1.Biomechanical Evaluation of Upper-Middle Thoracic Vertebrae Fixed by Cortical Bone Trajectory Screws: A Finite Element Simulation Study
Sunren SHENG ; Meichao ZHANG ; Qingan ZHU
Journal of Medical Biomechanics 2019;34(3):E251-E255
Objective To compare biomechanical properties of cortical bone trajectory (CBT) screw and traditional trajectory screw for fixing upper-middle thoracic spine. Methods The tomography images were obtained by CT scanning of normal T7 and T8 segments, and the three-dimensional (3D) model of T7-8 was reconstructed by Mimics software. The finite element model of upper-middle thoracic spine was established by optimizing FreeForm model and pre-processing function of ANSYS software. On this basis, the CBT screw and pedicle screw fixation models after discectomy were established, and 5 N·m flexion, extension, lateral bending and rotation loads were applied to the two model groups, respectively. The displacement and peak stress of vertebrae and implants under different working conditions were compared and analyzed. Results Under different loading conditions, the maximum displacement of CBT screw group was lower than that of pedicle screw group, and the range of motion of CBT screw group was lower than that of pedicle screw group. The stress level of both models was close, and the stress of CBT screw group was slightly lower than that of pedicle screw group. Under the load of flexion, extension and rotation, the maximum vertebral stress of pedicle screw group decreased by 31%, 17% and 18% compared with that of CBT screw group, and under lateral bending load, the vertebral stress of CBT screw group was 20% lower than that of pedicle screw group. Under the load of flexion and rotation, the maximum stress of pedicle screw group decreased by 2% and 11%; however, the maximum stress of CBT screw group was 11% and 1% lower than that of pedicle screw group. Conclusions The stability of CBT screw was better than that of pedicle screw, and the overall stress distribution was similar to that of pedicle screw. However, the vertebral stress distribution of CBT group was slightly inferior. The research findings provide a theoretical basis for the clinical application of cortical screw fixation after the failure in pedicle screw fixation for the upper-middle thoracic vertebrae.
2.Application of real-time transperineal ultrasound in radiotherapy of prostate cancer-4D analysis of intra-fractional prostate motion
Xin QI ; Bo ZHAO ; Shangbin QIN ; Xianshu GAO ; Hongzhen LI ; Shuchao ZHANG ; Siwei LIU ; Qingan WANG ; Min ZHANG ; Xueying LI
Chinese Journal of Radiation Oncology 2018;27(7):675-679
Objective To apply real-time transperineal ultrasound ( TPUS) to monitor the intra-fractional prostate motion,collect and analyze the data of the prostate motion,aiming to provide evidence for the optimization of the target area and plan of radiotherapy for prostate cancer. Methods TPUS is a non-invasive monitoring technique that utilizes an automatic scanning ultrasound probe to dynamically monitor and correct the motion of organs during radiotherapy. In this study, TPUS was utilized to collect 1588 intra-fractional data of 70 patients with prostate cancer. Prior to each cycle of radiotherapy,CBCT was adopted to correct the errors between intra-factional data by using VMAT. During radiotherapy, real-time ( once per second) ultrasound images were acquired to monitor the 3D motion of the prostate on the x (left+,right-),y (cranial+, caudal-), and z ( abdominal+, dorsal-) axes, emphasizing the analysis of 4D motion of the prostate. Results All patients successfully completed the treatment and data collection. The median time of effective monitoring per faction was 179 seconds (132-286 seconds). During 95% of the monitoring time,the distance of prostate motion was 2. 22 mm in the left direction,2. 17 mm in the right,2. 08 mm in the cranial, 1. 98 mm in the caudal,2. 44 mm in the abdominal and 2. 97 mm in the dorsal direction,respectively. In the x,y and z axes,the percentage of time in which the distance of prostate motion less than 1 mm among the total time was 83. 07%,85. 46% and 78. 27%,respectively,whereas 97. 70%,97. 87% and 96. 45% for<3 mm, respectively. Conclusions TPUS is a non-invasive real-time monitoring technique,which can detect the 4D motion of the prostate during radiotherapy. By using VMAT,the range of prostate motion is relatively small, and the motion range is less than 3 mm in each direction within 95% of the time.
