scholarly journals Studies in Depilation IV. Structural Changes in the Wool Follicle During Depilation With Alkali and Alkaline Reducing Systems

1968 ◽  
Vol 21 (4) ◽  
pp. 795
Author(s):  
JR Yates
Keyword(s):  
Structural Changes ◽  
Cell Structure ◽  
Ammonia Solution ◽  
Wool Fibre ◽  
Sodium Sulphide ◽  
Outer Root Sheath ◽  
Root Sheath ◽  
Wool Follicle

Structural changes in the wool follicle during depilation with sodium sulphide and with ammonia are described. Sodium sulphide exerts its principal action on the prekeratinous zone of the wool fibre, but also dissolves the lower part of the outer root sheath (ORS). The fibre breaks off in the prekeratinous zone and is easily removed with virtually no disturbance of the upper ORS or the epidermis, leaving a degraded bulb still in position. Ammonia solution (1M) causes a severe disruption of the cell structure of the ORS and some disorganization of the prekeratinous zone, but does not cause sufficient protein dissolution to permit depilation to go to completion.

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 in Depilation VII. Structural Changes in the Wool Follicle During Depilation With Acid and Enzyme Systems

1968 ◽  
Vol 21 (6) ◽  
pp. 1249
Author(s):  
JR Yates
Keyword(s):  
Acetic Acid ◽  
Enzyme Preparation ◽  
Structural Changes ◽  
Morphological Changes ◽  
Outer Root Sheath ◽  
Early Separation ◽  
Enzyme Systems ◽  
Root Sheath ◽  
Cylindrical Form ◽  
Wool Follicle

Structural changes in the wool follicle during depilation with acetic acid, crystalline trypsin, and a commercial enzyme preparation, Pancrozyme C1A, are described. A number of the morphological changes produced by acetic acid and Pancrozyme C1A are similar. Both cause early separation of the epidermal and outer root sheath (ORS) structures from the underlying tissues, and the resistance to fibre withdrawal at this stage is due largely to the physical obstruction of the ORS material. In both cases the separated ORS assumes a tightly packed cylindrical form around the fibre and is gradually digested away until there is no longer any resistance to fibre removal. In both cases separation of the fibre ultimately occurs in the lower part of the prekeratinous zone just above the bulb.

Distribution of acidic and basic fibroblast growth factors in ovine skin during follicle morphogenesis

1993 ◽  
Vol 105 (3) ◽  
pp. 667-674
Author(s):  
D.L. du Cros ◽  
K. Isaacs ◽  
G.P. Moore
Keyword(s):  
Growth Factors ◽  
Fibroblast Growth Factors ◽  
Follicle Cell ◽  
Fibroblast Growth ◽  
Basal Cells ◽  
Outer Root Sheath ◽  
Intermediate Layers ◽  
Root Sheath ◽  
Wool Follicle ◽  
Cell Aggregations

Acidic and basic fibroblast growth factors (aFGF and bFGF) have been localized by immunochemistry in ovine skin during wool follicle morphogenesis. At 40 days of gestation, prior to the appearance of follicle primordia, bFGF immunoreactivity was detected in the intermediate and periderm layers of the epidermis and at the dermal-epidermal junction. Antibodies to aFGF did not bind to skin at this age. During early follicle formation, at 76 days of gestation, both FGFs were found in the epidermis and associated with the follicle primordia. Antibodies to aFGF, in particular, bound to the basal cells of the epidermis and the follicle cell aggregations. With the development of epidermal plugs, bFGF was confined to the intermediate layers of the epidermis and the dermal-epidermal junction, whereas aFGF staining was associated with the cells of the epidermis and the plugs. At 90 days, when many different stages of follicle development were in evidence, immunoreactivity for both FGFs was associated with the cells of the elongating epidermal column, particularly those adjacent to the dermal-epidermal junction. During follicle maturation, bFGF was found in the suprabasal layer of the epidermis, in the outer root sheath of the follicle and in the basement membrane zone surrounding the bulb matrix. Conversely, strong staining for aFGF was observed in the epidermis and pilary canal contiguous with the epidermis, and in cells of the upper bulb matrix of the follicle in the region of the keratogenous zone. Western blotting of extracts of mature follicles that had been isolated from the skin showed the presence of a major aFGF immunoreactive band with an apparent molecular mass of 27 kDa.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Regulation of prolactin receptor expression in ovine skin in relation to circulating prolactin and wool follicle growth status

