Uso de sustancias psicoactivas entre estudiantes universitários

El objetivo del estudio fue identificar el perfil del uso de sustancias psicoactivas entre estudiantes de Ciencias Biológicas, Educación Física, Enfermería, Fisioterapia, Farmacia, Odontología y Nutrición. Se trata de un estudio transversal, cuantitativo, exploratorio y descriptivo, con 567 estudiantes. Los datos fueron recolectados por medio de un cuestionario y analizados a través de la estadística descriptiva. En los resultados, se constató que el 11,6% de los estudiantes nunca experimentó el consumo de sustancias psicoactivas. Las drogas prevalentemente consumidas fueron: alcohol (n = 501), tabaco (n = 161), marihuana (n = 115) y cocaína (n = 26). Se concluye que el consumo de sustancias psicoactivas entre los estudiantes es un problema y que debe ser enfrentado a través de acciones preventivas y de reducción de daños.The objective of this study was to identify the profile of use of psychoactive substances among students of Biological Sciences, Physical Education, Nursing, Physiotherapy, Pharmacy, Dentistry and Nutrition courses. It was a cross - sectional, quantitative, exploratory and descriptive study with 567 students. Data were collected through a questionnaire and analyzed through descriptive statistics. In the results, it was found that 11.6% of students had never tried psychoactive substances in their lives. The most prevalent drugs among university students were alcohol (n = 501), tobacco (n = 161), marijuana (n = 115), and cocaine (n = 26). The result led to the conclusion that consumption of psychoactive substances among students is a problem that must be faced through the implementation of preventive and harm reduction actions.O objetivo do estudo foi identificar o perfil do uso de substâncias psicoativas entre estudantes dos cursos de Ciências Biológicas, Educação Física, Enfermagem, Fisioterapia, Farmácia, Odontologia e Nutrição. Trata-se de estudo transversal, quantitativo, exploratório e descritivo, com 567 estudantes. Os dados foram coletados por meio de um questionário e analisados através da estatística descritiva. Nos resultados, verificou-se que 11,6% dos estudantes nunca experimentaram substâncias psicoativas na vida. As drogas mais prevalentes entre os universitários foram o álcool (n=501), tabaco (n=161), maconha (n=115) e cocaína (n=26). Conclui-se que o consumo de substâncias psicoativas entre os estudantes é problema que deve ser enfrentado através da implantação de ações preventivas e de redução de danos

Sphingosine 1-phosphate receptor 5 mediates the immune quiescence of the human brain endothelial barrier

BACKGROUND: The sphingosine 1-phosphate (S1P) receptor modulator FTY720P (Gilenya®) potently reduces relapse rate and lesion activity in the neuroinflammatory disorder multiple sclerosis. Although most of its efficacy has been shown to be related to immunosuppression through the induction of lymphopenia, it has been suggested that a number of its beneficial effects are related to altered endothelial and blood–brain barrier (BBB) functionality. However, to date it remains unknown whether brain endothelial S1P receptors are involved in the maintenance of the function of the BBB thereby mediating immune quiescence of the brain. Here we demonstrate that the brain endothelial receptor S1P(5) largely contributes to the maintenance of brain endothelial barrier function. METHODS: We analyzed the expression of S1P(5) in human post-mortem tissues using immunohistochemistry. The function of S1P(5) at the BBB was assessed in cultured human brain endothelial cells (ECs) using agonists and lentivirus-mediated knockdown of S1P(5). Subsequent analyses of different aspects of the brain EC barrier included the formation of a tight barrier, the expression of BBB proteins and markers of inflammation and monocyte transmigration. RESULTS: We show that activation of S1P(5) on cultured human brain ECs by a selective agonist elicits enhanced barrier integrity and reduced transendothelial migration of monocytes in vitro. These results were corroborated by genetically silencing S1P(5) in brain ECs. Interestingly, functional studies with these cells revealed that S1P(5) strongly contributes to brain EC barrier function and underlies the expression of specific BBB endothelial characteristics such as tight junctions and permeability. In addition, S1P(5) maintains the immunoquiescent state of brain ECs with low expression levels of leukocyte adhesion molecules and inflammatory chemokines and cytokines through lowering the activation of the transcription factor NFκB. CONCLUSION: Our findings demonstrate that S1P(5) in brain ECs contributes to optimal barrier formation and maintenance of immune quiescence of the barrier endothelium

