70 research outputs found

    Alterações mitocondriais em células neurais em resposta à adaptação ao estresse

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    O estresse é uma resposta não específica do organismo a ameaças à sua homeostase e o estresse crônico parece contribuir para o desenvolvimento de diversas patologias. Em situações estressantes são liberados glicocorticóides (GCs) pelo córtex adrenal, os quais se ligam aos receptores de glicocorticóides (RGs) para exercer suas ações. As mitocôndrias são organelas com diversas funções, dentre elas, a geração de energia na célula. Nos neurônios elas são essenciais para a função sináptica e sobrevivência neuronal, e podem ser encontradas tanto no corpo quanto na região sináptica. Uma vez que os GCs estão envolvidos na expressão de proteínas mitocondriais, alterações nos níveis de GCs ou RGs podem afetar as mitocôndrias e, consequentemente, a célula como um todo. Nessa tese, o foco de estudo foram as alterações que os GCs podem provocar na mitocôndria do sistema nervoso. No Capítulo I desta tese foi investigado os efeitos do estresse crônico por contenção sobre a cadeia respiratória mitocondrial e o conteúdo de RGs, de estriado, hipocampo e córtex de ratos machos e fêmeas, bem como a massa mitocondrial (MM) e o potencial de membrana mitocondrial (PMM) em dissociado de células e sinaptossomas destas mesmas estruturas cerebrais. Foi verificado que a resposta ao estresse envolveu alterações mitocondriais de forma sexo-específica, porém, não foi possível esclarecer se houve alteração na quantidade de mitocôndrias nestas respostas ao estresse. No Capítulo II estudamos se a ativação direta dos RGs com doses não tóxicas de dexametasona (DEX) provocaria alteração na quantidade de mitocôndrias em curto prazo. Para isso, células SH-SY5Y diferenciadas com ácido retinóico, que são corriqueiramente utilizadas como modelo neuronal, foram tratadas por 24 ou 48 horas com diferentes doses não tóxicas de DEX e foram avaliados MM e PMM. A DEX per se não afetou, em nenhuma dose ou tempo de tratamento, nem a MM, nem o PMM das células SHSY5Y diferenciadas, portanto, nos tempos e doses testadas, não altera a quantidade de mitocôndrias. No Capítulo III testamos os efeitos de altas doses de corticosterona (CORT) por um período mais longo, in vivo permitindo assim adaptações do animal. As estruturas analisadas foram hipocampo e estriado de camundongos machos, e as análises foram realizadas em células totais e sinaptossomas. Também testamos o efeito da diminuição dos GCs no cérebro utilizando um modelo hipocorticóide com DEX. O tratamento com DEX aumentou a MM e PMM de células totais, MM de neurônios e PMM de sinaptossomas de hipocampo; em estriado, reduziu a MM. O tratamento com CORT aumentou MM e PMM de sinaptossomas de estriado. Portanto, neste capítulo verificamos que a depleção dos GCs com DEX gerou aumento na quantidade de mitocôndrias no hipocampo demonstrada pelos aumentos na MM e PMM. Esse aumento na quantidade de mitocôndrias no corpo celular se refletiu também em um aumento na quantidade de mitocôndrias nos sinaptossomas. Com esse estudo concluímos que os principais efeitos do estresse sobre as mitocôndrias neuronais parecem ocorrer por diminuição da sensibilidade aos GCs e não pela presença de altas doses do hormônio. Essas alterações parecem ser adaptativas, favorecendo o manejo do estresse pelo animal, porém são necessários mais estudos para avaliar se, a mais longo prazo, essas adaptações continuam ocorrendo e como essas células adaptadas irão responder a insultos.Stress is a non-specific response to factors that threatens homeostasis and chronic stress seems to contribute to the development of several pathologies. In stressful situations, adrenal cortex releases glucocorticoids (GCs) which bind to glucocorticoid receptors (RGs) to exert their actions. Mitochondria are organelles with several functions, among them, the energy generation in the cell. In neurons they are essential for synaptic function and neuronal survival, and can be found in both the body and the synaptic region. Since GCs are involved in mitochondrial protein expression, changes in GCs or RGs may affect mitochondria and, consequently, the cell as a whole. In this thesis our focus was the changes that GCs can cause in the mitochondria present in the nervous system. In Chapter I we investigated the effects of chronic restraint stress on the mitochondrial respiratory chain and the RG content in striatum, hippocampus and cortex of male and female rats, as well as mitochondrial mass (MM) and mitochondrial membrane potential (PMM) in dissociated cells and synaptosomes in these same brain structures. It was verified that the stress response involved mitochondrial alterations in a sex-specific way; however, it was not possible to clarify if there was alteration in mitochondria quantity in these stress responses. In Chapter II we studied whether the direct RG activation with non-toxic doses of dexamethasone (DEX) would cause in short term changes in the mitochondrial amount. For this, retinoic acid-differentiated SH-SY5Y cells, which are commonly used as neuronal model, were treated for 24 or 48 hours with different non-toxic doses of DEX and were evaluated MM and PMM. DEX per se did not affect, at any dose or time of treatment, either MM or PMM of differentiated SH-SY5Y cells, therefore at the times and doses tested it does not alter the mitochondrial amount. In Chapter III we tested the effects of high doses of corticosterone (CORT) for a longer period, in vivo thus allowing animal adaptations to GC. We analyzed male mice’s hippocampus and striatum, and analyzes were performed on total cells and synaptosomes. We also tested the effect of GC decrease in the brain using a hipocorticoid model with DEX. Treatment with DEX increased the MM and PMM of total cells, MM of neurons and in PMM of hippocampal synaptosomes; in striatum, MM was reduced. Treatment with CORT increased synaptosomal MM and PMM in striatum. Therefore, in this chapter we verified that GCs depletion with DEX generated an increase in the mitochondrial amount in hippocampus demonstrated by increases in MM and PMM. This increase in the amount of mitochondria in the cell body was also reflected in an increase in the synaptosomal amount of mitochondria. With this study we conclude that the main effects of stress on neuronal mitochondria seem to occur due to decreased sensitivity to GCs and not to high doses of the hormone. These changes appear to be adaptive, favoring animal stress management, but further studies are needed to assess whether these adaptations continue to occur in the longer term and how these adapted cells will respond to insults

