ABSTRACT
Objective To investigate the influence of external electric fields on migration behavior and morphology of endo‐thelial progenitor cells (EPCs) cultured in vitro .Methods The in vitro cultured 3-4 generation EPCs were continuously stimula‐ted by direct‐current electric field with the field intensity of 0 mV/mm(group Ⅰ ) ,100 mV/mm(group Ⅱ) ,200 mV/mm(group Ⅲ) and 300 mV/mm (group Ⅳ )for 3 h .The live cell station was used to real time record the cell migration track and morphology change of EPCs .The influence of external electric field on the EPCs migration behavior and morphology was analyzed .Results Un‐der the stimulation of the direct‐current electric field with the intensity of group Ⅳ ,group Ⅲ and group Ⅱ ,the cells were directly migrated to anode ,while the cells under group Ⅰ displayed the random motion .The track migration velocity(Vt)、displacemnt ve‐locity(Vd) and electric field direction migration rate(Vx) were(98 .86 ± 6 .00) ,(63 .78 ± 2 .81) ,(63 .15 ± 2 .88)μm/h for the groupⅣ ,(88 .06 ± 8 .83) ,(35 .90 ± 1 .22) ,(34 .20 ± 1 .57)μm/h for the groupⅢ ,(42 .28 ± 2 .25) ,(13 .29 ± 0 .37) ,(12 .39 ± 0 .51)μm/h for the groupⅡ ,which were significantly higher than(37 .39 ± 2 .42) ,(6 .99 ± 0 .31) ,(4 .62 ± 0 .40)μm/h for the groupⅠ (P<0 .01) ,moreover Vt ,Vd and Vx in the group Ⅲ were significantly higher than those in the group Ⅱ andⅠ (P<0 .01) .EPCs had obvious morphological changes under the electric field action ,such as elongation and the cellular long axis parallel to the electric field direction .Conclusion External direct current electric fields may induce the directed migration of EPCs towards the anode ,ac‐celerates the migration rate ,moreover has obvious influence on EPCs morphology .
ABSTRACT
<p><b>OBJECTIVE</b>To evaluate the effects of health promotion for eight years on cardiovascular diseases based on the changes in knowledge (K), attitude (A) and behavior (B) (KAB) before and after intervention in rural population of Fangshan, Beijing.</p><p><b>METHODS</b>Five townships in Fangshan District, Beijing were divided into intervention and control communities with cluster sampling. Totally 772 farmers were selected randomly for interviews with a questionnaire of KAB, including 424 in the intervention communities (IC) and 348 in the control communities (CC) in 1992. After community-based health promotion and education on cardiovascular prevention for eight years, 895 farmers, including 431 in IC and 464 in CC, were selected randomly again in 1999 to be interviewed with the same questionnaire of KAB used in 1992.</p><p><b>RESULTS</b>From 1992 to 1999, knowledge of cardiovascular diseases was significantly improved in residents of IC (P < 0.01) and CC. Compared to the residents in CC, there was a net increase in knowledge in residents of IC. Significant improvement was found in 10 and 11 of the 18 items of knowledge in males and females (P < 0.01), respectively. Level of knowledge in cardiovascular diseases was significantly higher in the residents of IC than those of CC in 1999. Proportions of those with positive attitudes and appropriate behaviors were significantly elevated in the residents of IC (P < 0.01), as well as prevalence of smoking and alcohol drinking decreased. However, as compared to CC, attitude and behavior in most aspects in the residents of IC changed positively, but in few aspects changed negatively. It suggested knowledge improved better than attitude and behavior changed.</p><p><b>CONCLUSIONS</b>Community-based health promotion and education for a longer term had obvious effects on improvement of knowledge in cardiovascular disease for rural population, but slower effects on changes in attitude and behavior, which suggested there still existed certain barriers to transform knowledge into healthy behavior.</p>