[Histochemical aspects of the phylohistogenetic recapitulation of the epidermis]

Epidermis of human embryos and fetuses obtained at abortion and at premature delivery was studied, as well as cell carcinoma of the skin in the biopsies of cheek, external ear and lip. PAS-reaction, treatment with diastase and phenyl hydrosine, staining with alcian blue at pH 1.0 and 2.7 and with basic brown at pH 1.0 were applied. Determination of the total and cationic protein with brom phenol blue (pH 2.2 and 8.2, respectively), aminoacid debris of lisine and histidine, sulfhydril groups of cysteine, disulfate groups of cysteine and others were determined. Histochemical peculiarities of the epidermal protective zone in fetuses recapitulate the epidermal properties of water vertebrates. Presence of hydrophilic groups in the cells of nonkeratinizing type of epidermoid carcinoma resembles histochemical differentiation of amphibian epidermis. In the cells of keratinizing carcinoma, keratine detected is histologically close to that in reptilian squamae.