Home About us Contact
|
Home About us Contact | ||
|
|
||
Hair Samples (hair + sample)
Selected AbstractsStructural hair shaft abnormalities in hypomelanosis of Ito and other ectodermal dysplasiasACTA PAEDIATRICA, Issue 5 2000E Selvaag Hair samples from patients with different ectodermal dysplasias; hypohidrotic ectodermal dysplasia, pachyonychia congenita, tricho-dento-osseous syndrome, tricho-rhino-phalangeal syndrome, and hypomelanosis of Ito were investigated using a scanning electron microscope. The hairs of the patients showed different structural abnormalities; twisted hairs, longitudinal grooves, trichorrhexis nodosa as well as variations in the hair caliber. Hair shaft abnormalities, as in our patients with tricho-dento-osseous syndrome, and hypomelanosis of Ito have so far not been described. [source] Randomized controlled trial of dexamphetamine maintenance for the treatment of methamphetamine dependenceADDICTION, Issue 1 2010Marie Longo ABSTRACT Aim To investigate the safety and efficacy of once-daily supervised oral administration of sustained-release dexamphetamine in people dependent on methamphetamine. Design Randomized, double-blind, placebo-controlled trial. Participants Forty-nine methamphetamine-dependent drug users from Drug and Alcohol Services South Australia (DASSA) clinics. Intervention Participants were assigned randomly to receive up to 110 mg/day sustained-release dexamphetamine (n = 23) or placebo (n = 26) for a maximum of 12 weeks, with gradual reduction of the study medication over an additional 4 weeks. Medication was taken daily under pharmacist supervision. Measurements Primary outcome measures included treatment retention, measures of methamphetamine consumption (self-report and hair analysis), degree of methamphetamine dependence and severity of methamphetamine withdrawal. Hair samples were analysed for methamphetamine using liquid chromatography-mass spectrometry. Findings Treatment retention was significantly different between groups, with those who received dexamphetamine remaining in treatment for an average of 86.3 days compared with 48.6 days for those receiving placebo (P = 0.014). There were significant reductions in self-reported methamphetamine use between baseline and follow-up within each group (P < 0.0001), with a trend to a greater reduction among the dexamphetamine group (P = 0.086). Based on hair analysis, there was a significant decrease in methamphetamine concentration for both groups (P < 0.0001). At follow-up, degree of methamphetamine dependence was significantly lower in the dexamphetamine group (P = 0.042). Dexamphetamine maintenance was not associated with serious adverse events. Conclusions The results of this preliminary study have demonstrated that a maintenance pharmacotherapy programme of daily sustained-release amphetamine dispensing under pharmacist supervision is both feasible and safe. The increased retention in the dexamphetamine group, together with the general decreases in methamphetamine use, degree of dependence and withdrawal symptom severity, provide preliminary evidence that this may be an efficacious treatment option for methamphetamine dependence. [source] Ethyl Glucuronide in Hair Compared With Traditional Alcohol Biomarkers,A Pilot Study of Heavy Drinkers Referred to an Alcohol Detoxification UnitALCOHOLISM, Issue 5 2009Gudrun Høiseth Background:, Traditional biomarkers for heavy alcohol use include serum carbohydrate-deficient transferrin (CDT), the enzymes aspartate aminotranserase (AST), and alanine aminotransferase (ALT) as well as gamma-glutamyl transferase (GGT). Measurement of the nonoxidative ethanol metabolite, ethyl glucuronide (EtG) in hair, has been proposed as a new marker with superior qualities. The aim of this study was to investigate the sensitivity of EtG in hair to detect heavy alcohol use compared with CDT, AST, ALT, and GGT. We also wanted to study the quantitative relation between alcohol intake and the different biomarkers. Methods:, Sixteen patients with a history of heavy alcohol use over the previous 3 months were recruited directly after admission to a withdrawal clinic. They were thoroughly interviewed about their drinking pattern as well as relevant diseases and use of medicines or drugs. Serum was sampled and analyzed for %CDT, AST, ALT, and GGT. Hair samples were collected and analyzed for EtG. Results:, The mean estimated daily intake (EDI) over the previous 3 months was 206 ± 136 g pure alcohol. All patients fulfilled the criteria for heavy alcohol use. The sensitivity to detect heavy alcohol use was 64% for %CDT, 67% for AST, 67% for ALT, 93% for GGT, and 94% for EtG. There was no correlation between the quantitative values of EDI and %CDT, AST, ALT, and GGT. There was a positive, statistically significant correlation between EDI and the level of EtG in hair. Conclusions:, In this study, EtG in hair and GGT showed the best sensitivity to detect heavy alcohol use and there was a positive correlation between EDI and the concentrations of EtG in hair. Before giving recommendations for clinical practice, further studies should be carried out on larger materials and populations with a wider range of alcohol