Effect Of Hair Color Research Articles

Citalopram and escitalopram in hair segments from deceased individuals with mental illnesses

To aim of the study was determine concentrations of citalopram, escitalopram and their primary metabolite in hair segments from individuals with mental illnesses and correlate them to an estimated daily dose. Citalopram is a commonly sold antidepressant. It contains a chiral center and is used in therapy as the racemic mixture (RS-citalopram) or as the pure enantiomer (S-citalopram), escitalopram. The use of pharmaceuticals, polypharmacy and drug abuse can all been linked to elevated death rate among individuals with mental illnesses. Therefore, information on previous drug intake is important and can be obtained by hair analysis. Monthly drug intake before death is investigated using an average hair growth rate of 1 cm/month and analysis of 1 cm hair segments. Investigations on drug distribution in the hair and its relationship to the estimated dose provide insight into the interpretation of forensic cases. Hair samples were collected from 44 deceased individuals included in the autopsy-based study “SURVIVE” and had a presumed history of citalopram use based on results in the postmortem blood sample or the case history. Citalopram and N-demethylcitalopram were quantified using a previous method optimized to cover long-term drug intake. The method was successfully validated according to international guidelines with a measurement range of 0.005 to 100 ng/mg by using 12 C and 13 C isotopes. Depending on the length of the hair, hair samples were cut into 6 × 1 cm segments corresponding to six months before death. The segments were weighted, washed, pulverized, and incubated over night at 37 °C in an extraction medium of methanol, acetonitrile and 2 mM ammonium formate (25:29:46, v/v/v). After filtration, the extract was injected into an LC–MS/MS system. Soaked QCs in hair at three concentrations levels were included. After quantification, R- and S-citalopram were identified using a method adapted from chiral determination of citalopram in blood. Prescription data was used to estimate daily doses. We found citalopram concentrations in hair ranging from 0.12 to 67 ng/mg (10th–90th percentile) with a median of 8.2 ng/mg ( N = 40 individuals, n = 182 segments) and escitalopram concentrations ranging from 0.027 to 7.0 ng/mg (10th–90th percentile) with a median of 3.9 ng/mg ( N = 4, n = 23). Similar or decreasing concentrations throughout the segments were often detected, indicating a probable wash out of citalopram over time. The daily doses calculated varied from 1.3 to 69 mg/day (median 27 mg/day). We found no correlations between the hair concentrations and the estimated daily dose ( N = 30, P = 0.1). However, after accounting for the calculated daily doses, our findings revealed a propensity for dark hair to have higher citalopram concentrations than light hair, indicating a possible effect of hair color on the hair concentration. The 10th–90th percentile metabolite-to-drug ratios in hair were 0.053–0.63 ( N = 39, n = 166) with intraindividual variability of <25% for most individuals. Citalopram concentrations >30 ng/mg were found in 13 individuals suggesting very high levels in hair. The chiral analysis revealed that racemic citalopram had a median R/S ratio of 1.5 ( N = 27), which is consistent with blood ratios. This study determined concentrations of citalopram, escitalopram and N-demethylcitalopram in 1 cm segments from 44 deceased individuals with mental illnesses applying chiral separation of R- and S-citalopram. This is the first study reporting chiral separation of citalopram in hair samples. No correlations were found between the concentrations in hair and the estimated daily dose. However, our findings suggest that hair color has an impact on this. This research contributes to the establishment of reference values for citalopram in hair for future forensic investigations.

