Biomechanical study of different approach for lumbar interbody fusion surgeries under vibration load / 生物医学工程学杂志

The human spine injury and various lumbar spine diseases caused by vibration have attracted extensive attention at home and abroad. To explore the biomechanical characteristics of different approaches for lumbar interbody fusion surgery combined with an interspinous internal fixator, device for intervertebral assisted motion (DIAM), finite element models of anterior lumbar interbody fusion (ALIF), transforaminal lumbar interbody fusion (TLIF) and lateral lumbar interbody fusion (LLIF) are created by simulating clinical operation based on a three-dimensional finite element model of normal human whole lumbar spine. The fusion level is at L4-L5, and the DIAM is implanted between spinous process of L4 and L5. Transient dynamic analysis is conducted on the ALIF, TLIF and LLIF models, respectively, to compute and compare their stress responses to an axial cyclic load. The results show that compared with those in ALIF and TILF models, contact forces between endplate and cage are higher in LLIF model, where the von-Mises stress in endplate and DIAM is lower. This implies that the LLIF have a better biomechanical performance under vibration. After bony fusion between vertebrae, the endplate and DIAM stresses for all the three surgical models are decreased. It is expected that this study can provide references for selection of surgical approaches in the fusion surgery and vibration protection for the postsurgical lumbar spine.

CT diagnosis of parovarian cyst / 实用放射学杂志

Objective To investigate the CT performances and causes of misdiagnosis of parovarian cyst,to improve its diagnostic accuracy.Methods CT data of 75 patients with surgically and pathologically confirmed parovarian cyst were analyzed retrospectively. Results Among the 75 patients,there were 79 cysts,in which 48 patients (51 cysts)originated from the epoophoron and 27 patients (28 cysts) from the mesosalpinx.77 were simple serous cysts and 2 serous cystadenomas.38 were located in the right ovarian adnexa,36 in the left ovarian adnexa,3 in the anterosuperior uterus,1 in the rectouterine pouch and 1 in the right iliac fossa.The size of the cysts ranged from 10 mm × 13 mm to 174 mm × 227 mm.75 were single cysts and 4 double cysts,34 presented as ovoid cysts,25 as irregular cysts, 17 as round cysts and 3 as gourd-shaped cysts.All the 79 cysts showed clear boundaries,thin walls,non-mural nodules,cystic fluid with a homogeneous densitywith CT value of 0-31 HU.Enhanced scanning revealed curved “obvious enhancement of the fallopian tube”at the edge of 68 cysts.In addition,the ipsilateral ovary could be detected in 76 cysts.“Holding ball”was found in 1 9 cysts.Conclusion Indication in ipsilateral ovary,curved “obvious enhancement of the fallopian tube”at the edge of cysts and “holding ball”are distinctive CT performances of parovarian cysts.CT has an important diagnostic value in parovarian cyst.

A significance study on expression of SUZ12 and MMP-9 in retinoblastoma / 重庆医学

Objective To observe the expression of inhibitor of Zeste 12(SUZ12) and matrix metalloproteinase-9(MMP-9) in retinoblastoma(RB) and their significance .Methods The paraffin embedded specimens from 56 patients with RB were studied ,10 patients belong to intraocular stage ,28 patients intraocular pressure increased stage and 18 patients outside ocular stage among them .22 ,16 ,12 ,and 6 patients with invasion degree(N) from N0-N3 differently ,while10 ,16 ,18 and 12 patients with cell differenti-ations(D) from D0-D3 differently .The expressions of SUZ12 and MMP-9 protein in 56 patient s were detected in different clinical stages ,invasion degree and cell differentiation by immunohistochemical staining and their correlations were analyzed .Results The expressions of SUZ12 and MMP-9 in RB tissues[(31 .48 ± 12 .20)% ,(34 .49 ± 13 .25)% ]were obviously higher than in para-cancer tissue[(0 .26% ± 0 .06)% ,(0 .36 ± 0 .08)% ](P<0 .01) .The expression of SUZ12 was related to clinical stages ,invasion degree and cell differentiation .The expression of SUZ12 and MMP-9 in intraocular pressure increased stage was obviously higher than in-traocular stage(t=10 .299 ,16 .253 ;P<0 .01) ,and outside ocular stage was obviously higher than intraocular stage (t= 20 .819 , 36 .417 ;P<0 .01)and intraocular pressure increased stage (t= 10 .348 ,15 .061 ;P< 0 .01) .The expression of SUZ12 and MMP-9 was increasing from N0 to N3 but decreasing from D0 to D3 .The expression of SUZ12 in RB was related to MMP-9 expression(r=0 .840 ,P=0 .000) .Conclusion The expression of SUZ12 and MMP-9 increased in RB tissue and it is helpful to predict the malig-nancy degree of RB .