Serum levels of tumor necrosis factor α/cachectin (TNFα) were studied in a group of adult patients with sickle cell disease (SCD), which included 31 patients with homozygous SS hemoglobinopathy and 10 patients bearing double heterozygous SC hemoglobinopathy and in their matched normal controls. All patients tested did not show any form of crisis for at least 4 weeks prior to the extraction of the sample. The amount of TNFα in serum was quantitated by means of an immunoenzymatic assay with a lower limit of detection of 25 pg/ml. The percentage of sera with detectable levels of TNFα was significantly increased in SCD patients as compared with the normal controls. Mean TNFα values in individuals with detectable levels of the cytokine were also significantly higher in the whole group of SCD patients and in patients bearing either SS or SC hemoglobinopathies than in the control group. An inverse correlation was observed between the percentages of Hb F and the levels of TNFα found in the sera from the patients.
To study the capacity of peripheral blood mononuclear cells (PBMC) from patients with sickle cell disease to synthesize antibodies in vitro, the levels of IgM, IgG, and IgA were quantitated in supernatants of cultured PBMC from a group of asymptomatic adults with sickle cell disease and from normal controls. The rates of spontaneous synthesis of IgM were similar in nonstimulated cultures of PBMC from patients and controls, whereas the amounts of IgG and IgA produced spontaneously by nonstimulated lymphocytes from the patients were significantly greater than those from controls. Similar levels of IgM, IgG, and IgA were detected in the supernatants of cultures stimulated with pokeweed mitogen from patients and controls. Thus, the capacity of PBMC to respond in vitro to pokeweed mitogen was preserved in the patients. The enhanced spontaneous synthesis of IgG and IgA suggests the presence of chronic polyclonal activation of B cells and/or defective regulation of the production of antibodies.
Los escenarios en el ámbito educativo han cambiado con la pandemia por el virus SARS-CoV-2 (COVID-19). Muchos especialistas hicieron ejercicios de prospectiva, pero ninguno en el que la pandemia obligara al cierre de las instituciones educativas. Las tecnologías de la información y de la comunicación, así como los entornos virtuales de aprendizaje se vuelven el centro del discurso, aun cuando no se sabía si los alumnos contaban con computadora e Internet para continuar sus estudios desde casa. Es por ello que decidimos estudiar la percepción de los estudiantes sobre sus condiciones de aprendizaje ante la nueva modalidad de clase, a través de una plataforma en línea, en la Universidad Tecnológica de Tecámac y con ello identificar a grandes rasgos las tareas pendientes de la educación superior en México.
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