239 research outputs found

    Spinal Muscular Atrophy

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    Introdução: A Atrofia Muscular Espinhal (AME) é o nome dado a uma doença neuromuscular específica caracterizada pela degeneração dos neurónios motores medulares, condicionando atrofia e fraqueza muscular progressivas. É determinada pela alteração do gene Survival Motor Neuron-1 (SMN1), localizado no braço longo do cromossoma cinco. Uma cópia quase idêntica do gene SMN1, chamada SMN2, modula a gravidade da doença. A AME repercute-se a nível de vários órgãos e sistemas, envolvendo frequentemente os sistemas respiratório, osteoarticular e gastrintestinal. Estão descritos vários subtipos da doença, com base quer na idade do início dos sintomas quer na máxima aquisição motora alcançada. Objectivos: Estudar a população de doentes com o diagnóstico de AME (clínico e/ou genético) seguida na Consulta de Medicina Física e de Reabilitação (CMFR) do Hospital de Dona Estefânia (HDE) em Lisboa, no período de Janeiro de 2007 a Outubro de 2009. Métodos: Estudo retrospectivo com análise de parâmetros sócio-demográficos, clínica, exames complementares de diagnóstico, evolução e complicações da doença. Resultados e Discussão: A casuística é constituída por doze doentes, com idades compreendidas entre os 0 meses e os 21 anos de idade, tendo sete o diagnóstico de AME I, um AME II equatro o diagnóstico de AME tipo III. Verificou-se que a gravidade da doença era inversamente proporcional à idade no início dos sintomas e à função motora máxima atingida pelo indivíduo durante o seu desenvolvimento. Todos os doentes apresentaram infecções respiratórias recorrentes e nos óbitos ocorridos, verificou-se como causa de morte a insuficiência respiratória, complicada de paragem cardio-respiratória. As principais complicações ortopédicas foram o desenvolvimento de contracturas articulares das grandes articulações dos membros inferiores, bem como o desenvolvimento de escoliose. A disfagia foi a principal complicação gastrenterológica. Conclusão: A não aquisição de etapas do desenvolvimento motor está correlacionada com um agravamento do prognóstico funcional e vital

    Predicting the distribution of canine leishmaniasis in western Europe based on environmental variables.

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    The domestic dog is the reservoir host of Leishmania infantum, the causative agent of zoonotic visceral leishmaniasis endemic in Mediterranean Europe. Targeted control requires predictive risk maps of canine leishmaniasis (CanL), which are now explored. We databased 2187 published and unpublished surveys of CanL in southern Europe. A total of 947 western surveys met inclusion criteria for analysis, including serological identification of infection (504, 369 dogs tested 1971-2006). Seroprevalence was 23 2% overall (median 10%). Logistic regression models within a GIS framework identified the main environmental predictors of CanL seroprevalence in Portugal, Spain, France and Italy, or in France alone. A 10-fold cross-validation approach determined model capacity to predict point-values of seroprevalence and the correct seroprevalence class (20%). Both the four-country and France-only models performed reasonably well for predicting correctly the 20% seroprevalence classes (AUC >0 70). However, the France-only model performed much better for France than the four-country model. The four-country model adequately predicted regions of CanL emergence in northern Italy (<5% seroprevalence). Both models poorly predicted intermediate point seroprevalences (5-20%) within regional foci, because surveys were biased towards known rural foci and Mediterranean bioclimates. Our recommendations for standardizing surveys would permit higher-resolution risk mapping

    Electron impact ionization of R-carvone: I. Mass spectra and appearance energies

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    The mass spectrum of R-carvone measured at 70 eV electron impact energy, in the mass region of 1-151 amu, is reported in this work. We observed in this spectrum 103 peaks associated with ionic fragmentation, 55 of them with abundances greater than 1%. The relative abundances, from this study, compare reasonably well with the corresponding values reported in the literature where such a comparison can be made. The R-carvone Ionization Energy (IE), as well as the ionic energy formation thresholds (Appearance Energy - AE) were experimentally determined for the 35 most intense cations registered in the mass spectrum, which provided values for 38 AEs and Wannier exponents (p) and the IE of this molecule. The values of the AEs and Wannier exponents produced in this work, to the best of our knowledge, are being presented for the first time to the scientific community, except for the masses of 135 amu and 150 amu. We also suggest some ionic fragmentation mechanisms and molecular structural ionic fragmentation mechanisms for R-carvone, based on the AE and p values found in this work. (C) 2020 Elsevier B.V. All rights reserved

    Association between active genes occurs at nuclear speckles and is modulated by chromatin environment

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    Genes on different chromosomes can be spatially associated in the nucleus in several transcriptional and regulatory situations; however, the functional significance of such associations remains unclear. Using human erythropoiesis as a model, we show that five cotranscribed genes, which are found on four different chromosomes, associate with each other at significant but variable frequencies. Those genes most frequently in association lie in decondensed stretches of chromatin. By replacing the mouse α-globin gene cluster in situ with its human counterpart, we demonstrate a direct effect of the regional chromatin environment on the frequency of association, whereas nascent transcription from the human α-globin gene appears unaffected. We see no evidence that cotranscribed erythroid genes associate at shared transcription foci, but we do see stochastic clustering of active genes around common nuclear SC35-enriched speckles (hence the apparent nonrandom association between genes). Thus, association between active genes may result from their location on decondensed chromatin that enables clustering around common nuclear speckles

