Pharmacologic interventions in aging hair.

The appearance of hair plays an important role in people's overall physical appearance and self-perception. With today's increasing life-expectations, the desire to look youthful plays a bigger role than ever. The hair care industry has become aware of this and is delivering active products directed towards meeting this consumer demand. The discovery of pharmacological targets and the development of safe and effective drugs also indicate strategies of the drug industry for maintenance of healthy and beautiful hair. Hair aging comprises weathering of the hair shaft, decrease of melanocyte function, and decrease in hair production. The scalp is subject to intrinsic and extrinsic aging. Intrinsic factors are related to individual genetic and epigenetic mechanisms with interindividual variation: prototypes are familial premature graying, and androgenetic alopecia. Currently available pharmacologic treatment modalities with proven efficacy for treatment of androgenetic alopecia are topical minoxidil and oral finasteride. Extrinsic factors include ultraviolet radiation and air pollution. Experimental evidence supports the hypothesis that oxidative stress also plays a role in hair aging. Topical anti-aging compounds include photoprotectors and antioxidants. In the absence of another way to reverse hair graying, hair colorants remain the mainstay of recovering lost hair color. Topical liposome targeting for melanins, genes, and proteins selectively to hair follicles are currently under investigation.

EEMCO guidance for the assessment of hair shedding and alopecia.

Knowledge of the hair follicle anatomy and the dynamics of hair cycling is substantial. Recognizing the anagen, catagen and telogen phases as well as teloptosis and the hair eclipse phenomenon clearly characterizes the typical hair chronobiology. Physiological modulators include hormones, neuromediators, miscellaneous biomolecules, seasons, micro-inflammation and ageing. For individuals who present with the complaint of increased hair shedding or alopecia, a host of evaluation techniques are available in addition to history, physical examination and laboratory assessment. Various clinical hair techniques can help in assessing the efficacy of drugs and cosmetics on hair growth. The methods are quite similar to those used to establish a definite diagnosis in dermatological practice. Great strides have been made during the recent decades in the methodology of hair growth trials in dermatology and cosmetology. Clinical evaluations benefit from a few additional specific techniques that enhance the perception of hair (re-) growth, shedding and alopecia. These assessments include the determination of hair patterning and density that may be helped by the 'black-and-white felt' examination. Daily hair counts, the 'hair pull test' and the 'hair feathering test' are also available. Instrumental methods provide reliable quantitative information that is useful if there are adequate controls. Some photographic methods, the trichogram, hair weighing and variants of the hair growth window technique including the phototrichogram, videotrichogram and tractio-phototrichogram provide insight into the complexities of hair cycling and shedding. Skin biopsy is indicated for diagnostic purposes, especially when the hair loss is accompanied by scarring.

Laser hair reduction in the hirsute patient: a critical assessment.

Hirsutism affects 5-10% of unselected women, depending on ethnicity and definition. The past two decades have seen the development of lasers for the removal of unwanted hair, using selective destruction of the hair follicle without damage to adjacent tissues. Selective photothermolysis relies on the absorption of a brief radiation pulse by specific pigmented targets, which generates and confines the heat to that selected target. In general, laser hair removal is most successful in patients with lighter skin colours and dark coloured hairs. Some studies have documented the results of laser hair removal in a controlled setting, although few have extended their observations beyond 1 year. In general, treatment with the ruby, alexandrite or diode lasers, or the use of intense pulsed light results in similar success rates, although these are somewhat lower for the neodymium:Yttrium-Aluminum-Garnet (nd:YAG) laser. Overall, laser hair removal should not be considered 'permanent', at least when considering the current data available. Repeated therapies are necessary, although complete alopoecia is rarely achieved and it is unclear at what point the maximum benefit is achieved from multiple therapies. While larger prospective, controlled, blinded and uniform studies are still needed, laser hair removal appears to be a useful adjuvant in the treatment of the hirsute patient.

Assessment of functional impairment following permanent middle cerebral artery occlusion in a non-human primate species.

The purpose of the present study was to examine and quantify the functional consequence of a focal cerebral ischaemic lesion in a primate species, the marmoset. Following craniotomy and retraction of the frontal and temporal lobes, the middle cerebral artery was permanently occluded by means of electrocoagulation. Three and eight weeks after surgery, various behavioural tests were used to give a quantifiable measure to the neurological deficits produced. These tests required the monkeys to reach into tubes for foodbits, retrieve rewards from the steps of two designs of 'staircases', respond to one of two simultaneously presented rewarded tubes, remove adhesive labels attached to their feet, and respond to sensory stimuli. Unilateral motor impairment of the contralateral forelimb and neglect of contralateral tactile stimuli were seen in all subjects, and spatial neglect was also present in some monkeys. Subsequent histological analysis revealed unilateral cortical damage in all subjects with varying amounts of injury to the caudate and the putamen in some animals. These results demonstrate the potential for the use of this species in future investigations to examine the effect of neuroprotective treatment on functional outcome after a focal ischaemic insult.