BACKGROUNDTo evaluate the reversal effect of high dose tamoxifen on multidrug resistance to EP regimen in patients with non-small cell lung cancer.

METHODSA total of 41 patients with NSCLC were studied, who were resistant to EP regimen and were proved to have P-gp protein overexpression. All patients were randomizedly divided into two arms. Reversal group (n=21) received oral tamoxifen 100?mg, 2 times everyday on D1-5, together with EP regimen. Control group (n=20) were only given EP regimen.

RESULTSIn reversal group, complete response occurred in 1 patient, and partial response in 5; disease remained stable in 11 patients, and tumor progression occurred in 4 patients. The response rate was 28.6%(6/21). In control group, no response occurred; 9 patients had stable diseases, and the other 11 progressed. There was a significant difference in response rate between the two groups (P=0.012?1). In reversal and control groups, the median survivals were 8.4 and 4.6 months respectively (P < 0.01), and 1-year survial rates were 38.1% and 35.0% respectively. Reversal of P-gp occurred in 7 cases of reversal group (33.3%),and none in control group (P= 0.005?2) . There was no significant difference in toxicities between the two groups (P > 0.05).

CONCLUSIONSHigh dose tamoxifen can remarkably downregulate the expression of P-gp and partially reverse the multidrug resistance to EP regimen for non-small cell lung cancer.

Objective: To investigate the situation of dental fluorosis and residents awareness of dental flourosis in rural area of Tianjin, providing the basis for control of dental fluorosis prevalence level and continuous supervise of dental fluorosis prevalence. Methods: The objectives were selected by stratified cluster sampling method. Health interview survey and oral examination were perfor med. Results : The prevalence of dental fluorosis was 5.2% in 3-5 years children group, 68.6% in 12-14 years youth group, 64.5% in 15 years youth group, and 68.2% in 35-74 years group. The prevalence of dental fluorosis in 12-14 years group was lower than that in 2005 (χ2=21.62, P < 0.001). The community index of dental fluorosis (CFI ) was 0.1 in 3-5 years children group, 1.48 in 12-15 years youth group, 1.85 in 35-74 years old group. 47.7% students knew nothing about dental fluorosis, and 54.2% adult dental fluorosis patients did not know they were suffering from dental fluorosis. 47.4% of the subjects knew the relationship between dental fluorosis and fluoride in drinking water, and 18.8% subjects considered dental fluorosis was related with tooth cleaning. Conclusion The prevalence of dental fluorosis in 12-14 years old students was lower than 12 years old at 2005, but the increase of prevalence of dental fluorosis in 3-5 years children indicates the intake of fluorosis should be more strictly controlled. The awareness of dental fluorosis in rural area residents is poor and oral health education about fluorosis should be enhanced.