Contribution of the Hair Follicular Pathway to Total Skin Permeation of Topically Applied and Exposed Chemicals

PubMed Central

Mohd, Fadli; Todo, Hiroaki; Yoshimoto, Masato; Yusuf, Eddy; Sugibayashi, Kenji

2016-01-01

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 chemicals can be obtained in detail, their blood and skin concentrations can be more precisely predicted. In the present study, the contribution of the hair follicle pathway to the skin permeation of topically applied or exposed chemicals was calculated from the difference between their permeability coefficients through skin with and without hair follicle plugging, using an in vitro skin permeation experiment. The obtained results reveal that the contribution of the hair follicle pathway can be predicted by using the chemicals’ lipophilicity. For hydrophilic chemicals (logarithm of n-octanol/water partition coefficient (log Ko/w) < 0), a greater reduction of permeation due to hair follicle plugging was observed than for lipophilic chemicals (log Ko/w ≥ 0). In addition, the ratio of this reduction was decreased with an increase in log Ko/w. This consideration of the hair follicle pathway would be helpful to investigate the efficacy and safety of chemicals after topical application or exposure to them because skin permeation and disposition should vary among skins in different body sites due to differences in the density of hair follicles. PMID:27854289

Hair Treatments and Pregnancy

MedlinePlus

... Common chemicals in hair dyes include hydrogen peroxide, ammonia, and alcohols. Hair curling or permanent wave chemicals include ammonium thioglycolate and ammonia. Hair bleaching chemicals include hydrogen peroxide. Hair straighteners ( ...

Black women's hair: the main scalp dermatoses and aesthetic practices in women of African ethnicity *

PubMed Central

Tanus, Aline; Oliveira, Camila Caberlon Cruz; Villarreal, Delky Johanna Villarreal; Sanchez, Fernando Andres Vargas; Dias, Maria Fernanda Reis Gavazzoni

2015-01-01

Afro-ethnic hair is different from Caucasian and Asian hair and has unique features. Ethnic hair is more prone to certain conditions or diseases. Such diseases are not only related to the fragile inner structure of the hair, but also to the cultural habits of hairstyles that often exert traction forces upon the pilosebaceous follicle. Women with African hair subject their hair to chemical treatments such as hair straightening and relaxing, and thus modify the structure of their hair shaft, making it more susceptible to damage. For this reason, hair complaints are common among black women and represent a diagnostic challenge to the dermatologist, requiring a thorough clinical examination of the hair and scalp, and a detailed medical history of the patient. The purpose of this review is to warn of the potential side effects and sequelae related to hairstyles and hair treatments used by black women, and to highlight the major diseases that affect this ethnicity. PMID:26375213

Viscoelastic properties of α-keratin fibers in hair.

PubMed

Yu, Yang; Yang, Wen; André Meyers, Marc

2017-12-01

Considerable viscoelasticity and strain-rate sensitivity are a characteristic of α-keratin fibers, which can be considered a biopolymer. The understanding of viscoelasticity is an important part of the knowledge of the overall mechanical properties of these biological materials. Here, horse and human hairs are examined to analyze the sources of this response. The dynamic mechanical response of α-keratin fibers over a range of frequencies and temperatures is analyzed using a dynamic mechanical analyzer. The α-keratin fibers behave more elastically at higher frequencies while they become more viscous at higher temperatures. A glass transition temperature of ∼55°C is identified. The stress relaxation behavior of α-keratin fibers at two strains, 0.02 and 0.25, is established and fit to a constitutive equation based on the Maxwell-Wiechert model. The constitutive equation is further compared to the experimental results within the elastic region and a good agreement is obtained. The two relaxation constants, 14s and 359s for horse hair and 11s and 207s for human hair, are related to two hierarchical levels of relaxation: the amorphous matrix-intermediate filament interfaces, for the short term, and the cellular components for the long term. Results of the creep test also provide important knowledge on the uncoiling and phase transformation of the α-helical structure as hair is uniaxially stretched. SEM results show that horse hair has a rougher surface morphology and damaged cuticles. It also exhibits a lower strain-rate sensitivity of 0.05 compared to that of 0.11 for human hair. After the horse and human hairs are chemically treated and the disulfide bonds are cleaved, they exhibit a similar strain-rate sensitivity of ∼0.05. FTIR results confirms that the human hair is more sensitive to the -S-S- cleavage, resulting in an increase of cysteic acid content. Therefore, the disulfide bonds in the matrix are experimentally identified as one source of the strain

Dermatotoxicologic clinical solutions: hair dying in hair dye allergic patients?

PubMed

Edwards, Ashley; Coman, Garrett; Blickenstaff, Nicholas; Maibach, Howard

2015-03-01

This article describes how to identify allergic contact dermatitis resulting from hair dye, and outlines interventions and prevention principles for those who wish to continue dyeing their hair despite being allergic. Hair dye chemicals thought to be the most frequent sensitizers are discussed with instructions for health care providers on how to counsel patients about techniques to minimize exposure to allergenic substances. This framework should allow many patients to continue dyeing their hair without experiencing adverse side effects.

The proteomic profile of hair damage.

PubMed

Sinclair, R; Flagler, M J; Jones, L; Rufaut, N; Davis, M G

2012-06-01

Monilethrix is a congenital hair shaft disorder with associated fragility. Many of the changes seen in monilethrix hair on light microscopy and scanning electron microscopy are also seen in hair weathering and cosmetic damage to hair. We used monilethrix as a model to investigate the relationship between hair protein structure and hair strength and resistance to cosmetic insult. We applied proteomic techniques to identify novel peptide damage markers for chemical oxidative damage to hair. The findings suggest that specific sites in the protein structure of hair are targeted during oxidative damage from bleaching, a unique insight into how chemical damage compromises the structural integrity of the hair shaft at the molecular level. Applying proteomics to the study of congenital and acquired hair shaft disorders can deliver new insights into hair damage and novel strategies to strengthen hair. © 2012 The Authors. BJD © 2012 British Association of Dermatologists.

Diseases that turn African hair silky.

PubMed

Ajose, Frances O A

2012-11-01

African hair in its natural state poses tenacious grooming challenges; consequently a large portion of the African cosmetic industry is focused on means to relax the tight curls of African hair to make the hair more manageable. In malnourished and hypoproteinemic states, African hair straightens in an uncomplimentary manner. Recently, we observed that in certain diseases African hair changes to a desirable silky wavy texture. To identify the diseases that turn African hair silky and their parameters we examined 5612 dermatology patients at a tertiary hospital in Nigeria. We then studied the clinical and basic laboratory parameters of those patients whose diseases were accompanied by the silky hair change. Silky hair change similar to the hair of the African neonatal child was observed in five diseases, namely AIDS, rheumatoid arthritis, systemic lupus erythematosus, pulmonary tuberculosis with cachexia, and Behçet's disease. Our study identified retrogression of African hair to the neonatal structure in five diseases. Anemia of chronic illness, high erythrocyte sedimentation rate, and mild hypocalcemia were significant laboratory parameters. This is an important observation, which should excite and advance research into the nature and structure of African hair. The causes of structural hair changes should include these five diseases. © 2012 The International Society of Dermatology.

Hair analysis as a useful procedure for detection of vapour exposure to chemical warfare agents: simulation of sulphur mustard with methyl salicylate.

PubMed

Spiandore, Marie; Piram, Anne; Lacoste, Alexandre; Josse, Denis; Doumenq, Pierre

2014-06-01

Chemical warfare agents (CWA) are highly toxic compounds which have been produced to kill or hurt people during conflicts or terrorist attacks. Despite the fact that their use is strictly prohibited according to international convention, populations' exposure still recently occurred. Development of markers of exposure to CWA is necessary to distinguish exposed victims from unexposed ones. We present the first study of hair usage as passive sampler to assess contamination by chemicals in vapour form. This work presents more particularly the hair adsorption capacity for methyl salicylate used as a surrogate of the vesicant sulphur mustard. Chemical vapours toxicity through the respiratory route has historically been defined through Haber's law's concentration-time (Ct) product, and vapour exposure of hair to methyl salicylate was conducted with various times or doses of exposure in the range of incapacitating and lethal Ct products corresponding to sulphur mustard. Following exposure, extraction of methyl salicylate from hair was conducted by simple soaking in dichloromethane. Methyl salicylate could be detected on hair for vapour concentration corresponding to about one fifth of the sulphur mustard concentration that would kill 50% of exposed individuals (LCt50). The amount of methyl salicylate recovered from hair increased with time or dose of exposure. It showed a good correlation with the concentration-time product, suggesting that hair could be used like a passive sampler to assess vapour exposure to chemical compounds. It introduces great perspectives concerning the use of hair as a marker of exposure to CWA. Copyright © 2014 John Wiley & Sons, Ltd.

Unscheduled DNA synthesis in human hair follicles after in vitro exposure to 11 chemicals: comparison with unscheduled DNA synthesis in rat hepatocytes.

PubMed

van Erp, Y H; Koopmans, M J; Heirbaut, P R; van der Hoeven, J C; Weterings, P J

1992-06-01

A new method is described to investigate unscheduled DNA synthesis (UDS) in human tissue after exposure in vitro: the human hair follicle. A histological technique was applied to assess cytotoxicity and UDS in the same hair follicle cells. UDS induction was examined for 11 chemicals and the results were compared with literature findings for UDS in rat hepatocytes. Most chemicals inducing UDS in rat hepatocytes raised DNA repair at comparable concentrations in the hair follicle. However, 1 of 9 chemicals that gave a positive response in the rat hepatocyte UDS test, 2-acetylaminofluorene, failed to induce DNA repair in the hair follicle. Metabolizing potential of hair follicle cells was shown in experiments with indirectly acting compounds, i.e., benzo[a]pyrene, 7,12-dimethylbenz[a]anthracene and dimethylnitrosamine. The results support the conclusion that the test in its present state is valuable as a screening assay for the detection of unscheduled DNA synthesis. Moreover, the use of human tissues may result in a better extrapolation to man.

Hair product use, age at menarche and mammographic breast density in multiethnic urban women.

PubMed

McDonald, Jasmine A; Tehranifar, Parisa; Flom, Julie D; Terry, Mary Beth; James-Todd, Tamarra

2018-01-04

Select hair products contain endocrine disrupting chemicals (EDCs) that may affect breast cancer risk. We hypothesize that, if EDCs are related to breast cancer risk, then they may also affect two important breast cancer risk factors: age at menarche and mammographic breast density. In two urban female cohorts (N = 248): 1) the New York site of the National Collaborative Perinatal Project and 2) the New York City Multiethnic Breast Cancer Project, we measured childhood and adult use of hair oils, lotions, leave-in conditioners, root stimulators, perms/relaxers, and hair dyes using the same validated questionnaire. We used multivariable relative risk regression models to examine the association between childhood hair product use and early age at menarche (defined as <11 years of age) and multivariable linear regression models to examine the association between childhood and adult hair product use and adult mammographic breast density. Early menarche was associated with ever use of childhood hair products (RR 2.3, 95% CI 1.1, 4.8) and hair oil use (RR 2.5, 95% CI 1.2, 5.2); however, additional adjustment for race/ethnicity, attenuated associations (hair products RR 1.8, 95% CI 0.8, 4.1; hair oil use RR 2.3, 95% CI 1.0, 5.5). Breast density was not associated with adult or childhood hair product or hair oil use. If confirmed in larger prospective studies, these data suggest that exposure to EDCs through hair products in early life may affect breast cancer risk by altering timing of menarche, and may operate through a mechanism distinct from breast density.

Xanthotrichia (yellow hair) due to selenium sulfide and dihydroxyacetone.

PubMed

Prevost, Noel; English, Joseph C

2008-07-01

Hair shaft discoloration has been documented to be caused by disease states, medications, and exogenous chemicals. After researching the literature, xanthotrichia or yellow hair has been determined to be caused predominately by exogenous chemicals. Two cases of new chemicals causing yellow hair shaft discoloration are reported. The chemicals include selenium sulfide 2.5% shampoo and dihydroxyacetone.

Protective effect of conditioning agents on Afro-ethnic hair chemically treated with thioglycolate-based straightening emulsion.

PubMed

Dias, Tania Cristina de Sá; Baby, André Rolim; Kaneko, Telma Mary; Velasco, Maria Valéria Robles

2008-06-01

Straightening is a chemical process by which excessively curly hair is straightened in an irreversible way. Generally, products are formulated as emulsions with high pH value (9.0-12.0), which, after applied on hair, cause considerable damage, making it dry and fragile. This research work evaluated the protective effect of lauryl PEG/PPG-18/18 methicone, cyclopentasiloxane (and) PEG-12 dimethicone cross-polymer, jojoba oil, and aqua (and) cystine bis-PG propyl silanetriol, as conditioning agents, on Afro-ethnic hair locks treated with thioglycolate-based straightening emulsions by protein loss, combability, and traction to rupture. Standard Afro-ethnic hair locks were prepared following a protocol for straightening emulsion application. Considering the assays performed, the addition of conditioning agents to the straightening emulsion with ammonium thioglycolate benefited the hair fiber, thus diminishing protein loss, protecting the hair thread, and improving resistance to breakage. Jojoba oil and lauryl PEG/PPG-18/18 methicone were the conditioning agents that presented the best results. Straightening emulsions with ammonium thioglycolate containing aqua (and) cystine bis-PG propyl silanetriol and cyclopentasiloxane (and) PEG-12 dimethicone cross-polymer were the ones that provided higher breakage resistance of the thread.

Nanotribological effects of hair care products and environment on human hair using atomic force microscopy

NASA Astrophysics Data System (ADS)

Latorre, Carmen; Bhushan, Bharat

2005-07-01

Tribological properties are useful in the study of human hair and other biological materials. Major sources of investigation for conditioner treated hair includes localization of conditioner, mechanisms related to changes in surface roughness, friction, and adhesion on the nanoscale due to conditioner agents, and how the products change the microstructure of the cuticle. The paper presents nanotribological studies investigating surface roughness, friction, and adhesion using atomic force/friction force microscopy (AFM/FFM). Test samples include virgin and chemically damaged hair, both with and without commercial conditioner treatment, as well as chemically damaged hair with experimental conditioner treatments. Friction force mapping provides insight into the localized change in friction caused by the application of hair care materials. Adhesive force maps to study adhesion on the cuticle surface provide information about localization and distribution of conditioner as well. A discussion is presented on these properties of hair as a function of relative humidity, temperature, durability, and conditioning treatments.

Human hair pigmentation--biological aspects.

PubMed

Tobin, D J

2008-08-01

Skin and hair colour contribute significantly to our overall visual appearance and to social/sexual communication. Despite their shared origins in the embryologic neural crest, the hair follicle and epidermal pigmentary units occupy distinct, although open, cutaneous compartments. They can be distinguished principally on the basis of the former's stringent coupling to the hair growth cycle compared with the latter's continuous melanogenesis. The biosynthesis of melanin and its subsequent transfer from melanocyte to hair bulb keratinocytes depend on the availability of melanin precursors and on a raft of signal transduction pathways that are both highly complex and commonly redundant. These signalling pathways can be both dependent and independent of receptors, act through auto-, para- or intracrine mechanisms and can be modified by hormonal signals. Despite many shared features, follicular melanocytes appear to be more sensitive than epidermal melanocytes to ageing influences. This can be seen most dramatically in hair greying/canities and this is likely to reflect significant differences in the epidermal and follicular microenvironments. The hair follicle pigmentary unit may also serve as an important environmental sensor, whereby hair pigment contributes to the rapid excretion of heavy metals, chemicals and toxins from the body by their selective binding to melanin; rendering the hair fibre a useful barometer of exposures. The recent availability of advanced cell culture methodologies for isolated hair follicle melanocytes and for intact anagen hair follicle organ culture should provide the research tools necessary to elucidate the regulatory mechanisms of hair follicle pigmentation. In the longer term, it may be feasible to develop hair colour modifiers of a biological nature to accompany those based on chemicals.

Cross-reactions among hair dye allergens.

PubMed

Basketter, David A; English, John

2009-01-01

p-Phenylenediamine (PPD) is an important hair dye allergen, but there remains a reasonable suspicion that other hair dye chemicals may also be responsible for a proportion of the clinical burden of hair dye allergy. To assess to what extent presently assessed additional patch test agents contribute to the diagnosis of non-PPD hair dye allergy. A retrospective analysis was conducted of patch test results with hair dye allergens, focusing on the extent to which patients who were positive for allergic reactions to other hair dye allergens also had a concomitant positive reaction to PPD. For the hair dye allergens other than p-toluenediamine (PTD), reactions in the absence of a concomitant positive reaction to PPD were very rare. Positive reactors to PTD were also positive for reactions to PPD in 5 of every 6 cases. Pyrogallol positives often occurred in the absence of a PPD positive, but were never judged to be of clinical relevance. Hair dye chemicals other than PPD may be of importance, but the presently tested materials, with the possible exception of PTD, are normally positive only when a PPD-positive reaction is also present, suggesting that their use in patch testing in hair dye allergy is likely to be of limited value.

Advanced chemical imaging and comparison of human and porcine hair follicles for drug delivery by confocal Raman microscopy.

PubMed

Franzen, Lutz; Mathes, Christiane; Hansen, Steffi; Windbergs, Maike

2013-06-01

Hair follicles have recently gained a lot of interest for dermal drug delivery. They provide facilitated penetration into the skin and a high potential to serve as a drug depot. In this area of research, excised pig ear is a widely accepted in vitro model to evaluate penetration of drug delivery into hair follicles. However, a comparison of human and porcine follicles in terms of chemical composition has not been performed so far. In this study, we applied confocal Raman microscopy as a chemically selective imaging technique to compare human and porcine follicle composition and to visualize component distribution within follicle cross-sections. Based on the evaluation of human and porcine Raman spectra optical similarity for both species was successfully confirmed. Furthermore, cyanoacrylate skin surface biopsies, which are generally used to determine the extent of follicular penetration, were imaged by a novel complementary analytical approach combining confocal Raman microscopy and optical profilometry. This all-encompassing analysis allows investigation of intactness and component distribution of the excised hair bulb in three dimensions. Confocal Raman microscopy shows a high potential as a noninvasive and chemically selective technique for the analysis of trans-follicular drug delivery.

Advanced chemical imaging and comparison of human and porcine hair follicles for drug delivery by confocal Raman microscopy

NASA Astrophysics Data System (ADS)

Franzen, Lutz; Mathes, Christiane; Hansen, Steffi; Windbergs, Maike

2013-06-01

Hair follicles have recently gained a lot of interest for dermal drug delivery. They provide facilitated penetration into the skin and a high potential to serve as a drug depot. In this area of research, excised pig ear is a widely accepted in vitro model to evaluate penetration of drug delivery into hair follicles. However, a comparison of human and porcine follicles in terms of chemical composition has not been performed so far. In this study, we applied confocal Raman microscopy as a chemically selective imaging technique to compare human and porcine follicle composition and to visualize component distribution within follicle cross-sections. Based on the evaluation of human and porcine Raman spectra optical similarity for both species was successfully confirmed. Furthermore, cyanoacrylate skin surface biopsies, which are generally used to determine the extent of follicular penetration, were imaged by a novel complementary analytical approach combining confocal Raman microscopy and optical profilometry. This all-encompassing analysis allows investigation of intactness and component distribution of the excised hair bulb in three dimensions. Confocal Raman microscopy shows a high potential as a noninvasive and chemically selective technique for the analysis of trans-follicular drug delivery.

Hair dye use and risk of human cancer

PubMed Central

Zhang, Yawei; Kim, Christopher; Zheng, Tongzhang

2016-01-01

Over 50% of the adult population will use hair dyes at some point in their lifetimes. Hair dyes consist of various chemicals and the composition of these chemicals vary by hair dye types. Chemicals p-phenylenediamine and aminophenyl have been suggested as possible carcinogens or mutagens in experimental studies. The scientific community has been interested in this potential public health impact and the results of published epidemiological studies are summarized here. The current evidence provides limited evidences on the association between personal hair dye use and human cancer risk, except for the possibility of hematopoietic cancers and to a lesser extent, bladder cancer. Risk appears to be affected by time period of use and by specific genetic polymorphisms. Future studies should investigate potential gene and environment interaction to assess possible genetic susceptibility. Several methodological issues should also be considered in future studies including completed hair dye use information such as on timing, duration, frequency and type of hair dye product use. PMID:22201892

Hair dye use and risk of human cancer.

PubMed

Zhang, Yawei; Kim, Christopher; Zheng, Tongzhang

2012-01-01

Over 50% of the adult population will use hair dyes at some point in their lifetimes. Hair dyes consist of various chemicals and the composition of these chemicals vary by hair dye types. Chemicals p-phenylenediamine and aminophenyl have been suggested as possible carcinogens or mutagens in experimental studies. The scientific community has been interested in this potential public health impact and the results of published epidemiological studies are summarized here. The current evidence provides limited evidences on the association between personal hair dye use and human cancer risk, except for the possibility of hematopoietic cancers and to a lesser extent, bladder cancer. Risk appears to be affected by time period of use and by specific genetic polymorphisms. Future studies should investigate potential gene and environment interaction to assess possible genetic susceptibility. Several methodological issues should also be considered in future studies including completed hair dye use information such as on timing, duration, frequency and type of hair dye product use.

Efficacy of antioxidants in human hair.

PubMed

Fernández, Estibalitz; Martínez-Teipel, Blanca; Armengol, Ricard; Barba, Clara; Coderch, Luisa

2012-12-05

Hair is exposed every day to a range of harmful effects such as sunlight, pollution, cosmetic treatments, grooming practices and cleansing. The UV components of sunlight damage human hair, causing fibre degradation. UV-B attacks the melanin pigments and the protein fractions (keratin) of hair and UV-A produces free radical/reactive oxygen species (ROS) through the interaction of endogenous photosensitizers. Hair was dyed and the efficacy of two antioxidant formulations was demonstrated after UV exposure by evaluating, surface morphology, protein and amino acid degradation, lipidic peroxidation, colour and shine changes and strength/relaxation properties. UV treatment resulted in an increase in protein and lipid degradation, changes in colour and shine and in adverse consequences for the mechanical properties. Natural antioxidants obtained from artichoke and rice applied to pretreated hair improved mechanical properties and preserved colour and shine of fibres, coating them and protecting them against UV. Furthermore, the lipidic peroxidation of the protein degradation caused by UV was reduced for some treated fibres, suggesting an improvement in fibre integrity. This was more marked in the case of the fibres treated using the artichoke extract, whereas the rice extract was better preserving shine and colour of hair fibres. Copyright © 2012 Elsevier B.V. All rights reserved.

Transverse relaxation in the rotating frame induced by chemical exchange.

PubMed

Michaeli, Shalom; Sorce, Dennis J; Idiyatullin, Djaudat; Ugurbil, Kamil; Garwood, Michael

2004-08-01

In the presence of radiofrequency irradiation, relaxation of magnetization aligned with the effective magnetic field is characterized by the time constant T1rho. On the other hand, the time constant T2rho characterizes the relaxation of magnetization that is perpendicular to the effective field. Here, it is shown that T2rho can be measured directly with Carr-Purcell sequences composed of a train of adiabatic full-passage (AFP) pulses. During adiabatic rotation, T2rho characterizes the relaxation of the magnetization, which under adiabatic conditions remains approximately perpendicular to the time-dependent effective field. Theory is derived to describe the influence of chemical exchange on T2rho relaxation in the fast-exchange regime, with time constant defined as T2rho,ex. The derived theory predicts the rate constant R2rho,ex (= 1/T2rho,ex) to be dependent on the choice of amplitude- and frequency-modulation functions used in the AFP pulses. Measurements of R2rho,ex of the water/ethanol exchanging system confirm the predicted dependence on modulation functions. The described theoretical framework and adiabatic methods represent new tools to probe exchanging systems. Copyright 2004 Elsevier Inc.

Fullerene nanomaterials potentiate hair growth.

PubMed

Zhou, Zhiguo; Lenk, Robert; Dellinger, Anthony; MacFarland, Darren; Kumar, Krishan; Wilson, Stephen R; Kepley, Christopher L

2009-06-01

Hair loss is a common symptom resulting from a wide range of disease processes and can lead to stress in affected individuals. The purpose of this study was to examine the effect of fullerene nanomaterials on hair growth. We used shaved mice as well as SKH-1 "bald" mice to determine if fullerene-based compounds could affect hair growth and hair follicle numbers. In shaved mice, fullerenes increase the rate of hair growth as compared with mice receiving vehicle only. In SKH-1 hairless mice fullerene derivatives given topically or subdermally markedly increased hair growth. This was paralleled by a significant increase in the number of hair follicles in fullerene-treated mice as compared with those mice treated with vehicle only. The fullerenes also increased hair growth in human skin sections maintained in culture. These studies have wide-ranging implications for those conditions leading to hair loss, including alopecia, chemotherapy, and reactions to various chemicals.

MRI of human hair.

PubMed

Mattle, Eveline; Weiger, Markus; Schmidig, Daniel; Boesiger, Peter; Fey, Michael

2009-06-01

Hair care for humans is a major world industry with specialised tools, chemicals and techniques. Studying the effect of hair care products has become a considerable field of research, and besides mechanical and optical testing numerous advanced analytical techniques have been employed in this area. In the present work, another means of studying the properties of hair is added by demonstrating the feasibility of magnetic resonance imaging (MRI) of the human hair. Established dedicated nuclear magnetic resonance microscopy hardware (solenoidal radiofrequency microcoils and planar field gradients) and methods (constant time imaging) were adapted to the specific needs of hair MRI. Images were produced at a spatial resolution high enough to resolve the inner structure of the hair, showing contrast between cortex and medulla. Quantitative evaluation of a scan series with different echo times provided a T*(2) value of 2.6 ms for the cortex and a water content of about 90% for hairs saturated with water. The demonstration of the feasibility of hair MRI potentially adds a new tool to the large variety of analytical methods used nowadays in the development of hair care products.

Nuclear spin relaxation due to chemical shift anisotropy of gas-phase 129Xe.

PubMed

Hanni, Matti; Lantto, Perttu; Vaara, Juha

2011-08-14

Nuclear spin relaxation provides detailed dynamical information on molecular systems and materials. Here, first-principles modeling of the chemical shift anisotropy (CSA) relaxation time for the prototypic monoatomic (129)Xe gas is carried out, both complementing and predicting the results of NMR measurements. Our approach is based on molecular dynamics simulations combined with pre-parametrized ab initio binary nuclear shielding tensors, an "NMR force field". By using the Redfield relaxation formalism, the simulated CSA time correlation functions lead to spectral density functions that, for the first time, quantitatively determine the experimental spin-lattice relaxation times T(1). The quality requirements on both the Xe-Xe interaction potential and binary shielding tensor are investigated in the context of CSA T(1). Persistent dimers Xe(2) are found to be responsible for the CSA relaxation mechanism in the low-density limit of the gas, completely in line with the earlier experimental findings.

Hair chemical element contents and influence factors of reproductive-age women in the West Ujimqin Banner, Inner Mongolia, China.

PubMed

Zhou, Shanshan; Yuan, Haodong; Ma, Xiaoling; Liu, Ying

2017-01-01

Women have an increased risk for chemical element deficiencies during reproductive age, particularly due to higher chemical element requirements and poor diets. Twenty-one chemical elements (Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, Mg, Mn, Mo, Ni, Pb, Se, Si, Sn, Sr, Ti, V and Zn) in hair samples, which were collected from 71 non-pregnant and 236 pregnant women living in the West Ujimqin Banner, central Inner Mongolia, China, were measured, and the environment, dietary habits and ethnic group influence factors associated with the biomarker were analyzed. The results indicated that the average values of the chemical element contents from hair were greatly different compared to those from other areas, especially the Al, Cd, Pb, Ca and Sr contents. There was no significant difference among the three ethnicities for any element except Mn and Ti in non-pregnant women. Compared to non-pregnant women, in the first trimester group, the levels of nine chemical elements (Ba, Cd, Cu, Pb, Se, Si, Sn and Ti) decreased, while the others increased, and the contents of all of the chemical elements decreased in the second trimester group, while in the third trimester, there was a slight increase. Three chemical elements (Cu, Mn and Zn) displayed a synergistic correlation between each other in the third trimester group, which may protect the placenta from some oxidant damage. The high levels of Cd and Pb in hair likely originate from house renovations and traffic pollution. This study provided basic and useful information on the levels of chemical elements in reproductive-age women, and the results of this study are helpful to control the contents and improve the health of pregnant and non-pregnant women. Copyright © 2016 Elsevier Ltd. All rights reserved.

A Review: Hair Health, Concerns of Shampoo Ingredients and Scalp Nourishing Treatments.

PubMed

Chiu, Chin-Hsien T; Huang, Shu-Hung; Wang, Hui-Min D

2015-01-01

Human hair serves a biological purpose of protecting the scalp, as well as physical attractiveness to the perception of beauty. Hair loss, graying of hair, dandruff and other conditions affecting hair conditions can be distressing to patients, as hair condition is often considered important in people's own assessment of physical beauty. Different hair types can benefit from different treatment methods to promote hair health and growth. External factors like exposure to the sun and smoking, dietary factors including malnutrition of essential fatty acids and vitamins, and chemicals applied to the hair and scalp in shampoos and other treatments can all cause damage to existing hair and impair hair growth. Specific chemicals found in many shampoos, including antimicrobial agents, surfactants and preservatives, can all impair different aspects of hair health. In this review, we aim to discuss the main hair issues, such as hair loss, followed by the safety assessments of selected ingredients in shampoo, and possible nourishment for scalp improvement. This review highlights areas of disagreement in the existing literature, and points to new directions for future studies. Key conclusions include the carcinogenic chemicals to avoid, alternatives of such ingredients, and scalp nourishing treatments with micronutrients.

The nail and hair in forensic science.

PubMed

Daniel, C Ralph; Piraccini, Bianca Maria; Tosti, Antonella

2004-02-01

Drugs, chemicals, and biological substances accumulate and are stored in hair and nails where they can be detected and measured. Advantages of analyzing hair and nail samples also include their easy and non-invasive collection, the small sample size required for analysis, and their easy storage at room temperature. We report 3 examples of heavy metal poisoning diagnosed because of the hair or nail symptoms. Drugs and toxins that can be detected in hair and nails are reviewed and the application of hair/nail analysis in general and in forensic medicine is discussed.

Hair decontamination procedure prior to multi-class pesticide analysis.

PubMed

Duca, Radu-Corneliu; Hardy, Emilie; Salquèbre, Guillaume; Appenzeller, Brice M R

2014-06-01

Although increasing interest is being observed in hair analysis for the biomonitoring of human exposure to pesticides, some limitations still have to be addressed for optimum use of this matrix in that specific context. One main possible issue concerns the need to differentiate chemicals biologically incorporated into hair from those externally deposited on hair surface from contaminated air or dust. The present study focuses on the development of a washing procedure for the decontamination of hair before analysis of pesticides from different chemical classes. For this purpose, three different procedures of artificial contamination (with silica, cellulose, and aqueous solution) were used to simulate pesticides deposition on hair surface. Several washing solvents (four organic: acetone, dichloromethane, methanol, acetonitrile; and four aqueous: water, phosphate buffer, shampoo, sodium dodecylsulfate) were evaluated for their capacity to remove artificially deposited pesticides from hair surface. The most effective washing solvents were sodium dodecylsulfate and methanol for aqueous and organic solvents, respectively. Moreover, after a first washing with sodium dodecylsulfate or methanol, the majority of externally deposited pesticides was removed and a steady-state was reached since significantly lower amounts were removed by additional second and third washings. Finally, the effectiveness of a decontamination procedure comprising washing with sodium dodecylsulfate and methanol was successively demonstrated. In parallel, it was determined that the final procedure did not affect the chemicals biologically incorporated, as hair strands naturally containing pesticides were used. Such a procedure appears to remove in one-shot the fraction of chemicals located on hair surface and does not require repeated washing steps. Copyright © 2014 John Wiley & Sons, Ltd.

Grey hair: clinical investigation into changes in hair fibres with loss of pigmentation in a photoprotected population.

PubMed

Kaplan, P D; Polefka, T; Grove, G; Daly, S; Jumbelic, L; Harper, D; Nori, M; Evans, T; Ramaprasad, R; Bianchini, R

2011-04-01

Loss of pigmentation in hair fibres is one of the most obvious phenotypic changes with ageing and has been a topic of increasing interest in the study of follicle biology. The onset of greying brings cosmetic complaints that grey fibres are wild or difficult to manage. Of course, these perceptions may be the consequence of visual obviousness rather than underlying physical or chemical differences. Although several studies have compared pigmented and unpigmented fibres, few have tried to control genetic and ethnic difference as well as extrinsic factors such as photoexposure and chemical treatment. We have recruited subjects with salt-and-pepper hair from a population of Old Order Mennonites who, for cultural reasons, are not only prohibited from chemically treating their hair but also limit their exposure to sunlight. Hair samples were examined for elemental composition, surface energy, Young's modulus, break stress, bending modulus, shear modulus and water sorption/desorption isotherm. The parameters were evaluated statistically for global differences, individual differences and typical individual differences. Consistent with previous published literature, few global differences were found between pigmented and unpigmented hair across the population. We do find that many individual subjects had differences between pigmented and unpigmented fibres. These differences tend to be more pronounced in bulk than in surface properties. The small differences in mechanical properties and moisture uptake and loss lend support to the perception by consumers that grey hair is wilder, drier and less manageable. © 2011 TRI/Princeton. Journal compilation. © 2010 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Evidence for biological shaping of hair ice

NASA Astrophysics Data System (ADS)

Hofmann, D.; Preuss, G.; Mätzler, C.

2015-07-01

An unusual ice type, called hair ice, grows on the surface of dead wood of broad-leaf trees at temperatures slightly below 0 °C. We describe this phenomenon and present physical, chemical, and biological investigations to gain insight in the properties and processes related to hair ice. Tests revealed that the biological activity of a winter-active fungus is required in the wood for enabling the growth of hair ice. We confirmed the fungus hypothesis originally suggested by Wegener (1918) by reproducing hair ice on wood samples. Treatment by heat and fungicide suppresses the formation of hair ice. Fruiting bodies of Asco- and Basidiomycota are identified on hair-ice-carrying wood. One species, Exidiopsis effusa (Ee), was present on all investigated samples. Both hair-ice-producing wood samples and those with killed fungus show essentially the same temperature variation, indicating that the heat produced by fungal metabolism is very small, that the freezing rate is not influenced by the fungus activity, and that ice segregation is the common mechanism of ice growth on the wood surface. The fungus plays the role of shaping the ice hairs and preventing them from recrystallisation. Melted hair ice indicates the presence of organic matter. Chemical analyses show a complex mixture of several thousand CHO(N,S) compounds similar to fulvic acids in dissolved organic matter (DOM). The evaluation reveals decomposed lignin as being the main constituent. Further work is needed to clarify its role in hair-ice growth and to identify the recrystallisation inhibitor.

Evidence for biological shaping of hair ice

NASA Astrophysics Data System (ADS)

Hofmann, D.; Preuss, G.; Mätzler, C.

2015-04-01

An unusual ice type, called hair ice, grows on the surface of dead wood of broad-leaf trees at temperatures slightly below 0 °C. We describe this phenomenon and present physical, chemical, and biological investigations to gain insight in the properties and processes related to hair ice. Tests revealed that the biological activity of a winter-active fungus is required in the wood for enabling the growth of hair ice. We confirmed the fungus hypothesis originally suggested by Wegener (1918) by reproducing hair ice on wood samples. Treatment by heat and fungicide, respectively, suppresses the formation of hair ice. Fruiting bodies of Asco- and Basidiomycota are identified on hair-ice carrying wood. One species, Exidiopsis effusa (Ee), has been present on all investigated samples. Both hair-ice producing wood samples and those with killed fungus show essentially the same temperature variation, indicating that the heat produced by fungal metabolism is very small, that the freezing rate is not influenced by the fungus activity and that ice segregation is the common mechanism of ice growth at the wood surface. The fungus plays the role of shaping the ice hairs and to prevent them from recrystallisation. Melted hair ice indicates the presence of organic matter. Chemical analyses show a complex mixture of several thousand CHO(N,S)-compounds similar to fulvic acids in dissolved organic matter (DOM). The evaluation reveals decomposed lignin as the main constituent. Further work is needed to clarify its role in hair-ice growth and to identify the recrystallisation inhibitor.

Cosmetology. Computerized Learning Modules.

ERIC Educational Resources Information Center

Finnerty, Kathy, Ed.

Intended to help reading-limited students meet course objectives, these 11 modules are based on instructional materials in cosmetology that have a higher readability equivalent. Modules cover bacteriology, chemical waving, scalp and hair massage, chemistry, hair shaping, hairstyling, chemical hair relaxing, hair coloring, skin and scalp,…

Influence of functionalized silicones on hair fiber-fiber interactions and on the relationship with the macroscopic behavior of hair assembly.

PubMed

Dussaud, Anne; Fieschi-Corso, Lara

2009-01-01

It is well established that silicones alter hair surface properties and that silicones have a significant impact on the macroscopic behavior of hair assembly, such as visual appearance, combing performance and manageability of the hair. In order to fine-tune the chemistry of functionlized silicones for specific consumer benefits and hair types, we investigated the influence of silicones on hair fiber-fiber interactions and their correlation to hair volume. The incline plane fiber loop method, implemented with a high-precision motorized rotary stage, was used to quantify the fiber-fiber interactions. Low load static friction was studied as a function of polymer molecular weight, dose and chemical architecture. This information was related to the macroscopic behavior of hair assembly, using virgin curly hair in high humidity.

Assessment of chemical exchange in tryptophan-albumin solution through (19)F multicomponent transverse relaxation dispersion analysis.

PubMed

Lin, Ping-Chang

2015-06-01

A number of NMR methods possess the capability of probing chemical exchange dynamics in solution. However, certain drawbacks limit the applications of these NMR approaches, particularly, to a complex system. Here, we propose a procedure that integrates the regularized nonnegative least squares (NNLS) analysis of multiexponential T2 relaxation into Carr-Purcell-Meiboom-Gill (CPMG) relaxation dispersion experiments to probe chemical exchange in a multicompartmental system. The proposed procedure was validated through analysis of (19)F T2 relaxation data of 6-fluoro-DL-tryptophan in a two-compartment solution with and without bovine serum albumin. Given the regularized NNLS analysis of a T2 relaxation curve acquired, for example, at the CPMG frequency υ CPMG  = 125, the nature of two distinct peaks in the associated T2 distribution spectrum indicated 6-fluoro-DL-tryptophan either retaining the free state, with geometric mean */multiplicative standard deviation (MSD) = 1851.2 ms */1.51, or undergoing free/albumin-bound interconversion, with geometric mean */MSD = 236.8 ms */1.54, in the two-compartment system. Quantities of the individual tryptophan species were accurately reflected by the associated T2 peak areas, with an interconversion state-to-free state ratio of 0.45 ± 0.11. Furthermore, the CPMG relaxation dispersion analysis estimated the exchange rate between the free and albumin-bound states in this fluorinated tryptophan analog and the corresponding dissociation constant of the fluorinated tryptophan-albumin complex in the chemical-exchanging, two-compartment system.

Internal structure changes in bleached black human hair resulting from chemical treatments: A Raman spectroscopic investigation

NASA Astrophysics Data System (ADS)

Kuzuhara, Akio

2014-11-01

In order to investigate in detail the influence of chemical treatments (reduction, hydrolyzed eggwhite protein (HEWP) treatment, and oxidation) on damaged hair keratin fibers, the structure of cross-sections at various depths of excessively bleached (damaged) black human hair resulting from a permanent waving process was directly analyzed using Raman spectroscopy. It was found that L-cysteine (CYS) largely reacted with the gauche-gauche-gauche (GGG) conformation of disulfide (-SS-) groups (while CYS did not react with the trans-gauche-trans (TGT) conformation). In particular, not only the GGG content, but also the cysteic acid content existing throughout the cortex region of the excessively bleached human hair remarkably decreased by performing the oxidation process after reduction. On the other hand, the GGG content of the excessively bleached black human hair increased, while the TGT content decreased by performing the oxidation process after reduction and then HEWP treatment processes. From these experiments, the authors concluded that some of the keratin associated protein (KAP), which has a rich -SS- content and cysteic acid content was eluted from the cortex region along with the disconnection of -SS- groups, thereby leading to the remarkable reduction in the reconnection of -SS- groups of the excessively bleached black human hair after the permanent waving process (the reduction and oxidation processes). Also, the authors concluded that the HEWP treatment process in the permanent waving process caused the reconstruction of the KAP, thereby contributing to the acceleration of the reconnection of -SS- groups during the oxidation process.

Dyeing regions of oxidative hair dyes in human hair investigated by nanoscale secondary ion mass spectrometry.

PubMed

Kojima, Toru; Yamada, Hiromi; Yamamoto, Toshihiko; Matsushita, Yasuyuki; Fukushima, Kazuhiko

2013-06-01

To develop more effective oxidative hair coloring products, it is important to understand the localization of colored chromophores, which are formed from oxidative dyes, in the fine structure of hair. However, the dyeing regions of oxidative hair dyes in the fine structure of hair have not been extensively examined. In this study, we investigated the distribution and localization of colored chromophores formed by an oxidative hair coloring product in the fine structure of human hair by using a stable isotope-labeled oxidative dye with nanoscale secondary ion mass spectrometry (NanoSIMS). First, formation of the colored chromophore from a deuterium-labeled oxidative dye was examined by visible spectra similarly to a study of its formation using nonlabeled oxidative dye. Furthermore, the formation of binuclear indo dye containing deuterium in its chemical structure was confirmed using time-of-flight secondary ion mass spectrometry (TOF-SIMS) analysis. As a result of the NanoSIMS image on a cross-sectional dyed hair, although deuterium ions were detected in whole hair cross-section, quite a few of them were detected at particulate regions. These particulate regions of the dyed black hair in which deuterium ions were intensely detected were identified as melanin granules, by comparing the dyeing behaviors of black and white hair. NanoSIMS analysis revealed that melanin granules of black human hair are important dyeing regions in oxidative hair coloring. Copyright © 2013 Elsevier B.V. All rights reserved.

Hair casts due to a deodorant spray.

PubMed

Ena, Pasquale; Mazzarello, Vittorio; Chiarolini, Fausto

2005-11-01

A 7-year-old girl presented with itching and greyish-white sleeve-like structures in her hair. After ruling out other possible causes for the symptoms, such as nits and dandruff, it was determined that the patient was affected by hair casts. These are small cylindrical structures resembling louse eggs that encircle individual scalp hairs and are easily movable along the hair shafts. It was concluded that she had induced the condition through misuse of a deodorant body spray. Scanning electron microscopy combined with electron dispersive X-ray analysis (X-ray microanalysis) of the hair casts showed the chemical nature of the structures. Some elements present in the composition of the ingredients of the deodorant spray, such as aluminium, chlorine, silicon, magnesium and carbon, were also present in this uncommon type of hair casts.

Hair tonic poisoning

MedlinePlus

... health care provider tells you to. If the chemical is on the skin or in the eyes, flush with lots of water for at least 15 minutes. If the person swallowed the hair tonic, give them water or milk right away, ...

Hair bleach poisoning

MedlinePlus

... health care provider tells you to. If the chemical is on the skin or in the eyes, flush with lots of water for at least 15 minutes. If the person swallowed the hair bleach, give them water or milk right away, ...

Barber/Cosmetologist Curriculum. Program Information.

ERIC Educational Resources Information Center

Moraine Park Technical Coll., Fond du Lac, WI.

This guide provides the instructor with materials for a barber/cosmetologist program. Seventeen study guides are provided: anatomy and physiology; applied chemistry; chemical straightening/relaxing; chemical waving; electricity and light therapy; facial services; hair coloring and lightening (bleach); hair cutting; hair, skin, and nail disorders;…

Hair analyses: worthless for vitamins, limited for minerals.

PubMed

Hambidge, K M

1982-11-01

Despite many major and minor problems with interpretation of analytical data, chemical analyses of human hair have some potential value. Extensive research will be necessary to define this value, including correlation of hair concentrations of specific elements with those in other tissues and metabolic pools and definition of normal physiological concentration ranges. Many factors that may compromise the correct interpretation of analytical data require detailed evaluation for each specific element. Meanwhile, hair analyses are of some value in the comparison of different populations and, for example, in public health community surveys of environmental exposure to heavy metals. On an individual basis, their established usefulness is much more restricted and the limitations are especially notable for evaluation of mineral nutritional status. There is a wide gulf between the limited and mainly tentative scientific justification for their use on an individual basis and the current exploitation of multielement chemical analyses of human hair.

A closer look at the complex hydrophilic/hydrophobic interactions forces at the human hair surface

NASA Astrophysics Data System (ADS)

Baghdadli, N.; Luengo, G. S.; Recherche, L.

2008-03-01

The complex chemical structure of the hair surface is far from being completely understood. Current understanding is based on Rivett's model1 that was proposed to explain the macroscopic hydrophobic nature of the surface of natural hair. In this model covalently-linked fatty acids are chemically grafted to the amorphous protein (keratin) through a thio-ester linkage2,3. Nevertheless, experience like wetting and electrical properties of human hair surface4 shows that the complexity of the hair surface is not fully understand based on this model in literature. Recent studies in our laboratory show for the first time microscopic evidence of the heterogeneous physico-chemical character of the hair surface. By using Chemical Force Microscopy, the presence of hydrophobic and ionic species are detected and localized, before and after a cosmetic treatment (bleaching). Based on force curve analysis the mapping of the local distribution of hydrophilic and hydrophobic groups of hair surface is obtained. A discussion on a more plausible hair model and its implications will be presented based on these new results.

Kinetics and equilibrium of solute diffusion into human hair.

PubMed

Wang, Liming; Chen, Longjian; Han, Lujia; Lian, Guoping

2012-12-01

The uptake kinetics of five molecules by hair has been measured and the effects of pH and physical chemical properties of molecules were investigated. A theoretical model is proposed to analyze the experimental data. The results indicate that the binding affinity of solute to hair, as characterized by hair-water partition coefficient, scales to the hydrophobicity of the solute and decreases dramatically as the pH increases to the dissociation constant. The effective diffusion coefficient of solute depended not only on the molecular size as most previous studies suggested, but also on the binding affinity as well as solute dissociation. It appears that the uptake of molecules by hair is due to both hydrophobic interaction and ionic charge interaction. Based on theoretical considerations of the cellular structure, composition and physical chemical properties of hair, quantitative-structure-property-relationships (QSPR) have been proposed to predict the hair-water partition coefficient (PC) and the effective diffusion coefficient (D (e)) of solute. The proposed QSPR models fit well with the experimental data. This paper could be taken as a reference for investigating the adsorption properties for polymeric materials, fibres, and biomaterials.

Influence of pesticide physicochemical properties on the association between plasma and hair concentration.

PubMed

Chata, Caroline; M Hardy, Emilie; Grova, Nathalie; Appenzeller, Brice M R

2016-05-01

Although the relationship between chemical intake and resulting concentration in hair remains incompletely elucidated, the transfer from blood to hair bulb living cells is generally considered the main route of incorporation. The present work investigated the correlation between blood and hair concentration of 23 pesticides/metabolites from different chemical classes in rats submitted to chronic controlled exposure. Long-Evans rats were administered pesticides by gavage three times per week over a 90-day period. After hair sample decontamination, pulverization, and extraction, compounds were analyzed by gas chromatography tandem mass spectrometry (GC-MS/MS). Blood was collected at sacrifice, immediately turned into plasma, and analyzed after extraction for the same compounds by GC-MS/MS. The data obtained for all the investigated compounds demonstrated significant association between plasma and hair concentrations (P value of 2.97E-45 and R(Pearson) of 0.875), with the exception of three outliers. For all the target compounds, water solubility, lipophilicity, molecular weight, and charge were therefore investigated in order to understand the role of these parameters in outliers' specific behavior. Although a possible change in the charge through the transfer from blood to hair might be suspected for two outliers, on the whole the physicochemical parameters investigated here did not seem to influence incorporation of chemicals into hair. Our results support that the concentration of chemicals in hair mainly depends on the respective concentration in plasma and suggest that for most compounds, the transfer from blood to hair would not represent a limiting step in the incorporation.

Hair Breakage in Patients of African Descent: Role of Dermoscopy

PubMed Central

Quaresma, Maria Victória; Martinez Velasco, María Abril; Tosti, Antonella

2015-01-01

Dermoscopy represents a useful technique for the diagnosis and follow-up of hair and scalp disorders. To date, little has been published regarding dermoscopy findings of hair disorders in patients of African descent. This article illustrates how dermoscopy allows fast diagnosis of hair breakage due to intrinsic factors and chemical damage in African descent patients. PMID:27170942

Effects of solar radiation on hair and photoprotection.

