Four children, with histopathologically confirmed posterior fossa primitive neuroectoderrnal tumors, were examined by plain radiography, computed tomography (CT) and cerebral angiography. The homogeneously well enhanced solid mass in the midline of the posterior fossa and hydrocephalus of various degree were seen on all CT scans. One case had calcifications and another case had low density areas in the tumor mass. Three cerebral angiograms showed vascular displacement without tumor vascularities. Unfortunately, these CT and angiography findings are and other tumors. when a well enhanced solid mass in the midline posterior fossa is seen on CT scan in children.
Angiography ; Cerebral Angiography ; Child ; Humans ; Hydrocephalus ; Medulloblastoma* ; Neuroectodermal Tumors, Primitive* ; Pathology* ; Radiography ; Tomography, X-Ray Computed

The direct differentiation of hepatocytes from bone marrow cells remains controversial. Several mechanisms, including transdifferentiation and cell fusion, have been proposed for this phenomenon, although direct visualization of the process and the underlying mechanisms have not been reported. In this study, we established an efficient in vitro culture method for differentiation of functioning hepatocytes from murine lineage-negative bone marrow cells. These cells reduced liver damage and incorporated into hepatic parenchyma in two independent hepatic injury models. Our simple and efficient in vitro protocol for endodermal precursor cell survival and expansion enabled us to identify these cells as existing in Sca1+ subpopulations of lineage-negative bone marrow cells. The endodermal precursor cells followed a sequential developmental pathway that included endodermal cells and hepatocyte precursor cells, which indicates that lineage-negative bone marrow cells contain more diverse multipotent stem cells than considered previously. The presence of equivalent endodermal precursor populations in human bone marrow would facilitate the development of these cells into an effective treatment modality for chronic liver diseases.
Animals ; Ataxin-1/*analysis ; Bone Marrow Cells/*cytology ; Cell Differentiation ; Cell Proliferation ; Cells, Cultured ; Female ; Hepatocytes/*cytology ; Mice ; Mice, Inbred BALB C