130 research outputs found

    Ativação de neutrófilos de indivíduos saudáveis e imunocomprometidos por promastigotas de Leishmania spp.

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    Os neutrófilos são as primeiras células polimorfonucleares do sistema imunitário inato a chegar ao local de infeção, constituindo a primeira linha de defesa contra agentes invasores, como no caso do parasita Leishmania. Este parasita é causador da leishmaniose que tem sido reportada em mais de 98 países e que pode afetar animais e seres humanos. As diferentes espécies do parasita podem causar leishmaniose com diferentes apresentações clinicas, das quais salientamos a leishmaniose visceral e a leishmaniose cutânea. O presente trabalho teve como objetivo analisar a resposta imunitária de células polimórficas nucleares (PMN) de indivíduos com diferentes competências imunitárias quando expostas a parasitas de espécies viscerais (L. infantum) e cutâneas (L. amazonensis, L. shawi e L. guyanensis). A internalização parasitária foi confirmada por microscopia optica. A ativação celular foi avaliada através de técnicas laboratoriais que permitaram analisar os mecanismos oxidativos, nomeadamente a produção de ião superóxido, a exocitose de grânulos ricos em enzimas proteolíticas, como é o caso específico da elastase neutrofilica (NE) e da catepsina G (CatG) e a libertação de armadilhas extracelulares (NET). Verificou-se que as espécies de Leishmania induzem a exocitose de CatG e a libertação de NET, independentemente da competência imunitária dos indivíduos estudados. Contudo, idêntica situação não se verifica no caso do stress oxidativo ou da libertação de NE. Leishmania spp. estimulou o stress oxidativo, com produção do ião superóxido, nos PMN de indivíduos saudáveis enquanto os PMN de indivíduos imunocomprometidos apenas parece ficar ativado na presença de L. infantum e de L. amazonensis apontando para mecanismos de ativação diversos decorrentes quer da espécie do parasita quer do nível imunitário do hospedeiro. Situação similar ocorreu na exocitose de grânulos ricos em NE. L. infantum e L. shawi estimularam a libertação de NE por PMN de indivíduos saudáveis e imunocomprometidos. Porém, os PMN de indivíduos com comprometimento da imunidade também responderam aos parasitas da espécie L. amazonensis enquanto que L. guyanensis unicamente induziu a exocitose de NE nos PMN de indivíduos saudáveis. Estes resultados apontam para a existência de especificidades próprias na ativação destes mecanismos relativamente às espécies de Leishmania e ao estado imunitário do hospedeiro. Estudos complementares são necessários para esclarecer o processo de ativação, bem como identificar os eventuais antigénios parasitários (ou até ilhas CpG) que conduzem a ativação de PMN humanos.Neutrophils are the first polymorphonuclear cells of the innate immune system to reach the infection site, providing the first line of defense against invading pathogens, such as the Leishmania parasite. This parasite causes leishmaniasis that has been reported over 98 countries, affecting both animals and human beings. Different species of the parasite can cause leishmaniasis with diverse clinical presentations, as is the case of visceral leishmaniasis and cutaneous leishmaniasis. The present study aimed to evaluate the immune response of polymorphic nuclear cells (PMN) of individuals with different immune competence when exposed to visceral (L. infantum) and cutaneous parasitic species (L. amazonensis, L. guyanensis and L. shawi). Uptake of parasites by PMN was confirmed by optical microscopy. Laboratory techniques were used to evaluate the PMN activation by assessing oxidative mechanisms, namely the production of ion superoxide exocytosis, exocytosis of granules rich in proteolytic enzymes, as is the specific case of neutrophil elastase (NE) and cathepsin G (CatG) and the release of extracellular traps (NET). It was found that the species of Leishmania induce CatG exocytosis and NET release, regardless of the immune competence of the studied subjects. On the contrary, in the case of oxidative stress or the release of NE some differences were observed between PMN from healthy and immuncompromised individuals. All species of Leishmania induced oxidative stress, with production of superoxide ion in PMN of healthy individuals. However, PMN of immunocompromised individuals just seems to be activated in the presence of L. infantum and L. amazonensis parasites, pointing to the possible existence of more than one activation mechanism in association with the immune competence of the host that can be specifically primed by a particular parasite species. A similar situation was observed in the exocytosis of granules rich in NE. L. infantum and L. shawi stimulated the release of NE by PMN isolated from healthy and immunocompromised individuals. However, PMN from individuals with impaired immunity also appeared to respond to L. amazonensis parasites while L. guyanensis only induced PMN from healthy individuals to exocytosis NE. These findings suggest that the presence of specific features in the activation of these particular mechanisms might be related to the species of Leishmania and also to the immune status of the host. Additional studies are needed to clarify the activation process and identify parasitic antigens (or even CpG islands) that direct cell activation

