Drugs in nails: physiology, pharmacokinetics and forensic toxicology

Determination of glycation biomarkers in human fingernails by isotope-dilution liquid chromatography tandem mass spectrometry (LC-MS/MS)

Glycation is a non-enzymatic, post-translational modification of proteins which is elevated in several pathologies, notably diabetes. An early-stage glycation product, glycated hemoglobin (HbA1c), is used in the clinical management of diabetes, and advanced glycation end-products (AGEs) are implicated in the etiology of diabetic complications. Fingernail clippings contain a time-integrated repository of several metabolic processes during the preceding 3-5 months, are easily sampled, and various elements and molecules have been shown to remain stable within them for long periods without refrigeration. Building upon a few underexploited studies, we investigated fingernails as a non-invasive matrix to assess glycation using liquid chromatography-mass spectrometry to quantify ungual biomarkers of early- and advanced glycation (respectively furosine, as a fructose-lysine derivative, and two AGEs (Nε-carboxymethyllysine (CML) and Nε-carboxyethyllysine (CEL)). The method was appropriately validated and provided accurate and precise measurements of two amino acids and the glycation biomarkers. Sample storage at ± 25 °C for 12 months had no effect upon these analytes, and the method was applied to fingernails from 87 people with diabetes. There was a moderate, linear correlation between ungual furosine concentrations and HbA1c at the time of nail sampling (rs = 0.339, p = 0.0011). Among subjects for whom previous measurements were available, there was no correlation between ungual glycation and HbA1c measured > 3 months before nail sampling, indicating that ungual furosine reflects early-stage glycation over a similar period to HbA1c. This study provides further evidence, using modern analytical techniques, that fingernails offer the possibility to quantitatively and non-invasively assess glycation.

Towards an integrative approach to the biological profile

One of the most important tasks in forensic anthropology is the construction of the biological profile, classically defined as a set of four basic biological descriptors: biological sex, age-at-death, ancestry, and stature. Yet, our empirical and technological abilities in reconstructing the life experiences and health from skeletal remains far exceed these four parameters and forensic anthropology could benefit from further descriptors in the search for an identity. In this paper, we propose the inclusion of two other investigations to forensic anthropology practice to implement the already known biological profile: the interpretation of bone disease and lesions, and forensic toxicology on unconventional biological matrices. These analyses can provide information regarding health, habits, and disease burden, and by implementing them in our practice of forensic anthropology, they have the potential to improve the biological profile. We also propose a new term that can include not only the classical biological profile but also further descriptors, namely, the "biocultural profile".

Analytical Methods for Determining Psychoactive Substances in Various Matrices: A Review

Psychoactive substances pose significant challenges and dangers to society due to their impact on perception, mood, and behavior, leading to health and life disturbances. The consumption of these substances is largely influenced by their legal status, cultural norms, and religious beliefs. Continuous development and chemical modifications of psychoactive substances complicate their control, detection, and determination in the human body. This paper addresses the terminological distinctions between psychoactive and psychotropic substances and drugs. It provides a comprehensive review of analytical methods used to identify and quantify 25 psychoactive substances in various biological matrices, including blood, urine, saliva, hair, and nails. The analysis categorizes these substances into four primary groups: stimulants, neuroleptics, depressants, and hallucinogens. The study specifically focuses on chromatographic and spectrophotometric methods, as well as other novel analytical techniques. Methodology includes a review of scientific articles containing validation studies of these methods and innovative approaches to psychoactive substance determination. Articles were sourced from the PubMed database, with most research originating from the twenty first century. The paper discusses the limits of detection and quantitation for each method, along with current trends and challenges in the analytical determination of evolving psychoactive substances.

Effects of natural environments on drug contents in nails: comparison of drug residual rates between nails and hair to determine the drug-use history of corpses in unnatural death cases using micro-segmental analysis

PURPOSE

We previously developed evaluation methods using micro-segmental analysis (MSA) to examine the effects of external environments on drug content in hair and nails. In this study, the effects of the natural environmental factors (water, temperature, humidity, light, and soil) on drug contents in nails were examined and compared with our previous experimental data on hair.

METHODS

Four hay-fever medicines were used as model drugs (fexofenadine, epinastine, cetirizine, and desloratadine) to evaluate drug stability in the nails. Reference nails containing the four medicines were collected from patients with hay fever who ingested the medicines daily for four months. The nails were exposed to various natural environments for up to four months.

RESULTS

The effects of temperature, humidity, and light on drug contents in the nails were comparatively small. Soil significantly decomposed the nail surfaces and decreased the drug content of the nails (up to 17 %). Water also decreased the drug content (up to 12 %), although no apparent changes in nail surfaces were observed.

CONCLUSIONS

In comparison with hair data obtained under the same environmental conditions, light affected drugs in the hair rather than in nails, whereas water and soil greatly affected drugs in the nails rather than in hair. Although the disposition of drugs incorporated in the tissues differed between nails and hair, the analytes were detected in nails and hair strands left in severe natural environments. MSA could be useful for estimating drug-use histories and personal profiles using the nails and hair of a corpse.

Nailing it: Investigation of elephant toenails for retrospective analysis of adrenal and reproductive hormones

Hormone monitoring of at-risk species can be valuable for evaluation of individual physiological status. Traditional non-invasive endocrine monitoring from urine and faeces typically captures only a short window in time, poorly reflecting long-term hormone fluctuations. We examined toenail trimmings collected from African (Loxodonta africana) and Asian (Elephas maximus) elephants during routine foot care, to determine if long-term hormone patterns are preserved in these slow-growing keratinized tissues. We first measured the growth rate of elephant toenails biweekly for one year, to establish the temporal delay between deposition of hormones into nail tissue (at the proximal nail bed) and collection of toenail trimmings months later (at the distal tip of the nail). In African elephants, toenails grew ~0.18 ± 0.015 mm/day (mean ± SEM) and in Asian elephants, toenails grew ~0.24 ± 0.034 mm/day. This slow growth rate, combined with the large toenail size of elephants, may mean that toenails could contain a 'hormone timeline' of over a year between the nail bed and nail tip. Progesterone, testosterone and cortisol were readily detectable using commercial enzyme immunoassays, and all assays passed validations, indicating that these hormones can be accurately quantified in elephant toenail extract. In most cases, variations in hormone concentrations reflected expected physiological patterns for adult females and males (e.g. ovarian cycling and musth) and matched individual health records from participating zoos. Progesterone patterns aligned with our calculations of temporal delay, aligning with female ovarian cycling from over six months prior. Unexpectedly, male testosterone patterns aligned with current musth status at the time of sample collection (i.e. rather than prior musth status). Though this sample type will require further study, these results indicate that preserved hormone patterns in elephant toenails could give conservationists a new tool to aid management of elephant populations.

Sensitivity, specificity, and discordance with self-report of nail sample testing for alcohol and cannabis

BACKGROUND

Nails accumulate the alcohol metabolite, ethyl glucuronide (ETG), and the cannabis metabolite, carboxy- delta-9-THC over 3-6 months. Few studies have examined nail toxicology testing's sensitivity and specificity and the agreement between nail testing and self-reported alcohol and marijuana use.

METHODS

In an ongoing clinical trial, 1101 veterans completed initial telephone questionnaires and were then asked to mail nail clippings for substance use analysis. We examined sensitivity and specificity of ETG and carboxy- delta-9-THC in nails compared to self-report of alcohol use patterns (the AUDIT-C) and substance-related harms (alcohol and THC subscales of the ASSIST). We then examined factors associated with discordance between nails and self-report.

