Objective To assess boron intake through food and drinking water for the people living in the boron industrial area.Methods Workers from boron mining and processing plants were selected as the exposure group,the other workers from the area where was near to the boron industrial area were selected as the community control group and peoples from the area where was far from boron industrial area were selected as the background control group,all the subjects were healthy adult men,Jul.2003-Sep.2004.Total 24 h food and drinking water of the subjects were collected,the boron concentrations and daily boron intake were analyzed.Results Boron concentrations of drinking water for the workers from boron mining area,community control group and background control group were 2.05,0.86 and 0.05 mg/L respectively;the food boron concentrations of the three groups were 9.46,6.19 and 3.29 mg/kg(DW)respectively;and daily boron intake through food and water were 8.00,4.25 and 1.40 mg/d respectively.The workers drinking the water from the staff canteen well and having dinner in this canteen had 95.5-469 mg/d boron exposure through food and water with average of 219.0 mg/L which was much higher than that of the other people and even closed to the LOAEL(lowest observed adverse effect level)of animals.Conclusion The risk of boron exposure for workers from boron mining and processing area is much higher than that of the other people.

Objective To clone the cDNA encoding human HMGB1, express it in E. coli, and identify its biological activity. Methods Human HMGB1 cDNA was amplified by RT-PCR and cloned into vector pUC19. After sequence analysis, the cDNA was ligated into prokaryotic expression vector pQE-80L and induced by IPTG to express HMGB1. The protein was purified with Ni~(2+)-NTA chromatography and polymyxin B affinity column. To identify the function of purified protein, the product was co-cultured with THP1 cells. Results Recombinant expression plasmid pQE-80L/HMGB1 was constructed successfully. After purification, the protein purity reached 96%. The recombinant HMGB1 stimulated THP1 to secrete TNF-? . Conclusion The highly purified HMGB1 was obtained successfully, which showed biological activity. These results lay the foundation for further research on the function of human HMGB1.