Paretic upper extremity movement gains are retained 3 months after training with an electrical stimulation neuroprosthesis.

OBJECTIVE: To determine retention of upper extremity (UE) motor changes 3 months after participation in a regimen in which subjects with moderate UE hemiparesis engaged in repetitive task-specific training using an electrical stimulation neuroprosthesis (ESN). DESIGN: Prospective, blinded, cohort, pre-post study. SETTING: Outpatient rehabilitation hospital. PARTICIPANTS: Individuals (N=24) in the chronic stage of stroke exhibiting stable UE hemiparesis (11 men; mean age, 57.9±9.5y; age range, 39-75y; mean time since stroke at time of repetitive task-specific practice [RTP] using ESN intervention start, 36.7mo; range of onset, 7-162mo). INTERVENTION: As part of a larger trial, subjects had been randomly assigned to receive an 8-week regimen comprised of RTP on valued activities using the ESN. This observational study assessed this single group's paretic UE motor levels immediately after, and 3 months after, the intervention. MAIN OUTCOME MEASURES: The Fugl-Meyer (FM) assessment of sensorimotor impairment, the Action Research Arm Test (ARAT), the Arm Motor Ability Test (AMAT), and the Box and Block Test (BBT). RESULTS: None of the scores significantly changed from the period directly after intervention to the test 3-months follow-up (FM: t=1.64; ARAT: t=2.17; AMAT: t=.76, .92, and 1.01 for the functional ability, quality of movement, and time scales, respectively; BBT: t=.36; adjusted t critical value to reject the null [t(crit)]=2.90, 2-tailed α=.008 to preserve experiment-wise error rate of .05). CONCLUSIONS: Subjects exhibited no changes in the various functional tests, indicating that changes in paretic UE movement realized through RTP using ESN appear to be retained 3 months after the intervention has concluded. This was the first study to our knowledge to examine the longer-term effects of RTP using an ESN in any population.

A fluorescence polarization assay to quantify biotin and biotin-binding proteins in whole plant extracts using Alexa-Fluor 594 biocytin.

A high-throughput fluorescence polarization assay has been developed for the detection of biotin and biotin-binding proteins in whole leaf extracts. Various groups are investigating the insecticidal properties of avidin and other biotin-binding proteins expressed in leaves of transgenic plants. The methods commonly used to quantify biotin and avidin in leaf extracts are enzyme-linked immunosorbent assay (ELISA) and Western blotting. Here we describe a homogeneous fluorescence polarization (FP) method that quantifies transgenic avidin in whole leaf extract by the simple addition of the fluorescent avidin ligand Alexa-Fluor 594 biocytin (AFB). The FP assay exploits the fact that AFB excites and emits in regions of the spectrum that are relatively free of background fluorescence in leaf extract. Transgenic leaf avidin can be quantified within 1-2 h by the FP method, in comparison with 1-2 days for ELISA and Western blotting. The FP method can also measure the amount of biotin in control leaves, not expressing avidin. Functional avidin levels of 1.54 microM (26.1 microg/g leaf tissue) were detected in tobacco leaves expressing vacuole-targeted avidin. Control leaves had biotin levels of around 0.74 microM (approximately 0.18 microg/g leaf tissue). Reagent costs are minimal: typically AFB is used at concentrations of 1-10 nM, avidin is used at 1-100 nM, and sample volumes are 20 microL in 384-well microplates.