Objective To analyze the efficacy of a second dose of measles-mumps-rubella (MMR) vaccine in children aged 6 to 7 years in Xicheng District, Beijing, China in 2016.Methods Serum samples were collected in duplicate from 41 children aged 6 to 7 years before and one month after immunization with a second dose of MMR vaccine.ELISA was performed to detect IgG antibodies against measles, rubella and mumps in serum samples.Results The positive rates of antibodies against measles, rubella and mumps in the 41 children before immunization with a second dose of MMR vaccine were 95.12%, 90.24% and 92.68% and the antibody titers were (825.88±499.91), (53.83±32.48) and (697.83±535.82) IU/ml, respectively.The positive rates of the three antibodies were 100%, 97.56% and 100% after revaccination with MMR vaccine and the antibody titers were (1 102.98±356.77), (95.08±26.88) and (3 383.85±1 903.06) IU/ml.Titers of antibodies against measles, rubella and mumps increased significantly following revaccination (P<0.05), while no significant difference in the positive rates of the antibodies was observed before and after revaccination (P>0.05).Conclusion The second dose immunization of MMR vaccine achieves a high successful rate in children in Xicheng District of Beijing.It would be an effective immunization strategy to protect children from measles, rubella and mumps.

The finite element method(FEM)is a numerical computation method based on computer tech-nology, and has been gradually applied in the fields of medicine and biomechanics. The finite element analysis can be used to explore the loading process and injury mechanism of human body in traffic in-jury. FEM is also helpful for the forensic investigation in traffic injury. This paper reviews the develop-ment of the finite element models and analysis of brain, cervical spine, chest and abdomen, pelvis, limbs at home and aboard in traffic injury in recent years.

A comparative study on the cellular survival of grafts and the behavior improvement in the rats was performed following tissue transplantation of either fresh or freezing-stored adrenal medulla. The fresh or freezing-stored adrenal medullary tissues were transplanted into the head of caudate nucleus in the animal models with unilateral 6-hydroxydopamine lesions of the substantia nigra. Experimental groups got some improvement after operation in rotation behavior induced by apomorphine, and the differences were significant between experimental and control groups. Among the transplanted rats, those received fresh tissue seemed to show more improvement than those received freezing-stored tissue, but the statistical difference was not significant. With regard to fluorescent intensity of the adrenal cells, it showed to be stronger in the experimental group received fresh graft than the group received freezing-stored graft, but the difference was no statistically significant either. No essential difference could be found between experimental groups as to the cellular apperance and staining features in the grafts.

Objective To develop rat models of graft cholangiopathies and evaluated their values.Methods Four groups were constructed.The long-term cold preservation group(n=24) contained homogeneic inbred rat liver orthotopic transplantations (ROLT) performed in a rat combination of ♂ Wistar→ ♂ Wistar with the donor liver preserved in 4℃ UW for 12 h,the vessels reconstructed by the two-cuff method,and the hepatic artery and extrahepatic bile duct rebuilt by a stent.The chronic rejection group (n=24)(CsA 1 mg · kg-1 · d-1,cold preserved for 1 h) was allogeneic inbred ♂ DA→♂ Lewis rats induced for ROLT,and the revascularization methods were the same as the longterm cold preservation group.The control group (n=24) (cold preserved for 1 h) was homogeneic inbred ♂ Wistar→♂ Wistar rats with ROLT techniques the same as above.The sham group (n=24)was ♂ Wistar rats that had an exploratory laparotomy.The animals were followed for 16 weeks,complications were compared,and liver tissues were harvested.Histopathological and morphometric techniques were used to construct a time course of histological changes after liver transplantation.Results In both the long-term cold preservation group and chronic rejection group,the rats recovered slowly,the incidence of complications and mortality were higher than those of other groups,and the intrahepatic bile duct proliferation and immune cell infiltration were noticeable after the operation.In 16 weeks,the hepatic lobules were separated by the proliferating bile ducts,the normal structure of hepatic lobules disappeared,many biliary epithelial cells necrosed with disappearing cytoplasms,and there was immune cell infiltration and obliterative arteriopathy.Conclusions The rat models of graft cholangiopathies induced by long-term cold preservation or chronic rejection donor livers are stable and easily standardized.This model is ideal for studying the pathogenesis and prevention of graft cholangiopathies.

Objective To observe the effect of the chitosan tube combined with basic fibroblast growth factor(bFGF) on inducing nerve axon regeneration of rats with peripherial nerve injury.MethodsA novel chitosan tube combined with bFGF was developed and used to suture the 10 milimeter long right sciatic nerve gap of 10 rats,single injury group(10 rats) were the control with sciatic nerve injury alone,and other 10 rats were assigned to sham group.Immunohistochemistry and electrophysiology study had been done to observe the effect of repairing.Results3 months after operations,the sciatic nerve gap were repaired by the regeneration nerve in the experiment group.And there was no evident inflammation in the defects.ConclusionThe chitosan tube combined with bFGF can induce the sciatic nerve to regenerate.

Objective To explore the degeneration of motor end plates (MEP) by observing the expression of calcitonin gene-relative peptide (CGRP) and acetylcholine esterase (AChE) in the MEP after different types of spinal cord injury. Methods 60 adult female Wistar rats were randomly assigned to 3 groups: sham group, completely transection group and contusion group. The content of AChE in the MEP was detected with Karnovsky-Roots staining and the expression of CGRP was then determined with immunohistochemistry. Results The content of both AChE and CGRP significantly decreased after either type of spinal cord injury. However, their activity gradually recovered to the normal level in the contusion group, but not in the transection group. Moreover, the changes of CGRP occurred earlier than those of AChE. Conclusion The motor end plate degenerates differently after different kinds of spinal cord injury in adult rat, CGRP and AChE are related to the degeneration of MEP.

