Mucormycosis and cutaneous histoplasmosis in a renal transplant recipient.

Mucormycosis of the palate developed in a 31-year-old man while he was undergoing immunosuppression with prednisone and azathioprine after renal transplantation. The infection was excised and did not recur. Ten years later, while still receiving immunosuppressive therapy, cutaneous histoplasmosis of the fingers developed, which was treated successfully with intravenous amphotericin B. The occurrence of mucormycosis and histoplasmosis in this man emphasizes the need to suspect uncommon infections when unusual skin lesions occur in an immunosuppressed patient.

Effects of detergents on proliferation and metabolism of human keratinocytes.

Effects of low concentrations of detergents on cultured human foreskin keratinocytes were assessed in vitro. The viability and activity of keratinocytes were assessed by measuring reduction of a tetrazolium dye as an indicator of mitochondrial metabolism. The keratinocyte proliferative responses after incubation with detergents were assessed by a spectrophotometric assay employing crystal violet dye and a fluorometric assay determining total DNA content. Both the cationic detergent cetyltrimethylammonium bromide [CTAB] and the anionic detergent sodium lauryl sulfate [SLS] showed toxic effects on keratinocytes at concentrations as low as 3 micrograms/mg, but SLS was less toxic. However, both SLS and CTAB activated keratinocytes at very low concentrations. Proliferative activity and mitochondrial metabolism increased. Serum partially protected keratinocytes against toxic and stimulatory activities of both detergents. We suggest that detergents may directly damage keratinocytes and thereby produce irritant contact dermatitis, but activation of keratinocytes by low concentrations may also produce dermatitis, perhaps by causing keratinocytes to release cytokines.

Hereditary mucoepithelial dysplasia. Case report and review of the literature.

Hereditary mucoepithelial dysplasia, a dyshesive, dyskeratotic epithelial syndrome caused by an abnormality in desmosomes and gap junctions, involves the mucosae, skin, hair, eyes, and lungs. A 16-year-old patient had nontender, fire-red mucosae; keratosis pilaris; diffuse, nonscarring alopecia; cataracts; photophobia; corneal vascularization; and decreased visual acuity. Histologic examination of gingival sections showed a dyshesive epithelium with atrophy, dyskeratosis, lack of keratinization, and unusual cytoplasmic inclusions. Results of electron microscopic studies showed a reduced number of desmosomes, amorphous intercellular material, and cytoplasmic inclusions resembling tonofilaments and gap junction material. The patient described in this report represents an apparently sporadic case of hereditary mucoepithelial dysplasia. Other cases described previously in the literature are reviewed. We believe this disorder should be brought to the attention of dermatologists because patients with hereditary mucoepithelial dysplasia have numerous skin problems and are susceptible to recurrent infection and potentially fatal bullous lung disease. Also, misinterpreted abnormal results from cervical Pap smears could lead to hysterectomy being performed unnecessarily on these patients.

Computerized microassay of keratinocyte cell-plastic attachment and proliferation for assessing net stimulatory, inhibitory and toxic effects of compounds on nonimmortalized cell lines.

Testing of pharmacological agents that affect growth of epidermal keratinocytes (EK) requires a standardized assay. We have developed an assay measuring net effects of stimulatory (e.g. growth factors), inhibitory (e.g. methotrexate) or toxic (e.g. Triton X-100) compounds. The amount of crystal violet staining viable EK attached to the wells of standard 96-well microplates is measured in situ using an ELISA plate reader. Optical density readings are directly converted into cell counts by computer software. Counts obtained by this method strongly correlate with the results obtained using the [3H]thymidine uptake assay and direct cell counts. The assay standardizes measurements of nonimmortalized EK lines with different innate proliferative properties and allows accurate quantitation of EK numbers in the range of 2,500-500,000 EK/well.