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N Mandt

Publications and source records attributed to N Mandt.

5 recordsLinked to original sources
PubMed2006

Effect of 5alpha-dihydrotestosterone and testosterone on apoptosis in human dermal papilla cells.

Pathogenetic mechanisms in androgenetic alopecia are not yet fully understood; however, it is commonly accepted that androgens like testosterone (T) and 5alpha-dihydrotestosterone (5alpha-DHT) inhibit hair follicle activity with early induction of the catagen. Thus, we investigated the influence of T and 5alpha-DHT on proliferation, cell death and bcl-2/bax expression in cultured dermal papilla cells (DPC) from nonbalding scalp regions of healthy volunteers. T and 5alpha-DHT induced apoptosis in DPC in a dose-dependent and time-related manner; in addition a necrotic effect due to T at 10(-5) M was found. Interestingly, bcl-2 protein expression was decreased in T- and 5alpha-DHT-treated cells, leading to an increase in the bax/bcl-2 ratio. In addition, T and 5alpha-DHT induced proteolytic cleavage of caspase 8 and inhibited proliferation of DPC at 10(-5) M. High concentrations of T and 5alpha-DHT were needed to induce apoptotic effects in DPC. These data suggest that DPC from nonbalding scalp regions do have the capacity to undergo apoptosis, but need a high androgen stimulus. The present study provides an interesting new pathogenetic approach in androgenetic alopecia.

Apoptosis↗
PubMed2005

[Aging of hair and nails].

Human hair and nails, like all other organs, undergo chronological aging. Age-associated changes in growth, color, and structure of the hair and nails are common. In contrast to the aging process of the skin, the gerontobiological course of hair and nails has not been investigated comprehensively. Investigations on signaling pathways important for melanogenesis of the hair follicle improve our understanding of processes involved in hair greying. Differences in the structure and quality of the nails at an advanced age are determined mainly by age-dependent variations in lipid content of the nail plates. However, it is important to recognize age-dependent processes in hair shafts and nails and to distinguish between chronological aging and pathological changes. The possibilities to improve these aging processes have, primarily, to be seen in the field of external cosmetic procedures. Since the effect of preexisting hormonal substitution treatment has not yet been adequately investigated, it can be regarded as critical to evaluate the confirmed benefits and possible risks of such treatment either for hair or for nail quality improvement.

Aging↗
PubMedDate not supplied

Buschke-Ollendorff syndrome--differential diagnosis of disseminated connective tissue lesions.

We report a 5-year-old boy presenting with multiple elastic type nevi and osteopoikilosis who was diagnosed as having Buschke-Ollendorff syndrome at an early age. Connective tissue lesions may present as the main symptom of varying clinical entities with different outcomes. Differential diagnosis includes papular elastorrhexis, fibroelastolytic papules of the neck, papular acne scars, and late onset focal dermal elastosis. Rare genodermatoses, i.e. Buschke-Ollendorff syndrome, pseudoxanthoma elasticum, juvenile hyaline fibromatosis and familiar cutaneous collagenoma should be carefully evaluated to provide appropriate genetic counseling and to avoid unnecessary treatment procedures.

Child, Preschool↗