PubMed

Dario, Michelli F; Baby, André R; Velasco, Maria Valéria R

2015-12-01

In this paper the negative effects of solar radiation (ultraviolet, visible and infrared wavelengths) on hair properties like color, mechanical properties, luster, protein content, surface roughness, among others, will be discussed. Despite knowing that radiation damages hair, there are no consensus about the particular effect of each segment of solar radiation on the hair shaft. The hair photoprotection products are primarily targeted to dyed hair, specially auburn pigments, and gray shades. They are usually based on silicones, antioxidants and quaternary chemical UV filters that have more affinity for negatively charged hair surface and present higher efficacy. Unfortunately, there are no regulated parameters, like for skin photoprotection, for efficacy evaluation of hair care products, which makes impossible to compare the results published in the literature. Thus, it is important that researchers make an effort to apply experimental conditions similar to a real level of sun exposure, like dose, irradiance, time, temperature and relative humidity. Copyright © 2015 Elsevier B.V. All rights reserved.

[Forensic aspects of thermal changes in human head hair].

PubMed

Kijewski, Harald

2014-01-01

Under experimental conditions, head hairs of individuals of different age were exposed to defined increases of temperature up to 450 degrees C and examined by transmitted- and reflected-light microscopy with and without polarization. Preliminary tests had shown that the hair changes alone do not allow conclusions as to the temperature acting on the hair. Especially in the range of 200 to 300 degrees C, the temperature gradient during the heating process and the exposure time were additional influencing factors. Thick hair and hair with a high water content showed more pronounced thermal changes than thin hair. Elasticity and permeability of the cuticle and the cementing substance (cell membrane complex CMC) are also relevant factors. When heating head hairs lacking a medulla, a multiform pseudo-medulla formed under certain conditions. In the presence of thermally induced structural disturbances (e.g. by using hair straighteners), foreign substances can penetrate more easily into the hair shaft from outside. The possibility of such exogenous contamination has to be taken into consideration when performing chemical and toxicological analyses of hair.

The role of non-equilibrium fluxes in the relaxation processes of the linear chemical master equation

NASA Astrophysics Data System (ADS)

de Oliveira, Luciana Renata; Bazzani, Armando; Giampieri, Enrico; Castellani, Gastone C.

2014-08-01

We propose a non-equilibrium thermodynamical description in terms of the Chemical Master Equation (CME) to characterize the dynamics of a chemical cycle chain reaction among m different species. These systems can be closed or open for energy and molecules exchange with the environment, which determines how they relax to the stationary state. Closed systems reach an equilibrium state (characterized by the detailed balance condition (D.B.)), while open systems will reach a non-equilibrium steady state (NESS). The principal difference between D.B. and NESS is due to the presence of chemical fluxes. In the D.B. condition the fluxes are absent while for the NESS case, the chemical fluxes are necessary for the state maintaining. All the biological systems are characterized by their "far from equilibrium behavior," hence the NESS is a good candidate for a realistic description of the dynamical and thermodynamical properties of living organisms. In this work we consider a CME written in terms of a discrete Kolmogorov forward equation, which lead us to write explicitly the non-equilibrium chemical fluxes. For systems in NESS, we show that there is a non-conservative "external vector field" whose is linearly proportional to the chemical fluxes. We also demonstrate that the modulation of these external fields does not change their stationary distributions, which ensure us to study the same system and outline the differences in the system's behavior when it switches from the D.B. regime to NESS. We were interested to see how the non-equilibrium fluxes influence the relaxation process during the reaching of the stationary distribution. By performing analytical and numerical analysis, our central result is that the presence of the non-equilibrium chemical fluxes reduces the characteristic relaxation time with respect to the D.B. condition. Within a biochemical and biological perspective, this result can be related to the "plasticity property" of biological systems and to their

The role of non-equilibrium fluxes in the relaxation processes of the linear chemical master equation.

PubMed

de Oliveira, Luciana Renata; Bazzani, Armando; Giampieri, Enrico; Castellani, Gastone C

2014-08-14

We propose a non-equilibrium thermodynamical description in terms of the Chemical Master Equation (CME) to characterize the dynamics of a chemical cycle chain reaction among m different species. These systems can be closed or open for energy and molecules exchange with the environment, which determines how they relax to the stationary state. Closed systems reach an equilibrium state (characterized by the detailed balance condition (D.B.)), while open systems will reach a non-equilibrium steady state (NESS). The principal difference between D.B. and NESS is due to the presence of chemical fluxes. In the D.B. condition the fluxes are absent while for the NESS case, the chemical fluxes are necessary for the state maintaining. All the biological systems are characterized by their "far from equilibrium behavior," hence the NESS is a good candidate for a realistic description of the dynamical and thermodynamical properties of living organisms. In this work we consider a CME written in terms of a discrete Kolmogorov forward equation, which lead us to write explicitly the non-equilibrium chemical fluxes. For systems in NESS, we show that there is a non-conservative "external vector field" whose is linearly proportional to the chemical fluxes. We also demonstrate that the modulation of these external fields does not change their stationary distributions, which ensure us to study the same system and outline the differences in the system's behavior when it switches from the D.B. regime to NESS. We were interested to see how the non-equilibrium fluxes influence the relaxation process during the reaching of the stationary distribution. By performing analytical and numerical analysis, our central result is that the presence of the non-equilibrium chemical fluxes reduces the characteristic relaxation time with respect to the D.B. condition. Within a biochemical and biological perspective, this result can be related to the "plasticity property" of biological systems and to their

Understanding breakage in curly hair.

PubMed

Camacho-Bragado, G A; Balooch, G; Dixon-Parks, F; Porter, C; Bryant, H

2015-07-01

In 2005, the L'Oréal Institute for hair and skin research carried out a multiethnic study to investigate hair breakage in women residing in the U.S.A. In this study it was reported that a large percentage (96%) of the African-American respondents experience breakage. A combination of structural differences and grooming-induced stresses seem to contribute to the higher breakage incidence in the African-American group as the chemical composition of African-American hair is not significantly different from other ethnic groups. Some authors have proposed that the repeated elongation, torsion and flexion actions may affect the components of the hair fibre. However, considering the different properties of cuticle and cortex, one would expect a different wearing mechanism of each, leading to the ultimate failure of hair. Knowing in detail how each part of the structure fails can potentially lead to better ways to protect the hair from physical insults. To investigate crack propagation and fracture mechanisms in African-American hair. Virgin hair of excellent quality was collected, with informed consent, from a female African-American volunteer. A series of controlled mechanical stresses was applied to 10-mm hair sections using a high-resolution mechanical stage (20 mN) up to the fracture of the fibre. The surface was monitored using scanning electron microscopy imaging during the stress application. X-ray tomographic microscopy images were acquired and quantified to detect changes in energy absorption as a function of applied stress that could be linked to increase in crack density. Analysis of the mechanical response of hair combined with the two imaging techniques led us to propose the following mechanism of hair breakage: cuticle sliding; failure of the cuticle-cortex interface; nucleation of intercellular cracks and growth of cracks at the cuticle-cortex junction; and propagation of intercellular cracks towards the surface of the hair and final breakage when these

Coloring, bleaching, and perming: influence on EtG content in hair.

PubMed

Kerekes, Isabelle; Yegles, Michel

2013-08-01

Hair analysis of ethyl glucuronide (EtG) has become, beside fatty acid ethyl ester, a valuable marker for the detection of moderate and chronic excessive alcohol consumption. So far, only few studies exist about the influence of cosmetic treatment on EtG content in hair. The aim of this study was to evaluate the effect of coloring, bleaching, and perming on the concentration of this alcohol marker in hair. Studies were also performed to evaluate the chemical stability of EtG in the presence of hydrogen peroxide and ammonium thioglycolate. Six air samples were treated in vitro by the different commercial cosmetics following the suppliers' instructions. After washing, pulverization, incubation in ultrasonic bath, and solid phase extraction, EtG was determined by GC/MS-NICI after solid phase extraction and heptafluorobutyric anhydride derivatization. The results showed that samples (n = 10) treated with the coloring product did not show any important change in the EtG results. In the bleaching study (n = 23), a mean decrease of 73.5% was observed. After incubation of a solution of EtG with hydrogen peroxide (15%), a decrease of 45% was shown supporting the hypothesis of a chemical degradation of EtG and a leaching out effect from the hair matrix. In the perm treatment study (n = 23), a mean decrease of 95.7% of EtG was found. Incubation of a solution of EtG with ammonium thioglycolate (5%) showed a total decrease of EtG supporting the hypothesis of a chemical degradation. Coloring treatment did not importantly influence EtG content in hair. However, an important decrease of EtG in hair could be found after bleaching and permanent wave treatment. This decrease seems to be because of a chemical degradation of EtG, after bleaching, and a leaching out effect from the matrix. After perming, it seems to be more of a chemical degradation of EtG. These data have to be considered for the correct interpretation of EtG amounts in hair.

Long-term aging of elastomers: Chemical stress relaxation of fluorosilicone rubber and other studies

NASA Technical Reports Server (NTRS)

Kalfayan, S. H.; Mazzeo, A. A.; Silver, R. H.

1971-01-01

Aerospace applications of elastomers are considered, including: propellant binders, bladder materials for liquid propellant expulsion systems, and fuel tank sealants for high-speed aircraft. A comprehensive molecular theory for mechanical properties of these materials has been developed but has only been tested experimentally in cases where chemical degradation processes are excluded. Hence, a study is being conducted to ascertain the nature, extent, and rate of chemical changes that take place in some elastomers of interest. Chemical changes that may take place in the fluorosilicone elastomer, LS 420, which is regarded as a fuel and high-temperature-resistant rubber are investigated. The kinetic analysis of the chemical stress relaxation and gel permeation chromatography studies comprise the major portion of the report.

Hair dyeing, hair washing and hair cortisol concentrations among women from the healthy start study.

PubMed

Kristensen, Sheila K; Larsen, Sofus C; Olsen, Nanna J; Fahrenkrug, Jan; Heitmann, Berit L

2017-03-01

Hair cortisol concentration (HCC) has been suggested as a promising marker for chronic stress. However, studies investigating the influence of hair dyeing and hair washing frequency on HCC have shown inconsistent results. To examine associations between HCC and hair dyeing status or weekly hair washing frequency among women. This cross-sectional study was based on data from 266 mothers participating in the Healthy Start intervention study. HCC was measured in the proximal end of the hair (1-2cm closest to the scalp) while hair dyeing status, frequency of hair washing and covariates were reported by the women. Linear regression analyses were applied to assess the associations between HCC and hair dyeing or weekly frequency of hair washing. No statistically significant difference (p=0.91) in HCC was found between women who dyed hair (adjusted mean: 137pg/mg [95% CI: 122,153]) and women with natural hair color (adjusted mean: 139pg/mg [95% CI: 123,155]). Frequency of hair washing was not associated with HCC (β: -3.7 [95% CI: -9.0, 1.5; P=0.20]). This study of 266 Danish women provides no evidence in support of an association between HCC and hair dyeing status or hair washing frequency. Copyright © 2017 Elsevier Ltd. All rights reserved.

Functional mechanotransduction is required for cisplatin-induced hair cell death in the zebrafish lateral line.

PubMed

Thomas, Andrew J; Hailey, Dale W; Stawicki, Tamara M; Wu, Patricia; Coffin, Allison B; Rubel, Edwin W; Raible, David W; Simon, Julian A; Ou, Henry C

2013-03-06

Cisplatin, one of the most commonly used anticancer drugs, is known to cause inner ear hair cell damage and hearing loss. Despite much investigation into mechanisms of cisplatin-induced hair cell death, little is known about the mechanism whereby cisplatin is selectively toxic to hair cells. Using hair cells of the zebrafish lateral line, we found that chemical inhibition of mechanotransduction with quinine and EGTA protected against cisplatin-induced hair cell death. Furthermore, we found that the zebrafish mutants mariner (myo7aa) and sputnik (cad23) that lack functional mechanotransduction were resistant to cisplatin-induced hair cell death. Using a fluorescent analog of cisplatin, we found that chemical or genetic inhibition of mechanotransduction prevented its uptake. These findings demonstrate that cisplatin-induced hair cell death is dependent on functional mechanotransduction in the zebrafish lateral line.

Functional mechanotransduction is required for cisplatin-induced hair cell death in the zebrafish lateral line

PubMed Central

Thomas, Andrew J.; Hailey, Dale W.; Stawicki, Tamara M.; Wu, Patricia; Coffin, Allison B.; Rubel, Edwin W.; Raible, David W.; Simon, Julian A.; Ou, Henry C.

2013-01-01

Cisplatin, one of the most commonly used anti-cancer drugs, is known to cause inner ear hair cell damage and hearing loss. Despite much investigation into mechanisms of cisplatin-induced hair cell death, little is known about the mechanism whereby cisplatin is selectively toxic to hair cells. Using hair cells of the zebrafish lateral line, we found that chemical inhibition of mechanotransduction with quinine and EGTA protected against cisplatin-induced hair cell death. Furthermore, we found that the zebrafish mutants mariner (myo7aa) and sputnik (cad23) that lack functional mechanotransduction were resistant to cisplatin-induced hair cell death. Using a fluorescent analogue of cisplatin, we found that chemical or genetic inhibition of mechanotransduction prevented its uptake. These findings demonstrate that cisplatin-induced hair cell death is dependent on functional mechanotransduction in the zebrafish lateral line. PMID:23467357

Mechanistic Studies on the Use of Polygonum multiflorum for the Treatment of Hair Graying

PubMed Central

Han, Ming-Nuan; Lu, Jian-Mei; Zhang, Guang-Yuan; Zhao, Rong-Hua

2015-01-01

Polygonum multiflorum is a traditional Chinese medicine with a long history in hair growth promotion and hair blackening. The purpose of the study was to examine the effect and the mechanism of Polygonum multiflorum in hair blackening. C57BL/6 mice hair fade was induced with H2O2 and used in this research. Hair pigmentogenesis promotion activities of Polygonum Multiflorum Radix (PMR, raw crude drug), Polygonum Multiflorum Radix Preparata (PMRP, processed crude drug), and their major chemical constituent TSG were investigated. The regulation effects of several cytokines and enzymes such as POMC, α-MSH, MC1R, ASIP, MITF, TYR, TRP-1, and TRP-2 were investigated. PMR group gave out the most outstanding black hair among all groups with the highest contents of total melanin, α-MSH, MC1R, and TYR. Promotion of hair pigmentogenesis was slightly decreased after processing in the PMRP group. TSG as the major constituent of PMR showed weaker hair color regulation effects than both PMR and PMRP. PMR, but not PMRP, should be used to blacken hair. The α-MSH, MC1R, and TYR were the major targets in the medicinal use of PMR in hair graying. Chemical constituents other than TSG may contribute to the hair color regulation activity of PMR. PMID:26640791

Spontaneous Oscillation by Hair Bundles of the Bullfrog's Sacculus

PubMed Central

Martin, Pascal; Bozovic, D.; Choe, Y.; Hudspeth, A. J.

2007-01-01

One prominent manifestation of mechanical activity in hair cells is spontaneous otoacoustic emission, the unprovoked emanation of sound by an internal ear. Because active hair-bundle motility probably constitutes the active process of non-mammalian hair cells, we investigated the ability of hair bundles in the bullfrog's sacculus to produce oscillations that might underlie spontaneous otoacoustic emissions. When maintained in the ear's normal ionic milieu, many bundles oscillated spontaneously through distances as great as 80 nm at frequencies of 5-50 Hz. Whole-cell recording disclosed that the positive phase of movement was associated with the opening of transduction channels. Gentamicin, which blocks transduction channels, reversibly arrested oscillation; drugs that affect the cAMP phosphorylation pathway and might influence myosin's activity altered the rate of oscillation. Increasing the Ca2+ concentration rendered oscillations faster and smaller until they were suppressed; lowering the Ca2+ concentration moderately with chelators had the opposite effect. When a bundle was offset with a stimulus fiber, oscillations were transiently suppressed but gradually resumed. Loading a bundle by partial displacement clamping, which simulated the presence of the accessory structures to which a bundle is ordinarily attached, increased the frequency and diminished the magnitude of oscillation. These observations accord with a model in which oscillations arise from the interplay of the hair bundle's negative stiffness with the activity of adaptation motors and with Ca2+-dependent relaxation of gating springs. PMID:12805294

Body Hair

MedlinePlus

... girlshealth.gov/ Home Body Puberty Body hair Body hair Even before you get your first period , you ... removing pubic hair Ways to get rid of hair top Removing body hair can cause skin irritation, ...

Hair transplant

MedlinePlus

... this procedure: Scarring Unnatural-looking tufts of new hair growth It is possible that the transplanted hair will ... Most hair transplants result in excellent hair growth within several ... may be needed to create best results. The replaced hairs are ...

Hair highlights and severe acute irritant dermatitis ("burn") of the scalp.

PubMed

Chan, Heidi P; Maibach, Howard I

2010-12-01

These days, most celebrities--young and old--have their hair highlighted. That is why it is not surprising that even the youth have their hair highlighted as they emulate their favorite actors, unaware of the harmful consequences of this unsafe procedure. Hair highlighting involves decolorizing melanin pigments of select hair strands through an oxidation reaction under alkaline conditions by the active ingredients of the highlighting mixture--hydrogen peroxide, persulfates, and metasilicate. Hydrogen peroxide and the persulfates are flammable, necessitating that regulatory bodies (namely, the U.S. Food and Drug Administration [FDA] and the Cosmetic Ingredient Review [CIR] Expert Panel, the European Union's (EU), European Economic Community [EEC] directives, the Australian government's National Industrial Chemicals Notification and Assessment Scheme [NICNAS], and the Association of Southeast Asian Nations [ASEAN]) to regulate the permissible amounts of these chemicals in hair highlighting products. To review published case reports of resulting in severe acute irritant dermatitis ("burns") of the scalp caused by hair highlighting, to explain why these scalp burns happen, to identify preventive measures to avoid such occurrences, and to discuss the implications for society. We searched medical and scientific search engines and used keywords such as hair highlights, scalp burn, and other related terms.. Six articles were obtained, yielding 8 reported cases (2 of the 6 articles had 2 cases each) of hair highlighting resulting in scalp burns; these 8 cases were reviewed and analyzed. Five of the 8 patients belonged to the pediatric age group. The causes of scalp burn were classified into 2 categories: chemical (caustic nature of the highlighting mixture, spillage of the hot mixture, toxic reaction to the dyes) and thermal (by contact of the scalp with overheated aluminum foil and by the blow dryer). The 5 pediatric patients in the group unnecessarily suffered pain and

Electrophysiological property and chemical sensitivity of primary afferent neurons that innervate rat whisker hair follicles.

PubMed

Ikeda, Ryo; Gu, Jianguo

2016-01-01

Whisker hair follicles are sensory organs that sense touch and perform tactile discrimination in animals, and they are sites where sensory impulses are initiated when whisker hairs touch an object. The sensory signals are then conveyed by whisker afferent fibers to the brain for sensory perception. Electrophysiological property and chemical sensitivity of whisker afferent fibers, important factors affecting whisker sensory processing, are largely not known. In the present study, we performed patch-clamp recordings from pre-identified whisker afferent neurons in whole-mount trigeminal ganglion preparations and characterized their electrophysiological property and sensitivity to ATP, serotonin and glutamate. Of 97 whisker afferent neurons examined, 67% of them are found to be large-sized (diameter ≥45 µm) cells and 33% of them are medium- to small-sized (diameter <45 µm) cells. Almost every large-sized whisker afferent neuron fires a single action potential but many (40%) small/medium-sized whisker afferent neurons fire multiple action potentials in response to prolonged stepwise depolarization. Other electrophysiological properties including resting membrane potential, action potential threshold, and membrane input resistance are also significantly different between large-sized and small/medium-sized whisker afferent neurons. Most large-sized and many small/medium-sized whisker afferent neurons are sensitive to ATP and/or serotonin, and ATP and/or serotonin could evoke strong inward currents in these cells. In contrast, few whisker afferent neurons are sensitive to glutamate. Our results raise a possibility that ATP and/or serotonin may be chemical messengers involving sensory signaling for different types of rat whisker afferent fibers.

Hair Follicle Miniaturization in a Woolly Hair Nevus: A Novel "Root" Perspective for a Mosaic Hair Disorder.

PubMed

Veraitch, Ophelia; Perez, Alfonso; Hoque, Shamali R; Vizcay-Barrena, Gema; Fleck, Roland A; Fenton, David A; Stefanato, Catherine M

2016-03-01

Woolly hair nevus is a mosaic disorder characterized by unruly, tightly curled hair in a circumscribed area of the scalp. This condition may be associated with epidermal nevi. We describe an 11-year-old boy who initially presented with multiple patches of woolly hair and with epidermal nevi on his left cheek and back. He had no nail, teeth, eye, or cardiac abnormalities. Analysis of plucked hairs from patches of woolly hair showed twisting of the hair shaft and an abnormal hair cuticle. Histopathology of a woolly hair patch showed diffuse hair follicle miniaturization with increased vellus hairs.

Hair transplantation.

PubMed

Avram, Marc R

2012-12-01

Hair transplantation is a purely dermatologic surgical procedure that dermatologists should be able to perform in appropriate candidates with hair loss. Hair transplantation techniques performed in the 1960s through the 1990s utilized large grafts that created an unfortunate public image of unnatural-appearing transplanted hair. Over the last 15 years, hair transplantation has been performed using follicular units to create consistently natural-looking transplanted hair in both men and women. This article provides an overview of candidate selection and state-of-the-art techniques for performing hair transplantation.

Development and characterization of an IPMC hair-like transducer

NASA Astrophysics Data System (ADS)

Akle, Barbar J.; Challita, Elio; Khairalah, Nady

2015-04-01

Hair-like sensors are very common in natural and biological systems. Such sensors are used to measure acoustic pressures, fluid flows, and chemical concentrations among others. Hair-like actuators are also used to control fluid flows and perform temperature management. This study presents a manufacturing technique for a hair-like IPMC transducer. A thorough study is presented on the building process of the sensor. The method used to control the diameter and the electrodes thickness of the transducer is developed. The sensing behavior of the manufactured transducers is experimentally characterized.

Hair Cortisol Concentrations Are Associated with Hair Growth Rate.

PubMed

Xiang, Lianbin; Sunesara, Imran; Rehm, Kristina E; Marshall, Gailen D

2016-01-01

There is a growing interest in hair cortisol concentrations as a valuable biomarker for the assessment of metabolic diseases and chronic psychological stress. Fifty-three volunteers were recruited, and hair segments proximal to the scalp were collected from each individual. A cost-effective ball mill was used for the preparation of hair samples, and ELISA was performed to analyze cortisol concentrations. Results indicate that the frequency of hair washing affects the hair cortisol concentration. The group that washed their hair every day had significantly lower cortisol concentrations than the group that washed it less often. However, no significant differences were detected between cosmetic-treated and nontreated hair samples. The study also shows that hair cortisol concentrations in the first 3 cm of hair segments proximal to the scalp corresponded to average hair growth rate based on 1 cm/month. Thus, hair cortisol concentrations of segments 3 cm proximal to the scalp may represent cumulative stress exposure over the previous 3 months. These findings will allow more widespread research to validate the utility of hair cortisol as a potential biomarker to assess chronic stress. © 2017 S. Karger AG, Basel.

Hair: A Diagnostic Tool to Complement Blood Serum and Urine.

ERIC Educational Resources Information Center

Maugh, Thomas H., II

1978-01-01

Trace elements and some drugs can be identified in hair and it seems likely that other organic chemicals will be identifiable in the future. Since hair is so easily collected, stored, and analyzed it promises to be an ideal complement to serum and urine analysis as a diagnostic tool. (BB)

Numerical simulation of the hair formation -modeling of hair cycle

NASA Astrophysics Data System (ADS)

Kajihara, Narumichi; Nagayama, Katsuya

2018-01-01

In the recent years, the fields of study of anti-aging, health and beauty, cosmetics, and hair diseases have attracted significant attention. In particular, human hair is considered to be an important aspect with regard to an attractive appearance. To this end, many workers have sought to understand the formation mechanism of the hair root. However, observing growth in the hair root is difficult, and a detailed mechanism of the process has not yet been elucidated. Hair repeats growth, retraction, and pause cycles (hair cycle) in a repetitive process. In the growth phase, hair is formed through processes of cell proliferation and differentiation (keratinization). During the retraction phase, hair growth stops, and during the resting period, hair fall occurs and new hair grows. This hair cycle is believed to affect the elongation rate, thickness, strength, and shape of hair. Therefore, in this study, we introduce a particle model as a new method to elucidate the unknown process of hair formation, and to model the hair formation process accompanying the proliferation and differentiation of the hair root cells in all three dimensions. In addition, to the growth period, the retraction and the resting periods are introduced to realize the hair cycle using this model.

Hairstylist: Apprenticeship Course Outline. Apprenticeship and Industry Training. 42-1.3-10

ERIC Educational Resources Information Center

Alberta Advanced Education and Technology, 2010

2010-01-01

The graduate of the Hairstylist apprenticeship program is a certified journeyperson who will be able to perform the following tasks: (1) haircutting; (2) chemical texturing, chemical relaxing; (3) hair colouring; (4) eyebrow and eyelash treatment; (5) facial services for hairstyling purposes (moustaches and beards); (6) wigs and hair additions;…

Hairstylist: Apprenticeship Course Outline. Apprenticeship and Industry Training. 42-1-10.1

ERIC Educational Resources Information Center

Alberta Advanced Education and Technology, 2010

2010-01-01

The graduate of the Hairstylist apprenticeship program is a certified journeyperson who will be able to perform the following tasks: (1) haircutting; (2) chemical texturing, chemical relaxing; (3) hair colouring; (4) eyebrow and eyelash treatment; (5) facial services for hairstyling purposes (moustaches and beards); (6) wigs and hair additions;…

A highly resistant structure between cuticle and cortex of human hair.

PubMed

Takahashi, T; Yoshida, S

2017-06-01

To clarify the presence and properties of a unique structure which is located between the cuticle and cortex of human hair. Whole hair fibre and longitudinally split hair were used. Treated with a mixture of urea, reductant and alkaline, hair was split at the interface between cuticle and cortex. The residues in the solution were observed by microscope, and the distribution of lipids and protein was determined. From the treated longitudinally split hair, a membrane-like structure which was located at the interface between cuticle and cortex was obtained. This structure showed especially high resistance against chemical treatment and was thought to be the region into which the proximal roots of the cuticle cells are embedded. It was supposed that some steryl glucoside-like lipid, of which the presence in the cuticle and cortex interface was previously reported, is located in this structure. This study proposed the presence of a membrane-like structure, which is highly resistant against chemical treatment, at the region between cuticle and cortex of human hair. This may protect cortex from external stimuli more firmly than the surface part of cuticle. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Contaminant characterization on hair and fiber surfaces using imaging TOF-SIMS

NASA Astrophysics Data System (ADS)

Groenewold, Gary S.; Gresham, Garold L.; Gianotto, Anita K.; Avci, Recep

1999-02-01

Imaging time-of-flight secondary ion mass spectrometry (SIMS) was used to evaluate the detection of contaminant chemicals on the surfaces of single synthetic textile and canine hair fibers. The results of the study showed that a variety of chemical classes can be detected. Both cocaine and heroin could be easily observed as intact protonated molecules ([M + H]+) in the cation spectra acquired from textile fibers. Two organophosphates were evaluated: malathion, which is a common pesticide, and pinacolyl methyl phosphonic acid (PMPA), which is the principal degradation product of the nerve agent soman (a close relative of sarin). Malathion could be observed as (CH3O)2P(equalsS)S-, which is formed by thiophosphate cleavage of the intact malathion. PMPA is observed as the conjugate base ([PMPA - H]-). Surfactant chemicals found in hair care products were successfully detected on single hair fibers. Specifically, alkyl sulfates, ethoxylated alkyl sulfates, silicones, and alkylammonium compounds could be readily identified in spectra acquired from single hair fiber samples exposed to shampoo and/or conditioner. Generally, the results of the study show that imaging SIMS is applicable to single fiber analysis, for a range of adsorbed compound types. The forensic application of this instrumental approach has not been widely recognized. However, the ability of the technique to acquire specific chemical information from trace samples clearly points to applications where the need for chemical analysis is great, but the amount of sample is limited.

Toward structural dynamics: protein motions viewed by chemical shift modulations and direct detection of C'N multiple-quantum relaxation.

PubMed

Mori, Mirko; Kateb, Fatiha; Bodenhausen, Geoffrey; Piccioli, Mario; Abergel, Daniel

2010-03-17

Multiple quantum relaxation in proteins reveals unexpected relationships between correlated or anti-correlated conformational backbone dynamics in alpha-helices or beta-sheets. The contributions of conformational exchange to the relaxation rates of C'N coherences (i.e., double- and zero-quantum coherences involving backbone carbonyl (13)C' and neighboring amide (15)N nuclei) depend on the kinetics of slow exchange processes, as well as on the populations of the conformations and chemical shift differences of (13)C' and (15)N nuclei. The relaxation rates of C'N coherences, which reflect concerted fluctuations due to slow chemical shift modulations (CSMs), were determined by direct (13)C detection in diamagnetic and paramagnetic proteins. In well-folded proteins such as lanthanide-substituted calbindin (CaLnCb), copper,zinc superoxide dismutase (Cu,Zn SOD), and matrix metalloproteinase (MMP12), slow conformational exchange occurs along the entire backbone. Our observations demonstrate that relaxation rates of C'N coherences arising from slow backbone dynamics have positive signs (characteristic of correlated fluctuations) in beta-sheets and negative signs (characteristic of anti-correlated fluctuations) in alpha-helices. This extends the prospects of structure-dynamics relationships to slow time scales that are relevant for protein function and enzymatic activity.

Contact allergy to common ingredients in hair dyes.

PubMed

Søsted, Heidi; Rustemeyer, Thomas; Gonçalo, Margarida; Bruze, Magnus; Goossens, An; Giménez-Arnau, Ana M; Le Coz, Christophe J; White, Ian R; Diepgen, Thomas L; Andersen, Klaus E; Agner, Tove; Maibach, Howard; Menné, Torkil; Johansen, Jeanne D

2013-07-01

p-Phenylenediamine (PPD) is the primary patch test screening agent for hair dye contact allergy, and approximately 100 different hair dye chemicals are allowed. To examine whether PPD is an optimal screening agent for diagnosing hair dye allergy or whether other clinically important sensitizers exist. Two thousand nine hundred and thirty-nine consecutive patients in 12 dermatology clinics were patch tested with five hair dyes available from patch test suppliers. Furthermore, 22 frequently used hair dye ingredients not available from patch test suppliers were tested in subgroups of ~500 patients each. A positive reaction to PPD was found in 4.5% of patients, and 2.8% reacted to toluene-2,5-diamine (PTD), 1.8% to p-aminophenol, 1% to m-aminophenol, and 0.1% to resorcinol; all together, 5.3% (n = 156). Dying hair was the most frequently reported cause of the allergy (55.4%); so-called 'temporary henna' tattoos were the cause in 8.5% of the cases. p-Methylaminophenol gave a reaction in 20 patients (2.2%), 3 of them with clinical relevance, and no co-reaction with the above five well-known hair dyes. Hair dyes are the prime cause of PPD allergy. PPD identifies the majority of positive reactions to PTD, p-aminophenol and m-aminophenol, but not all, which justifies additional testing with hair dye ingredients from the used product. © 2013 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Hair Transplants

MedlinePlus

... Search Skin Experts Skin Treatments Hair Transplants Share » HAIR TRANSPLANTS Before (left) and after (right) - front of ... transplant. Photo courtesy of N. Sadick What are hair transplants? In punch transplanting, a plug containing hair ...

From Hair in India to Hair India.

PubMed

Trüeb, Ralph M

2017-01-01

In all cultures, human hair and hairdo have been a powerful metaphor. Tracing back the importance and significance of human hair to the dawn of civilization on the Indian subcontinent, we find that all the Vedic gods are depicted as having uncut hair in mythological stories as well as in legendary pictures. The same is true of the Hindu avatars, and the epic heroes of the Ramayana, and the Mahabharata. Finally, there are a number of hair peculiarities in India pertinent to the creed and religious practices of the Hindu, the Jain, and the Sikh. Shiva Nataraja is a depiction of the Hindu God Shiva as the cosmic dancer who performs his divine dance as creator, preserver, and destroyer of the universe and conveys the Indian conception of the never-ending cycle of time. The same principle manifests in the hair cycle, in which perpetual cycles of growth, regression, and resting underly the growth and shedding of hair. Finally, The Hair Research Society of India was founded as a nonprofit organisation dedicated to research and education in the science of hair. Notably, the HRSI reached milestones in the journey of academic pursuit with the launch of the International Journal of Trichology, and with the establishment of the Hair India conference. Ultimately, the society aims at saving the public from being taken for a ride by quackery, and at creating the awareness that the science of hair represents a subspecialty of Dermatology. In analogy again, the dwarf on which the Nataraja dances represents the demon of egotism, and thus symbolizes Shiva's, respectively, the HRSI's victory over ignorance.

From Hair in India to Hair India

PubMed Central

Trüeb, Ralph M

2017-01-01

In all cultures, human hair and hairdo have been a powerful metaphor. Tracing back the importance and significance of human hair to the dawn of civilization on the Indian subcontinent, we find that all the Vedic gods are depicted as having uncut hair in mythological stories as well as in legendary pictures. The same is true of the Hindu avatars, and the epic heroes of the Ramayana, and the Mahabharata. Finally, there are a number of hair peculiarities in India pertinent to the creed and religious practices of the Hindu, the Jain, and the Sikh. Shiva Nataraja is a depiction of the Hindu God Shiva as the cosmic dancer who performs his divine dance as creator, preserver, and destroyer of the universe and conveys the Indian conception of the never-ending cycle of time. The same principle manifests in the hair cycle, in which perpetual cycles of growth, regression, and resting underly the growth and shedding of hair. Finally, The Hair Research Society of India was founded as a nonprofit organisation dedicated to research and education in the science of hair. Notably, the HRSI reached milestones in the journey of academic pursuit with the launch of the International Journal of Trichology, and with the establishment of the Hair India conference. Ultimately, the society aims at saving the public from being taken for a ride by quackery, and at creating the awareness that the science of hair represents a subspecialty of Dermatology. In analogy again, the dwarf on which the Nataraja dances represents the demon of egotism, and thus symbolizes Shiva's, respectively, the HRSI's victory over ignorance. PMID:28761257

Your Hair

MedlinePlus

... Safe Videos for Educators Search English Español Your Hair KidsHealth / For Kids / Your Hair What's in this ... eyes from sweat dripping down from your forehead. Hair Comes From Where? Whether hair is growing out ...

Hair Loss

MedlinePlus

... Staying Safe Videos for Educators Search English Español Hair Loss KidsHealth / For Teens / Hair Loss What's in ... after the problem that causes it is corrected. Hair Basics Hair is made of a kind of ...

6-Gingerol inhibits hair shaft growth in cultured human hair follicles and modulates hair growth in mice.

PubMed

Miao, Yong; Sun, Yabin; Wang, Wenjun; Du, Benjun; Xiao, Shun-e; Hu, Yijue; Hu, Zhiqi

2013-01-01

Ginger (Zingiber officinale) has been traditionally used to check hair loss and stimulate hair growth in East Asia. Several companies produce shampoo containing an extract of ginger claimed to have anti-hair loss and hair growth promotion properties. However, there is no scientific evidence to back up these claims. This study was undertaken to measure 6-gingerol, the main active component of ginger, on hair shaft elongation in vitro and hair growth in vivo, and to investigate its effect on human dermal papilla cells (DPCs) in vivo and in vitro. 6-Gingerol suppressed hair growth in hair follicles in culture and the proliferation of cultured DPCs. The growth inhibition of DPCs by 6-gingerol in vitro may reflect a decrease in the Bcl-2/Bax ratio. Similar results were obtained in vivo. The results of this study showed that 6-gingerol does not have the ability to promote hair growth, on the contrary, can suppress human hair growth via its inhibitory and pro-apoptotic effects on DPCs in vitro, and can cause prolongation of telogen phase in vivo. Thus, 6-gingerol rather than being a hair growth stimulating drug, it is a potential hair growth suppressive drug; i.e. for hair removal.

6-Gingerol Inhibits Hair Shaft Growth in Cultured Human Hair Follicles and Modulates Hair Growth in Mice

PubMed Central

Miao, Yong; Sun, Yabin; Wang, Wenjun; Du, Benjun; Xiao, Shun-e; Hu, Yijue; Hu, Zhiqi

2013-01-01

Ginger (Zingiber officinale) has been traditionally used to check hair loss and stimulate hair growth in East Asia. Several companies produce shampoo containing an extract of ginger claimed to have anti-hair loss and hair growth promotion properties. However, there is no scientific evidence to back up these claims. This study was undertaken to measure 6-gingerol, the main active component of ginger, on hair shaft elongation in vitro and hair growth in vivo, and to investigate its effect on human dermal papilla cells (DPCs) in vivo and in vitro. 6-Gingerol suppressed hair growth in hair follicles in culture and the proliferation of cultured DPCs. The growth inhibition of DPCs by 6-gingerol in vitro may reflect a decrease in the Bcl-2/Bax ratio. Similar results were obtained in vivo. The results of this study showed that 6-gingerol does not have the ability to promote hair growth, on the contrary, can suppress human hair growth via its inhibitory and pro-apoptotic effects on DPCs in vitro, and can cause prolongation of telogen phase in vivo. Thus, 6-gingerol rather than being a hair growth stimulating drug, it is a potential hair growth suppressive drug; i.e. for hair removal. PMID:23437345

Biomonitoring of 21 endocrine disrupting chemicals in human hair samples using ultra-high performance liquid chromatography-tandem mass spectrometry.

PubMed

Rodríguez-Gómez, R; Martín, J; Zafra-Gómez, A; Alonso, E; Vílchez, J L; Navalón, A

2017-02-01

Rapid industrial growth has increased human exposure to a large variety of chemicals with adverse health effects. These industrial chemicals are usually present in the environment, foods, beverages, clothes and personal care products. Among these compounds, endocrine disrupting chemicals (EDCs) have raised concern over the last years. In the present work, the determination of 21 EDCs in human hair samples is proposed. An analytical method based on the digestion of the samples with a mixture of acetic acid/methanol (20:80, v/v) followed by a solid-liquid microextraction and analysis by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) was developed and validated. The most influential parameters affecting the extraction method were optimized. The method was validated using matrix-matched calibration and recovery assays. Limits of detection ranged from 0.2 to 4 ng g -1 , limits of quantification from 0.5 to 12 ng g -1 , and inter- and intra-day variability was under 15% in all cases. Recovery rates for spiked samples ranged from 92.1 to 113.8%. The method was applied for the determination of the selected compounds in human hair. Samples were collected weekly from six randomly selected volunteers (three men and three women) over a three-month period. All the analyzed samples tested positive for at least one of the analyzed compounds. Copyright © 2016 Elsevier Ltd. All rights reserved.

Racial/ethnic differences in hormonally-active hair product use: a plausible risk factor for health disparities.

PubMed

James-Todd, Tamarra; Senie, Ruby; Terry, Mary Beth

2012-06-01

Estrogen and endocrine-disrupting chemicals (EDCs) that are associated with several health outcomes have been found in hair products. We evaluated the proportion, frequency, duration, and content of hair products in a racially/ethnically diverse population. We recruited n = 301 African-American, African-Caribbean, Hispanic, and white women from the New York metropolitan area. We collected data on hair oil, lotion, leave-in conditioner, root stimulator, perm, and other product use. Estrogen and EDC information was collected from commonly used hair products' labels (used by >3% of population). African-American and African-Caribbean women were more likely to use all types of hair products compared to white women (P < 0.0001). Among hair product users, frequency varied significantly by race/ethnicity, but not duration. More African-Americans (49.4%) and African-Caribbeans (26.4%) used products containing placenta or EDCs compared to whites (7.7%). African-American and African-Caribbean women were more likely to be exposed to hormonally-active chemicals in hair products.

New aspects of the structure of human hair on the basis of optical microscopic observations of disassembled hair parts.

PubMed

Yamauchi, Asao; Yamauchi, Kiyoshi

2015-01-01

Infant' and adult' scalp hair fibers were disassembled to various cellular components and blocks by chemical and enzymatic treatments, followed by random scission with rapidly rotating cutters. The hair fibers were also fractured by the use of a vise. The optical microscopic inspection of these specimens led to the discovery of many previously unknown structures in the hair shaft. In particular, a cuticular cell (Cu) was found to take a trowel-like shape consisting of a part with a blade-like shape (CuB) and a part with a handle-like shape (CuH), where CuB overlapped one another and fused partially to build the honeycomb-like structure on a large cuticular thin plate (CuP). Whereas CuH was closely similar to the cortical cell in dimensions and richness of macrofibrils (Mf). It was considered that human hair is stabilized structurally and physicochemically by the presence of the honeycomb-like structure, the CuP and the Mf.

Investigation of hair dye deposition, hair color loss, and hair damage during multiple oxidative dyeing and shampooing cycles.

PubMed

Zhang, Guojin; McMullen, Roger L; Kulcsar, Lidia

2016-01-01

Color fastness is a major concern for consumers and manufacturers of oxidative hair dye products. Hair dye loss results from multiple wash cycles in which the hair dye is dissolved by water and leaches from the hair shaft. In this study, we carried out a series of measurements to help us better understand the kinetics of the leaching process and pathways associated with its escape from the fiber. Hair dye leaching kinetics was measured by suspending hair in a dissolution apparatus and monitoring the dye concentration in solution (leached dye) with an ultraviolet-visible spectrophotometer. The physical state of dye deposited in hair fibers was evaluated by a reflectance light microscopy technique, based on image stacking, allowing enhanced depth of field imaging. The dye distribution within the fiber was monitored by infrared spectroscopic imaging of hair fiber cross sections. Damage to the ultrafine structure of the hair cuticle (surface, endocuticle, and cell membrane complex) and cortex (cell membrane complex) was determined in hair cross sections and on the hair fiber surface with atomic force microscopy. Using differential scanning calorimetry, we investigated how consecutive coloring and leaching processes affect the internal proteins of hair. Further, to probe the surface properties of hair we utilized contact angle measurements. This study was conducted on both pigmented and nonpigmented hair to gain insight into the influence of melanin on the hair dye deposition and leaching processes. Both types of hair were colored utilizing a commercial oxidative hair dye product based on pyrazole chemistry.

Relationship Between Hair Cell Loss and Hearing Loss in Fishes.

PubMed

Smith, Michael E

2016-01-01

Exposure to intense sound or ototoxic chemicals can damage the auditory hair cells of vertebrates, resulting in hearing loss. Although the relationship between such hair cell damage and auditory function is fairly established for terrestrial vertebrates, there are limited data available to understand this relationship in fishes. Although investigators have measured either the morphological damage of the inner ear or the functional deficits in the hearing of fishes, very few have directly measured both in an attempt to find a relationship between the two. Those studies that have examined both auditory hair cell damage in the inner ear and the resulting hearing loss in fishes are reviewed here. In general, there is a significant linear relationship between the number of hair cells lost and the severity of hearing threshold shifts, although this varies between species and different hair cell-damaging stimuli. After trauma to the fish ear, auditory hair cells are able to regenerate to control level densities. With this regeneration also comes a restoration of hearing. Thus there is also a significant relationship between hair cell recovery and hearing recovery in fishes.

Hair shafts in trichoscopy: clues for diagnosis of hair and scalp diseases.

PubMed

Rudnicka, Lidia; Rakowska, Adriana; Kerzeja, Marta; Olszewska, Małgorzata

2013-10-01

Trichoscopy (hair and scalp dermoscopy) analyzes the structure and size of growing hair shafts, providing diagnostic clues for inherited and acquired causes of hair loss. Types of hair shaft abnormalities observed include exclamation mark hairs (alopecia areata, trichotillomania, chemotherapy-induced alopecia), Pohl-Pinkus constrictions (alopecia areata, chemotherapy-induced alopecia, blood loss, malnutrition), comma hairs (tinea capitis), corkscrew hairs (tinea capitis), coiled hairs (trichotillomania), flame hairs (trichotillomania), and tulip hairs (in trichotillomania, alopecia areata). Trichoscopy allows differential diagnosis of most genetic hair shaft disorders. This article proposes a classification of hair shaft abnormalities observed by trichoscopy. Copyright © 2013. Published by Elsevier Inc.

Alternative Method for Creating Fine Hairs with Hair Removal Laser in Hair Transplantation for Hairline Correction

PubMed Central

Park, Hyun Sun; Kim, Jin Yong; Choe, Yun Seon; Han, Wonseok; An, Jee Soo

2015-01-01

Background Foremost fine hairs in the frontal hairline region are critical in hair transplantation for hairline correction (HTHC) in women. However, there are few studies on a nonsurgical revisionary method for improving an unnatural foremost hairline with thick donor hairs resulting from a previous HTHC. Objective To investigate the efficacy and safety of using a hair removal laser (HRL) system to create fine hairs in Asian women with thick donor hairs. Methods Through a retrospective chart review, the HRL parameters, hair diameter (measured with a micrometer before and after the procedures), subjective results after the procedures, adverse effects, and the number of procedures were investigated. The reduction rate of the hair diameter was calculated. Results Twenty-four women who received long-pulse Neodymium-Doped:Yttrium Aluminum Garnet therapy after HTHC were included. The parameters were as follows: delivered laser energy, 35~36 J/cm2; pulse duration, 6 ms; and spot size, 10 mm. The mean number of laser sessions was 2.6. The mean hair diameter significantly decreased from 80.0±11.5 µm to 58.4±13.2 µm (p=0.00). The mean rate of hair diameter reduction was -25.7% (range, -44.6% to 5.7%). The number of laser sessions and the hair diameter after the procedures showed a negative correlation (r=-0.410, p=0.046). Most of the patients (87.5%) reported subjective improvement of their hairlines. Most complications were transient and mild. Conclusion HRL can be an alternative method for creating fine hairs and revising foremost hairline in Asian women with thick donor hairs. PMID:25673927

Transfer characteristics of the hair cell's afferent synapse

NASA Astrophysics Data System (ADS)

Keen, Erica C.; Hudspeth, A. J.

2006-04-01

The sense of hearing depends on fast, finely graded neurotransmission at the ribbon synapses connecting hair cells to afferent nerve fibers. The processing that occurs at this first chemical synapse in the auditory pathway determines the quality and extent of the information conveyed to the central nervous system. Knowledge of the synapse's input-output function is therefore essential for understanding how auditory stimuli are encoded. To investigate the transfer function at the hair cell's synapse, we developed a preparation of the bullfrog's amphibian papilla. In the portion of this receptor organ representing stimuli of 400-800 Hz, each afferent nerve fiber forms several synaptic terminals onto one to three hair cells. By performing simultaneous voltage-clamp recordings from presynaptic hair cells and postsynaptic afferent fibers, we established that the rate of evoked vesicle release, as determined from the average postsynaptic current, depends linearly on the amplitude of the presynaptic Ca2+ current. This result implies that, for receptor potentials in the physiological range, the hair cell's synapse transmits information with high fidelity. auditory system | exocytosis | glutamate | ribbon synapse | synaptic vesicle

Analysis of cosmetic residues on a single human hair by ATR FT-IR microspectroscopy

NASA Astrophysics Data System (ADS)

Pienpinijtham, Prompong; Thammacharoen, Chuchaat; Naranitad, Suwimol; Ekgasit, Sanong

2018-05-01

In this work, ATR FT-IR spectra of single human hair and cosmetic residues on hair surface are successfully collected using a homemade dome-shaped Ge μIRE accessary installed on an infrared microscope. By collecting ATR spectra of hairs from the same person, the spectral patterns are identical and superimposed while different spectral features are observed from ATR spectra of hairs collected from different persons. The spectral differences depend on individual hair characteristics, chemical treatments, and cosmetics on hair surface. The "Contact-and-Collect" technique that transfers remarkable materials on the hair surface to the tip of the Ge μIRE enables an identification of cosmetics on a single hair. Moreover, the differences between un-split and split hairs are also studied in this report. These highly specific spectral features can be employed for unique identification or for differentiation of hairs based on the molecular structures of hairs and cosmetics on hairs.

Desorption of sulphur mustard simulants methyl salicylate and 2-chloroethyl ethyl sulphide from contaminated scalp hair after vapour exposure.

PubMed

Spiandore, Marie; Souilah-Edib, Mélanie; Piram, Anne; Lacoste, Alexandre; Josse, Denis; Doumenq, Pierre

2018-01-01

Chemical warfare agents have been used to incapacitate, injure or kill people, in a context of war or terrorist attack. It has previously been shown that hair could trap the sulphur mustard simulants methyl salicylate and 2-chloroethyl ethyl sulphide. In order to investigate simulants persistency in hair after intense vapour exposure, their desorption kinetics were studied by using two complementary methods: hair residual content measurement and desorbed vapour monitoring. Results showed that both simulants were detected in air and could be recovered from hair 2 h after the end of exposure. Longer experiments with methyl salicylate showed that it could still be recovered from hair after 24 h. Our data were fitted with several kinetic models and best correlation was obtained with a bimodal first-order equation, suggesting a 2-step desorption kinetics model: initial fast regime followed by a slower desorption. 2-chloroethyl ethyl sulphide was also detected in the immediate environment after hair exposure for 2 h, and hair simulant content decreased by more than 80%. Our results showed that hair ability to release formerly trapped chemical toxics could lead to health hazard. Their persistency however confirmed the potentiality of hair analysis as a tool for chemical exposure assessment. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hair Transplantation Controversies.

