BACKGROUND:Transverse acetabular fracture often involves the damage of anterior and posterior columns of acetabulum. The most popular fixation of the anterior and posterior columns needs the combined anterior and posterior approach. Big trauma is not conducive to patient’s recovery after surgery. Limited incision or percutaneous minimaly invasive lag screw placement can reduce soft tissue injuries, but the strength of the fixation lacks of biomechanical verification. OBJECTIVE: To compare different types of fixations for transverse acetabular fracture, explore the appropriate fixation options that can achieve effective fixation and reduce tissue injury by combing with repair approach and the condition of soft tissue. METHODS: The fourth generation of synthetic semi-pelvic sawbones was set as a template to establish a model of acetabular transverse fracture using finite element analysis. Five different fixation options were used to fix the transverse acetabular fracture. The magnitudes of anterior and posterior displacement of transverse fracture were compared to assess the stability of different options under a simulated condition of incomplete weight bearing stand. RESULTS AND CONCLUSION:The motion at anterior column was minimal when fixed by anterior column locking plate + posterior column screw and the minimum displacement at posterior column was the fixation of anterior column screw + posterior column locking plate. Both of the motions of these two fixations were less than the reconstruction plate fixation respectively. The worst fixation was the anterior column and posterior column lag screw fixation with the largest displacement. The anterior column locking plate + posterior column screw, accomplished by single approach, could not only reduce surgical trauma, but also has a stronger stability. Moreover, this fixation option is effective method to place posterior column lag screw under direct vision and reduce the difficulty of screw implantation.

BACKGROUND:Intervertebral disc degeneration is an important cause of low back pain.At present,there are many modeling methods for disc degeneration in China and abroad,but there is not a model for low back pain due to disc degeneration. OBJECTIVE:To compare the effect of mechanical puncture combined with tumor necrosis factor α and complete Freund's adjuvant with a conventional disc mechanical puncture alone. METHODS:A total of 18 male adult Sprague-Dawley rats were randomly divided into 3 groups,with 6 animals in each group.No treatment was given in the blank group.Animal models of intervertebral disc degeneration were made in the L4-5 segments of rats in the control using conventional mechanical puncture.In the experimental group,on the basis of mechanical puncture,tumor necrosis factor α+complete Freund's adjuvant was injected into the L4-5 intervertebral discs using a microinjector to establish a model of disc degeneration induced by mechanical puncture combined with inflammatory factors.Four weeks after surgery,the pain threshold of rats was measured by the hot plate method for assessing the perception of heat injury in rats with intervertebral disc degeneration.MRI examination was performed to observe the disc degeneration in each group.ELISA was used to detect the levels of serum tumor necrosis factor α,interleukin 1β,interleukin 6 and prostaglandin E2.Hematoxylin-eosin and Safranin O-fast green staining were used to observe the morphological changes of the disc. RESULTS AND CONCLUSION:In terms of pain,the behavioral pain threshold of the experimental group was continuously decreased,and the levels of serum inflammatory factors were significantly higher compared with the control group.In terms of morphology,the MRI results showed that the L4-5 nucleus pulposus signal completely disappeared in the experimental group.Histopathological results showed that in the control group,the nucleus pulposus was intact,more notochord cells were visible,and some fiber rings were ruptured,while in the experimental group,there are fewer notochord cells and the structure of the nucleus pulposus and fibrous ring is disturbed,with the boundary disappearing.To conclude,mechanical puncture combined with tumor necrosis factor alpha and complete Freund's adjuvant can successfully establish a discogenic low back pain model in rats.This operation is simple and economical to achieve obvious disc degeneration and low back pain,with greatly shortened molding cycle.This model can be used as a reference for studying discogenic low back pain models.

Objective To solve the problem of fast locating primary radiation in dental panoramic tomography apparatus by designing a linear model-based positioning die body. Methods By applying the mathematical principle of solving the linear equation,the two-dimensional plane coordinates were mapped to the detector plane of dental panoramic tomography apparatus, and the horizontal coordinate position was determined by determining the vertical coordinate value through X-ray imaging in the detector plane. Finally, the position of primary radiation in the detector plane was determined. Results The longitudinal characteristics of the image were determined by analyzing the images taken after the application of the model, and the final position of the primary radiation in the detector plane was accurate. By comparing the detection results of die body method and film method, the localization results by the die body method fell within 90% of the image center by the film method. There was no significant difference in the localization results between the two methods by Shapiro-Wilk normality test and paired-samples t test (P > 0.05). Conclusion For narrow-beam devices, the positioning die body designed based on the linear model method can locate the position of the primary radiation in the detector plane quickly and effectively and replace the film method.

