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Norlén L. Molecular Organization of the Skin Barrier. Acta Derm Venereol 2023; 103:adv13356. [PMID: 37987626 PMCID: PMC10680981 DOI: 10.2340/actadv.v103.13356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 10/19/2023] [Indexed: 11/22/2023] Open
Abstract
Cryo-electron microscopy of vitreous sections allows for investigation directly in situ of the molecular architecture of skin. Recently, this technique has contributed to the elucidation of the molecular organization of the skin's permeability barrier and its stepwise formation process. The aim of this review is to provide an overview of the procedure for cryo-electron microscopy of vitreous sections, its analysis using atomic detail molecular dynamics modelling and electron microscopy simulation, and its application in the investigation of the barrier structure and formation process of the skin.
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Affiliation(s)
- Lars Norlén
- Department of Cellular and Molecular Biology (CMB), Karolinska Institutet, Biomedicum, SE-171 77 Stockholm, Sweden.
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The Skin's Barrier: A Cryo-EM Based Overview of its Architecture and Stepwise Formation. J Invest Dermatol 2021; 142:285-292. [PMID: 34474746 DOI: 10.1016/j.jid.2021.06.037] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Revised: 06/28/2021] [Accepted: 06/30/2021] [Indexed: 01/22/2023]
Abstract
A major role of the skin is to serve as a barrier toward the environment. The skin's permeability barrier consists of a lipid structure positioned in the stratum corneum. Recent progress in high-resolution cryo-electron microscopy (cryo-EM) has allowed for elucidation of the architecture of the skin's barrier and its stepwise formation process representing the final stage of epidermal differentiation. In this review, we present an overview of the skin's barrier structure and its formation process, as evidenced by cryo-EM.
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Wennberg CL, Narangifard A, Lundborg M, Norlén L, Lindahl E. Structural Transitions in Ceramide Cubic Phases during Formation of the Human Skin Barrier. Biophys J 2019. [PMID: 29539398 DOI: 10.1016/j.bpj.2017.12.039] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022] Open
Abstract
The stratum corneum is the outermost layer of human skin and the primary barrier toward the environment. The barrier function is maintained by stacked layers of saturated long-chain ceramides, free fatty acids, and cholesterol. This structure is formed through a reorganization of glycosylceramide-based bilayers with cubic-like symmetry into ceramide-based bilayers with stacked lamellar symmetry. The process is accompanied by deglycosylation of glycosylceramides and dehydration of the skin barrier lipid structure. Using coarse-grained molecular dynamics simulation, we show the effects of deglycosylation and dehydration on bilayers of human skin glycosylceramides and ceramides, folded in three dimensions with cubic (gyroid) symmetry. Deglycosylation of glycosylceramides destabilizes the cubic lipid bilayer phase and triggers a cubic-to-lamellar phase transition. Furthermore, subsequent dehydration of the deglycosylated lamellar ceramide system closes the remaining pores between adjacent lipid layers and locally induces a ceramide chain transformation from a hairpin-like to a splayed conformation.
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Affiliation(s)
- Christian L Wennberg
- Department of Physics, Swedish e-Science Research Center, KTH Royal Institute of Technology, Stockholm, Sweden; ERCO Pharma AB, Science for Life Laboratory, Stockholm, Sweden
| | - Ali Narangifard
- ERCO Pharma AB, Science for Life Laboratory, Stockholm, Sweden; Department of Cell and Molecular Biology (CMB), Karolinska Institutet, Stockholm, Sweden
| | - Magnus Lundborg
- ERCO Pharma AB, Science for Life Laboratory, Stockholm, Sweden
| | - Lars Norlén
- Department of Cell and Molecular Biology (CMB), Karolinska Institutet, Stockholm, Sweden; Dermatology Clinic, Karolinska University Hospital, Stockholm, Sweden.
| | - Erik Lindahl
- Department of Physics, Swedish e-Science Research Center, KTH Royal Institute of Technology, Stockholm, Sweden; Department of Biophysics and Biochemistry, Science for Life Laboratory, Stockholm University, Solna, Sweden.
