Análisis de la susceptibilidad de una línea celular de aedes aegypti (diptera: culicidae) a la infección con leishmania (L) chagasi, leishmania (V) braziliensis

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Susceptibility Analysis of a Cell Line Derived from Aedes aegypti (Diptera: Culicidae) to Leishmania (L) chagasi and Leishmania (V) braziliensis Infection

Se evaluó la susceptibilidad de los cultivos celulares derivados de tejidos embrionarios de Aedes aegypti a la infección con Leishmania (L) chagasi y Leishmania (V) braziliensis, agentes etiológicos de leishmaniasis visceral americana y leishmaniasis cutánea, respectivamente. Metodología: Se seleccionaron células de A. aegypti mantenidas en una mezcla de medio de cultivo Grace/L15, suplementado con suero fetal bovino al 15%, albendazol 5,4 mg/ml y una mezcla de antibióticos, e incubadas a una temperatura promedio de 26 °C. Los cultivos celulares fueron inoculados con promastigotes metacíclicos de la cepa MH/CO/84/CI-044B de L. chagasi y la cepa HOM/BR752903 de L. braziliensis en una concentración de 10 parásitos por célula. Como control positivo de la infección se utilizó la línea celular J774. Resultados: Los registros más altos en el porcentaje de infección y en el número de amastigotes por células en los cultivos celulares A. aegypti y en la línea celular J774 se obtuvieron en los días 6 y 9 pos-infección. Los resultados mostraron interacción, internalización y maduración in vitro de las dos especies del parásito en las células de este insecto no vector de Leishmania. Las células de A. aegypti infectadas mostraron cambios en el área por la influencia de los parásitos, contrario a lo registrado en las células no infectadas (P<0,05). Conclusión: Los cultivos celulares de A. aegypti emergen como un nuevo modelo in vitro para el estudio del ciclo biológico de L. chagasi y L. braziliensis.The susceptibility of culture cells derived from embryonic tissues of Aedes aegypti to the infection with Leishmania (L) chagasi and Leishmania (V) braziliensis was evaluated. Methodology: These parasites are etiological agents of American visceral leishmaniasis and cutaneous leishmaniasis, respectively. Selected cells of Aedes aegypti were maintained in culture medium Grace/L15, supplement with 15% bovine fetal serum, 5,4 mg/ml of albendazol and an antibiotic mixture and incubated at an average temperature of 26°C. The cultures were inoculated with metacyclic promastigotes of the strain MH/ CO/84/CI-044B of L. chagasi and the strain HOM/BR752903 of L. braziliensis in a concentration of 10 parasites by cell. The J774 cell line was used as positive control of infection. Results: The highest percentage of infection represented as the number of amastigotes per cell in A. aegyti cell cultures and in the J774 cell line were obtained on days 6 and 9 post-infection. The results showed interaction, internalization and maturation in vitro of the two species of the parasite in the cells of a non-vector insect of Leishmania. Infected A. aegypti cells showed changes in its area because of the influence of the parasites that differ significantly (P <0.05) compared to not infected cells. Conclusion: Cell cultures from A. aegypti emerge as a new in vitro model for the study of the biological cycle of L. chagasi and L. braziliensis

Molecular typing of Leishmania (Leishmania) amazonensis and species of the subgenus Viannia associated with cutaneous and mucosal leishmaniasis in Colombia: A concordance study

Introduction: Multilocus enzyme electrophoresis (MLEE) is the reference standard for the characterization of Leishmania species. The test is restricted to specialized laboratories due to its technical complexity, cost, and time required to obtain results. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) is used to identify Leishmania species. Objective: To establish the concordance between the two tests as identifying methods for circulating species in Colombia. Materials and methods: A total of 96 isolates from patients with cutaneous or mucosal leishmaniasis were selected and identified by MLEE and PCR-RFLP with miniexon and hsp70 as the molecular targets, which were used sequentially. Restriction enzymes HaeIII and BccI were similarly applied. Cohen’s kappa coefficient and the 95% confidence interval (CI) were calculated. Results: The kappa coefficient and the 95% CI between MLEE and PCR-RFLP displayed “very good” concordance with a coefficient of 0.98 (CI95%: 0.98 to 1.00). The identified species were Leishmania Viannia braziliensis, Leishmania Viannia panamensis, Leishmania Viannia guyanensis and Leishmania Leishmania amazonensis. A total of 80 of the 96 isolates were sequenced and the results obtained by PCR-RFLP were confirmed. Conclusion: Due to the concordance obtained between tests results with the amplification of the genes miniexon and hsp70, PCR-RFLP is proposed as an alternative for identifying circulating Leishmania species in Colombia

