A new substrate for mammalian cell culture was developed using a cellulose membrane produced by Acetobacter aceti. Modification of the ionic charge of the membrane and adsorption of collagen to it promoted cellular adhesion to the membrane surface. The growth of eight kinds of cells on the membrane, was comparable to that achieved in plastic Petri dishes. The membrane was tested for use in the production of recombinant Erythroid Differentiation Factor (EDF)/activin A using genetically engineered Chinese hamster ovary cells. Both the viability of the cells and production of EDF/activin A were maintained for about 1 month, while cultures on plastic dishes lasted only 12 days. It was considered that the mechanism of improved cell viability was related to the ultrastructure of the cellulose membrane.

The Turcot syndrome (TS) is a rare, probably autosomal recessive, disorder characterized by development of primary neuroepithelial tumors of the central nervous system (CNS) and numerous adenomatous colorectal polyps. To examine the possible involvement of mutations of the APC gene, which is responsible for familial adenomatous polyposis (FAP), in Turcot syndrome, we examined DNAs from TS patients for alterations in this gene by means of ribonuclease protection analysis. Germ-line APC mutations were detected in each of three unrelated cases of TS, and additional (somatic) mutations were observed in colonic adenomas that had developed in one of these patients. However, no somatic mutations in APC were found among 91 neuroepithelial tumors (medulloblastoma, glioblastoma, astrocytoma, and oligodendroglioma), whether sporadic or associated with TS. These results suggest that the APC gene is associated with pathogenesis of one feature of TS, but that at least one other gene is responsible for the genesis of neuroepithelial tumors in the CNS.

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