    The biotechnological and seafood potential of Stichopus regalis

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    Sea cucumbers are highly used not only for the production of the bêche-de-mer, but also recent studies have been showing the high potential of these marine invertebrates on the pharmaceutical industry, as they are rich in bioactive compounds with important functions. Stichopus regalis extracts (1 mg∙mL−1) were used in antioxidant, antimicrobial and antitumor assays. The lipid profile was also evaluated. No significant antioxidant activity was detected in both methanolic and dichloromethane extracts. The methanolic fraction showed the highest antimicrobial potential against Candida albicans with an IC50 of 475.4 μg∙mL−1. In the antitumor assays, the dichloromethane fraction showed a high potential for both cell lines, as revealed by the MTT method. The total fat content was 3.63% ± 0.11% and the fatty acid profile revealed the highest amount in C16:0 (9.43% ± 0.77%), C18:0 (12.43% ± 0.83%), C18:1 ω7 (5.63% ± 0.33%), EPA (12.49% ± 0.15%), DHA (7.35% ± 0.02%), ARA (19.29% ± 0.14%) and a ω3/ω6 ratio of 1.078. These findings led us to suggest the potential use of S. regalis as a new source of bioactive compounds with pharmacological potential and its nutritional benefits for human health.info:eu-repo/semantics/publishedVersio

    Sea cucumber Holothuria forskali, a new resource for aquaculture? Reproductive biology and nutraceutical approach

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    Sea cucumbers are highly marketable as a food product due to their nutritional value. Also, it has been suggested that sea cucumbers possess a wide range of bioactive compounds that can be used in the pharmaceutical industry. In this study, the reproductive biology of Holothuria forskali was performed by evaluating the gonadosomatic index (GI) and histological analyses of the gonadal tubules. The biotechnological potential was assessed through the evaluation of the antioxidant, antimicrobial and antitumor potential. Finally, the fatty acid profile was also evaluated. These three subjects were chosen to increase the interest and to focus the economic potential of this species rearing, predicting that it can be sold in Europe or export to Asia to be used for human consumption or for the pharmaceutical industry. The GI and the histological analysis of the gonadal tubules revealed that the range from February to March corresponds to the peak of gonads maturation. Furthermore, the methanolic fraction revealed the highest antimicrobial potential against Candida albicans with an IC50 of 233.2 mg mL -1. Also, this fraction presented the highest cytotoxic and anti-proliferative activities through the method for measuring cell proliferation method in both cell lines, with an IC50 of 238.2 and 396.0 mg mL -1 for MCF-7 cells respectively and 260.3 and 218.7 mg mL -1 for HepG-2 cells respectively. Regarding the fatty acid profile, the total fat content was 4.83% and the highest values were obtained for palmitic acid (9.96%), stearic acid (11.23%), eicosapentaenoic acid (10.49%) and arachidonic acid (20.36%).info:eu-repo/semantics/publishedVersio

