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At least 343 records · Page 19Linked to original sources
PubMed2006

Conformational differences in protein disulfide linkages between normal hair and hair from subjects with trichothiodystrophy: a quantitative analysis by Raman microspectroscopy.

Raman spectra of normal hair shafts and hair shafts from patients exhibiting trichothiodystrophy (TTD) were obtained using line focus laser illumination. Because hair from TTD patients has a significant decrease in the content of the sulfur-containing amino acids in comparison to normal hair, the 550-500 cm(-1) disulfide stretching mode region of the Raman spectrum was examined in detail. A quantitative spectral analysis demonstrates significant increases in the two energetically less favored gauche-gauche-trans (g-g-t) and trans-gauche-trans (t-g-t) forms. These observations suggest that the increased amounts of these less stable disulfide conformers are contributing factors to or associated with the hair brittleness observed for this congenital disorder. Structure-spectra correlations for the three dominant disulfide conformers are confirmed by quantum chemical calculations using modern density functional theory (DFT).

Biopolymers↗
PubMed2005

Is delayed micro-graft hair transplantation possible?--evaluation of viabilities of hair follicles preserved in two storage media.

BACKGROUND: Preservation of hair grafts for the purpose of delayed transplantation would allow use of thousands of hair grafts at one time. OBJECTIVE: To evaluate the viabilities of hair follicle units preserved in DMEM and Ringer's solution at 0 degrees C for various periods. METHODS: Cell cultures and transplantation of hair follicle units into athymic mice were used. RESULTS: Outer root sheath cells could be cultivated in 95.8% of those follicles preserved in Ringer's solution, and in 86.7% of those preserved in DMEM culture medium (p < 0.01). In 84.5% of those preserved in Ringer's and 72.5% of those preserved in DMEM for 24 h, hair follicles grew well after implantation into an athymic mouse model (p < 0.05).

Adult↗
PubMed2003

Short anagen hair with persistent synchronized pattern of scalp hair growth.

Unlike other mammals that molt hair seasonally, human beings have scalp hair follicles that exhibit an asynchronized pattern of cycling, with the growth and subsequent shedding of each hair being independent of others around it. This mosaic cycling behavior is established early and continues throughout life. We describe a boy who continues to have a synchronized pattern of hair growth and shedding, and a short anagen duration at 4 years of age. He appears to never have established the expected asynchronized pattern of hair growth.

Child, Preschool↗
PubMed1997

Effect of pigmentation on the drug deposition in hair of grey-haired subjects.

The hair samples of 15 grizzled patients with a permanent medical treatment by amitriptyline, carbamazepine, chlorprothixene, diclofenac, doxepine, indomethacine, maprotiline or metoclopramide, or with a chronic heroin and cocaine abuse were separated into white and pigmented fibers and both fractions were independently investigated by GC-MS. The drugs were found in pigmented fibers as well as in white fibers, but the concentrations in the white fibers were smaller than in the pigmented ones for the most of the samples investigated. The concentration ratio of the drugs or their metabolites in both hair fractions (white/pigmented) was found to be between 0.09 and 1.57 (mean 0.70, 30 concentration pairs). There are large differences in this ratio between different subjects with the same drug, whereas for different drugs in the same subject in many cases similar ratios were measured. As a reason a different grade of pigmentation of the hair and the influence of the drug structure are discussed. From these results it follows that the natural hair colour is an important parameter in the evaluation of drug concentration in hair.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1998

Pterins in human hair follicle cells and in the synchronized murine hair cycle.

