Human Fingernails Research Articles

The use of tree barks and human fingernails for monitoring metal levels in urban areas of different population densities of Porto Alegre, Brazil.

The aim of this study was to evaluate the use of tree barks as a bioindicator of atmospheric pollution in areas of contrasting population densities and to associate the levels of elements found in this bioindicator with those obtained in fingernail samples collected from students living in the same study areas. Tree bark samples were collected from urban areas near highways in regions with high (Area A), intermediate (Area B), and low (Area C) population densities of Porto Alegre, Brazil, and evaluated for chemical elements concentration. Since these areas also differed in traffic density, NO2 was measured by passive sampling. For a comparative purpose, the elements were also determined in fingernail samples collected from students living in the same areas. Accumulated elements were determined by inductively coupled plasma mass spectrometry (ICP-MS) and principal component analysis (PCA) was used as a tool in exploratory data analysis to identify possible sources. We found that Ba, Cd, Co, Cu, Mg, Mn, Ni, Pb, Sb, Sr, V, and Zn were at higher concentrations in tree barks in Area A, while Cd, Co, Cu, Mg, Mn, Ni, and Sr were at higher levels in students' fingernails of Area A as well. Furthermore, concentrations of elements found in barks were associated with those identified in fingernails collected from students living in the same areas. PCA demonstrated that vehicular traffic explained 66.4% of the variance in tree bark and 50.8% of the variance in fingernails. NO2 levels were significantly different among the areas, what is consistent with their respective vehicular flow and population density. In conclusion, we found conformance of elements levels accumulated in barks and fingernails at three monitoring areas with different profiles. The amount of traffic-related elements accumulated appears to be associated with the degree of urbanization and vehicular flow. Overall, data suggests a relationship between fingernails and tree bark as bioindicators of exposure to metals from air pollution.

Glycation in human fingernail clippings using ATR-FTIR spectrometry, a new marker for the diagnosis and monitoring of diabetes mellitus

Although HbA1c is a good diagnostic tool for diabetes, the precarity of the health system and the costs limit the use of this biomarker in developing countries. Fingernail clippings contain ±85% of keratins, which are prone to glycation. Nail keratin glycation may reflect the average glycemia over the last months. We explored if attenuated total reflection Fourier transform infrared spectroscopy (ATR-FTIR) can be used as a non-invasive tool for assessing glycation in diabetes. Using ATR-FTIR spectroscopy, glycation and deglycation experiments with fructosamine 3-kinase allowed to identify the spectrum that corresponds with keratin glycation in fingernail clippings. Clippings of 105 healthy subjects and 127 diabetics were subjected to the standardized ATR-FTIR spectroscopy method. In vitro glycation resulted in an increased absorption at 1047cm-1. Following enzymatic deglycation, this peak diminished significantly, proving that the AUC between 970 and 1140cm-1 corresponded with glycated proteins. Within-run CV of the assay was 3%. Storage of nail clippings at 37°C for 2weeks did not significantly change results. In diabetics, glycated nail protein concentrations (median: 1.51μmol/g protein, IQR: 1.37-1.85μmol/g protein) were significantly higher than in the controls (median: 1.19μmol/g protein, IQR: 1.09-1.26μmol/g protein) (p<0.0001). ROC analysis yielded an AUC of 0.92 at a cut-off point of 1.28μmol/g nail (specificity: 82%; sensitivity: 90%). No correlation was observed between the glycated nail protein concentrations and HbA1c. Protein glycation analysis in fingernails with ATR-FTIR spectroscopy could be an alternative affordable technique for diagnosing and monitoring diabetes. As the test does not consume reagents, and the preanalytical phase is extremely robust, the test could be particularly useful in developing countries.

Analysis of scattering statistics and governing distribution functions in optical coherence tomography.

