Repositório Científico de Acesso Aberto da ULisboa
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Assessment reliability and treatment of depression
No full textDepression is a global problem, which causes significant distress, heavy economic burden, and is potentially lethal. The amount of research articles that try to understand causes of depression and investigate potential cures, have been growing over the last few decades. To ensure the validity of depression research, it is important to use valid measurements of depression. In this work, we examine two measures of depression - the Child Behavior Checklist (CBCL) and a depression-related subset of scales of the Hierarchical Taxonomy of Psychopathology (HiTOP). We find both scales to be valid in their corresponding samples. Finally, we look into oxytocin, a neuropeptide that has shown potential as a treatment of depression in combination with antidepressants and/or cognitive behavior therapy. We look at the longevity of the effect of oxytocin on human brain, as measured by electroencephalography (EEG), and the nature of this effect. Our findings can inform the design of future experiments that use oxytocin in human research.NIH Pre-doctoral Intramural Research Training Award 693
The role of bacterial D-Lactate in recovering gut homeostasis during metabolic dysfunction-associated steatotic liver disease (MASLD)
No full textTese de mestrado, Ciências Biofarmacêuticas, 2024, Universidade de Lisboa, Faculdade de Farmácia.A doença hepática esteatótica associada à disfunção metabólica (do inglês, MASLD) é uma condição prevalente, para a qual existem poucos tratamentos eficazes. A manipulação do microbioma intestinal tem se revelado uma abordagem promissora para regular o eixo intestino-fígado. Espécies da família Lactobacillaceae têm demonstrado potencial na atenuação da gravidade da MASLD em parte devido à produção de D-lactato, um metabolito derivado do microbioma intestinal. Este estudo investiga se Limosilactobacillus reuteri DSM 17938, através da produção de D-lactato, pode melhorar a homeostase intestinal e proteger contra a MASLD.
Ratinhos C57BL/6J foram divididos em seis grupos (n=6) e alimentados com dieta controlo (CD) ou dieta rica em gordura e frutose (HFHFD) durante 20 semanas. D-lactato (1 mM) ou Limosilactobacillus reuteri (107 CFU/mL) foram suplementados através da água. O peso corporal foi monitorizado semanalmente. A permeabilidade intestinal foi determinada através do método FITC. Após sacrifício, os tecidos do fígado, íleo e ceco foram analisados. Os efeitos de L. reuteri foram também avaliados num modelo in vitro da microbiota do íleo.
Os resultados revelaram que o D-lactato reduziu significativamente o aumento de peso e a esteatose hepática induzidos pela HFHFD, além de possivelmente diminuir a permeabilidade intestinal. O D-lactato aumentou a expressão de genes relacionados com a integridade das junções celulares, a regulação inflamatória e a oxidação de ácidos gordos nos peroxissomas, ao mesmo tempo que reduziu a necessidade de defesas antioxidantes. Adicionalmente, melhorou o transporte de ácidos biliares, sugerindo uma modulação das interações entre o intestino e o fígado.
Por outro lado, L. reuteri contrariou algumas das alterações na expressão genética induzidas pela HFHFD, no entanto não afetou o ganho de peso ou a esteatose hepática, sugerindo que o D-lactato pode oferecer maiores benefícios terapêuticos ao longo de 20 semanas. Em condições de controlo, tanto o D-lactato como L. reuteri influenciaram a diversidade do microbioma intestinal, porém o impacto da HFHFD sobrepôs estes efeitos. As alterações na expressão genética foram mais pronunciadas no íleo do que no ceco. In vitro, L. reuteri aumentou a presença de Bifidobacterium, um probiótico associado à saúde intestinal e hepática.
Em conclusão, o D-lactato replicou muitos dos benefícios observados com L. reuteri, melhorando a integridade da barreira intestinal, a resposta imunitária e a oxidação de ácidos gordos. Estes resultados destacam o seu potencial terapêutico na MASLD, especialmente no que diz respeito à melhoria da função intestinal.Metabolic dysfunction-associated steatotic liver disease (MASLD) is a prevalent condition with few effective treatments. Emerging research highlights the potential of targeting the gut-liver axis via the gut microbiome. Lactobacillaceae species have shown promise in reducing MASLD severity, partly through the production of D-lactate, a gut microbiome-derived metabolite. This study explores whether Limosilactobacillus reuteri DSM 17938, through D-lactate production, can modulate gut homeostasis and protect against MASLD.
