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Influence of internal structures of hair fiber on hair appearance. III. Generation of light-scattering factors in hair cuticles and the influence on hair shine.

The effects of thermal treatments on hair fiber induced by blow-drying have been investigated. It was found that the hair shows whitish and powdery appearance after heat drying, especially when dark hair is rapidly dried from a wet condition. For all kinds of hair, the appearance of numerous glittering speckles was confirmed on the cuticle surface by optical microscopic observations. SEM images of hair transverse and longitudinal sections with glittering speckles revealed that the splitting of cuticle layers generated by blow-drying occurred not only at the outermost parts of cuticle cells but also at the inner parts of the cellular interfaces. The release and uptake of moisture through fiber surfaces induces deformation of cuticle cells, probably because of anisotropic swelling or drying of the cells. The cuticles with glittering speckles are found to be fragile and are easily damaged in combination with other mechanical stresses such as combing force. Furthermore, the authors have found an efficient system for both improving hair shine and preventing cuticle damage caused by the blow-drying/combing process.

Adult↗

Hair density, hair diameter and the prevalence of female pattern hair loss.

BACKGROUND: Female pattern hair loss is common but estimates of its prevalence have varied widely. The relationships between the clinical diagnosis of female pattern hair loss and objective measurements of hair density and hair diameter have not previously been evaluated. OBJECTIVES: To determine the prevalence of female pattern hair loss and to relate the clinical findings to hair density and hair diameter. METHODS: We examined 377 women, aged 18--99 years, who presented to a general dermatology clinic with complaints unrelated to hair growth (the unselected sample). A second group of 47 women referred with typical female pattern hair loss was included in analyses of the relationships between hair density, hair diameter and the clinical diagnosis. Hair density was measured using a photographic method. In each subject the major and minor axis diameters were measured in a random sample of 50 hairs. RESULTS: Six per cent of women aged under 50 years were diagnosed as having female pattern hair loss, increasing to 38% in subjects aged 70 years and over. The mean +/- SEM hair density was 293 +/- 61.3 hairs cm(-2) at age 35 years, falling to 211 +/- 55.1 hairs cm(-2) at age 70 years. Hair density showed a normal distribution in the unselected sample. Most women classified as having female pattern hair loss had hair densities within the lower half of the normal distribution. The perception of hair loss was determined mainly by low hair density (ANOVA P < 0.001), but there was overlap in hair density between women classified as having Ludwig I hair loss and the no hair loss group, which was partly accounted for by differences in mean hair diameter (ANOVA P < 0.001). Low hair density was associated with fewer hairs of all diameters. CONCLUSIONS: Hair density in women is distributed as a normal variable, indicating that it is determined as a multifactorial trait. Women with female pattern hair loss have a hair density which falls below the mean but lies within the spectrum of the normal distribution, although other factors, including hair diameter, may affect the subjective impression of hair loss. The hair diameter data suggest that low hair density is not due to progressive diminution in hair follicle size and that follicular miniaturization may occur within the space of a single hair cycle.

Adolescent↗

A genetic electrophoretic variant of high-sulfur hair proteins for forensic hair comparisons. II. Practical application of electrophoretic analysis of hair protein to forensic hair comparisons.

The influence of weathering and cosmetic treatment on the analysis of human hair-carboxymethylated protein has been studied by a 15% polyacrylamide gel electrophoresis. Usual cosmetic treatment, i.e., permanent waving, dyeing, and bleaching, and weathering, i.e., hair samples that had been buried for up to 2 years, did not evidence any significant change in their electrophoretic patterns, though weathering for 2.5 years or longer made it difficult to determine the electrophoretic patterns. Capillary gel disc electrophoresis of a single, 5 cm, hair strand, which previously had been subjected to ABO blood group determination by an absorption-elution test, was sufficient to provide a multiple protein pattern analysis. Successful use of this analysis in a forensic case is described.

Electrophoresis, Polyacrylamide Gel↗

The size and form of the medulla of human scalp hair is regulated by the hair cycle and cross-sectional size of the hair shaft.