Edible bio-based nanostructures: delivery, absorption and potential toxicity

The development of bio-based nanostructures as nanocarriers of bioactive compounds to specific body sites has been presented as a hot topic in food, pharmaceutical and nanotechnology fields. Food and pharmaceutical industries seek to explore the huge potential of these nanostructures, once they can be entirely composed of biocompatible and non-toxic materials. At the same time, they allow the incorporation of lipophilic and hydrophilic bioactive compounds protecting them against degradation, maintaining its active and functional performance. Nevertheless, the physicochemical properties of such structures (e.g., size and charge) could change significantly their behavior in the gastrointestinal (GI) tract. The main challenges in the development of these nanostructures are the proper characterization and understanding of the processes occurring at their surface, when in contact with living systems. This is crucial to understand their delivery and absorption behavior as well as to recognize potential toxicological effects. This review will provide an insight into the recent innovations and challenges in the field of delivery via GI tract using bio-based nanostructures. Also, an overview of the approaches followed to ensure an effective deliver (e.g., avoiding physiological barriers) and to enhance stability and absorptive intestinal uptake of bioactive compounds will be provided. Information about nanostructures potential toxicity and a concise description of the in vitro and in vivo toxicity studies will also be given.Joana T. Martins, Oscar L. Ramos, Ana C. Pinheiro, Ana I. Bourbon, Helder D. Silva and Miguel A. Cerqueira (SFRH/BPD/89992/2012, SFRH/BPD/80766/2011, SFRH/BPD/101181/2014, SFRH/BD/73178/2010, SFRH/BD/81288/2011, and SFRH/BPD/72753/2010, respectively) are the recipients of a fellowship from the Fundacao para a Ciencia e Tecnologia (FCT, POPH-QREN and FSE, Portugal). The authors thank the FCT Strategic Project PEst-OE/EQB/LA0023/2013 and the project "BioInd-Biotechnology and Bioengineering for improved Industrial and Agro-Food processes," REF.NORTE-07-0124-FEDER-000028, co-funded by the Programa Operacional Regional do Norte (ON.2-O Novo Norte), QREN, FEDER. We also thank to the European Commission: BIOCAPS (316265, FP7/REGPOT-2012-2013.1) and Xunta de Galicia: Agrupamento INBIOMED (2012/273) and Grupo con potencial de crecimiento. The support of EU Cost Action FA1001 is gratefully acknowledged

Abstracts from the 20th International Symposium on Signal Transduction at the Blood-Brain Barriers

https://deepblue.lib.umich.edu/bitstream/2027.42/138963/1/12987_2017_Article_71.pd

Rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART): Study protocol for a randomized controlled trial

Background: Acute respiratory distress syndrome (ARDS) is associated with high in-hospital mortality. Alveolar recruitment followed by ventilation at optimal titrated PEEP may reduce ventilator-induced lung injury and improve oxygenation in patients with ARDS, but the effects on mortality and other clinical outcomes remain unknown. This article reports the rationale, study design, and analysis plan of the Alveolar Recruitment for ARDS Trial (ART). Methods/Design: ART is a pragmatic, multicenter, randomized (concealed), controlled trial, which aims to determine if maximum stepwise alveolar recruitment associated with PEEP titration is able to increase 28-day survival in patients with ARDS compared to conventional treatment (ARDSNet strategy). We will enroll adult patients with ARDS of less than 72 h duration. The intervention group will receive an alveolar recruitment maneuver, with stepwise increases of PEEP achieving 45 cmH(2)O and peak pressure of 60 cmH2O, followed by ventilation with optimal PEEP titrated according to the static compliance of the respiratory system. In the control group, mechanical ventilation will follow a conventional protocol (ARDSNet). In both groups, we will use controlled volume mode with low tidal volumes (4 to 6 mL/kg of predicted body weight) and targeting plateau pressure <= 30 cmH2O. The primary outcome is 28-day survival, and the secondary outcomes are: length of ICU stay; length of hospital stay; pneumothorax requiring chest tube during first 7 days; barotrauma during first 7 days; mechanical ventilation-free days from days 1 to 28; ICU, in-hospital, and 6-month survival. ART is an event-guided trial planned to last until 520 events (deaths within 28 days) are observed. These events allow detection of a hazard ratio of 0.75, with 90% power and two-tailed type I error of 5%. All analysis will follow the intention-to-treat principle. Discussion: If the ART strategy with maximum recruitment and PEEP titration improves 28-day survival, this will represent a notable advance to the care of ARDS patients. Conversely, if the ART strategy is similar or inferior to the current evidence-based strategy (ARDSNet), this should also change current practice as many institutions routinely employ recruitment maneuvers and set PEEP levels according to some titration method.Hospital do Coracao (HCor) as part of the Program 'Hospitais de Excelencia a Servico do SUS (PROADI-SUS)'Brazilian Ministry of Healt

