scholarly journals Cell Differentiation in the Lower Outer Sheath of the Romney Wool Follicle: A Companion Cell Layer

1971 ◽  
Vol 24 (4) ◽  
pp. 989 ◽  
Author(s):  
DFG Orwin
Keyword(s):  
Cell Layer ◽  
Skin Surface ◽  
Morphological Evidence ◽  
Companion Cell ◽  
Outer Root Sheath ◽  
Outer Sheath ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Wool Follicle ◽  
Outer Root Sheath Cells

Morphological evidence is presented showing that, in the Romney wool follicle, the layer of cells in the outer root sheath lying next to Henle's layer differentiates in the bulb as a separate and distinct layer from other outer root sheath cells. The term "companion cell layer" is suggested for this layer. Its possible role in the movement of the inner root sheath toward the skin surface is discussed.

scholarly journals Migration and Keratinization of Cells in Wool Follicles

1980 ◽  
Vol 33 (5) ◽  
pp. 587 ◽  
Author(s):  
RE Chapman ◽  
AM Downes ◽  
PA Wilson
Keyword(s):  
Distal Part ◽  
Follicle Cells ◽  
Outer Root Sheath ◽  
Proximal Half ◽  
Outer Sheath ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Outer Root Sheath Cells ◽  
Migration Of Cells ◽  
Sheath Cells

Migration of' cells in wool follicles of an adult Merino sheep was studied autoradiographically in skin samples taken at intervals after an intravenous injection of [3Hjthymidine. Fibre arid inner root sheath cells incorporated [3Hjthymidine in a cone-shaped region of the follicle bulb. Labelled inner sheath cells migrated out of the bulb ahead of contemporaneous cells in the fibre and remained in advance, although to a progressively lesser extent, until the inner sheath cells sloughed into the follicle lumen. Outer root sheath cells incorporated [3Hjthymidine along the length of the follicle. Cells in the proximal half of the outer sheath migrated inwards and distally and sloughed into the follicle lumen before contemporaneous inner sheath cells. Other cells in the distal half of the outer sheath migrated past the level where cells from the proximal population were shed and also sloughed into the lumen. In the most distal part of the outer sheath, which formed the epidermis-like lining of the follicle canal, little migration of cells was observed during 8 days of observation.

scholarly journals Studies In Depilation Ii. Structural Ohanges in the Wool Follicle During Bacterial Wool Loosening ("Sweating")

1968 ◽  
Vol 21 (2) ◽  
pp. 361 ◽  
Author(s):  
JR Yates
Keyword(s):  
Epidermal Cells ◽  
Wool Fibre ◽  
Fat Cells ◽  
Elastic Tissue ◽  
Structural Components ◽  
Outer Root Sheath ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Wool Follicle ◽  
Histological Staining

The changes in the various structural components of the wool follicle during the "sweating" process were followed by histological staining of sections prepared from the skin at appropriate intervals. Tissue breakdown starts in the lower part of the outer root sheath, progresses up the sheath, and ultimately involves the epidermis. The epidermis usually separates from the underlying dermis at a certain stage in the depilation process before the epidermal cells start to disintegrate. The gradual breakdown of the cells of the wool root bulb is an integral part of the wool� loosening process. The inner root sheath, the elastic tissue, and the fat cells are all broken down during depilation, but this is incidental to, and not the cause of, the loosening of the wool fibre. Sulphated mucopolysaccharides are gradually removed from the skin during depilation.

scholarly journals Studies on the Follicle Bulb of Fibres I. Mitotio and Cellular Segmentation in the Wool Follicle With Reference to Ortho·and Parasegmentation

1964 ◽  
Vol 17 (2) ◽  
pp. 521 ◽  
Author(s):  
EB Fraser
Keyword(s):  
Mitotic Activity ◽  
Density Gradient ◽  
Cell Layer ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Wool Follicle

IThere is a gradient in the density of cells in mitosis which decreases in a proximodistal direction. Mitotic activity ends at a height one cell layer above the apex of the papilla. The decreasing mitotio density gradient commences at a level, in all bulbs, coincident with the proximal limit of differentiation of Henle's layer of the inner root sheath.