intake. [source] Nitrogen balance and ,15N: why you're not what you eat during nutritional stressRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 18 2005Benjamin T. Fuller While past experiments on animals, birds, fish, and insects have shown changes in stable isotope ratios due to nutritional stress, there has been little research on this topic in humans. To address this issue, a small pilot study was conducted. Hair samples from eight pregnant women who experienced nutritional stress associated with the nausea and vomiting of morning sickness (hyperemesis gravidarum) were measured for carbon (,13C) and nitrogen (,15N) stable isotope ratios. The ,13C results showed no change during morning sickness or pregnancy when compared with pre-pregnancy values. In contrast, the ,15N values generally increased during periods of weight loss and/or restricted weight gain associated with morning sickness. With weight gain and recovery from nutritional stress, the hair ,15N values displayed a decreasing trend over the course of gestation towards birth. This study illustrates how ,15N values are not only affected by diet, but also by the nitrogen balance of an individual. Potential applications of this research include the development of diagnostic techniques for tracking eating disorders, disease states, and nitrogen balance in archaeological, medical, and forensic cases. Copyright © 2005 John Wiley & Sons, Ltd. [source] Trichothiodystrophy-like Hair Abnormalities in a Child with Keratitis Ichthyosis Deafness SyndromePEDIATRIC DERMATOLOGY, Issue 4 2008L. De Raeve M.D., Ph.D. It appears to be genetically heterogeneous and may be caused by mutations in the connexin 26 (Cx26) gene (GJB2) or in the connexin 30 gene. It is characterized by the association of ichthyosis-like skin lesions, hearing loss, and vascularizing keratitis. We report the clinical and molecular findings in a 5-year-old girl with keratitis ichthyosis deafness syndrome. DNA sequencing in our patient revealed a p.Ser17Phe mutation in GJB2. Besides the typical clinical features of keratitis ichthyosis deafness syndrome, a peculiar intriguing finding not previously described in the literature in this condition was that polarizing light microscopy of the scalp hair in our patient revealed striking bright and dark bands as seen in trichothiodystrophy. Amino acid analysis of the hair sample also disclosed a reduced cysteine index. We emphasize that it would be of great benefit to examine hair shafts in other patients with keratitis ichthyosis deafness syndrome for trichothiodystrophy-like abnormalities. [source] Challenges to antagonist blockade during sustained-release naltrexone treatmentADDICTION, Issue 9 2010Nikolaj Kunøe ABSTRACT Aims Naltrexone is a competitive opioid antagonist that effectively blocks the action of heroin and other opioid agonists. Sustained-release naltrexone formulations are now available that provide long-acting opioid blockade. This study investigates the use of heroin and other opioids among opioid-dependent patients receiving treatment with long-acting naltrexone implants, their subjective experience of drug ,high' after opioid use, and factors associated with opioid use. Methods Participants (n = 60) were opioid-dependent patients receiving treatment with naltrexone implants. Outcome data on substance use, drug ,high', depression and criminal activity were collected over a 6-month period. Blood samples were taken to monitor naltrexone plasma levels, and hair samples to verify self-reported opioid use. Findings More than half [n = 34 or 56%; 95% confidence interval (CI) 44,68%)] the patients challenged the blockade with illicit opioids during the 6-month treatment period; 44% (n = 26; 95% CI 32,56%) were abstinent from opioids. Mean opioid use was reduced from 18 [standard deviation (SD)13] days during the month preceding treatment to 6 days (SD 11) after 6 months. Of the respondents questioned on opioid ,high' (n = 31), nine patients (30%; 95% CI 16,47%) reported partial drug ,high' following illicit opioid use, and three (12%; 95% CI 3,26%) reported full ,high'. Opioid use was associated with use of non-opioid drugs and criminal behaviour. Conclusions Challenging naltrexone blockade with heroin on at least one occasion is common among sustained-release naltrexone patients, but only a minority of patients use opioids regularly. Challenges represent a warning sign for poor outcomes and often occur in the context of polydrug use and social adjustment problems. [source] Estimating driver risk using alcohol biomarkers, interlock blood alcohol concentration tests and psychometric assessments: initial descriptivesADDICTION, Issue 2 2010Paul Marques ABSTRACT Aim To identify alcohol biomarker and psychometric measures that relate to drivers' blood alcohol concentration (BAC) patterns from ignition interlock devices (IIDs). Design, setting, participants, measurements In Alberta, Canada, 534 drivers, convicted of driving under the influence of alcohol (DUI), installed IIDs and agreed to participate in a research study. IID BAC tests are an established proxy for predicting future DUI convictions. Three risk groups were defined by rates of