RESUMO
This report presents the endemic status of schistosomiasis in the People's Republic of China at national level in 2016,and analyzes the data collected from the national schistosomiasis prevention and control system and 454 national schisto-somiasis surveillance sites. Among the 12 provinces(municipality and autonomous region)of endemic of schistosomiasis japoni-ca in P. R. China,5 provinces (municipality and autonomous region),i. e.,Shanghai,Zhejiang,Fujian,Guangdong and Guangxi,had achieved elimination,and 7 provinces of Sichuan,Yunnan,Jiangsu,Hubei,Anhui,Jiangxi and Hunan had achieved transmission control by the end of 2016. There are 451 endemic counties(cities,districts)covering 257 million peo-ple,specifically including 29692 endemic villages of 69.39 million people at risk. Among the 451 endemic counties(cities,dis-tricts),35.25％(159/451),42.35％(191/451)and 22.39％(101/451)reached the criteria of elimination,transmission inter-ruption and transmission control,respectively in 2016. By the end of 2016,it was estimated of 54454 infections of schistosome, decreased by 29.46％compared with 77194 in 2015. No acute schistosomiasis case was reported in 2016. There were 30573 ad-vanced schistosomiasis cases documented in 2016. A total of 8500710 individuals received schistosomiasis examinations and 600 individuals were parasitologically diagnosed,decreased by 83.36％compared with 3606 in 2015. The Oncomelania hupen-sis snail survey was performed in 22140 endemic villages and O. hupensis snails were found in 7106 villages,accounting for 32.109％of the total villages,with 20 newly detected villages with snails. The snail survey covered area of 813963.91 hm2 and snails were found in an area of 235096.04 hm2,including a newly detected area of 1346.48 hm2. No schistosome-infected snails were found in 2016. A total of 881050 bovines were raised in the schistosomiasis endemic area. Of them,510468 bovines re-ceived examinations,resulting in 8 schistosome-infected bovines. There were 147642 schistosomiasis cases receiving drug treat-ment in 2016,with 2303555 individuals undergoing expanded chemotherapy;there were 9 bovines with schistosomiasis receiv-ing drug treatment,with 439857 bovines undergoing expanded chemotherapy;a total of 139483.84 hm2 area with snail control by using molluscicides,with actual molluscicide-treated area of 73941.75 hm2;and 3101.52 hm2 snail habitants were treated by environmental modification. Based on the data from the 454 national schistosomiasis surveillance sites,the mean Schistosoma japonicum infection rate was 0.02％ and 0.0078％ in humans and bovines,respectively. No schistosome-infected snails were found in all the surveillance sites. The results demonstrate a decline in the endemicity of schistosomiasis in P. R. China com-pared with the level of 2015. However,the distribution area of snails in China is still large and the infection source of schistoso-miasis still exists to some extent in some endemic areas;in some regions,the task to reach the standard of transmission interrup-tion is still arduous. There are still objective factors of epidemic and transmission and risk factors of endemic reversal and re-bound for schistosomiasis. So,further control and effective surveillance as well as accurate prevention and control should be im-plemented to promote the elimination process on schistosomiasis in P. R. China.
RESUMO
<p><b>OBJECTIVE</b>To explore the mechanism and significance of cytochrome c oxidase subunit IV (COX IV) downregulation during apoptosis of NB4 cells induced by sodium selenite.</p><p><b>METHODS</b>NB4 cells were treated with 20 micromol/L sodium selenite at different time points. COX IV protein and mRNA were detected by Western blot and RT-PCR, respectively. NB4 cells were pretreated with reactive oxygen species (ROS) scavenger before selenite exposure, and then COX IV protein expression and caspase-3 activation were detected by Western blot. NB4 cells were pretreated with caspase-3 inhibitor before selenite exposure, and then COX IV protein expression was detected by Western blot. NB4 cells were transiently transfected with vectors to interfere with the expression of COX IV, and then the apoptosis induced by selenite was analyzed by flow cytometry.</p><p><b>RESULTS</b>Sodium selenite induced evident downregulation of COX IV protein in NB4 cells, while its mRNA level was almost unchanged. ROS scavenger completely reversed selenite-induced COX IV downregulation and caspase-3 activation. Caspase-3 inhibitor partially reversed selenite-induced COX IV downregulation. Interference with COX IV expression dramatically enhanced selenite-induced apoptosis of NB4 cells.</p><p><b>CONCLUSIONS</b>COX IV is remarkably downregulated during selenite-induced apoptosis of NB4 cells. ROS mediates COX IV downregulation and caspase-3 activation, while caspase-3 is partially involved in COX IV downregulation. COX IV interference markedly increases the sensitivity of NB4 cells to selenite-induced apoptosis.</p>