An experimental study on the effect of hair color in person perception

An experimental study on the effect of hair color in person perception

CONTENTS OF MANGANESE, ZINC, COPPER AND MOLYBDENUM IN THE HAIR OF THE FARM ANIMALS IN THE LOWER DNIESTER VALLEY

Aim. The aim is to identify the differences in the accumulation of manganese, zinc, copper and molybdenum in the hair of farm animals (cows and goats) and their spatial differentiation in the valley of the Lower Dniester. Methods. Sampling and sample preparation were carried out in accordance with generally accepted methods. The determination of metal content in hair samples was carried out in accredited laboratories using atomic absorption spectrometry (AAS) and Inductively Coupled Plasma Spectroscopy (ICP-S). Results. For the first time, data are presented on the content of biogenic metals (manganese, zinc, copper, molybdenum) in the hair of the tail of black-and-white cows and Russian White and Saanen goats in the valleys of the Lower Dniester. Conclusions. It is shown that the concentration of trace elements in the hair of farm animals reflects the relative homogeneity of the biogeochemical conditions of the Lower Dniester valley. It is established that cows and goats are characterized by a sharply differing elemental status for the studied metals estimated on the basis of an analysis of their concentrations in the hair of the tail. At the same time, the effect of hair color on the content of elements was revealed only for molybdenum in cows, and for goats there were no significant interbreed differences in metal concentrations.

Women's Hair Color and Survey Response Rate: A Field Experiment

Previous research found that survey response rates were influenced by physical characteristics of the interviewer. However, the effect of hair color on compliance to a survey request has never been studied. Female confederates wearing blond, brown, black, or red wigs solicited 1,200 male and female pedestrians for a survey. It was found those male passersby, but not the female, agreed more frequently to the confederates wearing blond wigs whereas they agreed less to the same confederates wearing red wigs. Greater youth and healthiness associated with blond hair in women is used to explain these results. The practical interest in face-to-face surveys is addressed.

Bispectral Index Dynamics During Propofol Hypnosis Is Similar in Red-Haired and Dark-Haired Subjects

We have previously shown that red hair is associated with increased desflurane requirement for immobility, compared with dark hair. The effect of red hair on IV anesthetic requirement remains unknown. We tested the hypothesis that the propofol concentration in the effect site associated with half maximal electroencephalogram response, Ce50, is at least 50% higher in subjects with red hair. We modeled the propofol concentration versus electroencephalogram response relationship using a 2-step approach in 29 healthy dark- and red-haired volunteers receiving a propofol infusion to produce loss of consciousness. Bispectral Index (BIS) was the measure of drug effect. The parameters of a 3-compartment pharmacokinetic model were fit to measured arterial propofol concentrations. The relationship between effect-site propofol concentration (Ce) and BIS was characterized using a sigmoid Emax model. Model performance and accuracy of the estimated parameters were evaluated using accepted metrics and bootstrap resampling. The effect of hair color on the Ce50 for BIS response in the final model was assessed using a threshold of 6.63 (P<0.01) in reduction of -2 log likelihood. The influence of body weight on the model was also assessed. The inclusion of hair color as a model covariate did not improve either the pharmacokinetic or the pharmacodynamic model. A separate analysis for the dark- and red-haired subjects estimated a median (95% confidence interval) Ce50 BIS of 2.71 μg/mL (2.28-3.36 μg/mL) and 2.57 μg/mL (1.68-3.60 μg/mL), respectively. Body weight was a significant covariate for the CL1 and V1. Red hair phenotype does not affect the pharmacokinetics or pharmacodynamics of propofol.

Waitresses’ Hair Color and Customers’ Tipping Behavior: Blondes Receive more Tips from Men but not from Women

Waitresses’ Hair Color and Customers’ Tipping Behavior: Blondes Receive more Tips from Men but not from Women The study of the effect of women’s hair color on people’s behavior has revealed discrepant results, which could be explained by many methodological differences and confounding variables in the literature on this topic. For this study, the effect of hair color on behavior was experimentally tested in a tipping context. Two waitresses in one restaurant located in Brittany, France, were instructed to wear blond, brown, or dark colored wigs. The effect of hair color on tipping according to the patrons’ gender was measured. It was found that the waitresses wearing blond wigs received more tips but only from male patrons. Waitresses’ hair color had no effect on women’s tipping behavior.

