RÉSUMÉ
Background Improper settings of outdoor smoking points in public places may increase the risk of secondhand smoke exposure among the population. Conducting research on air pollution in and around smoking spots and related influencing factors can provide valuable insights for optimizing the setting of outdoor smoking points. Objective To investigate the influence of the number of smokers at outdoor smoking points and the distance on the diffusion characteristics of surrounding air pollutants, in order to optimize the setting of outdoor smoking points. Methods Surrounding the exhibition halls in the China International Import Expo (CIIE), two outdoor smoking points were randomly selected, one on the first floor (ground level) and the other on the second floor (16 m above ground), respectively. At 0, 3, 6, and 9 m from the smoking points in the same direction, validated portable air pollutant monitors were used to measure the real-time fine particulate matter (PM2.5) and carbon dioxide (CO2) concentrations for consecutive 5 d during the exhibition, as well as the environmental meteorological factors at 0 m with weather meters including wind speed, wind direction, and air pressure. An open outdoor atmospheric background sampling point was selected on each of the two floors to carry out parallel sampling. Simultaneously, the number of smokers at each smoking point were double recorded per minute. The relationships between the number of smokers, distance from the smoking points, and ambient PM2.5 and CO2 concentrations were evaluated by generalized additive regression models for time-series data after adjustment of confounders such as temperature, relative humidity, and wind speed. Results The median numbers of smokers at smoking points on the first and second floors were 6 [interquartile range (IQR): 3, 9] and 9 (IQR: 6, 13), respectively. Windless (wind speed <0.6 m·s−1) occupied most of the time (85.9%) at both locations. The average concentration of ambient PM2.5 at the smoking points (0 m) [mean ± standard deviation, (106±114) μg·m−3] was 4.2 times higher than that of the atmospheric background [(25±7) μg·m−3], the PM2.5 concentration showed a gradient decline with the increase of distance from the smoking points, and the average PM2.5 concentration at 9 m points [(35±22) μg·m−3] was close to the background level (1.4 times higher). The maximum concentration of CO2 [(628±23) μmol·mol−1] was observed at 0 m, and its average value was 1.3 times higher than that of the atmospheric background [(481±40) μmol·mol−1], and there was no gradient decrease in CO2 concentration with increasing distance at 0, 3, 6, and 9 m points. The regression analyses showed that, taking smoking point as the reference, every 3 m increase in distance was associated with a decrease of ambient PM2.5 by 24.6 [95% confidence interval (95%CI): 23.5, 25.8] μg·m−3 (23.2%) and CO2 by 54.1 (95%CI: 53.1, 55.1) μmol·mol−1 (8.6%). Every one extra smoker at the smoking point was associated with an average increase of PM2.5 and CO2 by 2.0 (95%CI: 1.7, 2.8) μg·m−3 and 1.0 (95%CI: 0.7，1.2) μmol·mol−1, respectively. The sensitivity analysis indicated that, under windless conditions, the concentrations of PM2.5 and CO2 at the smoking points were even higher but the decreasing and dispersion characteristics remained consistent. Conclusion Outdoor smoking points could significantly increase the PM2.5 concentrations in the surrounding air and the risks of secondhand smoke exposure, despite of the noticeable decreasing trend with increasing distance. Considering the inevitable poor dispersion conditions such as windless and light wind, outdoor smoking points are recommended to be set at least 9 m or farther away from non-smoking areas.
RÉSUMÉ
Objective To investigate the effects of acitretin on T helper cell (Th) 1/Th2 balance and Th17 cells in psoriasis vulgaris (PV) patients. Methods A total of 13 men and 17 women with PV were investigated. 10 mg of acitretin was administered twice a day for 8 weeks for intervention therapy. Serum levels of interferon-gamma (IFN-γ), interleukin (IL)-4 and IL-17 were measured by enzyme-linked immunosorbent assay. T, Th1, Th2 and Th17 cells in skin biopsies were counted with double-labeled immunofluorescence. Psoriasis Area and Severity Index (PASI) score was calculated before and 8 weeks after treatment. Results Before treatment PV patients had higher serum levels of IFN-γ and IL-17, and increased T, Th1 and Th17 cells in skin biopsies. After treatment, both serum levels of IFN-γ and IL-17, and T, Th1 and Th17 cells infiltrating in PV skin decreased significantly. Th1/Th2 balance was restored to normal. However, their IL-4 and Th2 cells showed no significant change throughout the therapy. Conclusion Acitretin exerts influence on dermal Th1/Th2 balance and Th17 cell infiltration, so does it on production of systematic inflammatory cytokines IFN-γ and IL-17 in PV patients. However, Th2 cells and its derivative cytokine-IL-4 are not affected.
RÉSUMÉ
Objective To study the effect of NS398, an inhibitor of cyclooxygenase 2 (COX2), on the growth and apoptosis of human squamous cell carcinoma cell line Tca8113. Methods Cultured Tca8113 cells were incubated with NS398 (0, 6.25, 12.5, 25, 50, 100 μmol/L) for 24, 48 and 72 hours, respectively. Thereafter, MTT method, flow cytometry and transmission electron microscopy were applied to detect the proliferation, cell cycle and apoptosis of Tca8113 cells, respectively. Results The proliferation of Tca8113 cells was inhibited by NS398 in a dose- and time-dependent manner (both P<0.05). FCM analysis showed the appearance of a typical hypodiploid apoptotic (Sub-G1) peak, an increase in the percentage of cells at G0/G1 phase and a decrease in that at S and G2/M phases in NS398 ( 100 μmol/L) -treated Tca8113 cells. Moreover, the cell proliferation index was significantly downregulated by NS398 of 100 μmol/L from 41.03 to 24.33 (P<0.05). Under an electron microscope, morphological changes characteristic of apoptosis were observed in NS398-treated Tca8113 cells. Conclusion NS398, an inhibitor of COX2, could effectively inhibit the growth of Tca8113 cells in vitro by induction of apoptosis.