Objective To study the effect of lung cancer prevention in Baoji city, one of the cities with high lung cancer morbidity in China. Methods To investigate the mortality of lung cancer from 1992 to 1996 in Baoji and compare it with the data of Baoji in 1970s and the current data in whole China. Information of lung cancer pa- tients was collected from the Malignant Tunout Monitoring Station in Baoji. To investigate by sampling survey the status of smoking of Baoji population based on the principle of clustering random sampling. Information about air pollution in 1980s and 1990s was obtained from the Environmental Monitoring Station in Baoji. ResultsComparing with 1970s, the crude mortality rates of lung cancer in Baoji in 1992～ 1996 increased both in males and females,but the range was narrower than that in whole China. Ajusted mortality rates of lung cancer didn＇t change in females but decreased in males. However, either crude or adjusted mortality rate was lower than the average level of the whole country. The status of air pollution has been improved dramatically since the early 1980s in Baoji. So far, except to- tal suspended particles (TSP), NOx and SO2 levels have reached the Criteria of Air Quality of China. But the smoking rate was still higher. ConclusionThe prevention of lung cancer in Baoji is effective, but the role of measures needs further study. Baoji should not be considered as a city with high lung cancer morbidity in our country at present.

Thimerosal has been widely used as a preservative in drug and vaccine products for decades.Due to the strong propensity to modify thiols in proteins,conformational changes could occur due to covalent bond formation between ethylmercury(a degradant of thimerosal)and thiols.Such a conformational change could lead to partial or even complete loss of desirable protein function.This study aims to investigate the effects of thimerosal on the capsid stability and antigenicity of recombinant human papillomavirus(HPV)18 virus-like particles(VLPs).Dramatic destabilization of the recombinant viral capsid upon thimerosal treatment was observed.Such a negative effect on the thermal stability of VLPs preserved with thimerosal was shown to be dependent on the thimerosal concentration.Two highly neutralizing antibodies,13H12 and 3C3,were found to be the most sensitive to thimerosal treatment.The kinetics of antigenicity loss,when monitored with 13H12 or 3C3 as probes,yielded two distinctly different sets of kinetic parameters,while the data from both monoclonal antibodies(mAbs)followed a biphasic expo-nential decay model.The potential effect of thimerosal on protein function,particularly for thiol-containing proteinaceous active components,needs to be comprehensively characterized during formulation development when a preservative is necessary.