Hair regeneration from transected follicles in duplicative surgery: rate of success and cell populations involved.

BACKGROUND: The use of bisected hair follicles in hair transplantation has been previously reported, but the capacity of each half to regenerate the entire hair has not been clarified. OBJECTIVE: To evaluate duplicative surgery rate of success and to analyze the cell populations involved in hair regeneration. METHODS: We screened 28 patients undergoing duplicative surgery. Approximately 100 hair follicles from each patient were horizontally bisected and implanted. Upper and lower portions were stained for the known epithelial stem cell markers CD200, p63, beta1-integrin, CD34, and K19. RESULTS: Similar percentages of hair regrowth after 12 months were observed when implanting the upper (72.7 +/- 0.4%) and lower (69.2 +/- 1.1%) portions. Expression of CD200, p63, and beta1-integrin was detected in both portions, whereas K19 and CD34 stained different cell populations in the upper and lower fragment, respectively. CONCLUSION: Duplicative surgery might represent a successful alternative for hair transplantation, because both portions are capable of regenerating a healthy hair. Moreover, our results suggest the possible presence of stem cells in both halves of the follicle.

The legacy of Capt. Gino Pieri: a forgotten Italian contribution to the study of cutaneous blood supply during World War I.

Among the many scientists who studied the cutaneous blood supply, Gino Pieri, an Italian Army surgeon operating during World War I, deserves attention. During those times, amputations were frequent, and flaps used to cover stumps were often inadequately designed and became necrotic, because of poor knowledge of the skin's blood supply. Pieri solved the problem after drawing a perforator map of human body skin, injecting the main arteries with methylene blue dye. His flaps were mainly designed along the course of what Ian Taylor would call "source" arteries, to capture the greatest perforators.