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Norlén L. Current Understanding of Skin Barrier Morphology. Skin Pharmacol Physiol 2013; 26:213-6. [DOI: 10.1159/000351930] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2012] [Accepted: 02/14/2013] [Indexed: 11/19/2022]
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Abstract
We propose that skin barrier morphogenesis may take place via a continuous and highly dynamic process of intersection-free membrane unfolding with a concomitant crystallization of the emerging multilamellar lipid structure representing the developing skin barrier. This implies that the trans-Golgi network and lamellar bodies of the uppermost stratum granulosum cells as well as the multilamellar lipid matrix of the intercellular space at the border zone between stratum granulosum and stratum corneum could be representations of one and the same continuous membrane structure. The profound difference between the earlier Landmann model and the membrane folding model presented here is that the Landmann model includes changes in membrane topology, whereas topology is kept constant during skin barrier formation according to the membrane folding model. The main advantages of the membrane folding model with respect to the Landmann model are the following: (i) smaller energy cost (involves no budding or fusion); (ii) conserves membrane continuity (preserves water compartmentalization and allows control hereof; membrane continuity essential for barrier function); (iii) allows meticulous control (the thermodynamics of the unfolding procedure are related to curvature energy); (iv) faster (milliseconds, as membrane unfolding basically represents a phase transition from cubic-like to lamellar morphology; involves no budding or fusion); (v) membrane folding between lamellar and cubic-like morphologies has been identified in numerous biologic systems; (vi) there is experimental evidence for an "extensive intracellular tubulo-reticular cisternal membrane system within the apical cytosol of the outermost stratum granulosum"; and (vii) may explain the reported plethora of forms, numbers, sizes and general appearances of "lamellar bodies" in transmission electron microscopy micrographs.
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Affiliation(s)
- L Norlén
- Department of Physics, University of Geneva, GAP-Biomedical, Geneva, Switzerland.
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Affiliation(s)
- D Rudikoff
- Department of Dermatology, Mount Sinai Medical Center, New York, New York 10029-6574, USA
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Abstract
BACKGROUND The ideal topical anesthetic agent is one that provides 100% anesthesia in a short period of time, work on intact skin without systemic side effects, and invokes neither pain nor discomfort. The quest to find such an agent continues today. Because a topical anesthetic agent will induce anesthesia painlessly, the need for an effective agent is clear. This will serve to eliminate painful injections with lidocaine prior to many dermatologic procedures. OBJECTIVE To provide a review of topical agents used in the past, to present products that are being used today, and to look to the future of topical anesthesia. CONCLUSIVE: During the last three decades a variety of methods have been employed to administer topical anesthesia. Presently, EMLA (eutectic mixture of local anesthetics) is the most often used method among practicing dermatologists. However, iontophoresis and the anesthetic patch are equally effective with a few notable advantages over EMLA. Liposomal agents show promise as we enter into a new millennium.
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Swartzendruber DC, Burnett IH, Wertz PW, Madison KC, Squier CA. Osmium tetroxide and ruthenium tetroxide are complementary reagents for the preparation of epidermal samples for transmission electron microscopy. J Invest Dermatol 1995; 104:417-20. [PMID: 7861011 DOI: 10.1111/1523-1747.ep12665909] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Ruthenium tetroxide and osmium tetroxide were compared as post-fixatives in the preparation of human epidermis for transmission electron microscopic examination. Both reagents revealed characteristic lamellar granules within the granular layer and extruded lamellar granule contents in the upper granular layer. The transformation of the granule contents into multilamellar sheets at the interface between the granular and cornified layers and the persistence of these sheets through all levels of the stratum corneum were demonstrated only with ruthenium tetroxide fixation. Therefore, the reactivity of osmium tetroxide with isolated epidermal lipids was examined. The failure of osmium tetroxide to reveal membrane structures in the stratum corneum can be explained by its inability to react with many of the lipid components of these membranes, rather than to selective removal of lipids during tissue processing, as was formerly believed. Ruthenium tetroxide, a stronger oxidizing agent than osmium tetroxide, overcomes this problem but has other severe limitations as a post-fixative.
