Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Hair Color”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 379 records · Page 21Linked to original sources
PubMed2002

Dominant role of the niche in melanocyte stem-cell fate determination.

Stem cells which have the capacity to self-renew and generate differentiated progeny are thought to be maintained in a specific environment known as a niche. The localization of the niche, however, remains largely obscure for most stem-cell systems. Melanocytes (pigment cells) in hair follicles proliferate and differentiate closely coupled to the hair regeneration cycle. Here we report that stem cells of the melanocyte lineage can be identified, using Dct-lacZ transgenic mice, in the lower permanent portion of mouse hair follicles throughout the hair cycle. It is only the population in this region that fulfils the criteria for stem cells, being immature, slow cycling, self-maintaining and fully competent in regenerating progeny on activation at early anagen (the growing phase of hair follicles). Induction of the re-pigmentation process in K14-steel factor transgenic mice demonstrates that a portion of amplifying stem-cell progeny can migrate out from the niche and retain sufficient self-renewing capability to function as stem cells after repopulation into vacant niches. Our data indicate that the niche has a dominant role in the fate determination of melanocyte stem-cell progeny.

Animals↗
PubMed2000

Localized in vivo genotypic and phenotypic correction of the albino mutation in skin by RNA-DNA oligonucleotide.

We recently demonstrated that an RNA-DNA oligonucleotide corrected a point mutation in the mouse tyrosinase gene, resulting in permanent and inheritable restoration of tyrosinase enzymatic activity, melanin synthesis, and pigmentation changes in cultured melanocytes. In this study, we extended gene correction of melanocytes from tissue culture to live animals, using a chimeric oligonucleotide designed to correct a point mutation in the tyrosinase gene. Both topical application and intradermal injection of this oligonucleotide to albino BALB/c mouse skin resulted in dark pigmentation of several hairs in a localized area. The restored tyrosinase enzymatic activity was detected by dihydroxyphenylacetic acid (DOPA) staining of hair follicles in the treated skin. Tyrosinase gene correction was also confirmed by restriction fragment length polymorphism analysis and DNA sequencing from skin that was positive for DOPA staining and melanin synthesis. Localized gene correction was maintained three months after the last application of the chimeric oligonucleotides. These results demonstrated correction of the tyrosinase gene point mutation by chimeric oligonucleotides in vivo.

Administration, Cutaneous↗
PubMed1995

The feasibility of targeted selective gene therapy of the hair follicle.

Loss of hair and hair colour is associated with ageing, and when it involves the scalp hair, it can be distressing to both sexes. Hair loss resulting from cancer chemotherapy is particularly distressing. However, safe, effective therapies directed to hair have only just started to be developed. The hair follicle is a complex skin appendage composed of epidermal and dermal tissue, with specialized keratinocytes, the hair matrix cells, forming the hair shaft. Specific therapy of the hair follicle depends on selective targeting of specific cells of the hair follicle. We have developed the histoculture of intact hair-growing skin on sponge-gel matrices. We have recently found in histocultured skin that liposomes can selectively target hair follicles to deliver both small and large molecules. That liposomes can target the hair follicle for delivery has been confirmed independently. Two decades ago we introduced the technique of entrapping DNA in liposomes for use in gene therapy. In this report we describe the selective targeting of the lacZ reporter gene to the hair follicles in mice after topical application of the gene entrapped in liposomes. These results demonstrate that highly selective, safe gene therapy for the hair process is feasible.

Administration, Topical↗
PubMed1999

Sulfur containing tyrosine analogs can cause selective melanocytotoxicity involving tyrosinase-mediated apoptosis.

Sulfur-containing tyrosine analogs such as 4-S-cysteaminylphenol (4-S-CAP) and its N-acetyl derivative, N-acetyl-4-S-CAP, are tyrosinase substrates and can cause selective cytotoxicity or cell death of melanocytes and melanoma cells. It is not clear, however, if the cytotoxicity derives from a cytostatic or cytocidal effect. The latter can also be either apoptotic or necrotic. This paper summarizes our attempt to clarify the nature of melanocytotoxicity and cell death by using a new derivative of 4-S-CAP, N-propionyl-4-S-CAP (NPr-CAP). The i.p. administration of NPr-CAP caused marked depigmentation of black hair follicles in C57 mice. At 12 h postadministration of NPr-CAP, follicular melanocytes showed histochemical and morphologic features indicative of apoptosis by TdT-mediated dUTP-biotin nick end labeling (TUNEL) staining and electron microscopy. The agarose gel electrophoresis of DNA from drug-treated melan a2 cells, an immortal melanocyte line of C57 black mice, showed the nucleosomal DNA ladder pattern. NPr-CAP caused irreversible cytotoxicity in melan a2 and the effect was inhibited by a tyrosinase inhibitor, phenylthiocarbamide. The tyrosinase-mediated cytotoxicity of NPr-CAP was further confirmed by the decreased viability of COS 7 monkey-kidney cells, which expressed a level of high tyrosinase activity through transfection of human tyrosinase cDNA. NPr-CAP, however, also transiently inhibited the proliferation of melan c cells, a control tyrosinase-negative albino melanocyte line, and vector-transfected COS 7 cells. Thus, the major process of NPr-CAP-mediated melanocytotoxicity involves cytocidal apoptosis associated with active tyrosinase. In addition, there is transient, nontyrosinase-mediated cytostatic cytotoxicity.

