Melanocytic naevi may grow more rapidly during human growth hormone (hGH) therapy. With standardised skin photographs, the growth rate of the naevi was two-fold greater in 14 hypopituitary and 5 Turner's syndrome girls treated with hGH than in untreated patients or controls. HMB-45 immunoreactivity, a marker of stimulated melanocytes, was absent in naevi from 18 of 19 individuals not treated with hGH, including 5 Turner's syndrome patients studied 2-43 months after stopping hGH. In naevi from 39 hGH-treated patients, 22 showed unusual HMB-45 reactivity in dermal naevocytes. During administration of hGH, melanocytic naevi grow faster and there is reversible stimulation of naevocytes.
Metabolic activity and structure of the stroma adjacent to basel cell carcinomas are closely related to cytological aspects and proliferative activity of the neoplastic cells. Basal cell carcinomas without clear evidence for regression compress or infiltrate an apparently normal dermis where cellular replication is low. Conversely regressing zones of basal cell carcinomas are surrounded by a remodelled stroma where fibroblasts and endothelial cells show signs of proliferation. When regression affects the palisaded array of cells, clefts occur between the basal cell carcinoma and the adjacent stroma. Progression of most types of basal carcinomas may proceed by successive extension and partial regression. More than one type of stroma reaction may be present ina single basal cell carcinoma and the overall pattern may be regarded as the result of successive phases of growth and regression of the neoplasm.
On clinical grounds, the so-called dry skin corresponds in reality to a rough, sometimes flaky and scaly stratum corneum. The spectrum of xerotic disorders is quite large encompassing diverse aetiologies and physiopathological pathways. The clinical assessment of these conditions relies on close visual and tactile inspection. EEMCO guidances were proposed in this field for subject and expert evaluations. Scoring systems include analogue scales, the overall dry skin score and the SRRC score combining the grading of scaliness, roughness, redness and cracks. The dry skin extent area and severity index is defined for the dermatological evaluation of the entire body surface. The use of a video camera equipped with an internal ultraviolet light illumination unit is very informative and allows better comparative assessments.
Background: The stratum corneum (SC) structure and functions are altered by surfactants. Enhancing the repair mechanisms is a goal for some skin care formulations. Aim: To design an experimental procedure allowing the discrimination of repair efficacy for topical products applied to threatened SC. Method: Controlled SC strippings followed by repeated forearm soak sessions in surfactant solutions were used to compromise the SC barrier function in 20 volunteers. Two test formulations were compared. They were applied twice daily for 2 weeks before initiating the SC damages, and for the next 2 weeks while sustaining the procedure of soak sessions. Daily assessments involved objective measurements of parameters including transepidermal water loss, the value of the passive sustainable SC hydration and the epidermal turnover rate using the dihydroxyacetone test. Result: The experimental procedure allowed to clearly distinguish the differences in the kinetics of SC repair between the topical formulations. In the present study design, the repair of the barrier function mirrored the SC renewal. Conclusion: The present experimental design slows down the repair rate of the SC barrier function. Thus, it increases the sensitivity of biometrological measurements assessing some of the major SC properties. It also better mimics the common in vivo situation experienced by subjects chronically exposed to irritant xenobiotics.
Background: Ultraviolet light radiations (UVR) may be responsible for hair cycle synchronization and telogen effluvium in the animal and humans. The effect if any of cumulative UVR on chronic hair shedding and androgenic alopecia (AGA) is largely unknown. Objective: To compare the severity of AGA with the extent of solar elastosis. Method: The present study combining immunohistochemistry and computerized image analysis was undertaken in 140 men with AGA and 50 non-alopecic men. Solar elastosis was identified using the antibody to lysozyme, and collagen was revealed by Sirius red staining. The number and diameter of hair shafts were also assessed. Results: The scalp dermis was significantly thicker in AGA than in unaffected subjects. The difference was mainly due to a severer elastosis in baldness. The earliest signs of solar elastosis preceded hair thinning. When elastosis was thicker than 0.2 mm, a negative exponential correlation was found between hair diameter and severity of solar elastosis. Conclusion: Chronic UVR exposure of the scalp may affect the hair cycle and be one of the exogenous factors influencing negatively the progression of AGA. The induction of stress-induced premature senescence by reactive oxygen species and micro-inflammation might be operative at the level of the follicular stem cells.
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