Genetic programs associated with distinct levels of T-cell activation

Tese de mestrado. Biologia Molecular e Genética. Universidade de Lisboa, Faculdade de Ciências. 2010Versão públicaThe immune defense by CD8+ cytotoxic T-lymphocytes requires the priming of naïve T-cells, followed by clonal expansion and development of effector functions. It has been demonstrated in murine models that the quality (stimulation by immature vs mature DC) or the quantity (stimulation by an APC line for 4h or 20h) of the T cell stimulation signal give rise to effector T cells or partially activated T-cells. This latest population arise as a consequence of sub-optimal stimulation and are not deleted or tolerized. Instead these partially activated T cells are poised, in that they are programmed to survive in vivo over prolonged times and to become mobilized into a full-blown effector response capable of exerting therapeutic efficacy in tumor-bearing mice. Therefore, patients incapable of clearing tumors does not necessarily constitute a lost case, in that these 'poised' CD8+ T cells may be available for full activation. Microarrays were performed on OT-1 T cells stimulated for 0h, 4h or 20h and a histone demethylase and a transcription factor were considered in this study since they might play a functional role in the control of gene expression. Here we demonstrate that the mRNA levels of the genes decrease during the priming phase in OT-1 and TCRln5 T cells. Furthermore, the TCRln5 T cells showed a slower kinetic of cell division, confirmed by the slower acquisition of activation markers. Also, we demonstrated that the histone demethylase seem to be responsible for T cell proliferation independently of antigen, when overexpressed in unstimulated OT-1 T cells.As células dendriticas presentes nos tecidos apresentam um fenótipo imaturo, sendo incapazes de activar células T virgens. No entanto, a resposta a certos sinais estimulatórios induz a maturação das iDCs, tornando-se eficientes células apresentadoras de antigénio. A resposta imunitária mediada por linfócitos T CD8+ encontra-se dependente do priming de células T virgens, seguida de uma expansão clonal e desenvolvimento de uma função efectora e de memória imunológica. A activação de células T está dependente da formação da sinapse imunológica entre células T e APC, onde o despoletar do TCR pela ligação ao complexo antigénio-MHC inicia uma cascata de sinalização de sinal que resulta na entrada no ciclo celular. Foram desenvolvidas diversas condições laboratoriais que permitem o controlo sobre a qualidade da estimulação recebida pelas células T (estimulação através de DC imaturas e maturas) ou diferenças na duração do sinal (4h ou 20h) que resulta em dois níveis distintos de activação de linfócitos T CD8+. Verificou-se que uma óptima estimulação (estimulação através de DC maturas ou através de um contacto prolongado de 20h entre células T e APC) resulta no desenvolvimento de uma resposta efectora, acompanhada de uma expansão clonal, erradicação de células tumorais e formação de memória imunológica. No entanto, uma estimulação ineficiente (estimulação através de DC imaturas ou através de um curto contacto de 4h entre células T e APC) resulta num estado de activação de células T CD8+ onde há perda de expansão clonal e de uma resposta efectora funcional, impedindo a erradicação de células tumorais. Estas células parcialmente activadas não sofrem deleção clonal ou tolerância e são designadas células T ´poised‟. Esta população é de especial interesse devido ao seu potencial terapêutico visto que são capazes de reconhecer o antigénio e de desenvolver uma