PubMed

Avram, Marc R; Finney, Robert; Rogers, Nicole

2017-11-01

Hair transplant surgery creates consistently natural appearing transplanted hair for men. It is increasingly popular procedure to restore natural growing hair for men with hair loss. To review some current controversies in hair transplant surgery. Review of the English PubMed literature and specialty literature in hair transplant surgery. Some of the controversies in hair transplant surgery include appropriate donor harvesting technique including elliptical donor harvesting versus follicular unit extraction whether manual versus robotic, the role of platelet-rich plasma and low-level light surgery in hair transplant surgery. Hair transplant surgery creates consistently natural appearing hair. As with all techniques, there are controversies regarding the optimal method for performing the procedure. Some of the current controversies in hair transplant surgery include optimal donor harvesting techniques, elliptical donor harvesting versus follicular unit extraction, the role of low-level light therapy and the platelet-rich plasma therapy in the procedure. Future studies will further clarify their role in the procedure.

Hair Shaft Damage from Heat and Drying Time of Hair Dryer

PubMed Central

Lee, Yoonhee; Kim, Youn-Duk; Hyun, Hye-Jin; Pi, Long-quan; Jin, Xinghai

2011-01-01

Background Hair dryers are commonly used and can cause hair damage such as roughness, dryness and loss of hair color. It is important to understand the best way to dry hair without causing damage. Objective The study assessed changes in the ultra-structure, morphology, moisture content, and color of hair after repeated shampooing and drying with a hair dryer at a range of temperatures. Methods A standardized drying time was used to completely dry each hair tress, and each tress was treated a total of 30 times. Air flow was set on the hair dryer. The tresses were divided into the following five test groups: (a) no treatment, (b) drying without using a hair dryer (room temperature, 20℃), (c) drying with a hair dryer for 60 seconds at a distance of 15 cm (47℃), (d) drying with a hair dryer for 30 seconds at a distance of 10 cm (61℃), (e) drying with a hair dryer for 15 seconds at a distance of 5 cm (95℃). Scanning and transmission electron microscopy (TEM) and lipid TEM were performed. Water content was analyzed by a halogen moisture analyzer and hair color was measured with a spectrophotometer. Results Hair surfaces tended to become more damaged as the temperature increased. No cortex damage was ever noted, suggesting that the surface of hair might play a role as a barrier to prevent cortex damage. Cell membrane complex was damaged only in the naturally dried group without hair dryer. Moisture content decreased in all treated groups compared to the untreated control group. However, the differences in moisture content among the groups were not statistically significant. Drying under the ambient and 95℃ conditions appeared to change hair color, especially into lightness, after just 10 treatments. Conclusion Although using a hair dryer causes more surface damage than natural drying, using a hair dryer at a distance of 15 cm with continuous motion causes less damage than drying hair naturally. PMID:22148012

Advances and challenges in hair restoration of curly Afrocentric hair.

PubMed

Rogers, Nicole E; Callender, Valerie D

2014-04-01

Although the biochemical composition of hair is similar among racial and ethnic groups, the hair structure between them varies, and individuals with curly hair pose specific challenges and special considerations when a surgical option for alopecia is considered. Hair restoration in this population should therefore be approached with knowledge on the clinical characteristics of curly hair, hair grooming techniques that may influence the management, unique indications for the procedure, surgical instrumentation used, and the complications that may arise. Copyright © 2014 Elsevier Inc. All rights reserved.

Ethyl glucuronide: unusual distribution between head hair and pubic hair.

PubMed

Kintz, Pascal; Villain, Marion; Vallet, Emilie; Etter, Mathieu; Salquebre, Guillaume; Cirimele, Vincent

2008-03-21

Ethyl glucuronide (EtG) is a minor metabolite of ethanol that can be detected in hair. In some specific situations, head hair can be missing, and therefore, alternative anatomical locations of hair are of interest. In this study, paired hair specimens (head hair and pubic hair) from eight social drinkers were analyzed for EtG. Each sample was decontaminated by two dichloromethane bathes (5 ml) for 2 min. After cutting into small pieces, about 50 mg of hair was incubated in 2 ml water in the presence of 10 ng of EtG-d5, used as internal standard and submitted to ultra-sonication for 2 h. The aqueous phase was extracted by SPE using Oasis MAX columns. The hair extract was separated on an ACQUITY BEH HILIC column using a gradient of acetonitrile and formate buffer. Detection was based on two daughter ions: transitions m/z 221-85 and 75 and m/z 226-75 for EtG and the IS, respectively. This laboratory is using a positive cut-off at 50 pg/mg. All eight head hair specimens were negative for EtG at a limit of quantitation fixed at 10 pg/mg. Surprisingly, EtG was identified at high concentrations in pubic hair, in the range 12-1370 pg/mg. It appears, therefore, that it is not possible to document the drinking status of a subject by simply switching from head hair to pubic hair.

To Curl up or Relax? That Is the Question: Tenured Black Female Faculty Navigation of Black Hair Expression in Academia

ERIC Educational Resources Information Center

Gray, Sylvia

2017-01-01

One area of identity that challenges dominant ideals of professional, neat, or appropriate appearance is Black hair. Although Black hair expression is frequent in media, politics, and pop culture, there still remains a perceived stigma surrounding its presence in positions and environments (e.g. tenure positions or predominantly White…

Optical coherence tomography to evaluate the effects of oxidative hair dye on the fiber.

PubMed

Velasco, Maria Valéria Robles; de Abreu, Simone Rachid Pfannemüller; de Freitas, Anderson Zanardi; Bedin, Valcinir; Baby, André Rolim; da Gama, Robson Miranda

2016-11-01

Oxidative hair dyes can damage the hair, since these chemical procedures are involved to change the fiber structure and therefore changes in their mechanical and surface properties. Evaluate and compare the effect of the two colors of oxidative hair dye emulsions on Caucasian hair. This research analyzed the Dark brown hair untreated (I); Dark brown hair treated with light brown dye (II); Dark brown hair treated with light blond dye (III); Light blond hair untreated (IV); Light blond hair treated with light brown dye (V); Light blond hair treated with light blond dye (VI) on Caucasian hair. The hair samples were submitted to breaking strength, color, and optical coherence tomography (OCT) analysis. For the breaking strength assay no presented statistically significant differences between treatments. The parameters of color and brightness can differ in some hair dye formulations, but also the hair type can respond differently. The OCT images of the sample I and IV was possible observed, clearly Medulla and Cortex, which was not observed clearly after treatment with both oxidative hair dye colors. Based on the results, the oxidative hair dyes increased alteration in color and ultrastructure of hair. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Hair loss

MedlinePlus

... that is applied to the scalp to stimulate hair growth. Other medicines, such as hormones, may be prescribed to decrease hair loss and promote hair growth. Drugs such as finasteride and dutasteride can be ...

Normal and aging hair biology and structure 'aging and hair'.

PubMed

Goodier, Molly; Hordinsky, Maria

2015-01-01

Much like an individual's hairstyle, hair fibers along the scalp see a number of changes over the course of one's lifetime. As the decades pass, the shine and volume synonymous with youthful hair may give way to thin, dull, and brittle hair commonly associated with aging. These changes are a result of a compilation of genetic and environmental elements influencing the cells of the hair follicle, specifically the hair follicle stem cells and melanocytes. Telomere shortening, decrease in cell numbers, and particular transcription factors have all been implicated in this process. In turn, these molecular alterations lead to structural modifications of the hair fiber, decrease in melanin production, and lengthening of the telogen phase of the hair cycle. Despite this inevitable progression with aging, there exists an array of treatments such as light therapy, minoxidil, and finasteride which have been designed to mitigate the effects of aging, particularly balding and thinning hair. Although each works through a different mechanism, all aim to maintain or potentially restore the youthful quality of hair. © 2015 S. Karger AG, Basel.

Ingrowing Hair

PubMed Central

Luo, Di-Qing; Liang, Yu-Hua; Li, Xi-Qing; Zhao, Yu-Kun; Wang, Fang; Sarkar, Rashmi

2016-01-01

Abstract Cutaneous pili migrans and creeping eruption caused by parasitic diseases may present as a moving linear lesion in skin. The former, caused by a hair shaft or fragment embedded in the superficial skin or middle dermis, is a rare condition characterized by creeping eruption with a black line observed at the advancing end. In exceptionally rare instance, the hair grows inside the skin and burrows in the uppermost dermis, such a condition has been called “ingrown hair.” We report a 30-year-old Chinese man, who was accustomed to pull or extrude the beard hairs, with 1-year history of slowly extending black linear eruption on his right chin. Cutaneous examination revealed a 4-cm long black linear lesion beneath the skin associated with edematous erythema around and folliculitis on both ends of the lesion. After treatment with topical mupirocin ointment, the erythema and folliculitis improved and 2 hairs of the beard with hair follicles were pulled out from the skin. Two weeks later, another similar black line about 1 cm in length in the skin presented on the prior lesional area, which was pulled out by a shallow incision of the skin and was also demonstrated as a beard hair with hair follicle. The patient was diagnosed as “ingrowing hair” with multiple recurrences. The lesions recovered after the beard hairs were pulled out. No recurrence occurred in a year of follow-up. We suggest that “ingrowing hair” is better than “ingrown hair” to describe such a condition. Pulling out the involved hair and correcting the bad practice are its optimal management strategies. PMID:27175694

Removing Hair Safely

MedlinePlus

... For Consumers Home For Consumers Consumer Updates Removing Hair Safely Share Tweet Linkedin Pin it More sharing ... related to common methods of hair removal. Laser Hair Removal In this method, a laser destroys hair ...

Gaseous and Particulate Content of Laser Hair Removal Plume.

PubMed

Chuang, Gary S; Farinelli, William; Christiani, David C; Herrick, Robert F; Lee, Norman C Y; Avram, Mathew M

2016-12-01

Potentially harmful chemicals are released when tissues are vaporized. Laser hair removal (LHR) causes heating and often vaporization of hairs, producing both a signature malodorous plume and visible particulates. To characterize the chemical composition and quantify the ultrafine particle content of the plume generated during LHR. In the laser center of a large academic hospital, discarded terminal hairs from the trunk and extremities were collected from 2 adult volunteers. The hair samples were sealed in glass gas chromatography chambers and treated with a laser. The laser plume was analyzed by gas chromatography-mass spectrometry (GC-MS). During LHR treatment, two 6-L negative pressure canisters were used to capture 30 seconds of laser plume, and a portable condensation particle counter was used to measure ultrafine particulates (<1 µm). Ultrafine particle concentrations were measured within the treatment room, within the waiting room, and outside the building. The chemical content of the laser plume was analyzed with GC-MS and screened for aerosolized toxins using Environmental Protection Agency-certified methods. The ambient concentration of ultrafine particles during LHR was measured by condensation particle counters. Analysis with GC-MS identified 377 chemical compounds. Sixty-two of these compounds, of which 13 are known or suspected carcinogens and more than 20 are known environmental toxins, exhibited strong absorption peaks. During LHR, the portable condensation particle counters documented an 8-fold increase compared with the ambient room baseline level of ultrafine particle concentrations (ambient room baseline, 15 300 particles per cubic centimeter [ppc]; LHR with smoke evacuator, 129 376 ppc), even when a smoke evacuator was in close proximity (5.0 cm) to the procedure site. When the smoke evacuator was turned off for 30 seconds, there was a more than 26-fold increase in particulate count compared with ambient baseline levels (ambient baseline

Root Hairs

PubMed Central

Grierson, Claire; Nielsen, Erik; Ketelaarc, Tijs; Schiefelbein, John

2014-01-01

Roots hairs are cylindrical extensions of root epidermal cells that are important for acquisition of nutrients, microbe interactions, and plant anchorage. The molecular mechanisms involved in the specification, differentiation, and physiology of root hairs in Arabidopsis are reviewed here. Root hair specification in Arabidopsis is determined by position-dependent signaling and molecular feedback loops causing differential accumulation of a WD-bHLH-Myb transcriptional complex. The initiation of root hairs is dependent on the RHD6 bHLH gene family and auxin to define the site of outgrowth. Root hair elongation relies on polarized cell expansion at the growing tip, which involves multiple integrated processes including cell secretion, endomembrane trafficking, cytoskeletal organization, and cell wall modifications. The study of root hair biology in Arabidopsis has provided a model cell type for insights into many aspects of plant development and cell biology. PMID:24982600

Hair Loss

MedlinePlus

Hair loss Overview Hair loss can affect just your scalp or your entire body. It can be the result of heredity, hormonal changes, medical conditions or medications. Anyone can experience hair loss, but it's more common in men. Baldness ...

Microspectral investigation of hair of one girl during six years by laser emission analysis

NASA Astrophysics Data System (ADS)

Surmenko, Elena L.; Sokolova, Tatiana N.; Tuchin, Valery V.

2001-10-01

Multiple chemical elements of clinical and nutritional interest were measured in the hair of a girl - cerebral palsy patient. Sixteen samples of hair were cut and investigated to determine time and nutrition trends by using laser and arc emission spectroscopy.

Mechanism study of biopolymer hair as a coupled thermo-water responsive smart material

NASA Astrophysics Data System (ADS)

Xiao, Xueliang; Zhou, Hongtao; Qian, Kun

2017-03-01

Animal hairs existing broadly in nature are found to be effectively responsive to stimuli of heat and water in sequence for shape deformation and recovery, namely, coupled shape memory function (CSMF). In the paper, the ability of thermo-water sensitive CSMF was first time investigated for animal hairs, the structural and molecular networks for net-points and switches were therefrom identified. Experimentally, animal hair manifested a high ability of shape fixation in thermal processing and good shape recovery by water stimulus. Characterizations of two stimuli (heating and hydration) were performed systematically on hair’s deformation, recovery, viscoelasticity and chemical components (crystalline phase, key bonds inamorphous area). The variations of related chemical components in molecular networks were also explored. A hybrid structural network model was thereafter proposed to interpret the thermo-water sensitive CSMF of hair. This study of two-sequential-stimuli CSMF is original and inspired to explore more complex functions of other smart natural materials and expected to make much smarter synthetic polymers.

Microbial decolorization and detoxification of emerging environmental pollutant: Cosmetic hair dyes.

PubMed

Maiti, Swati; Sinha, Sudarson Sekhar; Singh, Mukesh

2017-09-15

Since the usage of hair dyes has increased in recent time, the removal of residual dye from environment is also an emerging issue. Hair dye contains mixture of chemicals including genotoxic chemical, p-phenylenediamine (p-PD or PPD). The present study reports bioremediation of hair dye using bacteria isolated from saloon effluent. Sugarcane bagasse powder (SBP) was used as a source of nutrient and surface for bacterial growth. The 16S rDNA sequencing confirmed the isolate as Enterobacter cloacae which was designated as DDB I. The decolourization of dye was studied using UV-vis spectrophotometer. The detoxification study was conducted on microbes isolated from fresh ponds using well diffusion assay. The 1mg/ml of dye was effectively decolourised within 18h of DDB I treatment in the minimal medium containing 30mg/ml of SBP. Copyright © 2017 Elsevier B.V. All rights reserved.

Hair disorders.

PubMed

Jackson, E A

2000-06-01

Disorders of the hair are commonplace in the primary care practice. Among these disorders are male pattern baldness, Telogen effluvium, alopecia areata, Trichotillomania, and fungal infections involving the hair shaft. A review of the normal anatomy and life cycle of hair also is presented.

Wooly hair nevus.

PubMed

Fernandes, Karen de Almeida Pinto; Fernandes, Karina de Almeida Pinto; Vargas, Thiago Jeunon de Sousa; Melo, Daniel Fernandes

2017-01-01

Woolly hair nevus is a rare condition characterized by a structural anomaly of the hair, restricted to certain areas of the scalp. The hair becomes coiled and slightly hypopigmented. The term woolly hair refers to changes that affect all the scalp and has a hereditary character. We present a case of woolly hair nevus, that developed at the age of 2 years, associated with dental diastema and verrucous epidermal nevus.

The influence of hair lipids in ethnic hair properties.

PubMed

Martí, M; Barba, C; Manich, A M; Rubio, L; Alonso, C; Coderch, L

2016-02-01

Biochemical studies have mainly focused on the composition of hair. African hair exhibited lower moisturization and less radial swelling when flushing with water compared with Asian or Caucasian hair, and they assumed a possible lipid differentiation among human populations. This study consists in the lipid characterization of different ethnic hairs (Caucasian, Asian and African hairs) and the influence of these lipids in different hair properties such as humidity and mechanical properties. Evaluation of water sorption and desorption of the different ethnic hairs and with and without lipids is also studied mainly to determine permeation changes of the keratin fibres. Extractions of exogenous and endogenous lipids with different organic solvents were performed; lipid analysis and its quantification using thin-layer chromatography coupled to an automated flame ionization detector (TLC/FID) were performed. Absorption and desorption curves were obtained in a thermogravimetric balance equipped with a controlled humidity chamber, the Q5000SA Sorption Analyzer (TA Instruments, New Castle, IL, U.S.A.). Also, mechanical properties (breaking stress and breaking elongation) were analysed using a computer programmable dynamometer (Instron 5500R). Lipid extraction showed the highest amount of total lipids for the African hair which may come from external sebaceous lipids compared with Asian or Caucasian hair. Caucasian fibres were found to be the most hydrated fibre, and a decrease in moisture was found in the extracted fibres, again, which is more important for the Caucasian hair. A superior lineal mass was found for the Asian fibres which supported their higher strength. The results obtained from the analysis of the mechanical properties of delipidized fibres indicate a surprising increase in the strength of African and Caucasian fibres. Perhaps this increase in strength could be related to the humidity decrease in lipid-extracted hair fibres. Results of water uptake and

Hair cortisol reflects socio-economic factors and hair zinc in preschoolers

PubMed Central

Vaghri, Ziba; Guhn, Martin; Weinberg, Joanne; Grunau, Ruth E.; Yu, Wayne; Hertzman, Clyde

2016-01-01

Summary This study examined the relationship between children’s hair cortisol and socioeconomic status of the family, as measured by parental education and income. Low family socioeconomic status has traditionally been considered a long-term environmental stressor. Measurement of hair cortisol provides an integrated index of cumulative stress exposure across an extended period of time. The present study is the first to examine the relationship between hair cortisol and parental education as well as parental income in a representative sample of preschoolers. Data on hair cortisol, family income, and parental education were collected for a representative sample of 339 children (Mean age = 4.6 years; SD = .5 years) from across 23 neighbourhoods of the city of Vancouver, Canada. As maternal education was shown previously to be associated with hair zinc level, hair zinc measurements were included as well in order to explore potential relationships between hair zinc and hair cortisol. The relationship between hair cortisol and parental education was examined using hierarchical regression, with hair zinc, gender, age, and single parenthood included as covariates. Maternal and paternal education both were correlated significantly with hair cortisol (r = −0.18; p = .001). The relationship remained statistically significant even after controlling for all demographic covariates as well as for hair zinc and after taking the neighbourhood-level clustering of the data into account. Parental income, on the other hand, was not related significantly to children’s hair cortisol. This study provides evidence that lower maternal and paternal education are associated with higher hair cortisol levels. As hair cortisol provides an integrated index of cortisol exposure over an extended time period, these findings suggest a possibly stable influence of SES on the function of the hypothalamic–pituitary–adrenal (HPA) axis. Cumulative exposure to cortisol during early childhood may

Wooly hair nevus*

PubMed Central

Fernandes, Karen de Almeida Pinto; Fernandes, Karina de Almeida Pinto; Vargas, Thiago Jeunon de Sousa; Melo, Daniel Fernandes

2017-01-01

Woolly hair nevus is a rare condition characterized by a structural anomaly of the hair, restricted to certain areas of the scalp. The hair becomes coiled and slightly hypopigmented. The term woolly hair refers to changes that affect all the scalp and has a hereditary character. We present a case of woolly hair nevus, that developed at the age of 2 years, associated with dental diastema and verrucous epidermal nevus. PMID:29267480

Hair cut

NASA Image and Video Library

2012-11-10

ISS033-E-018991 (10 Nov. 2012) --- Russian cosmonaut Oleg Novitskiy, Expedition 33 flight engineer, trims the hair of Russian cosmonaut Evgeny Tarelkin, flight engineer, in the Tranquility node of the International Space Station. Novitskiy used hair clippers fashioned with a vacuum device to garner freshly cut hair.

Regulation of root hair initiation and expansin gene expression in Arabidopsis

NASA Technical Reports Server (NTRS)

Cho, Hyung-Taeg; Cosgrove, Daniel J.

2002-01-01

The expression of two Arabidopsis expansin genes (AtEXP7 and AtEXP18) is tightly linked to root hair initiation; thus, the regulation of these genes was studied to elucidate how developmental, hormonal, and environmental factors orchestrate root hair formation. Exogenous ethylene and auxin, as well as separation of the root from the medium, stimulated root hair formation and the expression of these expansin genes. The effects of exogenous auxin and root separation on root hair formation required the ethylene signaling pathway. By contrast, blocking the endogenous ethylene pathway, either by genetic mutations or by a chemical inhibitor, did not affect normal root hair formation and expansin gene expression. These results indicate that the normal developmental pathway for root hair formation (i.e., not induced by external stimuli) is independent of the ethylene pathway. Promoter analyses of the expansin genes show that the same promoter elements that determine cell specificity also determine inducibility by ethylene, auxin, and root separation. Our study suggests that two distinctive signaling pathways, one developmental and the other environmental/hormonal, converge to modulate the initiation of the root hair and the expression of its specific expansin gene set.

Efficacy of scalp hair decontamination following exposure to vapours of sulphur mustard simulants 2-chloroethyl ethyl sulphide and methyl salicylate.

PubMed

Spiandore, Marie; Piram, Anne; Lacoste, Alexandre; Prevost, Philippe; Maloni, Pascal; Torre, Franck; Asia, Laurence; Josse, Denis; Doumenq, Pierre

2017-04-01

Chemical warfare agents are an actual threat and victims' decontamination is a main concern when mass exposure occurs. Skin decontamination with current protocols has been widely documented, as well as surface decontamination. However, considering hair ability to trap chemicals in vapour phase, we investigated hair decontamination after exposure to sulphur mustard simulants methyl salicylate and 2-chloroethyl ethyl sulphide. Four decontamination protocols were tested on hair, combining showering and emergency decontamination (use of Fuller's earth or Reactive Skin Decontamination Lotion RSDL ® ). Both simulants were recovered from hair after treatment, but contents were significantly reduced (42-85% content allowance). Showering alone was the least efficient protocol. Concerning 2-chloroethyl ethyl sulphide, protocols did not display significant differences in decontamination efficacy. For MeS, use of emergency decontaminants significantly increased showering efficacy (10-20% rise), underlining their usefulness before thorough decontamination. Our results highlighted the need to extensively decontaminate hair after chemical exposure. Residual amounts after decontamination are challenging, as their release from hair could lead to health issues. Copyright © 2016. Published by Elsevier B.V.

Hair cosmetics.

PubMed

O'Donoghue, M N

1987-07-01

Porosity, elasticity, and texture influence the hair's ability to be changed. The types of color--temporary, gradual, natural, semipermanent, and permanent--depend upon the size of the "coloring" molecule to determine whether they penetrate the cortex (permanent) or precipitate on the cuticle. Different types of hair--thick or coarse, fine or thin--have varying affinity for different products and coloring/waving methods. Damaged hair is treated differently from hair with healthy, less porous shafts. Because so many people have color-treated hair today, dermatologists should be aware of all the latest changes and improvements, in order to assist patients with damaged or congenitally deformed hair. Acid-based permanents are becoming the most commonly used. Daily care with shampooing and conditioning has attained its most sophisticated level with the use of anionic and cationic surfactants in all hair-care products. It is also important for the dermatologist to be aware of what help is available for his or her patients. Cosmetic companies are eager to help any patient with severe problems with texture, dullness, over-fine or congenitally defective hair. The physician should send the patient with a severe problem directly to the nearest company headquarters or major city office to have a hair analysis, and receive suggestions from the experts of that company. For patients with moderate to mild problems, the dermatologist should be able to recommend three or four good salons in the local area with which he or she is familiar. Our main goal as physicians is to take care of the entire patient and to enable him or her to have a good self-image.

Hair organ regeneration via the bioengineered hair follicular unit transplantation

PubMed Central

Asakawa, Kyosuke; Toyoshima, Koh-ei; Ishibashi, Naoko; Tobe, Hirofumi; Iwadate, Ayako; Kanayama, Tatsuya; Hasegawa, Tomoko; Nakao, Kazuhisa; Toki, Hiroshi; Noguchi, Shotaro; Ogawa, Miho; Sato, Akio; Tsuji, Takashi

2012-01-01

Organ regenerative therapy aims to reproduce fully functional organs to replace organs that have been lost or damaged as a result of disease, injury, or aging. For the fully functional regeneration of ectodermal organs, a concept has been proposed in which a bioengineered organ is developed by reproducing the embryonic processes of organogenesis. Here, we show that a bioengineered hair follicle germ, which was reconstituted with embryonic skin-derived epithelial and mesenchymal cells and ectopically transplanted, was able to develop histologically correct hair follicles. The bioengineered hair follicles properly connected to the host skin epithelium by intracutaneous transplantation and reproduced the stem cell niche and hair cycles. The bioengineered hair follicles also autonomously connected with nerves and the arrector pili muscle at the permanent region and exhibited piloerection ability. Our findings indicate that the bioengineered hair follicles could restore physiological hair functions and could be applicable to surgical treatments for alopecia. PMID:22645640

The color(s) of human hair--forensic hair analysis with SpectraCube.

PubMed

Birngruber, Christoph; Ramsthaler, Frank; Verhoff, Marcel A

2009-03-10

Human hair is among the most common kind of evidence secured at crime scenes. Although DNA analysis through STR-typing is possible in principle, it is not very promising for telogenic hair or single hairs. For the mixed traces frequently found in practice, composed of different hair from an unknown number of individuals, mtDNA sequencing of each individual hair seems to be the only possible, even if technically elaborate, solution. If it were possible to pool all hair belonging to an individual prior to DNA analysis, then this effort could not only be reduced, but the number of hair for an STR-approach could also be increased. Although it is possible to examine hair microscopically, this method must be considered unsuitable for pooling, since the results depend strongly on examiner experience, and the hair cannot always be correctly attributed to an individual. The goal of this study was to develop an objective non-DNA-contaminative pooling method for hair. To this end, the efficacy of spectral imaging as a method of obtaining information--beyond that obtained from a purely microscopic and morphological approach--for the identification of individuals was investigated. Three hairs each from 25 test persons (female: 18; male: 7) were examined with a SpectraCube-System and a light microscope. Six spectra were calculated for each hair, and the hairs from each individual were not only compared to each other, but also to those of the other individuals. From a forensic vantage, the examination showed, in particular, that individuals, whose hair could not be distinguished on the basis of morphology, could also not be accurately distinguished with the SpectraCube. The intra-individual differences were, in part, greater than the inter-individual differences. Altogether, the study shows that a person's hair color, as perceived, is composed of many naturally different, individual colors.

Light Microscopy of the Hair: A Simple Tool to “Untangle” Hair Disorders

PubMed Central

Adya, Keshavmurthy A; Inamadar, Arun C; Palit, Aparna; Shivanna, Ragunatha; Deshmukh, Niranjan S

2011-01-01

Light microscopy of the hair forms an important bedside clinical tool for the diagnosis of various disorders affecting the hair. Hair abnormalities can be seen in the primary diseases affecting the hair or as a secondary involvement of hair in diseases affecting the scalp. Hair abnormalities also form a part of various genodermatoses and syndromes. In this review, we have briefly highlighted the light microscopic appearance of various infectious and non-infectious conditions affecting the hair. PMID:21769242

Tryptophan and kynurenine determination in human hair by liquid chromatography.

PubMed

Dario, Michelli F; Freire, Thamires Batello; Pinto, Claudinéia Aparecida Sales de Oliveira; Prado, María Segunda Aurora; Baby, André R; Velasco, Maria Valéria R

2017-10-15

Tryptophan, an amino acid found in hair proteinaceous structure is used as a marker of hair photodegradation. Also, protein loss caused by several chemical/physical treatments can be inferred by tryptophan quantification. Kynurenine is a photo-oxidation product of tryptophan, expected to be detected when hair is exposed mainly to UVB (290-320nm) radiation range. Tryptophan from hair is usually quantified directly as a solid or after alkaline hydrolysis, spectrofluorimetrically. However, these types of measure are not sufficiently specific and present several interfering substances. Thus, this work aimed to propose a quantification method for both tryptophan and kynurenine in hair samples, after alkali hydrolysis process, by using high-performance liquid chromatography (HPLC) with fluorimetric and UV detection. The tryptophan and kynurenine quantification method was developed and validated. Black, white, bleached and dyed (blond and auburn) hair tresses were used in this study. Tryptophan and kynurenine were separated within ∼9min by HPLC. Both black and white virgin hair samples presented similar concentrations of tryptophan, while bleaching caused a reduction in the tryptophan content as well as dyeing process. Unexpectedly, UV/vis radiation did not promote significantly the conversion of tryptophan into its photo-oxidation product and consequently, kynurenine was not detected. Thus, this works presented an acceptable method for quantification of tryptophan and its photooxidation metabolite kynurenine in hair samples. Also, the results indicated that bleaching and dyeing processes promoted protein/amino acids loss but tryptophan is not extensively degraded in human hair by solar radiation. Copyright © 2017 Elsevier B.V. All rights reserved.

Hair Cosmetics: An Overview

PubMed Central

Gavazzoni Dias, Maria Fernanda Reis

2015-01-01

Hair cosmetics are an important tool that helps to increase patient's adhesion to alopecia and scalp treatments. This article reviews the formulations and the mode of action of hair cosmetics: Shampoos, conditioners, hair straightening products, hair dyes and henna; regarding their prescription and safetiness. The dermatologist's knowledge of hair care products, their use, and their possible side effects can extend to an understanding of cosmetic resources and help dermatologists to better treat hair and scalp conditions according to the diversity of hair types and ethnicity. PMID:25878443

Identification of hair shaft progenitors that create a niche for hair pigmentation

PubMed Central

Liao, Chung-Ping; Booker, Reid C.; Morrison, Sean J.; Le, Lu Q.

2017-01-01

Hair differentiates from follicle stem cells through progenitor cells in the matrix. In contrast to stem cells in the bulge, the identities of the progenitors and the mechanisms by which they regulate hair shaft components are poorly understood. Hair is also pigmented by melanocytes in the follicle. However, the niche that regulates follicular melanocytes is not well characterized. Here, we report the identification of hair shaft progenitors in the matrix that are differentiated from follicular epithelial cells expressing transcription factor KROX20. Depletion of Krox20 lineage cells results in arrest of hair growth, confirming the critical role of KROX20+ cells as antecedents of structural cells found in hair. Expression of stem cell factor (SCF) by these cells is necessary for the maintenance of differentiated melanocytes and for hair pigmentation. Our findings reveal the identities of hair matrix progenitors that regulate hair growth and pigmentation, partly by creating an SCF-dependent niche for follicular melanocytes. PMID:28465357

Hair cut

NASA Image and Video Library

2012-11-10

ISS033-E-018986 (10 Nov. 2012) --- Russian cosmonaut Evgeny Tarelkin, Expedition 33 flight engineer, trims the hair of Russian cosmonaut Oleg Novitskiy, flight engineer, in the Tranquility node of the International Space Station. Tarelkin used hair clippers fashioned with a vacuum device to garner freshly cut hair. NASA astronaut Kevin Ford, flight engineer, is visible in the background.

[Hormones and hair growth].

PubMed

Trüeb, R M

2010-06-01

With respect to the relationship between hormones and hair growth, the role of androgens for androgenetic alopecia (AGA) and hirsutism is best acknowledged. Accordingly, therapeutic strategies that intervene in androgen metabolism have been successfully developed for treatment of these conditions. Clinical observations of hair conditions involving hormones beyond the androgen horizon have determined their role in regulation of hair growth: estrogens, prolactin, thyroid hormone, cortisone, growth hormone (GH), and melatonin. Primary GH resistance is characterized by thin hair, while acromegaly may cause hypertrichosis. Hyperprolactinemia may cause hair loss and hirsutism. Partial synchronization of the hair cycle in anagen during late pregnancy points to an estrogen effect, while aromatase inhibitors cause hair loss. Hair loss in a causal relationship to thyroid disorders is well documented. In contrast to AGA, senescent alopecia affects the hair in a diffuse manner. The question arises, whether the hypothesis that a causal relationship exists between the age-related reduction of circulating hormones and organ function also applies to hair and the aging of hair.

Does the recipient site influence the hair growth characteristics in hair transplantation?

PubMed

Hwang, Sungjoo; Kim, Jung Chul; Ryu, Hyo Sub; Cha, Young Chang; Lee, Seok Jong; Na, Gun Yoen; Kim, Do Won

2002-09-01

Recently hair transplantation has been widely applied not only to correct androgenetic alopecia, but also to correct hair loss on other parts of the body such as the eyebrows and pubic area. It is believed that the transplanted hairs will maintain their integrity and characteristics after transplantation to new nonscalp sites. To evaluate whether the transplanted hairs maintain their hair growth characteristics after transplantation to a new anatomic site other than the scalp. Three study designs were used. Study I: Hair transplantation from the author's occipital scalp to his lower leg was performed and clinical evaluations were made at both 6 months and at 3 years after the transplantation. Study II: After finding changes in hair growth characteristics, transplanted hairs were harvested from the leg and retransplanted to the left side of the nape of the neck (group A). As a control study, occipital hairs were transplanted to the opposite side (group B). Observations were made at 6 months after the operation. Study III: An observational study was done in 12 patients with androgenetic alopecia about 1 year after transplantation of occipital hair to frontal scalp. At each step, survival rates were documented and the rate of growth and the diameter of the shafts were measured for both recipient and donor sites. Study I: Surviving hairs on the lower leg showed a lower growth rate (8.2 +/- 0.9 mm/month), but the same diameter (0.086 +/- 0.018 mm) compared with occipital hairs (16.0 +/- 1.1 mm/month, 0.088 +/- 0.016 mm). The survival rate 3 years after transplantation was 60.2%. Study II: There was no significant difference in the growth rate, shaft diameter, and survival rate between retransplanted hairs (group A) and controls (group B). Groups A and B showed a lower growth rate, but the same diameter, compared with occipital hairs. Study III: There was no significant difference in the growth rate and shaft diameter between the transplanted hairs on the frontal scalp

Hair cosmetics: dyes.

PubMed

Guerra-Tapia, A; Gonzalez-Guerra, E

2014-11-01

Hair plays a significant role in body image, and its appearance can be changed relatively easily without resort to surgical procedures. Cosmetics and techniques have therefore been used to change hair appearance since time immemorial. The cosmetics industry has developed efficient products that can be used on healthy hair or act on concomitant diseases of the hair and scalp. Dyes embellish the hair by bleaching or coloring it briefly, for temporary periods of longer duration, or permanently, depending on the composition of a dye (oxidative or nonoxidative) and its degree of penetration of the hair shaft. The dermatologist's knowledge of dyes, their use, and their possible side effects (contact eczema, cancer, increased porosity, brittleness) can extend to an understanding of cosmetic resources that also treat hair and scalp conditions. Copyright © 2013 Elsevier España, S.L.U. and AEDV. All rights reserved.

Hair and bare skin discrimination for laser-assisted hair removal systems.

PubMed

Cayir, Sercan; Yetik, Imam Samil

2017-07-01

Laser-assisted hair removal devices aim to remove body hair permanently. In most cases, these devices irradiate the whole area of the skin with a homogenous power density. Thus, a significant portion of the skin, where hair is not present, is burnt unnecessarily causing health risks. Therefore, methods that can distinguish hair regions automatically would be very helpful avoiding these unnecessary applications of laser. This study proposes a new system of algorithms to detect hair regions with the help of a digital camera. Unlike previous limited number of studies, our methods are very fast allowing for real-time application. Proposed methods are based on certain features derived from histograms of hair and skin regions. We compare our algorithm with competing methods in terms of localization performance and computation time and show that a much faster real-time accurate localization of hair regions is possible with the proposed method. Our results show that the algorithm we have developed is extremely fast (around 45 milliseconds) allowing for real-time application with high accuracy hair localization ( 96.48 %).

Healthy hair: what is it?

PubMed

Sinclair, Rodney D

2007-12-01

Shiny hair with a smooth texture and clean-cut ends or tapered tips is generally perceived to be healthy. Hair texture and shine relate to hair surface properties, whereas the integrity of hair ends relates to the hair cortex. Hair can be straight, wavy or curly, blonde, black, brown, red, gray white, and its natural variations are important to our identity. Manipulation of the normal structure of the hair shaft is epidemic and dictated by culture, fashion, and above all, celebrity. Although cosmetic procedures are intrinsically safe, there is potential for damage to the hair. Loss of lustre, frizz, split ends, and other hair problems are particularly prevalent among people who repeatedly alter the natural style of their hair or among people with hair that is intrinsically weak. This may be due to individual or racial variation or less commonly an inherited structural abnormality in hair fiber formation. Hair health is also affected by common afflictions of the scalp as well as age-related phenomena such as graying and androgenetic alopecia. Hair products that improve the structural integrity of hair fibers and increase tensile strength are available, as are products that increase hair volume, reduce frizz, improve hair manageability, and stimulate new hair growth.

The impact of oxidative stress on hair.

PubMed

Trüeb, R M

2015-12-01

Oxidative stress reflects an imbalance between the systemic manifestation of reactive oxygen species and a biological system's ability to detoxify the reactive intermediates or to repair the resulting damage. Reactive oxygen species or free radicals are highly reactive molecules that can directly damage lipids, proteins, and DNA. They are generated by a multitude of endogenous and environmental challenges, while the body possesses endogenous defense mechanisms. With age, production of free radicals increases, while the endogenous defense mechanisms decrease. This imbalance leads to progressive damage of cellular structures, presumably resulting in the aging phenotype. While the role of oxidative stress has been widely discussed in skin aging, little focus has been placed on its impact on hair condition. Moreover, most literature on age-related hair changes focuses on alopecia, but it is equally important that the hair fibers that emerge from the scalp exhibit significant age-related changes that have equal impact on the overall cosmetic properties of hair. Sources of oxidative stress with impact on the pre-emerging fiber include: oxidative metabolism, smoking, UVR, and inflammation from microbial, pollutant, or irritant origins. Sources of oxidative stress with impact on the post-emerging fiber include: UVR (enhanced by copper), chemical insults, and oxidized scalp lipids. The role of the dermatologist is recognition and treatment of pre- and post-emerging factors for lifetime scalp and hair health. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Organic components in hair-ice

NASA Astrophysics Data System (ADS)

Hofmann, Diana; Steffen, Bernhard; Disko, Ulrich; Wagner, Gerhard; Mätzler, Christian

2013-04-01

Hair-ice is a rather unknown phenomenon. In contrast to generally known frost needles, originating from atmospheric water and expanding e.g. from plant surfaces in all directions, hair ice grows from the basis of wet, rotten hardwood. The hair-like, flexible, linear structures may reach up to 10 cm in length without any ramifications. Hair-ice appears to be related to the biological activity of a fungus mycelium within the wood. Hair-ice can attract winter-active Collemboles (snow flea, Isotoma nivalis). At the onset of hair-ice melt a very thin fibre becomes apparent, which carries brownish pearl-like water drops. Therefore, it is supposed that organic substances are inherent, which could possibly act as freezing catalyst as well as recrystallization inhibitor. The aim of this work was the chemical characterization of organic substances contained in hair-ice. First analyses of melted hair-ice show a total organic carbon (TOC) value of 235 mg/l in contrast to 11 mg/l total nitrogen. Most of inherent nitrogen (70 %) exists thereby as ammonium. Screened by different (mass spectrometric) methods, no evidence could be found for the initially expected organic substances like proteins, lipids, small volatile substances or carboxylic acids. By coupling of Ultra Performance Liquid Chromatography with a triple quadrupol mass spectrometer (UPLC-MS) a non-resolved chromatogram from a melted hair-ice sample was received. Averaged spectra from different regions are similar among themselves with a broad peak spreading over the mass range 100-650 Da with favored intense, odd-numbered peaks. Such spectra are similar to dissolved organic matter (DOM), known e.g. from terrestrial and marine waters, soil extracts or aerosols. In the next step, samples were desalted and concentrated by solid phase extraction (SPE) and subsequently analyzed by flow injection analysis (FIA) in a Fourier Transform Ion Cyclotron Resonance Mass Spectrometer (FTICR-MS), equipped with an ESI source and a 7 T

Study of colouring effect of herbal hair formulations on graying hair

PubMed Central

Singh, Vijender; Ali, Mohammed; Upadhyay, Sukirti

2015-01-01

Objective: To screen the hair colouring properties of hair colorants/ herbal hair colouring formulations. Materials and Methods: The dried aqueous herbal extracts of Gudhal leaves (Hibiscus rosa-sinensis), Jatamansi rhizome (Nardostachys jatamansi), Kuth roots (Saussurea lappa), Kattha (Acacia catechu), Amla dried fruit (Embelica officinalis), were prepared. Coffee powder (Coffea arabica) and Henna powder (Lowsonia inermis) were taken in the form of powder (# 40). Fourteen herbal hair colorants were prepared from these dried aqueous herbal extracts and powders. Activities of hair colorants were observed on sheep wool fibers. On the basis of the above observation six hair colorants were selected. These six formulations were taken for trials on human beings. Observation: The formulation coded HD-3 gave maximum colouring effect on sheep wool fibers as well as on human beings and percentage of acceptance among the volunteers were in the following order: HD- 3 > HD- 4 > HD-1 > HD-13 > HD-14 > HD-11. Results and Discussion: The remarkable results were obtained from five herbal hair colorants, viz., HD-1, HD- 3, HD- 4, HD-13 and HD-14 on sheep wool fibers and human beings. Formulation HD-3, having gudhal, jatamansi, kuth, kattha, amla, coffee and henna, was the maximum accepted formulation and suggested that these herbs in combination acts synergistically in hair colouring action. It also concluded that jatamansi, present in different hair colorants, was responsible to provide maximum blackening on hair PMID:26130937

Hair Loss Myths.

PubMed

DiMarco, Gabriella; McMichael, Amy

2017-07-01

INTRODUCTION: Hair loss is a common complaint seen in dermatology clinics. From frustration and attempts at self-help, patients with hair loss may present to the dermatologist with false beliefs, or myths, about the causes of their condition and what treatments are effective.

METHODS: We identified 12 common myths about hair loss, categorized as myths about minoxidil treatment, vitamin and mineral supplements, natural topical treatments, and hair care practices. We performed a PubMed search to find evidence to support or refute each myth.

RESULTS: We found that there is little evidence to support many of these common hair loss myths. In some cases, randomized controlled trials have investigated the effects of particular therapies and point to the effectiveness of certain hair loss treatments.

DISCUSSION: In many cases, there have not been sufficient randomized controlled trials to evaluate the effect of different therapies and hair care practices on hair loss. It is best to guide patients toward treatments with a long track record of efficacy and away from those where little is known scientifically.

J Drugs Dermatol. 2017;16(7):690-694.

Identification of hair shaft progenitors that create a niche for hair pigmentation.

PubMed

Liao, Chung-Ping; Booker, Reid C; Morrison, Sean J; Le, Lu Q

2017-04-15

Hair differentiates from follicle stem cells through progenitor cells in the matrix. In contrast to stem cells in the bulge, the identities of the progenitors and the mechanisms by which they regulate hair shaft components are poorly understood. Hair is also pigmented by melanocytes in the follicle. However, the niche that regulates follicular melanocytes is not well characterized. Here, we report the identification of hair shaft progenitors in the matrix that are differentiated from follicular epithelial cells expressing transcription factor KROX20. Depletion of Krox20 lineage cells results in arrest of hair growth, confirming the critical role of KROX20 + cells as antecedents of structural cells found in hair. Expression of stem cell factor (SCF) by these cells is necessary for the maintenance of differentiated melanocytes and for hair pigmentation. Our findings reveal the identities of hair matrix progenitors that regulate hair growth and pigmentation, partly by creating an SCF-dependent niche for follicular melanocytes. © 2017 Liao et al.; Published by Cold Spring Harbor Laboratory Press.

To grow or not to grow: Hair morphogenesis and human genetic hair disorders

PubMed Central

Duverger, Olivier; Morasso, Maria I.

2014-01-01

Mouse models have greatly helped in elucidating the molecular mechanisms involved in hair formation and regeneration. Recent publications have reviewed the genes involved in mouse hair development based on the phenotype of transgenic, knockout and mutant animal models. While much of this information has been instrumental in determining molecular aspects of human hair development and cycling, mice exhibit a specific pattern of hair morphogenesis and hair distribution throughout the body that cannot be directly correlated to human hair. In this mini-review, we discuss specific aspects of human hair follicle development and present an up-to-date summary of human genetic disorders associated with abnormalities in hair follicle morphogenesis, structure or regeneration. PMID:24361867

To grow or not to grow: hair morphogenesis and human genetic hair disorders.

PubMed

Duverger, Olivier; Morasso, Maria I

2014-01-01

Mouse models have greatly helped in elucidating the molecular mechanisms involved in hair formation and regeneration. Recent publications have reviewed the genes involved in mouse hair development based on the phenotype of transgenic, knockout and mutant animal models. While much of this information has been instrumental in determining molecular aspects of human hair development and cycling, mice exhibit a specific pattern of hair morphogenesis and hair distribution throughout the body that cannot be directly correlated to human hair. In this mini-review, we discuss specific aspects of human hair follicle development and present an up-to-date summary of human genetic disorders associated with abnormalities in hair follicle morphogenesis, structure or regeneration. Published by Elsevier Ltd.

Cryopreservation of Hair-Follicle Associated Pluripotent (HAP) Stem Cells Maintains Differentiation and Hair-Growth Potential.

PubMed

Hoffman, Robert M; Kajiura, Satoshi; Cao, Wenluo; Liu, Fang; Amoh, Yasuyuki

2016-01-01

Hair follicles contain nestin-expressing pluripotent stem cells which originate above the bulge area of the follicle, below the sebaceous gland. We have termed these cells hair follicle-associated pluripotent (HAP) stem cells. We have established efficient cryopreservation methods of the hair follicle that maintain the pluripotency of HAP stem cells as well as hair growth. We cryopreserved the whole hair follicle by slow-rate cooling in TC-Protector medium or in DMSO-containing medium and storage in liquid nitrogen or at -80 °C. After thawing and culture of the cryopreserved whisker follicles, growing HAP stem cells formed hair spheres. The hair spheres contained cells that differentiated to neurons, glial cells, and other cell types. The hair spheres derived from slow-cooling cryopreserved hair follicles were as pluripotent as hair spheres from fresh hair follicles. We have also previously demonstrated that cryopreserved mouse whisker hair follicles maintain their hair-growth potential. DMSO better cryopreserved mouse whisker follicles compared to glycerol. DMSO-cryopreserved hair follicles also maintained the HAP stem cells, evidenced by P75 ntr expression. Subcutaneous transplantation of DMSO-cryopreserved hair follicles in nude mice resulted in extensive hair fiber growth over 8 weeks, indicating the functional recovery of hair-shaft growth of cryopreserved hair follicles. HAP stem cells can be used for nerve and spinal-cord repair. This biobanking of hair follicles can allow each patient the potential for their own stem cell use for regenerative medicine or hair transplantation.

Modulating hair follicle size with Wnt10b-DKK1 pair during hair regeneration

PubMed Central

Lei, Mingxing; Guo, Haiying; Qiu, Weiming; Lai, Xiangdong; Yang, Tian; Widelitz, Randall B.; Chuong, Cheng-Ming; Lian, Xiaohua; Yang, Li

2015-01-01

Hair follicles have characteristic sizes corresponding to their cycle specific stage. However, how the anagen hair follicle specifies its size remains elusive. Here, we show that in response to prolonged ectopic Wnt10b-mediated β-catenin activation, regenerating anagen hair follicles grow larger in size. In particular, the hair bulb, dermal papilla and hair shaft become enlarged. While the formation of different hair types (Guard, Awl, Auchene, and Zigzag) is unaffected. Interestingly, we found the effect of exogenous WNT10b was mainly on Zigzag and less on the other kinds of hairs. We observed dramatically enhanced proliferation within the matrix, DP and hair shaft of the enlarged AdWnt10b-treated hair follicles compared with those of normal hair follicles at P98. Furthermore, expression of CD34, a specific hair stem cell marker, was increased in its number to the bulge region after AdWnt10b treatment. Ectopic expression of CD34 throughout the ORS region was also observed. Many CD34 positive hair stem cells were actively proliferating in AdWnt10b-induced hair follicles. Importantly, subsequent co-treatment with the Wnt inhibitor, DKK1, reduced hair follicle enlargement, decreased proliferation and maintained proper hair stem cell localization. Moreover, injection of DKK1 during early anagen significantly reduced the width of prospective hairs. Together, these findings strongly suggest that a balance of Wnt10b/DKK1 governs reciprocal signaling between cutaneous epithelium and mesenchyme to regulate proper hair follicle size. PMID:24750467

Hair Pulling (Trichotillomania)

MedlinePlus

... for Families - Vietnamese Spanish Facts for Families Guide Hair Pulling (Trichotillomania) No. 96; Reviewed July 2013 It ... for children and adolescents to play with their hair. However, frequent or obsessive hair pulling can lead ...