3.Effect of ischemic postconditioning on IL-6 and ATP level during renal ischemia-reperfusion injury in obstructive jaundice rats
Yi LI ; Xuexia ZHANG ; Wenying ZHOU ; Wenhua LI ; Qingan ZENG
The Journal of Practical Medicine 2016;32(15):2442-2444
Objective To investigate the apoptosis effect of ischemic postconditioning on levels of IL-6 and ATP during renal ischemia/reperfusion injury in obstructive jaundice rats. Methods One hundred SD rats were randomly divided into 5 groups: the Sham control group , I/R group , OJ-Sham group , OJ-I/R group , and OJ- I/R+IPO group, with 20 cases in each group. According to the time after ischemia/reperfusion, each group was divided into four subgroups (n = 5), with reperfusion time of 0 h, 1 h, 3 h, 6 h, respectively. After 1 week of biliary obstruction , rats were sacrificed at 0 h , 1 h , 3 h , 6 h post-I/R , and the left kidneys were taken, renal tissue was used for determination of the levels of interleukin-6 (IL-6) and adenosinetriphosphate (ATP). Results Compared with the OJ-I/R group, the serum level of BUN,Cr decreased significantly in the OJ-I/R-IPO group (P < 0.05). Conclusion Ischemic postconditioning can reduce the injury of kidney ischemia-reperfusion in OJ rais , which may be related to the reduced inflammation reaction and the energy metabolism in the kidney.
4.Dynamic contrast-enhanced MRI in the estimation of tumor angiogenesis and pathologic grading of extrahepatic cholangiocarcinoma
Yu WANG ; Qingan XIA ; Yuxin ZHANG ; Peng PENG ; Haiping WANG ; Menghua MA
Chinese Journal of Hepatobiliary Surgery 2014;20(1):6-10
Objective To investigate the role of dynamic contrast-enhanced MRI (DCE-MRI) in the estimation of tumor angiogenesis and pathologic grading of extrahepatic cholangiocarcinoma.Methods Routine preoperative MRI and DCE-MRI scanning were performed on 57 patients with extrahepatic cholangiocarcinoma.The early signal enhancement ratio (eSER) and delayed signal enhancement ratio (dSER) of DCE-MRI were calculated.Microvessel density (MVD) and vascular endothelial growth factor (VEGF) expressions were detected in the extrahepatic cholangiocarcinoma tissue samples using immunohistochemical methods.The relations between the eSER or dSER and MVD,VEGF and the pathological grading of extrahepatic cholangiocarcinoma were analyzed.Results There was a positive correlation between the eSER or dSER and MVD of extrahepatic cholangiocarcinoma (r =0.62,P < 0.05 ; r =0.45,P < 0.05).The eSER of extrahepatic cholangiocarcinoma with a positive VEGF expression was higher than those with a negative VEGF expression (t =3.53,P < 0.05).There was no significant difference in dSER between the positive VEGF expression group and the negative VEGF expression group (t =1.35,P >0.05).There was no significant difference in the eSER or dSER among the different differentiated extrahepatic cholangiocarcinoma (F =2.65,P > 0.05 ; F =2.23,P > 0.05).Conclusions The eSER and dSER reflected tumor angiogenesis of extrahepatic cholangiocarcinoma,and DCE-MRI contributed to the evaluation of biological features of extrahepatic cholangiocarcinoma in vivo.
5.Biphasic calcium composite bone cement with a negative surface charge used in vertebroplasty
Shufang ZHANG ; Rongchun CHEN ; Jianming JIANG ; Qingan ZHU
Chinese Journal of Tissue Engineering Research 2014;(12):1805-1810
BACKGROUND:A newly developed calcium phosphate/β-tricalcium phosphate composite bone cement with a negative surface charge (genex?) has been reported to possess osteoinductivity properties. However, to our knowledge, no previous literatures have reported genex? for vertebroplasty in the osteoporotic spine.
OBJECTIVE:To evaluate the biomechanical properties and osteogenesis of vertebral bodies injected with genex? cement in a rabbit vertebroplasty defect model.