apropriada expansão clonal após um segundo encontro com o antigénio. Considerando que o estímulo recebido pela célula T ocorre antes da divisão celular, as diferenças na proliferação celular observadas deverão resultar de um programa intrínseco iniciado durante o priming da célula T. Consequentemente, as células T poised identificadas nos modelos in vivo (utilizando DC maturas e imaturas) e in vitro (contacto com APC por períodos de 4h ou 20h) deverão resultar de um mesmo programa genético associado a uma ineficiente activação das células T. De modo a identificar um mecanismo molecular responsável pelo fenótipo observado foram efectuados microarrays em células T estimuladas in vitro durante 4h e 20h, levando à identificação de dois genes candidatos. Verificou-se que a expressão de uma histona demetilase e de um factor de transcrição se encontra reprimida durante a fase de priming. Contudo, os resultados obtidos através do microarray não explicam o mecanismo molecular subjacente nem se o mesmo mecanismo se encontra presente nas células T dos modelos in vivo e in vitro. Assim, o objectivo deste estudo é tentar estabelecer uma ligação a nível molecular entre os dois tipos de células poised transgénicas através da sua caracterização no sistema in vitro de activação, avaliação funcional dos dois genes candidatos e quantificação dos níveis de mRNA. O modelo de activação in vitro permite o controlo da duração da estimulação das células T e, consequentemente, da quantidade de sinal recebido pelos linfócitos T durante o priming. Neste modelo, a linha celular SAMBOK funciona como célula apresentadora de antigénio e consiste numa linha celular de fibroblastos aderentes que expressam à superfície os epitopos reconhecidos pelos dois tipos de linfócitos T transgénicos, bem como moléculas responsáveis pela costimulação (CD80). A importância, a nível funcional, dos dois genes candidatos foi investigada através da transdução lentiviral dos linfócitos T. Deste modo, o efeito da expressão ectópica dos genes de interesse pode ser analisada, bem como o efeito da inibição da função do gene através de silenciamento por RNA de interferência (shRNA). Antes da sua transferência para ratinhos receptores, as células T transduzidas foram estimuladas in vitro durante 4h ou 20h na presença de SAMBOK. A análise funcional dos genes candidatos compreende a avaliação da proliferação celular e de marcadores de activação como CD69 e CD25. Neste estudo demonstrámos que os níveis de mRNA da histona demetilase e do factor de transcrição diminuem durante a fase de priming em ambos os linfócitos T transgénicos. Estes dois sistemas transgénicos apresentam perfis de proliferação idênticos quando estimulados durante 4h e 20h. No entanto, os linfócitos TCRln5 apresentam uma cinética de divisão celular menos rápida do que os linfócitos OT-1, confirmado pela aquisição tardia de marcadores de activação. A histona demetilase parece ser responsável pela proliferação de células T independente de antigénio, quando sobreexpressa em linfócitos OT-1 não estimulados. Após a transferência in vivo os níveis desta histona demetilase sobem. Deste modo, um estado de proliferação é observado em células T poised, quando estimuladas por apenas 4h, onde uma activação completa está ausente. Apesar de os mecanismos moleculares responsáveis pelaactivação de linfócitos T não serem totalmete conhecidos, futuros estudos serão importantes para desvendar a importância desta demetilase de histona no desenvolvimento de células T poised ou efectoras

Immune cell trafficking across the barriers of the central nervous system in multiple sclerosis and stroke

