Journal of neurotrauma
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Journal of neurotrauma · Dec 2013
Lactate uptake by the injured human brain - evidence from an arterio-venous gradient and cerebral microdialysis study.
Lactate has been regarded as a waste product of anaerobic metabolism of glucose. Evidence also suggests, however, that the brain may use lactate as an alternative fuel. Our aim was to determine the extent of lactate uptake from the circulation into the brain after traumatic brain injury (TBI) and to compare it with levels of lactate in the brain extracellular fluid. ⋯ Lactate uptake was associated with significantly higher AV difference in glucose values with a median (IQR) of 0.4 (0.03-0.7) mmol/L during uptake and 0.1 (-0.2-0.3) mmol/L during lactate export (Mann-Whitney U p=0.003). Despite relatively high brain lactate compared with arterial lactate concentrations, the brain appears to up-regulate lactate transport into the brain after TBI. This may serve to satisfy greater demands for energy substrate from the brain after TBI.
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Journal of neurotrauma · Dec 2013
Race and Insurance Disparities in Discharge to Rehabilitation for Patients with TBI.
Post-acute inpatient rehabilitation services are associated with improved functional outcomes among persons with traumatic brain injury (TBI). We sought to investigate racial and insurance-based disparities in access to rehabilitation. Data from the Nationwide Inpatient Sample from 2005-2010 were analyzed using standard descriptive methods and multivariable logistic regression to assess race- and insurance-based differences in access to inpatient rehabilitation after TBI, controlling for patient- and hospital-level variables. ⋯ Compared with insured whites, uninsured whites (OR 0.57; 95% CI 0.51-0.63), uninsured blacks (OR 0.33; 95% CI 0.26-0.42), uninsured Hispanics (OR 0.27; 95% CI 0.22-0.33), and uninsured Asians (OR 0.40; 95% CI 0.22-0.73) were less likely to be discharged to rehabilitation. Race and insurance are strong predictors of discharge to rehabilitation among adult TBI survivors in the United States. Efforts are needed to understand and eliminate disparities in access to rehabilitation after TBI.
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Journal of neurotrauma · Dec 2013
Traumatic brain injury in rats induces lung injury and systemic immune suppression.
Traumatic brain injury (TBI) is frequently complicated by acute lung injury, which is predictive for poor outcome. However, it is unclear whether lung injury develops independently or as a result of mechanical ventilation after TBI. Further, TBI is strongly associated with the development of pneumonia, suggesting a specific vulnerability for the development of nosocomial infections in the lung after TBI. ⋯ Further, after TBI, the release of tumor necrosis factor alpha was decreased when whole blood was stimulated ex vivo (p<0.05 TBI vs. sham), indicating systemic immune suppression. When TBI was followed by pneumonitis, the severity of subsequent pneumonitis was not different in rats previously subjected to TBI or sham treatment (p>0.05), suggesting that systemic immune suppression is not translated toward the pulmonary compartment in this specific model. We here show that during mild experimental TBI, acute pulmonary injury, as well as a decrease in the excitability of the systemic immune system, can be observed.
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Journal of neurotrauma · Dec 2013
Intracerebroventricular Transplantation of ex vivo Expanded Endothelial Colony-Forming Cells Restores Blood Brain Barrier Integrity and Promotes Angiogenesis of Mice with Traumatic Brain Injury.
Endothelial progenitor cells (EPCs) play a key role in tissue repair and regeneration. Previous studies have shown a positive correlation between the number of circulating EPCs and clinical outcomes of patients with traumatic brain injury (TBI). A recent study has further shown that intravenous infusion of human umbilical cord blood-derived endothelial colony-forming cells (ECFCs) improves outcomes of mice subjected to experimental TBI. ⋯ Consistent with the previous report, mice with ECFCs transplant had also increased microvascular density. Modified neurological severity score and Morris water maze test indicated significant improvements in motor ability, spatial acquisition and reference memory in mice receiving ECFCs, compared to those receiving saline. These data demonstrate the beneficial effects of ECFC transplant on BBB integrity and angiogenesis in mice with TBI.
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Journal of neurotrauma · Dec 2013
The complement terminal pathway is activated in focal penetrating but not in mild diffuse Traumatic Brain Injury.
The complement system plays an important role in the inflammatory response activated by many central nervous system disorders. However, its significance in traumatic diffuse traumatic axonal injury (TAI) is not fully known. Here we analyze the complement activity in two rat models of traumatic brain injury (TBI); a focal penetration injury (pen-TBI) and a rotational acceleration injury (rot-TBI) that leads to a mild TAI. ⋯ Our findings suggest that the terminal complement pathway is progressed to the formation of the C5b-9 membrane attack complex only in the penetrating TBI but not in isolated TAI model. This indicates that the complement activation does not lead to membrane-damaging effects and a subsequent secondary axotomy in TAI by the terminal complex C5b-9. The role of complement activation in TAI is unclear, but might indicate an alternative function following rot-TBI, such as opsonizing the synapses for elimination.