Langerhans' cells were studied in the epidermis of two patients with active Beh,et' s disease and compared with those in two normal controls. Ultrastructural morphology and the percentage of Langerhans' cells found were similar in patients' (1.88%o) and the control epidermis (1.79%). The density of Langerhans' cells in adjacent sites of the same epidermis was not homogeneous, being in the range...

Effects of the tumor initiator 7,12-dimethylbenz(a)anthracene (DMBA) and of the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA) on epidermis of human fetal and adult skin were studied in the nude mouse/human skin model. Human skin grafts on NC nude mice were exposed to two topical applications of 1 mg of DMBA in 50 microliter of acetone with an interval of 3 days and/or to application...

elongation of fatty acids while Sampath and Ntambi discuss the enzymes required for fatty acid desaturation. Finally, Rizzo discusses the key role of fatty aldehyde dehydrogenase and how mutations in this enzyme lead to defective barrier function and ichthyosis. Second, the utilization of fatty acids in the synthesis of phospholipids and triglycerides and the catabolism of these compounds is di...

A hormone induces a rapid and profound change in the metabolic balance of its target organ. Early studies emphasized the extraordinarily low concentrations in which many hormones are effective. The fact that catechoiamines and polypeptides are frequently unable to penetrate the surface of cells made this seem all the more remarkable. The mechanism of their action, which for many years remained ...

Patterning along the anteroposterior axis is a critical step during animal embryogenesis. In the vertebrate central nervous system (CNS), the patterned neural tube is characterized by regionspecific expression of many genes including homeobox genes such as dlx, otx, pax, Hox and cdx cognates (e.g., McGinnis and Krumlauf, 1992; Shimamura et al., 1995). The patterning of the vertebrate neural tub...

Epidermal gene delivery techniques are being developed as an experimental approach to understanding the pathogenesis of skin disorders and for developing therapeutic strategies for the treatment of disease. This technology is being evaluated in many clinical trials in the treatment of disorders such as cutaneous melanoma and skin wounding, with 20% of all gene therapy protocols being applied in...

The results obtained using morphometric variables which describe fin ray regeneration patterns are reported for individual fin ray amputations in the goldfish (Carassius auratus) and zebrafish (Brachydanio rerio). Classical and updated experiments are compared to verify previous morphogenetic models of cell tractions (Oster et al. 1983) or epidermis-mesenchyme induction (Saunders et al. 1959) a...

The murine epidermis with its hair follicles represents an invaluable model system for tissue regeneration and stem cell research. Here we used single-cell RNA-sequencing to reveal how cellular heterogeneity of murine telogen epidermis is tuned at the transcriptional level. Unbiased clustering of 1,422 single-cell transcriptomes revealed 25 distinct populations of interfollicular and follicular...

MOTIVATION Systems biology is currently focused on integrating intracellular networks, although clinically, diseases are largely defined by their histological features. For example, no computational model can simulate today the formation of a horizontally layered epidermis. Since the epidermis is the most complex structured epithelial tissue, systems biology models could yield important insight...

The results obtained using morphometric variables which describe fin ray regeneration patterns are reported for individual fin ray amputations in the goldfish (Carassius auratus) and zebrafish (Brachydanio rerio). Classical and updated experiments are compared to verify previous morphogenetic models of cell tractions (Oster et al. 1983) or epidermis-mesenchyme induction (Saunders et al. 1959) a...