    Um problema de afetação de pessoal a clientes de uma empresa de serviços domésticos

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    Mestrado em Decisão Económica e EmpresarialO presente trabalho final de mestrado é apresentado sob a forma de trabalho de projeto, em que se aplicam métodos e conhecimentos de Investigação Operacional e Computação, adquiridos ao longo do curso, à resolução de um problema real com que se deparou uma instituição de solidariedade social, a Pressley Ridge. Este problema que a instituição designa de "projeto Marias" consiste em promover o encontro entre os pedidos de clientes que procuram quem lhes faça determinados serviços domésticos e as funcionárias da instituição com formação para prestar os serviços procurados. Para conciliar os pedidos com as disponibilidades das funcionárias é preciso fazer a afetação de funcionárias a clientes, respeitando um conjunto de condições impostas por ambas as partes. Neste trabalho propõe-se um modelo de programação linear binária para descrever matematicamente o problema. Este modelo tem por base o problema de afetação clássico, no qual se incorporam restrições adicionais. Foram desenvolvidas duas heurísticas, uma construtiva e uma melhorativa para resolver o problema nos casos em que a dimensão não permite a resolução pelo Solver Premium Pro (Premium Solver Pro, 2006-2013), um suplemento do Excel. Quer as heurísticas, quer os procedimentos de tratamento dos ficheiros de dados e de apresentação de resultados foram programados em Visual Basic. Para comparar os diferentes métodos de resolução é realizada experiência computacional considerando um conjunto de instâncias de teste. São apresentadas conclusões acerca da qualidade das heurísticas e do desempenho do Solver Premium do Excel.This final master thesis is presented in the form of work project on the application of methods and acquired knowledge on Operations Research and Computer Science to the resolution of a real problem found by a private institution of social solidarity, the Pressley Ridge. This problem designated by the institution as "Projeto Marias" has the purpose of matching the requests of customers looking for people who do certain domestic services and trained employees of the institution who can provide the requested services. To match the clients' requests and employees' availability one has to assign employees to customers, respecting a set of conditions imposed by both parts. This paper proposes a binary linear programming model to mathematically describe the problem. The model is based on the classic assignment problem, where additional constraints are incorporated. Two heuristics were developed to provide feasible solutions for large instances that Premium Solver Pro (Premium Solver Pro, 2006-2013), an Excel add-in, could not solve. Either the heuristics or the procedures for input and output data files management were coded in Visual Basic. To compare the different methods computational experiment was carried out on a set of test instances. Conclusions are drawn about the quality of the heuristics and the performance of Excel Solver Premium

