Impacto da Radioterapia no stress oxidativo em modelos celulares radiorresistentes em contexto de obesidade

Introdu����o: Estudos anteriores em modelos tumorais de glioma e melanoma, tumores radiorresistentes, indicaram que a obesidade pode estar relacionada com um aumento do status oxidativo e com a diminui����o da resist��ncia �� radia����o. Como a Radioterapia �� o tratamento frequentemente utilizado para esta patologia, propomo-nos, desta forma, a explorar a influ��ncia da obesidade em c��lulas de glioma, as BC3H1, e melanoma, B16F10, submetidas a Radioterapia, na presen��a de agentes oxidantes e antioxidantes, para o estudo da sua influ��ncia ao n��vel da viabilidade celular e do impacto do stress oxidativo. M��todos: As c��lulas BC3H1 e B16F10 foram tratadas com t-BOOH (150��M e 50 ��M, respetivamente), TUDCA (25��M e 1��M, respetivamente) e com a mistura de t-BOOH+TUDCA em meio DMEM sem soro e meio condicionado (CM), a partir de adip��citos 3T3-L1. Em seguida, parte das c��lulas foram irradiadas com uma dose total de 2Gy. Posteriormente avaliou-se a viabilidade celular (teste MTT) e o stress oxidativo (teste TBARS, atividade da catalase, concentra����o da GSH, e status antioxidante total), ��s 4h e 12h. Resultados: Observou-se um aumento da capacidade antioxidante total das c��lulas irradiadas, comparativamente com as c��lulas n��o irradiadas. O meio condicionado reduziu o stress oxidativo nas BC3H1, ao mesmo tempo que reduziu a sua viabilidade celular. O TUDCA nas c��lulas incubadas com MC e submetidas a radioterapia, tendencialmente diminuiu a viabilidade celular, nas concerta����es em estudo. Discuss��o/Conclus��o: O meio condicionado e a radioterapia, por si s��, aumentam a resposta antioxidante total na c��lula, ��s 4h e ��s 12h. O TUDCA nas c��lulas incubadas com meio condicionado e submetidas a radioterapia, teve um comportamento citot��xico para as BC3H1, nas concentra����es testadas. Revelando a necessidade de aprofundar os estudos da a����o deste composto como agente radiossensibilizador, neste e noutros modelos celulares de carcinog��nese.

Matem��tica 100 stress: um projeto aberto no IPP

A Era Tecnol��gica em que nos vemos inseridos, cujos avan��os acontecem a uma velocidade vertiginosa exige, por parte das Institui����es de Ensino Superior (IES) uma atitude proactiva no sentido de utiliza����o dos muitos recursos dispon��veis. Por outro lado, os elementos pr��prios da sociedade da informa����o ��� flexibilidade, forma����o ao longo da vida, acessibilidade �� informa����o, mobilidade, entre muito outros ��� atuam como fortes impulsionadores externos para que as IES procurem e analisem novas modalidades formativas. Perante a mobilidade crescente, que se tem revelado massiva, a aprendizagem tende a ser cada vez mais individualizada, visual e pr��tica. A conjuga����o de v��rias formas/tipologias de transmiss��o de conhecimento, de m��todos did��ticos e mesmo de ambientes e situa����es de aprendizagem induzem uma melhor adapta����o do estudante, que poder�� procurar aqueles que melhor v��o ao encontro das suas expetativas, isto ��, favorecem um processo de ensino-aprendizagem eficiente na perspetiva da forma de aprender de cada um. A defini����o de pol��ticas estrat��gicas relacionadas com novas modalidades de ensino/forma����o tem sido uma preocupa����o constante na nossa institui����o, nomeadamente no dom��nio do ensino �� dist��ncia, seja ele e-Learning, b-Learning ou, mais recentemente, ���open-Learning���, onde se inserem os MOOC ��� Massive Open Online Courses (n��o esquecendo a vertente m-Learning), de acordo com as v��rias tend��ncias europeias (OECD, 2007) (Comiss��o Europeia, 2014) e com os objetivos da ���Europa 2020���. Neste sentido surge o Projeto Matem��tica 100 STRESS, integrado no projeto e-IPP | Unidade de e-Learning do Polit��cnico do Porto que criou a sua plataforma MOOC, abrindo em junho de 2014 o seu primeiro curso ��� Probabilidades e Combinat��ria. Pretendemos dar a conhecer este Projeto, e em particular este curso, que envolveu v��rios docentes de diferentes unidades org��nicas do IPP.

