Analysis of risk factors for necrosis of femoral head after internal fixation surgery in young and mid-aged patients with femoral neck fracture / 北京大学学报(医学版)

OBJECTIVE@#To retrospectively analyze the risk factors of avascular necrosis of femoral head (ANFH) after internal fixation in young and mid-aged adults.@*METHODS@#From January 2007 to December 2017, femoral neck fracture patients (18-60 years old) treated by reduction and internal fixation were retrospectively studied in Peking University Third Hospital. We recorded their gender, age, body mass index (BMI), American Society of Anesthesiology (ASA) grade, reason of injury, fracture side, interval between injury and surgery, location of fracture line, Garden classification, Pauwels classification, reduction method (open or closed), internal fixation and reduction quality. The diagnosis of ANFH was confirmed based on X-ray and MRI images during the follow-up. The internal fixation method included cannulated compression screw (CCS) or dynamic hip screw (DHS, with or without anti-rotation screw). χ2 test and Logistic regression analysis were used to analyze the relationship between the various factors and postoperative ANFH.@*RESULTS@#A total of 113 patients were included in this study, including 63 males and 50 females with an average age of (43.17 ± 12.34) years. They were followed up by (25.08 ± 16.17) months. ASA grade included grade I (21 cases), grade II (55 cases) and grade III (37 cases). The reasons of injury included low-energy trauma (76 cases) and high-energy (37 cases). The fracture line included subcapital type (37 cases), transverse type (74 cases) and basal type (2 cases). Garden classification included type I (3 cases), type II (46 cases), type III (39 cases) and type IV (25 cases). Pauwels classification included type I (21 cases), type II (55 cases) and type III (37 cases). Interval between injury and surgery was (3.88 ± 3.66) days, 108 patients and 5 patients performed closed and open reduction respectively. 63 patients performed CCS, and 50 patients performed DHS. The reduction quality included grade A (91 cases), grade B (18 cases) and grade C (4 cases). 18 patients developed ANFH after surgery, the incidence rate was 15.93% (18/113). The result of χ2 test showed the reason of injury (OR=0.19, P < 0.01), Garden classification (OR=0.13, P < 0.01), Pauwels classification (OR=0.12, P = 0.02), internal fixation method (OR=3.29, P = 0.04) and reduction quality (OR=0.33, P < 0.01) were significantly associated with ANFH. These five factors were further included into the Logistic regression analysis, and its results showed that the reason of injury (OR=4.11, P = 0.03) and Garden classification (OR=4.85, P = 0.04) were statistically significant.@*CONCLUSION@#The reason of injury, Garden classification, Pauwels classification, internal fixation and reduction quality may increase the risk of ANFH after surgery, and the reason of injury and Garden classification were much more significant.

Risk factors of recurrent kyphosis in thoracolumbar burst fracture patients treated by short segmental pedicle screw fixation / 北京大学学报(医学版)

