| 2970 Hyperbaric oxygen therapy: closure and microbial clearance in stressed wounds | ||
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J. RUTTENCUTTER, P. GAJENDRAREDDY, and P. MARUCHA, University of Illinois - Chicago, USA Objectives: In a murine model, stress delays wound closure, decreases oxygen in wound tissue, and increases opportunistic bacteria despite excess neutrophils in wound tissue. Hyperbaric oxygen therapy (HBOT) was capable of restoring wound closure to near control levels. Hypothesis: hyperbaric oxygen therapy ameliorates stress-impaired wound closure by restoring wound oxygen levels and microbial clearance. Methods: As a stressor, mice were placed into well-ventilated 50ml conical tubes for 12 hours during the night cycle three times pre- and five times post-wounding. Two wounds were placed on the dorsum of female SKH-1 mice using a 3.5mm biopsy punch. Mice received two 2-hour treatments of HBOT (2.5atm) daily beginning on the day of wounding. Wounds were harvested for analysis using a 6mm biopsy punch. To measure the oxygen level of wounds on day 3 post-wounding, a luciferase-based hypoxia responsive plasmid (HRE-pLuc) was utilized as previously described (Mogford 2003). Microbial clearance at day 5 was assessed by plating wound homogenates on brain heart infusion agar and counting resulting colonies. Results: Luciferase activity from homogenized wounds of restraint-stressed mice was 33% higher than control mice (n=13, p=0.055). Preliminary data suggest HBOT decreases the restraint-stressed luciferase measurements to near control levels. As shown previously, stress-impaired wound closure was ameliorated by HBOT. At day 5, control wounds contained 5.55 and restraint-stressed wounds 6.56 logs of bacteria (n=13). HBOT decreased these counts to 4.79 and 6.38 logs respectively (n=13). Conclusion: HBOT ameliorated stress-impaired wound closure in mice, but had no significant effect on microbial clearance. This suggests that HBOT ameliorates stress-delayed wound closure by a mechanism other than microbial clearance, e.g. wound reepithelialization and/or increased wound contraction. Since previous data suggested only partial amelioration of clearance by glucocorticoid blockade, stress-impaired microbial clearance is mediated by multiple/alternative pathways. Funding: 5F30DE017270-02, Matula Research Fund, UIC Dentistry | ||
| Seq #300 - Anti-Infectives and Anti-Inflammatories/ Animal and In Vitro Studies 10:45 AM-12:00 PM, Saturday, March 24, 2007 Ernest N. Morial Convention Center Exhibit Hall I2-J | ||
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