Hair Color and Courtship: Blond Women Received More Courtship Solicitations and Redhead Men Received More Refusals

Previous research on the effect of hair color on people’s evaluation and behavior has revealed discrepant results and the real effect of both male and female hair color on their mating attractiveness has never been tested. In Study 1, female confederates wearing blond, brown, black or red colored wigs were observed while sitting in a nightclub. In Study 2, male confederates wearing different colored wigs asked women in a nightclub for a dance. It was found that blond women were more frequently approached by men whereas blond males did not receive more acceptances to their requests. However, in both conditions, red hair was associated with less attractiveness. Evolutionary theory and differences in mating preferences are used to explain the blond hair effect. Scarcity of red-haired individuals in the population and negative stereotypes associated with red hair are used to explain the negative effect of red hair.

The Effect of Hair Colour on Anaesthetic Requirements and Recovery Time after Surgery

Patients with red hair are much more likely to have a variant of the melanocortin-1 receptor gene and this may affect sensitivity to general anaesthetics and pain response. We did a prospective, matched cohort study of 468 healthy adult patients undergoing general anaesthesia for elective surgery. All patients received an inhalational general anaesthetic. Anaesthetic drugs and doses used, hypnotic depth, recovery times, pain scores and quality of recovery scores were recorded. More men than women had red hair, so we did subgroup and multivariable analyses to account for this imbalance. There was no significant difference in recovery times, pain scores or quality of recovery scores in those with red hair. After adjusting for age, sex, American Society of Anesthesiologists physical status and duration of surgery, the recovery ratio for time to eye-opening in redheads was comparable to those with black or brown hair, 0.82 (0.57-1.19), P=0.30. We found no evidence that patient hair colour affects anaesthetic requirements or recovery characteristics in a broad range of surgical procedures.

Hair color and wages: Waitresses with blond hair have more fun

The effect of employees’ hair color on wages was experimentally tested in a tipping context. Waitresses in several restaurants were instructed to wear blond, red, brown or dark colored wigs. The effect of hair color on tipping according to patron's gender was measured. It was found that waitresses wearing blond wigs received more tips but only with male's patrons. Waitresses’ hair color had no effect on females’ tipping behavior.

Effect of hair color and sun sensitivity on nevus counts in white children in Colorado

It has been widely reported that individuals with a light phenotype (ie, light hair color, light base skin color, and propensity to burn) have more nevi and are at greater risk for developing skin cancer. No studies have systematically investigated how phenotypic traits may interact in relation to nevus development. We sought to systematically examine whether any combinations of phenotype are associated with a greater or lesser risk for nevus development in white children. In the summer of 2007, 654 children were examined to determine full body nevus counts, skin color by colorimetry, and hair and eye color by comparison with charts. Interviews of parents were conducted to capture sun sensitivity, sun exposure, and sun protection practices. Among 9-year-old children with sun sensitivity rating type II (painful burn/light tan), those with light hair had lower nevus counts than did those with dark hair (P value for interaction = .03). This relationship was independent of eye color, presence of freckling, sex, usual daily sun exposure, sunburn in 2004 to 2007, sun protection index, and waterside vacation sun exposure. The difference in nevus counts was further determined to be specific to small nevi (<2 mm) and nevi in intermittently exposed body sites. Geographic and genetic differences in other study populations may produce different results. The standard acceptance that dark phenotype is a marker for low melanoma risk and light phenotype a marker for high risk may need to be reevaluated. In non-Hispanic white children, dark-haired individuals who burn readily and then tan slightly are more prone to nevus development, and may therefore be a previously underrecognized high-risk group for melanoma.

Hitchhiking women's hair color.

To test the effect of women's hair color on the frequency of offering help, male (n = 1,508) and female (n = 892) French motorists were tested in a hitchhiking situation. Five 20- to 22- yr.-old female confederates wore a wig with blonde, brown, or black hair. Each confederate was instructed to stand by the side of a road frequented by hitchhikers and hold out her thumb to catch a ride. Blonde hair, compared with brown hair or black hair, was associated with a small but significantly larger number of male drivers who stopped to offer a ride (18 vs 14%). No difference was found for those with brown and black hair (14 and 13%, respectively). No effect of hair color was found for female drivers who stopped. The greater attractiveness associated with blonde hair for women appears to explain these data.

