Skin-reducing mastectomy.

BACKGROUND: The authors propose a combined flap technique to reconstruct large and medium-sized ptotic breasts in a single-stage operation by use of anatomical permanent implants. METHODS: The authors enrolled 28 patients fulfilling criteria for skin-sparing mastectomy and presenting with ptotic breasts whose areola-to-inframammary fold distance was more than 8 cm. All reconstructions were performed as a single-stage procedure. After preoperative planning, a large area in the lower half of the breast was deepithelialized according to the conventional Wise pattern. Mastectomy was then carried out. To perform reconstructions, the inferomedial fibers of the pectoralis major muscle were dissected and sutured to the superior border of the inferior dermal flap. An anatomical implant was then inserted into the pouch, which was closed laterally with the previously harvested serratus anterior fascia. Skin flaps were finally closed down to the inframammary fold. RESULTS: The authors performed 30 procedures on 28 patients. The medium size anatomical implants was 433 cc. Twelve women achieved symmetrization in a single stage ending in a symmetric inverted-T scar. The overall complication rate was 20 percent, with four cases (13 percent) complicated by severe, extensive necrosis of the skin flaps requiring implant removal. CONCLUSIONS: Breast cancer treatment must nowadays optimize cosmetic results. This can be accomplished in selected cases by means of a single-stage operation that the authors call "skin-reducing mastectomy." The final scars imitate those of cosmetic surgery. Careful patient selection and improvement in the learning curve may reduce the complication rate.

Presence of functional domains in Limulus polyphemus hemocyanin.

In an attempt to isolate structural domains of arthropod hemocyanins and possibly to investigate their functional properties, we have undertaken proteolytic digestion experiments of isolated subunits from Panulirus interruptus and Limulus polyphemus oxy-hemocyanin. Satisfactory results have been obtained using trypsin at high concentration and short digestion times. Results show that, in the case of Panulirus hemocyanin, only subunit alpha is susceptible to trypsin digestion, but that proteolytic cleavage is associated with the loss of the copper-oxygen band; on the other hand, in the case of Limulus hemocyanin, four subunits (I, II, III and IV) show a significant susceptibility to trypsin, and their fragmentation takes place with preservation of the oxygen-binding capacity. A more detailed study of the digestion products of subunit IV from Limulus hemocyanin reveals that the proteolytic fragments keep together in a single non-covalent complex. Attempts to separate the native fragments result in the precipitation of the digestion products. Subunit IV of Limulus with proteolytic cuts binds O2 and CO with the same affinity as the native subunit, suggesting that the copper site is still preserved structurally and is functionally active in a 37 kDa trypsin-resistant domain.