PERIPHERAL NERVE ISCHEMIA-We will continue our studies on the pathophysiology and treatment of experimental nerve ischemic fiber degeneration (IFD) and demyelination. We will study the molecular pathogenesis of nerve ischemia and reperfusion injury (Specific aim number 1), with particular focus on the roles of: (1) cytokines, (2) reactive oxygen species, (3) caspase-3, and (4) the important role of host defenses. Insights into the molecular pathophysiological chain could lead to expanded options in the prevention and treatment of nerve IFD. We will study the effects of ischemia alone and compare this with the effects of ischemia-reperfusion on nerve IFD and demyelination. We will use immunohistochemical methods to study ICAM expression and the inflammatory response, separately studying infiltration of polymorphonuclear neutrophils and monocytes. The expression pattern of TNF-alpha, IL-1beta, IL-6, and IL-10 mRNA will be measured using competitive RT-PCR, and their cellular localization by immunohistochemistry of the protein and in situ hybridization of the mRNA. These studies will be augmented in rats by selective anti-cytokine therapy and by the use of wild and genetically altered mice, of identical background genes, that overexpress, or do not express (knockout) TNF-alpha. The role of oxidative stress will be evaluated by measurements of endoneurial 4-hydroxynonenal (HNE), lipid hydroperoxides, and reduced glutathione (GSH). Cellular localization of oxidative damage will be sought, with particular focus on the Schwann cell, using immunohistochemical labeling of HNE. Caspase-3 message, protein expression and cellular localization will be evaluated using competitive RT-PCR, immunhistochemistry and in situ hybridization. We will test the hypothesis that reperfusion injury has two effects, augmenting IFD and selectively causing demyelination. We posit that demyelination evolves more slowly, affects a different population of fibers and is mediated by apoptosis (evaluated using light microscopy [TUNEL] staining) and electron microscopy. We will use single teased fiber analysis to categorically separate out axonal degeneration from demyelination. We will then define the therapeutic windows and evaluate the mechanisms of production of hypothermic and antioxidant neuroprotection (Specific aim number 2) from reperfusion injury.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS022352-19
Application #
6773319
Study Section
Special Emphasis Panel (ZRG1-BDCN-3 (01))
Program Officer
Jacobs, Tom P
Project Start
1985-07-01
Project End
2006-06-30
Budget Start
2004-07-01
Budget End
2006-06-30
Support Year
19
Fiscal Year
2004
Total Cost
$286,000
Indirect Cost
Name
Mayo Clinic, Rochester
Department
Type
DUNS #
006471700
City
Rochester
State
MN
Country
United States
Zip Code
55905
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Geser, F; Malunda, J A; Hurtig, H I et al. (2011) TDP-43 pathology occurs infrequently in multiple system atrophy. Neuropathol Appl Neurobiol 37:358-65
Kimpinski, Kurt; Iodice, Valeria; Sandroni, Paola et al. (2010) Effect of pregnancy on postural tachycardia syndrome. Mayo Clin Proc 85:639-44
Figueroa, Juan J; Basford, Jeffrey R; Low, Phillip A (2010) Preventing and treating orthostatic hypotension: As easy as A, B, C. Cleve Clin J Med 77:298-306
Kimpinski, Kurt; Iodice, Valeria; Low, Phillip A (2010) Postural Tachycardia Syndrome associated with peripartum cardiomyopathy. Auton Neurosci 155:130-1
Iodice, V; Kimpinski, K; Vernino, S et al. (2009) Efficacy of immunotherapy in seropositive and seronegative putative autoimmune autonomic ganglionopathy. Neurology 72:2002-8
Kimpinski, K; Iodice, V; Sandroni, P et al. (2009) Sudomotor dysfunction in autoimmune autonomic ganglionopathy. Neurology 73:1501-6
Kimpinski, Kurt; Iodice, Valeria; Vernino, Steve et al. (2009) Association of N-type calcium channel autoimmunity in patients with autoimmune autonomic ganglionopathy. Auton Neurosci 150:136-9
Wang, Annabel K; Fealey, Robert D; Gehrking, Tonette L et al. (2008) Patterns of neuropathy and autonomic failure in patients with amyloidosis. Mayo Clin Proc 83:1226-30
Vogel, Elizabeth R; Corfits, Jeanne L; Sandroni, Paola et al. (2008) Effect of position on valsalva maneuver: supine versus 20 degree position. J Clin Neurophysiol 25:313-6

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