Mitochondrial DNA deletions serve as biomarkers of aging in the skin, but are typically absent in nonmelanoma skin cancers.

The potential role of mitochondrial DNA (mtDNA) deletions in nonmelanoma skin cancer (NMSC) and in cutaneous photoaging was explored using a genetic approach. Tumors and photodamaged tumor-free "margin" skin were obtained from NMSC patients undergoing excision and the mtDNA from these specimens was screened for the presence of deletions using long extension PCR. mtDNA deletions were abundant in margin tissue specimens from older patients and their number correlated with the patient age. There was a statistically significant difference between the number of mtDNA deletions in tumors and margins. Fewer deletions were detected in the tumors than the margins and the tumors often had no deletions, implying a potential selection for full-length mtDNA or perhaps a protective role for mtDNA deletions in the process of tumorigenesis. The observed mtDNA deletions from skin were often unreported (19 of 21 deletions), but typically shared structural features with mtDNA deletions reported in other tissues. Some mtDNA deletions were detected from the skin of multiple individuals, including 3,715 and 6,278-base pair (bp) deletions, whose frequencies approached that of the previously well-characterized 4977-bp "common" deletion. These data support the use of mtDNA mutations as biomarkers of photoaging in the skin.

Useful adjuncts to harvest split-thickness skin grafts.

BACKGROUND: Split-thickness skin grafts are useful for repair of defects that are not amenable to primary closure or secondary intention healing. Because of the thinness of split-thickness skin grafts, damage to the graft and curling are common with standard harvesting techniques. Adjunctive methods for harvesting split-thickness skin grafts have not been well elucidated in the literature. METHODS: Lubrication and a tongue depressor facilitate even harvesting of the split-thickness skin graft. A semipermeable membrane is applied to the split-thickness skin graft donor site before harvesting the skin graft. This aids with harvesting and minimizes trauma to the graft. CONCLUSION: Use of lubrication, a tongue depressor, and a semipermeable membrane are useful adjuncts to harvesting split-thickness skin grafts.