The 5′-untranslated region of the mouse mammary tumor virus mRNA exhibits cap-independent translation initiation

In this study, we demonstrate the identification of an internal ribosome entry site (IRES) within the 5′-untranslated region (5′-UTR) of the mouse mammary tumor virus (MMTV). The 5′-UTR of the full-length mRNA derived from the infectious, complete MMTV genome was cloned into a dual luciferase reporter construct containing an upstream Renilla luciferase gene (RLuc) and a downstream firefly luciferase gene (FLuc). In rabbit reticulocyte lysate, the MMTV 5′-UTR was capable of driving translation of the second cistron. In vitro translational activity from the MMTV 5′-UTR was resistant to the addition of m7GpppG cap-analog and cleavage of eIF4G by foot-and-mouth disease virus (FMDV) L-protease. IRES activity was also demonstrated in the Xenopus laevis oocyte by micro-injection of capped and polyadenylated bicistronic RNAs harboring the MMTV-5′-UTR. Finally, transfection assays showed that the MMTV-IRES exhibits cell type-dependent translational activity, suggesting a requirement for as yet unidentified cellular factors for its optimal function

Different modes of interaction by TIAR and HuR with target RNA and DNA

TIAR and HuR are mRNA-binding proteins that play important roles in the regulation of translation. They both possess three RNA recognition motifs (RRMs) and bind to AU-rich elements (AREs), with seemingly overlapping specificity. Here we show using SPR that TIAR and HuR bind to both U-rich and AU-rich RNA in the nanomolar range, with higher overall affinity for U-rich RNA. However, the higher affinity for U–rich sequences is mainly due to faster association with U-rich RNA, which we propose is a reflection of the higher probability of association. Differences between TIAR and HuR are observed in their modes of binding to RNA. TIAR is able to bind deoxy-oligonucleotides with nanomolar affinity, whereas HuR affinity is reduced to a micromolar level. Studies with U-rich DNA reveal that TIAR binding depends less on the 2′-hydroxyl group of RNA than HuR binding. Finally we show that SAXS data, recorded for the first two domains of TIAR in complex with RNA, are more consistent with a flexible, elongated shape and not the compact shape that the first two domains of Hu proteins adopt upon binding to RNA. We thus propose that these triple-RRM proteins, which compete for the same binding sites in cells, interact with their targets in fundamentally different ways

Evaluation of the immune response against immature viral particles of infectious pancreatic necrosis virus (IPNV): A new model to develop an attenuated vaccine

Infectious pancreatic necrosis virus (IPNV) is a worldwide problem affecting both freshwater and seawater fish. Vaccines developed against IPNV are not as efficient in the field as they are in tests. Moreover, research in the development of vaccines against IPNV has often shown that vaccines can stimulate the immune response of fish antibodies but do not protect efficiently against IPNV. In fact, sometimes dead infected fish show high antibody titers against IPNV. This suggests that the magnitude of total antibodies stimulated by the vaccine is not necessarily related to the level of protection against IPN, suggesting that a new method is needed to evaluate vaccine stimulation of the immune system. We propose in vitro evaluation of the non-specific cytotoxic cells (NCC) of the innate immune response, in addition to humoral specific response. Moreover, it is necessary to develop innovative methods to improve fish vaccines. In this work, IPNV replicative intermediaries (provirus) were u

Bioinformatic Analysis of the Genome of Infectious Salmon Anemia Virus Associated with Outbreaks with High Mortality in Chile ▿ ‡

The infectious salmon anemia virus (ISAV), an orthomyxovirus, is the major cause of outbreaks of high mortality rates in salmon in Chile. It has been proposed that the virulence of ISAV isolates lies mainly in hemagglutinin-esterase and fusion glycoproteins. However, based on current information, the contribution of other viral genes cannot be ruled out. To study this, we isolated and determined the complete coding sequence of two high-prevalence Chilean isolates associated with outbreaks of high mortality rates: ISAV752_09 and ISAV901_09. These isolates were compared to 15 Norwegian isolates that exhibit differences in their virulence. For this purpose, we performed bioinformatic analyses of (i) functional domains, (ii) specific mutations, (iii) Bayesian phylogenetics, and (iv) structural comparisons between ISAV and influenza virus glycoproteins by using molecular modeling. Phylogenetic analysis shows two genogroups for each protein, one of them containing the Chilean isolates. The gene sequence of the polymerase complex and nucleoprotein indicated that they are closely related to homologues from highly pathogenic Norwegian viruses. Notably, seven of the eight mutations that are present only in the Chilean isolates are on the polymerase complex and nucleoprotein. Structural modeling of hemagglutinin-esterase shows patches of variable residues on its surface. Fusion protein modeling shows that insertions are flexible regions that could affect proteolytic processing, increasing either the accessibility or the number of recognition sites for specific proteases. We found antigenic drift processes related to insertion into the isolated segment 5 of the ISAV752_09. Our results confirm the European origin of Chilean isolates to be the result of reassortments from Norwegian ancestors

