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Biomedical subjects

F D Malkinson

Publications and source records attributed to F D Malkinson.

At least 37 records · Page 2Linked to original sources
PubMed1983

Pyoderma gangrenosum. Response to cyclophosphamide therapy.

A 46-year-old woman had a 17-year history of intermittently severe pyoderma gangrenosum without identifiable associated systemic disease. Her condition had become unresponsive to corticosteroid and sulfone therapy given for systemic effect, but responded completely to 150 mg/day of cyclophosphamide. Immunosuppressive therapy should be considered in patients with severe, recalcitrant pyoderma gangrenosum, even in the absence of associated systemic disease.

Adult↗
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↗
PubMed1980

Hydroxychloroquine treatment of porphyria cutanea tarda.

Six patients with skin changes and urinary porphyrin excretion patterns characteristic for porphyria cutanea tarda were treated with hydroxychloroquine sulfate therapy. During treatment periods ranging from five to 13 months, cutaneous symptoms disappeared and urinary porphyrin excretion abnormalities were completely or almost completely reversed. In three subjects, hydroxychloroquine therapy was accompanied by changes in the urinary excretion of iron. The first four patients, followed up for nine to 24 months after treatment, all had relapse, and substantial porphyrinuria developed once more; cutaneous symptoms recurred in two of these. Three of the four patients were re-treated, and their conditions again improved or went into remission with hydroxychloroquine therapy. In two patients, treatment responses were slower than those initially seen, despite the use of higher drug doses; in the third patient, the response to re-treatment was more rapid than that seen during the first treatment course.

Adult↗
PubMed1979

Effects of neutron radiation on mouse hair matrix cell populations.

We have investigated the effects of a single low dose of 42 rads neutron radiation on hair matrix cell kinetics. Anagen hair skin sites in 3-mo-old Carworth Farms no. 1 female mice were exposed to a fast neutron beam yielding a modal energy of 3.6 MeV. In contrast to low LET (linear energy transfer) radiation at a 2 1/2 fold higher dose, neutrons induced a markedly prolonged depression (greater than 60%) in the mitotic index for more than 18 hr postradiation. In addition, from 10--18 hr after neutron irradiation sharp elevations (greater than 80%) in the labeling indices apparently reflected significant impairment in cell maturation rates and/or slowed exit rates from the proliferative compartments. Postradiation reductions of up to 20% in the size of proliferating matrix cell populations were found. At the cellular level, this study confirms previous findings of a disproportionately high relative biological effectiveness for neutron radiation following low dose level exposure.

Animals↗
PubMed1977

Dapsone-induced peripheral neuropathy.

Peripheral neuropathy is a rare complication of dapsone therapy. This neuropathy appears primarily to be of the motor type, and recovery occurs on discontinuation of the drug therapy. The patient in this report developed a marked motor deficit as well as a selective marked loss of vibration sense shortly after the initiation of a relatively low dose of dapsone. Recovery was rapid on cessation of the therapy. This patient was found to be a slow acetylator of isoniazid, and therefore is probably a slow acetylator of dapsone. The possible mechanisms of the neurotoxicity of dapsone and the role of altered metabolism are discussed.

Acne Vulgaris↗
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↗
PubMed1976

Staphylococcal scalded skin syndrome in an adult and a child.

Two patients had staphylococcal scalded skin syndrome (SSSS) with typical clinical and histopathologic findings. In both cases, the disease was reproduced by injections of staphylococci into mice. The adult patient, who had no other physical or laboratory abnormalities, showed intact humoral and cellular immunity; her uneventful clinical course was clearly different from the eight previously reported cases in adults. To our knowledge, the child represents the first case report of SSSS as a result of infection by a non-group 2 Staphylococcus.

Adult↗