ABSTRACT
OBJECTIVE: Sulfur mustard (SM) causes blisters on the human skin. These blisters delay healing of the skin and make the victims more susceptible to infection. In vitro models have been used for protection studies against SM injury, but study on wound healing after SM exposure has not been explored. The purpose of this study was to test whether the addition of exogenous growth factors could improve the rate of SM wound healing. METHODS: The model consisted of normal human epidermal keratinocytes seeded into 6-well plates, exposed to SM, and wounded (disruption of the cell monolayer) with a sterile wounding instrument. Cells were then stained and images were captured to measure percentage wound fill. Epidermal growth factor (EGF) and keratinocyte growth factor (KGF) were tested in this model. RESULTS: EGF (1 ng/mL) significantly increased wound fill on all of the days tested (days 6, 9, and 12). KGF did not significantly improve wound healing. CONCLUSIONS: EGF showed promise as a potential therapy for SM-induced wounds. This in vitro model was a valuable tool for screening therapeutics before animal testing. These results will be used to develop a dressing that can slowly release EGF on to a debrided wound bed to help speed the healing process.
ABSTRACT
The present study evaluated the dose-response effects of subacute exposure to sublethal doses of the organophosphorus (OP) chemical warfare nerve agent (CWNA) sarin (GB) on the operant behavior of guinea pigs. Dietary restricted guinea pigs, trained to respond for food under a progressive ratio (PR) schedule of reinforcement, were injected five times per week (Monday-Friday) for 2 weeks with fractions (0.1, 0.2, and 0.4) of the established LD(50) of GB (42 microg/kg). Changes in body weight, whole blood (WB) acetylcholinesterase (AChE) levels, and operant performances were monitored over the 2 weeks of GB exposure and for an additional 2 weeks following the termination of exposures. There were dose-related changes in body weight and WB AChE levels throughout the exposure and post-exposure periods. Several parameters of PR performance were disrupted during exposure to 0.4 LD50 GB, however, concurrent weight loss indicated the presence of overt toxicity. PR performance recovered following the termination of exposures. Lower doses (0.1 and 0.2 LD50) of GB failed to produce reliable effects on operant performance during the exposure period. Overall responding decreased during exposure to 0.4 LD50 GB, resulting in reduced response rates and break points. The decrease in overall response rates was attributed to an increase in pausing since there was no decrease in running rate. Motor effects of 0.4 LD50 GB were evident as an increase in the proportion of lever press durations > or = 1.0 s. In the present study, doses of GB lower than 0.4 LD50 produced no marked alteration of operant performance in guinea pigs, although WB AChE levels were maximally inhibited to 20% of control.
