Use of the argon-pumped tunable dye laser for port-wine stains in children.

The authors reported previously a new technique using a low power argon-pumped tunable dye laser at a wave-length of 577nm (yellow light) to treat port-wine stains in adults. The authors report their results using this same technique as a form of treatment for 92 children with facial port-wine stains.

A superior method of tattoo removal using the Q-switched ruby laser.

The Q-switched ruby laser was used to treat 101 amateur and 62 professional tattoos in 80 patients over a period of 22 months. Using a 5- to 8-mm spot size and energy fluences of 2-4 joules/cm2, an average of three retreatments resulted in complete pigment removal in four, nearly complete pigment removal in 84, significant pigment removal in 11, and minimal pigment removal in two amateur tattoos. Using identical parameters for professional tattoos, there was complete pigment removal in two, nearly complete pigment removal in five, significant pigment removal in 18, minimal pigment removal in 25, and very little pigment removal in 12. Professional tattoos with red, yellow, and green pigments faded, but required multiple retreatments. While transient hypopigmentation occurred in many patients, skin texture and hair growth returned to normal in all cases and no hypertrophic scarring was seen.

Argon-pumped tunable dye laser therapy for facial port-wine stain hemangiomas in adults--a new technique using small spot size and minimal power.

A low power, argon-pumped tunable dye laser was used to deliver yellow light of 577 nm. Individual blood vessels within port-wine stain hemangiomas were treated with a 0.1-mm beam of light using 8 X magnification. This technique permits excellent resolution of facial and nuchal port-wine stain hemangiomas in adults without the adverse complications of textural change, permanent pigmentation abnormality, or hypertrophic scarring.

Ultrastructural changes in epidermal Langerhans cells and melanocytes in response to ultraviolet irradiation, in Australians of Aboriginal and Celtic descent.

The effects of exposure to small doses of artificial ultraviolet radiation (UVR) on the ultrastructure of epidermal Langerhans cells (LC) and melanocytes were studied in two groups of Australian subjects, one of Aboriginal and the other of Celtic descent. UV exposure induced an apparent depletion of LC in the epidermis of both groups. However, LC depletion in the Aboriginal subjects was associated with apoptosis, whereas organelle and membrane disruption in the LC of Celtic subjects suggested a reduction by direct cellular damage. LC in Aboriginal epidermis tended to become relocated at more superficial levels following UV exposure, and their Birbeck granules became more numerous. LC in Celtic epidermis appeared to become relocated in a basal location and contained fewer Birbeck granules. The central lamina of the Birbeck granules in Aboriginal LC, which was more electron-dense than that in Celtic subjects prior to UV treatment, was temporarily lost following treatment, while the ultrastructure of Birbeck granules in Celtic LC was unchanged. LC and 'indeterminate cells' in intimate association with lymphocyte-like cells occurred in the basal layer of Celtic epidermis 5 days after exposure. These complexes were not observed in Aboriginal epidermis although isolated lymphocyte-like cells were observed in the same location. Melanocytes in Aboriginal epidermis contained greater numbers of melanosomes than those in Celtic epidermis throughout the experiment. Inactive epidermal melanocytes in Celtic subjects initially responded to UV exposure with a slight increase in melanosome content followed by a substantial further increase, whereas active melanocytes in the Aboriginal subjects showed the opposite response. The implications of the different responses of LC and melanocytes in the two groups, in relation to immunological function of the epidermis and the marked racial difference in the incidence of skin cancer, are discussed. Cancer of the skin, particularly basal and squamous cell carcinoma, occurs primarily in people with fair skin who burn easily following exposure to ultraviolet radiation (UVR). In contrast, the incidence of skin cancer in inherently dark-skinned people is low. Melanin is synthesized by melanocytes in response to UVR and is thought to protect epidermal cells against damage to their genetic material by absorbing UVR and thereby reducing its penetration into the skin. Thus darkly pigmented skin is more resistant to the effects of UVR.(ABSTRACT TRUNCATED AT 400 WORDS)

T6+ and HLA-DR+ cell numbers in epidermis of immunosuppressed renal transplant recipients.

The increased susceptibility of the skin of chronically immunosuppressed individuals to viral infections and sunlight-induced malignancies suggests specific drug-induced, dysfunction of local immune mechanisms within the sun-exposed skin of these individuals. To help understand the effect of immunosuppressive therapy alone in the absence of ultraviolet light on the immune system of skin, biopsies were collected from non-sun-exposed buttock skin of control, healthy volunteers and kidney transplant recipients immunosuppressed with either azathioprine/prednisone or cyclosporin A/prednisone and examined for incidences of T6+, and HLA-DR+ cells. No significant differences in the incidences of these 2 cell types were found (a) between control individuals and transplants recipients, (b) between transplant recipients receiving either of the immunosuppressive drug regimes, or (c) between transplant recipients who either had or had not developed skin cancer.