The use of personal hair dye and its implications for human health.

PubMed

Kim, Ki-Hyun; Kabir, Ehsanul; Jahan, Shamin Ara

2016-01-01

Hair dye products now represent one of the most rapidly growing beauty and personal care industries as both men and women commonly change hair color to enhance youth and beauty and to follow fashion trends. Irrespective of economic and education status, people dye their hair to emphasize the importance given to appearance. Despite adverse reactions, many people continue dyeing mainly for cosmetic purposes. This paper provides a comprehensive review on various aspects of hair dying products, especially with respect to the hair-coloring process, classification, chemical ingredients, possible human health impacts, and regulations. Permanent hair dye, which is the most commonly used product type, is formed by an oxidative process involving arylamines to bring about concerns with long-term exposure. Hence, significant efforts have been put to understand the possible side effects of such exposure including cancer risk. However, hair dyes and their ingredients are mainly identified to have moderate to low acute toxicity such as the cause of allergic contact dermatitis. Although some hair dye components are reported to be carcinogenic in animals, such evidence is not consistent enough in the case of human studies. Consequently, further research is desirable to critically address the significance of this issue, especially with respect to the safety of hair dye ingredients. Copyright © 2016 Elsevier Ltd. All rights reserved.

DSC of human hair: a tool for claim support or incorrect data analysis?

PubMed

Popescu, C; Gummer, C

2016-10-01

Differential scanning calorimetry (DSC) data are increasingly used to substantiate product claims of hair repair. Decreasing peak temperatures may indicate structural changes and chemical damage. Increasing the DSC, wet peak temperature is, therefore, often considered as proof of hair repair. A detailed understanding of the technique and hair structure indicates that this may not be a sound approach. Surveying the rich literature on the use of dynamic thermal analysis (DTA) and differential scanning calorimetry (DSC) for the analyses of human hair and the effect of cosmetic treatments, we underline some of the problems of hair structure and data interpretation. To overcome some of the difficulties of data interpretation, we advise that DSC acquired data should be supported by other techniques when used for claim substantiation. In this way, one can provide meaningful interpretation of the hair science and robust data for product claims support. © 2016 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

A Study on Scalp Hair Health and Hair Care Practices among Malaysian Medical Students.

PubMed

Nayak, B Satheesha; Ann, Chua Yuet; Azhar, Azeldeen Bin; Ling, Emily Chan Su; Yen, Wong Hui; Aithal, P Ashwini

2017-01-01

Scalp care is essential because it determines the health and condition of the hair and prevents the diseases of scalp and hair. The objectives of our study were to correlate race and hair types, to determine the awareness of hair care among Malaysian medical students, and to distinguish the factors that affect the health of hair and scalp. It was a cross-sectional study wherein validated questionnaires were given to 240 medical undergraduate students who belonged to three ethnic races of Malaysia, i.e., Chinese, Malay, and Malaysian Indians after their informed consent. The results were then analyzed using percentage statistics. Chinese students had comparatively healthier scalp without dandruff. Most Chinese and Indians had silky type of hair while Malay had dry, rough hair. Chinese and Indians colored their hair and used various styling methods; while among the Malays, this percentage was very less. Regarding hair care practices, males used only shampoo and females used shampoo and conditioner for hair wash. Students also faced dietary and examination-related stress. Results indicate that there exist morphological differences in hair among the studied population. Since most students color their hair and employ various hairstyling methods, they should be educated regarding best hair care practices to improve their scalp hair condition and health.

Familial Uncombable Hair Syndrome: Ultrastructural Hair Study and Response to Biotin.

PubMed

Boccaletti, V; Zendri, E; Giordano, G; Gnetti, L; De Panfilis, G

2007-01-01

We report a family affected to the fourth generation by uncombable hair syndrome. This syndrome is characterized by unruly, dry, blond hair with a tangled appearance. The family pedigree strongly supports the hypothesis of autosomal dominant inheritance; some members of the family had, apart from uncombable hair, minor signs of atopy and ectodermal dysplasia, such as abnormalities of the nails. The diagnosis was confirmed by means of extensive scanning electron microscopy. A trial with oral biotin 5 mg/day was started on two young patients with excellent results as regards the hair appearance, although scanning electron microscopy did not show structural changes in the hair. After a 2-year-period of follow-up, hair normality was maintained without biotin, while nail fragility still required biotin supplementation for control.

Help! It's Hair Loss!

MedlinePlus

... Staying Safe Videos for Educators Search English Español Hair Loss KidsHealth / For Kids / Hair Loss What's in ... is alopecia (say: al-uh-PEE-shuh). The Hair-y Story The hair on your head is ...

Ethnic hair disorders.

PubMed

Lindsey, Scott F; Tosti, Antonella

2015-01-01

The management of hair and scalp conditions is difficult in any patient, especially given the emotional and psychological implications of hair loss. This undertaking becomes even more challenging in the ethnic patient. Differences in hair care practices, hair shaft morphology, and follicular architecture add complexity to the task. It is imperative that the physician be knowledgeable about these practices and the phenotypic differences seen in ethnic hair in order to appropriately diagnose and treat these patients. In this chapter, we will discuss cultural practices and morphologic differences and explain how these relate to the specific disorders seen in ethnic populations. We will also review the most prominent of the ethnic hair conditions including acquired trichorrhexis nodosa, traction alopecia, central centrifugal cicatricial alopecia, pseudofolliculitis barbae, dissecting cellulitis, and acne keloidalis nuchae. © 2015 S. Karger AG, Basel.

Upper D region chemical kinetic modeling of LORE relaxation times

NASA Astrophysics Data System (ADS)

Gordillo-Vázquez, F. J.; Luque, A.; Haldoupis, C.

2016-04-01

The recovery times of upper D region electron density elevations, caused by lightning-induced electromagnetic pulses (EMP), are modeled. The work was motivated from the need to understand a recently identified narrowband VLF perturbation named LOREs, an acronym for LOng Recovery Early VLF events. LOREs associate with long-living electron density perturbations in the upper D region ionosphere; they are generated by strong EMP radiated from large peak current intensities of ±CG (cloud to ground) lightning discharges, known also to be capable of producing elves. Relaxation model scenarios are considered first for a weak enhancement in electron density and then for a much stronger one caused by an intense lightning EMP acting as an impulsive ionization source. The full nonequilibrium kinetic modeling of the perturbed mesosphere in the 76 to 92 km range during LORE-occurring conditions predicts that the electron density relaxation time is controlled by electron attachment at lower altitudes, whereas above 79 km attachment is balanced totally by associative electron detachment so that electron loss at these higher altitudes is controlled mainly by electron recombination with hydrated positive clusters H+(H2O)n and secondarily by dissociative recombination with NO+ ions, a process which gradually dominates at altitudes >88 km. The calculated recovery times agree fairly well with LORE observations. In addition, a simplified (quasi-analytic) model build for the key charged species and chemical reactions is applied, which arrives at similar results with those of the full kinetic model. Finally, the modeled recovery estimates for lower altitudes, that is <79 km, are in good agreement with the observed short recovery times of typical early VLF events, which are known to be associated with sprites.

Determination of farm workers' exposure to pesticides by hair analysis.

PubMed

Schummer, Claude; Salquèbre, Guillaume; Briand, Olivier; Millet, Maurice; Appenzeller, Brice M R

2012-04-25

In the present work, a highly sensitive method based on solid phase microextraction and gas chromatography tandem (triple quadrupole) mass spectrometry was used to test hair samples for 50 pesticides including 39 molecules from different chemical families currently used in agriculture and 11 organochlorines. The population investigated was composed of 18 farm workers who provided hair samples repeatedly collected during the entire treatment period (from March to November 2009). Among the 62 hair samples that were collected, 33 different target molecules were detected. The most frequently detected agricultural pesticides were Diflufenican and Pyrimethanil, two herbicides which were detected in 13 subjects. The concentration in volunteers' hair matched with agricultural activity and the highest concentration was observed for Cyprodinil (1161pg/mg), an anilinopyrimidine used as a fungicide. For organochlorines, p,p'-DDE and γ-HCH were the most frequently detected molecules as they were present in at least one of the hair samples provided by each of the 18 volunteers. The highest concentrations detected for these chemicals reached 21.0pg/mg for p,p'-DDE and 23.5pg/mg for γ-HCH, but the highest concentration of organochlorine was observed for β-endosulfan (105pg/mg). The results suggest that farm workers have a weak, though constant exposure to organochlorine pesticides, especially to p,p'-DDE and γ-HCH, while exposure to currently used pesticides is strongly associated with occupation. Observations also suggest that spraying work would not necessarily be the only source of exposure to agricultural pesticides and that worker not directly involved in spraying can also be submitted to significant level of exposure. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Black hole hair formation in shift-symmetric generalised scalar-tensor gravity

NASA Astrophysics Data System (ADS)

Benkel, Robert; Sotiriou, Thomas P.; Witek, Helvi

2017-03-01

A linear coupling between a scalar field and the Gauss-Bonnet invariant is the only known interaction term between a scalar and the metric that: respects shift symmetry; does not lead to higher order equations; inevitably introduces black hole hair in asymptotically flat, 4-dimensional spacetimes. Here we focus on the simplest theory that includes such a term and we explore the dynamical formation of scalar hair. In particular, we work in the decoupling limit that neglects the backreaction of the scalar onto the metric and evolve the scalar configuration numerically in the background of a Schwarzschild black hole and a collapsing dust star described by the Oppenheimer-Snyder solution. For all types of initial data that we consider, the scalar relaxes at late times to the known, static, analytic configuration that is associated with a hairy, spherically symmetric black hole. This suggests that the corresponding black hole solutions are indeed endpoints of collapse.

Hair as a biomarker of polybrominated diethyl ethers' exposure in infants, children and adults.

PubMed

Aleksa, Katarina; Liesivuori, Jyrki; Koren, Gideon

2012-04-25

Over the last 20 years hair has moved from being a highly questionable biological matrix to mainstream and acceptable biomarker in forensic sciences where it is primarily used to determine past and present exposure to illicit drugs. In contrast, the use of hair to assess exposure to pesticides and persistent environmental pollutants is still not common. The applicability of this matrix to assess an individual's body burden of chemicals such as polybrominated diethyl ethers (PBDEs) can provide critical insight into current, but also to past exposure levels, which is not possible with more conventional matrices such as blood and urine. Furthermore, as PBDEs cross the placenta and since the hair the fetus is born with begins to grow during the third trimester, this matrix can be used to assess in utero exposure. These features of hair may therefore be used to determine the potential roles of chemicals such as PBDEs in mediating physiological or anatomical abnormalities in infants, children or adults. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.

Female Pattern Hair Loss

MedlinePlus

... Category: Share: Yes No, Keep Private Female Pattern Hair Loss Share | The most common type of hair loss seen in women is androgenetic alopecia, also ... men, it does not have to be complete hair loss. This is seen as hair thinning predominantly ...

Detection of polybrominated biphenyl ethers (PBDEs) in pediatric hair as a tool for determining in utero exposure.

PubMed

Aleksa, Katarina; Carnevale, Amanda; Goodyer, Cynthia; Koren, Gideon

2012-05-10

Cryptorchidism, or undescended/maldescended testis, is the most common birth defect of male genitalia. Its prevalence has been increasing over the past few decades. This may be due to an increase in the prevalence of anti-androgenic chemicals such as polychlorinated biphenyls, organochloride pesticides, plasticizers and fungicides. A newer group of chemicals, brominated flame retardants (BFRs), are being implicated as endocrine-disrupting chemicals. These chemicals are used worldwide in polymers that are incorporated into a variety of consumer products (e.g., textile, computers and televisions, insulating foam, electrical equipment and kitchen appliances). In order to quantify BFRs we introduce the use of hair levels of polybrominated diphenyl esters (PBDEs) as biomarkers of systemic exposure. This approach will allow for the estimation of in utero BFR exposure, in the process of evaluating the potential link between the incidence of cryptorchidism in newborn males and level of exposure of the pregnant mother to environmentally relevant BFRs. For that end we have developed a GC/MS assay in which children's hair is analyzed for the presence of polybrominated biphenyl ethers (PBDEs). In this pilot, 10-40mg of hair from 24 children (12 newborn and 12 from children 1 to 15 years) was extracted overnight at 40°C with 4N HCl and hexane (4:1). The samples were eluted from 2g NaSO(4):2g Florisil SPE columns with 8mL hexane. Dried samples are reconstituted with anhydrous isooctane and injected onto a GC/MS and analyzed for BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183 and BDE-209. PBDEs were detected in all of the newborn and child hair. The ΣPBDE ranged from 0.038 to 1.01pg/mg newborn hair and from 0.208 to 2.695ng/mg child hair. The most abundant PBDE in newborn hair was BDE-153 while in child hair the variable PBDEs were BDE-47 and BDE-99. The highest molecular weight congener BDE-209 was detected in 10/24 pediatric hair samples. The LOQ is 0.0625pg

Hair follicle stem cell proliferation, Akt and Wnt signaling activation in TPA-induced hair regeneration.

PubMed

Qiu, Weiming; Lei, Mingxing; Zhou, Ling; Bai, Xiufeng; Lai, Xiangdong; Yu, Yu; Yang, Tian; Lian, Xiaohua

2017-06-01

Regeneration of hair follicles relies on activation of hair follicle stem cells during telogen to anagen transition process in hair cycle. This process is rigorously controlled by intrinsic and environmental factors. 12-o-tetradecanoylphorbol-13-acetate (TPA), a tumor promoter, accelerates reentry of hair follicles into anagen phase. However, it is unclear that how TPA promotes the hair regeneration. In the present study, we topically applied TPA onto the dorsal skin of 2-month-old C57BL/6 female mice to examine the activity of hair follicle stem cells and alteration of signaling pathways during hair regeneration. We found that refractory telogen hair follicles entered anagen prematurely after TPA treatment, with the enhanced proliferation of CD34-positive hair follicle stem cells. Meanwhile, we observed Akt signaling was activated in epidermis, hair infundibulum, bulge and hair bulb, and Wnt signaling was also activated after hair follicle stem cells proliferation. Importantly, after overexpression of DKK1, a specific Wnt signaling inhibitor, the accelerated reentry of hair follicles into anagen induced by TPA was abolished. Our data indicated that TPA-induced hair follicle regeneration is associated with activation of Akt and Wnt/β-catenin signaling.

Hair-based sensors for micro-autonomous systems

NASA Astrophysics Data System (ADS)

Sadeghi, Mahdi M.; Peterson, Rebecca L.; Najafi, Khalil

2012-06-01

We seek to harness microelectromechanical systems (MEMS) technologies to build biomimetic devices for low-power, high-performance, robust sensors and actuators on micro-autonomous robot platforms. Hair is used abundantly in nature for a variety of functions including balance and inertial sensing, flow sensing and aerodynamic (air foil) control, tactile and touch sensing, insulation and temperature control, particle filtering, and gas/chemical sensing. Biological hairs, which are typically characterized by large surface/volume ratios and mechanical amplification of movement, can be distributed in large numbers over large areas providing unprecedented sensitivity, redundancy, and stability (robustness). Local neural transduction allows for space- and power-efficient signal processing. Moreover by varying the hair structure and transduction mechanism, the basic hair form can be used for a wide diversity of functions. In this paper, by exploiting a novel wafer-level, bubble-free liquid encapsulation technology, we make arrays of micro-hydraulic cells capable of electrostatic actuation and hydraulic amplification, which enables high force/high deflection actuation and extremely sensitive detection (sensing) at low power. By attachment of cilia (hair) to the micro-hydraulic cell, air flow sensors with excellent sensitivity (< few cm/s) and dynamic range (> 10 m/s) have been built. A second-generation design has significantly reduced the sensor response time while maintaining sensitivity of about 2 cm/s and dynamic range of more than 15 m/s. These sensors can be used for dynamic flight control of flying robots or for situational awareness in surveillance applications. The core biomimetic technologies developed are applicable to a broad range of sensors and actuators.

Topical Products for Human Hair Regeneration: A Comparative Study on an Animal Model

PubMed Central

Orasan, Meda Sandra; Coneac, Andrei; Muresan, Adriana; Mihu, Carmen

2016-01-01

Background Hair loss and hair growth is the subject of tremendous amount of research. Objective This study investigated the efficacy of three chemical treatments used in humans for hair loss, using a rat model of hair regrowth. The products tested were 2% minoxidil, Hairgrow (Dar-Al-Dawa Pharma), Aminexil, Dercos (Vichy Laboratoires), and Kerium, Anti-chute (La Roche-Posay). Methods Thirty-two adult female Wistar-Bratislava rats were assigned to 4 groups. Two rectangular areas (2×4 cm) were shaved on either sides of the mid dorsal line (left side - control; right side - test area). Group I was treated topically with 2% minoxidil, group II with Aminexil, and group III with Kerium. Each rat received 0.3 ml of substance applied topically to the shaved dorsal skin every day for 28 days. Rats in group IV served as sham controls receiving no treatment. Hair regrowth was evaluated by trichoscopy (with a dermatoscope), grown hair weight (from a surface area of 1 cm2), and histopathological examination for skin thickness, follicle count, and percentage of anagen induction (morphometric assessment). Results Treatment with 2% minoxidil significantly induced hair regrowth as assessed by trichoscopy, hair weight examination, and morphometric evaluation. Hair weight examination and morphometric assessment demonstrated the lowest hair growth effect with Aminexil among the tested products. Treatment with Kerium was found to significantly induce hair regrowth (p<0.05 as compared to the control group). Conclusion Our study demonstrates that hair regrowth efficacy of products recommended for human use is not similar when tested on an animal model. PMID:26848220

Severe facial swelling in a pregnant woman after using hair dye.

PubMed

van Genderen, Michel E; Carels, Ginette; Lonnee, Edward R; Dees, Adriaan

2014-03-31

A 33-year-old Caucasian pregnant woman (26 weeks' gestation) presented to the emergency department. She had a 2-day history of severe itching of the scalp and steadily worsening swelling of the face over the previous 12 h, which had extended to the neck. She had no difficulty breathing. The itching and swelling had developed 3 days after she had used hair dye. The patient had no history of allergic responses to hair dye or black henna tattoos. A diagnosis of type IV delayed hypersensitivity reaction was made. Permanent hair dyes are the most frequently used professional hair dyes and are most commonly based on paraphenylenediamine (PPD) or related chemicals. PPD is known to be one of the most potent allergens which cause allergic contact dermatitis. After treatment with intravenous antihistamines and steroids, the facial swelling reduced and the patient had completely recovered by the following day.

Red ginseng extract promotes the hair growth in cultured human hair follicles.

PubMed

Park, Gyeong-Hun; Park, Ki-young; Cho, Hong-il; Lee, Sang-Min; Han, Ji Su; Won, Chong Hyun; Chang, Sung Eun; Lee, Mi Woo; Choi, Jee Ho; Moon, Kee Chan; Shin, Hyoseung; Kang, Yong Jung; Lee, Dong Hun

2015-03-01

Ginseng has been shown to promote hair growth in several recent studies. However, its effects on human hair follicles and its mechanisms of action have not been sufficiently elucidated. This study aimed to investigate the hair growth-promoting effects of red ginseng extract (RGE) and its ginsenosides. The proliferative activities of cultured human hair follicles treated with RGE and ginsenoside-Rb1 were assessed using Ki-67 immunostaining. Their effects on isolated human dermal papilla cells (hDPCs) were evaluated using cytotoxicity assays, immunoblot analysis of signaling proteins, and the determination of associated growth factors. We examined the ability of RGE and ginsenosides to protect hair matrix keratinocyte proliferation against dihydrotestosterone (DHT)-induced suppression and their effects on the expression of androgen receptor. The in vivo hair growth-promoting effect of RGE was also investigated in C57BL/6 mice. Both RGE and ginsenoside-Rb1 enhanced the proliferation of hair matrix keratinocytes. hDPCs treated with RGE or ginsenoside-Rb1 exhibited substantial cell proliferation and the associated phosphorylation of ERK and AKT. Moreover, RGE, ginsenoside-Rb1, and ginsenoside-Rg3 abrogated the DHT-induced suppression of hair matrix keratinocyte proliferation and the DHT-induced upregulation of the mRNA expression of androgen receptor in hDPCs. Murine experiments revealed that the subcutaneous injection of 3% RGE resulted in more rapid hair growth than the negative control. In conclusion, RGE and its ginsenosides may enhance hDPC proliferation, activate ERK and AKT signaling pathways in hDPCs, upregulate hair matrix keratinocyte proliferation, and inhibit the DHT-induced androgen receptor transcription. These results suggest that red ginseng may promote hair growth in humans.

Red Ginseng Extract Promotes the Hair Growth in Cultured Human Hair Follicles

PubMed Central

Park, Gyeong-Hun; Park, Ki-young; Cho, Hong-il; Lee, Sang-Min; Han, Ji Su; Chang, Sung Eun; Lee, Mi Woo; Choi, Jee Ho; Moon, Kee Chan; Shin, Hyoseung; Kang, Yong Jung; Lee, Dong Hun

2015-01-01

Abstract Ginseng has been shown to promote hair growth in several recent studies. However, its effects on human hair follicles and its mechanisms of action have not been sufficiently elucidated. This study aimed to investigate the hair growth-promoting effects of red ginseng extract (RGE) and its ginsenosides. The proliferative activities of cultured human hair follicles treated with RGE and ginsenoside-Rb1 were assessed using Ki-67 immunostaining. Their effects on isolated human dermal papilla cells (hDPCs) were evaluated using cytotoxicity assays, immunoblot analysis of signaling proteins, and the determination of associated growth factors. We examined the ability of RGE and ginsenosides to protect hair matrix keratinocyte proliferation against dihydrotestosterone (DHT)-induced suppression and their effects on the expression of androgen receptor. The in vivo hair growth-promoting effect of RGE was also investigated in C57BL/6 mice. Both RGE and ginsenoside-Rb1 enhanced the proliferation of hair matrix keratinocytes. hDPCs treated with RGE or ginsenoside-Rb1 exhibited substantial cell proliferation and the associated phosphorylation of ERK and AKT. Moreover, RGE, ginsenoside-Rb1, and ginsenoside-Rg3 abrogated the DHT-induced suppression of hair matrix keratinocyte proliferation and the DHT-induced upregulation of the mRNA expression of androgen receptor in hDPCs. Murine experiments revealed that the subcutaneous injection of 3% RGE resulted in more rapid hair growth than the negative control. In conclusion, RGE and its ginsenosides may enhance hDPC proliferation, activate ERK and AKT signaling pathways in hDPCs, upregulate hair matrix keratinocyte proliferation, and inhibit the DHT-induced androgen receptor transcription. These results suggest that red ginseng may promote hair growth in humans. PMID:25396716

Hair and Salivary Testosterone, Hair Cortisol, and Externalizing Behaviors in Adolescents.

PubMed

Grotzinger, Andrew D; Mann, Frank D; Patterson, Megan W; Tackett, Jennifer L; Tucker-Drob, Elliot M; Harden, K Paige

2018-05-01

Although testosterone is associated with aggression in the popular imagination, previous research on the links between testosterone and human aggression has been inconsistent. This inconsistency might be because testosterone's effects on aggression depend on other moderators. In a large adolescent sample ( N = 984, of whom 460 provided hair samples), we examined associations between aggression and salivary testosterone, hair testosterone, and hair cortisol. Callous-unemotional traits, parental monitoring, and peer environment were examined as potential moderators of hormone-behavior associations. Salivary testosterone was not associated with aggression. Hair testosterone significantly predicted increased aggression, particularly at low levels of hair cortisol (i.e., Testosterone × Cortisol interaction). This study is the first to examine the relationship between hair hormones and externalizing behaviors and adds to the growing literature that indicates that androgenic effects on human behavior are contingent on aspects of the broader endocrine environment-in particular, levels of cortisol.

Evaluation of concordance between labelling and content of 52 hair dye products: overview of the market of oxidative hair dye.

PubMed

Antelmi, Annarita; Bruze, Magnus; Zimerson, Erik; Engfeldt, Malin; Young, Ewa; Persson, Lena; Foti, Caterina; Sörensen, Östen; Svedman, Cecilia

2017-04-01

Hair dyes contain strong allergens and are widely available. Correct labelling is a necessity in order to provide information about the contents. To compare the labelling and content of hair dyes. In total, 52 hair dyes, from 11 different countries, were bought over the counter. High-pressure liquid chromatography was used for the analysis of p-phenylenediamine (PPD), toluene-2,5-diamine (2,5-TDA), and three oxidation products of PPD. There was good agreement between labelling and content, although seven of the 52 products (13.5%) studied were incorrectly labelled. There were differences in the geographical use of PPD and 2,5-TDA; 2,5-TDA was more common in European products, while PPD was more common in products purchased outside Europe and was present in higher concentrations. All dyes purchased in Europe contained PPD and 2,5-TDA at levels within the limits defined by European legislation, however, levels were higher in some products purchased outside Europe. Only a small group of hair dyes sold in Europe were mislabelled. Further improvement in labelling, by providing the concentration of chemicals, may facilitate products to be purchased both locally and within the global market, when travelling or on the internet.

Hair cell ribbon synapses

PubMed Central

Brandt, Andreas; Lysakowski, Anna

2010-01-01

Hearing and balance rely on the faithful synaptic coding of mechanical input by the auditory and vestibular hair cells of the inner ear. Mechanical deflection of their stereocilia causes the opening of mechanosensitive channels, resulting in hair cell depolarization, which controls the release of glutamate at ribbon-type synapses. Hair cells have a compact shape with strong polarity. Mechanoelectrical transduction and active membrane turnover associated with stereociliar renewal dominate the apical compartment. Transmitter release occurs at several active zones along the basolateral membrane. The astonishing capability of the hair cell ribbon synapse for temporally precise and reliable sensory coding has been the subject of intense investigation over the past few years. This research has been facilitated by the excellent experimental accessibility of the hair cell. For the same reason, the hair cell serves as an important model for studying presynaptic Ca2+ signaling and stimulus-secretion coupling. In addition to common principles, hair cell synapses differ in their anatomical and functional properties among species, among the auditory and vestibular organs, and among hair cell positions within the organ. Here, we briefly review synaptic morphology and connectivity and then focus on stimulus-secretion coupling at hair cell synapses. PMID:16944206

[Hair and their environment].

PubMed

Piérard-Franchimont, C; Piérard, G E

2015-02-01

Hair is influenced by the effects of the daily environment. Some toxic xenobiotics slow down or block the cell renewal of the hair matrix, thus inhibiting hair growth. The ultraviolet light obviously influences the physical structure and physiology of the hair follicle. Tobacco is similarly responsible for negative influences on the evolution of various alopecias. Several cosmetic procedures for maintaining and making hair more attractive are not always harmless, and they occasionally represent a possible origin for alopecia.

Hair cell regeneration

PubMed Central

Edge, Albert SB; Chen, Zheng-Yi

2017-01-01

The mammalian inner ear largely lacks the capacity to regenerate hair cells, the sensory cells required for hearing and balance. Recent studies in both lower vertebrates and mammals have uncovered genes and pathways important in hair cell development and have suggested ways that the sensory epithelia could be manipulated to achieve hair cell regeneration. These approaches include the use of inner ear stem cells, transdifferentiation of nonsensory cells, and induction of a proliferative response in the cells that can become hair cells. PMID:18929656

Hairdressing is associated with scalp disease in African schoolchildren.

PubMed

Khumalo, N P; Jessop, S; Gumedze, F; Ehrlich, R

2007-07-01

Anecdotal reports suggest that certain disorders are common in African hair and may be associated with hairstyles. A cross-sectional study of 1042 schoolchildren was performed to test this hypothesis. A questionnaire was administered and scalp examinations performed, after ethics approval. Participants included 45% boys and 55% girls. The majority of boys, 72.8%, kept natural hair with frequent haircuts (within 4 weeks). The prevalence of acne (folliculitis) keloidalis nuchae (AKN) was 0.67% in the whole group and highest (4.7%) in boys in the final year of high school, all of whom had frequent haircuts. The majority of girls (78.4%) had chemically relaxed hair, which was usually combed back or tied in ponytails, vs. 8.6% of boys. Traction alopecia (TA) was significantly more common with relaxed than natural hair, with an overall prevalence of 9.4% (98 of 1042) and of 17.1% in girls, in whom it increased with age from 8.6% in the first year of school to 21.7% in the last year of high school. The proportion with TA in participants with a history of braids on natural hair was lower (22.9%), but not significantly, than among those with a history of braids on relaxed hair (32.1%). No cases of central centrifugal cicatricial alopecia were identified. We found associations between hairstyle and disease in our population of schoolchildren. AKN appears to be associated with frequently cut natural hair and TA with relaxed hair. These associations need further study for purposes of disease prevention.

Hair loss in women.

PubMed

Tosti, A; Piraccini, B M; Sisti, A; Duque-Estrada, B

2009-10-01

Hair loss in women is a very common clinical complaint, and is usually associated with severe emotional distress. In this article, the authors review the most common clinical causes of hair loss in women, and emphasize the role of hormonal changes in the regulation of hair loss and hair growth.

Facial hair restoration: hair transplantation to eyebrows, beard, sideburns, and eyelashes.

PubMed

Epstein, Jeffrey

2013-08-01

Refinements in hair transplantation techniques allow the experienced surgeon to create natural-appearing facial hair transplants. Restoring eyebrows, beards/goatees, and sideburns have all become popular procedures, and the results can be outstanding. This article provides a comprehensive review of hair grafting techniques to achieve the best results in restoring various hair-bearing areas of the face, including the eyebrows, beard/goatee, and sideburns, and repairing the alopecic scarring from prior facial plastic surgery. Copyright © 2013 Elsevier Inc. All rights reserved.

The biology of hair diversity.

PubMed

Westgate, Gillian E; Botchkareva, Natalia V; Tobin, Desmond J

2013-08-01

Hair diversity, its style, colour, shape and growth pattern is one of our most defining characteristics. The natural versus temporary style is influenced by what happens to our hair during our lifetime, such as genetic hair loss, sudden hair shedding, greying and pathological hair loss in the various forms of alopecia because of genetics, illness or medication. Despite the size and global value of the hair care market, our knowledge of what controls the innate and within-lifetime characteristics of hair diversity remains poorly understood. In the last decade, drivers of knowledge have moved into the arena of genetics where hair traits are obvious and measurable and genetic polymorphisms are being found that raise valuable questions about the biology of hair growth. The recent discovery that the gene for trichohyalin contributes to hair shape comes as no surprise to the hair biologists who have believed for 100 years that hair shape is linked to the structure and function of the inner root sheath. Further conundrums awaiting elucidation include the polymorphisms in the androgen receptor (AR) described in male pattern alopecia whose location on the X chromosome places this genetic contributor into the female line. The genetics of female hair loss is less clear with polymorphisms in the AR not associated with female pattern hair loss. Lifestyle choices are also implicated in hair diversity. Greying, which also has a strong genetic component, is often suggested to have a lifestyle (stress) influence and hair follicle melanocytes show declining antioxidant protection with age and lowered resistance to stress. It is likely that hair research will undergo a renaissance on the back of the rising information from genetic studies as well as the latest contributions from the field of epigenetics. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Expression and localization of VEGFR-2 in hair follicles during induced hair growth in mice.

PubMed

Wu, Xian-Jie; Jing, Jing; Lu, Zhong-Fa; Zheng, Min

2018-06-16

Recently, VEGFR-2 has been detected not only in vascular and lymphatic endothelial cells but also in some non-vascular endothelial cells, particularly human hair follicles, sebaceous glands, and sweat glands. In addition, VEGFR-2 has been confirmed to play direct roles in hair follicle keratinocyte regulation beyond simply angiogenesis. To elucidate whether VEGFR-2 activation plays a role in hair follicle cycling regulation, immunofluorescence of VEGFR-2 expression was performed during hair cycling of the dorsum of the mouse induced by hair plucking. We observed that staining for VEGFR-2 in hair follicles during anagen II and IV was much stronger than during anagen VI, catagen and telogen. During anagen II, intense staining for VEGFR-2 was observed on the keratinocyte strands of the hair follicle. Subsequently, we detected intense staining for VEGFR-2 in the ORS, IRS and hair bulb during anagen IV. Moderate staining for VEGFR-2 was detected in the ORS and hair bulb, but staining was most intense in IRS during anagen VI. During catagen, staining for VEGFR-2 in the IRS remained intense, while staining in the ORS and hair bulb was significantly weakened and was negative in the dermal papilla. During telogen, we detected VEGFR-2 in germ cells, cap, and club hair adjoining the epidermis. In conclusion, VEGFR-2 was expressed on the hair follicles of the dorsum of the mouse and varied in expression on the mouse hair follicles during hair cycling, suggesting that VEGFR-2 may exert roles in hair cycle regulation in hair follicles on the dorsum of mice.

Ingrown Hair

MedlinePlus

... needed to determine whether a single- or multiple-blade razor is best for preventing ingrown hair. See ... in the direction of hair growth. Rinse the blade after each stroke. Rinse your skin and apply ...

Hair-care practices in African American women: potential for allergic contact dermatitis.

PubMed

Stallings, Alicia; Sood, Apra

2016-12-01

Allergic contact dermatitis (ACD) is a delayed hypersensitivity reaction that occurs when the skin is re-exposed to a substance to which it was previously sensitized. One significant source of exposure to sensitizing chemicals is through personal grooming and beauty products. While the role of cosmetics and hair-care products in the development of ACD is well-documented, there has been very little literature that specifically addresses the role of hair-care practices of patients with tightly curled hair, such as in patients of African descent, in the development of ACD in this population. This review provides an integrated summary of the hair-care practices of female African American patients and the potential for exposure to sensitizing agents at each stage. This review will also discuss the challenges faced in recognizing and assessing ACD in these patients. ©2016 Frontline Medical Communications.

Activating Hair Follicle Stem Cells via R-spondin2 to Stimulate Hair Growth.

PubMed

Smith, Andrew A; Li, Jingtao; Liu, Bo; Hunter, Daniel; Pyles, Malcolm; Gillette, Martin; Dhamdhere, Girija R; Abo, Arie; Oro, Anthony; Helms, Jill A

2016-08-01

Wnt signaling is required for the development of the hair follicle, and for inciting the growth (anagen) phase of the hair cycle. Most strategies to enhance Wnt signaling for hair growth create a state of constitutive Wnt activation, which leads to neoplastic transformation of the epithelial hair matrix. Using Axin2(LacZ/+) and Axin2(Cre/+)R26R(mTmG/+) reporter mice and RNA analyses, we show that Wnt signaling is elevated during anagen, is reduced at the onset of catagen, and can be reamplified in the skin and surrounding hair follicles via intradermal injection of recombinant R-spondin2 protein. Using Lgr5(LacZ/+) reporter mice, we demonstrate that this amplified Wnt environment leads to activation of leucine-rich repeat-containing G-protein coupled receptor 5-positive stem cells in the hair follicle. The onset of catagen is repressed by R-spondin2 injection, and the anagen phase persists. As a consequence, hair shafts grow longer. We conclude that R-spondin2 treatment activates hair follicle stem cells and therefore may have therapeutic potential to promote hair growth. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

Hair bundles of cochlear outer hair cells are shaped to minimize their fluid-dynamic resistance.

PubMed

Ciganović, Nikola; Wolde-Kidan, Amanuel; Reichenbach, Tobias

2017-06-15

The mammalian sense of hearing relies on two types of sensory cells: inner hair cells transmit the auditory stimulus to the brain, while outer hair cells mechanically modulate the stimulus through active feedback. Stimulation of a hair cell is mediated by displacements of its mechanosensitive hair bundle which protrudes from the apical surface of the cell into a narrow fluid-filled space between reticular lamina and tectorial membrane. While hair bundles of inner hair cells are of linear shape, those of outer hair cells exhibit a distinctive V-shape. The biophysical rationale behind this morphology, however, remains unknown. Here we use analytical and computational methods to study the fluid flow across rows of differently shaped hair bundles. We find that rows of V-shaped hair bundles have a considerably reduced resistance to crossflow, and that the biologically observed shapes of hair bundles of outer hair cells are near-optimal in this regard. This observation accords with the function of outer hair cells and lends support to the recent hypothesis that inner hair cells are stimulated by a net flow, in addition to the well-established shear flow that arises from shearing between the reticular lamina and the tectorial membrane.

Compositional changes of human hair melanin resulting from bleach treatment investigated by nanoscale secondary ion mass spectrometry.

PubMed

Kojima, Toru; Yamada, Hiromi; Isobe, Mitsuru; Yamamoto, Toshihiko; Takeuchi, Miyuki; Aoki, Dan; Matsushita, Yasuyuki; Fukushima, Kazuhiko

2014-11-01

It is important to understand the influence of bleach treatment on human hair because it is one of the most important chemical treatments in hair cosmetic processes. A comparison of the elemental composition of melanin between virgin hair and bleached hair would provide important information about the structural changes of melanin. To investigate the elemental composition of melanin granules in virgin black hair and bleached hair, these hair cross-sections are analyzed by using a nanoscale secondary ion mass spectrometry (NanoSIMS). The virgin black hair and bleached hair samples were embedded in resin and smooth hair cross-sections were obtained using an ultramicrotome. NanoSIMS measurements were performed using a Cs(+) primary ion beam to detect negative secondary ions. More intensive (16) O(-) ions were detected from the melanin granules of bleached hair than from those of virgin black hair in NanoSIMS (16) O(-) ion image. In addition, it was indicated that (16) O(-) ion intensity and (16) O(-) /(12) C(14) N(-) ion intensity ratio of melanin granules in bleached hair were higher than those in virgin black hair. Nanoscale secondary ion mass spectrometry analysis of the cross-sections of virgin black hair and bleached hair indicated that the oxygen content in melanin granules was increased by bleach treatment. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

"I think gorilla-like back effusions of hair are rather a turn-off": 'Excessive hair' and male body hair (removal) discourse.

PubMed

Terry, Gareth; Braun, Virginia

2016-06-01

Men's hair removal practices are becoming mainstream, seen as a consequence of changing masculine norms and men's relationships to their bodies. This is often presented as a straightforward 'shift' from men's ideal bodies as naturally hairy, to increased hairlessness, and the consequence on men's body concerns as inevitable. This paper analyses qualitative survey data from Aotearoa/New Zealand using critical thematic analysis, and describes three themes. Two themes capture contradictory ideas: that men's body hair is natural, and that men's body hair is unpleasant. A third theme introduces the concept of 'excess' hair, which allowed sense-making of this contradiction, mandating men's grooming of 'excessive' hair. However its vagueness as a concept may provoke anxiety for men resulting in hair removal. This paper adds to a body of research demonstrating a cultural transition: the ways changing masculinities, increased commodification of male bodies, and shifting gender roles impact on men's hair removal practices. Copyright © 2016 Elsevier Ltd. All rights reserved.

Processing and characterization of epoxy composites reinforced with short human hair

NASA Astrophysics Data System (ADS)

Prasad Nanda, Bishnu; Satapathy, Alok

2017-02-01

Human hair is a biological fiber with well characterized microstructure. It has many unique properties like high tensile strength, thermal insulation, unique chemical composition, elastic recovery, scaly surface etc. But due to its slow decomposition, it creates many environmental problems. Although a number of utilization avenues are already in place, hair is still considered as a biological waste. In view of this, the present work makes an attempt to explore the possibility of fabricating a class of polymer composites reinforced with short human hair fibers. Epoxy composites with different proportions of hair fiber (0, 2, 4, 6 and 8 wt.%) are prepared by simple hand lay-up technique. Mechanical properties such as tensile, flexural and compressive strengths were evaluated by conducting tests as per ASTM standards. It was found out that with the increase in fiber content, the tensile and flexural strength of the composite were increasing significantly while the compressive strength improved marginally. Scanning electron microscopy was done on these samples to observe the microstructural features.

Adenosine increases anagen hair growth and thick hairs in Japanese women with female pattern hair loss: a pilot, double-blind, randomized, placebo-controlled trial.

PubMed

Oura, Hajimu; Iino, Masato; Nakazawa, Yosuke; Tajima, Masahiro; Ideta, Ritsuro; Nakaya, Yutaka; Arase, Seiji; Kishimoto, Jiro

2008-12-01

Adenosine upregulates the expression of vascular endothelial growth factor and fibroblast growth factor-7 in cultured dermal papilla cells. It has been shown that, in Japanese men, adenosine improves androgenetic alopecia due to the thickening of thin hair due to hair follicle miniaturization. To investigate the efficacy and safety of adenosine treatment to improve hair loss in women, 30 Japanese women with female pattern hair loss were recruited for this double-blind, randomized, placebo-controlled study. Volunteers used either 0.75% adenosine lotion or a placebo lotion topically twice daily for 12 months. Efficacy was evaluated by dermatologists and by investigators and in phototrichograms. As a result, adenosine was significantly superior to the placebo according to assessments by dermatologists and investigators and by self-assessments. Adenosine significantly increased the anagen hair growth rate and the thick hair rate. No side-effects were encountered during the trial. Adenosine improved hair loss in Japanese women by stimulating hair growth and by thickening hair shafts. Adenosine is useful for treating female pattern hair loss in women as well as androgenetic alopecia in men.

Hair cycle in dogs with different hair types in a tropical region of Brazil.

PubMed

Favarato, Evandro S; Conceição, Lissandro Gonçalves

2008-02-01

Hair cycle activity has been extensively studied in humans, sheep and laboratory animals, but there is a lack of information in dogs. Besides varying according to species, breed, sex and general health, hair growth is mainly affected by climatic variations. The aim of the study was to evaluate the follicle activity in three breeds of dogs with different hair types, in the city of Viçosa, Minas Gerais (latitude 20 degrees 45'S), Brazil. Twenty-one male dogs of boxer, labrador and schnauzer breeds were trichographically analysed monthly over 12 consecutive months. Hair percentage of telogen and anagen hairs at the different stages of the hair cycle in boxers and labradors was not significantly different, but both differed from the schnauzers. A significant correlation between hair follicle cycle and environmental temperature and photoperiod was noted in the boxers and labradors. In these breeds, a larger number of telogen hairs were observed during the hottest months of the year, and an increase in anagen hairs during the coldest months. The mean percentage of telogen hairs was 93, 90 and 55.3% for boxer, labrador and schnauzer, respectively.

The influence of hair bleach on the ultrastructure of human hair with special reference to hair damage.

PubMed

Imai, Takehito

2011-05-01

The influence of human hair bleaching agents with different bleaching strength on the ultrastructure of human hair was studied using a transmission electron microscope (TEM) and an energy dispersive X-ray spectrometer equipped with TEM (EDS-TEM). Two kinds of bleaching agents were used: a lightener agent with a weak bleaching effect and a powder-bleach with a stronger bleaching effect. From the comparison of the bleaching properties obtained by the electronic staining of black and white hair samples, it was suggested that the permeability of hair was increased by bleaching, and there was an increase of the stainability of hair subjected to electronic staining. The bleaching action provoked the decomposition of melanin granules and the flow out of granular contents into the intermacrofibrillar matrix. Some metal elements were detected in the melanin granular matrix by EDS-TEM. As a result, the diffusion of metal elements into the intermacrofibrillar matrix promoted further damage to the hair by catalytic action with the hydrogen peroxide in the bleaching agents outside the melanin granules. Further study will lead us to the edge of the development of a new bleaching agent, which reacts only with melanin granules and causes the minimum of damage to outside the melanin granules.

Primary Teeth and Hair as Indicators of Environmental Pollution.

PubMed

Shishniashvili, T E; Suladze, N N; Margvelashvili, V V

2016-01-01

To study the influence of environmental pollution on the mineralization of dental hard tissues by using biosubstrates: teeth and hair. : At the first stage epidemiological survey was conducted in polluted and less polluted areas of Tbilisi (Georgia). We studied 525 children aged 3 and 4 years. Caries prevalence and intensity was defined by the methodology of World Health Organization. At the second stage the chemical elements content was studied in hair and teeth hard tissues of 24 children by X-ray fluorescent spectroscopy method. The prevalence of dental caries in the polluted region was 46%, caries intensity--1.92 (± 2.842). In the less polluted region prevalence was 37%, caries intensity--1.47 (± 2.571). These data are statistically reliable (p < 0.05). The study of hair and tooth tissues showed that the toxic elements (Pb, Hg, Sn, Ti) content in these tissues was higher in environmentally unfavorable than in favorable conditions. Hair and dental tissues can be used as indicators of environmental pollution. Our survey showed that toxic elements content in dental hard tissues was higher and the level of essential elements was less in polluted than in less polluted areas of Tbilisi.

The hair follicle enigma.

PubMed

Bernard, Bruno A

2017-06-01

The hair follicle is a mini-organ endowed with a unique structure and cyclic behaviour. Despite the intense research efforts which have been devoted at deciphering the hair follicle biology over the past 70 years, one must admit that hair follicle remains an enigma. In this brief review, various aspects of hair follicle biology will be addressed, and more importantly, unsolved questions and new possible research tracks will be highlighted, including hair follicle glycobiology and exosome-mediated cell-cell interactions. Even though bricks of knowledge are solidly being acquired, an integrative picture remains to emerge. One can predict that computer science, algorithms and bioinformatics will assist in fostering our understanding hair biology. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Hair cell regeneration: Look to the future

NASA Astrophysics Data System (ADS)

Rubel, Edwin W.

2005-04-01

Less than 2 decades ago it was discovered that birds can regenerate hair cells in the auditory and vestibular parts of the inner ear after the native hair cells are destroyed by exposure to excessive noise or by mechanical trauma of aminoglycoside antibiotics. This discovery issued in a new era of hearing research-it suggested that some day it may be possible to actually restore hearing in people with congenital or acquired hearing loss due to the degeneration of sensory cells or supporting cells in the inner ear. Fifteen years is a very short time in the history of science. Consider the fact that we have actively sought chemical treatments to prevent or cure cancers for well over a half century and the ``war on Cancer,'' resulted in enormous public and private support. Progress has been great, and some forms of cancer can be treated with great success, but the overall 5-year survival rates have only risen from about 50% to 63%. Progress will continue and many more forms of cancer will be cured and prevented during the next half century. Similarly, during the first 15 years of hair cell regeneration research enormous progress has been made, and we now know that postnatal mammalian ears have the capacity to produce new hair cells. We are indeed a long way from restoring hearing through hair cell regeneration, but the future is pretty clear. I will review the progress of this field with an eye toward the future and what it means for treatments of today. In particular, I will address the potential cost versus benefits of bilateral implantation when applied to babies and young children.

Causes and Consequences of Sensory Hair Cell Damage and Recovery in Fishes.

PubMed

Smith, Michael E; Monroe, J David

2016-01-01

Sensory hair cells are the mechanotransductive receptors that detect gravity, sound, and vibration in all vertebrates. Damage to these sensitive receptors often results in deficits in vestibular function and hearing. There are currently two main reasons for studying the process of hair cell loss in fishes. First, fishes, like other non-mammalian vertebrates, have the ability to regenerate hair cells that have been damaged or lost via exposure to ototoxic chemicals or acoustic overstimulation. Thus, they are used as a biomedical model to understand the process of hair cell death and regeneration and find therapeutics that treat or prevent human hearing loss. Secondly, scientists and governmental natural resource managers are concerned about the potential effects of intense anthropogenic sounds on aquatic organisms, including fishes. Dr. Arthur N. Popper and his students, postdocs and research associates have performed pioneering experiments in both of these lines of fish hearing research. This review will discuss the current knowledge regarding the causes and consequences of both lateral line and inner ear hair cell damage in teleost fishes.

Optical hair removal.

PubMed

Ort, R J; Anderson, R R

1999-06-01

Traditional methods of hair removal have proven unsatisfactory for many individuals with excessive or unwanted hair. In the last few years, several lasers and xenon flashlamps have been developed that promise to fulfill the need for a practical, safe, and long-lasting method of hair removal. Aggressive marketing of these has contributed to their popularity among patients and physicians. However, significant controversy and confusion surrounds this field. This article provides a detailed explanation of the scientific underpinnings for optical hair removal and explores the advantages and disadvantages of the various devices currently available (Nd:YAG, ruby, alexandrite, diode lasers, and xenon flashlamp). Treatment and safety guidelines are provided to assist the practitioner in the use of these devices. Although the field of optical hair removal is still in its infancy, initial reports of long-term efficacy are encouraging.

Fourier transform infrared attenuated total reflection analysis of human hair: comparison of hair from breast cancer patients with hair from healthy subjects.

