The Heterogeneity of the Keratin Fibers

Mercer, E. H.

doi:10.1177/004051755302300603

Cited by 135 publications

(61 citation statements)

References 19 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Disposition of the cortical segments, on the other hand, is related to crimp form (Fraser and Rogers 1953;Horio and Kondo 1953;Mercer 1953;Ahmad and Lang 1957;Glynn, Lang, and Wardle 1960;and present results), and to some extent to fibre thickness (Fraser and Rogers 1955;Ahmad and Lang 1957;Thorsen 1958). Poorly crimped fibres exhibit segmental distributions not observed in well-crimped fibres (see Section III), and are produced by follicles with gross irregular enlargements of the outer root sheaths adjacent to the supra-bulbar and keratogenous zones of the fibres (Chapman, Short, and Hyland 1960).…”

Section: Discussionsupporting

confidence: 58%

“…If the period between the final division of a cell and completion of its subsequent hardening approaches half the time of formation of a crimp, the changes in follicle configuration would be such that a cell which hardens on the inside of a crimp, i.e. in the paracortex (Fraser and Rogers 1953;Horio and Kondo 1953;Mercer 1953), and apparently on the thin side of the follicle would have formed on the concave side of the bulb flexure adjacent to the thickened portion of the outcr root sheath.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Crimp in Wool: Cortical Segmentation and Tensile Properties of Well-Crimped and Abnormally Crimped Fibres of Merino Wool

Chapman¹

1965

Aust. Jnl. Of Bio. Sci.

View full text Add to dashboard Cite

SummaryPoorly crimped (or doggy) fibres, produced by follicles with hyperplasia of the outer root sheath tissue, have greater proportions of paracortex than adjacent wellcrimped fibres. Associated with this increase in paracortex is an increase in strength, as indicated by significant increases in the stresses in wet poorly crimped fibres at the turnover and breaking points on the stress-strain curve. Use of the stronger mechanical properties of doggy fibres as a means of distinguishing such fibres from the poorly crimped fibres in steely wool, produced by sheep on a copper-deficient diet, is proposed.The possibility that the state of follicle outer root sheaths can influence the distribution and proportions of the cortical segments in the wool fibres produced is discussed.

show abstract

Section: Discussionsupporting

confidence: 58%

Section: Discussionmentioning

confidence: 99%

Crimp in Wool: Cortical Segmentation and Tensile Properties of Well-Crimped and Abnormally Crimped Fibres of Merino Wool

Chapman¹

1965

Aust. Jnl. Of Bio. Sci.

View full text Add to dashboard Cite

show abstract

“…The concept of ortho-and paracortex was first proposed for the bilateral segmentation observed in fine wool fibres (Fraser and Rogers 1953;Horio and Kondo 1953;Mercer 1953) and this was later expanded to include a component of intermediate morphology, designated mesocortex (Rogers 1959a, b;Brown and Onions 1960;Bones and Sikorski 1967). Electron microscopy of metalstained thin sections (Rogers 1959a, b) indicated that each of the cortical cell types contained a different proportion and arrangement of microfibrils.…”

Section: Cortical Keratin Synthesismentioning

confidence: 99%

Hair Keratin: Composition, Structure and Biogenesis

Powell

Rogers

1986

Biology of the Integument

View full text Add to dashboard Cite

“…The residue (Fig. 1.8) consists of cell membranes, nuclei, and other cytoplasmic constituents (23). (b) and (c) Arrangements of filaments within the keratin fibrils giving the appearance of whorls or finger prints which are shown in Fig.…”

Section: Human Hair Follicle Partmentioning

confidence: 99%

The Electron Microscopy of the Human Hair Follicle

Birbeck

Mercer

1957

The Journal of Cell Biology

247

View full text Add to dashboard Cite

1. The presumptive cortical cells of hair in the undifferentiated matrix of the bulb contain mitochondria, agranular vesicles, and many small dense R.N.P. particles, but no keratin, pigment granules, or endoplasmic reticulum. 2. In the mid-bulb region intercellular adhesion is limited to small localised areas. Intercellular gaps are common and the cell surfaces are irregularly convoluted. The melanocyte processes penetrate the cell gaps. The relation between their pigment-bearing tips and the involutions of the cell membranes suggests an active phagocytosis of the tips. 3. Fibrous keratin first appears in loose parallel strands of fine filaments (ca. 60 A diameter) in the mid-bulb. The filaments, the long mitochondria, and elongated nucleus are all parallel to the long axis of the cell and the axis of the follicle. 4. At the level of the constriction of the bulb and above, a dense amorphous substance appears between the fine filaments and apparently acts as adhesive cement. The bundles of filaments now form well defined fibrils. The packing of the filaments within the fibrils is in places hexagonal and elsewhere in the form of "whorls." 5. At higher levels further filaments and interfilamentous cement are added together and the whole cytoplasmic space becomes packed with fibrils which finally condense to massive blocks of keratin. The residual cellular material occupies the interstices. 6. The addition of the interfilamentous substance is regarded as an essential factor in keratinisation. Keratin is considered to be a complex made of fine filaments (α-filaments) embedded in an amorphous substance (γ-keratin) which has the higher cystine content. 7. The wide-angle fibre-type x-ray pattern is thought to be due to scattering by the fine α-filaments and some low angle lateral spacings to the filament-plus-cement structure.

show abstract

The Heterogeneity of the Keratin Fibers

Cited by 135 publications

References 19 publications

Crimp in Wool: Cortical Segmentation and Tensile Properties of Well-Crimped and Abnormally Crimped Fibres of Merino Wool

Crimp in Wool: Cortical Segmentation and Tensile Properties of Well-Crimped and Abnormally Crimped Fibres of Merino Wool

Hair Keratin: Composition, Structure and Biogenesis

The Electron Microscopy of the Human Hair Follicle

Contact Info

Product

Resources

About