BACKGROUND: The active component in recombinant human bone morphogenetic protein-2/poly(lactide-co-glycolide) (rhBMP-2/PLGA) microsphere prone to be absorbed or lost during solution with physiological saline, and the setting time is uncontrollable using blood solution, so it is necessary to explore an sustained-release carrier that can control the setting time.OBJECTIVE: To construct an injectable BMP release system by combing rhBMP-2/PLGA microsphere with fibrin glue. DESIGN, TIME AND SETTING: An experimental comparative study was performed at the Department of Othopaedics, General Hospital of Chinese PLA from January 2005 to April 2008.MATERIALS: PLGA (polylactic acid/polyglycolic acid 75/25, M_r=3 000, with 0.025 L/g viscosity) was supplied by Shandong Institute of Medical Instruments; rhBMP-2 was offered by The Academy of Military Medical Sciences; and fibrin glue was supplied by Hangzhou Puji Medicine Technology Development Co., Ltd.METHODS:The rhBMP-2/PLGA microsphere was prepared using W/O/W solvent evaporation methods. rhBMP-2 loaded PLGA microsphere were incorporated in fibrin glue to establish injectable BMP release system.MAIN OUTCOME MEASURES: The setting time,release behaviors, electron spectroscopy for chemical analysis (ESCA) as well as pH values of composites were measured.RESULTS:①Compared with fibrin glue, the setting time of composites were slightly increased.②Initial burst release of the composites occurred, the drug release exceeded 16.76% within 2 days, and 76.75% of the drug was release within 42 days. ③ESCA showed that composites prolonged release times.④The PH value of composites was between microsphere and fibrin glue.CONCLUSION: RhBMP-2/PLGA microsphere/fibrin glue composite has satisfactory slow-release effect and syringeability, which not only degrade partial acid environment but also maintain the biological effect of higher density. Therefore, it forms a promising synthetic bone graft.

Objective To investigate the serum C-reactive protein (CRP) level in patients with acute cerebral infarction and acute massive cerebral infarction with multiple organ dysfunction syndrome (MODS),and analyze the clinical value of CRP. Methods The serum CRP level of 50 patients of control group and 50 patients of cerebral infarction admitted to hospital within 7 days (30 patients were admitted into acute cerebral infarction group and 20 patients into acute massive cerebral infarction with MODS group) were determined by immune scatter turbidimetry. Results (1)In cerebral infarction patients,serum CRP level in 48 cases(96%) was equal and over 5 mg/L.In control group,serum CRP level in 3 cases(6%) was equal and over 5 mg/L(P＜0.0 5).(2)The level of serum CRP acute in cerebral infarction group and in acute massive cerebral infarction with MODS group increased significantly than that in control group (P＜0.01).The level of serum CRP in acute massive cerebral infarction with MODS group increased significantly than that in acute cerebral infarction group.(3)When the level of CRP＜25 mg/L,the incidence of MODS in patients with acute cerebral infarction was zero.When the level of CRP≥25 mg/L,the incidence of MODS increased gradually with the rise of CRP. Conclusions There is positive correlation between the serum level of CRP and the severity of acute cerebral infarction and the incidence of MODS.CRP is a useful marker in predicting the prognosis of acute massive cerebral infarction with MODS.

Objective To investigate the clinical effect of bone transport technique in the treatment of large segment infective nonunion of femoral shaft.Methods A retrospective case series study was conducted to analyze the clinical data of 33 patients with large segment infective nonunion of femoral shaft admitted to Chinese PLA General Hospital from June 2012 to October 2015.There were 25 males and eight females,aged 19-58 years (mean,34.6 years).In terms of the initial injury,23 patients were with open fracture and 10 with closed fracture.All patients previously received 1-9 times of operation,with an average of 2.3 times.The duration from injury to operation ranged from 7-60 months,with an average of 34 months.All patients underwent treatment with bone transport technique.After thorough debridement,the length of femoral defect ranged from 6 cm to 18 ema,with an average of 10.5 cm.The single arm limb reconstruction external fixator was placed on the lateral side of the femur under C-ann X-ray fluoroscopy.The wound healing,bone healing time,external fixation index (EFI),and complications were recorded.The function of the affected limb was evaluated using the modified criteria of Association for the Study and Application of the Method of Ilizarov (ASAMI).Results All patients were followed up for 21-53 months (average,38.5 months).Femoral defects were completely repaired,with no recurrent infection reported.Bone healing time ranged from 8 months to 25 months (average,13 months).The external fixation index (EFI) ranged from 1.13 months/cm to 1.83 months/cm,with an average of 1.26 months/cm.The infection rate of the nail tract was 55％ (18/33).There were 12 patients with Type A,five with Type B,and one with Type C.The function of the affected limb was graded as excellent in 18 patients,good in six,fair in five,and poor in four,with an excellent and good rate of 73％ (24/33).Conclusions In the treatment of large segment infective nonunion of femoral shaft,bone transport technique can eontrol the infection,promote defect repair,and restore the function of affected limbs.

Background Mercury, as a global heavy metal pollutant, poses a serious threat to human health. The toxicity of mercury depends on its chemical form. Distinguishing the forms of mercury in the environment is of great significance for mercury management and reducing human mercury exposure risks. Objective To establish a non-targeted metallomics method based on synchrotron radiation X-ray fluorescence (SRXRF) spectroscopy combined with machine learning to screen inorganic mercury (IHg) or methylmercury (MeHg) exposed rice plants. Methods Rice seeds were exposed to ultra-pure water (control group), 0.1 mg·L⁻¹ IHg (IHg group) or MeHg (MeHg group) solutions, respectively. After germination, the seedlings were cultured for 21 d, and rice leaves were collected, dried, weighed, and pressed. The content of metallome in rice leaves was determined by SRXRF. Machine learning models including soft independent modeling cluster analysis (SIMCA), partial least squares discriminant analysis (PLS-DA), and logistic regression (LR) were used to classify the SRXRF full spectra of different groups and find the best model to distinguish rice exposed to IHg or MeHg. Besides, characteristic elements were selected as input parameters to optimize the model by improving computing speed and reducing model calculation. Results The SRXRF spectral intensities of the control group, IHg group, and MeHg group were different, indicating that exposure to IHg and MeHg can interfere the homeostasis of metallome in rice leaves. The results of principal component analysis (PCA) of SRXRF spectra showed that the control group could be well distinguished from the mercury exposed groups, but the IHg group and the MeHg group were mostly overlapped. The accuracy rates of the three models (PLS-DA, SIMCA, and LR) were higher than 98% for the training set, higher than 95% for the validation set, and higher than 94% for the cross-validation set. Besides, the accuracy of the LR model was higher than that of the PLS-DA model and the SIMCA model. Furthermore, the accuracy was 92.05% when using characteristic elements K, Ca, Mn, Fe, and Zn selected by LR to distinguish the IHg group and the MeHg group. Compared with the full spectra model, although the prediction accuracy of the characteristic spectral model decreased, the input parameters of the model decreased by 99.51%, and precision, recall, and F1 score were above 84.48%, indicating that the model could distinguish rice exposed to different mercury forms. Conclusion Non-targeted metallomics method based on SRXRF and machine learning can be applied for high-throughput screening of rice exposed to different forms of mercury and thus decrease the risks of people being exposed to mercury.