PubMed

Lyman, Donald J; Murray-Wijelath, Jacqueline

2005-01-01

A comparative study of Fourier transform infrared attenuated total reflection (FTIR-ATR) spectra of 32 scalp and pubic hair samples from individuals diagnosed with breast cancer and those who were negative for breast cancer showed increases in the beta-sheet/disorder structures (relative to alpha-helix structures) and C-H lipid content of hair from breast cancer patients. Thus, the presence of breast cancer appears to alter the hair growth process, resulting in changes in the composition and conformation of cell membrane and matrix materials of hair fiber. These appear to be consistent with the changes observed in X-ray diffraction patterns for hair from breast cancer patients. A blind study of 12 additional hair samples using these FTIR-ATR spectral differences as markers correctly identified all four hair samples from cancer patients (100%). Two of these samples were from breast cancer patients. Of the remaining two samples analyzing positive for cancer, one was from a prostate cancer patient and one from a lung cancer patient. Thus, it appears that the mechanism that alters hair fiber synthesis in the three types of cancer may be similar. The blind study incorrectly identified as positive for cancer three hair samples from two apparently healthy individuals and one patient considered cured from prostate cancer.

[Residue of organic fluorine pollutants in hair and nails collected from Tianjin].

PubMed

Yao, Dan; Zhang, Hong; Chai, Zhi-Fang; Shen, Jin-Can; Yang, Bo; Wang, Yan-Ping; Liu, Guo-Qing

2013-02-01

In order to explore the residue and distributions of organic fluorine pollutants in hair and nails, the residue levels of total fluorine (TF), extractable organic fluorine (EOF) and perfluorinated chemicals (PFCs) in hair and nails collected from Tianjin adults were measured by the cyclic neutron activation analysis (CNAA) combined with the high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS). The results showed that inorganic fluorine (mean: 2.0 mg.kg-1, 4.5 mg.kg-1) was the primary fluorine in TF while EOF(mean: 0.7 mg.kg-1, 1.8 mg.kg-1) was minor. The average amount of identified fluorine (IF) was 0.038 mg.kg-1 in hair and 0.047 mg.kg-1 in nails, accounting or 7.1% (2.6%-16%) and 3.5% (1.1%-11%) of EOF, respectively, which indicated that more than 84% of EOF was unknown. The major residue in hair and nails were medium-and short-chain PFCs,in which perfluorooctane sulfonate, perfluorooctanoic acid and perfluorononanoic acid were the main species. TF, EOF and IF levels in dyed and permed hair were significantly higher than untreated hair (P <0.05), and the concentrations of Sigma PFCs in hair and nails showed no difference between genders. With significantly higher levels of sigma PFCs and PFOS residues than hair (P <0.01), nails could potentially become a more sensitive bioindicator for the exposure level of PFCs in human.

Hair dyes are mutagenic: identification of a variety of mutagenic ingredients.

PubMed Central

Ames, B N; Kammen, H O; Yamasaki, E

1975-01-01

We have previously described a sensitive bacterial test for dectecting carcinogens as mutagens. We have previously described a sensitive bacterial test for detecting carcinogens as mutagens. We show here that 89% (150/169) of commercial oxidative-type (hydrogen peroxide) hair dye formulations are mutagenic in this test. Of the 18 components of these hair dyes, nine show various degrees of mutagenicity:2,4-diaminoanisole, 4-nitro-o-phenylenediamine, 2-nitro-p-phenylenediamine, 2,5-diaminoanisole, 2-amino-5-nitrophenol, m-phenylenediamine, o-phenylenediamine, 2-amino-4-nitrophenol, and 2,5-diaminotoluene. Three hair dye components (p-phenylenediamine, 2,5-diaminotuluene, and 2,5-diaminoanisole) become strongly mutagenic after oxidation by H2O2: the mutagenic product of p-phenylenediamine is identified as the known trimer, Bandrowski's base. 2,4-Diaminotoluene, a hair dye component until recently, is also shown to be mutagenic: this compound has been shown to be a carcinogen in rats and is used in large amounts in the polyurethane foam industry. About 20,000,000 people (mostly women) dye their hair in the U.S. and the hazard could be considerable if these chemicals are actually mutagenic and carcinogenic in humans. Images PMID:1094469

The time-dependence of exchange-induced relaxation during modulated radio frequency pulses.

PubMed

Sorce, Dennis J; Michaeli, Shalom; Garwood, Michael

2006-03-01

The problem of the relaxation of identical spins 1/2 induced by chemical exchange between spins with different chemical shifts in the presence of time-dependent RF irradiation (in the first rotating frame) is considered for the fast exchange regime. The solution for the time evolution under the chemical exchange Hamiltonian in the tilted doubly rotating frame (TDRF) is presented. Detailed derivation is specified to the case of a two-site chemical exchange system with complete randomization between jumps of the exchanging spins. The derived theory can be applied to describe the modulation of the chemical exchange relaxation rate constants when using a train of adiabatic pulses, such as the hyperbolic secant pulse. Theory presented is valid for quantification of the exchange-induced time-dependent rotating frame longitudinal T1rho,ex and transverse T2rho,ex relaxations in the fast chemical exchange regime.

Effects of gamma rays on the regeneration of murine hair follicles in the natural hair cycle.

PubMed

Sugaya, Kimihiko

2017-09-01

This review evaluates the effects of γ-rays on the regeneration of murine hair follicles in the natural hair cycle. A series of studies were performed to investigate this issue, in which the whole bodies of C57BL/10JHir mice in the 1st telogen phase of the hair cycle were irradiated with γ-rays. The dermis of the irradiated skin showed a decrease in hair follicle density and induction of curved hair follicles along with the presence of white hairs and hypopigmented hair bulbs in the 2nd and 3rd anagen phases. An increased frequency of hypopigmented hair bulbs was still observed in the later hair cycle at postnatal day 200. There was no significant difference in the number of stem cells in the hair bulge region between control and irradiated skin. These results show that the effects of γ-rays on the pigmentation of murine hair follicles are persistently carried over to later hair cycles, although those on the number and structure of hair follicles appear to be hidden by the effects of aging. Our findings may be important for understanding the mechanisms of the actions of stem cells on hair regeneration in connection with age-related phenotypes.

Fumonisin mycotoxins in human hair.

PubMed

Sewram, Vikash; Mshicileli, Ndumiso; Shephard, Gordon S; Marasas, Walter F O

2003-01-01

This study shows for the first time the accumulation of fumonisin mycotoxins in human hair of population clusters exposed to contaminated maize, and thus the feasibility of human hair analysis for the assessment of past fumonisin exposure. Composite hair samples were obtained from the Bizana, Butterworth and Centane districts within the Transkei region of the Eastern Cape Province of South Africa. Following methanol extraction and strong anion exchange clean up, the fumonisins FB(1), FB(2) and FB(3) were detected using high performance liquid chromatography coupled to electrospray ionization-mass spectrometry (HPLC-ESI-MS). Hair from Centane and Butterworth showed mean levels of FB(1) of 26.7 and 23.5 microg kg(-1) hair, respectively. FB(2) was only detected in hair from Centane and in one sampling point in Butterworth, with mean levels of 6.5 and 5.7 microg kg(-1) hair, respectively. Hair samples from Bizana, on the other hand, were found to contain higher levels of FB(1) (mean 33.0 microg kg(-1) hair) and FB(2) (mean 11.1 microg kg(-1) hair). No samples contained more than trace levels of FB(3). Recoveries from spiked hair samples using this method ranged from 81% to 101%, demonstrating the applicability of hair analysis in assessing human exposure to fumonisin mycotoxins.

Analytical requirements, perspectives and limits of immunological methods for drugs in hair.

PubMed

Cassani, M; Spiehler, V

1993-12-01

The analytical requirements for analysis of drugs in hair are sensitivity in the range of picograms per milligram of hair, specificity for lipophilic drugs and absence of matrix effects with hair digests. These requirements are met by immunoassays which are also inexpensive, rapid and easy to use. However, in applying immunoassays to hair testing, certain limitations of the assay and of interpretation of assay results should be kept in perspective. These limitations are illustrated in this review with examples of the analysis of opiates in hair from patients and opiate addicts. The first requirement for immunological analysis of hair digests is that the digest must not denature the antibody proteins of the immunoassay reagents. For this reason enzymatic digests are better for immunological assay than chemical digests. Strongly acidic or alkaline digests must be brought to a neutral pH before immunoassay. Immunoassays used for analysis of hair should be calibrated with spiked hair digest standards to correct for possible matrix effects. The second requirement is that the immunoassay have the sensitivity and specificity to detect the drug in hair. Drugs of abuse are found in hair in the range of 10 pg-10 ng/mg hair. Radioimmunoassays are capable of detection and quantitation in this concentration range. Although the mechanism of drug incorporation into hair is not known, it is now apparent that primarily the parent drug and lipophilic metabolites are found in hair. For example, the ratio of cocaine/benzoylecgonine averages 10 (range 2-50) in published reports of analysis of hair from cocaine users. Therefore, immunoassays which are highly sensitive for the parent drug are required and results of immunoassays should be expressed as equivalents. When spiking standards for calibration of hair digest immunoassays, parent drug known to be present in hair should be used, e.g. cocaine not benzoylecgonine. With immunoassays which are specific for the lipophilic metabolite

Novel preparation and characterization of human hair-based nanofibers using electrospinning process.

PubMed

Park, Mira; Shin, Hye Kyoung; Panthi, Gopal; Rabbani, Mohammad Mahbub; Alam, Al-Mahmnur; Choi, Jawun; Chung, Hea-Jong; Hong, Seong-Tshool; Kim, Hak-Yong

2015-05-01

Human hair-based biocomposite nanofibers (NFs) have been fabricated by an electrospinning technique. Aqueous keratin extracted from human hair was successfully blended with poly(vinyl alcohol) (PVA). The focus here is on transforming into keratin/PVA nanofibrous membranes and insoluble property of electrospun NFs. The resulting hair-based NFs were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning colorimetry (DSC), and thermogravimetric analysis (TGA). Toward the potential use of these NFs after cross-linking with various weight fractions of glyoxal, its physicochemical properties, such as morphology, mechanical strength, crystallinity, and chemical structure were investigated. Keratin/PVA ratio of 2/1 NFs with 6 wt%-glyoxal showed good uniformity in fiber morphology and suitable mechanical properties, and excellent antibacterial activity providing a potential application of hair-based NFs in biomedical field. Copyright © 2015 Elsevier B.V. All rights reserved.

Hair camouflage: A comprehensive review.

PubMed

Saed, Stephanie; Ibrahim, Omer; Bergfeld, Wilma F

2016-12-01

Hair is venerated, cherished, and desired in societies throughout the world. Both women and men express their individual identities through their hairstyles. Healthy hair contributes to successful social assimilation, employment, and overall quality of life. Therefore, hair loss can have detrimental effects on almost every aspect of a person's life. In this review, we discuss the myriad of options that aid in concealing and camouflaging hair loss to facilitate a healthier-appearing scalp. Camouflage options for patients who suffer from hair loss include full or partial wigs, hair extensions, concealing powders and sprays, surgical tattoos, and hair transplants. We describe these modalities in detail and discuss their respective advantages and disadvantages.

Hair camouflage: A comprehensive review.

PubMed

Saed, Stephanie; Ibrahim, Omer; Bergfeld, Wilma F

2017-03-01

Hair is venerated, cherished, and desired in societies throughout the world. Both women and men express their individual identities through their hairstyles. Healthy hair contributes to successful social assimilation, employment, and overall quality of life. Therefore, hair loss can have detrimental effects on almost every aspect of a person's life. In this review, we discuss the myriad of options that aid in concealing and camouflaging hair loss to facilitate a healthier-appearing scalp. Camouflage options for patients who suffer from hair loss include full or partial wigs, hair extensions, concealing powders and sprays, surgical tattoos, and hair transplants. We describe these modalities in detail and discuss their respective advantages and disadvantages.

Artificial sensory hairs based on the flow sensitive receptor hairs of crickets

NASA Astrophysics Data System (ADS)

Dijkstra, M.; van Baar, J. J.; Wiegerink, R. J.; Lammerink, T. S. J.; de Boer, J. H.; Krijnen, G. J. M.

2005-07-01

This paper presents the modelling, design, fabrication and characterization of flow sensors based on the wind-receptor hairs of crickets. Cricket sensory hairs are highly sensitive to drag-forces exerted on the hair shaft. Artificial sensory hairs have been realized in SU-8 on suspended SixNy membranes. The movement of the membranes is detected capacitively. Capacitance versus voltage, frequency dependence and directional sensitivity measurements have been successfully carried out on fabricated sensor arrays, showing the viability of the concept.

Telogen Effluvium Hair Loss

MedlinePlus

... pillow. This is the result of the normal hair growth cycle. Hairs will grow for a few years, ... the name for the resting stage of the hair growth cycle. A telogen effluvium is when some stress ...

Taking Care of Your Hair

MedlinePlus

... Educators Search English Español Taking Care of Your Hair KidsHealth / For Teens / Taking Care of Your Hair ... role in how healthy it looks. Caring for Hair How you take care of your hair depends ...

Ecabet sodium alleviates neomycin-induced hair cell damage.

PubMed

Rah, Yoon Chan; Choi, June; Yoo, Myung Hoon; Yum, Gunhwee; Park, Saemi; Oh, Kyoung Ho; Lee, Seung Hoon; Kwon, Soon Young; Cho, Seung Hyun; Kim, Suhyun; Park, Hae-Chul

2015-12-01

Ecabet sodium (ES) is currently applied to some clinical gastrointestinal disease primarily by the inhibition of the ROS production. In this study, the protective role of ES was evaluated against the neomycin-induced hair cell loss using zebrafish experimental animal model. Zebrafish larvae (5-7 dpf), were treated with each of the following concentrations of ES: 5, 10, 20, 40, and 80 μg/mL for 1 h, followed by 125 μM neomycin for 1h. The positive control group was established by 125 μM neomycin-only treatment (1h) and the negative control group with no additional chemicals was also established. Hair cells inside four neuromasts ( SO1, SO2, O1, OC1) were assessed using fluorescence microscopy (n = 10). Hair cell survival was calculated as the mean number of viable hair cells for each group. Apoptosis and mitochondrial damage were investigated using special staining (TUNEL and DASPEI assay, respectively), and compared among groups. Ultrastructural changes were evaluated using scanning electron microscopy. Pre-treatment group with ES increased the mean number of viable hair cells as a dose-dependent manner achieving almost same number of viable hair cells with 40 μM/ml ES treatment (12.98 ± 2.59 cells) comparing to that of the negative control group (14.15 ± 1.39 cells, p = 0.72) and significantly more number of viable hair cells than that of the positive control group (7.45 ± 0.91 cells, p < 0.01). The production of reactive oxygen species significantly increased by 183% with 125 μM neomycin treatment than the negative control group and significantly decreased down to 105% with the pre-treatment with 40 μM/ml ES (n = 40, p = 0.04). A significantly less number of TUNEL-positive cells (reflecting apoptosis, p < 0.01) and a significantly increased DASPEI reactivity (reflecting viable mitochondria, p < 0.01) were observed in 40 μM/ml ES pre-treatment group. Our data suggest that ES could protect against neomycin-induced hair cell loss possibly by reducing

Hair transplantation update.

PubMed

Rogers, Nicole E

2015-06-01

Contemporary hair transplant surgery offers results that are natural and undetectable. It is an excellent treatment option for male and female pattern hair loss. Patients are encouraged to also use medical therapy to help protect their surgical results and prevent ongoing thinning of the surrounding hairs. The two major techniques of donor elliptical harvesting and follicular unit extraction are discussed here. ©2015 Frontline Medical Communications.

Trichotillomania (Hair-Pulling Disorder)

MedlinePlus

Trichotillomania (hair-pulling disorder) Overview Trichotillomania (trik-o-til-o-MAY-nee-uh), also called hair-pulling disorder, is a mental disorder that involves recurrent, irresistible urges to pull out hair from your scalp, eyebrows or other areas of ...

Investigating the use of hair to assess polybrominated diphenyl ether exposure retrospectively.

PubMed

Carnevale, Amanda; Aleksa, Katarina; Goodyer, Cynthia G; Koren, Gideon

2014-04-01

Polybrominated diphenyl ethers (PBDEs) are chemicals that are added to a variety of consumer products as flame-retardants and have been classified as emerging endocrine disruptors. They are persistent and have been detected in humans. Previous studies have suggested that hair is a suitable matrix for examining human exposure to organic pollutants such as PBDEs. It is believed that the majority of exposure is from our indoor environment. The aim of this study was to investigate the changes in PBDE patterns and levels along the hair shaft, by using segmental analysis to retrospectively assess long-term exposure over a 1-year period. Questionnaires and hair samples from 65 women were collected at the Hospital for Sick Children, in Toronto, as part of a larger study. To assess long-term stability, hair samples were separated into 4- and 3-cm segments representing a 1-year period. Hair segments were analyzed for levels of 8 PBDE congeners, BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, BDE-154, BDE-183, and BDE-209 on gas chromatography-mass spectrometry (MS). A Friedman test was used to detect the differences in exposure among segments, and factors such as dietary habits, hair care routine, and site of residence were investigated to determine if they might affect hair levels. A significant increase (P < 0.0001) in total PBDEs was seen among segments moving from proximal (root end) to distal along the hair shaft (median in pg/mg): first (33.3), second (43.0), third (61.6), and fourth (75.5) segments. Significantly lower levels of PBDEs were observed in artificially colored hair samples (P = 0.032), and a significant increase in PBDE levels was observed in women who consumed meat on a daily basis as opposed to weekly consumption (P = 0.040). The increase in PBDEs along the hair shaft suggests that hair PBDEs may be influenced by diet and artificial coloring. More work is needed to validate the use of PBDEs in hair as a biomarker of long-term exposure.

The potential use of diisononyl phthalate metabolites hair as biomarkers to assess long-term exposure demonstrated by a rat model.

PubMed

Hsu, Jen-Yi; Ho, Hsin-Hui; Liao, Pao-Chi

2015-01-01

Diisononyl phthalate (DINP) is a widely used industrial plasticizer. People come into contact with this chemical by using plastic products made with it. Human health can be adversely affected by long-term DINP exposure. However, because the body rapidly excretes DINP metabolites, the use of single-point urine analysis to assess long-term exposure may produce inconsistent results in epidemiologic studies. Hair analysis has a useful place in biomonitoring, particularly in estimating long-term or historical exposure for some chemicals. Several studies have reported using hair analysis to assess the concentrations of heavy metals, drugs and organic pollutants in humans. As a biomarker, DINP metabolites were measured in rat hair in animal experiments to evaluated long-term exposure to DINP. In addition, we evaluated the correlation between the levels of DINP metabolites in hair and in urine. The levels of DINP metabolites in rat hair were significantly higher in the exposure group, relative to the control group (p<0.05). DINP metabolites had a positive correlation with increasing administered dose. Significant positive correlations for MINP, MOINP and MHINP were found between hair and urine (r=0.86, r=0.79 and r=0.74, respectively, p<0.05). Several metabolites in urine showed earlier saturation than in hair. In this report, we detected eight metabolites in hair and demonstrate that hair analysis has potential applications in the assessment of long-term exposure to DINP. Copyright © 2014 Elsevier Ltd. All rights reserved.

Pharmacologic interventions in aging hair

PubMed Central

Trüeb, Ralph M

2006-01-01

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. PMID:18044109

An ultrastructural study on corkscrew hairs and cigarette-ash-shaped hairs observed by dermoscopy of tinea capitis.

PubMed

Lu, Mao; Ran, Yuping; Dai, Yaling; Lei, Song; Zhang, Chaoliang; Zhuang, Kaiwen; Hu, Wenying

2016-01-01

This study was aimed to explain the formation mechanisms of corkscrew hairs and cigarette-ash-shaped hairs observed by dermoscopy of tinea capitis. In the present work, the ultrastructure of the involved hairs collected from a girl with tinea capitis caused by Trichophyton violaceum was observed by scanning electron microscope (SEM) and transmission electron microscope (TEM). SEM observation of the corkscrew hair revealed bent hair shaft and asymmetrically disrupted cuticle layer. TEM findings demonstrated the hair shaft became weak. The corkscrew hairs closely covered by scales on the scalp were observed under dermoscopy. We speculate that the formation of corkscrew hairs is a result of a combination of internal damage due to hair degradation by T. violaceum and external resistance due to scales covering the hair. SEM observation of the cigarette-ash-shaped hair revealed irregularly disrupted and incompact end, which might represent the stump of the broken corkscrew hair after treatment. © Wiley Periodicals, Inc.

Application of a flux-split algorithm to chemically relaxing, hypervelocity blunt-body flows

NASA Technical Reports Server (NTRS)

Balakrishnan, A.

1987-01-01

Viscous, nonequilibrium, hypervelocity flow fields over two axisymmetric configurations are numerically simulated using a factored, implicit, flux-split algorithm. The governing gas-dynamic and species-continuity equations for laminar flow are presented. The gas-dynamics/nonequilibrium-chemistry coupling procedure is developed as part of the solution procedure and is described in detail. Numerical solutions are presented for hypervelocity flows over a hemisphere and over an axisymmetric aeroassisted orbital transfer vehicle using three different chemistry models. The gas models considered are those for an ideal gas, for a frozen gas, and for chemically relaxing air consisting of five species. The calculated results are compared with existing numerical solutions in the literature along the stagnation line of the hemisphere. The effects of free-stream Reynolds number on the nonequilibrium flow field are discussed.

Hair dye poisoning

MedlinePlus

Hair tint poisoning ... Different types of hair dye contain different harmful ingredients. The harmful ingredients in permanent dyes are: Naphthylamine Other aromatic amino compounds Phenylenediamines Toluene ...

Splitting hairs: differentiating between entomological activity, taphonomy, and sharp force trauma on hair.

PubMed

Mazzarelli, Debora; Vanin, Stefano; Gibelli, Daniele; Maistrello, Lara; Porta, Davide; Rizzi, Agostino; Cattaneo, Cristina

2015-03-01

The analysis of hair can provide useful information for the correct evaluation of forensic cases, but studies of trauma on hair are extremely rare. Hair may present lesions caused by traumatic events or by animals: in fact, signs of sharp force weapons on hair may provide important information for the reconstruction of the manner of death, and, for example, may suggest fetishist practice. This study stemmed from a judicial case where it was fundamental to distinguish between sharp force lesions and insect activity on hair. In order to highlight differences between sharp force lesions and insect feeding activity, different experiments were performed with high power microscopy: hair samples were subjected to several lesions by blunt and sharp force trauma; then samples were used as pabulum for two taxa of insects: the common clothes moth (Tineola bisselliella Lepidoptera, Tineidae) and the carpet beetle (Anthrenus sp., Coleoptera, Dermestidae). Hairs were examined from a macroscopic and microscopic point of view by stereomicroscopy and scanning electron microscopy (SEM): the morphological characteristics of the lesions obtained from the different experimental samples were compared. Results show that sharp force trauma produces lesions with regular edges, whereas insects leave concave lesions caused by their "gnawing" activity. These two types of lesions are easily distinguishable from breaking and tearing using SEM. This study demonstrates that insect activity leaves very specific indications on hair and sheds some light on different hair lesions that may be found in forensic cases.

Talking Back in Cyberspace: Self-Love, Hair Care, and Counter Narratives in Black Adolescent Girls' Youtube vlogs

ERIC Educational Resources Information Center

Phelps-Ward, Robin J.; Laura, Crystal T.

2016-01-01

While the "natural hair movement" has grown in popularity and criticism, educational researchers have not attended to how Black adolescent girls with all textures of natural hair are navigating the implications of foregoing chemical alterations to their curl patterns. This article reports on an investigation of self-talk in 56 internet…

Le Chatelier's principle with multiple relaxation channels

NASA Astrophysics Data System (ADS)

Gilmore, R.; Levine, R. D.

1986-05-01

Le Chatelier's principle is discussed within the constrained variational approach to thermodynamics. The formulation is general enough to encompass systems not in thermal (or chemical) equilibrium. Particular attention is given to systems with multiple constraints which can be relaxed. The moderation of the initial perturbation increases as additional constraints are removed. This result is studied in particular when the (coupled) relaxation channels have widely different time scales. A series of inequalities is derived which describes the successive moderation as each successive relaxation channel opens up. These inequalities are interpreted within the metric-geometry representation of thermodynamics.

Creeping hair: an isolated hair burrowing in the uppermost dermis resembling larva migrans.

PubMed

Sakai, Rie; Higashi, Kushio; Ohta, Miyuki; Sugimoto, Yasushi; Ikoma, Yukiko; Horiguchi, Yuji

2006-01-01

A 55-year-old Japanese male presented with a slowly moving linear erythema that looked like an eruption of creeping disease, or cutaneous larva migrans. The eruption extended linearly along Langer's line of the lateral side of the abdomen to the lower back, leaving wave-like erythema. In the top third of the erythematous eruption, close examination demonstrated a black thin line, which was revealed to be a hair shaft by a shallow incision of the skin. After removal of the hair, the eruption diminished immediately, leaving a slight pigmentation. An ingrown pubic hair seemed to have migrated with the lower end forward along Langer's line, because of the arrangement of hair cuticle and the force of body motion. Linearly moving erythematous eruptions that look like that of larva migrans should be differentiated from creeping hair by close examination detecting burrowing hair.

Zebrafish hair cell mechanics and physiology through the lens of noise-induced hair cell death

NASA Astrophysics Data System (ADS)

Coffin, Allison B.; Xu, Jie; Uribe, Phillip M.

2018-05-01

Hair cells are exquisitely sensitive to auditory stimuli, but also to damage from a variety of sources including noise trauma and ototoxic drugs. Mammals cannot regenerate cochlear hair cells, while non-mammalian vertebrates exhibit robust regenerative capacity. Our research group uses the lateral line system of larval zebrafish to explore the mechanisms underlying hair cell damage, identify protective therapies, and determine molecular drivers of innate regeneration. The lateral line system contains externally located sensory organs called neuromasts, each composed of ˜8-20 hair cells. Lateral line hair cells are homologous to vertebrate inner ear hair cells and share similar susceptibility to ototoxic damage. In the last decade, the lateral line has emerged as a powerful model system for understanding hair cell death mechanisms and for identifying novel protective compounds. Here we demonstrate that the lateral line is a tractable model for noise-induced hair cell death. We have developed a novel noise damage system capable of inducing over 50% loss of lateral line hair cells, with hair cell death occurring in a dose- and time-dependent manner. Cell death is greatest 72 hours post-exposure. However, early signs of hair cell damage, including changes in membrane integrity and reduced mechanotransduction, are apparent within hours of noise exposure. These features, early signs of damage followed by delayed hair cell death, are consistent with mammalian data, suggesting that noise acts similarly on zebrafish and mammalian hair cells. In our future work we will use our new model system to investigate noise damage events in real time, and to develop protective therapies for future translational research.

Female Pattern Hair Loss

MedlinePlus

... susceptible women, but is most commonly seen after menopause. In female pattern hair loss some excess loss of hair is noted, but ... all. Spironolactone pills help many women, especially whose hair loss starts before menopause but takes many months. Hormone replacement pills, such ...

Gender differences in scalp hair growth rates are maintained but reduced in pattern hair loss compared to controls.

PubMed

Van Neste, D J J; Rushton, D H

2016-08-01

Hair loss is related to follicular density, programmed regrowth and hair productivity. The dissatisfaction with hair growth in patients experiencing hair loss might be due to slower linear hair growth rate (LHGR). LHGR and hair diameter was evaluated in Caucasian controls and patients with patterned hair loss employing the validated non-invasive, contrast-enhanced-phototrichogram with exogen collection. We evaluated 59,765 anagen hairs (controls 24,609, patients 35,156) and found thinner hairs grew slower than thicker hairs. LHGR in normal women was generally higher than in normal men. LHGR correlates with hair diameter (P < 0.006) and global thinning is associated with slower growth rates. Compared with hair of equal thickness in controls, subjects affected with patterned hair loss showed reduced hair growth rates, an observation found in both male and female patients. Males with pattern hair loss showed further reduction in growth rates as clinical severity worsened. However, sample size limitations prevented statistical evaluation of LHGR in severely affected females. Caucasian ethnicity. In pattern hair loss, LHGR significantly contributes to the apparent decrease in hair volume in affected areas. In early onset, LHRG might have a prognostic value in females but not in males. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Association of hair dye use with circulating levels of sex hormones in premenopausal Japanese women.

PubMed

Nagata, Chisato; Wada, Keiko; Tsuji, Michiko; Hayashi, Makoto; Takeda, Noriyuki; Yasuda, Keigo

2015-10-01

Substances identified as animal carcinogens are no longer used as ingredients of hair dyes. However, hair dyes are diverse groups of chemicals, and certain compounds may affect endogenous sex hormone levels. We examined the association between hair dye use and sex hormone levels among premenopausal women. Study subjects were 431 premenopausal Japanese women who had regular menstrual cycles less than 40 days long. Information on the use of hair dyes or hair bleach, the type of hair coloring used, the duration of use and the frequency of application was collected using a self-administered questionnaire. Fasting plasma samples were obtained to measure estradiol, testosterone, dehydroepiandrosterone sulfate, sex hormone-binding globulin, follicle-stimulating hormone and luteinizing hormone. After controlling for covariates, the mean plasma total testosterone level was about 14% higher in women who had used hair dyes for 10 or more years than that among women who had never used them (P for trend = 0.02). A similar association was observed when the type of hair dye was restricted to permanent hair dyes. A higher frequency of applying non-permanent hair dyes was marginally significantly associated with higher total and free estradiol levels. Data suggest that long-term use of hair dyes may be associated with an increase in circulating testosterone levels. As this is, to our knowledge, the first study examining the association between hair dye use and sex hormone levels, replication of the results is required. © The Author 2015. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Hair and Physiological Baldness

PubMed Central

Mercantini, Edward S.

1965-01-01

Human hair is one of the structures of the body about which little is generally known. Disease affecting the hair is often minimized or ignored by physicians because of lack of knowledge of this rudimentary organ. However, the patient's attitude toward hair loss is very different from the doctor's and he feels great concern about such loss. The development, growth and morphology of human hair are briefly presented. Experimental work which will increase our knowledge of hair growth and loss is reviewed. The various forms of physiological alopecia from birth onward are discussed, with special emphasis on the least-known type of physiological baldness, “male-pattern baldness” in the adult female. PMID:14312445

Determination of Tebuconazole and Penconazole Fungicides in Rat and Human Hair By Liquid Chromatography/Tandem Mass Spectrometry.

PubMed

Polledri, Elisa; Mercadante, Rosa; Fustinoni, Silvia

2018-05-04

Tebuconazole (TEB) and penconazole (PEN) are widely applied fungicides and environmental contaminants; their toxicological properties include possible effects to the unborn child, therefore the evaluation of human exposure is relevant to risk assessment. Hair is a non-invasive specimen that incorporates pollutants allowing an extended exposure window to be surveyed. Aim of this work was to develop and validate an assay for the determination of TEB and PEN in human hair. Under optimised conditions, analytes were extracted soaking hair in acetonitrile, in the presence of deuterated analogues, under heating and agitation. Chemical separation was achieved using a C18 reversed-phase chromatographic column and detection and quantification were performed, after a positive electrospray ionization, by triple quadrupole mass spectrometry operating in selected reaction monitoring mode. The assay validation showed a linear dynamic range up to 5 μg/L or 200 pg/mg hair, inter- and intra-run precisions <6%, and accuracies within 5% of spiked concentrations. Limits of quantification were 0.001 μg/L or 1 pg/mg hair for both TEB and PEN. Matrix effect experiments showed that the isotope dilution approach allowed for the control of bias sources. TEB and PEN were determined in hair of rats exposed to a low dose of TEB and in hair of agricultural workers exposed to TEB and/or PEN during the application season, indicating that both chemicals are incorporated into the hair upon exposure. The results of this study indicate that the developed assay is useful to evaluate the exposure to TEB and PEN in humans. This article is protected by copyright. All rights reserved.

Multicenter clinical trial on a permanent hair dye containing paratoluenediamine.

PubMed

Foti, Caterina; Balato, Nicola; Cristaudo, Antonio; Patruno, Cataldo; Pigatto, Paolo; Ambrifi, Marina; Bufano, Tamara; Damiani, Giovanni; De Rocco, Mariagrazia; Diani, Marco; Napolitano, Maddalena; Romita, Paolo

2018-08-01

Adverse reactions to hair dyes are frequent and usually caused by sensitization to paraphenylenediamine (PPD). The aim of the study was to evaluate the tolerability of a PPD-free permanent hair dye (Shine On, BioNike, Milan, Italy) containing paratoluenediamine (PTD) in a group of subjects sensitized to PPD. The trial, which carried out at four dermatology centers, included subjects sensitized to PPD that turned out negative to patch testing to PTD. The subjects underwent to an open test consisting in the application of two hair dye colors of the product under examination. Finally, subjects who were negative upon the open test were offered to undergo the usage test with the dye, with dermatological evaluations carried out 48 and 96 hours after product application. Sixty subjects were enrolled. They underwent the open test with two shades of dyes: "color 1 - black," the dye color with the highest concentration of color intermediates, and "color 7.3 - golden blonde," the dye color with the highest number of chemically different color intermediates. No reactions occurred with "color 7.3 - golden blonde," while 3 cases (3 out of 60) showed erythema and edema reactions to color 1. The hair dye usage test was negative for all the 21 subjects that were enrolled. The hair dye evaluated in this study (Shine On, BioNike) can be a valid alternative for subjects sensitized to PPD.

Female pattern hair loss.

PubMed

Ioannides, Dimitrios; Lazaridou, Elizabeth

2015-01-01

Female pattern hair loss, or female pattern androgenetic alopecia, is a nonscarring alopecia with a multi-factorial etiology that mostly affects postmenopausal women and is characterized by a reduction in hair density over the crown and frontal scalp. The clinical picture is characterized by a diffuse rarefaction of scalp hair over the mid-frontal scalp and a more-or-less intact frontal hairline without any signs of inflammation or scarring. Although the disease poses only a cosmetic concern, it is chronic and may have a significant negative psychological impact on the affected person. The aim of treating female pattern hair loss is to reduce hair loss and, to a certain extent, succeed in promoting hair regrowth. Various treatment methods are available, but it remains unclear which are the most effective. Early initiation of treatment and the combination of various modalities seem to be more efficacious than monotherapy. © 2015 S. Karger AG, Basel.

Module Based Complexity Formation: Periodic Patterning in Feathers and Hairs

PubMed Central

Chuong, Cheng-Ming; Yeh, Chao-Yuan; Jiang, Ting-Xin; Widelitz, Randall

2012-01-01

Patterns describe order which emerges from homogeneity. Complex patterns on the integument are striking because of their visibility throughout an organism's lifespan. Periodic patterning is an effective design because the ensemble of hair or feather follicles (modules) allows the generation of complexity, including regional variations and cyclic regeneration, giving the skin appendages a new lease on life. Spatial patterns include the arrangements of feathers and hairs in specified number, size, and spacing. We explore how a field of equivalent progenitor cells can generate periodically arranged modules based on genetic information, physical-chemical rules and developmental timing. Reconstitution experiments suggest a competitive equilibrium regulated by activators / inhibitors involving Turing reaction-diffusion. Temporal patterns result from oscillating stem cell activities within each module (micro-environment regulation), reflected as growth (anagen) and resting (telogen) phases during the cycling of feather and hair follicles. Stimulating modules with activators initiates the spread of regenerative hair waves, while global inhibitors outside each module (macro-environment) prevent this. Different wave patterns can be simulated by Cellular Automata principles. Hormonal status and seasonal changes can modulate appendage phenotypes, leading to “organ metamorphosis”, with multiple ectodermal organ phenotypes generated from the same precursors. We discuss potential evolutionary novel steps using this module based complexity in several amniote integument organs, exemplified by the spectacular peacock feather pattern. We thus explore the application of the acquired knowledge of patterning in tissue engineering. New hair follicles can be generated after wounding. Hairs and feathers can be reconstituted through self-organization of dissociated progenitor cells. PMID:23539312

Module-based complexity formation: periodic patterning in feathers and hairs.

PubMed

Chuong, Cheng-Ming; Yeh, Chao-Yuan; Jiang, Ting-Xin; Widelitz, Randall

2013-01-01

Patterns describe order which emerges from homogeneity. Complex patterns on the integument are striking because of their visibility throughout an organism’s lifespan. Periodic patterning is an effective design because the ensemble of hair or feather follicles (modules) allows the generation of complexity, including regional variations and cyclic regeneration, giving the skin appendages a new lease on life. Spatial patterns include the arrangements of feathers and hairs in specific number, size, and spacing.We explorehowa field of equivalent progenitor cells can generate periodically arranged modules based on genetic information, physical–chemical rules and developmental timing. Reconstitution experiments suggest a competitive equilibrium regulated by activators/inhibitors involving Turing reaction-diffusion. Temporal patterns result from oscillating stem cell activities within each module (microenvironment regulation), reflected as growth (anagen) and resting (telogen) phases during the cycling of feather and hair follicles. Stimulating modules with activators initiates the spread of regenerative hair waves, while global inhibitors outside each module (macroenvironment) prevent this. Different wave patterns can be simulated by cellular automata principles. Hormonal status and seasonal changes can modulate appendage phenotypes, leading to ‘organ metamorphosis’, with multiple ectodermal organ phenotypes generated from the same precursors. We discuss potential novel evolutionary steps using this module-based complexity in several amniote integument organs, exemplified by the spectacular peacock feather pattern. We thus explore the application of the acquired knowledge of patterning in tissue engineering. New hair follicles can be generated after wounding. Hairs and feathers can be reconstituted through self-organization of dissociated progenitor cells. © 2012 Wiley Periodicals, Inc.

Optical coherence tomography using images of hair structure and dyes penetrating into the hair.

PubMed

Tsugita, Tetsuya; Iwai, Toshiaki

2014-11-01

Hair dyes are commonly evaluated by the appearance of the hair after dyeing. However, this approach cannot simultaneously assess how deep the dye has penetrated into hair. For simultaneous assessment of the appearance and the interior of hair, we developed a visible-range red, green, and blue (RGB) (three primary colors)-optical coherence tomography (OCT) using an RGB LED light source. We then evaluated a phantom model based on the assumption that the sample's absorbability in the vertical direction affects the tomographic imaging. Consistent with theory, our device showed higher resolution than conventional OCT with far-red light. In the experiment on the phantom model, we confirmed that the tomographic imaging is affected by absorbability unique to the sample. Furthermore, we verified that permeability can be estimated from this tomographic image. We also identified for the first time the relationship between penetration of the dye into hair and characteristics of wavelength by tomographic imaging of dyed hair. We successfully simultaneously assessed the appearance of dyed hair and inward penetration of the dye without preparing hair sections. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Keratins and lipids in ethnic hair.

PubMed

Cruz, C F; Fernandes, M M; Gomes, A C; Coderch, L; Martí, M; Méndez, S; Gales, L; Azoia, N G; Shimanovich, U; Cavaco-Paulo, A

2013-06-01

Human hair has an important and undeniable relevance in society due to its important role in visual appearance and social communication. Hair is mainly composed of structural proteins, mainly keratin and keratin associated proteins and lipids. Herein, we report a comprehensive study of the content and distribution of the lipids among ethnic hair, African, Asian and Caucasian hair. More interestingly, we also report the study of the interaction between those two main components of hair, specifically, the influence of the hair internal lipids in the structure of the hair keratin. This was achieved by the use of a complete set of analytical tools, such as thin layer chromatography-flame ionization detector, X-ray analysis, molecular dynamics simulation and confocal microscopy. The experimental results indicated different amounts of lipids on ethnic hair compositions and higher percentage of hair internal lipids in African hair. In this type of hair, the axial diffraction of keratin was not observed in X-ray analysis, but after hair lipids removal, the keratin returned to its typical packing arrangement. In molecular dynamic simulation, lipids were shown to intercalate dimers of keratin, changing its structure. From those results, we assume that keratin structure may be influenced by higher concentration of lipids in African hair. © 2013 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Hair straightener poisoning

MedlinePlus

... this page: //medlineplus.gov/ency/article/002706.htm Hair straightener poisoning To use the sharing features on this page, please enable JavaScript. Hair straightener poisoning occurs when someone swallows products that ...

Hair spray poisoning

MedlinePlus

... this page: //medlineplus.gov/ency/article/002705.htm Hair spray poisoning To use the sharing features on this page, please enable JavaScript. Hair spray poisoning occurs when someone breathes in (inhales) ...

Perturbation of longitudinal relaxation rate in rotating frame (PLRF) analysis for quantification of chemical exchange saturation transfer signal in a transient state.

PubMed

Wang, Yi; Zhang, Yaoyu; Zhao, Xuna; Wu, Bing; Gao, Jia-Hong

2017-11-01

To develop a novel analytical method for quantification of chemical exchange saturation transfer (CEST) in the transient state. The proposed method aims to reduce the effects of non-chemical-exchange (non-CE) parameters on the CEST signal, emphasizing the effect of chemical exchange. The difference in the longitudinal relaxation rate in the rotating frame ( ΔR1ρ) was calculated based on perturbation of the Z-value by R1ρ, and a saturation-pulse-amplitude-compensated exchange-dependent relaxation rate (SPACER) was determined with a high-exchange-rate approximation. In both phantom and human subject experiments, MTRasym (representative of the traditional CEST index), ΔR1ρ, and SPACER were measured, evaluated, and compared by altering the non-CE parameters in a transient-state continuous-wave CEST sequence. In line with the theoretical expectation, our experimental data demonstrate that the effects of the non-CE parameters can be more effectively reduced using the proposed indices (  ΔR1ρ and SPACER) than using the traditional CEST index ( MTRasym). The proposed method allows for the chemical exchange weight to be better emphasized in the transient-state CEST signal, which is beneficial, in practice, for quantifying the CEST signal. Magn Reson Med 78:1711-1723, 2017. © 2016 International Society for Magnetic Resonance in Medicine. © 2016 International Society for Magnetic Resonance in Medicine.

Three-dimensional architecture of macrofibrils in the human scalp hair cortex.

PubMed

Harland, Duane P; Walls, Richard J; Vernon, James A; Dyer, Jolon M; Woods, Joy L; Bell, Fraser

2014-03-01

Human scalp hairs are comprised of a central cortex enveloped by plate-like cuticle cells. The elongate cortex cells of mature fibres are composed primarily of macrofibrils-bundles of hard-keratin intermediate filaments (IFs) chemically cross-linked within a globular protein matrix. In wool, three cell types (ortho-, meso- and paracortex) contain macrofibrils with distinctly different filament arrangements and matrix fractions, but in human hair macrofibril-cell type relationships are less clear. Here we show that hair macrofibrils all have a similar matrix fraction (∼0.4) and are typically composed of a double-twist architecture in which a central IF is surrounded by concentric rings of tangentially-angled IFs. The defining parameter is the incremental angle increase (IF-increment) between IFs of successive rings. Unlike the wool orthocortex, hair double-twist macrofibrils have considerable inter-macrofibril variation in IF increment (0.05-0.35°/nm), and macrofibril size and IF increment are negatively correlated. Correspondingly, angular difference between central and outer-most IFs is up to 40° in small macrofibrils, but only 5-10° in large macrofibrils. Single cells were observed containing mixtures of macrofibrils with different diameters. These new observations advance our understanding of the nano-level and cell-level organisation of human hair, with implications for interpretation of structure with respect the potential roles of cortex cell types in defining the mechanical properties of hair. Copyright © 2014 Elsevier Inc. All rights reserved.

Protection of oxidative hair color fading from shampoo washing by hydrophobically modified cationic polymers.

PubMed

Zhou, Y; Foltis, L; Moore, D J; Rigoletto, R

2009-01-01

The fading of oxidative color in hair as a result of daily shampoo washing activities has become a common problem and a source of frequent complaints by consumers. The fading occurs primarily through hair dye solubility in water. One aspect of the current study investigates the physical and chemical factors that influence hair color fading during the washing process. This is accomplished by testing hair dye dissolution in water from dyed hair samples with variation of surfactant type, pH, and hair type. Furthermore, a new approach to preventing color fading is developed aiming to provide an effective barrier function for hair dye from dissolving into water. The preliminary investigation of a series of polymers with various functional groups indicates that polymers with hydrophobically modified and cationic functionalities are most effective in preventing hair dye dissolution in water. It is also evident that a synergistic effect of the polymer's hydrophobic moieties and cationic charges are important on hair color protection during shampoo washing processes. A primary example of a polymer within this category is a cationic terpolymer of vinylpyrrolidone, dimethylaminopropyl methacrylamide, and methacryloylaminopropyl lauryldimonium chloride (INCI: Polyquaternium-55). The color protection benefit of this polymer is evaluated using newly developed methodologies for evaluating hair color changes, such as hair color fading tests through multiple shampoo washes with mannequin heads and hair tresses, both derived from human hair, colorimetry, and quantitative digital image analysis. In addition, new infrared spectroscopic imaging techniques are used to detect the hair dye deposition behavior inside hair fibers both with and without the color protection treatment. Both visual and instrumental measurement results indicate that Polyquaternium-55 provides a high level of color protection when formulated in a hair color protection regimen with up to 50% color protection. This

Solid-state fermentation and composting as alternatives to treat hair waste: A life-cycle assessment comparative approach.

PubMed

Catalán, Eva; Komilis, Dimitrios; Sánchez, Antoni

2017-07-01

One of the wastes associated with leather production in tannery industries is the hair residue generated during the dehairing process. Hair wastes are mainly dumped or managed through composting but recent studies propose the treatment of hair wastes through solid-state fermentation (SSF) to obtain proteases and compost. These enzymes are suitable for its use in an enzymatic dehairing process, as an alternative to the current chemical dehairing process. In the present work, two different scenarios for the valorization of the hair waste are proposed and assessed by means of life-cycle assessment: composting and SSF for protease production. Detailed data on hair waste composting and on SSF protease production are gathered from previous studies performed by our research group and from a literature survey. Background inventory data are mainly based on Ecoinvent version 3 from software SimaPro® 8. The main aim of this study was to identify which process results in the highest environmental impact. The SSF process was found to have lower environmental impacts than composting, due to the fact that the enzyme use in the dehairing process prevents the use of chemicals traditionally used in the dehairing process. This permits to reformulate an industrial process from the classical approach of waste management to a novel alternative based on circular economy.

Uncovering the structure of human red hair pheomelanin: benzothiazolylthiazinodihydroisoquinolines as key building blocks.

PubMed

Greco, Giorgia; Panzella, Lucia; Verotta, Luisella; d'Ischia, Marco; Napolitano, Alessandra

2011-04-25

Biomimetic oxidation of the pheomelanin precursor 5-S-cysteinyldopa in the presence of Zn(2+) ions led to the isolation of two isomeric products, one of which could be identified as the benzothiazolylthiazinodihydroisoquinoline 5, while the other proved too unstable for a complete characterization. Both these products were converted into more stable oxidized forms, which after ethylchloroformate derivatization were characterized as the ethyl ester/ethoxycarbonyl isoquinolines 8 and 9. Compound 5 exhibited absorption characteristics similar to those of red hair pheomelanin, including a main band around 400 nm in acids. Similarly to red hair pheomelanin and synthetic pigments, 5 afforded on chemical degradation a thiazolylpyridinecarboxylic acid fragment. Model chemical studies allowed the proposal of a formation mechanism for the benzothiazole and dihydroisoquinoline systems in compound 5.

Coping with cancer - hair loss

MedlinePlus

Cancer treatment - alopecia; Chemotherapy - hair loss; Radiation - hair loss ... Many chemotherapy drugs attack fast-growing cells. This is because cancer cells divide rapidly. Since the cells in hair ...

Managing hair loss in midlife women.

PubMed

Mirmirani, Paradi

2013-02-01

Hair is considered one of the most defining aspects of human appearance. Hair loss, or alopecia in women is often met with significant emotional distress and anxiety. In midlife, women may encounter various hormonal and age-related physiologic changes that can lead to alterations in hair texture and growth. The most significant hormonal alteration is the onset of menopause in which there is a cessation of ovarian estrogen production. This decrease in estrogen is known to have deleterious effects on the skin and cutaneous appendages. As our understanding of the molecular and hormonal controls on the hair follicle has grown, there has been increased interest in the various modulators of hair growth, including the potential role of estrogen. Further study of hair changes in midlife women provides an important opportunity for identification of the complex regulation of hair growth as well as identification of treatment targets that may specifically benefit women. In this review, management of hair loss in midlife women is discussed with a focus on three most commonly encountered clinical conditions: female pattern hair loss, hair shaft alterations due to hair care, and telogen effluvium. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Contact allergy to ingredients of hair cosmetics - a comparison of female hairdressers and clients based on IVDK 2007-2012 data.

PubMed

Uter, Wolfgang; Gefeller, Olaf; John, Swen Malte; Schnuch, Axel; Geier, Johannes

2014-07-01

Cosmetics for bleaching, waving/relaxing and dyeing hair contain well-known allergens, leading to a substantial number of cases of allergic contact dermatitis. To compare the frequency of important contact allergens (i) between two distinct groups of exposed patients, and (ii) with previous surveillance data. On the basis of data collected by the Information Network of Departments of Dermatology (IVDK; www.ivkd.org) between 2007 and 2012 in 824 female hairdressers and 2067 female clients, the current spectrum of contact sensitization to ingredients of hair cosmetics, as contained in different pertinent series, is described. A similar burden of sensitization as in previous analyses was observed, but with some increase in sensitization to oxidative hair dye components in clients. Some allergens mainly affected hairdressers, such as ammonium persulfate (18.7% positive) and glyceryl monothioglycolate (GMTG; still 4.7% positive, with a few cases also in young hairdressers, despite removal from the German market). Hair dyes remain important contact allergens, despite various attempts by the cosmetic industry to introduce hair dyes with lower allergenic potential. The re-emergence of GMTG as an occupational allergen should be considered as a warning signal ('sentinel event') prompting close monitoring. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Strontium-90 in hair.

