Journal of neurotrauma
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Journal of neurotrauma · Jun 2013
Beneficial function of cell division cycle 2 activity in astrocytes on axonal regeneration after spinal cord injury.
Migrating activity of reactive astrocytes induced after spinal cord injury (SCI) controls glial scar formation by limiting inflammatory responses around the injury area, and, therefore, can be beneficial for regenerative responses of spinal axons. Recently, we found that cell division cycle 2 (cdc2) activity in primary astrocytes facilitated neurite outgrowth of co-cultured neurons. Here, we investigated the effects of cdc2 activity on regenerative processes in vivo after SCI. ⋯ After SCI, regenerative responses of anterogradely labeled corticospinal tract (CST) axons were attenuated by purvalanol A treatment. Using the polymeric tube that was implanted into the spinal cord as a nerve guide conduit, we found that purvalanol A treatments reduced astrocyte migration into the tube graft and, in parallel, retarded the extension of spinal axons into the tube. These results suggest that astrocytes with cdc2 activity may play a permissive role in mediating regrowth of spinal axons after lesion.
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Journal of neurotrauma · Jun 2013
Acute delivery of EphA4-Fc improves functional recovery after contusive spinal cord injury in rats.
Blocking the action of inhibitory molecules at sites of central nervous system injury has been proposed as a strategy to promote axonal regeneration and functional recovery. We have previously shown that genetic deletion or competitive antagonism of EphA4 receptor activity promotes axonal regeneration and functional recovery in a mouse model of lateral hemisection spinal cord injury. ⋯ Consistent with functional improvement, using high-resolution ex vivo magnetic resonance imaging at 16.4T, we found that rats treated with EphA4-Fc had a significantly increased cross-sectional area of the dorsal funiculus caudal to the injury epicenter compared with controls. Our findings indicate that EphA4-Fc promotes functional recovery following contusive spinal cord injury and provides further support for the therapeutic benefit of treatment with the competitive antagonist in acute cases of spinal cord injury.
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Journal of neurotrauma · Jun 2013
S100b as a prognostic biomarker in outcome prediction for patients with severe traumatic brain injury.
As an astrocytic protein specific to the central nervous system, S100b is a potentially useful marker in outcome prediction after traumatic brain injury (TBI). Some studies have questioned the validity of S100b, citing the extracerebral origins of the protein as reducing the specificity of the marker. This study evaluated S100b as a prognostic biomarker in adult subjects with severe TBI (sTBI) by comparing outcomes with S100b temporal profiles generated from both cerebrospinal fluid (CSF) (n = 138 subjects) and serum (n = 80 subjects) samples across a 6-day time course. ⋯ Possibly as a result of extracerebral sources of S100b in serum, as represented by high ISS scores (p = 0.032), temporal serum profiles were associated with acute mortality (p = 0.015). High CSF S100b levels were observed in women (p = 0.022) and older subjects (p = 0.004). Multivariate logistic regression confirmed CSF S100b profiles in predicting GOS and DRS and showed mean and peak serum S100b as acute mortality predictors after sTBI.
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Journal of neurotrauma · Jun 2013
Clinical TrialGrowth hormone replacement therapy in patients with traumatic brain injury.
In patients with severe traumatic brain injury (TBI), a growth hormone deficiency (GHD) is frequent and may contribute to the cognitive sequelae and reduction in quality of life (QoL). Recent studies have suggested that GH replacement therapy (GHRT) can improve processing speed and memory. The aim of the study was to analyze the efficacy of GHRT on cognition, activities of daily living (ADL), and QoL and the factors that predicted and contributed to these effects. ⋯ Greatest improvements were associated with lower performance before treatment. The magnitude of the improvements in ADL and QoL was moderately correlated with the improvement in cognition. In conclusion, replacement therapy can improve cognition and QoL in patients with TBI who have GHD, especially in those with severe disabilities.
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Journal of neurotrauma · Jun 2013
The influence of chronic cigarette smoking on neurocognitive recovery after mild traumatic brain injury.
The majority of the approximately 1.7 million civilians in the United States who seek emergency care for traumatic brain injury (TBI) are classified as mild (MTBI). Premorbid and comorbid conditions that commonly accompany MTBI may influence neurocognitive and functional recovery. This study assessed the influence of chronic smoking and hazardous alcohol consumption on neurocognitive recovery after MTBI. ⋯ Hazardous alcohol consumption was not significantly associated with change in any neurocognitive domain. For sMTBI, over the AP1-AP2 interval, greater lifetime duration of smoking and pack-years were related to significantly less improvement on multiple domains. Results suggest consideration of the effects of chronic cigarette smoking is necessary to understand the potential factors influencing neurocognitive recovery after MTBI.