Percorrer por autor "Almeida Vieira, Mónica Andreia"
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- Betulinic acid and obesity-related disordersPublication . Azevedo, Lara; Ferraz, Ricardo; Vieira, Mónica; Prudêncio, Cristina; Fernandes, Sílvia; Ferraz, Ricardo; Almeida Vieira, Mónica Andreia; Prudêncio, Cristina; Fernandes, SílviaThe obesity epidemic is not just a health issue, it is increasingly driving a shift in the prevalence of chronic diseases, affecting 890 million adults and straining healthcare systems worldwide. Conditions such as type 2 diabetes mellitus, cardiovascular diseases, non-alcoholic fatty liver disease, and various cancer types are closely tied to this growing crisis. Betulinic acid has anti-inflammatory, antioxidant and anti-cancer properties and modulates key metabolic pathways such as NF-κB and AMPK signaling. This compound improves insulin sensitivity, reduces hepatic steatosis, mitigates the progression of atherosclerosis and fibrosis, and suppresses inflammatory responses, which are important in treating those obesity-related disorders. Additionally, betulinic acid use in cancer treatment has been explored due to its potential in angiogenesis and metastasis inhibition and promotion of apoptosis. This review spotlights the therapeutic potential of the natural compound betulinic acid in processes such as insulin sensitivity, glucose and lipid metabolism, adiposity, inflammation, oxidative stress, intestinal microbiota, and other mechanisms underlying different obesity-related disorders. Overall, besides strong therapeutic potential of betulinic acid, described limitations such as poor aqueous solubility, limited bioavailability, production and extraction have resulted in scarce clinical data making it premature to draw definitive conclusions regarding its application in clinical practice.
- Clustering health data time series with the generalized affinity coefficientPublication . Nascimento, Ana Paula; Vieira, Mónica; Faria, Brígida Mónica; Oliveira, Alexandra; Prudêncio, Cristina; Bacelar-Nicolau, Helena; Almeida Vieira, Mónica Andreia; Faria, Brigida Monica; Oliveira, Alexandra; Prudêncio, CristinaDiabetes mellitus (DM) is one of the non-communicable diseases. The behavior of Disability-Adjusted Life Years (DALYs) over time, in the context of DM, for each country was modeled by ARIMA models. Agglomerative hierarchical cluster analysis was employed using the associated distance of the generalized Affinity coefficient to measure the dissimilarity between ARIMA models . The hierarchy shows three country clusters based on DALY trends over the years.
- CS genetic variants affect the stability of the CS-Eculizumab ComplexPublication . Peixoto, Vanda; Prudêncio, Cristina; Vieira, Mónica; Sousa, Sérgio F.; Prudêncio, Cristina; Almeida Vieira, Mónica Andreia; Peixoto, VandaThe monoclonal antibody eculizumab targets complement protein CS. It is a treatment for disorders involving complement system dysregulation, such as the rare disease Paroxysmal Nocturnal Hemoglobinuria (PNH). PNH is an acquired condition affecting hematopoietic stem cells, leading to abnormal red blood cell destruction, chronic hemolytic anemia, and increased risk of thrombosis 1,2. This study applies molecular dynamics simulations to explore the molecular interactions between C5 and eculizumab. It focuses on how specific single-nucleotide polymorphisms in the C5 gene -particularly the Arg88ºHis and Arg88õCys variants - may alter the protein's structure and compromise its binding with the antibody. The findings indicate that these mutations cause conformational changes at key interaction sites reducing the stability of the C5-eculizumab complex. These insights help explain reduced treatment responses in patients carrying these mutations and may support the development of improved therapeutic strategies.
