Hair Sections Research Articles

High Spatial-Resolution Matrix-Assisted Laser Desorption/Ionization-Ion Trap-Time-of-Flight Tandem Mass Spectrometry Imaging for Depicting Longitudinal and Transverse Distribution of Drugs Incorporated into Hair.

This study aims to achieve high spatial-resolution tandem mass spectrometry (MS/MS) imaging for depicting longitudinal and transverse distribution of drugs in hair, which can provide indispensable information for the proper interpretation of hair test results, including the mechanism of drug incorporation into hair. Two types of hair samples were obtained and analyzed: User's Hair, sampled from a volunteer who took an over-the-counter medicine containing methoxyphenamine (MOP), a nonregulated analogue of methamphetamine; and Soaked Hair, prepared by soaking blank hair in MOP solution. Longitudinal and transverse-sectioning of single hair shafts was accomplished by freeze-sectioning using customized microtomes. Vapor deposition of α-cyano-4-hydroxycinnamic acid provided the finest matrix layer (resolution <1 μm, 0.7-μm thickness), although it provided less effective ionization of MOP compared to aerosol spraying or a combination of both. Matrix-assisted laser desorption/ionization (MALDI)-ion trap (IT)-time-of-flight (TOF) MS/MS permitted the imaging of trace-level MOP in hair with a MS/MS window setting of ±0.02 Da and a spatial resolution setting at 5 or 10 μm. For Soaked Hair, localization of MOP in the peripheral part was clearly depicted, but no such biased distribution was observed in the transverse sections of User's Hair. MOP-positive bands generated corresponding to the time periods of MOP intake could be observed on the longitudinal sections of User's Hair. This method can provide forensically crucial information regarding hair analysis for drugs: drug incorporation mechanism into hair, discrimination of undesired surface contamination from endogenous incorporation of ingested drugs, and precise elucidation of drug-use history.

Proteomic analysis of decedent scalp hair segments exhibiting a postmortem hair root band

A postmortem root band (PMRB) is an opaque microscopic band that can be observed near the root area of hairs from a decomposing body. Although PMRB is a recognized phenomenon in the forensic trace evidence community, protein signatures that are associated with PMRB formation are not well understood. To characterize the specific hair proteins affected by PMRB formation, comparative protein profiles of banded and non-banded hair sections were performed via site specific enzymatic digestion followed by nano-flow liquid chromatography tandem-mass spectrometry (nLC-MS/MS). The sequence coverage in banded sections of hair was ~35% less than in non-banded sections of hair, which reduces the confidence in protein identification and indicates that the abundance or integrity of the proteins is compromised. These findings suggest that proteolysis may play a role in the formation of PMRB.

한방추출 천연혼합물의 탈모 유발 쥐에 대한 발모 효과

This paper aims to assess the effect of herbal extract mixture, Ahn Tonic, on hair growth and examine the stability of this percutaneous hair growth ointment. The hair on the back of the mice C57b1/6N was removed, and 1% of the TXN(testosterone) was then applied for a week to prevent the hair growth. The experimental group was then treated with Ahn Tonic, 0.2 mL per day. The degree of newly grown hair was observed with a vernier caliper. We also measured the proportion of the newly growing hair section to the entire shaved section in the 4th week and 8th week by distinguishing the section turning black from the shaved area. To observe the effect of the test chemical product on hair follicles and hair roots, the biopsy was executed between week 4 and week 8. Gene expressions, which operate as a factor for growing hair in the skin tissues extracted from each experimental animals, were also observed through a real-time PCR gene amplification method. The results showed that the Ahn tonic group had statistically significant hair restoring effect compared to the control group in terms of microscopy, biopsy, and gene expressions. Ahn Tonic is considered to have an impact on the hair growth.

