Biomedical subjects

P Don

Publications and source records attributed to P Don.

5 recordsLinked to original sources

PubMed1998

Cutaneous cryptococcosis mimicking basal cell carcinoma in a patient with AIDS.

BACKGROUND: Cryptococcosis is an opportunistic infection caused by the encapsulated yeast Cryptococcus neoformans. This ubiquitous organism has emerged as a frequent finding in immunosuppressed patients, especially those with underlying malignancies, organ transplants, and the acquired immune deficiency syndrome (AIDS). Cutaneous manifestations of cryptococcosis occur in 10 to 15% of patients having systemic involvement. These skin lesions may simulate a variety of different disease entities. METHODS: A case of crytococcosis mimicking a basal cell carcinoma is the subject of a case report presentation. RESULTS: A case of cutaneous cryptococcosis mimicking basal cell carcinoma occurred in a patient with AIDS, who did not appear to have dissemination, but was treated aggressively to stem possible occult systemic disease. CONCLUSION: Cutaneous crytococcosis may mimic other dermatologic disorders.

AIDS-Related Opportunistic Infections↗

PubMed1994

Cutaneous protothecosis and AIDS.

Cutaneous protothecosis is an uncommon algal infection with a varied clinical presentation that occurs mainly in immunocompromised patients. We describe a 33-year-old Hispanic woman with AIDS who had a verrucous plaque on the dorsum of her hand. A biopsy specimen revealed organisms suggestive of Prototheca. Culture confirmed the organism to be Prototheca wickerhamii. To our knowledge, this is the first case of cutaneous protothecosis reported in a patient with AIDS.

Acquired Immunodeficiency Syndrome↗

PubMed1993

Cutaneous reactions to vitamin K1 injections.

Cutaneous reactions to vitamin K1 injections are reported infrequently. Most previously reported cases have been associated with liver disease, primarily alcoholic cirrhosis and viral hepatitis. Four new cases are reported. One patient had polycythemia vera and the Budd-Chiari syndrome, the second such report in the literature. The other three patients had no known hepatic disease. The reactions consisted of erythematous plaques at the injection site without progression to sclerodermatous plaques. Histopathologic examination in three cases showed spongiotic changes and mononuclear infiltrates typical of cutaneous reactions to vitamin K1. In one instance a neutrophilic infiltrate was associated with the reaction site. Our findings support the observation that liver disease is not a necessary condition for the occurrence of vitamin K1 hypersensitivity.

Adult↗

PubMed1984

Culture of normal adult human melanocytes.

Melanocytes isolated from normal adult human skin were cultured in vitro. Separation of the epidermis from the dermis by trypsin flotation proved better than collagenase treatment for providing viable cultures of melanocytes with a minimum of fibroblast contamination. Centrifugation on a discontinuous, rather than a continuous Percoll gradient, was more efficient in separating the epidermal cell types. Most of the melanocytes were usually found in one particular layer, and most of the viable keratinocytes were in the sediment. None of the layers produced a uniformly high percentage of melanocytes on routine culture, but enriched melanocyte cultures could be obtained by seeding the epidermal cells in magnesium- and calcium-free medium for 24 to 48 hours, and then transferring them to fibroblast-conditioned medium containing horse serum and polyamines. Melanocytes were identified by their dendritic morphology, ultrastructure, reaction to cholera toxin and pigment production after treatment with melanocyte stimulating hormone. Pure cultures of melanocytes have been cultivated by this method for more than 43 weeks (ten passages).

Adult↗

PubMedDate not supplied

A classification of human urothelial cells propagated in vitro.

Human urothelial cell lines of non-malignant and malignant origin were classified into three grades of transformation, i.e. TGr I, TGr II, and TGr III, which differ from primary and early cultures of normal bladder mucosa (TGr 0) by growth in the absence of fibroblasts, prolonged survival, increasing chromosomal abnormalities, and antigenic modifications. Non-malignant pure epithelial cell lines with a prolonged, but finite life span (18-38 passager in vitro) were classified as TGr I. These cells were characterized by chromosomal counts showing a considerable variation but with a near-diploid mode and a smaller size but otherwise normal morphology. TGr II cells differed from TGr I by infinite growth transformation and wide morphological variability. TGr III cells were above all characterized by their ability to produce tumors in nude mice and to invade and destroy fragments of embryonic heart in vitro. These immortalized cells were small with a large nucleus and a uniform polygonal shape. Chromosomal counts showed pronounced aneuploidy with an increased number of chromosomes.

Aged↗