The probability density function (PDF) of light scattering intensity can be used to characterize the scattering medium. We have recently shown that in optical coherence tomography (OCT), a PDF formalism can be sensitive to the number of scatterers in the probed scattering volume and can be represented by the K-distribution, a functional descriptor for non-Gaussian scattering statistics. Expanding on this initial finding, here we examine polystyrene microsphere phantoms with different sphere sizes and concentrations, and also human skin and fingernail in vivo. It is demonstrated that the K-distribution offers an accurate representation for the measured OCT PDFs. The behavior of the shape parameter of K-distribution that best fits the OCT scattering results is investigated in detail, and the applicability of this methodology for biological tissue characterization is demonstrated and discussed.

Hair and Nails as Noninvasive Biomarkers of Human Exposure to Brominated and Organophosphate Flame Retardants.

After the phase-out of polybrominated diphenyl ethers (PBDEs), the use of alternative flame retardants (AFRs), such as FireMaster 550, and of organophosphate esters (OPEs) has increased. However, little is known about human exposure to these chemicals. This lack of biomonitoring studies is partially due to the absence of reliable noninvasive biomarkers of exposure. Human hair and nails can provide integrated exposure measurements, and as such, these matrices can potentially be used as noninvasive biomarkers of exposure to these flame retardants. Paired human hair, fingernail, toenail, and serum samples obtained from 50 adult participants recruited at Indiana University Bloomington campus were analyzed by gas chromatographic mass spectrometry for 36 PBDEs, 9 AFRs, and 12 OPEs. BDE-47, BDE-99, 2-ethylhexyl-2,3,4,5-tetrabromobenzoate (TBB), di(2-ethylhexyl) tetrabromophthalate (TBPH), tris(1,3-dichloro-2-propyl)phosphate (TDCIPP), and triphenyl phosphate (TPHP) were the most abundant compounds detected in almost all hair, fingernail, and toenail samples. The concentrations followed the order OPEs > TBB+TBPH > Σpenta-BDE. PBDE levels in the hair and nail samples were significantly correlated with their levels in serum (P < 0.05), suggesting that human hair and nails can be used as biomarkers to assess human exposure to PBDEs.

Uric acid quantification in fingernail of gout patients and healthy volunteers using HPLC-UV.

The presence of elevated uric acid (UA) levels is a sign of gout, that is, hyperuricemia. In this study the monitoring of the UA levels in less-invasive biological samples, such as the human fingernail, is suggested for the diagnosis and therapy of gout. Twenty-six healthy volunteers (HV) and 22 gout patients (GP) were studied. The UA was extracted from human fingernail samples, then separated on an Inertsil ODS-3 column (250 × 4.6 mm i.d., 4.0 μm, GL Sciences) by isocratic elution using methanol-74 mm phosphate buffer (pH 2.2) 2:98 (v/v). A UV detector was used to monitor the samples at 284 nm. Using the developed method, different UA concentrations were found in the GP and HV. When comparing the concentrations from GP with those from HV, a statistically significant correlation was observed between the UA (p < 0.01). In this study, the UA was confirmed as a potential biomarker for the diagnosis and therapy of gout. We have developed a novel sensitive, and simple method for the determination of UA in the fingernails of GP and HV. The human fingernail may serve as a noninvasive biosample for the diagnosis of gout. Copyright © 2016 John Wiley & Sons, Ltd.

Degradation Mechanism Induced by Psoriasis in Human Fingernails: A Different Approach

Degradation Mechanism Induced by Psoriasis in Human Fingernails: A Different Approach

Determination of Strontium in Human Teeth and Fingernails of Healthy and Carious Patients Resident in Karbala, Iraq by Using ICP-OES

Determination of Strontium in Human Teeth and Fingernails of Healthy and Carious Patients Resident in Karbala, Iraq by Using ICP-OES

Evaluation of a novel portable x-ray fluorescence screening tool for detection of arsenic exposure

