffery H.; Berg, Daniela; Kalia, Lorraine V.
The potential association between Parkinson's disease (PD), melanoma, and levodopa (l-dopa) use can be a source of uncertainty and concern in clinical practice. Several etiopathological hypotheses have been proposed, including a possible role of the protein α-synuclein that, in addition to being a major component of Lewy bodies in PD, is expressed in melanocytes.1 However, a definitive mechanistic link between PD and melanoma has yet to be defined. Epidemiological data examining whether l-dopa treatment increases melanoma risk in PD patients have been contradictory, and a causal connection has not been established. Nonetheless, product monographs for l-dopa-containing medications continue to cite a history of melanoma as a contraindication and list malignant melanoma as a potential adverse effect. This discrepancy between regulatory language and the available evidence can create uncertainty for both clinicians and people with PD when initiating or continuing l-dopa therapy. The aim of this article is to provide practical recommendations for clinicians based on current evidence regarding the (1) risk of melanoma in PD independent of l-dopa treatment based on epidemiological evidence and shared pathobiological mechanisms, (2) potential risk of developing melanoma with l-dopa use in PD, and (3) safety of l-dopa treatment in PD patients with a history of melanoma
Cationic lignin derivatives in hair conditioners: Formulation development and rheological modeling
Publication . Fernandes, Catarina; Crespo, Catarina; Cabaça, Daniela; Pocinho, Ana; Alves, Luís; Medronho, Bruno; Rasteiro, Maria da Graça; Varela, Carla
Replacing petrochemical-based cationic conditioning polymers with renewable alternatives is a key challenge in the redesign of more sustainable hair care products. In this work, cationic lignin-derivatives, prepared via a single-step cationization process using 3-chloro-2-hydroxypropyltrimethylammonium chloride (CHPTAC) were explored as alternatives to petrochemical-based cationic conditioning agents in hair conditioning products. Formulations were prepared using either these derivatives or a widely used synthetic cationic polymer (polyquaternium-11, PQ11) and characterized in terms of their physicochemical and rheological properties, and stability. Replacing PQ11 with cationic lignin derivatives did not affect the stability or the physicochemical properties of the formulations. The effect of the formulation components on the viscosity was systematically studied using a design of experiments, resulting in a predictive model describing the relationship between composition and viscosity. In addition, the lignin-based conditioners exhibited higher UV absorption than a commercial conditioner reference, with a 15-fold relative UV absorption. A preliminary proof-of-concept application on hair demonstrated improved definition and reduced frizz, supporting the potential of cationic lignin derivatives as alternative biobased conditioning agents.
Digital healthcare and the emergence of a more-than-now ethics of care: speculative practices in Portugal
Publication . Pinto da Costa, José Carlos
Portuguese healthcare is being transformed as digital technologies intersect with institutional infrastructures, professional practices, and patient experiences. These shifts are not simply imposed but unfold through everyday negotiations, improvisations, and collaborative work among healthcare professionals, system designers, policymakers, and patients. Drawing on ethnographic engagement and participatory, speculative methods, this presentation explores how actors experiment with care in ways that generate a new, emergent ethics. Unlike traditional ethical frameworks—principlism, virtue ethics, consequentialism, or classical ethics of care—this ethics arises through situated practice, mediated by digital infrastructures, data flows, and collaborative decision-making. It emphasizes responsiveness, relationality, and collective moral reasoning enacted in real time. From an STS perspective, these practices reveal how healthcare futures are actively co-produced in the present. Speculative interventions—such as design experiments—make visible the contingency of socio-technical arrangements and open alternative pathways for more just, equitable, and resilient care across various stakeholders’ standpoints. Aligned with the panel’s focus on speculative and design-based approaches to caring world-making, this contribution demonstrates how digital transformations do not just implement care but reshape what ethical responsibility looks like, creating new modes of reflection, collaboration, and experimentation in healthcare.
The cultural adaptation of value-based health care model
Publication . Pinto da Costa, José Carlos
Precision medicine is a set of practices that seek to adjust medical treatments according to the genetic variability of individuals and the socio-environmental contextin which they live. Due to this genetic-environmental interference, everyone has different organic characteristics that require different clinical and preventive approaches. The goal of precision medicine is therefore “to classify individuals into subpopulations that differ in their susceptibility to a particular disease or their response to a specific treatment.” (The National Research Council, 2011, cited by Ginsburg & Phillips, 2018: 2).