PubMed

HOPKINS, B J; TUTTLE, L W; PORIES, W J; STRAIN, W H

1963-03-15

The hair of rats injected with strontium-90 retains a significant amount of the radionuclide. Although the strontium-90 content of hair is variable in these rats and appears to be subject to a variety of influences, determination of the radionuclide content of hair may offer a nondestructive method of estimating strontium-90 in bone.

Excessive or unwanted hair in women

MedlinePlus

Hypertrichosis; Hirsutism; Hair - excessive (women); Excessive hair in women; Hair - women - excessive or unwanted ... much of this hormone, you may have unwanted hair growth. In most cases, the exact cause is ...

Duration of detection of methamphetamine in hair after abstinence.

PubMed

Suwannachom, Natiprada; Thananchai, Thiwaphorn; Junkuy, Anongphan; O'Brien, Timothy E; Sribanditmongkol, Pongruk

2015-09-01

Researchers in the field of hair analysis have known for at least two decades that test results for many chemical compounds remain positive for a considerable period of time after subjects have reported cessation of use. These findings were generally based on small sample populations or individual case studies. Within the last decade, hair analyses of larger populations have investigated the phenomenon of residual positives in abstinent individuals in order to determine the period of time required for various compounds to present negative hair test results at internationally accepted cutoff levels. Such data has primarily been used to establish guidelines for retesting former abusers of illicit drugs in order to evaluate claims of abstinence. To date, research has focused on cocaine and opiates. The present study is the first to examine the duration of detection of methamphetamine (MA) and its metabolite amphetamine (AP) in the hair of chronic MA users who recently ceased their consumption of the drug. The study population (n=63) consisted of inpatients at a hospital drug rehabilitation program in Chiang Mai, Thailand. Drug taking behavior was collected by personal interview at the time of enrollment. Subjects provided hair samples at approximately monthly intervals for MA and AP analysis by gas chromatography-mass spectrometry at 0.2ng/mg cutoff levels. The correlation of baseline MA and AP concentrations in hair at the beginning of abstinence with corresponding duration of detection indicated great individual variability for the rate of clearance of MA and AP from hair. In regard to duration of detection, the majority of chronic MA users remained MA positive for up to about 90 days of reported abstinence, but by 120 days, the detection rate had fallen to about 16%. All subjects tested negative for MA after 153 days of abstinence. For AP, the limit of the duration of detection was reached at 106 days. With the adoption of a margin of safety to compensate for

Essentials of Hair Care often Neglected: Hair Cleansing

PubMed Central

Draelos, Zoe D

2010-01-01

Why does the selection of hair cleansing products and conditioners seem complex? Why are there clear, opalescent, green, blue, glittery, cheap, expensive, thick, thin, fragrant, and unscented varieties of shampoos and conditioners? Why the whole cleansing process cannot be simplified by using the same bar soap used on the body for the hair? Does the shampoo selected really make a difference? What can a conditioner accomplish? PMID:21188020

Targeting of CXXC5 by a Competing Peptide Stimulates Hair Regrowth and Wound-Induced Hair Neogenesis.

PubMed

Lee, Soung-Hoon; Seo, Seol Hwa; Lee, Dong-Hwan; Pi, Long-Quan; Lee, Won-Soo; Choi, Kang-Yell

2017-11-01

The Wnt/β-catenin pathway has been implicated in hair follicle development and hair regeneration in adults. We discovered that CXXC-type zinc finger protein 5 (CXXC5) is a negative regulator of the Wnt/β-catenin pathway involved in hair regrowth and wound-induced hair follicle neogenesis via an interaction with Dishevelled. CXXC5 was upregulated in miniaturized hair follicles and arrector pili muscles in human balding scalps. The inhibitory effects of CXXC5 on alkaline phosphatase activity and cell proliferation were demonstrated using human hair follicle dermal papilla cells. Moreover, CXXC5 -/- mice displayed accelerated hair regrowth, and treatment with valproic acid, a glycogen synthase kinase 3β inhibitor that activates the Wnt/β-catenin pathway, further induced hair regrowth in the CXXC5 -/- mice. Disrupting the CXXC5-Dishevelled interaction with a competitor peptide activated the Wnt/β-catenin pathway and accelerated hair regrowth and wound-induced hair follicle neogenesis. Overall, these findings suggest that the CXXC5-Dishevelled interaction is a potential target for the treatment of hair loss. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

Aging changes in hair and nails

MedlinePlus

... page: //medlineplus.gov/ency/article/004005.htm Aging changes in hair and nails To use the sharing ... you age, your hair and nails begin to change. HAIR CHANGES AND THEIR EFFECTS Hair color change . ...

Effect of SDS on human hair: Study on the molecular structure and morphology.

PubMed

Singh, Bhawana; Umapathy, Siva

2011-05-01

This paper presents a model study to understand the effect of surfactants on the physicochemical properties of human hair. FT-IR ATR spectroscopy has been employed to understand the chemical changes induced by sodium dodecyl sulfate (SDS) on human scalp hair. In particular, the SDS induced changes in the secondary structure of protein present in the outer protective layer of hair, i.e. cuticle, have been investigated. Conformational changes in the secondary structure of protein were studied by curve fitting of the amide I band after every phase of SDS treatment. It has been found that SDS brings rearrangements in the protein backbone conformations by transforming β -sheet structure to random coil and β -turn. Additionally, AFM and SEM studies were carried out to understand the morphological changes induced on the hair surface. SEM and AFM images demonstrated the rupture and partial erosion of cuticle sublayers. Copyright © 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Health status by gender, hair color, and eye color: Red-haired women are the most divergent

PubMed Central

Frost, Peter; Kleisner, Karel

2017-01-01

Red hair is associated in women with pain sensitivity. This medical condition, and perhaps others, seems facilitated by the combination of being red-haired and female. We tested this hypothesis by questioning a large sample of Czech and Slovak respondents about the natural redness and darkness of their hair, their natural eye color, their physical and mental health (24 categories), and other personal attributes (height, weight, number of children, lifelong number of sexual partners, frequency of smoking). Red-haired women did worse than other women in ten health categories and better in only three, being particularly prone to colorectal, cervical, uterine, and ovarian cancer. Red-haired men showed a balanced pattern, doing better than other men in three health categories and worse in three. Number of children was the only category where both male and female redheads did better than other respondents. We also confirmed earlier findings that red hair is naturally more frequent in women than in men. Of the ‘new’ hair and eye colors, red hair diverges the most from the ancestral state of black hair and brown eyes, being the most sexually dimorphic variant not only in population frequency but also in health status. This divergent health status may have one or more causes: direct effects of red hair pigments (pheomelanins) or their by-products; effects of other genes that show linkage with genes involved in pheomelanin production; excessive prenatal exposure to estrogen (which facilitates expression of red hair during fetal development and which, at high levels, may cause health problems later in life); evolutionary recentness of red hair and corresponding lack of time to correct negative side effects; or genetic incompatibilities associated with the allele Val92Met, which seems to be of Neanderthal origin and is one of the alleles that can cause red hair. PMID:29284020

Health status by gender, hair color, and eye color: Red-haired women are the most divergent.

PubMed

Frost, Peter; Kleisner, Karel; Flegr, Jaroslav

2017-01-01

Red hair is associated in women with pain sensitivity. This medical condition, and perhaps others, seems facilitated by the combination of being red-haired and female. We tested this hypothesis by questioning a large sample of Czech and Slovak respondents about the natural redness and darkness of their hair, their natural eye color, their physical and mental health (24 categories), and other personal attributes (height, weight, number of children, lifelong number of sexual partners, frequency of smoking). Red-haired women did worse than other women in ten health categories and better in only three, being particularly prone to colorectal, cervical, uterine, and ovarian cancer. Red-haired men showed a balanced pattern, doing better than other men in three health categories and worse in three. Number of children was the only category where both male and female redheads did better than other respondents. We also confirmed earlier findings that red hair is naturally more frequent in women than in men. Of the 'new' hair and eye colors, red hair diverges the most from the ancestral state of black hair and brown eyes, being the most sexually dimorphic variant not only in population frequency but also in health status. This divergent health status may have one or more causes: direct effects of red hair pigments (pheomelanins) or their by-products; effects of other genes that show linkage with genes involved in pheomelanin production; excessive prenatal exposure to estrogen (which facilitates expression of red hair during fetal development and which, at high levels, may cause health problems later in life); evolutionary recentness of red hair and corresponding lack of time to correct negative side effects; or genetic incompatibilities associated with the allele Val92Met, which seems to be of Neanderthal origin and is one of the alleles that can cause red hair.

[Tufted hair folliculitis].

PubMed

Trüeb, R M; Pericin, M; Hafner, J; Burg, G

1997-04-01

A case of tufted hair folliculutis presenting as circumscribed, tender and inflamed areas in the occiput with residual tufted follicles in a 28-year old man is reported. Tufted hair folliculitis is a characteristic localized scarring bacterial folliculitis of the scalp due to Staphylococcus aureus. Histopathological studies reveal perifollicular inflammation around the upper portions of the follicles sparing the hair root level. Within areas of inflammation, several follicles converge toward a common follicular duct with a widely dilated opening. Currently, tufted hair folliculitis is considered a variant of folliculitis decalvans of Quinquaud. Staphylococcal infection is believed to be an initial causative factor, and underlying differences in follicular anatomy or host response may be important in determining which reaction pattern occurs in an affected individual. The development of atrophy with loss of adnexal structures (in folliculitis decalvans) or of hair tufts (in tufting folliculitis) may depend upon the depth and destructive potential of the inflammatory process. The therapeutic approach is problematic; prolonged treatment with oral antibiotics may stabilize the disease, but good and at times more definitive results (as in the presented case) have been reported after radical surgical excision of the involved areas.

Feather keratin hydrolysates obtained from microbial keratinases: effect on hair fiber

PubMed Central

2013-01-01

Background Hair is composed mainly of keratin protein and a small amount of lipid. Protein hydrolysates, in particular those with low molecular weight distribution have been known to protect hair against chemical and environmental damage. Many types of protein hydrolysates from plants and animals have been used in hair and personal care such as keratin hydrolysates obtained from nails, horns and wool. Most of these hydrolysates are obtained by chemical hydrolysis and hydrothermal methods, but recently hydrolyzed hair keratin, feather keratin peptides, and feather meal peptides have been obtained by enzymatic hydrolysis using Bacillus spp in submerged fermentation. Results Keratin peptides were obtained by enzymatic hydrolysis of keratinases using Bacillus subtilis AMR. The microorganism was grown on a feather medium, pH 8.0 (1% feathers) and supplemented with 0.01% of yeast extract, for 5 days, at 28°C with agitation. The supernatant containing the hydrolysates was colleted by centrifugation and ultra filtered in an AMICON system using nano–membranes (Millipore – YC05). The Proteins and peptides were analyzed using HPTLC and MALDI-TOF-MS. Commercial preparations of keratin hydrolysates were used as a comparative standard. After five days the feather had been degraded (90-95%) by the peptidases and keratinases of the microorganism. MALDI-TOF mass spectrometry showed multiple peaks that correspond to peptides in the range of 800 to 1079 Daltons and the commercial hydrolysate was in the range of 900 to 1400 Da. HPTLC showed lower molecular mass peptides and amino acids in the enzymatic hydrolysate when compared with the commercial hydrolysate . A mild shampoo and a rinse off conditioner were formulated with the enzymatic hydrolysate and applied to hair fibers to evaluate the hydration, with and without heat, using a Corneometer® CM 825. The hydration was more efficient with heat, suggesting a more complete incorporation of hydrolysates into the fibers

The structure of people's hair.

PubMed

Yang, Fei-Chi; Zhang, Yuchen; Rheinstädter, Maikel C

2014-01-01

Hair is a filamentous biomaterial consisting mainly of proteins in particular keratin. The structure of human hair is well known: the medulla is a loosely packed, disordered region near the centre of the hair surrounded by the cortex, which contains the major part of the fibre mass, mainly consisting of keratin proteins and structural lipids. The cortex is surrounded by the cuticle, a layer of dead, overlapping cells forming a protective layer around the hair. The corresponding structures have been studied extensively using a variety of different techniques, such as light, electron and atomic force microscopes, and also X-ray diffraction. We were interested in the question how much the molecular hair structure differs from person to person, between male and female hair, hair of different appearances such as colour and waviness. We included hair from parent and child, identical and fraternal twins in the study to see if genetically similar hair would show similar structural features. The molecular structure of the hair samples was studied using high-resolution X-ray diffraction, which covers length scales from molecules up to the organization of secondary structures. Signals due to the coiled-coil phase of α-helical keratin proteins, intermediate keratin filaments in the cortex and from the lipid layers in the cell membrane complex were observed in the specimen of all individuals, with very small deviations. Despite the relatively small number of individuals (12) included in this study, some conclusions can be drawn. While the general features were observed in all individuals and the corresponding molecular structures were almost identical, additional signals were observed in some specimen and assigned to different types of lipids in the cell membrane complex. Genetics seem to play a role in this composition as identical patterns were observed in hair from father and daughter and identical twins, however, not for fraternal twins. Identification and characterization

28 CFR 551.4 - Hair length.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 28 Judicial Administration 2 2013-07-01 2013-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service or...

28 CFR 551.4 - Hair length.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 28 Judicial Administration 2 2014-07-01 2014-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service or...

28 CFR 551.4 - Hair length.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 28 Judicial Administration 2 2012-07-01 2012-07-01 false Hair length. 551.4 Section 551.4 Judicial... Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The Warden shall require an inmate with long hair to wear a cap or hair net when working in food service or...

Recent Trends in Analytical Methods to Determine New Psychoactive Substances in Hair

PubMed Central

Kyriakou, Chrystalla; Pellegrini, Manuela; García-Algar, Oscar; Marinelli, Enrico; Zaami, Simona

2017-01-01

New Psychoactive Substances (NPS) belong to several chemical classes, including phenethylamines, piperazines, synthetic cathinones and synthetic cannabinoids. Development and validation of analytical methods for the determination of NPS both in traditional and alternative matrices is of crucial importance to study drug metabolism and to associate consumption to clinical outcomes and eventual intoxication symptoms. Among different biological matrices, hair is the one with the widest time window to investigate drug-related history and demonstrate past intake. The aim of this paper was to overview the trends of the rapidly evolving analytical methods for the determination of NPS in hair and the usefulness of these methods when applied to real cases. A number of rapid and sensitive methods for the determination of NPS in hair matrix has been recently published, most of them using liquid chromatography coupled to mass spectrometry. Hair digestion and subsequent solid phase extraction or liquid-liquid extraction were described as well as extraction in organic solvents. For most of the methods limits of quantification at picogram per milligram hair were obtained. The measured concentrations for most of the NPS in real samples were in the range of picograms of drug per milligram of hair. Interpretation of the results and lack of cut-off values for the discrimination between chronic consumption and occasional use or external contamination are still challenging. Methods for the determination of NPS in hair are continually emerging to include as many NPS as possible due to the great demand for their detection. PMID:27834146

Recent Trends in Analytical Methods to Determine New Psychoactive Substances in Hair.

PubMed

Kyriakou, Chrystalla; Pellegrini, Manuela; García-Algar, Oscar; Marinelli, Enrico; Zaami, Simona

2017-01-01

New Psychoactive Substances (NPS) belong to several chemical classes, including phenethylamines, piperazines, synthetic cathinones and synthetic cannabinoids. Development and validation of analytical methods for the determination of NPS both in traditional and alternative matrices is of crucial importance to study drug metabolism and to associate consumption to clinical outcomes and eventual intoxication symptoms. Among different biological matrices, hair is the one with the widest time window to investigate drug-related history and demonstrate past intake. The aim of this paper was to overview the trends of the rapidly evolving analytical methods for the determination of NPS in hair and the usefulness of these methods when applied to real cases. A number of rapid and sensitive methods for the determination of NPS in hair matrix has been recently published, most of them using liquid chromatography coupled to mass spectrometry. Hair digestion and subsequent solid phase extraction or liquid-liquid extraction were described as well as extraction in organic solvents. For most of the methods limits of quantification at picogram per milligram hair were obtained. The measured concentrations for most of the NPS in real samples were in the range of picograms of drug per milligram of hair. Interpretation of the results and lack of cut-off values for the discrimination between chronic consumption and occasional use or external contamination are still challenging. Methods for the determination of NPS in hair are continually emerging to include as many NPS as possible due to the great demand for their detection. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Hair transplantation in patients with inadequate head donor supply using nonhead hair: report of 3 cases.

PubMed

Umar, Sanusi

2011-10-01

Follicular unit extraction is becoming an increasingly popular technique for hair transplantation, as it obviates the linear scarring associated with strip harvesting, and can provide highly presentable results. Using this technique, a few reports have described the small scale use of nonhead hair for head hair transplantation in men with inadequate head hair donor supply. In this report, 3 patients who were severely bald had hair transplanted from the chest, abdomen, legs, shoulders, or beard, as well as the head to achieve full coverage and excellent hairlines. Of the 3 cases, 2 had undergone previously unsuccessful hair transplant surgeries. Approximately 80% to 85% of the transplanted grafts survived. Although hair length and quality, surgery time, and the requirement for improved surgical skills remain challenges when using this technique, the sufficiently good outcomes from these selected candidates suggest that this technique may offer the possibility of restoring even severely bald states to normality in patients who would otherwise not be candidates for traditional hair transplantation surgery.

Harvesting electricity from human hair.

PubMed

Tulachan, Brindan; Singh, Sushil K; Philip, Deepu; Das, Mainak

2016-01-01

Electrical conductivity of human hair is a debatable issue among hair experts and scientists. There are unsubstantiated claims that hair conducts electricity. However, hair experts provided ample evidence that hair is an insulator. Although wet hair exhibited drastic reduction in resistivity; scientists regarded hair as a proton semiconductor at the best. Here, we demonstrate that hair filaments generate electricity on absorbing water vapor between 50 degrees and 80 degrees C. This electricity can operate low power electronic systems. Essentially, we are exposing the hydrated hair polymer to a high temperature (50 degrees-80 degrees C). It has long been speculated that when certain biopolymers are simultaneously hydrated and exposed to high temperature, they exhibit significant proton hopping at a specific temperature regime. This happens due to rapid movement of water molecules on the polymer surface. This lead us to speculate that the observed flow of current is partly ionic and partly due to "proton hopping" in the hydrated nano spaces of hair filament. Such proton hopping is exceptionally high when the hydrated hair polymer is exposed to a temperature between 50 degrees and 80 degrees C. Differential scanning calorimetry data further corroborated the results and indicated that indeed at this temperature range, there is an enormous movement of water molecules on the hair polymer surface. This enormously rapid movement of water molecules lead to the "making and breaking" of innumerable hydrogen bonds and thus resulting in hopping of the protons. What is challenging is "how to tap these hopping protons to obtain useful electricity?" We achieved this by placing a bundle of hair between two different electrodes having different electro negativities, and exposing it to water vapor (water + heat). The two different electrodes offered directionality to the hopping protons and the existing ions and thus resulting in the generation of useful current. Further, by

Does D matter? The role of vitamin D in hair disorders and hair follicle cycling.

PubMed

Amor, Karrie T; Rashid, Rashid M; Mirmirani, Paradi

2010-02-15

The role of vitamin D in the proliferation and differentiation of keratinocytes is well known within the field of dermatology. We sought to evaluate the role that vitamin D and the vitamin D receptor play in the hair cycle and assess how this can be clinically applied to the treatment of hair disorders. A MEDLINE search (1955-July 2009) was preformed to find relevant articles pertaining to vitamin D, the vitamin D receptor, and hair loss. The vitamin D receptor, independent of vitamin D, plays an important role in hair cycling, specifically anagen initiation. The role of vitamin D in hair follicle cycling is not as well understood. The review is broad and there are limited human studies available to date. Additional studies to evaluate the role of vitamin D in the hair cycle should be done. Treatments that up regulate the vitamin D receptor may be successful in treating hair disorders and are a potential area of further study.

Longitudinal relaxation optimized amide 1H-CEST experiments for studying slow chemical exchange processes in fully protonated proteins.

PubMed

Yuwen, Tairan; Kay, Lewis E

2017-04-01

Chemical Exchange Saturation Transfer (CEST) experiments are increasingly used to study slow timescale exchange processes in biomolecules. Although 15 N- and 13 C-CEST have been the approaches of choice, the development of spin state selective 1 H-CEST pulse sequences that separate the effects of chemical and dipolar exchange [T. Yuwen, A. Sekhar and L. E. Kay, Angew Chem Int Ed Engl 2016 doi: 10.1002/anie.201610759 (Yuwen et al. 2017)] significantly increases the utility of 1 H-based experiments. Pulse schemes have been described previously for studies of highly deuterated proteins. We present here longitudinal-relaxation optimized amide 1 H-CEST experiments for probing chemical exchange in protonated proteins. Applications involving a pair of proteins are presented establishing that accurate 1 H chemical shifts of sparsely populated conformers can be obtained from simple analyses of 1 H-CEST profiles. A discussion of the inherent differences between 15 N-/ 13 C- and 1 H-CEST experiments is presented, leading to an optimal strategy for recording 1 H-CEST experiments.

Hair restoration surgery: challenges and solutions

PubMed Central

Rose, Paul T

2015-01-01

Hair loss is a common problem affecting both men and women. The most frequent etiology is androgenetic alopecia, but other causes of hair loss such as trauma, various dermatologic diseases, and systemic diseases can cause alopecia. The loss of hair can have profound effects on one’s self esteem and emotional well-being, as one’s appearance plays a role in the work place and interpersonal relationships. It is therefore not surprising that means to remedy hair loss are widely sought. Hair transplant surgery has become increasingly popular, and the results that we are able to create today are quite remarkable, providing a natural appearance when the procedure is performed well. In spite of this, hair transplant surgery is not perfect. It is not perfect because the hair transplant surgeon is still faced with challenges that prevent the achievement of optimal results. Some of these challenges include a limit to donor hair availability, hair survival, and ways to conceal any evidence of a surgical procedure having taken place. This article examines some of the most important challenges facing hair restoration surgery today and possible solutions to these challenges. PMID:26203266

Co-composting of hair waste from the tanning industry with de-inking and municipal wastewater sludges.

PubMed

Barrena, Raquel; Pagans, Estel la; Artola, Adriana; Vázquez, Felícitas; Sánchez, Antoni

2007-06-01

Production of waste hair in the leather manufacturing industry is increasing every year due to the adoption of hair-save unhairing techniques, leaving the tanners with the problem of coping with yet another solid by-product. Numerous potential strategies for hair utilisation have been proposed. However, the use of hair waste as agricultural fertiliser is one of its most promising applications due to the high nitrogen content of hair. Agricultural value of hair can be increased by composting. This paper deals with the composting of hair from the unhairing of bovine hide. Results indicated that hair cannot be either composted on its own or co-composted with de-inking sludge, a chemical complementary co-substrate. However, good results were obtained when co-composted with raw sludge from a municipal wastewater treatment plant at hair:raw sludge weight ratios 1:1, 1:2 and, 1:4 in lab scale and pilot plant scale composters. In all cases, a more stable product was achieved at the end of the process. Composting in the pilot plant composter was effectively monitored using Static Respiration Indices determined at process temperature at sampling (SRI(T)) and at 37 degrees C (SRI(37)). Notably, SRI(T) values were more sensitive to changes in the biological activity. In contrast, Respiratory Quotient (RQ) values were not adequate to follow the development of the process.

Hair to document drug-facilitated crimes: four cases involving bromazepam.

PubMed

Villain, Marion; Chèze, Marjorie; Dumestre, Véronique; Ludes, Bertrand; Kintz, Pascal

2004-09-01

The use of a drug to modify a person's behavior for criminal gain is not a recent phenomenon. However, the recent increase in reports of drug-facilitated crimes (sexual assault, so-called DFSA, robbery) has caused alarm in the general public. Drugs used can be difficult to detect (active products at low dosages, chemical instability), possess amnesic properties, and can be quickly cleared from body fluids. In case of long delay between the alleged crime and clinical examination, collection of blood or even urine can be of little value. This is the reason why this laboratory developed an original approach based on hair testing by liquid chromatography-tandem mass spectrometry. To explore the detectability of a single absorption of bromazepam in hair, two volunteers (male and female) received a 6-mg dose. A strand of hair was sampled about one month after exposure and was cut into three segments of 2-cm long. After pulverization, 20 mg of hair was incubated overnight in a phosphate buffer (pH 8.4). The aqueous phase was extracted with 5 mL of a mixture of diethyl ether/methylene chloride (80:20) in the presence of diazepam-d5, which was used as internal standard (IS). Hair extract was separated on a XTerra MS C18 column using a gradient of acetonitrile and formate buffer. Detection was based on two daughter ions: transitions m/z 316.0 to 182.2 and 209.3 and m/z 290.1 to 154.1 and 198.2 for bromazepam and the IS, respectively. In the hair of the two subjects, bromazepam was detected in the proximal segment at 0.8 and 4.7 pg/mg, respectively. Hair analysis was applied to four authentic criminal cases. In the two first cases, bromazepam tested positive in the corresponding hair segment at 5.7, and 10.3 pg/mg. In another case, head hair was sampled 19 weeks after the alleged offense, and its length (< 4 cm) did not allow analysis of the corresponding period. However, 4.1 pg/mg of bromazepam was quantified in the victim's pubic hair. In these three cases, concentrations

Comparative transduction mechanisms of hair cells in the bullfrog uticulus. 2: Sensitivity and response dynamics to hair bundle displacement

NASA Technical Reports Server (NTRS)

Baird, Richard A.

1994-01-01

The present study was motivated by an interest in seeing whether hair cell types in the bullfrog utriculus might differ in their voltage responses to hair bundle displacement. Particular interest was in assessing the contributions of two factors to the responses of utricular hair cells. First, interest in examining the effect of hair bundle morphology on the sensitivity of hair cells to natural stimulation was motivated by the observation that vestibular hair cells, unlike many auditory hair cells, are not free-standing but rather linked to an accessory cupular or otolithic membrane via the tip of their kinocilium. Interest also laid in examining the contribution, if any, of adaptation to the response properties of utricular hair cells. Hair cells in auditory and vibratory inner ear endorgans adapt to maintained displacements of their hair bundles, sharply limiting their low frequency sensitivity. This adaptation is mediated by a shift in the displacement-response curve (DRC) of the hair cell along the displacement axis. Observations suggest that the adaptation process occurs within the hair bundle and precedes mechanoelectric transduction. Recent observations of time-dependent changes in hair bundle stiffness are consistent with this conclusion. Adaptation would be expected to be most useful in inner ear endorgans in which hair cells are subject to large static displacements that could potentially saturate their instantaneous response and compromise their sensitivity to high frequency stimulation. The adaptation process also permits hair cells to maintain their sensory hair bundle in the most sensitive portion of their DRC. In vestibular otolith organs in which static sensitivity is desirable, any adaptation process in the hair cells may be undesirable. The rate and extent of the decline of the voltage responses was measured of utricular hair cells to step and sinusoidal hair bundle displacements. Then for similar resting potentials and response amplitudes, the

Scanning electron microscopy analysis of hair index on Karachi's population for social and professional appearance enhancement.

PubMed

Ali, N; Zohra, R R; Qader, S A U; Mumtaz, M

2015-06-01

Hair texture, appearance and pigment play an important role in social and professional communication and maintaining an overall appearance. This study was especially designed for morphological assessment of hair damage caused to Karachi's population due to natural factors and cosmetic treatments using scanning electron microscopy (SEM) technique. Hair samples under the study of synthetic factor's effect were given several cosmetic treatments (hot straightened, bleached, synthetic dyed and henna dyed) whereas samples under natural factor's effect (variation in gender, age and pigmentation) were left untreated. Morphological assessment was performed using SEM technique. Results obtained were statistically analysed using minitab 16 and spss 18 softwares. Scanning electron microscopy images revealed less number of cuticular scales in males than females of same age although size of cuticular scales was found to be larger in males than in females. Mean hair index of white hair was greater than black hair of the same head as it is comparatively newly originated. Tukey's method revealed that among cosmetic treatments, bleaching and synthetic henna caused most of the damage to the hair. Statistical evaluation of results obtained from SEM analysis revealed that human scalp hair index show morphological variation with respect to age, gender, hair pigmentation, chemical and physical treatments. Individuals opting for cosmetic treatments could clearly visualize the extent of hair damage these may cause in long run. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Pubic hair and sexuality: a review.

PubMed

Ramsey, Sara; Sweeney, Clare; Fraser, Michael; Oades, Gren

2009-08-01

Hair is a distinguishing feature of mammals, though the persistence of visible head, axillary, and pubic hair remains anthropologically unclear. Humans throughout the ages have modified their head and body hair, but aesthetic removal of pubic hair has become the "the ultimate barometer of how fashionable you really are" in the 21st century. The aim of the article is to examine the trends in pubic hair removal and its impact on health and sexuality. A literature search was performed, with a further search performed using an Internet-based search engine. For discussion, the results have been classified into the topics of "Development and anthropology","Cultural and artistic significance", "Medical implications", "Psychological and sexual significance and popular culture", "Impact of body hair loss on sexuality" and "Style and terminology." Pubic hair removal has been common since the ancient times. Pubic hair was rarely depicted in artistic representations of the nude until the late 19th century. It is postulated that the current trend of pubic hair removal may be related to the increased accessibility of Internet-based pornography. Anecdotally, pubic hair removal may carry benefits regarding increased sexual sensation and satisfaction though there is no quantative research in this field. There is a recognized morbidity to pubic hair removal, and also a lack of standardization of terms for styles adopted. We propose a definitive grading system for male and female body hair based on the widely used Tumor Node Metastasis staging system. Pubic hair removal appears to be an important aspect of expressing one's sexuality and participation in sexual activity. This practice has an interesting psychosexual basis which, to date, has not yet been fully explored in sexual medicine.

Side Effects: Hair Loss (Alopecia)

Cancer.gov

Hair loss, also called alopecia, is a side effect of cancer treatments, such as chemotherapy and radiation therapy. Learn how to cope with and manage hair loss. Listen to tips from others who have experienced hair loss.

The Actions of Calcium on Hair Bundle Mechanics in Mammalian Cochlear Hair Cells

PubMed Central

Beurg, Maryline; Nam, Jong-Hoon; Crawford, Andrew; Fettiplace, Robert

2008-01-01

Sound stimuli excite cochlear hair cells by vibration of each hair bundle, which opens mechanotransducer (MT) channels. We have measured hair-bundle mechanics in isolated rat cochleas by stimulation with flexible glass fibers and simultaneous recording of the MT current. Both inner and outer hair-cell bundles exhibited force-displacement relationships with a nonlinearity that reflects a time-dependent reduction in stiffness. The nonlinearity was abolished, and hair-bundle stiffness increased, by maneuvers that diminished calcium influx through the MT channels: lowering extracellular calcium, blocking the MT current with dihydrostreptomycin, or depolarizing to positive potentials. To simulate the effects of Ca2+, we constructed a finite-element model of the outer hair cell bundle that incorporates the gating-spring hypothesis for MT channel activation. Four calcium ions were assumed to bind to the MT channel, making it harder to open, and, in addition, Ca2+ was posited to cause either a channel release or a decrease in the gating-spring stiffness. Both mechanisms produced Ca2+ effects on adaptation and bundle mechanics comparable to those measured experimentally. We suggest that fast adaptation and force generation by the hair bundle may stem from the action of Ca2+ on the channel complex and do not necessarily require the direct involvement of a myosin motor. The significance of these results for cochlear transduction and amplification are discussed. PMID:18178649

Dark Matter Hairs Around Earth

NASA Image and Video Library

2015-11-23

This illustration shows Earth surrounded by filaments of dark matter called "hairs," which are proposed in a study in the Astrophysical Journal by Gary Prézeau of NASA's Jet Propulsion Laboratory, Pasadena, California. A hair is created when a stream of dark matter particles goes through the planet. According to simulations, the hair is densest at a point called the "root." When particles of a dark matter stream pass through the core of Earth, they form a hair whose root has a particle density about a billion times greater than average. The hairs in this illustration are not to scale. Simulations show that the roots of such hairs can be 600,000 miles (1 million kilometers) from Earth, while Earth's radius is only about 4,000 miles (6,400 kilometers). http://photojournal.jpl.nasa.gov/catalog/PIA20176

Direct Simulation of Magnetic Resonance Relaxation Rates and Line Shapes from Molecular Trajectories

PubMed Central

Rangel, David P.; Baveye, Philippe C.; Robinson, Bruce H.

2012-01-01

We simulate spin relaxation processes, which may be measured by either continuous wave or pulsed magnetic resonance techniques, using trajectory-based simulation methodologies. The spin–lattice relaxation rates are extracted numerically from the relaxation simulations. The rates obtained from the numerical fitting of the relaxation curves are compared to those obtained by direct simulation from the relaxation Bloch–Wangsness–Abragam– Redfield theory (BWART). We have restricted our study to anisotropic rigid-body rotational processes, and to the chemical shift anisotropy (CSA) and a single spin–spin dipolar (END) coupling mechanisms. Examples using electron paramagnetic resonance (EPR) nitroxide and nuclear magnetic resonance (NMR) deuterium quadrupolar systems are provided. The objective is to compare those rates obtained by numerical simulations with the rates obtained by BWART. There is excellent agreement between the simulated and BWART rates for a Hamiltonian describing a single spin (an electron) interacting with the bath through the chemical shift anisotropy (CSA) mechanism undergoing anisotropic rotational diffusion. In contrast, when the Hamiltonian contains both the chemical shift anisotropy (CSA) and the spin–spin dipolar (END) mechanisms, the decay rate of a single exponential fit of the simulated spin–lattice relaxation rate is up to a factor of 0.2 smaller than that predicted by BWART. When the relaxation curves are fit to a double exponential, the slow and fast rates extracted from the decay curves bound the BWART prediction. An extended BWART theory, in the literature, includes the need for multiple relaxation rates and indicates that the multiexponential decay is due to the combined effects of direct and cross-relaxation mechanisms. PMID:22540276

ROOT HAIR DEFECTIVE SIX-LIKE Class I Genes Promote Root Hair Development in the Grass Brachypodium distachyon

PubMed Central

Kim, Chul Min

2016-01-01

Genes encoding ROOT HAIR DEFECTIVE SIX-LIKE (RSL) class I basic helix loop helix proteins are expressed in future root hair cells of the Arabidopsis thaliana root meristem where they positively regulate root hair cell development. Here we show that there are three RSL class I protein coding genes in the Brachypodium distachyon genome, BdRSL1, BdRSL2 and BdRSL3, and each is expressed in developing root hair cells after the asymmetric cell division that forms root hair cells and hairless epidermal cells. Expression of BdRSL class I genes is sufficient for root hair cell development: ectopic overexpression of any of the three RSL class I genes induces the development of root hairs in every cell of the root epidermis. Expression of BdRSL class I genes in root hairless Arabidopsis thaliana root hair defective 6 (Atrhd6) Atrsl1 double mutants, devoid of RSL class I function, restores root hair development indicating that the function of these proteins has been conserved. However, neither AtRSL nor BdRSL class I genes is sufficient for root hair development in A. thaliana. These data demonstrate that the spatial pattern of class I RSL activity can account for the pattern of root hair cell differentiation in B. distachyon. However, the spatial pattern of class I RSL activity cannot account for the spatial pattern of root hair cells in A. thaliana. Taken together these data indicate that that the functions of RSL class I proteins have been conserved among most angiosperms—monocots and eudicots—despite the dramatically different patterns of root hair cell development. PMID:27494519

Nutrition and hair: deficiencies and supplements.

PubMed

Finner, Andreas M

2013-01-01

Hair follicle cells have a high turnover. A caloric deprivation or deficiency of several components, such as proteins, minerals, essential fatty acids, and vitamins, caused by inborn errors or reduced uptake, can lead to structural abnormalities, pigmentation changes, or hair loss, although exact data are often lacking. The diagnosis is established through a careful history, clinical examination of hair loss activity, and hair quality and confirmed through targeted laboratory tests. Examples of genetic hair disorders caused by reduced nutritional components are zinc deficiency in acrodermatitis enteropathica and copper deficiency in Menkes kinky hair syndrome. Copyright © 2013 Elsevier Inc. All rights reserved.

Physiological Maturation of Regenerating Hair Cells

NASA Technical Reports Server (NTRS)

Baird, Richard A.

2003-01-01

The bullfrog saccule, a sensor of gravity and substrate-borne vibration, is a model system for hair cell transduction. Saccular hair cells also increase in number throughout adult life and rapidly recover after hair cell damage, making this organ an ideal system for studying hair cell development, repair, and regeneration. We have used of hair cell and supporting cell immunocytochemical markers to identify damaged hair cells and hair cell precursors in organotypic cultures of the bullfrog saccule. We then used an innovative combination of confocal, electron, and time-lapse microscopy to study the fate of damaged hair cells and the origin of new hair cells after gentamicin ototoxicity in normal and mitotically blocked saccular cultures. These studies have shown that gentamicin ototoxicity produces both lethal and sublethal hair cell damage. They have also shown that hair cell recovery in this organ takes place by both the repair of sublethally damaged hair cells and by the replacement of lost hair cells by mitotic regeneration. In parallel studies, we have used biophysical and molecular biological techniques to study the differentiation and innervation of developing, repairing, and regenerating hair cells. More specifically, we have used RT-PCR to obtain the bullfrog homologues of L-type voltage- gated calcium (L-VGCC) and large-conductance Ca(2+)-activated potassium (BK) channel genes. We have then obtained probes for these genes and, using in situ hybridization, begun to examine their expression in the bullfrog saccule and amphibian papilla. We have also used fluorescent-labeled channel toxins and channel toxin derivatives to determine the time of appearance of L-type voltage-gated calcium (L-VGCC) and Ca(2+)-activated potassium (BK) channels and to study dynamic changes in the number, distribution, and co-localization of these proteins in developing, repairing, and regenerating hair cells. Using time-lapse microscopy, we are also studying the dynamic relationship

Demonstration of protein-based human identification using the hair shaft proteome [Protein-based human identification: A proof of concept using the hair shaft proteome

DOE PAGES

Parker, Glendon J.; Leppert, Tami; Anex, Deon S.; ...

2016-09-07

Human identification from biological material is largely dependent on the ability to characterize genetic polymorphisms in DNA. Unfortunately, DNA can degrade in the environment, sometimes below the level at which it can be amplified by PCR. Protein however is chemically more robust than DNA and can persist for longer periods. Protein also contains genetic variation in the form of single amino acid polymorphisms. These can be used to infer the status of non-synonymous single nucleotide polymorphism alleles. To demonstrate this, we used mass spectrometry-based shotgun proteomics to characterize hair shaft proteins in 66 European-American subjects. A total of 596 singlemore » nucleotide polymorphism alleles were correctly imputed in 32 loci from 22 genes of subjects’ DNA and directly validated using Sanger sequencing. Estimates of the probability of resulting individual non-synonymous single nucleotide polymorphism allelic profiles in the European population, using the product rule, resulted in a maximum power of discrimination of 1 in 12,500. Imputed non-synonymous single nucleotide polymorphism profiles from European–American subjects were considerably less frequent in the African population (maximum likelihood ratio = 11,000). The converse was true for hair shafts collected from an additional 10 subjects with African ancestry, where some profiles were more frequent in the African population. Genetically variant peptides were also identified in hair shaft datasets from six archaeological skeletal remains (up to 260 years old). Furthermore, this study demonstrates that quantifiable measures of identity discrimination and biogeographic background can be obtained from detecting genetically variant peptides in hair shaft protein, including hair from bioarchaeological contexts.« less

Demonstration of protein-based human identification using the hair shaft proteome [Protein-based human identification: A proof of concept using the hair shaft proteome

DOE Office of Scientific and Technical Information (OSTI.GOV)

Parker, Glendon J.; Leppert, Tami; Anex, Deon S.

Human identification from biological material is largely dependent on the ability to characterize genetic polymorphisms in DNA. Unfortunately, DNA can degrade in the environment, sometimes below the level at which it can be amplified by PCR. Protein however is chemically more robust than DNA and can persist for longer periods. Protein also contains genetic variation in the form of single amino acid polymorphisms. These can be used to infer the status of non-synonymous single nucleotide polymorphism alleles. To demonstrate this, we used mass spectrometry-based shotgun proteomics to characterize hair shaft proteins in 66 European-American subjects. A total of 596 singlemore » nucleotide polymorphism alleles were correctly imputed in 32 loci from 22 genes of subjects’ DNA and directly validated using Sanger sequencing. Estimates of the probability of resulting individual non-synonymous single nucleotide polymorphism allelic profiles in the European population, using the product rule, resulted in a maximum power of discrimination of 1 in 12,500. Imputed non-synonymous single nucleotide polymorphism profiles from European–American subjects were considerably less frequent in the African population (maximum likelihood ratio = 11,000). The converse was true for hair shafts collected from an additional 10 subjects with African ancestry, where some profiles were more frequent in the African population. Genetically variant peptides were also identified in hair shaft datasets from six archaeological skeletal remains (up to 260 years old). Furthermore, this study demonstrates that quantifiable measures of identity discrimination and biogeographic background can be obtained from detecting genetically variant peptides in hair shaft protein, including hair from bioarchaeological contexts.« less

Ecklonia cava promotes hair growth.

PubMed

Bak, S S; Ahn, B N; Kim, J A; Shin, S H; Kim, J C; Kim, M K; Sung, Y K; Kim, S K

2013-12-01

Previous studies have reported the protective effects on skin elasticity of the edible marine seaweed Ecklonia cava, which acts through regulation of both antioxidative and anti-inflammatory responses. We evaluated the effect of E. cava and one of its components, dioxinodehydroeckol, on hair-shaft growth in cultured human hair follicles and on hair growth in mice. The MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay was used to check cell viability of human dermal papilla cells (DPCs) and outer root sheath (ORS) cells after treatment with E. cava and its metabolite, dioxinodehydroeckol. Hair-shaft growth was measured using the in vitro hair-follicle organ-culture system, in the presence or absence of E. cava and dioxinodehydroeckol. Anagen induction activity was examined by topical application of E. cava to the dorsal skin of C57BL/6 mice. Insulin-like growth factor (IGF)-1 expression was measured by reverse transcriptase PCR and ELISA. The proliferation activity was found to be highest for the ethyl acetate-soluble fraction of E. cava (EAFE) in DPCs and in ORS cells. Treatment with EAFE resulted in elongation of the hair shaft in cultured human hair follicles, and promoted transition of the hair cycle from the telogen to the anagen phase in the dorsal skin of C57BL/6 mice. In addition, EAFE induced an increase in IGF-1 expression in DPCs. Dioxinodehydroeckol, a component of E. cava, induced elongation of the hair shaft, an increase in proliferation of DPCs and ORS cells, and an increase in expression of IGF-1 in DPCs. These results suggest that E. cava containing dioxinodehydroeckol promotes hair growth through stimulation of DPCs and ORS cells. © 2013 British Association of Dermatologists.

Dark Matter Hairs Around Jupiter

NASA Image and Video Library

2015-11-23

This illustration shows Jupiter surrounded by filaments of dark matter called "hairs," which are proposed in a study in the Astrophysical Journal by Gary Prézeau of NASA's Jet Propulsion Laboratory, Pasadena, California. A hair is created when a stream of dark matter particles goes through the planet. According to simulations, the hair is densest at a point called the "root." When particles of a dark matter stream pass through the core of Jupiter, they form a hair whose root has a particle density about a trillion times greater than average. The size of Jupiter relative to the distance between Jupiter and the hair roots is to scale. http://photojournal.jpl.nasa.gov/catalog/PIA20178

Hair dosimetry following neutron irradiation.

PubMed

Lebaron-Jacobs, L; Gaillard-Lecanu, E; Briot, F; Distinguin, S; Boisson, P; Exmelin, L; Racine, Y; Berard, P; Flüry-Herard, A; Miele, A; Fottorino, R

2007-05-01

Use of hair as a biological dosimeter of neutron exposure was proposed a few years ago. To date, the (32)S(n,p)(32)P reaction in hair with a threshold of 2.5 MeV is the best choice to determine the fast neutron dose using body activation. This information is essential with regards to the heterogeneity of the neutron transfer to the organism. This is a very important parameter for individual dose reconstruction from the surface to the deeper tissues. This evaluation is essential to the adapted management of irradiated victims by specialized medical staff. Comparison exercises between clinical biochemistry laboratories from French sites (the CEA and COGEMA) and from the IRSN were carried out to validate the measurement of (32)P activity in hair and to improve the techniques used to perform this examination. Hair was placed on a phantom and was irradiated at different doses in the SILENE reactor (Valduc, France). Different parameters were tested: variation of hair type, minimum weight of hair sample, hair wash before measurement, delivery period of results, and different irradiation configurations. The results obtained in these comparison exercises by the different laboratories showed an excellent correlation. This allowed the assessment of a dose-activity relationship and confirmed the feasibility and the interest of (32)P measurement in hair following fast neutron irradiation.

Reflectance spectroscopy for evaluating hair follicle cycle

NASA Astrophysics Data System (ADS)

Liu, Caihua; Guan, Yue; Wang, Jianru; Zhu, Dan

2014-02-01

Hair follicle, as a mini-organ with perpetually cycling of telogen, anagen and catagen, provides a valuable experimental model for studying hair and organ regeneration. The transition of hair follicle from telogen to anagen is a significant sign for successful regeneration. So far discrimination of the hair follicle stage is mostly based on canonical histological examination and empirical speculation based on skin color. Hardly a method has been proposed to quantitatively evaluate the hair follicle stage. In this work, a commercial optical fiber spectrometer was applied to monitor diffuse reflectance of mouse skin with hair follicle cycling, and then the change of reflectance was obtained. Histological examination was used to verify the hair follicle stage. In comparison with the histological examination, the skin diffuse reflectance was relatively high for mouse with telogen hair follicles; it decreased once hair follicles transited to anagen stage; then it increased reversely at catagen stage. This study provided a new method to quantitatively evaluate the hair follicle stage, and should be valuable for the basic and therapeutic investigations on hair regeneration.

Post-mortem quetiapine concentrations in hair segments of psychiatric patients - Correlation between hair concentration, dose and concentration in blood.

PubMed

Günther, Kamilla Nyborg; Johansen, Sys Stybe; Nielsen, Marie Katrine Klose; Wicktor, Petra; Banner, Jytte; Linnet, Kristian

2018-04-01

Drug analysis in hair is useful when seeking to establish drug intake over a period of months to years. Segmental hair analysis can also document whether psychiatric patients are receiving a stable intake of antipsychotics. This study describes segmental analysis of the antipsychotic drug quetiapine in post-mortem hair samples from long-term quetiapine users by ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) analysis. The aim was to obtain more knowledge on quetiapine concentrations in hair and to relate the concentration in hair to the administered dose and the post-mortem concentration in femoral blood. We analyzed hair samples from 22 deceased quetiapine-treated individuals, who were divided into two groups: natural hair colour and dyed/bleached hair. Two to six 1cm long segments were analyzed per individual, depending on the length of the hair, with 6cm corresponding to the last six months before death. The average daily quetiapine dose and average concentration in hair for the last six months prior to death were examined for potential correlation. Estimated doses ranged from 45 to 1040mg quetiapine daily over the period, and the average concentration in hair ranged from 0.18 to 13ng/mg. A significant positive correlation was observed between estimated daily dosage of quetiapine and average concentration in hair for individuals with natural hair colour (p=0.00005), but statistical significance was not reached for individuals with dyed/bleached hair (p=0.31). The individual coefficient of variation (CV) of the quetiapine concentrations between segments ranged from 3 to 34% for individuals with natural hair colour and 22-62% for individuals with dyed/bleached hair. Dose-adjusted concentrations in hair were significantly lower in females with dyed/bleached hair than in individuals with natural hair colour. The quetiapine concentrations in post-mortem femoral blood and in the proximal hair segment, segment 1 (S1), representing

African american women, hair care, and health barriers.

PubMed

Gathers, Raechele Cochran; Mahan, Meredith Grace

2014-09-01

The objective of this study was to elucidate the prevalence of hair loss among African American women; explore the psychosocial impact of hair grooming difficulties; and examine both perceptions related to physician encounters in this group and the relationship between hair grooming, physical activity, and weight maintenance. An anonymous retrospective and qualitative survey, the Hair Care Assessment Survey, is an 18-question novel survey instrument designed at the Henry Ford Hospital Department of Dermatology Multicultural Dermatology Center. The Hair Care Assessment Survey was distributed at church-related functions at predominantly African American metropolitan Detroit churches. Two hundred African American women from metropolitan Detroit, Michigan, aged 21 to 83. The Hair Care Assessment Survey collected data relating to hair loss and hair care, psychosocial experiences relating to hair loss, and hair care as it relates to exercise and body weight management. Data was collected on doctor-patient hair-related medical visits and experiences with commercially available ethnic hair care products. More than 50 percent reported excessive hair loss. Twenty-eight percent had visited a physician to discuss hair issues, but only 32 percent felt their physician understood African American hair. Forty-five percent reported avoiding exercise because of hair concerns, and 22 percent felt that their hair impeded maintaining healthy body weight. Hair loss affects a compelling number of African American women, and a significant number express dissatisfaction in hair-related physician encounters. Additionally, hair styling problems present a serious impediment to physical activity and weight management among this already high-risk population.