Hairs were sampled from long-haired Caucasian females, and cross-sectional measurements were performed using a rotating profile method at fixed humidity (100%). The effect of the hair cycle on medullation was investigated by examining medulla size and form along the lengths of anagen and telogen terminal hairs and also from a composite model of the entire medulla, as produced from a full cycle's growth, by amalgamating the results from the anagen and telogen hairs. The effect of hair shaft cross-sectional size on medullation has been investigated by controlling any effect of the hair cycle on terminal hairs and by use of the maximal medulla size in short, fine (vellous) hairs from the same subjects. All terminal hairs were medullated for the majority of their lengths. The presence and size of the medulla, in terminal hairs, was profoundly affected by the hair cycle. It was largest early in anagen, where the medulla minor axis, major axis and cross-sectional area represented about 26%, 23% and 7% of the corresponding whole hair shaft parameters (at 100% humidity). The medulla was virtually absent towards the end of anagen. The shape of the medulla cross-section was less elliptical than that of the whole hair shaft and was close to circular. There was no significant change in medulla shape through anagen. The form of the medulla was also affected by the hair cycle; approximately, it was continuous for the first 50% of anagen, discontinuous for the next 25% and virtually absent or absent for the final 25%. The maximal size of the medulla, as occurred in early anagen, was markedly associated with the cross-sectional size of the whole hair shaft, both within terminal hairs and between all scalp hairs. The medulla was large in terminal hairs and small or absent in very small hairs. The proportion of the whole hair shaft occupied by the medulla increased with increase in hair size and reached a maximum in terminal hairs, in which the medulla minor axis represented about 30% of the whole hair shaft minor axis. Furthermore, this proportion was constant in the terminal hairs and was not related to whole hair shaft size. Such maximal proportional medullation might represent a defining feature of terminal hairs. Variation in size of the medulla is not the cause of the previously reported cycle-dependent change in cross-sectional size of the whole hair shaft of terminal hairs.

Female↗

Human scalp hair as evidence of individual dosage history of haloperidol: a possible linkage of haloperidol excretion into hair with hair pigment.

We report a method for determining haloperidol concentration in human scalp hair and discuss a possible linkage of haloperidol excretion into hair with the hair pigment melanin. First, an animal study was conducted to support the idea that hair contains amounts of haloperidol corresponding to the doses given and pigmented hair contains much more drug than does unpigmented hair. The haloperidol concentration was measured using a radioimmunoassay technique after hairs were dissolved in 2.5 N NaOH solution and the drug extracted. Pigmented and albino rats, whose hair from an area on the back had been removed beforehand by plucking, were administered either 1, 3, or 10 mg of haloperidol (i.p.) per kg body weight every day for 3 weeks. At the end of the administration period hair which had newly grown on the denuded area was plucked and collected. In each of the two groups classified by hair color the drug levels in the hair correlated with the doses given; however, the concentrations in the hair from the albino rats were much lower than those in the hair from the pigmented rats (which was less than 8.5%). Second, black and white hair was collected from each of seven human subjects with grizzled hair, who were receiving or had been administered haloperidol at fixed daily doses for more than 1 month, and the concentration of haloperidol in each type of hair was measured. In the same subject the concentration in the white hair was found to be much lower than that in the black (less than 10%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

Reconstitution of hair follicle development in vivo: determination of follicle formation, hair growth, and hair quality by dermal cells.

Combinations of cultured and uncultured epidermal and dermal cell preparations from newborn and perinatal mice were grafted onto the backs of athymic nude mouse hosts to elucidate the cellular requirements for skin appendage formation. All epidermal populations studied, including a total epidermal keratinocyte preparation from trypsin-split skin, developing hair follicle buds isolated from epidermis, and preformed hair follicles isolated from dermis, make haired skin when grafted with fresh dermal cells. Only pre-formed hair follicles produce haired skin on grafts without an additional dermal component. Hair follicle buds grafted alone or with cultured dermal cells will reconstitute skin but without appendage formation. Thus, cells or factors present in fresh, but not cultured, dermal cells are essential for supporting hair growth from budding follicles, whereas more developed (pre-formed) follicles appear to contain all the necessary components for hair formation. Dissociation of isolated hair follicles by trypsin/ethylenediaminetetraacetic acid prior to grafting is permissive for hair growth, suggesting that follicle cells can be re-induced or reassociate in vivo. Dermal papilla cells, microdissected from rat vibrissal follicles and cultured for up to 14 passages, stimulate hair growth from follicle buds and influence the quality of hair growth from pre-formed hair follicles. Thus, dermal papilla cells maintain inductive capacity in culture and contribute to the reconstituted skin. This reconstitution model should be useful for identifying cell populations within the hair follicle compartment necessary for hair growth and for examining the effects of specific gene products on hair follicle growth and development in vivo.