Human dermal papilla cells (HDPC) express mRNA for the key enzymes for de novo synthesis/recycling and regulation of the pterin (6R)-L-erythro-5,6,7,8-tetrahydrobiopterin (6BH4). HDPC had significantly higher enzyme activities and 6BH4 levels in a comparative study with dermal fibroblasts, epidermal melanocytes, and keratinocytes under in vitro conditions. In addition, a significantly more rapid uptake of 14C-L-phenylalanine was demonstrated in HDPC compared with fibroblasts, whereas the differences in turnover to L-tyrosine were insignificant, suggesting a pooling of L-phenylalanine in HDPC. These results suggested that HDPC driven 6BH4 synthesis could be of major functional importance in the hair cycle. In order to follow this hypothesis in vivo, expression of enzyme activities and levels of the produced cofactor during the synchronized hair cycle were determined employing the murine model C57BL/6. These data revealed a significantly increased de novo synthesis for 6BH4 via GTP-cyclohydrolase I concomitant with high levels of 6BH4, and the induction of phenylalanine hydroxylase activities during the telogen/early anagen stage (days 0-1). Pterin levels and enzyme activities fall on day 3 and plateau during the rest of the entire cycle. In addition, thioredoxin reductase and glutathione reductase activities were measured, where the latter enzyme remained constant but thioredoxin reductase activities showed a biphasic behavior. The first peak coincided with the induction of 6BH4 de novo synthesis at the beginning of the hair cycle. The second peak was observed at mid-anagen, when melanogenesis takes place. Taken together, our results show the presence of autocrine pterin synthesis/recycling in human hair follicle cells under in vitro conditions, and a possible role for 6BH4 in the synchronized murine hair cycle.

Animals↗
PubMed1998

Localization of rat FGF-5 protein in skin macrophage-like cells and FGF-5S protein in hair follicle: possible involvement of two Fgf-5 gene products in hair growth cycle regulation.

It has been reported that the gene for murine fibroblast growth factor-5 (Fgf-5) is expressed in the rat hair follicle and that this expression may be associated with catagen induction (Hebert et al, 1994). In this study, we analyzed the Fgf-5 gene product in skin because the gene generates two mRNA that translate into the FGF-5 protein and a short form of the FGF-5 protein (FGF-5S) as a result of an alternative splicing (Hattori et al, 1996; Ozawa et al, 1996). Indeed, we detected both types of FGF-5 mRNA in rat skin samples. Two monoclonal anti-FGF-5 antibodies, one (E723) being specific for FGF-5 long-form protein and the other (B2B6) being reactive with both FGF-5 and FGF-5S proteins, were used to locate these proteins by immunohistochemistry. Staining of the rat skin revealed that only the B2B6 antibody reacted with hair follicles and that both antibodies reacted with macrophage-like round cells, suggesting that the product of the Fgf-5 gene in the hair follicle is FGF-5S. The immunoreactivity of the FGF-5S protein increased during early anagen VI and decreased rapidly during catagen. The density of FGF-5-positive macrophage-like cells in the dermis increased during anagen and decreased during catagen and telogen, whereas the density of these cells in the panniculus adiposus did not change during anagen and increased during catagen and telogen. There was no apparent association between the density of FGF-5-positive macrophage-like cells and that of FGF-5-negative, dendritic macrophage-like cells. Thus, the results suggest the possible involvement of FGF-5S in the hair follicle in anagen VI and catagen development and that the density of FGF-5-positive macrophage-like cells may also be associated with the hair growth cycle.

Animals↗
PubMed1998

Proanthocyanidins from grape seeds promote proliferation of mouse hair follicle cells in vitro and convert hair cycle in vivo.

For the purpose of discovering natural products which possess hair growing activity, we examined about 1000 kinds of plant extracts concerning growth-promoting activity with respect to hair follicle cells. After an extensive search, we discovered that proanthocyanidins extracted from grape seeds promote proliferation of hair follicle cells isolated from mice by about 230% relative to controls (100%); and that proanthocyanidins possess remarkable hair-cycle-converting activity from the telogen phase to the anagen phase in C3H mice in vivo test systems. The profile of the active fraction of the proanthocyanidins was elucidated by thiolytic degradation and tannase hydrolysis. We found that the constitutive monomers were epicatechin and catechin; and that the degree of polymerization was 3.5. We demonstrated the possibility of using the proanthocyanidins extracted from grape seeds as agents inducing hair growth.

Animals↗
PubMedDate not supplied

Skin and hair reflectance in women with red hair.