C57BL/6J mice were divided into six groups (n=6) and fed a control diet (CD) or a high-fat, high-fructose diet (HFHFD) for 20 weeks. D-lactate (1 mM) or L. reuteri (10⁷ CFU) was supplemented in drinking water. Mice body weights were measured weekly. Intestinal permeability was evaluated using the FITC method. After mice sacrifice, liver, ileum and ceacum tissues were analyzed. The effects of L. reuteri were also studied in an in vitro ileum microbial model.
Results showed D-lactate significantly reduced HFHFD-induced weight gain and liver steatosis, and potentially reduced gut permeability. D-lactate enhanced the expression of genes involved in cell junction integrity, inflammatory regulation, and peroxisomal fatty acid oxidation, while reducing the need for antioxidant defenses. Additionally, it improved bile acid transport, likely modulating gut-liver interactions.
In contrast, L. reuteri counteracted some HFHFD-induced gene expression changes but did not affect weight gain or liver steatosis, suggesting that D-lactate may offer greater therapeutic benefits over 20 weeks. Under control conditions, both D-lactate and L. reuteri influenced gut microbiota diversity, although HFHFD overshadowed these effects. Gene expression changes were more pronounced in the ileum than in the caecum. In vitro, L. reuteri increased Bifidobacterium, a probiotic associated with gut and liver health.
In conclusion, D-lactate replicated many of L. reuteri benefits, improving gut barrier integrity, immune response, and fatty acid oxidation, highlighting its therapeutic potential in MASLD, especially in enhancing intestinal function.Research Institute for Medicines (iMed.ULisboa), Faculty of Pharmacy, University of Lisbon
Tratamento cirúrgico da escoliose severa : diferentes abordagens em múltiplos tempos operatórios
No full textTrabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2024Introdução: A escoliose é uma deformidade tridimensional da coluna, que afeta os planos coronal e sagital e inclui um componente rotacional. Pode causar dor, assimetria corporal e afetar a autoimagem. Com etiologia variada, 80% dos casos são idiopáticos. A classificação considera a idade, deformidade e localização, e o tratamento varia de vigilância a cirurgia, conforme a gravidade.
Métodos: Foram analisados 188 pacientes com escoliose operados entre 2004-2023 na Unidade Local de Saúde Santa Maria. Incluíram-se os doentes submetidos a correção cirúrgica em dois tempos com curvas escolióticas graves, excluindo-se aqueles com registos/arquivo clínico incompleto, curva major <75° e doentes que realizaram correção cirúrgica incluindo uma via anterior. Foram colhidos dados sobre a classificação etiológica, procedimentos cirúrgicos e internamento.
Resultados: O estudo analisou 12 pacientes (10 femininos e 2 masculinos) com idade média à data da cirurgia de 14 anos e escoliose de etiologia neuromuscular, idiopática ou congénita. Todos os doentes realizaram duas cirurgias, com 1 tempo de libertação, osteotomias, instrumentação e um tempo final de estabilização definitiva, intervalados por um período variável de tração. Registou-se um tempo cirúrgico total médio de 457 minutos, perdas hemáticas médias de 943 ml, havendo um período de tração médio total de 28,1 dias. A hospitalização média foi de 35,8 dias, com 3,3 dias nos cuidados intensivos. Registaram-se quatro complicações pós-operatórias. A correção média da curvatura major foi de 60,5%, reduzindo o ângulo de Cobb inicial de 112,5° para 44,4°, com uma perda de correção média de 2.2° após dois anos de seguimento.
Conclusão: Este estudo indica que a correção da escoliose severa em duas etapas por via posterior é uma opção válida, segura e proporcionando boas correções da deformidade, implicando a necessidade de um tempo de internamento prolongado e o apoio multidisciplinar de um centro diferenciado.Introduction: Scoliosis is a three-dimensional deformity of the spine that affects the coronal and sagittal planes and includes a rotational component. It can cause pain, body asymmetry, and impact self-image. With varied etiology, 80% of cases are idiopathic. Classification considers age, deformity, and location, and treatment ranges from surveillance to surgery, depending on severity.