METHODS:Thirty New Zealand rabbits were used to establish osteoporosis models. Four weeks after modeling, model rabbits had an iatrogenical y created cavitary lesion at L 3 and L 5 and were injected with either genex? cement (experimental group) or polymethyl methacrylate bone cement (control group). The L 1 vertebral body served as model group without treatment. After 3 and 6 months, 15 rats from each group were executed respectively, and three vertebral samples were taken for Micro-CT analysis and biomechanical tests.
RESULTS AND CONCLUSION:(1) The Micro-CT showed better three-dimensional structure parameters of the trabecular bone in the experimental group than the control group (P<0.05) after 3 months, which however had no difference from the model group (P>0.05). After 6 months, the structure parameters in the experimental group were superior to those in the control and model groups (P<0.05). (2) After 3 months, the vertebral body compression strength of the experimental group was lower than that of the control group (P<0.05), but higher than that in the model group (P<0.05). The vertebral stiffness of the experimental group was lower than that in control and model groups (P<0.05). After 6 months, the vertebral body compression strength of the experimental group was not different from that of the control group (P>0.05), but stil higher than that of the model group (P<0.05). The vertebral stiffness showed no difference between three groups (P>0.05). These findings indicate that genex? cement can rapidly repair osteoporotic vertebral defects and improve the bone strength. Verterbroplasty with genex? cement has adequate osteoinductivity, biocompatibility, and adequate compressive strength.
6.Biomechanical study of vertebroplasty with geneX(®) cement augmentation in a calf osteoporotic vertebral compression fracture model.
Shufang ZHANG ; Jianming JIANG ; Qingan ZHU ; Zhiping HUANG
Journal of Southern Medical University 2012;32(6):843-846
OBJECTIVETo evaluate the biomechanical properties of geneX cements for use in vertebroplasty in a calf osteoporotic vertebral compression fracture model.
METHODSThirty vertebral bodies (T(9)-L(4)) were harvested from 4 fresh calf spines. The bone mineral density was measured with dual-energy radiographic absorption. Osteoporotic vertebral model was induced in each vertebra using decalcifying chemical agents, and was then compressed to determine their initial strength and stiffness before injecting the cement. Thirty vertebral bodies were divided randomly into geneX(®) cement group, CSC group, and PMMA group. The fractures were repaired using a transpedicular injection of cements and re-compressed to measure posttreatment strength and stiffness.
RESULTSThe normal mean BMD of the calf vertebra was 1.425∓0.072 g/cm(2), which was reduced significantly to 1.074∓0.065 g/cm(2) after decalcification. The mean injected volume was similar between geneX(®) (4.5∓0.7 ml), CSC (4.3∓0.8 ml) and PMMA (3.8∓0.4 ml) groups. The vertebral strength was restored after the treatment to 1198∓529 N in geneX(®) group, 1212∓430 N in CSC group and 1672∓704 N in PMMA group. All the cements produced significantly greater strength than the initial strength (P<0.05). The augmented strength in geneX(®) and CSC groups were similar (P>0.05), but both were significantly less than that in PMMA group (P<0.05). The stiffness in geneX(®), CSC, and PMMA groups was 233∓130, 242∓191, and 323∓145 N/mm, respectively, showing no significant difference between them (P>0.05). No significant difference was found in the augmented stiffness among the 3 cements (P>0.05).
CONCLUSIONgeneX(®) cement is a useful alternative to PMMA in vertebroplasty for osteoporotic vertebral compression fractures, but further study is needed to evaluate its biosorption in vivo.