Skin and hair reflectance were measured with the Photovolt Spectrophotometer in 33 young women with red hair. Four skin sites were measured: forehead, check, inner arm and shoulder. A subsample of 15 red-headed women were tested before and at the end of the summer to test for tanning effects. The study was designed to test for relationships between hair and skin colour by reflectance spectrophotometry. As expected, subjects generally had very pale skin colour, pronounced freckling and very little tanning ability. Eumelanin (brown-black) pigment, as estimated by reflectance at 650 nm, was minimal at all skin and hair sites. Hair and inner arm reflectance values were highly correlated at short wavelengths, suggesting phaeomelanin as the source of the relationship. Estimates of tanning ability by use of the R/G ratio were very low in this sample of redheads.

Adult↗
PubMed2002

Alopecia of IFN-gamma knockout mouse as a model for disturbance of the hair cycle: a unique arrest of the hair cycle at the anagen phase accompanied by mitosis.

Interferon-gamma(-/-) (IFN-gamma(-/-)) and IFN-gamma(+/+) C57BL/6 mice (3 weeks of age) completed the production of morphogenesis-derived hair. Around 6 weeks of age, however, most of the IFN-gamma(-/-) but none of the IFN-gamma(+/+) mice began to lose hairs in the dorsal and occipital areas in the absence of inflammatory reactions, and the alopecia was sustained for at least several 10-week periods of observation. A single subcutaneous injection of IFN-gamma to IFN-gamma(-/-) mice at 3, but not 4, 5, or 8 weeks of age could protect all the mice from alopecia, revealing that the lack of IFN-gamma around 3 weeks of age is directly responsible for the alopecia. Histologic features showed that the hair follicles of the IFN-gamma(+/+) mice passed through the anagen (4-5 weeks of age) and catagen/telogen ( approximately 6 weeks of age) phases, whereas those of IFN-gamma(-/-) mice (5 weeks of age or older) stayed in the anagen phase. TUNEL and bromodeoxyuridine experiments suggested that an arrest with unlimited DNA synthesis of the hair cycle in the anagen phase by the lack of IFN-gamma-dependent apoptosis in the midfollicle region and diffuse shedding of previously formed hair induced alopecia in IFN-gamma(-/-) mice.

Age Factors↗
PubMed2000

Gating energies and forces of the mammalian hair cell transducer channel and related hair bundle mechanics.

We quantified the molecular energies and forces involved in opening and closing of mechanoelectrical transducer channels in hair cells using a novel generally applicable method. It relies on a thermodynamic description of the free energy of an ion channel in terms of its open probability. The molecular gating force per channel as reflected in hair bundle mechanics is shown to equal kT/I(X) x dI(X)/dX, where I is the transducer current and X the deflection of the hair bundle. We applied the method to previously measured I(X) curves in mouse outer hair cells (OHCs) and vestibular hair cells (VHCs). Contrary to current models of transduction, gating of the transducer channel was found to involve only a finite range of free energy (< 10 kT), a consequence of our observation that the channel has a finite minimum open probability of ca. 1% for inhibitory bundle deflections. The maximum gating forces per channel of both cell types were found to be comparable (ca. 300-500 fN). Because of differences in passive restoring forces, gating forces result in very limited mechanical nonlinearity in OHC bundles compared to that in VHC bundles. A kinetic model of channel activation is proposed that accounts for the observed transducer currents and gating forces. It also predicts adaptation-like effects and spontaneous bundle movements ensuing from changes in state energy gaps possibly related to interactions of the channel with calcium ions.

Animals↗
PubMedDate not supplied

Cytoskeletal basis for contractility of outer hair cells in the normal adult human organ of Corti: comparisons with vestibular hair cells.

The present study is the first consecutive analysis of the adult normal human organ of Corti and vestibular hair cells with regard to the expression of F-actin, actin-associated proteins (alpha-actinin, alpha- and beta-spectrins, vinculin and tropomyosin), beta-tubulin and the calcium-binding protein synaptophysin. The expression of these cytoskeletal and their associated proteins in man is largely similar to, although not identical with, that previously described for several other mammalian species. However, a few very unusual staining patterns were found. In several long outer hair cells a rod of F-actin extended from the infracuticular area to the cell nucleus. Fluorescence for tropomyosin occurred both in the cuticular plates of the outer and inner hair cells, and in the area of close apposition between the base of the outer hair cell and the apical part of Deiter's cell. In contrast, the vestibular hair cells showed immunoreactivity for tropomyosin only in the cuticular plates.

