Differential Diagnostics of Toxic Epidermal Necrolysis (Lyell’s Syndrome) in ICU: Case Reports

Toxic epidermal necrolysis (TEN) is a critical life-threating condition developing as the total detachment of epidermidis and characterized by severe pathological reactions of all body systems. The current article describes two cases of TEN with similar clinical and laboratory signs. In one case the diagnosis of TEN was subsequently refused.The objective: analysis of methods of clinical and differential diagnostics of conditions accompanied with massive epidermidis detachment in ICU patients.Results. The immunomorphological evaluation of skin specimen obtained from the patient with a torpid form of TEN showed linear IgG fixation in the intercellular space of stratum basale, stratum spinosum and stratum granulosum and C3 fixation in the intercellular space of stratum basale.Conclusion. The complex of anamnesis data and pathomorphological evaluation of skin are crucial for the diagnosis and treatment of patients with atypical TEN.

The Epidermis: Redox Governor of Health and Diseases

A functional epithelial barrier necessitates protection against dehydration, and ichthyoses are caused by defects in maintaining the permeability barrier in the stratum corneum (SC), the uppermost protective layer composed of dead cells and secretory materials from the living layer stratum granulosum (SG). We have found that loricrin (LOR) is an essential effector of cornification that occurs in the uppermost layer of SG (SG1). LOR promotes the maturation of corneocytes and extracellular adhesion structure through organizing disulfide cross-linkages, albeit being dispensable for the SC permeability barrier. This review takes psoriasis and AD as the prototype of impaired cornification. Despite exhibiting immunological traits that oppose each other, both conditions share the epidermal differentiation complex as a susceptible locus. We also review recent mechanistic insights on skin diseases, focusing on the Kelch-like erythroid cell-derived protein with the cap “n” collar homology-associated protein 1/NFE2-related factor 2 signaling pathway, as they coordinate the epidermis-intrinsic xenobiotic metabolism. Finally, we refine the theoretical framework of thiol-mediated crosstalk between keratinocytes and leukocytes in the epidermis that was put forward earlier.

Ichthyoses—A Clinical and Pathological Spectrum from Heterogeneous Cornification Disorders to Inflammation

Ichthyoses are inborn keratinization disorders affecting the skin only (non-syndromic) or are associated with diseases of internal organs (syndromic). In newborns, they can be life-threatening. The identification of the gene defects resulted in reclassification and a better understanding of the pathophysiology. Histopathologic patterns include orthohyperkeratosis with a reduced or well-developed stratum granulosum, hyperkeratosis with ortho- and parakeratosis with preserved or prominent stratum granulosum, and epidermolytic ichthyosis. Another pattern features “perinuclear vacuoles and binucleated keratinocytes”, which is associated with keratin mutations. Some ichthyoses are histologically defined by psoriasis-like features, and distinct subtypes show follicular hyperkeratosis. In addition to histological and immunohistochemical methods, these patterns allow a better histopathologic diagnosis.

Immunoreactivities of AR, ERα, ERβ and aromatase in the nuptial pad of Chinese brown frog (Rana dybowskii) during pre-hibernation and the breeding period

There is a prominent local raised pad called nuptial pad on the forelimb of Chinese brown frog (Rana dybowskii), which is hypothetically concluded as an enhancement of the grip and a spreader of pheromone during the amplexus. In this study, we investigated the immunolocalization and protein expression levels of AR, ERα, ERβ and aromatase in the nuptial pad of R. dybowskii during pre-hibernation and the breeding period. Histologically, the annual development of the nuptial pad in R. dybowskii is manifested as the larger area of specialized mucous gland and the longer length of papillary epidermal projection during the breeding period. AR, ERα, ERβ and aromatase are present in the stratum granulosum, stratum spinosum, stratum basale and the secretory portion of specialized mucous glands during both periods. Western blotting results confirmed that AR, ERα and ERβ protein levels are higher during pre-hibernation than those during the breeding season. These results suggest that nuptial pad is the direct target organ of androgen and estrogen. Androgen may participate in the regulation of annual development and glandular function of nuptial pad, and estrogen may play an endocrine, autocrine or paracrine role during pre-hibernation and the breeding period.

Histomorphological and Histochemical Studies on Esophagus in Gaddi Sheep (Ovis aries)

The present work was conducted to study the histoarchitecture and histochemical characteristics of esophagus in six adult Gaddi sheep. Lamina epithelialis consisted of keratinized stratified squamous epithelium with four functional regions: stratum corneum, stratum granulosum, stratum spinosum and stratum basale. In the stratum spinosum layer, the cell nuclei appeared polygonal whereas in the stratum corneum the cell nuclei were flattened and condensed. The stratum spinosum was the thicker layer and stratum granulosum was a thin layer that contained basophilic keratohyalin granules. Pyknotic cells were observed towards the luminal side of stratum corneum. Blood capillaries and lymphoid aggregations in the form of dark stained cells were present in the connective tissue of lamina propria. Connective tissue of lamina propria layer was denser than the same of the submucosa. The tunica muscularis consisted of striated muscle cells throughout the length of esophagus. Stratum corneum of the stratified epithelium of esophagus showed strong periodic acid-Schiff reaction indicating accumulation of glycogen whereas the cells of the basal layer lacked glycogen. The intercellular spaces in the upper layers of stratum spinosum of the epithelium contained acidic mucopolysaccharides as indicated by their reactivity to alcian blue stain.

Ultrastructural and Molecular Analysis of Ribose-Induced Glycated Reconstructed Human Skin

Aging depicts one of the major challenges in pharmacology owing to its complexity and heterogeneity. Thereby, advanced glycated end-products modify extracellular matrix proteins, but the consequences on the skin barrier function remain heavily understudied. Herein, we utilized transmission electron microscopy for the ultrastructural analysis of ribose-induced glycated reconstructed human skin (RHS). Molecular and functional insights substantiated the ultrastructural characterization and proved the relevance of glycated RHS beyond skin aging. In particular, electron microscopy mapped the accumulation and altered spatial orientation of fibrils and filaments in the dermal compartment of glycated RHS. Moreover, the epidermal basement membrane appeared thicker in glycated than in non-glycated RHS, but electron microscopy identified longitudinal clusters of the finest collagen fibrils instead of real thickening. The stratum granulosum contained more cell layers, the morphology of keratohyalin granules decidedly differed, and the stratum corneum lipid order increased in ribose-induced glycated RHS, while the skin barrier function was almost not affected. In conclusion, dermal advanced glycated end-products markedly changed the epidermal morphology, underlining the importance of matrix–cell interactions. The phenotype of ribose-induced glycated RHS emulated aged skin in the dermis, while the two to three times increased thickness of the stratum granulosum resembled poorer cornification.