Abstract: A method for determining whether the skin surface of a subject is mature/immature in its organization/function, by taking a skin sample and determining the corneodesmosome distribution within the stratum corneum of the sample by an immunoelectron microscopy method.

Abstract: The invention concerns a use of C7 sugars and derivatives of formula (I), called avocado perseose, which have, inter alia, a protective activity to epidermal skin cells. These C7 sugars and derivatives are capable of maintaining the expression of markers of adult stem cells, in particular basal stem cells. Avocado perseose can also be used for preventing the deleterious effects of environmental damage. Avocado perseose has a beneficial effect on the conservation of the potential of epidermal stem cells and thus helps maintain skin homeostasis.

Abstract: The invention relates to biomarkers of the skin of children and, in particular, that of infants, having altered expression in the presence of urine. Such markers are particularly advantageous as they allow the skin's response to urine to be monitored. The inventors have developed methods for evaluating the efficacy in vitro of formulations in preventing the harmful effects of urine on a child's skin, using a skin model specifically capable of reproducing the characteristics of children's skin.