Evaluation of high-density, multi-contact nerve cuffs for activation of grasp muscles in monkeys.

OBJECTIVE: The objective of this work was to evaluate whether nerve cuffs can selectively activate hand muscles for functional electrical stimulation (FES). FES typically involves identifying and implanting electrodes in many individual muscles, but nerve cuffs only require implantation at a single site around the nerve. This method is surgically more attractive. Nerve cuffs may also more effectively stimulate intrinsic hand muscles, which are difficult to implant and stimulate without spillover to adjacent muscles. APPROACH: To evaluate its ability to selectively activate muscles, we implanted and tested the flat interface nerve electrode (FINE), which is designed to selectively stimulate peripheral nerves that innervate multiple muscles (Tyler and Durand 2002 IEEE Trans. Neural Syst. Rehabil. Eng. 10 294-303). We implanted FINEs on the nerves and bipolar intramuscular wires for recording compound muscle action potentials (CMAPs) from up to 20 muscles in each arm of six monkeys. We then collected recruitment curves while the animals were anesthetized. MAIN RESULT: A single FINE implanted on an upper extremity nerve in the monkey can selectively activate muscles or small groups of muscles to produce multiple, independent hand functions. SIGNIFICANCE: FINE cuffs can serve as a viable supplement to intramuscular electrodes in FES systems, where they can better activate intrinsic and extrinsic muscles with lower currents and less extensive surgery.

Rapid identification of uropathogenic Escherichia coli of the O25:H4-ST131 clonal lineage using the DiversiLab repetitive sequence-based PCR system.

Several recent studies have highlighted the emergence of a globally disseminated clone of uropathogenic and invasive Escherichia coli isolates of serotype O25:H4 and sequence type 131. The ability to characterize rapidly E. coli isolates of this lineage would facilitate enhanced surveillance for this pathogen. We have used the semi-automated DiversiLab repetitive PCR-based system to analyse a collection of 35 clinical isolates of uropathogenic E. coli from across the UK, with particular focus on the O25:H4-ST131 lineage. All isolates had been characterized using multilocus sequence typing (MLST), and 14 had previously been typed using pulsed-field gel electrophoresis (PFGE). The DiversiLab system allowed discrimination of O25:H4-ST131 isolates from those of other E. coli lineages. It was slightly more discriminatory than MLST, but was less discriminatory than PFGE. With an analysis time of <4 h between receipt of a cultured organism and provision of a typing result, the system offers information on a real-time basis, a major advantage over current practice. We suggest that introduction of the DiversiLab system would be useful for rapid exclusion of E. coli isolates during outbreak investigations, and that the approach could be employed for surveillance for pathogenic or antibiotic-resistant clones of this organism.