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BACKGROUND Fractional laser resurfacing is a new procedure for skin rejuvenation. We have found that it has a skin tightening effect in humans. OBJECTIVE To assess the mechanism of the skin tightening effect of fractional laser treatment in animals using histologic approaches. METHODS 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. RESULTS 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. CONCLUSION 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.

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.

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.

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.

27歳の男性。半年前より右第I趾蹠側基部が疼痛を伴って発赤, 腫脹するようになり, 抗菌剤内服にて軽快するものの再燃の度に増大し当科を受診した。初診時には圧痛を伴った不均一に淡紅色調で境界不明瞭の7×4cmの板状硬結局面が存在し, 表面には痂皮を伴う不整な陥凹性瘢痕を認めた。生検では真皮のほぼ全層に淡い胞体を持つやや大型の細胞が密に増生し, その細胞は線維成分で満たされた好酸性の豊富な胞体を持ち, 核は卵円形で明瞭な核小体を持つ類上皮細胞様細胞であった。一部分には, 好塩基性に染まり紡錘形の核を持つやや小型の線維芽細胞様の細胞が索状に配列していた。胞体内の線維成分はビメンチンに強陽性, サイトケラチン(AE1/AE3)は類上皮細胞様細胞のみ淡く陽性であった。類上皮肉腫と診断し広範囲切除術を行った。電顕では, 類上皮細胞様細胞は大きな胞体, 偏在する核, 不完全な基底膜構造を持ち, 小型のミトコンドリアは多数存在するが細胞内小器官には乏しく, 胞体の大部分を10nmの中間径線維が占めていた。線維芽細胞様細胞は核膜が過剰で核の輪郭が入り組んでおり, 細胞内小器官がよく発達し不規則な基底膜様の構造に包まれていた。興味深い所見は, これら2種類の細胞の間にgap junctionが存在したことである。以上より, 本腫瘍は胞体内に間葉系の中間径線維を持つ類上皮細胞様細胞と線維芽細胞様細胞とが密接に関係しながら増生した腫瘍であり, その意味では滑膜肉腫と類似していると考えた。

Salicylic acid is used in chemical peeling procedures. However, they have caused many side effects, even salicylism. To achieve a salicylic acid peeling that would be safer for topical use, we recently developed a new formulation consisting of 30% salicylic acid in polyethylene glycol (PEG) vehicle. In an extension of our previous research, we studied the absorption of 30% salicylic acid labeled with 14C in PEG vehicle applied topically to the intact and damaged skin of male hairless mice. An ointment containing 3 mg salicylic acid in 10 mg vehicle was applied to both groups. In animals with intact skin, 1 h after application the plasma concentration of radioactivity was 1665.1 ng eq/ml, significantly lower than the 21437.6 ng eq/ml observed in mice with damaged skin. Microautoradiograms of intact skin showed that the level of radioactivity in the cornified cell layer was similar at 6 h after application. However, in damaged skin, the overall level of radioactivity showed a decrease by 3 h after application. In the carcasses remaining after the treated intact and damaged skin had been removed, 0.09 and 11.38% of the applied radioactivity remained, respectively. These findings confirm that 30% salicylic acid in PEG vehicle is little absorbed through the intact skin of hairless mice, and suggest that salicylism related to absorption through the skin of quantities of topically applied salicylic acid is not likely to occur in humans with intact skin during chemical peeling with this preparation. This new preparation of 30% salicylic acid in PEG vehicle is believed to be safe for application as a chemical peeling agent.

BACKGROUND Fractional laser resurfacing is a new procedure for skin rejuvenation. OBJECTIVE To assess the skin remodeling effect of fractional laser treatment. METHODS 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. RESULTS 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

SummaryBackground 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. Objectives To evaluate the effects of chemical peeling with 30% salicylic acid in PEG on skin tumour formation in treated vs. control mice. Methods 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. Results 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-γ production did not differ. Conclusions 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.