- Enhancing antifungal activity against Candida albicans using novel organic compoundsPublication . Alves, Beatriz; Silva, Rui; Vieira, Mónica; Ferraz, Ricardo; Fernandes, Silvia; Teixeira, Vitor; Pereira, Clara; Almeida Vieira, Mónica Andreia; Fernandes, SílviaCandida albicans is the predominant cause of inva-sive candidiasis, a major global health threat [1 The increasing emergence of resistance to commonly used antifungals (ex.:iazoles and polyenes) demonstrates an urgent need for alternative therapeutic strategies. The objective of this study was to evaluate the antifungal activity of novel organic derivatives from bioactive natural compound, including Naphthalene, Betulinic Acid (BA) [2]; Protocatechuic Acid (PCA) and Gallic Acid (GA), alone, or in combination with conventional antifungals to investigate synergistic effects that en-hance their efficacy. Antifungal susceptibility assays were performed in C. albicans ATCC 10231 using the broth microdilution method, according to CLSI M27 guidelines, to determine Minimum Inhibitory Concen-trations (MICs) and Minimum Fungicidal Concentra-tions (MFC). The interaction between BA derivatives and amphotericin B was assessed by checkerboard assay and fractional inhibitory concentration index (FICI). Naphthalene, PCA and GA derivatives showed low antifungal activity, falling within the moderate to weak bioactivity range (MIC ≥ 100 μg mL−1; [3]). Among BA derivatives, BA-4 and BA-5 exhibited the best antifungal activity, with MIC values of 0,95 and 1,91 μg mL−1, respectively, achieving 99% fungicidal activity at the same concentration. Furthermore, in combination assays, both compounds enhanced Am-photericin B activity, showing synergistic effects (FICI = 0.50), resulting in a decrease in MIC. Although most newly synthesized compounds exhibited limited anti-fungal potential, BA-4 and BA-5 demonstrated very strong bioactivity and fungicidal effects against C. albicans. The observed synergy with amphotericin B highlights their potential role as antifungal adjuvants and supports the further exploration of betulinic acid derivatives as viable approaches to overcoming anti-fungal resistance.
- Evaluation of adherence to different pureed diets in a hospital contextPublication . Serdoura, Sara; Lopes, Mariana; Gomes, Isabel; Rodrigues, João Costa; Vieira, Mónica Almeida; Almeida Vieira, Mónica Andreia; Costa-Rodrigues, JoaoFood waste in hospital settings is higher than in other food sectors. Hospital diets constitute the main food and nutritional source for patients, so that incomplete food intake can have negative clinical consequences. In the pureed texture diet, foods are presented in a homogeneous, moist, cohesive manner and without lumps or pieces, resembling the texture of a pudding. The aim of present study was to evaluate adherence to a homogeneous and tri-compartmentalized pureed diet in adult patients admitted to a public hospital. Observational study to assess adherence to a creamy diet at lunch and dinner, on three different days. The pureed tri-compartmentalized diet dish was provided at lunch and a homogeneous diet at dinner. The tricompartmental diet plate presented individualized macronutrients (protein, carbohydrates and vegetables) and in the homogeneous diet these components were mixed. As regards the soup and dessert provided, there was no distinction between the meals. To quantify food waste, the physical method of individual weighing was considered. A satisfaction questionnaire was applied to determine patient preferences. A total of 152 complete meals were evaluated from 76 patients with a mean age of 78.9 years (SD=9.4), of which 51.3% were male (n=39). Plate waste in the homogeneous diet was 71.0% and in the tri-compartmentalized diet it was 65.8%. Regarding the waste of soup and dessert, it was greater at lunch than at dinner. It was found that 33.3% of patients preferred the tri-compartmentalized pureed diet due to its improved presentation and flavor, however 45.1% of patients reported having no preference regarding the presentation of the dish in this diet (Table 1). The high food waste of the pureed diet requires intervention, so presenting the meal plate in a tri-compartmentalized format appears to be a possible action to improve food intake.
