Rare coexistence of metastatic neuroblastoma of liver and solid pseudo papillary tumor of pancreas: Case report and literature review

Neuroblastoma is the second most common malignant solid tumor in children, and often metastasizes to liver, most notably in patients with stage 4S tumors. Solid pseudopapillary tumor of the pancreas (SPT) is a pancreatic borderline tumor with low malignant potential. Coexistence of these two tumors in one patient has never been reported before. Hereby, we present a case of an 8-month-old infant with coexisting tumors of SPT and metastatic neuroblastoma of liver. Dysdifferentiation of neural crest might be responsible for histogenesis of the coexisting tumors

Wnt inhibitory factor-1 functions as a tumor suppressor through modulating Wnt/β-catenin signaling in neuroblastoma

Neuroblastoma is the most common extracranial solid tumor in childhood and is associated with serious morbidity and mortality. The effective treatment of neuroblastoma remains one of the major challenges in pediatric oncology. The Wnt signaling pathway has been shown to play a significant role in the pathogenesis of adult and pediatric tumors. WIF-1 has been identified as an important Wnt antagonist which inhibits Wnt/β-catenin signaling by directly binding to Wnt proteins. However, the expression and function of WIF-1 in neuroblastoma remains unknown. The present study showed that WIF-1 was downregulated with high level promoter methylation in neuroblastoma cells, and was significantly upregulated after exposure to demethylating agent. This finding suggests that downregulation of WIF-1 was associated with its promoter methylation in neuroblastoma. To further study the potential function of WIF-1 in neuroblastoma, we constructed a plasmid that over-expressed WIF-1 and transfected the plasmid into one neuroblastoma cell line SK-N-SH. We found that restoration of WIF-1 inhibited the growth and proliferation of neuroblastoma cells in vitro. Morever, Wnt/β-catenin signaling activity and target genes expression were reduced by WIF-1 restoration. These results provide support that WIF-1 is downregulated and functions as a tumor suppressor by antagonizing Wnt/β-catenin signaling in neuroblastoma, suggesting a potential role as a therapeutic target in neuroblastoma

Enfoques teóricos,lengua, alumno y docente

Este ensayo es una reflexión sobre la manera como las variaciones en la didáctica derivan de modificaciones tanto en las teorías de la especialidad, como en las corrientes pedagógicas y psicológicas que las sustentan. Analiza algunos de los cambios más relevantes en la enseñanza de la lengua y hace énfasis sobre el papel que desempeña el docente a la luz de dichas teorías y la transformación que se requiere para modificar los usos y costumbres impuestos por las teorías previas. Finalmente comenta hacia dónde se encauzan las tendencias actuales y el tipo de maestro que demandan. una nueva corriente teórica, no implica la cancelación de la anterior, pues los enfoques posteriores han retomado conceptos previos y han hecho, a su vez, aportaciones, lo que implica una suma y no necesariamente una sustitución. Empecemos por considerar a la Retórica, uno pensaría que no tiene sentid