B cells at the crossroad of immune responses : insights from primary B-cell immunodeficiencies

Tese de doutoramento, Ciências Biomédicas (Imunologia), Universidade de Lisboa, Faculdade de Medicina, 2012B lymphocytes are important players in adaptive immunity and the main targets of current vaccination strategies, with the interaction between B and T cells being fundamental to generate long-term immunity. B cells also play a key role in linking innate and adaptive immunity by expressing receptors that recognize both specific antigens and microbial patterns. The general aim of this work was to investigate the interplay between B cells and other components of the immune system through the study of B-cell immunodeficiencies, namely Common Variable Immunodeficiency (CVID), characterized by impaired antibody production due to defective mature B-cell differentiation, and Congenital Agammaglobulinemia, where early Bcell development is abrogated, commonly resulting in the absence of peripheral B cells. We found BAFF-R expression to be reduced in CVID, particularly in patients with low memory B cells, and associated with high serum levels of BAFF, while TACI expression was significantly increased. BAFF induced BAFF-R down-regulation in vitro, both in healthy individuals and CVID patients. However, the degree of modulation in CVID was impaired, suggesting that these dynamics are affected, with a possible impact in B-cell homeostasis. We also observed that CVID was associated with monocyte activation, irrespective of LPS levels, but in direct association with T-cell activation and B-cell imbalances. To explore the mechanisms underlying chronic immune activation, we studied the role of IL-17, a major pro-inflammatory cytokine implicated in autoimmunity and inflammatory conditions, frequently found in CVID. However, no increase in TH17 cells was found and their frequency was inversely correlated with markers of germinal centre impairment. TH17 cells were severely reduced in Congenital Agammaglobulinemia and directly associated with switchedmemory B cells in healthy subjects. Our data support a link between B-cell differentiation and TH17 homeostasis, with implications for the understanding of the pathogenesis of inflammatory/autoimmune diseases and the physiology of B-cell depleting therapies.Linfócitos B têm um papel preponderante na imunidade adaptativa e são os principais alvos das estratégias de vacinação, sendo a interacção entre linfócitos B e T fundamental para desenvolver imunidade a longo prazo. Linfócitos B têm também um papel importante no estabelecimento da ponte entre imunidade inata e adaptativa. O objectivo principal deste trabalho foi investigar o diálogo entre linfócitos B e outros elementos do sistema imunitário, através do estudo da Imunodeficiência Comum Variável (IDCV), caracterizada por produção deficiente de anticorpos resultante de defeitos na maturação de linfócitos B, e da Agamaglobulinémia Congénita, em que ocorre um bloqueio precoce no desenvolvimento de linfócitos B, resultando frequentemente na sua ausência em circulação. A expressão de BAFF-R encontrou-se diminuída na IDCV, particularmente em doentes que possuíam uma frequência baixa de linfócitos B de memória, associada a níveis séricos de BAFF elevados. BAFF induziu diminuição de expressão de BAFF-R in vitro, no entanto de forma alterada na IDCV, sugerindo que esta dinâmica está afectada, com possível impacto na homeostasia de linfócitos B. A IDCV associou-se com activação monocitária, não relacionada com níveis de LPS, mas com activaçãode de linfócitos T e alterações de linfócitos B. Para explorar os mecanismos subjacentes à activação imunitária crónica, estudámos o papel da IL-17, citocina pró-inflamatória envolvida em autoimunidade e manifestações inflamatórias, as quais são frequentemente associadas a IDCV. No entanto, não houve aumento de linfócitos TH17 e a sua frequência associou-se inversamente com evidências de defeitos de centros germinativos. Linfócitos TH17 estavam reduzidos na Agamaglobulinémia Congénita, e em indivíduos saudáveis encontravam-se associados com a frequência de linfócitos B de memória com switch. Estes resultados mostram que a homeostasia de linfócitos TH17 se associa à maturação de linfócitos B, com implicações para a compreensão da patogénese de doenças inflamatórias/autoimunes e da fisiologia de terapêuticas depletivas de linfócitos B.Fundação para a Ciência e a Tecnologia (FCT, SFRH/BD/46542/2008); POCI 2010 e o FS