Methods: A total of 188 patients with scoliosis operated on between 2004-2023 at the Local Health Unit of Santa Maria were analyzed. Were included patients who underwent two-stage surgical correction for severe scoliotic curves, excluding those with incomplete clinical records/files, major curve <75° and patients who underwent surgical correction including an anterior approach. Data were collected on etiological classification, surgical procedures, and hospitalization.
Results: The study analyzed 12 patients (10 females and 2 males) with a mean age at surgery of 14 years and scoliosis of neuromuscular, idiopathic or congenital etiology. All patients underwent two surgeries, with the first stage involving release, osteotomies, instrumentation, and the final stage involving definitive stabilization, separated by a variable traction period. The average total surgical time was 457 minutes, with an average blood loss of 943 ml, and a total average traction period of 28.1 days. The average hospitalization was 35.8 days, with 3.3 days in intensive care. Four postoperative complications were recorded. The average correction of the major curve was 60.5%, reducing the initial Cobb angle from 112.5° to 44.4°, with an average correction loss of 2.2° after two years of follow-up.
Conclusion: This study indicates that severe scoliosis correction in two stages via the posterior approach is a valid and safe option, providing good deformity corrections, requiring a prolonged hospitalization period and multidisciplinary support from a specialized center
Prevenção secundária na população pediátrica
No full textTrabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2024Introdução: O contacto frequente das crianças e adolescentes com o médico de família nas unidades de saúde faz com que estas sejam um local importante para fornecer recomendações e implementar medidas preventivas. Os rastreios, fundamentais na prevenção secundária, visam a deteção precoce de doença, na fase assintomática, quando o tratamento ainda pode travar a sua progressão. Objetivos: O objetivo da presente revisão é identificar os atos de prevenção secundária atualmente recomendados por autoridades de saúde/organizações médicas até os 18 anos (inclusive). Como objetivos secundários procura-se identificar atos de prevenção secundária recomendados com relação benefício/risco favorável, de acordo com a U.S. Preventive Services Task Force (USPSTF) e averiguar entre estes os que não constam no Programa Nacional de Saúde Infantil e Juvenil (PNSIJ). Métodos: Realização de pesquisa bibliográfica nos sites da Sociedade Portuguesa de Neonatologia, Sociedade Portuguesa de Pediatria, Direção-Geral da Saúde, American Academy of Pediatrics, USPSTF e Royal Australian College of General Practitioners. Foram incluídas recomendações publicadas entre 1 de junho de 2013 e 31 de março de 2024 sobre deteção precoce de doença desde o nascimento até os 18 anos (inclusive). Foram excluídas recomendações sobre deteção precoce de doença durante a gravidez. As recomendações foram selecionadas com base na leitura do título e resumo respetivos.Resultados: Foram obtidas 31 referências bibliográficas. Identificaram-se 19 atos de prevenção secundária atualmente recomendados, 7 com uma relação benefício/risco favorável, de acordo com a USPSTF. Entre os atos identificados, 5 não constam no PNSIJ. Discussão e conclusão: A prevenção secundária na população pediátrica é de extrema relevância. Há que considerar a incorporação no PNSIJ de atitudes preventivas com relação benefício/risco favorável, tendo em conta fatores como a prevalência de cada doença em Portugal, a disponibilidade e o custo dos recursos necessários para o rastreio, investigação diagnóstica e tratamento subsequentes.Introduction: Frequent contact of children and adolescents with the family physician at healthcare facilities makes these places important for providing recommendations and implementing preventive measures. Screenings are essential in secondary prevention, aiming at the early detection of diseases in the asymptomatic phase, when treatment can still halt their progression. Objectives: The aim of this review is to identify secondary prevention interventions currently recommended by health authorities and medical organizations up to 18 years of age. As secondary objectives, we seek to identify secondary prevention interventions with a favorable benefit/risk ratio, as defined by the U.S. Preventive Services Task Force (USPSTF), and to ascertain which of these interventions are not included in the National Child and Youth Health Program (PNSIJ). Methods: A bibliographic search was conducted on the websites of the Portuguese Society of Neonatology, Portuguese Society of Pediatrics, Directorate-General of Health, American Academy of Pediatrics, USPSTF, and Royal Australian College of General Practitioners. Recommendations published between June 1, 2013, and March 31, 2024, on early disease detection from birth to 18 years of age were included. Recommendations on early disease detection during pregnancy were excluded. Recommendations were selected based on their respective titles and abstracts.Results: 31 bibliographic references were obtained. 