Hair Segments Research Articles

Hair cortisol concentration, a biomarker of stress, is gradually increased in patients with acute myocardial infarction before the acute episode

Abstract Background/Introduction Chronic stress is considered to be an important element of residual cardiovascular risk and modern guidelines recommend its systematic assessment and treatment. Its pathophysiologic contribution, however, in acute myocardial infarction (AMI) was not, until recently, easy to elucidate. This arises from difficulties in objectively quantifying stress levels using conventional research methods, like questionnaires. Purpose The purpose of our study was to measure stress levels at the days preceding an acute myocardial infarction using a solid biomarker, Hair Cortisol Concentration (HCC). Methods 102 consecutive patients with AMI (71 patients with ST-elevation Myocardial Infarction [STEMI] and 31 with Non ST-elevation Myocardial Infarction) from our institution were recruited for this study. We took hair samples from them to precisely measure HCC, which reflects cumulative cortisol levels for the time period preceding the acute event. We also did full clinical, biochemical and psychological evaluation. HCC levels were then compared with 50 age-matched healthy controls. Results To assess the temporal trend of HCC in hair segments, corresponding to specific time periods, we fitted linear mixed models. The mixed effects linear model including the main effects of time and group (AMI versus controls) and their interaction showed that cortisol concentration in hair increased over time with higher rate of increase in AMI patients versus controls (beta of interaction = 3.57; 95%CI: 1.74, 5.40; p < 0.001) The model explained a high percentage of the variance (conditional R2=0.940). No other baseline variable had a significant effect when added to the basic model. There was no significant difference between STEMI and NSTEMI (beta of interaction = 1.15; 95%CI: -1.330, 3.59; p = 0.358) Conclusions Hair cortisol levels, presumably reflecting stress levels, were gradually increasing before an acute myocardial infarction with higher rate of increase in patients compared to healthy controls. There was no significant difference between STEMI and NSTEMI patients. Picture 1. Predicted hair concentrations of cortisol over time prior to the event, based on linear mixed models.

Age and Hair Cortisol Levels as Predictors of SARS-CoV-2 Infection.

Chronic psychosocial stress is known to adversely impact immune function. During the SARS-CoV-2 pandemic, occupational stress among workers in healthcare was at an unprecedented level due to risks of infection and work demands. We performed a nested case-control study to investigate the associations between chronic stress and the risks of contracting SARS-CoV-2. We collected 3 cm of hair from employees at an academic medical center who tested positive for SARS-CoV-2 (N = 49) and controls who tested negative (N = 49), matched for age, race, and sex. The diagnosis of SARS-CoV-2 was based on polymerase chain reaction or antibody tests. As a proxy for chronic stress, we segmented hair into 1 cm sections each representing one month and measured cortisol levels using a cortisol enzyme-linked immunosorbent assay. For cases, we used cortisol concentrations measured in hair segments from the month prior to a positive SARS-CoV-2 test, and for controls, we used time-matched hair segments. We fitted conditional logistic regression models adjusted for sex, age, race, body mass index, and healthcare worker status, and stratified models by older vs. younger age (cutoff = 41 years). African Americans had higher hair cortisol levels relative to participants of other races and ethnicities. In adjusted models, higher hair cortisol concentrations were associated with an increased odds of infection with SARS-CoV-2 (OR = 1.84; CI: 1.10-3.07) among older, but not younger, participants. The results suggest that psychosocial stress may be a risk factor for SARS-CoV-2 infection; stress management may be an important part of a comprehensive approach to protect against SARS-CoV-2 infection.

Relationship of Inflammatory Mediators (Interleukin and Cortisol Concentrations) with Corneal Epithelial Quantifiable Metrics

