Caracterización y efecto de Azotobacter, Azospirillum y Pseudomonas asociadas a Ipomoea Batatas del Caribe Colombiano

El uso de Rizobacterias promotoras de crecimiento vegetal (PGPR, por sus siglas en ingles) constituye una alternativa al uso de fertilizantes químicos favoreciendo el rendimiento de los cultivos. La presente investigación tuvo como objetivo la búsqueda, selección y caracterización de PGPR de los géneros Azotobacter, Azospirillum y Pseudomonas nativas de la rizósfera de cultivos de Ipomoea batatas de zonas productoras representativas del Caribe Colombiano. Los aislados seleccionados se caracterizaron molecularmente y realizaron pruebas de solubilización de fósforo, producción de índoles y reducción de acetileno. Las cepas fueron probadas a nivel de invernadero en plántulas de Ipomoea batatas producidas in vitro en las que se evaluó la altura, longitud radicular, masa seca de la parte aérea y radicular. Asociada a la rizósfera de Ipomoea batatas se obtuvieron cepas de Azotobacter vinelandii, Azotobacter chroococcum, Azospirillum lipoferum, Azospirillum brasilense y Pseudomonas denitrificans, las cepas fueron capaces de solubilizar fósforo, producir índoles y reducir acetileno. Se obtuvo incrementos en parámetros de crecimiento como longitud radicular, altura, peso seco aéreo y radicular en plántulas de Ipomoea batatas en invernadero con la inoculación de las bacterias seleccionadas frente a plántulas sin inocular. Los resultados catalogan a los aislados obtenidos como posibles microorga-nismos con potencial como biofertilizantes en batata.The use of plant growth promoting Rhizobacteria (PGPR) is an alternative to replace chemical fertilizers for the cultivation of agricultural crops. The aim of this research was to search, selection and characterization of PGPR from the genus Azotobacter, Azospirillum and Pseudomonas natives from sweet potato (Ipomoea batatas) plants and rhizosphere of representative production regions of the Colombian Caribbean. Selected isolates were identified by molecular methods and they were screened in vitro for activities related to plant growth such as phosphate solubilization, indole production and acetylene reduction. The strains were tested in the greenhouse on plants of Ipomoea batatas produced in vitro. The height, root length, dry mass of the shot and root were evaluated. Associated with sweet potato crop us finded strains identificated as Azotobacter vinelandii, Azotobacter chroococcum, Azospirillum lipoferum, Azospirillum brasilense and Pseudomonas denitrificans. The strains were able to solubilize phosphate, synthesize indole-3-acetic acid (IAA) and reduce acetylene. The inoculation of bacteria selected increased growth parameters such as root length, height, dry weight root and shoot in plants of sweet potato in greenhouse. Those results catalog to the isolated obtained as possible microorganisms with potential as biofertilizers in sweet potato

End-binding protein 1 controls signal propagation from the T Cell Receptor

The role of microtubules (MTs) in the control and dynamics of the immune synapse (IS) remains unresolved. Here, we show that T cell activation requires the growth of MTs mediated by the plus-end specific protein end-binding 1 (EB1). A direct interaction of the T cell receptor (TCR) complex with EB1 provides the molecular basis for EB1 activity promoting TCR encounter with signalling vesicles at the IS. EB1 knockdown alters TCR dynamics at the IS and prevents propagation of the TCR activation signal to LAT, thus inhibiting activation of PLCγ1 and its localization to the IS. These results identify a role for EB1 interaction with the TCR in controlling TCR sorting and its connection with the LAT/PLCγ1 signalosome

Educational inclusion in distance education through management platforms

The mode of distance education through management platforms, being a pedagogical environment with its particularities, requires the incorporation of the theoretical assumptions of developing learning. The objective of the present work is to analyze educational inclusion in the context of distance education, with emphasis on the use of certain mediators as a pedagogical way of solving this problem. On the theoretical bases of the developing learning and the mediators´ epistemological conceptions in the process of teaching learning, schemes are developed on mediators´ didactics, fundamental elements to guarantee an inclusive education in the modality of distance education

