Richard W. Gange

Treatment of telangiectases and other benign vascular lesions with the 577 nm pulsed dye laser

BACKGROUND This study was undertaken to evaluate the effectiveness and safety of the 577 nm pulsed dye laser in the treatment of various vascular lesions of the face. OBJECTIVE Our purpose was to make observations on the effects of different variables that could affect response. METHODS Ninety-two adults with telangiectases of the face were sequentially selected for treatment according to a protocol previously established. Evaluation consisted of visual inspection by two investigators, and before and after photographs at 2-months intervals. A few patients with other vascular lesions were also treated and reported. RESULTS Ninety-one percent of the patients (84 of 92) showed good to excellent response after a single treatment. Recurrence occurred in 2%. Atrophy of the skin occurred in 2%. Venous lakes, pyogenic granulomas, and mucosal vascular malformations showed significant improvement. CONCLUSION The 577 nm pulsed dye laser is effective and safe for vascular lesions of the face.

Immediate pigment darkening : visual and reflectance spectrophotometric analysis of action spectrum

Immediate pigment darkening (IPD) occurs in human skin upon exposure to ultraviolet‐A and visible radiation. The spectral changes that occur during IPD were measured with a rapid scanning reflectance spectrophotometer (RS) which employs optical fiber bundles for delivery and detection of light between 400 and 750 nm. The radiation dose dependence and wavelength dependence (334–549 nm irradiation) of IPD were studied by both the classical visual grading method and by spectrophotometric scoring using the RS system. The spectral changes that occur at long wavelengths with IPD mimic the natural absorption spectrum of melanin. Therefore, the IPD was scored in terms of the apparent change in melanin optical density, using the method Kollias and Baqer [Photochem. Photobiol. 43,49–54 (1986)], based on reflectance in the620–720 nm range. The nonlinearity of the visual grading method is demonstrated. The degree of IPD is first‐order with respect to delivered dose and saturates after high doses. The maximum amount of IPD attained at saturation is greater for shorter wavelengths. Extrapolation of the reflectance data suggests the longest wavelength capable of eliciting IPD is about 470 nm.

PYRIMIDINE DIMER FORMATION IN HUMAN SKIN

Cyclobutyl pyrimidine dimers are major photoproducts formed upon irradiation of DNA with ultraviolet light. We have developed a method for detecting as few as one pyrimidine dimer per million bases in about 50 ng of non‐radioactive DNA, and have used this method to quantitate dimer yields in human skin DNA exposed in situ to UV. We found that UVA radiation (320–400 nm) produces detectable levels of dimers in the DNA of human skin. We also measured UVB‐induced dimer yields in skin of individuals of differing sun sensitivity and found higher yields in individuals with higher UVB minimal erythema doses and greater sun sensitivity. These approaches should provide important information on damage induced in human skin upon exposure to natural or artificial sources of ultraviolet radiation.

DO PYRIMIDINE DIMER YIELDS CORRELATE WITH ERYTHEMA INDUCTION IN HUMAN SKIN IRRADIATED in situ WITH ULTRAVIOLET LIGHT (275–365 nm)?

Ultraviolet radiation produces erythema in human skin, and damages the DNA of living cells in skin. Previous work showed that broad‐band UV‐B (290–320 nm) radiation produced higher levels of cyclobutyl pyrimidine dimers in DNA of individuals with high UV‐B sensitivity (low minimal erythema dose) than in subjects of low UV‐B sensitivity [Freeman et al. (1986) J. Invest. Dermatol., 86, 34–36]. We examined the relationship between erythema induction and dimer yields in DNA of human skin irradiated in situ with narrow band radiation spanning the wavelength range 275–365 nm. We find that, in general, higher dimer yields are produced per incident photon in volunteers with higher susceptibility to erythema induced by radiation of the same wavelength.

Actinic reticuloid: Response to combination treatment with azathioprine, hydroxychloroquine, and prednisone

We treated an intractable case of actinic reticuloid with azathioprine, hydroxychloroquine, prednisone, and solar protection with E-Z film and obtained a clinically worthwhile effect. The patient was initially sensitive to less than 2 mjoules/cm2 ultraviolet B (UVB) and less than 1 joule/cm UVA, which caused erythematous and infiltrated scaly plaques that persisted for more than 6 weeks after testing. The case is also instructive in the difficulty presented in differentiating it from mycosis fungoides, and for the presence of Sézary-type cells in skin, blood, and lymph nodes.