PurposeTo investigate the relationship of inflammatory biomarkers with corneal epithelial quantifiable metrics in patients with keratoconus and in healthy eyes. DesignProspective observational comparative study. ParticipantsThis study included 100 eyes of 100 patients, 48 eyes of 48 patients with KC, and 52 healthy eyes of 52 healthy controls. MethodsThe concentrations of tear cytokines were investigated in both groups: interleukin (IL) 1B, IL6, IL8, IL10, IL12p70 and TNFα were obtained by capillary flow and measured using flow cytometer. Cortisol concentrations were determined in both groups from the most proximal hair segment as an index of cumulative secretion and measured by liquid chromatography mass spectrometry. Epithelial variables were obtained with optical coherence tomography (OCT). Pearson correlation (r) was used to measure linear dependence between two different variables. Main Outcome MeasuresInvestigating the existence, strength, and significance of any correlation between inflammatory biomarkers (IL1B, IL6, IL8, IL10, IL12p70, TNFα and hair cortisol concentration) and OCT corneal epithelial quantifiable variables such as minimum and maximum epithelial thickness of the map, difference between the minimum and maximum (Epithelial Min-Max) and standard deviation of the epithelial thickness of the map (Epithelial Std Dev) and average epithelial thickness of the superior and inferior regions of the map. ResultsEyes with keratoconus presented statistically significantly higher levels of IL1b (p=0.02), IL6 (p <0.0001), IL8 (p <0.0001), and TNFα (p <0.0001) and hair cortisol concentration (p=0.01) compared to healthy controls.There was a significant correlation between IL6 and measurement Epithelium Min-Max [Pearson= -0.59 (-0.69, -0.47); p<0.0001] and Epithelial standard deviation (Std Dev) [Pearson= +0.56 (0.44, 0.67); p<0.0001]. There was a significant correlation between hair cortisol concentration and Epithelium Min-Max [Pearson=-0.27 (-0.42, -0.1); p<0.0001] and Epithelium Std Dev groups [Pearson= +0.2 (0.03, 0.36); p=0.021]. There was also a significant correlation between TNFα and Epithelial Max. [Pearson= -0.37 (-0.55, 0.17); p<0.0001]. We found no significant correlation between the concentration of IL1b, IL8, IL10 and IL2p70 with any epithelium parameters. ConclusionsThe higher concentration of inflammatory markers (IL6 and hair cortisol) in eyes with keratoconus present a significant correlation with OCT metrics identifying epithelial variability, such as Epithelial Min-Max and Std Dev. These findings demonstrate the role of chronic inflammation in eyes with keratoconus, and that these epithelial changes detectable with OCT are sensitive to this inflammatory process.

First Case of HIV Seroconversion With Integrase Resistance Mutations on Long-Acting Cabotegravir for Prevention in Routine Care.

Long-acting cabotegravir (CAB-LA) is highly effective for HIV prevention, but delayed HIV diagnoses and integrase strand transfer inhibitor (INSTI) resistance were observed in trials. We report the first case in routine clinical care of HIV infection on CAB-LA with INSTI resistance. The SeroPrEP study enrolls individuals in the United States who acquire HIV on pre-exposure prophylaxis modalities to assess diagnostics, antiretroviral (ARV) drug levels, resistance, and treatment outcomes. Resistance mutations in full-length HIV-1 integrase were identified by single-genome sequencing (SGS). Cabotegravir concentrations in plasma and hair segments were measured by liquid chromatography-tandem mass spectrometry. A 23-year-old gender-nonbinary person, male at birth, restarted CAB-LA 6 months after discontinuation due to losing insurance. Prior to restart, HIV-1 RNA was not detected, but 20 days elapsed before CAB-LA injection. After the second CAB-LA injection, HIV antigen/antibody returned reactive (HIV-1 RNA 451 copies/mL). SGS of plasma HIV-1 RNA identified INSTI mutation Q148R in 2/24 sequences 2 days postdiagnosis; commercial genotype failed amplification. Cabotegravir hair concentration was 0.190 ng/mg 2 weeks prediagnosis; plasma cabotegravir was high (3.37 μg/mL; ∼20× PA-IC90) 14 days postdiagnosis. Viral suppression was maintained for 6 months on darunavir/cobicistat/emtricitabine/tenofovir alafenamide, then switched to doravirine + emtricitabine/tenofovir alafenamide due to nausea. In this first case of HIV infection on CAB-LA with INSTI resistance in routine care, cabotegravir resistance was detected only with a sensitive research assay. Accelerated pathways to minimize time between HIV testing and CAB-LA initiation are needed to optimize acute HIV detection and mitigate resistance risk. Sustained product access regardless of insurance is imperative to reduce HIV infections on CAB-LA.

