Fibroblast morphology, growth rate and gene expression in facial melasma.

Background: In addition to melanocytic hyperfunction, changes are observed in the upper dermis of melasma, and fibroblasts play a central role in collagen synthesis and pigmentation induction.

Objective: To explore the morphology, growth rate, and gene expression profile of fibroblasts from the skin with melasma in comparison to fibroblasts from the adjacent healthy skin.

Methods: Ten women with facial melasma were biopsied (lesion and adjacent healthy skin), and the fragments were processed for fibroblast culture.

Exploratory Study of Epidermis, Basement Membrane Zone, Upper Dermis Alterations and Wnt Pathway Activation in Melasma Compared to Adjacent and Retroauricular Skin.

Background: Melasma is a chronic acquired focal hypermelanosis which pathogenesis has not been fully elucidated. Classical pathophysiologic studies have analysed the affected and perilesional areas, but little is known about the status of sun-protected skin, which is subjected to the same endogenous and genetic factors.

Objective: To assess the histological characteristics of melasma compared to adjacent and retroauricular skin.

Ultrastructural characterization of damage in the basement membrane of facial melasma.

The pathogenesis of melasma is not fully understood, and the role of skin basement membrane zone (BMZ) alterations in disease development and the maintenance of hypermelanogenesis are also poorly known. We performed a comparative study to characterize the ultrastructural alterations that occur in BMZ in melasma and adjacent normal skin, as well as we discuss the implications of these changes in the physiopathology of the disease. Pairs of facial skin biopsies (2 mm) from 10 women with melasma and normal skin (< 2 cm apart) were processed by Transmission Electronic Microscopy or immunohistochemistry for Melan-A counterstained with Periodic acid-Schiff stain.

Aryl hydrocarbon receptor overexpression in miniaturized follicles in female pattern hair loss.

The etiopathogenesis of female pattern hair loss is still poorly understood. In addition to genetic and hormonal elements, environmental factors could be involved. The aryl hydrocarbon receptor is expressed in keratinocytes and can be activated by environmental pollutants leading to alterations in the cell cycle, inflammation, and apoptosis.

The pH of the main Brazilian commercial moisturizers and liquid soaps: considerations on the repair of the skin barrier.

The pH of the skin is slightly acidic (4.6 to 5.8) which is important for appropriate antibacterial, antifungal, constitution of barrier function, as well as structuring and maturation of the stratum corneum.

Nuclear morphometry and chromatin textural characteristics of basal cell carcinoma.

Histological subtypes of basal cell carcinoma have biological, evolutionary and distinct prognostic behavior. The analysis of characteristics of the nucleus can provide data on their cellular physiology and behavior. The authors of this study evaluated nuclear morphological parameters and textural patterns of chromatin from different subtypes of basal cell carcinoma: nodular (n=37), superficial (n=28) and sclerodermiform (n=28).

Dermal type I collagen assessment by digital image analysis.

Type I collagen is the main dermal component, and its evaluation is relevant to quantitative studies in dermatopathology. However, visual gradation (0 to 4+) has low precision and high subjectivity levels. This study aimed to develop and validate a digital morphometric analysis technique to estimate type I collagen levels in the papillary dermis.

Techniques of digital image analysis for histological quantification of melanin.

Morphometric analysis of tissue melanin may quantitatively contribute to research on pigmentation disorders. The authors present three methods for image analysis, which allow for identification of melanin-equivalent pixels in the epidermis using Fontana-Masson stain and, therefore, for the calculation of its percentage in the different epidermal layers. Moreover, they discuss the main elements related to the analysis and the need for rigorous standardization of the process.

Evaluation epidermal p53 immunostaining by digital image analysis.

Background/purpose: Digital techniques have been developed and validated to assess semiquantitatively immunohistochemical nuclear staining. Currently visual classification is the standard for qualitative nuclear evaluation. Analysis of pixels that represents the immunohistochemical labeling can be more sensitive, reproducible and objective than visual grading.

Morphometric analysis of dermal collagen by color clusters segmentation.

Morphometric analysis of dermal collagen can provide quantitative support to dermatologic research. The authors of this article disclose a technique of digital image analysis which allows the identification of microscopic structures by color cluster segmentation regarding the estimate intensity and density of dermal collagen fibers.