RESULTS

Almost two-thirds (707/1101) of respondents mailed in nail clippings. Those with returned nails were disproportionately married, white race, older, and less depressed. At a threshold of 8pg/mg, sensitivity was only.50 to detect risky alcohol use and.49 to detect alcohol-related issues. Sensitivity for marijuana issues was only.61. Specificity was greater than.77 for all measures. Factors associated with positive nails/negative self-report (i.e. false positives) for risky alcohol use on the Audit-C included more pain and being unmarried; false positive nails for alcohol-related issues on the ASSIST were associated with being unmarried and non-Hispanic ethnicity. False positive nails for THC-related issues on the ASSIST were associated with being African American, Hispanic, and having had legal issues.

CONCLUSIONS

At standard cut-offs, nail measures had low sensitivity and higher specificity. The groups who disproportionately submit positive nails/negative self-report could have substance use patterns not adequately captured by self-report, inaccurate self-report due to social pressures, or distinct drug metabolism.

SPE-UHPLC-ESI-MS/MS Analysis of Cocaine and Its Metabolites in Conventional and Alternative Biological Specimens: Application to Real Samples

An increase in cocaine abuse has been observed globally since the past decade. Cocaine is among the commonly abused stimulants used for recreational purposes. In this study, the SPE-UHPLC-MS/MS method was developed and validated to be applied on real specimens of 20 chronic cocaine abusers to quantify cocaine/metabolites in conventional as well as alternative biological matrices. Cocaine was extracted from biological specimens using solid-phase extraction followed by liquid chromatography tandem mass spectrometry analysis. Chromatographic separation was achieved on a Poroshell120EC-18 column (2.1 mm × 50 mm, 2.7 μm particle size) using water-acetonitrile in 0.1% formic acid as a mobile phase in gradient elution mode. The flow rate of the mobile phase was 0.5 mL/min with a gradient varying the percentage of acetonitrile linearity ranging 15-95% in 6.0 min acquisition time, and the injection volume was set at 5 μL. Positive electrospray ionization with multireaction ion monitoring mode using two ion transitions for cocaine/metabolites and one for cocaine-d3 was employed. The quantification method demonstrated good linear ranges of 0.025-250 ng/mL in blood, urine, and oral fluid (ng/mg for hair and nail) with a ≥0.991% determination coefficient. The detection limit and lower quantification limit were 0.005 and 0.025 ng/mL in all matrices, respectively. The mean extraction recovery and ionization suppression ranged from 89.3 to 99.8% and -4.6 to -14.4% in the studied matrices. Within-run and between-days precisions were 1.8-7.2% and 1.9-6.1%, respectively. This study will not only help in quantifying cocaine/metabolites in alternative specimens (hair, nail, and oral fluid) but also guide clinical and forensic toxicologists in interpretation of exhumation cases. Furthermore, multiple specimens' analyses can be of significance in estimating the time/manner of drug exposure, in confirming the results of laboratories in cases of doubtful clinical histories, or in aiding medico-legal investigations.

Assessment of pheniramine in alternative biological matrices by liquid chromatography tandem mass spectrometry

Pheniramine is an over-the-counter antihistamine drug. Its accessibility and low cost made it more popular among drug abusers in Pakistan. In this study, pheniramine was quantified in both conventional and alternative specimens of twenty chronic drug abusers, aged 16-50 years, who were positive for pheniramine in comprehensive toxicological screening for drugs by gas chromatography with mass spectral detection in positive electron impact mode. Pheniramine was extracted from biological specimens using solid phase extraction and liquid chromatography tandem mass spectrometry was employed for quantification. Chromatographic separation was carried out on a Poroshell120EC-18 (2.1 mm × 50 mm × 2.7 µm) column using water-acetonitrile in formic acid (0.1%) mobile phase in gradient elution mode with 500 μL/min flow rate. Positive electrospray ionization mode and multi-reaction monitoring with ion transitions m/z 241.3 → 195.8 and 167.1 for pheniramine and m/z m/z 247.6 → 173.1 for pheniramine-d6 were employed. The quantification method showed good linear ranges of 2-1000 ng/mL in blood, urine, and oral fluid; 2-1000 ng/mg in hair and 5-1000 ng/mg in nail with ≥ 0.985% coefficient of linearity. The retention time of pheniramine was 3.0 ± 0.1 min. The detection and lower quantification limits were 1 ng/mL and 2 ng/mL for blood, urine, oral fluid and hair whereas 2.5 ng/mg and 5 ng/mg for nail, respectively. Mean extraction recovery and ionization suppression ranged 86.3-95.1% and -4.6 to -14.4% in the studied matrices. Intra-day and inter-day precision were 4.1-9.3% and 2.8-11.2%, respectively. Pheniramine levels in specimens of drug abusers were 23-480 ng/mL in blood, 72-735 ng/mL in urine, 25-379 ng/mL in oral fluid, 10-170 ng/mg in hair and 8-86 ng/mg in nail specimens. Alternative specimens are of utmost significance in clinical and medico-legal cases. In this study, authors compared matrix-matched calibration curves to blood calibration curve and obtained results within ± 10%; thereby justifying the use of blood calibration curve for urine, oral fluid, hair, and nail specimens.

Micro-distribution of arsenic in toenail clippings using laser ablation inductively coupled plasma mass spectrometry: implications for biomonitoring

Toenails are a common monitoring tool for arsenic exposure, but the risk of external contamination of toenails has cast doubt on its usefulness. The main objective of this study is to investigate the micro-distribution of arsenic through the dorsoventral plane of nail clippings to understand endogenous vs exogenous sources. We used laser-ablation inductively coupled plasma mass spectrometry to measure arsenic through a dorsoventral cross-section of the nail plate collected from reference (N = 17) and exposed individuals (N = 35). Our main results showed (1) bulk toenail concentrations measured using ICP-MS in this study ranged from 0.54 to 4.35 µg/g; (2) there was a double-hump pattern in arsenic concentrations, i.e., dorsal and ventral layers had higher arsenic than the inner layer; (3) the double-hump was more pronounced in the exposed group (ventral: 6.25 μg/g; inner: 0.75 μg/g; dorsal: 0.95 μg/g) than the reference group (ventral: 0.58 μg/g; inner: 0.15 μg/g; dorsal: 0.29 μg/g) on average; (4) the distribution was, in part, associated with different binding affinity of nail layers (i.e., ventral > dorsal > inner); (5) most individuals in the higher exposure group showed > 25% contamination in ventral and dorsal nail layers; and (6) there were no statistically significant correlations between LA-ICP-MS arsenic with either bulk toenail arsenic or urine arsenic from the same individuals. Our results on micro-distribution and binding affinity provide insight into the impact of external contamination on arsenic concentrations and show how LA-ICP-MS can access the protected inner nail layer to provide a more accurate result.

