Histopathologic characterization of a superficial dermal sulfur mustard-induced lesion in the weanling swine model
 
Reid, F.M., Graham, J.S., Niemuth, N.A., Matthews, C., Hoffman, T., Vasconcelos, D.
Sulfur mustard (SM) is a severe vesicating agent. Although a SM-induced, full-thickness, dermal injury model has been developed in swine, a superficial dermal model (injury restricted to the upper third of the dermis) is still needed. A dose ranging study with exposure times ranging from 15 s to16 min demonstrated SM exposure times of 7 and 8 min would produce superficial dermal lesions. Six, female, Yorkshire-cross pigs weighing 10 ± 2 kg were dosed with 400 μL undiluted SM at each of six ventral abdominal sites for 7 or 8 min (one row of three sites – anterior, middle, posterior- per side per exposure time). Lesions were photographed, measured, and assessed for edema presence on Day 1 and Day 2 after SM exposure, after which the animals were euthanatized and lesions excised for histopathology. Three sections (ventral, middle, dorsal) were taken from each lesion and processed to provide H&E stained slides. Image analysis indicated an increase in lesion size from Day 1 to Day 2 for both 7 min (5.8 to 6.6 cm2) and 8 min (6.1 to 7.0 cm2) exposure times. Lesion area was significantly greater for 8 min than for 7 min exposures (p = 0.02) on Day 2. Anterior and middle lesions were greater in size than posterior lesions by Day 2. The depth of injury (targeted injury depth of 18 to 36 percent) for both exposure times was the upper one third of the dermis, with dermal coagulation reported as 20.8 percent (SE = 1.2) for the 7 min exposure and 21.5 percent (SE of 1.1) for the 8 min exposure. Percent of lesion area affected by basal cell necrosis was not significantly different between the two exposure times with an average of 40.1 percent for 7 min and 43.1 percent for 8 min. No significant differences between the two exposure times were observed for basal cell necrosis, dermal depth, dermal coagulation, intraepidermal blisters/pustules, endothelial cell damage, and follicular necrosis. With respect to side of body, basal cell necrosis, dermoepidermal bullae, and dermal hemorrhage were slightly greater for the right side than left. The ventral section had only a slightly greater degree of basal cell necrosis than the dorsal or middle sections. In general, the magnitude of the differences was not considered biologically significant, but was sufficient to select an 8 min exposure time.
Proceedings of the medical defense bioscience review, 2004
153-1
 
© Copyright 2007 Joshua P. Gray