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The association of systemic antioxidant activity with ambient air pollution has been unclear. A panel of 40 healthy college students underwent repeated blood collection for 12 occasions under three exposure scenarios before and after relocating from a suburban area to an urban area in Beijing, China in 2010–2011. We measured various air pollutants including fine particles (PM 2.5 ) and determined circulating levels of antioxidant enzymes extracellular superoxide dismutase (EC-SOD) and glutathione peroxidase 1 (GPX1) in the laboratory. An interquartile range increase of 63.4 μg/m 3 at 3-d PM 2.5 moving average was associated with a 6.3% (95% CI: 0.6, 12.4) increase in EC-SOD and a 5.5% (95% CI: 1.3, 9.8) increase in GPX1. Several PM 2.5 chemical constituents, including negative ions (nitrate and chloride) and metals (e.g., iron and strontium), were consistently associated with increases in EC-SOD and GPX1. Our results support activation of circulating antioxidant enzymes following exposure to particulate air pollution. [ABSTRACT FROM AUTHOR]

Background: Tuberculosis is one of the most infectious diseases in the world. Molecular typing methods such as spoligotyping, and VNTR (variable number tandem repeats), IS6110 in the NTF region and LSP (large sequence polymorphisms) analysis are generally useful tools for the resolution of various issues related to the classical epidemiology of Mycobacterium tuberculosis (M. tuberculosis). Methods: To determine the transmission characteristics of M. tuberculosis strains isolated in Beijing, China, and their genetic relationships, especially those among Beijing family strains, 260 M. tuberculosis strains isolated from patients presenting pulmonary tuberculosis were analyzed by spoligotyping, and by examining 22 VNTR loci and the presence/absence of IS6110 in the NTF region, RD105 and RD181. Results: 81% (211 strains) of the isolates studied were Beijing family strains, 174 (82.5%) of which were identified as modern Beijing strains based on the presence of IS6110 upstream of the NTF region. RD181 was intact in 9 of the other 37 (17.5%) ancestral Beijing strains. The percentage of Beijing family strains in this study was consistent with previous reports. There are many differences, however, in allele diversity among VNTR loci between reports on strains from different areas. Conclusions: The Beijing family is the most prevalent genotype in Beijing city and the predominance of Beijing family strains has not altered in almost twenty years. Differences in the alleles and discrimination ability of VNTR loci between different regions is likely due to population differences in the regions where these M. tuberculosis strains were isolated or to differences in sampling times. [ABSTRACT FROM AUTHOR]

Abstract: Background: Ambient fine particulate air pollution has been associated with impaired lung function, but the chemical components behind the association are not well understood. Objectives: We investigated the short-term effects of various air pollutants and chemical components of ambient fine particles (PM2.5) on lung function in a panel of 40 healthy university students. Methods: The study subjects underwent biweekly spirometry tests for 12 times before and after their natural relocation from a suburban area to an urban area with changing air pollution levels and contents in Beijing, China. We estimated the short-term air pollution effects on lung function by applying four different mixed-effects models: single-pollutant model, component-PM2.5 joint model (two-pollutant model), component residual model, and exposure partitioned model. Results: Among the air pollutants, PM2.5 showed the most robust estimated effects on different lung function measures in a similar action pattern. Most air pollutants and PM2.5 chemical components were positively associated with lung function measures at a short-term averaging time (3-d moving average) and inversely associated with them at a longer averaging time (14-d moving average). We found consistent positive associations between chloride, zinc, copper, vanadium, lead, stannum and different lung function measures at 3-d moving average. We also found consistent inverse associations between calcium, magnesium and peak expiratory flow at 14-d moving average. Conclusions: Our findings suggest that PM2.5 and several metallic components may be the major air pollutants that contribute to the lung function changes. These findings may help achieve a better understanding of the features of a complex air pollution mixture that are most deleterious to health, and may also have implications for more targeted and effective pollution regulations aiming to improve the public health. [Copyright &y& Elsevier]