Time-course changes in fingernail cortisol levels during pregnancy and postpartum

The cortisol level in fingernails can reflect the cumulative hormones produced in the body several months prior. However, previous studies have only demonstrated the cross-sectional associations of fingernail cortisol with salivary or hair cortisol, and not longitudinal changes in fingernail cortisol in situations where cortisol levels in the body could be expected to change. Therefore, this study focused on pregnancy as a model for changes in cortisol levels over a prolonged period of time, and investigating the time courses of fingernail cortisol during pregnancy and the postpartum period. We collected nail samples from 30 healthy women during pregnancy and 12 months postpartum to measure the cortisol levels in the nail. Results showed that cortisol levels in fingernail clippings increased from 1 month before childbirth to 4 months postpartum, with the levels peaking at 2 months postpartum. Additionally, we found higher cortisol levels in fingernail clippings in primiparas than in those of multiparas. The time course of fingernail cortisol levels could replicate the longitudinal changes in cortisol in the body, and differences between multiparas and primiparas seemed to be biologically plausible, which could support the concept of fingernail cortisol as a retrospective index of hormone production.

Assessment of substance exposures in nail clipping samples: A systematic review

BACKGROUND

Studies of prenatal substance exposure often rely on self-report, urine drug screens, and/or analyses of blood or meconium biomarkers. Accuracy of these measures is limited when assessing exposure over many weeks or months of gestation. Nails are increasingly being considered as a matrix from which to assess substance exposure. This systematic review synthesizes data on the validity of detecting alcohol, nicotine, cannabis, and opioid from nail clippings, with an emphasis on prenatal exposure assessment.

METHODS

The systematic review was conducted using PRISMA 2020 guidelines. Seven databases were searched with keywords relevant to the four substances of interest. Results were summarized grouping manuscripts by the exposure of interest with focus on accuracy and feasibility.

RESULTS

Of 2384 papers initially identified, 35 manuscripts were included in our qualitative synthesis. Only a few studies specifically looked at pregnant individuals or mother-child dyads. Across the four substances, many studies demonstrated a dose-response relationship between exposure and concentration of analytes in nails. Nail assays appear to detect lower level of exposure compared to hair; however, sample insufficiency, especially for multi-substance assays, remains a limitation.

CONCLUSIONS

Based on the reviewed studies, nail clippings are an acceptable and potentially preferable matrix for the evaluation of these four prenatal substances when sampling frequency and/or study design necessitates assessment of past exposures over an extended period. Nails have the advantage of infrequent sampling and minimal invasiveness to assess a broad exposure period. Future studies should examine validity of analytes in toenail versus fingernail clippings.

Determination of well-being-related markers in nails by liquid chromatography tandem mass spectrometry

Well-being is a multifactorial positive state that is highly influenced by some endogenous molecules that control happiness and euphoric feelings. These molecules, e.g., neurotransmitters, hormones and their derivatives, play a crucial role in metabolism and may be referred to as "well-being-related markers". The deregulation of well-being-related markers can lead to organism malfunctions and life-threatening states. In this research, we aimed to evaluate the potential of nails for the chronic production of several well-being-related markers. For this purpose, we developed an LCMS /MS-based method for the determination of 10 well-being-related markers, including melatonin, serotonin, cortisol, kynurenine and several precursors and metabolites. The method was optimized regarding different analytical steps: required sample amount, extraction time, number of required extractions, preconcentration, injection volume and MS conditions. Method validation was performed by two different approaches: (i) using surrogate nail matrix and (ii) using authentic nail samples by standard additions. The method was found to be linear in the expected endogenous range and sensitive enough to determine the low endogenous concentration levels in nails. Accuracy and precision were appropriate in both validation approaches. As proof of concept, the method was used (i) to correlate fingernail and toenail levels for all metabolites in 22 volunteers, (ii) to establish the endogenous concentration range of all metabolites in females (n = 50) and males (n = 34) and (iii) to correlate the metabolite levels with age. For some metabolites, the calculated ranges have been reported for the first time. In summary, the present strategy to evaluate well-being-related markers in nails may be a useful tool for the evaluation of the production of these important compounds with high potential for a wide range of clinical purposes.

Challenges and future trends in wearable closed-loop neuromodulation to efficiently treat methamphetamine addiction

Achieving abstinence from drugs is a long journey and can be particularly challenging in the case of methamphetamine, which has a higher relapse rate than other drugs. Therefore, real-time monitoring of patients' physiological conditions before and when cravings arise to reduce the chance of relapse might help to improve clinical outcomes. Conventional treatments, such as behavior therapy and peer support, often cannot provide timely intervention, reducing the efficiency of these therapies. To more effectively treat methamphetamine addiction in real-time, we propose an intelligent closed-loop transcranial magnetic stimulation (TMS) neuromodulation system based on multimodal electroencephalogram-functional near-infrared spectroscopy (EEG-fNIRS) measurements. This review summarizes the essential modules required for a wearable system to treat addiction efficiently. First, the advantages of neuroimaging over conventional techniques such as analysis of sweat, saliva, or urine for addiction detection are discussed. The knowledge to implement wearable, compact, and user-friendly closed-loop systems with EEG and fNIRS are reviewed. The features of EEG and fNIRS signals in patients with methamphetamine use disorder are summarized. EEG biomarkers are categorized into frequency and time domain and topography-related parameters, whereas for fNIRS, hemoglobin concentration variation and functional connectivity of cortices are described. Following this, the applications of two commonly used neuromodulation technologies, transcranial direct current stimulation and TMS, in patients with methamphetamine use disorder are introduced. The challenges of implementing intelligent closed-loop TMS modulation based on multimodal EEG-fNIRS are summarized, followed by a discussion of potential research directions and the promising future of this approach, including potential applications to other substance use disorders.

Coat, Claw and Dewclaw 17-β-Estradiol and Testosterone Concentrations in Male and Female Postpubertal Cats: Preliminary Results

In the recent past, tissue materials such as hair/coat and nails/claws have proved to be useful for the study of long-term hormonal changes in humans and animals and shown to be advantageous in terms of being collectable without invasiveness, with a benefit in terms of animal welfare. However, studies using these tissue materials in cats are scarce, especially on sexual hormone measurement. In this study, the concentrations of 17-β-estradiol (E2) and testosterone (T) were assessed in 20 male and 18 female domestic postpubertal cats at the time of neutering/spaying during the breeding season. Hormones were measured in coat shaved from the forearm (ACOAT) and from the surgical area (SCOAT); claws were collected from the forearms (CLAWS) and the dewclaws (DCLAWS). Although all these tissue materials were shown to be useful for E2 and T long-term measurement, only T concentrations were higher (p < 0.001) in males from both ACOAT and SCOAT samples when compared to females and therefore useful for distinguishing between the two sexes. Within each sex, E2 and T concentrations can be assessed on coat, but also on the dewclaws, providing an alternative, practical, matrix for sexual steroid measurement in postpubertal cats during the breeding season.

Follow-up of Favipiravir-Induced Nail Fluorescence: Implications for Nail and Drugs

INTRODUCTION

Favipiravir creates fluorescence on nails, which can be seen with Wood's light.

OBJECTIVES

The objectives of this study are to examine the properties of fluorescence in the nail due to favipiravir and to observe whether other drugs also produce fluorescence in the nail.

METHODS

The research is descriptive, prospective, and quantitative. This study recruited 30 healthcare workers who received favipiravir treatment and 30 volunteers who took or did not take any medication except favipiravir from March 2021 to December 2021. Fingernails of the patients and control groups were examined under Wood's light in the darkroom. If fluorescence was observed in the fingernails, we followed up once a month until the fluorescence disappeared. We calculated the nail growth rate by dividing the distance of nail fluorescence from the proximal nail fold by the number of days since favipiravir was started.

