Identificación morfofisiologica de hongos en genotipos de maíz

El cultivo de maíz es la base de la alimentación para México, el objetivo de este trabajo fue identificar la micobiota en cuatro genotipos de maíz de Saltillo, Coahuila y cuatro de Tepalcingo, Morelos. Se realizó de acuerdo a la prueba papel secante y congelamiento, se tomaron 1000 semillas de maíz por cada genotipo, las cuales se desinfectaron con hipoclorito de sodio al 3 % (2 veces) y posteriormente se enjuagaron con agua destilada por 1 min. (2 veces). La siembra fue realizada en charolas de plástico 18.5 x 25 cm, sobre papel secante estéril previamente humedecido, las charolas se mantuvieron a temperatura ambiente de 26 °C ± 2 °C durante 11 días en la cámara bioclimática del Laboratorio de Fitopatología de la Universidad Autónoma Agraria Antonio Narro. Terminado el periodo de la incubación, se procedió a contar y aislar el número de las colonias de hongos por su color por repetición, para su posterior purificación e identificación, así como las semillas sanas, es decir, aquellas que no presentaron crecimiento de micelio y la incidencia reportándose como porcentaje de semilla colonizada, analizando los datos en el programa de la Universidad de Nuevo León versión 2.5. Se observó diferencia estadística entre la incidencia de hongos en los genotipos de maíz P>F 0.00, con un coeficiente de variación del 22.77 %, los genotipos de Tepalcingo con una media del 77.925% y Saltillo 87.725%, reportando por primera vez a Acremonium sp. en Saltillo, Coahuila y Tepalcingo, Morelos, México

ANTAGONISMO DE Trichoderma spp. EN HONGOS ASOCIADOS AL DAÑO DE Diatraea saccharalis Fabricius. (LEPIDOPTERA : CRAMBIDAE ) EN MAIZ

El objetivo del presente trabajo, fue evaluar in vitro, mediante cultivo dual la capacidad antagónica de las cepas de Trichoderma asperellum T11, Trichoderma harzianum T1 4, y Trichoderma longibrachiatum T1 40 sobre hongos asociados; Alternaria arborescens, Bipolaris shoemakeri, Bipolaris victoriae, Epicocum sorghinum, Exserohilum longirostratum, Fusarium brevicatenulatum, Penicillium polonicum, Phaeocytostroma ambiguum y Fusarium equiseti, el muestreo se realizó en Tepalcingo, Morelos en tallos de maíz y el experimento se estableció en el laboratorio de Fitopatología de la Universidad Autónoma Agraria Antonio Narro en el mes de abril de 2018. La evaluación se realizó bajo un diseño factorial AxB, con nueve niveles en A y tres en B con cuatro repeticiones por tratamiento, siendo A las cepas de hongos fitopatógenos y B las tres cepas de Trichoderma, se colocó en el extremo de la placa de Petri un explante de PDA con micelio de Trichoderma spp. de 5 mm de diámetro, y en el extremo opuesto un explante del hongo fitopatógeno, las siembras fueron incubadas a 25 ± 2 ºC por 120 h, evaluándose las medias del Porcentaje de Inhibición en el Crecimiento del Micelio (PICM) mediante la fórmula de Fakhrunnisa modificada y se determinó el área de desarrollo de los hongos mediante el software GeoGebra Classic versión 5.0.473.0-d, los resultados se analizaron con el programa (FAUANL) versión 2.5, mediante Tukey con nivel de significancia de 0.05, con efectos de antagonismo mayores del 67.74%

Establishment of triple-negative breast cancer cells based on BMI: A novel model in the correlation between obesity and breast cancer

IntroductionObesity has been associated with an increased risk of biologically aggressive variants in breast cancer. Women with obesity often have tumors diagnosed at later stages of the disease, associated with a poorer prognosis and a different response to treatment. Human cell lines have been derived from specific subtypes of breast cancer and have served to define the cell physiology of corresponding breast cancer subtypes. However, there are no current cell lines for breast cancer specifically derived from patients with different BMIs. The availability of those breast cancer cell lines should allow to describe and unravel functional alterations linked to these comorbidities. MethodsCell cultures were established from tumor explants. Once generated, the triple negative subtype in a patient with obesity and a patient with a normal BMI were chosen for comparison. For cellular characterization, the following assays were conducted: proliferation assays, chemo – sensitivity assays for doxorubicin and paclitaxel, wound healing motility assays, matrix invasion assays, breast cancer cell growth to estradiol by chronic exposure to leptin, induction of endothelial permeability and tumorigenic potential in athymic mice with normo - versus hypercaloric diets with an evaluation of the epithelium – mesenchymal transformation proteins.ResultsTwo different cell lines, were established from patients with breast cancer: DSG-BC1, with a BMI of 21.9 kg/m2 and DSG-BC2, with a BMI of 31.5 kg/m2. In vitro, these two cell lines show differential growth rates, motility, chemosensitivity, vascular permeability, response to leptin with an activation of the JAK2/STAT3/AKT signaling pathway. In vivo, they displayed distinct tumorigenic potential. In particular, DSG-BC2, presented higher tumorigenicity when implanted in mice fed with a hypercaloric diet.DiscussionTo our knowledge, these primary cultures are the first in vitro representation of both breast cancer and obesity. DSG – BC2 presented a more aggressive in vivo and in vitro phenotype. These results support the hypothesis that breast cancer generated in an obese metabolic state may represent a contrasting variant within the same disease. This new model will allow both further comprehension, functional studies and the analysis of altered molecular mechanisms under the comorbidity of obesity and breast cancer

Risk of COVID-19 after natural infection or vaccinationResearch in context

Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health

Risk of COVID-19 after natural infection or vaccinationResearch in context

Summary: Background: While vaccines have established utility against COVID-19, phase 3 efficacy studies have generally not comprehensively evaluated protection provided by previous infection or hybrid immunity (previous infection plus vaccination). Individual patient data from US government-supported harmonized vaccine trials provide an unprecedented sample population to address this issue. We characterized the protective efficacy of previous SARS-CoV-2 infection and hybrid immunity against COVID-19 early in the pandemic over three-to six-month follow-up and compared with vaccine-associated protection. Methods: In this post-hoc cross-protocol analysis of the Moderna, AstraZeneca, Janssen, and Novavax COVID-19 vaccine clinical trials, we allocated participants into four groups based on previous-infection status at enrolment and treatment: no previous infection/placebo; previous infection/placebo; no previous infection/vaccine; and previous infection/vaccine. The main outcome was RT-PCR-confirmed COVID-19 >7–15 days (per original protocols) after final study injection. We calculated crude and adjusted efficacy measures. Findings: Previous infection/placebo participants had a 92% decreased risk of future COVID-19 compared to no previous infection/placebo participants (overall hazard ratio [HR] ratio: 0.08; 95% CI: 0.05–0.13). Among single-dose Janssen participants, hybrid immunity conferred greater protection than vaccine alone (HR: 0.03; 95% CI: 0.01–0.10). Too few infections were observed to draw statistical inferences comparing hybrid immunity to vaccine alone for other trials. Vaccination, previous infection, and hybrid immunity all provided near-complete protection against severe disease. Interpretation: Previous infection, any hybrid immunity, and two-dose vaccination all provided substantial protection against symptomatic and severe COVID-19 through the early Delta period. Thus, as a surrogate for natural infection, vaccination remains the safest approach to protection. Funding: National Institutes of Health