Faculty Bibliography

Osteoma cutis is the aberrant development of bone within the skin. The bone formation may be de novo (primary) or result from an injury to the skin (secondary). Here we present a healthy 53-year-old man with no known abnormalities in calcium or phosphate metabolism with plate-like osteoma cutis of the scalp. Plate- or plaque-like osteoma cutis was initially described as a congenital condition but has now been reported several times in the literature as an idiopathic process that occurs in adults. Treatment options are limited and are only required if the lesion is bothersome to the patient.

A 42-year-old woman presented with a 2-year history of persistent, gray-white lip discoloration and discomfort that had not improved after empiric treatment with topical 5-fluorouracil cream. Histopathologic examination demonstrated interface dermatitis with epidermal atrophy. A diagnosis of oral lichen planus was made based on clinicopathologic correlation, and treatment with topical tacrolimus ointment was initiated

Environmental signals, such as growth factors and cytokines, modulate the activity of nuclear transcription factors, thus regulating gene expression. This regulation is of particular importance in skin where a large variety of signals, especially in activated keratinocytes associated with disease states or wound healing, stimulate new gene expression in keratinocytes. In this study, we used electrophoretic mobility-shift assays (EMSA) to define the changes in DNA binding activity of transcription factors in such activated keratinocytes. Normal human epidermal keratinocytes were grown in a serum-free medium and treated with 10% fetal calf serum, EGF, TNF? or Oncostatin M (OsM) for different periods of time. Wholecell extracts, without purification of the nuclei, were prepared and combined with a series of 32-P-labeled synthetic oligonucleotide probes containing consensus binding sequences for the transcription factors AP1, NF?B, C/EBP?, and Sp1. Serum activates all four transcription factors in keratinocytes; TNF? activates AP1, NF?B and C/EBP?, but not Sp1, whereas EGF activates AP1 and NF?B, but not C/EBP? or Sp1. On the other hand, OsM specifically activates Sp1. The activation of transcription factors is transient, usually reaching a peak 20 to 60 minutes after stimulation and returning to the basal level after two hours. We conclude that different signaling pathways are activated in response to various extracellular signals. This orchestrates the activity of transcription factors on the promoters of regulated genes in epidermis thus determining the levels of gene expression