RESULTS

We found nail fluorescence in all patients receiving a loading dose of favipiravir. The fluorescence in the nail decreased and disappeared in the 3rd month. The average nail growth rate at the first visit was 0.14 mm/day. The nail growth rate at the second visit was 0.10 mm/day. A statistically significant difference was found between the first and second visit nail growth rates (z: -2.576; p=0.010<0.05). We found that other drugs did not produce any fluorescence in the nail.

CONCLUSIONS

Nail fluorescence induced by favipiravir is dose-dependent and decreases in intensity over time. Nail fluorescence due to favipiravir is likely due to the active ingredient of the drug.

Evaluation of thumbnail clipping as a specimen for retrospectively assessing average production of testosterone

BACKGROUND

The chronic abnormal production of testosterone (T) is associated with many disorders in men. Fingernail clippings might be more suited for the diagnosis and medium-to-long term therapeutic monitoring for the T-related chronic disorders than the blood-derived specimens. The objective of this study was to characterize a thumbnail clipping as the specimen for assessing the several months-old T status.

METHODS

Thumbnail clippings from various subjects were analyzed by liquid chromatography/electrospray ionization-tandem mass spectrometry to evaluate the gender difference, and changes caused by aging and androgen deprivation therapy (ADT) in the thumbnail T concentration.

RESULTS

There was an evident gender difference in the thumbnail T concentrations [male; 2.55 ± 0.85 ng/g and female; 0.48 ± 0.29 ng/g, mean ± SD (n = 25 each), Welch t-test]. The thumbnail T concentrations significantly decreased with age in men (n = 268, Scheffé F-test), which was similar to those of the free or bioavailable T in serum/plasma. The thumbnail T concentrations sharply decreased by a 6-months ADT (especially the effect of the luteinizing hormone-releasing hormone agonist/antagonist) for patients with prostate cancer (n = 10).

CONCLUSIONS

The thumbnail clipping can be a specimen to retrospectively assess the average T production.

Hair and Claw Dehydroepiandrosterone Concentrations in Newborn Puppies Spontaneously Dead within 30 Days of Age

The latest intrauterine fetal developmental stage and the neonatal period represent the most challenging phases for mammalian offspring. Toward the term of pregnancy, during parturition, and after birth, the hypothalamic−pituitary−adrenal axis (HPA) is a key system regulating several physiologic processes, through the production of cortisol and dehydroepiandrosterone (DHEA). This study was aimed to assess DHEA concentrations in hair and claws of 126 spontaneously dead newborn puppies, classified as premature puppies (PRE-P), stillborn puppies (STILL-P) and puppies that died from the 1st to the 30th day of life (NEON-P). The possible influence of newborn sex, breed body size, and timing of death on DHEA concentrations in both matrices was evaluated. Claw DHEA concentrations were higher in the PRE-P group when compared to STILL-P and NEON-P puppies (p < 0.05), whilst no significant differences were found in hair for all the studied factors. The results confirm the hypothesis that higher amounts of DHEA are produced during the intrauterine life in dogs, also in puppies that will die soon after birth.

Detection of Morphine and Opioids in Fingernails: Immunohistochemical Analysis and Confirmation with Ultra-High-Performance Liquid Chromatography Coupled with High-Resolution Mass Spectrometry

This study aimed to investigate the detection of morphine in fingernails from forensic autopsies using immunohistochemistry (IHC), with confirmation by ultra-high-performance liquid chromatography coupled with high-resolution mass spectrometry (UHPLC-HRMS). A primary antibody specific to morphine and a secondary antibody conjugated to horseradish peroxidase (HRP) was used. IHC on specimens of Subjects A and B (both drug addicts) resulted in the detection of morphine on a cell layer of the nail plate matrix. UHPLC-HRMS and GC-MS analysis showed that Subject A had a morphine concentration of 0.35 ng/mg in the fingernail and 472 ng/mL in the blood, while Subject B reached 1.23 ng/mg in the fingernail and 360 ng/ml in the blood. Most of those matrices were positive for codeine, methadone, EDDP, and 6-MAM. The use of IHC in Subject C (a former addict) showed no positivity for morphine in the fingernail, while the UHPLC-HRMS analysis confirmed its absence in the fingernail and blood. Additionally, an analysis of the scalp or pubic hair of the subjects was carried out using UHPLC-HRMS. The results suggest that IHC can be used to establish the site of accumulation of morphine in the nail matrix; for postmortem diagnosis; and that basic substances can be detected by UHPLC-HRMS. There are no previous studies on the use of IHC as a technique for forensic purposes in unconventional matrices, such as nails.

The Nail and Hair Findings Developing In Patients Treated For COVID-19 Infection Flourescence of Keratinized Tissues on Wood's Lamp In COVID-19 Disease

The new severe acute respiratory syndrome coronavirus 2 (SARS-Cov-2) is the causative agent of coronavirus 2019 (COVID-2019) disease. A wide variety of symptoms of the disease have been frequently reported in the literature in recent years. However, information on the findings in keratinized tissues is stil limited. Data on changes in keratinized tissues such as nails, teeth and hair and oral mucousa due to drugs used in the treatment of this disease are also extremely insufficient. With this study, it was aimed to evaluate the changes in the keratinized tissues of our patients with COVID-19, who are frequently encountered in the Ear Nose and Throat outpatient clinic. The study was carried out on patients who applied to Başkent University Ear Nose and Throat clinic. There were 3 groups. The first group consisted of patients diagnosed with COVID-19 and received relevant medical treatments, the second group included individuals who have never experienced COVID-19 infection but have been vaccinated against COVID-19, and the third group is the control group with normal healthy individuals who have never been diagnosed with COVID-19 infection and have not been vaccinated so far. With the Wood's lamp, fluorescent changes in nails, hair, tooth and the oral mucousa were recorded. A total of 124(75 females, 49 males) patients were included in the study. Positive Wood's finding was significantly higher in COVID-19 group(Group 1) who received Favipravir when compared to individuals who did not receive Favipravir (p<0,001). Wood's positivity was not detected in any of the individuals who did not use favipravir. The rate of determining Wood's positivity in favipravir users decreases after 58 days. The adverse effects of the accumulation of the drugs- mainly Favipravir- used in the treatment of COVID-19 disease, have not yet been clearly demonstrated so far. Revealing the findings in these tissues with this study will pave the way for investigating changes or drug sequestrations in other organs in the long term.

Hair and nail nicotine levels of mothers and their infants as valid biomarkers of exposure to intrauterine tobacco smoke

INTRODUCTION

Tobacco use remains the single most modifiable cause of adverse pregnancy outcomes. It is crucial to be able to accurately quantify the burden of tobacco exposure on both the mother and fetus to have better measures of efficacy with interventions being studied.

METHODS

This is a descriptive and exploratory study conducted within a randomized controlled trial. Pregnant smoking and non-smoking women were followed from ≤22 weeks' gestation through delivery with monthly maternal smoking questionnaires, urine cotinine levels, and collection of maternal and infant hair and nail samples, at delivery. Nicotine was extracted and measured (ng/mg) using high-performance liquid chromatography with electrochemical detection.

