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 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.

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.

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.

Wool follicle morphology and cell proliferation in New Zealand Romney sheep: a seasonal comparison of fleeceweight-selected and control rams

1994 ◽  
Vol 45 (4) ◽  
pp. 769 ◽  
Author(s):  
SA Holle ◽  
PM Harris ◽  
AS Davies ◽  
MJ Birtles
Keyword(s):  
New Zealand ◽  
Three Dimensional ◽  
Dermal Papilla ◽  
Proliferating Cells ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Dimensional Measurements ◽  
Wool Follicle ◽  
Seasonal Influences ◽  
And Control

Effects of selection for high fleeceweight in the New Zealand Romney sheep were investigated in relation to the morphology of individual follicles and changes in the germinative cell population of the follicle bulb. Two-year-old Romney rams, 10 from each of two selection lines (Massey University fleeceweight-selected (FWT) and control (CLT) flock), were run together on pasture for a period from June to early December. At three times during this observation period (June, August and November) skin samples were taken from their midside flanks after local injection of bromodeoxyuridine (BrdU), to assess proliferation of bulb cells and several dimensional measurements of the follicle bulb and dermal papilla. FWT sheep had larger follicle dimensions than CLT sheep during winter and summer, with a greater number of proliferating bulb cells. Both flocks showed a seasonal change in follicle size, with a decline during winter, but the size of the dermal papilla was less affected than the germinative tissue area. Measurements of proliferation density (number of proliferating cells per area/volume of bulb tissue) suggest that changes in proliferation density do not contribute to flock differences in fleece production. However, during summer, FWT showed a 40% advantage over CLT sheep in hourly cell production based on data from three dimensional follicle bulb extrapolation. The different genotypes showed variations in width, as well as area of cortex and inner root sheath (IRS), measured across the top of the dermal papilla. The expression of these differences was further enhanced through seasonal influences, suggesting that there is an interaction between genetic/flock influences and seasonal influences on cell distribution to cortex and inner root sheath.

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)

Cell Migration in Wool Follicles of Sheep

1971 ◽  
Vol 9 (3) ◽  
pp. 791-803 ◽  
Author(s):  
R. E. CHAPMAN
Keyword(s):  
Cell Migration ◽  
Tritiated Thymidine ◽  
Proximal Part ◽  
Outer Root Sheath ◽  
Migration Rates ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Skin Biopsies ◽  
Migration Of Cells ◽  
Definitive Form

The migration of cells in wool follicles was studied by autoradiography of skin biopsies taken at half-day intervals from 2 to 5 days after intradermal injections of tritiated thymidine in 8 Corriedale sheep on different planes of nutrition. Cell migration rates were not the same in all follicles. Therefore, the shortest and longest times for cells to migrate to defined levels in the follicles were determined. Cells of the inner root sheath moved up the proximal part of some follicles ahead of contemporaneously formed cells in the fibre. Subsequently, cells in the fibre reached the level where the fibre attained its definitive form in about 2.5-4 days. Cell migration also occurred in the outer root sheath, and sloughing of both outer and inner root sheath cells was observed. In the distal half of the follicles, cells of the root sheaths and of the fibre migrated at similar rates, which suggested that the inner root sheath and fibre were carried through the upper part of the follicle by migrating cells of the outer root sheath. Cell migration times were about 0.5 day less in fat sheep on large and moderate food intakes than in lean sheep on restricted intakes.

scholarly journals Theoretical Mechanism for Crimp

1981 ◽  
Vol 34 (2) ◽  
pp. 189 ◽  
Author(s):  
B N Nagorcka
Keyword(s):  
Mathematical Model ◽  
Cortical Cells ◽  
Rotational Movement ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Wool Follicle ◽  
Theoretical Mechanism

A mechanism for crimp in wool fibres is proposed in which the inner root sheath of the wool follicle and the fibre cuticle rotate around the fibre cortex in the region just above the follicle bulb. The rotational movement of the fibre cuticle is passed on to groups of microfibrils in the cortical cells of the fibre through a gearing action, which causes them to be twisted into helices or spirals with the result that the cortical cells tend to shorten. The fibre deforms while still in the follicle causing the position of the fibre cortex near the bulb to change. This changes the magnitude and direction of the rotational movement of the inner root sheath and cuticle. A mathematical model of the mechanism is developed and several crimp forms, produced by using the model, are compared to those commonly observed.

Sign in / Sign up

Export Citation Format

Share Document