Objective To study the effect of-1 site single nucleotide polymorphism(SNP) on CCNH gene promoter transcription activity.Methods PCR and site-directed mutagenesis technology were used to construct CCNH basic promoter and-1G mutate promoter.Dual-Luciferase Reporter assay system was used to detect the transcription activity of constructed promoter.Results In AD293 cells,the activity of-1G mutate type promoter was significantly lower than that of wild type-1T promoter(P

Objective To study different test positions on vestibular evoked myogenic potentials (VEMPs) in youth ,and to find a suitable position and provide a guidance for clinical practice .Methods Thirty normal young vol-unteers were tested by vestibular evoked myogenic potentials ,using three different positions :supine with the head held straight up(SHU),supine with the head held up and turned away from the test ear(SHT),sitting with the head turned away from the test(SIT) ,the derivation rate ,latency and amplitude were analyzed .Results The deri-vation rate of SHU ,SHT and SIT were 100% ,100% and 63 .3% ,respectively .The derivation rate ,p13 ,n23 la-tency and p13 n23 inter-latency between SHU and SIT ,and between SHT and SIT had statistical differences (P<0 .05) .No statistical significant differences were found in derivation rate ,p13 ,n23 latency and p13n23 inter-latency between SHU and SHT (P>0 .05) .The amplitude was significantly different among the three positions (P<0 .05) . No statistical significant difference were found in derivation rate ,p13 ,n23 latency ,p13 n23 inter -latency and am-plitude between men and women of the three positions (P> 0 .05) .Conclusion The derivation rate of SHT was 100% with maximum amplitude .SHT is the most recommended position for clinical test in youth .The derivation rate of SHU was 100% ,and no statistical significant difference were found in p13 ,n23 latency and p13n23 inter-la-tency between SHU and SHT (P>0 .05) .SHU can be used in clinical test .SIT is not recommended for using in clinical test .Gender does not affect VEM Ps test .

10.3969/j.issn.1008-9691.2013.03.011