【Objective】 To investigate the effect and mechanism of arctigenin (ARG) on hypoxia-reoxygenation (H/R) induced pyroptosis of cardiomyocytes. 【Methods】 H9C2 cells were cultured in vitro, and underwent hypoxia for 2 hours and reoxygenation for 4 hours to establish H/R cell injury model. The cells were divided into control group (Control), model group (H/R), ARG group, miR-21 simulation group (miR-21 mimic), and ARG+miR-21 inhibitor group (ARG+miR-21 inhibitor). TUNEL staining was used to detect the pyroptosis index of H9C2 cells; the lactate dehydrogenase (LDH) kit was used to detect the release of LDH in each group of cells; the enzyme-linked immunosorbent assay (ELISA) was used to detect the content of interleukin-1β (IL-1β) and interleukin-18 (IL-18). Western blotting was used to detect the expressions of pyroptosis-related proteins (Caspase-1, GSDMD, IL-1β and IL-18) in each group. 【Results】 Compared with those in the control group, the pyroptosis index, the release of LDH, IL-1β and IL-18, and the protein expressions of Caspase-1p20, GSDMD-N, IL-1β and IL-18 in the H/R group were significantly increased (P<0.01). Compared with H/R group, ARG group and miR-21 mimic group had significantly reduced pyroptosis index, LDH, IL-1β and IL-18 release, and protein expressions of Caspase-1 p20, GSDMD-N, IL-1β and IL-18 (P<0.01), and the above-mentioned index changes could be reversed after treatment with +miR-21 inhibitor. 【Conclusion】 ARG can inhibit H/R-induced pyroptosis of cardiomyocytes, and its mechanism is related to the promotion of miR-21 expression.

OBJECTIVE：To stud y the effects of sinapine thiocyanate （ST） on the proliferation ，epithelial mesenchymal transformation（EMT）and metastasis of human cutaneous squamous cell carcinoma SCL- 1 cells，and to investigate its possible mechanism. METHODS ：Human cutaneous squamous cell carcinoma SCL- 1 cells were divided into blank control group （0.1％ DMSO） and ST different concentration groups （5，10，20 μmol/L）. CCK- 8 assay，5-ethynyl-2′-deoxyuridine（EDU）test， scratch test and Transwell chamber invasion test were adopted to test the proliferation ，migration and invasion ability. The expression of N-cadherin and E-cadherin were detected by Western blot and immunofluorescence assay . Other SCL- 1 cells were collected and divided into blank control group （0.1％ DMSO），ST group （20 μmol/L），ST+NSC228155 group [ 20 μmol/L ST+100 μmol/L NSC228155（EGFR agonist ）] and ST+SC 79 group [ 20 μmol/L ST+20 μmol/L SC79（PI3K/Akt agonist ）]. The proliferation ，migration and invasion ability of SCL- 1 cells in each group were detected by CCK- 8 assay，scratch test and Transwell chamber invasion assay. The expression of epidermal growth factor receptor （EGFR），phosphatidylinositol 3 kinase（PI3K），phosphorylated phosphatidylinositol 3 kinase（p-PI3k），protein kinase B （Akt）and phosphorylated protein Akt （p-Akt）protein of cells in blank control group and ST different concentration groups（5，10，20 μmol/L）were determined by Western blot assay so as to validate the relationship between ST effect and EGFR/ PI3K/Akt signaling pathway. SCL- 1 cells and human normal skin fibroblasts cell WS 1 were divided into blank control group （0.1％ DMSO），ST group （20 μmol//L），ZD1839 group（positive control ，20 μmol//L，EGFR inhibitor ）and LY 294002 group（positive control，20 μmol//L，PI3K/Akt inhibitor ）. CCK- 8 assay was used to detect the cell proliferation in order to evaluate the cells cytotoxicity of ST. RESULTS ：Compared with blank control group ，the proliferation ，migration and invasion ability of SCL- 1 cells were significantly decreased in 5，10，20 μmol/L ST groups（P＜0.05）. Western blot and immunofluorescence assay showed that the expression of N-cadherin in SCL- 1 cells were decreased significantly in 5，10，20 μmol/L ST groups（P＜0.05），while the protein expression of E-cadherin was increased significantly （P＜0.05）；the protein expressions of EGFR ，p-PI3K and p-Akt were significantly decreased （P＜0.05）. Compared with ST group ，the proliferation ，migration and invasion ability of SCL- 1 cells were increased significantly in ST + NSC 228155 group and ST + SC 79 group （P＜0.05）. Compared with blank control group ，the proliferation ability of WS 1 cells had no significant change in ST group ，while the proliferation ability of SCL- 1 cells was decreased significantly （P＜0.05）；the proliferation ability of the two kinds of cells were decreased significantly in ZD 1839 group and LY 294002 group（P＜0.05）. Compared with ST group ，the proliferation ability of WS 1 cells was decreased significantly in ZD1839 group and LY 294002 group（P＜0.05），but there was no significant difference in the proliferation ability of SCL- 1 cells （P＞0.05）. CONCLUSIONS ：ST may inhibit the proliferation ，EMT and metastasis of SCL- 1 cells through inhibiting the activation of EGFR/PI 3K/Akt signaling pathway ，and its side effects are few.