Recommendations for safe dental care : A systematic review of clinical practice guidelines in the first year of the covid-19 pandemic

Altres ajuts: Agencia Nacional de Investigation y Desarrollo (ANID), Chile (COVID0700).In the context of a pandemic, the rapid development of clinical practice guidelines (CPGs) is critical to guide dental staff towards the safe provision of dental care; detailed knowledge of the recommendations will help to achieve the intended results. We carried out a systematic review of the recommendations in clinical practice guidelines (CPGs) on the provision of dental care issued during the first year of the COVID-19 pandemic. A systematic database search was performed in MEDLINE, EMBASE, LILACS, Epistemonikos, and Trip databases to identify documents with recommendations intended to minimize the risk of COVID-19 transmission during dental care. The selection process and data extraction were carried out by two researchers independently. The majority of CPGs recommended the use of rubber dam, high-volume evacuator, mouthwash prior to dental care, four-handed work, and mechanical barriers. The use of aerosol-generating equipment should be avoided whenever possible. In aerosol-generating procedures, the use of a N95 respirator (or similar) is recommended, in addition to a face protector, an impermeable disposable apron/gown, a cap, and gloves. The CPGs developed during the first year of the pandemic offer recommendations which guide dental staff in providing safe dental care, minimizing exposure to SARS-CoV-2 and reducing the risk of COVID-19 infection in the clinical environment. Such recommendations must, however, be updated as new evidence arises

Allende vive 30 años

El Seminario Internacional 30 Años Allende Vive, convocado por la Revista América Libre, el Centro de Educación Popular, CEPIS, de Brasil, el Centro Martín Luther King de Cuba y el ICAL, en un momento en que las luchas populares retoman la iniciativa, se planteó rescatar la memoria del proceso de la Unidad Popular y del ejemplo de Salvador Allende y proyectarla a las búsquedas que los movimientos populares realizan para construir alternativas al neoliberalismo, la emergencia de nuevos gobiernos populares, los caminos de creación de poder popular, la perspectiva socialista como proyecto y como opción. La publicación del seminario 30 Años Allende Vive constituye un aporte para la reflexión de la izquierda latinoamericana, y una importante fuente de consulta tanto para referencias históricas como para los muy actuales debates sobre la construcción de alternativas de cambio con perspectiva socialista.Presentación; Discurso de Inauguración del Seminario Internacional 30 Años, Allende Vive; Inauguración del Seminario 30 Años, Allende Vive; Saludos; Transformaciones de Estructura y Redistribución del Ingreso; La educación y la cultura en el Gobierno Popular; Reforma Agraria y Soberanía Alimentaria; Los logros de la Unidad Popular y las perspectivas en diferentes sectores sociales; Soberanía sobre los Recursos Naturales. El Cobre; El programa de gobierno de Salvador Allende; La Verdad sobre la Unidad Popular y el Golpe de Estado; Unidad Popular, Impacto y Solidaridad Internacional; Presentación del libro Salvador Allende, Textos Escogidos; La política imperialista. El ALCA y la militarización del mundo. El Plan Colombia; La unidad de los pueblos contra la estrategia imperialista, guerrerista, desestabilizadora y golpista de Estados Unidos; Ponencia de las Fuerzas Armadas Revolucionarias de Colombia Ejército del Pueblo (FARC-EP); Los cristianos en la lucha por el socialismo; Fuerzas Armadas, Democracia y Soberanía Nacional; Situación del movimiento sindical antes y después del golpe; Derechos Humanos antes y después del golpe de estado; Movimientos GLBTT y Procesos Revolucionarios en América Latina. Construyendo el nuevo sujeto histórico; Políticas de Género de la Izquierda Latinoamericana; Panel sobre Medios de comunicación; Gobernar la revolución. Por una gobernabilidad revolucionaria para la revolución bolivariana; La integración latinoamericana y el sueño bolivariano; Las alternativas populares en América Latina ayer y hoy. Izquierda e Institucionalidad, Reforma y Revolución; Los movimientos sociales y los partidos políticos en la construcción de las alternativas populares. Sujeto histórico, alianzas, programas, estrategias; La perspectiva socialista en la construcción de las alternativas populare