Cloning and heterologous expression of Lactobacillus reuteri uroporphyrinogen III synthase/methyltransferase gene (cobA/hemD): Preliminary characterization

Some strains of Lb. reuteri produce cobalamin (vitamin B12). Cobalamin biosynthesis relies on the sequential action of more than 25 enzymes in a complex metabolic pathway. We have cloned, expressed and characterized the gene in Lb. reuteri that codes for the S-adenosy L-methionine uroprophyrinogen III methyltransferase/synthase (CobA/HemD), a key bifunctional enzyme in the biosynthesis of cobalamin and other tetrapyrrols.Fil: Vannini, María Verónica. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Rodríguez, Adriana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Vera, José Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: de Valdéz, Graciela F.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentina. Universidad Nacional de Tucumán. Facultad de Bioquímica, Química y Farmacia; ArgentinaFil: Taranto, Maria Pia. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; ArgentinaFil: Sesma, Fernando Juan Manuel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán. Centro de Referencia para Lactobacilos; Argentin

Implementación de un sistema de información geográfica en municipios de la zona norte de la provincia de Santa Cruz

Los Sistemas de Información Geográfica, nacen de la necesidad constante de la sociedad de obtener información acerca de los territorios, constituyendo uno de los campos más dinámicos y novedosos de aplicación de la Informática, con un indudable efecto en la sociedad. Este artículo pretende presentar la iniciativa de investigación acerca de Sistemas de Información Geográfica (SIG) en general, y en particular aplicados en la Subsecretaría de Planeamiento de la Municipalidad de Caleta Olivia (MCO), en la provincia de Santa Cruz, en áreas tales como Catastro, Obras Particulares, Tierras, Topografía, Infraestructura Urbana y Producción. Esta investigación se está realizando en el Laboratorio de Tecnologías Emergentes de la Universidad Nacional de la Patagonia Austral, con el objetivo de desarrollar una aplicación de Software Libre y permitir la unificación de la información de dicha Municipalidad que posibilite agilizar la gestión administrativa.Eje: Ingeniería de Software y Base de DatosRed de Universidades con Carreras en Informática (RedUNCI

Implementación de un sistema de información geográfica en municipios de la zona norte de la provincia de Santa Cruz

Los Sistemas de Información Geográfica, nacen de la necesidad constante de la sociedad de obtener información acerca de los territorios, constituyendo uno de los campos más dinámicos y novedosos de aplicación de la Informática, con un indudable efecto en la sociedad. Este artículo pretende presentar la iniciativa de investigación acerca de Sistemas de Información Geográfica (SIG) en general, y en particular aplicados en la Subsecretaría de Planeamiento de la Municipalidad de Caleta Olivia (MCO), en la provincia de Santa Cruz, en áreas tales como Catastro, Obras Particulares, Tierras, Topografía, Infraestructura Urbana y Producción. Esta investigación se está realizando en el Laboratorio de Tecnologías Emergentes de la Universidad Nacional de la Patagonia Austral, con el objetivo de desarrollar una aplicación de Software Libre y permitir la unificación de la información de dicha Municipalidad que posibilite agilizar la gestión administrativa.Eje: Ingeniería de Software y Base de DatosRed de Universidades con Carreras en Informática (RedUNCI

Desinformación en tiempos de pandemia: tipología de los bulos sobre la Covid-19

Se presenta un análisis de contenido de todos los bulos (N=292) relacionados con la pandemia Covid-19 identificados por las tres plataformas de verificación acreditadas en España, durante el primer mes del estado de alarma decretado por el Gobierno (14 marzo 2020 – 13 abril 2020). El estudio muestra que los bulos sobre el coronavirus fueron diseminados principalmente en las redes sociales y, entre ellas, sobre todo en las cerradas, como la aplicación móvil de mensajería WhatsApp. También detecta las particularidades formales y de contenido más frecuentes de los contenidos falsificados. Los resultados revelan que la pandemia, además de generar un gran número de bulos sobre salud y ciencia, casi un tercio de la muestra, también propició la difusión de numerosos contenidos falsos de tema político y gubernamental. El artículo explora los formatos, fuentes y territorios de procedencia de los bulos. Más allá de sus resultados empíricos, este estudio realiza contribuciones teóricas en el marco de los emergentes estudios sobre desórdenes informativos. En concreto, aporta una definición propia de bulo, así como una tipología en la que se identifican cuatro tipos de bulos: broma, exageración, descontextualización y engaño. A partir de esos cuatro tipos, se propone un ‘diagrama de gravedad de los bulos’

Human macrophages differentiated in the presence of vitamin D3 restrict dengue virus infection and innate responses by downregulating mannose receptor expression

