To sum up the methods which can be used to prevent dislocation after total hip replacement.Recent original articles about the reasons of dislocation and methods which were used to treat or prevent dislocation were extensively reviewed,and retrospective and comprehensive analysis was performed.Dislocation after THA can be reduced by careful assessment of patients,selecting suitable prosthesis,improving the position of prosthesis and avoidance risk movements.Dislocation after THA can be reduced by careful pre-,intra-,and postoperative assessment.

Objective To explore the value of the percentage of necrotic surface area in predicting collapse of osteonecrosis. Methods 15 hips of avascular necrosis of the femoral head(ANFH) in 9 patients underwent MRI scan. On the MRI films, the percentage of necrotic surface area were calculated. While on the specimens of the 15 hips, the percentage of necrotic surface area were also measured. In 16 hips of 8 patients of ANFH with serials MRI at mean 18.9 months intervals (range, 6-41 months), the percentage of necrotic surface area were calculated and compared. In 38 hips of 27 patients without collapse, the percentage of necrotic surface area and the index of necrosis were calculated on MRI films. Follow-up was terminated when crescentic sign illustrated on X-ray film or CT demonstrated articular facet collapse. Those hips without collapse were followed up more than 24 months. The value of the percentag of necrotic surface area and the index of necrosis in predicting collapse of osteonecrosis was observed. Results The percentage of necrotic surface area were 63.23%?10.16% on specimens and 63.60%?7.78% on MRI films respectively. There were no significant differences between them. The percentage of necrotic surface area on specimens were coincidence with those on MRI. In the 16 hips with serials MRI; the percentage of necrotic surface area were 52.37%?19.91% on the first MRI films, 51.70%?21.29% on the second. There were no significant differences between them. This result revealed that the percentage of necrotic surface area did not vary with the extension of course of disease. In the 38 cases of early necrosis, 28(73.7%) hips collapsed and 10(26.3%) hips did not. The relative risk of the percentage of necrotic surface area was 1.043, and the relative risk of the index of necrosis was 1.020. No significant difference was found in ARCO staging for patients with or without femoral head collapse. It demonstrated that whether ischemic necrotic femoral head collapse or not had no relation with its ARCO stage. Conclusion The percentage of necrotic surface area can be used as more accurate predictor for future collapse.

[Objective]To explore the causes and treatments of recurrent dislocation after total hip replacement.[Method]From July 1999 to January 2007,there were 47 cases of dislocation after total hip replacement.Thirteen cases were recurrent.CT and serial X-rays were taken to observe the position of prosthesis.The strength of their hip abductor was also tested.Stability test was used to value the stability of hip.Closed reduction,modular adjustments and revision were adopted according to patients,willingness,prosthesis and stability.[Result]All of the 13 patients had malposition.Eleven cases were tested with instability.Five cases were successfully treated by closed reduction.Despite dislocation reoccurred 1～2 times every year in 3 patients treated by closed reduction,patients felt satisfactory.In the 4 cases with modular revision procedure,2 cases changed the neck length,1 case used elevated liner and larger neck length,1 cases treated by using larger offset and adjusting abnormal liner.Another one treated by revision.[Conclusion]Malposition is the major causes of recurrent dislocation.The prosthesis test whowed instability.The treatments of recurrent dislocation after THA should use different ways according to the causes of dislocation,stability of prosthesis and the willingness of patients.

Objective By virtual screening in MDL,to search for a novel γ-secretase inhibitor.Methods A series of compounds were designed,synthesized,and evaluated based on pharmacophore model of γ-secretase inhibitors by virtual screening in MDL.Results The drug-likeness analytic data synthesized indicated that target compounds had drug-likeness.Each svnthesized compound was checked by IR spectroscopy,~1H and ~(13)C-NMR spectroscopy.Conclusion The designed compounds had better activity by model prediction.And the optimal compound showed a significant estimated activity value of 0.025 nmol/L and can be used as a lead for further drug development.

