Upper Extremity Function Assessment Using a Glove Orthosis and Virtual Reality System.

Hand motor control deficits following stroke can diminish the ability of patients to participate in daily activities. This study investigated the criterion validity of upper extremity (UE) performance measures automatically derived from sensor data during manual practice of simulated instrumental activities of daily living (IADLs) within a virtual environment. A commercial glove orthosis was specially instrumented with motion tracking sensors to enable patients to interact, through functional UE movements, with a computer-generated virtual world using the SaeboVR software system. Fifteen stroke patients completed four virtual IADL practice sessions, as well as a battery of gold-standard assessments of UE motor and hand function. Statistical analysis using the nonparametric Spearman rank correlation reveals high and significant correlation between virtual world-derived measures and the gold-standard assessments. The results provide evidence that performance measures generated during manual interactions with a virtual environment can provide a valid indicator of UE motor status.

Characterizing nerve growth factor-p75(NTR) interactions and small molecule inhibition using surface plasmon resonance spectroscopy.

Nerve growth factor (NGF) is critical for the proliferation, differentiation, and survival of neurons through its binding to the p75(NTR) and TrkA receptors. Dysregulation of NGF has been implicated in several pathologies, including neurodegeneration (i.e., Parkinson's and Alzheimer's diseases) and both inflammatory and neuropathic pain states. Therefore, small molecule inhibitors that block NGF-receptor interactions have significant therapeutic potential. Small molecule antagonists ALE-0540, PD90780, Ro 08-2750, and PQC 083 have all been reported to inhibit NGF from binding the TrkA receptor. Interestingly, the characterization of the ability of these molecules to block NGF-p75(NTR) interactions has not been performed. In addition, the inhibitory action of these molecules has never been evaluated using surface plasmon resonance (SPR) spectroscopy, which has been proven to be highly useful in drug discovery applications. In the current study, we used SPR biosensors to characterize the binding of NGF to the p75(NTR) receptor in addition to characterizing the inhibitory potential of the known NGF antagonists. The results of this study provide the first evaluation of the ability of these compounds to block NGF binding to p75(NTR) receptor. In addition, only PD90780 was effective at inhibiting the interaction of NGF with p75(NTR), suggesting receptor selectivity between known NGF inhibitors.

Using surface plasmon resonance spectroscopy to characterize the inhibition of NGF-p75(NTR) and proNGF-p75(NTR) interactions by small molecule inhibitors.

Nerve growth factor (NGF), a member of the neurotrophin family, acts to influence the survival and differentiation of neurons in both the central and peripheral nervous systems via its binding to the p75(NTR) and TrkA receptors. Its precursor, proNGF, has been shown to be the dominant form of NGF in the central nervous system, suggesting a biological function beyond its role as a precursor. Like NGF, proNGF is known to bind the p75(NTR) receptor. The dysregulation of both NGF and proNGF have been implicated in several pathologies, including neurodegenerative diseases linked to p75(NTR)-mediated apoptotic signaling. Therefore, the identification of small molecule inhibitors capable of inhibiting both NGF and proNGF-p75(NTR) interactions may be of therapeutic interest. In the present study, we examine the inhibitory action of known small molecule-based inhibitors PD90780, ALE-0540, Ro 08-2750, and PQC 083, as well as novel derivatives of these compounds, using surface plasmon resonance (SPR) spectroscopy.

A Surface Plasmon Resonance Spectroscopy Method for Characterizing Small-Molecule Binding to Nerve Growth Factor.

Small-molecule inhibitors have been previously investigated to identify possible therapeutics for the treatment of chronic pain. In the present study, known nerve growth factor (NGF) inhibitors identified by (125)I-NGF binding were characterized using affinity and binding evaluations by surface plasmon resonance (SPR) spectroscopy. A novel strategy for characterizing NGF inhibitors was used to determine the binding affinity (KD) and saturation ability of each compound with immobilized NGF. Seventy-four percent of compounds screened demonstrated a positive binding event to NGF. A KD less than 10 µM and a percent saturation greater than 50% were used as thresholds to identify inhibitors that would warrant further investigation. This study details for the first time a methodology that can be used to directly characterize the binding event between small-molecule inhibitors and NGF.