데스틸 기법을 응용한 헤어아트 제작에 관한 연구

This study attempted to create hairstyles using De Stijl ideas. For this, it examined De Stijl techniques and features through previous studies and literature records and classified the results into neo-plasticism and elementalism. Hairstyles were then created on a mannequin primarily through coloring and haircut. To express horizontal and vertical aspects emphasized in neo-plasticism, a hair section was blocked into several sides, and hair was textured. In hairstyle, vertical direction created equilibrium and balance while horizontality delivered calm, passive, and stable feelings. According to the analysis of hairstyles in elementalism, slants were added to conventional horizontal and vertical styles in neo-plasticism, creating more dynamic and cubic styles. It is anticipated that creative art works which combine hairstyling ideation and development with art trends would evolve into a formative art field and accelerate technical systematization.

The Nitrogen Isotope Ratio Is a Biomarker of Yup'ik Traditional Food Intake and Reflects Dietary Seasonality in Segmental Hair Analyses

The nitrogen isotope ratio (NIR) is a promising index of traditional food intake for an Alaska Native (Yup'ik) population, which can be measured in blood and hair. However, the NIR has not been calibrated to high-quality measures of Yup'ik traditional food intake. Our primary objective was to examine associations between intakes of Yup'ik traditional food groups, including fish, marine mammals, birds, land mammals, berries, greens, and total traditional foods, and the NIR. In an exploratory analysis, we also examined whether NIR analyzed sequentially along hair could reflect dietary seasonality. We recruited 68 participants from 2 Yup'ik communities in the Yukon Kuskokwim region of Southwest Alaska (49% female, aged 14-79 y). Participants completed 4 unscheduled 24-h food recalls over the period peak of RBC and hair synthesis preceding a specimen collection visit. The NIR was measured in RBCs ( n=68), a proximal hair section (n=58), and sequential segments of hair from individuals in the upper 2 quartiles of traditional food intake having hair >6 cm in length, plus 2 low subsistence participants for reference (n=18). Diet-biomarker associations were assessed using Pearson's correlation and linear regression. Intakes of fish, marine mammals, berries, and greens were significantly associated with the NIR. The strongest dietary association was with total traditional food intake (R2=0.62), which indicated that each 1‰ increase in the RBC NIR corresponded to 8% of energy from traditional foods. Hair NIR appeared to fluctuate seasonally in some individuals, peaking in the summertime. Findings support the use of the RBC and hair NIR to assess total traditional food intake in a Yup'ik population. Analyses of sequential hair NIR provided evidence of seasonality in traditional food intake, although seasonal variations were modest relative to interindividual variation.

A comparison of levels of nicotine and cotinine in hair of tobacco smokers and users of e-cigarettes using GC-MS

The objective of this research project was to develop and validate an analytical method for the determination of nicotine and cotinine in hair samples. Following analysis, a comparison was made in the levels of nicotine and cotinine found in the hair of e-cigarette and tobacco cigarette smokers. The differences in Environmental Tobacco Smoke exposure were also investigated to determine whether e-cigarettes or tobacco cigarettes result in a greater level of nicotine exposure. A total of 23 hair samples were collected from volunteers, and sectioned as both 0–3 cm overview sections, in addition to 3 × 1 cm segmental analysis (subject to sufficient sample). Hair sections were washed, submitted to methanol sonication, alkaline digestion, liquid-liquid extraction, and clean-up using solid-phase extraction [1] . All samples were submitted to GC-MS/MS using a TRACE 1310 GC coupled to TSQ 8000 Evo tandem mass spectrometer from Thermo Fisher Scientific (Waltham, MA, USA) utilising timed-SRM acquisition. Chromatographic separation was achieved using a Thermo Scientific TraceGOLD TG-5MS (20 m × 0.18 mm, 0.18 μm) column. Mean analysis results obtained are presented in Table 1 . When comparing the relative levels of nicotine and cotinine from tobacco smokers and e-cigarette users, the results indicate that tobacco exposure results in nicotine concentrations, approximately 37% higher than those detected in users of e-cigarettes. Hair from e-cigarette users generally contained a higher level of cotinine in all samples, compared to nicotine. A more effective absorption of nicotine may account for a higher level of metabolite (cotinine) detection in the e-cigarette samples. Results indicate there are higher concentrations of the analytes, nicotine and cotinine, in the untreated hair samples when compared to levels detected treated hair samples. The study also investigated the effect of hair colour; grey, white and blonde hair samples contained lower nicotine and cotinine concentrations than brown or black hair in both tobacco and e-cigarette users. A full method validation was performed, providing an analytical method with a measurement of uncertainty at 18% (at cut-off level), linearity was observed for both nicotine and cotinine up to 8 times the top calibrator and within method validation acceptance criteria of R2 > 0.99. The research indicates the usefulness of hair analysis to assess exposure to nicotine and cotinine. The pattern of results indicates a more effective absorption of nicotine from e-cigarette vapour, when compared to nicotine contained within tobacco smoke. The effective bioavailability may vary as a function of solution pH and other ingredients in the vapour liquid [2] .