Feature-Based Molecular Network for New Psychoactive Substance Identification: The Case of Synthetic Cannabinoids in a Seized e-Liquid and Biological Samples.

The comprehensive detection of new psychoactive substances, including synthetic cannabinoids along with their associated metabolites in biological samples, remains an analytical challenge. To detect these chemicals, untargeted approaches using appropriate bioinformatic tools such as molecular networks are useful, albeit it necessitates as a prerequisite the identification of a node of interest within the cluster. To illustrate it, we reported in this study the identification of synthetic cannabinoids and some of their metabolites in seized e-liquid, urine, and hair collected from an 18-year-old poisoned patient hospitalized for neuropsychiatric disorders. A comprehensive analysis of the seized e-liquid was performed using gas chromatography coupled with electron ionization mass spectrometry, 1H NMR, and liquid chromatography coupled with high resolution tandem mass spectrometry combined with data processing based on molecular network strategy. It allowed researchers to detect in the e-liquid known synthetic cannabinoids including MDMB-4en-PINACA, EDMB-4en-PINACA, MMB-4en-PINACA, and MDMB-5F-PICA. Compounds corresponding to transesterification of MDMB-4en-PINACA with pentenol, glycerol, and propylene glycol were also identified. Regarding the urine sample of the patient, metabolites of MDMB-4en-PINACA were detected, including MDMB-4en-PINACA butanoic acid, dihydroxylated MDMB-4en-PINACA butanoic acid, and glucurono-conjugated MDMB-4en-PINACA butanoic acid. Hair analysis of the patient allowed the detection of MDMB-4en-PINACA and MDMB-5F-PICA in the two investigated hair segments. This untargeted analysis of seized materials and biological samples demonstrates the utility of the molecular network strategy in identifying closely related compounds and metabolites of synthetic cannabinoids. It also emphasizes the need for developing strategies to anchor molecular networks, especially for new psychoactive substances.

Incorporation of suvorexant and lemborexant into hair and their distributions after a single intake.

This study examined the applicability of hair analysis as an approach to identify suvorexant (SUV) and lemborexant (LEM) intake by analyzing black hair specimens collected from study participants after a single oral administration. Hair specimens were collected form participants who took a single dose of 10 mg SUV or 5 mg LEM. Identification of the dual orexin receptor antagonists (DORAs) and their metabolites was performed by liquid chromatography-tandem mass spectrometry. Reference standards of S-M9 and L-M4, the metabolites of SUV and LEM, respectively, were synthesized in our laboratory. Sectional analysis of 1-mm segments of the single-hair strands was also performed to investigate the incorporation behavior of the drugs into hair. Unchanged SUV and LEM, and their metabolites S-M9 and L-M4 were detected even in the single-hair specimens. Results of the segmental hair analysis showed predominant incorporation of the drugs into hair through the hair bulb region rather than through the upper dermis zone of the hair root. The drug concentrations in the hair specimens, collected about 1month after intake, were 0.033-0.037pg/hair strand (0.17-0.19pg/mg) for SUV and 0.054-0.28pg/hair strand (0.28-1.5pg/mg) for LEM. The calculated distribution ratios of the DORAs into hair to the oral doses were much lower than those of benzodiazepines and zolpidem reported in a previous study. This is the first report of the detection of the DORAs in hair. The incorporation behavior of the DORAs into hair revealed herein are crucial for proper interpretation of hair test results.

Evaluation and comparison of sensitivity of alcohol biomarkers PEth, EtG and EtPa in civil cases in England 2022–2023

