Trichofolliculoma is a rare hair follicle hamartoma, which is often regarded as a hair follicle tumor. Mostly, it presents as a papule or nodule, involving the skin of the face and scalp area. A central, dilated keratin plugged ostium with vellus hair(s) is often present. We report a 19-year-old woman with typical clinical and histopathological findings of trichofolliculoma.

The Notch signalling pathway is an important mediator of cell fate selection whose involvement in epidermal appendage formation is now becoming recognised. Hair follicle development and hair formation involve the co-ordinated differentiation of several different cell types in which Notch appears to have a role. We report intricate expression patterns for the Notch-1 receptor and three ligands, ...

The cell surface marker CD34 marks mouse hair follicle bulge cells, which have attributes of stem cells, including quiescence and multipotency. Using a CD34 knockout (KO) mouse, we tested the hypothesis that CD34 may participate in tumor development in mice because hair follicle stem cells are thought to be a major target of carcinogens in the two-stage model of mouse skin carcinogenesis. Follo...

We have previously studied mouse whisker follicles in Gelfoam® histoculture to determine the role of nestin-expressing plutipotent stem cells, located within the follicle, in the growth of the follicular sensory nerve. Long-term Gelfoam® whisker histoculture enabled hair follicle nestin-expressing stem cells to promote the extensive elongation of the whisker sensory nerve, which contained axon ...

Multipotent skin stem cells give rise to epidermis and its appendages, including the hair follicle. The Lef-1/Tcf family of Wnt-regulated transcription factors plays a major role in specification of the hair shaft, but little is known about how the equally important hair channel, the inner root sheath (IRS), develops in concert to shape and guide the hair. In a microarray screen to search for t...

Trichofolliculoma is a rare hair follicle hamartoma, which is often regarded as a hair follicle tumor. Mostly, it presents as a papule or nodule, involving the skin of the face and scalp area. A central, dilated keratin plugged ostium with vellus hair(s) is often present. We report a 19-year-old woman with typical clinical and histopathological findings of trichofolliculoma.

Generally, the blood and skin concentration profiles and steady-state skin concentration of topically applied or exposed chemicals can be calculated from the in vitro skin permeation profile. However, these calculation methods are particularly applicable to chemicals for which the main pathway is via the stratum corneum. If the contribution of hair follicles to the total skin permeation of chem...

A hairy kinase o get a hairy mouse, look to the Sgk3 kinase. So say Alonso et al. on page 559. The control of hair follicle growth has been an enigma for cell biologists. While growth factors such as EGF are known for their ability to stimulate proliferation in epithelial cells, EGF causes hair loss. In addition, the downstream signals that control hair growth are largely unknown. Now, an Akt r...

Senile graying of human hair has been the subject of intense research since ancient times. Reactive oxygen species have been implicated in hair follicle melanocyte apoptosis and DNA damage. Here we show for the first time by FT-Raman spectroscopy in vivo that human gray/white scalp hair shafts accumulate hydrogen peroxide (H(2)O(2)) in millimolar concentrations. Moreover, we demonstrate almost ...