A Selectable Biomarker in Hair Follicle Cycles – Cathepsins: A Preliminary Study in Murine

2021 ◽  
pp. 1-7
Author(s):  
Jingzhu Bai ◽  
Zijian Gong ◽  
Qingfang Xu ◽  
Haiyan Chen ◽  
Qiaoping Chen ◽  
...  
Keyword(s):  
Hair Follicle ◽  
Hair Cycle ◽  
Biological Factors ◽  
Outer Root Sheath ◽  
Physiological Processes ◽  
Intervention Measures ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Preliminary Study ◽  
Paraffin Method

<b><i>Background/Objective:</i></b> Hair cycle is regulated by many biological factors. Cathepsins are involved in various physiological processes in human skin. Here, we investigated the cathepsin expression and distribution changes in follicular growth cycles for better understanding the hair cycles and to explore new intervention measures. <b><i>Methods:</i></b> The 24 mice (C57BL/6, female, 7-week old) were selected and removed the back hair via rosin/paraffin method. At Day 8, Day 20, and Day 25, biopsy on post-plucking area was done. Immunohistochemical staining, Western blot, and Q-PCR were used to test the cathepsin B/D/L/E. <b><i>Results:</i></b> In anagen, cathepsins (B, D, L, and E) were distributed in the hair follicle matrix, inner hair root sheath, and hair. In catagen, cathepsins were mainly observed in un-apoptosis inner root sheath and outer root sheath. Expression of cathepsins B-mRNA and L-mRNA was decreased from anagen and catagen to telogen. Cathepsin D-mRNA was increased in catagen and then decreased in telogen. Cathepsin E-mRNA was decreased in catagen and slightly increased in telogen. <b><i>Conclusions:</i></b> The distribution and expression of cathepsins B, D, L, and E in hair follicle changed with hair growth process which indicated that cathepsins might act as selectable biomarkers of hair cycle in different stages.

scholarly journals THE ELECTRON MICROSCOPY OF THE HUMAN HAIR FOLLICLE

1957 ◽  
Vol 3 (2) ◽  
pp. 223-230 ◽  
Author(s):  
M. S. C. Birbeck ◽  
E. H. Mercer
Keyword(s):  
Hair Follicle ◽  
Cross Sections ◽  
Plasma Membranes ◽  
Membrane Complex ◽  
Outer Sheath ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Cell Layers ◽  
Adhesive Contacts ◽  
Similar Complex

1. The three cylinders of cells, each one cell thick, which together constitute the inner root sheath, arise from the peripheral portions of the undifferentiated matrix. These cells, like the hair cuticle, are stabilised by the spread of adhesive contacts between their plasma membranes which occurs in the mid-bulb and upper bulb of the hair follicle. 2. The characteristic intracellular product of all three cell layers is trichohyaline. This substance is formed in the first place as amorphous droplets which subsequently transform into a birefringent form. 3. This transformation, involving the formation of a birefringent product from an amorphous precursor, is in contrast to the formation in the cortex of keratin which originates in a fibrous form. 4. Trichohyaline appears first and transforms first in the cells of Henle which are nearest the outer sheath and the dermal supply vessels. This transformation occurs at the level of the neck of the follicle. Synthesis and transformation in the cells of Huxley and the sheath cuticle lag behind the similar events in the cells of Henle. The transformation does not begin until the lower prekeratinous zone in the Huxley and cuticle cells. 5. The amorpous-fibrous transformation occurs rapidly cell by cell and involves the conversion of all the trichohyaline droplets. In longitudinal sections the birefringent modification can be seen extending from the droplets in both directions parallel to the axis of the hair. In cross-sections the images of the transformed material are difficult to interpret. They may be seen as sections of corrugated sheets (∼100 A thick) or condensed fibrils ∼100 A in width. 6. At the same time that the trichohyaline transforms, the spacing between the cell membranes increases and a dark deposit appears centrally between them. This membrane complex, and the similar complex of the hair cuticle cells described in Part 2, may be specialised formations whose purpose is to hold the hardened cells together.

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