Each year about 650,000 Europeans die from stroke and a similar number lives with the sequelae of multiple sclerosis (MS). Stroke and MS differ in their etiology. Although cause and likewise clinical presentation set the two diseases apart, they share common downstream mechanisms that lead to damage and recovery. Demyelination and axonal injury are characteristics of MS but are also observed in stroke. Conversely, hallmarks of stroke, such as vascular impairment and neurodegeneration, are found in MS. However, the most conspicuous common feature is the marked neuroinflammatory response, marked by glia cell activation and immune cell influx. In MS and stroke the blood-brain barrier is disrupted allowing bone marrow-derived macrophages to invade the brain in support of the resident microglia. In addition, there is a massive invasion of auto-reactive T-cells into the brain of patients with MS. Though less pronounced a similar phenomenon is also found in ischemic lesions. Not surprisingly, the two diseases also resemble each other at the level of gene expression and the biosynthesis of other proinflammatory mediators. While MS has traditionally been considered to be an autoimmune neuroinflammatory disorder, the role of inflammation for cerebral ischemia has only been recognized later. In the case of MS the long track record as neuroinflammatory disease has paid off with respect to treatment options. There are now about a dozen of approved drugs for the treatment of MS that specifically target neuroinflammation by modulating the immune system. Interestingly, experimental work demonstrated that drugs that are in routine use to mitigate neuroinflammation in MS may also work in stroke models. Examples include Fingolimod, glatiramer acetate, and antibodies blocking the leukocyte integrin VLA-4. Moreover, therapeutic strategies that were discovered in experimental autoimmune encephalomyelitis (EAE), the animal model of MS, turned out to be also effective in experimental stroke models. This suggests that previous achievements in MS research may be relevant for stroke. Interestingly, the converse is equally true. Concepts on the neurovascular unit that were developed in a stroke context turned out to be applicable to neuroinflammatory research in MS. Examples include work on the important role of the vascular basement membrane and the BBB for the invasion of immune cells into the brain. Furthermore, tissue plasminogen activator (tPA), the only established drug treatment in acute stroke, modulates the pathogenesis of MS. Endogenous tPA is released from endothelium and astroglia and acts on the BBB, microglia and other neuroinflammatory cells. Thus, the vascular perspective of stroke research provides important input into the mechanisms on how endothelial cells and the BBB regulate inflammation in MS, particularly the invasion of immune cells into the CNS. In the current review we will first discuss pathogenesis of both diseases and current treatment regimens and will provide a detailed overview on pathways of immune cell migration across the barriers of the CNS and the role of activated astrocytes in this process. This article is part of a Special Issue entitled: Neuro inflammation: A common denominator for stroke, multiple sclerosis and Alzheimer's disease, guest edited by Helga de Vries and Markus Swaninger

Acid Sphingomyelinase-Derived Ceramide Regulates ICAM-1 Function during T Cell Transmigration across Brain Endothelial Cells

Multiple sclerosis (MS) is a chronic demyelinating disorder of the CNS characterized by immune cell infiltration across the brain vasculature into the brain, a process not yet fully understood. We previously demonstrated that the sphingolipid metabolism is altered in MS lesions. In particular, acid sphingomyelinase (ASM), a critical enzyme in the production of the bioactive lipid ceramide, is involved in the pathogenesis of MS; however, its role in the brain vasculature remains unknown. Transmigration of T lymphocytes is highly dependent on adhesion molecules in the vasculature such as intercellular adhesion molecule-1 (ICAM-1). In this article, we hypothesize that ASM controls T cell migration by regulating ICAM-1 function. To study the role of endothelial ASM in transmigration, we generated brain endothelial cells lacking ASM activity using a lentiviral shRNA approach. Interestingly, although ICAM-1 expression was increased in cells lacking ASM activity, we measured a significant decrease in T lymphocyte adhesion and consequently transmigration both in static and under flow conditions. As an underlying mechanism, we revealed that upon lack of endothelial ASM activity, the phosphorylation of ezrin was perturbed as well as the interaction between filamin and ICAM-1 upon ICAM-1 clustering. Functionally this resulted in reduced microvilli formation and impaired transendothelial migration of T cells. In conclusion, in this article, we show that ASM coordinates ICAM-1 function in brain endothelial cells by regulating its interaction with filamin and phosphorylation of ezrin. The understanding of these underlying mechanisms of T lymphocyte transmigration is of great value to develop new strategies against MS lesion formatio