Math without stress: an open online learning project

MOOC (as an acronym for Massive Open Online Courses) are a quite new model for the delivery of online learning to students. As ���Massive��� and ���Online���, these courses are proposed to be accessible to many more learners than would be possible through conventional teaching. As ���Open��� they are (frequently) free of charge and participation is not limited by the geographical situation of the learners, creating new learning opportunities in Higher Education Institutions (HEI). In this paper we describe a recently started project ���Matem��tica 100 STRESS��� (Math Without STRESS) integrated in the e-IPP project | e-Learning Unit of Porto���s Polytechnic Institute (IPP) which has created its own MOOC platform and launched its first course ��� Probabilities and Combinatorics ��� in early June/2014. In this MOOC development were involved several lecturers from four of the seven IPP schools.

Stress Ratio Effects on the fatigue Properties of Biaxially Loaded Tubular FRP-Specimens ��� Experimental Study

In this work tubular fiber reinforced specimens are tested for fatigue life. The specimens are biaxially loaded with tension and shear stresses, with a load angle �� of 30�� and 60�� and a load ratio of R=0,1. There are many factors that affect fatigue life of a fiber reinforced material and the main goal of this work is to study the effects of load ratio R by obtaining S-N curves and compare them to the previous works (1). All the other parameters, such as specimen production, fatigue loading frequency and temperature, will be the same as for the previous tests. For every specimen, stiffness, temperature of the specimen during testing, crack counting and final fracture mode are obtained. Prior to testing, a study if the literature regarding the load ratio effects on composites fatigue life and with that review estimate the initial stresses to be applied in testing. In previous works (1) similar specimens have only been tested for a load ratio of R=-1 and therefore the behaviour of this tubular specimens for a different load ratio is unknown. All the data acquired will be analysed and compared to the previous works, emphasizing the differences found and discussing the possible explanations for those differences. The crack counting software, developed at the institute, has shown useful before, however different adjustments to the software parameters lead to different cracks numbers for the same picture, and therefore a better methodology will be discussed to improve the crack counting results. After the specimen���s failure, all the data will be collected and stored and fibre volume content for every specimen is also determinate. The number of tests required to make the S-N curves are obtained according to the existent standards. Additionally are also identified some improvements to the testing machine setup and to the procedures for future testing.

Oxidative stress in pregnancy and fertility pathologies

Oxidative stress designates the state of imbalance between reactive oxygen species (ROS) production and antioxidant levels. In a healthy placenta, there is an increase in ROS production, due to formation of new tissues and inherent metabolism, but this is balanced by higher levels of antioxidants. However, this balance is lost in some situations, with a consequent increase in oxidative stress levels. Oxidative stress has been implicated in several placental disorders and pregnancy pathologies. The present review intends to summarize what is known about the relationship between oxidative stress and well-known pregnancy disorders.

A influ��ncia do modelo pedag��gico em vari��veis psicol��gicas de estudantes do 1�� ano da ESTSP-IPP

Introdu����o ��� A adapta����o ao ensino superior reveste-se de experi��ncias acad��micas que podem constituir fonte de stress para os estudantes. A implementa����o de novos modelos pedag��gicos, no ��mbito do processo de Bolonha, introduz novas vari��veis cujo impacto, designadamente em termos de sa��de, importa conhecer. Este estudo tem como objetivo analisar as associa����es entre modelo pedag��gico (Problem Based Learning ��� PBL vs. modelos pr��ximos do tradicional) e vari��veis psicol��gicas (coping, desregula����o emocional, sintomas psicossom��ticos, perce����o de stress e afeto). Metodologia ��� O estudo tem um design transversal. Foram usados os seguintes question��rios online: Brief-COPE, Escala de Dificuldades de Regula����o Emocional, Question��rio de Manifesta����es F��sicas de Mal-Estar, Escala de Stress Percebido e Escala de Afeto Positivo e Negativo. A amostra �� constitu��da por 183 estudantes do primeiro ano (84% do g��nero feminino) de cursos da Escola Superior de Tecnologia da Sa��de do Porto ��� Instituto Polit��cnico do Porto (ESTSP-IPP). Resultados ��� Foram encontradas correla����es significativas entre as vari��veis demogr��ficas e psicol��gicas. Considerando diferentes modelos pedag��gicos, foram encontradas diferen��as significativas nas vari��veis psicol��gicas. Os principais preditores de stress na amostra foram: ser mulher, frequentar uma licenciatura no modelo PBL, ter maiores ��ndices de desregula����o emocional, apresentar mais sintomas psicossom��ticos, menos afeto positivo e mais afeto negativo. Conclus��o ��� As diferen��as encontradas entre modelos pedag��gicos s��o discutidas, possibilitando a reflex��o sobre as implica����es pr��ticas e sugest��es para futuras investiga����es.