Animals↗
PubMed2004

Human hair greying is linked to a specific depletion of hair follicle melanocytes affecting both the bulb and the outer root sheath.

BACKGROUND: Although hair greying is a very common phenomenon characterized by loss of pigment in the hair shaft, the events that cause and control natural hair whitening with age in humans are still unclear. OBJECTIVES: To decipher the origin of natural hair whitening. METHODS: Human hair melanocytes were immunohistochemically characterized at different stages of whitening. RESULTS: Loss of hair shaft melanin was found to be associated with a decrease in both bulb melanin content and bulb melanocyte population. Although few melanocytes were present in the bulbs of grey hair, they still expressed tyrosinase and tyrosinase-related protein-1, synthesized and transferred melanins to cortical keratinocytes as seen by the presence of melanin granules. In white hair bulbs, no melanocytes could be detected either with pMel-17 or vimentin labelling. Pigmented hair follicles are known to contain inactive melanocytes in the outer root sheath (ORS), and grey and white hairs were also found to contain some of these quiescent melanocytes. However, their population was decreased compared with pigmented hair follicles, ranging from small to nil. This depletion of melanocytes in the different areas of white hairs was detected throughout the hair cycle, namely at telogen and early anagen stages. In contrast, the infundibulum and sebaceous gland of both pigmented and white hairs showed a similar distribution of melanocytes. Furthermore, other distinct cell populations located in the ORS, namely putative stem cells, Merkel cells and Langerhans cells were equivalently identified in pigmented and white hairs. CONCLUSIONS: Thus, hair greying appears to be a consequence of an overall and specific depletion of bulb and ORS melanocytes of human hair.

Adult↗
PubMed2002

Disappearance of pili annulati following an episode of alopecia areata.

Pili annulati is a distinctive autosomal dominant hair shaft disorder that produces alternating light and dark bands that can give a spangled appearance to the hair. The literature contains three case reports of patients in whom the condition has disappeared following recovery from alopecia totalis. None of these reports contain a direct microscopic comparison of pre- and post-regrowth hairs. We report a 6-year-old girl who was first noted to have pili annulati at the age of 2 years and who developed alopecia totalis at the age of 3 years. When the hair regrew spontaneously, 18 months later, the pili annulati was no longer visible. Hair samples obtained before and after the episode of alopecia areata were compared by normal and cross-polarized light microscopy. While not apparent on careful clinical examination, banding was present on light microscopy in 20% of the hairs. Eighty per cent of the affected hairs displayed banding throughout their entire length. In contrast, prior to the episode of alopecia totalis, when the pili annulati was clearly visible, 50% of the hair obtained was banded on microscopy and 90% of the affected hairs showed banding throughout their microscopic length.

Alopecia Areata↗
PubMed2003

Nonsynchronized segmented heterochromia in black scalp hair.

Nonsynchronized segmented heterochromia in black scalp hair is a rarely reported entity, the only previous report being described in association with iron deficiency anaemia. A 14-year-old girl presented with a 2-year history of nonsynchronized segmented heterochromia. She was otherwise well and her serum iron, copper, zinc and protein levels were all within the normal range. She had no clinical evidence of vitiligo or alopecia areata. This patient is believed to represent the first reported case of nonsynchronized segmented heterochromia in black scalp hair as a presentation of premature greying of the hair.

Adolescent↗
PubMed1998

Myosin V colocalizes with melanosomes and subcortical actin bundles not associated with stress fibers in human epidermal melanocytes.

