673 research outputs found

    It comes from the sea: macroalgae-derived bioactive compounds with anti-cancer potential

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    Nature derived compounds represent a valuable source of bioactive molecules with enormous potential. The sea is one of the richest environments, full of skilled organisms, where algae stand out due to their unique characteristics. Marine macroalgae adapt their phenotypic characteristics, such as chemical composition, depending on the environmental conditions where they live. The compounds produced by these organisms show tremendous potential to be used in the biomedical field, due to their antioxidant, anti-inflammatory, immunomodulatory, and anti-cancer properties. Cancer is one of the deadliest diseases in the world, and the lack of effective treatments highlights the urgent need for the development of new therapeutic strategies. This review provides an overview of the current advances regarding the anti-cancer activity of the three major groups of marine macroalgae, i.e., red algae (Rhodophyta), brown algae (Phaeophyceae), and green algae (Chlorophyta) on pancreatic, lung, breast, cervical, colorectal, liver, and gastric cancers as well as leukemia and melanoma. In addition, future perspectives, and limitations regarding this field of work are also discussed.info:eu-repo/semantics/publishedVersio

    Educação para a liberdade

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    In situ enabling approaches for tissue regeneration: current challenges and new developments

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    In situ tissue regeneration can be defined as the implantation of tissue-specific biomaterials (by itself or in combination with cells and/or biomolecules) at the tissue defect, taking advantage of the surrounding microenvironment as a natural bioreactor. Up to now, the structures used were based on particles or gels. However, with the technological progress, the materials’ manipulation and processing has become possible, mimicking the damaged tissue directly at the defect site. This paper presents a comprehensive review of current and advanced in situ strategies for tissue regeneration. Recent advances to put in practice the in situ regeneration concept have been mainly focused on bioinks and bioprinting techniques rather than the combination of different technologies to make the real in situ regeneration. The limitation of conventional approaches (e.g., stem cell recruitment) and their poor ability to mimic native tissue are discussed. Moreover, the way of advanced strategies such as 3D/4D bioprinting and hybrid approaches may contribute to overcome the limitations of conventional strategies are highlighted. Finally, the future trends and main research challenges of in situ enabling approaches are discussed considering in vitro and in vivo evidence.info:eu-repo/semantics/publishedVersio

    Group A Streptococci clones associated with invasive infections and pharyngitis in Portugal present differences in emm types, superantigen gene content and antimicrobial resistance

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    © 2012 Friães et al.; licensee BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly citedBackground: A few lineages of Group A streptococci (GAS) have been associated with a reemergence of severe invasive streptococcal disease in developed countries. However, the majority of the comparisons between invasive and non-invasive GAS isolates have been performed for collections of reduced genetic diversity or relied on limited typing information to distinguish clones. We characterized by several typing methods and compared a collection of 160 isolates recovered from normally sterile sites with 320 isolates associated with pharyngitis and recovered in the same time period in Portugal. Results: Although most of the isolates belonged to clones that were equally prevalent in invasive infections and pharyngitis, we identified markers of invasiveness, namely the emm types 1 and 64, and the presence of the speA and speJ genes. In contrast, emm4, emm75, and the ssa and speL/M genes were significantly associated with pharyngitis. There was a strong agreement between the emm type, the superantigen (SAg) genes and the clusters defined by pulsed-field gel electrophoresis (PFGE) profiling. Therefore, combinations of particular emm types and SAg genes frequently co-occurred in the same PFGE cluster, but there was no synergistic or antagonistic interaction between them in determining invasiveness. Only macrolide-susceptible PFGE clones were significantly associated with invasive infections or pharyngitis, while the clones of resistant isolates sharing all other molecular properties analyzed were equally prevalent in the two groups of isolates. Conclusions: This study confirmed the importance of the widely disseminated emm1-T1-ST28 clone in invasive infections but also identified other clones linked to either invasive infections (emm64-ST164) or pharyngitis (emm4-T4-ST39), which may be more limited in their temporal and geographical spread. Clonal properties like some emm types or SAg genes were associated with disease presentation, highlighting the importance of bacterial genetic factors to the outcome of GAS infections, although other, yet unidentified factors may also play an important role.This work was partially supported by Fundação para a Ciência e Tecnologia, Portugal (PTDC/SAU-ESA/72321/2006), Fundação Calouste Gulbenkian and unrestricted research grant from Glaxo SmithKline.info:eu-repo/semantics/publishedVersio

    Influence of PDLA nanoparticles size on drug release and interaction with cells

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    Polymeric nanoparticles (NPs) are strong candidates for the development of systemic and targeted drug delivery applications. Their size is a determinant property since it defines the NP–cell interactions, drug loading capacity, and release kinetics. Herein, poly(D,L-lactic acid) (PDLA) NPs were produced by the nanoprecipitationmethod, in which the influence of type and concentration of surfactant as well as PDLA concentration were assessed. The adjustment of these parameters allowed the successful production of NPs with defined medium sizes, ranging from 80 to 460 nm. The surface charge of the different NPs populations was consistently negative. Prednisolone was effectively entrapped and released from NPs with statistically different medium sizes (i.e., 80 or 120 nm). Release profiles indicate that these systems were able to deliver appropriate amounts of drug with potential applicability in the treatment of inflammatory conditions. Both NPs populations were cytocompatible with human endothelial and fibroblastic cells, in the range of concentrations tested (0.187–0.784 mg/mL). However, confocal microscopy revealed that within the range of sizes tested in our experiments, NPs presenting amedium size of 120 nmwere able to be internalized in endothelial cells. In summary, this study demonstrates the optimization of the processing conditions to obtain PDLA NPs with narrow size ranges, and with promising performance for the treatment of inflammatory diseases.info:eu-repo/semantics/publishedVersio

