Granular layer, absence

Fleckman, P. and Brumbaigh, S., Absence of the granular layer and keratohyaline define a morphologically distinct subset of individuals with ichthyosis vulgaris, Exp. Dermatol., 11, 327, 2002. 

Immunodeficiency with short-limbed dwarfism is an autosomal recessive disorder ". Antibody and cell-mediated immunity is defective. From the first few weeks after birth, there is a severe scaling erythroderma with large coarse scales (Figure 15.1) some areas are free, in others the symptoms rapidly subside for short periods of time then reappear. Histologically the stratum corneum shows parakeratosis and hyperkeratosis and contains some neutrophils. There is an absence of the granular layer, papillomatosis and a moderate acanthosis with many mitoses. There is a mononuclear infiltrate in the upper and papillary dermis. 

Place the distillate in a separating-funnel and extract the benzonitrile twice, using about 30 ml. of ether for each extraction. Return the united ethereal extracts to the funnel and shake with 10% sodium hydroxide solution to eliminate traces of phenol formed by decomposition of the benzenediazonium chloride. Then run off the lower aqueous layer, and shake the ethereal solution with about an equal volume of dilute sulphuric acid to remove traces of foul-smelling phenyl isocyanide (CaHjNC) which are always present. Finally separate the sulphuric acid as completely as possible, and shake the ether with water to ensure absence of acid. Run off the water and dry the benzonitrile solution over granular calcium chloride for about 20 minutes. 

The latest innovation is the introduction of ultra-thin silica layers. These layers are only 10 xm thick (compared to 200-250 pm in conventional plates) and are not based on granular adsorbents but consist of monolithic silica. Ultra-thin layer chromatography (UTLC) plates offer a unique combination of short migration distances, fast development times and extremely low solvent consumption. The absence of silica particles allows UTLC silica gel layers to be manufactured without any sort of binders, that are normally needed to stabilise silica particles at the glass support surface. UTLC plates will significantly reduce analysis time, solvent consumption and increase sensitivity in both qualitative and quantitative applications (Table 4.35). Miniaturised planar chromatography will rival other microanalytical techniques. 

A considerable amount of severely degraded wood substance appears to remain, even after a very extensive attack. This wood substance, the bacteria, and the concentric layers make up an amorphous substance resembling that described earlier for erosion attack. Although the middle lamella and the S3 layer will be extensively degraded in localized areas, large parts of these cell wall layers will remain. A quite distinct granular structure and absence of cavitylike attack differentiate decay by tunneling bacteria from that of erosion bacteria. 

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