Salicylic acid is used in chemical peeling procedures. However, they have caused many side effects, even salicylism. To achieve a salicylic acid peeling that would be safer for topical use, we recently developed a new formulation consisting of 30% salicylic acid in polyethylene glycol (PEG) vehicle. In an extension of our previous research, we studied the absorption of 30% salicylic acid labeled with 14C in PEG vehicle applied topically to the intact and damaged skin of male hairless mice. An ointment containing 3 mg salicylic acid in 10 mg vehicle was applied to both groups. In animals with intact skin, 1 h after application the plasma concentration of radioactivity was 1665.1 ng eq/ml, significantly lower than the 21437.6 ng eq/ml observed in mice with damaged skin. Microautoradiograms of intact skin showed that the level of radioactivity in the cornified cell layer was similar at 6 h after application. However, in damaged skin, the overall level of radioactivity showed a decrease by 3 h after application. In the carcasses remaining after the treated intact and damaged skin had been removed, 0.09 and 11.38% of the applied radioactivity remained, respectively. These findings confirm that 30% salicylic acid in PEG vehicle is little absorbed through the intact skin of hairless mice, and suggest that salicylism related to absorption through the skin of quantities of topically applied salicylic acid is not likely to occur in humans with intact skin during chemical peeling with this preparation. This new preparation of 30% salicylic acid in PEG vehicle is believed to be safe for application as a chemical peeling agent.

Background: chemical peelings injure the superficial skin, which is then restored by healing of the wound. Objectives: 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. Design: 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. Results: 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. Conclusions: 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.

Background: Q-switched laser therapy is known to be highly effective in treating dermal melanocytosis and pigmented epidermal lesions. However, to our knowledge, there are no reports on the effectiveness of laser therapy for congenital nevi. We evaluated the clinical efficacy and side effects of normal-mode ruby laser therapy for congenital pigmented lesions containing abundant melanin. Observations: A normal-mode ruby laser (pulse duration, 0.3-1.0×10 -3 seconds; energy fluence, 10-30 J/cm 2 ; and spot size, 10×10 or 15×15 mm) (Toshiba Corp, Tokyo, Japan) was used to treat 3 patients with congenital nevi at intervals of 1 to 4 months. In all 3 cases, the pigmented lesions were significantly reduced almost to the level of the surrounding normal skin after 4 laser treatments. The treated areas were virtually free of scarring, and the skin texture resembled that of the surrounding normal skin. Unsightly hair growth was also reduced. Conclusions: The normal-mode ruby laser was effective in treating congenital nevi and produced good cosmetic results. The risk of recurrence is unknown, but the 3 patients in our study did not have any recurrences during the 18- to 39-month study period. Arch Dermatol. 1997;133:355-359

21才女子の左頬に生じた表面に星芒状血管拡張をともなつた血管平滑筋腫の1例を報告した。筋腫の摘出により血管拡張は消失した。臨床像と組織所見から筋腫の発生母地を皮膚の糸球部と考えた。電顕所見についてものべた。

1才7ヵ月，男児。 3ヵ月前より眉間，眉毛部，両頬部によう性落屑面をきたし，難治性である。鱗屑のKOH標本で真菌要素は発見されず，多数の毛包虫を認めた。クンメルフェルド液の外用にて治療をおこない，急速に軽快した。文献的に毛包虫の形態，寄生部位，検出率，病原性などについて言及した。本症例は本邦におけるる最年少例と思われ，5才以下の幼児では第2例目であろう。

A highly purified peptide antigen was produced from the cultured mycelia of Trichophyton mentagrophytes. Mycelia were extracted with 0.1 N-HCl at 37 degrees C repeatedly. The protein fraction was precipitated with picric acid and the final product was tentatively designated as Trichophyton mentagrophytes peptide (TMP). Total yield of TMP was about 3% of the original mycelia. When skin tests were done on sensitized guinea pigs, TMP showed a delayed-type reaction. The minimal dose which gave a positive reaction was 3 micrograms (0.1 ml of 30 micrograms/ml solution). Chemical analyses showed that TMP was almost exclusively of a peptide nature and digestion with bacterial peptidase (pronase) completely destroyed its skin test activity, thereby suggesting that protein fraction carried the entire antigenic activity. With chemical and/or physical processings, TMP showed firm stability; the skin test activity was unchanged after heating to 120 degrees C or after processing with HCl or NaOH. Fractionation of TMP by gel filtration demonstrated a considerable heterogeneity in its molecular size, while the antigenic activity was virtually the same in all the fractions. Disc electrophoresis also showed a wide-spread heterogeneous pattern. In the MIF test using peritoneal exudate cells from sensitized guinea pigs, 100 micrograms/ml of TMP had definite inhibitory effect on cell migration.