Evaluation of tissue viability and pathological changes of transplanted grafts.

<p>(a-A, B): Isografts in groups 1 and 2 survived well. (a-C, D): Allografts in groups 3 and 4 that received N.S showed obvious rejection profiles at 10–12 days postoperatively. (a-E): Allografts in group 5 survived rejection-freely for up to 100 days. With the same CsA protocol, the B–R hind limbs in group 6 were all rejected within 2 months (a-F). (b-A): Skin histologic sections from isograft groups showed normal epidermis and dermis. (b-B): Skin histologic sections from rejection control groups showed necrotic epidermis features of grade 3 rejection reaction at POD 11. (b-C, D): Skin biopsies from CsA treatment groups 5 and 6 at POD 30 showed grade 1 rejection reaction with focal epidermal mononuclear cell infiltration, respectively. (b-E): At POD 100, skin biopsies from recipients in group 5 showed grade 1 rejection and a mild increase in the number of lymphocytes infiltrating the upper dermis at POD 100. (b-F): Skin biopsy from group 6 when the allograft was rejected showed necrotic features of grade 3 rejection reaction in the epidermis and a marked increase in the number of lymphocytes infiltrating all tissues from the dermis down to the muscles (H&E, ×20).