Objective To establish and characterize human colorectal cancer orthotopic implantation model in nude mice.Methods Established the human colorectal cancer orthotopic implantation model by surgery,characterize its biological characteristics by immunohistochemistry.Results Human colorectal cancer orthotopic implantation model was established in nude mice successfully,the proliferating cell nuclear antigen and Survivin were overexpressed in the models which were simulated the characteristics of human colorectal cancer perfectly.Conclusion This human colorectal cancer orthotopic implantaion model will provide an excellent animal model for us to study the development and metastasis mechanism of human colorectal cancer.

Clinical practice is a key step that seven-year clinic student take to become doctors.Take the First Affiliated Hospital of Xi'an Jiaotong University as an example,in the medical practice of seven-year clinic students,there still exist some problems such as students' being unable to transform from probationers to doctors,not good at treating with interpersonal relationship in the department and having no perseverant practice attitude.So training before practice should be perfected and supervision should be strengthened to make the seven-year clinic students better.