IN VITRO CHARACTERISTICS OF A FOURTH VENTRICLE EPENDYMOMA MAINTAINED IN ORGAN CULTURE SYSTEMS: LIGHT AND ELECTRON MICROSCOPY OBSERVATIONS

Abstract

1976) Neuropathology and Applied Neurobiology 2, 349-364 I n ritro characteristics of a fourth ventricle ependymoma maintained in organ culture systems : light and electron microscopy observationsExplants of a well-differentiated fourth ventricle ependymoma were grown on collagen-coated coverslips and in organ culture systems using gelatin sponge foam matrices and Millipore filter platforms. Viable explants were maintained on Millipore filter platforms up to 44 days and on sponge foam matrices up to 86 days. The structure of ependymal rosettes was well maintained throughout the period of study. By electron microscopy, additional features of differentiation were seen after 3 weeks, consisting of an increase in size and complexity of microrosettes, to which large numbers of cellular apical profiles contributed. Cilia with variable internal configurations were present. After 4 weeks there was frequent ependymal differentiation along the surface of the explants at their interface with the supporting matrix. Increased gliofibrillogenesis and glycogen rosettes were also evident after 3 weeks in culture. The explants were intensely positive when tested by immunofluorescence for the antigen of the glial fibrillary acidic protein. After 3 weeks in uitro, dense bands of basement membrane material forming complex intercellular finger-like projections became prominent. 349

Neuron-associated class III ?-tubulin, tau, and MAP2 in the D-283 Med cell line and in primary explants of human medulloblastoma

“…The previously established medulloblastoma cell line D283 Med (Friedman et al, 1985) and primary explants of five medulloblastomas derived from patients ranging in age from ten months to I6 years were cultured on a Gelfoam matrix system which has been shown to favour differentiation, as assessed morphologically, in a variety of human and experimental gliomas (Rubinstein et al, 1973;Rubinstein & Herman, 1975;Sipe et al, 1974;Vraa-Jensen et al;1976). Antigenic expression of the neuron-associated class III [3-tubulin, MAP2, tau protein, and synaptophysin demonstrate the neuroblastic phenotype of the medulloblastoma cultures and all were found to be highly variable and focal in Gelfoam cultures of the D283 Med line and in primary explants.…”

Homer Wright rosettes in ependymoma

“…The possibility of mixed ependymoma and neuronal tumor was considered, however, the immunohistochemical [3,7,8] and ultrastructural [9][10][11][12][13] studies confirmed the tumor to be an ependymoma.…”