[Show abstract][Hide abstract] ABSTRACT: Fractional laser resurfacing is a new procedure for skin rejuvenation. We have found that it has a skin tightening effect in humans.
To assess the mechanism of the skin tightening effect of fractional laser treatment in animals using histologic approaches.
The dorsal skin of hairless guinea pigs was irradiated with a fractional 1,540-nm erbium glass laser. Biopsy specimens were taken serially from 0 hour until 1 year after irradiation and evaluated histologically.
Histologic evaluation indicated dermal remodeling within 2 months, in which regenerated collagen bundles and fibroblasts aligned in a horizontal direction, suggesting a traction stress on the dermal components. The treated part became less obvious over a period of more than 3 months by recovery of fine collagen bundles without fibrosis.
These results suggest that improvement of the tension in a horizontal direction is essential for skin remodeling and improvement of facial laxity using fractional laser resurfacing.
Dermatologic Surgery 01/2010; 36(1):71-5. · 1.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Fractional laser resurfacing is a new procedure for skin rejuvenation.
To assess the skin remodeling effect of fractional laser treatment.
Twelve Asian patients with acne were irradiated using a fractional 1,540-nm erbium glass laser on a random half of the face twice with a 4-week interval.
The faces were contoured on the treated side of most patients. Statistical analyses of the facial images showed that the skin tightening effect was significant 4 weeks after the first and second irradiation (p<.001 after both treatments).
These results suggest that fractional laser resurfacing is a possible alternative to nonsurgical skin tightening of the face.
Dermatologic Surgery 11/2009; 36(1):66-70. · 1.87 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chemical peeling with salicylic acid in polyethylene glycol vehicle (SA-PEG) is a safe and effective method for the rejuvenation of photo-damaged skin. The procedure removes photo-damaged stratum corneum, which consists of immature, fragile cornified envelopes (CEs) and stimulates the reconstruction of the stratum corneum with mature, rigid CEs. In UVB-irradiated hairless mice this procedure, which affects the stratum corneum only, suppresses skin tumor development. In addition, chemical peeling with SA-PAG suppresses p53 expression in mice and normalizes keratinocyte differentiation in both mice and humans. The stratum corneum functions as a barrier against physical and chemical insult and various infectious agents. Here, we hypothesize on a new function of the stratum corneum: a brace function that structurally protects keratinocytes from atypical differentiation or disordered proliferation. Although the precise mechanism remains to be elucidated, there is definite value to be gained from further investigation. This review discusses basic information about chemical peeling with SA-PEG, looks at its action on photo-induced tumor suppression, and proposes a new function for the stratum corneum in keratinocyte proliferation/differentiation.
Archives for Dermatological Research 05/2008; 300 Suppl 1:S31-8. · 2.71 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chemical peeling with salicylic acid in polyethylene glycol vehicle (SA-PEG), which specifically acts on the stratum corneum, suppresses the development of skin tumors in UVB-irradiated hairless mice. To elucidate the mechanism through which chemical peeling with SA-PEG suppresses skin tumor development, the effects of chemical peeling on photodamaged keratinocytes and cornified envelopes (CEs) were evaluated in vivo. Among UVB-irradiated hairless mice, the structural atypia and expression of p53 protein in keratinocytes induced by UVB irradiation were intensely suppressed in the SA-PEG-treated mice 28 days after the start of weekly SA-PEG treatments when compared to that in the control UVB-irradiated mice. Incomplete expression of filaggrin and loricrin in keratinocytes from the control mice was also improved in keratinocytes from the SA-PEG-treated mice. In photo-exposed human facial skin, immature CEs were replaced with mature CEs 4 weeks after treatment with SA-PEG. Restoration of photodamaged stratum corneum by treatment with SA-PEG, which may affect remodeling of the structural environment of the keratinocytes, involved the normalization of keratinocyte differentiation and suppression of skin tumor development. These results suggest that the stratum corneum plays a protective role against carcinogenesis, and provide a novel strategy for the prevention of photo-induced skin tumors.