OBJECTIVE@#To analyze the risk factors of recurrent kyphosis after removal of short segmental pedicle screw fixation in patients with thoracolumbar burst fractures.@*METHODS@#Retrospective analysis was conducted of 144 cases of thoracolumbar burst fractures without neurological impairment treated in Peking University Third Hospital from January 2010 to December 2017. There were 74 males and 70 females, with an average age of (39.1±13.2) years. The distribution of the injured vertebrae was T12: 42, L1: 72 and L2: 30, with fracture types of A3: 90, B1: 25 and B2: 29. The patients were divided into two groups: Recurrent kyphosis group (n=92) and non-recurrent kyphosis group (n=52). SPSS 26.0 software was used for univariate analysis and Logistic regression analysis.@*RESULTS@#The average follow-up time was 28 (20-113) months. The imaging indexes of pre-operation, 3 days post-operation, 12 months post-operation and the last follow-up were measured and compared. Anterior vertebral body height, segmental kyphosis, vertebral wadge angle and Gardner deformity were significantly improved after operation (P < 0.05), and there were some degrees of loss in the 1-year follow-up; anterior vertebral body height and vertebral wadge angle were no longer changed after the removal of the screws; however, segmental kyphosis and Gardner deformity were still aggravated after the removal of the screws (P < 0.05). There were some degrees of collapse of the height of the upper and lower discs during the follow-up. Univariate analysis showed that there were statistically significant differences (P < 0.05) between the two groups in gender, age (36.9 years vs. 43.0 years), upper disc injury, CT value (174 vs. 160), segmental kyphosis (16.6° vs. 13.3°), vertebral wadge angle (16.7° vs. 13.6°), Gardner deformity (19.1° vs. 15.2°) and ratio of anterior vertebral body height (0.65 vs. 0.71). Logistic regression analysis showed that male (OR: 2.88, 95%CI: 1.196-6.933), upper disc injury (OR: 2.962, 95%CI: 1.062-8.258) and injured vertebral wedge angle were risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture (P < 0.05).@*CONCLUSION@#The patients with thoracolumbar burst fracture can obtain satisfactory effect immediately after posterior short segmental pedicle screw fixation, however, there may be some degree of loss during the follow-up. Male, upper disc injury and injured vertebral wedge angle are the risk factors of recurrent kyphosis after removal of internal fixation for thoracolumbar burst fracture.

The role of poloxamer 188 for cord blood mononuclear cells into megakaryocytes cultivation and induction in three-dimensional WAVE Bioreactor / 中华血液学杂志

Objective: To observe the effect of poloxamer 188 (P188) on megakaryocyte cultivation and induction from cord blood mononuclear cells in order to obtain more megakaryocyte progenitor cells (MPC). Methods: The cord blood mononuclear cells were isolated and inoculated in cell culture bag or cell culture flask respectively. The WIGGENS shaker and cell culture bags were used to mimick WAVE Bioreactor for three-dimensional (3D) cell culture, and the P188 was added to induction medium, The cells were detected for morphology, surface marker, viability, and number on day 14. Results: In the two-dimensional (2D) culture, CD41(+), CD41(+)/CD61(+), CD61(+) megakaryocytic numbers increased significantly after adding P188 (all P<0.01). And in the 3D culture of adding P188, the cell volume became larger and the nuclear shape was irregular, the cytoplasm appeared magenta granules, and the megakaryocyte cells became more mature. By 3D culture, the expression of CD41/CD61 was (36.30±1.27)% vs (23.95±1.34)%, hence the differentiation for MPC was significantly higher than that in the 2D group (P<0.01). Furthermore, adding P188 in 3D culture resulted in highest differentiation efficiency for MPC [(59.45±1.20)%]. There were no significantly differences in terms of cell viability and cell number among 3D culture containing P188, 2D and 3D culture groups (all P>0.05). Conclusion: 3D culture was beneficial for the differentiation of MPC, but the cell viability was lower than 2D group; However, the satisfied cell growth and better induction efficiency were obtained by adding of P188, which might provide a new method of megakaryocytes production for clinical application.

HyaIuronic acid scaffoIds: appIication research and product prospects / 中国组织工程研究

BACKGROUND: Hyaluronic acid is an important component of extracellular matrix, has good biocompatibility, unique rheological properties and a variety of physiological functions. Therefore, it has wide application prospect in the tissue engineering. OBJECTIVE: To review the latest research progress in hyaluronic acid scaffold materials in different directions of tissue engineering. METHODS: Using the keywords of "hyaluronic acid, tissue engineering, regeneration, scaffold" in English and Chinese, we retrieved relevant articles published from January 2013 to September 2016 in the databases of PubMed, ScienceDirect and CNKI. RESULTS AND CONCLUSION: The application of hyaluronic acid tissue engineering scaffold materials mainly focuses on the regeneration of bone, cartilage, cardiovascular and nerve. The researchers optimize the composition, ratio of different materials, and modification or cross-linking methods to obtain the ideal scaffold materials to match the mechanical properties and physiological activity of the target tissue. However, there are not enough data on the influence of the molecular weight of hyaluronic acid and the original source of other raw materials on the scaffold properties. Further investigations are needed on the clinical transformation of hyaluronic acid tissue engineering products.

