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Biomedical subjects

J T Keane

Publications and source records attributed to J T Keane.

6 recordsLinked to original sources
PubMed1984

Nalidixic acid-induced photosensitivity in mice: a model for pseudoporphyria.

Porphyria cutanea tarda (PCT)-like photosensitivity eruptions have occurred in patients treated with nalidixic acid, furosemide (Lasix), or tetracycline. An animal model for nalidixic acid photosensitivity was developed in young CF-1 female mice. The hair on the back was plucked from groups of animals that were injected i.p. each day with nalidixic acid or saline. The animals were exposed to black-lamp radiation for 12 h daily for 6 weeks, followed by a 2-week rest period, and then 4 more weeks of UV radiation exposure. The nalidixic acid-treated animals developed far greater gross and chronic inflammatory changes than the saline-treated animals; microscopically and ultrastructurally they showed blister formation beneath the basal lamina at the same level as that found in PCT. This model appears to be suitable for the study of PCT-like and other photosensitivity reactions.

Animals↗
PubMed1983

Progressive vaccinia associated with combined variable immunodeficiency.

Progressive vaccinia developed in a previously healthy woman following smallpox vaccination and was successfully treated with vaccinia immune human globulin and methisazone. Immunologic evaluation over the next 4 1/2 years revealed evidence for combined variable immunodeficiency with increased numbers of circulating OKT 8 positive (suppressor-cytotoxic T) cells and the virtual absence of OKT 4 positive (helper-inducer T) cells.

Female↗
PubMed1981

Radiobiology of the skin: review of some effects on epidermis and hair.

Significant doses of ionizing radiation produce an acute skin reaction characterized by erythema, epilation, and dry or moist desquamation with or without erosions. These early acute changes are dose-dependent and reflect damage to the germinative cells of the epidermis and to the cutaneous vasculature. Studies in the pig, for example, have shown that the degenerative phase of cell loss (2-3 weeks) results from reproductive failure in germinative cells and a sharp reduction in the proliferation rate of basal cell "survivors." D0 values for epidermal cells in different species generally range from 100-140 rads. Cell maturation and ascension rates in the suprabasilar layers are largely unaffected. A regenerative phase of cell replacement, characterized by sharply increased cell replication rates, occurs from the 3rd to 5th postradiation weeks. The postregenerative phase of hyperplasia reflects a temporary overshoot of cell density above control levels; a subsequent decrease in hyperplasia indicates feedback control of cellular proliferation. Postradiation changes in the highly proliferative anagen hair matrix cell populations result in hair dysplasia, slowed growth rates, impaired metabolic processes, and alopecia. Dosages of 700-800 rads or more induce some degree of permanent hair loss. G0 telogen matrix cells are 2-3 times more radioresistant than proliferating anagen matrix cells, but may "store" radiation damage for prolonged periods. Altered matrix cell uptake of amino acids, the incidence of dysplasia, and the degree of alopecia occurring after irradiation have all been used as quantitative biological end-points for the general study of cellular radiation effects, as well as studies on the enhancement of or protection against radiation damage provided by certain pharmacologic or physical agents.

Alopecia↗
PubMed1976

Herpesvirus hominis hepatitis and disseminated intravascular coagulation. Occurrence in an adult with pemphigus vulgaris.

Herpesvirus hominis (HVH) hepatitis, a rarely recognized manifestation of HVH infection in adults, occurred in a 36-year-old woman who had received prednisone therapy for pemphigus vulgaris continuously for seven years. After an acute terminal illness that was characterized by fulminant hepatic failure and disseminated intravascular coagulation (DIC), postmortem examination disclosed massive hepatic necrosis. Herpesvirus hominis (type 1) was isolated from the liver. The association of disseminated HVH infection with impaired immunologic defenses, as well as the occurrence of DIC in association with acute hepatic failure, are discussed. Greater awareness of the clinical manifestations of HVH hepatitis should lead to early diagnosis, although sucessful modes of therapy await development.

Adolescent↗