This study details trends in direct alcohol biomarker concentrations from civil cases within the United Kingdom (UK). Our subject cohort in this study related to family law litigation, where an individual was subject to an alcohol monitoring order by the court. This monitoring was conducted by quantification of alcohol biomarkers Phosphatidlyethanol (PEth) in dried blood spots (DBS) and Ethyl Glucuronide (EtG) and Ethyl Palmitate (EtPa) from hair segments. In total 298 PEth cases predominantly from the South East of England during the period July 2022 to August 2023 were analysed for alcohol biomarkers in DBS and hair. Subjects alcohol intake was classified as abstinence/low alcohol consumption, moderate or excessive alcohol consumption, based on a combination of Society for Hair Testing and PEth Net guidelines. Our results indicate that 33 % of PEth concentrations were consistent with excessive alcohol use (>200 ng/mL DBS), with 36 % consistent with social or moderate alcohol use (20–200 ng/mL DBS). In relation to EtG and EtPa 23 % and 31 % of subjects were classified as excessive alcohol users respectively. This study indicates that DBS sampling of PEth is a more sensitive predictor of alcohol use, in particular, at differentiating between moderate and excessive alcohol use compared to EtG and EtPa testing in hair. The authors suggest that increased frequency in the sampling of PEth in DBS (multiple occasions per month) may provide a more accurate assessment and simplification of the interpretation criteria of alcohol patterns rather than the combined hair testing and DBS sampling that are typically requested by UK courts.

Intersection-union dual-stream cross-attention Lova-SwinUnet for skin cancer hair segmentation and image repair

Skin cancer images have hair occlusion problems, which greatly affects the accuracy of diagnosis and classification. Current dermoscopic hair removal methods use segmentation networks to locate hairs, and then uses repair networks to perform image repair. However, it is difficult to segment hair and capture the overall structure between hairs because of the hair being thin, unclear, and similar in color to the entire image. When conducting image restoration tasks, the only available images are those obstructed by hair, and there is no corresponding ground truth (supervised data) of the same scene without hair obstruction. In addition, the texture information and structural information used in existing repair methods are often insufficient, which leads to poor results in skin cancer image repair. To address these challenges, we propose the intersection-union dual-stream cross-attention Lova-SwinUnet (IUDC-LS). Firstly, we propose the Lova-SwinUnet module, which embeds Lovasz loss function into Swin-Unet, enabling the network to better capture features of various scales, thus obtaining better hair mask segmentation results. Secondly, we design the intersection-union (IU) module, which takes the mask results obtained in the previous step for pairwise intersection or union, and then overlays the results on the skin cancer image without hair to generate the labeled training data. This turns the unsupervised image repair task into the supervised one. Finally, we propose the dual-stream cross-attention (DC) module, which makes texture information and structure information interact with each other, and then uses cross-attention to make the network pay attention to the more important texture information and structure information in the fusion process of texture information and structure information, so as to improve the effect of image repair. The experimental results show that the PSNR index and SSIM index of the proposed method are increased by 5.4875 and 0.0401 compared with the other common methods. Experimental results unequivocally demonstrate the effectiveness of our approach, which serves as a potent tool for skin cancer detection, significantly surpassing the performance of comparable methods.

LC-MS/MS quantification of olanzapine in hair after alkaline digestion.

Olanzapine (OLZ), a second-generation antipsychotic drug, is effective in the treatment of acute psychosis, schizophrenia, agitation, bipolar mania, and other psychiatric problems. Antipsychotics are prescribed drugs, which lead the drug abuser to illegal methods of access. This behavior also demonstrates the association of OLZ with criminal involvement, commonly observed at forensic crime scenes. The acute toxicity and even death resulting from OLZ exposure have been highlighted in numerous studies. Therefore, developing analytical techniques to detect OLZ is essential for forensic toxicology. This study aimed to develop a specific and reliable LC-MS/MS method for OLZ detection and quantification in hair samples. The method was validated in terms of selectivity, linearity, limit of detection (LOD), limit of quantification (LOQ), trueness, precision, and uncertainty. The range of linearity was between 0.1-100 ng/mg, with LOD and LOQ values established at 0.036 ng/mg and 0.1ng/mg, respectively. All validation results are within acceptable parameters. The validated method has been applied to authentic hair samples. The variation of OLZ concentrations in 12 hair segments (2 from Case 1 and 10 from Case 2) from two drug-positive patients, ranging from 0.131 to 0.460 ng/mg, is presented in this study. Although several studies have been conducted to determine OLZ in hair samples using segmental analysis via hair solubilization, this study is the first to determine OLZ in hair samples after "digestion" with comparative parameters prior to chromatographic analysis.