Roles of integrin αvβ3 in SDF-1/CXCR4-induced choroidal neovascularization / 眼科新进展

Objective To explore the role of integrin αvβ3 in the promotion of the development of choroidal neovascularization (CNV) by SDF-1/CXCR4.Methods This study was divided into two parts in vitro and in vivo.As for the in vivo study,a CNV model was induced by laser on C57BL/6J mice,and then assigned into 4 groups:mice with solely CNV modeling as control group,with intravitreal injection of SDF-1 after immediate CNV modeling as SDF-1 group,with intravitreal injection of SDF-1 + CXCR4 inhibitor (AMD3100) after CNV modeling as SDF-1 + AMD3100 group,and mice with intravitreal injection of SDF-1 + αvβ3 inhibitor (SB273005) after modeling as SDF-1 + SB273005 group.CXCR4 and αvβ3 expression levels in laser-induced eyes were quantified by qRT-PCR at time points of day 1,3,5,7,10 and 14 after modeling,and immunofluorescence staining was applied to detect αvβ3 expression in regional CNV and its endothelial cells in the four groups.Finally,OCT was used to observe the height of retinal pigment epithelial (RPE) layers in CNV after treatment in the four groups.Moreover,in the experiment in vitro,Western blot was used to measure the expression of CXCR4 protein of RF/6A cells in normal control group,Si-CXCR4 knockdown group and Si-NC knockdown model group.Meanwhile,the expression of integrin subunit β3 protein was determined in the normal control group,SDF-1 group,SDF-1 + AMD3100group,SDF-1 + Si-NC group and SDF-1 + Si-CXCR4 group.Transwell assay was conducted to detect the migration ability of RF/6A cells in the normal control group,SDF-1group,SDF-1 +AMD3100 group,SDF-1 + SB273005 group.Results On the one hand,the study in vivo,qRT-PCR showed that the expression of CXCR4 and integrin subunit β3 mRNA was up-regulated at first,and then down-regulated with time passed after CNV induction,with the highest expression level of CXCR4 mRNA (4.263 ± 0.464) on day 3,and the peak expression of β3 mRNA (3.678 ±0.364) on day 7 after CNV modeling.The results of immunofluorescence staining showed that the β3 fluorescence intensity of SDF-1 group was significantly enhanced,and the ratio of β3/CD31 was also significantly increased,which both were significantly higher than those of the control group (P ＜ 0.01).However,the β3 fluorescence intensity and β3/CD31 ratio of SDF-1 +AMD3100 group and SDF-1 + SB273005 group were significantly weakened and decreased,respectively (P ＜0.05).OCT showed that the elevation level of RPE layer inSDF-1 group was significantly higher than that in the control group [(135.503 ± 10.301) μm vs.(94.443 ± 12.156) μm](P＜0.05).The height of RPE uplift in SDF-1 + AMD3100 group [(95.283 ±20.062) μm] and SDF-1 + SB273005 group [(99.807 ± 10.403) μm] was significantly decreased (P ＜ 0.05).On the other hand,in experiment in vitro,Western blot showed that the expression levels of integrin β3 in SDF-1 group and SDF-1 + Si-NC group were significantly higher than those in the control group [(1.301 ± 0.043) and (1.273 ± 0.077) vs.(0.244 ± 0.069)] (P ＜ 0.01).The levels of integrin subunit β3 protein in SDF-1 + si-CXCR4 group (0.322 ± 0.042) and SDF-1 + AMD3100 group (0.336 ± 0.077) were significantly down-regulated (P ＜ 0.01).Transwell assay showed that the amount of migrating cells in SDF-1 group increased,which was significantly higher than that of the control group (P ＜ 0.01),while the number of migrating cells in SDF-1 +AMD3100 group and SDF-1 + SB273005 group was significantly decreased.Conclusion Integrin αvβ3 can promote the development of CNV by mediating SDF-1/CXCR4 signaling in endothelial cells.