3T3 Cells↗

Determination of triazolam involving its hydroxy metabolites in hair shaft and hair root by reversed-phase liquid chromatography with electrospray ionization mass spectrometry and application to human hair analysis.

A sensitive method using reversed-phase liquid chromatography coupled with electrospray ionization mass spectrometry has been developed for simultaneous determination of triazolam and its hydroxy metabolites in hair. After the addition of deuterium-labeled 1-hydroxymethyltriazolam as an internal standard, the analytes in hair shaft and hair root samples were extracted with a basic medium, CH(2)Cl(2):MeOH:28% NH(4)OH (20:80:2) at room temperature overnight. The chromatographic separation of the analytes was achieved using a semimicro HPLC column (3-microm particle size; 100 x 2.0-mm i.d.) by gradient elution with acetonitrile in water containing 1% acetic acid as eluent. The mass spectrometer was operated in selected-ion monitoring mode at quasi-molecular ions [M+H](+) of triazolam and its metabolites. The method has been applied to determine the incorporation of triazolam and its metabolites into the hair shafts and hair roots of Dark Agouti rats administered 3 or 6 mg/kg triazolam intraperitoneally twice a day for 5 days. Triazolam, 1-hydroxymethyltriazolam, and 4-hydroxytriazolam were incorporated into the hair shafts and the hair roots. The concentration of 4-hydroxytriazolam was the highest of all compounds detected. An unknown substance considered to be 1,4-dihydroxytriazolam also appeared in the hair samples. The structural elucidation was performed with online HPLC-MS after acetylation of the substance with acetic anhydride and pyridine. The time course studies of triazolam and the metabolites in both rat hair roots and plasma were carried out after single intraperitoneal administration of triazolam. The concentrations of triazolam and the metabolites in the hair roots reflected those in the plasma. The proposed method using selected-reaction monitoring was applied to the determination of triazolam and the metabolites in human hairs of a triazolam addict. Triazolam, 1-hydroxymethyltriazolam, and 4-hydroxytriazolam were identified in the black hair shafts, whereas only triazolam was detected in the hair roots and the white hair shafts. This is the first report on the detection of triazolam and its metabolites in human hairs.

Aged↗

The sinus hair follicle of the cat. Hair growth and hair cycle.

The cat's sinus hair follicle is described histologically with special regard to structural characteristics and functional mechanisms of sinus hair growth and sinus hair cycle. Special features of both cornification of the inner epithelial root sheath and hair fixation, respectively, result in a loss of traction that is required for hair growth and hair expulsion. Instead, there is the outgrowing new anagen sinus hair that pushes the preceeding sinus hair upwards, and - secondly - there is a long-lasting cell pro- liferation. Cell proliferation - immunocytochemically detected with anti-proliferating cell nuclear antigen - continues in the preceeding sinus hair while the formation of a new, succeeding sinus hair follicle begins. No distinct, 'typical' catagen state of sinus hair follicle has been found even in a large number of collected specimens. These findings stress that the well known features of hair growth and hair cycle in the pelage hair follicle cannot be generalized and adopted in all details to the sinus hair follicle.

Animals↗

Bubble hair. Case caused by an overheating hair dryer and reproducibility in normal hair with heat.

BACKGROUND: Bubble hair is an acquired hair shaft deformity characterized by bubble-like areas in the hair shaft seen with light microscopy and corresponding cavitary defects with scanning electron microscopy. OBJECTIVE: Our purpose was to report the fourth case of bubble hair, to demonstrate a cause, and to determine whether the cavities contain gas or liquid. METHODS: Light and scanning electron microscopy were performed. The patient's hair dryer was examined. We applied heat to normal hair of the patient and that of 16 human volunteers. Approximate temperatures for bubble formation were measured. The bubble contents were investigated by applying aqueous and nonaqueous liquids to affected hairs. RESULTS: No person's hair failed to develop bubbles when subjected to sufficient heat. The cause of bubble hair in the patient was an overheating hair dryer. The cavitations contained a gas. CONCLUSION: Bubble hair is a reproducible hair shaft defect caused by heat. The use of overheating hair dryers, or any other hair care equipment that overheats, should be avoided.

Adult↗

[Changes in telogen rate, hair density, hair diameter and rate of growth in androgenetic alopecia of the male. Simultaneously a contribution to the significance of dysplastic hair].

