Bond strength of an alkylene bis(dilactoyl)-methacrylate bone adhesive: a biomechanical evaluation in sheep.

The purpose of this study is to assess the mechanical efficacy of an alkylene bis(dilactoyl)-methacrylate-based degradable bone adhesive in 36 sheep. Bone segmentation with osteotomies of the metaphyseal ulna was performed and adhesive was applied into the osteotomy gaps in 18 sheep. The remaining 18 animals served as controls.

Plasticity of orientation preference maps in the visual cortex of adult cats.

In contrast to the high degree of experience-dependent plasticity usually exhibited by cortical representational maps, a number of experiments performed in visual cortex suggest that the basic layout of orientation preference maps is only barely susceptible to activity-dependent modifications. In fact, most of what we know about activity-dependent plasticity in adults comes from experiments in somatosensory, auditory, or motor cortex. Applying a stimulation protocol that has been proven highly effective in other cortical areas, we demonstrate here that enforced synchronous cortical activity induces major changes of orientation preference maps (OPMs) in adult cats.

A silastic positioner for a modiolus-hugging position of intracochlear electrodes: electrophysiologic effects.

Hypothesis: It was postulated that an electrode array that achieved a close modiolar proximity would result in reduced threshold levels and amplitude slopes, as measured with electrically evoked auditory brainstem responses (EABRs).

Background: Quality and quantity of auditory information transmitted by a cochlear implant to patients with sensorineural hearing loss depend on spatial and temporal resolution achieved by the electrical intracochlear stimulation.

Methods: To improve spatial resolution, a new electrode system was developed by Advanced Bionics Corp.

Measurements of threshold shifts observed when using normal and preformed electrodes.

Objective: To investigate the efficacy of short-term electrical stimulation with different human electrodes using high stimulation rates and different electrode designs.

Materials And Methods: Human electrodes of two different designs were implanted in cats, and electrically evoked auditory brain stem responses (EABR) were recorded.

Results And Discussion: Thresholds from the EABR recordings at the apical end of the electrode array were comparable in both types of implants.

Development of the evoked auditory brain stem response amplitude peak IV during chronic electrical, intracochlear, multichannel high-rate stimulation.

Objective: To investigate the effect of high stimulation rates on the developing auditory system.

Materials And Methods: Neonatally deafened kittens with human intracochlear electrode implants received sustained electric stimulation.

Results And Discussion: No loss of brain stem responses was observed.