Relationship of the low-density lipoprotein (LDL)/high-density lipoprotein (HDL) index with antioxidant enzymes and with the oxLDL/HDL index

Introduction: The low-density lipoprotein (LDL)/high-density lipoprotein (HDL) index is a predictive factor for atherosclerosis, which is associated with oxidative modifications. Objective: To assess the association of the index with oxidative stress markers. Methods: 444 subjects were included and were clinically, anthropometrically and biochemically characterized; superoxide dismutase, glutathione peroxidase 3 (GPx3), magnesium and oxidized LDL (oxLDL) index (oxLDL/HDL) were quantified. Results: A decrease of 1.014 units in the LDL/HDL index was associated with a superoxide dismutase increase of 1 unit/mL (p = 0.030), while a decrease of 0.023 units was associated with a GPx3 increase of 1 nmol/min/mL (p < 0.0005). An increase of one unit in the index was associated with an increase of 0.831 in the oxLDL/HDL index (p < 0.05). After controlling for the effect of gender, age, smoking, obesity and insulin resistance, a reduction of 0.001 per index unit was associated with an increase of 1 µg/g of magnesium in the nails (p = 0.020). Conclusions: The LDL/HDL index shows an inverse relationship with the antioxidant status and a direct relationship with oxidation status, regardless of other cardiovascular and oxidative stress risk factors.

Influence of fluoridated groundwater and 1, 100 ppm fluoride dentifrice on biomarkers of exposure to fluoride

Abstract This research aimed to determine the influence of fluoridated groundwater and 1,100 ppm fluoride dentifrice on biomarkers of exposure to fluoride in preschoolers. A cross-sectional study was performed on thirty preschoolers recruited from naturally fluoridated and non-fluoridated areas (n=15). Total Daily Fluoride Intake (TDFI) from diet and dentifrice, and Daily Urinary Fluoride Excretion (DUFE) was measured over 24 h. Nails samples were collected twice during 30 days. Fluoride analyses were performed using a fluoride-ion-specific electrode. Data were evaluated using the Student and paired t-test, Pearson correlation analysis, multiple linear regression analysis (α≤0.05). Fluoridated groundwater and dentifrice were the dominant sources (r2 > 0.83) of TDFI in children from a naturally fluoridated and a non-fluoridated area, respectively. A positive correlation between TDFI and DUFE (r=0.50), and between [F] in fingernails and toenails (r=0.60) were found in children from a naturally fluoridated area. The [F] in nails of finger and toe were not correlated to TDFI. The consumption of fluoridated groundwater influenced the fluoride concentration in urine. In addition, the use of 1,100 ppm fluoride dentifrice did not influence the fluoride concentration in urine and fingernails.

Resumo Esta pesquisa teve como objetivo determinar a influência de águas fluoretadas subterrâneas e do dentifrício com 1.100 ppm de fluoreto nos biomarcadores de exposição ao flúor em pré-escolares. Foi realizado um estudo transversal em trinta pré-escolares recrutados em áreas naturalmente fluoretadas e não fluoretadas (n = 15). A ingestão diária total de flúor (TDFI) a partir da dieta e do dentifrício, assim como a excreção urinária diária de flúor (DUFE), foram medidas ao longo de 24 horas. Amostras de unhas foram coletadas duas vezes durante 30 dias. As análises de flúor foram realizadas usando um eletrodo específico para íon flúor. Os dados foram analisados utilizando o teste t de Student e pareado, a análise de correlação de Pearson, e a análise de regressão linear múltipla (a≤0,05). As águas subterrâneas e dentifrícios fluoretados foram as fontes dominantes (r2>0,83) do TDFI em crianças da área naturalmente fluoretada e não fluoretada, respectivamente. Uma correlação positiva entre TDFI e DUFE (r=0,50) e entre [F] nas unhas das mãos e dos pés (r=0,60) foi encontrada em crianças da área naturalmente fluoretada. A [F] nas unhas das mãos e dos pés não foi correlacionada com TDFI. O consumo de águas subterrâneas fluoretadas influenciou a concentração de flúor na urina. Além disso, o uso de dentifrício com 1.100 ppm de fluoreto não influenciou a concentração de fluoreto na urina e nas unhas.

Freeze grinding combined ultrasonic technique for the treatment of nail test material / 法医学杂志

OBJECTIVE@#To investigate the feasibility of the new method of combining freeze grinding with ultrasonic technique for the pretreatment of the nail for toxicological and pharmaceutical analysis and to compare the advantages and disadvantages of this method with other traditional methods.@*METHODS@#Five pretreatment methods were examined. Scanning electron microscope (SEM) was used to observe the microstructural changes of the nail.@*RESULTS@#The microscopic structure of nail totally destroyed after alkali treatment. The hierarchy mode of the internal structure became obvious and tight after acid hydrolysis, which became indistinct after methanol infiltration. The structure of nail broke to pieces after ultrasonic technique. After freeze grinding combined ultrasonic technique, the particle structure kept original shape, and its size was one hundred times smaller than which after manual way.@*CONCLUSION@#The freeze grinding combined ultrasonic technique can improve the release efficiency, and ensure the stability of the toxicant or drug during the pretreatment process. It is appropriate for toxicological and pharmaceutical analysis in the nail.

