1.
Early lead exposure and childhood adiposity in Mexico city.
Liu, Y, Peterson, KE, Montgomery, K, Sánchez, BN, Zhang, Z, Afeiche, MC, Cantonwine, DE, Ettinger, AS, Cantoral, A, Schnaas, L, et al
International journal of hygiene and environmental health. 2019;(6):965-970
Abstract
BACKGROUND Prenatal and early childhood lead exposures have been associated with reduced weight in infants and young children, while studies that have examined such associations in children during peripubescence are rare. OBJECTIVES We investigated the associations of prenatal and early-life exposure to lead with indices of adiposity in peripubertal children living in Mexico City. METHODS Maternal bone lead (as a proxy for cumulative fetal exposure) was assessed at 1 month postpartum. Blood samples were obtained from children annually from 1 to 4 years. Multivariable linear regression models were used to examine the association between each lead biomarker and BMI z-score, waist circumference, sum of skinfolds and body fat percentage in 248 children aged 8-16 years. RESULTS After adjusting for covariates, maternal patella lead was associated with lower child BMI z-score (β = -0.02, 95% CI: 0.03, -0.01, p = 0.004), waist circumference (β = -0.12 cm, 95% CI: 0.22, -0.03, p = 0.01), sum of skinfolds (β = -0.29 mm, 95% CI: 0.50, -0.08, p = 0.007) and body fat percentage (β = -0.09%, 95% CI: 0.17, -0.01, p = 0.03). No significant associations were detected from the postnatal exposure period. CONCLUSIONS We observed a significant and inverse association of prenatal lead exposure with body composition in Mexican children, suggesting the potential role of early lead exposure in the fetal programming of child growth. Further research on the biological mechanisms underlying these associations is needed.
2.
Wavelength-interrogated surface plasmon resonance sensor with mesoporous-silica-film-enhanced sensitivity to small molecules.
Zhang, Z, Lu, DF, Liu, Q, Qi, ZM, Yang, L, Liu, J
The Analyst. 2012;(20):4822-8
Abstract
Sol-gel copolymer-templated mesoporous silica films with a thickness of 70 nm and interpore spacing of 4.34 nm were fabricated on gold layer covered glass substrates for application as a wavelength-interrogated surface plasmon resonance (SPR) sensor. The resonance wavelength (λ(R)) of the sensor with a solution sample was determined by absorptiometry at a given incident angle. A comparison between the experimental data obtained with the coated and uncoated SPR chips demonstrated that the mesoporous silica film effectively enhanced sensor response to individual adsorption of cysteamine molecules and lead(II) ions. An approximate proportional relationship between the resonance-wavelength shift of the sensor and the volume fraction of analyte molecules adsorbed in the mesoporous silica film was obtained by numerical simulation. Porosities of 0.865 and 0.785 for the two silica films used as well as the volume fractions of 0.048 and 0.116 for adsorbed lysozyme and cysteamine molecules were determined by fitting the simulation results to the experimental data. The adsorbed amount of cysteamine (∼0.5 nm) is equivalent to more than 16 full monolayers on the geometric surface of the mesoporous silica film used. In contrast, an equivalence of less than 2 full monolayers for adsorbed lysozyme molecules (3 nm × 3 nm × 4.5 nm) suggests that the mesoporous silica film has good size-selective adsorption capability due to its uniform pore size distribution. Cysteamine modification of the mesoporous silica film renders the SPR sensor able to detect lead(II) ions at concentrations as low as 1 nM.
3.
[Effects of lead, copper and cadmium stresses on growth and inherent quality of Prunalla vulgaris].
Wu, Z, Guo, Q, Wang, Q, Zhou, L, Zhang, Z, Zhang, L, Huang, T
Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica. 2010;(3):263-7
Abstract
OBJECTIVE Prunalla vulgaris was used as the experimental material to study the effects of lead (Pb), copper (Cu) and cadmium (Cd) on the related physiological and growth indexes of the plant. METHOD By referencing the GAP and the soil environmental quality standard, the growth and inherent quality of the plant were observed under different concentrations of the heavy metals stresses. The data were statistically processed. RESULT The results showed that the plant grew normally when the heavy metal concentrations in soil were close to up limits of the soil environmental quality standard II. The content of heavy metal in spica met the requirement of the standard, and under the circumstances the content of ursolic acid was increased in a certain range. The critical values of Pb, Cu, Cd in the P. vulgaris grown soil were set at 450, 100, 1.0 mg x kg(-1), respectively. CONCLUSION The harmful influence of the heavy metal stress at a lower concentration is lighter than at a higher concentration, and it could increase the content of ursolic acid. The stress of Pb, Cu and Cd is more obvious than that of Zn.