Report of the Executive Committee for 2021.

The report of the Executive Committee for 2021 is presented.

Report of the Executive Committee for 2020.

The report of the Executive Committee for 2020 is presented.

Report of the Executive Committee for 2019.

The report of the Executive Committee for 2019 is presented.

Report of the Executive Committee for 2018.

The report of the Executive Committee for 2018 is presented.

Report of the Executive Committee for 2017.

The report of the Executive Committee for 2017 is presented.

Report of the Executive Committee for 2016.

The report of the Executive Committee for 2016 is presented.

Extracellular matrix derived from hair and skin fibroblasts stimulates human skin melanocyte tyrosinase activity.

There is indirect evidence that both skin and hair melanocytes are regulated by the activity of adjacent cells. In hair, the specialized fibroblasts (dermal papilla cells) appear to play a role in the regulation of hair growth. Hair pigmentation may relate to hair growth. In skin, melanocytes are located adjacent to the basement membrane zone. As far as we are aware, direct interactions of fibroblasts with melanocytes have not previously been investigated. Accordingly, the objective of this study was to develop co-culture conditions in which to investigate whether dermal fibroblasts from skin or hair could influence melanocyte differentiation. The influence of fibroblast-conditioned media, co-culture with fibroblasts, and fibroblast-derived extracellular matrix (ECM) on normal human skin melanocyte tyrosinase activity was examined. Fibroblasts from both skin and hair were capable of altering melanocyte morphology and significantly increasing tyrosinase activity when melanocytes were cultured in the absence, but not the presence, of the major proliferative drives. Although stimulation of tyrosinase activity was detectable with conditioned medium and co-culture with fibroblasts, the most striking result was obtained with the fibroblast-produced ECM which, on average, produced a four-fold increase in tyrosinase activity within 6 days. Thus, the study describes co-culture conditions in which the stimulatory effect of the fibroblast on melanocyte differentiation can be examined.

Cyclosporin A prolongs human hair growth in vitro.

We studied the effect of cyclosporin A on human hair growth using a recently described model in which isolated hair follicles are grown in vitro. Cyclosporin A had no effect on the rate of hair growth, but at 10(-7) M, a dose within the therapeutic blood range, it maintained hair growth for longer than control to give a 42% greater mean follicle elongation after 15 d (p < 0.05). Eighteen of 42 cyclosporin-treated follicles (43%) were still growing after 15 d compared with one of 42 control follicles (2%). These results suggest that the hypertrichotic action of cyclosporin A may be due to prolongation of the anagen phase of the hair-growth cycle.

Glycosaminoglycan synthesis by cultured human hair follicle dermal papilla cells: comparison with non-follicular dermal fibroblasts.

The extracellular matrix of the hair follicle dermal papilla is rich in glycosaminoglycans, the expression of which varies during the hair growth cycle being maximal in anagen and becoming undetectable as the follicle enters telogen. These observations, together with other experimental and clinical evidence, suggest that glycosaminoglycans may be involved in regulating hair growth. To investigate the metabolism of glycosaminoglycans by the dermal papilla we have measured the incorporation of radiolabelled precursors into glycosaminoglycans released into extracellular matrix and culture medium by cultured human dermal papilla cells. We also studied glycosaminoglycan synthesis by cells cultured from the lower follicular connective tissue sheath and by non-follicular dermal fibroblasts. Compared with dermal fibroblasts, dermal papilla cells showed a three to fourfold higher level of incorporation of 35S-sulphate and 3H-glucosamine into extracellular matrix glycosaminoglycans. Dermal papilla cells also released more 3H-glucosamine-labelled glycosaminoglycan into culture medium than dermal fibroblasts but there was no difference in 35S-sulphate labelling. These findings indicate that dermal papilla cells maintain a high level of glycosaminoglycan synthesis in vitro. Specific enzyme/chemical degradation showed that dermal papilla cells and dermal fibroblasts synthesized the same glycosaminoglycan types. However, the results suggested that dermal papilla glycosaminoglycans are less sulphated than those synthesized by dermal fibroblasts and that a higher proportion of sulphated glycosaminoglycans is retained in an extracellular matrix. The synthesis of glycosaminoglycans by connective tissue sheath cells was similar to that of dermal papilla cells, supporting the view that the dermal papilla and connective tissue sheath share certain properties.