Detection of Th17 cells in thymoma patients with myasthenia gravis and its clinical sig-nificance / 中国肿瘤临床

Objective:To study the clinical significance of Th17 cell detection in patients with thymoma associated with myasthenia gra-vis(MG).Methods:From October 2015 to October 2017,78 patients with thymoma who treated in Cardio-Thoracic Surgery of Tianjin Medical University General Hospital and 15 normal controls were collected.Flow cytometry was used to detect the proportion of Th17 cells,and the levels of IL-17,IL-21 and AchR-Ab in peripheral blood were detected before operation.The correlation of Th17 with the corresponding cytokines was analyzed,and the independent risk factor was predicted for thymoma with myasthenia gravis.Results:The percentage of Th17 cells in the MG group was 10.33%±1.28%,compared with 7.33%±0.58% for the Con group and 7.67%±2.18% for the Tm group.These differences were statistically significant.The MG group was recorded as having(18.05 ± 7.23)pg/mL IL-17, (180.67±16.17)pg/ml IL-21,and(37.29±7.48)pmol/L AchR-Ab compared to(7.45±3.46)pg/mL,(84.33±5.13)pg/mL,and(15.23±3.32) pmol/L for the Con group and(8.22±1.67)pg/mL,(93.00±7.21)pg/mL,and(16.87±4.89)pmol/L for the Tm group for the same cyto-kines,respectively.These differences were also statistically significant(P<0.001).The percentage of Th17/CD4+T cells in the MG group was positively correlated with IL-17(r=0.830,P<0.001),IL-21(r=0.734,P<0.001),and AchR-Ab(r=0.809,P<0.001).IL-17,IL-21,and AchR-Ab are independent risk factors for predicting the combination of thymoma with MG.Conclusions:Th17 cells are involved in the development of thymoma with MG,which promote cell proliferation by secreting IL-21 and regulate MG growth by secreting IL-17.

Flavor and meridian tropism classification analysis of Callianthemum taipaicum / 中国中药杂志

To explore the flavor and meridian tropism classification of Callianthemum taipaicum by principal components analysis(PCA) and partial least square analysis(PLS). Meanwhile,to establish a high performance liquid chromatography-tandem mass spectrometry(HPLC-ESI-MS) method for the simultaneous determination of 55 active components from 13 kinds of Ranunculaceae of Chinese traditional herbs. Samples were separated on HPLC system by Agilent 5 TC-C₁₈（2）（4.6 mm×250 mm，5 μm）column and eluted with acetonitrile and 0.1% formic acid at the flow rate of 0.6 mL·min⁻¹. The data were performed by HPLC-ESI-MS with multiple reaction monitoring（MRM）scanning mode under positive and negative ion modes and quantified by external standards. The data from 13 Ranunculaceae herbs were analyzed by the PLS-tree and cooman's prediction of PCA and PLS to evaluate the similarities and differences of C. taipaicum in flavor and meridian tropism. The results showed that calibration curves of 55 components all showed good linearity, >0.99,with good precision, repeatability and stability. After compared to other 12 herbs,PCA and PLS results revealed that the C. taipaicum belonged to lung and bladder meridians while its flavor attributive to pungent,warm in nature. In conclusion,the analysis approach of chemometric calculation combined with multi-components quantification is suitable for the classification of meridian tropism and flavor of Chinese traditional medicine,which can be used for alternative research of rare herbs.

