Search PubMed⌕ Search

Biomedical subjects

T F Downham

Publications and source records attributed to T F Downham.

At least 19 recordsLinked to original sources
PubMed1998

The shadow rule: a simple method for sun protection.

The intensity of ultraviolet radiation (UVR) from the sun is directly related to the angle of the sun or altitude above the horizon. Solar altitude at any given clock time varies with season and latitude-longitude. The shadow rule indirectly determines the sun's altitude by observing the length of a person's shadow during the time course of a day. When the shadow on a horizontal surface in the sun is equal in length to height of the person casting the shadow, then the altitude of the sun above the horizon is 45 degrees. The tangent of 45 degrees altitude (tan alt) equals 1 or the ratio of the height of the person casting a shadow (y) to the length of the person's shadow (x). In middle latitudes, the intensity of UVR is approximately inversely proportional to the length of the person's shadow. Thus, when a person's shadow is shorter than the person is tall, the intensity of UVR from the sun is more likely to cause sunburn.

Altitude↗
PubMed1986

Chronic leg ulcers and Klinefelter's syndrome.

Venous and arterial leg ulcers have been reported in patients with Klinefelter's syndrome. We report a case of Klinefelter's syndrome associated with chronic leg and foot ulcers and thrombophlebitis. Both venous and arterial vascular disease seems to be associated with Klinefelter's syndrome and should be considered in men presenting with chronic leg and foot ulcers.

Adult↗
PubMed1981

Erythema multiforme associated with Rhus contact dermatitis.

A case of erythema multiforme and Rhus contact dermatitis is presented herein. Due to the association of nephritis and other complications with Rhus poison oak, we recommend that patients with contact dermatitis due to poison ivy who incur secondary erythema multiforme be hospitalized and closely monitored.

Dermatitis, Toxicodendron↗
PubMed1980

Contact dermatitis to photographic print coating liquid.

A case of allergic contact dermititis secondary to photographic print coating liquid is described herein. Patch test reactions to the mixture were positive, but negative to the individual components which included dimethylhydantoin formaldehyde resin, the logical allergen. Formaldehyde resin allergic dermatitis, in some instances, may not be reproduced by patch testing because of various contributing factors. In this patient, the combination of components was necessary to yield a sensitivity reaction. To the best of our knowledge contact dermatitis secondary to this product has not been previously reported.

Adult↗
PubMed1979

Parapsoriasis with hyper-IgE.

A 56-year-old black man had generalized chronic dermatitis for two years before parapsoriasis en plaque (large type) with hyper-IgE (12,000-22,000 ng/ml) was diagnosed. Lymphocyte cultures showed decreased response to mitogens. Direct immunofluorescence of involved skin showed epidermal and dermal mast cells with bound IgE. Parapsoriasis with hyper-IgE may represent a form of "hypersensitive immunosurveillance" allowing a patient to reject a clone of malignant cells and retard transformation from a benign state (parapsoriasis) to a malignant state (mycosis fungoides).

Fluorescent Antibody Technique↗
PubMed1979

Ultrastructural and cell surface changes of human psoriatic skin following Goeckerman therapy.

Ultrastructural and cell surface studies of skin in psoriatic patients prior to and after Goeckerman therapy (crude coal tar and UVB-light) have demonstrated significant cellular changes following this treatment: hyperactivity of melanocytes with melanosome polymorphism, increase of desmosomes, tonofilaments, keratohyaline granules, a decrease in mitochondria, keratinosomes, polysomes, dark cells and a reduction in size of nuclei and nucleoli. The enlargement of intercellular spaces and the redundancy of basement membrane were also reduced. Langerhans cells were moderately decreased and exhibited a normal ultrastructural pattern. No significant changes in cutaneous nerve distribution or morphology were observed in these cases. Scanning electron microscopy following treatment revealed a regular surface and orientation of corneocytes, with flattened surfaces; and a reduction of their ridges on the surfaces, as well as of the intercellular spaces and red blood cells. These findings indicate that Goeckerman therapy restored the ultrastructural and cell surface pattern in the psoriatic skin by inducing orthokeratinogenesis, development of the tonofibrillar-desmosome system, and decrease in mitochondria, nuclei and nucleoli.

Coal Tar↗
PubMed1978

Bullous pemphigoid:therapy in patients with and without diabetes mellitus.

Retrospective analysis of 34 patients with bullous pemphigoid (BP) showed 24 (70.6%) with widespread disease and 10 (29.4%) with localized disease. Initial prednisone therapy was significantly lower for patients with localized BP, mean dose of 38 mg vs 58 mg, compared with widespread disease. Fifteen of 24 (62%) patients responded; however, 9 (38%) failed to respond to moderate-dose prednisone therapy and ultimately required daily doses of 100 mg or more and/or an immunosuppressive agent. Adult-onset diabetes mellitus was present in 14 of 34 (41%) patients. Initial prednisone dose for diabetic patients with widespread BP was significantly greater, 70 mg vs 54 mg, compared with nondiabetic patients. Addition of methotrexate, 2.5 to 15 mg, every other day or twice-weekly oral administration, was effective when moderate-dose prednisone therapy failed. It is possible that insulin-dependent diabetic patients with BP should be preferentially started on immunosuppressive drugs.

Adult↗
PubMed1978

Auricular calcification.

Auricular calcification in two patients was discovered by palpation and x-ray of the pinnae of the ears. In one patient auricular calcification was locally secondary to chronic inflammation, while in the other patient systemically secondary to adrenal insufficiency, a systemic factor.

Adrenal Insufficiency↗
PubMed1978

Unusual fungal infections associated with immunologic hyporeactivity.

Two patients had unusual fungal infections, considered to be contaminants, which suggested immunologic hyporeactivity. One patient with a Fusarium infection had an associated occult malignancy. The other patient had an initial localized, then disseminated Curvularia infection. Both patients, following analysis of subpopulations of lymphocytes, showed evidence of relative T and B cell defects.

Adult↗
PubMed1978

Oral squamous-cell carcinoma within a white-sponge nevus.

A 59-year-old woman had thick plaques of leukoplakia on the tongue bilaterally. The condition was initially diagnosed by biopsy as a white-sponge nevus. A second biopsy of a suspicious area on the right side showed squamous-cell carcinoma two years later. It is speculated that prednisone therapy for steroid-dependent intrinsic asthma may have caused a loss of "immunologic surveillance," which permitted development of malignancy in a previously benign condition.

Carcinoma, Squamous Cell↗
PubMed1978

Coexistent bullous pemphigoid and systemic lupus erythematosus.

A case of coexistent bullous pemphigoid and systemic lupus erythematosus is reported. Evidence for an immunologic pathogenesis is reviewed for both disorders. It is suggested that the coexistence of bullous pemphigoid and systemic lupus erythematosus may represent a similar pathomechanism.

Adult↗