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Panchagnula R, Ritschel WA. Development and evaluation of an intracutaneous depot formulation of corticosteroids using Transcutol as a cosolvent: in-vitro, ex-vivo and in-vivo rat studies. J Pharm Pharmacol 1991; 43:609-14. [PMID: 1685517 DOI: 10.1111/j.2042-7158.1991.tb03548.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
A topical delivery system has been developed using 50% Transcutol (diethylene glycol monoethyl ether) to decrease the body burden of topically administered dexamethasone and hydrocortisone. The delivery system was evaluated in-vitro using a dissolution apparatus to measure the release of steroid from the gel. In 10 h, 29.6 +/- 0.39% dexamethasone and 45.5 +/- 0.84% hydrocortisone was released from the formulation compared with 23.0 +/- 0.48 and 39.9 +/- 0.77%, respectively, from control formulations without Transcutol. Ex-vivo evaluation was made using rat whole skin in a diffusion cell; the amount of steroid reaching the acceptor cell was significantly less from the formulation containing Transcutol compared with controls. There was also a 2-fold increase in the retention of dexamethasone and a 3-fold increase in the retention of hydrocortisone in the skin at the end of the permeation experiments compared with control experiments. In-vivo studies were made using a formulation containing [3H]hydrocortisone applied to rat skin, followed by measurement of total radioactivity in the blood. For the Transcutol formulation the area under the blood concentration-time curve (0-96 h) was 6.06 +/- 1.27 compared with 2.52 +/- 0.43 x 10(6) d min-1 mL-1 h for the control formulation, indicating a 58% reduction in body burden.
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Affiliation(s)
- R Panchagnula
- Division of Pharmaceutics and Drug Delivery Systems, College of Pharmacy, University of Cincinnati Medical Center, OH 45267
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Hou SY, Mitra AK, White SH, Menon GK, Ghadially R, Elias PM. Membrane structures in normal and essential fatty acid-deficient stratum corneum: characterization by ruthenium tetroxide staining and x-ray diffraction. J Invest Dermatol 1991; 96:215-23. [PMID: 1991982 DOI: 10.1111/1523-1747.ep12461361] [Citation(s) in RCA: 245] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Despite the importance of intercellular lamellar bilayers for stratum corneum (SC) barrier function, knowledge about the structure of these bilayers is limited due to their poor visualization and/or retention. Whereas substitution of ruthenium tetroxide (RuO4) for osmium tetroxide fixation provides clear images of these bilayers, the usefulness of RuO4 has been limited by its slow penetration and cytotoxicity. Utilizing a new fixation protocol for RuO4, we obtained clear images of lamellar domains at all levels of murine SC. Computer-aided image reconstructions demonstrated a lamellar spacing of 129 +/- 2 A, which agreed with x-ray diffraction data from parallel, unfixed samples (131 +/- 2 A), a spacing not affected by hydration. Furthermore, novel structures were seen in the intercellular spaces of normal SC. Finally, in murine essential fatty acid deficiency (EFAD), the overall lamellar spacing is comparable to normal [127 +/- 7 A by computer transform vs. 131.9 +/- 2 A (hydrated) and 129.6 +/- 2.2 A (dry) by x-ray diffraction]. Yet, these domains are structurally abnormal, displaying regions with either an excess or absence of lamellae. The new RuO4 protocol provides quantitative information about SC lamellar dimensions and morphologic abnormalities in bilayer distribution and substructure in EFAD stratum corneum that are not detected by either x-ray diffraction or computer-aided image reconstruction. Thus, the barrier abnormality in EFAD stratum corneum can be ascribed either to focal depletion of lamellae or abnormalities in lamellar substructure.
