In this task, you are given a passage which has a question and the context. You have to generate an answer to the question based on the information present in the context.

Context: Recent work has identified deficits in dual-task gait balance control for up to 2 months after adolescent concussion; however, how resumption of preinjury physical activities affects recovery is unknown.', 'The objective of this study is to examine how return to activity (RTA) affects recovery from concussion on measures of symptom severity, cognition, and balance control during single-task and dual-task walking.', 'Nineteen adolescents with concussion who returned to preinjury activity within 2 months after injury and 19 uninjured, matched controls completed symptom inventories, computerized cognitive testing, and single-task and dual-task gait analyses. Concussion participants were assessed at five time points: within 72 h, 1 wk, 2 wk, 1 month, and 2 months postinjury. Control participants were assessed at the same time points as their matched concussion counterparts. RTA day was documented as the postinjury day in which physical activity participation was allowed. The effect of returning to physical activity was assessed by examining the percent change on each dependent variable across time before and directly after the RTA. Data were analyzed by two-way mixed effects ANOVAs.', 'After the RTA day, concussion participants significantly increased their total center-of-mass medial/lateral displacement (P = 0.009, ηp = .175) and peak velocity (P = 0.048, ηp = 0.104) during dual-task walking when compared with pre-RTA data, whereas no changes for the concussion group or between groups were detected on measures of single-task walking, forward movement, or cognition.\Question: Does return to activity after concussion affect dual-task gait balance control recovery?
Adolescents with concussion displayed increased center-of-mass medial/lateral displacement and velocity during dual-task walking after RTA, suggesting a regression of recovery in gait balance control. This study reinforces the need for a multifaceted approach to concussion management and continued monitoring beyond the point of clinical recovery.

Context: The expression of growth-associated protein 43 (GAP-43), a marker of axonal growth, in the dorsal root ganglion (DRG) neurons innervating the lumbar intervertebral disc was assessed using the retrograde tracing method and immunohistochemistry.', 'To study whether disc inflammation affects GAP-43 expression in DRG neurons innervating the disc in rats.', 'Persistent inflammation and nerve ingrowth into the inner layer of degenerated discs can be a cause of discogenic pain. Although the presence of GAP-43-expressing nerve fibers in painful discs has been reported, the expression of GAP-43 in DRG neurons innervating the disc has not been studied.', "Seven days after the application of Fluoro-Gold to the L5-L6 disc, 50 microL of saline (n = 10, control group) or complete Freund's adjuvant (n = 10, inflammatory group) was applied to the disc in rats. Ten days after the Fluoro-Gold application, T13-L5 DRGs were double-stained with GAP-43 and either calcitonin gene-related peptide or isolectin B4 (IB4).", 'The percentage of Fluoro-Gold-labeled neurons that were positive for GAP-43 was significantly higher in the inflammatory group (44%) than in the control group (24%, P < 0.001). In both groups, the majority of GAP-43-positive neurons were small and positive for calcitonin gene-related peptide but not IB4.\Question: Does disc inflammation potentially promote axonal regeneration of dorsal root ganglion neurons innervating lumbar intervertebral disc in rats?
The present results suggest that disc inflammation potentially promotes axonal growth of DRG neurons innervating the disc. In light of the strong correlation between the expression of calcitonin gene-related peptide and nerve growth factor receptor, it is most likely that nerve growth factor-sensitive DRG neurons extend their axons following disc inflammation.

Context: To determine interrelationships between the expression of long intergenic (noncoding) RNA-p21 (lincRNA-p21), NF-κB activity, and responses to methotrexate (MTX) in rheumatoid arthritis (RA) by analyzing patient blood samples and cell culture models.', 'Expression levels of long noncoding RNA and messenger RNA (mRNA) were determined by quantitative reverse transcription-polymerase chain reaction. Western blotting and flow cytometry were used to quantify levels of intracellular proteins. Intracellular NF-κB activity was determined using an NF-κB luciferase reporter plasmid.', 'Patients with RA expressed reduced basal levels of lincRNA-p21 and increased basal levels of phosphorylated p65 (RelA), a marker of NF-κB activation. Patients with RA who were not treated with MTX expressed lower levels of lincRNA-p21 and higher levels of phosphorylated p65 compared with RA patients treated with low-dose MTX. In cell culture using primary cells and transformed cell lines, MTX induced lincRNA-p21 through a DNA-dependent protein kinase catalytic subunit (DNA PKcs)-dependent mechanism. Deficiencies in the levels of PRKDC mRNA in patients with RA were also corrected by MTX in vivo. Furthermore, MTX reduced NF-κB activity in tumor necrosis factor α-treated cells through a DNA PKcs-dependent mechanism via induction of lincRNA-p21. Finally, we observed that depressed levels of TP53 and lincRNA-p21 increased NF-κB activity in cell lines. Decreased levels of lincRNA-p21 did not alter NFKB1 or RELA transcripts; rather, lincRNA-p21 physically bound to RELA mRNA.\Question: Does methotrexate inhibit NF-κB activity via long intergenic ( noncoding ) RNA-p21 induction?

Our findings support a model whereby depressed levels of lincRNA-p21 in RA contribute to increased NF-κB activity. MTX decreases basal levels of NF-κB activity by increasing lincRNA-p21 levels through a DNA PKcs-dependent mechanism.