Association of maternal chronic arsenic exposure with the risk of neural tube defects in Northern China

Numerous animal studies have shown that high arsenic exposure can induce neural tube defect (NTD) formation. However, epidemiological evidence related to this finding is scarce. The key objective of our study is to evaluate whether maternal arsenic exposure is associated with NTD risk in Northern China. Our case–control study was conducted in 11 countries or cities in Shanxi and Hebei provinces during 2003–2007. A total of 774 mothers were included as participants: 511 controls and 263 cases (including 123 with anencephaly, 115 with spina bifida, 18 with encephalocele, and 7 with other NTD subtypes). The arsenic concentration was measured in a specific section of hair that grew from 3 months before to 3 months after conception. We found a higher hair arsenic concentration in the NTD cases with median (inter-quartile range) of 0.093 (0.025–0.387) μg/g hair than that in the controls with a value of 0.082 (0.030–0.414) μg/g hair. Maternal hair arsenic concentration above its median of the controls was associated with an increased risk of the total NTDs with an adjusted odds ratio (OR) of 1.32 [95% confidence interval (CI): (0.91–1.92)], which was not statistically significant (p = 0.14), although the crude OR without adjusting for the confounders of 1.68 (95% CI: 1.24–2.27; p < 0.001) suggested that hair arsenic is a risk factor of NTDs. There was no dose-response relationship between maternal hair arsenic concentration and the risk of total NTDs. Similar phenomena were found for anencephaly and spina bifida, respectively. Overall, our findings showed that maternal periconceptional arsenic exposure may not significantly contribute to the risk of NTD development in Northern China; other risk factors need to be further examined in future studies.

A case report of carfentanil-related fatality in France

Today, NPS are increasingly being related to post-mortem cases, and this problem drastically intensifies as a result of the New Synthetic Opioids (NSOs) surge. Among NSOs, carfentanil (CaF) is the most potent fentanyl analogue and was central to a large number of NSOs-related fatalities in North America, as well as in UE, since 2016. In this worrisome context, this manuscript reports the first CaF-related fatality occurred in France. A 41-years-old man was found dead with a syringe planted under his tongue. This man has a psychiatric follow-up for opiate addiction and his recent medical history included intoxication with fentanyl derivatives. Toxicological investigations of post-mortem samples (blood, urine and hair), and syringe were requested. CaF (with several other psychoactive drugs at non-toxic level) was detected in biological samples and in syringe residue using LC-HRMS, and quantified using LC-MS/MS in blood, urine and hair (from proximal to distal hair section – 3 cm length each) at 4.20, 0.40 μg/L and 54/114/166 pg/mg, respectively. The relatively high post-mortem CaF blood concentration together with the absence of metabolite (especially NorCaF) suggests a sudden death of the victim immediately following a significant CaF dose intake (presumably injected) that can explain the decease.

Correlation of hair risperidone concentration and serum level among patients with schizophrenia

BackgroundRisperidone (RSP) has a rapid onset in vivo, low dosage and high plasma protein binding rate, therefore therapeutic drug monitoring (TDM) is needed to ensure safety in clinical treatment. However,...

