Diffuse axonal injury (DAI) in the white matter of the cerebral hemispheres and brainstem, and combinations of brain swelling and ischemia, appear to be the principal cause of death and disability after head injury. Based on studies of cerebral blood flow using 133-Xenon IV techniques and measurements of cerebral 02 metabolism (CMR02) we now have evidence that hyperventilation increases CMR02 in comatose patients and, since metabolic acidosis is a common finding in acute head injury patients, hyperventilation may create a more favorable environment for cerebral metabolic processes in the comatose patient. We have also established the importance of CBF and CMR02 in the acute phase of head injury for subsequent outcomes. Analysis of data from our model of nonimpact acceleration injury in the rhesus monkey and baboon has provided evidence that the head has a profound directional sensitivity to damage induced by angular acceleration. Also, we have found that the pathophysiological mechanisms of DAI and gliding contusions may be similar. We have developed a model of axonal injury in the guinea pig optic nerve and initial evidence indicates that such injury has the same morphology as that produced by DAI in whole primate brains and in humans. We now have evidence that there are marked increases in intracellular calcium ion concentration after stretch injuries in the squid giant axon which appear to be related to recovery. Ischemic injury to the subiculum and anterior dentate may be caused by additional lactic acid derived from glucose in the CSF of the adjacent 3rd ventricle. Using 31P and 1H NMR techniques we have evidence that threshold ischemia, as indicated by increased lactate and phosphocreatine levels, occurs at perfusion pressures of 10-20mm Hg. Finally, we have begun a new set of NMR experiments to quantitatively measure rCBF from clearance curves of flourine containing compounds. Initial results are very encouraging. The clearance curves are biexponential and look very much like 133- Xenon clearance curves.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Program Projects (P01)
Project #
5P01NS008803-18
Application #
3099316
Study Section
Neurological Disorders Program Project Review A Committee (NSPA)
Project Start
1976-08-01
Project End
1990-03-31
Budget Start
1988-04-01
Budget End
1989-03-31
Support Year
18
Fiscal Year
1988
Total Cost
Indirect Cost
Name
University of Pennsylvania
Department
Type
Schools of Medicine
DUNS #
042250712
City
Philadelphia
State
PA
Country
United States
Zip Code
19104
Browne, Kevin D; Chen, Xiao-Han; Meaney, David F et al. (2011) Mild traumatic brain injury and diffuse axonal injury in swine. J Neurotrauma 28:1747-55
Riess, Peter; Zhang, Chen; Saatman, Kathryn E et al. (2002) Transplanted neural stem cells survive, differentiate, and improve neurological motor function after experimental traumatic brain injury. Neurosurgery 51:1043-52; discussion 1052-4
Blaha, G R; Raghupathi, R; Saatman, K E et al. (2000) Brain-derived neurotrophic factor administration after traumatic brain injury in the rat does not protect against behavioral or histological deficits. Neuroscience 99:483-93
Morrison 3rd, B; Eberwine, J H; Meaney, D F et al. (2000) Traumatic injury induces differential expression of cell death genes in organotypic brain slice cultures determined by complementary DNA array hybridization. Neuroscience 96:131-9
Morrison 3rd, B; Meaney, D F; Margulies, S S et al. (2000) Dynamic mechanical stretch of organotypic brain slice cultures induces differential genomic expression: relationship to mechanical parameters. J Biomech Eng 122:224-30
Guluma, K Z; Saatman, K E; Brown, A et al. (1999) Sequential pharmacotherapy with magnesium chloride and basic fibroblast growth factor after fluid percussion brain injury results in less neuromotor efficacy than that achieved with magnesium alone. J Neurotrauma 16:311-21
Shreiber, D I; Smith, D H; Meaney, D F (1999) Immediate in vivo response of the cortex and the blood-brain barrier following dynamic cortical deformation in the rat. Neurosci Lett 259:5-8
Muir, J K; Raghupathi, R; Saatman, K E et al. (1999) Terminally differentiated human neurons survive and integrate following transplantation into the traumatically injured rat brain. J Neurotrauma 16:403-14
Muir, J K; Raghupathi, R; Emery, D L et al. (1999) Postinjury magnesium treatment attenuates traumatic brain injury-induced cortical induction of p53 mRNA in rats. Exp Neurol 159:584-93
Bareyre, F M; Saatman, K E; Helfaer, M A et al. (1999) Alterations in ionized and total blood magnesium after experimental traumatic brain injury: relationship to neurobehavioral outcome and neuroprotective efficacy of magnesium chloride. J Neurochem 73:271-80

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