24 research outputs found

    Respiratory viruses detected in Mexican children younger than 5 years old with community-acquired pneumonia: a national multicenter study

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    Background: Acute respiratory infections are the leading cause of mortality in children worldwide, especially in developing countries. Pneumonia accounts for 16% of all deaths of children under 5 years of age and was the cause of death of 935 000 children in 2015. Despite its frequency and severity, information regarding its etiology is limited. The aim of this study was to identify respiratory viruses associated with community-acquired pneumonia (CAP) in children younger than 5 years old. Methods: One thousand four hundred and four children younger than 5 years of age with a clinical and/or radiological diagnosis of CAP in 11 hospitals in Mexico were included. Nasal washes were collected, placed in viral medium, and frozen at �70 C until processing. The first 832 samples were processed using the multiplex Bio-Plex/Luminex system and the remaining 572 samples using the Anyplex multiplex RT-PCR. Clinical data regarding diagnosis, clinical signs and symptoms, radiographic pattern, and risk factors were obtained and recorded. Results: Of the samples tested, 81.6% were positive for viruses. Respiratory syncytial virus (types A and B) was found in 23.7%, human enterovirus/rhinovirus in 16.6%, metapneumovirus in 5.7%, parainfluenza virus (types 1–4) in 5.5%, influenza virus (types A and B) in 3.6%, adenovirus in 2.2%, coronavirus (NL63, OC43, 229E, and HKU1) in 2.2%, and bocavirus in 0.4%. Co-infection with two or more viruses was present in 22.1%; 18.4% of the samples were negative. Using biomass for cooking, daycare attendance, absence of breastfeeding, and co-infections were found to be statistically significant risk factors for the presence of severe pneumonia. Conclusions: Respiratory syncytial virus (types A and B), human enterovirus/rhinovirus, and metapneumovirus were the respiratory viruses identified most frequently in children younger than 5 years old with CAP. Co-infection was present in an important proportion of the children

    Ciencias de la Biología y Agronomía

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    Este volumen I contiene 17 capítulos arbitrados que se ocupan de estos asuntos en Tópicos Selectos de Ciencias de la Biología y Agronomía, elegidos de entre las contribuciones, reunimos algunos investigadores y estudiantes. Se presenta un Estudio Comparativo de los Recursos Hidrológico-Forestales de la Microcuenca de la Laguna de Epatlan, Pue. (1993 a 2014); la Situación Actual de la Mancha de Asfalto en Maíz (Zea mays L.) en los Municipios de Jiquipilas y Ocozocoautla, Chiapas, México; las poblaciones sobresalientes de maíz de la raza Zapalote Chico, en la Región Istmeña de Oaxaca; Se indica el índice de área foliar de cultivo de Chile Poblano mediante dos métodos en condiciones protegidas; Esquivel, Urzúa y Ramírez exploran el efecto de la biofertilización con Azospirillum en el crecimiento y producción de Jitomate; esbozan su artículo sobre la determinación del nivel de Heterosis en híbridos de Maíz para la Comarca Lagunera; una investigación sobre la estabilización de semilla de Solanum lycopersicum durante el almacenamiento y estimulación de la germinación; acotan sobre el CTAB como una nueva opción para la detección de Huanglongbing en cítricos, plantean su evaluación sobre el aluminio y cómo afecta la vida de florero de Heliconia psittacorum; indican sobre el impacto del H-564C, como un híbrido de maíz con alta calidad de proteina para el trópico húmedo de México; presetan su investigación sobre la producción de Piña Cayena Lisa y MD2 (Ananas comosus L.) en condiciones de Loma Bonita, en Oaxaca; acotan sobre el efecto de coberteras como control biológico por conservación contra áfidos en Nogal Pecanero; esbozan sobre la caracterización de cuatro genotipos de Frijol Negro en Martínez de la Torre, Veracruz, México; presentan una caracterización hidroecológica de la microcuenca de Arroyo Prieto, Yuriría, Gto., y alternativas para su restauración ambiental; presentan su investigación sobre el efecto del hongo Beauveria bassiana sobre solubilización de fosfatos y la disponibilidad de fósforo en el suelo; plantean su investigación sobre la Germinación y regeneración in vitro de Epidendrum falcatum LINDL; esbozan su artículo sobre genotipos de frijol negro y su tolerancia a sequía terminal en Veracruz, México

