[Time-series analysis on the relationship between ambient PM2.5 and daily outpatient visits due to allergic conjunctivitis among children in Shenzhen].

Objective: To explore the short-term effects of ambient PM2.5 on the outpatient visits of allergic conjunctivitis among children in Shenzhen. Methods: It was a ecological study. Data on daily visits including date of visit, sex and age from children with allergic conjunctivitis were collected from Shenzhen Eye Hospital and Shenzhen Children's Hospital in 2018. Related data on air pollution (PM2.5, PM10, SO2, NO2, CO and O3) and meteorology (atmospheric pressure, temperature and relative humidity) were also collected. Pearson correlation analysis was used for normal distribution data and Spearman rank correlation analysis was used for non-normal distribution data. Generalized additive model was used to estimate the impact of PM2.5 pollution on allergic conjunctivitis outpatients and the lagging effects. Results: In 2018, there were 16 133 allergic conjunctivitis outpatients in the two hospitals. The maximum age was 18 years and the minimum age was 2 months. Males accounted for 49.3%. The daily average concentration of PM2.5 was 22 (15, 31) µg/m3. Changes of the concentration of PM2.5 had a positive correlation with the amount of allergic conjunctivitis visits, and the Spearman correlation coefficient was 0.150 (P=0.004). The single pollutant model showed that the strongest effect appeared at 3 days (RR=1.111， 95%CI:1.071-1.152). A 10 µg/m3 increase of PM2.5 would result in an excessive number of allergic conjunctivitis outpatients as much as 11.112% (95%CI：7.011%-15.212%). In the multiple air pollutants models, after the introduction of NO2, O3 and CO, the concentration of PM2.5 showed an enhanced effect on the number of hospital visits due to allergic conjunctivitis on the same day, and the difference was statistically significant (P<0.05). Conclusion: Changes of the concentration of PM2.5 had a positive correlation with daily outpatient visits of allergic conjunctivitis among children in Shenzhen. (Chin J Ophthalmol, 2020, 56: 608-614).

Left ventricular longitudinal rotation changes in primary hypertension patients with normal left ventricular ejection fraction detected by two-dimensional speckle tracking imaging.

In order to assess the left ventricular (LV) longitudinal rotation (LR) in primary hypertension (PH) patients with a normal LV ejection fraction. Conventional echocardiography was performed in 61 healthy subjects and 64 PH patients. The apical four-chamber views in these patients were acquired by GE-Vivid7 or E9, then the peak radial strain in the systolic period and the strain rate in systole, in early and late diastolic periods, were measured. Segmental LR and global LR were assessed by using two-dimensional speckle tracking imaging (2D-STI). The peak radial strain rate in the early diastolic period in PH patients was significantly lower than that in healthy subjects. The rotational degrees of the middle and base lateral, the apex and the middle septum walls in PH patients were significantly different from those of the healthy subjects. The healthy subjects had prominent counter-clockwise LR (0.29°±2.86°) and the PH patients had prominent clockwise LR (-2.13°±2.93°) in non-LV wall hypertrophy and (-2.43°±2.66°) in LV wall hypertrophy. The time delay between the LV lateral wall and the septum wall in PH patients correlated to the peak LR. We concluded that 2D-STI can assess the time delay between the LV lateral wall and the septum wall to the peak LR and clockwise LR in patients with PH, and prove that PH patients have a clockwise LR. By this, we conclude that in PH patients, the LV early systolic function have changed.