Electron Microscope Studies of the Chemical Reactivity in Keratin Cuticle

Sikorski, J.; Simpson, W. Sparrow

doi:10.1038/1821235a0

Cited by 23 publications

(4 citation statements)

References 14 publications

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“…The general pattern of staining was similar to that observed when sections were treated with silver nitrate solution for up to 24 hours and similar to that reported by other workers who have stained keratin fibres in bulk with silver nitrate prior to sectioning (Dobb & Sikorski, 1961). In summary, a narrow layer approximately 60 nm thick ectal to each cuticle cell and known as the a-layer (Sikorski & Simpson, 1958) was intensely stained. A broader layer approximately 0.2 pm thick immediately adjacent to the a-layer (the exocuticle) and a somewhat narrower layer adjacent to the cuticle cell membrane on the ental side of the cell, were also stained though with less intensity than that of the a-layer.…”

Section: R E S U L T Ssupporting

confidence: 88%

The electron histochemistry of cystine—containing proteins in thin transverse sections of human hair

Swift

1968

Journal of the Royal Microscopical Society

108

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S Y N O P S I SWhen thin sections of human hair are treated with a solution containing silver nitrate and hexamethylene tetramine (Gomori's silver-methenamine reagent) under alkaline conditions not only does morphological staining of the sections occur but with increasing time of treatment metallic silver particles are also produced in the sections. It is shown that these particles are the results of the interaction of the reagent with cystine.The metal-precipitation technique was used to determine the location and distribution of cystine in Caucasian human hair.

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Section: R E S U L T Ssupporting

confidence: 88%

The electron histochemistry of cystine—containing proteins in thin transverse sections of human hair

Swift

1968

Journal of the Royal Microscopical Society

108

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“…The most resistant part of the exocuticle is an electron dense layer bordering the external edge of the cell. This layer (A-layer, Sikorski and Simpson, 1958) forms ribbon-like structures observable even at the most advanced decomposition stages (Fig. 5 ) .…”

Section: Resultsmentioning

confidence: 98%

“…Thus, its maximal resistance t o keratinolysis is not surprising. A similar highly keratinized layer accompanies the internal cytoplasmic membrane of cuticular cells (Sikorski and Simpson, 1958;Swift, 1968;Dobb et al, 1972). It is essentially thinner and can be observed usually after reduction of the hairs only.…”

Section: Discussionmentioning

confidence: 96%

An Electron Microscopy Study of Keratin Degradation by the Fungus Microsporum gypseum in vitro

Kunert

Krajčí

2009

Mycoses

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Summary: The authors examined by means of transmission electron microscopy the keratin degradation in human hair invaded by the dermatophyte Microsporum gypseum in vitro. Initial growth of the fungus in hair was intercellular; later on, the hyphae were found mostly inside the cells. The digestion showed all features of an enzymatic breakdown. Mechanical action of penetrating mycelia on surrounding cells could be observed in the cuticle only. The sequence of degradation of the individual hair components corresponded to their degrees of keratinization viz. to the cystine content. In the cuticle, the structures first invaded were the nonkeratinous cell membrane complex and the endocuticle containing cytoplasmic remnants. The exocuticle and especially its A‐layer were more resistant. A similar resistant layer was found below the inner membrane of cuticular cells. In the cortex, the cell membrane complex and cytoplasmic residues inside the cells were again digested first. Macrofibril bundles were disintegrated from the surface as well as from the centre. Marked increase of overall osmiophilia was typical of the places of the most intensive degradation. The fungus digested both structural components of the “hard” keratin‐microfibrils (filaments) and matrix. However, in the final phases of keratinolysis the remnants of the matrix retained their form a little longer. Zusammenfassung: Die Autoren untersuchten mit Hilfe der Transmissions‐Elektronen‐mikroskopie den Keratinabbau bei menschlichen Haaren, befallen durch den Dermatophyten Microsporum gypseum in vitro. Die Hyphen im Haar wuchsen zuerst interzellulär, später befanden sie sich aber meist im Innern der Zellen. Der Keratinabbau wies alle Zeichen einer enzymatischen Lyse auf. Die mechanische Wirkung des durchwachsenden Myzels auf die umliegenden Zellen wurde nur in der Cuticula beobachtet. Die Reihenfolge des Abbaues der einzelnen Haarbestandteile entsprach ihrem Keratinisierungsgrad bzw. ihrem Cystingehalt. In der Cuticula wurden zuerst die nicht aus Keratin bestehende Interzellular‐Lamelle und die Endocuticula mit zytoplasmatischen Resten verdaut. Die Exocuticula und besonders ihre “A‐Schicht” waren widerstandsfähiger. Eine ähnliche resistente Schicht wurde unter der inneren Plasmamembran der Cuticula‐Zellen gefunden. Auch im Cortex wurden die Interzellular‐Lamelle und die zytoplasmatischen Reste unter den Makrofibrillen am schnellsten gelöst. Die Makrofibrillen‐Bündel wurden nicht nur von der Oberfläche, sondern auch von der Mitte her desintegriert. An den Stellen des intensiv verlaufenden Abbaues wurde eine deutliche Erhöhung der Osmiophilie beobachtet. Der Pilz verdaute beide Strukturkomponenten des “harten” Keratins, die Fibrillen (Filamente) und die Matrix. In den letzten Phasen der Auflösung blieben aber die Matrix‐Reste etwas länger erhalten.

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“…B. The structure of biological cell membranes proposed by Sj6strand [10). unit membranes postulated by S jostrand ~11].…”

Section: Discussionmentioning

confidence: 99%

Degradation of Human Hair by Papain

Swift

Holmes

1965

Textile Research Journal

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Papain/bisulfite is shown to disintegrate the cuticle of human hair by dissolution of the endocuticle. Ethanol extraction removes cell membrane material, which is presumed to allow increased access of the enzyme and hence speed disintegration of the hair. In addition it has been shown that a thin layer of electron transparent material is also removed from the surface of the hair by hot ethanol extraction. It is suggested that this component of the fiber may be regarded as the epicuticle described previously. The origin and nature of this material is discussed.

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Electron Microscope Studies of the Chemical Reactivity in Keratin Cuticle

Cited by 23 publications

References 14 publications

The electron histochemistry of cystine—containing proteins in thin transverse sections of human hair

The electron histochemistry of cystine—containing proteins in thin transverse sections of human hair

An Electron Microscopy Study of Keratin Degradation by the Fungus Microsporum gypseum in vitro

Degradation of Human Hair by Papain

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