84 research outputs found

    The elusive mitochondrial genomes of Apicomplexa: where are we now?

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    Mitochondria are vital organelles of eukaryotic cells, participating in key metabolic pathways such as cellular respiration, thermogenesis, maintenance of cellular redox potential, calcium homeostasis, cell signaling, and cell death. The phylum Apicomplexa is entirely composed of obligate intracellular parasites, causing a plethora of severe diseases in humans, wild and domestic animals. These pathogens include the causative agents of malaria, cryptosporidiosis, neosporosis, East Coast fever and toxoplasmosis, among others. The mitochondria in Apicomplexa has been put forward as a promising source of undiscovered drug targets, and it has been validated as the target of atovaquone, a drug currently used in the clinic to counter malaria. Apicomplexans present a single tubular mitochondria that varies widely both in structure and in genomic content across the phylum. The organelle is characterized by massive gene migrations to the nucleus, sequence rearrangements and drastic functional reductions in some species. Recent third generation sequencing studies have reignited an interest for elucidating the extensive diversity displayed by the mitochondrial genomes of apicomplexans and their intriguing genomic features. The underlying mechanisms of gene transcription and translation are also ill-understood. In this review, we present the state of the art on mitochondrial genome structure, composition and organization in the apicomplexan phylum revisiting topological and biochemical information gathered through classical techniques. We contextualize this in light of the genomic insight gained by second and, more recently, third generation sequencing technologies. We discuss the mitochondrial genomic and mechanistic features found in evolutionarily related alveolates, and discuss the common and distinct origins of the apicomplexan mitochondria peculiarities

    First complete mitochondrial genome of the South American annual fish Austrolebias charrua (Cyprinodontiformes: Rivulidae): peculiar features among cyprinodontiforms mitogenomes

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    Selected nucleotide substitution models after the third codon positions were removed from the codon alignments. (PDF 7 kb

    Deciphering the role of miR-71 in Echinococcus multilocularis early development in vitro.

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    Echinococcosis represents a major public health problem worldwide and is considered a neglected disease by the World Health Organization. The etiological agents are Echinococcus tapeworms, which display elaborate developmental traits that imply a complex control of gene expression. MicroRNAs (miRNAs), a class of small regulatory RNAs, are involved in the regulation of many biological processes such as development and metabolism. They act through the repression of messenger RNAs (mRNAs) usually by binding to the 3' untranslated region (3'UTR). Previously, we described the miRNome of several Echinococcus species and found that miRNAs are highly expressed in all life cycle stages, suggesting an important role in gene expression regulation. However, studying the role of miRNAs in helminth biology remains a challenge. To develop methodology for functional analysis of miRNAs in tapeworms, we performed miRNA knockdown experiments in primary cell cultures of Echinococcus multilocularis, which mimic the development of metacestode vesicles from parasite stem cells in vitro. First, we analysed the miRNA repertoire of E. multilocularis primary cells by small RNA-seq and found that miR-71, a bilaterian miRNA absent in vertebrate hosts, is one of the top five most expressed miRNAs. Using genomic information and bioinformatic algorithms for miRNA binding prediction, we found a high number of potential miR-71 targets in E. multilocularis. Inhibition of miRNAs can be achieved by transfection of antisense oligonucleotides (anti-miRs) that block miRNA function. To this end, we evaluated a variety of chemically modified anti-miRs for miR-71 knockdown. Electroporation of primary cells with 2'-O-methyl modified anti-miR-71 led to significantly reduced miR-71 levels. Transcriptomic analyses showed that several predicted miR-71 targets were up-regulated in anti-miR-treated primary cells, including genes potentially involved in parasite development, host parasite interaction, and several genes of as yet unknown function. Notably, miR-71-silenced primary cell cultures showed a strikingly different phenotype from control cells and did not develop into fully mature metacestodes. These findings indicate an important function of miR-71 in Echinococcus development and provide, for the first time, methodology to functionally study miRNAs in a tapeworm

