Proteinaceous intercellular

The predominant mechanism of biofilm accumulation in staphylococci involves polysaccharide intercellular adhesin (PIA) [60-66], S. epidermidis strains lacking this adhesin are also regularly isolated from biomaterial-related infections, a fact which prompted a search for an alternative, PIA-independent accumulation mechanism [51, 52, 60-62, 67, 68], The responsible molecule was identified as accumulation associated protein, Aap [69-71], and there may also be a role for additional proteinaceous intercellular adhesins [52], Aap has a similar-acting homolog, SasG, in S. aureus [72], adding to the accumulating evidence that proteinaceous intercellular adhesins are also of importance in S. aureus biofilm formation and device-related infection [52, 72-74],... 

Figure 35.2. Schematic representation of the barrier property of skin composed of proteinaceous keratinocytes (corneocytes) embedded in an extracellular nonhomogenous matrix of lipid. Arrow depicts intercellular lipid pathway.

Part of the intercellular complex may be isolated by oxidation of the hbers with peracetic acid according to the method of Alexander and Earland [92], This isolated complex is called beta keratose, and it amounts to about 15% of the hair hber mass [133] consisting of proteinaceous material with low disulhde content. 

Based on the early models of Swift and Holmes [46], Leeder described the three major components of the CMC [16]. The intercellular material (8-layer) is composed mainly of proteinaceous material with low cross-link density. The p-layers are assumed to consist of lipids, possibly as bilayers coupled with inert proteinous (resistant membranes) outer boundaries. Some confusion arises as to whether an additional associated intracellular membrane band (i-layer) should be considered as part of the CMC [11,32]. Although the intracellular band is usually considered as an internal part of the cell, it appears to play an important role in the stabilization of the CMC. A detailed understanding of this i-layer as well as of the other regions of the CMC is important for understanding the transport processes of chemical reagents into keratinized cells. 

Lopashov attached great importance to the interaction of embryonic cells with intercellular medium. According to his view, these interactions could have an important effect on primary cell differentiation. Specifically, the internal medium of the blastocele and gastrocele - into which a surface layer of compact cells turns -could contain certain proteinaceous compounds. In the presence of these compounds the cell surfaces do not compact. Therefore, these cells retain their ability for inductional interactions (Lopashov, 1965, 1977). 

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