Recent increase of surface particulate matter concentrations in the Seoul Metropolitan Area, Korea

Recent changes of surface particulate matter (PM) concentration in the Seoul Metropolitan Area (SMA), South Korea, are puzzling. The long-term trend of surface PM concentration in the SMA declined in the 2000s, but since 2012 its concentrations have tended to incline, which is coincident with frequent severe hazes in South Korea. This increase puts the Korean government's emission reduction efforts in jeopardy. This study reports that interannual variation of surface PM concentration in South Korea is closely linked with the interannual variations of wind speed. A 12-year (2004-2015) regional air quality simulation was conducted over East Asia (27-km) and over South Korea (9-km) to assess the impact of meteorology under constant anthropogenic emissions. Simulated PM concentrations show a strong negative correlation (i.e. R = -0.86) with regional wind speed, implying that reduced regional ventilation is likely associated with more stagnant conditions that cause severe pollutant episodes in South Korea. We conclude that the current PM concentration trend in South Korea is a combination of long-term decline by emission control efforts and short-term fluctuation of regional wind speed interannual variability. When the meteorology-driven variations are removed, PM concentrations in South Korea have declined continuously even after 2012

Effects of Slide Storage on Detection of Molecular Markers by IHC and FISH in Endometrial Cancer Tissues From a Clinical Trial: An NRG Oncology/GOG Pilot Study

We performed a pilot study in anticipation of using long-aged precut formalin fixed paraffin embedded (FFPE) tissue sections stored in real-world conditions for translational biomarker studies of TOP2A, Ki67, and HER2 in endometrial cancer. FFPE tissue blocks or unstained slides or both from GOG-0177 were collected centrally (1999-2000) and stored at room temperature. During 2004-2011 specimens were stored at 4°C. Matched pairs of stored slides and freshly cut slides from stored blocks were analyzed for TOP2A (KiS1), Ki67 (MIB1) and HER2 (Herceptest™) proteins. To assess DNA stability (HER2 PathVision), FISH was repeated on stored slides from 21 cases previously shown to be HER2-amplified. IHC staining intensity and extent, mean FISH copies/cell, and copy number ratios were compared using the kappa statistic for concordance or signed rank test for differences in old cut versus new cut slides. IHC results reflected some protein degradation in stored slides. The proportion of cells with TOP2A staining was lower on average by 12% in older sections (p=.03). The proportion of Ki67 positive cells was lower in stored slides by an average of 10% (p<.01). Too few cases in the IHC cohort were FISH positive for any conclusions. HER2 amplification by FISH was unaffected by slide storage. We conclude that use of aged stored slides for proliferation markers TOP2A and Ki67 is feasible but may modestly underestimate true values in endometrial cancer. Pilot studies for particular storage conditions/durations/antigens to be used in translational studies are warranted