Avaliação celular das estruturas cutâneas por meio da microscopia confocal de reflectância / Evaluation of cutaneous cellular structures by reflectance confocal microscopy

A microscopia confocal de reflectância (MCR) ganhou grande destaque na área cosmética e dermatológica, pois permite a análise morfológica e estrutural da pele de forma não invasiva.Esse estudo utiliza a MCR na avaliação das diferentes células e dos tecidos cutâneos, além da análise morfológica da unidade pilossebácea. Comparou-se a morfologia microscópica das células cutâneas e da unidade pilossebácea, das imagens de 21 voluntárias do estudo com os dados já publicados na literatura científica. O estrato córneo apresentou células anucleadas e com contraste devido à queratina. As camadas granulosa e espinhosa apresentaram células nucleadas, com núcleo escuro e o citoplasma claro. Na camada basal se observaram células brilhantes devido à melanina. As papilas dérmicas se apresentaram como células com contraste, formando anéis ao redor de células mais escuras. A derme papilar e a reticular superficial mostraram estruturas com contraste, devido ao colágeno. O folículo piloso apareceu como canal com pelo e a glândula sebácea apresentou formato oval, com células de núcleo escuro e citoplasma claro. Os folículos pilosos com comedões continham obstruções no lúmen folicular. A MCR possibilitou a identificação e a diferenciação das camadas da pele e da unidade pilossebácea, mostrando seu potencial para avaliação cutânea dinâmica.

Cigarette Smoke-Induced Interleukin-1 Alpha May Be Involved in the Pathogenesis of Adult Acne

BACKGROUND: Lipid peroxide (LPO) in comedones, which are produced as a result of sebum oxidation, might potentially induce interleukin-1alpha (IL-1alpha) and exacerbate comedogenesis and inflammatory changes in comedones. OBJECTIVE: To investigate the relationship of proinflammatory cytokines and LPO levels in the extracts of comedones with the acne of clinical difference between smokers and non-smokers, and with the severity and distribution of the acne lesions. METHODS: Twenty-two non-smoking and 21 smoking adult acne patients were evaluated by comedone extraction and measurement of proinflammatory cytokines and LPO levels. Acne severity and distribution of the lesions were also analyzed. RESULTS: Relative to the non-smoking group, smokers had significantly higher levels of IL-1alpha and LPO in comedones. Their levels showed a positive correlation. However, there were no statistically significant difference between the severity or distribution of the disease and the levels of LPO and IL-1alpha in comedones. CONCLUSION: Smoking may be involved in the pathogenesis of adult acne by increasing the oxidative stress that results in subsequent accumulation of LPO in comedones.

Effect of Topically Applied Multi-lamellar Emulsion Containing Linoleic Acid on Experimentally Induced Comedones / 대한피부과학회지

BACKGROUND: Disturbed keratinization of the follicular infundibulum is the earliest change in comedo formation. The relative decrease in linoleic acid in the sebum could be responsible, in part, for this abnormal keratinization. OBJECTIVE: This study was conducted to evaluate the effects of topically applied multi-lamellar emulsion containing linoleic acid (MLE/LA) on experimentally induced comedones. METHODS: To induce comedo formation, 50% oleic acid (OL) in macrogol 400 was applied to the ventral surface of both ears of New Zealand white rabbits. Twenty ears of ten rabbits were randomly divided into four treatment groups (5 ears in each group). Four groups (OL only, OL and MLE/LA, OL and MLE, OL and control vehicle containing LA) were treated twice daily for 2 weeks. The relative increase in areas of the comedo was evaluated by digital image analysis. The morphologic changes around the epithelial lining of the comedo were observed by light microscopy and scanning electron microscopy. RESULTS: After 2 weeks of application, only the OL and MLE/LA combined treated group showed significantly less (by 1.23-fold, p<0.05) increase in comedo size when compared to the OL treated group (by 1.86-fold). Upon light microscopy and scanning electron microscopy examination, the MLE/LA treated ears showed a lesser degree of epidermal hyperplasia and hyperkeratosis in the follicular infundibulum compared with the OL treated ears. CONCLUSION: Topical MLE/LA might have an inhibitory effect on the formation of OL induced comedones.

Treatment of Acne

Acne vulgaris is a self-limited disease, seen primarily in adolescents. Most cases of acne are pleomorphic, presenting various lesions consisting of comedones, pustules, and nodules. Although it has been traditionally classified as a disease of the sebaceous gland, it actually involves the pilosebaceous unit. There are four major principles in the treatment of acne: (1) correct the altered pattern of follicular keratinization; (2) decrease the sebaceous gland activity; (3) decrease the follicular bacterial population; and (4) produce anti-inflammatory effect. The natural course of acne varies greatly, and therefore, the determination of the therapeutic efficacy of medications for the treatment of acne is far from being simple.

Effect of Panax Ginseng Extracts on the Experimentally Induced Comedones / 대한피부과학회지

In this animal study, comedones were induced by topical application of oleic acid onto the rabbit ear canal and the histopathologic and ultrastructural changes in response to topical application of HO and hexane extracts of red ginseng, and saponin were measured. No microscopical difference was observed between treatment groups. Nucle ir remnants were observed in the horny cell layer as well as the thinning of the granular cell layer. Scattered and decreased keratohyaline granules were also noted. Six weeks after initiation of treatment, we observed the thinning of epidermis and veappearance of granular cell layer with normal keratohyaline granules. After treatment, scanning electron microscopy showed a decrease in the size of comedones, and loosened and desquamating horny cells in the comedones. From the above results, it could be concluded that Panax ginseng extracts might have effects on the keratinization process of the skin.

An Electron Microscopic Study on the Effect of Vitamin A Acid on Experimentally Induced Comedones in Rabbit / 대한피부과학회지

Comedones were induced at external ears of rabbits by daily application of 50% oleic acid in paraffin oil for 3 weeks. 13 cis-retinoic acid(RA) solution(0.1%)wae apllied to experimentally induced comedones. The morphologic changes around the epithelial lining of comedones were observed by transmission electron microscopy to define the effect of RA on comedones. In follicles treated with RA, the results were summarized as follows: l) The thickness of the stratum corneum of the epithelium was markedly decreased with widening of intercellular spaces. 2)The number of desomosomes and desmosoma1 bodies between horny cells was decreased. 3) Abnormally appeared tight junction in the stratum corneum and disappearance of membrane coating granules in the straurn granulosum were reversed to normal state, disappearance of tight junction and increment of membrane coating granule respectively by the application of RA. These observations suggest that RA has comedolytir. effect by decreasing cohesive- ness between horny cells.

Electron Microscopic Observation of Experimentally Induced Comedones in Rabbit / 대한피부과학회지

Accurnulation of keratinized cells within the infundibulum of pilosebaceous canal is important in the pathogenesis of acne. Light and electron microscopic study of experimentally induced comedones, from the rabbit's external ear canal, was performed to define the earIy morphologic changes within and around the epithelial lining of the comedones. In light microscopic observation, early comedone was composed of loose cohesive horny cells and late comedone was composed of a mixture of loose and tight cohcsive horny cells. Cohesion between horny cells occured, in eIectron microscopic study, in two different ways: initially, by the persistence of desmosomes; later, and to a lesser extent, by tight junctions, which tightly bound the horny cells together. Multiple lipid droplets within the horny ceIls and a gradual decrease in the numbrane coating granules were observed.