Journal of Investigative Dermatology 03/2006; 126(2):416-21. · 6.19 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Chemical peeling with salicylic acid in polyethylene glycol (PEG) vehicle is used clinically to improve the cosmetic appearance of skin that has been damaged by exposure to the sun. It is well known that cancers of the skin such as basal cell carcinoma and squamous cell carcinoma may be induced by the sun. However, the carcinogenic potential of chemical peeling agents has not been studied.
To evaluate the effects of chemical peeling with 30% salicylic acid in PEG on skin tumour formation in treated vs. control mice.
To serve as a model of sun-damaged skin, hairless SKH/hr1 mice were irradiated with ultraviolet (UV) B for 14 weeks, with or without treatment every 2 weeks with 30% salicylic acid in PEG for a total of 18 weeks.
Not only was the total number of tumours greatly reduced in the treated vs. the control mice, but skin tumour development was also slower in the treated vs. the control mice. At the final treatment, the fractions of T and B lymphocytes and natural killer cells from spleens of both groups of mice were comparable, and interferon-gamma production did not differ.
Our findings suggest that chemical peeling with salicylic acid in PEG may help to prevent as well as to reduce the number of UVB-induced skin tumours.
British Journal of Dermatology 06/2003; 148(5):906-12. · 3.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: chemical peelings injure the superficial skin, which is then restored by healing of the wound.
to document the acute and chronic histological changes produced by applying chemical peeling agents used clinically to the UVB-irradiated skin of hairless mice, which served as a model of sun-damaged skin.
three chemical peeling agents, 30% salicylic acid, dissolved in macrogol (a new formulation), 35% trichloroacetic acid (TCA) dissolved in distilled water and 20% glycolic acid dissolved in glycerin were applied to the backs of UVB-irradiated hairless mice. Untreated, irradiated areas of skin served as controls. Specimens were evaluated histologically at 3, 14, 28, and 70 days.
chronic UVB irradiation produced an irregular hypertrophy of the epidermis. The treated areas of irradiated skin recovered by day 70. At 28 days, all skin specimens treated with chemical peeling agents exhibited a unique connective tissue layer composed of fine collagen fibers beneath the epidermis. While 35% TCA produced severe tissue damage marked by inflammation up to day 14, no inflammatory infiltrates were seen with 30% salicylic acid in macrogol at 70 days.
chemical peeling with 30% salicylic acid dissolved in macrogol led to reorganization of the epidermis and a rebuilding of the superficial dermal connective tissue important in reducing wrinkles, and without evidence of inflammatory infiltrates in an animal model of sun-damaged skin. Findings suggest a possible clinical benefit.
[Show abstract][Hide abstract] ABSTRACT: To clarify the histologic alterations produced by the application of salicylic acid solution, which has been used effectively in chemical peeling without producing a wound or inflammation.
We applied 7.5%, 15.0%, and 30.0% salicylic acid in solutions of ethanol or macrogol to the backs of hairless mice for 20 minutes. The skin was histologically evaluated immediately and at 1, 3, 12, 24, and 48 hours following treatment.
The Department of Dermatology, Faculty of Medicine, Kyushu University, Fukuoka, Japan.
A loss of cornified cells was the only morphologic alteration associated with the treatment, and was followed by the activation of the epidermal basal cells and the underlying fibroblasts.
The 7.5% and 15. 0% salicylic acid solutions produced few histologic changes, whereas the 30.0% salicylic acid in both vehicles macerated and then exfoliated the cornified cells. As the epidermis became thinner, the residual epidermal cells became flattened and were rearranged parallel to the tensile surface load. The cornified material within the hair follicles also became macerated, dilated the follicles, and then dropped off. An apparent increase occurred in the number of cells in the S phase in the epidermal basal cells in 24 hours, leaving the follicular cells unchanged. As the cornified layer thickened in 48 hours, the epidermal cells below it and the underlying fibroblasts resumed their random pretherapy arrangement. Except for the occasional infiltrate of lymphocytes, no degenerative or inflammatory changes occurred. While similar changes occurred with each vehicle, they were relatively faster with the ethanol preparations.