Effects of therapy with azathioprine and prednisolone and ultraviolet irradiation on mouse skin immune function and immune cell markers.

The effects of ultraviolet irradiation (UVI) (290-400 nm) and/or systemic immunosuppressive drug therapy (azathioprine and prednisolone) on the immunocompetence of the skin of hairless (HRA/Skh-1) mice were investigated. Mice were studied for the density of ATPase+, Ia+ and Thyl X 2+ cells in the dorsal epidermis and contact hypersensitivity (CH) of skin to dinitrofluorobenzene (DNFB). Prednisolone therapy alone and UVI alone each reduced the densities of the three skin immune cell markers and CH responsiveness; azathioprine therapy alone had no such effects. When a suberythemal dose of UVI that induced a moderately depressive effect on these two skin parameters was used, additional azathioprine therapy produced no further depression; additional prednisolone therapy further depressed the densities of ATPase+ and Ia+ cells and CH responsiveness; additional therapy with combined azathioprine and prednisolone induced profound depression of the incidences of the three immune cell markers and of CH responsiveness. These data point to interaction between azathioprine/prednisolone therapy and UVI in depressing local immune function within skin which may contribute to the increased susceptibility of the sun-exposed skin of immunosuppressed kidney transplant recipients to infective and carcinogenic processes.

Effects of exposure to ultraviolet light on epidermal Langerhans cells and melanocytes in Australians of aboriginal, Asian and Celtic descent.

The effects of 3 daily, 7-min exposures to artificial ultraviolet light (UVL), designed to simulate natural sunlight, on epidermal Langerhans cells (LC) and melanocytes were studied in 17 healthy Australian volunteers of differing skin pigmentation. Six were of Celtic, 6 of Asian and 5 of Aboriginal descent. LC were visualized using the immunofluorescence method for HLA-DR and T6 antigens, and the histochemical method for ATPase. UVL induced a transient reduction in the LC population density and an increase in the number of melanocytes in all subject groups. The reduction in number of immunocompetent LC or the disruption of their surface markers was greatest in the Celtic subjects, who had the fairest skin, and least in the Aboriginal and Asian subjects, who had the darkest skin. However, neither the inherently dark skin pigmentation nor the UVL-induced increase in pigmentation were sufficient to prevent the depletion of immunocompetent epidermal LC. Non-dendritic, rounded cells and very large dendritic, non-LC, which were present in the epidermis of some subjects, were stimulated to increase in number by exposure to UVL. The identity and function of these cells is uncertain and they require further investigation.

Effects of sunlight exposure on Langerhans cells and melanocytes in human epidermis.

The effects of 12 daily, half-hour exposures to sunlight on epidermal Langerhans cells (LC), and melanocytes were studied in 31 healthy volunteers. Nineteen were of Celtic and 12 of mixed European descent. Sunlight appeared to have both a direct, transient, detrimental effect and an indirect stimulating effect on the LC, and a direct and an indirect stimulating effect on the melanocytes. The mixed Europeans had a somewhat greater increase in the melanocyte population density following exposure to sunlight than the Celts. However, the number of LC fell following sunlight exposure regardless of the melanocyte response. Thus the melanocytes did not appear to provide the LC with immediate protection from ultraviolet light.

Demographic study of clinically atypical (dysplastic) nevi in patients with melanoma and comparison subjects.

We examined 296 patients with a history of melanoma and 145 controls for the presence of atypical (dysplastic) nevi. We found that 34% of patients with melanoma and 7% of controls had clinically atypical (dysplastic) nevi. Patients and controls with atypical (dysplastic) nevi had more nevi than the subjects without. The number of nevi varies negatively and significantly with age (r = 0.37, P less than 0.001). Ten % of patients and controls had hypopigmented halos around one or more nevi. Both patients and comparison subjects with atypical (dysplastic) nevi tended to have this subtle variant of halo nevi more often than those without (r = 0.17, P less than 0.01). The number of nevi on the irides of melanoma patients was greater than that in the comparison group. The results of this study suggest that patients with a melanoma exhibit more commonly cutaneous and ocular pigmentary lesions than comparison subjects without a melanoma.