Journal of neurotrauma
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Journal of neurotrauma · Mar 2013
The effect of cigarette smoke exposure on spinal cord injury in rats.
In this study, we examined whether cigarette smoke has neuroprotective or toxic effects on spinal cord injury (SCI). Male Sprague-Dawley rats were included in the study and received either cigarette smoke exposure or fresh air exposure. Twenty-four hours after the last cigarette smoke or fresh air exposure, all rats were injured at thoracic level 12 (T12), using an established static compression model. ⋯ These results suggested that cigarette smoke can reinforce the oxidative stress injury via HIF-1α and AQP4 in the early stage after SCI. It is possible that cigarette smoke exposure does not affect SCI recovery in the long term; however, it can aggravate the edema and deteriorate BSCB disruption via HIF-1α and AQP4 in the early stage after SCI. More studies will be essential to consider this hypothesis and elucidate the mechanisms involved.
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Journal of neurotrauma · Mar 2013
Randomized Controlled TrialDivergent modulation of clinical measures of volitional and reflexive motor behaviors following serotonergic medications in human incomplete spinal cord injury.
Incomplete spinal cord injury (SCI) can result in profound impairments in volitional strength and reflex excitability, which contribute to loss of function. Human and animal models suggest that disruption of endogenous monoaminergic input, particularly serotonin (5-HT), from supraspinal centers contributes to this impaired motor function following SCI. In the present study, we investigated the effects of 5-HT medications on motor function in individuals with chronic (>1 year) SCI. ⋯ Results indicated that 5-HT medications modulated both volitional and reflexive behaviors with little change in walking performance; 5-HT antagonist medications depressed clinical measures of strength and spasticity/spasms, whereas SSRIs augmented both strength and spasticity/spasms. These changes are consistent with the dysregulation of 5-HT sensitive spinal neurons following SCI. This understanding may augment clinicians' awareness of the motor consequences of 5-HT medications.
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Spinal Cord Injury (SCI) is an acute trauma to the neural elements resulting in temporary or permanent sensory and motor deficit. Studies have indicated that although 66% of SCI occur in Caucasians, there are a growing number of other racial groups affected by SCI. Furthermore, there has been a lack of research concerning racial disparities in outcomes following SCI. ⋯ For disposition status, African Americans (OR 0.844, CI 0.730-0.976) and Asians (OR 0.475, CI 0.297-0.760) were much less likely than Caucasians or Hispanic populations to be discharged to an acute rehabilitation program. The results from this large-scale study (n=18,671) demonstrate a number of racial disparities following SCI at the national level, including rate of complications, length of stay, and disposition to acute rehabilitation centers. This should raise awareness to cultural differences but also serve as an opportunity to reduce gaps in care across ethnicities for this universally life-altering condition.
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Journal of neurotrauma · Mar 2013
Calpain 1 knockdown improves tissue sparing and functional outcomes after spinal cord injury in rats.
To evaluate the hypothesis that calpain 1 knockdown would reduce pathological damage and functional deficits after spinal cord injury (SCI), we developed lentiviral vectors encoding calpain 1 shRNA and eGFP as a reporter (LV-CAPN1 shRNA). The ability of LV-CAPN1 shRNA to knockdown calpain 1 was confirmed in rat NRK cells using Northern and Western blot analysis. To investigate the effects on spinal cord injury, LV-CAPN1shRNA or LV-mismatch control shRNA (LV-control shRNA) were administered by convection enhanced diffusion at spinal cord level T10 in Long-Evans female rats (200-250 g) 1 week before contusion SCI, 180 kdyn force, or sham surgery at the same thoracic level. ⋯ Intraspinal administration of LV-CAPN1shRNA 1 week before contusion SCI resulted in a significant improvement in locomotor function over 6 weeks postinjury, compared with LV-control administration (p<0.05, n=10 per group). Histological analysis of spinal cord sections indicated that pre-injury intraspinal administration of LV-CAPN1shRNA significantly reduced spinal lesion volume and improved total tissue sparing, white matter sparing, and gray matter sparing (p<0.05, n=10 per group). Together, results support the hypothesis that calpain 1 activation contributes to the tissue damage and impaired locomotor function after SCI, and that calpain1 represents a potential therapeutic target.
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Journal of neurotrauma · Mar 2013
B-cell maturation antigen, a proliferation-inducing ligand, and B-cell activating factor are candidate mediators of spinal cord injury-induced autoimmunity.
Autoimmunity is thought to contribute to poor neurological outcomes after spinal cord injury (SCI). There are few mechanism-based therapies, however, designed to reduce tissue damage and neurotoxicity after SCI because the molecular and cellular bases for SCI-induced autoimmunity are not completely understood. Recent groundbreaking studies in rodents indicate that B cells are responsible for SCI-induced autoimmunity. ⋯ Real-time polymerase chain reaction analysis from ribonucleic acid samples confirmed upregulation of these three genes in SCI. To our knowledge, this is the first report that peripheral blood mononuclear cells produce increased levels of BAFF and APRIL in chronic SCI. This finding provides evidence of systemic regulation of SCI-autoimmunity via APRIL and BAFF mediated activation of B cells through BMCA and points toward these molecules as potential targets of therapies designed to reduce neuroinflammation after SCI.