    Cerebral malaria model applying human brain organoids

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    Neural injuries in cerebral malaria patients are a significant cause of morbidity and mortality. Nevertheless, a comprehensive research approach to study this issue is lacking, so herein we propose an in vitro system to study human cerebral malaria using cellular approaches. Our first goal was to establish a cellular system to identify the molecular alterations in human brain vasculature cells that resemble the blood–brain barrier (BBB) in cerebral malaria (CM). Through transcriptomic analysis, we characterized specific gene expression profiles in human brain microvascular endothelial cells (HBMEC) activated by the Plasmodium falciparum parasites. We also suggest potential new genes related to parasitic activation. Then, we studied its impact at brain level after Plasmodium falciparum endothelial activation to gain a deeper understanding of the physiological mechanisms underlying CM. For that, the impact of HBMEC-P. falciparum-activated secretomes was evaluated in human brain organoids. Our results support the reliability of in vitro cellular models developed to mimic CM in several aspects. These systems can be of extreme importance to investigate the factors (parasitological and host) influencing CM, contributing to a molecular understanding of pathogenesis, brain injury, and dysfunction.This research was funded by National funds through the Foundation for Science and Technology (FCT) SFRH/BD/131540/2017, SFRH/BD/5813/2020, COVID/BD/152416/2022 and UMINHO/BIM-CNCG/2022/143. This work has been funded by ICVS Scientific Microscopy Platform, member of the national infrastructure PPBI - Portuguese Platform of Bioimaging (PPBIPOCI-01-0145-FEDER-022122; by National funds, through the FCT—project UIDB/50026/2020 and UIDP/50026/2020. Moreover, this work was funded by IF/00143/2015/CP1294/CT0001, PTDC/SAU-PAR/2766/2021 and UIDB/04469/2020. O.M. is funded by the project NORTE-01- 0247-FEDER-045914, supported by POFC–COMPETE and FCT, under the programs PT2020 and NORTE2020. M.I.V. thanks FCT for her contract funding provided through 2020.03113.CEECIND.info:eu-repo/semantics/publishedVersio

    Antimicrobial activity of Mycobacteriophage D29 Lysin B during Mycobacterium ulcerans infection

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    Buruli Ulcer (BU) is a necrotizing skin disease caused by Mycobacterium ulcerans. Although the current antibiotic treatment for BU is effective, daily administrations for a prolonged period of time, combined with potential risk of severe side effects, negatively impact on patient adherence. In that sense, we tested the efficacy of an alternative strategy based on Lysin B (LysB), a phage encoded lipolytic enzyme that degrades the mycolylarabinogalactan-peptidoglycan complex present in the mycobacterial cell wall. In this study, we show that LysB not only displays lytic activity against M. ulcerans isolates in vitro, but also leads to a decrease of M. ulcerans proliferation in infected mouse footpads. These findings highlight the potential use of lysins as a novel therapeutic approach against this neglected tropical disease.The projectwas developed withinthescopeof the projectsNORTE-01-0145-FEDER-000013and NORTE-01-0145-FEDER-000023,supported by the Northern Portugal Regional Operational Programme (NORTE2020),under the Portugal2020 Partnership Agreement through FEDER.This work was also supported by BioTecNorte operation (NORTE-01-0145-FEDER -000004) funded by the European Regional Development Fund under the scope of NORTE2020.This study was supportedby the Portuguese Foundation for Scienceand Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit; the Competitiveness Factors Operational Programme (COMPETE 2020) projectsPOCI-01-0145-FEDER-006684 and POCI-01-0145-FEDER-007038; and the project PTDC/BBB-BSS/6471/2014 (POCI-01-0145-FEDER-016678). This study was also supported by Infect-ERA grant Infect-ERA/0002/2015 :BU_SPONT_HEAL. AGF,GT, and HO wouldlike to acknowledge FCT for the individual fellowships SFRH/BPD/112903/2015, SFRH/BPD/64032/2009,and SFRH/BPD/111653/2015,respectively. CMG received an individual QRENfellowship (UMINHO/BPD/15/2014). GangaGen acknowledges CSIR/ OSDD,Govt of India,for funding this project.The funders had no role in study design,data collection and analysis, decision to publish, or preparation of the manuscriptinfo:eu-repo/semantics/publishedVersio

    Recomendações e Consensos do Grupo de Estudos de Esclerose Múltipla e da Sociedade Portuguesa de Neurorradiologia sobre Ressonância Magnética na Esclerose Múltipla na Prática Clínica: Parte 1