Assessment of long-term subacute exposure to dimethoate by hair analysis of dialkyl phosphates DMP and DMTP in exposed rabbits: The effects of dose, dose duration and hair colour

Hair analysis for dialkyl phosphates' (DAPs) residues could provide a measure of chronic exposure to organophosphate pesticides (OPs). The aim of this study was to determine whether these metabolites can be internally incorporated into the hair of rabbits exposed to dimethoate and also to investigate the influence of dose and dose duration of this OP, as well as the effect of hair colour on the concentrations of its DAPs in hair. Two-coloured rabbits were daily exposed to dimethoate (0, 12 or 24mgkg(-1) body weight) via their drinking water. Hair samples of both colours were obtained 4 and 6 months after the beginning of exposure from the back of all treated rabbits, and each hair colour sample was analyzed for dimethyl phosphate (DMP) and dimethyl thiophosphate (DMTP) by gas chromatography-mass spectrometry (GC-MS). Analysis revealed the incorporation of these metabolites into the rabbit hair in a dose-dependent manner. The mean concentrations found ranged from 0.18 to 0.77ngmg(-1) for DMP and from 0.43 to 1.53ngmg(-1) for DMTP. Mixed results for the significance of the relationship between dose duration and the levels of the two DAPs in hair are observed. Hair pigmentation does not appear to affect the concentration values of DMTP, whereas it seems to be a critical factor in the incorporation of DMP into hair. These data confirm the ability of hair testing to assess chronic OP exposure by the detection of DAPs.

Assessing the potential of a “color effect” for hair analysis of 11-nor-9-carboxy-Δ 9-tetrahydrocannabinol: Analysis of a large sample of hair specimens

It has been hypothesized that hair color may play a role in the concentration of various drugs of abuse in hair. Several studies have shown that melanin in hair appears to play a binding role for at least some commonly abused drugs. However, these studies have been limited by a number of factors when assessing the clinical significance of a hypothesized melanin or color effect. This study evaluates the possible effect of hair color on the concentration of 11-nor-9-carboxy-Δ 9-tetrahydrocannabinol (c-THC) in human hair. The analysis is based on 3,886 positive c-THC hair specimens drawn from a universe of approximately 80,000 specimens of scalp hair harvested from the posterior vertex of the head. Analysis of variance of color categorization by c-THC concentration shows that c-THC concentration does not have a significant association with hair color (Hair Color F = 1.148, p = .332) and therefore does not have a demonstrable “color effect”.

The Effect of Hair Color on the Incorporation of Codeine into Human Hair

The influence of melanin on the binding of xenobiotics in hair will impact the interpretation of drug concentrations determined by hair testing. The purpose of this study was to determine if codeine, as a model compound of abused drugs, would be incorporated into black, brown, blond, or red hair as a function of melanin concentration. Such data would assist in the interpretation of codeine concentrations in hair and help elucidate the potential influence of hair color on incorporation of drugs. Male and female Caucasians with black (n = 6), brown (n = 12), blond (n = 8), or red hair (n = 6) and non-Caucasians with black hair (n = 12) aged 21-40 years were enrolled in the study. Each subject was administered oral codeine phosphate syrup in a dosage of 30 mg three times a day for five days. Twenty-four hours after the end of the treatment period, a 30-mg codeine dose was administered and the subject's plasma area under the concentration time curve (AUC) for codeine was determined. Codeine and melanin were measured in the first 3 cm of hair closest to the vertex region of the scalp prior to and 1, 4, 5, 6, and 7 weeks after dosing. The quantitative and qualitative melanin profiles were determined for each subject's hair to provide an objective measure of hair color. The plasma concentrations of codeine were measured to eliminate differences in the bioavailability and clearance of codeine as factors that might account for the differences in codeine hair concentrations. The subjects were asked not to cut their hair in the vertex region of the scalp or to use any form of chemical treatment on their hair, but otherwise normal hygienic measures were permitted. The mean (+/- SE) hair codeine concentrations 5 weeks after dosing were 1429 (+/- 249) pg/mg in black hair; 208 (+/- 17) pg/mg in brown hair; 99 (+/- 10) pg/mg in blond hair; and 69 (+/- 11) in red hair pg/mg. In black hair, codeine concentrations were 2564 (+/- 170) pg/mg for Asians and 865 (+/- 162) pg/mg for Caucasians. Similar concentration relationships were observed at weeks 4, 6, and 7. A strong relationship between the hair concentrations of codeine and melanin (R(2) = 0.73) was observed. Normalization of the codeine concentration with the melanin concentration reduced the hair color differences observed. These data demonstrate that the interpretation and reporting of hair test results for codeine are influenced by hair color. After this dosing protocol, the proposed federal guideline cutoff of 200 pg/mg of codeine would result in 100% of subjects with black hair and 50% of subjects with brown hair being reported as positive, and subjects with blond or red hair would be reported as negative. The incorporation of these drugs into hair should be studied carefully in humans to ensure the appropriate interpretation of drug concentrations.