failed BAC tests. Program entry and follow-up blood samples (n = 302, 171) were used to measure phosphatidyl ethanol (PETH), carbohydrate deficient transferrin (%CDT), gamma glutamyltransferase (GGT) and other biomarkers. Program entry urine (n = 130) was analyzed for ethyl glucuronide (ETG) and ethyl sulphate (ETS). Entry hair samples were tested for fatty acid ethyl esters (FAEE) (n = 92) and ETG (n = 146). Psychometric measures included the DSM-4 Diagnostic Interview Schedule Alcohol Module, Alcohol Use Disorders Identification Test (AUDIT), the time-line follow-back (TLFB), the Drinker Inventory of Consequences (DRINC) and the Temptation and Restraint Inventory (TRI). Findings Except for FAEE, all alcohol biomarkers were related significantly to the interlock BAC test profiles; higher marker levels predicted higher rates of interlock BAC test failures. PETH, the strongest with an overall analysis of variance F ratio of 35.5, had significant correlations with all nine of the other alcohol biomarkers and with 16 of 19 psychometric variables. Urine ETG and ETS were correlated strongly with the IID BAC tests. Conclusions The findings suggest that several alcohol biomarkers and assessments could play an important role in the prediction and control of driver alcohol risk when re-licensing. [source] Ethyl glucuronide in hair.ADDICTION, Issue 6 2009A sensitive, specific marker of chronic heavy drinking ABSTRACT Aims This study aims to define a cut-off concentration for ethyl glucuronide in hair to determine if there was a history of heavy drinking. Settings Pavia, Italy. Participants We analysed hair samples from 98 volunteers among teetotallers, social drinkers and heavy drinkers, whose ethanol daily intake (EDI) was estimated by means of a written questionnaire. Measurements Ethyl glucuronide hair concentration (HEtG) was measured by liquid chromatography-tandem mass spectrometry (lower limit of quantification: 3 pg/mg) using a fully validated method. Findings The HEtG level providing the best compromise between sensitivity (0.92) and specificity (0.96) at detecting an EDI of 60 g or higher during the last 3 months was 27 pg/mg. None of the factors examined among those known to affect ethanol metabolism and/or the diagnostic power of other markers of ethanol use or hair analyses, including age, gender, body mass index, tobacco smoke, prevalent beverage, hair colour, cosmetic treatments and hygienic habits was found to influence marker performance significantly. However, the slight differences in HEtG performance observed for some factors (e.g. body mass index, smoke and hair treatments) require further studies on larger groups of individuals in order to assess their influence more precisely. Conclusions Our results confirm further that HEtG is a sensitive and specific marker of chronic heavy drinking. [source] Fluorescence and coloration of grey hairINTERNATIONAL JOURNAL OF COSMETIC SCIENCE, Issue 5 2009S. Daly Synopsis Grey hair samples were collected from 11 individuals and separated into un-pigmented and pigmented fibres (International Hair Importers). Fluorescence measurements were obtained by using a double-grating fluorescence spectrophotometer and a bifurcated fibre optics accessory to measure the spectra directly from the surface of hair at various distances from the fibre root. Colour measurements were carried out by using a Hunter colorimeter. The fluorescence spectra of un-pigmented hair obtained by the excitation at 290 nm show a peak at 356 nm [tryptophan (Trp)], and multi-peak emissions in the range from 395 to 500 nm. A significant variation in the Trp emission intensity at 356 nm vs. the intensity of emission in the 395,500 nm range was observed for hair collected from various individuals with yellow coloured hair producing stronger relative emission in 395,500 nm range. Quantitative measurements of coloration and the calculation of the Yellowness Index (YI) showed linear correlation between YI and the ratio of fluorescence intensities I440/I356 The spectra obtained by excitation at 320 nm showed the emission peaks at 395 nm (unidentified), 420 nm (N -formylkynurenine), 460 nm (kynurenine), and 495 nm (3-hydroxykynurenine), which are the products of oxidative or metabolic conversion of tryptophan. Un-pigmented, yellow hair showed a build-up of the fluorescence band corresponding to 3-hydroxykynurenine at 495 nm. The data also showed the fluorescence quenching effect of melanin resulting in the lowering of the fluorescence intensity of pigmented hair. The spectra obtained at various positions along the fibres demonstrated gradual photo-decomposition of hair chromophores during their lifetimes. This was indicated by a decrease of Trp fluorescence intensity, which was relatively fast (8·10,4,1.5·10,3 [day,1] as calculated for hair obtained from various individuals) for un-pigmented hair and slower for pigmented hair. A decrease in Trp emission was accompanied by an increase in the yellow coloration toward the ends of un-pigmented fibres. Resume Des échantillons de cheveux gris ont été collectés chez onze personnes et triés entre fibres non pigmentés et fibres pigmentés (International Hair Importers). Les