3,4-Epoxy-1-butene, a reactive metabolite of 1,3-butadiene, induces somatic mutations in Xpc-null mice

Xpc-null (Xpc-/-) mice, deficient in the global genome repair subpathway of nucleotide excision repair (NER-GGR), were exposed by intraperitoneal (i.p.) injection to a 300 mg/kg mutagenic dose of 3,4-epoxy-1-butene (EB), to investigate NER's potential role in repairing butadiene (BD) epoxide DNA lesions. Mutagenic sensitivity was assessed using the Hprt assay. Xpc-/- mice were significantly more sensitive to EB exposure, exhibiting an average 2.8-fold increase in Hprt mutant frequency (MF) relative to those of exposed Xpc+/+ (wild-type) mice. As a positive control for NER-GGR, additional mice were exposed by i.p. injection to a 150 mg/kg mutagenic dose of benzo[a]pyrene (B[a]P). The Xpc-/- mice had MFs 2.9-fold higher than those of exposed Xpc+/+ mice. These results suggest that NER-GGR plays a role in recognizing and repairing some of the DNA adducts formed following in vivo exposure to EB. Additional research is needed to examine the response of Xpc-/- mice, as well as other NER-deficient strains, to inhaled BD. Furthermore, it is likely that alternative DNA repair pathways also are involved in restoring genomic integrity compromised by BD-epoxide DNA damage. Collaborative studies are currently underway to address these critical issues.

Giant adenoid basal cell carcinoma

The giant adenoid basal cell carcinoma is an unusual skin tumor that has aggressive biological behavior and has been reported to exhibit geometric growth, deep invasion, and metastasis. A case of giant adenoid basal cell carcinoma is presented, with recommendations for diagnosis and treatment.

Plexiform fibrohistiocytic tumor of skin

The plexiform fibrohistiocytic tumor is a recently described skin tumor that has unpredictable biological behavior and occurs primarily in children and young adults. The tumor exhibits a high recurrence rate and the potential for regional metastasis. In this article, I report a patient with plexiform fibrohistiocytic tumor and discuss treatment implications.

Reconstruction of facial contour deformity with the buccal fat pad flap

The primary goal in unilateral facial reconstruction is to mirror, with three-dimensional or volume symmetry considerations, the contralateral normal structures in form and function. This case study indicates that, along with other proved options, the buccal fat pad can successfully be used to add small to moderate volume in facial reconstructions.

Adiposis dolorosa (Dercum's disease): liposuction as an effective form of treatment

The clinical picture of adiposis dolorosa makes a lasting impression on the examining physician. The patient is typically an obese, asthenic woman who appears to have a low pain threshold. She has an unusual distribution of fatty tumors, and her complaint of pain in these tumors seems out of proportion to the physical findings. Alcoholism, emotional instability, and depression are common, and narcotic pain medicine is frequently requested. The patient is easily dismissed as a malingerer after a brief examination. However, liposuctioning of the painful fatty tumors appears to be both practical and effective. While adiposis dolorosa is an unusual disease, it is one that plastic surgeons can recognize and treat.