Objective: To use vertical and humidity correcting method to calibrate aerosol optical depth (AOD), and to explore the feasibility of calibrated-AOD as exposure index to measure the level of air pollutants from the ground and to establish the exposure-response relationship between calibrated-AOD and people's health outcomes.Methods: First of all, we interpolated AOD, PM2.5, relative humidity and planetary boundary layer height using Kriging method to obtain data at different locations and matched different data with respiratory death in Beijing by geographical coordinates.Then, the planetary boundary layer height and aerosol hygroscopic growth factor calculated based on relative humidity was used to calbrate the AOD.To compare the effects of calibrated-AOD and PM2.5, we used standardization method to get non dimensionless calibrated-AOD and PM2.5.At last, we used the generalized additive mixed model (GAMM) to estimate the acute effects of calibrated-AOD and PM2.5 on respiratory death and chronic obstructive pulmonary disease (COPD) death, after controlling the time trend, temperature and humidity effects, days of the week effect and holiday effects.Results: The correlation coefficient between calibrated-AOD and PM2.5 was 0.72.The effects of calibrated-AOD on respiratory death and COPD death was the strongest at lag 0-3, one unit of calibrated-AOD increases was associated with 3.64% (95%CI: 0.58%-6.78%) increase of respiratory death and 4.92% (95%CI: 1.81%-8.14%) increase of COPD death.As for PM2.5, the strongest effects appeared at lag 0-1, one unit of PM2.5 (about 155 μg/m3) increases was associated with excess risks of 3.96% (95%CI: 0.82%-7.19%) and 6.12% (95%CI: 1.44%-11.02%) for respiratory death and COPD death respectively.Compared with PM2.5, the effects of calibrated-AOD on respiratory death and COPD death had narrower confidence intervals.The calibrated-AOD was sensitive to capture the lag effects, and the cumulative lag effects of calibrated-AOD were all significant on multiple lag days which indicated that the calibrated-AOD was sensitive to capture cumulative lag effects of air pollutants on respiratory death and COPD death as well.Conclusion: We believe that calibrated-AOD can be used as an index to reflect the effects of air pollutants on respiratory death in Beijing.In the absence of ground monitoring, calibrated-AOD can be used to mea-sure the relationship between air pollutants and some health outcomes.

Objective:To establish a method for the determination of trace nickel in agomelatine. Methods:An inductive coupled plasma atomic emission spectrometry method was applied in the determination at 221. 648 nm. The sample solution was prepared by the ignited residue of agomelatine. The content of nickel was determined using the standard curve. Results:The linear range was 0. 025-1. 000 μg·ml-1(r=0. 999 8). The RSD of precision was 0. 63%. The detection limit was 0. 000 8μg·ml-1. The quantitative limit was 0. 003μg·ml-1 . The average recovery was 99. 4% with RSD of 2. 20%. The RSD of repeatability was 1. 33%. Conclusion:The method is simple, sensitive and accurate in the determination of trace nickel in agomelatine.

Objective To explore the roles of PKCθ(protein kinase Cθ)signaling pathway on the activation,proliferation and TH1/TH2 cytokines production of the γδT lymphocytes stimulated by Mycobacterium tuberculosis antigen(Mtb-Ag) in vitro.Methods Peripheral blood mononuclear cells(PBMC)were pretreated with or without Rottlerin at 5.0 μmol/L,and stimulated with Mtb-Ag and cultured in rhIL-2 containing medium.After different time of culture,activation molecules and cytokines production of γδT cells were measured by flow cytometry.The proliferation proportion and the percentage of each generation of γδT cells were determined by carboxylfluoreseein diacetate succinmidyl ester(CFSE)labeling technique and flow cytometry.Results After 3d of stimulation with Mtb-Ag,the expression rates of CD69 and CD25 of γδT cells were 46.2%and 45.6%,respectively.Pretreatment of 5.0 μmol/L Rottlerin markedly inhibited the both expressions of CD69 and CD25 in γδT cells(P＜0.01).After stimulation and expansion in vitro for 5,10,and 15 d,the percentages of the γδT cell were 9.6%,54.6%and 82.4%,respectively.There was a few γδT cells in propagation on the 5th day of culture,and almost all γδT cell divisions were above 6 generations on the 10th and 15th day of culture.Pretreatment of the Rotflerin significantly suppressed the γδT cell proliferation,but after 10 d culture,there were still a few parts of γδT cells in propagation.Meanwhile,after 7,14,and 21d of culture,upon stimulation with PMA+Ionomycin,the IFN-γ producing-γδT cells were about 80%at all times.But only after 21d culture,IL-4-producing γδT cells was 2.6%.,The percentage of IFN-γ producing γδT cells markedly reduced in Rottlerin group(P＜0.01).IL-4 secretion of the γδT cells was almost completely blocked.Conclusion PKCO signal pathway involves in activation,proliferation and differentiation of the γδT lymphocytes stimulated by Mtb-Ag.