A new portable x-ray fluorescence (XRF) screening tool was evaluated for its effectiveness in arsenic (As) quantification in human finger and toe nails (). Nail samples were measured for total As concentration by XRF and inductively coupled plasma-mass spectrometry (ICP-MS). Using concordance correlation coefficient (CCC), kappa, diagnostic sensitivity (Sn) and specificity (Sp), and linear regression analyses, the concentration of As measured by XRF was compared to ICP-MS. The CCC peaked for scaled values of fingernail samples, at 0.424 (95% CI: 0.065–0.784). The largest kappa value, 0.400 (95% CI: −0.282–1.000), was found at a 1.3 μg g−1 cut-off concentration, for fingernails only, and the largest kappa at a clinically relevant cut-off concentration of 1.0 μg g−1 was 0.237 (95% CI: −0.068–0.543), again in fingernails. Analyses generally showed excellent XRF Sn (up to 100%, 95% CI: 48–100%), but low Sp (up to 30% for the same analysis, 95% CI: 14–50%). Portable XRF shows some potential for use as a screening tool with fingernail samples. The difference between XRF and ICP-MS measurements decreased as sample mass increased to 30 mg. While this novel method of As detection in nails has shown relatively high agreement in some scenarios, this portable XRF is not currently considered suitable as a substitute for ICP-MS.

Raman spectroscopy of fingernails: A novel tool for evaluation of bone quality?

Raman data from human fingernails has been analysed to determine if a relationship exists between spectral features and bone quality. Previous work demonstrated a relationship between the manually determined intensity of the disulphide peak (Bone Quality Test; BQT) and osteoporotic fracture. A computer program is now described that automates the BQT determi- nation for large sample-sets. In this study the ability of the automated BQT to discriminate between fractures and controls was compared to that of bone mineral density (BMD) and biomarkers of bone remodelling. Females aged 18-67 years participated in the study (n = 159). Fingernails were analysed using Raman spectroscopy. Lumbar and Femoral BMD was measured by dual energy X-ray absorptiometry (DXA). Fasting venepuncture samples were analysed for osteocalcin and CTx (collagen C-telopeptides) by electrochemiluminescence. No correlation was found between the BQT and BMD or the biomarkers. The BQT and BMD were found to be equally accurate in identifying subjects with a history of fracture ( p< 0.01) and both outper- formed osteocalcin and CTx. It appears that keratin and collagen are related structural proteins that require disulphide bonding for stability. Therefore, these preliminary results suggest that Raman spectroscopy of keratin may have potential as a diagnostic tool for screening bone quality in large populations.

Human nails metabolite analysis: A rapid and simple method for quantification of uric acid in human fingernail by high-performance liquid chromatography with UV-detection.

A rapid and simple analytical method for the quantification of uric acid (UA) in human fingernails by high-performance liquid chromatography (HPLC) with ultraviolet (UV) detection is described. UA was extracted from human fingernail samples at 90°C for 20min, then separated on an Inertsil ODS-2 column (250×4.6mm I.D., 5.0μm, GL Sciences) by isocratic elution using methanol: 74mM phosphate buffer (pH 2.2) 2:98 (v/v). An UV detector was used to monitor at 284nm. The results indicated that under optimized measurement conditions results were achieved within 8.0min, and a good linearity was achieved from the calibration curves (r(2)>0.9999) in the range of 1.0-10000ng; the limit of detection (S/N=3) was 2.0pg, the inter-day and intra-day assay precisions were all less than 0.46% and the mean recoveries (%) of the uric acid spiked in the human fingernail were 101.95%. The amounts of UA in the fingernails of healthy volunteers were determined.