Educational inclusion in distance education through management platforms

The mode of distance education through management platforms, being a pedagogical environment with its particularities, requires the incorporation of the theoretical assumptions of developing learning. The objective of the present work is to analyze educational inclusion in the context of distance education, with emphasis on the use of certain mediators as a pedagogical way of solving this problem. On the theoretical bases of the developing learning and the mediators´ epistemological conceptions in the process of teaching learning, schemes are developed on mediators´ didactics, fundamental elements to guarantee an inclusive education in the modality of distance education

Identificación de hongos asociados a la pudrición seca del ñame bajo condiciones de almacenamiento

Dry rot of yam tubers is a disease that currently causes the greatest economic losses to small producers associated with this crop in the Colombian Caribbean, as it deteriorates the internal tissues of tubers, causing loss of its commercial value and the seeds. Currently, we are not certain about the identity of the causal agents, so this research was carried out in order to objetive collect, isolate and characterize the fungi associated with the dry rot disease of yam tubers cv. "Espino" in the Caribbean region of Colombia in storage conditions. This study was carried out between February and October 2019, identifying the yam-producing areas in the Colombian Caribbean region and collecting in the municipalities and sidewalks, tubers in storage. In laboratory, the associated fungi were isolated from the lesions and identified through the amplification of the ITS (Internal Transcribed Spacer) region of the ribosomal DNA, complemented by the Calmodulin and β-tubulin gene 2.  A total of 56 fungi associated with lesions were isolated, which were grouped into 10 morphotypes, achieving their classification by genus and species. According to our results, the species DH2-Lasiodiplodia theobromae, DH3-Fusarium solani, and DH6-Neocosmospora rubicola were identified as the main causal agents associated to dry rot disease of yam tubers under storage conditions in the Colombian Caribbean region.La pudrición seca de los tubérculos de ñame es la enfermedad que en la actualidad ocasiona las mayores pérdidas económicas a los pequeños productores asociados a este cultivo en el Caribe colombiano, pues deteriora los tejidos internos del tubérculo, ocasionando la pérdida de su valor comercial y de la semilla.  Actualmente, no se tiene certeza de la identidad de los agentes causales, por lo que la presente investigación se llevó a cabo con el objeto de colectar, aislar y caracterizar los hongos asociados a la pudrición seca de tubérculos de ñame cv. "Espino" en la región Caribe de Colombia en almacenamiento. El estudio se desarrolló entre los meses de febrero a octubre del año 2019, identificando las zonas productoras de ñame en la región Caribe colombiana y colectando en los municipios y veredas, tubérculos en almacenamiento.  En el laboratorio se aislaron de las lesiones los hongos asociados y se identificaron a través de la amplificación de la región ITS (Internal Transcribed Spacer) del DNA ribosomal, complementado con los genes Calmodulina y β-tubulina 2. En total se aislaron 56 hongos asociados a las lesiones, los cuales fueron agrupados en 10 morfotipos, logrando la clasificación por género y especie de los mismos. De acuerdo con la caracterización realizada se puede definir que las especies DH2-Lasiodiplodia theobromae, DH3-Fusarium solani y DH6-Neocosmospora rubicola, se constituyen como los principales agentes causales de la enfermedad de la pudrición seca de tubérculos de ñame espino en almacenamiento en la región Caribe de Colombia

Azotobacter chroococcum y Azospirillum lipoferum como bioestimulantes en cultivo de Ipomoea batatas Lam.