RESULTS

Forty-six mother-infant dyads (34 pregnant smokers and 12 pregnant non-smokers) had successful completion of maternal and infant hair and nails samples. The median hair nicotine levels of the smoking mothers and their infants was significantly higher than those of the non-smokers (1.015 vs 0.037 ng/ mg, p<0.05 for the mothers; 0.445 vs 0.080 ng/mg, p<0.01 for the infants). Similarly, the median nail nicotine levels for smoking mothers and their infants were significantly higher than the non-smokers (2.130 vs 0.056 ng/mg, p<0.01 for the mothers; 0.594 vs 0.132 ng/mg, p<0.05 for the infants). We found a moderate but significant correlation between maternal hair and nail nicotine (r=0.64, p<0.001), infant hair and nail nicotine (r=0.64; p<0.001), maternal and infant hair nicotine (r=0.61, p<0.001), and maternal and infant nail nicotine levels (r=0.58, p<0.001).

CONCLUSIONS

Our study shows that both infant hair and nail nicotine levels are valid biomarkers of intrauterine tobacco smoke exposure, and can be used to identify prenatal smoke exposure, correlating well with the level of maternal nicotine exposure.

The Application of Metabolomics in Forensic Science with Focus on Forensic Toxicology and Time-of-Death Estimation

Recently, the diagnostic methods used by scientists in forensic examinations have enormously expanded. Metabolomics provides an important contribution to analytical method development. The main purpose of this review was to investigate and summarize the most recent applications of metabolomics in forensic science. The primary research method was an extensive review of available international literature in PubMed. The keywords “forensic” and “metabolomics” were used as search criteria for the PubMed database scan. Most authors emphasized the analysis of different biological sample types using chromatography methods. The presented review is a summary of recently published implementations of metabolomics in forensic science and types of biological material used and techniques applied. Possible opportunities for valuable metabolomics’ applications are discussed to emphasize the essential necessities resulting in numerous nontargeted metabolomics’ assays.

Biomarkers of disease in human nails: a comprehensive review

Diagnostic, monitoring, response, predictive, risk, and prognostic biomarkers of disease are all widely studied, for the most part in biological fluids or tissues, but there is steadily growing interest in alternative matrices such as nails. Here we comprehensively review studies dealing with molecular or elemental biomarkers of disease, as opposed to semiological, pharmacological, toxicological, or biomonitoring studies. Nails have a long history of use in medicine as indicators of pathological processes and have also been used extensively as a matrix for monitoring exposure to environmental pollution. Nail clippings are simple to collect noninvasively as well as to transport and store, and the matrix itself is relatively stable. Nails incorporate, and are influenced by, circulating molecules and elements over their several months of growth, and it is widely held that markers of biological processes will remain in the nail, even when their levels in blood have declined. Nails thus offer the possibility to not only look back into a subject's metabolic history but also to study biomarkers of processes that operate over a longer time scale such as the post-translational modification of proteins. Reports on ungual biomarkers of metabolic and endocrine diseases, cancer, and psychological and neurological disorders will be presented, and an overview of the sampling and analytical techniques provided.

The Penetrance of Topical Nail Therapy: Limitations and Current Enhancements

The chemical composition and thickness of nails are obstacles for treatments of various nail diseases, such as onychomycosis. Topical medications are currently the preferred method of treatment because of reduced adverse systemic effects. However, penetration of the product from the nail plate into the nail bed continues to be an issue because of factors such as distance required to reach the target area, chemical barriers, and drug inactivation upon keratin binding. Beyond developing novel drugs, some studies have investigated mechanical and chemical methods to optimize drug delivery. The issue of nail diseases is still a challenge and requires multifactorial treatments.

Hepatitis B virus DNA in the fingernails and hair of children with acute hepatitis B

Hepatitis B virus (HBV) DNA is detectable in the nails and hair of patients with chronic HBV infection. However, it remains unclear whether HBV DNA can be detectable in the nails and hair of patients with acute HBV infection. We encountered two cases of children with acute HBV infection. HBV DNA in the nails and hair from the two children was evaluated by real-time PCR. To clarify the characteristics of HBV DNA, full-length HBV genome sequencing and phylogenetic tree analysis were performed. The levels of serum HBV DNA in children of cases 1 and 2 at day 0 were 7.6 Log IU/mL and 7.4 Log IU/mL, respectively. Nail HBV DNA was detected in both children (case 1: 4.6 Log IU/mL at day 0, case 2: 5.5 Log IU/mL at day 14). Moreover, hair HBV DNA was detectable in case 2 (4.0 Log IU/mL at day 14). Serum HBV DNA became undetectable within approximately 3-4 months after the first hospital visit. After the resolution of HBV viremia, nail and hair HBV DNA became undetectable. The sequence analysis of serum, nail and hair HBV DNA showed the same HBV genotype in each case (case1: genotype C, case 2: genotype A). In case 1, 3 nucleotides were different in the full-genome HBV sequence between the serum and nails. In case 2, the full-genome HBV sequences were identical among the serum, nails and hair. In conclusion, HBV DNA was detectable in nails and hair of children with acute HBV infection.

Nail Melatonin Content: A Suitable Non-Invasive Marker of Melatonin Production

Melatonin plays multiple physiological roles in the human body. Evaluation of melatonin production by the determination of urinary 6-sulfatoxymelatonin in 24-h samples has important drawbacks which hinder the successful evaluation of melatonin production in large cohorts. Here, we evaluated the potential of nail analysis for estimating melatonin production. Firstly, mass spectrometry methodology for the determination of melatonin in nails was optimized and successfully validated. The method was found to be linear in the range 6.5-830 fg/mg with intraday and interday accuracy in the range 100-104 %, precision below 15 % and a LOD of 3.5 fg/mg. Secondly, nail melatonin concentrations from 84 volunteers (age 5-96) were determined. The expected correlation between melatonin and age was obtained (correlation coefficient -0.615; p < 0.001). Additionally, we showed that fingernails are preferable to toenails to determine nail melatonin content. Finally, fingernails collected for 180 days after melatonin administration (two volunteers, 1.9 mg/night during 5 days) were analyzed. Nail melatonin concentrations immediately rose after administration and went back to pre-administration values after ≈100 days in both volunteers. Our results suggest that melatonin determination in nails is a suitable non-invasive tool for the estimation of global melatonin production. Due to the easy collection and storage of nails, the long-term information obtained and the multiple functions of melatonin, nail melatonin content might complement dim light melatonin onset, which is commonly measured from plasma/saliva samples, paving the way for melatonin research.

Human nail cortisol as a retrospective biomarker of chronic stress: A systematic review

Cortisol is the primary glucocorticoid produced by the activation of the hypothalamic pituitary adrenal (HPA) axis after a psychological or physiological stressor. The dysregulation of the HPA axis by chronic stress has been associated with psychiatric disorders. Although hair is currently the main validated source of chronic cortisol concentrations, cortisol is also bound to human nails, another keratinised matrix. Therefore, nail cortisol has the potential to be an alternative retrospective chronic measure of HPA activation. The aim of this systematic review was to assess the temporal resolution, methodological issues, HPA correlates, and target populations in nail cortisol investigations. A qualitative synthesis was performed to assess current literature exploring cortisol concentrations from human nails. A total of 18 eligible human studies extracted from Medline (PubMed and Ovid), ProQuest (PsycINFO), and Scopus found that immunoassays and mass spectrometry were the two primarily methods of analysis. However, methodological variability remained evident between studies. Nail cortisol correlated with saliva and hair in some studies and was investigated across multiple developmental periods. Finally, when applied as an outcome measure in health disorders, higher nail cortisol concentrations have been shown to be associated with acute coronary syndrome and depression. In conclusion, nail cortisol may serve as a retrospective biomarker of chronic stress; however, the ability to track how much cortisol is accumulating within nail clippings is complex and may represent a large timespan. Further, very few studies have reported effect sizes and investigated the effects of covariates, such as age, sex, ethnicity, and nail characteristics, which limits the validation of this measure. Further studies are required to validate the utility of nail cortisol as a biomarker of chronic stress across the human lifespan.