    Aspectos éticos na organização do conhecimento na prática profissional arquivística: um estudo dos princípios de ética da AAB, CIA e SAA

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    An axiological discussion is drawn from the analysis of the three codes of ethics in archives developed by the Association of Brazilian Archivists (AAB), the International Council on Archives (ICA) and the Socie-ty of American Archivists (SAA), presenting a frame-work of ethical values for the activities related to the organization and representation of knowledge, thus contributing to the theoretical framework underlying the social issues in Archival science.Se propone un debate axiológico a partir del análisis de los tres códigos de ética profesional archivística desarrollados por la Asociación de Archiveros de Brasil (AAB), el Consejo Internacional de Archivos (CIA) y la Sociedad de Archiveros Americanos (SAA), presentando un cuadro de valores éticos en los que el profesional de la información debe basar sus acti-vidades relacionadas con la organización y represen-tación del conocimiento, contribuyendo al avance en el marco teórico para el tratamiento de las cuestiones sociales dentro de la archivística.Actualmente, la tecnología se ha convertido en una poderosa herramienta utilizada por los profesionales de la información para organizar la misma, incluyendo a los archivos y los archiveros. Gracias a esto, las actividades realizadas por estos profesionales son cada vez más exigentes, generando cada vez más, estudios sobre su conducta y actuación. Con el objetivo de contribuir a estos estudios, en el presente artículo, se propone un debate axiológico a partir del análisis de tres principios de ética profesional archivística desarrollados por la Asociación de Archiveros de Brasil (AAB), el Consejo Internacional de Archivos (CIA) y la Sociedad de Archiveros Americanos (SAA), presentando un cuadro de valores éticos en los que el profesional de la información debe basar sus actividades relacionadas con la organización y representación del conocimiento, y así contribuir al universo teórico que sustenta las cuestiones sociales de la Archivística

    Complete genome sequence of Campylobacter fetus subsp. venerealis biovar Intermedius, isolated from the prepuce of a bull

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    Campylobacter fetus subsp. venerealis is the causative agent of bovine genital campylobacteriosis, a sexually transmitted disease distributed worldwide. Campylobacter fetus subsp. venerealis biovar Intermedius strains differ in their biochemical behavior and are prevalent in some countries. We report the first genome sequence for this biovar, isolated from bull prepuce.Fil: Iraola, Gregorio. Instituto Pasteur de Montevideo; Uruguay. Facultad de Ciencias; UruguayFil: Pérez, Ruben. Facultad de Ciencias; UruguayFil: Naya, Hugo. Universidad de la República; Uruguay. Instituto Pasteur de Montevideo; Uruguay. Universidad de la República; UruguayFil: Paolicchi, Fernando Alberto. Universidad Nacional de Mar del Plata; Argentina. Instituto Nacional de Tecnología Agropecuaria; ArgentinaFil: Harris, David. Wellcome Trust; Reino UnidoFil: Lawley, Trevor D.. Wellcome Trust; Reino UnidoFil: Rego, Natalia. Instituto Pasteur de Montevideo; UruguayFil: Hernández, Martín. Facultad de Ciencias; UruguayFil: Calleros, Lucía. Facultad de Ciencias; UruguayFil: Carretto, Luis. Facultad de Ciencias; UruguayFil: Velilla, Alejandra Vanesa. Universidad Nacional de Mar del Plata; ArgentinaFil: Morsella, Claudia. Universidad Nacional de Mar del Plata; ArgentinaFil: Méndez, Alejandra. Universidad Nacional de Mar del Plata; ArgentinaFil: Gioffré, Andrea Karina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Instituto Nacional de Tecnología Agropecuaria. Centro Regional Buenos Aires; Argentin

    Evaluation of Ventral Laparoscopic Abomasopexy Using Surgical Staples Associated with Suture Material in Dairy Cattle