Dent versus mèche de cheveux. Quelle matrice utiliser pour documenter une exposition répétée ? À propos d’un cas impliquant l’aripiprazole

In recent years, remarkable advances in sensitive analytical techniques have enabled the analysis of drugs in unconventional biological specimens such as oral fluid, sweat or hair. However, other matrices, including tooth, deserve attention as they can be the unique remain on a crime scene. The authors present here the comparison between tooth and hair specimens collected from a long-term subject under aripiprazole therapy (5 mg per day). Tooth was collected during a standard consultation for removal of wisdom tooth. At the same time, after oral consent, a strand of hair (blonde in colour) was collected from a 19-year-old man. After careful elimination of organic material, the tooth was pulverized in a ball mill and 20 mg were incubated under alkaline conditions (pH 8.4) followed by a mixture of organic solvents. After decontamination by dichloromethane, the hair was segmented, cut into very small segments (< 1 mm), overnight incubated in buffer and 20 mg were extracted by a mixture of organic solvents. Drugs were tested by LC/MS-MS. Aripiprazole was identified by 2 ion transitions (m/z 450.2 > 287.1 and 450.2 > 98.0). Aripiprazole was identified in the tooth at 1.4 pg/mg. The drug tested also positive in the 3 x 3 cm segments, at 3.5, 3.9 and 2.6 ng/mg. The concentrations of aripiprazole in the hair segments were in a 1000-fold magnitude when compared to what was measured in the tooth. Although there is an interest to test for drugs in tooth when this element is the unique remain of a cadaver, this approach cannot overrule the interest of hair to document long-term drug exposure. Tooth preparation is tedious and the measured concentration is close to the limit of quantitation. In addition, the window of drug detection in tooth remains unknown at this time.

Rapid Separation and Detection of Drugs in Complex Biological Matrix Using TD-CDI Mass Spectrometer.

The drug detection technology plays a pivotal role in the domains of pharmaceutical regulation and law enforcement. In this study, we introduce a method that combines thermal desorption corona discharge ionization (TD-CDI) with mass spectrometry for efficient drug detection. The TD-CDI module, characterized by its compact and simple design, enables the separation of analytes within seconds and real-time presentation of one or two analyte peaks on the mass spectrum most of the time, which reduces matrix interference and improves detection performance. Through experimental investigation, we studied the characteristics of TD-CDI for analyte separation and detection, even with the same mass number, and optimized the TD-CDI approach. TD-CDI-MS was employed for the rapid detection of drugs in various traditional medicine, food products, and human samples. Additionally, by utilizing TD-CDI for segmented hair direct analysis, it becomes possible to trace the drug usage cycle of individuals. This underscores the feasibility of the proposed analytical method within the realm of drug detection.

Hair steroid before and after COVID-19 in preschoolers: the moderation of family characteristics

BackgroundFrequent or prolonged exposure to stressors may jeopardize young children’s health. The onset of the COVID-19 pandemic, coupled with disruptions in daily routines and social isolation resulting from public health preventive measures, have raised concerns about its potential impact on children’ experienced stress, particularly for young children and vulnerable families. However, whether the pandemic was accompanied by changes in physiological stress remains unknown as perceived stress is not a good proxy of physiological stress. This study examined if preschoolers showed increasing hair steroid concentrations following the onset of the COVID-19 pandemic and whether family characteristics may have exacerbated or buffered these changes. Methods136 preschoolers (2–4 years) provided hair for steroid measurement (cortisol, dehydroepiandrosterone (DHEA), cortisone, cortisol-to-DHEA ratio, cortisol-to-cortisone ratio) in October-November 2019 (T0) and in July-August 2020 (T1). A 2-centimeter hair segment was analyzed, reflecting steroid production over the two months leading up to collection. Family income, conflict resolution and lack of cohesion, as well as parents’ COVID-19 stress were reported by parents. Linear mixed models for repeated measures and Bayes factors were used. ResultsNo significant changes were noted from before to after the onset of the COVID-19 pandemic for most hair steroids. However, a moderating role of family conflict resolution was noted. Children living with parents with a better ability to resolve conflicts had lower levels of DHEA compared to those who had more difficulty managing conflicts. Additionally, lower levels of family cohesion and income were linked to some steroids, especially DHEA, suggesting that these factors may relate to children’s physiological stress. Finally, boys had higher DHEA levels than girls. ConclusionOur findings suggest that stress biomarkers were comparable from before to during the COVID-19 pandemic. This observation holds true despite the pandemic being perceived by many as a novel, unpredictable, and potentially threatening event. Findings further suggest that family characteristics are associated with hair steroid, especially DHEA, which deserves further investigation.

