Search PubMed⌕ Search

Biomedical subjects

W L Morison

Publications and source records attributed to W L Morison.

At least 37 records · Page 2Linked to original sources
PubMed1995

Ultraviolet-induced suppression of the primary allergic reaction. Four times the minimal erythema dose of ultraviolet B administered 24 hours prior to sensitization.

The effect of localized irradiation with 4 times the minimal erythema dose (MED) of ultraviolet B (UVB) 24 h prior to sensitization with dinitrochlorobenzene (DNCB) was examined. In a placebo-controlled design, 9 of 19 subjects were locally irradiated on the right buttock; 24 h later, DNCB (1000 micrograms) was applied to the right buttock in all 19 subjects, and subjects were examined 7 and 14 days later for the development of a primary allergic response (PAR). In those not developing a PAR, a challenge dose of DNCB (50 micrograms) was applied to the volar forearm and examined 2 days later for an elicitation response. A statistically significant difference was seen in the number of subjects developing a PAR, comparing the group irradiated with UVB versus the group not irradiated (33% vs 80%). There was no statistically significant difference seen in elicitation responses between the 2 groups. We have shown that intense localized UVB irradiation as early as 24 h prior to sensitization with a potent allergen at this site may inhibit the PAR but does not appear to affect the elicitation response at a distant site.

Adolescent↗
PubMed1995

Prevention of UVB-induced immunosuppression in humans by a high sun protection factor sunscreen.

BACKGROUND AND DESIGN: To date, studies of the effectiveness of sunscreens in preventing UVB-induced suppression of contact hypersensitivity in humans have not been published. Several studies in mice of the protection afforded by sunscreens from UVB-induced suppression of contact hypersensitivity and rejection of transplanted skin cancers have yielded dissimilar results, ranging from "no" to "complete" protection. We sought to determine whether the effect of preapplication of a sun protection factor (SPF) 29 sunscreen (containing octyl methoxycinnamate, oxybenzone, and octyl salicylate) could prevent local UVB-induced suppression of contact hypersensitivity to dinitrochlorobenzene (DNCB). Nineteen subjects received either three minimal erythema doses of UVB daily on three consecutive days (UVB group) or sunscreen followed by this same dose of UVB irradiation (sunscreen plus UVB group) to a 16-cm2 area of the buttock. One day after completion of irradiation, DNCB was applied to this buttock site, and 2 weeks later, forearm challenge with four different concentrations of DNCB was performed. A control group of 10 subjects underwent DNCB testing as above, but with no prior exposure to UVB (no-UVB group). RESULTS: The UVB group had a reduced response rate to all challenge doses of DNCB (3.125, 6.25, and 8.8 micrograms), except for the highest dose (12.5 micrograms) compared with the no-UVB control group (Fisher's Exact test, P < or = .008), and compared with the sunscreen plus UVB group (P < or = .02). The no-UVB and sunscreen plus UVB groups showed no significant differences in response rates to any of the doses of DNCB tested (P > or = .53). CONCLUSIONS: These results indicate that application of a sunscreen with over ninefold greater protection than that needed to prevent erythema prior to localized UVB radiation prevents localized UVB-induced suppression of contact hypersensitivity. Further studies are needed to determine whether sunscreens providing less protection, yet still preventing erythema, adequately prevent suppression of contact hypersensitivity, a possible surrogate marker for skin cancer tumor antigen recognition and rejection.

Adult↗
PubMed1994

Chronic actinic dermatitis. An analysis of 51 patients evaluated in the United States and Japan.

BACKGROUND AND DESIGN: We studied the clinical and photobiologic features of 51 patients with chronic actinic dermatitis who were evaluated at three institutions. The following criteria for patient selection were used: (1) a persistent eczematous eruption in the sun-exposed areas of greater than 3 months' duration; (2) decreased phototest results; and (3) when available, histologic changes of a dermal infiltrate of lymphocytes and macrophages, with or without epidermal spongiosis and atypical mononuclear cells in the dermis and epidermis. RESULTS: The 51 patients had a mean age of 62.7 years, a male-to-female ratio of 2.6:1, and a mean duration of eruption of 5.8 years. The most common abnormal results of the phototests were decreased minimal erythema doses to both UV-A and UV-B, followed by decreased minimal erythema doses to UV-A alone. Patients with abnormally low responses to UV-A or visible light and normal minimal erythema doses to UV-B had the same clinical profile as the overall patient population. Aside from protection from sunlight, treatment modalities that have been used include PUVA (8-methoxypsoralen and UV-A) photochemotherapy, azathioprine, hydroxychloroquine sulfate, and, for recalcitrant cases, cyclosporine. CONCLUSIONS: Chronic actinic dermatitis is a persistent photodermatosis associated with abnormal phototest responses to UV-A, and/or UV-B, and/or increased sensitivity to visible light; histopathologic changes are consistent with photodermatitis. Treatment consists of combinations of topical and oral medications.