In a pilot study, comparative measurements of frontal and occipital trichograms, hair density, hair diameter and hair growth rate were performed on 26 male volunteers (ages 20-33 years) with androgenetic alopecia between stages II and V (Norwood scale). In the frontal region, the proportion of telogen hair was, in general, pathologically higher and increased according to stage. The density of the frontal hair was significantly lower (166 +/- 28/cm2) compared with that of the occipital region (193 +/- 24/cm2) and decreased according to stage. The average hair diameter in the higher Norwood stages decreased similarly in both the frontal and occipital regions, as shown by the correspondence between the two measurement points (frontal, 0.068 +/- 0.011 mm; occipital, 0.069 +/- 0.010 mm). Anagen and dysplastic hair from both the frontal and occipital regions was significantly thicker than telogen hair (0.07 mm vs 0.05 mm). The frontal growth rate (0.355 +/- 0.024 mm/day) was significantly lower than that of the occipital region (0.389 +/- 0.021 mm/day). In addition, the frontal growth rate decreased according to stage. Dysplastic hair exhibited high growth rates and diameters similar to those of typical anagen hair. In our opinion, dysplastic hair is growing hair, the roots of which have been artificially modified by plucking. - These intra-individual comparisons of frontal and occipital regions showed a reduction in the anagen phase, density, diameter and growth rate of the endangered frontal hair. A reduction in the size and dividing activity of the matrix is indicated by our data. It seems that these regressive changes occur primarily without a prior indication of accelerated hair growth.

Adult↗

Analysis of ofloxacin in hair as a measure of hair growth and as a time marker for hair analysis.

The distribution of ofloxacin (OFLX) along a single hair shaft was analyzed in detail for use as an index of hair growth and as a time marker for drug analysis in hair. A single hair obtained from each of seven subjects, who had taken OFLX for 1-4 days (total of 200-1,200 mg) 2.7-5.3 months before hair sampling, was cut into 1-cm-long portions successively from its scalp end. OFLX in each hair portion was measured by high-performance liquid chromatography with a fluorescence detector, and the distance from the scalp end of the hair portion containing OFLX was determined. Then the other 2-cm long segment of hair, which had the above-determined distance at its middle, was cut successively into 2-mm-long pieces and OFLX was determined in each piece. This procedure was repeated in a total of three to four hair strands collected from one subject. OFLX was observed to distribute only in one to three consecutive 2-mm-long pieces of hair, showing no large diffusion of OFLX along the hair shaft with time. Therefore, OFLX distribution may serve as a time marker for analyzing other drugs in hair. Hair growth rate could be thus estimated and ranged from 0.99 to 1.27 cm/month (1.12 +/- 0.11 cm/month, mean +/- SD) among individuals. The intraindividual variability of hair growth rate was 4.8-18.1% (10.3 +/- 5.1%) as coefficient of variation.

Adult↗

Hair analysis for drugs of abuse. XIX. Determination of ephedrine and its homologs in rat hair and human hair.

A sensitive GC-MS method was developed for the quantitative analysis of ephedrine (EP), phenylpropanolamine (PPA) and methylephedrine (ME) in animal and human hair. After washing with 0.1% sodium dodecyl sulfate, hair samples (10 mg) were added with deuterated internal standards, extracted by 1-h sonication and over night soaking in 2 ml of 5 M HCl-methanol (1:20) at room temperature. Following evaporation of the liquid phase, the residue was dissolved in phosphate buffer solution (pH 6.0) and purified using a solid-phase extraction procedure with Bond Elut Certify columns. Two types of derivatization were compared - using trifluoroacetic anhydride (TFAA) and pentafluoropropionic anhydride (PFPA) - for discrimination of EP and methamphetamine (MA). Derivatized extracts were analyzed by GC-MS in the EI mode using a capillary column (OV-1 equivalent). From the results comparing three GC-MS conditions, PFP-derivatives separated with a temperature gradient of 20 degrees C/min from 60 degrees C to 280 degrees C gave the best resolution between EP and MA. ME was analyzed as a trimethylsilyl derivative using N,O-bis-trimethylsilyl acetamide at the above GC condition. The assay was linear from 0.5 to 50 ng/mg (r=0.998) and capable of detecting less than 50 pg of derivatized EP, PPA and ME on-column. Intra-assay precision was characterized by C.V. values from 5 to 16% in the concentration range of 1-10 ng/mg hair. The method was used for the quantitative determination of EP, PPA and ME in the hair obtained from three rats with dark brown hair after ten intraperitoneal injections (5 mg/kg/day) of the three drugs and from three male and one female volunteers with black hair after an oral dose of 50 mg/day of EP-HCl for three days. Hair samples were collected by shaving from the back of rats and cutting from the scalp of humans 28 days after the first dose. The incorporation rates of EP, PPA and ME into hair (the ratios of [hair concentration] to [AUC]) obtained from the animal experiment were 0.10, 0.07 and 0.03, respectively, which are a little lower than those (0.14, 0.10 and 0.04) of their desoxy-compounds, MA, amphetamine and dimethylamphetamine. EP was detected at an average of 2.25 ng/mg (n=4) in human scalp hair and at a range of 1-29 ng/mg (n=3) in human beard hair until day 14, but its metabolite (PPA) was at a trace level in the hair of the four subjects. The method was successfully used for detection of ME and EP in the hair of a neonate and its mother who was abusing Bron syrup containing ME during the pregnancy.

