Objective:To investigate the effect of sesamin on mast cell activation and its inflammatory mediator release,as well as its possible mechanisms of action.Methods:HCM-1 cells were activation by stimulation with 10 μg/ml anti-DNP IgE for 6 h and challenge with 100 ng/ml DNP-HAS for 10 min.Sesamin was administration at the concentration of 25,50 and 100 μg/L prior to DNP-HAS challenge,subsequently the effect of sesamin on mast cell degranulation was investigated by light microscope,and histamine release and expression of cytokines such as TNF-α IL-6,IL-1β,IL-8 of mast cells after sesamin treatment were investigated by ELISA.Western blot was used to determine the effect of sesamin on FcεRI downstream signaling including Lyn,Syk and PKCα activation,and IκBα phosphorylation and NF-κB activation.Results:DNP-HAS significantly increased mast cell degranulation,histamine release and those cytokines expression,enhanced Lyn,Syk,PKCα,IκBα phosphorylation and NF-κB activation(P<0.05). Sesamin(50,100 μg/L) significantly decreased mast cell degranulation,histamine release and cytokines expression (TNF-α,IL-4,IL-1β,and IL-8),reduced activity of Lyn,Syk,kinases and PKCα and IκBα phosphorylation,and inhibited NF-κB activation(P<0.05).Conclusion: Sesamin suppresses mast cell activation and inflammatory mediators release through inhibition of PKCα/NF-κB signaling pathway.

OBJECTIVE: To analyze the correlation between occupational stress and hypertension in steel production workers.METHODS: By the stratified cluster sampling method,1 580 steel production workers from an iron and steel group company were selected as study subjects. Occupational stress was measured by the Chinese version of Job Content Questionnaire.The identification of having occupational stress was the ratio of job requirement dimension score over job self-decision dimension score turned to be ≥1. 00. The steel production workers' blood pressure was measured by the updated mercury sphygmomanometer. The effect of occupational stress on blood pressure in steel production workers was analyzed. RESULTS: The dimension score of job self-decision in hypertension group was lower than that in non-hypertension group [20( 16,23) vs 20( 17,24) scores,P < 0. 05]. There was no statistical significant difference in occupational stress ratio,job requirement and social support dimension scores between two groups( P > 0. 05). The multiple logistic regression analysis showed that job self-decision and social support scores were negatively correlated with the incidence of hypertension [odds ratios( 95% confidence intervals) were 0. 68( 0. 51,0. 90) and 0. 54( 0. 45,0. 76),P < 0. 01]. CONCLUSION: Job selfdecision and social support are the influencing factors of the incidence of hypertension in steel production workers. The correlation among occupational stress,job requirement and hypertension are not found in steel production workers.