mesures de fluorescence ont été réalisées à l'aide d'un spectrophotomètre de fluorescence double grille et d'un accessoire constitué d'une fibre optique bifurquée. Ce dispositif permet la mesure du spectre directement depuis la surface d'un cheveu à diverses distances de sa racine. Les mesures de couleur ont été réalisées à l'aide d'un colorimètre HUNTER. Le spectre de fluorescence d'un cheveu non pigmenté obtenu par excitation à 290 nm montre un pic à 356 nm (tryptophane : Trp) et des émissions multi pics dans l'intervalle 395 à 500 nm. On observe une variation significative de l'intensité du Trp à 356 nm par rapport à l'intensité d'émission dans l'intervalle 395,500 nm sur les cheveux prélevés sur diverses personnes, les cheveux colorés en jaune produisant une émission relative plus forte dans l'intervalle 395,500 nm. Les mesures quantitatives de la couleur et le calcul de l'indice de jaunissement (YI) montrent une corrélation linéaire entre YI et le rapport des intensités de fluorescence I 440/I356. Le spectre obtenu par excitation à 320 nm montre des pics d'émission à 395 nm (non identifiés), 420 nm (N-formylkynurenine), 460 nm (kynurenine), 495 nm (3-hydroxy kinurenine) propres aux produits d'oxydation ou de conversion métabolique du Tryptophane. Les cheveux jaunes non pigmentés présentent une saturation de la bande de fluorescence correspondant à la 3-hydroxykynurenine à 495 nm. Ces données montrent également l'effet de quenching de la mélanine entraînant un affaiblissement de l'intensité de la fluorescence des cheveux pigmentés. Le spectre obtenu en divers endroits le long des fibres indique une photodécomposition graduelle des chromophores des cheveux durant leur temps de vie. Ceci se traduit par une diminution de l'intensité de fluorescence du Trp qui est relativement rapide pour les cheveux non pigmentés (8,10,4,1,5,10,3 [jour , 1], conformément aux calculs effectués sur des cheveux prélevés sur différents individus) et par une diminution plus lente pour les cheveux pigmentés. Une diminution de l'émission du Trp s'accompagne d'une augmentation de la coloration jaune de l'extrémité des cheveux, détectable sur des cheveux non pigmentés. [source] Skin surface lipids and skin and hair coat condition in dogs fed increased total fat diets containing polyunsaturated fatty acidsJOURNAL OF ANIMAL PHYSIOLOGY AND NUTRITION, Issue 4 2009N. A. Kirby Summary It is generally believed that diets containing increased amounts of polyunsaturated fatty acids (PUFA) result in improved canine skin and hair coat (SHC). However, the extent to which dietary fat amount and type play a role remains to be systematically investigated. The objective of this study was to investigate the role of both increased dietary fat amount and type on SHC assessments of dogs. Improvements of SHC conditions were investigated after feeding three diets containing increased total dietary fat (i.e. 13% total fat) for 12 weeks in relation to a lower fat acclimation diet (i.e. 9% total fat). The higher fat diets varied in polyunsaturated and saturated fat types and amounts but total fat was kept constant. Skin and hair coat assessments were performed at selected intervals by a trained group of veterinarians and graduate students. In addition, hair lipids were fractionated by thin layer chromatography after extraction of plucked hair samples. Significant improvements were found in hair coat glossiness and softness in all dogs fed the higher fat diets in relation to the acclimation diet. Improvements as a result of fat type were also seen but only at 12 weeks. A parallel finding was a marked increase in hair cholesteryl ester content determined at the end of the study at which time SHC scores were significantly improved. Skin and hair coat condition improvements may thus be related to increased cholesteryl ester deposited on the hair shaft surface when high fat diets are fed. Whereas this finding is preliminary, hair lipid analysis may be a useful, non-invasive technique with which to help assess dietary effects on canine SHC. [source] A novel LCD (coal tar) solution for psoriasis does not discolor naturally light or color-processed hair in an exaggerated exposure test modelJOURNAL OF COSMETIC DERMATOLOGY, Issue 3 2009Colleen Johnson BS Summary Background, Scalp psoriasis is reported to occur in 50,80% of psoriasis sufferers. Treatment of scalp psoriasis requires special consideration of product esthetics and staining potential due to the presence of hair. Aim, To evaluate the potential of a new, marketed liquor carbonis distillate (LCD; coal tar) solution to discolor naturally light or color-processed hair under exaggerated exposure conditions. Methods, Samples of naturally light and color-processed hair from a single donor were exposed to LCD solution repeatedly over 14 days and via submergence for 24 h. Color of LCD-treated hair samples was compared with untreated control hair samples. Results, LCD solution did not discolor naturally light or color-processed hair following repeated exposures and 24 h submergence. Conclusion, The marketed LCD solution does not appear to discolor naturally light or color-processed hair. [source] Trichophyton Mentagrophytes