ObjectiveTo evaluate the biocompatibility of a kind of scaffolding material,Injured Nerve Regenerated Materid(INRM), which play the roles of regeneration of nerve after traumatic brain injury.MethodsINRM scaffolding material were transplanted into cortex of rats after traumatic injury.The brain coronal sections were stained for Nissel, astrocyte and microglia at 1 week, 1 month, and 2 months after injury.ResultsThe presence of INRM did not alter patterns of astrocyte compared with the control group (detected with antibodies against GFAP) at any time point; but decreased the expression of microglias (detected with antibodies against OX42) compared with the control group.ConclusionThe biomaterial INRM is well suited as a biocompatible scaffold material for the repair of brain injury in the brain.

Objective To explore the restoration of motor function and the expression of calcitonin gene-related peptide(CGRP)and acetylcholine esterase(AChE)in the anterior horn motoneurons after different types of spinal cord injury.Methods 60 adult female Wistar rats were randomly assigned to 3 groups:sham group,completely transection group and contusion group.Average combined scores(ACOS)were applied to assess the motor function at various time after the surgery.The content of AChE in the anterior horn of L2-L4 was detected with Karnovsky-Roots staining and the expression of CGRP was then determined with immunohistochemistry.Results The scores of ACOS were much higher in the contusion group than in the transection group at each time point examined.The content of both AChE and CGRP significantly decreased after either type of spinal cord injury.However,their activity gradually recovered to the normal level in the contusion group,but not in the transection group.Moreover,the changes of CGRP occurred earlier than those of AChE.Conclusion There is strong relationship between the motor function recovery and the functional state of anterior horn cells.CGRP or AChE may play an important role in the functional recovery of locomotion after spinal cord injury in rats.

ObjectiveTo explore the possibility of repairing sciatic nerve gap of rats with artifical nerve graft.MethodsA novel artifical nerve guide was developed and used to suture the 15 milimeter long right sciatic nerve gap of 10 rats, other 7 rats were the control with the right sciatic nerve gap alone.2 and 4 monthes after operation, immunohistochemistry, Osmium staining, Bodian staining,motor end plate staining,WGA-HRP stain tracing have been done to observe the effect of repairing.Results2 months after operations, the sciatic nerve gap were repaired by the regeneration nerve.There was not evident inflammation in the defects.ConclusionsThe artifical nerve graft can induce the nerve to regenerate.

BACKGROUND: Our previous findings indicate that inflammation-activated bone marrow mesenchymal stem cell conditioned medium (MSC-CM) contribute to repairing the structure and function of the small intestine after radiation-induced acute intestinal injury. However, it is unclear whether the repair effect can be achieved by regulating small intestinal stem cells. OBJECTIVE: To investigate the effects of inflammation-activated bone marrow MSC-CM on the small intestinal epithelial stem cells after acute radiation-induced intestinal injury and to further discuss the repairing mechanism. METHODS: Bone marrow mesenchymal stem cells of Sprague-Dawley rats were separated, cultured and identified. Then, the bone marrow mesenchymal stem cells were co-cultured with normal or radiation-induced IEC-6 cell lines in the Transwell system for 24 hours. Inflammation-activated bone marrow mesenchymal stem cells were cultured alone for 48 hours. Non-activated MSC-CM (MSC-CMNOR) and MSC-CM under radiation-induced inflammatory condition (MSC-CMIR) were collected. Adult Sprague-Dawley rats (provided by the Experimental Center of Sun Yat-Sen University North Campus) were randomly divided into four groups with 20 rats in each group: control group, radiation group, radiation+MSC-CMNOR group and radiation+MSC-CMIR group. The rats in the latter three groups were exposed to one-off 14 Gy whole abdominal radiation to make a rat model of acute radiation-induced small intestinal injury. Three-day continuous administration beginning within 4 hours after successful modeling was given via the tail vein and intraperitoneal implantation of Alzet micro-osmotic pumps: EMEM-F12 (200 μL/d) for the radiation group, MSC-CMNOR for radiation+MSC-CMNOR group and MSC-CMIR for radiation+MSC-CMIR group. There was 2 mL of concentrated conditioned medium in the pump which was released at a constant rate of 10 μL/h into the abdominal cavity after implantation. Intestinal samples were collected at 1, 3, 5, 7 days after radiation for immunochemistry staining, western blot and qRT-PCR detection. RESULTS AND CONCLUSION: (1) On the 3rd day after radiation, Lgr5 positive cells, which were actively proliferating on the base of crypts, became significantly reduced compared with the normal control group, and there was nearly no existing Lgr5 positive cells. However, after infusion of MSC-CMIR, Lgr5 positive intestinal stem cells were significantly increased compared with the radiation group, while in the radiation+MSCNOR group, there was no significant increase in Lgr5 positive intestinal stem cells. (2) On the 3rd day after radiation injury, Bmi1 positive intestinal stem cells were almost invisible. After infusion of MSC-CMIR, Bmi1 positive intestinal stem cells increased significantly, and it was observed not only in the +4 cell position but also in the common position used to be Lgr5 stem cells, indicating that Bmi1 stem cells could differentiate into Lgr5 positive cells to act its repairing effect. (3) Western blot and qRT-PCR further confirmed that the radiation+MSC-CMIR group was significantly higher on the Lgr5 expression level than the radiation group and the radiation+MSC-CMNOR group, and it returned to the normal level on the 7th day after the continuous high expression level. The repair effect of radiation+MSC-CMNOR group was weaker, and only on the 7th day, the expression level of Lgr5 was statistically different from the radiation group. To conclude, inflammation-activated bone marrow MSC-CM exert a protective effect on the small intestinal epithelial stem cells after acute radiation-induced intestinal injury