Objective To study the influence of defection of Fragile X mental retardation-1 gene (FMR1) on cyclic adenosine monophosphate (cAMP) and to discuss its mechanism. Methods FMR1 gene of peripheral blood mononuclear cell was silenced in vitro by sodium nitrointroprusside. The effect of gene-silencing was detected using reverse transcript polymerase chain reaction (RT-PCR). The specific activity of adenylate cyclase and phosphodiesterase was showed by the activity ratio of yield or consumption of cAMP during a unit time. Spectrophotometry was used to measure the two key enzymes (adenylate cyclase and phosphodiesterase), as to determining the level of intracellular cyclic adenosine monophosphate in the process of cAMP metabolism. Results FMR1 gene was fully silenced by sodium nitrointroprusside at 12th, 24th and 48th hour separately, re-expressed at 72th hour. If the cultivated fluild was replaced with new sodium nitrointroprusside at 48th hour, FMR1 gene would be silenced continuously. The intracellular cAMP level in the gene silenced group was lower, and significant depression of adenylate cyclase specific activity was found in the FMR1 gene silenced group (P=0.000). No significant difference was found on phosphodiesterase specific activity (P=0.983). Conclusions The results suggest that the yield of cAMP could be influenced by defection of FMR1. The depression of adenylate cyclase activity might be one of the causes of the decrease of intracellular cAMP production.

Objective:To analyze the level and changing trend of significant injury-caused deaths in the Chinese population from 2010 to 2019 and provide evidence for related intervention.Methods:Data on notable injury-caused deaths in areas under National Disease Surveillance Programs were collected from 2010 to 2019. Crude and standardized mortality rates of four significant injuries were calculated to describe the status of injury-caused deaths. The trend of changes in standardized mortality rates was analyzed using the Joinpoint regression model.Results:The overall trend of standardized mortality rate on an injury during 2010-2019 was consistently decreasing (AAPC=-3.5%, P<0.001) while the general direction of accidental fall standardized mortality rate was increasing (AAPC=1.0%, P=0.104). The standardized mortality rate for significant injuries fluctuated with age, increasing for those aged 50-79 years (AAPC=3.9% for the 50- group, AAPC=5.6% for the 60- group, and AAPC=4.6% for the 70- group, all P<0.001). The standardized mortality rates for all major injuries were higher in males than those in females, with road traffic accidents and drowning declining faster in males than that in females (AAPC=-5.3% in the male road traffic accident group, AAPC=-3.8% in the female road traffic accident group, AAPC=-4.0% in the male drowning group, AAPC=-3.5% in the female drowning group, all P<0.001), and suicide and sequelae declining faster in females than that in males (AAPC=-6.4% in female, AAPC=-4.7% in male, all P<0.001). The standardized mortality rate for significant injuries was higher in rural than that in urban areas and decreased faster than that in urban areas. The central region had the highest standardized mortality rate for suicide and sequelae. The western part had the highest standardized mortality rates for road traffic accidents, accidental falls, and drowning, with the fastest decline in road traffic accidents and drowning (AAPC=-5.3% in the road traffic accident group and AAPC=-5.3% in the drowning group, both P<0.001). Conclusions:The mortality rate from significant injuries in the Chinese population showed a continuous downward trend from 2010 to 2019, with a rebound in the standardized mortality rate from accidental falls in recent years among the elderly, males, rural residents, and central and western regions being the focus of future prevention and control.