Perforates Hair of Adult Corpses in the Gaseous Period,JOURNAL OF FORENSIC SCIENCES, Issue 5 2010Renato Evando M. Filho M.S Abstract:, Despite the substantial literature on mycology, there are still limited reports of the interaction between fungi and human hosts in the postmortem period. Thus, the main goal of this study was to investigate the in vitro perforation test using Trichophyton mentagrophytes on hair from adult corpses in the postmortem period (gaseous period). The protocol was carried out with positive (prepubescent children's hair) and negative controls (healthy adult hair) as well. One strain of Trichophyton rubrum was also used as a negative perforation control. Perforations were found in all the hair samples from corpses and prepubescent children after 12,14 days exposure to T. mentagrophytes and were absent in the hair samples of healthy adults. Furthermore, hair perforation was not observed with T. rubrum. Our preliminary findings suggest the use of T. mentagrophytes as a potential marker of the death interval in forensic science. [source] Heteroplasmy in Hair: Study of Mitochondrial DNA Third Hypervariable Region in Hair and Blood Samples,JOURNAL OF FORENSIC SCIENCES, Issue 3 2010Greiciane G. Paneto M.Sc. Abstract:, Mitochondrial DNA (mtDNA) analysis has proved useful for forensic identification especially in cases where nuclear DNA is not available, such as with hair evidence. Heteroplasmy, the presence of more than one type of mtDNA in one individual, is a common situation often reported in the first and second mtDNA hypervariable regions (HV1/HV2), particularly in hair samples. However, there is no data about heteroplasmy frequency in the third mtDNA hypervariable region (HV3). To investigate possible heteroplasmy hotspots, HV3 from hair and blood samples of 100 individuals were sequenced and compared. No point heteroplasmy was observed, but length heteroplasmy was, both in C-stretch and CA repeat. To observe which CA "alleles" were present in each tissue, PCR products were cloned and re-sequenced. However, no variation among CA alleles was observed. Regarding forensic practice, we conclude that point heteroplasmy in HV3 is not as frequent as in the HV1/HV2. [source] Microbeam synchrotron imaging of hairs from Ancient Egyptian mummiesJOURNAL OF SYNCHROTRON RADIATION, Issue 5 2003L. Bertrand Developments in microfocus synchrotron techniques have led to new results regarding the long-term alteration of archaeological samples of biological origin. Here, ancient hair samples from two Egyptian mummies have been analyzed using a conjunction of structural and elemental synchrotron methods. In this favored context of conservation, structural analysis revealed a remarkable preservation of keratin supramolecular organization at any observed length scale. Bulk keratin structure has therefore not been modified significantly over 2000 years. However, infrared spectroscopy indicated a partial disorganization of keratins close to the hair surface through polypeptide bond breakage. Elemental mapping showed a strongly heterogeneous distribution which can be related to mummification and cosmetic treatments. [source] Near Infrared Spectroscopy as a Tool for the Determination of Eumelanin in Human HairPIGMENT CELL & MELANOMA RESEARCH, Issue 4 2004Marina Zoccola Eumelanins are brown-black pigments present in the hair and in the epidermis which are acknowledged as protection factors against cell damage caused by ultraviolet radiation. The quantity of eumelanin present in hair has recently been put forward as a means of identifying subjects with a higher risk of skin tumours. For epidemiological studies, chromatographic methods of determining pyrrole-2,3,5-tricarboxylic acid (PTCA; the principal marker of eumelanin) are long, laborious and unsuitable for screening large populations. We suggest near infrared (NIR) spectroscopy as an alternative method of analysing eumelanin in hair samples. PCTA was determined on 93 samples of hair by means of oxidizing with hydrogen peroxide in a basic environment followed by chromatographic separation. The same 93 samples were then subjected to NIR spectrophotometric analysis. The spectra were obtained in reflectance mode on hair samples which had not undergone any preliminary treatment, but had simply been pressed and placed on the measuring window of the spectrophotometer. The PTCA values obtained by means of HPLC were correlated with the near infrared spectrum of the respective samples. A correlation between the PTCA values obtained by means of HPLC and the PTCA values obtained from an analysis of the spectra was obtained using the principal component regression (PCR) algorithm. The correlation obtained has a coefficient of regression (R2) of 0.89 and a standard error of prediction (SEP) of 13.8 for a mean value of 108.6 ng PTCA/mg hair. Some considerations about the accuracy of the obtained correlation and the main sources of error are made and some validation results are shown. [source] Scramble or contest competition over food in solitarily foraging mouse lemurs (Microcebus spp.): New insights from stable isotopesAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 