37 research outputs found

    G-Quadruplex Aptamer Beacon for Detection of Prostate Cancer Biomarker

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    The prostate is the major male reproductive gland involved in male fertility and plays an important role in triggering of molecular pathways relevant to fertility success. Unfortunately, in Portugal prostate cancer is the most common cancer type among men, being asymptomatic in earlier stages. Thus, is important early detection of disease. NCL is a multifunctional protein involved in multiple biological processes under both physiological and pathological processes and can have several cellular localizations. Cell surface protein overexpression was found restricted to cancer cells, namely in prostate cancer cells. Thus, we can consider NCL as a potential biomarker for cancer diagnosis and a target for cancer treatment. The AS1411 is an aptamer capable to recognise and binds specifically NCL and have a therapeutic effect on cancer cells through of induction of antiproliferative activity. Beyond its therapeutic use, AS1411 can be used in imaging and diagnostic, particularly on aptasensors development. One of the most relevant characteristics of this aptamer is the ability to fold in a G4 conformation, a secondary structure of nucleic acids. G4 structure confers stabilization to sequence and availability to bind NCL. Thus, in this work is presented the first approach of use AS1411 aptamer to prostate cancer diagnosis, namely through the design of molecular beacon (MB) designated by AS1411N5. Initially, biophysical characterization of AS1411-N5 was done by circular dichroism, nuclear magnetic resonance or fluorometric spectroscopies. Additionally, it was performed microfluidic experiments, to detect NCL using AS1411-N5 in biological samples. The results demonstrated that the proposed AS1411-N5 adopt a G4 structure and it is capable to bind with specificity and selectivity NCL, even in plasma of human patients with prostate cancer.A próstata é a maior glândula reprodutiva masculina e tem um papel importante nas vias moleculares relevantes para o sucesso da fertilização. Infelizmente, em Portugal o cancro da próstata é o cancro mais comum entre os homens, sendo assintomático em estadios iniciais. Assim é imperativo a deteção precoce da doença. A nucleolina (NCL) é uma proteína multifuncional envolvida em múltiplos processos biológicos sob condições fisiológicas e patológicas, podendo ter várias localizações celulares. A sobre-expressão da proteína na superfície das células é apenas encontrada em células cancerosas, nomeadamente as do cancro da próstata. Assim a NCL pode ser considerada como um potencial biomarcador para o diagnóstico e tratamento do cancro da próstata. O AS411 é um aptamero capaz de reconhecer e ligar especificamente a esta proteína, e de ter um efeito terapêutico nas células cancerosas ao induzir atividade antiproliferativa. Além do uso terapêutico, a sequência pode ser utilizada na imagiologia e diagnóstico, particularmente através do desenvolvimento de aptasensores. Uma das características mais relevantes do aptamero AS1411 é a capacidade de adotar a configuração de G-quadruplex (G4), uma estrutura secundária dos ácidos nucleicos. As estruturas G4 conferem estabilização à sequência e capacidade de ligar à NCL quando adota esta estrutura. Assim, neste trabalho é apresentada uma primeira abordagem do uso do AS1411 no diagnóstico do cancro da próstata, nomeadamente através da construção de uma sonda a partir da sequência deste aptamero designado por AS1411N5. Inicialmente foi efetuada a caracterização biofísica do AS1411-N5 a nível da estrutura e interação com o alvo, recorrendo às espectroscopias dicroísmo circular e ressonância magnética nuclear, e ensaios fluorométricos. Adicionalmente foram efetuadas experiências de microfluídica, para o uso do AS1411N5 como sonda de deteção da NCL. Estes resultados demonstraram, que o AS1411-N5adota a estrutura G4 e é capaz de ligar especificamente e com seletividade com a NCL, mesmo em amostras biológicas

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear un derstanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5–7 vast areas of the tropics remain understudied.8–11 In the American tropics, Amazonia stands out as the world’s most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepre sented in biodiversity databases.13–15 To worsen this situation, human-induced modifications16,17 may elim inate pieces of the Amazon’s biodiversity puzzle before we can use them to understand how ecological com munities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple or ganism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region’s vulnerability to environmental change. 15%–18% of the most ne glected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lostinfo:eu-repo/semantics/publishedVersio

