No / Hair follicle development and its postnatal regeneration are characterized by dramatic changes in its microanatomy and cellular activity, which are controlled by multiple signalling pathways, transcription factors and epigenetic regulators, including microRNAs (miRNAs). miRNAs and their targets form remarkably diverse regulatory networks, playing a key role in the execution of gene expression programmes in the different cell lineages of the hair follicle. This review summarizes the roles of miRNAs in the control of hair follicle development, cycling and hair pigmentation, emphasizes the remaining problems/unanswered questions, and provides future directions in this rapidly growing and exciting area of research / MRC

Lack of hair due to alopecia or skin grafting procedures causes significant distress due to hair's role in social and sexual communication. Only limited pharmacological agents are currently available to stimulate hair growth; their development is hampered by inappropriate model systems. Most research involves large terminal scalp follicles rather than the clinical targets of tiny vellus or intermediate follicles. The overall aim of this thesis was to develop a novel model system based on intermediate hair follicles. Initially, intermediate follicles from female pre-auricular skin were characterised and compared to matched terminal follicles. Intermediate follicles were smaller, less pigmented, shorter and possessed a more 'tubular' bulb morphology than their more 'bulbous' terminal counterparts. Significant correlations were demonstrated between various hair follicle measurements and corresponding dermal papilla diameters. Isolated terminal follicles grew significantly more than intermediate hair follicles in organ culture for 9 days. Testosterone (10nM), the major regulator of human hair growth, increased only intermediate follicle growth; the anti-androgen, cyproterone acetate (1¿M), prevented this stimulation, unlike the 5¿-reductase type 2 inhibitor finasteride (40ng/ml). Immunohistochemistry demonstrated androgen receptor and 5¿-reductase type 2 proteins in both follicle types, while quantitative real-time PCR and gene microarray analysis detected their increased gene expression in intermediate follicles. Thus, smaller intermediate follicles showed major morphological and gene expression differences to terminal follicles in vivo and retained significant, biologically-relevant differences in vitro in organ culture including androgen-responsiveness. Therefore, intermediate hair follicles offer a novel, exciting, more clinically relevant, albeit technically difficult, model for future investigations into hair growth.

Yes / Hair fibres show wide diversity across and within all human populations, suggesting that hair fibre form and colour have been subject to much adaptive pressure over thousands of years. All human hair fibres typically have the same basic structure. However, the three-dimensional shape of the entire fibre varies considerably depending on ethnicity and geography, with examples from very straight hair with no rotational turn about the long axis, to the tightly sprung coils of African races. The creation of the highly complex biomaterials in hair follicle and how these confer mechanical functions on the fibre so formed is a topic that remains relatively unexplained thus far. We review the current understanding on how hair fibres are formed into a nonlinear coiled form and which genetic and biological factors are thought to be responsible for hair shape. We report on a new GWAS comparing low and high curl individuals in South Africa, revealing strong links to polymorphic variation in trichohyalin, a copper transporter protein CUTC and the inner root sheath component keratin 74. This builds onto the growing knowledge base describing the control of curly hair formation. / Unilever R&D

No / It is known that hair growth disorders and hair loss can cause personal distress and affect well‐being. Whilst clinical conditions remain a target for medical research, current research on hair follicle biology and hair growth control mechanisms also provides opportunities for a range of non‐medical and cosmetic interventions that have a modulating effect on the scalp and follicle function. Furthermore, an improvement of the hair fibre characteristics (cuticle structure, cortex size and integrity) could add to the overall positive visual effect of the hair array. Since phytochemicals are a popular choice because of their traditional appeal, this review provides a critical evaluation of the available evidence of their activity for hair benefit, excluding data obtained from animal tests, and offers recommendations on improving study validity and the robustness of data collection in pre‐clinical and clinical studies.

This thesis addresses the negative cultural and social connotations of natural hair for African American women. This issue is examined throughout history from slavery to present day with a visual analysis of hair care advertisements. Presently, natural hair is gaining more positive implications; which can be affected by creating more positive images with natural hair. Using art as the vehicle for social change and using research to inform art has a positive impact on teaching and learning in the art classroom.

This thesis addresses the negative cultural and social connotations of natural hair for African American women. This issue is examined throughout history from slavery to present day with a visual analysis of hair care advertisements. Presently, natural hair is gaining more positive implications; which can be affected by creating more positive images with natural hair. Using art as the vehicle for social change and using research to inform art has a positive impact on teaching and learning in the art classroom.

No description available.

Thesis (doctoral)--Westfälische Wilhelms-Universität zu Münster i.W., 1912.

No / The DNA content of hair [1.] and [2.] is typically low compared to other tissues, as hair cells undergo dehydration and catabolic breakdown of nucleic acids and organelles during keratinisation [3]. As a consequence, ancient hair specimens have not been widely used as a source of ancient DNA. However, mitochondrial DNA (mtDNA) has been extracted from degraded and old hair samples, including burnt specimens [4], 100-year-old Native American samples [5], and wool from a 9,400 year old Bighorn sheep [6]. We have investigated the potential of hair as an aDNA source by analyzing DNA survival in 12 samples which range from 60 to >64,800 years of age and their susceptibility to contamination with modern DNA. mtDNA was successfully amplified, cloned, and sequenced from 10 of the 12 hair samples following decontamination procedures (Table 1). DNA was quantified using Quantitative Real-Time PCR in a subset of the samples (Table 1). The survival of high copy numbers of 16S DNA from the 3,000 year-old Pazyryk horse hairs is consistent with the observation that DNA survives longer at sub-zero temperatures [7]. Of greater surprise was the persistence of high numbers of 16S and Control Region DNA molecules in hairs sampled from a bison mummy 14C dated to >64,800 years. This result was independently replicated and extends the time frame from which authentic DNA has been retrieved from hair by at least seven-fold, placing it on a par with the oldest authentic DNA retrieved from bones and teeth [8]. No nuclear DNA could be amplified from the bison hair, consistent with observations of modern hair samples [1.] and 9. M.R. Wilson, D. Polanskey, J. Butler, J.A. DiZinno, J. Replogle and B. Budowle, Extraction, PCR amplification and sequencing of mitochondrial DNA from human hair shafts, Biotechniques 18 (1995), pp. 662¿669.[9.]. It is probably significant that the bison hairs are exceedingly well preserved ¿ the atomic carbon to nitrogen ratio (3.47) is similar to modern mammal hair [10.] and [11.] and histological analysis of the specimen demonstrates the only structural modifications to be slight cuticular loss and adherent deposits (Supplemental data).

No / This authoritative book combines contributions from experts in academic, governmental and industrial environments, to provide a unique, comprehensive look at: - Why hair can serve as an invaluable bio-resource in toxicology, with up-to-date reviews on hair growth, hair fibre formation and hair pigmentation - Information (including regulatory details) on the exposure of hair (and by extension the body) to drug and non-drug chemicals and pollutants - Toxicological issues relevant to the use of hair products (including colourants, shampoos and depilatories) - The ability of hair to capture information on personal identity, chemical exposure, and environmental interactions - How hair can provide an understanding of human life from archaeological and historical perspectives - Future direction in the use of hair in toxicology Hair in Toxicology: An Important Biomonitor is ideal as a reference and guide to investigations in the biomedical, biochemical and pharmaceutical sciences at the graduate and post graduate level.