Mutations of the gene encoding myosin V can produce a dilute or silvery hair color and various neurologic defects in mice and patients with Griscelli syndrome, leading to speculations that the myosin V motor protein plays a critical role in transporting melanosomes within melanocytes and neurosecretory vesicles within neurons. Therefore, we investigated the in vitro expression of myosin V in cultured normal human melanocytes, keratinocytes, and dermal fibroblasts using reverse transcriptase-polymerase chain reaction and northern blot analysis. Subcellular distribution of myosin V and proximity to actin bundles and melanosomes were determined by double indirect immunofluorescence labeling and immunogold electron microscopy. In all studied cells myosin V is expressed and treatment of melanocytes with the cyclic AMP-inducer 3-isobutyl-1-methylxanthine causes an induction of the myosin V message. In all cells myosin V colocalizes with actin bundles, concentrating in the subcortical cell zone. In the melanocyte it is closely associated with melanosomes. Quantitative analysis of myosin V labeling in melanocytes reveals a significantly higher (p < 0.005) presence of myosin V in the periphery of dendrites. These results suggest that myosin V is important in melanosome transport in human melanocytes. Possible roles in the other skin cells remain to be elucidated.

1-Methyl-3-isobutylxanthine↗
PubMedDate not supplied

Pseudopili annulati in a dark-haired individual: a light and electron microscopic study.

We report pseudopili annulati for the first time in a dark-haired Chinese girl. The hair was elliptical in shape and twisted along its long axis. The banded or ringed appearance was due to incident light being reflected by the flattened segments. Banding was also noted under polarized light but was not present under transmitted light. Under transmitted light the whole length of the hair appeared dark and the thickness varied at regular intervals, giving rise to fusiform segments due to the twisted nature of the hair shaft. Scanning and transmission electron microscopic examinations revealed no abnormalities in the cuticle and cortex.

Child, Preschool↗
PubMed2004

Laser hair removal.

Laser hair removal is a minimally invasive cosmetic procedure that is well suited to the office-based practice. A great deal of improvement has occurred in the past 5 years with the technology and the understanding of how and for whom the procedure works. A review of the physics of laser-skin interactions is included as well as guidelines for safe and effective clinical treatments. Four wavelengths of lasers and intense light sources have proven successful for a variety of skin types. Average rates of long-term hair reduction, for properly treated subjects, are consistently reported between 70 and 90% at a minimum of 6 months. When performed by physician extenders under the supervision of a physician, maximal use of time and resources can be achieved.

Follow-Up Studies↗
PubMed2005

Laser hair removal in Fitzpatrick type IV to VI patients.

Laser hair removal is one of the most popular laser procedures performed. Dark-skinned patients are the most challenging hair-removal patients because of the melanin found in both the hair and the skin. This article discusses options for hair removal that are safe and effective in dark-skinned patients.

Hair Color↗
PubMed1985

Sunlight exposure as risk factor for intraocular malignant melanoma.

In a case-control study, we compared 444 patients with intraocular malignant melanoma with matched controls to evaluate the role of exposure to ultraviolet radiation and other risk factors in the pathogenesis of this tumor. Persons born in the southern United States had a relative risk of 2.7 (95 per cent confidence interval, 1.3 to 5.9) as compared with those born in the North. Subjects with brown eyes were protected as compared with those with blue eyes (relative risk, 0.6; 95 per cent confidence interval, 0.4 to 0.8), but complexion and hair color were not important risk factors. Patients with intraocular malignant melanoma were also more likely to have spent time outdoors in their gardens, to have sunbathed, and to have used sunlamps. Rarely wearing hats, visors, or sunglasses while in the sun was a risk factor for the disease (relative risk, 1.9; 95 per cent confidence interval, 1.6 to 2.2). These data suggest that sunlight exposure is an important risk factor for intraocular melanoma.

Eyeglasses↗
PubMed2004

Effective epilation of white and blond hair using combined radiofrequency and optical energy.

OBJECTIVE: The present study examined the long-term photoepilatory effect on blond and white hair of a combined intense pulsed light (680-980 nm) device with a bipolar radiofrequency component producing electrical current at a depth of 4 mm. MATERIALS AND METHODS: Thirty-six adult women with white and blond hair (skin phenotypes I-V) were included in the study. The chin and upper lip were treated with four treatment sessions over 9-12 months with long-term follow-up performed at month 18 (6 months after the last treatment). The level of RF energy was 20 J/cm3, while optical fluences varied from 24 to 30 J/cm2. Hair counts and photographic evaluation of some sites were obtained at baseline, months 1, 3 and 5 and the final treatment session. RESULTS: An average hair removal of 48% was observed at month 18 (6 months following the final treatment session). A slightly higher photoepilatory efficiency was noted for blond hair (52%) versus white hair (44%) treatment sites. CONCLUSION: Combined radiofrequency and optical energy technology may produce effective photoepilation of blond and white hair phenotypes.