Objective To label neural stem cells (NSCs) with superparamagnetic iron oxides (SPIO) and to explore the tropism of NSCs after transplantation into the hippocampus of APP/PS1 AD mice by MRI.Methods NSCs from C57BL/6 mouse were cultured and identified.Feridex and Poly-L-Lysine were added into the medium to be co-cultured to make magnetic labeled NSCs and transmission electron microscopy was used to identify the iron particles in NSCs.Transgenic (tg) and wild-type (wt) mice at 12 months of age were divided into three groups: SPIOs labeled NSCs group (A and C),unlabeled NSCs group(B).Feridex-labeled NSCs were migrated into the hippocampus of APP/PS1 AD mice to monitor in vivo by MRI.After 1,2,4 and 6 weeks,the mice were sacrificed and their brain tissues were sectioned to investigate the migration of SPIO labeled NSCs and compared with MRI.Results NSCs of C57BL/6 mice were cultured successfully.Transmission electron microscope showed visible iron granules in cytoplasm.MRI detection of labeled cells: T2WI and T2* WI showed remarkable low signal intensity at the hippocampus injection points 1 week after transplantation,particularly on T2* WI.Area of low signal intensity enlarged increasingly along the injection points after 2 weeks.At 4 weeks,area of low signal intensity spread throughout the hippocampus,but intensity shadowed Six weeks later,low signal intensity almost disappeared.There was no obvious low signal change in unlabeled cell transplantation group.For wt mice,size and location of low signal did not appear obvious change at all designated time points.Prussian blue positive cells were observed in the hippocampus,indicating that NSCs labeled with SPIO could survive,migrate and differentiate in the brain of the APP/PS1 AD mice.Changes of pathology were well correlated with the area where a signal intensity loss was observed in MRI 1,2,4 and 6 weeks after transplantation Conclusions Diffuse migration of transplanted NSCs labeled with SPIO is observed in the hippocampus in APP/PS1 tg mice,and MRI technique is an ideal method for tracking labeled stem cells after grafting in vivo.

Objective To explore the value of 1H-MRS on the evaluation of Alzheimer's disease (AD) with neural stem cells (NSCs) transplantation in an APP-PS1 double transgenic (tg) AD mouse model.Methods NSCs from C57BL/6 mice were cultured and amplified.APP-PS1 tg mice (n =30) aged 12 months were used as the study group,and mild-type mice (n =15) were used as the control group.Animals in the study group were randomized into two subgroups,the AD mice in one subgroup received NSCs transplantation (NSCs group) and in another subgroup received phosphate buffer saline (PBS,PBS group)in bilateral hippocampal CA1.Animals in the control group were not treated.Using a 7.0 T high-fieldstrength MR imager,1H-MRS was performed before and 6 weeks after transplantation to measure the area under the peak of n-acetyl aspartate (NAA),glutamate (Glu),myo-inositol ( mI),choline (Cho) and creatine (Cr) in the hippocampal area,NAA/Cr,Glu/Cr,mI/Cr and Cho/Cr ratio were calculated and compared with histopathological results (including Nissl's staining and electron microscope examination).Comparisons among NSCs,PBS and control groups were conducted by one-way ANOVA.Results NSCs from C57BL/6 mice were cultured successfully. Before transplantation,the mean NAA/Cr,Glu/Cr and mI/Cr in NSCs,PBS and control groups were 0.89 ± 0.05,0.88 ± 0.04 and 1.15 ± 0.05,0.40 ± 0.03,0.39 ± 0.03 and 0.45 ± 0.05,0.67 ± 0.05,0.67 ± 0.05 and 0.52 ± 0.04,respectively,and differences were statistically significant (F =148.918,7.529,59.468,P ＜ 0.01 ). There were no significant differences in NAA/Cr,mI/Cr and Glu/Cr ratios between NSCs and PBS groups before transplantation (t =0.147,0.096,0.207,P ＞ 0.05 ),but the differences were significant compared with the control group (t =0.255,0.467,0.171 and t =0.269,0.527,0.151,P ＜0.05).Six weeks after transplantation,the mean NAA/Cr,Glu/Cr and mI/Cr in three groups were 1.13 ±0.07,0.86 ±0.05 and 1.14 ±0.05,0.45 ± 0.04,0.38 ± 0.02 and 0.44 ± 0.03,0.58 ± 0.04,0.67 ± 0.04 and 0.53 ± 0.04,respectively,and differences were statistically significant ( F =112.092,23.076,44.367,P ＜ 0.01 ).NAA/Cr and Glu/Cr ratios were increased and mI/Cr was decreased in NSCs group,and the difference was significant compared with PBS group at the same time point ( t =0.271,0.071,0.089,P ＜ 0.05 ).There were no significant differences in NAA/Cr and Glu/Cr ( t =0.013,0.012,P ＞ 0.05 ),but there was a significant difference in mI/Cr between NSCs and control groups ( t =0.046,P ＜ 0.05).There were no significant differences in Cho before and after transplantation among the three groups (P ＞ 0.05 ). Nissl's staining showed that the number of neurons in the hippocampal area increased more significantly in tg mice receiving NSCs than that without receiving NSCs.Electron microscopy showed that most hippocampal NSCs in NSCs group were morphologically normal with abundant organelles,while hippocampal NSCs in PBS group were swollen with sparse synapses.Conclusion 1H-MRS is able to display intracranial metabolite changes before and after NSCs in APP-PS1 double transgenic AD mice and has an applicable value in evaluating the therapeutic effect of NSCs on AD.