A mito-y conundrum: is more general or less but specific sequence data optimal? A comparison of the ForenSeq mtDNA whole genome and control region kits

ABSTRACT Mitochondrial DNA (mtDNA) is more prevalent than genomic DNA, making it useful for challenging forensic samples such as degraded bones and hair shafts. A comparison of the ForenSeq whole genome and control region mtDNA kits was undertaken on bones burnt to high temperatures and hair shafts covering a range of hair colours and treatments. Haplogroup predictions were made from the same haplogroup branch per donor for one bone burnt ≥ 700°C and all hair segments. Overall, the whole genome mtDNA kit was both more successful and produced more discriminatory haplogroup predictions than the control region kit.

Variation in Muskox (Ovibos moschatus) Guard Hair Growth Rates: Implications for Measuring Chronological Biomarkers.

Segmental analyses of hair may be useful for measuring biomarkers over several seasons to years from a single sample. To attribute hair segments to specific time periods, a known chronological marker, or a hair growth rate, is needed. We examined guard hair growth rates of captive muskoxen (Ovibos moschatus) in Fairbanks, Alaska, USA. We sought to determine if a general growth rate could be applied across muskox populations, thus facilitating the use of segmental analyses for various biomarkers. We used archived samples from 16 muskoxen that had guard hairs sampled at six, 14, and 30 wk after shaving. We measured the lengths of 10 guard hairs per sample, calculated weekly and annual growth rates, and then fitted linear mixed-effects models to assess the effect of different covariates on hair growth rate. The period in which hair had been grown had a significant effect (P<0.05) on growth rate. Extrapolated annual hair growth rates were 277±40 mm/yr (weeks 0-6), 248±47 mm/yr (weeks 7-14), and 165±36 mm/yr (weeks 15-30), with an overall average rate of 210±14 mm/yr. These rates were significantly faster than those of free-ranging Greenland muskoxen-78 mm/yr as measured by stable isotope analyses-and varied intra-annually. This suggests that a universal growth rate cannot be generalized across muskox populations and time.

Single hair analysis for gamma-hydroxybutyric acid-Method optimization, validation, and application.

As gamma-hydroxybutyric acid (GHB) underlies fast metabolization, its determination from hair may presumably offer a detection window superior to that of body fluids. Due to the wide range of endogenous concentration levels, the evidence of an exogenous ingestion is challenging. As already shown for other drugs, the temporal resolution obtained by applying single hair microanalysis provides further information. Therefore, a method for the extraction and quantification of GHB in 2-mm hair segments (seg) was optimized and validated (limit of detection [LOD]: 2.5 pg/seg, lower limit of quantification [LLOQ]: 5 pg/seg), and five single hairs were examined, each for three non-users and for three (alleged) users. A major challenge was the choice of appropriate extraction tubes without remains of GHB. In two samples from non-users, GHB could not or could only be detected in trace amounts. In the third sample, concentrations between the LOD and 31.1 pg/seg (mean: 9.5, median: 8.4; each pg/seg) were detected with decreasing values towards the tips. In two samples of persons with assumed GHB intake, maximum concentrations of 6.8 and 30.7 pg/seg were measured, but no significant concentration peaks indicating a single ingestion could be observed. The third sample showed concentrations of 7.6-55.2 pg/seg (mean: 28.8, median: 29.6; each pg/seg). In this case, the obtained profiles showing at least two reproducible concentration maxima between 20 and 40 mm point to an ingestion of GHB. The concentration profiles from single hairs were reproducible in each case, reflecting the concentration course of routine 1-cm segmental analysis. These are the first results published on GHB testing in segmented single hairs, and the results must be verified further.

Analysing and quantifying chronic stress-associated endogenous steroids in hair samples.

