OBJECTIVETo clone and identify MF-1 gene which responded to extremely low frequency magnetic fields(ELF MF) in Daudi cells, and explore the response universality of MF-1 gene in several MF-sensitive cell lines, so as to provide experimental basis for revealing the mechanism of biological effects induced by magnetic field.

METHODSThe DNA fragment of MF-1 was cloned and sequenced; the mRNA level of MF-1 gene were analysed in MF-sensitive cell lines(HL-60, L1210 and CHL) by Northern blot after these cells being treated with 0.1 mT and 0.8 mT MF for 20 minutes and 24 hours, respectively.

RESULTSThe MF-1 cDNA sequence had 100% homology with cytochrome oxidase subunit 1 gene(CO1) by searching Gene Bank database; the transcription of CO1 in HL-60, L1210 and CHL cell lines which exposed to 0.1 mT and 0.8 mT MF for 20 minutes were significantly lower(0.38 +/- 0.12 and 0.37 +/- 0.04) than that of control(0.58 +/- 0.12) and so did for 24 hours exposure(0.46 +/- 0.09 and 0.45 +/- 0.09 vs 0.65 +/- 0.06) (P < 0.05).

CONCLUSIONCO1 is a MF-responsive gene. Cytochrome oxidase activity may be affected through low level of CO1 transcription by magnetic fields, thus induce bioeffects in organisms.

Animals ; Cricetinae ; Electron Transport Complex IV ; genetics ; metabolism ; radiation effects ; HL-60 Cells ; Humans ; Leukemia L1210 ; Magnetics ; Mice ; Protein Subunits ; RNA, Messenger ; analysis ; Transcription, Genetic ; radiation effects

Objective To investigate the prevalence of nonalcoholic fatty liver disease (NAFLD) and understand the relationship between NAFLD and metabolic risk factors in middle-aged and elderly adults.Methods This cross-sectional study recruited 2 935 subjects in Guangzhou,Guangdong province.Face-to-face interviews and laboratory analyses were conducted to collect general information and other covariates.Analysis of covariance and logistic regression analysis were performed to investigate the relationship between metabolic factors and the prevalence of NAFLD.NAFLD was diagnosed based on standard criteria recommend by the Fatty Liver Disease and Alcoholic Liver Disease Branch of Chinese Hepatology Society,and the degree of steatosis was assessed (mild,moderate or severe).Results Compared with normal subjects,those with NAFLD had higher levels of WC,BMI,FPG,TG,SBP,DBP and greater prevalence of metabolic syndrome,but lower levels of physical activity and HDL-C.After adjusted for covariates,the OR for each standard deviation change was 2.70(95％CI:2.45-2.98) for WC,1.47(95％ CI:1.35-1.59) for SBP,1.48 (95％CI:1.37-1.60) for DBP,1.88 (95％CI:1.66-2.12) for TG,1.25 (95％ CI:1.15-1.36) for FPG and 0.51 (95％CI:0.47-0.56) for HDL-C (all P＜0.001).Higher levels of WC,BMI,TG,SBP,DBP and FPG were significantly related with the increase in degree of NAFLD (P-trend＜0.001).Conclusion There is a relatively high prevalence of NAFLD in middle-aged and elderly adults in China.NAFLD is closely related with the different forms of metabolic syndrome,and WC is the leading risk factor for NAFLD.