Magnetite Nanoparticles Functionalized with RNases against Intracellular Infection of Pseudomonas aeruginosa

Altres ajuts: Fundació La Marató de TV3/20180310Current treatments against bacterial infections have severe limitations, mainly due to the emergence of resistance to conventional antibiotics. In the specific case of Pseudomonas aeruginosa strains, they have shown a number of resistance mechanisms to counter most antibiotics. Human secretory RNases from the RNase A superfamily are proteins involved in a wide variety of biological functions, including antimicrobial activity. The objective of this work was to explore the intracellular antimicrobial action of an RNase 3/1 hybrid protein that combines RNase 1 high catalytic and RNase 3 bactericidal activities. To achieve this, we immobilized the RNase 3/1 hybrid on Polyetheramine (PEA)-modified magnetite nanoparticles (MNPs). The obtained nanobioconjugates were tested in macrophage-derived THP-1 cells infected with Pseudomonas aeruginosa PAO1. The obtained results show high antimicrobial activity of the functionalized hybrid protein (MNP-RNase 3/1) against the intracellular growth of P. aeruginosa of the functionalized hybrid protein. Moreover, the immobilization of RNase 3/1 enhances its antimicrobial and cell-penetrating activities without generating any significant cell damage. Considering the observed antibacterial activity, the immobilization of the RNase A superfamily and derived proteins represents an innovative approach for the development of new strategies using nanoparticles to deliver antimicrobials that counteract P. aeruginosa intracellular infection

Unveiling the multifaceted mechanisms of antibacterial activity of buforin II and frenatin 2.3S peptides from skin micro-organs of the orinoco lime treefrog (Sphaenorhynchus lacteus)

Amphibian skin is a rich source of natural compounds with diverse antimicrobial and immune defense properties. Our previous studies showed that the frog skin secretions obtained by skin micro-organs from various species of Colombian anurans have antimicrobial activities against bacteria and viruses. We purified for the first time two antimicrobial peptides from the skin micro-organs of the Orinoco lime treefrog (Sphaenorhynchus lacteus) that correspond to Buforin II (BF2) and Frenatin 2.3S (F2.3S). Here, we have synthesized the two peptides and tested them against Gram-negative and Gram-positive bacteria, observing an effective bactericidal activity at micromolar concentrations. Evaluation of BF2 and F2.3S membrane destabilization activity on bacterial cell cultures and synthetic lipid bilayers reveals a distinct membrane interaction mechanism. BF2 agglutinates E. coli cells and synthetic vesicles, whereas F2.3S shows a high depolarization and membrane destabilization activities. Interestingly, we found that F2.3S is able to internalize within bacterial cells and can bind nucleic acids, as previously reported for BF2. Moreover, bacterial exposure to both peptides alters the expression profile of genes related to stress and resistance response. Overall, these results show the multifaceted mechanism of action of both antimicrobial peptides that can provide alternative tools in the fight against bacterial resistance

La Imagen y la Narrativa como Herramientas para el Abordaje Psicosocial en Escenarios de Violencia Departamento de Casanare

