[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.
Full-text · Article · Jan 2010 · Dermatologic Surgery
[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.
Full-text · Article · Nov 2009 · Dermatologic Surgery
[Show abstract][Hide abstract] ABSTRACT: BACKGROUND: Chemical peeling by salicylic acid in ethanol or another vehicle may be accompanied by stinging and burning followed by postinflammatory hyperpigmentation in the treated area, or salicylism. We have developed a new formulation: 30% salicylic acid in polyethylene glycol (SA-PEG). A topical application of SA-PEG remodels photodamaged skin in mice and humans, without systemic absorption. OBJECTIVE: The objective was to evaluate the safety and efficacy of SA-PEG for clinical use in the treatment of acne. MATERIALS AND METHODS: We evaluated the effects of the preparation histologically in mice and its safety and efficacy in 44 volunteers with normally aged skin and in 436 patients with acne. RESULTS: Histologic studies in animals showed no inflammatory changes in the skin following topical application of SA-PEG. Volunteers noted an improved skin texture. In the acne patients, the comedones and papules disappeared, resulting in an excellent outcome. There was a notable absence of stinging and burning, edema, bleeding, or crusting in the treated area. CONCLUSION: The SA-PEG preparation appeared to be safe and effective, with minimal associated inflammation or adverse effects, even in Asian patients who tend to develop hyperpigmentation or keloids. This preparation is thus ideal for chemical peeling.
No preview · Article · Jul 2008 · Dermatologic Surgery
[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.
No preview · Article · May 2008 · Archives for Dermatological Research
[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.
Full-text · Article · Mar 2006 · Journal of Investigative Dermatology
[Show abstract][Hide abstract] ABSTRACT: We studied a case of epithelioid sarcoma that had developed on the right sole of a 27-year-old Japanese man. The lesion, which had a history of 6 months, presented as indurated erythematous plaque of 4 × 7 cm scattered with several irregular scars. Microscopically, the majority of the proliferated tumor cells were large, plump epithelioid-like cells with eosinophilic cytoplasm and an oval nucleus. The remainder were fibroblast-like, bearing spindle-shaped cell bodies. Immunohistochemistry indicated that the epithelioid-like cells were positive for Vimentin and AE1/AE3, but that the fibroblast-like cells were negative. Electron microscopy revealed that the former cells were characterized by an abundant and monotonous cytoplasm being filled with intermediate filaments densely arranged throughout the cell bodies. Small mitochondria were the only organelles around the nucleus. On the other hand, the fibroblast-like cells were characterized by prominent cytoplasmic organelles, including mitochondria, rough endoplasmic reticulum, Golgi apparatus and free ribosomes, and by abundant glycogen within the cytoplasm. Regardless of such different features, both cells were partially surrounded by basal lamina and exhibited close contact with juxta cells with gap junctions. These findings support the belief that the tumor was related etiologically to synovial sarcoma.
No preview · Article · Jan 2004 · Nishi Nihon Hifuka
[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.
No preview · Article · Sep 2001 · Journal of Dermatological Science
[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.
No preview · Article · Dec 2000 · Archives of Dermatology
[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.
No preview · Article · Nov 1999 · Archives of Dermatology