ABSTARCT: Severe dengue disease is associated with high viral loads and overproduction of pro-inflammatory cytokines, suggesting impairment in the control of dengue virus (DENV) and the mechanisms that regulate cytokine production. Vitamin D3 has been described as an important modulator of immune responses to several pathogens. Interestingly, increasing evidence has associated vitamin D with decreased DENV infection and early disease recovery, yet the molecular mechanisms whereby vitamin D reduces DENV infection are not well understood. METHODS AND PRINCIPAL FINDINGS: Macrophages represent important cell targets for DENV replication and consequently, they are key drivers of dengue disease. In this study we evaluated the effect of vitamin D3 on the differentiation of monocyte-derived macrophages (MDM) and their susceptibility and cytokine response to DENV. Our data demonstrate that MDM differentiated in the presence of vitamin D3 (D3-MDM) restrict DENV infection and moderate the classical inflammatory cytokine response. Mechanistically, vitamin D3-driven differentiation led to reduced surface expression of C-type lectins including the mannose receptor (MR, CD206) that is known to act as primary receptor for DENV attachment on macrophages and to trigger of immune signaling. Consequently, DENV bound less efficiently to vitamin D3-differentiated macrophages, leading to lower infection. Interestingly, IL-4 enhanced infection was reduced in D3-MDM by restriction of MR expression. Moreover, we detected moderate secretion of TNF-α, IL-1β, and IL-10 in D3-MDM, likely due to less MR engagement during DENV infection. CONCLUSIONS/SIGNIFICANCE: Our findings reveal a molecular mechanism by which vitamin D counteracts DENV infection and progression of severe disease, and indicates its potential relevance as a preventive or therapeutic candidate

Development of Trypanosoma cruzi in vitro assays to identify compounds suitable for progression in Chagas’ disease drug discovery

Chagas' disease is responsible for significant mortality and morbidity in Latin America. Current treatments display variable efficacy and have adverse side effects, hence more effective, better tolerated drugs are needed. However, recent efforts have proved unsuccessful with failure of the ergosterol biosynthesis inhibitor posaconazole in phase II clinical trials despite promising in vitro and in vivo studies. The lack of translation between laboratory experiments and clinical outcome is a major issue for further drug discovery efforts. Our goal was to identify cell-based assays that could differentiate current nitro-aromatic drugs nifurtimox and benznidazole from posaconazole. Using a panel of T. cruzi strains including the six major lineages (TcI-VI), we found that strain PAH179 (TcV) was markedly less susceptible to posaconazole in vitro. Determination of parasite doubling and cycling times as well as EdU labelling experiments all indicate that this lack of sensitivity is due to the slow doubling and cycling time of strain PAH179. This is in accordance with ergosterol biosynthesis inhibition by posaconazole leading to critically low ergosterol levels only after multiple rounds of division, and is further supported by the lack of effect of posaconazole on the non-replicative trypomastigote form. A washout experiment with prolonged posaconazole treatment showed that, even for more rapidly replicating strains, this compound cannot clear all parasites, indicative of a heterogeneous parasite population in vitro and potentially the presence of quiescent parasites. Benznidazole in contrast was able to kill all parasites. The work presented here shows clear differentiation between the nitro-aromatic drugs and posaconazole in several assays, and suggests that in vitro there may be clinically relevant heterogeneity in the parasite population that can be revealed in long-term washout experiments. Based on these findings we have adjusted our in vitro screening cascade so that only the most promising compounds are progressed to in vivo experiments

Growth and Biochemical Composition of Navicula sp. Cultivated at Two Light Intensities and Three Wavelengths

Many studies have reported that the exposure of microalgae cultures to red light increases the production of carbohydrates, while blue light promotes the production of protein. There are several studies about Navicula, however there are few, if any, studies of the combined effects of wavelength and light intensity on the biochemical composition of this genus In this study we evaluated the combined effect of three wavelengths: white (400-750nm), blue (430-480nm), and red (650-750nm), at two light intensities (50 and100 μmol/m2/sec) on the growth and biochemical composition of Navicula sp. cultured on a laboratory scale. The experiment was carried out under controlled conditions utilizing a factorial design 2x3 (light intensity and wavelength) with white light as the control. The cell concentration was measured daily. Dry biomass of filtered cells was incinerated at 450ºC in a muffle oven. The biochemical content was measured using micro methods. The cell concentration was higher with white light at both intensities (291,875 and 90,938 cells/mL at 50 and100 μmol photon/m2/sec, respectively). Microalgae grown under blue wavelengths at 100 μmol photon/m2/sec had the highest dry biomass (1607 pg/cell). The highest percentage of protein was obtained under the blue light (22.83%), carbohydrates under the white light (4.13) and lipids under the red light (35.25%) all these results were observed under the low light intensity (50 μmol photon/m2/sec). The highest cell concentration and growth rate was observed under the low light intensity the largest proportions of which were proteins produced under the blue light. Lipid composition was not affected by light intensity or wavelength