Animals ; Biomechanical Phenomena ; Bone Cements ; therapeutic use ; Cattle ; Disease Models, Animal ; Fractures, Compression ; etiology ; surgery ; Lumbar Vertebrae ; injuries ; Osteoporosis ; complications ; pathology ; Thoracic Vertebrae ; injuries ; Vertebroplasty
7.Clinical study on primary suture of common bile duct and T-tube drainage
Bin QU ; Qingan WANG ; Quanmin XIANG ; Haiyang KONG ; Peng ZHANG ; Weidong WANG ; Zhilong TIAN ; Lei KONG
Chinese Journal of Postgraduates of Medicine 2012;35(11):4-7
ObjectiveTo explore the clinical significance of primary suture of common bile duct and early intermittented clamping of T-tube.MethodsOne hundred and one cases underwent bile duct surgery were divided into three group by random digits table,in which 33 cases were performed with primary suture of common bile duct (group A),33 cases were applied of early intermittented clamping of T-tube (group B),the other 35 cases were clamped T-tube as in routine measures (group C).The efficacy was compared between three groups.ResultsThe postoperative intestinal function recovery time,fluid support,hospitalization time in group A and group B was (47.63 ± 12.42) h,(2.75 ± 0.27) L/d,(8.0 ± 0.3) d and (57.63 ± 14.15) h,(2.97 ±0.49) L/d,(10.0 ± 0.4) d,which was significantly decreased compared with those in group C [ ( 98.27 ± 30.35 ) h,( 3.63 ± 0.38 ) L/d,( 19.0 ± 1.1 ) d ] (P < 0.05 ).Postoperative intestinal function recovery in group A was significantly increased compared with those in group B (P < 0.05 ).Alanine aminotransferase,aspartate aminotransferase,Gamma-glutamine transferase,body temperature,white blood cell count,total bilirubin,postoperative biliary fistula,common bile duct residual stones,stenosis of the common bile duct had no significant differences among three groups (P > 0.05). ConclusionsPrimary suture of common bile duct and early intermittented clamping of T-tube can accelerate recovery of intestinal function,avoid electrolyte disturbance,reducing fluids,electrolytes and nutrition support,reducing the length of stay and costs,it has changed the traditional way of surgical treatment of bile duct,and is safe,efficient,also has significance of clinical application.
8.SCGPred: a score-based method for gene structure prediction by combining multiple sources of evidence.
Xiao LI ; Qingan REN ; Yang WENG ; Haoyang CAI ; Yunmin ZHU ; Yizheng ZHANG
Genomics, Proteomics & Bioinformatics 2008;6(3-4):175-185
Predicting protein-coding genes still remains a significant challenge. Although a variety of computational programs that use commonly machine learning methods have emerged, the accuracy of predictions remains a low level when implementing in large genomic sequences. Moreover, computational gene finding in newly sequenced genomes is especially a difficult task due to the absence of a training set of abundant validated genes. Here we present a new gene-finding program, SCGPred, to improve the accuracy of prediction by combining multiple sources of evidence. SCGPred can perform both supervised method in previously well-studied genomes and unsupervised one in novel genomes. By testing with datasets composed of large DNA sequences from human and a novel genome of Ustilago maydi, SCG-Pred gains a significant improvement in comparison to the popular ab initio gene predictors. We also demonstrate that SCGPred can significantly improve prediction in novel genomes by combining several foreign gene finders with similarity alignments, which is superior to other unsupervised methods. Therefore, SCG-Pred can serve as an alternative gene-finding tool for newly sequenced eukaryotic genomes. The program is freely available at http://bio.scu.edu.cn/SCGPred/.
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Chromosome Mapping
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Computational Biology
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methods
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Exons
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genetics
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Genes, Fungal
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Genome, Human
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Reproducibility of Results
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Ustilago
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genetics
9.SCGPred: A Score-based Method for Gene Structure Prediction by Combining Multiple Sources of Evidence
Li XIAO ; Ren QINGAN ; Weng YANG ; Cai HAOYANG ; Zhu YUNMIN ; Zhang YIZHENG
Genomics, Proteomics & Bioinformatics 2008;6(3):175-185
Predicting protein-coding genes still remains a significant challenge. Although a variety of computational programs that use commonly machine learning methods have emerged, the accuracy of predictions remains a low level when implementing in large genomic sequences. Moreover, computational gene finding in newly sequenced genomes is especially a difficult task due to the absence of a training set of abundant validated genes. Here we present a new gene-finding program, SCGPred,to improve the accuracy of prediction by combining multiple sources of evidence.SCGPred can perform both supervised method in previously well-studied genomes and unsupervised one in novel genomes. By testing with datasets composed of large DNA sequences from human and a novel genome of Ustilago maydi, SCGPred gains a significant improvement in comparison to the popular ab initio gene predictors. We also demonstrate that SCGPred can significantly improve prediction in novel genomes by combining several foreign gene finders with similarity alignments, which is superior to other unsupervised methods. Therefore, SCGPred can serve as an alternative gene-finding tool for newly sequenced eukaryotic genomes. The program is freely available at http://bio.scu.edu.cn/SCGPred/.

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