Journal of neurotrauma
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Journal of neurotrauma · Sep 2009
Traumatic injury activates MAP kinases in astrocytes: mechanisms of hypothermia and hyperthermia.
Hyperthermia is common following traumatic brain injury (TBI) and has been associated with poor neurologic outcome, and hypothermia has emerged as a potentially effective therapy for TBI, although its mechanism is still unclear. In this study we investigated the effects of temperature modulations on astrocyte survival following traumatic injury and the involved MAPK pathways. Trauma was produced by scratch injury of a monolayer of confluent astrocytes in culture, followed by incubation at hypothermia (308 degree C), normothermia (378 degree C), or hyperthermia (398 degree C). ⋯ Prolonged hyperthermia as a secondary insult worsens apoptosis by increasing JNK activation. Hypothermia protects against traumatic injury via early suppression on JNK activation and subsequent prevention of apoptosis. Manipulation of the JNK pathway in astrocytes may represent a therapeutic target for ameliorating the devastating progression of tissue injury and cell death after TBI.
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Journal of neurotrauma · Sep 2009
The persistent effects of concussion on neuroelectric indices of attention.
Mild traumatic brain injuries (mTBIs) that result from participation in sports are a major public health issue affecting 1.6-3.8 million individuals annually. The injury has been postulated as transient and void of long-term consequences when rapidly diagnosed and properly managed. Emerging evidence, however, has suggested an increased risk for late life cognitive dysfunction in those with previous injuries. ⋯ Significant decrements in the N2 and P3b amplitudes of the stimulus-locked ERP were noted for those with a history relative to those without a history of concussion. Although the previously concussed participants performed equal to those without injury on the clinical cognitive assessment, these findings support the notion that sport mTBI can no longer be thought of as a transient injury resulting in short-lived neurological impairment. It is not clear if these persistent deficits will manifest into clinical pathologies later in life.
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Journal of neurotrauma · Sep 2009
Apolipoprotein E4 as a predictor of outcomes in pediatric mild traumatic brain injury.
The epsilon4 allele of the apolipoprotein E (APOE) gene has been linked to negative outcomes among adults with traumatic brain injury (TBI) across the spectrum of severity, with preliminary evidence suggesting a similar pattern among children. This study investigated the relationship of the APOE epsilon4 allele to outcomes in children with mild TBI. Participants in this prospective, longitudinal study included 99 children with mild TBI between the ages of 8 and 15 recruited from consecutive admissions to Emergency Departments at two large children's hospitals. ⋯ Those with an epsilon4 allele exhibited better performance than children without an epsilon4 allele on a test of constructional skill, but the groups did not differ on any other neuropsychological tests. Children with and without an epsilon4 allele also did not differ on measures of post-concussive symptoms. Overall, the findings suggest that the APOE epsilon4 allele is not consistently related to the outcomes of mild TBI in children.
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Journal of neurotrauma · Sep 2009
Validation of serum markers for blood-brain barrier disruption in traumatic brain injury.
The blood-brain barrier (BBB), which prevents the entry into the central nervous system (CNS) of most water-soluble molecules over 500 Da, is often disrupted after trauma. Post-traumatic BBB disruption may have important implications for prognosis and therapy. Assessment of BBB status is not routine in clinical practice because available techniques are invasive. ⋯ ROC analysis demonstrated a significant relationship between Q(A) and serum S100B concentrations at 12 h after TBI (AUC = 0.800; SE 0.147, 95% CI 0.511-1.089). Using an S100B concentration cutoff of 0.027 ng=ml, specificity for abnormal Q(A) was 90% or higher at each time point. We conclude that serum S100B concentrations accurately indicate BBB dysfunction at 12 h after TBI.
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Journal of neurotrauma · Sep 2009
Systemic sepsis exacerbates mild post-traumatic brain injury in the rat.
The development of sepsis in patient suffering from traumatic brain injury (TBI) represents a frequent complication that has been associated with worsened global and neurological outcome. In an effort to better characterize the influence of sepsis following TBI, we developed an in vivo model of combined TBI and sepsis in the rat by coupling two validated models: (1) Controlled Cortical Impact (CCI) and (2) Cecal Ligation and Puncture (CLP). Possible contributing effects of sepsis on post-traumatic outcome were evaluated as mortality rate, body weight change, neurological motor (beam balance), cognitive (Morris water maze [MWM] for memory and learning) function, histopathological damage (lesion volume, cell counts in the CA1 and CA3 hippocampal areas), and morphological indices of inflammation (activated microglia and astrocytes) for the 14-day study period. ⋯ The histological counterpart was represented by a cortical lesion in the area of impact at 14 days post-injury, associated with cell loss in the CA1 and CA3 hippocampal regions, and scarce infiltration of microglia. The superimposition of sepsis on this mild TBI model resulted in worsening of post-injury mortality and weight loss, significant exacerbation of post-injury motor deficit and cognitive impairments, and further exacerbation of neuronal cell death in the CA3 area together with over-expression and activation of microglial cells in the peri-lesional area. Altogether, our findings indicate that sepsis, when superimposed on TBI, exerts a negative effect on the evolution of post-traumatic damage.