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Balneotherapy and Hydrotherapy
Published in Mehwish Iqbal, Complementary and Alternative Medicinal Approaches for Enhancing Immunity, 2023
Ferdinand von Hebra, the pioneer of contemporary dermatology, was the first and foremost to observe mineral water's benefits on skin suffering from psoriasis. Louis also discussed the significance of water baths during the management of pemphigus and ichthyosis (Nestle et al., 2009). There are inscribed reports about the favourable outcomes of alkaline waters and sulfur in the management of eczema and psoriasis (Nestle et al., 2009). It is recognised that peloids and mineral water application on the skin bring about chemical, thermal and mechanical effects. It decreases the thickness of the stratum lucidum and stratum corneum of the epidermis, enhances the number of eosinophilic granulocytes, histiocytes and lymphocytes and escalates the skin's permeability, decreases inflammation and makes the immunity and microcirculation better (Langenbruch et al., 2012).
Comparative Anatomy, Physiology, and Biochemistry of Mammalian Skin
Published in David W. Hobson, Dermal and Ocular Toxicology, 2020
The human stratum lucidum is a constituent only of thick skin and hairless regions (i.e., plantar and palmar surfaces) and lies between the stratum granulosum and stratum corneum. A thin, clear, homogeneous line exists which consists of closely compacted cells whose nuclei and cytoplasmic organelles are no longer present. This clear or translucent layer consists of a semifluid substance known as eleidin.49
Structure and Function of Human Skin
Published in Marc B. Brown, Adrian C. Williams, The Art and Science of Dermal Formulation Development, 2019
Marc B. Brown, Adrian C. Williams
The stratum lucidum is a thin and translucent layer (hence the name) 3–5 cells thick. Here, the cell nucleus disintegrates and there is an increase in keratinisation of the cells; the cells contain eleidin, derived from keratohyalin which is then converted to keratin in the upper stratum lucidum and stratum corneum. Concomitantly, the cells undergo further morphological changes and flatten. Occasionally, droplets of an oily substance may be seen in this cell layer, probably arising from exocytosis of the lamellar bodies. The stratum lucidum tends to be seen most clearly in relatively thick skin specimens, such as from the load-bearing areas of the body (the soles of the feet and the palms). Indeed, some researchers question whether this layer is functionally distinct from the other epidermal layers, or if it is an artefact of tissue preparation. Many researchers tend to view the stratum lucidum as the lower portion of the stratum corneum and hence bracket these two layers together.
Dermato-pharmacokinetic: assessment tools for topically applied dosage forms
Published in Expert Opinion on Drug Delivery, 2021
Vamshi Krishna Rapalli, Gautam Singhvi
Skin is the outermost largest organ in the body. It protects the body from physical, chemical, and microbial assaults and also prevents water loss from the body. The skin comprises three layers, i.e. epidermis, dermis, and subcutaneous tissue. Epidermis is made up of five layers composed of stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale. The stratum corneum is the outermost layer and comprise dead keratinocytes, and lamellar granules. The corneocytes and lipids form tight junctions in the stratum corneum like brick and mortar. Stratum corneum acts as a permeation and diffusional barrier for topically applied dosage form for skin disorders and transdermal drug delivery. The topical formulations are considered as a mainstay for the treatment of these skin disorders. Topical drug delivery systems are mostly preferred to deliver the drugs to the target site with minimal systemic adverse effects.
Rat hippocampal CA3 neuronal injury induced by limb ischemia/reperfusion: A possible restorative effect of alpha lipoic acid
Published in Ultrastructural Pathology, 2018
Ola A. Hussein, Amel M. M. Abdel-Hafez, Ayat Abd el Kareim
Immunostaining with GFAP reveals the presence of numerous astrocytes distributed in all layers (Figure 5(d)). The astrocytes have large amount of strongly positive cytoplasm and thick profusely branching processes (Figure 5(e)). The astrocytic processes surrounding blood capillaries appear thick and strongly positive to GFAP (Figure 5(c)). Pyramidal neurons reveal many degenerated electron dense neurons with ill-defined nuclei and ill-defined cytoplasmic organelles (Figure 6(a)). The pale pyramidal neurons with rarified cytoplasm contain many heterogeneous electron dense lipofuscin granules and mitochondria with damaged cristae. Moderate and marked dilatation of RER cisternae is observed (Figure 6(b)). Stratum lucidum exhibits marked degeneration of unmyelinated and myelinated nerve fibers and contains numerous empty spaces within the neuropil (Figures 6(c) and 7(a)). Disorganization of microtubules and increased electron density of mitochondria are observed in the dendrites of pyramidal neurons and in the mossy fibers (Figure 6(c)). Myelinated nerve fibers reveal degeneration of the axon and discontinuity of its surrounding myelin sheath (Figure 7(a)).
Nanocrystal: a novel approach to overcome skin barriers for improved topical drug delivery
Published in Expert Opinion on Drug Delivery, 2018
Viral Patel, Om Prakash Sharma, Tejal Mehta
Epidermis forms the outermost layer of the skin, which is broadly divided into different layers, stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum germinativum [28]. The outermost covering of the epidermis is made up of dead cells, known as corneocytes, which have lost their cellular components including nucleus due to the deposition of protein, keratin. Corneocyte are tightly arranged; thus, they act as a major barrier restricting the entry of foreign particles/materials through the skin [29]. This layer of epidermis is known as stratum corneum. The stratum corneum is having protein bricks and lipid mortar-like structure. The protein bricks are created by the crosslinking of proteins through disulfide bond surrounding the corneocytes providing biomechanical strength [30]. While the lipid mortar plays a significant role as a functional barrier. The stratum corneum is much thicker in some parts of the body. The skin surface of palms of hand and foot soles bear vertically stacked corneocytes with average thickness of 400–600 µm and are known as stratum lucidum. The keratinocytes in this layer are dead, densely packed, transparent in appearance and provide barrier to water. The keratinocytes gradually become flatter, their cell membrane thickens, and the protein keratin gets accumulated as lamellar granules within the cells. This layer containing granular cells is called as stratum granulosum. Below stratum granulosum lies the stratum spinosum. This layer appears spiny due to protruding cell structures called desmosomes. The desmosomes create an interlock with each other, thereby strengthening the bond between the adjacent cells. Keratin and water repelling glycolipid which prevents water loss through skin are synthesized by the keratinocytes present in the stratum spinosum. The deepest layer of epidermis is stratum germinativum. The cells in this layer form bonds with dermis by intertwining with collagen fiber. It is composed of one to two layers of basal cells. These basal cells are precursors of keratinocytes and hence are stem cells with cuboidal shape. As new cells are formed by mitosis, the existing keratinocytes are pushed superficially toward the stratum corneum. The basal and the spinous cells are collectively called as Malpighian layer [29,31–35].