Background Caffeine reportedly counteracts the suppression of hair shaft production by testosterone in organ-cultured male human hair follicles (HFs). Objectives We aimed at investigating the impact of caffeine a) on additional key hair growth parameters, b) on major hair growth-regulatory growth factors and c) on male versus female HFs in the presence of testosterone. This article is protected...

OBJECTIVE In humans, the process of hair shedding, referred to as exogen, is believed to occur independently of the other hair cycle phases. Although the actual mechanisms involved in hair shedding are not fully known, it has been hypothesized that the processes leading to the final step of hair shedding may be driven by proteases and/or protease inhibitor activity. In this study, we investigat...

We developed a rapid and convenient extraction procedure of human hair proteins to examine their biochemical properties in detail. This procedure is based upon the fact that the combination of thiourea and urea in the presence of a reductant can effectively remove proteins from the cortex part of human hair. The extracted fraction mainly consisted of hard alpha-keratins with molecular masses of...

BACKGROUND/AIM The lipopolysaccharide (LPS)-like compound derived from Pantoea agglomerans (immunopotentiator from Pantoea agglomerans 1 (IP-PA1)) has been used not only as dietary supplement or cosmetic for humans, but also by Japanese veterinarians as an anti-tumor, anti-allergy, "keep a fine coat of fur" and hair growth-promoting functional food for dogs and cats. In the present study, we fo...

BACKGROUND Caffeine reportedly counteracts the suppression of hair shaft production by testosterone in organ-cultured male human hair follicles (HFs). OBJECTIVES We aimed to investigate the impact of caffeine (i) on additional key hair growth parameters, (ii) on major hair growth regulatory factors and (iii) on male vs. female HFs in the presence of testosterone. METHODS Microdissected male...

Human hair as a biologic measure of exposure to persistent organic pollutants (POPs) has some advantages over the more commonly used blood and adipose tissue samples. However, one of the primary limitations is the difficulty in distinguishing between exogenous and endogenous contamination. In addition, there are currently no standardized methods for hair sample collection, washing, and chemical...

Humans are unusual among mammals in appearing hairless. Several hypotheses propose explanations for this phenotype, but few data are available to test these hypotheses. To elucidate the evolutionary history of human "hairlessness," a comparative approach is needed. One previous study on primate hair density concluded that great apes have systematically less dense hair than smaller primates. Whi...