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Craig W. Senders, MD, and associates present a landmark article that modifies the current concepts of upper-lip development. They studied upper-lip development in 20 primate embryos and 2 primate fetuses with scanning electron microscopy to determine the contribution of specific prominences to the upper lip and nose. The maxillary and medial nasal prominences form the upper lip while the lateral nasal, medial nasal, and maxillary prominences form the nose. The maxillary prominence fuses with the medial nasal prominence. This fusion has not been previously described and the resulting modified theory of upper-lip development is termed by the authors the dynamic fusion theory. The dynamic fusion theory of prominence movement observes the interaction between epithelial layers, which must fuse properly to avoid cleft lip deformities.
Matthew M. Hanasono, MD, R. James Koch, MD, MS, and colleagues studied one of the most important problems in facial plastic surgery—the regulation of scar healing. Fetal wounds heal without evidence of scarring, whereas the problems associated with hypertrophic and keloidal scarring are well known. With their serum-free cell culture model, these investigators measured levels of transforming growth factor β1 (TGF-β1) and basic fibroblast growth factor in fibroblasts from various scars. Both fetal and keloid fibroblasts produce significantly greater TGF-β1 than normal adult fibroblasts. This type of quantitative measurement of autocrine growth factors may, in the future, allow better prevention and treatment of undesirable scarring.
Steven Ross Mobley, MD, Richard E. Davis, MD, and associates investigated tissue concentrations of the endogenous vasoactive peptide endothelin 1 (ET-1) in random-pattern skin flaps (RPSF) treated with either the topical anti-ischemic drug nifedipine or a placebo. Random-pattern skin flaps remain an important reconstructive tool for cutaneous defects, and despite improved techniques, flap failures remain a complication. The authors found that ET-1 levels in the distal necrotic flap segments were increased compared with ET-1 levels in normal tissue, and that animals treated with nifedipine had decreased ET-1 levels compared with controls. Their data both confirm the role of ET-1 in flap necrosis and show a potential method of pharmacologic control using nifedipine. Endogenous vasoactive peptide ET-1 may be a mediator involved in skin flap ischemia, and topical nifedipine may serve to decrease tissue levels of this potent vasoconstrictor.
Babak Azizzadeh, MD, Keith E. Blackwell, MD, and associates studied the effects of inhibitors of nitric acid (NO) on the rate of microvascular thrombosis in an animal model. A free flap failure, in most cases initiated by platelet-mediated events, results in thrombosis at the microvascular anastomosis, and the incidence of free flap failure reaches 5% to 9%. Nitric acid plays a critical role by inhibiting platelet adhesion and aggregation. In this study the rate of microvascular thrombosis in animals exposed to an NO inhibitor (L-NAME) was significantly higher, at 76.9%, than that observed in the control animals, which was 46.9% (P<.05). The use of L-arginine, an NO precursor, did not change the thrombotic rate. The results of this study may have applications in human microvascular surgery.
Charles Rennie Mackintosh (1868-1928). Glasgow School of Art, main entrance.Article
Highlights of Archives of Facial Plastic Surgery. Arch Facial Plast Surg. 2003;5(1):6. doi:10.1001/archfaci.5.1.6