Actinin↗
PubMedDate not supplied

The ultrastructural characteristics of the hair bulb of segmented heterochromia in the scalp hair.

Segmented heterochromia is a pigmentary disorder characterized by alternating dark and light segments on each hair shaft. Our aim was to observe the ultrastructure of hair shafts and bulbs to understand the pathogenesis of the disease. Biopsy specimens including normal or diseased hair follicles were prepared for transmission electron microscopy. In dark segments, dense and ellipsoidal melanosomes were noted while small, round ones were found in the light segments. Two groups of melanosomes lined up on the matrix, one of which was composed of compact ellipsoidal melanosomes, and the other was composed of melanosomes with irregular sizes and shapes. Melanocytes seemed to be under necrosis, apoptosis, or dark cell transformation. Langerhans cells were found in the bulb. Two kinds of melanosomes were produced in the same hair bulb simultaneously. Degenerating melanocytes might produce deformed melanosomes. Langerhans cells might be involved in the death of melanocytes. It is unknown how either group of melanosomes is adopted and transferred to the hair cortex producing the characteristic pattern of pigmentation.

Adolescent↗
PubMed1989

Methadone concentrations in human hair of the head, axillary and pubic hair.

The concentrations of methadone and its metabolites in the hair of the head, axillary and pubic hair obtained from patients receiving a daily maintenance doses, were determined. Comparison of the concentrations provides the highest values in the axillary hair, followed by pubic hair and the hair of the head.

Adult↗
PubMed1989

Two-dimensional electrophoretic analysis of human hair keratins, especially hair matrix proteins.

Human hair keratins are composed of hair fibrous proteins (HFP) forming 10-nm filaments and nonfilamentous cysteine-rich hair matrix proteins (HMP); these proteins are highly cross-linked by disulfide bonds. In order to obtain high-resultional separation of HFP and HMP by two-dimensional polyacrylamide gel electrophoresis according to isoelectric point (IP) in the first dimension and molecular weight (MW) in the second dimension, these proteins were converted to S-carbamoylmethylated (SCam) derivatives with nonionizable iodoacetamide; this treatment hardly modified the electrophoretic mobility. SCam-HFP were separated into polypeptides with MW 41.5-59 kD (IP pH 5.1-6.8). SCam-HMP were subdivided into two groups; 14 polypeptides of acidic HMP with MW 15-28 kD (IP pH 5.0-7.0) and 12 polypeptides of basic HMP with MW 18.5-28 kD (IP pH 7.8-8.8). Variation in electrophoretic patterns among hair samples obtained from 15 persons in four Japanese families was found in acidic HMP, but not in HFP in basic HMP. The present method appears to be very suitable for the biochemical analysis of human hair keratins, especially HMP of nonfilamentous proteins.

Amino Acids↗
PubMed1996

Hair analysis for drugs of abuse. XIII. Effect of structural factors on incorporation of drugs into hair: the incorporation rates of amphetamine analogs.

In order to clarify the incorporation mechanism of drugs from blood into hair, seven effects of structural factors on the incorporation rate (ICR) were studied using 32 amphetamine analogs: (1) effect of a straight chained N-alkyl group; (2) effect of benzene and furan ring at N-position; (3) effect of aliphatic and aromatic hydroxy groups; (4) effect of triple bond group at N-position; (5) effect of N-acyl group and ketone group; (6) effect of methylenedioxy and methoxy groups on benzene ring; and (7) comparison between phenyltertiarybutylamines and phenylisopropylamines. After shaving the back hair and i.p. administration of drugs to Dark-Agouti rats (5 mg/kg, 10 days, n = 3), the areas under the concentration versus time curve (AUCs) of drugs in the plasma and the concentrations in hair newly grown for 4 weeks were determined by gas chromatography-mass spectrometry. The ICRs represented by the ratios of hair concentrations to AUCs were compared with those of amphetamine (AP) and methamphetamine (MA). The ICRs of N-alkyl AP increased depending on the length of carbon branches from proton to propyl (C3 > C2 > C1 > H) at N-position. The compounds containing a benzene or furan ring at the N-position (benzphetamine, clobenzorex, norbenzphetamine, prenylamine, furfenorex, and norfurfenorex) had much higher ICRs than those of AP or MA, suggesting that a benzene or furan ring increases their ICRs. The ICRs of deprenyl, nordeprenyl, and fenproporex were significantly low, implying that triple bonds such as of a propargyl or cyano group serve as a negative factor for the ICRs. An ephedrine group (ephedrine, methylephedrine, phenylpropanolamine) showed slightly lower ICRs than the corresponding amphetamine group. However, a hydroxy group on benzene ring apparently decreased the ICRs. Methoxy and methylenedioxy groups on benzene ring distinctly increased their ICRs. The lack of basicity such as N-formyl MA, N-acetyl AP, and N-acetyl MA dramatically lowered their ICRs to zero or nearly zero. Moreover, the compounds containing a ketone group adjacent to benzene ring, e.g., cathinone and amfepramone, showed very low ICRs. Chlorine on propyl group (mefenorex) or benzene ring (clobenzorex) seemed to act positively for the ICR. These results showed that structural factors related to the lipophilicity and basicity clearly affect the drug incorporation into hair from blood.