Introducción. La utilización excesiva de fertilizantes nitrogenados en cultivos de batata contribuye con la contaminación de los ecosistemas, para disminuir este efecto y mejorar la productividad del cultivo, la incorporación, de rizobacterias promotoras de crecimiento vegetal (PGPRs, por sus siglas en inglés) en las estrategias de manejo del cultivo, constituyen una herramienta sostenible. Objetivo. El objetivo de esta investigación fue incorporar las cepas bacterianas Azotobacter chroococcum IBCR19 y Azospirillum lipoferum IBSC7 en la fertilización nitrogenada y evaluar su efecto en el rendimiento y composición bromatológica de las raíces tuberosas de batata (Ipomoea batatasLam). Materiales y métodos. El estudio se realizó en el municipio de Corozal (Sucre, Colombia), durante los meses de junio a octubre del 2017. Se utilizó un área experimental de 840 m2, donde se establecieron veinticuatro parcelas con esquejes apicales de la accesión 15020078, distribuidas bajo un diseño completamente aleatorizado con arreglo factorial aumentado (3x2+2). Se evaluó materia seca radicular, rendimiento y composición bromatológica de las raíces de batata.Resultados. El rendimiento fresco y de materia seca radicular presentó diferencias significativas (p≤0,05) entre lostratamientos, en donde la aplicación de A. chroococcum IBCR19 y un 75 % de fertilización nitrogenada alcanzó los mayores valores medios de rendimiento y materia seca radicular 12,18 t.ha-1 y 2,92 t.ha-1, respectivamente. De igualforma, las concentraciones de proteína y extracto etéreo difirieron significativamente (p≤0,05) entre los tratamientosinoculados con relación al testigo absoluto. Conclusión. Con base en los resultados obtenidos se puede inferir que la inoculación con A. chroococcum IBCR19 logró reducir en un 25 % los niveles de fertilización nitrogenada y constituye una cepa promisoria como bioestimulante

In vivo activity of plant-based interleukin-12 in the lung of Balb/c mouse

<p>Abstract</p> <p>Background</p> <p>In the last years, plants are being used for the production of a wide variety of biopharmaceuticals, including cytokines, and have the potential to serve as vehicles for mucosal administration of these molecules. We had previously reported the expression of a cytokine, interleukin-12 (IL-12), in transgenic tomato plants and had demonstrated that it retained its biologic activity <it>in vitro</it>.</p> <p>Findings</p> <p>In this work, we administered crude extracts of IL-12-containing tomato fruits to mice through the intratracheal route, measuring endogenous IL-12 and determining biologic activity by quantification of interferon-gamma (IFN-γ) in lungs and by histological analysis. IFN-γ expression in lungs, as well as histological analysis, indicate that tomato-expressed IL-12 retains its biologic activity and, most importantly, its effects are restricted to the site of administration.</p> <p>Conclusion</p> <p>Our results indicate that the functional activity of tomato-expressed IL-12 is comparable to that of commercial recombinant IL-12 when given via the mucosal route. This opens the possibility of using crude extracts prepared from tomatoes expressing IL-12 for certain immunotherapies.</p

Anti-IL-6 Receptor Tocilizumab in Refractory Graves? Orbitopathy: National Multicenter Observational Study of 48 Patients

Graves’ orbitopathy (GO) is the most common extrathyroidal manifestation of Graves’ disease (GD). Our aim was to assess the e cacy and safety of Tocilizumab (TCZ) in GO refractory to conventional therapy. This was an open-label multicenter study of glucocorticoid-resistant GO treated with TCZ. The main outcomes were the best-corrected visual acuity (BVCA), Clinical Activity Score (CAS) and intraocular pressure (IOP). These outcome variables were assessed at baseline, 1st, 3rd, 6th and 12th month after TCZ therapy onset. The severity of GO was assessed according to the European Group on Graves’ Orbitopathy (EUGOGO). We studied 48 (38 women and 10 men) patients (95 eyes); mean age standard deviation 51 11.8 years. Before TCZ and besides oral glucocorticoids, they had received IV methylprednisolone (n = 43), or selenium (n = 11). GO disease was moderate (n =29) or severe (n = 19) and dysthyroid optic neuropathy (DON) (n = 7). TCZ was used in monotherapy (n = 45) or combined (n = 3) at a dose of 8 mg/kg IV every four weeks (n = 43) or 162 mg/s.c. every week (n = 5). TCZ yielded a significant improvement in all of the main outcomes at the 1st month that was maintained at one year. Comparing the baseline with data at 1 year all of the variables improved; BCVA (0.78 0.25 vs. 0.9 0.16; p = 0.0001), CAS (4.64 1.5 vs. 1.05 1.27; p = 0.0001) and intraocular pressure (IOP) (19.05 4.1 vs. 16.73 3.4 mmHg; p = 0.007). After a mean follow-up of 16.1 2.1 months, low disease activity (CAS 3), was achieved in 88 eyes (92.6%) and TCZ was withdrawn in 29 cases due to low disease activity (n = 25) or ine cacy (n = 4). No serious adverse events were observed. In conclusion, TCZ is a useful and safe therapeutic option in refractory GO treatment.This work was also partially supported by RETICS Programs, RD08/0075 (RIER) and RD12/0009/0013 from “Instituto de Salud Carlos III” (ISCIII) (Spain)

