Journal of neurotrauma
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Journal of neurotrauma · Jun 2012
Lateralized response of dynorphin a peptide levels after traumatic brain injury.
Traumatic brain injury (TBI) induces a cascade of primary and secondary events resulting in impairment of neuronal networks that eventually determines clinical outcome. The dynorphins, endogenous opioid peptides, have been implicated in secondary injury and neurodegeneration in rodent and human brain. To gain insight into the role of dynorphins in the brain's response to trauma, we analyzed short-term (1-day) and long-term (7-day) changes in dynorphin A (Dyn A) levels in the frontal cortex, hippocampus, and striatum, induced by unilateral left-side or right-side cortical TBI in mice. ⋯ In naive animals, Dyn A was symmetrically distributed between the two hemispheres. Thus, trauma may reveal a lateralization in the mechanism mediating the response of Dyn A-expressing neuronal networks in the brain. These networks may differentially mediate effects of left and right brain injury on lateralized brain functions.
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Journal of neurotrauma · Jun 2012
Phosphorylation and cleavage of the family of collapsin response mediator proteins may play a central role in neurodegeneration after CNS trauma.
The family of the collapsin response mediator proteins (CRMPs) plays a significant physiological role in neuronal cell bodies and axons within the integrated mammalian central nervous system (CNS). Trauma-induced damage to the CNS results in variable degrees of axonal degeneration, and this may lead to neuronal cell death in key grey matter regions. Site-specific phosphorylation of certain CRMPs has been associated with trauma-induced axonal degeneration. ⋯ The precise structure of cleaved CRMP has yet to be elucidated, as is the reason for nuclear translocation. Once the crystal structure of the cytoplasmic and nuclear-translocated forms of CRMPs is determined, a greater molecular understanding of why these forms can initiate neurodegeneration following CNS injury will be established. Such information will be particularly informative in the design of inhibitors of specific protein-protein interaction sites between cleaved CRMP and vital cytosolic or nuclear molecules.
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Journal of neurotrauma · Jun 2012
Mechanical characterization of the injured spinal cord after lateral spinal hemisection injury in the rat.
The glial scar formed at the site of traumatic spinal cord injury (SCI) has been classically hypothesized to be a potent physical and biochemical barrier to nerve regeneration. One longstanding hypothesis is that the scar acts as a physical barrier due to its increased stiffness in comparison to uninjured spinal cord tissue. However, the information regarding the mechanical properties of the glial scar in the current literature is mostly anecdotal and not well quantified. ⋯ Injured tissue exhibited significantly lower stiffness and elastic modulus in comparison to uninjured control tissue, and the results from the model parameters indicated that the relaxation time constant and viscosity of injured tissue were significantly higher than controls. This study presents direct micromechanical measurements of injured spinal cord tissue post-injury. The results of this study show that the injured spinal tissue displays complex viscoelastic behavior, likely indicating changes in tissue permeability and diffusivity.
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Journal of neurotrauma · Jun 2012
Beta-trace protein in ascites and pleural effusions: limits of CSF leakage detection.
Rhino- and/or otoliquorrhea can be diagnosed by detecting beta-trace protein (β-TP) in nasal or ear secretions, as β-TP is found in high concentrations in cerebrospinal fluid (CSF) but not in serum. CSF fistulae following trauma or surgery can also occur at other anatomical sites, resulting in CSF leakage into the thoracic and abdominal cavities. By analogy, determination of ß-TP has also been used to diagnose CSF admixture in pleural effusions and ascites. ⋯ Protein analysis confirmed the presence of β-TP in pleural effusion and ascites. Ascites and pleural effusion contain high concentrations of β-TP that exceed the levels in corresponding plasma. Therefore, β-TP is not a specific marker for the presence of CSF in these fluids.
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Journal of neurotrauma · Jun 2012
Review Meta AnalysisQuality of life in children and adolescents post-TBI: a systematic review and meta-analysis.
Traumatic brain injury is (TBI) a leading cause of morbidity and mortality in children and adolescents in first-world nations. Research from our team investigating adult survivors of pediatric TBI indicate that survivors of severe TBI are particularly vulnerable to global impairments, including poorer school performance, greater employment difficulties, poor quality of life (QoL), and increased risk of mental health problems. Investigation into less observable consequences, including QoL, has emerged recently as an important outcome to assess in TBI populations. The status of QoL in pediatric TBI populations is mixed, likely a reflection of the varied methodological and theoretical perspectives on QoL. ⋯ This systematic study will clarify the nature of QoL in survivors of pediatric TBI, and identify predictors of QoL in this group. Of 419 articles identified, 11 studies met our inclusion criteria, and 9 were ultimately analyzed in this review. Four studies reported good QoL and 5 poor QoL. The difference between good and poor QoL was statistically significant due to TBI severity [chi-square(3)=77.38, p<0.001], timing of outcome assessment [chi-square(1)=565, p<0.001], and definition of QoL [chi-square(3)=34.73, p<0.001]. The odds of having a poor QoL increased 5.8 times (RR=1.21) when injuries were more severe. Good outcomes are contingent on milder injuries, proxy reporting, and early assessment, whereas poor outcomes reflect more severe injuries and later assessment (≤ 6 months versus ≥ 1 year post-trauma, respectively).