PGE_2 reduced pulsation in concentration of 4 ng/ml and pause in 40 ng/ml for cultured rat heart muscle cells. Membrane and microfilament changes slightly in cultured heart muscle cells exposed to PGE_2 4 ng/ml for 6 min. But membrane presented marked distortion in cultured heart muscle cells exposed to PGE_2 4 ng/ml for 6 hr. These data indicated that effect of PGE_2 is time-dependent.

Objective:To explore the application of microfluidic chip in detection of hereditary deafness-associated hotspot mutations.Methods:The dedicatedly designed and fabricated microfluidic chip was integrated with kompetitive allele-specific polymerase chain reaction amplification system, scanned via laser-excited confocal fluorescence scanner, and finally analyzed programmatically to acquire the typing results of the 23 mutation sites of the four common genes associated with hereditary hearing loss. Dried blood spots were collected from 276 neonates containing the 131 cases with hearing loss who were born in 2019 in Chengdu (deafness group) and the 145 cases with normal hearing who were born in 2020 in Chengdu (control group), and analyzed by the microfluidic chip to evaluate its clinical performance.Results:By cluster analysis, the microfluidic chip correctly analyzed the 23 positive reference samples and acquired the same typing results as their actual results, with a limit of detection of 1 mg/L. For the 276 newborn blood spots, the detection results of the microfluidic chips were confirmed to be correct by the contrasting methods. Among Deafness Group, 66 (50.4%) tested positive for the selected 23 mutation hotspots; among Control Group, 40(27.6%) were positive. Among these mutations, c.109G>A of the GJB2 gene was the most prevalent one, whose carrier rate in deafness group and control group were 46.6%(61/131) and 23.4% (34/145), respectively.Conclusions:The micro-fluidic chip system was succeeded in fulfilling the hereditary deafness-related mutation detection, and offered many advantages including high specificity, avoiding the amplicon carryover contamination, simplifying the entire experimental operation process and short detection time, so as to better meet the detection requirement of genetic testing for deafness in newborn screening and other fields.