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Affiliation(s)
- S Y Hou
- Dermatology Service, Veterans Administration Medical Center, San Francisco, California 94121
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Elias PM, Menon GK. Structural and lipid biochemical correlates of the epidermal permeability barrier. ADVANCES IN LIPID RESEARCH 1991; 24:1-26. [PMID: 1763710 DOI: 10.1016/b978-0-12-024924-4.50005-5] [Citation(s) in RCA: 425] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
As reviewed in this article, the stratum corneum must now be accorded the respect due to a structurally heterogeneous tissue possessing a selected array of enzymatic activity. The sequestration of lipids to intercellular domains and their organization into a unique multilamellar system have broad implications for permeability barrier function, water retention, desquamation, and percutaneous drug delivery. Yet, the functions and organization of specific lipid species in this membrane system are still unknown. Certain novel insights have resulted from comparative studies in avians and marine mammals. Further elucidation of the molecular architecture and interactions of lipid and nonlipid components of the stratum corneum intercellular domains will be a prerequisite for a comprehensive understanding of stratum corneum function.
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Affiliation(s)
- P M Elias
- Dermatology Service, Veterans Administration Medical Center, San Francisco, California 94121
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Brody I. A light and electron microscopy study of normal human stratum corneum with particular reference to the intercellular space. Ups J Med Sci 1989; 94:29-45. [PMID: 2652847 DOI: 10.3109/03009738909179245] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Intercellular and skin-surface substances, and exfoliating corneocytes, were clearly visualized by both light and electron microscopy. The intercellular space constituted an essential part of the normal human stratum corneum, in the basal and middle zones of which this space was filled with substances producing a compact appearance. The intercellular constituents were a nonhomogeneous substance, intact, single and "compound" lamellar granules and an intensely stained, membrane-like material that in some parts, but not in others, had a lamellar pattern. The artifacts produced by ultrathin sectioning for electron microscopy were too small to provide sufficient explanation for the porous appearance of the superficial zone. More important factors seemed to be enlargement of the intercellular space with decrease in the number of desmosomes and alterations of the intercellular substances, with decrease in the amount of nonhomogeneous substance and transformation of the single and "compound" lamellar granules into single and "compound" vesicular bodies. The hypothesis is advanced that the single and "compound" vesicular bodies together with the decreased amount of nonhomogeneous substance may contribute to maintain the patency of the intercellular space in the superficial zone (stratum disjunctum), thereby facilitating absorption of surface-applied agents into the stratum corneum by some shunt mechanism, while the content of the intercellular space in the basal and middle zones (stratum compactum) forms the principal barrier to free diffusion.
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Affiliation(s)
- I Brody
- Department of Dermatology, General Hospital, Eskilstuna, Sweden
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Elias PM, Cooper ER, Korc A, Brown BE. Percutaneous transport in relation to stratum corneum structure and lipid composition. J Invest Dermatol 1981; 76:297-301. [PMID: 7205031 DOI: 10.1111/1523-1747.ep12526137] [Citation(s) in RCA: 205] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Despite the acknowledged importance of the stratum corneum in limiting water loss and in controlling skin permeability, the basis for these functions remains unknown. To pinpoint those factor(s) of importance for cutaneous barrier function, we correlated the thickness, number of cell layers, and lipid composition of leg vs. abdominal stratum corneum samples with penetration of 3H-water and 14C-salicylic acid across the same tissue sample. Viable upper epidermal sheets were obtained by incubating fresh autopsy or amputation full-thickness skin with staphylococcal exfoliatin. Each sheet was divided into 3 portions. The first piece was mounted in a diffusion cell for penetration studies. The second stratum corneum sample was frozen sectioned, stained with the fluorochrome, ANS, and measured with a micrometer eyepiece. The 3rd piece was pooled with other leg (n = 6) and abdomen (n = 15) specimens for determination of lipid weight percent. In all cases, leg stratum corneum was congruent to 2 times more permeable than abdominal stratum corneum to water and slightly more permeable to salicylic acid, as well. Penetration of both substances correlated inversely with lipid weight % of leg (mean = 3.0%) vs. abdomen (mean = 6.8%), but neither the penetration of water nor of salicylic acid was influenced by the number of cell layers or the thickness of the stratum corneum. We conclude that: differences in the thickness and the number of cell layers in the stratum corneum are insufficient to account for differences in percutaneous transport across leg and abdomen, and that total lipid concentration may be the critical factor governing skin permeability.