    Pervasive gaps in Amazonian ecological research

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    Photography-based taxonomy is inadequate, unnecessary, and potentially harmful for biological sciences

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    The question whether taxonomic descriptions naming new animal species without type specimen(s) deposited in collections should be accepted for publication by scientific journals and allowed by the Code has already been discussed in Zootaxa (Dubois & Nemésio 2007; Donegan 2008, 2009; Nemésio 2009a–b; Dubois 2009; Gentile & Snell 2009; Minelli 2009; Cianferoni & Bartolozzi 2016; Amorim et al. 2016). This question was again raised in a letter supported by 35 signatories published in the journal Nature (Pape et al. 2016) on 15 September 2016. On 25 September 2016, the following rebuttal (strictly limited to 300 words as per the editorial rules of Nature) was submitted to Nature, which on 18 October 2016 refused to publish it. As we think this problem is a very important one for zoological taxonomy, this text is published here exactly as submitted to Nature, followed by the list of the 493 taxonomists and collection-based researchers who signed it in the short time span from 20 September to 6 October 2016

    Pervasive gaps in Amazonian ecological research

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    Biodiversity loss is one of the main challenges of our time,1,2 and attempts to address it require a clear understanding of how ecological communities respond to environmental change across time and space.3,4 While the increasing availability of global databases on ecological communities has advanced our knowledge of biodiversity sensitivity to environmental changes,5,6,7 vast areas of the tropics remain understudied.8,9,10,11 In the American tropics, Amazonia stands out as the world's most diverse rainforest and the primary source of Neotropical biodiversity,12 but it remains among the least known forests in America and is often underrepresented in biodiversity databases.13,14,15 To worsen this situation, human-induced modifications16,17 may eliminate pieces of the Amazon's biodiversity puzzle before we can use them to understand how ecological communities are responding. To increase generalization and applicability of biodiversity knowledge,18,19 it is thus crucial to reduce biases in ecological research, particularly in regions projected to face the most pronounced environmental changes. We integrate ecological community metadata of 7,694 sampling sites for multiple organism groups in a machine learning model framework to map the research probability across the Brazilian Amazonia, while identifying the region's vulnerability to environmental change. 15%–18% of the most neglected areas in ecological research are expected to experience severe climate or land use changes by 2050. This means that unless we take immediate action, we will not be able to establish their current status, much less monitor how it is changing and what is being lost

    Abstracts from the Food Allergy and Anaphylaxis Meeting 2016

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    Variation in type of adjuvant chemotherapy received among patients with stage I breast cancer: a multi-institutional Portuguese cohort study

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    © 2016 Elsevier Ltd. All rights reserved.Background: A contemporary US study showed an increase in the use of chemotherapy in the last decade for some patients with stage-I breast cancer; with a rise in more intensive regimens, and declining use of anthracyclines. Nevertheless, there is still uncertainty on the absolute benefit of chemotherapy for these patients and the optimal regimen. In this study we compare those findings with the patterns of care among a Portuguese cohort of stage-I breast cancers. Methods: Retrospective cohort study of patients with stage-I breast cancer diagnosed from 2006 to 2008 at four Portuguese institutions. The use and type of chemotherapy was evaluated. Results: Among patients with stage I-III breast cancer 39.4% (n = 682) had stage I disease. Of the 595 eligible patients, 22.4% were treated with chemotherapy, 33.9% aged 65 years (p < 0.001). Thirteen percent of patients with hormone receptor (HR)+/HER2- tumors, 52.7% of patients with HER2+ and 66.0% of patients with HR-/HER2- received chemotherapy (p < 0.001). In addition, we found inter-institutional variability, with the use of chemotherapy ranging from 0.0% to 43.4% (p < 0.001). Eighty-five percent of patients treated with chemotherapy received less-intensive regimens with anthracycline-based regimens, such as doxorubicin and cyclophosphamide, being the most frequently used, while docetaxel and cyclophosphamide was only used in 1.5% of cases. Conclusions: Overall, almost one-quarter of patients received chemotherapy with institutional variability. When treated, mostly less-intensive associations including anthracyclines were used, which contrasts with contemporary US practice. This study highlights the need for health-services research to understand local practices and tailor quality improvement interventions.Fundação para a Ciência e a Tecnologia (FCT) grants HMSP-ICS/0004/201 to IVL and HMSP-ICJ/0007/2013 to ARF.info:eu-repo/semantics/publishedVersio