Amphetamines↗

The effect of hair bundle shape on hair bundle hydrodynamics of inner ear hair cells at low and high frequencies.

The relationship between size and shape of the hair bundle of a hair cell in the inner ear and its sensitivity at asymptotically high and low frequencies was determined, thereby extending the results of an analysis of hair bundle hydrodynamics in two dimensions (Freeman and Weiss, 1990. Hydrodynamic analysis of a two-dimensional model for micromechanical resonance of free-standing hair bundles. Hear. Res. 48, 37-68) to three dimensions. A hemispheroid was used to represent the hair bundle. The hemispheroid had a number of advantages: it could represent shapes that range from thin, pencil-like shapes, to wide, flat, disk-like shapes. Also analytic methods could be used in the high frequency range to obtain an exact solution to the equations of motion. In the low frequency range, where an approximate solution was found using boundary element methods, the sensitivity of the responses of hair cells was mainly proportional to the cube of the heights of their hair bundles, and at high frequencies, the sensitivity of the hair cells was mainly proportional to the inverse of their heights. An excellent match was obtained between measurements of sensitivity curves in the basillar papilla of the alligator and bobtail lizards and the model's predictions. These results also suggest why hair bundles of hair cells in vestibular organs which are sensitive to low frequencies have ranges of heights that are an order of magnitude larger than the range of heights of hair bundles of hair cells found in auditory organs.

Acoustic Stimulation↗

Ruby laser-assisted hair removal: a preliminary report of the correlation between efficacy of treatment and melanin content of hair and the growth phases of hair at a specific site.

An unpredictable response, even in patients with dark hair, often undermines successful ruby laser hair removal. A prospective clinical study was carried out to evaluate the roles of melanin content and growth phases of hair in treatment efficacy. Thirty-six volunteers with white skin and dark hair were recruited for the study, and were all treated using the Chromos 694 Depilation Ruby Laser. The overall efficacy of treatment was assessed at the end of 3 months. The efficacy of laser treatment is not due solely to the proportion of hair in the growing or static phase of the hair cycle. There is a lack of correlation between the melanin content and the overall efficacy of laser hair removal in those treated once, but patients with darker hair responded better after repeated treatments. The proportion of hair in the growth phase and the melanin content of hair do not contribute solely to the efficacy of ruby laser hair removal.

Hair↗

Actin filaments, stereocilia, and hair cells of the bird cochlea. I. Length, number, width, and distribution of stereocilia of each hair cell are related to the position of the hair cell on the cochlea.