    Gestión del conocimiento: perspectiva multidisciplinaria. Volumen 11

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    El libro “Gestión del Conocimiento. Perspectiva Multidisciplinaria”, Volumen 11, de la Colección Unión Global, es resultado de investigaciones. Los capítulos del libro, son resultados de investigaciones desarrolladas por sus autores. El libro cuenta con el apoyo de los grupos de investigación: Universidad Sur del Lago “Jesús María Semprúm” (UNESUR), Zulia – Venezuela; Universidad Politécnica Territorial de Falcón Alonso Gamero (UPTAG), Falcón – Venezuela; Universidad Politécnica Territorial de Mérida Kleber Ramírez (UPTM), Mérida – Venezuela; Universidad Guanajuato (UG) - Campus Celaya - Salvatierra - Cuerpo Académico de Biodesarrollo y Bioeconomía en las Organizaciones y Políticas Públicas (C.A.B.B.O.P.P), Guanajuato – México; Centro de Altos Estudios de Venezuela (CEALEVE), Zulia – Venezuela, Centro Integral de Formación Educativa Especializada del Sur (CIFE - SUR) - Zulia - Venezuela, Centro de Investigaciones Internacionales SAS (CIN), Antioquia - Colombia.y diferentes grupos de investigación del ámbito nacional e internacional que hoy se unen para estrechar vínculos investigativos, para que sus aportes científicos formen parte de los libros que se publiquen en formatos digital e impreso

    Toll-like Receptor Signaling Activation by <em>Entamoeba histolytica</em> Induces Beta Defensin 2 in Human Colonic Epithelial Cells: Its Possible Role as an Element of the Innate Immune Response

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    <div><p>Background</p><p><i>Entamoeba histolytica</i>, a protozoan parasite of humans, produces dysenteric diarrhea, intestinal mucosa damage and extraintestinal infection. It has been proposed that the intestinal microbiota composition could be an important regulatory factor of amebic virulence and tissue invasion, particularly if pathogenic bacteria are present. Recent <i>in vitro</i> studies have shown that <i>Entamoeba histolytica</i> trophozoites induced human colonic CaCo2 cells to synthesize TLR-2 and TLR-4 and proinflammatory cytokines after binding to the amebic Gal/GalNac lectin carbohydrate recognition domain. The magnitude of the inflammatory response induced by trophozoites and the subsequent cell damage were synergized when cells had previously been exposed to pathogenic bacteria.</p> <p>Methodology/Principal Findings</p><p>We show here that <i>E. histolytica</i> activation of the classic TLR pathway in CaCo2 cells is required to induce β defensin-2 (HBD2) mRNA expression and production of a 5-kDa cationic peptide with similar properties to the antimicrobial HBD2 expressed by CaCo2 cells exposed to enterotoxigenic <i>Escherichia coli</i>. The induced peptide showed capacity to permeabilize membranes of bacteria and live trophozoites. This activity was abrogated by inhibition of TLR2/4-NFκB pathway or by neutralization with an anti-HBD2 antibody.</p> <p>Conclusions/Significance</p><p><i>Entamoeba histolytica</i> trophozoites bind to human intestinal cells and induce expression of HBD2; an antimicrobial molecule with capacity to destroy pathogenic bacteria and trophozoites. HDB2's possible role as a modulator of the course of intestinal infections, particularly in mixed ameba/bacteria infections, is discussed.</p> </div

    Pediatría-ME100-201801

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    Pediatría es un curso de la especialidad de la carrera de medicina de carácter teórico-práctico dirigido a los estudiantes del ciclo 11que busca desarrollar las competencias específicas de Práctica clínica diagnósticopromociónprevención y tratamiento (nivel 3) y Profesionalismo- sentido ético y legal y responsabilidad profesional (nivel 3) a través de la atención integral del paciente pediátrico sano y enfermo.La atención del paciente pediátrico difiere del manejo del adulto requiriendo contar con un grupo de adicionales habilidades debido a que existe un variado y numeroso conjunto de enfermedades pediátricas tantas como sistemas del cuerpo humano las cuales se van a presentar de acuerdo no sólo a las características biológicas del niño y las diferentes etapas de su crecimiento y desarrollo sino también en interacción con el medio ambiente y sobre todo a su estado nutricional.Este curso le permitirá al estudiante en su vida profesional establecer el manejo del niño sano y del que presenta diferentes problemas de salud a lo largo de su desarrollo

    Permeabilizing effect of HBD2 released by CaCo2 cells after exposure to <i>Entamoeba histolytica</i> trophozoites.