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    Background: Displaced Abomasum is known for being on of the main illnesses that affect milking cows. Increase in diagnosis of this illness is due to advancement in diagnosis techniques. Increase in incidence of this illness can be explained by genetic selection of animals with high production, breed systems and changes to the diet with a higher level of protein. For laparoscopic treatment, several surgical changes were performed to optimize the procedure and thus achieve better results. The main purpose of this study was to evaluate applicability of the ventral laparoscopic abomasopexy technique, using surgical clamps attached to the suture thread, to milking cows.Materials, Methods & Results: Six adult cows were placed under anesthesia with isoflurane and placed in dorsal decubitus. Animals were kept with no water for 24 h and no food for 48 h. Four laparoscopic accesses were performed. The first one was created with the intention of inspecting the abdominal cavity and the remaining three for access of surgical instruments. Serous membrane of the abomasum was cauterized, combined with suture threads and placed at the greater abomasal curvature. The free part of suture threads was kept out of the abdominal cavity and after traction of the abomasum against the abdominal wall was tied to the skin. Ultrasound exam was performed for abdominal evaluation after abomasopexy. Anesthesia time and surgery time were recorded and analyzes through average and standard deviation (SD). The average anesthesia time recorded was 94 min (SD 14.63 min) and average surgery time was 51 min (SD 14.71 min). The fasting period was considered adequate, however all animals had to undergo intubation with orogastric tube to drain liquids and gas during the procedure. Four of the six animals had lineal adhesion. Three of the four animals that had adhesion did not keep the abomasum at the retroperitoneal area, however viscera movement was stopped in the abdominal cavity.Discussion: Abomasopexy through laparoscopy is a safe technique, especially when compared with other invasive methods of abomasopexy. However, to perform this type of surgery availability of adequate equipment and a well trained surgical team are required. This study was performed at a surgery room under full anesthesia. In a field situation, the veterinarian can have some difficulties but such adversities must not be considered and impediment for performance of surgery on the field as its performance is possible. Even though surgical clamps were small, they were considered adequate for what was suggested. The applied 0 degree laparoscopic optic presented restrictions for cavity inspection, therefore we believe that an optical lenses with 30 degree angle could facilitate this laparoscopy inspection. To induce greater and more lasting adherence we suggest cauterizing a greater area of the serous membrane of the abomasum. We also suggest not performing this procedure during lactation peak, when fasting and surgery can cause economic losses. Complications associated with this technique could not be avoided. The technique has shown favorable results, but its clinical applicability depends on application on animals subjected to the conditions of a milk production cycle

    Cambio climático y dinámica del paisaje en Galicia

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    Las secuencias polínicas, y en concreto las obtenidas a partir de sedimentos limnéticos, se han revelado como la herramienta más eficaz a la hora de valorar los cambios climáticos cuaternarios a nivel regional y su incidencia sobre los ecosistemas. Una parte importante de los registros obtenidos en el NW ibérico, presenta una antigüedad menor de 3.000; las secuencias continuas de más de 6.000 años, que alcanzan cronologías de 10.000 o 12.000 años, se limita a grandes turberas de zonas de montaña; finalmente, los periodos de más de 17.000 años, únicamente aparecen representados en sedimentos fosilizados, en los que se han obtenido registros continuos de 10.000 o 20.000 años y excepcionalmente periodos de más de 50.000. Las más de 200 secuencias disponibles para el NW ibérico, permiten realizar una correcta evaluación de la incidencia de los cambios climáticos y de la influencia antrópica sobre los ecosistemas, a lo largo de los últimos 100.000 años. La abundancia de datos, accede a reconocer la diferente influencia de estos cambios sobre las distintas áreas biogeográficas del territorio

    Technology enabling the largest free and accessible event worldwide on COVID-19 management: experience report: Tecnologia viabilizando o maior evento gratuito e acessível do mundo sobre gestão da COVID-19: relato de experiência

