Home About us Contact
|
Home About us Contact | ||
|
|
||
Anagen Hair Follicles (anagen + hair_follicle)
Selected AbstractsDesmocollin 1 expression and desmosomal remodeling during terminal differentiation of human anagen hair follicle: an electron microscopic studyEXPERIMENTAL DERMATOLOGY, Issue 5 2004Elena Donetti Abstract:, The terminal differentiation (TD) program of keratinocytes of the human hair follicle (HF) occurs with specific temporal and spatial features in the various layers of the inner root sheath (IRS) and in the innermost layer of the outer root sheath (companion layer). This process is characterized by complex nuclear and cytoplasmic morphological changes, accompanied by profound modifications in intercellular junctions. As no correlation exists between the structure and the molecular composition of desmosomes during TD of the IRS/companion unit, the aim of our study was to investigate by transmission electron microscopy the remodeling of desmosomes in keratinizing cells of these compartments. By immunogold post embedding technique, we studied in anagen HFs the modulation of the synthesis of desmocollin 1 (Dsc1), a transmembrane glycoprotein specifically synthesized in the IRS and in the companion layer. Dsc1 immunoreactivity was actually confined to these compartments and tended to increase just before the level of TD, particularly in the Henle's layer and in the IRS cuticle. In Huxley's layer, the immunolabeling was patchy and in the companion layer Dsc1 synthesis was detected above the level of keratinization of Huxley's layer. In the whole IRS, concomitantly with TD, there was an abrupt and almost complete disappearance of Dsc1 synthesis. An asymmetric distribution of Dsc1 was noticed (i) between cells at different stages of differentiation and (ii) between cells belonging to layers with different spatial/temporal features of TD. Our results show that the ultrastructural modifications of desmosomes during TD of HF are paralleled by the modulation of the synthesis of desmocollin 1. [source] Melanocytic matricoma: case confirmation of a recently described entityJOURNAL OF CUTANEOUS PATHOLOGY, Issue 4 2003Christy M. Williams Background:, In 1999, Carlson et al. reported two cases of a matrical neoplasm that recapitulates the bulb of the anagen hair follicle, which they designated as melanocytic matricoma. Methods:, Here we report a similar case in a 78-year-old white male, who presented with a 0.4 cm purple-black firm papule in the left preauricular area. Results:, Histologically, the tumor is composed of a dual cell population including admixed epithelial matrical and supramatrical cells with "shadow" cell formation and pigmented dendritic melanocytes. Immunohistochemical studies for cytokeratin highlighted the epithelial component and studies for S-100 protein, HMB-45, and vimentin confirmed the melanocytic component. The differential diagnosis considered includes pigmented variants of pilomatricoma, matrical carcinoma, basal cell carcinoma and malignant melanoma. Conclusions:, The case reported herein is the first confirmation of melanocytic matricoma, a distinctive adnexal neoplasm with characteristic clinical and pathologic features, which differentiate it from pigmented pilomatricoma. [source] Human melanocytes can be isolated, propagated and expanded from plucked anagen hair folliclesEXPERIMENTAL DERMATOLOGY, Issue 6 2010Christina Dieckmann Please cite this paper as: Human melanocytes can be isolated, propagated and expanded from plucked anagen hair follicles. Experimental Dermatology 2010; 19: 543,545. Abstract:, Herein, we report a technically simple method for isolation and culture of human follicular melanocytes based on explant cultures of epilated hair follicles. This technique does not require any surgical intervention and allows the isolation and cultivation of follicular melanocytes from a comparatively small amount of raw material. Generally, 30,60 human anagen hair follicles have been plucked from the scalp of healthy donors and cultivated under low oxygen pressure (5%). After a short period of time cells of various types were growing out from the outer root sheath (ORS) of the hair follicles. Under the selected culture conditions, most of the cells other than melanocytes have been eliminated and a nearly 100% pure population of melanocytes has been achieved, as confirmed by immunohistochemical analyses for melanocyte-specific markers, for example, Tyrosinase-1, S-100 and premelanosomal antigens. These melanocytes derived from the ORS were proliferating for up to 2 months. [source] Influence of prostaglandin F2, and its analogues on hair regrowth and follicular melanogenesis in a murine modelEXPERIMENTAL DERMATOLOGY, Issue 5 2005S. Sasaki Abstract:, Latanoprost and isopropyl unoprostone, which are analogues of prostaglandin F2, (PGF2,), are promising drugs for the reduction of intra-ocular pressure. However, they have been reported to have side effects, including hypertrichosis and hyperpigmentation of the eyelashes and periocular skin, and occasionally poliosis. In order to investigate these effects further, PGF2,, latanoprost and isopropyl unoprostone were applied to the dorsal skin of 7-week-old C57BL/6 mice, and hair length was measured during the treatment. The three molecules all showed stimulatory effects on the murine hair follicles and the follicular melanocytes in both the telogen and anagen stages, and stimulated conversion from the telogen to the anagen phase. PGE2 is known to act synergistically with PGF2,, and hence the influence of PGE2 was also examined. PGE2 did not induce distinct telogen-to-anagen conversion, but showed moderate growth stimulatory effects on early anagen hair follicles. In addition, we observed a case of hypertrichosis and trichomegaly with an excess of melanogenesis, leading to the emergence of white hair, suggesting that poliosis can occur as a side effect of eye treatment with solutions of PGF2, analogues. The stimulatory effects of PGF2,and PGE2 on hair growth have been discussed with regard to the role of protein kinase C and mast cells. [source] | ||||||||||