2 2010Melanie Dammhahn Abstract The relationships between resource distribution, type of competition, and consequences for social organization have been formalized in the socioecological model (SEM) which predicts that ecological factors are the main determinants of female distribution. We tested this basic prediction in two solitary primates (Microcebus berthae and M. murinus) which differ in female association patterns. Using stable nitrogen and carbon isotope data of hair samples and food sources we quantified inter-specific differences in diet. ,13C in M. berthae reflected a diet composed mainly of insect secretions. Higher within-species as well as seasonal variation in ,13C of M. murinus indicated a wider trophic niche including plant and animal source food. Constantly elevated ,15N in M. murinus most likely reflected extended torpor during the lean season. This energy-saving strategy together with a wider, more opportunistic feeding niche might reduce female competition in this species, facilitating smaller female ranges, and a higher association potential. In contrast, ,15N fluctuated seasonally in M. berthae, most likely indicating varying amounts of arthropod food in the diet. Intense scramble competition over small and seasonally limited resources might lead to female spatial avoidance and a reduced association potential in M. berthae. Thus, differences in female association patterns between these two solitary foragers are due to different types of competition and overall intensities of intra-specific competition. Am J Phys Anthropol, 2010. © 2009 Wiley-Liss, Inc. [source] Dietary and physiological controls on the hydrogen and oxygen isotope ratios of hair from mid-20th century indigenous populationsAMERICAN JOURNAL OF PHYSICAL ANTHROPOLOGY, Issue 4 2009Gabriel J. Bowen Abstract A semimechanistic model has recently been proposed to explain observed correlations between the H and O isotopic composition of hair from modern residents of the USA and the isotopic composition of drinking water, but the applicability of this model to hair from non-USA and preglobalization populations is unknown. Here we test the model against data from hair samples collected during the 1930s,1950s from populations of five continents. Although C and N isotopes confirm that the samples represent a much larger range of dietary "space" than the modern USA residents, the model is able to reproduce the observed ,2H and ,18O values given reasonable adjustments to 2 model parameters: the fraction of dietary intake derived from locally produced foods and the fraction of keratin H fixed during the in vivo synthesis of amino acids. The model is most sensitive to the local dietary intake, which appears to constitute between 60% and 80% of diet among the groups sampled. The isotopic data are consistent with a trophic-level effect on protein H isotopes, which we suggest primarily reflects mixing of 2H-enriched water and 2H-depleted food H in the body rather than fractionation during biosynthesis. Samples from Inuit groups suggest that humans with marine-dominated diets can be identified on the basis of coupled ,2H and ,18O values of hair. These results indicate a dual role for H and O isotopic measurements of keratin, including both biological (diet, physiology) and environmental (geographic movement, paleoclimate) reconstruction. Am J Phys Anthropol, 2009. © 2009 Wiley-Liss, Inc. [source] Simultaneous determination of morphine, codeine, 6-acetylmorphine, cocaine and benzoylecgonine in hair by liquid chromatography/electrospray ionization tandem mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 7 2009Da-Kong Huang A fast and sensitive liquid chromatography/triple quadrupole tandem mass spectrometry (LC/MS/MS) method was developed for the simultaneous determination of morphine, codeine, 6-acetylmorphine (6-AM), cocaine and benzoylecgonine (BE) in hair. Pulverized hair samples were extracted with methanol, and a 50,µL supernatant aliquot was injected into the LC/MS/MS system. Chromatography was performed with an XBridgeÔ phenyl column (3.5,µm particle size, 4.6,×,150,mm), and the mobile phase was composed of methanol and 10,mM ammonium acetate adjusted to pH 4.00 with 99% formic acid (95:5, v/v). A separation run with isocratic elution was completed in 10,min at a flow rate of 500,µL/min. Positive electrospray ionization and multiple reaction monitoring (MRM) with one precursor ion/product ion transition were used for the identification of each analyte. Deuterated analogues as internal standards were used for quantification and qualification. Linearity was established in the concentration range of 100,3000,pg/mg. The limits of detection were 10,pg/mg for morphine, codeine and 6-AM; and 1,pg/mg for cocaine and BE. The precision and accuracy were determined by spiking hair samples at six concentration levels. For all analytes, the relative standard deviations of intra- and inter-day precision were 0.1,6.3% and 1.5,10.6%, respectively. The accuracy ranged from 92.7 to 109.7%. The validated LC/MS/MS method was successfully applied to the analysis of 79 authentic hair samples. Copyright © 2009 John Wiley & Sons, Ltd. [source] Potentials of