In previous studies, various steroids have been associated with stress and have therefore been quantified to investigate stress-related questions. Since the main stress-related steroid cortisol follows a circadian rhythm, often hair is analysed to quantify this steroid. Further, hair analysis gives the unique possibility of long-time monitoring by analysing a certain segment of hair, since hair grows on average 1 cm per month. Hair is a difficult matrix due to the complex sample preparation with many steps including washing and grinding, followed by various extraction steps. Additionally, steroids are endogenous and are therefore present in the hair matrix. Hence, no analyte free matrix is available, which is needed for the quantification via external calibrators. To overcome this problem, the so-called surrogate methods can be used, for which a 13 C3 labelled or deuterated reference compound of the steroid of interest is used for quantification. In the present study, a surrogate method was developed and fully validated for the quantitative analysis of seven steroids in human hair. Validation experiments showed that the method is further suitable for semi-quantitative analysis of estradiol. However, it is not suitable for the analysis of androsterone and DHEAS. The method was successfully used to analyse steroids in a comprehensive study of 360 adolescent hair samples, enabling research into stress markers.

A meta-analysis highlighting the increasing relevance of the hair matrix in exposure assessment to organic pollutants

Owing to a wide range of advantages, such as stability, non-invasiveness, and ease of sampling, hair has been used progressively for comprehensive biomonitoring of organic pollutants for the last three decades. This has led to the development of new analytical and multi-class analysis methods for the assessment of a broad range of organic pollutants in various population groups, ranging from small-scale studies to advanced studies with a large number of participants based on different exposure settings. This meta-analysis summarizes the existing literature on the assessment of organic pollutants in hair in terms of residue levels, the correlation of hair residue levels with those of other biological matrices and socio-demographic factors, the reliability of hair versus other biomatrices for exposure assessment, the use of segmental hair analysis for chronic exposure evaluation and the effect of external contamination on hair residue levels. Significantly high concentrations of organic pollutants such as pesticides, flame retardants, polychlorinated biphenyls and polycyclic aromatic hydrocarbon were reported in human hair samples from different regions and under different exposure settings. Similarly, high concentrations of pesticides (from agricultural activities), flame retardants (E-waste dismantling activities), dioxins and furans were observed in various occupational settings. Moreover, significant correlations (p < 0.05) for hair and blood concentrations were observed in majority of studies featuring pesticides and flame retardants. While among sociodemographic factors, gender and age significantly affected the hair concentrations in females and children in general exposure settings, whereas adult workers in occupational settings. Furthermore, the assessment of the hair burden of persistent organic pollutants in domestic and wild animals showed high concentrations for pesticides such as HCHs and DDTs whereas the laboratory-based studies using animals demonstrated strong correlations between exposure dose, exposure duration, and measured organic pollutant levels, mainly for chlorpyrifos, diazinon, terbuthylazine, aldrin, dieldrin and pyrethroid metabolites. Considering the critical analysis of the results obtained from literature review, hair is regarded as a reliable matrix for organic pollutant assessment; however, some limitations, as discussed in this review, need to be overcome to reinforce the status of hair as a suitable matrix for exposure assessment.

Therapeutic drug monitoring of corticosteroids/β2-agonists in the hair of patients with asthma: an open-label feasibility study.

Background: Although adherence to inhaled medication is critically important for treatment efficiency, around half of patients taking these drugs are non-adherent or make critical errors when using their delivery device. Segmental hair analysis might be a valuable tool for therapeutic monitoring because hair concentrations reflect exposure from month to month. The objective of the present proof-of-concept study was to establish the feasibility of segmental hair analysis of inhaled budesonide and formoterol in asthma patients. Methods: We conducted a prospective, open-label, interventional study of adult patients being treated with budesonide/formoterol for controlled, moderate-to-severe asthma (CorticHair, NCT03691961). Asthma control, lung function, and medication adherence were recorded. Hair samples were taken 4 months after enrolment and cut into four 1cm segments. Results: Samples were available from 21 patients (20 women; median age: 53; median budesonide dose: 600μg/d). Budesonide and formoterol were detected in samples from 18 to 13 patients, respectively. The median hair concentrations were 6.25pg/mg for budesonide and 0.9pg/mg for formoterol. The intrapatient coefficient of variation between hair segments was 21% for budesonide and 40% for formoterol. Pearson's coefficients for the correlations between the hair concentration and the self-reported drug dose and the prescribed drug dose were respectively 0.42 (p = 0.08) and 0.29 (p = 0.25) for budesonide and 0.24 (p = 0.44) and 0.17 (p = 0.57) for formoterol. Conclusion: Segmental hair analysis of inhaled medications was feasible, with low intrapatient variability. This innovative, non-invasive means of assessing monthly drug exposure might help physicians to personalize drug regimens for patients with difficult-to-treat asthma.