Nail DNA and Possible Biomarkers: A Pilot Study / 예방의학회지

OBJECTIVES: Nail has been a substitute DNA source for genotyping. To investigate the integrity and consistency of nail DNA amplification for biomarker study, nail clippings from 12 subjects were collected at monthly intervals. The possibility of longer amplification and existence of GAPDH RNA/protein, were also investigated with three nail samples. METHODS: Three primer sets were designed for quantitative amplification of nuclear and mitochondrial genes and analysis of their consistency. The mean threshold cycles in amplification of the target genes were compared to test the consistency of polymerase chain reaction (PCR) performance among individual factors including age groups, sex, family, the nail source, and by the size of the amplification segments. RESULTS: The amplification of the target genes from nail DNA showed similar integrity and consistency between the nail sources, and among the serial collections. However, nail DNA from those in their forties showed earlier threshold cycles in amplification than those in their teens or seventies. Mitochondrial DNA (mtDNA) showed better DNA integrity and consistency in amplification of all three targets than did nuclear DNA (nucDNA). Over 9 kb of mtDNA was successfully amplified, and nested quantitative PCR showed reliable copy numbers (%) between the two loci. Reverse transcription PCR for mRNA and immunoblotting for GAPDH protein successfully reflected their corresponding amounts. Regarding the existence of RNA and protein in nails, more effective extraction and detection methods need to be set up to validate the feasibility in biomarker study. CONCLUSIONS: Nail DNA might be a feasible intra-individual monitoring biomarker. Considering integrity and consistency in target amplification, mtDNA would be a better target for biomarker research than nucDNA.

Fingernail may not be a reliable biomarker of fluoride body burden from dentifrice

Fingernail has been suggested as a biomarker of fluoride (F) body burden, but there is no consensus if it would be a reliable indicator of F exposure from dentifrice. Therefore, the present study was conducted to investigate if fingernails would have sensitivity to detect F exposure from dentifrice in young children. Twenty-three 1-3-year-old children living in the city of Piracicaba (0.72 ppm F in water), Brazil, were enrolled in two phases of different F exposure: in phase A (1st to 11th week), they were exposed to the combination of F from diet (solids and liquids) and dentifrice (1,500 µg F/g as MFP), and in phase B (12th to 29th week), only to F from diet (the use of F dentifrice was interrupted). Fingernails were weekly clipped during 35 weeks for F determination. F intake from diet and dentifrice in each phase was also determined. Both analyses were made with ion-specific electrode. F intake (Mean ± SD) was significantly higher (p<0.01) when the children were exposed to F from diet+dentifrice than only to F from diet (0.086 ± 0.032 and 0.040 ± 0.009 mg F/day/kg body weight, respectively). However, F concentrations in nails collected during the whole experimental period of 35 weeks presented great variation with no trend of decreasing after F dentifrice intake interruption. The findings suggest that fingernail may not be a reliable F biomarker of body burden from dentifrice.

As unhas têm sido consideradas um biomarcador para a exposição ao flúor (F), mas não há consenso se é um indicador confiável para exposição ao F a partir do dentifrício. Vinte e três crianças, com idade entre 1 a 3 anos, moradoras de Piracicaba (0,72 ppm F na água), Brasil, foram submetidas a duas fases de diferentes exposição ao F: fase A (1a a 11a semanas), as crianças foram expostas à combinação de F a partir da dieta (sólidos e líquidos) e dentifrício (1500 µg F/g como MFP); e na fase B (12ª a 29ª semanas), apenas ao F da dieta, uma vez que usaram dentifrício não fluoretado. As unhas das mãos foram coletadas semanalmente durante 35 semanas para determinação de F. A exposição ao F a partir da dieta e dentifrício foi também determinada. Ambas análises foram feitas com eletrodo específico para F. A exposição ao F foi significativamente maior (p<0,001) quando as crianças foram expostas ao F da dieta + dentifrício que ao F da dieta (0,086 ± 0,032 e 0,040 ± 0,009 mg F/kg corpóreo/dia, respectivamente). Entretanto, a concentração de F nas unhas coletadas durante todo o período experimental não diminuiu após a interrupção da ingestão do F a partir do dentifrício. Os resultados sugerem que as unhas das mãos não são um biomarcador confiável para refletir a exposição ao F pelo dentifrício.

Reduction in urinary arsenic with bottled-water intervention.

