Analysis of methyl tert-butyl ether in urine of primary school students in Beijing / 中国学校卫生

Objective@#To investigate the urine methyl tert-butyl ether (MTBE) level of a primary school students in Changping District, Beijing, and analysis the effect factors, give the advice if the MTBE is eligibility as an exposure biomarker of automobile exhaust.@*Methods@#Using the panel study, randomly selected 20 sixthgrade students (10 male and 10 female) from Zhixing School in Changping district, Beijing, from June 7th to 13th, 2018. All participants completed a questionnaire for collecting demographic and geographic information and daily activities. All participants were given guidance to repeatedly collected urine samples 3 times (8:00, 11:00 and 16:00 instant urien) a day for 7 days, totally 420 urine samples were collected. Urine MTBE were measured and the statistic significant of the Urine MTBE at different groups were evaluated.@*Results@#MTBE were detected in all 420 urine samples of primary school students, the geometric mean of creatinine-corrected MTBE exposure level in 8:00, 11:00 and 16:00 instant urine were 0.12, 0.12 and 0.12 mg/g creatinine, respectively. Urine MTBE concentration was statistical significant in different daily outdoor activity time, the distance of home address to the main road, and daily use time of air purification equipment in class(P=0.00, 0.04, 0.00).@*Conclusion@#There was a universal MTBE exposure among students in a primary school in Beijing, and the impact factors to exposure level were daily outdoor activity time, distance from home address to the closest main road, and daily use time of air purification equipment in class. This result indicate MTBE may be a valuable candidate for exposure biomarker of automobile exhaust, and more research should be done.

Losartan attenuates vascular remodeling of the aorta in spontaneously hypertensive rats and the underlying mechanism / 中南大学学报(医学版)

Objective To determine the effect of losartan on vascular remodeling and the underlying mechanism in spontaneously hypertensive rats(SHR). Methods SHR of 12 weeks old were given losartan orally [0,15,30 mg/(kg·d),n=12]. The tail arterial pressure was measured every week.Eight weeks later, the pathological changes and p22phox expression in the thoracic aorta, the activity of catalase (CAT), the contents of H2O2 and AngⅡ in the plasma were evaluated. Results Blood pressure was increased in the SHR accompanied by the thickened wall and increased p22phox expression in the thoracic aorta. The plasma levels of H2O2 and AngⅡwere elevated while the CAT level was decreased in the SHR. Administration of losartan reversed the thickened wall and increased the CAT activity concomitantly with the decreased plasma levels of H2O2 and p22phox expression in the SHR. The plasma level of AngⅡincreased after the losartan treatment. Conclusion Oxidative stress induces the vascular remodeling of the aorta in the SHR. Losartan can reverse the vascular remodeling through down-regulating p22phox expression and inhibiting the oxidative stress.