A COMPARATIVE-STUDY OF CRYOGENIC LESIONS IN ORGAN-CULTURED HUMAN SKINAND IN RECONSTITUTED HUMAN SKIN EQUIVALENT

Cryosugery is a technique that is widely used in the treatment of cuta neous tumors. However, there are still features of healing in cryosuge ry wounds that are incompletely understood and necessitate further stu dy. In the present paper, we describe two in vitro models that were de veloped to study the initial stages of development of the cryolesion: reconstituted human skin and organ-cultured human skin. Cryolesions we re generated in both models by applying a 2-mm-diameter cryoprobe at - 196 degrees C for 35 s. Histological features were analyzed at days 0, 3, 5, and 14 following crytotreatment and showed epidermal detachment and keratinocyte necrosis very close to the findings reported in vivo . Results were similar in the two models. Gross alteration of the derm al architecture was noticed beneath the cryolesion, particularly in th e reconstituted skin model. Cell proliferation was investigated at day s 0, 3, and 5 by [H-3]thymidine incorporation and Ki-67 antigen immuno labeling. In the case of organ-cultured skin, a significant increase i n keratinocyte and fibroblast proliferation was observed at day 3, com pared to the controls. At day 5, a return to die basic level was notic ed. This was not observed in the reconstituted skin model at either da y 3 or day 5. These data led us to propose that organ-cultured skin ma y be a useful model for evaluating the response of human skin to freez ing, reconstituted skin was not adequate for this purpose. (C) 1998 Ac ademic Press.