1,637 research outputs found

    Functional characterization of 8-oxoguanine DNA glycosylase of Trypanosoma cruzi

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    The oxidative lesion 8-oxoguanine (8-oxoG) is removed during base excision repair by the 8-oxoguanine DNA glycosylase 1 (Ogg1). This lesion can erroneously pair with adenine, and the excision of this damaged base by Ogg1 enables the insertion of a guanine and prevents DNA mutation. In this report, we identified and characterized Ogg1 from the protozoan parasite Trypanosoma cruzi (TcOgg1), the causative agent of Chagas disease. Like most living organisms, T. cruzi is susceptible to oxidative stress, hence DNA repair is essential for its survival and improvement of infection. We verified that the TcOGG1 gene encodes an 8-oxoG DNA glycosylase by complementing an Ogg1-defective Saccharomyces cerevisiae strain. Heterologous expression of TcOGG1 reestablished the mutation frequency of the yeast mutant ogg1-/- (CD138) to wild type levels. We also demonstrate that the overexpression of TcOGG1 increases T. cruzi sensitivity to hydrogen peroxide (H2O2). Analysis of DNA lesions using quantitative PCR suggests that the increased susceptibility to H2O2 of TcOGG1-overexpressor could be a consequence of uncoupled BER in abasic sites and/or strand breaks generated after TcOgg1 removes 8-oxoG, which are not rapidly repaired by the subsequent BER enzymes. This hypothesis is supported by the observation that TcOGG1-overexpressors have reduced levels of 8-oxoG both in the nucleus and in the parasite mitochondrion. The localization of TcOgg1 was examined in parasite transfected with a TcOgg1-GFP fusion, which confirmed that this enzyme is in both organelles. Taken together, our data indicate that T. cruzi has a functional Ogg1 ortholog that participates in nuclear and mitochondrial BER. © 2012 Furtado et al

    Effect of farnesol on structure and composition of staphylococcus epidermidis biofilm matrix

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    Staphylococcus epidermidis is the most frequent cause of nosocomial sepsis and catheter-related infections in which biofilm formation is considered to be one of the main virulence mechanisms. Moreover, their increased resistance to conventional antibiotic therapy enhances the need to develop new therapeutical agents. Farnesol, a natural sesquiterpenoid present in many essential oils, has been described as impairing bacterial growth. The aim of this study was to evaluate the effect of farnesol on the structure and composition of biofilm matrix of S. epidermidis. Biofilms formed in the presence of farnesol (300 μM) contained less biomass, and displayed notable changes in the composition of the biofilm matrix. Changes in the spacial structure were also verified by confocal scanning laser microscopy (CSLM). The results obtained by the quantification of extracellular polymers and by wheat germ agglutinin (WGA) fluorescent detection of glycoproteins containing β(1→4)-N-acetyl-d-glucosamine support the hypothesis that farnesol causes disruption of the cytoplasmic membrane and consequently release of cellular content.Fernanda Gomes and Pilar Teixeira fully acknowledge the financial support of Fundacao para a Ciencia e Tecnologia (FCT) through the grants SFRH/BD/32126/2006 and SFRH/BPD/26803/2006, respectively

    Complete blood count parameters as biomarkers of retinopathy of prematurity: a Portuguese multicenter study

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    Purpose: To evaluate complete blood count (CBC) parameters in the first week of life as predictive biomarkers for the development of retinopathy of prematurity (ROP). Methods: Multicenter, prospective, observational study of a cohort of preterm infants born with gestational age (GA) < 32 weeks or birth weight < 1500 g in eight Portuguese neonatal intensive care units. All demographic, clinical, and laboratory data from the first week of life were collected. Univariate logistic regression was used to assess risk factors for ROP and then multivariate regression was performed. Results: A total of 455 infants were included in the study. The median GA was 29.6 weeks, and the median birth weight was 1295 g. One hundred and seventy-two infants (37.8%) developed ROP. Median values of erythrocytes (p < 0.001), hemoglobin (p < 0.001), hematocrit (p < 0.001), mean corpuscular hemoglobin concentration (p < 0.001), lymphocytes (p = 0.035), and platelets (p = 0.003) of the group of infants diagnosed with ROP any stage were lower than those without ROP. Mean corpuscular volume (MCV) (p = 0.044), red blood cell distribution width (RDW) (p < 0.001), erythroblasts (p < 0.001), neutrophils (p = 0.030), neutrophils-lymphocytes ratio (p = 0.028), and basophils (p = 0.003) were higher in the ROP group. Higher values of MCV, erythroblasts, and basophils remained significantly associated with ROP after multivariate regression. Conclusion: In our cohort, the increase in erythroblasts, MCV, and basophils in the first week of life was significantly and independently associated with the development of ROP. These CBC parameters may be early predictive biomarkers for ROP.info:eu-repo/semantics/publishedVersio

