Library

Notes: After the initial discovery that, in vivo, mammalian skin both transcribes and translates the proopiomelanocortin (POMC) gene, and processes its product into melanocortins (Slominski et al., Experientia 1992), it has become increasingly appreciated that the hair follicle – including the human one – is a prime source and target not only of POMC-derived “pituitary” hormones, e.g. alpha-MSH, ACTH and ß-endorphin, but also expresses the most proximal control element of the hypothalamic-pituitary-adrenal (HPA) axis, corticotropin-releasing hormone (CRH) and its receptor (e.g. Roloff et al. FASEB J 1998, Ito et al. J Invest Dermatol 2004). However, while all proximal elements of the HPA are expressed in both murine and human hair follicles (CRH, CHR-R, POMC, ACTH and ACTH-R), it has neither been shown that these are functionally linked (i.e., is CRH actually capable of modulating intrafollicular POMC gene expression and ACTH production?), nor has it been known whether the most distal HPA component – cortisol synthesis – is also present in the hair follicle. Therefore, we have investigated whether the stimulation of microdissected, organ-cultured human hair follicles with CRH or ACTH elicits responses inside this peripheral miniorgan that imitate a functional HPA – in the absence of any systemic or neural connections and under serum-free culture conditions. Here, we show that CRH stimulation of organ-cultured human scalp hair follicles in the anagen VI stage of the hair cycle indeed results in significant upregulation of POMC transcription, and of alpha-MSH, ACTH, MC1, MC2 and glucocorticoid receptor (GR) immunoreactivity in situ (immunofluorescence). ACTH stimulation, in turn, significantly up-regulates the – already constitutively present!– cortisol-immunoreactivity as well as cortisol secretion into the culture medium. This represents the first available evidence that normal human skin (more precisely: the hair follicle) can actually synthesize the “adrenal” steroid hormone cortisol in situ, and that this acticity is regulated by the same “hypothalamic” and “pituitary” hormones that operate as key controls of adrenal cortisol synthesis. Moreover, we show that cortisol stimulation exerts classical feedback responses inside the human anagen hair follicle recognized for the central HPA: cortisol up-regulates GR, while it down-regulates CRH expression. Given that the HPA operates as the major system for coordinating stress-responses of the mammalian organism and for integrating them into changing metabolic demands and neuro-endocrine-immune signaling circuits, it has fascinating implications (e.g. for general skin physiology and dermatological therapy), and raises most intriguing questions, that human hair follicles are utilizing a fully functional peripheral equivalent of the central HPA.

Notes: Background  Stress, which mediates anxiety, worsens skin symptoms in patients with atopic dermatitis (AD). The contribution of anxiety to immune dysfunction, which plays a critical role in the pathogenesis of AD, requires clarification.Objectives  To examine the relationship between anxiety and atopy-relevant immune function in AD.Methods  Eighty-five patients with AD and 58 normal individuals without a history of allergic disorders were enrolled in this study. To assess anxiety, the state–trait anxiety inventory was completed for both groups. In the AD group, measurements were made of SCORAD scores, serum IgE levels, itching (visual analogue scale), blood eosinophil count and T-helper (Th) 1/Th2 ratio in the peripheral blood.Results  Anxiety was significantly higher among the subjects with AD than the normal subjects, and trait anxiety (TA) was higher than state anxiety (SA) in the AD group. Serum total IgE levels were correlated positively with TA and the TA/SA ratio and inversely with SA, and the Th1/Th2 ratio was correlated inversely with TA and the TA/SA ratio.Conclusions  The patients with AD had higher anxiety levels than normal individuals, and those with a stronger perception of TA than SA showed enhanced serum IgE synthesis and Th2 shifting.

Notes: Background  Interferon (IFN)-γ appears to be an important hair cycle modulator in mice. It is unclear whether it has similar hair growth modulatory functions in human hair follicles.Objectives  To study whether IFN-γ can be exploited to modulate the growth, pigmentation and/or cycling of organ-cultured human anagen scalp hair follicles, as an in vitro indicator system for how IFN-γ affects human hair growth in vivo. This was correlated with the hair follicle expression patterns of IFN-γ receptors α and β. In addition, we wanted to establish a new, simple tool for the rapid experimental induction of catagen in vitro.Methods  Normal human scalp hair follicles in the anagen VI stage of the hair cycle were cultured according to the method of Philpott et al., with or without IFN-γ (50–1000 IU mL−1). Hair shaft elongation and pigmentation changes were measured, complemented by quantitative histomorphometry to assess changes in hair follicle cycling (hair cycle score), proliferation (Ki-67), melanogenesis (Masson–Fontana) and apoptosis (TUNEL). IFN-γ receptors were also localized by immunofluorescence and EnVision technique. As transforming growth factor (TGF)-β2 is a recognized key inducer of catagen in human hair follicles, TGF-β2 expression was investigated by tyramide signal amplification and reverse transcription-polymerase chain reaction in anagen hair follicles treated with vehicle (phosphate-buffered saline) or IFN-γ.Results  IFN-γ rapidly inhibited hair elongation in cultured human anagen hair follicles and induced morphological signs of catagen transformation after only 4 days of culture, i.e. faster than with other reported catagen-inducers (e.g. TGF-β2). Proliferation was inhibited, apoptosis was increased and follicular melanogenesis was switched off in hair bulb keratinocytes treated in situ with IFN-γ. Anagen hair follicles displayed strong IFN-γ receptor α-like immunoreactivity, while the immunoreactivity for IFN-γ receptor β in the hair matrix was only weak. TGF-β2 immunoreactivity and mRNA transcript levels were enhanced in hair follicles treated with IFN-γ.Conclusions  These data suggest that IFN-γ is a potent catagen inducer in normal human scalp hair follicles, which express cognate receptors, and show that IFN-γ administration offers an excellent tool for experimental catagen induction in organ-cultured human hair follicles. This catagen induction probably occurs at least in part via upregulation of the recognized catagen-stimulatory growth factor TGF-β2.

Notes: There is little information concerning the physical properties of various commercializedwater-based temporary filling materials. In this study, the setting characteristics of 5 water-basedtemporary filling cements, i.e., Caviton, HY-seal, Lumicon, Cavit-G, and Cavit-W, were examined.Reinforced plastic pipes were filled with the test materials, and the specimens were then immersedin distilled water at 37°C. Setting time of each specimen was determined by a penetration test usinga Vicat penetrometer; and setting layer depth was measured with micrometer calipers. Cavit-Wexhibited the fastest setting time, whereas Caviton and HY-seal demonstrated the slowest settingtime. These results indicate that the setting properties of these materials used in this study weresignificantly different for each material, which showed some changes on the surface and the internalpart after the start of water absorption