Objective To investigate the developmental feasibility of early human fetal testes (<3 months) using xenografting technique and to acquire an accessible donor derivation that is essential for studying human germ cell development. Methods Nine testes from 10-13 weeks aborted fetus were grafted under the back skin of 6 castrated nude mice. Grafts were collected at different time point according to the growth of the donor tissues and the health condition of the recipients. Morphological and histological analyses were performed for the observation of the development of grafted immature testicular tissues. Results The mass of grafts was increased from about 5-7mg to 84.1mg (the biggest). Six of 9 testes were to be in developing. Histological observations showed a significant expansion of seminiferous tubules from (44.26±3.14)μm to (77.69±7.47)μm. Cells dispersedly distributed in seminiferous cords at the time of grafting migrated towards the basal part of seminiferous epithelium. Some germ cells with spermatogonium-like characteristics located on the basement membrane. Sertoli cells were in stages from immature into matured with abundant cytoplasm which were orderly arranged around spermatogonia forming a niche-like structure. Conclusion Testes from early aborted human fetus grafted under the back skin of castrated nude mice showed further development and therefore could be used as an easier accessible donor tissues for the investigation of human spermatogenetic mechanism.

By means of literature review and comparative study, the paper studied the organization and policy system of emergency drug administration in the U.S. As found by the authors, that the U.S. has established a horizontal and vertical organizational structure system centering on the Department of Health and Human Services. This system covers a series of policy and legal regulations, such as the research and development, procurement, storage, emergency use, and clinical treatment of emergency medical products. In consideration of the experience of emergency drug administration in the U.S. and problems existing in China's current system in command and management, departmental coordination, resource allocation, and legal system construction of emergency drug, it is suggested that China should establish a core organization for emergency drug command and management, and improve relevant legal system. China also needs to focus on enhancing capabilities of local medical emergency rescue and information transmission, in order to establish a coordinated, well-organized, resource-sharing system of drug emergency administration in the country.