Purpose To study the reversal effect on multidrug resistance (MDR) by TNF-α gene combined with verapamil (VRP) or tamoxifen (TAM). Methods By using recombinant retrovirus vector, TNF-α gene was transfected into multidrug-resistant human breast cancer cell line MCF7/ADR. The TNF-α secreting cell clone MCF7/ADR-TNF was obtained by G418 screening. The integrating and secreting of TNF-α were analyzed by PCR and ELISA. MTT assay and formula"I = d/D1 + d/D2" were used to evaluate the reversal effect of multidmg resistance with TNF-α gene combined with verapamil or tamoxifen. ResultsThe level of TNF-α secreted by MCF7/ADR-TNF was 1 737 pg/ml (106cells/48 h). Compared with control,the resistance to ADR of MCF7/ADR-TNF was reversed by 1.6 times. The reversal effect produced by combination of TNF-α gene and VRP was antagonistic. The combination of TNF-α gene and TAM produced synergic effect (interaction index I = 0.64). ConclusionsTNF-α gene combined with TAM has synergic effect on reversing MDR.

Objective To investigate the association of prevalence of periodontitis with metabolic syndrome (MS). Methods Data were analyzed from 1 650 Uygur rural residents in Moyu County. The subjects, aged over 18 years, were sampled randomly from 15 villages out of total 364 villages. Questionnaire, oral examination, and blood biochemical indicators were collected. The subjects were divided into groups with and without periodontitis based on chronic periodontitis diagnostic criteria, and the group with periodontitis was further divided into subgroups, each with mild, moderate, and severe periodontitis respectively. The diagnosis of MS was madeaccording to the definition of the International Diabetes Federation in 2005. Results Among 1 415 subjects whosedata were complete, there were 275 ( 19.4% ) subjects with MS and 934 (66.0%) subjects with periodontitis. The prevalence of MS was higher in the group with periodontitis than that without perionontitis (23.1% vs 12.3%, x2=23.9, P<0. 001 ). The prevalence of MS was increased with the grade of periodontitis, being 19.8%, 20.8%,27.6% in the mild, moderate, and severe periodontitis groups, respectively(x2= 31.9, P<0. 001 ). Multiple logistic regression analysis showed that the risk of MS increased with the grade of periodontitis, with OR 1. 6, 1.7,1.9, respectively, in the groups with mild, moderate, and severe periodontitis compared with that without perionontitis ( P<0.05 or P<0.01 ). Conclusions The prevalence of MS was related to periodontitis in the Uygur nationality and increased with the grade of periodontitis.