The role of matrix-degrading enzymes, particularly plasminogen activators and matrix metalloproteinases, in the acute wound healing response has been the focus of many scientific studies. Only recently have these classes of endogenously produced proteinases been studied with regard to their involvement in the chronic wound environment. Using both in situ histologic zymography and immunohistochemical techniques, we examined the distribution of plasminogen activators and matrix metalloproteinase in the granulation tissue of pressure ulcers. Using in situ histologic zymography, urokinase was found to be the predominant plasminogen activator activity in the chronic wound granulation tissue, with little or no tissue-type plasminogen activator activity. These results were confirmed with the use of immunohistochemical techniques. In contrast, tissue-type plasminogen activator was found to be constitutively expressed in normal skin. Levels of matrix metalloproteinases were also found to be elevated in the granulation tissue of pressure ulcers. Immunohistochemical localization of leukocyte-associated proteinases (PMN elastase and cathepsin G) suggested a highly inflamed environment within the pressure ulcer granulation tissue. These results suggest a highly proteolytic environment within the chronic wound.

The novel fibrin sealant, Vivostat, is as effective as Surgicel cellulose gauze in achieving haemostasis after porcine partial hepatic lobectomy.

This study assessed the role of a novel fibrin sealant (Vivostat in adhesion reduction after flexor tendon surgery. The deep flexor tendons of the 2nd and 4th digits of the left paw of 20 rabbits were exposed and a standard partial injury was performed on each. The rabbits were randomized to either immediate post-injury treatment with Vivostat or no treatment. In each case active movement of the 2nd digit was prevented while the 4th digit was allowed to move normally. The two groups were assessed at 14 days for adhesion formation with a tensiometer. The right paw acted as the unoperated control. Results showed that there was no significant difference in the force needed to remove the tendon from its sheath when comparing the two Vivostat((R))-treated groups to the unoperated controls. There was, however, a highly significant difference in this force between the non-Vivostat-treated groups and the unoperated controls. This suggests a beneficial effect of Vivostat in reducing post surgical tendon adhesion formation.