Figure 5.

Healing Response Histology

Composite images (Masson’s trichrome, right; hematoxylin and eosin stain, left) of PTA control arm, nominal-dose (PCB × 1) arm and high-dose (PCB × 3) arm at 14 and 28 days post-treatment, respectively (bar scale = 1 mm). Arrows indicate the approximate demarcation of the normal (nonwounded) skins to the left and right of the healing wound. Histological appearance of the healing responses across the study arms is similar; at 14 days, the dermal collagen is not as dense, and the collagen bundles are not as thick appearing in the center of the wound as in the flanking nonwounded skin areas and there is gradation of the collagen density along the wound border and from the base to the surface representing normal healing and progressive production of dermal collagen. At 28 days the wound surfaces are covered by keratinized epidermis and the wound defect is filled with mature granulation tissue. Abbreviations as in Figure 1.