Objective: To investigate the effect of the gene interfering technology on fatty acid synthase (FAS) gene silencing for lipid contents in human hepatic cell line HepG2 and to study the lipid metabolism related gene expression in HepG2 cells. Methods: A total of 3 pairs of small interfering RNA (siRNA) targeting different sequences of FAS mRNA were synthesized as FAS-siRNA-1, FAS-siRNA-2 and FAS-siRNA-3, meanwhile, 2 controls were established as Blank control group, in which HepG2 cells were not treated, and Negative control group, in which HepG2 cells were transfected by non-effective siRNA. The mRNA, and protein expression levels of FAS in HepG2 cells were examined by real-time lfuorescence quantitative RCR and Western blot analysis to screen the most effective pair of siRNA for FAS gene silencing; and that speciifc siRNA was transtected to HepG2 cells for 48 hours to detect the intra-/extra-cellular TG, TC levels and the mRNA expression related to lipid metabolism in HepG2 cells. Results: The screening experiment indicated that FAS-siRNA-3 was most effective for FAS gene silencing. Compared with Blank control group, the mRNA and protein expressions in FAS-siRNA-3 transfected HepG2 cells (Transfected group)decreased to (52.33 ± 3.07) % and (51.57 ± 3.14) % respectively. Compared with Blank control group, Transfected group had the reduced intra-/extra-cellular TG levels and reduced extracellular TC level; while increased mRNA expression of hepatic lipase,P<0.0001 and decreased mRNA expression of TG transfer protein in HepG2 microsome,P<0.05. Conclusion: FAS gene silencing could signiifcantly decrease the intra-/extra- cellular TG level and extracellular TC level in HepG2 cells, those ifndings need to be conifrmed by furtherin vivo andin vitro studies.

Objective To evaluate the Mandarin tracking of noise tolerance(TNT)test material and compare the differences between the average tolerable noise level(aTNL)value obtained from assessment and the program-estimated tolerable noise level(eTNL).Methods A total of 25 subjects with normal hearing and aural communica-tional ability were selected to undergo two of the mandarin TNT tests successively(respectively test 1,C1;test 2,C2),and 13 of them completed the third test(C3)under the same test condition as test 2 at least 1 week later.The stimulus for the three test conditions was presented with"speech 0°,continuous noise 180°".Results The aTNL of 25 participants for C1 and C2 was 83.42±3.09 dB SPL and 83.50±3.18 dB SPL,respectively.The eTNL of 25 participants for C1 and C2 were 84.08±3.53 dB SPL and 83.95±3.85 dB SPL,respectively.The aTNL and eT-NL for 13 subjects who participated in C3 was 83.16±2.13 dB SPL and 83.18±2.64 dB SPL,respectively.The intra-session(C1 vs C2)and inter-session(C2 vs C3)test-retest reliability were 2.36 dB and 2.75 dB,respectively.Pearson correlation analysis showed that intra-session(r=0.837,P＜0.001)and inter-session(r=0.867,P＜0.001)test-retest reliability was good.There was no statistical difference between aTNL and eTNL in the other TNT tests(P＞0.05 for both)except that aTNL and eTNL were statistically different in C1(P＜0.01),and more than 90％of the subjects could obtain eTNL within 1 minute.Conclusion The test-retest reliability of Mandarin tracking of noise tolerance test is good,with advantages of high reliability and efficiency.

Objective To develop and evaluate the equivalence of the Mandarin test material for tracking of noise tolerance(TNT)test.Methods Six different speech materials were developed(themes including daily life,entertainment,family,festivals,outdoors,and school).Four-minute TNT tests were measured in 21 normal hear-ing subjects using six different test materials.For each session,the tolerable noise level(TNL)and TNT scores were acquired and calculated for 3 time windows(31～240 s,31～120 s,151～240 s).Results Statistic analysis showed significant differences in the TNL(F=43.611,P＜0.05)among the normal hearing listeners.There were statistically significant differences in standardize z-scored TNT scores of the six different materials in the three time windows(P＜0.05).Post-hoc comparisons revealed that all significant differences involved the family and daily life themes.Conclusion Entertainment,festival,outdoors and school themed test materials can serve as the materials of Mandarin tracking of noise tolerance test and can be appied in research and clinical testing.