Dissociable Effects of Psychopathic Traits on Executive Functioning: Insights From the Triarchic Model

The relationship between executive functioning and psychopathy lacks consistent findings. The heterogeneity of the psychopathic personality structure may contribute to the mixed data that emerged from clinical-categorical approaches. Considering the link between antisocial behavior and executive dysfunction from the perspective of the Triarchic Model of Psychopathy, it is suggested that executive impairments in psychopathy are specifically explained by meanness and disinhibition traits, reflecting externalizing vulnerability. In turn, boldness is conceptualized as an adaptive trait. The current study assessed updating (N-back), inhibition (Stroop), and shifting (Trail Making Test) in a forensic (n = 56) and non-forensic sample (n = 48) that completed the Triarchic Psychopathy Measure. A positive association between boldness and inhibition was found, while meanness accounted for the lack of inhibitory control. In addition, disinhibition explained updating dysfunction. These findings provide empirical evidence for dissociable effects of psychopathic traits on executive functioning, in light of the Triarchic Model of Psychopathy

Effects of age on the identification of emotions in facial expressions: a meta-analysis

© 2018 Gonçalves et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, reproduction and adaptation in any medium and for any purpose provided that it is properly attributed. For attribution, the original author(s), title, publication source (PeerJ) and either DOI or URL of the article must be cited.Background: Emotion identification is a fundamental component of social cognition. Although it is well established that a general cognitive decline occurs with advancing age, the effects of age on emotion identification is still unclear. A meta-analysis by Ruffman and colleagues (2008) explored this issue, but much research has been published since then, reporting inconsistent findings. Methods: To examine age differences in the identification of facial expressions of emotion, we conducted a meta-analysis of 24 empirical studies (N = 1,033 older adults, N = 1,135 younger adults) published after 2008. Additionally, a meta-regression analysis was conducted to identify potential moderators. Results: Results show that older adults less accurately identify facial expressions of anger, sadness, fear, surprise, and happiness compared to younger adults, strengthening the results obtained by Ruffman et al. (2008). However, meta-regression analyses indicate that effect sizes are moderated by sample characteristics and stimulus features. Importantly, the estimated effect size for the identification of fear and disgust increased for larger differences in the number of years of formal education between the two groups. Discussion: We discuss several factors that might explain the age-related differences in emotion identification and suggest how brain changes may account for the observed pattern. Furthermore, moderator effects are interpreted and discussed.This research was supported by a grant from the Fundação BIAL. Carina Fernandes was supported by a doctoral grant from the Fundação para a Ciência e Tecnologia (Carina Fernandes - SFRH/BD/112101/2015).info:eu-repo/semantics/publishedVersio

Skin-Integrated wearable systems and implantable biosensors: a comprehensive review

Biosensors devices have attracted the attention of many researchers across the world. They have the capability to solve a large number of analytical problems and challenges. They are future ubiquitous devices for disease diagnosis, monitoring, treatment and health management. This review presents an overview of the biosensors field, highlighting the current research and development of bio-integrated and implanted biosensors. These devices are micro- and nano-fabricated, according to numerous techniques that are adapted in order to offer a suitable mechanical match of the biosensor to the surrounding tissue, and therefore decrease the body’s biological response. For this, most of the skin-integrated and implanted biosensors use a polymer layer as a versatile and flexible structural support, combined with a functional/active material, to generate, transmit and process the obtained signal. A few challenging issues of implantable biosensor devices, as well as strategies to overcome them, are also discussed in this review, including biological response, power supply, and data communication.This research was funded by FCT- FUNDAÇÃO PARA A CIÊNCIA E TECNOLOGIA, grant numbers: PTDC/EMD-EMD/31590/2017 and PTDC/BTM-ORG/28168/2017