Impact of different mechanical pre-treatment to the EPR signals of human fingernails towards studying dose response and fading subjected to UV exposure or beta irradiation

In this study, fingernails were investigated by means of Electron Paramagnetic Resonance (EPR) technique, further exploiting its potential use in the field of retrospective dosimetry. The behavior of the radiation induced signal was investigated under beta irradiation and UV light exposure. Nevertheless, before these aforementioned experiments, the optimum handling procedure was established by studying the mechanical impact of various pre-treatments to the mechanically induced signal. The dose response was studied in the range between 1 and 100 Gy of beta irradiation for both accidental as well as high dose dosimetry purposes. The signal growth was observed to yield a saturation exponential behavior, while the signal was found to be appropriate for use towards retrospective dosimetry studies for assessing doses of the order of 1–2 Gy, provided that the samples are collected just after irradiation. One week after irradiation, the beta-radiation induced dose response indicated linear behavior. In order to estimate a dose from RIS2, first you have to subtract the BKS contribution from the EPR signal and also the MIS. After prolonged UV exposure of roughly 7 h, the UV-induced dose response reaches saturation, while the fading of thıs specific signal was also studied.

A Hydroxypropyl Chitosan (HPCH) Based Medical Device Prevents Fungal Infections: Evidences from an In Vitro Human Nail Model

A long lasting, protective and film forming HPCH-based medical device was developed and tested in a novel human nail infection model. HPCH-treated and untreated human distal fingernail fragments were disposed on the culture surface of or . After incubation for one or three weeks, the fragments were collected and histological analysis was performed. Results obtained in untreated nails evidenced, as expected, that the fungal invasion was different depending on the species: it was completed with spp., partial with sp. and limited to the surface with sp.. On the other hand, HPCH-treated nails were not invaded by fungal elements, neither dermatophytes nor moulds or yeasts. Besides showing the barrier effect of HPCH this paper describes a novel model of nail infection that is simple, reproducible and closely represents the human situation.

Repeatability improvement of laser-induced breakdown spectroscopy using an auto-focus system

Laser-induced breakdown spectroscopy (LIBS) is a novel technique for elemental analysis of materials. The repeatability of LIBS results is an important issue in many applications. Many factors influence the repeatability of LIBS results. The aim of this study is to examine the effect of laser beam focusing position or lens to sample distance (LTSD) as one of the most important factors influencing LIBS spectra. A point auto-focus system is designed and applied to provide the same lens to sample distance in every LIBS experiment. This system is employed and the result is compared to that of non-auto-focus technique on samples with different degrees of evenness such as aluminum, paper, tape and human fingernail. The standard deviation of this experiment is measured in the range of 4 to 26 μm. Then, spectrum’s repeatability is examined with two samples of aluminum and human fingernail. The standard deviation of spectra is considerably reduced. In conclusion, repeatability of LIBS results could be optimized by using the auto-focus system.

Determination of fingernail chromium, cadmium, and lead in tannery workers

Purpose: To determine whether chromium, cadmium, and lead levels in human Fingernails reflected the exposure to workplace contamination in tanneries.Approach: 49 exposed tanning workers and 33 controls were monitored for fingernail levels of chromium, cadmium, and lead by graphite furnace and hydride atomic absorption spectroscopy.Results: The mean levels of fingernail chromium, cadmium, and lead in the exposed workers were significantly higher than those in the controls. In regression models for the tannery workers, the significant risk factor that affected the fingernail chromium, Cadmium, and lead level were occupational exposure, respectively. Current smoker it showed a significant change in trend of increased fingernail cadmium levels.Conclusion: These findings indicate that chromium, cadmium, and lead absorbed from. Leather tanning compounds result in raised levels of chromium, cadmium, and lead in fingernails and that improvement of the industrial health should be more practiced in the tanneries in Taiwan.

An efficient phase analysis-based wavenumber linearization scheme for swept source optical coherence tomography systems

This letter reports an efficient phase analysis-based direct time domain resampling scheme for swept source-based optical coherence tomography (SS-OCT) systems. The unwrapped phase values, representing non-linear frequency sweeping of the laser, are extracted from the calibration signal generated by a Mach–Zehnder interferometer. Equidistant wavenumber spaces are calculated by normalizing obtained phase values followed by scaling to the maximum number of sampling points. The non-uniform fractional time index values corresponding to the uniformly distributed phase values are computed directly from the linearizer coordinates in order to eliminate the use of the polynomial fitting approach that is used in existing phase-based time domain resampling methods. This proposed linearization scheme shows a significant improvement in performance in terms of accuracy and speed in comparison with the major existing schemes. The robustness of the algorithm, as well as its impact on the resolution and sensitivity, are illustrated using an in-house-developed SS-OCT system and by performing imaging of a human finger nail and an eye model as test samples.