19 currently recommended secondary prevention acts were identified, 7 with a favorable benefit/risk ratio according to the USPSTF. Of the identified acts, 5 are not included in the PNSIJ. Discussion and Conclusion: Secondary prevention in the pediatric population is extremely relevant. The incorporation into the PNSIJ of preventive measures with a favorable benefit/risk ratio should be considered, taking into account factors such as the prevalence of each disease in Portugal, the availability and cost of resources necessary for screening, diagnostic investigation, and subsequent treatment
A escrita do outro: mentiras de realidade e verdades de papel
No full textEste trabalho é financiado por fundos nacionais através da FCT – Fundação para a Ciência e a Tecnologia, I.P., no âmbito do projeto UIDB/00077/2020.info:eu-repo/semantics/publishedVersio
Harnessing human iPSC-derived 3D brain models to study the innate immune response
No full textTese de mestrado, Biologia Molecular e Genética, 2024, Universidade de Lisboa, Faculdade de CiênciasNeuroinflammation is a protective response to central nervous system (CNS) injuries that, when
prolonged, may contribute to CNS pathologies. Microglia, the CNS-resident innate immune cells, undergo
morphological, transcriptomic and functional changes upon injury, acquiring a proinflammatory profile and
increasing proliferation.
Recombinant adeno associated virus (rAAV)-mediated gene therapy offers therapeutic options for
previously untreatable neurological disorders. However, some patients experienced unexpected immune
reactions after the delivery of rAAV-based gene therapy, highlighting the translational gap and the need for
innate immune competent CNS preclinical models.
Three dimensional (3D) CNS models incorporating microglia provide a better mimicry of tissue
architecture and cell-cell interactions. However, most models combine full differentiated microglia and
neurons, limiting the evaluation of interactions occurring during differentiation.
This project aimed to develop a human induced pluripotent stem cell (hiPSC)-derived
neurospheroid model through the 3D co-differentiation of neural and erythromyeloid progenitor cells in
stirred tank bioreactors, optimizing medium composition to promote microglial differentiation. The
evaluation of the cellular composition of the neurospheroids allowed the detection of functional neurons,
astrocytes and microglia at day 28. To characterize the morphofunctional status of microglia, a
morphometric analysis workflow was developed. Microglia were characterized and clustered based on a
toolbox of morphometric parameters fitting the specific morphotypes observed in the neurospheroids, which
lacked typically ramified microglia and mostly exhibit immature characteristics. Pro- and anti-inflammatory
challenge demonstrated that microglia were functional, responding as expected regarding gene expression,
and exhibited different, cell line-dependent, morphological changes, highlighting the need for customized
morphometric workflows.
Overall, this work culminated with the development of a human preclinical CNS model
incorporating functional microglia, along with the development of a bioanalytical imaging tool to better
assess the morphofunctional status of microglia. These will help to unravel the complex and dynamic nature
of innate immunity in the CNS and reduce the translational gap
Unveiling the mechanism of single nuclear inactivation in multinucleated cells
No full textMaintaining genomic integrity is crucial to prevent the activation of tumorigenic mechanisms caused by DNA damage. To achieve this, specialized mechanisms must be timely and coherently activated in response to DNA damage. Collectively known as the DNA damage response (DDR), these cellular mechanisms detect damaged sites and activate downstream effectors to repair the DNA. If repair fails, cells can trigger senescence or apoptosis mechanisms to prevent the propagation of unhealthy cells. Among various forms of DNA damage, DNA double-strand breaks (DSBs) pose the most severe threat. Cells have evolved two core pathways, namely homologous recombination (HR) and non-homologous end joining (NHEJ), to repair DSBs. These pathways have notable differences, as HR requires homologous sequences and is limited to specific cell cycle phases with sister chromatids available, while NHEJ operates throughout the entire cell cycle, but with error prone ligation