The skin is one of the major systems affected by spinal cord injury and insufficient care can lead to subsequent major secondary complications following rehabilitation as years post injury increase. Notable among spinal cord injured individuals is the development of pressure sores which have been reported to occur in 25-85% of this population and cost up to 1.5 billion annually. As years post injury advance the percent of those with pressure scores increases from 11.6% at year one, to 41.2% at year 15. Chronological age also seems to be a factor with a marked increase being noted for those over 40 years of age. During rehabilitation, nurses are largely responsible for educating spinal cord injured individuals to prevent pressure sores and care for these patients if a skin breakdown occurs. Presently, the effect of spinal cord injury on the chronic wound environment is poorly understood. The long term objective of this project is to develop more effective therapies to prevent and treat pressure sores for those with spinal cord injury. During the five years of the proposed study, research will focus on the cellular and biochemical features of wound fluid and tissue samples collected from pressure scores of the spinal cord injured. The following specific aims will be systematically studied: I. Protease profiles of fluids from pressure sores of spinal cord injured patients will be examined for the class, level and form of proteases and compared to fluids from pressure sores of patients without spinal cord injury. Protease inhibitors will be used to identify the class of proteases found in gelatin, fibronectin, or casein zymograms. Levels of proteases will be determined using scanning densitometry or ELISA. Activators, reducing agents, and antibodies will be used to study the form of the proteases. II. Fluids collected from spinal cord injured individuals will also be examined for the presence of normally occurring serum and tissue proteinase inhibitors. Normal serum protease inhibitors, alpha-2 macroglobulin, alpha-1 protease inhibitor, PAI-1, PAI-2, and tissue inhibitors, TIMP-1 and TIMP-2 will be assayed using thermolysin, trypsin, or elastase assays, ELISA, antisera, and antibodies. III. Since wound fluids do not give a complete view of the wound environment we will examine tissue sections to see whether in spinal cord injury the skin has a higher expression of plasminogen activators (PA) and TGF-beta since these are involved in extracellular proteolysis which accompanies tissue remodeling and matrix synthesis. This will be done using zymographies and immunochemistry of cryostat tissue sections. IV. Lastly we will examine tissue sections from spinal cord injury to determine if scar/skin changes occur over time in the junctional integrity of the dermal-epidermal junction and in the distribution of fibronectin and collage, types I, III, and IV. This will be done using histological and immunohistochemical methods using fluorescent conjugated antibodies.
| Wysocki, A B (1996) Wound fluids and the pathogenesis of chronic wounds. J Wound Ostomy Continence Nurs 23:283-90 |