The identification of Takin Budorcas taxicolor (Mammalia: Bovidae) through dorsal guard hair

The dorsal guard hairs of Takin Budorcas taxicolor was examined using the optical light and scanning electron microscopes for species identification. It is found that the dorsal guard hair of B. taxicolor is possessed a completely unique microscopic characteristic especially the medullary character-uniserial ladder structure, which differs from other species of mammals. The ‘irregular wave’ of scale patterns and ‘rippled’ scale margins of cuticular, and the ‘circular’ shape of a transverse section of hair also determines the species identity of B. taxicolor, because these characteristics are infrequent in other species of mammals. The micro-photographs and characters of hairs are presented here can be used in the forensic science, as an appropriate reference for species identification of B. taxicolor.

Longitudinal and transverse variation of trace element concentrations in elephant and giraffe hair: implication for endogenous and exogenous contributions.

The spatial distribution of trace elements in hair is highly heterogeneous at the microscale. The relatively mild spatial variation of endogenous signal incorporated during hair growth may be amplified by orders of magnitude due to later exogenous contaminations. Here, we studied the longitudinal and transverse distributions of trace elements in elephant and giraffe hair and discussed the possible endogenous and exogenous contributions. Laser ablation ICP-MS analyses were performed on cross sections of hair to assess the surface contamination and transverse variation. We also removed the contaminated surface layer at various distances from hair root of single hair strands using physical abrasion and measured the concentrations by microwave digestion followed by ICP-MS. By comparing the concentrations of 11 trace elements between the intact and abraded hair segments as a function of distance from root and their laser ablation profiles, we rationalized the endogenous and exogenous contributions: Al and Ti concentrations are dominated by the exogenous contamination on the elephant hair surface, probably in the form of insoluble particles, but not in the giraffe hair; Mg, Ca, Sr, Ba, and Mn are enhanced on the elephant hair surface by exogenous contaminations, but a comparable amount was found in the hair interior suggesting migration of these elements from the surface towards the core; Cu, Zn, Se, and Pb did not have surface accumulation and thus were dominated by the endogenous signal. Overall, giraffe hair had minimal surficial contamination, suggesting the origin of its trace elements is predominantly endogenous, except for Mn, which might get contaminated with airborne particles. We thus demonstrate that contamination of hair may be strongly related to behavioral traits and that the interpretation of trace elemental analyses in hair as a biomonitor or for provenance studies would be highly dependent on the species considered.

Using Hair Analysis to Assess the Exposure Level of Rare Earth Elements among Rural Housewives

Several studies have observed that population living near coal mining areas may have higher exposure level of rare earth elements (REEs). However, it is still a challenge to assess their exposure level of REEs, and the adverse effects of REEs on human health were also rarely investigated by an epidemiological study. Our study aimed to use hair analysis to assess their exposure level of REEs among women in Shanxi Province, which has the leading coal production around the world. In addition, we investigated the associations between hair concentrations of REEs and risk of hypertension among female adults and fetal neural tube defects (NTDs). About 14 concerned REEs in the specific hair sections were analyzed including lanthanum, samarium, europium, gadolinium, terbium, dysprosium, holmium, erbium, thulium, ytterbium, lutetium, yttrium, cerium, praseodymium, and neodymium. Population exposure level to indoor air pollution from coal combustion (IAPCC) was evaluated by the questionnaires of energy usage characteristics and life style. It was observed that hair concentrations of 13 REEs were overall positively correlated with the exposure level of IAPCC, except for europium. For the rural women, our study results revealed that the hair concentrations of the 14 REEs, except for europium, in hypertensive case women were higher than those in controls. The univariate odds ratios (ORs) of the 14 REEs were systematically &amp;gt; 1, of which four REEs (i.e. dysprosium, thulium, ytterbium, and yttrium) had adjusted ORs &amp;gt; 1. In addition, we found that hair REEs concentrations grown during the early preganancy had potential adverse effect on NTD risk. It was concluded that hair REEs could be used as a marker to indicate population exposure level to REEs and may be a risk factor of the development of hypertension and fetal NTDs.