The study was conducted to measure the effectiveness of providing bottled water in reducing arsenic exposure. Urine, tap-water and toenail samples were collected from non-smoking adults residing in Ajo (n=40) and Tucson (n=33), Arizona, USA. The Ajo subjects were provided bottled water for 12 months prior to re-sampling. The mean total arsenic (microg/L) in tap-water was 20.3+/-3.7 in Ajo and 4.0+/-2.3 in Tucson. Baseline urinary total inorganic arsenic (microg/L) was significantly higher among the Ajo subjects (n=40, 29.1+/-20.4) than among the Tucson subjects (n=32, 11.0+/-12.0, p<0.001), as was creatinine-adjusted urinary total inorganic arsenic (microg/g) (35.5+/-25.2 vs 13.2+/-9.3, p<0.001). Baseline concentrations of arsenic (microg/g) in toenails were also higher among the Ajo subjects (0.51+/-0.72) than among the Tucson subjects (0.17+/-0.21) (p<0.001). After the intervention, the mean urinary total inorganic arsenic in Ajo (n=36) dropped by 21%, from 29.4+/-21.1 to 23.2+/-23.2 (p=0.026). The creatinine-adjusted urinary total inorganic arsenic and toenail arsenic levels did not differ significantly with the intervention. Provision of arsenic-free bottled water resulted in a modest reduction in urinary total inorganic arsenic.

Fingernails as biological indices of metal exposure.

Metal determination in human tissues is the most common application of biological monitoring for screening, diagnosis and assessment of metal exposures and their risks. Various biopsy-materials may be used. This paper deals with the quantitative determination of Cd, Pb, Cr, Mn, Fe, Ni, Cu, and Zn concentrations in nails of male subjects exposed to these metals along with their respective controls, while working in locomotive, carriage and road ways workshops, and lead battery factories. The levels of Cd, Pb, Cr, Mn, Fe, Ni, Cu and Zn in fingernails, assayed by atomic absorption spectrophotometry, were compared with their respective controls by student 't' test. All the obtained values were correlated to the personal and medical history of the subjects under study. Significantly high levels of Cd, Pb, Cr, Fe, Ni, Cu and Zn were present in smokers, compared to nonsmokers. The concentrations of Cd, Pb, Cr, Mn and Fe were not significantly high in vegetarian subjects. It was also observed that there is no contribution of liquor towards nail-metal concentration. Significant correlations were observed between skin disease and Cr, Mn, Fe, Cu; hypertension and Cd, Mn, Cu; mental stress and Cd, Pb, Mn, Ni, Cu, Zn; diabetes and Cr, Mn, Ni; chest pain and Pb; respiratory trouble and Cr, Mn, Fe, Ni, Zn; tuberculosis and Zn; acidity and Cd; and ophthalmic problems and Mn, Fe, Ni, and Zn.

Nail and bone surface as indicators of acute exposure to fluoride in rats

Este estudo avaliou o uso de unhas e superfícies ósseas como indicadores da exposição aguda ao flúor em ratos. Seis grupos (n=10/grp), com idade de 70 dias, receberam, por gastro-gavagem, doses únicas de fluoreto de sódio contendo 10, 35, 45, 60, 75 e 90 mg flúor/kg peso corpóreo. O grupo controle recebeu água deionizada. Duas horas após a administração de flúor, os ratos foram mortos e seu plasma, unhas (metades próximas à porção de crescimento) e fêmur foram coletados. As concentrações de flúor na unha e plasma foram analisadas com o eletrodo após difusão facilitada por HMDS. O flúor da superfície do fêmur foi removida de uma área circular (4,52 mm2) por imersão em HCl 0,5 M por 15 segundos, tamponado com TISAB (contendo NaOH) e analisado com o eletrodo. Os dados foram analisados por ANOVA e teste de Tukey (p<0,05) e por regressão linear (p<0,001). As concentrações médias de flúor variaram de 55,4 a 91,5 mg/g para as unhas; de 0,019 a 6,937 mg/mL para o plasma e de 617 a 2.394 mg/g para a superfície do fêmur. A concentração de flúor nas unhas do grupo experimental não foi diferente do controle. Quanto ao flúor no plasma, todos os grupos experimentais diferiram do controle, exceto o grupo que recebeu a menor dose. Em respeito ao flúor na superfície do fêmur, apenas o grupo que recebeu a maior dose diferiu do controle. Uma forte correlação foi encontrada entre o flúor plasmático e a dose administrada (r=0,736) e uma correlação média foi encontrada entre a superfície do fêmur e a dose administrada (r=0,510). Os dados sugerem que após duas horas de administração aguda de flúor, unhas e superfície do fêmur não são bons indicadores da exposição ao flúor.

Comparison of biological specimens for manganese determination among highly exposed welders.

This research aimed to determine if less invasive biological specimens (other than blood), such as feces and clipped toenails could be used to determine manganese concentrations among occupationally exposed human subjects. In addition to blood samples, which have routinely been used in determining manganese concentration, specimens were collected from welders working at the Electricity Generating Authority of Thailand, Mae Moh Thermal Power Plant, Lampang Province. Manganese concentrations in these three biological samples were determined by atomic absorption spectrophotometer. Correlations of manganese concentrations among these three biological samples were measured, and found to be rather poor (Pearson's r <+/-0.2, p > 0.1 for any pair-wise comparisons). Blood remains the recommended material for biomonitoring manganese concentrations in occupationally exposed subjects.