- Fungal-mediated biodegradation of microplastics: Evaluation of degradative potential and pathogenic traitsPublication . Barbosa, Joel; Fernandes, Virgínia Cruz; Rufo, João; Vieira, Mónica; Prudêncio, Cristina; Pereira, Clara; Fernandes, Virgínia; Cavaleiro Rufo, João; Almeida Vieira, Mónica Andreia; Prudêncio, CristinaThe increasing accumulation of plastics and micro-plastics in the environment represents a major global concern due to their persistence, widespread distribu-tion, and potential impact on ecosystems and human health1. Microbial biodegradation has emerged as a promising and sustainable strategy for plastic reme-diation, particularly through the use of fungi with en-zymatic degradative capacity. This project aims to test the biodegradative potential of different fungal spe-cies against the widely used microplastics Polypropyl-ene, Polystyrene and Poly(ehylene-co-cinyl acetate), under optimized growth conditions. The fungi, Mucor spp, Rhizopus spp, Scedosporium spp. and Nigrospora spp. were specifically selected because they have nev-er previously been investigated as plastic degraders, thereby offering the opportunity to identify novel bio-degradation capabilities. Aspergillus flavus will also be included as a control, since this species has recognized degradative capacity against some types of microplas-tics2.To identify growth conditions that maximize bio-degradation, preliminary studies using Scedosporiumspp. were performed under different glucose concen-trations and medium replacement intervals. Low-glu-cose media combined with fortnightly medium renew-al promoted the highest degradative activity and were selected for the subsequent biodegradation assays. Biodegradation will be assessed through microplastic mass loss determination, Fourier-transform infrared spectroscopy (FTIR), and Raman spectroscopy, allow-ing the identification of structural and chemical mod-ifications on microplastic surfaces. Fungal adherence to microplastics will be evaluated by microscopic ob-servation and surface colonization analysis, providing insight into biofilm formation and the role of fungal activity in the degradation process. Additionally, fun-gal pathogenicity-related traits, including biofilm for-mation and antifungal susceptibility, will be evaluated to determine whether long-term exposure to micro-plastics influences fungal virulence. This study may support the development of sustainable plastic bio-degradation strategies and improve understanding of fungal adaptation to plastic-rich environments.
- Glioblastoma: therapeutic effect of betulinic acid under an adipocytic environmentPublication . Azevedo, Lara; Ferraz, Ricardo; Vieira, Mónica; Fernandes, Silvia; Almeida Vieira, Mónica Andreia; Fernandes, SílviaGlioblastoma is the most common malignant tumor of the central nervous system, characterized by high incidence and poor survival rates, Current treatment strategies face significant challenges due to therapy resistance and tumor recurrence, highlighting the need for novel therapeutic approaches. Moreover, obesity has emerged as a potential risk factor in glioblastoma progression, being linked to chronic inflammation, metabolic dysregulation, and elevated levels of growth factors, all of which may promote tumor growth and invasiveness, Betulinic acid (BA) has shown anticancer activity in several tumor models, which along with anti-adipogenic properties, makes it a promising candidate for addressing these conditions, This study aims at: 1) assessing the BA effect on tumoral cell's apoptosis; 2) assessing the BA effect on adiposity and adipocytes secretome pattern, Thus, U251 and A172 human glioblastoma cells, and normal 3T3-Ll cell line were treated with 1-20 μM BA and cell's viability was quantified through MTT assays, Adiposity pattern and adipocytes differentiation with or without BA treatment were assessed and quantified. Results show that BA treatment significantly decreases tumoral cells viability without affecting non-tumoral cells, including for higher doses of the compound. These in vitro studies were essential to define BA doses of 1μ M, 2.5μ M, and 10μM as suitable for the adipocytes' differentiation and production of adipocytes-conditioned medium using 3T3-Ll cells. These preliminary results will promote the assessment of the secretome composition under BA treatment and will allow to explore the anti-tumoral potential of BA under an adipocytic environment. By exploring the potential therapeutic effects of BA in the glioblastoma-obesity relationship, this study seeks to contribute to the development of novel treatment approaches for glioblastoma and obesity.
