Transdermal delivery of salicylic acid in the treatment of viral papillomas.

Healthy adult (New Zealand, Dutch Belt, and Wild) rabbits were infected with rabbit papilloma virus (Shope variety). The resultant papillomas were treated with salicylic acid in a new transdermal drug delivery system utilizing a karaya gum glycol matrix. Biopsy samples of treated papillomas were taken at 1, 2, and 3 weeks after initiation of treatment and examined by electron microscopy. The observed changes during the course of treatment indicated that the karaya gum glycol matrix effectively released salicylic acid into the stratum corneum. Further, the rate of delivery of salicylic acid was such that the desired keratolytic activity was achieved with minimal inflammatory response.

Pigmentation of open comedones. An ultrastructural study.

Ultrastructural examination of expressed "black" open comedones did not disclose any single melanosomes or melanosome complexes. If there is any melanin present in comedonal plugs, the amount is minimal, and it cannot be the source of the black color.

Elastic tissue changes in skin following PUVA therapy.

Treatment of psoriasis with psoralens and high-intensity long-wave ultraviolet light (PUVA) produces changes in the ultrastructure of elastic tissue in skin. Early alterations consist of a loss of elastin followed by a breakdown of the microfibrils and subsequent fragmentation of the elastic fiber. Tissue examined 15 months after treatment was stopped still showed marked ultrastructural changes in the elastic fibers.

Melanocyte changes following PUVA therapy.

The effect of psoralens and long-wave ultraviolet light (PUVA) therapy on human melanocytes was studied at the ultrastructural level. The results demonstrate an increase in the number of melanocytes, a change in their location, and an increase in the size of the melanosomes. Significantly, some of the melanocytes extend in narrow columns deep into the dermis, limited by the basal lamina, while others are found free within the dermis. Other morphologic alterations in the melanocytes consist of abnormal mitochondria, a swollen and distorted endoplasmic reticulum, and large lysosomes. The aforementioned abnormalities were also present in PUVA-treated skin that was examined 15 months after the treatment had been stopped.

Netherton's syndrome: an electronmicroscopic study.

An ultrastructural study of 2 patients with Netherton's syndrome (bamboo hair, scaling dermatosis, and an atopic diathesis) showed features of psoriasis and a dermatitis. Although the biopsies from the patients showed histological and ultrastructural similarities, the clinical presentations were different. One patient had ichthyosis linearis circumflexa, while the other had a generalized ichthyosiform eruption. The ultrastructural findings in the 2 patients, while not specific, may help distinguish the eruption of Netherton's syndrome from other scaling dermatoses.

Keratinosomes in psoriatic skin.

Keratinosomes in psoriatic skin can be slightly larger than those in normal skin. Some seem to develop an unusual internal morphology, and some reach their full development while they are still within the immediate Golgi area. Observational evidence indicates that there may be more kerantinosomes in psoriatic skin than are generally found in normal skin. Keratinosomes appear extracellularly from the spinous layer through the horny layer. Some keratinosomes do not move to the outside of the cell and can be seen within cells of the horny layer. There appears to be an increased number of keratinosomes in and between the outer cells of sweat ducts. Keratinosomes are also present within the dark cells of the duct and the extracellular space between the dark cells contains material from keratinosomes.