BackgroundProliferative vitreo-retinal disease (PVD)is one group of ocular complications marked by the enhanced proliferation of various cells included retinal pigment epithelial (RPE) cells.Insulin-like growth factor-1 (IGF-1)and vascular endothelial growth factor(VEGF) are implicated in the aberrant cell proliferation and pathological neovascularization that characterizes PVD,but the signaling mechanism is unclear now. Objective This study was to explore the effect of IGF-1 on VEGF in cultured human RPE cells under the small hairpin loop RNA (shRNA) keeping hypoxia-inducible factor-1 α ( HIF-1 α) silencing. Methods Human retinas were isolated from 4 healthy male donors,and the RPE cells were harvested and cultured.The ceils were identified using anti-human keratin antibody.The third to fifth generation of human RPE cells were used in the experiment.One target site of HIF-1α mRNA was chosen by certain design principle,and shRNA was designed and synthesized by the target site and transferred into the cells in vitro,and then the cells were cultivated with 50 μg/L IGF-1 for 24 hours.The mRNA and protein expressions of HIF-1α and VEGF were detected by RT-PCR and Western blot respectively. Results Cultured human RPE cells showed the flat irregularly multangular shape,and 97％cells appeared the positive response for keratin.HIF-1α mRNA expression in human RPE cells was significantly lower in 50 μg/L IGF-1 group than the 0 pg/L IGF-1 group ( 1.49±0.18 vs 1.46±0.17 ) ( t =0.335,P =0.743 ),however,the expressing levels of HIF-1α protein( 1049.86±172.54 vs 0.00±0.00) and VEGF mRNA(0.95±0.15 vs 0.35±0.07) and VEGF protein (391.98±56.77 vs 214.36±37.15)were raised in the 50 μg/L IGF-I group compared with 0 μg/L IGF-1 group (t=16.098,9.935,6.928,P＜0.05).After the HIF-1α-specific shRNA was transferred into cultured RPE cells,the expressions of both HIF-1α mRNA and its protein significantly decreased in RPE cells under 50 μg/L IGF-1 concentration condition( F=68.679,89.904,P=0.000),moreover,the expression of VEGF mRNA and its protein were significantly lowed(F=21.770,6.205,P＜0.05). ConclusionsIGF-1 promotes the accumulation of HIF-1α protein and induce the expression of VEGF in human RPE cells,which probably play a pivotal role in the development of PVD.

Objective To analyze the status of quality indicators(QI) on specimen acceptability and establish preliminary qual ity specification.Methods Web based External Quality Assessment system was used to collect data of laboratories partici pated in "Medical quality control indicators in clinical laboratory" from 2015 to 2017,including once in 2015 and 2017 and twice in 2016.Rate and sigma scales were used to evaluate incorrect sample type,incorrect sample container,incorrect fill level and anticoagulant sample clotted.The 25th percentile (P25) and 75th percentile (P75) of the distribution of each QI were employed to establish the high,medium and low specification.Results 5 346,7 593,5 950 and 6 874 laboratories sub mitted the survey results respectively.The P50 of biochemistry (except incorrect fill level),immunology and microbiology reach to 6σ.The P50 of clinical laboratory is 4 to 6σ except for incorrect sample container.There is no significant change of the continuous survey results.Based on results in 2017 to establish the quality specification,the P25 and P75 of the four QIs is 0 and 0.084 4 ％,0 and 0.047 6 ％,0 and 0.114 2 ％,0 and 0.078 4 ％,respectively.Conclusion According to the results of the survey,most laboratories had a faire performance in biochemistry,immunology and microbiology,and clinical laboratory needs to be strengthened.Laboratories should strengthen the laboratory information system construction to ensure the actual and reliable data collection,and make a long time monitoring to achieve a better quality.