Journal of neurotrauma
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Journal of neurotrauma · Aug 2014
Nrf2 activation in astrocytes contributes to spinal cord ischemic tolerance induced by hyperbaric oxygen preconditioning.
In this study, we investigated whether nuclear factor erythroid 2-related factor 2 (Nrf2) activation in astrocytes contributes to the neuroprotection induced by a single hyperbaric oxygen preconditioning (HBO-PC) against spinal cord ischemia/reperfusion (SCIR) injury. In vivo: At 24 h after a single HBO-PC at 2.5 atmospheres absolute for 90 min, the male ICR mice underwent SCIR injury by aortic cross-clamping surgery and observed for 48 h. HBO-PC significantly improved hindlimb motor function, reduced secondary spinal cord edema, ameliorated the reactivity of spinal motor-evoked potentials, and slowed down the process of apoptosis to exert neuroprotective effects against SCIR injury. ⋯ HBO-PC significantly increased the survival rate of neurons and the glutathione content in culture medium, which was mainly released from asctrocytes. Moreover, the Nrf2 activity and downstream genes expression induced by HBO-PC were mainly enhanced in astrocytes, but not in neurons. In conclusion, our findings demonstrated that spinal cord ischemic tolerance induced by HBO-PC may be mainly related to Nrf2 activation in astrocytes.
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Journal of neurotrauma · Aug 2014
ReviewHelmet Use and Cervical Spine Injury: A Review of Two-wheeled Vehicle Accidents at a Level 1 Trauma Center.
Helmet use in two-wheeled vehicle accidents is widely reported to decrease the rates of death and traumatic brain injury. Previous reports suggest that there exists a trade off with helmet use consisting of an increased risk of cervical spine injuries. Recently, a review of a national trauma database demonstrated the opposite, with reduction in cervical spinal cord injuries in motorcycle crashes (MCC). ⋯ One hundred thirty-five total cervical spine injuries were identified. No evidence was found to suggest an increased risk of cervical spine injury or increased severity of cervical spine injury with helmet use. This fact, in combination with our previous findings, suggest that the law's age and insurance exemption should be revoked and a universal helmet law be reinstated in the state of Florida.
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Journal of neurotrauma · Jul 2014
Cost-effectiveness analysis (CEA) of an early-initiated, continuous chain of rehabilitation after severe traumatic brain injury.
The aim of this study is to estimate the long-term cost-effectiveness of two different rehabilitation trajectories after severe traumatic brain injury (sTBI). A decision tree model compared hospitalization costs, health effects, and incremental cost-effectiveness ratios (ICER) of a continuous chain versus a broken chain of rehabilitation. The expected costs were estimated by the reimbursement system using diagnosis-related group and based on point estimates of the Disability Rating Scale (DRS); the health effects were measured by means of area under the curve (AUC). ⋯ By replacing the broken chain with the continuous chain, NOK 37.000 could be saved and 4.06 DRS points gained. By means of probabilistic sensitivity analysis, the majority of ICER estimates (67% of the Monte Carlo simulations) indicated that a continuous chain of rehabilitation was less costly and more effective. These findings indicate that the trajectory of continuous rehabilitation represents a dominant strategy in that it reduces costs and improves outcomes after sTBI under reasonable assumptions.
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Journal of neurotrauma · Jul 2014
Using the Olfactory System as an in vivo Model to Study Traumatic Brain Injury and Repair.
Loss of olfactory function is an early indicator of traumatic brain injury (TBI). The regenerative capacity and well-defined neural maps of the mammalian olfactory system enable investigations into the degeneration and recovery of neural circuits after injury. Here, we introduce a unique olfactory-based model of TBI that reproduces many hallmarks associated with human brain trauma. ⋯ Behavioral experiments measured 4 days after impact also demonstrated loss of olfactory function, yet following a 30-day recovery period, we observed a significant improvement in olfactory function and partial recovery of olfactory circuitry, despite the persistence of TBI markers. Interestingly, by using the M71-IRES-tauLacZ reporter line to track OSN organization, we further determined that inducing neural activity during the recovery period with intense odor conditioning did not enhance the recovery process. Together, these data establish the mouse olfactory system as a new model to study TBI, serving as a platform to understand neural disruption and the potential for circuit restoration.
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Journal of neurotrauma · Jul 2014
Activation of NF-κB Mediates Astrocyte Swelling and Brain Edema in Traumatic Brain Injury.
Brain edema and associated increased intracranial pressure are major consequences of traumatic brain injury (TBI). While astrocyte swelling (cytotoxic edema) represents a major component of the brain edema in the early phase of TBI, its mechanisms are unclear. One factor known to be activated by trauma is nuclear factor-κB (NF-κB). ⋯ By contrast, traumatized astrocyte cultures derived from NF-κB Tg mice showed no swelling. We also found increased astrocytic NF-κB activation and brain water content in rats after FPI, while BAY 11-7082 significantly reduced such effects. Our findings strongly suggest that activation of astrocytic NF-κB represents a key element in the process by which cytotoxic brain edema occurs after TBI.