Journal of neurotrauma
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Journal of neurotrauma · Sep 2011
Transplanted L1 expressing radial glia and astrocytes enhance recovery after spinal cord injury.
A major obstacle for the transplantation of neural stem cells (NSCs) into the lesioned spinal cord is their predominant astrocytic differentiation after transplantation. We took advantage of this predominant astrocytic differentiation of NSCs and expressed the paradigmatic beneficial neural cell adhesion molecule L1 in radial glial cells and reactive and nonreactive astrocytes as novel cellular vehicles to express L1 under the control of the promoter for the human glial fibrillary acidic protein (GFAP-L1 NSCs). ⋯ Morphological analysis revealed that mice grafted with GFAP-L1 NSCs exhibited increased neuronal differentiation and migration of transplanted cells, as well as increased soma size and cholinergic synaptic coverage of host motoneurons and increased numbers of endogenous catecholaminergic nerve fibers caudal to the lesion site. These findings show that L1-expressing astrocytes and radial glial cells isolated from GFAP-L1 NSC cultures represent a novel strategy for improving functional recovery after spinal cord injury, encouraging the use of the human GFAP promoter to target beneficial transgene expression in transplanted stem cells.
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Journal of neurotrauma · Sep 2011
The association between apolipoprotein E and traumatic brain injury severity and functional outcome in a rehabilitation sample.
Traumatic brain injury (TBI) can result in significant disability, but outcome is variable. The impact of known predictors accounts for a limited proportion of the variance in outcomes. Apolipoprotein E (ApoE) genotype has been investigated as an additional source of variability in injury severity and outcome, with mixed findings reflecting variable methodology and generally limited sample sizes. ⋯ Prediction of worse Glasgow Outcome Scale-Extended (GOSE) scores for ɛ4 carriers was supported with greater susceptibility seen in females. These results indicate the ApoE ɛ4 allele may be associated with poorer long-term outcome, but not acute injury severity. Possible mechanisms include differential effects of the ɛ4 allele on inflammatory and cellular repair processes, and/or amyloid deposition.
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Journal of neurotrauma · Sep 2011
Anti-inflammatory treatments during the chronic phase of spinal cord injury improve locomotor function in adult mice.
Our previous data suggested that ongoing inflammation in the spinal cord 6 weeks following spinal cord injury was detrimental to locomotor function. Others have shown in the acute and sub-acute post-injury phase that microglial/macrophage activation and T regulatory cells are detrimental to recovery. Here, C57BL/6 mice with a moderately severe T9 contusion were injected intravenously daily with minocycline, which reduces microglial/macrophage activation, or with CD25 antibodies, which reduce T regulatory cell function, starting at 6 weeks after injury. ⋯ The effects diminished within 1 week after termination of the treatments, suggesting an ongoing and dynamic inflammatory process. The area of white matter or the inflammatory markers CD68 for activated microglia/macrophages and CD45 for leukocytes were not different between the groups. These data suggest that inflammation during the chronic phase following spinal cord injury reduces conduction through the epicenter, possibly by release of cytokines, and is amenable to treatment for improved neurological function.
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Journal of neurotrauma · Sep 2011
Prevention of both neutrophil and monocyte recruitment promotes recovery after spinal cord injury.
Strategies that block infiltration of leukocytes into the injured spinal cord improve sparing of white matter and neurological recovery. In this article, we examine the dependency of recovery on hematogenous depletion of neutrophils and monocytes. Mice were depleted of neutrophils or monocytes by systemic administration of anti-Ly6G or clodronate-liposomes. ⋯ Matrix metalloproteinase-9, a protease involved in early damage, was most strongly reduced in animals depleted of both leukocyte subsets. Finally, disruption of the blood-spinal cord barrier and abnormal nonheme iron accumulation were reduced only in animals depleted of both neutrophils and monocytes. Together, these findings indicate cooperation between neutrophils and monocytes in mediating early pathogenesis in the contused spinal cord and defining long-term neurological recovery.
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Journal of neurotrauma · Sep 2011
Multicenter StudyNatural history of headache after traumatic brain injury.
Headache is one of the most common persisting symptoms after traumatic brain injury (TBI). Yet there is a paucity of prospective longitudinal studies of the incidence and prevalence of headache in a sample with a range of injury severity. We sought to describe the natural history of headache in the first year after TBI, and to determine the roles of prior history of headache, sex, and severity of TBI as risk factors for post-traumatic headache. ⋯ Overall, headache is common in the first year after TBI, independent of the severity of injury range examined in this study. Use of the International Classification of Headache Disorders criteria requiring onset of headache within 1 week of injury underestimates rates of post-traumatic headache. Better understanding of the natural history of headache including timing, type, and risk factors should aid in the design of treatment studies to prevent or reduce the chronicity of headache and its disruptive effects on quality of life.