Current nanotechnology advances in diagnostic biosensors

Current diagnostics present challenges that are imposed by increased life expectancy in the worldwide population. These challenges are related, not only to satisfy the need for higher performance of diagnostic tests, but also to the capacity of creating pointâ ofâ care, wearable, multiplexing and implantable diagnostic platforms that will allow early detection, continuous monitoring and treatment of health conditions in a personalized manner. These health challenges are translated into technological issues that need to be solved with multidisciplinary knowledge. Nanoscience and technology play a fundamental role in the development of miniaturized sensors that are cheap, accurate, sensitive and consume less power. At nanometre scale, these materials possess higher volumeâ toâ surface ratio and display novel properties (composition, charge, reactive sites, physical structure and potential) that are exploited for sensing purposes. These nanomaterials can therefore be integrated into diagnostic sensing platforms allowing the creation of novel technologies that tackle current health challenges. These nanomaterialâ enhanced sensors are extremely diverse, since they use numerous types of materials, nanostructures and detection modes for a multitude of biomarkers. The purpose of this review is to summarize the current stateâ ofâ theâ art of nanomaterialâ enhanced sensors, emphasizing and discussing the diagnostic challenges that are addressed by the different engineering and nanotechnology approaches. This review also aims to identify the drawbacks of nanomaterialâ enhanced sensors, as well as point out future developmental directions.This research was funded by FCT- FUNDAÇÃO PARA A CIÊNCIA E TECNOLOGIA, grant numbers: PTDC/EMD-EMD/31590/2017 and PTDC/BTM-ORG/28168/2017

MÍDIAS NA EDUCAÇÃO E O PROCESSO DE MEDIAÇÃO DO EDUCADOR NA FORMAÇÃO ACADÊMICA

Este artigo tem como objetivo investigar o papel do educador como possível mediador no processo de construção do conhecimento por meio da discussão sobre o papel das mídias no processo formativo acadêmico.Utilizou-se como investigação a pesquisa bibliográfica norteada pelos referenciais teóricos e análises de entrevistas. Ao final das análises e das reflexões teóricas, compreende-se que a mediação só é possível por meio de uma troca enfim, da dialogicidade

3D biosensors in advanced medical diagnostics of high mortality diseases

Cardiovascular diseases, cancer, and diabetes are high mortality diseases, which account for almost two thirds of all deaths worldwide. Their early detection and continuous evaluation is fundamental for an improved patient prognosis and reduced socioeconomic impact. Current biosensor technologies are typically based on the analysis of whole blood samples from patients for the detection of disease-specific biomarkers. However, these technologies display serious shortcomings, such as reduced sensitivity and dynamic range, limited in vivo applicability, and lack of continuous monitoring. There is the urgent need for new diagnostic and treatment follow-up tools, which allow for the early detection of the pathology as well as for the continuous monitoring of the physiological response to specific therapies. During the last years, a new generation of biosensor technologies with improved performance has emerged in the biomedical sector. The combination of advanced biomaterial methods, biochemical tools, and micro/nanotechnology approaches has resulted in the development of innovative three-dimensional (3D) biosensor platforms for advanced medical diagnosis. In this review, we report the most recent advances in the field of 3D biosensors for clinical applications, focusing on the diagnosis and monitoring of cardiovascular diseases, cancer, and diabetes. We discuss about their clinical performance compared to standard biosensor technologies, their implantable capability, and their integration into microfluidic devices to develop clinically-relevant models. Overall, we anticipate that 3D biosensors will drive us toward a new paradigm in medical diagnosis, resulting in real-time in vivo biosensors capable to significantly improve patient prognosis.V.M.C., S.C.K, and D.C. acknowledge thefinancial support from theEuropean Union Framework Programme for Research and InnovationHorizon 2020 on Forefront Research in 3D Disease Cancer Models asinvitroScreening Technologies (FoReCaST) under Grant agreement no.668983. V.M.C also thanks the Portuguese Foundation for Science andTechnology (FCT) for his distinction attributed under the FCTInvestigator program (IF/01214/2014). D.C. and S.C.K also acknowl-edge the support from the FCT under the scope of the project ModellingCancer Metastasis into the Human Microcirculation System using aMulti-organ-on-a-Chip Approach (2MATCH) (PTDC/BTM-ORG/28070/2017) funded by the Programa Operacional Regional do Norte sup-ported by Fundo Europeu de Desenvolvimento Regional (FEDER). A.I.B.acknowledges thefinancial support of project FROnTHERA (NORTE-01-0145-FEDER-000023