Chronic Disease↗
PubMed1994

Effects of psoralen plus UVA radiation (PUVA) on HIV-1 in human beings: a pilot study.

BACKGROUND: Laboratory data document the activation of the HIV-1 genome on exposure to UV radiation, including PUVA. The overall effects of UV radiation exposure on HIV-1 infection in human beings are unknown. OBJECTIVE: Our purpose was to observe CD4 cell counts and quantitative markers of HIV-1 load in late-stage HIV-1-infected human beings receiving PUVA for various cutaneous diseases. METHODS: Samples of peripheral blood were obtained on days 0, 14, 30, and 60 of PUVA administered in therapeutic doses. Number of CD4+ T lymphocytes was determined by flow cytometry, and HIV-1 load was measured by semiquantitative polymerase chain reaction for viral genome in peripheral blood mononuclear cells, semiquantitative RNA-polymerase chain reaction for HIV-1 RNA in serum, and determination of p24 in serum. RESULTS: No significant changes in the measurements were observed. CONCLUSION: This study did not detect a deleterious effect on CD4 cell count or HIV-1 load during 2 months of PUVA treatment for patients in late stages of infection, with low CD4 cell counts and high HIV-1 loads.

AIDS-Related Opportunistic Infections↗
PubMed1994

Photochemotherapy beyond psoriasis.

Photochemotherapy involves the therapeutic use of nonionizing radiation in combination with a photosensitizing chemical to trigger a photochemical reaction that mediates a beneficial effect. The successful introduction and widespread use of psoralen photochemotherapy (PUVA) in the management of psoriasis was the chief stimulus for recent interest in the therapeutic use of nonionizing radiation in various other dermatoses. This article discusses the expanding spectrum of diseases responding to PUVA therapy. More than 30 conditions such as atopic dermatitis, mycosis fungoides, vitiligo, the photodermatoses, chronic graft-versus-host disease, and granuloma annulare have been successfully treated with oral psoralen photochemotherapy. Various mechanisms of response to treatment are discussed including photoimmunologic effects, selective cytotoxicity, alterations of cell function, and stimulation of melanocytes. Finally, the limitations to the use of PUVA therapy are identified and its future use in other cutaneous and systemic diseases are discussed.

Humans↗
PubMed1992

Autografting and PUVA. A combination therapy for vitiligo.

A novel approach to the management of vitiligo is described using a combination of epidermal autografts transplanted into the depigmented areas and psoralen-ultraviolet-A (PUVA) therapy. Epidermal autografts can be obtained rapidly and in large numbers using a device that combines the synergistic effects of suction and heat on the skin. Subsequent exposure to PUVA therapy promotes spread of pigmentation out of the grafts resulting in even and complete pigmentation. In certain situations, the combination therapy appears to offer the potential for avoiding the disadvantages of both of the two treatments when they are used alone. This article presents our preliminary work in the development of the methodology for this combined approach.

Combined Modality Therapy↗
PubMed1991

PUVA therapy for chronic cutaneous graft-vs-host disease.

Chronic graft-vs-host disease (GVHD) is an immunologic disorder frequently occurring as a late sequelae of allogeneic bone marrow transplantation and characterized in the skin with lichenoid or sclerodermoid lesions. Systemic immunosuppressive agents such as corticosteroids or cyclosporine are usually required to control the disease. Therapy with psoralen and UVA (PUVA) has recently been shown to be effective for skin and oral mucosa in a few cases of GVHD. We present our experience with PUVA in six patients, five with lichenoid and one with sclerodermoid GVHD. None of these patients had significant systemic involvement. All five patients with lichenoid GVHD showed clinical improvement after PUVA therapy. Three of these patients had complete clearance of skin lesions. Clinical clearance of the disease was accompanied by microscopic clearance. The patient with sclerodermoid GVHD did not respond to therapy. No significant complications or exacerbation of systemic disease occurred. We confirm that PUVA is an effective and safe therapy for the cutaneous manifestations of lichenoid chronic GVHD. We postulate that PUVA therapy clears chronic lichenoid GVHD by selective cytotoxicity for the activated lymphoid cells in the inflammatory infiltrate.

Adolescent↗
PubMed1991

Disseminated hypopigmented keratoses.