Psychometric Properties of the Portuguese Version of the Posttraumatic Growth Inventory Short Form Among Divorced Adults

The aim of this study was to develop and validate a Portuguese version of the Short Form of the Posttraumatic Growth Inventory (PTGI-SF). Using an online convenience sample of Portuguese divorced adults (N = 482), we confirmed the oblique five-factor structure of the PTGI-SF by confirmatory factor analysis. The results demonstrated the measurement invariance across divorce initiator status groups. Total score and factors of PTGI-SF showed good internal consistency, with the exception of the New Possibilities factor, which revealed an acceptable reliability. The Portuguese PTGI-SF showed a satisfactory convergent validity. In terms of discriminant validity, posttraumatic growth assessed by the Portuguese PTGI-SF was a distinct factor from posttraumatic psychological adjustment. These preliminary findings suggest the cultural adaptation and also psychometric properties of the present Portuguese PTGI-SF to measure posttraumatic growth after personal crisis.

Heat stress adaptation in hyperthermophiles: bosynthesis of inositol-containing compatible solutes

Dissertation presented to obtain the Ph.D. degree in Biochemistry

Disposable immunosensor using a simple method for oriented antibody immobilization for label-free real-time detection of an oxidative stress biomarker implicated in cancer diseases

This work proposes a novel approach for a suitable orientation of antibodies (Ab) on an immunosensing platform, applied here to the determination of 8-hydroxy-2���-deoxyguanosine (8OHdG), a biomarker of oxidative stress that has been associated to chronic diseases, such as cancer. The anti-8OHdG was bound to an amine modified gold support through its Fc region after activation of its carboxylic functions. Non-oriented approaches of Ab binding to the platform were tested in parallel, in order to show that the presented methodology favored Ab/Ag affinity and immunodetection of the antigen. The immunosensor design was evaluated by quartz-crystal microbalance with dissipation, atomic force microscopy, electrochemical impedance spectroscopy (EIS) and square-wave voltammetry. EIS was also a suitable technique to follow the analytical behavior of the device against 8OHdG. The affinity binding between 8OHdG and the antibody immobilized in the gold modified platform increased the charge transfer resistance across the electrochemical set-up. The observed behavior was linear from 0.02 to 7.0 ng/mL of 8OHdG concentrations. The interference from glucose, urea and creatinine was found negligible. An attempt of application to synthetic samples was also successfully conducted. Overall, the presented approach enabled the production of suitably oriented Abs over a gold platform by means of a much simpler process than other oriented-Ab binding approaches described in the literature, as far as we know, and was successful in terms of analytical features and sample application.

A molecularly imprinted sensor for sensitive detection of 8-hydroxy-2'-deoxyguanosine (8-OHdG) oxidative stress biomarker

6th Graduate Student Symposium on Molecular Imprinting

A biomimetic sensor for monitoring oxidative stress biomarker in point-of-care

1st ASPIC International Congress

Functional and molecular characterization of SR45, a plant-specific factor involved in sugar and stress signaling in Arabidopsis thaliana