The maternal hair metabolome is capable of discriminating intrahepatic cholestasis of pregnancy from uncomplicated pregnancy.

Intrahepatic cholestasis of pregnancy (ICP) is a pregnancy-specific liver disease associated with elevated bile acids in the blood. Diagnosis typically only occurs after the manifestation of clinical symptoms and the metabolic mechanisms underlying its development remain unclear. The aim of this study was to investigate potential specific metabolites and the underlying metabolic changes occurring during the development of ICP in the maternal plasma and hair metabolomes of women diagnosed with either ICP or having a healthy pregnancy. A total of 35 Chinese women with ICP and 42 healthy pregnancies were enrolled in our study. Plasma and hair samples, total bile acid levels (TBA), alanine transaminase levels (ALT), aspartate aminotransferase levels (AST), and additional clinical information were collected during the third trimester. Metabolites from maternal plasma and hair segments collected pre-conception and analyzed using gas chromatography-mass spectrometry (GC-MS). Three plasma metabolites (p < 0.05, q < 0.38) and 21 hair metabolites (p < 0.05, q < 0.05) were significantly different between ICP and healthy pregnancies. A combination of the eight most significant hair metabolites in a multivariate receiver operating characteristic curve model showed the best area under the curve (AUC) was 0.885, whereas the highest AUC using metabolites from plasma samples was only 0.74. Metabolic pathway analysis revealed 32 pathways were significantly (p and q values < 0.05) affected in the hair samples of patients with ICP. Pathways associated with glutathione metabolism and ABC transporters were affected. No metabolic pathways were significantly affected in plasma. Overall, this study showed that the hair metabolome could be more useful than the plasma metabolome for distinguishing ICP from normal pregnancy.

Estimating the heritability of nitrogen and carbon isotopes in the tail hair of beef cattle

BackgroundThe natural abundance of nitrogen (δ15N) and carbon (δ13C) isotopes in animal tissues are used to estimate an animal’s efficiency in nitrogen utilization, and their feed conversion efficiency, especially in tropical grazing systems with prolonged protein restriction. It is postulated that selection for improving these two characteristics (δ15N and δ13C) would assist the optimisation of the adaptation in ever-changing environments, particularly in response to climate change. The aim of this study was to determine the heritability of δ15N and δ13C in the tail hair of tropically adapted beef cattle to validate their inclusion in genetic breeding programs.MethodsIn total, 492 steers from two breeds, Brahman (n = 268) and Droughtmaster (n = 224) were used in this study. These steers were managed in two mixed breed contemporary groups across two years (year of weaning): steers weaned in 2019 (n = 250) and 2020 (n = 242). Samples of tail switch hair representing hair segments grown during the dry season were collected and analysed for δ15N and δ13C with isotope-ratio mass spectrometry. Heritability and variance components were estimated in a univariate multibreed (and single breed) animal model in WOMBAT and ASReml using three generations of full pedigree.ResultsThe estimated heritability of both traits was significantly different from 0, i.e. 0.43 ± 0.14 and 0.41 ± 0.15 for δ15N and δ13C, respectively. These traits had favourable moderate to high genetic and phenotypic correlations (− 0.78 ± 0.16 and − 0.40 ± 0.04, respectively). The study also provides informative single-breed results in spite of the limited sample size, with estimated heritability values of 0.37 ± 0.19 and 0.19 ± 0.17 for δ15N and δ13C in Brahman, and 0.36 ± 0.21 and 0.46 ± 0.22 for δ15N and δ13C in Droughtmaster, respectively.ConclusionsThe findings of this study show, for the first time, that the natural abundances of both nitrogen and carbon isotopes in the tail hair in cattle may be moderately heritable. With further research and validation, tail hair isotopes can become a practical tool for the large-scale selection of more efficient cattle.