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Abstract
The case of a 10 year-old Japanese boy with erythrokeratodermia variabilis is reported in addition to a review of the Japanese literature. The patient was first examined in our clinic on October 21, 1965, because of generalized hyperkeratotic lesions and erythematous lesions which had persisted since he was 3 months old. Hyperkeratotic and verrucous lesions were noted on his auricles and trunk, on which there were also sharply demarcated erythematous lesions of various sizes and shapes which were not elevated from the adjacent skin. Laboratory findings were within normal limits. Histopathological examination revealed a remarkable hyperkeratosis with a basket weave appearance, moderate acanthosis and a slightly thickened granular layer. Polyethylenglycol 400 and corticosteroid ointment were slightly beneficial to the hyperkeratotic lesions.
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Affiliation(s)
- Y Maekawa
- Department of Dermatology, Kumamoto University Medical School, Honjo 1-1-1, Kumamoto 860, Japan
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The ultrastructure of the interfollicular epidermis of the hairless (hr/hr) mouse. ACTA ACUST UNITED AC 1976. [DOI: 10.1007/bf02899155] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Gonzalez LF, Krawczyk WS, Wilgram GF. Ultrastructural observations on the enzymatic activity of keratinosomes. JOURNAL OF ULTRASTRUCTURE RESEARCH 1976; 55:203-11. [PMID: 1271515 DOI: 10.1016/s0022-5320(76)80067-6] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Lavker RM. Membrane coating granules: the fate of the discharged lamellae. JOURNAL OF ULTRASTRUCTURE RESEARCH 1976; 55:79-86. [PMID: 1263304 DOI: 10.1016/s0022-5320(76)80083-4] [Citation(s) in RCA: 151] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
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Raknerud N. The ultrastructure of the interfollicular epidermis of the hairless (hr/hr) mouse. II. Plasma membrane modifications during keratinization. VIRCHOWS ARCHIV. B, CELL PATHOLOGY 1975; 17:113-35. [PMID: 4141812 DOI: 10.1007/bf02912841] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
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Abstract
The structural basis of the permeability barrier in mammalian epidermis was examined by tracer and freeze-fracture techniques. Water-soluble tracers (horesradish peroxidase, lanthanum, ferritin) were injected into neonatal mice or into isolated upper epidermal sheets obtained with staphylococcal exfoliatin. Tracers percolated through the intercellular spaces to the upper stratum granulosum, where further egress was impeded by extruded contents of lamellar bodies. The lamellar contents initially remain segregated in pockets, then fuse to form broad sheets which fill intercellular regions of the stratum corneum, obscuring the outer leaflet of the plasma membrane. These striated intercellular regions are interrupted by periodic bulbous dilatations. When adequately preserved, the interstices of the stratum corneum are wider, by a factor of 5-10 times that previously appreciated. Freeze-fracture replicas of granular cell membranes revealed desmosomes, sparse plasma membrane particles, and accumulating intercellular lamellae, but no tight junctions. Fractured stratum corneum displayed large, smooth, multilaminated fracture faces. By freeze-substitution, proof was obtained that the fracture plane had diverted from the usual intramembranous route in the stratum granulosum to the intercellular space in the stratum corneum. We conclude that: (a) the primary barrier to water loss is formed in the stratum granulosum and is subserved by intercellular deposition of lamellar bodies, rather than occluding zonules; (b) a novel, intercellular freeze-fracture plane occurs within the stratum corneum; (c) intercellular regions of the stratum corneum comprise an expanded, structurally complex, presumably lipid-rich region which may play an important role in percutaneous transport.