Assessment of markers expressed in human hair follicles according to different skin regions.

Body region-dependent hair follicle (HF) characteristics are concerned with follicular size and distribution, and have been demonstrated to have characteristics for each region of the body. The aim of the present study was to investigate the expression patterns of the markers called cytokeratin 15 (K15), cytokeratin 6 (K6) and monoclonal antibody Ki-67, and also apoptosis in HFs, which can be observed in different parts of the human body. In this study, healthy human HFs were taken by biopsy from 5 various donor sites of the human body: the scalp, the leg, the abdomen, the back and waist. HF-containing skin specimens taken using cryosection were stained with hematoxylin & eosin (H&E) and K15, K6, Ki-67 and terminal deoxynucleotidyl transferase-mediated digoxigenin-dNTP nick end-labelling (TUNEL) immunofluorescence staining protocol was performed. Different skin regions from the human body were examined histologically. While the HFs of scalp tissue showed anatomically obvious hair layers, some hair sections from other regions, like the leg, the abdomen, back and waist, were not as distinct as in the scalp region. According to our findings, K15 expression was highest in the scalp. In addition, the immunoreactivity (IR) intensity of K15 was significantly decreased in the HFs on the waist and abdominal regions, compared to the scalp and back regions (p < 0.001). However, the IR intensity of K6 in the scalp region was statistically significantly higher than the IR intensity of K6 in the abdomen region (p < 0.05). Moreover, we showed intraepithelial apoptosis and proliferation of keratinocytes in the bulge of HF. In the study, Ki-67-positive and TUNEL-positive cell numbers were not statistically significant (p > 0.05). Our findings are important for further investigation of molecular aspects of the human hair follicle stem cells compartments in health and disease, which might be a promising model for comparative studies with different human diseases.

Associations between Typical Environmental Factors and the Risk of Fetal Neural Tube Defects in North China

Background: The relationship between the levels of various environmental chemicals and the high prevalence of neural tube defects (NTDs) in north China remains unclear. This study aimed to classify the associations of maternal exposure to polycyclic aromatic hydrocarbons (PAHs), passive smoking, and widely concerned trace metal elements with NTD risk. Methods: Our case-control study recruited a total of 828 subjects: 285 women who delivered a fetus with NTDs (cases) and 543 women a healthy newborn without NTDs (controls). We measured the concentrations of PAHs, nicotine/cotinine, and various trace metal elements in two hair sections grown near the early pregnancy. Findings: Overall, no significant associations were found between the risk of any NTD subtypes and the hair levels of PAHs, nicotine/cotinine, and some metals (i.e., Cd, Sb, Pb, Cr, Mn, Fe, Ni, Co, and Cu). According to the cross-validation results for the two hair sections, hair concentrations of Mo and Sn were inversely associated with anencephaly risk, and the hair concentration of Zn was inversely associated with the risk of spina bifida. Interpretation: We concluded that maternal exposure to either PAHs or passive smoking was not a significant risk factor for NTDs, whereas the maternal less intake of certain trace metal elements may contribute to the high NTD prevalence in north China. It suggested that much effort should be spent to improve the dietary quality of various essential trace metal elements to reduce NTD risk for population living in North China. Funding: This research was supported by grants from the National Key Research and Development Program, P.R. China (Grant No. 2016YFC1000501) and the National Natural Science Foundation of China (No. 41771527 and 81373014). Conflict of Interest: The authors declare they have no actual or potential competing financial interests. Ethics Approval Statement: The study protocol was approved by the Institutional Review Board of Peking University (PU-IRB) and the signed consent was obtained from all subjects.

Using 13C in cattle hair to trace back the maize level in the feeding regime-A field test.

