A review of device failure in more than 23 years of clinical experience of a cochlear implant program with more than 3,400 implantees.

Background: During the last 25 years, the cochlear implant (CI), an active implantable assistive hearing device designed to provide electrical stimulation to the inner ear of the profoundly hearing-impaired individual, has been provided to more than 150,000 recipients worldwide. More recently, implants have been placed in young children as young as 6 months old. With the expectation of lifelong implant use, as with all active implantable medical devices, CI device failure is an inherent risk.

Development of an in vitro blood-brain barrier model based on immortalized porcine brain microvascular endothelial cells.

Immortalized porcine brain microvessel endothelial cells (PBMEC/C1-2) were used to develop a model for measurement of blood-brain barrier permeation of central nervous system active drugs. Previous studies showed that a system using C6 astrocyte glioma conditioned medium leads to cell layers with transendothelial electrical resistance values up to 300 Omega cm(2) and a permeability coefficient P(e) of 3.24 +/- 0.