Objective The aim of this study was to investigate the masculinizing effects of progesterone ( PRO) exposure at different concentrations on the morphology of female mosquitofish (Gambusia affinis).Methods Immature female G.affinis individuals were put into static water with 0.5, 5, 50 and 500 nmol/L progesterone (n=56), respective-ly.In addition, control group and parallel groups were set up .After 42-day-long exposure, we measured four main indexes of the G.affinis:the body length, body weight, morphological changes in the anal fin 3rd fin and the 14, 15 and 16 verte-bral ribs.We also observed the state of ovarian development .Results The body lengths (BL) of experimental groups ex-posed at concentration of 50 and 500 nmol/L progesterone for 42 d showed significant differences , respectively ( P<0.01 for both), when compared with those of the control group .The body weights (BW) of experimental groups exposed to pro-gesterone at all concentrations were significantly or very significantly decreased (P<0.05 or P<0.01).Only the proges-terone at 5 nmol/L concentration showed significant effect on the body health index (CF) (P<0.05).The section number (FJ) of the anal fin 3rd fin, the section length (FL)and the widest portion width (FW)in the experimental groups had sig-nificant difference (P<0.05), respectively, showing significant changes in morphology after the exposure to 500 nmol/L progesterone .However , there was no significant difference between the values resulted by progesterone in other concentra -tions (P>0.05).When exposed to 500 nmol/L PRO, the L, D and L:D values of the 14th, 15th and 16th vertebral ribs of the female G.affinis had very significant difference ( P<0.01 for all ) , respectively , indicating significant changes of morphological masculinization .Histological examination revealed that the developmental status of the ovaries of G.affinis in the experimental groups were to different degrees inhibited , and the nuclei appeared swelling in stage II and III oocytes . Conclusions The results of this study indicate apparent masculinizing effects of progesterone on immature female mosquit -ofish.

Objective To study the epidemic situation and associated risk factors of hypertension among the empty-nest elderly in Shangha of community. Methods Using pure random sampling method, a face-to-face questionnaire survey and the blood pressure measuring of the empty-nest elderly aged 60-year-old or above in the two communities of Shanggang were performed by trained investigators. Results There are 634 empty-nest elderlies in the two communities. The prevalence rate of hypertension was 51.7% in the subjects. The associated risk factors of hypertension among the empty-nest elderly include smoking, drinking, excess salt diet, lacking of sports and family history of hypertension. There was significant difference between the groups of hypertension and non-hypertension in the distribution of keeping healthy behaviors. The rate of awareness, management and control were 62. 8% ,49. 2%, and 28.7% respectively in the hypertension subjects. Conclusion The prevalence rate of hypertension among the empty-nest elderly is high, Public health education programs, multiple prevention and intervention measures of hypertension should be strengthened among the empty-nest elderly.