The hair follicle and apocrine gland population of cattle skin.

1954 ◽  
Vol 5 (4) ◽  
pp. 745 ◽  
Author(s):  
HB Carter ◽  
DF Dowling
Keyword(s):  
Population Density ◽  
Hair Follicle ◽  
Bos Taurus ◽  
Mammalian Species ◽  
Age Groups ◽  
Hair Follicles ◽  
Severe Drought ◽  
Apocrine Gland ◽  
True Nature ◽  
South Wales

Skin biopsy specimens were collected at a standard midside position from 321 individual cattle (Bos taurus L.) of known age or in defined age groups on pastoral properties in New South Wales and Queensland. Beef cattle were represented by samples from the breeds: Aberdeen Angus, Devon, Hereford, and Shorthorn. Dairy cattle were represented by samples from the breeds: Australian Illawarra Shorthorn, Holstein-Friesian, Jersey, and Red Poll. Data were also obtained on 30 beef Shorthorns repeatedly sampled from birth to the age of 2-1/2 years under severe drought conditions in north Queensland. In all specimens each hair follicle was associated with an apocrine gland as well as a sebaceous gland and an arrector pili muscle. Thus, all hair follicles were homologous with the primary follicles of sheep; no secondary follicles were at any time observed; hence, there was no follicle group comparable in its complexity to that in the sheep and many other mammalian species. Further and more systematic observations by the biopsy and histological methods used in this work are necessary to examine the true nature of breed differences in the follicle and apocrine gland population density of the skin. The Jersey appears to have a denser coat. The data presented in this paper emphasize the dual importance of age and nutritional status of the animal on the hair follicle population density.

The hair follicle and apocrine gland populations of Zebu (Bos indicus L.) and Shorthorn (B. taurus L.) cattle skin.

1955 ◽  
Vol 6 (4) ◽  
pp. 645 ◽  
Author(s):  
DF Dowling
Keyword(s):  
Hair Follicle ◽  
Bos Taurus ◽  
Bos Indicus ◽  
Age Groups ◽  
Hair Follicles ◽  
Regression Coefficients ◽  
Apocrine Gland ◽  
Apocrine Glands ◽  
Significant Difference ◽  
The Mean

Skin samples taken with a trephine of known size from Shorthorn (Bos taurus L.) and Zebu (B. indicus L.) cattle were used to determine the density of hair follicles and apocrine glands in the skin. The repeatability of the measurement of density on the same animal was found to lie between 78 and 90 per cent. The expansion of the skin as the animal grows, and the manner in which the plane of nutrition can modify growth and so the extent of expansion, has a predominating effect on the hair follicle and apocrine gland density. There is a significant difference between ages, but for each breed the regression coefficients of log follicle number on log heart girth within age groups are not significantly different. The mean number of hair follicles per sq. cm in Zebus was 1698, in Zebu crosses 1321, and in Shorthorns on a low plane of nutrition 1064. In Shorthorns on a high plane the number was 764. All differences were statistically significant.

scholarly journals The Pre-Natal Development of Skin and hair in Cattle (Bos Taurus L.)

1959 ◽  
Vol 12 (1) ◽  
pp. 72 ◽  
Author(s):  
AG Lyne ◽  
Margaret J Heideman
Keyword(s):  
Hair Follicle ◽  
Bos Taurus ◽  
Histological Study ◽  
Hair Follicles ◽  
Serial Sections ◽  
Lateral Region ◽  
New Born ◽  
Whole Mount ◽  
Skin Samples

A histological study has been made of the development of the skin and hair follicles in 33 foetuses, ranging in age from 68 to 274 days, and seven new-born specimens, of various breeds of Bos taurus L. Skin samples were taken from the mid-lateral region of the trunk, and both serial sections and whole mount preparations have been examined. Extensive use has been made of' counts of the follicle and hair population as well as skin and hair follicle measurements which hitherto have apparently received little attention in studies of this type.

A method for culturing human hair follicle cells. (II). Plucked human hair follicles.

1988 ◽  
Vol 50 (2) ◽  
pp. 271-276 ◽  
Author(s):  
Ryuichiro KUWANA ◽  
Seiji ARASE ◽  
Yasushi SADAMOTO ◽  
Hideki NAKANISHI ◽  
Katsuyuki TAKEDA
Keyword(s):  
Hair Follicle ◽  
Human Hair ◽  
Hair Follicles ◽  
Follicle Cells ◽  
Human Hair Follicle