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Brody I. The ultrastructure of epidermis in lichen ruber planus as revealed by electron microscopy. 3. Stratum corneum. JOURNAL OF ULTRASTRUCTURE RESEARCH 1973; 43:362-76. [PMID: 4578326 DOI: 10.1016/s0022-5320(73)90015-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
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Hashimoto K. Fine structure of horny cells of the vermilion border of the lip compared with skin. Arch Oral Biol 1971; 16:397-410. [PMID: 4103336 DOI: 10.1016/0003-9969(71)90164-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Brody I. An electron microscopic study of non-fixed and non-dehydrated normal human stratum corneum. ZEITSCHRIFT FUR ZELLFORSCHUNG UND MIKROSKOPISCHE ANATOMIE (VIENNA, AUSTRIA : 1948) 1971; 118:97-112. [PMID: 4103614 DOI: 10.1007/bf00331769] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Obel AL, Nicander L. Epithelial changes in porcine exudative epidermitis. An ultrastructural study. PATHOLOGIA VETERINARIA 1970; 7:329-45. [PMID: 5535252 DOI: 10.1177/030098587000700403] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
The normal fine structure of the epidermis in piglets is similar to that in other mammals. Ten cases of exudative epidermitis were studied in different stages. In acute cases a crust of parakcratotic cells was evident. The cells of the stratum intermedium and the outer layers of the stratum spinosum were swollen and vacuolated. Desmosomes and tonofibrils were reduced in size and number. The intercellular spaces were enlarged and contained an opaque material. In subacute and mild cases the lesions were less pronounced. The healing process was studied in one less severe, acute case. The observations arc interpreted as indicating a primary lesion in the Stratum granulosum and possibly in adjacent cells of the stratum spinosum. No evidence of a bacterial etiology was found. The observed changes are similar to those seen in viral disease of the skin.
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Obel AL. Epithelial changes in porcine exudative epidermitis. The light-microscopical picture. PATHOLOGIA VETERINARIA 1968; 5:253-69. [PMID: 5749199 DOI: 10.1177/030098586800500306] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The cutaneous lesions in 25 spontaneous cases of porcine exudative epidermitis (EE) were studied. During the first 4 days mild acanthosis, increase of cytoplasmic RNA, enlarged nucleoli, and intercellular oedema in the stratum spinosum with formation of vesicles occur. A PAS-positive, diastase-resistant material accumulates in the stratum intermedium. The keratohyaline granules disappear and parakeratotic horn containing abundant protein-bound SH-groups and lipids is produced. Beyond 4 days duration acanthosis and the formation of parakeratotic horn with microabscesses are increased. During healing keratohyaline granules reappear and the formation of normal horn cells is resumed. Acid phosphatase and succinic dehydrogenase are increased in the parakeratotic horn. Lactic acid dehydrogenase is increased in the transitional zone and alkaline phosphatase in the stratum basale. The observations indicate inhibition in the stratum intermedium of the differentiation of epithelial cells to horny cells. The disease is believed to be of viral origin.
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Bonneville MA, Weinstock M, Wilgram GF. An electron microscope study of cell adhesion in psoiatic epidermis. JOURNAL OF ULTRASTRUCTURE RESEARCH 1968; 23:15-43. [PMID: 5670838 DOI: 10.1016/s0022-5320(68)80029-2] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Grubb C, Hackemann M, Hill KR. Small granules and plasma membrane thickening in human cervical squamous epithelium. JOURNAL OF ULTRASTRUCTURE RESEARCH 1968; 22:458-68. [PMID: 5658647 DOI: 10.1016/s0022-5320(68)90034-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
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Hashimoto K, Lever WF. An electron microscopic study on pemphigus vulgaris of the mouth and the skin with special reference to the intercellular cement. J Invest Dermatol 1967; 48:540-52. [PMID: 6028007 DOI: 10.1038/jid.1967.86] [Citation(s) in RCA: 101] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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Rowden G. “Membrane-Coating” Granules of Mouse Oesophageal and Gastric Epithelium**From the Department of Biology, Royal Free Hospital Medical School, London, W.C.1, England. J Invest Dermatol 1966. [DOI: 10.1038/jid.1966.154] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
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