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    Magnetic resonance imaging is established as a recognizable tool in the diagnosis and monitoring of multiple sclerosis patients. In the present, among multiple sclerosis centers, there are different magnetic resonance imaging sequences and protocols used to study multiple sclerosis that may hamper the optimal use of magnetic resonance imaging in multiple sclerosis. In this context, the Group of Studies of Multiple Sclerosis and the Portuguese Society of Neuroradiology, after a joint discussion, appointed a committee of experts to create recommendations adapted to the national reality on the use of magnetic resonance imaging in multiple sclerosis. The purpose of this document is to publish the first Portuguese consensus recommendations on the use of magnetic resonance imaging in multiple sclerosis in clinical practice.This work had a investigational grant from Roche Farmaceutica Quimica LDA: EPAM129844-G.info:eu-repo/semantics/publishedVersio

    Recommendations about multiple sclerosis management during pregnancy, partum and post-partum : consensus position of the Portuguese Multiple Sclerosis Study Group

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    Copyright © Ordem dos Médicos 2020Multiple sclerosis typically affects young women of reproductive age. Therefore, all healthcare professionals involved in the follow-up of multiple sclerosis patients must be prepared to discuss pregnancy and breastfeeding issues and provide the best possible counselling. However, there are still many doubts and heterogeneous clinical approaches partly due to the lack of consensus and guidelines. Concerning the handling of disease modifying therapies during pregnancy and postpartum, existing uncertainties have been complicated by the increase in the number of treatments available in recent years. This article aims to present the state-of-the-art and provide guidance based on the best level of available evidence and expert opinion regarding the management of multiple sclerosis patients at different stages: pregnancy planning, pregnancy, partum, and the postpartum period.Este trabalho teve o financiamento de uma bolsa de investigação da Roche Farmacêutica Química LDA: EPAM129844-G.info:eu-repo/semantics/publishedVersio

    Recommendations about multiple sclerosis management during pregnancy, partum and post-partum: consensus position of The Portuguese Multiple Sclerosis Study Group and The Portuguese Society of Obstetrics and MaternalFetal Medicine

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    A esclerose múltipla afeta tipicamente mulheres jovens em idade reprodutiva. Desta forma, todo os profissionais de saúde envolvidos no seguimento destes doentes deverão estar preparados para abordar as questões relacionadas com a gravidez e amamentação e fornecer o melhor aconselhamento possível. No entanto, existem ainda muitas dúvidas e abordagens clínicas heterogéneas em parte devido à ausência de consensos e normas orientadoras. No que concerne ao manuseamento das terapêuticas modificadoras de doença durante os períodos de gravidez e pós-parto, as incertezas têm sido agravadas devido ao aumento do número de fármacos disponíveis nos últimos anos. Este artigo visa apresentar a informação mais atual e fornecer orientações baseadas no melhor nível de evidência disponível e na opinião de peritos relativamente ao seguimento das doentes com esclerose múltipla em diferentes etapas: planificação da gravidez, gravidez, parto e período pós-parto.Multiple sclerosis typically affects young women of reproductive age. Therefore, all healthcare providers involved in the follow-up of multiple sclerosis patients must be prepared to discuss pregnancy and breastfeeding issues, and provide the best possible counselling. However, there are still many doubts and heterogeneous clinical approaches partly due to the lack of consensus and guidelines. Concerning the handling of disease modifying therapies during pregnancy and the postpartum period, uncertainties have been complicated by the increase in recent years of the number of available treatments. This article aims to present the state-of-the-art and provide guidance based on the best level of available evidence and expert opinion regarding the management of multiple sclerosis patients at different stages: pregnancy planning, pregnancy, partum, and the postpartum period

    Multiple Myeloma Treatment Guidelines by the Portuguese Group of Multiple Myeloma

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    The treatment of multiple myeloma has profoundly changed with the introduction of several innovative therapies. The optimization of therapeutic sequencing through the combined use of the various drugs developed in recent years and the attention given to the characteristics of patients have allowed the reduction of toxicities and increased survival and quality of life of patients with multiple myeloma. These treatment recommendations from the Portuguese Multiple Myeloma Group offer guidance for first-line treatment and progression/relapse situations. These recommendations are given highlighting the data that justify each choice and referring to the respective levels of evidence that support these options. Whenever possible, the respective national regulatory framework is presented. These recommendations constitute an advance towards the best treatment of multiple myeloma in Portugal.publishersversionpublishe
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