Dissertation presented to obtain the Ph.D degree in Molecular Biology

Aborto recorrente das causas na mulher ��s consequ��ncias para o casal

RESUMO: O aborto recorrente (AR) �� um evento extremamente traum��tico com grande impacto na vida dos casais. Apesar de avan��os significativos verificados na investiga����o m��dica, cerca de 50% dos casos continua sem uma causa identificada. Alguns aspectos como a caracteriza����o inadequada das doentes e das perdas gestacionais, assim como diferentes metodologias utilizadas no seu estudo, t��m influenciado a preval��ncia de alguns dos factores causais e dificultado a compreens��o do AR. Da mesma forma, pouco se sabe sobre as diferen��as de g��nero na viv��ncia psicol��gica do aborto recorrente e das suas eventuais repercuss��es para o relacionamento do casal, centrando-se os poucos estudos existentes preferencialmente na mulher. Por esta raz��o, o objectivo desta tese foi a caracteriza����o dos factores m��dicos associados ao AR e das consequ��ncias psicol��gicas desta entidade, contribuindo para promover estrat��gias cl��nicas baseadas na evid��ncia espec��fica. Na primeira parte desta tese (cap��tulos 1 e 2), ap��s uma breve introdu����o geral e atrav��s de uma revis��o da literatura, efectua-se uma reflex��o sobre o tema, abordando a epidemiologia do aborto recorrente, os factores m��dicos e os aspectos psicol��gicos associados. Nos cap��tulos 3 e 4 descrevemos tr��s estudos efectuados em mulheres portuguesas com aborto recorrente. O primeiro estudo teve por objectivo caracterizar os factores m��dicos e determinar o padr��o da perda recorrente de gravidez, numa coorte de mulheres submetidas a um protocolo de diagn��stico definido. As participantes foram agrupadas de acordo com a paridade (AR prim��rio ou secund��rio) e a idade gestacional das perdas (embrion��rias ou fetais). As anomalias da cavidade uterina, a SAAF e as transloca����es equilibradas parentais foram os factores mais prevalentes. 15,6% das participantes eram obesas. Em 55,5% dos casos n��o foi identificado nenhum factor. A hist��ria obst��trica materna influenciou significativamente os resultados encontrados: os factores anat��micos e a SAAF foram mais prevalentes em nul��paras e as perdas inexplicadas foram mais frequentes em mulheres com AR secund��rio. Assim, os nossos dados refor��am os resultados de pesquisas anteriores sobre a import��ncia da obesidade, da s��ndrome de anticorpos antifosfol��pidos e das anomalias uterinas estruturais como factores associados ao AR e mostram que os a paridade �� um moderador da import��ncia desses factores. Cap��tulo 6 94 A aus��ncia de resultados consensuais na literatura sobre a etiologia do AR condiciona a pesquisa sistem��tica de alguns factores, envolvendo exames dispendiosos, muitas vezes sem que exista evid��ncia que suporte a sua associa����o com esta entidade. A trombofilia heredit��ria �� uma das condi����es frequentemente investigadas nestas doentes. O nosso segundo estudo pretende contribuir para clarificar o papel de duas muta����es (factor V Leiden e protrombina G20210A) na perda recorrente de gravidez e esclarecer a necessidade do seu rastreio nestas situa����es. Foi efectuada a pesquisa destes polimorfismos em 100 mulheres com AR inexplicado e num grupo de controlo de mult��paras sem hist��ria de perdas de gravidez. Na nossa amostra n��o se verificou uma associa����o entre perdas embrion��rias recorrentes e estas muta����es. Nas mulheres com este tipo de perdas, a preval��ncia do FLV foi inclusive menor do que a verificada nos controlos. Pelo contr��rio, nas participantes com perdas fetais a preval��ncia destes polimorfismos foi muito superior �� verificada nos controlos, sugerindo uma poss��vel associa����o entre estas duas entidades. A pequena dimens��o deste ��ltimo subgrupo de mulheres, n��o nos permitiu contudo tirar conclus��es. Uma investiga����o prospectiva multic��ntrica �� necess��ria antes de recomendar a pesquisa da trombofilia heredit��ria na investiga����o do AR. Procur��mos incluir tamb��m nesta tese uma dimens��o psicol��gica e contribuir assim para o conhecimento dos processos relacionais originados pelo AR. No terceiro estudo foram investigadas as diferen��as de g��nero na viv��ncia do AR e o seu impacto no relacionamento e sexualidade do casal. Participaram neste estudo 30 casais sem filhos, com pelo menos 3 abortos espont��neos consecutivos. Cada membro do casal respondeu a um conjunto de question��rios (Impact of Events Scale, Perinatal Grief Scale, Partnership Questionnaire e Intimate Relationship Scale). Os resultados mostram que as mulheres sofrem mais intensamente do que os homens com o AR, relacionando-se a intensidade do seu sofrimento com a qualidade do relacionamento conjugal. A sexualidade do casal �� tamb��m afectada pelo stress e pelo sofrimento associados ao AR. Uma avalia����o e acompanhamento deste tipo de problemas s��o imprescind��veis para ajudar estes casais a manterem a qualidade afectiva e sexual da sua rela����o. Finalmente, no cap��tulo 5 sumari��mos as conclus��es de toda a contribui����o pessoal para a investiga����o sobre os factores associados e repercuss��es para o casal da perda recorrente de gravidez.