    O DISCURSO NAS METODOLOGIAS ATIVAS NA ENGENHARIA DE ALIMENTOS: UM RELATO

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    Vivemos um tempo de constantes mudanças, e é inegável que essas mudanças são muito mais notórias na área da tecnologia. Com essa desenfreada corrida tecnológica vemos a necessidade de nos adequar e inserir tais tecnologias nas mais diferentes áreas. A educação como não seria diferente passa por esse processo de mudança e inserção de tecnologias e novas técnicas de ensino, no entanto diferentemente de outras áreas abre uma espaço para discussão de quão eficiente são os novos meios. O objetivo deste trabalho é analisar o conceito de discurso presente no tema metodologias ativas na educação, utilizando-se de pesquisa bibliográfica para obtenção de fundamentação teórica necessária para reflexão temática do problema formulado. Como resultados foram verificadas reflexões sobre um discurso que com urgência adquire força devido ao momento histórico que passamos, os avanços e mudanças sociais cada vez mais se adentram no campo da educação, em forma de discurso pró metodologias ativas, promovendo mudanças constantes no modo como ensinamos e aprendemos

    Test-Retest Reliability of Automatic and Manual Image Analyses of Muscle Size

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    Brightness-mode (B-mode) ultrasound is a non-invasive imaging modality that has risen in popularity. In research settings, B-mode ultrasound is often used to assess skeletal muscle size via the quantification of the anatomical cross-sectional area (ACSA). Typically, these images are analyzed by an experienced investigator using open-source software, though it is a time-consuming process that may introduce implicit bias into the analysis. Recently, a novel, automatic ultrasound image analysis tool has been developed which may reduce bias and increase the reliability of ultrasound ACSA image analysis. PURPOSE: The purpose of the project was to compare the test-retest reliability of manual and automatic ACSA quantification techniques. METHODS: Nine participants (mean ± SD: age = 25 ± 3 years; BMI = 23.96 ± 2.62 kg/m2) completed one laboratory visit where each participant had non-invasive ultrasound imaging performed on their rectus femoris (i.e., RF) for two data collection trials separated by 10 minutes. For each participant, ultrasound image settings were held constant (i = 6 cm, frequency = 10 MHz, gain = 52 dB). All images were manually analyzed by an experienced technician using an open-source image analysis tool. The investigator would carefully select only the surrounding muscle fascia of the RF. Automatic analyses were performed using DeepACSA, a deep learning approach for the assessment of ACSA. Both manual and automatic analyses were conducted on all images. Analysis of variance (ANOVA) was conducted to compare differences between trials and test-retest reliability (i.e., intraclass correlation coefficients [ICC] model 2,1, standard error of measure expressed as a percentage of the mean [SEM%], and the minimal differences [MD] values needed to be considered real) were calculated from the ANOVA output. RESULTS: The manual analyses of ACSA (p = 0.20, ICC2,1 = 0.84, SEM (%) = 11.67%, MD = 1.75 cm2) were more reliable than the DeepACSA analyses (p = 0.13, ICC2,1 = 0.47, SEM (%) = 30.28%, MD = 4.70 cm2). CONCLUSION: The results of the present investigation suggest that the DeepACSA approach may be less reliable compared to the manual quantification of RF muscle size. Future studies should investigate using a larger sample size and additional muscle groups