    Outcomes of Trypanosoma cruzi and Trypanosoma evansi infections on health of Southern coati (Nasua nasua), crab-eating fox (Cerdocyon thous), and ocelot (Leopardus pardalis) in the Brazilian Pantanal.

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    The occurrence of Trypanosoma spp. in wild carnivore populations has been intensively investigated during the last decades. However, the impact of these parasites on the health of free-living infected animals has been largely neglected. The Pantanal biome is the world's largest seasonal wetland, harboring a great diversity of species and habitats. This includes 174 species of mammals, of which 20 belong to the order Carnivora. The present study aimed to investigate the effect of Trypanosoma evansi and Trypanosoma cruzi infections and coinfections on the health of the most abundant carnivores in the Pantanal: coati (Nasua nasua), crab-eating fox (Cerdocyon thous), and ocelot (Leopardus pardalis). We captured 39 coatis, 48 crab-eating foxes, and 19 ocelots. Diagnostic tests showed T. cruzi infection in 7 crab-eating foxes and 5 coatis. Additionally, 7 crab-eating foxes, 10 coatis, and 12 ocelots were positive for T. evansi. We observed coinfections in 9 crab-eating foxes, 8 coatis, and 2 ocelots. This is the first report of T. evansi and T. cruzi infection on the health of free-living ocelots and crab-eating foxes. We showed that single T. evansi or T. cruzi infection, as well as coinfection, caused some degree of anemia in all animals, as well as an indirect negative effect on body condition in coatis and crab-eating foxes via anemia indicators and immune investment, respectively. Furthermore, the vigorous immune investment observed in sampled coatis, crab-eating foxes and ocelots infected by T. evansi, T. cruzi and coinfected can be highly harmful to their health. Overall, our results indicate that single and combined infection with T. evansi and T. cruzi represent a severe risk to the health of wild carnivores in the Pantanal region

    Portuguese guide lines for the use of biological agents in rheumatoid arthritis - october 2011 update

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    The authors present the revised version of the Portuguese Society of Rheumatology (SPR) guidelines for the treatment of Rheumatoid Arthritis (RA) with biological therapies. In these guidelines the criteria for introduction and maintenance of biological agents are discussed as well as the contraindications and procedures in the case of non-responders. Biological treatment (with a tumour necrosis factor antagonist, abatacept or tocilizumab) should be considered in RA patients with a disease activity score 28 (DAS 28) equal to or greater than 3.2 des pite treatment with at least 20mg-weekly-dose of methotrexate (MTX) for at least 3 months or, if such treatment is not possible, after 3 months of other conventional disease modifying drug or combination therapy. A DAS 28 score between 2.6 and 3.2 with a significant functional or radiological deterioration under treatment with conventional regi -mens could also constitute an indication for biological treatment. The treatment goal should be remission or, if that is not achievable, at least a low disease activity, defined by a DAS28 lower than 3.2,without significative functional or radiological worsening. The response criteria, at the end of the first 3 months of treatment, are a decrease of at least 0.6 in the DAS28 score. After 6 months of treatment res ponse criteria is defined as a decrease greater than 1.2 in the DAS28 score. Non-responders, in accordance to the Rheumatologist's clinical opi -nion, should try a switch to another biological agent (tumour necrosis factor antagonist, abatacept, rituxi mab or tocilizumab).publishersversionpublishe
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