El desplazamiento forzado es un fenómeno complejo que afecta a millones de personas en todo el mundo. En Colombia, se ha convertido en una de las principales causas de desplazamiento interno, con más de 8 millones de personas desplazadas desde 1985 (Centro de Estudios sobre Desplazamiento Forzado, 2023, p. 1). Es crucial anotar que la cifra dada a conocer por el gobierno colombiano incluye un acumulado histórico de 8.375.715 víctimas de reubicación forzada por hechos ocurridos entre 1985 y el 31 de diciembre de 2022. Según el informe final de la comisión de la verdad, los tres resultados más significativos del proceso de desplazamiento forzado que han sufrido muchas personas, familias, comunidades y pueblos indígenas en Colombia son el exilio, el despojo y la reubicación. Dependiendo de la edad, el género y la etnia de las personas afectadas, estos tres efectos comunes a cualquier desplazamiento forzado tienen significados, impactos y respuestas diferenciales para afrontarlos. Los departamentos de Casanare y Meta, ubicados en la región llanera de Colombia, han sido escenarios de violencia durante décadas. El conflicto armado, el narcotráfico y la delincuencia han dejado profundas secuelas en la población, a nivel individual, familiar y comunitario. En este contexto, la imagen y la narrativa se han convertido en recursos útiles para el abordaje psicosocial de las víctimas de violencia. Estas herramientas permiten a las personas expresar sus experiencias, emociones y pensamientos, este es un paso crucial en el proceso de sanación y recuperación.Forced displacement is a complex phenomenon that affects millions of people around the world. In Colombia, it has become one of the main causes of internal displacement, with more than 8 million people displaced since 1985 (Center for Studies on Forced Displacement, 2023, p. 1). It is crucial to note that the figure released by the Colombian government includes a historical total of 8,375,715 victims of forced relocation due to events that occurred between 1985 and December 31, 2022. According to the final report of the truth commission, the three most significant results of the process of forced displacement that many individuals, families, communities and indigenous peoples in Colombia have suffered are exile, dispossession and relocation. Depending on the age, gender and ethnicity of the affected people, these three effects common to any forced displacement have differential meanings, impacts and responses to address them. The departments of Casanare and Meta, located in the plains region of Colombia, have been scenes of violence for decades. The armed conflict, drug trafficking and crime have left deep consequences on the population, at the individual, family and community level. In this context, image and narrative have become useful resources for the psychosocial approach of victims of violence. These tools allow people to express their experiences, emotions and thoughts, this is a crucial step in the healing and recovery process

Magnetoliposomas multifuncionales como vehículos de administración de fármacos para el tratamiento potencial de la enfermedad de Parkinson

La enfermedad de Parkinson (EP) es el segundo trastorno neurodegenerativo más frecuente después de la enfermedad de Alzheimer. Por ello, el desarrollo de nuevas tecnologías y estrategias para tratarla es una prioridad sanitaria mundial. Los tratamientos actuales incluyen la administración de levodopa, inhibidores de la monoaminooxidasa, inhibidores de la catecol-O-metiltransferasa y fármacos anticolinérgicos. Sin embargo, la liberación efectiva de estas moléculas, debido a la limitada biodisponibilidad, es un reto importante para el tratamiento de la EP. Como estrategia para resolver este desafío, en este estudio desarrollamos un novedoso sistema de liberación de fármacos multifuncional magnético y sensible a estímulos redox, basado en nanopartículas de magnetita funcionalizadas con la proteína translocadora de alto rendimiento OmpA y encapsuladas en liposomas de lecitina de soja. Los magnetoliposomas multifuncionales (MLP) obtenidos se ensayaron en neuroblastoma, glioblastoma, astrocitos primarios humanos y de rata, células endoteliales de rata de barrera hematoencefálica, células endoteliales microvasculares primarias de ratón y en un modelo celular inducido por EP. Los MLP demostraron un excelente rendimiento en ensayos de biocompatibilidad, incluyendo hemocompatibilidad (porcentajes de hemólisis por debajo del 1%), agregación plaquetaria, citocompatibilidad (viabilidad celular por encima del 80% en todas las líneas celulares probadas), potencial de membrana mitocondrial (alteraciones no observadas) y producción intracelular de ROS (impacto insignificante en comparación con los controles). Además, las nanovehículas mostraron una aceptable internalización celular (área cubierta cercana al 100% a los 30 min y a las 4 h) y capacidad de escape endosomal (disminución significativa de la colocalización lisosomal tras 4 h de exposición). Además, se emplearon simulaciones de dinámica molecular para comprender mejor el mecanismo de translocación subyacente de la proteína OmpA, mostrando hallazgos clave relativos a interacciones específicas con fosfolípidos. En general, la versatilidad y el notable rendimiento in vitro de este novedoso nanovehículo lo convierten en una tecnología de administración de fármacos adecuada y prometedora para el tratamiento potencial de la EP.Parkinson’s disease (PD) is the second most common neurodegenerative disorder after Alzheimer’s disease. Therefore, development of novel technologies and strategies to treat PD is a global health priority. Current treatments include administration of Levodopa, monoamine oxidase inhibitors, catechol-O-methyltransferase inhibitors, and anticholinergic drugs. However, the effective release of these molecules, due to the limited bioavailability, is a major challenge for the treatment of PD. As a strategy to solve this challenge, in this study we developed a novel multifunctional magnetic and redox-stimuli responsive drug delivery system, based on the magnetite nanoparticles functionalized with the high-performance translocating protein OmpA and encapsulated into soy lecithin liposomes. The obtained multifunctional magnetoliposomes (MLPs) were tested in neuroblastoma, glioblastoma, primary human and rat astrocytes, blood brain barrier rat endothelial cells, primary mouse microvascular endothelial cells, and in a PD-induced cellular model. MLPs demonstrated excellent performance in biocompatibility assays, including hemocompatibility (hemolysis percentages below 1%), platelet aggregation, cytocompatibility (cell viability above 80% in all tested cell lines), mitochondrial membrane potential (non-observed alterations) and intracellular ROS production (negligible impact compared to controls). Additionally, the nanovehicles showed acceptable cell internalization (covered area close to 100% at 30 min and 4 h) and endosomal escape abilities (significant decrease in lysosomal colocalization after 4 h of exposure). Moreover, molecular dynamics simulations were employed to better understand the underlying translocating mechanism of the OmpA protein, showing key findings regarding specific interactions with phospholipids. Overall, the versatility and the notable in vitro performance of this novel nanovehicle make it a suitable and promising drug delivery technology for the potential treatment of PD