The amino acid composition of cat (Felis catus) hair

AbstractThe amino acid composition of cat hair was determined by conventional 24-h acid hydrolysis and non-linear least-squares extrapolation to time zero of the amino acid composition data from a series of hydrolysis intervals. Twenty-five individual samples of cat hair, consisting of four colours, were also analysed (24-h hydrolysis) to determine if there was an effect of hair colour on amino acid composition. Amino acids were determined following HCl hydrolysis (6 mol/l) with cysteine and methionine determined by performic acid oxidation of the sample prior to hydrolysis.There was no significant (P &gt; 0·05) effect of hair colour on the amino acid composition of cat hair. The non-linear compartmental model used to determine the amino acid composition of cat hair took into account the simultaneously occurring processes of hydrolysis and degradation of amino acids over time. The amino acids cysteic acid, methionine-sulphone, threonine and serine exhibited high loss rates during 6 molll HCl hydrolysis while the peptide bonds involving valine and leucine were slowly hydrolysed. Amino acid nitrogen accounted for 0·94 of the total nitrogen in cat hair when determined by conventional 24-h hydrolysis and 0·99 of the total nitrogen when the compartmental model was applied. The average nitrogen proportion in cat hair protein was found to be 0·175. The amino acid composition of cat hair protein is comparable with that of dog, horse, sheep and human hair although the proline content of cat hair protein appears to be lower than that in the other species.

The effect of hair color on the incorporation of methadone into hair in the rat.

Six groups of six male, hooded, Lister rats were administered methadone in their drinking water over the concentration range 0-0.25 mg/mL for 6 weeks. Black pigmented and white nonpigmented hair and trunk blood samples were collected. Plasma and alkali digests of hair were analyzed for methadone by radioimmunoassay. Hair melanin content was estimated in digests by turbidimetry. Oral methadone intake rose in a linear fashion over the six dose groups, and plasma methadone concentration followed a similar trend. The methadone content of both white and black hair increased over the six dose groups, but concentrations were significantly higher in black compared with white hair. The mean ratio of methadone concentration between black and white hair was 21.3:1, and the mean ratio in hair melanin content was 3.5:1. The results demonstrate that pigmented hair incorporates larger quantities of methadone than nonpigmented hair and that methadone binds with higher affinity to the pigmented components as compared with other components of hair.

‘Dumb Blonde’ and ‘Temperamental Redhead’: The Effect of Hair Colour on Some Attributed Personality Characteristics of Women

In a person perception study examining stereotypes based on physical appearance, 150 subjects were presented with 5 photographs of equally physically attractive females whom they rated on each of 5 characteristics: ‘shy’, ‘aggressive’, ‘intelligent’, ‘popular’ and ‘temperamental’. Three groups (25 males and 25 females per group) rated a different photograph of the same woman – as a brunette, as a blonde or as a redhead – as one of the 5 photographs, and rated 4 other photographs that were the same for all 3 groups. It was found that a ‘dumb blonde’ stereotype exists among males, but not females, while ‘temperamental redhead’ is a stereotype found among both males and females.