of broken DNA strands. Although proliferating cells' DDR mechanisms are well-characterized, our understanding of such mechanisms in post-mitotic cells, such as skeletal muscle cells, remains limited. Terminally differentiated skeletal muscle cells are among the longest-lived cells in the human body and lack the advantage of proliferative renewal. Thus, they must adapt to stress to ensure vital functions for the organism while handling DNA lesions and preserving cell viability. Differentiated muscle cells, unable to re-enter the cell cycle and employ accurate DNA repair via HR, rely on the more mutagenic NHEJ pathway to repair DSBs. Unfortunately, this mechanism leads to progressive accumulation of mutations, compromising genomic stability. In this study, we examined the DDR in differentiated skeletal muscle cells. Our findings demonstrate that myotubes exhibit a prolonged DDR, yet remain competent in repairing DSBs. Through live-cell microscopy and single-molecule kinetic measurements, we observed that myotubes respond to DNA damage by temporarily suppressing global gene expression and altering the epigenetic landscape of the damaged nucleus. Surprisingly, despite the prolonged activation of the DDR compared to their precursor cells, differentiated skeletal muscle cells show remarkable resistance to cell death. This suggests the existence of a specific pathway that helps these cells avoid the catastrophic consequences of DNA damage. Our study reveals evidence that autophagy, the cellular process responsible for clearing damaged cellular material, plays a vital role in the DDR of skeletal muscle cells. We discovered a novel mechanism employed by these cells, whereby unrepaired DNA is removed from the nucleus and processed through autophagy. This process operates in conjunction with DNA repair proteins and contributes to the apoptotic resistance phenotype observed in skeletal muscle cells. Our findings provide insights into the strategy employed by human skeletal muscle to preserve genetic integrity and the remarkable resistance of these cells to DNA damage-induced apoptosis, ensuring long-term organ function even after DNA damage occurs
Unravelling caffeine´s influence on adult neurogenesis and behavior
No full textTrabalho Final do Curso de Mestrado Integrado em Medicina, Faculdade de Medicina, Universidade de Lisboa, 2024A neurogénese ocorre no cérebro adulto, principalmente na zona subventricular e na zona subgranular do hipocampo. Nestes nichos, as células estaminais neurais promovem plasticidade cerebral e contribuem para capacidades de aprendizagem e memória. Um dos reguladores deste processo é o sistema adenosinérgico, sendo a cafeína um antagonista não seletivo dos receptores de adenosina. Apesar de ser a substância psicoativa mais consumida, o seu papel na modulação da neurogénese adulta é largamente desconhecido.
Assim, o nosso objetivo foi avaliar os efeitos da administração de cafeína no comportamento de ratinhos, para no futuro avaliar o seu impacto na neurogénese adulta.
Para tal, ratinhos C57BL/6 adultos do mesmo sexo foram expostos a 4 semanas de cafeína (0,3g/L na água de beber) e foram submetidos a uma bateria de testes comportamentais, para estudar a atividade motora (Open Field e Rotarod performance), o comportamento ansioso (Elevated plus maze) e a aprendizagem e memória (Barnes maze e novel object recognition).
A administração de cafeína em ratos adultos machos mostrou uma tendência para prejudicar a aprendizagem e memória espacial avaliadas no Barnes Maze Test, sem afetar o desempenho dos ratinhos fêmeas. A cafeína induziu significativamente um comportamento ansiedade-like em ambos os sexos, avaliado pelo Elevated Plus Maze Test. A coordenação motora avaliada pelo Rotarod performance test foi aumentada nas fêmeas, mas não nos machos. A cafeína não afetou a memória de reconhecimento, avaliado pelo Novel object recognition test.
São necessários mais estudos celulares, especificamente para avaliar a proliferação e a diferenciação neuronal em ambos os nichos neurogénicos, para determinar completamente os efeitos da cafeína na neurogénese adulta em ratos.
Em conjunto, este projeto revelou os efeitos específicos da cafeína no comportamento animal, dando novas perspetivas sobre os seus efeitos na fisiologia cerebral, o que terá um impacto relevante na saúde pública.Neurogenesis occurs in the adult brain, mainly in the subventricular zone and the hippocampal subgranular zone. Within these niches, neural stem cells promote brain plasticity and contribute to learning and memory capabilities. One regulator of this process is the adenosinergic system, with caffeine being a nonselective antagonist of adenosine receptors. Despite being the most widely consumed psychoactive substance, its role in modulating adult neurogenesis is largely unknown.