Adult↗
PubMed2006

Blond hair removal using ELOS systems.

OBJECTIVE: The aim of this study was to test blond hair removal using the ELOS system, which is optical energy and radio-frequency combined. METHODS: Seventeen patients with blond hair were randomly selected from the Department of Lasertherapy, Medical Centre Maastricht, The Netherlands. The mean age of the patients was 57.4 years. The mean energy used per patient was 23.2 J/cm2 and the mean radio-frequency was 18.6 J/cm2. RESULTS: A mean hair reduction of 57.4% was obtained with a mean of 8.5 treatments. There was a trend found between hair removal and the number of treatments. No correlation was found between the percentage of hair removal and age. Furthermore, there was no correlation between hair removal and the device's technical data. No major side effects were observed postoperatively. CONCLUSIONS: This study showed that ELOS can effectively be used for blond hair reduction.

Aged↗
PubMed1976

Teratology and percutaneous toxicity studies on hair dyes.

Twelve hair dye formulations were tested for systemic toxicity by topical application twice weekly for 13 wk to groups of 12 New Zealand white rabbits and for teratologic effects following applications to groups of 20 pregnant Charles River CD rats on days 1, 4, 7, 10, 13, 16, and 19 of gestation. The three semipermanent formulations were applied as is, and the nine oxidation dyes were mixed 1:1 with 6% hydrogen peroxide just prior to application, as in normal use. The formulations induced a broad spectrum of dyes and dye intermediates used or considered useful in oxidative and semipermanent hair color products. In the teratology study no biologically significant soft tissue or skeletal changes were noted. Similarly, the mean numbers of corpora lutea, implantation sites, live fetuses, and resorptions per pregnancy, as well as numbers of litters with resporptions, were not significantly affected by the dye treatment. In the percutaneous toxicity study there was no evidence of compound-induced systemic effects. Microscopic examination of 25 tissues from each animal gave no indication of histomorphologic evidence of toxicity. No dye discoloration of urine was seen at any time during the test or at necropsy. Some of the dye groups showed epidermal hyperplasia, which was probably a reflection of slight irritation due to the frequency of application of the oxidation formulations.

Abnormalities, Drug-Induced↗
PubMed1974

Genetics of restricted antibodies to streptococcal group polysaccharides in mice. I. Strain differences of isoelectric focusing spectra of group A hyperimmune antisera.

The immune response of nine inbred and one outbred strain of mice to the streptococcal group A polysaccharide was investigated with respect to magnitude and restriction. Analytical isoelectric focusing served as a tool to estimate the degree of restriction of Group A polysaccharide-specific antibodies. It proved feasible to distinguish low and intermediate from high responder strains, and to delineate strain-specificity of isoelectric focusing spectra of the immune sera. For example, immune sera of BALB/c mice, restricted high responders, and of C57BL/6 mice, heterogeneous low responders, had distinct focusing properties. Responsiveness was a dominant autosomal genetic trait in C57BL/6 x BALB/c F(1) hybrid mice, irrespective of the maternal and the paternal genotype; the immune sera of these mice had their own, rather uniform isoelectric focusing spectra whereby structural genes of the low responder strain were expressed to predominant levels in 81% of the hybrids. Responsiveness in C57BL/6 x BALB/c F(2) progeny segregated into 79% high and 21% low responders, and showed no genetic linkage to the following characteristics: hair color, sex, H-2 type, and Ig allotype of the heavy chain. The isoelectric focusing properties of these immune sera indicated segregation into patterns like BALB/c mice (40%), F(1) hybrids (48%), and C57BL/6 mice (12%). Since this segregation is independent of any of the above criteria in these F(2) mice a regulatory gene(s) is postulated that controls the clonal pattern of the immune response.

Animals↗
PubMed1982

Five-year follow-up of a man with subcutaneous mycetomas caused by Microsporum audouinii.

A black man with subcutaneous mycetomas caused by Microsporum audouinii was treated by a combination of griseofulvin, 18.5 g of amphotericin B, excisional surgery, and later, ketoconazole, resulting in a satisfactory arrest or cure of the clinical illness. Complications of therapy included residual impaired renal function and a change in hair color from black to a rust brown color. The continued use of the term mycetoma to describe such lesions is justified.

Adult↗