    Embryonal rhabdomyosarcoma of the uterine cervix: a rare case report

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    Embryonal rhabdomyosarcoma of the female genital tract is a rare tumour. It tends to occur during childhood in the vagina and, rarely, it can arise in the uterine cervix, with a peak incidence in the second decade. We report a case of a 18-year-old female with an embryonal rhabdomyosarcoma (sarcoma botryoides) presenting himself as a cervical polyp. This tumour consisted of rhabdomyoblasts with miscellaneous differentiation surrounded by a loose, myxoid stroma. The patient was successfully treated with cervical conization and adjuvant chemotherapy. She is now disease-free at the 28th month follow-up. Awareness of this uncommon lesion in the cervix and its clinical implications is important to prevent misdiagnosis. Therapy has recently inclined to conservative and fertility-sparing treatment

    Continuous production of highly tuned silk/calcium-based composites: exploring new pathways for skin regeneration

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    Calcium plays an important role in barrier function repair and skin homeostasis. In particular, calcium phosphates (CaPs) are well established materials for biomedical engineering due to their biocompatibility. To generate biomaterials with a more complete set of biological properties, previously discarded silk sericin (SS) has been recovered and used as a template to grow CaPs. Crucial characteristics for skin applications, such as antibacterial activity, can be further enhanced by doping CaPs with cerium (Ce) ions. The effectiveness of cell attachment and growth on the materials highly depends on their morphology, particle size distribution, and chemical composition. These characteristics can be tailored through the application of oscillatory flow technology, which provides precise mixing control of the reaction medium. Thus, in the present work, CaP/SS and CaP/SS/Ce particles were fabricated for the first time using a modular oscillatory flow plate reactor (MOFPR) in a continuous mode. Furthermore, the biological behavior of both these composites and of previously produced pure CaPs was assessed using human dermal fibroblasts (HDFs). It was demonstrated that both CaP based with plate-shaped nanoparticles and CaP-SS-based composites significantly improved cell viability and proliferation over time. The results obtained represent a first step towards the reinvention of CaPs for skin engineering.info:eu-repo/semantics/publishedVersio

    Factors associated with the age of the onset of diabetes in women aged 50 years or more: a population-based study

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    Investigate factors associated with the onset of diabetes in women aged more than 49 years. Cross-sectional, population-based study using self-reports with 622 women. The dependent variable was the age of occurrence of diabetes using the life table method. Cox multiple regression models were adjusted to analyse the onset of diabetes according to predictor variables. Sociodemographic, clinical and behavioural factors were evaluated. Of the 622 women interviewed, 22.7% had diabetes. The mean age at onset was 56 years. The factors associated with the age of occurrence of diabetes were self-rated health (very good, good) (coefficient=-0.792; SE of the coefficient=0.215; p=0.0001), more than two individuals living in the household (coefficient=0.656, SE of the coefficient=0.223; p=0.003), and body mass index (BMI) (kg/m(2)) at 20-30 years of age (coefficient= 0.056, SE of the coefficient=0.023; p=0.014). Self-rated health considered good or very good was associated with a higher rate of survival without diabetes. Sharing a home with two or more other people and a weight increase at 20-30 years of age was associated with the onset of type 2 diabetes.Investigate factors associated with the onset of diabetes in women aged more than 49 years. Design and Cross-sectional, populationbased study using self-reports with 622 women. The dependent variable was the age of occurrence of diabetes using the life t416FAPESP - FUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO04/10524-

    Prevalence of Sexual Dysfunction and its Associated Factors in Women Aged 40–65 Years with 11 Years or More of Formal Education: A Population-Based Household Survey

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    OBJECTIVE: To evaluate the prevalence of sexual dysfunction and its associated factors in middle-aged women with 11 years or more of formal education. METHODS: A cross-sectional, population-based study was carried out using an anonymous, self-response questionnaire. A total of 315 Brazilian-born women, 40-65 years of age with 11 years or more of schooling, participated in the study. The instrument used in the evaluation was based on the Short Personal Experiences Questionnaire. Sexual dysfunction was calculated from the mean score of sexual responsiveness (pleasure in sexual activities, excitation and orgasm), frequency of sexual activities and libido. Sociodemographic and clinical factors were evaluated. Poisson multiple regression analysis was carried out and the prevalence ratios with respective 95% confidence intervals (95%CI) were calculated. RESULTS: The prevalence of sexual dysfunction was 35.9% among our study population. Multiple regression analysis showed that sexual dysfunction was positively associated with older age (prevalence ratios=1.04; 95%CI:1.01-1.07) and with the presence of hot flashes (prevalence ratios=1.37; 95%CI:1.04-1.80). Having a sexual partner (PR=0.47; 95%CI:0.34-0.65) and feeling well or excellent (prevalence ratios= 0.68; 95%CI: 0.52-0.88) were factors associated with lower sexual dysfunction scores. CONCLUSIONS: Sexual dysfunction was present in more than one-third of women that were 40-65 years of age with 11 years or more of formal education. Within that age group, older age and hot flashes were associated with higher sexual dysfunction scores, whereas feeling well and having a sexual partner were associated with better sexuality
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