Nano-Lipidic Carriers as a Tool for Drug Targeting to the Pilosebaceous Units

2020 ◽  
Vol 26 (27) ◽  
pp. 3251-3268
Author(s):  
Shweta Ramkar ◽  
Abhishek K. Sah ◽  
Nagendra Bhuwane ◽  
Ishwari Choudhary ◽  
Narayan Hemnani ◽  
...  
Keyword(s):  
Drug Delivery ◽  
Hair Follicle ◽  
Hair Follicles ◽  
Prolonged Release ◽  
Pilosebaceous Unit ◽  
Tissue Targeting ◽  
Bulge Region ◽  
Drug Reservoir ◽  
Fast Transport ◽  
Topical Applications

The pilosebaceous unit is the triad comprising of hair follicle, arrector pilli muscle, and sebaceous gland. Drug delivery to and through the hair follicles has garnered much attention of the researchers and the hair follicles represent an attractive target site via topical applications. They are bordered by capillaries and antigenpresenting cells, connected to the sebaceous glands and the bulge region of the hair follicle anchors the stem cells. The nano lipid carriers have the propensity to penetrate through the skin via transcellular route, intracellular route and follicular route. It has been established that nano lipid carriers have the potential for follicular drug delivery and provide some advantages over conventional pathways, including improved bioavailability, enhanced penetration depth, fast transport into the skin, tissue targeting and form a drug reservoir for prolonged release. This review describes the pilosebaceous unit (PSU) and related diseases and the recent lipid-based nanotechnology approaches for drug delivery to the follicular unit as well as related issues. Different types of nano lipid carriers, including ethosomes, liposomes, nanoparticles, solid lipid nanoparticles (SLNs), and nano lipid carriers (NLCs) have been reported for follicular drug delivery. Targeted drug delivery with nano-lipid carriers has the potential to augment the efficacy of drugs/bioactives to treat diseases of PSU. This review systematically introduces the activities of different formulations and the use of nano lipid carriers in treating PSU related disorders like alopecia, acne, and hirsutism.

scholarly journals Localisation and regulation of cholesterol transporters in the human hair follicle: mapping changes across the hair cycle

2021 ◽  
Author(s):  
Megan A. Palmer ◽  
Eleanor Smart ◽  
Iain S. Haslam
Keyword(s):  
Hair Follicle ◽  
Human Hair ◽  
Vital Role ◽  
Transport Proteins ◽  
Hair Follicles ◽  
Regulatory Control ◽  
Cholesterol Transport ◽  
Hair Cycle ◽  
Human Hair Follicle

AbstractCholesterol has long been suspected of influencing hair biology, with dysregulated homeostasis implicated in several disorders of hair growth and cycling. Cholesterol transport proteins play a vital role in the control of cellular cholesterol levels and compartmentalisation. This research aimed to determine the cellular localisation, transport capability and regulatory control of cholesterol transport proteins across the hair cycle. Immunofluorescence microscopy in human hair follicle sections revealed differential expression of ATP-binding cassette (ABC) transporters across the hair cycle. Cholesterol transporter expression (ABCA1, ABCG1, ABCA5 and SCARB1) reduced as hair follicles transitioned from growth to regression. Staining for free cholesterol (filipin) revealed prominent cholesterol striations within the basement membrane of the hair bulb. Liver X receptor agonism demonstrated active regulation of ABCA1 and ABCG1, but not ABCA5 or SCARB1 in human hair follicles and primary keratinocytes. These results demonstrate the capacity of human hair follicles for cholesterol transport and trafficking. Future studies examining the role of cholesterol transport across the hair cycle may shed light on the role of lipid homeostasis in human hair disorders.

scholarly journals A Mouse Model for Studying Stem Cell Effects on Regeneration of Hair Follicle Outer Root Sheaths

2020 ◽  
Vol 15 (1) ◽  
pp. 41-50
Author(s):  
Jingxu Guo ◽  
Shuwei Li ◽  
Hongyang Wang ◽  
Tinghui Wu ◽  
Zhenhui Wu ◽  
...  
Keyword(s):  
Stem Cells ◽  
Stem Cell ◽  
Mouse Model ◽  
Hair Follicle ◽  
Smooth Muscle Actin ◽  
Hair Follicles ◽  
Alpha Smooth Muscle Actin ◽  
Papillary Structure ◽  
Glass Membrane