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    <p>A. Permeabilization of <i>Staphylococcus aureus</i> bacteria, a known strain sensitive to HBD2 activity, by CM from CaCo2 cells exposed to pathogens. One hundred thousand bacteria from an overnight culture were exposed for 1 h to CM from CaCo2 cells exposed to ETEC (CaCo2+ETEC, positive control), to CM from cells exposed to PFA-fixed trophozoites (CaCo2+Eh) or incubated with 10 ng/ml of CECE-HBD2. Propidium iodide internalization into permeabilized bacteria was quantified by flow cytometry. B. Permeabilization of <i>E. histolytica</i> trophozoites by CM from CaCo2 cells exposed to pathogens. One hundred thousand trophozoites were exposed to CM from CaCo2 cells exposed to ETEC (CaCo2+ETEC, positive control), to CM from cells exposed to PFA-fixed trophozoites (CaCo2+Eh) or incubated with 10 ng/ml of CECE-HBD2. In parallel, CM from CaCo2 cell cultures also exposed to either pathogen and incubated with inhibitors of the TLR2/4-NFκB pathway, Bay117085 and IMG-2005-5, were used to permeabilize <i>S. aureus</i> bacteria or <i>E. histolytica</i> trophozoites. Propidium iodide internalization into trophozoites was quantified as indicated for bacteria. C and D. Neutralization of HBD2 activity present in CM. Media obtained from CaCo2 cell cultures exposed to pathogens were neutralized with anti-HBD2 antibody (2.0 µg/ml for 2 h); then, <i>S. aureus</i> bacteria or <i>E. histolytica</i> trophozoites were incubated with these neutralized media. As control, a non-related polyclonal antibody (anti-human Sirt1) was used. Permeabilization levels were evidenced by propidium iodide penetration and quantified by flow cytometry. Data for all panels are presented as percentage of permeabilized cells ± SD. * indicates differences between control cells and cells exposed to pathogens. ** Indicates statistical differences between inhibited (panels A and B) or neutralized (panels C and D) conditions versus values obtained in non-inhibited or non-neutralized conditions in three experiments done in triplicate (<i>P</i> value<0.01).</p

    HBD2 mRNA expression is induced by <i>Entamoeba histolytica</i> trophozoites in CaCo2 cells by activation of TLR2/4 classic pathway.

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    <p>A. CaCo2 cells were exposed to PFA-fixed <i>E. histolytica</i> trophozoites (Eh) in a 1∶2 ratio for 2 h in culture media containing only 1% serum. Cells exposed to Enterotoxigenic <i>Escherichia coli</i> (ETEC) in a 1∶100 ratio, in the same conditions, were used as reference or positive control of HBD2 mRNA induction. After pathogen exposure, CaCo2 cells were washed extensively as indicated in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002083#s2" target="_blank">Methods</a> before been lysed for total RNA isolation. Expression of HBD2 mRNA was measured by relative quantitative RT-PCR. To investigate the participation of the classic pathway of TLR2/4 in the induction of HBD2 mRNA expression, CaCo2 cells exposed to pathogens were incubated with the inhibitors of NFκB activity, Bay117085, or MyD88 signaling, IMG-2005-5, as described in <a href="http://www.plosntds.org/article/info:doi/10.1371/journal.pntd.0002083#s2" target="_blank">Methods</a> section. Data are presented as fold change relative to control CaCo2 cells ± SD from two independent experiments done in triplicate. * Indicates statistical differences in CaCo2 cells exposed to pathogens in comparison to non-exposed cells, <i>P</i> value<0.01. ** Indicates statistical differences between expression of HBD2 mRNA in cells exposed to the same pathogen in presence or absence of the inhibitors. <i>P</i> value<0.001. B. Translocation of NFκB p65 subunit to nuclei of CaCo2 cells after exposure to <i>Entamoeba histolytica</i> trophozoites. Cells treated as indicated in A were fixed and permeabilized for detection of NFκB p65 subunit with a specific antibody and a secondary antibody tagged with FITC. Nuclei were visualized by DAPI staining. Cells exposed to <i>E. histolytica</i> (+Eh), cells exposed to ETEC (+ETEC), cells exposed to pathogens in presence of inhibitors BAY117085 (+Bay) or IMG-2005-5 (+IMG). Bar = 20 µm.</p