Located on the sensory epithelium of the sickle-shaped cochlea of a 7- to 10-d-old chick are approximately 5,000 hair cells. When the apical surface of these cell is examined by scanning microscopy, we find that the length, number, width, and distribution of the stereocilia on each hair cell are predetermined. Thus, a hair cell located at the distal end of the cochlea has 50 stereocilia, the longest of which are 5.5 microns in length and 0.12 microns in width, while those at the proximal end number 300 and are maximally 1.5 microns in length and 0.2 micron in width. In fact, if we travel along the cochlea from its distal to proximal end, we see that the stereocilia on successive hair cells gradually increase in number and width, yet decrease in length. Also, if we look transversely across the cochlea where adjacent hair cells have the same length and number of stereocilia (they are the same distance from the distal end of the cochlea), we find that the stereocilia of successive hair cells become thinner and that the apical surface area of the hair cell proper, not including the stereocilia, decreases from a maximum of 80 microns2 to 15 microns2. Thus, if we are told the length of the longest stereocilium on a hair cell and the width of that stereocilium, we can pinpoint the position of that hair cell on the cochlea in two axes. Likewise, if we are told the number of stereocilia and the apical surface of a hair cell, we can pinpoint the location of that cell in two axes. The distribution of the stereocilia on the apical surface of the cell is also precisely determined. More specifically, the stereocilia are hexagonally packed and this hexagonal lattice is precisely positioned relative to the kinocilium. Because of the precision with which individual hair cells regulate the length, width, number, and distribution of their cell extensions, we have a magnificent object with which to ask questions about how actin filaments that are present within the cell are regulated. Equally interesting is that the gradient in stereociliary length, number, width, and distribution may play an important role in frequency discrimination in the cochlea. This conclusion is amplified by the information presented in the accompanying paper (Tilney, L.G., E.H. Egelman, D.J. DeRosier, and J.C. Saunders, 1983, J. Cell Biol., 96:822-834) on the packing of actin filaments in this stereocilia.

Animals↗

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.

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.

Adult↗

Hair analysis for drugs of abuse. XI. Disposition of benzphetamine and its metabolites into hair and comparison of benzphetamine use and methamphetamine use by hair analysis.

In order to study the disposition of benzphetamine (BZP) and its metabolites, desmethyl benzphetamine (norBZP), p-hydroxy desmethyl benzphetamine (OHnorBZP), methamphetamine (MA) and amphetamine (AP), from plasma to hair in rats, an analytical method for identifying these drugs in plasma, urine and hair was developed with selected ion monitoring of gas chromatograph/mass spectrometry (GC/MS-SIM) results. After the intraperitoneal administration of BZP to rats (10 mg/kg/d, 10d, n = 3), concentrations of BZP and its metabolites in rat hair newly grown for 4 weeks were compared to the areas under the concentration versus time curve (AUCs) of these drugs in the rat plasma. The concentrations of BZP, norBZP, OHnorBZP, MA and AP in the rat hair were 14.8 +/- 1.4, 6.1 +/- 0.3, 2.6 +/- 0.5, 2.3 +/- 0.1 and 9.2 +/- 0.3 ng/mg, and the ratio of the concentrations in the hair to AUCs in the rat plasma was 3.0:0.1:0.1:0.6:0.2, respectively. This fact suggested that BZP tends to be readily incorporated into hair from blood. The method was applied to the determination of the metabolites in scalp hair and pubic hair of humans who orally ingested BZP (30 mg/d, 5d, n = 2). BZP, norBZP, MA and AP were detected at 0.14-0.56, 0.29-0.63, 0.10 and 1.06-1.66 ng/mg in the scalp hair and at 0.10-0.20, 0.13-0.18, trace-0.15 and 0.23 ng/mg in the pubic hair, respectively. It was shown that BZP use could be retrospectively distinguished from MA use by the detection of BZP and/or norBZP in hair.

Adult↗

Hair analysis for drugs of abuse. III. Movement and stability of methoxyphenamine (as a model compound of methamphetamine) along hair shaft with hair growth.

This paper describes the movement of methoxyphenamine (MOP, a model compound of methamphetamine) along the hair shaft at the rate of hair growth and the stability of drugs in hair for several months. Five healthy subjects (3 males and 2 females) took 50 mg of methoxyphenamine orally once a day for 7 days. Scalp hairs from the posterior vertex were collected every 2 weeks or every 8 weeks after the first dosage. The hairs were cut into 1-cm sections and extracted with methanol-5N HCl (20:1). MOP in the extract was determined by gas chromatography/mass spectrometry (GC/MS) with tetradeuterium labeled MOP as an internal standard. The drug moved along hair shaft at the rate of 2.8-3.2 mm/week, according to hair growth, without diffusion. When drug bands were extrapolated according to the sections in which drug was detected, the bands were approximately 5 mm wide, equivalent to 1.7-2.4 periods of 7-day hair growth. In the case of identical doses, the drug level was highest in the root side and lowest in the distal side. In our data, we found that the drug level in hair had decreased approximately 50% five months later. The ratio of drug levels in corresponding sections correlated well to the ratio of doses, except where the hair shafts had been damaged or the drugs had decomposed.

Adult↗