AbstractObjectiveStem cells hold promise for treating hair loss. Here an in vitro mouse model was developed using outer root sheaths (ORSs) isolated from hair follicles for studying stem cell-mediated dermal papillary regeneration.MethodsUnder sterile conditions, structurally intact ORSs were isolated from hair follicles of 3-day-old Kunming mice and incubated in growth medium. Samples were collected daily for 5 days. Stem cell distribution, proliferation, differentiation, and migration were monitored during regeneration.ResultsCell proliferation began at the glass membrane periphery then spread gradually toward the membrane center, with the presence of CD34 and CD200 positive stem cells involved in repair initiation. Next, CD34 positive stem cells migrated down the glass membrane, where some participated in ORS formation, while other CD34 cells and CD200 positive cells migrated to hair follicle centers. Within the hair follicle matrix, stem cells divided, grew, differentiated and caused outward expansion of the glass membrane to form a dermal papillary structure containing alpha-smooth muscle actin. Neutrophils attracted to the wound site phagocytosed bacterial and cell debris to protect regenerating tissue from infection.ConclusionIsolated hair follicle ORSs can regenerate new dermal papillary structures in vitro. Stem cells and neutrophils play important roles in the regeneration process.

scholarly journals Neighbourhood characteristics as a predictor of adherence to dietary recommendations: A population-based cohort study of Finnish adults

2020 ◽  
pp. 140349482097149
Author(s):  
Hanna Lagström ◽  
Jaana I. Halonen ◽  
Sakari Suominen ◽  
Jaana Pentti ◽  
Sari Stenholm ◽  
...  
Keyword(s):  
Population Density ◽  
Dietary Habits ◽  
Metabolic Diseases ◽  
Adult Population ◽  
Age Groups ◽  
Population Based ◽  
Dietary Recommendations ◽  
Neighbourhood Characteristics ◽  
Severe Life Events ◽  
Dietary Score

Aims: To investigate the association of six-year cumulative level of socioeconomic neighbourhood disadvantage and population density with subsequent adherence to dietary recommendations, controlling for preceding dietary adherence, in adults in Finland. Methods: Population-based Health and Social Support (HeSSup) study participants from four age groups (20–24, 30–34, 40–44 and 50–54 years at baseline in 1998). Data on diet and alcohol consumption were obtained from the 2003 and 2012 surveys and information on neighbourhoods from Statistics Finland Grid database ( n = 10,414 men and women). Participants diet was measured as adherence to Nordic Nutrition recommendation (score range 0–100). Neighbourhood disadvantage was measured by median household income, proportion of those with primary education only and unemployment rate, and population density by the number of adult population between years 2007 and 2012. Linear models were used to assess the associations of neighbourhood characteristics with the score for adherence to dietary recommendations in 2012. Results: Cumulative neighbourhood socioeconomic disadvantage was associated with slightly weaker (1.49 (95% confidence interval (CI) −1.89 to −1.09) point decrease in dietary score) adherence while higher population density was associated with better (0.70 (95% CI 0.38−1.01) point increase in dietary score) adherence to dietary recommendations. These associations remained after controlling for prior dietary habits, sociodemographic, chronic cardio-metabolic diseases, and severe life events. Conclusions: These longitudinal findings support the hypothesis that neighbourhood characteristics affect dietary habits.

scholarly journals Neisseria meningitidis carriage and risk factors among teenagers in Suizhou city in China

2020 ◽  
Vol 148 ◽  
Author(s):  
Fei He ◽  
Hong mei Yang ◽  
Guo ming Li ◽  
Bing qing Zhu ◽  
Yating Zhang ◽  
...  
Keyword(s):  
Risk Factors ◽  
Population Density ◽  
Neisseria Meningitidis ◽  
Old Age ◽  
Age Groups ◽  
Significant Risk ◽  
Epidemiological Data ◽  
Significant Risk Factor ◽  
Antibiotic Use ◽  
Carriage Rate

Abstract Teenagers are important carriers of Neisseria meningitidis, which is a leading cause of invasive meningococcal disease. In China, the carriage rate and risk factors among teenagers are unclear. The present study presents a retrospective analysis of epidemiological data for N. meningitidis carriage from 2013 to 2017 in Suizhou city, China. The carriage rates were 3.26%, 2.22%, 3.33%, 3.53% and 9.88% for 2013, 2014, 2015, 2016 and 2017, respectively. From 2014 to 2017, the carriage rate in the 15- to 19-year-old age group (teenagers) was the highest and significantly higher than that in remain age groups. Subsequently, a larger scale survey (December 2017) for carriage rate and relative risk factors (population density, time spent in the classroom, gender and antibiotics use) were investigated on the teenagers (15- to 19-year-old age) at the same school. The carriage rate was still high at 33.48% (223/663) and varied greatly from 6.56% to 52.94% in a different class. Population density of the classroom was found to be a significant risk factor for carriage, and 1.4 persons/m2 is recommended as the maximum classroom density. Further, higher male gender ratio and more time spent in the classroom were also significantly associated with higher carriage. Finally, antibiotic use was associated with a significantly lower carriage rate. All the results imply that attention should be paid to the teenagers and various measures can be taken to reduce the N. meningitidis carriage, to prevent and control the outbreak of IMD.

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