Effect of Overground Training Augmented by Mental Practice on Gait Velocity in Chronic, Incomplete Spinal Cord Injury

OBJECTIVE: To compare efficacy of a regimen combining mental practice (MP) with overground training with the efficacy of a regimen comprised of overground training only on gait velocity and lower extremity motor outcomes in individuals with chronic (> 12 months post injury), incomplete, spinal cord injury (SCI). DESIGN: Randomized controlled, single blinded, study SETTING: Outpatient rehabilitation laboratories located in the Midwestern and Western United States PARTICIPANTS: 18 subjects with chronic, incomplete SCI INTERVENTIONS: Subjects were randomly assigned to receive: (a) Overground Training only (OT), occurring 3 days/week for 8 weeks; or (b) OT augmented by MP (MP + OT), during which randomly assigned subjects listened to a mental practice audio recording directly following OT sessions. MAIN OUTCOME MEASURES: Subjects were administered a test of gait velocity as well as the Tinetti Performance Oriented Mobility Assessment (POMA), Spinal Cord Injury Independence Measure (SCIM), and Satisfaction with Life Scale (SWLS) on 2 occasions before intervention, 1 week after intervention, and 12 weeks after intervention. RESULTS: A significant increase in gait velocity was exhibited across subjects at both 1 week post-therapy (p=0.0046) and at 12 weeks post-therapy (p=0.0056). However, no differences were seen in intervention response at either 1 or 12 weeks post intervention among subjects in the MP + OT versus the OT groups. CONCLUSION: Overground training was associated with significant gains in gait velocity, and that these gains were not augmented by further addition of mental practice

CRISPR-Cas9-based target validation for p53-reactivating model compounds

Inactivation of the p53 tumor suppressor by Mdm2 is one of the most frequent events in cancer, so compounds targeting the p53-Mdm2 interaction are promising for cancer therapy. Mechanisms conferring resistance to p53-reactivating compounds are largely unknown. Here we show using CRISPR-Cas9-based target validation in lung and colorectal cancer that the activity of nutlin, which blocks the p53-binding pocket of Mdm2, strictly depends on functional p53. In contrast, sensitivity to the drug RITA, which binds the Mdm2-interacting N terminus of p53, correlates with induction of DNA damage. Cells with primary or acquired RITA resistance display cross-resistance to DNA crosslinking compounds such as cisplatin and show increased DNA cross-link repair. Inhibition of FancD2 by RNA interference or pharmacological mTOR inhibitors restores RITA sensitivity. The therapeutic response to p53-reactivating compounds is therefore limited by compound-specific resistance mechanisms that can be resolved by CRISPR-Cas9-based target validation and should be considered when allocating patients to p53-reactivating treatments