A case of extraventricular neurocytoma of the spinal cord.

Central neurocytoma is a rare neuroectodermal tumor generally found in young adults. It mainly originates from lateral ventricles. Extraventricular location of this kind of tumor, especially spinal cord involvement, is extremely rare. This article is the ninth case of central neurocytoma derived from the spinal region, and includes a review of the literature. The patient in this case is a 49-year-old woman presenting with C3-C5 spinal mass with typical histopathologic findings and low MIB-1 index.

Effect of oxygen supply on metabolism of immobilized and suspended Escherichia coli.

The effect of reduced oxygen supply on the production of a recombinant protein (plasmid-encoded beta-galactosidase) was investigated in Escherichia coli. A novel modified bubble tank reactor was used to provide a direct comparison between immobilized and suspended cells in identical environments except for the immobilization matrix. Decreased oxygen supply led to increased beta-galactosidase synthesis by both immobilized and suspended cells. Immobilized cells produced similar amounts of beta-galactosidase as the suspended cells. Lactose consumption and acetate production, on a per cell basis, were significantly higher in immobilized cells, suggesting that immobilized cells utilized fermentative metabolism. However, a transport analysis of the immobilized cell system showed that immobilized cells were not subject to either external or internal mass transfer gradients.