Polyester urethane urea (PEUU) functionalization for enhanced anti-thrombotic performance: advancing regenerative cardiovascular devices through innovative surface modifications

Introduction: Thrombogenesis, a major cause of implantable cardiovascular device failure, can be addressed through the use of biodegradable polymers modified with anticoagulating moieties. This study introduces a novel polyester urethane urea (PEUU) functionalized with various anti-platelet deposition molecules for enhanced antiplatelet performance in regenerative cardiovascular devices.Methods: PEUU, synthesized from poly-caprolactone, 1,4-diisocyanatobutane, and putrescine, was chemically oxidized to introduce carboxyl groups, creating PEUU-COOH. This polymer was functionalized in situ with polyethyleneimine, 4-arm polyethylene glycol, seleno-L-cystine, heparin sodium, and fondaparinux. Functionalization was confirmed using Fourier-transformed infrared spectroscopy and X-ray photoelectron spectroscopy. Bio-compatibility and hemocompatibility were validated through metabolic activity and hemolysis assays. The anti-thrombotic activity was assessed using platelet aggregation, lactate dehydrogenase activation assays, and scanning electron microscopy surface imaging. The whole-blood clotting time quantification assay was employed to evaluate anticoagulation properties.Results: Results demonstrated high biocompatibility and hemocompatibility, with the most potent anti-thrombotic activity observed on pegylated surfaces. However, seleno-L-cystine and fondaparinux exhibited no anti-platelet activity.Discussion: The findings highlight the importance of balancing various factors and addressing challenges associated with different approaches when developing innovative surface modifications for cardiovascular devices

Premio a la Investigación e Innovación Educativa: Experiencias 2021

232 pàginasEstas experiencias pedagógicas de investigación e innovación son la muestra de las resistencias que surgen desde la escuela para enfrentar un mundo convulsionado por la violencia, la crisis existencial, el cambio climático y la incertidumbre, pues son los maestros y maestras quienes al reflexionar sobre su práctica logran llevar al máximo todo su poder transformador y mantener viva la esperanza en la siguiente generación. Por ello, la Secretaría de Educación del Distrito (SED) y el Instituto para la Investigación Educativa y el Desarrollo Pedagógico (IDEP), se enorgullecen en ofrecer a Bogotá y al país esta obra que contiene las propuestas ganadoras del XV Premio a la Investigación e Innovación.Serie Premio n.º 5, de 202