Journal of neurotrauma
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Journal of neurotrauma · Aug 2004
Effect of age at time of spinal cord injury on behavioral outcomes in rat.
Spinal cord injury (SCI) often leads to chronic central pain (CCP) syndromes such as allodynia and hyperalgesia. Although several experimental animal models for CCP studies exist, little is known about the effect of age on the development of CCP following SCI. In this study, we evaluated behavioral responses to mechanical and thermal stimuli following SCI using three different age groups of adult Sprague-Dawley rats: young (40 days), adult (60 days), and middle-age (12 months). ⋯ In both forelimbs and hindlimbs, the young group displayed a significant increase in PWF and a significant decrease in PWL compared to presurgical and sham values or values from the adult and middle-age groups. These results indicate that younger rats developed more robust neuropathic behaviors than middle-age rats, indicating that age selection is an important factor in animal models of CCP syndromes following SCI. Additionally, our data suggest that age at the time of injury may be one risk factor in predicting the development of CCP after SCI in people.
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Journal of neurotrauma · Aug 2004
Increased expression of vasopressin v1a receptors after traumatic brain injury.
Experimental evidence obtained in various animal models of brain injury indicates that vasopressin promotes the formation of cerebral edema. However, the molecular and cellular mechanisms underlying this vasopressin action are not fully understood. In the present study, we analyzed the temporal changes in expression of vasopressin V1a receptors after traumatic brain injury (TBI) in rats. ⋯ This increase in the V1a receptor expression was apparent between 2 and 4 days after TBI. As early as 1-2 h following the impact, there was also a striking increase in the number of the V1a receptor-immunopositive beaded axonal processes, with greatly enlarged varicosities, that were localized to various areas of the injured parenchyma. It is suggested that the increased expression of V1a receptors plays an important role in the vasopressin-mediated formation of edema in the injured brain.
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Journal of neurotrauma · Aug 2004
Erythropoietin attenuates post-traumatic injury in organotypic hippocampal slices.
Recent experimental evidence indicates that erythropoietin (Epo), in addition to its hormonal role in regulating red cell production, operates as a neuroprotective agent. So far, the neuroprotective effect of human recombinant Epo (rhEpo) has been mainly demonstrated in models of cerebral ischemia/hypoxia and in selected in vivo studies of traumatic neuronal injury. To further investigate the potential role of this multifunctional trophic factor in post-traumatic cell death, we examined the protective effects of rhEpo in a newly developed model of mechanical trauma in organotypic hippocampal slices. ⋯ At 48 h after trauma, the protective effect of rhEpo was greater (by about 47%) and significantly more pronounced than that of MK-801 (28%). Our results suggest that the neuroprotective activity of rhEpo is particularly effective against delayed, secondary post-traumatic damage. This well tolerated agent could provide a therapeutic benefit in pathologies involving post-traumatic neurodegeneration.
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Journal of neurotrauma · Jul 2004
Meta AnalysisA meta-analysis of clinical correlates that predict significant intracranial injury in adults with minor head trauma.
Previous studies have resulted in conflicting results regarding the predictive effect of various clinical symptoms, signs, and plain imaging for intracranial pathology in adults with minor head injury. We sought to perform a meta-analysis of the literature to assess the significance of these factors for the prediction of intracranial hemorrhage (ICH). The literature was searched using Medline, Embase, Experts, and the Grey literature. ⋯ Reasons for the heterogeneity are discussed. This study has determined the relative risks of 23 clinical variables that may predict the presence of an ICH in patients after minor head injury. These risks should prove invaluable to clinicians for the assessment of individual patients as well as the assessment of guidelines presented for the management of minor head injuries.
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Journal of neurotrauma · Jul 2004
Comparative StudyPatterns of energy substrates during ischemia measured in the brain by microdialysis.
The purpose of this study was to examine the patterns of change in microdialysate concentrations of glucose, lactate, pyruvate, and glutamate in the brain during periods of hypoxia/ischemia identified by monitoring brain tissue pO2 (PbtO2). Of particular interest was a better understanding of what additional information could be obtained by the microdialysis parameters that was not available from the PbtO2. Fifty-seven patients admitted with severe traumatic brain injury who had placement of both a brain tissue pO2 (PbtO2) and microdialysis probe were studied. ⋯ The dialysate concentration of lactate was significantly increased as the PbtO2 decreased to less than 10 mm Hg. Dialysate glutamate was significantly elevated only when PbtO2 decreased to very low levels. Although changes in the PbtO2 provided the earliest sign of hypoxia/ischemia, the microdialysis assays provided additional information about the consequences that the reduced tissue pO2 has on brain metabolism, which may be helpful in managing these critically ill patients.