Rapid and Sensitive Determination of Diacetylpolyamines in Human Fingernail by Ultraperformance Liquid Chromatography Coupled with Electrospray Ionization Tandem Mass Spectrometry

A rapid and sensitive ultraperformance liquid chromatography coupled with electrospray ionization tandem mass spectrometry (UPLC-ESI-MS/MS) method has been developed and validated for quantitatively determining diacetylpolyamines in the human fingernail. N(1),N(8)-diacetylspermidine (DiAct-Spd), N(1),N(12)- diacetylspermine (DiAct-Spm) and 1,6-diaminohexane (DAH) the [internal standard (IS)] were extracted from human fingernail samples by MeOH: 5 M HCl solution, followed by 4-(N,N-dimethylaminosulfonyl)-7-fluoro- 2,1,3-benzoxadiazole (DBD-F) derivatization, and then separated on an ACQUITY BEH C18 column with a gradient elution of acetonitrile and water containing 0.1% formic acid. The derivatives of the diacetylpolyamines were fully separated within a short run time (3.0 min). The triple quadrupole mass spectrometric detection was performed in the multiple reactions monitoring (MRM) mode by the UPLC-ESI- MS/MS system in the positive ionization mode. MRM using the fragmentation transitions of m/z 455.20→ 100.07, 737.25 → 100.07 and 567.10 → 479.07 in the positive ESI mode was performed to quantify DiAct-Spd, DiAct-Spm and IS, respectively. The calibration curve is between 0.04 ng mL(-1) for DiAct-Spd and DiAct-Spm. The detection limits (signal to noise ratio of five) were 5-10 pg mL(-1). A good linearity was achieved from the calibration curves (r(2) >0.9999), and the intra-day and inter-day assay precisions were less than 7.06%. Furthermore, the recoveries (%) of the diacetylpolyamines spiked in the human fingernails were 79.18-97.11. The present method proved that the high sensitivity is characterized by the specificity and feasibility of the sample analysis. Consequently, the proposed method was used to analyze human fingernail samples from 15 lung- cancer patients and 22 healthy volunteers. Diacetylpolyamines were detected from the fingernails of the lung- cancer patients for the first time. The concentration of DiAct-Spd in the lung-cancer patient group tended to be higher than those in the healthy volunteers.

A microwave resonator for limiting depth sensitivity for electron paramagnetic resonance spectroscopy of surfaces

A microwave Surface Resonator Array (SRA) structure is described for use in Electron Paramagnetic Resonance (EPR) spectroscopy. The SRA has a series of anti-parallel transmission line modes that provides a region of sensitivity equal to the cross-sectional area times its depth sensitivity, which is approximately half the distance between the transmission line centers. It is shown that the quarter-wave twin-lead transmission line can be a useful element for design of microwave resonators at frequencies as high as 10 GHz. The SRA geometry is presented as a novel resonator for use in surface spectroscopy where the region of interest is either surrounded by lossy material, or the spectroscopist wishes to minimize signal from surrounding materials. One such application is in vivo spectroscopy of human finger-nails at X-band (9.5 GHz) to measure ionizing radiation dosages. In order to reduce losses associated with tissues beneath the nail that yield no EPR signal, the SRA structure is designed to limit depth sensitivity to the thickness of the fingernail. Another application, due to the resonator geometry and limited depth penetration, is surface spectroscopy in coating or material science. To test this application, a spectrum of 1.44 μM of Mg(2+) doped polystyrene 1.1 mm thick on an aluminum surface is obtained. Modeling, design, and simulations were performed using Wolfram Mathematica (Champaign, IL; v. 9.0) and Ansys High Frequency Structure Simulator (HFSS; Canonsburg, PA; v. 15.0). A micro-strip coupling circuit is designed to suppress unwanted modes and provide a balanced impedance transformation to a 50 Ω coaxial input. Agreement between simulated and experimental results is shown.

