Transcranial electrical stimulation as predictor of elicitation of intraoperative muscle-evoked potentials.

Study Design: Preoperative electrophysiological and neurologic findings from patients with cervical myelopathy were evaluated statistically to determine their predictive value relative to the success of eliciting intraoperative motor-evoked potentials.

Objectives: To determine which preoperative variables accurately predicted the success of eliciting an intraoperative muscle-evoked potential.

Summary Of Background Data: Motor-evoked potential recorded from the muscles after transcranial electrical stimulation is one of the most widely used methods for intraoperative spinal cord monitoring.

Visualization of incomplete conduction block by neuromagnetic recording.

Objective: We previously reported on evoked compound action magnetic fields (CAFs) in isolated sciatic nerves with complete conduction block. In this study, we examined evoked CAFs of the nerve with incomplete conduction block, which is clinically common.

Methods: Rabbits' isolated nerves were electrically stimulated in a chamber containing Ringer's solution.

Estimation of localization of neural activity in the spinal cord using a biomagnetometer.

Spinal cord evoked potentials (SCEPs) measurement is widely used for level diagnosis of spondylotic myelopathy. However, because of the restriction of spatial resolution, SCEPs do not distinguish the neurophysiological activities among tracts in the spinal cord without invasive methods. Magnetic field measurement has the theoretical advantage of high spatial resolution, compared with electric measurement.

Imaging of neural conduction block by neuromagnetic recording.

Objective: For the clinical application of neuromagnetic recordings in neural conduction block, the patterns of magnetic fields in the region should be clarified. Using an experimental in vitro model, the spatiotemporal course of the neuromagnetic fields at the site of complete conduction block was examined. Additionally, the magnetic compound action fields (CAFs) and electric compound action potentials (CAPs) were compared and correlated.

Hypervalent Iodine(V)-Induced Asymmetric Oxidation of Sulfides to Sulfoxides Mediated by Reversed Micelles: Novel Nonmetallic Catalytic System.

Although several types of chiral hypervalent iodine reagents have been used for asymmetric induction, all of them have needed more than a stoichiometric amount of chiral reagents and have shown low enantioselectivities. The described new catalytic asymmetric oxidation using a hypervalent iodine(V) reagent, iodoxybenzene (PhIO(2)), in a cationic reversed micellar system provides the first example of a catalytic asymmetric oxidation of sulfides to sulfoxides in high chemical yield with moderate to good enantioselectivity without the use of any transition-metal catalysts. The solubilization and activation of PhIO(2) by adding catalytic amounts of both cetyltrimethylammonium bromide (CTAB) and a chiral tartaric acid derivative were found to be indispensable for the enhancement of chemical and optical yields.