    Physical activity level in people with high blood pressure

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    This study aimed to analyze the level of physical activity for people with high blood pressure cared for in a health center. This cross-sectional study was conducted with 310 individuals between 18 and 69 years of age through the International Physical Activity Questionnaire (IPAQ). The majority (80%) of participants presented low or moderate levels of physical activity. The analysis of association between sociodemographic variables and physical activity level revealed that older men from the interior of the state with higher educational levels have a greater chance of exhibiting lower levels of physical activity. The logistic regression model revealed that origin, schooling and diabetes are predictors of low physical activity level. The conclusion is that part of the sample does not match the desirable profile to practice regular physical activity.El objetivo de este estudio fue analizar el nivel de actividad física de personas portadoras de hipertensión arterial, acompañadas en un centro de atención ambulatorial. Se trata de un estudio transversal desarrollado con 310 individuos de 18 a 69 años. Se utilizó como base el International Physical Activity Questionnaire (IPAQ). La mayor parte del grupo (80%) fue encuadrada en los niveles de baja y moderada actividad física. En el análisis de asociación entre las variables sociodemográficas y el nivel de actividad física, se verificó que personas del sexo masculino, procedentes del interior del Estado, con más edad y con mayor nivel de escolaridad son más propensas a desarrollar un nivel de actividad física bajo. En el modelo de regresión logística, la procedencia, tiempo de escolaridad y de diabetes fueron indicadores obtenidos como factores de predicción significativos para el nivel bajo de actividad física. Se concluye que parte de la muestra no posee un perfil deseable en relación a la práctica regular de actividad física.O objetivo desse estudo foi analisar o nível de atividade física de pessoas portadoras de hipertensão arterial, acompanhadas em centro de atendimento ambulatorial. É um estudo transversal desenvolvido com 310 indivíduos de 18 a 69 anos. Utilizou-se como base o International Physical Activity Questionnaire (IPAQ). A maior parcela do grupo (80%) foi enquadrada nos níveis de baixa e moderada atividade física. Na análise de associação entre as variáveis sociodemográficas e o nível de atividade física, verificou-se que pessoas do sexo masculino, procedentes do interior do Estado, mais velhas e com maior nível de escolaridade são mais propensas para desenvolver nível de atividade física baixo. No modelo de regressão logística, a procedência, tempo de escolaridade e de diabetes foram indicadores obtidos como preditores significantes para o nível baixo de atividade física. Concluiu-se que parte da amostra não possui perfil desejável em relação à prática regular de atividade física

    Electrospinning polypropylene with an amino acid as a strategy to bind the antimicrobial peptide Cys-LC-LL-37

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    Hospital isolation gowns are increasingly competitive, with brands and manufacturers contesting consumer preferences. The textile materials in contact with the skin can acquire secretions and multiresistant microorganisms, causing discomfort and health risks, respectively. A new nanofibrous substrate---polypropylene grafted with l-Cys---was developed with an increased crystallinity, providing its surface with --SH hooks necessary to efficiently cross-link the antimicrobial peptide Cys-LC-LL-37 in order to protect against nosocomial pathogens and their spread to community. Furthermore, this application does not require environmental control of humidity, and it is not susceptible to enzyme and microorganism degradation.The authors acknowledge the Fundação para a Ciência e Tecnologia (FCT) for the PhD Grant SFRH/ BD/91444/2012 and Programa Operacional Capital Humano (POCH) and European Union for co-funding the work.info:eu-repo/semantics/publishedVersio

    Biodiversity, Species Protection, and Animal Welfare Under International Law

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    The chapter explores the influence of the concept of animal welfare on international biodiversity law. A close examination of the recent evolution of this branch of international law shows that animal welfare has an ambivalent place in biodiversity-related agreements. Indeed, while welfare is only a faint consideration in the development of international regimes dealing with biodiversity as a whole, the concept has become an essential element for agreements dealing with the conservation of specific endangered species. Despite its role in these agreements, the place of animal welfare in international biodiversity law highlights that this corpus of rules is currently insufficient to be an effective tool for the protection of wildlife welfare. The last section of this study suggests that the adoption of international rules aiming at ensuring the protection of wild animals’ welfare could serve the double purpose of strengthening the conservation purpose of biodiversity regimes while also filling the welfare gap of international biodiversity law

    Cancer Survivor Study (CASUS) on colorectal patients: longitudinal study on physical activity, fitness, nutrition, and its influences on quality of life, disease recurrence, and survival. Rationale and design

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    Purpose: Evidence suggests that being physically active in combination with a healthy diet contributes to diminish colorectal cancer risk. However, if this is true for colorectal cancer primary prevention, the same is not clear for its recurrence after colorectal cancer treatments. Data on cancer survival are scarce, and there is a need for greater attention on these survivors’ lifestyle behavior. This manuscript describes rationale and design of the Cancer Survival Study (CASUS) on colorectal patients, a longitudinal observational study with the aim of investigating how physical activity, physical fitness, and dietary intake are related with their quality of life, disease recurrence, and survival. Methods: The CASUS on colorectal patients is a longitudinal cohort study on colorectal survivors, aged 18 years or older, recruited 6, 12, and 24 months after surgery. Upon recruitment, patients fill in a battery of questionnaires about physical activity, dietary intake, and quality of life, donate blood samples, do physical fitness tests, and use an accelerometer during 7 days. Repeated analyses will be performed to assess changes over time in physical activity, physical fitness, dietary intake, and other factors in relation to recurrence and survival. Conclusions: Results will contribute to highlight the role of physical activity, physical fitness, and nutrition in the quality of life of colorectal cancer survivors, recurrence, and survival. This study will provide important information for policymakers on the potential benefits of future physical activity and nutritional interventions, which are inexpensive, as a way to improve general health of colorectal cancer survivors.Luisa Soares-Miranda is supported by the grant SFRH/BPD/76947/2011 funded by FCT (QREN-POPH-Type 4.1-Advanced Training, subsidized by the European Social Fund and national funds of MEC), PTDC/DES/099018/2008-FCT/FCOMP-01-0124-FEDER-009573, and the Research Centre in Physical Activity Health and Leisure is supported by FCT: UID/DTP/00617/2013. Carla Costa is supported by the grant SFRH/BPD/96196/2013, funded by FCT (QREN-POPH-Type 4.1-Advanced Training, subsidized by the European Social Fund and national funds of MEC)
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