Understanding breakage in curly hair.

Background: In 2005, the L'Oréal Institute for hair and skin research carried out a multiethnic study to investigate hair breakage in women residing in the U.S.A.

Cytokine expression correlates with differential sensory perception between lye and no-lye relaxers.

Differences in perceived sensory scalp discomfort between guanidine carbonate/calcium hydroxide (no-lye) and sodium hydroxide (lye) relaxer technologies have been reported by users for decades. However, the biochemical processes responsible for the perceived differences have not been fully studied. We have used an in vitro three-dimensional skin model with well-developed epidermis to explore the expression of cytokines that may partially explain the biological response resulting in differences in sensory perception.

Characterization of the response to moisture of talc and perlite in the environmental scanning electron microscope.

This article focuses on the application of ESEM to study the dynamic interaction of hydrophobic and hydrophilic filler materials of interest for the cosmetic and pharmaceutical industries. The ability of ESEM to attain different thermodynamic stages was used to record real-time information of hydration and dehydration processes of those materials in the presence of water and sweat (used as a model physiological fluid). This information is of great importance to understand the behavior of a product containing those fillers as well as to identify potential processing issues related to the interaction of the filler with moisture.

The behavior of hair from different countries.

The properties of curly hair from different countries were assessed using geometrical measurements from a laser scanning micrometer and a new hair shape classification method. In addition, tensile tests, 2-D gel electrophoresis, and differential scanning calorimetry (DSC) were performed. Results concluded that hair characteristics are influenced by the degree of curl.

Comparative study of the hydration of the stratum corneum between four ethnic groups: influence of age.

Background: Several recent overviews have reported that significant work remains to be performed to understand and quantify the ethnic differences in skin properties. In this way, we have carried out a set of in vivo biophysical experiments on the skin of American women from different ethnic populations living in the same environment. Inter- and intraethnic skin micro relief results were already published, skin hydration differences are now reported here.

Ethnic cosmetic products.

Based both on actual differences in the hair and skin and on cultural desire, people of color do have special considerations for cosmetic products. As the experts in hair and skin, it is incumbent on dermatologists to understand the needs of a diverse patient base, to be knowledgeable about the products that patients need and desire, and to be aware of possible adverse effects related to product use or misuse. Further research is needed both to continue to understand the needs of the hair and skin of people of color and to understand the effects of products on ethnic hair and skin.