Desarrollo profesoral : oportunidades y desafíos en la Universidad del Rosario. Mesa de trabajo: Docencia de excelencia-formación profesoral

El presente documento expone un resumen de las principales reflexiones de los miembros de la mesa de trabajo: Docencia de excelencia-formación profesoral. En primer lugar, se analiza el concepto de desarrollo profesoral. En segundo lugar, se realiza una ubicación contextual de los antecedentes de la formación profesoral en el ámbito global. Después, se presentan los antecedentes institucionales sobre el tema y se hace un análisis de las percepciones de los profesores frente a los cursos de desarrollo profesoral agenciados en 2016. Finalmente, se hace referencia a las oportunidades, retos y desafíos en torno a la formación profesoral en la Universidad

Tocilizumab in refractory Caucasian Takayasu's arteritis: a multicenter study of 54 patients and literature review

Objective: To assess the efficacy and safety of tocilizumab (TCZ) in Caucasian patients with refractory Takayasu's arteritis (TAK) in clinical practice. Methods: A multicenter study of Caucasian patients with refractory TAK who received TCZ. The outcome variables were remission, glucocorticoid-sparing effect, improvement in imaging techniques, and adverse events. A comparative study between patients who received TCZ as monotherapy (TCZMONO) and combined with conventional disease modifying anti-rheumatic drugs (cDMARDs) (TCZCOMBO) was performed. Results: The study comprised 54 patients (46 women/8 men) with a median [interquartile range (IQR)] age of 42.0 (32.5-50.5) years. TCZ was started after a median (IQR) of 12.0 (3.0-31.5) months since TAK diagnosis. Remission was achieved in 12/54 (22.2%), 19/49 (38.8%), 23/44 (52.3%), and 27/36 (75%) patients at 1, 3, 6, and 12 months, respectively. The prednisone dose was reduced from 30.0 mg/day (12.5-50.0) to 5.0 (0.0-5.6) mg/day at 12 months. An improvement in imaging findings was reported in 28 (73.7%) patients after a median (IQR) of 9.0 (6.0-14.0) months. Twenty-three (42.6%) patients were on TCZMONO and 31 (57.4%) on TCZCOMBO: MTX (n = 28), cyclosporine A (n = 2), azathioprine (n = 1). Patients on TCZCOMBO were younger [38.0 (27.0-46.0) versus 45.0 (38.0-57.0)] years; difference (diff) [95% confidence interval (CI) = -7.0 (-17.9, -0.56] with a trend to longer TAK duration [21.0 (6.0-38.0) versus 6.0 (1.0-23.0)] months; diff 95% CI = 15 (-8.9, 35.5), and higher c-reactive protein [2.4 (0.7-5.6) versus 1.3 (0.3-3.3)] mg/dl; diff 95% CI = 1.1 (-0.26, 2.99). Despite these differences, similar outcomes were observed in both groups (log rank p = 0.862). Relevant adverse events were reported in six (11.1%) patients, but only three developed severe events that required TCZ withdrawal. Conclusion: TCZ in monotherapy, or combined with cDMARDs, is effective and safe in patients with refractory TAK of Caucasian origin.Funding: This work was partially supported by RETICS Programs, RD08/0075 (RIER), RD12/0009/0013 and RD16/0012 from “Instituto de Salud Carlos III” (ISCIII) (Spain)