Journal of neurotrauma
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Journal of neurotrauma · May 2009
The effect of hypothermia on the expression of TIMP-3 after traumatic brain injury in rats.
To investigate the effect of hypothermia on the expression of apoptosis-regulating protein TIMP-3 after fluid percussion traumatic brain injury (TBI) in rats. 210 adult male Sprague Dawley rats were randomly assigned to the groups of TBI with hypothermia treatment (32 degrees C), TBI with normothermia (37 degrees C), and sham injured control. TBI model was induced by fluid percussion TBI device. Mild hypothermia (32 degrees C) was achieved by partial immersion in a water bath (0 degrees C) under general anesthesia for 4 hours. ⋯ In contrast, post-traumatic hypothermia significantly attenuated such an increase. According to the RT-PCR and western blot analysis, the maximum mRNA levels of TIMP-3 were reduced to 60.60%+/-2.30, 55.83%+/-1.80, 66.03%+/-2.10 and 64.51%+/-1.50 of the corresponding values in the normothermic group in injured and uninjured hemispheres (cortex and hippocampus) by hypothermia treatment, respectively (p < 0.01), while the respective maximum protein levels of TIMP-3 were reduced to 57.50%+/-1.50, 52.67%+/-2.20, 60.31%+/-2.50and 54.76%+/-1.40 (p < 0.01). Our data suggests that moderate F-P brain injury would significantly upregulate TIMP-3 expression, while such an increase could be efficiently suppressed by hypothermia treatment.
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Journal of neurotrauma · May 2009
Forced exercise as a rehabilitation strategy after unilateral cervical spinal cord contusion injury.
Evaluation of locomotor training after spinal cord injury (SCI) has primarily focused on hind limb recovery, with evidence of functional and molecular changes in response to exercise. Since trauma at a cervical (C) level is common in human SCI, we used a unilateral C4 contusion injury model in rats to determine whether forced exercise (Ex) would affect spinal cord biochemistry, anatomy, and recovery of fore and hind limb function. SCI was created with the Infinite Horizon spinal cord impactor device at C4 with a force of 200 Kdyne and a mean displacement of 1600-1800 microm in adult female Sprague-Dawley rats that had been acclimated to a motorized exercise wheel apparatus. ⋯ The BBB test showed no change with Ex at the end of the 8-week period, however hind limb grid performance was improved during weeks 2-4. Lesion size was not affected by Ex, but the presence of phagocytic and reactive glial cells was reduced with Ex as an intervention. These results suggest that Ex alone can influence the evolution of the injury and transiently improve fore and hind limb function during weeks 2-4 following a cervical SCI.
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Journal of neurotrauma · May 2009
Cerebral hemodynamic predictors of poor 6-month Glasgow Outcome Score in severe pediatric traumatic brain injury.
Little is known regarding the cerebral autoregulation in pediatric traumatic brain injury (TBI). We examined the relationship between cerebral hemodynamic predictors, including cerebral autoregulation, and long-term outcome after severe pediatric TBI. After Institutional Review Board (IRB) approval, a retrospective analysis of prospectively collected data (May 2002 to October 2007) for children age < or =16 years with severe TBI (admission Glasgow Coma Scale [GCS] score <9) was performed. ⋯ Independent risk factors for poor 6-month GOS were impaired cerebral autoregulation (adjusted odds ratio [aOR] 12.0; 95% confidence interval [CI] 1.4-99.4) and hypotension (SBP <5th percentile; aOR 8.8; 95% CI 1.1-70.5), respectively. Previous studies of TBI describing poor outcome with hemodynamics did not consider the status of cerebral autoregulation. In this study, both impaired cerebral autoregulation and SBP <5th percentile were independent risk factors for poor 6-month GOS.
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Journal of neurotrauma · May 2009
Intrathecal morphine attenuates recovery of function after a spinal cord injury.
Prior work has shown that a high dose (20 mg/kg) of systemic morphine, required to produce significant analgesia in the acute phase of a contusion injury, undermines the long-term health of treated subjects and increases lesion size. Moreover, a single dose of systemic morphine in the early stage of injury (24 h post-injury) led to symptoms of neuropathic pain 3 weeks later, in the chronic phase. The present study examines the locus of the effects using intrathecal morphine administration. ⋯ Morphine is one of the most effective pharmacological agents for the treatment of neuropathic pain and, therefore, is indispensable for the spinally injured. Treatment can, however, adversely affect the recovery process. A morphine-induced attenuation of recovery may result from increases in immune cell activation and, subsequently, pro-inflammatory cytokine concentrations in the contused spinal cord.
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Journal of neurotrauma · May 2009
Cytoskeletal and activity-related changes in spinal motoneurons after root avulsion.
Compelling evidence shows that after root avulsion motoneurons attempt to survive and regenerate before dying. In order to study these mechanisms, unilateral avulsion of L4-L5 spinal roots was performed in adult rats, and the ventral spinal cords were studied from 3 to 28 days post-operation (dpo). Electrophysiological results indicated complete denervation of L4-L5 muscles in the injured limb without functional effects on the contralateral hindlimb. ⋯ Intense SMI32 immunostaining was observed during the first week after avulsion, appearing in 37% (+/-0.9) of surviving motoneurons, but it was not associated with GAP43 expression. Calcitonin gene-related peptide (CGRP) expression in motoneurons was markedly reduced from the second week after avulsion. This study presents a detailed description of motoneuron reaction after root avulsion, which suggests an early time-window during the first 2 weeks for attempts to repair the injury and promote motoneuron survival and regeneration.