Objective :The study discussed the relationship between the cell differentiation and its func-tion differentiation of enamel organ durrng the development of enamel ,explained the meaning of shape andfunction of SA and RA in the mature enameloblasts. Methods:The rats were fixed with pouring hearts ,em-bed with Epon and GMA resin,made semi-thin slice ,stained with toluidine blue and histochemistry, thenwe observed the changes of histomorphology and the law of distribution of enamel. Results:The develop-memt of tooth germ of rat incisor could be divided into proliferation stage, difference stage and maturestage. Enameloblasts expressed special periodic changes in mature stage :SA legion and RA legion present-ed altermately. Histochemical study indicated that most of amelogenin stayed in enamel matrix and othersdiffused to dentin, dental tube and odontoblast layer. Conclusion: (1) The proliferation stage, differencestage and mature stage of tooth of development of enamel organ in rat were similar to the bud stage ,capstage and bell stage of human being. There was a relationship between the RA legion in mature enam-eloblast and mineral substance pouring into them. RA legion was presented because water and protein lost.)That amelogenin spread into dentin could promote the odontoblast differentiation and induce dentin calci-fication.

Objective: This paper studies the nutritional and vision health status of Tibetan migrant students and the differences between the local students in Lanzhou and them to provide a theoretical basis for nutrition intervention and vision protection for students. Methods: Cluster sampling method was used to select 2 434 students migrating from Gannan Tibetan Autonomous Prefecture to a boarding middle school, and 3 291 students from three middle schools in Qilihe District of Lanzhou from September to December 2020. All the students were administered physical and visual examination. Proportion of nutritional status, poor eyesight and myopia by gender and age groups between Tibetan migrant students and local students were analyzed. Results: The detection rate of overweight and obesity in Tibetan migrant boys(2.8%,5.7%) and girls(11.0%,8.3%) was lower than that of local students of the same sex(5.6%,8.3%;24.9%,20.9%) ( χ 2=12.17,7.21, P <0.05; χ 2=81.33,91.34, P <0.05); The detection rate of malnutrition in Tibetan migrant boys(9.9%) was higher than that in local boys(7.2%) ( χ 2=6.65, P <0.05). The detection rate of poor vision in Tibetan migrant boys was lower than that in local boys ( χ 2=3.93, P <0.05). The detection rate of myopia was significantly lower than that of local students ( χ 2=975.82, P <0.01). The detection rate of abnormal color vision in Tibetan migrant boys was higher than that in local boys ( χ 2=8.38, P <0.05). The detection rate of abnormal color vision in Tibetan migrant girls was lower than that in local girls ( χ 2=8.08, P <0.05). The detection rate of mild and moderate visual impairment was lower among Tibetan migrant boys than local boys ( χ 2=3.88, 8.32, P <0.05); the detection rate of mild, moderate and severe myopia was lower than local boys ( χ 2= 13.72 ,55.96, 338.50, P <0.05). The detection rate of mild, moderate and severe myopia was lower among Tibetan migrant girls than local girls ( χ 2=7.62, 37.79,424.00, P <0.05). Conclusion Tibetan migrant students was lower than that of local students. More attention should be paid to nutrition intake of Tibetan boys to prevent malnutrition. The detection rate of myopia in Tibetan migrant students is low,but the detection rate of severe poor vision among Tibetan students in the junior high school group is higher than that of local students, and attention should be paid to the visual health of Tibetan students in junior high school.