Amphetamines↗
PubMed1994

Hair analysis for drugs of abuse. VIII. Effective extraction and determination of 6-acetylmorphine and morphine in hair with trifluoroacetic acid-methanol for the confirmation of retrospective heroin use by gas chromatography-mass spectrometry.

A procedure for the detection and determination of 6-acetylmorphine (6AM) and morphine in rat and human hair is described. The efficiency of extraction of 6AM and morphine from hair was compared between five extraction methods using methanol, 0.1 M hydrochloric acid, methanol-5 M hydrochloric acid (20:1), helicase and methanol-trifluoroacetic acid (TFA) (9:1). Methanol-TFA was found to be the best solvent for extracting 6AM and morphine with minimum hydrolysis and maximum extraction efficiency of 6AM. The extraction rates of 6AM and morphine from heroin abuser's hair with methanol-TFA reached a plateau after 8-10 h. After the extraction from hair with deuterated internal standards added, the extract was purified by Bond Elut Certify in the usual manner. The 6AM and morphine were then derivatized with bis(trimethylsilyl)acetamide, which were characterized by GC-MS with electron impact ionization. Confirmation was accomplished by comparing their retention times and the relative abundances of major four selected ions with those of the standards. Quantification was based on the deuterated internal standards. Linearity was obtained in the concentration range 0.1-50 ng/mg. The overall recoveries after solvent extraction and solid-phase purification were 95% for 6AM and 97% for morphine. The limit of detection for confirmation was 0.2 ng/mg. The coefficients of variations for 6AM and morphine at concentrations of 4 ng/mg were generally less than 8%. 6AM was stable during extraction with methanol-TFA (9:1) at room temperature. This method was applied to the elucidation of heroin drug history by using hair sectional analysis.

Adult↗
PubMed2003

Hair transplanting: an important but often forgotten treatment for female pattern hair loss.

The techniques used in the early days of hair transplanting were not suitable for the treatment of a majority of women with pattern hair loss. For at least the last 10 years, changes in those techniques have resulted in a reversal of that situation. Today, many women with female pattern hair loss are suitable candidates for transplanting, however, this is not widely appreciated. This article provides potential explanations for this and demonstrates examples of the current methods. Hair transplanting should be considered as a potential treatment option for most women with pattern hair loss.

Adult↗
PubMed2001

Characterization of Wnt gene expression in developing and postnatal hair follicles and identification of Wnt5a as a target of Sonic hedgehog in hair follicle morphogenesis.

Mutations in WNT effector genes perturb hair follicle morphogenesis, suggesting key roles for WNT proteins in this process. We show that expression of Wnts 10b and 10a is upregulated in placodes at the onset of follicle morphogenesis and in postnatal hair follicles beginning a new cycle of hair growth. The expression of additional Wnt genes is observed in follicles at later stages of differentiation. Among these, we find that Wnt5a is expressed in the developing dermal condensate of wild type but not Sonic hedgehog (Shh)-null embryos, indicating that Wnt5a is a target of SHH in hair follicle morphogenesis. These results identify candidates for several key follicular signals and suggest that WNT and SHH signaling pathways interact to regulate hair follicle morphogenesis.

Animals↗