African American Women, Hair Care, and Health Barriers

PubMed Central

Mahan, Meredith Grace

2014-01-01

Objectives: The objective of this study was to elucidate the prevalence of hair loss among African American women; explore the psychosocial impact of hair grooming difficulties; and examine both perceptions related to physician encounters in this group and the relationship between hair grooming, physical activity, and weight maintenance. Design: An anonymous retrospective and qualitative survey, the Hair Care Assessment Survey, is an 18-question novel survey instrument designed at the Henry Ford Hospital Department of Dermatology Multicultural Dermatology Center. Setting: The Hair Care Assessment Survey was distributed at church-related functions at predominantly African American metropolitan Detroit churches. Participants: Two hundred African American women from metropolitan Detroit, Michigan, aged 21 to 83. Measurements: The Hair Care Assessment Survey collected data relating to hair loss and hair care, psychosocial experiences relating to hair loss, and hair care as it relates to exercise and body weight management. Data was collected on doctor-patient hair-related medical visits and experiences with commercially available ethnic hair care products. Results: More than 50 percent reported excessive hair loss. Twenty-eight percent had visited a physician to discuss hair issues, but only 32 percent felt their physician understood African American hair. Forty-five percent reported avoiding exercise because of hair concerns, and 22 percent felt that their hair impeded maintaining healthy body weight. Conclusion: Hair loss affects a compelling number of African American women, and a significant number express dissatisfaction in hair-related physician encounters. Additionally, hair styling problems present a serious impediment to physical activity and weight management among this already high-risk population. PMID:25276273

Effect of Miracle Fruit (Synsepalum dulcificum) Seed Oil (MFSO®) on the Measurable Improvement of Hair Breakage in Women with Damaged Hair

PubMed Central

Zhang, Yu; Wakeford, Charles

2017-01-01

Background: Hair breakage is a common unrecognized form of hair loss in women most often the result of hair weathering and traumatic grooming practices. Lipids are major determinants of the physical properties of the hair. Synsepalum dulcificum seed oil (MFSO®; Miracle Fruit Oil Co., Miami Beach, Florida), is an exotic fruit oil with physicochemical properties suited to providing a superior ability to reduce hair breakage. Objective: To assess the safety and efficacy of a hair oil containing MFSO and its effects on hair breakage rates. Methods: Healthy, long-haired women (age range: 19–63 years, mean age: 36.7 years, standard deviation: 10.77 years) with excessive hair breakage were randomized in this double-blind, placebo-controlled study to receive MFSO (n=24), vehicle (n=17), or argan oil (n=16). Measurements of hair length, hair diameter, and Hair Mass Index were performed at baseline, Month 4, and Month 8. Hair Breakage Index and the Healthy Hair Index values were calculated from the trichometer measurements, and subject self-assessment questionnaires were conducted. The primary efficacy endpoints were the percent change in Healthy Hair Index 75 and Healthy Hair Index 50 measurements from baseline to the eighth month. Results: The Healthy Hair Index calculations, expressed as percent change from baseline to Month 4 and from baseline to Month 8, revealed that the MFSO® treatment group improved by 103.6 percent and 215.7 percent for the Healthy Hair Index 75 and 133.7 and 188.3 percent for the Healthy Hair Index 50 values, respectively. When compared with the vehicle and the argan oil brand groups, the Healthy Hair Index levels were significantly higher (p < 0.001) for the MFSO® treatment group, indicating a much greater ability to increase the levels of unbroken hairs by reducing hair breakage. With respect to the mean percent improvements from baseline to Month 4 and Month 8, the MFSO® hair oil treatment group was better than each of the other two

Hair growth induction by substance P.

PubMed

Paus, R; Heinzelmann, T; Schultz, K D; Furkert, J; Fechner, K; Czarnetzki, B M

1994-07-01

In vitro, some neuropeptides, including the tachykinin, substance P (SP), act as growth factors. The cyclic growth of the richly innervated hair follicle offers a model for probing such functions in a complex, developmentally regulated tissue interaction system under physiologic conditions. Dissecting the role of neuropeptides in this system may also reveal as yet obscure neural mechanisms of hair growth control. The neuropeptide-releasing neurotoxin, capsaicin was injected intradermally, or SP slow-release formulations were implanted subcutaneously in the back skin of C57BL/6 mice with all follicles in the resting stage of the hair cycle (telogen) in order to see whether this induced hair growth (anagen). In addition, the endogenous SP skin concentration and the activity of the main SP-degrading enzyme, neutral endopeptidase, were determined during the induced murine hair cycle by high performance liquid chromatography-controlled radioimmuno-assay (SP) or by fluorometry (neutral endopeptidase). Both capsaicin and SP induced significant hair growth (anagen) in the back skin of telogen mice. This was associated with substantial mast cell degranulation. The endogenous SP skin concentration showed significant, hair cycle-dependent fluctuations during the induced murine hair cycle, which were largely independent of the activity of neutral endopeptidase. SP may play a role in the neural control of hair growth. Whereas this pilot study does not address the underlying mechanisms of action, it demonstrates that SP has potential as a hair growth-stimulatory agent in vivo, and serves as a basis for exploring the role of tachykinins in epithelial-mesenchymal-neuroectodermal interaction systems like the hair follicle.

Why Does Hair Turn Gray?

MedlinePlus

... Videos for Educators Search English Español Why Does Hair Turn Gray? KidsHealth / For Kids / Why Does Hair Turn Gray? Print en español ¿Por qué se ... ever watched someone try to cover up gray hair by dyeing it? Or maybe you wonder why ...

Hair Follicle Bulb as a Biodosimeter for Low-Level VX Vapor Exposure: Initial Studies Validating the Presence of Potential Protein Biomarkers of Exposure in the Sprague-Dawley Rat Whisker Follicle

DTIC Science & Technology

2006-10-01

lead to false positive segmental hair analysis results.13 Due to the increased risk of false positives associated with segmental hair analysis ...to 200 mg of hair (to allow confirmation testing). 7 The segments are typically washed to remove external contaminants and the chemicals in the hair ...further confirmation. The method overcomes the false positives associated with traditional segmental hair analysis such. By measuring the

Integral lipids of mammalian hair.

PubMed

Wertz, P W; Downing, D T

1989-01-01

1. It has been demonstrated that hair contains lipids which cannot be removed by extensive extraction with chloroform-methanol mixtures. These integral lipids can be extracted only after the hair has been subjected to alkaline hydrolysis. 2. Integral hair lipids include cholesterol sulfate (0.7-2.9 mg/g hair), ceramides (0.6-1.4 mg/g), cholesterol (0.3-1.4 mg/g), fatty alcohols (trace-0.2 mg/g) and fatty acids (2.3-4.0 mg/g). 3. One of the major integral hair lipids, representing 38.4-47.6% of the total fatty acids, is the anteisobranched 18-methyleicosanoic acid. 4. The species examined included human (Homo sapiens), pig (Sus scrofa), dog (Canis familiaris), sheep (Ovis ammon aries) and cow (Bos taurus).

A survey of the awareness, knowledge and behavior of hair dye use in a korean population with gray hair.

PubMed

Kim, Jung Eun; Jung, Hee Dam; Kang, Hoon

2012-08-01

Gray hair naturally develops in the process of human aging. Many people with gray hair periodically dye their hair. Hair dyeing products are widely used and they can cause adverse effects. Therefore, the user's knowledge and recognition about hair dyeing and related side effects are important. The goal of this study was to lay the foundation for understanding, preventing and treating side effects caused by hair coloring products. We conducted a questionnaire survey for adult males and females aged over 20 who had gray hair. A total of 500 subjects were included in this study and statistical analysis was performed. Large numbers of the people who had experience with hair dye (233 out of 319 people, 73.0%) did not know about the exact brand name of the hair dye product that they were using. Of 319 hair dye users, 23.8% (76 out of 319) people stated that they experienced side effects. Despite the occurrence of side effects from hair dyeing products, it seems they did not realize the seriousness of the side effects or the need for treatment. It is advisable to introduce a system that enables users to become aware of the ingredients and side effects of hair coloring products and give opportunities for users to become aware of the side effects of hair coloring through education, publicity and publication of an informational booklet.

The biology, structure, and function of eyebrow hair.

PubMed

Nguyen, Jennifer V

2014-01-01

Eyebrow hair serves many important biologic and aesthetic functions. This article reviews the structure and function of the hair follicle, as well as hair follicle morphogenesis and cycling. Eyebrow hair follicles share the same basic structure as hair follicles elsewhere on the body, but are distinguished by their shorter anagen (growing) phase. Knowledge of the hair follicle structure and cycle is important for understanding the pathophysiology of alopecia, as diseases affecting the stem cell portion of the hair follicle in the bulge region may cause permanent hair loss. Furthermore, therapeutic agents that target distinct phases and hormones involved in the hair cycle may be useful for promoting hair growth.

Dissecting the bulge in hair regeneration

PubMed Central

Ito, Mayumi; Myung, Peggy

2012-01-01

The adult hair follicle houses stem cells that govern the cyclical growth and differentiation of multiple cell types that collectively produce a pigmented hair. Recent studies have revealed that hair follicle stem cells are heterogeneous and dynamic throughout the hair cycle. Moreover, interactions between heterologous stem cells, including both epithelial and melanocyte stem cells, within the hair follicle are just now being explored. This review will describe how recent findings have expanded our understanding of the development, organization, and regeneration of hair follicle stem cells. At a basic level, this review is intended to help construct a reference point to integrate the surge of studies on the molecular mechanisms that regulate these cells. PMID:22293183

Activating β-catenin signaling in CD133-positive dermal papilla cells increases hair inductivity

PubMed Central

Zhou, Linli; Yang, Kun; Xu, Mingang; Andl, Thomas; Millar, Sarah; Boyce, Steven; Zhang, Yuhang

2016-01-01

Bioengineering hair follicles using cells isolated from human tissue remains as a difficult task. Dermal papilla (DP) cells are known to guide the growth and cycling activities of hair follicles by interacting with keratinocytes. However, DP cells quickly lose their inductivity during in vitro passaging. Rodent DP cell cultures need external addition of chemical factors, including WNT and BMP molecules, to maintain the hair inductive property. CD133 is expressed by a small subpopulation of DP cells that are capable of inducing hair follicle formation in vivo. We report here that expression of a stabilized form of β-catenin promoted clonal growth of CD133-positive (CD133+) DP cells in in vitro three-dimensional hydrogel culture while maintaining expression of DP markers, including alkaline phosphatase (AP), CD133, and Integrin α8. After a two-week in vitro culture, cultured CD133+ DP cells with up-regulated β-catenin activity led to an accelerated in vivo hair growth in reconstituted skin than control cells. Further analysis showed that matrix cell proliferation and differentiation were significantly promoted in hair follicles when β-catenin signaling was upregulated in CD133+ DP cells. Our data highlight an important role for β-catenin signaling in promoting the inductive capability of CD133+ DP cells for in vitro expansion and in vivo hair follicle regeneration, which could potentially be applied to cultured human DP cells. PMID:27312243

Beam shaping for cosmetic hair removal

NASA Astrophysics Data System (ADS)

Lizotte, Todd E.; Tuttle, Tracie

2007-09-01

Beam shaping has the potential to provide comfort to people who require or seek laser based cosmetic skin procedures. Of immediate interest is the procedure of aesthetic hair removal. Hair removal is performed using a variety of wavelengths from 480 to 1200 nm by means of filtered Xenon flash lamps (pulsed light) or 810 nm diode lasers. These wavelengths are considered the most efficient means available for hair removal applications, but current systems use simple reflector designs and plane filter windows to direct the light to the surface being exposed. Laser hair removal is achieved when these wavelengths at sufficient energy levels are applied to the epidermis. The laser energy is absorbed by the melanin (pigment) in the hair and hair follicle which in turn is transformed into heat. This heat creates the coagulation process, which causes the removal of the hair and prevents growth of new hair [1]. This paper outlines a technique of beam shaping that can be applied to a non-contact based hair removal system. Several features of the beam shaping technique including beam uniformity and heat dispersion across its operational treatment area will be analyzed. A beam shaper design and its fundamental testing will be discussed in detail.

Estrogenic and anti-estrogenic activity of off-the-shelf hair and skin care products.

PubMed

Myers, Sharon L; Yang, Chun Z; Bittner, George D; Witt, Kristine L; Tice, Raymond R; Baird, Donna D

2015-05-01

Use of personal care products is widespread in the United States but tends to be greater among African Americans than whites. Of special concern is the possible hazard of absorption of chemicals with estrogenic activity (EA) or anti-EA (AEA) in these products. Such exposure may have adverse health effects, especially when it occurs during developmental windows (e.g., prepubertally) when estrogen levels are low. We assessed the ethanol extracts of eight commonly used hair and skin products popular among African Americans for EA and AEA using a cell proliferation assay with the estrogen sensitive MCF-7:WS8 cell line derived from a human breast cancer. Four of the eight personal care products tested (Oil Hair Lotion, Extra-dry Skin Lotion, Intensive Skin Lotion, Petroleum Jelly) demonstrated detectable EA, whereas three (Placenta Hair Conditioner, Tea-Tree Hair Conditioner, Cocoa Butter Skin Cream) exhibited AEA. Our data indicate that hair and skin care products can have EA or AEA, and suggest that laboratory studies are warranted to investigate the in vivo activity of such products under chronic exposure conditions as well as epidemiologic studies to investigate potential adverse health effects that might be associated with use of such products.

Solubility of structurally complicated materials: 3. Hair.

PubMed

Horvath, Ari L

2009-04-27

Hair is composed of proteins, lipids, water, and small amounts of trace elements. All proteins in animal and human bodies are built from permutations of amino acid molecules in a polypeptide string. The polypeptide chains of protein keratin are organized into filaments in hair cells. Hair is one of the most difficult proteins to digest or solubilize. Among the most common dissolving procedures for hair are acidic, alkaline, and enzymatic hydrolysis. For the analysis of hair, the solid samples are transferred by solubilization via digestion into a liquid phase. Small molecular solvents and molecules with hydrophobic groups appear to have higher affinity for hair. A good solvent attacks the disulfide bonds between cystine molecules and hydrates the hair shaft. Consequently, the hair becomes a jelly-like mass.

Trichoscopic Findings of Hair Loss in Koreans

PubMed Central

Park, Jin; Kim, Joo-Ik; Kim, Han-Uk; Yun, Seok-Kweon

2015-01-01

Background Trichoscopic findings of hair loss have been well described for the differential diagnosis of alopecia; however, critical findings were not thoroughly investigated or compared among all ethnic groups, including Asians. Objective We aimed to find any characteristic trichoscopic findings in Korean alopecia patients and to verify whether those findings are closely related to previously reported observations. Methods Three hundred and twenty-seven patients with hair loss of various causes and 160 normal scalps were analyzed. Trichoscopic examination was performed with a polarized-light handheld dermoscope. Results A total of 35 patterns of trichoscopic features were represented, and certain features were significantly common or observed exclusively in a particular type of alopecia as follows: yellow dots, exclamation mark hairs, and proximal tapering hairs (alopecia areata), trichoptilosis and pointed hairs (trichotillomania), corkscrew hairs, septate hyphae hairs, and comma hairs (tinea capitis), diffuse white area, fibrotic white dots, and tufting hairs (primary cicatricial alopecia), hair diameter diversity and peripilar sign (androgenetic alopecia), and short nonvellus hairs (telogen effluvium). Conclusion The characteristic trichoscopic features for the differential diagnosis of alopecia in Koreans, shown as follicular, perifollicular, and hair shaft patterns, are similar to those of Caucasians; however, the frequencies of the pigment patterns are different between Koreans and Caucasians because of the contrast effect of the skin and hair color. Therefore, racial difference should be considered in the trichoscopic evaluation for differential diagnosis. PMID:26512168

Childhood hair product use and earlier age at menarche in a racially diverse study population: a pilot study.

PubMed

James-Todd, Tamarra; Terry, Mary Beth; Rich-Edwards, Janet; Deierlein, Andrea; Senie, Ruby

2011-06-01

Previous studies suggest that hair products containing endocrine disrupting chemicals could alter puberty. We evaluated the association between childhood hair product use and age at menarche in a racially diverse study population. We recruited 300 African-American, African-Caribbean, Hispanic, and white women from the New York City metropolitan area who were between 18-77 years of age. Data were collected retrospectively on hair oil, lotion, leave-in conditioner, perm, and other types of hair products used before age 13. Recalled age at menarche ranged from 8 to 19 years. We used multivariable binomial regression to evaluate the association between hair product use and age at menarche (<12 vs. ≥12), adjusting for potential confounders. African-Americans were more likely to use hair products and reached menarche earlier than other racial/ethnic groups. Women reporting childhood hair oil use had a risk ratio of 1.4 (95% confidence interval [CI]: 1.1-1.9) for earlier menarche, adjusting for race/ethnicity and year of birth. Hair perm users had an increased risk for earlier menarche (adjusted risk ratio = 1.4, 95% CI: 1.1-1.8). Other types of hair products assessed in this study were not associated with earlier menarche. Childhood hair oil and perm use were associated with earlier menarche. If replicated, these results suggest that hair product use may be important to measure in evaluating earlier age at menarche. Copyright © 2011 Elsevier Inc. All rights reserved.

Contribution of hair density and hair diameter to the appearance and progression of androgenetic alopecia in Japanese men.

PubMed

Ishino, A; Takahashi, T; Suzuki, J; Nakazawa, Y; Iwabuchi, T; Tajima, M

2014-11-01

Androgenetic alopecia (AGA) is the most common type of baldness in men. The balding process is associated with the gradual miniaturization of hair follicles and successive hair loss. However, the relative contributions of hair density and diameter to AGA are still unclear. Hair density and hair diameter were investigated in Japanese men with or without AGA to elucidate the importance of these factors in the balding process. Male Japanese subjects with or without AGA (n = 369) were included in this study. Hair appearance at the vertex was evaluated by comparison with a series of standard photographs. Hair density was measured using a phototrichogram-based videomicroscopy technique, and hair diameter was assessed by comparison with a series of calibrated threads on the phototrichogram image. All subjects with AGA were ≥ 25 years of age. The mean percentage of thick hairs (> 80 μm) in all subjects with AGA was significantly lower than that in subjects without AGA aged ≥ 25 years (P < 0·01), but the mean percentage of vellus hairs (< 40 μm) in subjects with AGA was significantly higher (P < 0·001). By contrast, the mean density of the hair in all patients with AGA did not significantly differ from the density of those without AGA aged ≥ 25 years. However, the mean density of the hair in subjects without AGA aged < 25 years was significantly higher than that of both subjects without AGA aged ≥ 25 years (P < 0·001) and all subjects with AGA. Hair loss in men with AGA results mainly from the miniaturization of hair follicles rather than the loss of hair (shedding), at least for individuals who are ≥ 25 years of age and present with AGA. © 2014 British Association of Dermatologists.

Analysis of human hair to assess exposure to organophosphate flame retardants: Influence of hair segments and gender differences.

PubMed

Qiao, Lin; Zheng, Xiao-Bo; Zheng, Jing; Lei, Wei-Xiang; Li, Hong-Fang; Wang, Mei-Huan; He, Chun-Tao; Chen, She-Jun; Yuan, Jian-Gang; Luo, Xiao-Jun; Yu, Yun-Jiang; Yang, Zhong-Yi; Mai, Bi-Xian

2016-07-01

Hair is a promising, non-invasive, human biomonitoring matrix that can provide insight into retrospective and integral exposure to organic pollutants. In the present study, we measured the concentrations of organophosphate flame retardants (PFRs) in hair and serum samples from university students in Guangzhou, China, and compared the PFR concentrations in the female hair segments using paired distal (5~10cm from the root) and proximal (0~5cm from the root) samples. PFRs were not detected in the serum samples. All PFRs except tricresyl phosphate (TMPP) and tri-n-propyl phosphate (TPP) were detected in more than half of all hair samples. The concentrations of total PFRs varied from 10.1 to 604ng/g, with a median of 148ng/g. Tris(chloroisopropyl) phosphate (TCIPP) and tri(2-ethylexyl) phosphate (TEHP) were the predominant PFRs in hair. The concentrations of most PFRs in the distal segments were 1.5~8.6 times higher than those in the proximal segments of the hair (t-test, p<0.05), which may be due to the longer exposure time of the distal segments to external sources. The values of log (PFR concentrations-distal/PFR concentrations-proximal) were positively and significantly correlated with log KOA of PFRs (p<0.05, r=0.68), indicating that PFRs with a higher log KOA tend to accumulate in hair at a higher rate than PFRs with a lower log KOA. Using combined segments of female hair, significantly higher PFR concentrations were observed in female hair than in male hair. In contrast, female hair exhibited significantly lower PFR concentrations than male hair when using the same hair position for both genders (0-5cm from the scalp). The controversial results regarding gender differences in PFRs in hair highlight the importance of segmental analysis when using hair as an indicator of human exposure to PFRs. Copyright © 2016 Elsevier Inc. All rights reserved.

Household Chemical Emergencies

MedlinePlus

... ammonia, may react, ignite or explode. Never use hair spray, cleaning solutions, paint products, or pesticides near an open flame Clean up any chemical spill immediately. Allow the fumes in the rags ...

The current status of microscopical hair comparisons.

PubMed

Rowe, W F

2001-12-08

Although the microscopical comparison of human hairs has been accepted in courts of law for over a century, recent advances in DNA technology have called this type of forensic examination into question. In a number of cases, post-conviction DNA testing has exonerated defendants who were convicted in part on the results of microscopical hair comparisons. A federal judge has held a Daubert hearing on the microscopical comparison of human hairs and has concluded that this type of examination does not meet the criteria for admission of scientific evidence in federal courts. A review of the available scientific literature on microscopical hair comparisons (including studies conducted by the Royal Canadian Mounted Police and the Federal Bureau of Investigation) leads to three conclusions: (1) microscopical comparisons of human hairs can yield scientifically defensible conclusions that can contribute to criminal investigations and criminal prosecutions, (2) the reliability of microscopical hair comparisons is strongly affected by the training of the forensic hair examiner, (3) forensic hair examiners cannot offer estimates of the probability of a match of a questioned hair with a hair from a randomly selected person. In order for microscopical hair examinations to survive challenges under the U.S. Supreme Court's Daubert decision, hair microscopists must be better trained and undergo frequent proficiency testing. More research on the error rates of microscopical hair comparisons should be undertaken, and guidelines for the permissible interpretations of such comparisons should be established. Until these issues have been addressed and satisfactorily resolved, microscopical hair comparisons should be regarded by law enforcement agencies and courts of law as merely presumptive in nature, and all microscopical hair comparisons should be confirmed by nuclear DNA profiling or mitochondrial DNA sequencing.

RELAX: detecting relaxed selection in a phylogenetic framework.

PubMed

Wertheim, Joel O; Murrell, Ben; Smith, Martin D; Kosakovsky Pond, Sergei L; Scheffler, Konrad

2015-03-01

Relaxation of selective strength, manifested as a reduction in the efficiency or intensity of natural selection, can drive evolutionary innovation and presage lineage extinction or loss of function. Mechanisms through which selection can be relaxed range from the removal of an existing selective constraint to a reduction in effective population size. Standard methods for estimating the strength and extent of purifying or positive selection from molecular sequence data are not suitable for detecting relaxed selection, because they lack power and can mistake an increase in the intensity of positive selection for relaxation of both purifying and positive selection. Here, we present a general hypothesis testing framework (RELAX) for detecting relaxed selection in a codon-based phylogenetic framework. Given two subsets of branches in a phylogeny, RELAX can determine whether selective strength was relaxed or intensified in one of these subsets relative to the other. We establish the validity of our test via simulations and show that it can distinguish between increased positive selection and a relaxation of selective strength. We also demonstrate the power of RELAX in a variety of biological scenarios where relaxation of selection has been hypothesized or demonstrated previously. We find that obligate and facultative γ-proteobacteria endosymbionts of insects are under relaxed selection compared with their free-living relatives and obligate endosymbionts are under relaxed selection compared with facultative endosymbionts. Selective strength is also relaxed in asexual Daphnia pulex lineages, compared with sexual lineages. Endogenous, nonfunctional, bornavirus-like elements are found to be under relaxed selection compared with exogenous Borna viruses. Finally, selection on the short-wavelength sensitive, SWS1, opsin genes in echolocating and nonecholocating bats is relaxed only in lineages in which this gene underwent pseudogenization; however, selection on the functional

Hair breakage during combing. III. The effects of bleaching and conditioning on short and long segment breakage by wet and dry combing of tresses.

PubMed

Robbins, Clarence; Kamath, Yash

2007-01-01

A recent publication (1), provided evidence for two types of hair breakage during combing, short segment breakage (approximately less than 1.27 cm) and longer segment breakage. We have confirmed these results and refined the separation distance between short and long segment breakage at about 2.54 cm. Furthermore, chemical bleaching increased both short and long segment breakage while a commercial hair conditioner decreased both types of breakage. Whether the hair is chemically bleached or conditioned, for dry combing, short segment breakage increases with increasing comb strokes, that is, short segment breakage increases as combing damages the ends of the hair, however, long segment breakage does not increase with increasing comb strokes. Wet combing provided a decrease in short segment breakage and an increase in long segment breaks, but no increase in breakage with increasing comb strokes. Mechanical combing of tresses shows similar results qualitatively, however the variance was too large and adjustments need to be made to provide for a larger number of broken hairs to bring the mechanical and hand combing results in line. For dry combing, as the comb descends through the hair, hairs above it are made parallel and those beneath are either made parallel or knot by, hairs looping around other hairs or hairs looping around comb teeth and other hairs several cm between the comb and the hair tips. As the comb advances through the looped/knotted hairs long breaks occur or as the comb descends near the tips wrapped ends can result. End wrapping by inertia & possibly static charge produces short segment breaks which are more severe if the hair is cut at 90 degrees versus a tapered cut. For wet combing, clumping of hairs by a capillary action produces fewer short segment breaks, by reducing end wrapping: however, crossed hair interactions occur & because of higher friction more severe snags arise higher up in the tress, and lower hair breaking load due to plasticization

Proteomic Analysis of Hair Follicles

NASA Astrophysics Data System (ADS)

Ishioka, Noriaki; Terada, Masahiro; Yamada, Shin; Seki, Masaya; Takahashi, Rika; Majima, Hideyuki J.; Higashibata, Akira; Mukai, Chiaki

2013-02-01

Hair root cells actively divide in a hair follicle, and they sensitively reflect physical conditions. By analyzing the human hair, we can know stress levels on the human body and metabolic conditions caused by microgravity environment and cosmic radiation. The Japan Aerospace Exploration Agency (JAXA) has initiated a human research study to investigate the effects of long-term space flight on gene expression and mineral metabolism by analyzing hair samples of astronauts who stayed in the International Space Station (ISS) for 6 months. During long-term flights, the physiological effects on astronauts include muscle atrophy and bone calcium loss. Furthermore, radiation and psychological effects are important issue to consider. Therefore, an understanding of the effects of the space environment is important for developing countermeasures against the effects experienced by astronauts. In this experiment, we identify functionally important target proteins that integrate transcriptome, mineral metabolism and proteome profiles from human hair. To compare the protein expression data with the gene expression data from hair roots, we developed the protein processing method. We extracted the protein from five strands of hair using ISOGEN reagents. Then, these extracted proteins were analyzed by LC-MS/MS. These collected profiles will give us useful physiological information to examine the effect of space flight.

The Growth of Human Hair.

ERIC Educational Resources Information Center

Jones, Helen J.

1984-01-01

Suggests a simple technique for collecting and observing human hair roots to compare structure, function, and variation. Students extract their own hair samples and view them using a 40-power microscope objective. Differences between active/inactive phases of hair growth are readily observed. (The activity can be adapted for younger students.) (DH)

Hair today, gone tomorrow: a comparison of body hair removal practices in gay and heterosexual men.

PubMed

Martins, Yolanda; Tiggemann, Marika; Churchett, Libby

2008-09-01

Although hairlessness is rapidly becoming a component of the ideal male body, little research has examined men's concerns about their body hair or their hair removal practices. Samples of gay and heterosexual men completed questionnaires that assessed whether they had ever removed their back, buttock or pubic hair, the frequency with which they did so, the methods used and their self-reported reasons for removing this hair, as well as their level of appearance investment. Results indicated that many gay and heterosexual men remove their back, buttock and pubic hair regularly and that their primary reason for doing so is to maintain or improve their appearance. The frequency of hair removal was also associated with the motivational salience component of appearance investment. The findings offer further support to the premise that gay and heterosexual men exhibit similar body image concerns.

Stimulation of hair cells with ultraviolet light

NASA Astrophysics Data System (ADS)

Azimzadeh, Julien B.; Fabella, Brian A.; Hudspeth, A. J.

2018-05-01

Hair bundles are specialized organelles that transduce mechanical inputs into electrical outputs. To activate hair cells, physiologists have resorted to mechanical methods of hair-bundle stimulation. Here we describe a new method of hair-bundle stimulation, irradiation with ultraviolet light. A hair bundle illuminated by ultraviolet light rapidly moves towards its tall edge, a motion typically associated with excitatory stimulation. The motion disappears upon tip-link rupture and is associated with the opening of mechanotransduction channels. Hair bundles can be induced to move sinusoidally with oscillatory modulation of the stimulation power. We discuss the implications of ultraviolet stimulation as a novel hair-bundle stimulus.

Solubility of Structurally Complicated Materials: 3. Hair

PubMed Central

Horvath, Ari L.

2009-01-01

Hair is composed of proteins, lipids, water, and small amounts of trace elements. All proteins in animal and human bodies are built from permutations of amino acid molecules in a polypeptide string. The polypeptide chains of protein keratin are organized into filaments in hair cells. Hair is one of the most difficult proteins to digest or solubilize. Among the most common dissolving procedures for hair are acidic, alkaline, and enzymatic hydrolysis. For the analysis of hair, the solid samples are transferred by solubilization via digestion into a liquid phase. Small molecular solvents and molecules with hydrophobic groups appear to have higher affinity for hair. A good solvent attacks the disulfide bonds between cystine molecules and hydrates the hair shaft. Consequently, the hair becomes a jelly-like mass. PMID:19412554

Alterations in Hair Follicle Dynamics in Women

PubMed Central

Piérard-Franchimont, Claudine; Piérard, Gérald E.

2013-01-01

Endocrine changes supervening after parturition and menopause participate in the control of sebum production and hair growth modulation. The ensuing conditions include some peculiar aspects of hair loss (effluvium), alopecia, and facial hirsutism. The hair cycling is of major clinical relevance because most hair growth disorders result from disturbances in this chronobiological feature. Of note, any correlation between a biologic abnormality and hair cycling disturbance does not prove a relationship of causality. The proportion of postmenopausal women is rising in the overall population. Therefore, the prevalence of these hair follicle disturbances is globally on the rise. Current therapies aim at correcting the underlying hormonal imbalances, and at improving the overall cosmetic appearance. However, in absence of pathogenic diagnosis and causality criteria, chances are low that a treatment given by the whims of fate will adequately control hair effluvium. The risk and frequency of therapeutic inertia are further increased. When the hair loss is not controlled and/or compensated by growth of new hairs, several clinical aspects of alopecia inexorably develop. Currently, there is little evidence supporting any specific treatment for these endocrine hair disorders in post-partum and postmenopausal women. Current hair treatment strategies are symptomatic and nonspecific so current researchers aim at developing new, targeted methods. PMID:24455742

Alterations in hair follicle dynamics in women.

PubMed

Piérard-Franchimont, Claudine; Piérard, Gérald E

2013-01-01

Endocrine changes supervening after parturition and menopause participate in the control of sebum production and hair growth modulation. The ensuing conditions include some peculiar aspects of hair loss (effluvium), alopecia, and facial hirsutism. The hair cycling is of major clinical relevance because most hair growth disorders result from disturbances in this chronobiological feature. Of note, any correlation between a biologic abnormality and hair cycling disturbance does not prove a relationship of causality. The proportion of postmenopausal women is rising in the overall population. Therefore, the prevalence of these hair follicle disturbances is globally on the rise. Current therapies aim at correcting the underlying hormonal imbalances, and at improving the overall cosmetic appearance. However, in absence of pathogenic diagnosis and causality criteria, chances are low that a treatment given by the whims of fate will adequately control hair effluvium. The risk and frequency of therapeutic inertia are further increased. When the hair loss is not controlled and/or compensated by growth of new hairs, several clinical aspects of alopecia inexorably develop. Currently, there is little evidence supporting any specific treatment for these endocrine hair disorders in post-partum and postmenopausal women. Current hair treatment strategies are symptomatic and nonspecific so current researchers aim at developing new, targeted methods.

Hair analysis for drugs of abuse. XVI. Disposition of fenethylline and its metabolite into hair and discrimination between fenethylline use and amphetamine use by hair analysis.

PubMed

Kikura, R; Nakahara, Y

1997-01-01

The incorporation tendency of fenethylline (FNT) and its metabolite into rat hair and the discrimination between FNT use and amphetamine (AP) use by hair analysis using gas chromatography-mass spectrometry with selected ion monitoring are described. After the intraperitoneal administrations of FNT to pigmented hairy rats (5 mg/kg/day, 10 days, n = 3), concentrations of FNT and its metabolite, AP, in the rat hair newly grown over 4 weeks were compared with area under the concentration versus time curves (AUCs) of the drugs in the rat plasma. The hair concentrations of FNT and AP were 52 +/- 1.4 and 4.9 +/- 0.6 ng/mg, whereas those of plasma AUCs were 55.9 +/- 23.1 and 22.3 +/- 4.9 micrograms.min/mL, respectively. The ratios of the hair concentrations to the AUCs of FNT tends to be highly incorporated into hair from suggests that FNT tends to be highly incorporated into hair from blood. The analytical method was applied to the determination of the metabolites in scalp hair of humans who were given FNT orally in multiple doses (50 mg/day, 3 days, n = 5) or in a single dose (50 mg/day, 1 day, n = 1). FNT and AP were detected at 0.51 +/- 0.23 and 0.35 +/- 0.12 ng/mg, respectively, in the proximal 1-cm hair segments from subjects given FNT orally for 3 days and 0.25 and 0.11 ng/mg, respectively, in the single-dose sample. In addition, it was found that the concentrations of FNT were 1.2 to 2.7 times greater than those of AP in the human hair samples, except for one sample, although FNT rapidly disappeared from the urine compared with AP. It was concluded that hair would be a good specimen for disclosure of drug history of FNT and for discrimination between FNT use and AP abuse.

Genetics Home Reference: uncombable hair syndrome

MedlinePlus

... Twitter Home Health Conditions Uncombable hair syndrome Uncombable hair syndrome Printable PDF Open All Close All Enable ... to view the expand/collapse boxes. Description Uncombable hair syndrome is a condition that is characterized by ...

Genetics Home Reference: cartilage-hair hypoplasia

MedlinePlus

... Twitter Home Health Conditions Cartilage-hair hypoplasia Cartilage-hair hypoplasia Printable PDF Open All Close All Enable ... to view the expand/collapse boxes. Description Cartilage-hair hypoplasia is a disorder of bone growth characterized ...

Steady-state stiffness of utricular hair cells depends on macular location and hair bundle structure.

PubMed

Spoon, Corrie; Moravec, W J; Rowe, M H; Grant, J W; Peterson, E H

2011-12-01

Spatial and temporal properties of head movement are encoded by vestibular hair cells in the inner ear. One of the most striking features of these receptors is the orderly structural variation in their mechanoreceptive hair bundles, but the functional significance of this diversity is poorly understood. We tested the hypothesis that hair bundle structure is a significant contributor to hair bundle mechanics by comparing structure and steady-state stiffness of 73 hair bundles at varying locations on the utricular macula. Our first major finding is that stiffness of utricular hair bundles varies systematically with macular locus. Stiffness values are highest in the striola, near the line of hair bundle polarity reversal, and decline exponentially toward the medial extrastriola. Striolar bundles are significantly more stiff than those in medial (median: 8.9 μN/m) and lateral (2.0 μN/m) extrastriolae. Within the striola, bundle stiffness is greatest in zone 2 (106.4 μN/m), a band of type II hair cells, and significantly less in zone 3 (30.6 μN/m), which contains the only type I hair cells in the macula. Bathing bundles in media that break interciliary links produced changes in bundle stiffness with predictable time course and magnitude, suggesting that links were intact in our standard media and contributed normally to bundle stiffness during measurements. Our second major finding is that bundle structure is a significant predictor of steady-state stiffness: the heights of kinocilia and the tallest stereocilia are the most important determinants of bundle stiffness. Our results suggest 1) a functional interpretation of bundle height variability in vertebrate vestibular organs, 2) a role for the striola in detecting onset of head movement, and 3) the hypothesis that differences in bundle stiffness contribute to diversity in afferent response dynamics.

Steady-state stiffness of utricular hair cells depends on macular location and hair bundle structure

PubMed Central

Spoon, Corrie; Moravec, W. J.; Rowe, M. H.; Grant, J. W.

2011-01-01

Spatial and temporal properties of head movement are encoded by vestibular hair cells in the inner ear. One of the most striking features of these receptors is the orderly structural variation in their mechanoreceptive hair bundles, but the functional significance of this diversity is poorly understood. We tested the hypothesis that hair bundle structure is a significant contributor to hair bundle mechanics by comparing structure and steady-state stiffness of 73 hair bundles at varying locations on the utricular macula. Our first major finding is that stiffness of utricular hair bundles varies systematically with macular locus. Stiffness values are highest in the striola, near the line of hair bundle polarity reversal, and decline exponentially toward the medial extrastriola. Striolar bundles are significantly more stiff than those in medial (median: 8.9 μN/m) and lateral (2.0 μN/m) extrastriolae. Within the striola, bundle stiffness is greatest in zone 2 (106.4 μN/m), a band of type II hair cells, and significantly less in zone 3 (30.6 μN/m), which contains the only type I hair cells in the macula. Bathing bundles in media that break interciliary links produced changes in bundle stiffness with predictable time course and magnitude, suggesting that links were intact in our standard media and contributed normally to bundle stiffness during measurements. Our second major finding is that bundle structure is a significant predictor of steady-state stiffness: the heights of kinocilia and the tallest stereocilia are the most important determinants of bundle stiffness. Our results suggest 1) a functional interpretation of bundle height variability in vertebrate vestibular organs, 2) a role for the striola in detecting onset of head movement, and 3) the hypothesis that differences in bundle stiffness contribute to diversity in afferent response dynamics. PMID:21918003

Comparative Transduction Mechanisms of Vestibular Otolith Hair Cells

NASA Technical Reports Server (NTRS)

Baird, Richard A.

1994-01-01

Hair cells in the bullfrog vestibular otolith organs regenerate following aminoglycoside ototoxicity. Hair cells in these organs are differentially sensitive to gentamicin, with saccular hair cells and hair cells in the utricular striola being damaged at lower gentamicin concentrations than hair cells in the utricular extrastriola. Regenerating hair cells in these organs have short hair bundles and can be classified into a number of phenotypes using the same morphological criteria used to identify their mature counterparts. Our studies suggest that some supporting cells can convert, or transdifferentiate,into hair cells without an intervening cell division. By stimulating these processes in humans, clinicians may be able to alleviate human deafness and peripheral vestibular disorders by regenerating and replacing lost hair cells. In vivo and in vitro studies were done on cell proliferation and hair cell regeneration.

Microtubules in root hairs.

PubMed

Traas, J A; Braat, P; Emons, A M; Meekes, H; Derksen, J

1985-06-01

The microtubules of root hairs of Raphanus sativus, Lepidium sativum, Equisetum hyemale, Limnobium stoloniferum, Ceratopteris thalictroides, Allium sativum and Urtica dioica were investigated using immunofluorescence and electron microscopy. Arrays of cortical microtubules were observed in all hairs. The microtubules in the hairs show net axial orientations, but in Allium and Urtica helical microtubule patterns are also present. Numerical parameters of microtubules in Raphanus, Equisetum and Limnobium were determined from dry-cleave preparations. The results are discussed with respect to cell wall deposition and cell morphogenesis.

2-Amino-4-hydroxyethylaminoanisole sulfate - a coupler causing contact allergy from use in hair dyes.

PubMed

Madsen, Jakob T; Andersen, Klaus E

2016-02-01

Allergic contact dermatitis resulting from the use of permanent hair dyes is common. Approximately 100 hair dye chemicals are permitted in Europe. Hair dye ingredients may change over time, and hence new hair dye allergens should be looked for continuously. To review positive patch test reactions to the coupler 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. Patch test results from the Allergen Bank database for eczema patients patch tested with 2-amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014 were reviewed. A total of 902 dermatitis patients (154 from the dermatology department and 748 from 65 practices) were patch tested with amino-4-hydroxyethylaminoanisole sulfate 2% pet. from 2005 to 2014. Thirteen (1.4%) patients had a positive patch test reaction. Our results do not indicate irritant reactions. 2-Amino-4-hydroxyethylaminoanisole sulfate is a new but rare contact allergen. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Geometric classification of scalp hair for valid drug testing, 6 more reliable than 8 hair curl groups.

PubMed

Mkentane, K; Van Wyk, J C; Sishi, N; Gumedze, F; Ngoepe, M; Davids, L M; Khumalo, N P

2017-01-01

Curly hair is reported to contain higher lipid content than straight hair, which may influence incorporation of lipid soluble drugs. The use of race to describe hair curl variation (Asian, Caucasian and African) is unscientific yet common in medical literature (including reports of drug levels in hair). This study investigated the reliability of a geometric classification of hair (based on 3 measurements: the curve diameter, curl index and number of waves). After ethical approval and informed consent, proximal virgin (6cm) hair sampled from the vertex of scalp in 48 healthy volunteers were evaluated. Three raters each scored hairs from 48 volunteers at two occasions each for the 8 and 6-group classifications. One rater applied the 6-group classification to 80 additional volunteers in order to further confirm the reliability of this system. The Kappa statistic was used to assess intra and inter rater agreement. Each rater classified 480 hairs on each occasion. No rater classified any volunteer's 10 hairs into the same group; the most frequently occurring group was used for analysis. The inter-rater agreement was poor for the 8-groups (k = 0.418) but improved for the 6-groups (k = 0.671). The intra-rater agreement also improved (k = 0.444 to 0.648 versus 0.599 to 0.836) for 6-groups; that for the one evaluator for all volunteers was good (k = 0.754). Although small, this is the first study to test the reliability of a geometric classification. The 6-group method is more reliable. However, a digital classification system is likely to reduce operator error. A reliable objective classification of human hair curl is long overdue, particularly with the increasing use of hair as a testing substrate for treatment compliance in Medicine.

Geometric classification of scalp hair for valid drug testing, 6 more reliable than 8 hair curl groups

PubMed Central

Mkentane, K.; Gumedze, F.; Ngoepe, M.; Davids, L. M.; Khumalo, N. P.

2017-01-01

Introduction Curly hair is reported to contain higher lipid content than straight hair, which may influence incorporation of lipid soluble drugs. The use of race to describe hair curl variation (Asian, Caucasian and African) is unscientific yet common in medical literature (including reports of drug levels in hair). This study investigated the reliability of a geometric classification of hair (based on 3 measurements: the curve diameter, curl index and number of waves). Materials and methods After ethical approval and informed consent, proximal virgin (6cm) hair sampled from the vertex of scalp in 48 healthy volunteers were evaluated. Three raters each scored hairs from 48 volunteers at two occasions each for the 8 and 6-group classifications. One rater applied the 6-group classification to 80 additional volunteers in order to further confirm the reliability of this system. The Kappa statistic was used to assess intra and inter rater agreement. Results Each rater classified 480 hairs on each occasion. No rater classified any volunteer’s 10 hairs into the same group; the most frequently occurring group was used for analysis. The inter-rater agreement was poor for the 8-groups (k = 0.418) but improved for the 6-groups (k = 0.671). The intra-rater agreement also improved (k = 0.444 to 0.648 versus 0.599 to 0.836) for 6-groups; that for the one evaluator for all volunteers was good (k = 0.754). Conclusions Although small, this is the first study to test the reliability of a geometric classification. The 6-group method is more reliable. However, a digital classification system is likely to reduce operator error. A reliable objective classification of human hair curl is long overdue, particularly with the increasing use of hair as a testing substrate for treatment compliance in Medicine. PMID:28570555

Investigating the origins of nanostructural variations in differential ethnic hair types using X-ray scattering techniques.

PubMed

Wade, M; Tucker, I; Cunningham, P; Skinner, R; Bell, F; Lyons, T; Patten, K; Gonzalez, L; Wess, T

2013-10-01

Human hair is a major determinant of visual ethnic differentiation. Although hair types are celebrated as part of our ethnic diversity, the approach to hair care has made the assumption that hair types are structurally and chemically similar. Although this is clearly not the case at the macroscopic level, the intervention of many hair treatments is at the nanoscopic and molecular levels. The purpose of the work presented here is to identify the main nanoscopic and molecular hierarchical differences across five different ethnic hair types from hair fibres taken exclusively from the scalp. These are Afro (subdivided into elastic 'rubber' and softer non-elastic 'soft'), Chinese, European and Mullato (mixed race). Small angle X-Ray scattering (SAXS) is a technique capable of resolving nanostructural variations in complex materials. Individual hair fibres from different ethnic hair types were used to investigate structural features found in common and also specific to each type. Simultaneous wide angle X-Ray scattering (WAXS) was used to analyse the submolecular level structure of the fibrous keratin present. The data sets from both techniques were analysed with principal component analysis (PCA) to identify underlying variables. Principal component analysis of both SAXS and WAXS data was shown to discriminate the scattering signal between different hair types. The X-ray scattering results show a common underlying keratin intermediate filament (KIF) structure. However, distinct differences were observed in the preferential orientation and intensity signal from the lipid component of the hair. In addition, differences were observed in the intensity distribution of the very low-angle sample-dependent diffuse scatter surrounding the 'beamstop.' The results indicate that the fibrous keratin scaffold remains consistent between ethnic hair types. The hierarchies made by these may be modulated by variation in the content of keratin-associated proteins (KAPs) and lipids that

Negative hair-bundle stiffness betrays a mechanism for mechanical amplification by the hair cell.

PubMed

Martin, P; Mehta, A D; Hudspeth, A J

2000-10-24

Hearing and balance rely on the ability of hair cells in the inner ear to sense miniscule mechanical stimuli. In each cell, sound or acceleration deflects the mechanosensitive hair bundle, a tuft of rigid stereocilia protruding from the cell's apical surface. By altering the tension in gating springs linked to mechanically sensitive transduction channels, this deflection changes the channels' open probability and elicits an electrical response. To detect weak stimuli despite energy losses caused by viscous dissipation, a hair cell can use active hair-bundle movement to amplify its mechanical inputs. This amplificatory process also yields spontaneous bundle oscillations. Using a displacement-clamp system to measure the mechanical properties of individual hair bundles from the bullfrog's ear, we found that an oscillatory bundle displays negative slope stiffness at the heart of its region of mechanosensitivity. Offsetting the hair bundle's position activates an adaptation process that shifts the region of negative stiffness along the displacement axis. Modeling indicates that the interplay between negative bundle stiffness and the motor responsible for mechanical adaptation produces bundle oscillation similar to that observed. Just as the negative resistance of electrically excitable cells and of tunnel diodes can be embedded in a biasing circuit to amplify electrical signals, negative stiffness can be harnessed to amplify mechanical stimuli in the ear.

Hair transplantation in burn scar alopecia

PubMed Central

Farjo, Bessam; Farjo, Nilofer; Williams, Greg

2015-01-01

Treating patients with burn alopecia or hair loss can often be a challenge to both the surgeon and the patient. As with other reconstructive procedures that are required in the post-burn phase, this is usually a multiple stage process often requiring surgery over several years. This is because graft take is not as reliable as in healthy non-scarred skin and may need repeating to achieve adequate density. Also, different areas of hair loss may need to be addressed in separate procedures. There are several limiting factors that will determine whether or not a patient is a candidate for hair restoration which includes but is not limited to the amount of hair loss and the availability of suitable donor hair. Here we discuss how the current surgical technique of hair transplant surgery by follicular unit extraction (FUE) or strip follicular unit transplant (FUT) has become the treatment of choice for alopecic areas that require a more refined aesthetic result. Eyebrow, eyelash, beard and scalp hair loss can all have a negative impact on a burn survivor’s self-esteem and even if surgery is not a possibility, there are non-surgical options available for hair restoration and these are also discussed. PMID:29799573

Parathyroid hormone-related peptide and the hair cycle - is it the agonists or the antagonists that cause hair growth?

