Objective To explore the effect of air pollution on oxidative stress indices(SOD,GSH-Px,MDA) in serum of traffic policemen. Methods From Jun to Aug,2007,sixty-two traffic policemen and thirty-five male suburban inhabitants were selected. The ambient concentrations of PM2.5,polycyclic aromatic hydrocarbons(PAHs) ,nitrogen dioxide,formaldehyde,benzene and toluene were monitored within two consecutive days in the work places of traffic policemen and in the residential areas of suburban inhabitants to assess their air pollution exposure levels. The activity of SOD,GSH-Px and the concentration of MDA in serum were determined with regent kits,while the information on smoking,drinking alcohol,exercising habit and so on was investigated by questionnaire. Results There were significant differences in the concentrations of nitrogen dioxide,formaldehyde,benzene and toluene between the two study groups. The average levels of PM2.5 and PAHs in the traffic policeman group were also higher than those in the control group,but this difference was not significant for small sample size. The activities of SOD and GSH-Px in the traffic policeman group were significantly higher than those in the control group,while the difference of MDA concentration between the two groups was not significant. The relationship between air pollution and the activity of SOD and GSH-Px were also significant after controlling the influence of other factors. Conclusion Air pollution can decrease the activity of SOD and GSH-Px in serum of traffic policemen and induce oxidative stress.

Objective To explore the value of MSCT in diagnosis of pulmonary atresia complicated with ventricular septal defect (PA/VSD).Methods Clinical and imaging data of 81 patients with PA/VSD were retrospectively analyzed.All patients underwent transthoracic echocardiography (TTE) and MSCT before surgical operation,and the imaging data were compared with surgical findings.Results There were 23 patients of type A1,17 of type A2,34 of type B and 7 of type C PA/VSD.The accuracy rate of MSCT classification of PA/VSD (93.82％ [76/81]) was higher than that of TTE (59.26％ [48/81];x2=26.95,P＜0.01).The accuracy rate of MSCT diagnosis of origin of major aortopulmonary collateral arteries (MAPCAs,100％ [93/93]) was higher than that of TTE (51.84％ [51/93];x2 =54.25,P＜0.01).Fifty cardiac malformations (50/53,94.34％) were detected with MSCT,53 with TTE ([53/53,100％];x2 =1.37,P=0.24),while 66 heart-vessel conjunction abnormalities (66/66,100％) were detected with MSCT,and 65 with TTE ([65/66,98.48％],P＞0.05).Meanwhile,106 extracardiac great vessel abnormalities (106/106,100％) were detected with MSCT and 87 with TTE ([87/106,82.08％],x2 =20.87,P＜0.05).McGoon index,pulmonary artery index and total neo-pulmonary arterial indexes (TNPAI) measured with MSCT were not statistical different with findings of surgical operation (all P＞ 0.05).Conclusion MSCT can accurately diagnose type of PA/VSD and display pulmonary artery developmental state,therefore providing guidance for clinical treatment of PA/VSD.