Widespread axonal injury in gunshot wounds to the head using amyloid precursor protein as a marker

In order to determine whether axonal injury (AI) is a factor in cases of penetrating head injury, the brains of 14 patients who died shortly after sustaining a fatal gunshot wound (GSW) to the head were examined, and the presence of AI determined using immunohistochemical staining for amyloid precursor protein (APP). The distribution of AI was mapped throughout the cerebral hemispheres and brain stem. AI was present in all cases in a diffuse distribution distant to the missle track with severe involvement of the brain stem in all cases. There was no axonal APP immunoreactivity in the direct region of the missle track at the point of primary axotomy. The APP-positive AI in these cases is likely to be a mixture of primary and secondary AI as APP immunostaining is unable to distinguish primary AI due to mechanical deformation from AI secondary to hypoxic-ischemic damage.Koszyca, B; Blumbergs, P C; Manavis, J; Wainwright, H; James, R; Gilbert, J; Jones, N; Reilly, P

Upregulation of neuronal amyloid precursor protein (APP) and APP mRNA following magnesium sulphate (MgSO4) therapy in traumatic brain injury

Poster session 7: Neurotrauma models 2, Paper P230 Also cited as - Restorative Neurology and Neuroscience, 2000; 16(3-4):238The aim of this study was to assess and quantitate topographically the effects of posttraumatic intravenous magnesium sulphate (MgSO4) on neuronal perikaryal APP antigen and messenger RNA (mRNA) expression in sheep brains 2 h after a controlled focal head impact. The percentage brain area with APP immunoreactive neuronal perikarya was 71, 56, 27.5 and 5.5%, respectively, in MgSO4-treated head-injured animals, head-injured animals without any treatment, MgSO4 treated nonimpacted animals, and nontreated nonimpacted control sheep. Although there was no statistically significant difference in APP immunoreactive neuronal perikarya in the MgSO4-treated HI group (mean 71%) compared to the HI group without any treatment (mean 56%), northern analysis showed that there was a 2.3-+/-0.2-fold increase in APP mRNA in the thalamus of treated impacted animals compared to untreated impacted animals (p < 0.005). However, MgSO4 treated nonimpacted control animals also showed a 1.6-+/-0.1-fold increase in APP mRNA compared to untreated nonimpacted controls (p < 0.005). MgSO4 therapy results in upregulation of neuronal APP mRNA and APP expression that is quantitatively greater following a focal head impact