Determination and Distribution of Cannabinoids in Nail and Hair Samples

Hair has been used for decades in toxicology as a biological matrix for long-term detection of substances. Nails are another keratinized matrix that is being studied as an alternative when hair cannot be obtained. Although cannabis is the most prevalent illicit drug in the world, cannabinoid distribution in nails compared with hair has been scarcely studied. In this work, we described two methods for the determination of cannabidiol (CBD), cannabinol (CBN) and Δ9-tetrahydrocannabinol (THC), and main metabolites of THC [11-nor-9-carboxy-THC (THCCOOH), 11-hydroxy-THC (OHTHC) and 8-β-11-dihydroxyTHC (diOHTHC)] in nail and hair samples. After an alkaline hydrolysis, samples were submitted to solid-phase extraction and analyzed by liquid chromatography with tandem mass spectrometry (LC–MS-MS). The methods were fully validated, with good linearity (r2 &gt; 0.99) in the range of 20 to 100 to 20,000 pg/mg. No endogenous or exogenous interferences were found. Accuracy was from 99.5% to 109.8%, and imprecision was &lt;6.9%. Ion suppression (up to −74.4%) was observed for all the analytes, except for diOHTHC at low concentrations in hair (46.1%). Extraction efficiency ranged from 21.5% to 84.5%. The methods were applied to matched nail and hair specimens from 23 cannabis users to study the incorporation and distribution of the cannabinoids into these matrices. Only CBD, CBN and THC were detected in the samples, with much higher concentrations in fingernails than in toenails and hair. Correlations between analyte concentrations in the different matrices and with reported drug consumption were studied. A preliminary cut-off for THC in toenails was calculated using the cut-off proposed by the Society of Hair Testing in hair for the identification of chronic cannabis use.

Detection of C-peptide in human hair and nail: a comparison between healthy persons and persons with type 1 diabetes

OBJECTIVES

Serum and urinary C-peptide has clinical implications in people with/without diabetes. Recently, C-peptide was detected in hair samples of healthy adults but not studied in people with diabetes. It is not known whether C-peptide can be detectable in nail tissue or not. This study aims to assess the detection of C-peptide in hair and nail samples and to find whether hair and nail C-peptide levels are different in type 1 diabetes mellitus (T1DM) compared with healthy individuals.

RESEARCH DESIGN AND METHODS

In a prospective case-control study on 41 subjects with T1DM and 42 control subjects, hair and nail samples were collected and prepared. C-peptide was extracted by incubating the samples with methanol and measuring the extract with an immunoassay. The hair and nail C-peptide values were compared between the T1DM and control group and their correlations with each other and with other variables were assessed with a significant level set at 0.05.

RESULTS

Hair and nail C-peptide levels were detected in both groups, with significantly lower values in T1DM compared with the control group. T1DM with >7-year diabetes duration had significantly lower C-peptide in serum, nails and hair. Hair and nail C-peptide levels have significant positive correlations with each other and negative correlations with age.

CONCLUSIONS

We conclude that C-peptide are detectable in the hair and nails of healthy persons and persons with T1DM. Compared with the healthy persons, persons with T1DM had significantly lower hair and nail C-peptide and significant hair/nail C-peptide reduction after 7 years of diagnosis. Our results suggest that hair and nails are suitable matrices for the measurement of C-peptide in healthy persons and persons with T1DM.

Fingernail cortisol - State of research and future directions

The extraction of cortisol from fingernails represents a recent advancement in the retrospective, long-term assessment of hypothalamic-pituitaryadrenal (HPA) axis activity: Fingernail cortisol has the potential to overcome some of the major disadvantages of established HPA axis markers. However, the introduction of any novel methodology also raises certain caveats. This review provides a comprehensive summary of the current state of research on fingernail cortisol. It identifies a number of strengths of his novel methodology (e.g., its high feasibility), while also pointing out open questions which currently challenge the interpretability of fingernail findings, in particular regarding the time period of cortisol secretion reflected in fingernail samples, as well as regarding potential determinants or confounders of fingernail cortisol (e.g. sociodemographic, lifestyle, or health characteristics). Clarification of these issues in the context of further methodological studies is necessary to validate the use of fingernail cortisol as a retrospective marker of HPA axis activity.

Fingernail cortisol as a marker of chronic stress exposure in Indigenous and non-Indigenous young adults

Cumulative exposure to stress over a long period can negatively impact an individual's health. Significant advancements in biomarkers of chronic stress have been made, with the use of fingernails recently explored. Cross sectional data from the Australian Aboriginal Birth Cohort (Indigenous) and Top End Cohort (non-Indigenous) were used to investigate the associations (sociodemographic and emotional) of fingernail cortisol in Indigenous and non-Indigenous young adults. Details on sociodemographic (age, gender, and Indigenous identification), smoking and alcohol use, emotional wellbeing, and emotional stress (perceived stress and stressful events), and fingernail samples were obtained face-to-face. Fingernail samples were analyzed for 179 Indigenous and 66 non-Indigenous participants (21-28 years). Indigenous participants were subjected to higher rates of stressful events compared to non-Indigenous (Median 6.0; interquartile range (IQR) 4, 9 vs. 1.0; IQR 0, 2; p < .001). Median cortisol levels were similar between Indigenous and non-Indigenous participants (4.36 pg/mg; IQR 2.2, 10.0 vs. 3.87 pg/mg: IQR 2.0, 9.7; p = .68). However, Indigenous participants had a higher cortisol level on adjustment for emotional distress and exposure to stressful events (Geometric Mean 1.82; 95CI: 1.07-3.09), with a negative association with increasing number of stressful events (Geometric Mean 0.94; 95CI 0.90, 0.99). Collection of fingernails was an easily conducted, well-tolerated method to measure stress markers in this multicultural cohort. Indigenous young adults experienced a high number of stressful events which was associated with a lowering of fingernail cortisol levels.Lay abstractChronic stress can impact negatively on health and emotional wellbeing. A fingernail sample provided a culturally acceptable, noninvasive method of measuring chronic stress in Indigenous and non-Indigenous young adults. Cortisol levels, a marker of chronic stress, were different between Indigenous and non-Indigenous young adults and were influenced by emotional status and occurrence of multiple stressful events.

