Objective To compare the biomechanical difference of two internal fixation approaches for the posterior pelvic ring fracture dislocation.Methods Six fresh adult cadaver pelvic specimens were tested biomechanically.Then,the specimens were subjected to Denis-I sacral pelvic fracture.The specimen was first fixed with improved Galveston fixation and then with improved Galveston fixation plus sacral rod.Biomechanical tests were performed from vertical and reversed directions on the fixed pelvis.Results Under vertical compression,the biomeehanical value of the improved Galveston fixation plus sacral rod was lower than that of the improved Galveston fixation,with no statistical difference between two methods(P ＞ 0.05).Under the reversed compression,the biomeehanieal value of the improved Galveston fixation plus sacral rod was lower than that of the improved Galveston fixation,with statistical difference between two groups(P ＜ 0.05).Conclusion The improved Galveston fixation combined with sacral rod can increase the anti-reverse stability of the posterior pelvic ring.

Objective An effective reproducible protocol for complete plant regeneration via somatic embryogenesis has beendeveloped for Herpetospermum pedunculosum,an endangered Tibetan medicinal herb.Methods The cotyledonexplants used in this study were excised from seedlings germinated in vitro.Callus was induced from cotyledonexplants on Murashige and Skoog's medium,supplemented with 2,4-dichlorophenoxyacetic acid(2,4-D,0.1-1.0mg/L)alone or in combination with 6-benzylaminopurine(BA,0.5,1.0,and 2.0 mg/L).Results The calli showeddifferentiation of globular embryos after three weeks of incubation on MS medium supplemented with variouscombinations of BA and NAA.Sixty-two percent of the embryogenic calli produced somatic embryos in MS basalmedium supplemented with BA(1.0 mg/L)+NAA(2.0 mg/L).The addition of KN(0.5 mg/L)to MS mediumcontaining both BA and NAA(2.0 mg/L each)significantly increased the frequency of somatic embryogenesis.Themaximum percentage of embryogenic calli formation was 83%,and globular embryos formed and germinatedsuccessfully in this medium.Then,transferring the regenerated plants from this medium to hormone-free MSmedium will further enhanced the development of the plants,and the healthy plantlets are formed successfullywithin four weeks.The plantlets were transferred to soil to acclimatize under greenhouse conditions and 75%survived.Conclusion Somatic embryogenesis protocol as reported here can play a key role in the propagation andconservation of this endangered species.

Objective To explore the feasibility of mechanical chest compression to establish a rat model of car?diopulmonary resuscitation ( CPR) . Methods 4?month old healthy male Sprague Dawley rats were randomly divided into control group ( n=6 ) and model group ( n=10 ) . After induction of anaesthesia with 10% chloraldurate ( 3 ml/kg, i. p. ) , tracheal intubation and left femoral artery cannulation were performed. Under electrocardiographic and artery blood pressure monitoring, tracheal obstruction ( TO) was performed to rats in model group. At 2 min after the cardiac arrest ( CA) occurred, CPRs were administered to the rats using a self?made animal chest compressor, which provided chest?com?pression at a rate of 200 bpm. Results Shortly after TO, rats in the model group had respiratory arrest, cyanosis and ar?rhythmia. Electrocardiography indicated that CA occurred within 4-5 min, with a decreased artery systolic blood pressure ( <40 mmHg) and a zero pulse pressure. Return of spontaneous circulation ( ROSC) after the CPR was successfully a?chieved in 8 rats (80%), with a transient reperfusion arrhythmia. Finally, 60% of the rats (n=6) recovered to con?sciousness and survived for 24 hrs. The serum biochemical analysis indicated that there were electrolyte disturbances, aci?dosis, impaired renal functions and increased myocardial enzyme spectrum. Pathological examination revealed cardiac rhab? domyolysis, no?reflow phenomenon in renal glomeruli, decrease of neurons and pulmonary congestion in the model group rats. Conclusions Mechanical chest compression can provide minimal cardiac output for the requirement of CPR incardiac arrestin rats. It is feasible to establish rat CPR model with the mechanical chest compression.

Nearly a quarter of the world's population is infected with Mycobacterium tuberculosis and remains long-term asymptomatic infection. Rv2626c is a latent infection-related protein regulated by DosR of M. tuberculosis. In this study, the Rv2626c protein was prokaryotically expressed and purified, and its immunobiological characteristics were analyzed using RAW264.7 cells and mice as infection models. SDS-PAGE and Western blotting analysis showed that the Rv2626c-His fusion protein was mainly expressed in soluble form and specifically reacted with the rabbit anti-H37RV polyclonal serum. In addition, we found that the Rv2626c protein bound to the surface of RAW264.7 macrophages and up-regulated the production of NO. Moreover, the Rv2626c protein significantly induced the production of pro-inflammatory cytokines IFN-γ, TNF-α, IL-6 and MCP-1, and induced strong Th1-tendency immune response. These results may help to reveal the pathogenic mechanism of M. tuberculosis and facilitate the development of new tuberculosis vaccine.
Animals ; Mice ; Rabbits ; Mycobacterium tuberculosis/genetics* ; Tuberculosis ; Antigens, Bacterial ; Cytokines ; Immunity, Cellular