Injection of illicit drugs into the granulation tissue of chronic ulcers.

Chronic skin ulcers are rare among healthy young adults. Local injection of cocaine and heroin has been identified as a cause of chronic skin ulcers in young adults abusing intravenous drugs. These patients use both engorged veins surrounding the ulcers and the granulation tissue itself for the injection of drugs. We believe that chronic skin ulcers in young adults should be a marker for intravenous drug abuse, and should be considered in the differential diagnosis of nonhealing wounds.

Transfer of melanosomes in a skin equivalent model in vitro.

The transfer of pigment granules from melanocytes to keratinocytes was studied using a new living skin equivalent (SE) model in vitro. The model was constructed by plating human neonatal melanocytes onto a dermal equivalent (DE) before it was overgrown with keratinocytes. The dermal component of the SE arises in vitro through the action of fibroblasts, which compact matrix proteins into a tissue. It becomes keratinized as keratinocytes migrate out of 2-mm punch biopsies of human neonatal skin embedded in the DE; keratinocytes from the biopsies covered the lattice in 14 days. A basal lamina develops at the dermal-epidermal junction in vitro. Exposure of some SEs to UVB irradiation for 14 days stimulated and enhanced pigment transfer. Pigment transfer from melanocytes to keratinocytes was documented in light and electron microscopic studies. Melanosomes, identified by their pigment as well as by dopa oxidase staining, were dispersed throughout the keratinocyte cytoplasm. We conclude that the SE model is valuable for studying the relationship between melanocytes and keratinocytes in vitro; since the SE has been shown to serve as a skin replacement, pigmenting it may be expected to increase its usefulness.

Systemic mastocytosis with extensive large cutaneous mastocytomas: surgical management.

A case of systemic mastocytosis is reported with an observation period of 20 years. During these two decades multiple manifestations of the disease appeared including urticaria pigmentosis, episodic histamine release, gastro-intestinal involvement and hepatosplenomegaly. The most extraordinary, and possibly unique phenomenon, has been the development of a massive proliferation of large mastocytomas mainly, but not exclusively, limited to the lower extremities. For different reasons (mechanical disability, bleeding, cosmesis), these tumors have required repeated admissions for surgical removal. The most successful technique has involved use of the ultrasonic scalpel.

The use of antihistamine to retard the growth of fibroblasts derived from human skin, scar, and keloid.

Sixty percent of the fibroblast strains derived from normal skin, scar, and keloid reached elevated growth plateaus when cultured in the presence of histamine. A pharmacologic level of the antihistamine diphenhydramine hydrochloride was able to suppress the stimulation in all the keloid strains that were histamine-sensitive.