    Physical activity and dietary habits in portuguese college students

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    The present study aimed to investigate the association between time spent on the practice of physical activity and dietary habits in college students. This is a transversal and correlational study, which has a sample of 121 students aged between 18 and 28 years old. Data were collected through three questionnaires, socio-demographic, time management and food diary; the latter two were fi lled for 3 days. Subsequently, a descriptive and inferential statistical analysis was used. To investigate the association between time spent on the practice of physical activity and dietary habits in college students we used the test of Spearman correlation and Kendall´s test, assuming a confidence interval of 95%. 81.8% of the sample were female and 18.2% male. About the practice of physical activity it was found that 21% were sedentary/low active and 79% active/very active. From the active/very active students 88,5% revealed a non-recommended intake of fat and all of the sedentary/low active students presented a non-recommended consumption of protein. From the present results it can be concluded that dietary habits are not correlated with time spent on physical activity. Such as this study,Ottevaere et al. (2011) concluded that no statistical differences were found in energy intake between the levels of physical activity but they observed an inverse association between the consumption of cereal and physical activity level. Many studies observed positive associations between the consumption of fi ber and protein and physical activity level. These results are in discrepancy with our findings. So, it is noteworthy that longitudinal studies are necessary to examine the energy balance among these students to obtain more accurate conclusions

    Bismuth subcitrate, metronidazole and tetracycline – a rare cause of drug-induced liver injury

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    Drug-induced liver injury (DILI) is a liver condition caused by any drug or toxic substance. The spectrum of DILI manifestations can range from asymptomatic elevation of liver enzymes to acute liver failure. Antibiotics are one of the major causes of DILI. The authors report the case of a 37-year-old male with nausea, right hypochondrium pain and fever with history of bismuth subcitrate, metronidazole and tetracycline combination treatment in the previous five days. DILI was suspected and other aetiologies of acute hepatitis were excluded such as viral, autoimmune or even haemochromatosis and Wilson’s disease. Liver biopsy was performed, being compatible with the diagnosis of DILI; DILI is a diagnosis of exclusion. Bismuth subcitrate, metronidazole and tetracycline combination treatment is a rare cause of DILI

    Associativismo na cidade de Wanderlândia – Tocantins

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    Trabalho apresentado no II Congresso Nacional do PROJETO RONDON, realizado em Florianópolis, SC, no período de 23 a 25 de setembro de 2015 - Universidade Federal de Santa Catarina.O associativismo é uma forma coletiva de atuação representativa. Pode existir de maneira formal ou informal e tem como intuito estimular pessoas ou empresas a buscar a melhoria técnica, de relacionamento profissional e social dos seus associados. Nesse aspecto e reconhecendo o potencial turístico da cidade de Wanderlândia no estado do Tocantins, foi ministrada, durante a Operação Itacaiúnas, a Oficina de Associativismo em três momentos distintos e com os seguintes tópicos: a) passo a passo da formação de associações; b) elaboração de projetos; c) captação de recursos e fontes de financiamento. Todas as atividades foram realizadas no Centro Municipal de Educação Infantil (CMEI) e tiveram como público alvo associações, pessoas interessadas em formar associações e funcionários da prefeitura. No primeiro momento foram abordados os assuntos referentes a importância e a formação de associações. Já no segundo momento foram apresentados os elementos essenciais de projetos de ação. E finalmente focou-se em elementos de captação de recursos e informações sobre financiamentos governamentais e não governamentais. Para embasamento teórico, foram utilizados os pressupostos da economia solidária, onde o diferencial está na ideia da solidariedade no centro da atividade econômica, além de ser uma alternativa superior ao capitalismo, criada para que às pessoas que a abracem, enquanto produtoras, poupadoras, consumidoras, uma vida melhor. O Objetivo da atividade foi orientar e motivar a população a formar associações para desenvolver e potencializar o turismo local e a partir do que foi discutido nas oficinas elas possam tornar a cidade mais bem organizada e estruturada. A adesão foi dos representantes locais, tendo chegado a 15 participantes. Acreditamos que teremos como resultado a melhoria da cidade, afinal, observamos no momento “Desbravando minha terra: conhecendo os potenciais turísticos” a beleza, espaço e hospitalidade que podem ser o “start” para maior rentabilidade de Wanderlândia