Sections from cattle hair serve as an isotopic archive—they contain information on the cattle diet from different time periods. We tested the reliability of 13C signatures (δ13C) in cattle tail switch hair to retrospectively trace back the annual dietary proportion of maize of different production systems without having to sample and analyze the feed. Furthermore, we investigated if differences in dietary proportion of maize during summer and winter feeding can be detected in a single tail switch hair by sampling hair only once a year. We sampled hair and obtained information on management and annual composition of diets on 23 cattle farms in northern Germany. Farms differed in dietary proportions of maize, grass and concentrates as well as in grazing regime (year-round grazing, summer grazing, no grazing). We found that the annual mean δ13C values (δ13CY) of two hair sections that contain the isotopic information of summer and winter feeding is a robust indicator for the annual proportion of maize in cattle diet on a farm. The grazing regimes could clearly be distinguished by analyzing seasonal mean δ13C values (δ13CS). We could also demonstrate short term changes in the diet changes by means of δ13CS. We conclude that the method can be used in different cattle production systems to check on dietary proportions of maize for a period of one year before sampling of hair.

Are concentrations of alkaline earth elements in maternal hair associated with risk of neural tube defects?

The relationship between maternal intake of alkaline earth elements (AEEs) during the period of neural tube closure and the risk of neural tube defects (NTDs) is still unclear. We propose that AEE deficiency during the early period of pregnancy is associated with an elevated risk of NTDs in the offspring. In this study, we recruited 191 women with NTD-affected pregnancies (cases) and 261 women who delivered healthy infants (controls). The concentrations of four AEEs (Ca, Mg, Sr, Ba) in maternal hair sections that grew during early pregnancy were analyzed. Information on the dietary habits of the mothers was also collected by questionnaire. Higher concentrations of the four AEEs in hair had protective effects against the risk of total NTDs, with odds ratios with 95% confidence interval (comparing groups separated by each median level) of 0.44 (0.28–0.68) for Mg, 0.56 (0.36–0.87) for Ca, 0.45 (0.28–0.70) for Sr, and 0.41 (0.26–0.65) for Ba. Significant negative dose-response trends were identified for the relationships between the four AEE concentrations in maternal hair and the risks of anencephaly and spina bifida, but not for encephalocele. The frequencies of maternal consumption of fresh green vegetables, fresh fruit, and meat or fish were positively correlated with the concentrations of AEEs in hair. We concluded that the maternal intake of AEEs may play an important role in preventing NTD formation in offspring, and that this intake is related to maternal dietary habits of consuming fresh green vegetables, fresh fruit, and fish or meat.

The Role of Segmental Analysis of Clonazepam in Hair in Drug Facilitated Cases

To infer the frequency of dosage and medication history investigate of the victims in drug facilitated cases by the segmental analysis of clonazepam in hair. Freezing milling under liquid nitrogen environment combined with ultrasonic bath was used as sample pretreatment in this study, and liquid chromatography-tandem mass spectrometry was used for the segmental analysis of the hair samples collected from 6 victims in different cases. The concentrations of clonazepam and 7-aminoclonazepam were detected in each hair section. Clonazepam and its metabolite 7-aminoclonazepam were detected in parts of hair sections from the 6 victims. The occurrence time of drug peak concentration was consistent with the intake timing provided by victims. Segmental analysis of hair can provide the information of frequency of dosage and intake timing, which shows an unique evidential value in drug facilitated crimes.

Matrix-assisted laser-desorption/ionization mass spectrometric imaging of olanzapine in a single hair using esculetin as a matrix