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    Introdução: O uso das redes sociais como fonte de informação durante a pandemia de Covid-19 possibilitou o acesso do grande público a informações atualizadas, mas também permitiu uma intensa disseminação de notícias falsas no Brasil e no mundo. Objetivo: Este relatório tem como objetivo apresentar a experiência da tecnologia que possibilita a organização e implantação de um evento científico online gratuito de grande escala sobre a Covid-19, com foco em informações baseadas em evidências, atendimento e gestão do paciente. Métodos: O "Primeiro Congresso Brasileiro de Evidências Clínicas sobre Covid-19" aconteceu entre os dias 03 e 07 de maio de 2021 e foi realizado pela Universidade Federal de Minas Gerais, a principal universidade federal do Brasil. Resultados: Houve 27.102 cadastros. A transmissão teve 29.170 visualizações no primeiro dia. Em 25 de junho de 2021, foram 80.923 visualizações para a versão original em áudio e 10.352 visualizações para a tradução simultânea. Os tópicos compreenderam prevenção da Covid-19, gestão na atenção primária, atendimento pré-hospitalar, assistência hospitalar, unidade de terapia intensiva, longa-COVID-19, vacinas, saúde mental e custos. Minipalestras foram seguidas de discussão e interação com os participantes. Palestrantes e moderadores de todo o Brasil e do exterior foram escolhidos de acordo com sua expertise em temas de Covid-19 e em medicina baseada em evidências. Entre as sessões, foram apresentados depoimentos em vídeo de pessoas que não puderam trabalhar em casa sobre o que tocou seu coração durante a pandemia. A acessibilidade foi garantida por meio de tradução simultânea para a Língua Brasileira de Sinais. A satisfação dos participantes foi avaliada, com 2.228 respondentes, dos quais 97,4% disseram que suas expectativas foram superadas e 86,8% relataram adquirir novos conhecimentos sobre a Covid-19. Final considerations: Essa experiência mostrou que a tecnologia possibilitou a divulgação de evidências científicas acessíveis sobre a Covid-19 para um grande público por meio de um evento online gratuito

    Phylogenetic analysis and assessment of the pathogenic potential of the first H9N2 avian influenza viruses isolated from wild birds and Lagoon water in Tunisia

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    H9N2 avian influenza virus (AIV) has been isolated from various species of wild birds and domestic poultry worldwide. It has been reported since the late 1990s, that H9N2 AIV has infected humans as reported in some Asian and North African countries. This subtype has already been circulating and constituting a serious threat to the poultry industry in Tunisia back in 2009. To investigate zoonotic potential and pathogenicity of H9N2 AIV in chickens and mice in Tunisia, five strains have been isolated during the period from 2014 to 2018. Samples were withdrawn from several wild bird species and environment (Lagoon water) of Maamoura and Korba Lagoons as well as Kuriat Island. Phylogenetic analyzes demonstrated that the isolated H9N2 strains belonged to the G1-like sublineage and were close to AIV H9N2 poultry viruses from North Africa, West Africa and the Middle East. All strains carried in their hemagglutinin the residue 226 L, which is an important marker for avian-to-human viral transmission. The hemagglutinin cleavage site has several motifs: PSKSSR/G, PARSSR/G and HARSSR/G. The neuraminidase showed S372A and R403W substitutions that have been previously detected in H3N2 and H2N2 viruses that were reported in human pandemics. Many mutations associated with mammalian infections have been detected in internal proteins. Pathogenicity evaluation in chickens showed that GF/14 replicates effectively in the lungs, tracheas, spleens, kidneys and brains and that it was transmitted among contact chickens. However, GHG/18 replicates poorly in chickens and has not an efficient transmission in contact chickens. GF/14 and GHG/18 could not kill mice though they replicated in their respiratory tract and caused a significant body weight loss (p < 0.05). This study highlights the importance of H9N2 AIV monitoring in both migratory birds and the environment to prevent virus transmission to humans
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