    The Antiproliferative Effect of Cyclodipeptides from Pseudomonas aeruginosa PAO1 on HeLa Cells Involves Inhibition of Phosphorylation of Akt and S6k Kinases

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    Pseudomonas aeruginosa PAO1, a potential pathogen of plants and animals, produces the cyclodipeptides cyclo(l-Pro-l-Tyr), cyclo(l-Pro-l-Phe), and cyclo(l-Pro-l-Val) (PAO1-CDPs), whose effects have been implicated in inhibition of human tumor cell line proliferation. Our purpose was to investigate in depth in the mechanisms of HeLa cell proliferation inhibition by the PAO1-CDPs. The results indicate that PAO1-CDPs, both purified individually and in mixtures, inhibited HeLa cell proliferation by arresting the cell cycle at the G0–G1 transition. The crude PAO1-CDPs mixture promoted cell death in HeLa cells in a dose-dependent manner, showing efficacy similar to that of isolated PAO1-CDPs (LD50 of 60–250 µM) and inducing apoptosis with EC50 between 0.6 and 3.0 µM. Moreover, PAO1-CDPs showed a higher proapoptotic activity (~103–105 fold) than their synthetic analogs did. Subsequently, the PAO1-CDPs affected mitochondrial membrane potential and induced apoptosis by caspase-9-dependent pathway. The mechanism of inhibition of cells proliferation in HeLa cells involves inhibition of phosphorylation of both Akt-S473 and S6k-T389 protein kinases, showing a cyclic behavior of their expression and phosphorylation in a time and concentration-dependent fashion. Taken together our findings indicate that PI3K–Akt–mTOR–S6k signaling pathway blockage is involved in the antiproliferative effect of the PAO1-CDPs

    Malfunctioning of the iron-sulfur cluster assembly machinery in Saccharomyces cerevisiae produces oxidative stress via an iron-dependent mechanism, causing dysfunction in respiratory complexes.

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    Biogenesis and recycling of iron-sulfur (Fe-S) clusters play important roles in the iron homeostasis mechanisms involved in mitochondrial function. In Saccharomyces cerevisiae, the Fe-S clusters are assembled into apoproteins by the iron-sulfur cluster machinery (ISC). The aim of the present study was to determine the effects of ISC gene deletion and consequent iron release under oxidative stress conditions on mitochondrial functionality in S. cerevisiae. Reactive oxygen species (ROS) generation, caused by H2O2, menadione, or ethanol, was associated with a loss of iron homeostasis and exacerbated by ISC system dysfunction. ISC mutants showed increased free Fe2+ content, exacerbated by ROS-inducers, causing an increase in ROS, which was decreased by the addition of an iron chelator. Our study suggests that the increment in free Fe2+ associated with ROS generation may have originated from mitochondria, probably Fe-S cluster proteins, under both normal and oxidative stress conditions, suggesting that Fe-S cluster anabolism is affected. Raman spectroscopy analysis and immunoblotting indicated that in mitochondria from SSQ1 and ISA1 mutants, the content of [Fe-S] centers was decreased, as was formation of Rieske protein-dependent supercomplex III2IV2, but this was not observed in the iron-deficient ATX1 and MRS4 mutants. In addition, the activity of complexes II and IV from the electron transport chain (ETC) was impaired or totally abolished in SSQ1 and ISA1 mutants. These results confirm that the ISC system plays important roles in iron homeostasis, ROS stress, and in assembly of supercomplexes III2IV2 and III2IV1, thus affecting the functionality of the respiratory chain
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