We present two cases of asymptomatic, widespread keratotic eruptions in young female patients. Clinically, the lesions are well-demarcated, small, hypopigmented, flat-topped papules occurring on the trunk and extremities in a uniform distribution. Skin biopsy specimens from one patient revealed hyperorthokeratosis, papillomatosis, and a normal amount of melanin. We suggest that this is a newly recognized dermatologic entity that may be descriptively termed disseminated hypopigmented keratoses. Disseminated hypopigmented keratoses may be distinguished by clinical and histologic criteria from similar keratotic eruptions. Since the lesions of disseminated hypopigmented keratoses are both inconspicuous and asymptomatic, it is likely that the disorder is more prevalent than our two cases would suggest.

Adult↗
PubMed1990

Recent advances in phototherapy and photochemotherapy of skin disease.

The therapeutic spectrum for ultraviolet radiation treatment of skin disease has continued to be broadened. Psoralen photochemotherapy is beneficial in chronic lichenoid graft-versus-host disease and disseminated granuloma annulare. This treatment is now being found more useful in atopic eczema and chronic photosensitivity with some modifications of the therapy. UV phototherapy has also been found useful in mild to moderate atopic eczema. The nature of these treatments is also changing with greater use of selective UV phototherapy and definition of the required schedule for maintenance treatment with UVB phototherapy. The mechanism of therapeutic benefit remains unknown although one possibility is selective phototoxicity for inflammatory cells in the dermis. Nonmelanoma skin cancer, premature aging of the skin and freckling are the main long-term adverse effects of these treatments.

Humans↗
PubMed1990

Systemic suppression of contact hypersensitivity associated with suppressor lymphocytes: is a lesion in DNA an essential step in the pathway?

Exposure of mice to ultraviolet B (UVB) radiation and treatment with methoxsalen and UVA radiation produces a systemic suppression of contact hypersensitivity (CHS) that is associated with suppressor lymphocytes. Both UVB and methoxsalen and UVA radiation produce lesions in DNA, and this suggests that alterations in that molecule might be an essential step in the pathway. This possibility has been explored by testing the effect of other modalities that do and do not interact with DNA. Treatment of mice with superficial X radiation, which mainly produces single-strand breaks in DNA, or with 5-methylisopsoralen and UVA radiation, which produces monofunctional adducts in DNA, results in systemic suppression of CHS. In both instances, the suppression can be transferred to untreated mice by injection of lymphoid cells obtained from suppressed mice. Treatment of mice with rose bengal and visible (greater than 400 nm) radiation, a photochemical interaction that does not produce lesions in DNA, results in systemic suppression of CHS; however, in contrast to the other treatments, the suppression cannot be transferred with lymphoid cells. In addition, treatment of mice with eosin and visible radiation, which also does not interact with DNA, did not produce suppression of CHS. These findings suggest that a molecular alteration in DNA may be either an initiating or an essential step in the development of the systemic suppression of CHS that is mediated by suppressor lymphocytes.

Animals↗
PubMed1990

The photoaggravated dermatoses.

The photoaggravated dermatoses are diverse diseases adversely affected by sunlight or artificial ultraviolet (UV) exposure. The role of UVR is often well-recognized, as in lupus erythematosus (LE) and bullous pemphigoid (BP). Immunologic theories for the cause of the photosensitivity in lupus erythematosus are the production of UV-DNA antibodies with subsequent immune complex formation, a partial defect in DNA repair following UV exposure, and the release or stimulation of potent cutaneous immunologic mediators. However, mechanisms are still not fully elucidated. Photosensitivity has also been described in erythema multiforme, actinic lichen planus, viral exanthems, cutaneous T-cell lymphoma, eczema, and psoriasis. Treatment is restriction of light exposure, use of high protection sunscreens, and treatment of the underlying disorder.

Animals↗
PubMed1990

Photochemotherapy of generalized granuloma annulare.

Various forms of treatment for generalized granuloma annulare have been employed with little success. The results of treatment with topical and intralesional corticosteroids, as well as systemic therapy with corticosteroids, salicylates, aspirin, niacinamide, and chloroquine, have been generally disappointing. We describe five patients with generalized granuloma annulare of several years' duration who were treated with oral psoralen plus ultraviolet A irradiation. Lesions were present on the extremities, buttocks, and trunk in the form of macules, papules, and plaques. One patient also had perforating lesions on her thighs. Flattening of the lesions with decreased erythema and pigmentation was noted as early as 1 month after initiation of treatment. Complete clearance was achieved in all patients. Maintenance therapy has been required, resulting in prolonged disease-free intervals. Although the mechanism of action of oral psoralen plus ultraviolet A irradiation in granuloma annulare is unclear, one possibility is selective elimination of the cells that are responsible for initiating the disease.

Adult↗