ABSTRACT
Objective To compare the effects of cortical bone trajectory ( CBT) and traditional trajectory ( TT)pedicle screw internal fixation on the range of motion (ROM) and rod system stress of normal and osteoporotic(OP) spines. Methods The L3-S1 finite element models of normal and OP spines were established. The screwrod system with two kinds of trajectory was used for internal fixation of the L4-5 segment, so as to simulate sixphysiological loads, namely, flexion, extension, left / right bending, left / right rotation. The effects of two internalfixation methods on ROMs and maximum equivalent stress of screws in normal and OP spines were compared.Results For both bone conditions, CBT and TT significantly reduced ROM of the fixed segment (L4-5) and theentire segment of lower lumbar spine ( L3-S1). However, the ROM decline of CBT group was slightly smaller than that of TT group, and their ROMs were similar under flexion and extension, but the ROM differences were significant under lateral bending and axial rotation. In addition, for both the normal and OP spine models, themaximum equivalent stress of screws in CBT group was significantly higher than that in TT group. Compared withTT group, the screw stress of CBT group in normal spine model under flexion and extension, lateral bending,axial rotation was increased by 27% , 268% and 58% , respectively. However, when CBT technique was used atthe same time, the OP spine model had a smaller screw stress distribution than the normal spine model.Conclusions Compared with TT technique, CBT technique can achieve higher screw stress under OP conditionand reduce screw stress concentration under normal bone condition. In addition, CBT slightly increases ROMs of each segment, which is conducive to recovery of spinal physiological function after surgery. Lateral bending and axial rotation can produce negative mechanical effects, and these two physiological loads should be avoided.
ABSTRACT
Purpose To observe the functional expression of calcium sensing receptor ( CaSR) in human gastric cancer SGC-7901 cell line, the effect of CaSR on intracellular calcium, cell proliferation and migration of SCG-7901. Methods The expression and distribu-tion of CaSR were detected by Western blotting and immunofluorescence observation in SGC-7901. The intracellular concentration of free calcium ( [ Ca2+] i ) was determined by confocal laser scanning microscopy. MTT, flow cytometry and scratch test were used to an-alyze the impact of CaSR the proliferation and the migration capabilities of SGC-7901 cell. Results CaSR protein was expressed in SGC-7901. Extracellular calcium or calindol significantly increased the expression of [Ca2+]i, CaSR and E-cadherin;In addition, the migration capabilities were decreased. Conclusion CaSR is expressed in SGC-7901. The activation of CaSR induces the expression of E-cadherin, and decreases migration ability.
ABSTRACT
Objective To study the risk prediction for new intracerebral hemorrhage (ICH) with high sensitivity C-reactive protein ( hs-CRP) level. Methods In a retrospective, nested, case-controlled study, 323 cases of ICH were identified and matched with 646 controls. The hs-CRP levels at baseline were compared between the two groups. The relevance of different hs-CRP levels and the risk of ICH were analyzed. Results The ICH group had a higher median hs-CRP levels (1.10 mg/L) as compared with the control group (0. 66 mg/L) with significant difference ( P<0.01 ). In addition, the increase of risk associated with hs-CRP levels was primarily observed in the individuals with the highest quartile of hs-CRP levels(>2.12 mg/L). These patients had an increased risk of ICH (OR 2. 58, 95% CI 1. 77 to 3. 76) as compared with those in the lowest quartile(≤=0.30 mg/L). Individuals with basiline hs-CRP levels above the specified cut point of 3 mg/L ormore and those in the 80th percentile were at a markedly increased risk of ICH (for specified cut point of 3 mg/L,0R2.26, 95% CI 1.60-3.20, P<0.01; for 80th percentile, OR 2.24,95% CI 1.60-3.13, P <0.01, respectively). Conclusions Risk of ICH might be predicted with the level of hs-CRP. With the increase of hs-CRP level at baseline, the risk of ICH was increased.