Epidermal cell culture

In the initial studies of trace elements of human skin cross sections, a Ca profile evolved which was increasing from the basal, germinative level of the epidermis toward the horny layer. The drastic concentration drop of Ca concentration down to threshold values at the border of the stratum germinativum and the stratum corneum was a particularly interesting feature.15-17 Only a few years later this finding could be correlated to the fact that a Ca concentration >0.1 mmol was essential if a fully cornified stratum corneum was to be obtained in cell culture. This relationship between Ca and terminal differentiation of the epidermal cells was verified in a PIXE study of epidermal cell cultures.18... 

At the heart of any search for bioactive molecules is the need for effective bioassays. Several bioassays have been developed for the identification of compounds with anti-juvenile hormone (AJH) activity. The most common of these AJH bioassays involves the treatment of young larvae or nymphs with the potential AJH by incorporation into the diet or contact application, and then waiting for several days (or, in some cases, weeks) for precocious development (or other AJH response) to occur ( 1, ). Alternatively, AJH activity can be determined using jri vitro assays such as corpora allata cultures or epidermal cell cultures to monitor for inhibition of juvenile hormone (JH) biosynthesis (3-6) or blockage of the JH induced inhibition of pupal commitment (7), respectively. 

Cultured biological dressings are derived from mammalian cell culture procedures which facilitate the development of sheets of cells derived from a few of the patients own epidermal cells. Cultured human keratinocytes form cultured epithelial grafts that are not bioengineered tissues but are cultured cell products with limited use. These cultures may be regarded as a precursor which has led to the development of other products through bioengineering.t ... 

A second bioassay, a soft agar transformation assay, has been utilized at the University of Illinois at Chicago to determine the inhibition of transformation of the JB6 cell line by treatment of the test materials [88]. The primary epidermal cell cultures from newborn BALB/c mice have been previously well developed for use as a tool in chemical... 

Epidermal (perinatal mouse skin) Rat tail tendon collagen Epidermal cells cultured for 2 to 4 d in vitro Worst et al. (1974)... 

Worst, P.K.M., Valentine, E.A. and Fusenig, N.E, (1974) Formation of epidermis after reimplantation of pure primary epidermal cell cultures from perinatal mouse skin/. Natl. Cancer Inst., 53, 1061-1064. 

Several other experiments on cultured epidermal cells deserve mention. Newborn mouse epidermal cells cultured in semm-free defined medium respond to retinoid treatment in a dose-dependent manner, with an increase in both DNA and RNA synthesis (Spom et al., 1973). The response is extremely sensitive with an EDjq of 4 X 10 Af for all-rrmw-retinoic acid (Spom et al., 1976) and has been standardized in a sensitive assay for measurement of stmcture-function... 

Suhonen, T.M., Pasonen-Seppanen, S., Kirjavainen, M., Tammi, M., Tammi, R., and Urtti, A. (2003). Epidermal cell culture model derived from rat keratinocytes with permeability characteristics comparable to human cadaver skin. Eur. J. Pharm. Sci. 20 107. 

However, NAD+ depletion is not the only mechanism involved in cell death. Prophylactic or therapeutic treatment of human epidermal cell cultures with NAD+ precursors [ie. nicotinamide) in an attempt to maintain NAD+ levels do not protect these cells from SM. ... 

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