-------------------ABSTRACT: Recurrent miscarriage (RM), a rare condition, has been described as a traumatic event for couples. Parental chromosomal anomalies, maternal thrombophilic disorders and structural uterine anomalies have been directly associated with RM. However, despite significant advances in medical research, the vast majority of cases remain unexplained. Aspects as the ethnic diversity of the population with different expression of genes, the inappropriate characterization of patients and of pregnancy losses, as well as different methodologies used in their study, have influenced the prevalence of etiological factors and have hampered the understanding of this problem. Similarly, little is known about gender differences in psychological experience of RM and its implications for the relationship of the couple. The first objective of this thesis is the characterization of the medical factors and of the psychological consequences related with RM, in the Portuguese population, helping to promote specific evidence-based clinical strategies. In the first part of this thesis, and after a brief general introduction (Chapter 1), a critical review of literature on the definition, the epidemiology and the dimensions involved, with a special emphasis on associated medical and psychological aspects of recurrent miscarriage, is presented (Chapter 2). In Chapters 3 and 4 we describe three studies carried out in Portuguese couples with RM. The first study aimed to investigate the etiological factors and the pattern of pregnancy loss in a cohort of women with RM. Subjects were divided in groups according to their parity (primary or secondary RM) and time of pregnancy loss (embryonic or fetal). Parental chromosome anomalies, uterine anomalies and antiphospholipid syndrome were the most prevalent medical factors. 15.6% of the women were obese. In the majority of cases (55.5%) no identifiable cause was detected. Parity influenced significantly our results. There was a higher prevalence of anatomic factors and antiphospholipid syndrome in primary RM. On the other hand, unexplained losses were more frequent in secondary RM. Except for the parental chromosomal abnormalities; the frequency of risk factors was similar among women with fetal or embryonic losses. Our data emphasizes the results of previous research on the importance of obesity, antiphospholipid syndrome and structural uterine abnormalities as known risk factors for RM, and shows that parity is an important moderator of the weight of those risk factors. Our second study aims to clarify the role of two mutations (factor V Leiden and prothrombin G20210A) and elucidate the need for their screening in Portuguese women with RM. FVL and PT G20210A analysis was carried out in 100 women with three or more consecutive miscarriages and a control group of 100 parous controls with no history of pregnancy losses. Secondary analysis was made regarding gestational age at miscarriage (embryonic and fetal loss). Overall the prevalence of FVL and PT G20210A was similar in RM women compared with controls. In the RM embryonic subgroup of women, FVL prevalence was inclusively lower than that of controls. Conversely in women with fetal losses both polymorphisms were much more frequent, although statistical significance was not reached due to the small size of this subgroup of patients. These data indicate that inherited maternal thrombophilia is not associated with RM prior to 10 weeks of gestation. Therefore, its screening is not indicated as an initial approach in Portuguese women with RM and a negative personal history of thromboembolic.96 Our second study aims to clarify the role of two mutations (factor V Leiden and prothrombin G20210A) and elucidate the need for their screening in Portuguese women with RM. FVL and PT G20210A analysis was carried out in 100 women with three or more consecutive miscarriages and a control group of 100 parous controls with no history of pregnancy losses. Secondary analysis was made regarding gestational age at miscarriage (embryonic and fetal loss). Overall the prevalence of FVL and PT G20210A was similar in RM women compared with controls. In the RM embryonic subgroup of women, FVL prevalence was inclusively lower than that of controls. Conversely in women with fetal losses both polymorphisms were much more frequent, although statistical significance was not reached due to the small size of this subgroup of patients. These data indicate that inherited maternal thrombophilia is not associated with RM prior to 10 weeks of gestation. Therefore, its screening is not indicated as an initial approach in Portuguese women with RM and a negative personal history of thromboembolic. In our third study, we investigate gender differences in RM experience and its impact on the couple's relationship and sexuality. Each member of 30 couples with RM answered a set of questionnaires, including the Impact of Events Scale (Horowitz et al., 1979), the Perinatal Grief Scale (Toedter et al., 1988), the Partnership Questionnaire (Hahlweg, 1979) and the Intimate Relationship Scale (Hetherington e Soeken, 1990). Results showed that men do grieve, but less intensely than women. Although the quality of the couple���s relationship seemed not to be adversely affected by RM, both partners described sexual changes after those events. Grief was related to the quality of communication in the couple for women, and to the quality of sex life for men. An understanding of such issues is critical in helping these couples to maintain sexual and affective quality of their relationship. Finally, in Chapter 5, conclusions and clinical implications of all personal contribution to the investigation on associated factors and relational consequences of recurrent miscarriage are presented.