Classification analysis for Schisandra sphenanthera during different grades of maturity by chemical pattern recognition approach / 中草药

Objective To establish the simultaneous determination method of six lignans from Schisandra sphenanthera and classify the different maturity of Schisandra sphenanthera via chemical pattern recognition approach. Methods The simultaneous determination method was established by UPLC technology, the samples were performed by Acquity UPLC BEH C18 (50 mm × 2.1 mm, 1.7 μm) and eluted with acetonitrile and 0.1% formic acid, the flow rate was 0.4 mL/min, column temperature was 35 ℃, and the detection wavelength was 254 nm. The collected data were analyzed and classified by principal component analysis (PCA) and hierarchical cluster analysis (HCA) that the Schisantherin was selected as the monitoring component. Results Six lignans were in good linear relationship with the linear range 1.257-156.250 μg/mL (r < 0.999); Moreover, the RSD values of the repeatability, stability, and precision test were all less than 3%. According to the variation of main components in different grades of maturity, six different grades of maturity of S. sphenanthera were divided into three groups: 60%-mature sample, 70%-mature sample, and mature sample. Conclusion Cluster analysis based on UPLC technology and PCA joint analysis method are simple, rapid, sensitive, and accurate, which provides technical support and scientific basis for the selection of quality control and harvest time.

An improved method for in vivo electroporation of morpholinos into the adult zebrafish retina / 生理学报

In vivo electroporation of morpholinos (MOs) into the retina of adult zebrafish is an efficient method to study gene function related to retinal disease and regeneration. However, the currently reported methods are complicated with low MO transfer efficiency and high probability to cause collateral damage. The present study was aimed to optimize the existing MO electroporation methods. Two major changes were made to MO electroporation procedure in zebrafish retina. One was to coat the inner side of the electrode with ultrasonic gel. The other was to replace the commonly used round electrode with novel rectangular one. The results showed that the use of ultrasonic gel reduced collateral damage caused by retinal electroporation and simplified the experimental procedure. The rectangular electrode significantly increased transfection efficiency of MO electroporation. In particular, knocking down the expression of Ascl1a in the retina by using our method significantly inhibited the generation of retinal progenitor cells. These results suggest our method is the optimization of the current MO electroporation methods and may be a better alternative for relevant researchers.

Stretch-induced Expression of CYR61 Increases the Secretion of IL-8 in A549 Cells via the NF-κβ/Iκβ Pathway / 华中科技大学学报（医学）（英德文版）

Mechanical ventilation (MV) with large tidal volumes can increase lung alveolar permeability and initiate inflammatory responses,resulting in ventilator-induced lung injury (VILI).The mechanisms of the injurious effects of MV and the genetic susceptibility remain unclear.VILI-related genes such as cysteine-rich angiogenic inducer 61 (Cyr61)have been demonstrated to play a detrimental role in the aggressive ventilation strategies.In the present study,we investigated the involvement of Cyr61 in the VIM and the underlying mechanism.A549 cells were exposed to cyclic stretch of varying durations and then the mRNA and protein levels of Cyr61 were measured by real-time PCR and Western blotting,respectively.Additionally,after exposure ofA549 cells to cyclic stretch for 5 min to 1 h,the expression levels of nuclear factor kappaB (NF-κB) and IL-8 were detected by ELISA and Western blotting.Thereafter,Cyr61 expression was depressed in A549 cells with the siRNA pGenesill.1-Cyr61-3 before the cyclic stretch,and IL-8 secretion and the activation of NF-κB pathways were probed by ELISA and Western blotting,respectively.Moreover,a NF-κB inhibitor (PDTC) and an activator (TNF) were used before mechanical stretch.Realtime PCR and ELISA were performed to detect the mRNA and protein of IL-8,respectively.The results showed that the mechanical cyclic stretch led to increased Cyr61 expression at mRNA and protein levels in A549 cells.Additionally,cyclic stretch also mobilized NF-κB from the cytoplasm to the nucleus and increased IL-8 secretion in A549 cells.The inhibition of Cyr61 blocked the NF-κB activation and IL-8 secretion in response to cyclic stretch.Inhibition of NF-κB attenuated the mRNA and protein expression of IL-8 in A549 cells transfected with Cyr61 siRNA.It was suggested that Cyr61/NF-κB signaling pathway mediates the upregulation of IL-8 in response to cyclic stretch in A594 cells.These findings support the hypothesis that Cyr61 plays a critical role in acute lung inflammation triggered by mechanical strain.