ion trap collisional spectrometry for liquid chromatography/electrospray ionization tandem mass spectrometry determination of buprenorphine and nor -buprenorphine in urine, blood and hair samplesRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 8 2006Donata Favretto A liquid chromatography/electrospray ionization tandem mass spectrometry (LC/ESI-MS/MS) method has been developed for the analysis of buprenorphine (BUP) and nor -buprenorphine (NBUP) in biological fluids. Analytes are isolated from urine and blood, after addition of d4 -buprenorphine (d4 -BUP) as internal standard, by solid-phase extraction. Preparation of hair involves external decontamination, mechanical pulverization, overnight incubation in acidic medium, and neutralization prior to extraction. Enzymatic hydrolysis with , -glucuronidase may be performed to distinguish between free and total BUP. Chromatographic separation is accomplished by gradient elution on a cyanopropyl 2.1,×,150,mm column. Positive ion ESI and MS analyses are carried out in an ion trap mass spectrometer. The use of this mass analyzer allows effective collisional experiments to be performed on ESI-generated MH+ species. Abundant product ions are produced, which can be monitored together with precursor ions without losing sensitivity. Thus, assay selectivity is definitely increased with respect to LC/ESI-MS/MS methods in which only precursor ions are monitored. The method has good linearity (calibration curves were linear in the range 0.1,10,ng/mL in urine and blood, in the range 10,160,pg/mg in hair) and limits of detection of 0.05,ng/mL for both BUP and NBUP in blood and urine samples, of 4,pg/mg for both analytes in hair. Both intra- and inter-assay precision and accuracy were satisfactory at three concentrations studied: relative standard deviations were <13.7% in urine, <17.3% in blood, <17.8% in hair; percent deviation of the mean from the true value was always <10.5% in urine and blood, <16.1% in hair. The method can be used to determine both analytes in the urine and hair of drug addicts on replacement therapy, and in post-mortem blood specimens when there is suspicion of drug-related death. Copyright © 2006 John Wiley & Sons, Ltd. [source] Treatment methods for the determination of ,2H and ,18O of hair keratin by continuous-flow isotope-ratio mass spectrometryRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 17 2005Gabriel J. Bowen The structural proteins that comprise ,90% of animal hair have the potential to record environmentally and physiologically determined variation in ,2H and ,18O values of body water. Broad, systematic, geospatial variation in stable hydrogen and oxygen isotopes of environmental water and the capacity for rapid, precise measurement via methods such as high-temperature conversion elemental analyzer/isotope ratio mass spectrometry (TC/EA-IRMS) make these isotope systems particularly well suited for applications requiring the geolocation of hair samples. In order for such applications to be successful, however, methods must exist for the accurate determination of hair ,2H and ,18O values reflecting the primary products of biosynthesis. Here, we present the results of experiments designed to examine two potential inaccuracies affecting ,2H and ,18O measurements of hair: the contribution of non-biologic hydrogen and oxygen to samples in the form of sorbed molecular water, and the exchange of hydroxyl-bound hydrogen between hair keratin and ambient water vapor. We show that rapid sorption of molecular water from the atmosphere can have a substantial effect on measured ,2H and ,18O values of hair (comprising ,7.7% of the measured isotopic signal for H and up to ,10.6% for O), but that this contribution can be effectively removed through vacuum-drying of samples for 6 days. Hydrogen exchange between hair keratin and ambient vapor is also rapid (reaching equilibrium within 3,4 days), with 9,16% of the total hydrogen available for exchange at room temperature. Based on the results of these experiments, we outline a recommended sample treatment procedure for routine measurement of ,2H and ,18O in mammal hair. Copyright © 2005 John Wiley & Sons, Ltd. [source] Application of tandem mass spectrometry combined with gas chromatography and headspace solid-phase dynamic extraction for the determination of drugs of abuse in hair samplesRAPID COMMUNICATIONS IN MASS SPECTROMETRY, Issue 5 2003Dirk W. Lachenmeier A new method combination, headspace solid-phase dynamic extraction coupled with gas chromatography/tandem mass spectrometry (HS-SPDE/GC/MS/MS), is introduced to determine drugs of abuse in hair samples. This highly automated procedure utilizes SPDE for pre-concentration and on-coating derivatization as well as GC and triple quadrupole MS/MS for selective and sensitive detection. All these steps, apart from washing and cutting of the hair samples, are performed without manual intervention on a robot-like autosampler. SPDE is a solventless extraction technique related to solid-phase microextraction (SPME). The analytes are absorbed from the sample headspace directly into a hollow needle with an internal coating of polydimethylsiloxane by repeated