Deer antlers are the unique mammalian organs that can be periodically regenerated,i.e.,they hold interest for researchers on stem cells and regenerative medicine,and have the potential to become an excellent biomedical research model.Deer antler regeneration may use stem cells.Antler growth appears to involve specific stimulation of the necessary stem cells present in the locality,and involves similar mechanisms to those used in limb development,unlike the regenerative process in the newt.Development regulation of antler and growth mechanism of antler stem cells have significance in limb regenerated medicine and stem cell research.Many scientists have carried out thorough research on the deer antlers development,thus,have drawn many concepts.This article reviews the field of deer antlers development such as antler regeneration and stem cells,and introduces research technique of antler development and relevant theories.

Objective To observe the vaccination reactions and immunogenicity of the application of lyophilized Vero cell rabies vaccine without adjuvant in a way of low-dose intradermal injection for post-exposure group. Methods Conducting post-exposure immunization for 256 persons with the class Ⅱ level exposure to rabies. Based on a randomized, single-blind principle, all subjects were divided into intradermal injection (ID) group (n= 128),injected 0.1 ml for each site in accordance with 0,3,7,28,90 d,2 sites,2 sites,2sites,1 site,1 site respectively, and intramuscular injection(IM) group(n= 128) in accordance with 0,3,7,14,28 d in full-volume (0.5ml) PVRV Deltoid injection. The local and systemic vaccination reactions were observed for the different injection ways. The indirect sandwich ELISA assay was used to analyze the antibody levels. Results For the intradermal injection group, the incidence rates for local redness and swelling, induration, pain, itch were 1.27%, 0.29% ,0.49% ,11.43% respectively,for the intramuscular group, the incidence rates were 1.09% ,0. 16% ,2. 81% ,1.41% respectively. From the point of systemic reactions,the incidence rates of fever,rash,headache,fatigue and weakness were 0.31 % ,0. 16% ,0. 31 % , 1.09% respectively in the intradermal injection group,and the rates were 0.31% ,0.31% ,0.63% , 1.09% respectively in intramuscular group. All the adverse effects often occurred following the 1st,2nd injection. The seroconversion rates for intradermal injection and intramuscular were 94.53% ,95.31% following 14 d immunization respectively,the rates were 96. 83% ,97.64% following 42 d immunization respectively. For the post-exposure group,no statistical difference in significance was found between the two seroconversion rates. Conclusion For the application of domestic lyophilized Vero cell rabies vaccine,its adverse reactions are mild,and immunogenicity is good.