2002 ◽  
Vol 172 (3) ◽  
pp. 605-614 ◽  
Author(s):  
AJ Nixon ◽  
CA Ford ◽  
JE Wildermoth ◽  
AJ Craven ◽  
MG Ashby ◽  
...  
Keyword(s):  
In Situ Hybridisation ◽  
Dermal Papilla ◽  
Hair Follicles ◽  
Receptor Expression ◽  
Ribonuclease Protection Assay ◽  
Plasma Prolactin ◽  
Follicle Growth ◽  
Outer Root Sheath ◽  
Root Sheath ◽  
Wool Follicle

Seasonal patterns of hair growth are governed, at least in part, by levels of prolactin in circulation, and although receptors for prolactin (PRLR) have been demonstrated in hair follicles, little is known of their regulation in relation to follicular cycles. In this study, a photoperiod-generated increase in prolactin was used to induce a wool follicle cycle during which changes in PRLR expression in sheep skin were determined by ribonuclease protection assay and in situ hybridisation. mRNA for prolactin and both isoforms of PRLR were also detected in skin by reverse transcription and polymerase chain reaction. As circulating prolactin began to rise from low levels, PRLR mRNA in the skin initially fell. These changes immediately preceded the catagen (regressive) phase of the hair cycle. Further increase in prolactin resulted in up-regulation of PRLR during telogen (dormancy), particularly in the epithelial hair germ, to reach a peak during proanagen (reactivation). In anagen (when follicle growth was fully re-established), PRLR mRNA returned to levels similar to those observed before the induced cycle. Hence, this longer term rise and fall of PRLR expression followed that of plasma prolactin concentration with a lag of 12-14 days. PRLR mRNA was most abundant in the dermal papilla, outer root sheath, hair germ, skin glands and epidermis. Location of PRLR in the dermal papilla and outer root sheath indicates action of prolactin on the growth-controlling centres within wool follicles. These cycle-related patterns of PRLR expression suggest dynamic regulation of PRLR by prolactin, thereby modulating hormonal responsiveness of seasonally growing hair follicles.

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.

Observations on the wool follicle abnormalities in Merino sheep exposed to prolonged wetting conducive to the development of fleece-rot

1977 ◽  
Vol 28 (6) ◽  
pp. 1095 ◽  
Author(s):  
T Nay ◽  
JE Watts
Keyword(s):  
Wool Fibre ◽  
Histopathological Changes ◽  
Merino Sheep ◽  
Fibre Breakage ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Vertical Distributions ◽  
Wool Follicle ◽  
Preliminary Study ◽  
Horizontal And Vertical Distributions

Groups of sheep found to be resistant and susceptible to fleece-rot following prolonged periods of natural and experimental rainfall were used in a preliminary study of the histopathological changes associated with the development of this condition. Wool follicle abnormalities affecting the growth of the wool fibre and inner root sheath were frequently observed. Weakened stretches of fibres, which appeared to result from impaired keratinization, were the sites of fibre breakage in the skin. Hypertrophic thickening and duplication of the inner root sheath occurred, and this material encased the proximal ends of broken fibres to form 'plugs'. The plugs grew vigorously in sheep that developed fleece-rot, apparently breaking the continuity of the skin as they emerged into the fleece. Fragments of plugs, broken wool fibres and exudate were present in fleece-rot bands along with cornified epithelial cells. Attempts to quantify the frequency of these abnormalities were complicated by marked variations in their horizontal and vertical distributions in the skin.

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.

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