aspirate/dispense cycles. The HS-SPDE/GC/MS/MS procedure was applied to the analysis of methadone, the trimethylsilyl derivatives of cannabinoids and the trifluoroacetyl derivatives of amphetamines and designer drugs. The method was shown to be sensitive with detection limits between 6 and 52 pg/mg hair matrix and precision between 0.4 and 7.8% by the use of an internal standard technique. Linearity was obtained from 0.1,20,ng/mg with coefficients of correlation between 0.995 and 0.999. Compared with conventional methods of hair analysis, HS-SPDE/GC/MS/MS is easier to use, substantially faster, with the degree of sensitivity and reproducibility demanded in clinical and forensic toxicology. The main advantage of the SPDE technique in relation to SPME is the robustness of the capillary. Copyright © 2003 John Wiley & Sons, Ltd. [source] Hair Analysis Versus Conventional Methods of Drug Testing in Substance Abusers Seeking Organ TransplantationAMERICAN JOURNAL OF TRANSPLANTATION, Issue 5 2010D. L. Haller As substance abusers need to demonstrate abstinence prior to transplant, valid/reliable drug tests are needed. Patients may deny use, fearing surgery will be delayed. Breath, blood and urine tests have brief detection windows that allow patients to evade detection. Routine laboratory tests do not include all substances of abuse. Hair analysis overcomes these barriers, increasing the likelihood that active users will be identified. This study compared results for alcohol, opioids and cocaine based on 445 self-report, breath, urine and hair samples from 42 patients who had been denied a transplant due to recent substance abuse. Compared to hair toxicology, sensitivity for conventional drug tests was moderate for cocaine and opioids, but poor for alcohol. Of positive hair tests, only half were corroborated through other tests. In contrast, specificity was high across tests and substances, with positive findings from conventional tests confirmed through hair toxicology. Based on a 90-day detection window for hair analysis, two negative tests suggest 6 months of continuous abstinence. Hair testing should be considered as an alternative approach for monitoring substance use in the transplant population, either as a routine procedure or when the veracity of findings from conventional tests is in doubt. [source] Crime scene investigation: An exercise in generating and analyzing DNA evidence,BIOCHEMISTRY AND MOLECULAR BIOLOGY EDUCATION, Issue 1 2003Karen M. Lounsbury Abstract The goal of this project is to introduce students to molecular biology techniques using an experimental setting that inspires both scientific and personal interest. The project is designed as a small group apprenticeship for gifted high school juniors or seniors who can spend full time in a sponsor's laboratory for at least 1 week. The students begin by examining evidence from a mock crime scene that consists of hair samples from the crime scene and from five potential suspects. Students extract DNA from the hair samples and amplify a hypervariable region within the mitochondrial genome using the polymerase chain reaction. Amplified products are then sequenced and compared with the crime scene sequence using DNA alignment software. In consecutive projects, students from four different schools successfully identified the suspect who matched the crime scene evidence. This project is a valuable learning tool not only due to the comprehensive introduction to molecular biology techniques but also because it helps the students to connect scientific exploration with well publicized media events and provides a window into potential career opportunities in the field of molecular biology. [source] Determination of terbinafine hydrochloride in cat hair by two chromatographic methodsBIOMEDICAL CHROMATOGRAPHY, Issue 8 2001Jernej Kuz Terbinafine hydrochloride (terbHCl) concentration on the site of infection with Microsporum canis is a very important indicator of drug effectiveness. Several chromatographic methods exist that can be used for the determination of terbHCl concentration in biological samples. A high performance liquid chromatographic (HPLC) method and a gas chromatographic (GC) method have been compared and critically evaluated for the determination of a terbHCl levels in cat hair. The sensitivity and the linearity of the previously developed HPLC method were 0.25,ng/mL and 0.25,3000,ng/mL, respectively. The limit of quantification (LOQ) was 0.01,µg/g of terbHCl in cat hair, and reproducibility of 96.6% and recovery of 93.8% were achieved using appropriate sample pre-treatment and optimal chromatographic conditions. The sensitivity of the GC method, 25,ng/mL (LOQ 625 ppb), was much lower than that of the HPLC method. The GC method still enables determination of terbHCl in a range of concentrations in cat hair. The reproducibility of terbHCl for the cat hair samples was 95.3% and the recovery was only 70.0%. Both methods can be used for the evaluation of drug effectiveness in cats and both of them require only basic chromatographic equipment that can be found in most analytical laboratories. Copyright © 2001 John Wiley & Sons, Ltd. [source] | ||||||||||||||||