    Sugarcane light-colored lignin: a renewable resource for sustainable beauty

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    Lignin has emerged as a promising eco-friendly multifunctional ingredient for cosmetic applications, due to its ability to protect against ultraviolet radiation and its antioxidant and antimicrobial properties. However, its typical dark color and low water solubility limit its application in cosmetics. This study presents a simple process for obtaining light-colored lignin (LCLig) from sugarcane bagasse (SCB) alkaline black liquor, involving an oxidation treatment with hydrogen peroxide, followed by precipitation with sulfuric acid. The physico-chemical characterization, antioxidant and emulsifying potential of LCLig, and determination of its safety and stability in an oil-in-water emulsion were performed. A high-purity lignin (81.6%) with improved water solubility was obtained, as a result of the balance between the total aromatic phenolic units and the carboxylic acids. In addition, the antioxidant and emulsifying capacities of the obtained LCLig were demonstrated. The color reduction treatment did not compromise the safety of lignin for topical cosmetic applications. The emulsion was stable in terms of organoleptic properties (color, pH, and viscosity) and antioxidant activity over 3 months at 4, 25, and 40 °C.info:eu-repo/semantics/publishedVersio

    Sex-dependent effect on mitochondrial and oxidative stress parameters in the hypothalamus induced by prepubertal stress and access to high fat diet

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    Objective: Some factors related to lifestyle, including stress and high-fat diet (HFD) consumption, are associated with higher prevalence of obesity. These factors can lead to an imbalance between ROS production and antioxidant defenses and to mitochondrial dysfunctions, which, in turn, could cause metabolic impairments, favoring the development of obesity. However, little is known about the interplay between these factors, particularly at early ages, and whether long-term sex-specific changes may occur. Here, we evaluated whether social isolation during the prepubertal period only, associated or not with chronic HFD, can exert long-term effects on oxidative status parameters and on mitochondrial function in the whole hypothalamus, in a sex-specific manner. Methods: Wistar male and female rats were divided into two groups (receiving standard chow or standard chow + HFD), that were subdivided into exposed or not to social isolation during the prepubertal period. Oxidative status parameters, and mitochondrial function were evaluated in the hypothalamus in the adult age. Results: Regarding antioxidant enzymes activities, HFD decreased GPx activity in the hypothalamus, while increasing SOD activity in females. Females also presented increased total thiols; however, non-protein thiols were lower. Main effects of stress and HFD were observed in TBARS levels in males, with both factors decreasing this parameter. Additionally, HFD increased complex IV activity, and decreased mitochondrial mass in females. Complex I-III activity was higher in males compared to females. Conclusion: Stress during the prepubertal period and chronic consumption of HFD had persistent sex-specific effects on oxidative status, as well as on its consequences for the cell and for mitochondrial function. HFD had more detrimental effects on females, inducing oxidative imbalance, which resulted in damage to the mitochondria. This HFD-induced imbalance may be related to the development of obesity
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