Biomedical Frontiers: Fall 1996, Vol.4, No.1
Additional Work in Dermatology

A 20-year population study of individuals with porphyrin metabolism disorders is yielding insights into the mechanisms and genetics of these diseases. Porphyrin metabolism disorders result from inherited or acquired deficiencies in the activities of various enzymes in the heme biosynthetic pathway. (Porphyrins are pigments, which include heme and bile.) CPMC is one of the few centers in this country studying and treating the diseases, says Dr. Maureen B. Poh-Fitzpatrick, P&S professor of dermatology at St. Luke's-Roosevelt Hospital Center.

Dr. Poh-Fitzpatrick is particularly interested in erythropoietic protoporphyria, a disorder that begins in childhood and is characterized by cutaneous photosensitivity of the immediate type and dysfunction of the bone marrow and hepato-biliary systems. In individuals with this condition, protoporphyrin--which is a photo-excitable chemical--builds up in the skin, causing oxidative damage when the skin is exposed to sunlight.

In addition to the population study, Dr. Poh-Fitzpatrick is searching for the genetic mutations behind the disorders. So far, many of the known mutations have been identified by her lab.

Dr. Vincent A. DeLeo is studying the effect of short- and long-wave ultraviolet (UV) radiation on signal transduction in cells. "Our work has looked at what UV radiation can do to phospholipases, protein kinases, and epidermal growth factor," says Dr. DeLeo, associate professor and vice chair of dermatology at P&S and director of the dermatology service at St. Luke's-Roosevelt. Dr. DeLeo was also instrumental in developing an assay that reduces the need to test the skin irritation potential of certain consumer products on animals.