Review of the German Dermatological Literature 1969

Abstract

HASHIMOTO has presented electron microscopio evidence of the formation of a marginal band during keratinization. This band forms de novo and precipitates along tho cytoplasmic side of the original plasma membrane, often having outer and inner delimiting lines of high electron density. This is the true cellular envelope of the cornifled human epidermal cell.Schreiner and Wolff''''''^ injected horseradish peroxidase into human and guinea-pig skin and followed the tracer svibstance by electron microscopy. It penetrated rapidly into the intercellular spaces of the epidermis as far as the stratum granulosum. The peroxidase accumulated partly in the perinuclear cysterns ofthe epidermal cells which communicate with the intercellular spaces. The investigations showed that the latter, which are filled with mvicopolysaccharide, are very permeable. The significance of the perinuclear cysterns is obscure.In an extension of their work they showed that 2 hr. after peroxidase had been injected, the exogenous protein had entered the epidermal cells. The protein was embraced by phagosomes which flowed together to form large paranuclear spaces. These phagosomes contained increased quantities of acid phosphatase perhaps capable of modifying the absorbed protein.Rupee et al.^'-estimated the cross sectional area of mitochondria in the guinea-pig epidermis by electron microscopy and found a significant diminution from the basal layer towards the surface. This reduction of mitochondria towards the periphery is related to a deficiency of substrate and the corresponding depletion of cristae in the more superficial living cells.Rupee'" also studied the ultrastructure of sebaceous gland cells and distinguished between undifferentiated cells, those about to differentiate and fully differentiated ones by demonstrating the presence of smooth endoplasmic reticulum followed by the appearance of lipid droplets.The experimental depigmentation of guinea-pig skin by hydroquinone monoethyl ether was studied electron microscopically by Frenk'', who found selective damage of melanocytes which were then taken up by invading macrophages. After treatment for 6 days the epidermis no longer showed any normal melanocytes whilst the Langerhans cells remained unaltered.Braun-Falco and Wolff* have studied the ultrastruetural changes in Lyell's disease. They found enlargement of the intercellular spaces in the basal layer of the epidermis together with consequent extensive intercellular oedema. The desmosomes were preserved whilst all organelles showed signs of degeneration. After further damage of the epidermal cells, coarsened tonofibrillae remained-desmosomes survived longest. The initial appearance of pinocytotic vesicles, the increase in ribosomes and of invagination of nuclei are interpreted as expressions of an abrupt increase of epidermal metabolism. BIOCHEMISTRYBrehm et al.^ have determined quantitatively the rates of dehydroepiandrosterone, androsterone, aetiocholanone, total oestrogen and testosterone, in the plasma of men and women with acne. It was...