The present results suggest that the architecture of the epidermis and the papillary dermis can be regenerated by simply injuring the cornified layer by using topical agents such as salicylic acid that do not cause degeneration or inflammation.
Archives of Dermatology 12/2000; 136(11):1390-5. · 4.79 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Lesions of naevus of Ota range in colour from light brown to blue, and even greenish-black. To develop guidelines for optimal treatment, we evaluated the number of Q-switched ruby laser treatments required to eliminate the pigmentation of such lesions classified by colour. Over a period of 6 years, we evaluated 151 Japanese patients with naevus of Ota who had been treated with the Q-switched ruby laser at a low energy level (wavelength 694.3 nm; pulse duration 28 x 10-9 s; energy fluence 5 J/cm2; spot size 6.5 mm) every 2 months. Each lesion was classified by colour as brown (n = 22), brown-violet (n = 42), violet-blue (n = 81) and blue-green (n = 6). The 22 predominantly brown lesions attained an excellent (100-95%) or good (95-75%) cosmetic result following three laser treatments in all patients who received this number of treatments. In the 42 brown-violet lesions, 25 of the 29 good or excellent results were achieved after four treatments; the 13 less successful results were in patients who had one to three treatments. In the 81 violet-blue lesions, 54 of the 65 good or excellent results were achieved after four treatments and 64 of 65 after five treatments, whereas all 16 less good results were in patients who had only one to three treatments. However, in the six blue-green lesions, six or more treatments were required to achieve a similarly favourable result. At the end of treatment, the area was virtually free of scarring, and its texture resembled that of the surrounding normal skin. We have confirmed that the use of the Q-switched ruby laser at a low energy level can eliminate the pigmentation of naevus of Ota. While the desired improvement can be obtained within 1 year, the number of treatments appears to depend on the predominant colour of the lesion.
British Journal of Dermatology 02/2000; 142(1):77-83. · 3.76 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To evaluate histologically the long- and short-term changes associated with cosmetic improvement or failure of normal-mode ruby laser treatment of patients with congenital nevi.
A biopsy of the laser-treated lesions of 10 patients with good or poor cosmetic results was performed at periods up to 8 years 10 months after treatment (mean, 4 years 9 months). Short-term findings were evaluated in 3 patients.
Ueda Setsuko Clinic and the Dermatology Unit of the Kyushu University, Fukuoka, Japan.
Of the 85 Japanese patients with relatively large congenital nevi who had been treated with the normal-mode ruby laser since 1990, 13 gave informed consent for biopsy and histological examination of the treated area.
A long-term follow-up study of the 8 patients with good cosmetic results showed the presence of residual nevus cells 1.11 +/- 0.35 mm (mean +/- SD) (range, 0.63-2.05 mm) below the skin surface. Above these cells was a layer of connective tissue that formed a subtle microscopic scar that preserved the normal structure of the papillary dermis. Hair follicles were damaged at the base, and the hairs were attenuated. However, in the 2 patients with poor cosmetic results, nests of pigmented cells were commonly seen in the epidermis, and melanin was relatively abundant in basal keratinocytes. No malignant changes were observed in any patient. A short-term study in 3 patients showed damage to pigmented cells in the epidermis and upper dermis as observed following electrodesiccation.
Multiple treatments with the normal-mode ruby laser produced immediate thermal damage to the superficial nests of nevus cells and a subsequent remodeling of the superficial connective tissue. When the thickness of the subtle microscopic scar reached 1 mm, it masked the underlying residual nevus cells and achieved a good cosmetic result. Follow-up for at least 8 years after laser treatment showed no evidence of malignant change in the treated areas.
Archives of Dermatology 11/1999; 135(10):1211-8. · 4.79 Impact Factor