- How electric fields may shape inhibition: A molecular dynamics study of GABA-ReceptorsPublication . Almeida, Nuno; Sousa, Nuno; Vieira, Mónica; Rocha, Nuno; Almeida Vieira, Mónica AndreiaTranscranial direct current stimulation (tDCS) is a non-invasive technique used to treat psychiatric and neurological disorders by modulating brain activity using electrical currents. Although effective the mechanisms by which tDCS alters brain function. particularly its effect on proteins such as GABA-A receptors, are still unclear. GABA-A receptors regulate neuronal excitability by allowing chloriele ions to enter the cells. leading to inhibitory effects. It is assumed that tDCS alters the conformation and dynamics of these receptors and thus impairs their function. To investig te these changes, molecular dynamics simulations could be used to model how electric fields affect GABA-A receptors embedded in a bilipid membrane. The hypothesis is that tDCS causes rapid, transient conformational changes that influence the duration of ion channel opening and thus modulate chloriele entry. The bilipiel membrane also plays a crucial role, as its interaction with the receptor can enhance or attenuate the tDCS effects. Due to the complexity of the system, high-performance computing resources are essential to capture dynamic changes at atomic resolution over biologically relevant timescales. Although the results are not yet available at the time of this submission, this work-in-progress poster will present the simulation strategy, system setup, and computational protocols employed. By sharing our methodological approach, we aim to foster discussion and receive early feedback from the scientific community, which will inform subsequent data analysis and interpretation.
- ln Vitro and Ex Vivo permeation studies of Polyphenols: assessing the safety of these ingredients for topical applicationPublication . Marques, Mariana; Teixeira, Filipa; Vieira, Mónica; Sut, Stefania; Dall'Acqua, Stefano; Rodrigues, Francisca; Almeida Vieira, Mónica AndreiaThe study of permeation of natural cosmetic active ingredients is essential to ensure product safety and compliance with European Regulation (EC) No. 1223/2009 [l]. Phenolic compounds are highly valued in cosmetics for their potent antioxidant properties and their role in supporting extracellular matrix integrity, which contributes to improved skin appearance and function [2]. This work aimed to evaluate the effects of catechin, epicatechin, chlorogenic acid, neochlorogenic acid, and their combination on the viability of keratinocytes (HaCaT) using the MTT assay, after exposure to various concentrations (15.625-500 μg/mL). Moreover, a permeation study using Franz diffusion cells coupled to human skin over a 24-hour period was performed. The compounds permeation was quantified by LC-MS. In terms of cell viability, exposure to lower concentrations (15.625-125μ g/mL) significantly enhanced cell viability. Conversely, the combination of the four compounds resulted in lower overall viability, suggesting potential antagonistic interactions. At the highest tested concentration (500 μg/mL), most compouncls exhibited cytotoxic effects, except for epicatechin, which maintained cell viability at levels comparable to the control. The ex vivo permeation results showed a time-dependent increase in the permeation of all tested phenolic compounds, with the highest concentrations observed at the final time points. Future perspectives of this work include optimizing phenolic compound formulations to enhance skin permeation through encapsulation.
- Patterns and trends of Klebsiella pneumoniae resistance to CarbapenemsPublication . Nascimento, Ana Paula; Vieira, Mónica; Faria, Brígida Mónica; Oliveira, Alexandra; Vinhal, Cláudia; Prudêncio, Cristina; Bacelar-Nicolau, Helena; Almeida Vieira, Mónica Andreia; Faria, Brigida Monica; Oliveira, Alexandra; Prudêncio, CristinaThe growing prevalence of drug-resistant infections has led to increased morbidity, mortality, and healthcare costs worldwide. Bacterial resistance to antimicrobials has been increasing in Europe over the last few years. According to WHO, new antimicrobials or strategies are urgently needed to treat this kind of infections. Addressing this issue, it is needed not only coordinated policy action but also a deep understanding of the epidemiological patterns and trends underlying antimicrobial resistance (AMR), particularly across different European countries. ln the present study, and considering the WHO alert reports, the particular case of carbapenem-resistant Gram-negative bacterial infections was evaluated. Agglomerative hierarchical cluster analysis was employed to explore patterns and relationships among various countries in the context of AMR, particularly in the case of the pair Klebsiella pneumoniae Carbapenems. These data are time series of different lengths; therefore, to perform the cluster analysis, the Autoregressive Integrated Moving Average (ARIMA) models are the ones that best represent the behaviour of resistant isolate percentage values over time, in the case of the pair Klebsiella pneumoniae Carbapenems, across several countries. To measure the similarity among different countries in the context of AMR, in the case of the pair Klebsiella pneumoniae Carbapenems, the generalized Affinity coefficient between ARIMA models was applied R software was used, and, for that reason, the associated distance of the generalized Affinity coefficient is also applied.