    Cold atmospheric plasma, a novel approach against bladder cancer, with higher sensitivity for the high-grade cell line

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    Antitumor therapies based on Cold Atmospheric Plasma (CAP) are an emerging medical field. In this work, we evaluated CAP effects on bladder cancer. Two bladder cancer cell lines were used, HT-1376 (stage III) and TCCSUP (stage IV). Cell proliferation assays were performed evaluating metabolic activity (MTT assay) and protein content (SRB assay). Cell viability, cell cycle, and mitochondrial membrane potential (Δψm) were assessed using flow cytometry. Reactive oxygen and nitrogen species (RONS) and reduced glutathione (GSH) were evaluated by fluorescence. The assays were carried out with different CAP exposure times. For both cell lines, we obtained a significant reduction in metabolic activity and protein content. There was a decrease in cell viability, as well as a cell cycle arrest in S phase. The Δψm was significantly reduced. There was an increase in superoxide and nitric oxide and a decrease in peroxide contents, while GSH content did not change. These results were dependent on the exposure time, with small differences for both cell lines, but overall, they were more pronounced in the TCCSUP cell line. CAP showed to have a promising antitumor effect on bladder cancer, with higher sensitivity for the high-grade cell line.info:eu-repo/semantics/publishedVersio

    Independent evolution of ancestral and novel defenses in a genus of toxic plants (Erysimum, Brassicaceae)

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    Phytochemical diversity is thought to result from coevolutionary cycles as specialization in herbivores imposes diversifying selection on plant chemical defenses. Plants in the speciose genus Erysimum (Brassicaceae) produce both ancestral glucosinolates and evolutionarily novel cardenolides as defenses. Here we test macroevolutionary hypotheses on co-expression, co-regulation, and diversification of these potentially redundant defenses across this genus. We sequenced and assembled the genome of E. cheiranthoides and foliar transcriptomes of 47 additional Erysimum species to construct a phylogeny from 9868 orthologous genes, revealing several geographic clades but also high levels of gene discordance. Concentrations, inducibility, and diversity of the two defenses varied independently among species, with no evidence for trade-offs. Closely related, geographically co-occurring species shared similar cardenolide traits, but not glucosinolate traits, likely as a result of specific selective pressures acting on each defense. Ancestral and novel chemical defenses in Erysimum thus appear to provide complementary rather than redundant functions.Austrian Science Fund (FWF) PZ00P3-161472National Science Foundation (NSF) 1811965 1645256Triad FoundationGerman Research Foundation (DFG) DFG-PE 2059/3-1Agencia Estatal de Investigacion CGL2017-86626-C2-2-PLOEWE Program Insect Biotechnology and BioresourcesJunta de Andalucía A-RNM505-UGR1

    Aplicação das técnicas de deteção de apoptose em ensaios clínicos

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    A aplicação de metodologias capazes de identificar células apoptóticas constitui uma valiosa ferramenta em vários estudos biomédicos. A hemorragia grave continua a ser a principal causa de morbilidade e mortalidade em animais de companhia vítimas de trauma, situação também comum em humanos, sobretudo jovens vítimas de acidentes de viação. A reperfusão é fundamental, nestas situações, para fomentar a redistribuição do fluxo sanguíneo, repor a disponibilidade de oxigénio e retomar a síntese de ATP, para reconstruir as reservas de energia perdidas e prevenir a morte celular, incluindo a apoptose. Este estudo tem como objectivo principal avaliar os niveis de apoptose no intestino delgado e rim, num ensaio clínico que reproduz a situação de hemorragia pós-trauma, comparando a reperfusão feita com hidroxietilamido 130/0,4 (HES), um coloide, e o Lactato de Ringer (LR), um cristaloide. Dezoito porcos da raça Large White foram submetidos a anestesia total intravenosa (TIVA) com propofol e remifentanil. Nos grupos 1 e 2, os animais foram submetidos a hemorragia controlada e a reposição de volume foi feita usando solução de LR no grupo 1 e HES 130/0.4 no grupo 2. O grupo 3 (grupo controlo), foi apenas submetido a TIVA, sem nenhum outro procedimento. Uma hora após a reposição do volume, os animais foram eutanasiados

    Proximity-Induced Nucleic Acid Degrader (PINAD) approach to targeted RNA degradation using small molecules

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    Nature has evolved intricate machinery to target and degrade RNA, and some of these molecular mechanisms can be adapted for therapeutic use. Small interfering RNAs and RNase H-inducing oligonucleotides have yielded therapeutic agents against diseases that cannot be tackled using protein-centered approaches. Because these therapeutic agents are nucleic acid-based, they have several inherent drawbacks which include poor cellular uptake and stability. Here we report a new approach to target and degrade RNA using small molecules, proximity-induced nucleic acid degrader (PINAD). We have utilized this strategy to design two families of RNA degraders which target two different RNA structures within the genome of SARS-CoV-2: G-quadruplexes and the betacoronaviral pseudoknot. We demonstrate that these novel molecules degrade their targets using in vitro, in cellulo, and in vivo SARS-CoV-2 infection models. Our strategy allows any RNA binding small molecule to be converted into a degrader, empowering RNA binders that are not potent enough to exert a phenotypic effect on their own. PINAD raises the possibility of targeting and destroying any disease-related RNA species, which can greatly expand the space of druggable targets and diseases.info:eu-repo/semantics/publishedVersio
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