Nails Analysis for Drugs Used in the Context of Chemsex: A Pilot Study

Nail analysis can be performed as a substitute or complement to hair analysis for the retrospective determination of psychotropic drugs consumption in forensic contexts. The application of nail analysis in a "chemsex" context is reported herein. An ultra-performance liquid chromatography-tandem mass spectrometry method was developed to quantify the most common drugs of abuse, synthetic cannabinoids, synthetic cathinones and GHB in fingernails and toenails of individuals presumptively using these drugs in music and sex settings. Results were compared to the concentrations measured in hair. Nail and hair keratin matrices were digested with VMA-TM3® buffer reagent and underwent a solid phase extraction before chromatographic separation with reversed phase columns and a linear gradient elution with 5 mM ammonium formate and acetonitrile, for detecting classic drugs of abuse, or 0.1% formic acid and methanol, for detecting synthetic cathinones, synthetic cannabinoids, and GHB. Analytes were detected with a triple quadrupole mass spectrometer operated in multiple reaction monitoring mode after positive electrospray ionization. Nails of individuals practicing "chemsex" contained at least three different psychoactive drugs, and up to eight drugs simultaneously. Identified drugs included cocaine, benzoylecgonine, cocaethylene, delta-9-tetrahydrocannabinol, amphetamine, methamphetamine, 3,4-methylenedioxymethamphetamine, 3,4-methylenedioxyamphetamine, ketamine, norketamine, mephedrone, methylone, 4-methyletcathinone, methcathinone, γ-hydroxybutyric acid (GHB) and γ-butyrolactone. Most used drugs were MDMA and GHB followed by cocaine and ketamine. Drugs concentrations ranged from 0.1 to 690 ng/mg in fingernails. In the two individuals who also provided toenails, concentrations were always higher in fingernails than in toenails, while in two other individuals who donated also hair, concentrations in this latter matrix were either higher or lower than those measured in fingernails. This study demonstrated that nails may well represent an appropriate non-conventional biological matrix to provide additional information in forensic toxicology.

Endogenous steroid hormones in hair: Investigations on different hair types, pigmentation effects and correlation to nails

Steroid hormone analysis is widely used in health- and stress-related research to get insights into various diseases and the adaption to stress. Hair analysis has been used as a tool for the long-term monitoring of these steroid hormones. In this study, a liquid chromatography-tandem mass spectrometry (LC-MS/MS) method was developed and validated for the simultaneous identification and quantification of seven steroid hormones (cortisone, cortisol, 11-deoxycortisol, androstenedione, 11-deoxycorticosterone, testosterone, progesterone) in hair. Cortisol, cortisone, androstenedione, testosterone and progesterone were detected and quantified in authentic hair samples of different individuals. Significantly higher concentrations for body hair were found for cortisone and testosterone compared to scalp hair. Furthermore, weak correlations for the majority of steroids between scalp and body hair indicate that body hair is not really suitable as alternative when scalp hair is not available. The influence of hair pigmentation was analyzed by comparing pigmented to non-pigmented hair of grey-haired individuals. The results showed no differences for cortisol, cortisone, androstenedione, testosterone and progesterone concentrations (p > 0.05) implying that hair pigmentation has not a strong effect on steroid hormone concentrations. Correlations between hair and nail steroid levels were also studied. Higher concentrations of cortisol and cortisone in hair were found compared to nails (p < 0.0001). No significant correlation for cortisone, cortisol, androstenedione, testosterone and progesterone concentrations were found between hair and nails. These results demonstrate that matrix-dependent value ranges for hair and nail steroid levels should be established and applied for interpretation.

Transungual Delivery of Ciclopirox Is Increased 3⁻4-Fold by Mechanical Fenestration of Human Nail Plate in an In Vitro Model

Onychomycosis is a fungal infection of nails that is widespread and difficult to treat because of the impermeable nature of human nails. Topically applied anti-fungal agents cannot penetrate this structure, and treatment regimens often resort to systemic antifungals with concomitant side effects. One recent clinical study suggested that mechanical fenestration of the nail using an intelligent nail drill might be a possible solution to this problem. In this work, an in vitro model of the transungual delivery of antifungal agents is presented, which utilizes real nail tissue and an inline flow system. This system was deployed to measure transungual delivery of ciclopirox and determined that nail fenestration improved drug delivery by 3–4-fold after 42 days. This study bolsters the argument that nail fenestration should be accepted as a pretreatment for onychomycosis and offers a way of evaluating new drugs or formulations designed to combat this condition.

When should the driver with a history of substance misuse be allowed to return to the wheel? A review of the substance misuse section of the Australian national guidelines

Assessing fitness to drive in applicants with a historical or current substance use disorder presents a specific clinical challenge. The Australian guidelines require evidence of remission and absence of cognitive change when considering applications for re-licensing driver or individuals applying to reengage in safety-sensitive work. This paper reviews some of the clinical and biochemical indicators that determine whether a particular person is in 'remission' and meets the criteria for return to driving or other safety-sensitive occupation. It provides an overview of the challenges in establishing an evidence-based approach to determining fitness for safety critical activities. There is no internationally accepted definition of 'remission'. Review of the literature and examination of assessment protocols from other national jurisdictions are available for alcohol and the more important drugs of interest in road safety. Assessing fitness to drive when there is a history of substance misuse and/or substance use disorders is a complex issue that requires assessment of biomarkers, clinical findings and clinical assessment before the person returns to driving. We propose that hair testing provides a reliable and reproducible way to demonstrate remission and provide cost-effective monitoring. Standardised psychological tests could provide a reproducible assessment of the cognitive effects of drug use and suitability to resume driving. We recommend that AustRoads amend the national guidelines to reflect an evidence-based approach to assessing fitness to drive after conviction for offences related to alcohol and drug use.

High-Frequency Heating Extraction Method for Sensitive Drug Analysis in Human Nails

Background: A simple, sensitive, and rapid extraction method based on high-frequency (H-F) heating was developed for drug analysis in human nails. Methods: A human nail was placed in a glass tube with an extraction solvent (methanol and 0.1% formic acid; 7:3, v/v), and a ferromagnetic alloy (pyrofoil) was wrapped in a spiral around the glass tube. Then, the glass tube was placed in a Curie point pyrolyzer, and a H-F alternating voltage (600 kHz) was applied. The sample and extraction solvent were heated at the Curie temperature for 3 min. Different Curie temperatures were applied by changing the pyrofoil (160 °C, 170 °C, 220 °C, and 255 °C). Results: The caffeine in the nail was effectively and rapidly extracted into the extraction solvent with the pyrofoil at 220 °C. The peak area obtained for the caffeine using liquid chromatography mass spectrometry (LC-MS/MS) was five times that of what was obtained after conventional ultrasonic irradiation extraction. Because the extraction uses high-pressure and high-temperature conditions in a test tube, the drugs that were strongly incorporated in nails could be extracted into the solvent. The amount of caffeine extracted was independent of the size of the pieces in the sample. Conclusions: Therefore, the sensitive determination of target drugs in nails is possible with rapid (20 min, including H-F extraction for 3 min) and simple sample preparation. The developed method was applied to a nail from a patient with hypertension.

Steroid profiling in nails using liquid chromatography-tandem mass spectrometry

The retrospective analysis of endogenous steroid hormones in nails can be used to elucidate endocrine diseases and thus help with their diagnosis and treatment. A liquid chromatography-tandem mass spectrometry (LC-MS/MS) based method was developed for the simultaneous identification and quantification of 12 steroid hormones (aldosterone, cortisone, cortisol, corticosterone, 11-deoxycortisol, androstenedione, 11-deoxycorticosterone, testosterone, dehydroepiandrosterone (DHEA), 17α-hydroxyprogesterone (17-OHP), dihydrotestosterone (DHT) and progesterone) in human fingernails. Steroid hormones were extracted from 0.5 mg to 10 mg pulverized nail clippings by methanolic extraction, followed by a liquid-liquid extraction. The analysis was conducted with LC-MS/MS in electrospray ionization positive mode. The method was validated in terms of linearity, limit of detection (LOD), limit of quantification (LOQ), precision, accuracy, matrix effect, recovery and robustness. It was successfully applied for steroid profiling in nails of mothers and their infants where cortisol, cortisone, testosterone, progesterone, androstenedione and 11-deoxycorticosterone could be detected. Furthermore, it could be shown that there is no significant difference in concentrations between left and right hand for cortisol, cortisone and progesterone. A positive linear correlation between cortisol and cortisone in nails was found. In conclusion, it could be shown that nails are a suitable matrix for the retrospective monitoring of cumulative steroid hormone levels.