Matrix-assisted laser desorption/ionization-mass spectrometric imaging (MALDI-MSI) for the analysis of intact hair is a powerful tool for monitoring changes in drug consumption. The embedding of a low drug concentration in the hydrophobic hair matrix makes it difficult to extract and detect, and requires an improved method to increase detection sensitivity. In this study, an MSI method using MALDI-Fourier transform ion cyclotron resonance was developed for direct identification and imaging of olanzapine in hair samples using the positive ion mode. Following decontamination, scalp hair samples from an olanzapine user were scraped from the proximal to the distal end three times, and 5mm hair sections were fixed onto an Indium-Tin-Oxide (ITO)-coated microscopic glass slide. Esculetin (6,7-dihydroxy-2H-chromen-2-one) was used as a new hydrophobic matrix to increase the affinity, extraction and ionization efficiency of olanzapine in the hair samples. The spatial distribution of olanzapine was observed using five single hairs from the same drug user. This matrix improves the affinity of olanzapine in hair for molecular imaging with mass spectrometry. This method may provide a detection power for olanzapine to the nanogram level per 5mm hair. Time course changes in the MSI results were also compared with quantitative HPLC–MS/MS for each 5mm segment of single hair shafts selected from the MALDI target. MALDI imaging intensities in single hairs showed good semi-quantitative correlation with the results from conventional HPLC–MS/MS. MALDI-MSI is suitable for monitoring drug intake with a high time resolution.

Association of essential trace metals in maternal hair with the risk of neural tube defects in offspring.

The relationship between essential trace metals (ETMs) and the risk of neural tube defects (NTDs) is still unclear. One of the challenges is to evaluate the intake of ETMs of women during their early period of pregnancy. We proposed the hypothesis that an ETM deficiency in women during their early period of pregnancy is associated with an elevated risk of NTDs in offspring. We recruited 191 women with NTD-affected pregnancies (case group) and 261 women who delivered healthy infants (control group). Nine ETMs in hair sections grown during maternal early pregnancy were analyzed: iron (Fe), zinc (Zn), copper (Cu), cobalt (Co), manganese (Mn), chromium (Cr), nickel (Ni), molybdenum (Mo), and stannum (Sn). Information on maternal dietary habits were collected by questionnaire. We observed a significant decreasing trend in the dose-response relationships between the Ni and Mo concentrations in hair and NTD risks. A Zn deficiency was only associated with an elevated risk of spina bifida, and a Sn deficiency was only associated with anencephaly. The Ni and Zn concentrations in hair were positively correlated with the frequency of consumption of fresh green vegetables and fresh fruits, while the Zn concentration was also associated with fish or meat consumption. We concluded that maternal intakes of the four ETMs (Ni, Mo, Zn, and Sn) played an important role in the formation of NTDs in our study population, and that this intake is related to maternal dietary habits.Birth Defects Research 109:234-243, 2017.© 2016 Wiley Periodicals, Inc.

Using nicotine in scalp hair to assess maternal passive exposure to tobacco smoke

Quantifying population exposure level to tobacco smoke is important for investigating its adverse effects on human health. We aimed to investigate the feasibility and application of using population hair concentrations of nicotine and cotinine to indicate their exposure level to tobacco smoke among pregnant women. Our study recruited 256 mothers who delivered healthy babies and collected their hair samples from scalp, of which 172 mothers were self-reported non-passive smokers and the other 84 mothers were self-reported passive smokers. We analyzed nicotine and cotinine concentrations of the hair section grown during the early pregnancy. The linear relationship between cotinine and nicotine was developed and validated by internal cross-validation method. Our results revealed that self-reported passive smokers had higher concentrations of nicotine [2.08 (1.00–4.46) ng/mg hair, i.e. median value (inter-quartile range)] and cotinine [0.063 (0.041–0.148) ng/mg hair] than non-passive smokers [1.35 (0.58–2.59) ng/mg hair of nicotine and 0.049 (0.022–0.087) ng/mg hair of cotinine, respectively]. There existed a linear regression model between hair cotinine and nicotine concentrations, i.e. [cotinine] = 0.024 × [nicotine]+0.0184 (R2 = 0.756) for this population. The internal cross-validation squared correlation coefficient slightly increased from 0.689 to 0.734 with the training subjects varying from 20% to 90%, suggesting that this regression model had high robustness and predictive accuracy. It was concluded that nicotine in maternal hair can evaluate the hair cotinine level and reflect maternal passive exposure level to ambient tobacco smoke with high sensitivity.