In vivo EDXRF scanning analysis of human nail

This paper presents the results of a new technique for in vivo energy dispersive X‐ray fluorescence (EDXRF) scan analysis, applied to human fingernails. The scan employs a specially designed EDXRF spectrometer, which allows a concentration profile of the elements detected in a human nail. In order to carry out this technique, a group of nail fragments taken from different people was analyzed. The elements S, Ca, Cu, Fe, Cu, Zn, and Pb were detected in most of the samples. A bidimensional (x, y) scan was also performed on a whole removed nail in which the 2D spatial distribution of the detected elements was observed. Significant differences in some of the detected elements were noted. Minimum time of average detection per element was determined, based on the EDXRF spectra of the nail fragment. The time required to obtain an in vivo element profile of a typical nail was thus determined, applying the same geometry and acquisition conditions for all cases. The dose that the person undergoing this type of EDXRF scan analysis would be exposed to was also determined. Exposure time does not exceed 15 s, and the calculated administered dose is in the surface nail region of 0.1 mGy/s. The results of this study demonstrate that it is possible to carry out an in vivo X‐ray fluorescence scan analysis. This information may be used in different fields of medicine, such as nutrition and toxicology, and in other areas that establish a correlation between the concentration of the detected elements and certain diseases. Nail and hair are known to be ‘accumulating tissues’ unlike bodily fluids. In some aspects, nail analysis can be equal to a blood test. Copyright © 2014 John Wiley &amp; Sons, Ltd.

Detection of short tandem repeat polymorphisms from human nails using direct polymerase chain reaction method.

Human nail is an important forensic material for parental testing and individual identification in large-scale disasters. Detection of STR polymorphism from hard tissues generally requires DNA purification, which is technically complicated and time consuming. In the present study, we attempted to detect STR polymorphisms from untreated human nail samples by direct PCR amplification method using the primer mixture supplied with the GenePrint® SilverSTR® III System or the AmpFℓSTR® Identifiler® PCR Amplification Kit, and Tks Gflex DNA polymerase known to be effective for amplification from crude samples. A nail fragment measuring approximately 1.5 mm in breadth and 0.5 mm in length was placed directly into a PCR tube, and various PCR conditions were tested. The PCR products were analyzed by denaturing acrylamide gel electrophoresis or CE. Multiple STR polymorphisms were detected successfully. This method that detects STR polymorphisms not only from fresh human fingernails, but also from old nail fragments stored at room temperature for up to 10 years is expected to become a novel DNA analytical method in forensic medicine and genetic studies.

Stable isotope composition of human fingernails from Slovakia

Stable isotope composition of human fingernails has proven to be useful for documenting human dietary information and geographical patterns in archeological, forensic, anthropological and biological studies. Therefore, it is of interest to detect all factors influencing the stable isotopic composition in the certain regions in the world.Carbon and nitrogen isotope data of human fingernail keratin from 52 individuals from Slovakia were reported in this study. The online combustion and continuous flow isotope-ratio mass spectrometer Delta V Advantage was used for δ13C and δ15N analysis of fingernail keratin samples from 24 vegetarian and 28 omnivorous individuals.A group of people with frequent meat consumption showed enrichment in 13C and 15N isotopes in fingernails. A similar trend was observed with increasing seafood in an individual's diet. Moreover a significant difference was revealed between smokers and nonsmokers for both δ13C and δ15N values. These data were compared to previously published δ13C and δ15N fingernail values from across the globe.This study brings new information on the stable isotope signature of individuals from Slovakia and characterizes the Central European region for the first time. The stable isotope composition of fingernails is influenced by the frequency of meat and seafood consumption as well as smoking.