title: [Stereology of the dermo-epithelial interface of the matrix-papilla unit of the hair bulb. Computerized processing of tridimensional images].
abstract: Images of the spatial relations of the matrix-papilla unit of the human hair bulb are shown. Hair bulbs were reconstructed in 3 dimensions by a computer graphics system from measurements made on horizontal sections parallel to the scalp surface. The outlines of hair matrix and dermal papilla of every fifth serial sections were fed into a computer as a segment 30 mu high (5 sections, each 6 mu thick). Processing of these segments into 3 dimensional models, using techniques adapted from those currently used for architectural drawing enabled us to avoid major distortion of the printed pictures. As an end result, the hair bulbs appear as wire frame structures in which the boundaries between consecutive segments have been connected to improve rendering of the dermal papilla interacting with the overlying epithelial hair matrix. This computerized method has been used to evaluate dermal-epithelial stereology of the interacting dermal papilla and epithelial hair matrix in hair bulbs. In a patient with trichorhinophalangeal syndrome the hair bulbs, and especially their dermal papillae, were found to the hypotrophic as compared with a sex- and age-matched control. Even though the pictures are somewhat artifactual in their present form, there are several means of improving the rendering of relief and of the interrelation between the hair follicle and other surrounding structures. This method could be useful to demonstrate disturbed dermal-epithelial interactions in other types of alopecia and to evaluate potential biological effects of drugs used in the treatment of alopecia.
mesh_terms: D003196:Computer Graphics; D004848:Epithelium / Q000033:anatomy & histology; D006197:Hair / Q000033:anatomy & histology* / Q000473:pathology; D006201:Hair Diseases / Q000473:pathology*; D006801:Humans; D012535:Scalp; D012867:Skin / Q000033:anatomy & histology* / Q000473:pathology
vernacular_title: Stéréologie de l'interface dermo-épithéliale de l'unité matrico-papillaire du bulbe pilaire. Génération informatisée d'images tridimensionnelles.