Chitosan micro-membranes with integrated gold nanoparticles as an LSPR-based sensing platform

Currently, there is an increasing need to develop highly sensitive plasmonic sensors able to provide good biocompatibility, flexibility, and optical stability to detect low levels of analytes in biological media. In this study, gold nanoparticles (Au NPs) were dispersed into chitosan membranes by spin coating. It has been demonstrated that these membranes are particularly stable and can be successfully employed as versatile plasmonic platforms for molecular sensing. The optical response of the chitosan/Au NPs interfaces and their capability to sense the medium’s refractive index (RI) changes, either in a liquid or gas media, were investigated by high-resolution localized surface plasmon resonance (HR-LSPR) spectroscopy, as a proof of concept for biosensing applications. The results revealed that the lowest polymer concentration (chitosan (0.5%)/Au-NPs membrane) presented the most suitable plasmonic response. An LSPR band redshift was observed as the RI of the surrounding media was incremented, resulting in a sensitivity value of 28 ± 1 nm/RIU. Furthermore, the plasmonic membrane showed an outstanding performance when tested in gaseous atmospheres, being capable of distinguishing inert gases with only a 10−5 RI unit difference. The potential of chitosan/Au-NPs membranes was confirmed for application in LSPR-based sensing applications, despite the fact that further materials optimization should be performed to enhance sensitivity.This research was sponsored by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Funding UIDB/04650/2020, by the project CO2Plasmon with reference EXPL/CTM-REF/0750/2021 and by the project with reference PTDC/CTM-CTM/2846/2020. Diana I. Meira acknowledges her Ph.D. Scholarship from FCT, with reference SFRH/BD/143262/2019. Manuela Proença acknowledges her Ph.D. Scholarship from FCT, with reference SFRH/BD/137076/2018

Különböző országokból származó cianobaktérium populációk toxicitása

7 Microcystis és 2 Planktothrix toxintermelő cianobaktérium minta vizsgálatára került sor, melyek a Velencei tóból, Braziliából és Németországból származnak. A minták egy része a természetben gyűjtött biomassza, míg másik része törzsizolátum. A toxicitás detektálására Thamnotox kittet, patkány májsejtvonalat, egértesztet alkalmaztunk. Az eredményeket összevetettük a HPLC-s analízis eredményeivel, mely szerint a brazil mintákban microcystin LR forma, vagyis a legtoxikusabb variáns nem fordult elő. A magyar és német minták egyaránt tartalmazták mindhárom vizsgált microcystin formát (LR, RR, YR), azonban a magyar mintákban az LR forma koncentrációja egy nagyságrenddel nagyobb volt, mint a német mintákban. Toxicitásban a magyar és brazil minták mutattak hasonlóságot, bár a brazil minták nem tartalmaztak LR variánst, de az RR forma koncentrációja olyan magas volt (12,5 és 14,8 mg/g), hogy ez jelentkezett a hasonló toxicitásban. A német minták alacsonyabb toxicitása a kisebb toxintartalommal magyarázható. A korreláció a Thamnotox teszt eredmények és az egérteszt eredmények között igen szoros (r: 0,967), míg a teljes toxin koncentráció és az egérteszt között 0,473, ugyanígy a teljes toxin koncentráció és a Thamnotoxkit teszt között (r: 0,680) jóval gyengébb az összefüggés. Hasonló eredményre jutottunk a májsejtekre kifejtett toxikus hatással kapcsolatban is. A biomassza kivonatok toxikusabbnak tűnnek, mint az a microcystin tartalommal magyarázható lenne, tehát feltételezhető, hogy a már ismert toxinokon kívül más toxikus hatású vegyületekkel is kell számolnunk a cianobaktériumoknál