PubMed

Gensure, Robert C

2014-12-01

While the effects of PTHrP have been studied for almost 20 years, most of these studies have focused on effects on the termination of the anagen phase, giving an incomplete picture of the overall effect of PTHrP on the hair cycle. PTHrP was determined in several experimental models to promote transition of hair follicles from anagen to catagen phase, which by itself would suggest that PTHrP blockade might prolong the anagen phase and promote hair growth. However, clinical trials with topically applied PTHrP antagonists have been disappointing, leading to a reconsideration of this model. Additional studies performed in mouse models where hair follicles are damaged (alopecia areata, chemotherapy-induced alopecia) suggest that PTHrP has effects early in the hair cycle as well, promoting hair follicles' entry into anagen phase and initiates the hair cycle. While the mechanism of this has yet to be elucidated, it may involve activation of the Wnt pathway. Thus, the overall effect of PTHrP is to stimulate and accelerate the hair cycle, and in the more clinically relevant models of hair loss where hair follicles have been damaged or become quiescent, it is the agonists, not the antagonists, which would be expected to promote hair growth. © 2014 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Female pattern hair loss: Current treatment concepts

PubMed Central

Dinh, Quan Q; Sinclair, Rodney

2007-01-01

Fewer than 45% of women go through life with a full head of hair. Female pattern hair loss is the commonest cause of hair loss in women and prevalence increases with advancing age. Affected women may experience psychological distress and impaired social functioning. In most cases the diagnosis can be made clinically and the condition treated medically. While many women using oral antiandrogens and topical minoxidil will regrow some hair, early diagnosis and initiation of treatment is desirable as these treatments are more effective at arresting progression of hair loss than stimulating regrowth. Adjunctive nonpharmacological treatment modalities such as counseling, cosmetic camouflage and hair transplantation are important measures for some patients. The histology of female pattern hair loss is identical to that of male androgenetic alopecia. While the clinical pattern of the hair loss differs between men, the response to oral antiandrogens suggests that female pattern hair loss is an androgen dependant condition, at least in the majority of cases. Female pattern hair loss is a chronic progressive condition. All treatments need to be continued to maintain the effect. An initial therapeutic response often takes 12 or even 24 months. Given this delay, monitoring for treatment effect through clinical photography or standardized clinical severity scales is helpful. PMID:18044135

Nonlinear flow response of soft hair beds

NASA Astrophysics Data System (ADS)

Alvarado, José; Comtet, Jean; de Langre, Emmanuel; Hosoi, A. E.

2017-10-01

We are `hairy' on the inside: beds of passive fibres anchored to a surface and immersed in fluids are prevalent in many biological systems, including intestines, tongues, and blood vessels. These hairs are soft enough to deform in response to stresses from fluid flows. Yet fluid stresses are in turn affected by hair deformation, leading to a coupled elastoviscous problem that is poorly understood. Here we investigate a biomimetic model system of elastomer hair beds subject to shear-driven Stokes flows. We characterize this system with a theoretical model that accounts for the large-deformation flow response of hair beds. Hair bending results in a drag-reducing nonlinearity because the hair tip lowers towards the base, widening the gap through which fluid flows. When hairs are cantilevered at an angle subnormal to the surface, flow against the grain bends hairs away from the base, narrowing the gap. The flow response of angled hair beds is axially asymmetric and amounts to a rectification nonlinearity. We identify an elastoviscous parameter that controls nonlinear behaviour. Our study raises the hypothesis that biological hairy surfaces function to reduce fluid drag. Furthermore, angled hairs may be incorporated in the design of integrated microfluidic components, such as diodes and pumps.

Biologic Rhythms Derived from Siberian Mammoths' Hairs

PubMed Central

Spilde, Mike; Lanzirotti, Antonio; Qualls, Clifford; Phillips, Genevieve; Ali, Abdul-Mehdi; Agenbroad, Larry; Appenzeller, Otto

2011-01-01

Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ∼31 cms/year and ∼16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna. PMID:21747920

Biologic rhythms derived from Siberian mammoths' hairs.

PubMed

Spilde, Mike; Lanzirotti, Antonio; Qualls, Clifford; Phillips, Genevieve; Ali, Abdul-Mehdi; Agenbroad, Larry; Appenzeller, Otto

2011-01-01

Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending on location and differed from humans. Hair growth for mammoths was ∼31 cms/year and ∼16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.

21 CFR 895.101 - Prosthetic hair fibers.

Code of Federal Regulations, 2012 CFR

2012-04-01

... fibers are devices intended for implantation into the human scalp to simulate natural hair or conceal... modacrylic, polyacrylic, and polyester; and natural fibers, such as processed human hair. Excluded from the banned device are natural hair transplants, in which a person's hair and its surrounding tissue are...

21 CFR 895.101 - Prosthetic hair fibers.

Code of Federal Regulations, 2011 CFR

2011-04-01

... fibers are devices intended for implantation into the human scalp to simulate natural hair or conceal... modacrylic, polyacrylic, and polyester; and natural fibers, such as processed human hair. Excluded from the banned device are natural hair transplants, in which a person's hair and its surrounding tissue are...

21 CFR 895.101 - Prosthetic hair fibers.

Code of Federal Regulations, 2014 CFR

2014-04-01

... fibers are devices intended for implantation into the human scalp to simulate natural hair or conceal... modacrylic, polyacrylic, and polyester; and natural fibers, such as processed human hair. Excluded from the banned device are natural hair transplants, in which a person's hair and its surrounding tissue are...

21 CFR 895.101 - Prosthetic hair fibers.

Code of Federal Regulations, 2013 CFR

2013-04-01

... fibers are devices intended for implantation into the human scalp to simulate natural hair or conceal... modacrylic, polyacrylic, and polyester; and natural fibers, such as processed human hair. Excluded from the banned device are natural hair transplants, in which a person's hair and its surrounding tissue are...

7 CFR 3201.70 - Hair care products.

Code of Federal Regulations, 2013 CFR

2013-01-01

... 7 Agriculture 15 2013-01-01 2013-01-01 false Hair care products. 3201.70 Section 3201.70... Designated Items § 3201.70 Hair care products. (a) Definitions. (1) Personal hygiene products specifically formulated for hair cleaning and treating applications, including shampoos and conditioners. (2) Hair care...

7 CFR 3201.70 - Hair care products.

Code of Federal Regulations, 2012 CFR

2012-01-01

... 7 Agriculture 15 2012-01-01 2012-01-01 false Hair care products. 3201.70 Section 3201.70... Designated Items § 3201.70 Hair care products. (a) Definitions. (1) Personal hygiene products specifically formulated for hair cleaning and treating applications, including shampoos and conditioners. (2) Hair care...

7 CFR 3201.70 - Hair care products.

Code of Federal Regulations, 2014 CFR

2014-01-01

... 7 Agriculture 15 2014-01-01 2014-01-01 false Hair care products. 3201.70 Section 3201.70... Designated Items § 3201.70 Hair care products. (a) Definitions. (1) Personal hygiene products specifically formulated for hair cleaning and treating applications, including shampoos and conditioners. (2) Hair care...

Evaluation Indicators of Aesthetic Effects on Hair Transplantation.

PubMed

Miao, Yong; Liu, Bing-Cheng; Fan, Zhe-Xiang; Hu, Zhi-Qi

2016-02-01

Hair transplantation involves the transplantation of hair, beard, eyebrows, eyelashes, and pubic hair. Based on our experience, the aesthetic result of hair transplantation mainly relies on 4 indicators, including selection of the donor site, direction and angle of grafted hairs, density, and survival rate of implanted hair follicles. We believe that good results can be achieved as long as attention is paid to the above 4 points.

Demonstration of Protein-Based Human Identification Using the Hair Shaft Proteome

PubMed Central

Leppert, Tami; Anex, Deon S.; Hilmer, Jonathan K.; Matsunami, Nori; Baird, Lisa; Stevens, Jeffery; Parsawar, Krishna; Durbin-Johnson, Blythe P.; Rocke, David M.; Nelson, Chad; Fairbanks, Daniel J.; Wilson, Andrew S.; Rice, Robert H.; Woodward, Scott R.; Bothner, Brian; Hart, Bradley R.; Leppert, Mark

2016-01-01

Human identification from biological material is largely dependent on the ability to characterize genetic polymorphisms in DNA. Unfortunately, DNA can degrade in the environment, sometimes below the level at which it can be amplified by PCR. Protein however is chemically more robust than DNA and can persist for longer periods. Protein also contains genetic variation in the form of single amino acid polymorphisms. These can be used to infer the status of non-synonymous single nucleotide polymorphism alleles. To demonstrate this, we used mass spectrometry-based shotgun proteomics to characterize hair shaft proteins in 66 European-American subjects. A total of 596 single nucleotide polymorphism alleles were correctly imputed in 32 loci from 22 genes of subjects’ DNA and directly validated using Sanger sequencing. Estimates of the probability of resulting individual non-synonymous single nucleotide polymorphism allelic profiles in the European population, using the product rule, resulted in a maximum power of discrimination of 1 in 12,500. Imputed non-synonymous single nucleotide polymorphism profiles from European–American subjects were considerably less frequent in the African population (maximum likelihood ratio = 11,000). The converse was true for hair shafts collected from an additional 10 subjects with African ancestry, where some profiles were more frequent in the African population. Genetically variant peptides were also identified in hair shaft datasets from six archaeological skeletal remains (up to 260 years old). This study demonstrates that quantifiable measures of identity discrimination and biogeographic background can be obtained from detecting genetically variant peptides in hair shaft protein, including hair from bioarchaeological contexts. PMID:27603779

[Hair growth effect of minoxidil].

PubMed

Otomo, Susumu

2002-03-01

The length and size of hair are depend on the anagen term in its hair cycle. It has been reported that the some cell growth factors, such as VEGF, FGF-5S, IGF-1 and KGF, induce the proliferation of cells in the matrix, dermal papilla and dermal papillary vascular system and increase the amount of extra cellular matrix in dermal papilla and then maintain follicles in the anagen phase. On the other hand, negative factors, like FGF-5, thrombospondin, or still unknown ones, terminate the anagen phase. If the negative factors become dominant against cell proliferation factors according to fulfilling some time set by the biological clock for hair follicles, TGF beta induced in the matrix tissues evokes apoptosis of matrix cells and shifts the follicles from anagen to catagen. Androgenetic alopecia is caused by miniaturizing of hair follicles located in the frontal or crown part of scalp and are hereditarily more sensitive to androgen. In their hair cycles, the androgen shortens the anagen phase of follicles and shifts them to the catagen phase earlier than usual. The mode of action of hair growth effect of minoxidil is not completely elucidated, but the most plausible explanation proposed here is that minoxidil works as a sulfonylurea receptor (SUR) activator and prolongs the anagen phase of hair follicles in the following manner: minoxidil (1) induces cell growth factors such as VEGF, HGF, IGF-1 and potentiates HGF and IGF-1 actions by the activation of uncoupled SUR on the plasma membrane of dermal papilla cells, (2) inhibits of TGF beta induced apoptosis of hair matrix cells by opening the Kir 6.0 channel pore coupled with SUR on the mitochondrial inner membrane, and (3) dilates hair follicle arteries and increases blood flow in dermal papilla by opening the Kir 6.0 channel pore coupled with SUR on the plasma membrane of vascular smooth muscle cells.

Effect of sinapic acid on hair growth promoting in human hair follicle dermal papilla cells via Akt activation.

PubMed

Woo, Hyunju; Lee, Seungjun; Kim, Seungbeom; Park, Deokhoon; Jung, Eunsun

2017-07-01

Hair loss known as alopecia is caused by abnormal hair follicle cycling including shortening of the anagen (growth) phase and changing of hair follicle morphology with miniaturization. In accordance with the life extension, the quality of life is considered to be a most important thing. The yearning for healthy and beautiful hair and low self esteem due to hair loss had negative influence on the quality of life with psychosocial maladjustment. The objective of this research was to identify new compound that can be used as a drug to promote hair growth. We investigated whether the function of sinapic acid (SA) is able to promote hair growth in human hair follicle dermal papilla cells (hHFDPC). We showed that treatment of SA in hHFDPC could induce proliferation and the activation of Akt signaling in HFDPC. In addition, SA could stimulate the expressions of the several growth factors, insulin-like growth factor 1, and vascular endothelial growth factor for hair growth. We showed that SA led to an increased level of phospho-GSK-3β and β-catenin accumulation in HFDPC. Finally, the promoting effect of SA in hHFDPC cell growth occurred by the induction of cell cycle progression. These results suggest that SA could be one of the potential candidate compounds for the treatment of alopecia by inducing hair growth through triggering the expressions of growth factors via activation of Akt and subsequent inactivation of GSK-3β /β-catenin pathway.

Therapeutic strategy for hair regeneration: Hair cycle activation, niche environment modulation, wound-induced follicle neogenesis and stem cell engineering

PubMed Central

Chueh, Shan-Chang; Lin, Sung-Jan; Chen, Chih-Chiang; Lei, Mingxing; Wang, Ling Mei; Widelitz, Randall B.; Hughes, Michael W.; Jiang, Ting-Xing; Chuong, Cheng Ming

2013-01-01

Introduction There are major new advancements in the fields of stem cell biology, developmental biology, regenerative hair cycling, and tissue engineering. The time is ripe to integrate, translate and apply these findings to tissue engineering and regenerative medicine. Readers will learn about new progress in cellular and molecular aspects of hair follicle development, regeneration and potential therapeutic opportunities these advances may offer. Areas covered Here we use hair follicle formation to illustrate this progress and to identify targets for potential strategies in therapeutics. Hair regeneration is discussed in four different categories. (1) Intra-follicle regeneration (or renewal) is the basic production of hair fibers from hair stem cells and dermal papillae in existing follicles. (2) Chimeric follicles via epithelial-mesenchymal recombination to identify stem cells and signaling centers. (3) Extra-follicular factors including local dermal and systemic factors can modulate the regenerative behavior of hair follicles, and may be relatively easy therapeutic targets. (4) Follicular neogenesis means the de novo formation of new follicles. In addition, scientists are working to engineer hair follicles, which require hair forming competent epidermal cells and hair inducing dermal cells. Expert opinion Ideally self-organizing processes similar to those occurring during embryonic development should be elicited with some help from biomaterials. PMID:23289545

Mutations in gasdermin 3 cause aberrant differentiation of the hair follicle and sebaceous gland.

PubMed

Lunny, Declan P; Weed, Erica; Nolan, Patrick M; Marquardt, Andreas; Augustin, Martin; Porter, Rebecca M

2005-03-01

Defolliculated (Dfl) is a spontaneous mouse mutant with a hair-loss phenotype that includes altered sebaceous gland differentiation, short hair shafts, aberrant catagen stage of the hair cycle, and eventual loss of the hair follicle. Recently a similar mutant, finnegan (Fgn), with an identical phenotype was discovered during a phenotypic screen for mutations induced by chemical mutagenesis. The gene underlying the phenotype of both finnegan and defolliculated has been mapped to chromosome 11 and here we show that both mice harbor mutations in gasdermin 3 (Gsdm3), a gene of unknown function. Gsdm3(Dfl) is a B2 insertion near the 3' splice site of exon 7 and Gsdm3(Fgn) is a point mutation T278P. To investigate the role of the gasdermin gene family an antiserum was raised to a peptide highly homologous to all three mouse gasdermins and human gasdermin. Immunohistochemical analysis revealed that gasdermins are expressed specifically in cells at advanced stages of differentiation in the upper epidermis, the differentiating inner root sheath and hair shaft and in the most mature sebocytes of the sebaceous gland and preputial, meibomium, ceruminous gland, and anal glands. This expression pattern suggests a role for gasdermins in differentiation of the epidermis and its appendages.

Estrogenic and anti-estrogenic activity of off-the-shelf hair and skin care products

PubMed Central

Myers, Sharon L.; Yang, Chun Z.; Bittner, George D.; Witt, Kristine L.; Tice, Raymond R.; Baird, Donna D.

2014-01-01

Use of personal care products is widespread in the United States but tends to be greater among African Americans than whites. Of special concern is the possible hazard of absorption of chemicals with estrogenic activity (EA) or anti-EA (AEA) in these products. Such exposure may have adverse health effects, especially when it occurs during developmental windows (e.g., prepubertally) when estrogen levels are low. We assessed the ethanol extracts of eight commonly used hair and skin products popular among African Americans for EA and AEA using a cell proliferation assay with the estrogen sensitive MCF-7:WS8 cell line derived from a human breast cancer. Four of the eight personal care products tested (Oil Hair Lotion, Extra-dry Skin Lotion, Intensive Skin Lotion, Petroleum Jelly) demonstrated detectable EA, whereas three (Placenta Hair Conditioner, Tea-Tree Hair Conditioner, Cocoa Butter Skin Cream) exhibited AEA. Our data indicate that hair and skin care products can have EA or AEA, and suggest that laboratory studies are warranted to investigate the in vivo activity of such products under chronic exposure conditions as well as epidemiologic studies to investigate potential adverse health effects that might be associated with use of such products. PMID:24849798

Fast relaxations in foam

NASA Astrophysics Data System (ADS)

Krishan, Kapilanjan; Helal, Ahmed; Höhler, Reinhard; Cohen-Addad, Sylvie

2010-07-01

Aqueous foams present an anomalous macroscopic viscoelastic response at high frequency, previously shown to arise from collective relaxations in the disordered bubble packing. We demonstrate experimentally how these mesoscopic dynamics are in turn tuned by physico-chemical processes on the scale of the gas-liquid interfaces. Two specific local dissipation processes are identified, and we show how the rigidity of the interfaces selects the dominant one, depending on the choice of the surfactant.

Asynchronous, macrotasked relaxation strategies for the solution of viscous, hypersonic flows

NASA Technical Reports Server (NTRS)

Gnoffo, Peter A.

1991-01-01

A point-implicit, asynchronous macrotasked relaxation of the steady, thin-layer, Navier-Stokes equations is presented. The method employs multidirectional, single-level storage Gauss-Seidel relaxation sweeps, which effectively communicate perturbations across the entire domain in 2n sweeps, where n is the dimension of the domain. In order to enhance convergence the application of relaxation factors to specific components of the Jacobian is examined using a stability analysis of the advection and diffusion equations. Attention is also given to the complications associated with asynchronous multitasking. Solutions are generated for hypersonic flows over blunt bodies in two and three dimensions with chemical reactions, utilizing single-tasked and multitasked relaxation strategies.

Limitations of human occipital scalp hair follicle organ culture for studying the effects of minoxidil as a hair growth enhancer.

PubMed

Magerl, Markus; Paus, Ralf; Farjo, Nilofer; Müller-Röver, Sven; Peters, Eva M J; Foitzik, Kerstin; Tobin, Desmond J

2004-10-01

Minoxidil induces new hair growth in approximately one-third of patients with androgenetic alopecia after 1 year of treatment. With several conflicting reports in the literature based on small-scale studies, the current study aimed to clarify whether organ culture of human scalp anagen VI hair follicles is a suitable in vitro test system for reproducing, and experimentally dissecting, the recognized in vivo hair-growth-promoting capacity of minoxidil. Hair shaft elongation was studied in terminal anagen VI hair follicles microdissected from the occipital scalp of 36 healthy adults. A total of 2300 hair follicles, approximately 65 per individual, were tested using modifications of a basic organ culture protocol. It is shown here that minoxidil does not significantly increase hair shaft elongation or the duration of anagen VI in ex vivo culture despite several enhancements on the conventional methodology. This disparity to what is seen clinically in minoxidil responders may be explained by the following: (i) use of occipital (rather than frontotemporal or vertex) hair follicles; (ii) use of, already maximally growing, anagen VI hair follicles; (iii) a predominance of hair follicles from minoxidil unresponsive-donors; (iv) use of minoxidil rather than its sulfate metabolite; and/or (v) use of a suboptimal minoxidil dosage. This disparity questions the usefulness of standard human hair follicle organ culture in minoxidil research. Unexpectedly, minoxidil even inhibited hair shaft elongation in the absence of insulin, which may indicate that the actual hair-growth-modulatory effects of minoxidil depend on the concomitant local presence/absence of other growth modulators.

Nonlinear flow response of soft hair beds

NASA Astrophysics Data System (ADS)

Alvarado, José

2017-11-01

We are hairy inside: beds of passive fibers anchored to a surface and immersed in fluids are prevalent in many biological systems, including intestines, tongues, and blood vessels. Such hairs are soft enough to deform in response to stresses from fluid flows. Fluid stresses are in turn affected by hair deformation, leading to a coupled elastoviscous problem which is poorly understood. Here we investigate a biomimetic model system of elastomer hair beds subject to shear- driven Stokes flows. We characterize this system with a theoretical model which accounts for the large-deformation flow response of hair beds. Hair bending results in a drag-reducing nonlinearity because the hair tip lowers toward the base, widening the gap through which fluid flows. When hairs are cantilevered at an angle subnormal to the surface, flow against the grain bends hairs away from the base, narrowing the gap. The flow response of angled hair beds is axially asymmetric and amounts to a rectification nonlinearity. We identify an elastoviscous parameter which controls nonlinear behavior. Our study raises the hypothesis that biological hairy surfaces function to reduce fluid drag. Furthermore, angled hairs may be incorporated in the design of integrated microfluidic components, such as diodes and pumps. J.A. acknowledges support the U. S. Army Research Office under Grant Number W911NF-14-1-0396.

Containing Hair During Cutting In Zero Gravity

NASA Technical Reports Server (NTRS)

Haines, Richard F.

1992-01-01

Proposed device collects loose hair during barbering and shaving in zero gravity to prevent hair clippings from contaminating cabin of spacecraft. Folds for storage, opens into clear, bubblelike plastic dome surrounding user's head, tray fits around user's throat, and fanlike ring surrounds back of neck. Device fits snugly but comfortably around neck, preventing hair from escaping to outside. Flow of air into hose connected to suction pump removes hair from bubble as cut. Filter at end of hose collects hair.

Relaxation Assessment with Varied Structured Milieu (RELAX).

ERIC Educational Resources Information Center

Cassel, Russell N.; Cassel, Susie L.

1983-01-01

Describes Relaxation Assessment with Varied Structured Milieu (RELAX), a clinical program designed to assess the degree to which an individual is able to demonstrate self-control for overall general relaxation. The program is designed for use with the Cassel Biosensors biofeedback equipment. (JAC)

An overview of unwanted female hair.

PubMed

Blume-Peytavi, U

2011-12-01

Unwanted facial hair (UFH) is an important but often overlooked issue, with over 40% of women experiencing some degree of UFH. In the female population a wide spectrum of unwanted hair concerns is represented - from biologically normal but undesirable to excessive unwanted hair with an underlying pathology. While women may seek to manage unwanted hair across their bodies, UFH is a particular concern, due to its negative impact on perceived femininity. There may not always be a direct correlation between degree of severity diagnosed objectively by the physician and level of concern and impact upon the patient. This review discusses the spectrum of facial hair experience and outlines the clinical approach to unwanted hair management including UFH. It highlights the importance of a treatment regimen which should respond to the causation factors and needs of the individual. This will lead to a holistic treatment approach including evaluation of the implementation of emotional coping strategies and on-going support, lifestyle modifications, pharmacological interventions (to address underlying pathologies) and the use of cosmetic hair removal methods as either a stand-alone or adjunct treatment as appropriate to the individual. © 2011 The Author. BJD © 2011 British Association of Dermatologists.

[Scrotal hair in infants].

PubMed

Sentchordi Montane, L; Quintanar Rioja, A; Ayala Bernardo de Quirós, L; Martínez Granero, M A; Bonet Serra, B

2008-02-01

The presence of pubic hair is exceptional in healthy infants of both sexes. In most of the cases described in the literature, the process was self-limited and no etiology was found. Nevertheless, in some patients, this finding has been associated with other manifestations of hyperandrogenism related to potentially serious diseases such as congenital adrenal hyperplasia or virilizing tumors. In the present article, we describe seven infants followed-up in the Pediatric Endocrine Clinic because of scrotal hair. In all patients, the process was self-limited and resolved spontaneously and no hormonal or developmental alterations were observed. Key words: Scrotal hair, infants, virilization.

The use of human hair as biodosimeter.

PubMed

Tepe Çam, S; Polat, M; Seyhan, N

2014-12-01

The potential use of human hair samples as biologic dosimeter was investigated by electron spin resonance (ESR) spectroscopy. The hair samples were obtained from female volunteers and classified according to the color, age and whether they are natural or dyed. Natural black, brown, red, blonde and dyed black hair samples were irradiated at low doses (5-50Gy) and high doses (75-750Gy) by gamma source giving the dose rate of 0.25Gy/s in The Sarayköy Establishment of Turkish Atomic Energy Authority. While the peak heights and g-values (2.0021-2.0023) determined from recorded spectra of hair were color dependent, the peak-to-peak line widths were varied according to natural or dyed hair (ΔHpp: 0.522-0.744mT). In all samples, the linear dose-response curves at low doses saturated after ~300Gy. In black hair samples taken from different individuals, differences in the structure of the spectrum and signal intensities were not observed. The EPR signal intensities of samples stored at room temperature for 22 days fell to their half-values in 44h in black hair, 41h in blonde and brown hairs, 35h in dyed black hair and in 17h in red hair. The activation energies of samples annealed at high temperatures for different periods of time were correlated well with those obtained in the literature. In conclusion, hair samples can be used as a biological dosimeter considering the limitations showed in this study. Copyright © 2014 Elsevier Ltd. All rights reserved.

Clinical Evidence of Increase in Hair Growth and Decrease in Hair Loss without Adverse Reactions Promoted by the Commercial Lotion ECOHAIR®.

PubMed

Alonso, María Rosario; Anesini, Claudia

2017-01-01

Hair exerts protection, sensory functions, thermoregulation, and sexual attractiveness. Hair loss (alopecia) is caused by several diseases, drug intake, hormone imbalance, stress, and infections (Malassesia furfur). Drugs usually used in alopecia produce irreversible systemic and local side effects. An association of extracts of Coffea arabica and Larrea divaricata (ECOHAIR®) is successfully being commercialized in Argentina for hair growth. The aim of this study was to provide scientific support for the efficacy and innocuousness of ECOHAIR® in patients with noncicatricial alopecia during a 3-month treatment. The efficacy was determined through the assessment of an increase in hair volume, improvement in hair looks, growth of new hair, and a decrease in hair loss by the test of hair count and hair traction. The capacity to decrease the amount of dandruff was also evaluated as well as the adverse local effects caused by the treatment. ECOHAIR® spray improved the overall hair volume and appearance; it increased its thickness, induced hair growth, and decreased hair loss. Besides, no adverse local reactions were observed upon treatment with the product. This study provides scientific support for the clinical use of ECOHAIR® as a treatment to be used in noncicatricial alopecia. © 2017 S. Karger AG, Basel.

Mouse models for human hair loss disorders

PubMed Central

Porter, Rebecca M

2003-01-01

The outer surface of the hand, limb and body is covered by the epidermis, which is elaborated into a number of specialized appendages, evolved not only to protect and reinforce the skin but also for social signalling. The most prominent of these appendages is the hair follicle. Hair follicles are remarkable because of their prolific growth characteristics and their complexity of differentiation. After initial embryonic morphogenesis, the hair follicle undergoes repeated cycles of regression and regeneration throughout the lifetime of the organism. Studies of mouse mutants with hair loss phenotypes have suggested that the mechanisms controlling the hair cycle probably involve many of the major signalling molecules used elsewhere in development, although the complete pathway of hair follicle growth control is not yet understood. Mouse studies have also led to the discovery of genes underlying several human disorders. Future studies of mouse hair-loss mutants are likely to benefit the understanding of human hair loss as well as increasing our knowledge of mechanisms controlling morphogenesis and tumorigenesis. PMID:12587927

Regulation and functional diversification of root hairs.

PubMed

Cui, Songkui; Suzaki, Takuya; Tominaga-Wada, Rumi; Yoshida, Satoko

2017-10-13

Root hairs result from the polar outgrowth of root epidermis cells in vascular plants. Root hair development processes are regulated by intrinsic genetic programs, which are flexibly modulated by environmental conditions, such as nutrient availability. Basic programs for root hair development were present in early land plants. Subsequently, some plants developed the ability to utilize root hairs for specific functions, in particular, for interactions with other organisms, such as legume-rhizobia and host plants-parasites interactions. In this review, we summarize the molecular regulation of root hair development and the modulation of root hairs under limited nutrient supply and during interactions with other organisms. Copyright © 2017 Elsevier Ltd. All rights reserved.

Ion beam microanalysis of human hair follicles

NASA Astrophysics Data System (ADS)

Kertész, Zs.; Szikszai, Z.; Pelicon, P.; Simčič, J.; Telek, A.; Bíró, T.

2007-07-01

Hair follicle is an appendage organ of the skin which is of importance to the survival of mammals and still maintains significance for the human race - not just biologically, but also through cosmetic and commercial considerations. However data on composition of hair follicles are scarce and mostly limited to the hair shaft. In this study we provide detailed information on the elemental distribution in human hair follicles in different growth phases (anagen and catagen) using a scanning proton microprobe. The analysis of skin samples obtained from human adults undergoing plastic surgery and of organ-cultured human hair follicles may yield a new insight into the function, development and cyclic activity of the hair follicle.

Biologic Rhythms Derived from Siberian Mammoths Hairs

DOE Office of Scientific and Technical Information (OSTI.GOV)

M Spilde; A Lanzirotti; C Qualls

2011-12-31

Hair is preserved for millennia in permafrost; it enshrines a record of biologic rhythms and offers a glimpse at chronobiology as it was in extinct animals. Here we compare biologic rhythms gleaned from mammoth's hairs with those of modern human hair. Four mammoths' hairs came from varying locations in Siberia 4600 km, four time zones, apart ranging in age between 18,000 and 20,000 years before present. We used two contemporaneous human hairs for comparison. Power spectra derived from hydrogen isotope ratios along the length of the hairs gave insight into biologic rhythms, which were different in the mammoths depending onmore » location and differed from humans. Hair growth for mammoths was {approx}31 cms/year and {approx}16 cms/year for humans. Recurrent annual rhythms of slow and fast growth varying from 3.4 weeks/cycles to 8.7 weeks/cycles for slow periods and 1.2 weeks/cycles to 2.2 weeks/cycles for fast periods were identified in mammoth's hairs. The mineral content of mammoth's hairs was measured by electron microprobe analysis (k-ratios), which showed no differences in sulfur amongst the mammoth hairs but significantly more iron then in human hair. The fractal nature of the data derived from the hairs became evident in Mandelbrot sets derived from hydrogen isotope ratios, mineral content and geographic location. Confocal microscopy and scanning electron microscopy showed varied degrees of preservation of the cuticle largely independent of age but not location of the specimens. X-ray fluorescence microprobe and fluorescence computed micro-tomography analyses allowed evaluation of metal distribution and visualization of hollow tubes in the mammoth's hairs. Seasonal variations in iron and copper content combined with spectral analyses gave insights into variation in food intake of the animals. Biologic rhythms gleaned from power spectral plots obtained by modern methods revealed life style and behavior of extinct mega-fauna.« less

A review of hair product use on breast cancer risk in African American women.

PubMed

Stiel, Laura; Adkins-Jackson, Paris B; Clark, Phyllis; Mitchell, Eudora; Montgomery, Susanne

2016-03-01

The incidence rate of breast cancer for African American women has recently converged with that of non-Hispanic White women in the United States, although African Americans have a higher mortality rate due to this disease. Although most research exploring health disparities associated with this phenomenon has focused on differences between women based on biology and behavior, both the academic and lay communities have begun to explore the potential role of environmental exposure to estrogen and endocrine disrupting chemicals (EDCs). This study reviews the current state of the science associating one such means of exposure, hair products containing EDCs, with breast cancer risk in African American women. We found a growing body of evidence linking: (1) environmental estrogen and EDC exposures to breast cancer risk, (2) the presence of such chemicals in personal care products, including hair products, and (3) the use of certain hair products with potential breast cancer risk in African Americans. At the same time, there is also increasing concern in the lay community about this risk. These results indicate the need for additional research, and the opportunity to benefit from strategic partnerships in community-collaborative approaches in order to better understand the potential "cost of beauty." © 2016 The Authors. Cancer Medicine published by John Wiley & Sons Ltd.

[Monilethrix--rare syndrome of structural hair abnormalities].

PubMed

Brzezińska-Wcisło, L; Bogdanowski, T; Szeremeta-Bazylewicz, G; Pierzchała, E

1999-11-01

Monilethrix is a rare structural disorder of hair. Characteristic abnormalities in the form of alternating thinning and fusiform thickening are observed in most of hair shafts that we call beaded hair. Macroscopic estimation shows lustreless, dry, rough, fragile hair. Trichological examination usually reveals a considerable percentage of anagenic hair. According to our own experiences and literature data systemic therapy (vitamins) and topical treatment (desquamative ointments) are not effective sufficiently. Spontaneous regression of symptoms often appears with time. Five cases of familial occurrence of monilethrix have been presented.

Penile strangulation by hair.

PubMed

Acimi, Smail

2014-07-01

To know the causes and results of treatment of complications from a penile strangulation by hair in seven boys. From April 2000 to December 2012, seven boys presenting serious penile complications by hair strangulation have been operated in two centers. All seven boys had transection of the urethra at the coronal level. And none of our patients were at the stage of necrosis or amputation of the glans. The age of the patients at surgery ranged from 34 to 134 months (mean 96 months). Four children presented urethrocutaneous fistulas (57% of cases), and the innervation and vascularization of the glans remained poor after repair in three patients. The penile strangulation by hair was due to a simple accident. However, several predisposing factors were discovered in our patients: lack of cleanliness; a moist environment with nocturnal enuresis; the presence of pubic hair in young children reported in the four children, and a coronal sulcus not covered by the foreskin in circumcised children.

Stress and the Hair Growth Cycle: Cortisol-Induced Hair Growth Disruption.

PubMed

Thom, Erling

2016-08-01

The stress hormone, cortisol, is known to affect the function and cyclic regulation of the hair follicle. When cortisol is present at high levels it has been demonstrated to reduce the synthesis and accelerate the degradation of important skin elements, namely hyaluronan and proteoglycans by approximately 40%. The following discussion outlines the relationship between stress, cortisol, and the effect on the normal function of the hair follicle. As a result of this connection, important correlations have been established in the literature to form a basis for novel, effective treatments of stress-related hair growth disorders.
Amongst various treatment methods and substances, oral supplementation with a specific bioavailable proteoglycan stands out as a promising new therapeutic treatment method.

J Drugs Dermatol. 2016;15(8):1001-1004.

Hair curvature: a natural dialectic and review.

PubMed

Nissimov, Joseph N; Das Chaudhuri, Asit Baran

2014-08-01

Although hair forms (straight, curly, wavy, etc.) are present in apparently infinite variations, each fibre can be reduced to a finite sequence of tandem segments of just three types: straight, bent/curly, or twisted. Hair forms can thus be regarded as resulting from genetic pathways that induce, reverse or modulate these basic curvature modes. However, physical interconversions between twists and curls demonstrate that strict one-to-one correspondences between them and their genetic causes do not exist. Current hair-curvature theories do not distinguish between bending and twisting mechanisms. We here introduce a multiple papillary centres (MPC) model which is particularly suitable to explain twisting. The model combines previously known features of hair cross-sectional morphology with partially/completely separated dermal papillae within single follicles, and requires such papillae to induce differential growth rates of hair cortical material in their immediate neighbourhoods. The MPC model can further help to explain other, poorly understood, aspects of hair growth and morphology. Separate bending and twisting mechanisms would be preferentially affected at the major or minor ellipsoidal sides of fibres, respectively, and together they exhaust the possibilities for influencing hair-form phenotypes. As such they suggest dialectic for hair-curvature development. We define a natural-dialectic (ND) which could take advantage of speculative aspects of dialectic, but would verify its input data and results by experimental methods. We use this as a top-down approach to first define routes by which hair bending or twisting may be brought about and then review evidence in support of such routes. In particular we consider the wingless (Wnt) and mammalian target of rapamycin (mTOR) pathways as paradigm pathways for molecular hair bending and twisting mechanisms, respectively. In addition to the Wnt canonical pathway, the Wnt/Ca(2+) and planar cell polarity (PCP) pathways

Guidelines on Hair Restoration for East Asian Patients.

PubMed

Lee, In-Joon; Jung, Jae Heon; Lee, Young-Ran; Kim, Jung Chul; Hwang, Sungjoo Tommy

2016-07-01

In East Asian countries, hair transplantation is a quite common procedure for treating pattern hair loss, cosmetically correcting the hairline, and correcting eyebrow and pubic hair defects. Although there are general guidelines concerning hair transplantation, certain factors need to be addressed to make the guidelines more specific and suitable to East Asian requirements. To provide guidelines for hairline design, donor harvesting, graft preparation and placement, and medical treatment that are appropriate for hair transplantation in East Asian patients. Recommendations are based on the experience of the authors, surgeons who perform hair transplantation, and a comprehensive review of the available literature on hair transplantation in East Asians. Data on hair thickness and graft density, hairline design, and graft creation and placement techniques have been collaboratively evaluated and used to establish overall guidelines. The use of the proposed guidelines by surgeons will hopefully enhance outcomes and bring greater consistency to hair transplantation procedures for East Asian patients.

A new path in defining light parameters for hair growth: Discovery and modulation of photoreceptors in human hair follicle.

PubMed

Buscone, Serena; Mardaryev, Andrei N; Raafs, Bianca; Bikker, Jan W; Sticht, Carsten; Gretz, Norbert; Farjo, Nilofer; Uzunbajakava, Natallia E; Botchkareva, Natalia V

2017-09-01

Though devices for hair growth based on low levels of light have shown encouraging results, further improvements of their efficacy is impeded by a lack of knowledge on the exact molecular targets that mediate physiological response in skin and hair follicle. The aim of this study was to investigate the expression of selected light-sensitive receptors in the human hair follicle and to study the impact of UV-free blue light on hair growth ex vivo. The expression of Opsin receptors in human skin and hair follicles has been characterized using RT-qPCR and immunofluorescence approaches. The functional significance of Opsin 3 was assessed by silencing its expression in the hair follicle cells followed by a transcriptomic profiling. Proprietary LED-based devices emitting two discrete visible wavelengths were used to access the effects of selected optical parameters on hair growth ex vivo and outer root sheath cells in vitro. The expression of OPN2 (Rhodopsin) and OPN3 (Panopsin, Encephalopsin) was detected in the distinct compartments of skin and anagen hair follicle. Treatment with 3.2 J/cm 2 of blue light with 453 nm central wavelength significantly prolonged anagen phase in hair follicles ex vivo that was correlated with sustained proliferation in the light-treated samples. In contrast, hair follicle treatment with 3.2 J/cm 2 of 689 nm light (red light) did not significantly affect hair growth ex vivo. Silencing of OPN3 in the hair follicle outer root sheath cells resulted in the altered expression of genes involved in the control of proliferation and apoptosis, and abrogated stimulatory effects of blue light (3.2 J/cm 2 ; 453 nm) on proliferation in the outer root sheath cells. We provide the first evidence that (i) OPN2 and OPN3 are expressed in human hair follicle, and (ii) A 453 nm blue light at low radiant exposure exerts a positive effect on hair growth ex vivo, potentially via interaction with OPN3. Lasers Surg. Med. 49:705-718, 2017. © 2017 Wiley

Methodological Considerations for Hair Cortisol Measurements in Children

PubMed Central

Slominski, Radomir; Rovnaghi, Cynthia R.; Anand, Kanwaljeet J. S.

2015-01-01

Background Hair cortisol levels are used increasingly as a measure for chronic stress in young children. We propose modifications to the current methods used for hair cortisol analysis to more accurately determine reference ranges for hair cortisol across different populations and age groups. Methods The authors compared standard (finely cutting hair) vs. milled methods for hair processing (n=16), developed a 4-step extraction process for hair protein and cortisol (n=16), and compared liquid chromatography-mass spectrometry (LCMS) vs. ELISA assays for measuring hair cortisol (n=28). The extraction process included sequential incubations in methanol and acetone, repeated twice. Hair protein was measured via spectrophotometric ratios at 260/280 nm to indicate the hair dissolution state using a BioTek® plate reader and dedicated software. Hair cortisol was measured using an ELISA assay kit. Individual (n=13), pooled hair samples (n=12) with high, intermediate, and low cortisol values and the ELISA assay internal standards (n=3) were also evaluated by LCMS. Results Milled and standard methods showed highly correlated hair cortisol (rs=0.951, p<0.0001) and protein values (rs=0.902, p=0.0002), although higher yields of cortisol and protein were obtained from the standard method in 13/16 and 14/16 samples respectively (p<0.05). Four sequential extractions yielded additional amounts of protein (36.5%, 27.5%, 30.5%, 3.1%) and cortisol (45.4%, 31.1%, 15.1%, 0.04%) from hair samples. Cortisol values measured by LCMS and ELISA were correlated (rs=0.737; p<0.0001), although cortisol levels (median [IQR]) detected in the same samples by LCMS (38.7 [14.4, 136] ng/ml) were lower than by ELISA (172.2 [67.9, 1051] ng/ml). LCMS also detected cortisone, which comprised 13.4% (3.7%, 25.9%) of the steroids detected. Conclusion Methodological studies suggest that finely cutting hair with sequential incubations in methanol and acetone, repeated twice, extracts greater yields of cortisol

Complications in hair restoration.

PubMed

Lam, Samuel M

2013-11-01

Hair restoration requires a high level of specialized skill on the part of both the surgeon and the assistant team. Recipient-site problems can manifest from either surgeon or assistant error. The surgeon can create an unnatural hairline due to lack of knowledge of natural hair-loss patterns or badly executed recipient sites. He must also be cognizant of how hairs naturally are angled on the scalp to re-create a pattern that appears natural when making recipient sites. Assistants can also greatly contribute to the success or failure of surgery in their task of graft dissection and graft placement. Copyright © 2013 Elsevier Inc. All rights reserved.

28 CFR 551.4 - Hair length.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 28 Judicial Administration 2 2011-07-01 2011-07-01 false Hair length. 551.4 Section 551.4 Judicial Administration BUREAU OF PRISONS, DEPARTMENT OF JUSTICE INSTITUTIONAL MANAGEMENT MISCELLANEOUS Grooming § 551.4 Hair length. (a) The Warden may not restrict hair length if the inmate keeps it neat and clean. (b) The...

A boy with oral hair: case report.

PubMed

Agha-Hosseini, Farzaneh; Etesam, Farideh; Rohani, Bita

2007-09-01

In personal communication we have never seen or heard of hair being detected in the oral cavity. Even Julia Pastrana, the famous "Bearded Lady" of the 1800's, had no record of oral hair, although her entire body was covered with hair. Extensive records of her oral condition, including plaster models of her teeth have been preserved in the Odontological Museum of the Royal College of Surgeons in London city. She suffered from excessive gingival hyperplasia, but apparently no hair existed within the mouth. Some rodents have oral hair as a normal occurrence, but the condition is apparently limited in the animal kingdom. A case of hair occurring naturally in the mouth has been reported only twice previously. A third case of this rare anomaly is reported here. In this case, multiple hairs were found at the gingival sulcus in the labial, buccal, lingual and palatal tooth surfaces in an 11-year-old boy.

Sox2 in the dermal papilla niche controls hair growth by fine-tuning Bmp signaling in differentiating hair shaft progenitors

PubMed Central

Clavel, Carlos; Grisanti, Laura; Zemla, Roland; Rezza, Amelie; Barros, Rita; Sennett, Rachel; Mazloom, Amin; Chung, Chi-Yeh; Cai, Xiaoqiang; Cai, Chen-Leng; Pevny, Larysa; Nicolis, Silvia; Ma’ayan, Avi; Rendl, Michael

2012-01-01

SUMMARY How dermal papilla (DP) niche cells regulate hair follicle progenitors to control hair growth remains unclear. Using Tbx18Cre to target embryonic DP precursors, we ablate the transcription factor Sox2 early and efficiently, resulting in diminished hair shaft outgrowth. We find that DP niche expression of Sox2 controls the migration rate of differentiating hair shaft progenitors. Transcriptional profiling of Sox2 null DPs reveals increased Bmp6 and decreased Bmp inhibitor Sostdc1, a direct Sox2 transcriptional target. Subsequently, we identify upregulated Bmp signaling in knockout hair shaft progenitors and demonstrate that Bmps inhibit cell migration, an effect that can be attenuated by Sostdc1. A shorter and Sox2-negative hair type lacks Sostdc1 in the DP and shows reduced migration and increased Bmp activity of hair shaft progenitors. Collectively, our data identify Sox2 as a key regulator of hair growth that controls progenitor migration by fine-tuning Bmp-mediated mesenchymal-epithelial crosstalk. PMID:23153495

Identification and analysis of damaged or porous hair.

PubMed

Hill, Virginia; Loni, Elvan; Cairns, Thomas; Sommer, Jonathan; Schaffer, Michael

2014-06-01

Cosmetic hair treatments have been referred to as 'the pitfall' of hair analysis. However, most cosmetic treatments, when applied to the hair as instructed by the product vendors, do not interfere with analysis, provided such treatments can be identified by the laboratory and the samples analyzed and reported appropriately for the condition of the hair. This paper provides methods for identifying damaged or porous hair samples using digestion rates of hair in dithiothreitol with and without proteinase K, as well as a protein measurement method applied to dithiothreitol-digested samples. Extremely damaged samples may be unsuitable for analysis. Aggressive and extended aqueous washing of hair samples is a proven method for removing or identifying externally derived drug contamination of hair. In addition to this wash procedure, we have developed an alternative wash procedure using 90% ethanol for washing damaged or porous hair. The procedure, like the aqueous wash procedure, requires analysis of the last of five washes to evaluate the effectiveness of the washing procedure. This evaluation, termed the Wash Criterion, is derived from studies of the kinetics of washing of hair samples that have been experimentally contaminated and of hair from drug users. To study decontamination methods, in vitro contaminated drug-negative hair samples were washed by both the aqueous buffer method and a 90% ethanol method. Analysis of cocaine and methamphetamine was by liquid chromatography-tandem mass spectrometry (LC/MS/MS). Porous hair samples from drug users, when washed in 90% ethanol, pass the wash criterion although they may fail the aqueous wash criterion. Those samples that fail both the ethanolic and aqueous wash criterion are not reported as positive for ingestion. Similar ratios of the metabolite amphetamine relative to methamphetamine in the last wash and the hair is an additional criterion for assessing contamination vs. ingestion of methamphetamine. Copyright © 2014

Soft Hair on Black Holes

NASA Astrophysics Data System (ADS)

Hawking, Stephen W.; Perry, Malcolm J.; Strominger, Andrew

2016-06-01

It has recently been shown that Bondi-van der Burg-Metzner-Sachs supertranslation symmetries imply an infinite number of conservation laws for all gravitational theories in asymptotically Minkowskian spacetimes. These laws require black holes to carry a large amount of soft (i.e., zero-energy) supertranslation hair. The presence of a Maxwell field similarly implies soft electric hair. This Letter gives an explicit description of soft hair in terms of soft gravitons or photons on the black hole horizon, and shows that complete information about their quantum state is stored on a holographic plate at the future boundary of the horizon. Charge conservation is used to give an infinite number of exact relations between the evaporation products of black holes which have different soft hair but are otherwise identical. It is further argued that soft hair which is spatially localized to much less than a Planck length cannot be excited in a physically realizable process, giving an effective number of soft degrees of freedom proportional to the horizon area in Planck units.

Soft Hair on Black Holes.

PubMed

Hawking, Stephen W; Perry, Malcolm J; Strominger, Andrew

2016-06-10

It has recently been shown that Bondi-van der Burg-Metzner-Sachs supertranslation symmetries imply an infinite number of conservation laws for all gravitational theories in asymptotically Minkowskian spacetimes. These laws require black holes to carry a large amount of soft (i.e., zero-energy) supertranslation hair. The presence of a Maxwell field similarly implies soft electric hair. This Letter gives an explicit description of soft hair in terms of soft gravitons or photons on the black hole horizon, and shows that complete information about their quantum state is stored on a holographic plate at the future boundary of the horizon. Charge conservation is used to give an infinite number of exact relations between the evaporation products of black holes which have different soft hair but are otherwise identical. It is further argued that soft hair which is spatially localized to much less than a Planck length cannot be excited in a physically realizable process, giving an effective number of soft degrees of freedom proportional to the horizon area in Planck units.

Hair follicle nevus - A dermoscopic approach.

PubMed

Okada, Junna; Moroi, Yoichi; Tsujita, Jun; Takahara, Masakazu; Urabe, Kazunori; Kiryu, Hiromaro; Furue, Masutaka

2008-01-01

We report the case of a 26-year-old man who presented with small soft nodules with tiny hairs that had been present on his nose since childhood. The nodules were initially diagnosed as melanocytic nevi. However, dermoscopy showed many uniform hair follicles and an interfollicular 'pseudo-pigment network' in the nodules. Histologically, many well-differentiated hair follicles and sebaceous glands were seen in the dermis. Serial sectioning revealed neither central cysts nor a central canal. We therefore diagnosed this case as hair follicle nevus. Dermoscopy is now widely used as a non-invasive, in vivo technique for the diagnosis of pigmented skin lesions. Hair follicle nevus is a very rare disease and this is the first report to demonstrate the manifestation of this clinical entity by dermoscopy.