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 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.

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.

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.

scholarly journals Trichohyalin, an intermediate filament-associated protein of the hair follicle.

1986 ◽  
Vol 102 (4) ◽  
pp. 1419-1429 ◽  
Author(s):  
J A Rothnagel ◽  
G E Rogers
Keyword(s):  
Molecular Weight ◽  
Hair Follicle ◽  
Polyclonal Antibodies ◽  
Side Chain ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Arginine Residues ◽  
Wool Follicle ◽  
Sheep Wool

A precursor protein associated with the formation of the citrulline-containing intermediate filaments of the hair follicle has been isolated and characterized. The protein, with a molecular weight of 190,000, was isolated from sheep wool follicles and purified until it yielded a single band on a SDS polyacrylamide gel. The Mr 190,000 protein has a high content of lysine and glutamic acid/glutamine residues and is rich in arginine residues, some of which, it is postulated, undergo a side chain conversion in situ into citrulline residues. Polyclonal antibodies were raised to the purified protein, and these cross-react with similar proteins from extracts of guinea pig and human follicles and rat vibrissae inner root sheaths. Tissue immunochemical methods have localized the Mr 190,000 protein to the trichohyalin granules of the developing inner root sheath of the wool follicle. We propose that the old term trichohyalin be retained to describe this Mr 190,000 protein. Immunoelectron microscopy has located the Mr 190,000 protein to the trichohyalin granules but not to the newly synthesized filaments. This technique has revealed that trichohyalin becomes associated with the filaments at later stages of development. These results indicate a possible matrix role for trichohyalin.

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 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.

scholarly journals Immunolocalization Studies of the High-sulfur Protein Fraction of Merino Wool using Monoclonal Antibodies

1987 ◽  
Vol 40 (3) ◽  
pp. 249 ◽  
Author(s):  
Peter W French ◽  
Dean R Hewish
Keyword(s):  
High Performance Liquid Chromatography ◽  
Monoclonal Antibodies ◽  
Liquid Chromatography ◽  
High Performance ◽  
Merino Sheep ◽  
Merino Wool ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Sulfur Protein ◽  
Antibody Localization

Monoclonal antibodies raised to the high-sulfur fraction of solubilized wool protein were used to study the location of these proteins in sections of Merino sheep skin, using indirect immunofluorescence. Poor antibody binding was observed to untreated wool follicles, but mild trypsin digestion of the sections allowed penetration of the antibodies and specific antibody localization was observed. The high-sulfur protein monoclonal antibodies bound to the cells of the wool cortex in the keratogenous zone, and to the cells of the inner root sheath and fibre cuticle regions. The specificities of the antibodies were determined by their binding to high-sulfur proteins separated using high-performance liquid chromatography.

Changes in wool growth and the skin of Merino sheep following administration of cyclophosphamide

1974 ◽  
Vol 25 (6) ◽  
pp. 931 ◽  
Author(s):  
PJ Reis ◽  
RE Chapman
Keyword(s):  
Body Weight ◽  
Sweat Glands ◽  
Sebaceous Glands ◽  
Merino Sheep ◽  
Length Growth ◽  
Wool Growth ◽  
Root Sheath ◽  
Inner Root Sheath ◽  
Fibre Growth ◽  
Pre Treatment

Two Merino sheep were dosed orally, and two intravenously, with cyclophosphamide at the rate of 30 mg/kg body weight; the effects on wool growth were measured, and changes in the histology of skin and of wool follicles were studied. All sheep were readily defleeced following treatment. This effect was associated with a complete cessation of wool growth for a period of about 2 weeks with oral dosing and 2½ weeks with intravenous dosing. There was considerable variation in the time taken for new fibres to commence growth. Length growth rates during the period 28–36 days after dosing were consistently greater than pre-treatment rates. Post-treatment fibre diameters were variable compared with the pretreatment values. The extent to which the enhanced length growth after dosing would compensate for the loss of wool growth requires further investigation. Degenerative changes were observed in some wool follicles 1 hr after dosing, and proliferation of cells of the fibre and inner root sheath appeared to have ceased at 1 day. Fibre growth ceased prior to 4 days. Regeneration of most follicles commenced prior to 14 days after dosing, and regrowth of wool was apparent above the skin by 21 days. A small proportion of follicles was still inactive after 36 days. Changes were observed in the sebaceous and sweat glands, epidermis and dermis following dosing. Even 36 days after dosing, sebaceous glands were considerably enlarged and excess stratum corneum remained on the epidermis. Infiltration of the dermis by lymphocytes was observed as early as 1 hr after dosing and was intense by 28 days.

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