Ultra-High-Performance Liquid Chromatography Tandem Mass Spectrometry Assay for Determination of Endogenous GHB and GHB-Glucuronide in Nails

Background: The short chain fatty acid gamma-hydroxybutyric acid (GHB) is a precursor, and the metabolite of gamma-aminobutyric acid is commonly used as an illegal recreational drug of abuse. Methods: An ultra-high-performance liquid chromatography tandem mass spectrometry was developed and validated for endogenous GHB and its glucuronide in nails, to complement hair in forensic contexts for a retrospective detection of psychotropic drugs consumption. Results: GHB endogenous values for children and adolescents, adult females, and adult males in fingernails ranged from 0.3 to 3.0, 3.2, and 3.8 ng/mg, respectively, and toenails values ranged from 0.3 to 1.8, 2.0, and 2.4 ng/mg, respectively. In the three different groups, values of GHB in fingernails were statistically higher than those in toenails. GHB glucuronide could only be detected in finger nails with values ranging from 0.08 to 0.233, 0.252 and 0.243 in children and adolescents, adult females and adult males, respectively. Conclusions: The validated method was efficaciously applied to real finger and toe nails specimens from a population of males and females non GHB consumers. A preliminary cut-off of 5.0 ng/mg nail for endogenous GHB and 0.5 ng/mg for endogenous GHB-Gluc in the general population was proposed.

Quantification of Methadone and Main Metabolites in Nails

The quantification of drugs of abuse in keratinized matrices is becoming of special relevance for monitoring consumption and for post-mortem investigations. We aimed to implement an analytical method for the simultaneous detection of morphine (MORF), 6-monoacetylmorphine (6-MAM), methadone (MET), 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP) and 2-ethyl-5-methyl-3,3-diphenylpyrrolidine (EMDP) in nails. After decontamination, the nail samples (30 mg) were submitted to an alkaline digestion followed by a two-step liquid-liquid and SPE extraction using mixed-mode cation exchange cartridges. The analytes were eluted with 5% NH4OH/methanol. After derivatization with N-methyl-N-(trimethylsilyl) trifluoroacetamide, the analytes were quantified by gas chromatography-mass spectrometry. The method was optimized and fully validated only for MET, EDDP and EMDP, since for MOR and 6-MAM it was not possible to obtain adequate recovery rates after extraction, although detection of MOR was still possible. The method was selective, accurate and precise. Regression analysis demonstrated linearity over a concentration range of 20.8-333.3 ng/mg for MET and 10.4-166.7 ng/mg for EDDP and EMDP. Limits of detection and quantification values ranged from 3.3 to 6.0 ng/mg and 10.4 to 20.8 ng/mg, respectively, and recovery rates ranged from 82% to 98%. The applicability of the method was demonstrated by analyzing nail and urine samples obtained from heroin consumers under substitution therapy with MET.

Keratinous matrices for the assessment of drugs of abuse consumption: A correlation study between hair and nails

Keratinous matrices - hair and nails - accumulate substances over time and allow retrospective investigation of past consumption. Analysis of these matrices can provide information complementary to blood and urine analysis or can be used as standalone. So far, research has primarily focused on the detection of substances in hair, while studies in nails are scarce. In this study, we assessed concentrations of drugs of abuse and their metabolites in hair, fingernails, and toenails collected from the same individuals to evaluate differences and correlations between matrices. A total of 26 hair, 24 fingernail, and 18 toenail samples were collected. Samples were analysed by a validated liquid chromatography-tandem mass spectrometry method able to simultaneously detect the following compounds: amphetamine (AMP), methamphetamine, 3,4-methylenedioxymethamphetamine (MDMA), 3,4-methylenedioxyethylamphetamine, morphine (MOR), codeine (COD), 6-monoacetylmorphine (6-MAM), methadone (MTD), 2-ethylidene-1,5-dimethyl-3,3-diphenylpyrrolidine (EDDP), cocaine (COC), benzoylecgonine (BE), and ecgonine methyl ester (EME). Strong positive correlations between hair, fingernails, and toenails were present for COC, BE, EME, AMP and MDMA. MOR, COD, 6-MAM, MTD and EDDP showed positive trends. Concentrations were generally higher in nails compared to hair. Ratios between parent compounds and their metabolites were assessed for 6-MAM/MOR, EDDP/MTD, BE/COC and EME/COC. Preliminary cut-off concentrations for COC, BE, EME and AMP in fingernails and toenails were proposed. In light of these results, nails can be considered as a useful alternative to hair for monitoring of long-term drug consumption. However, care should be taken regarding the variability in the accumulation of compounds between the matrices.

Study of trace metal imbalances in the blood, scalp hair and nails of oral cancer patients from Pakistan

Oral cancer is an important cause of cancer morbidity and mortality globally and exposure to trace metals alongside tobacco, alcohol and HPV are the important etiological factors in its development. Selected essential and toxic trace metals (Cd, Cr, Cu, Fe, Mn, Ni, Pb and Zn) were measured in the blood, scalp hair and nails of oral cancer patients and counterpart controls by atomic absorption spectrometry. Mean concentrations of Cd, Ni and Pb were found to be significantly higher (p<0.05) and those of Cu, Fe and Zn were considerably lower in the blood, scalp hair and nails of the patients than the controls. Most of the metal concentrations exhibited higher dispersion and asymmetry in the blood, scalp hair and nails of the patients compared with the controls. The correlation study revealed significantly diverse relationships among the metals in blood, scalp hair and nails of both donor groups. Variations in the metal levels were also noted for various stages (I, II, III & IV) as well as the types (adenocarcinoma and squamous cell carcinoma) of oral cancer. Multivariate cluster analysis of the metal levels in the patients were also significantly dissimilar than the controls. The study evidenced considerably divergent variations in the metal levels in oral cancer patients in comparison with the controls.

Age-related testosterone declines can be detected in men's fingernails

Testosterone plays multiple roles in the regulation of development, physiology, reproduction, and behavior. Age-related testosterone declines are expected in the population. However, measuring circulating testosterone is especially challenging because concentrations are labile, responding to social situations and challenges. Matrices that integrate long-term testosterone levels are therefore valuable as biomarkers of endogenous levels as well as chronic exposures. Here, we report on a simple method to extract and measure accumulated testosterone from human fingernails using commercial enzyme immunoassay kits. Furthermore, we demonstrate known human testosterone sex and age trends. Our method is especially useful for quantifying testosterone in men's nails, where a small amount of matrix is required. Thus, this approach is a potential tool for biomonitoring endogenous as well as exogenous testosterone exposure. We suggest considering nails as an alternative matrix for quantifying other steroids as well.