Does exposure of human skin in situ to 385 or 405 nm UV induce pyrimidine dimers in DNA

Abstract— A previous report [Freeman et al.(1986) Photochem. Photobiol.43S, 93S] indicated that irradiation of human skin in situ with 385 or 405 nm radiation produced detectable levels of pyrimidine dimers in DNA. Since these wavelengths are absorbed poorly by DNA, these results suggested that DNA damage was sensitized by other absorbing molecules present in skin. Examination of two experimental aspects of the previous work indicates that (1) the static gel electrophoresis method for DNA dispersion used in lesion determination gave accurate values of the levels of induced dimers, and (2) the DNA damage apparently induced by 385 nm was actually induced by shorter wavelength UV present in the 20 nm bandpass beam of the monochromator. The current results indicate that monochromatic 385 and 405 nm radiation are ineffective in dimer production in human skin in situ.

Effect of preirradiation tissue target temperature upon selective vascular damage induced by 577-nm tunable dye laser pulses

The effect of hamster cheek pouch temperature upon the microvascular injury induced by pulsed laser dye radiation was studied. An appropriate wavelength (577 nm) and pulse width (300 nsec) were delivered by a flashlamp-pumped dye laser to induce selective vascular damage, as previously described. With increasing pulse energies, transient slowing of blood flow, stasis with brown discoloration of blood, and hemorrhage were observed. Cooling the cheek pouch to 8 degrees before irradiation increased the laser exposure threshold for induction of such injury. Measurement of the exposure thresholds for hemorrhage at different temperatures suggests that microvessels are heated to between 90 and 100 degrees, before hemorrhage occurs. These data are consistent with microvaporization as a major event in the sequence leading to hemorrhage, but do not exclude other possible mechanisms.

Contribution of topical tar oil to ultraviolet B phototherapy for psoriasis

A bilateral comparison study of twenty-two outpatients with psoriasis assessed clearing experience and remission time on halves of the body to which tar oil and oil vehicle (an emollient) were applied twice daily. In addition, both sides were treated three times a week with suberythemogenic doses of ultraviolet B radiation. Of the eighteen patients who complied with the protocol, fourteen (78%) had clearing. There was no significant difference between body halves with regard to the number of treatments to clearing, the dose of ultraviolet B to clearing, or the remission time (p greater than 0.2, all comparisons). Our data indicate with 95% confidence that using tar oil in conjunction with ultraviolet B phototherapy reduces the average total ultraviolet B dose required for clearing by a maximum of 9%, in comparison with using oil vehicle and ultraviolet B. These findings suggest that there is insufficient evidence for substantial clinical benefit to recommend tar oil use in conjunction with outpatient ultraviolet B phototherapy for psoriasis.

Photoreactivation and Other Ultraviolet/Visible Light Effects on DNA in Human Skina

A computer-based system was devised for examining low levels (1 dimer/10/sup 8/ d) of DNA damage in human skin exposed to ultraviolet or visible radiation. The production of measurable levels of dimers was determined for light of wavelengths absorbed directly by DNA (290-320 nm). Exposure of skin to uv-A (320-380 nm) sources also produced significant numbers of endonuclease-sensitive sites. The immediate pigment darkening reaction (IPD) was tested to see whether IPD protects against uv-induced dimer formation. 29 references, 2 figures, 1 table. (ACR)

DNA damage and repair in human skin: Pathways and questions

Skin, the principal barrier between human internal organs and the external environment, is assaulted daily with physical and chemical carcinogens, promoters, and modifiers of biological responses to such agents. DNA is the principal target for most carcinogens, and DNA in skin is particularly at risk. It is subject to damage not only from ingested compounds and their metabolic products, but also from externally applied or encountered chemicals, as well as from physical carcinogens such as sunlight and cosmetic or medical sources of ultraviolet radiation. Three major factors determine the balance between damage to DNA of skin and the biological consequences of that damage: (1) the frequencies and types of lesions, (2) the ability of the individual to repair a lesion, and (3) the strategy that skin employs to deal with the different spectra of lesions inflicted under varying environmental conditions. Thus, cellular responses to DNA damage, including repair of DNA lesions, are critical factors in determining the final level of damage and its consequences.