Therefore, we aimed to assess the effects of caffeine administration on behavioral outcomes in mice, to in the future evaluate its impact on adult neurogenesis.
For that, adult sex-matched C57BL/6 mice were exposed to 4-weeks of caffeine (0.3g/L in drinking water) and were subjected to a battery of behavioral tests, to study motor activity (open field and rotarod performance tests), anxiety-like behavior (elevated-plus maze test) and learning and memory (Barnes maze and novel object recognition tests).
Caffeine administration in adult male mice showed a tendency to impair spatial learning and memory evaluated in the Barnes maze test whilst not impacting female mice performance. Caffeine significantly induced anxiety-like behavior in both sexes, evaluated by the elevated plus maze test. Motor activity evaluated by the rotarod performance test was enhanced in females, but not in males. Caffeine did not affect recognition memory recognition, evaluated by the novel object recognition.
Further cellular studies, specifically to evaluate proliferation and neuronal differentiation in both neurogenic niches, are required to fully ascertain caffeine effects on adult neurogenesis in mice.
Taken together, this project unveiled sex-specific effects of caffeine in animal behavior, that might be underlying differences in adult neurogenesis, giving novel insights about its effects in brain physiology, which will have a relevant impact in public health
Silence and nostalgia in Giuseppe Ungaretti’s poetry
No full textThis volume analyzes how people of diverse cultural and religious backgrounds living around the “Middle Sea” perceived, felt, and described homesickness, using a multidisciplinary approach which brings new perspectives to known phenomena and their evolving meanings. The sixteen chapters in this book span the fields of history, literary and cultural studies, and musicology to explore and revisit old and new subjects including diasporas, renegades, expatriates, travelogues, testaments, inquisitorial processes, songbooks, movies, and photos. Together, they provide a comprehensive picture of homesickness across states, cultures, religions, and people, furthering understanding of how individuals, communities, and nations created and expressed images, ideas, and emotions on this subject. Though centered around the Mediterranean, this volume also studies the impact of homesickness in a larger geography touched by the Iberian empires. This important contribution to the history of emotions offers studies on subjects seldom available in the English-speaking world and will appeal to undergraduates, postgraduates, scholars, and non-specialists alike.This work is financed with National Funds through FCT (Foundation for Science and Technology), through the project UIDB/00019/2020 (https://doi.org/10.54499/UIDB/00019/2020).info:eu-repo/semantics/acceptedVersio
Development of a Mobile Platform as a Diagnostics and Monitoring tool for Neurodegenerative Diseases
No full textTese de mestrado, Engenharia Biomédica e Biofísica (Engenharia Clínica e Instrumentação Médica), 2024, Universidade de Lisboa, Faculdade de CiênciasIt is predicted that by 2029, about 73% of the world’s population will have a smartphone.
Alongside many different core phone functions smartphones, the use of mobile applications as
medical diagnosis and monitoring tools for physicians is becoming increasingly important in
today’s day and age. Recent advancements in the medical field have led to more robust
diagnosis enabling optimal patient treatment. However, the current diagnostic techniques are
limited to centralized healthcare facilities, hindering the use of evidence-based diagnosis for
settings where the resources are much more limited, leaving patients without a helpful method.
The effort provided for this project enabled the implementation of a framework for
cognitive assessment that does not require the physical presence of a patient and a physician,
the creation of a mobile application using gamification concepts while being of use as a cognitive
monitoring tool, and the centralization of cognitive data from all users that provides evidencebased diagnosis. The data from the users aims to be accessed by physicians to study and
determine the cognitive function of a patient. The application provides multimodal sensory
interactions where the focus of the user is to split his/her between different sensory inputs
(visual, audio, haptic) that are linked to studies about cognitive function. This data is analyzed in
order to provide insights on sensory perception and working memory’s relation with cognitive
impairment.
25 participants, including cognitive impaired individuals, were put through a cognitive test
to evaluate their performance, and during a period of 30 days tried out the platform. At the end
they were asked to rate their cognitive abilities and rate the usability of the platform.
The usability of the mobile application received a good score and the data extracted had key
points that are good indicators of a framework to diagnose and monitor neurodegenerative
disease patients, although due to the small number of participants there is not a definitive
conclusion to be made