Wear Simulation on Tibiofemoral Joint Surface of Rotating Hinge Knee Prosthesis / 医用生物力学

Objective To study the wear condition of rotating hinge knee prosthesis (RHKP) during horizontal walking gait, and provide technical references for wear prediction and clinical application of this kind of prosthesis. Methods A finite element wear model of RHKP was established based on the standard ISO 14243, and the simulation results including the wear distribution and mass wear rate of tibiofemoral joint surface were compared with the results from in vitro experiments on the same type of prosthesis. Results The mass wear rate of the polyethylene insert was 26.01 mg/MC (million cycle)from finite element analysis (FEA) and (30.06±1.21) mg/MC from in vitro experiments, and the mass wear rate of the upper surface of polyethene insert from FEA was about 3.3 times that of the lower surface. The wear area obtained by FEA was basically consistent with that obtained by in vitro wear measurement. The main wear area was symmetrically distributed in the middle and back of the upper surface. Conclusions The mass wear rate of RHKP, as a semi-restrictive prosthesis, is obviously higher than that of primary total knee joint prosthesis. More attention should be paid to wear test and evaluation of RHKP.

Wear Simulation of Tibiofemoral Joint Surface of Total Knee Prosthesis with High Conformity / 医用生物力学

Objective To investigate the effect of the tibiofemoral joint surface with high conformity on total knee prosthesis motion and insert wear. Methods A type of knee prosthesis with a high coronal conformity was designed and manufactured, and its insert wear was studied by in vitro wear testing combined with finite element simulation. ResultsThe mass wear rates calculated by the in vitro wear testing and finite element simulation were (14.29±3.19) mg/MC and 14.67 mg/MC (MC, million cycle), respectively. After five MCs, the areas of the insert wear obtained by both the methods were basically consistent, and severe wear was found to occur in the middle part of the insert. ConclusionsThe result of the finite element simulation coincided with that of the in vitro testing. The wear rate of the tibiofemoral joint surface of the total knee prosthesis with a high coronal conformity was relatively low. The research outcomes have practical significance for the evaluation and clinical application of the total knee prosthesis with a high conformity.

Preoperative CA125 and fibrinogen in patients with endometrial cancer: a risk model for predicting lymphovascular space invasion / 부인종양

OBJECTIVE: The aim of this study was to build a model to predict the risk of lymphovascular space invasion (LVSI) in women with endometrial cancer (EC). METHODS: From December 2010 to June 2013, 211 patients with EC undergoing surgery at Shanghai First Maternity and Infant Hospital were enrolled in this retrospective study. Those patients were divided into a positive LVSI group and a negative LVSI group. The clinical and pathological characteristics were compared between the two groups; logistic regression was used to explore risk factors associated with LVSI occurrence. The threshold values of significant factors were calculated to build a risk model and predict LVSI. RESULTS: There were 190 patients who were negative for LVSI and 21 patients were positive for LVSI out of 211 patients with EC. It was found that tumor grade, depth of myometrial invasion, number of pelvic lymph nodes, and International Federation of Gynecology and Obstetrics (FIGO) stage (p0.05) were not associated with LVSI. Receiver operating characteristic (ROC) curves revealed that the threshold values of the following factors were correlated with positive LVSI: 28.1 U/mL of CA19-9, 21.2 U/mL of CA125, 2.58 mg/dL of fibrinogen (Fn), 1.84 U/mL of carcinoembryonic antigen (CEA) and (6.35×10⁹)/L of white blood cell (WBC). Logistic regression analysis indicated that CA125 ≥21.2 (p=0.032) and Fn ≥2.58 mg/dL (p=0.014) were significantly associated with LVSI. CONCLUSION: Positive LVSI could be predicted by CA125 ≥21.2 U/mL and Fn ≥2.58 mg/dL in women with EC. It could help gynecologists better adapt surgical staging and adjuvant therapies.

Effect of silencing a disintegrin and metalloprotease 12 expression on self-renewal capacity of CD133 posi-tive giloma cells / 中国神经精神疾病杂志

Objective To investigate the inhibitory effect of a disintegrin and metalloprotease 12 silenced by shR?NA on self-renewal capacity of CD133 positive giloma cells. Methods The shRNA recombinant lentivirus aimed at si?lencing ADAM12 was prepared. Human glioma cells U87 were employed in this study and assigned into three groups:shRNA-ADAM12, shRNA-NCandshRNA-C. ADAM12 expression was detected at mRNA and protein level using Re?al-time quantitative-PCR and western bloting, respectively. U87 cells were cultured with stem cell culture medium, to obtain cell sphere formation in which CD133 positive glioma cells were enriched. Immunofluorescence was employed to detect the expression of ADAM12 and CD133 in cell spheres and U87 cells; Self-renewal was tested by using tumor sphere formation assay. Molecular markers for differentiated or undifferentiated cells (CD133,GFAP and Tuj1) were de?tected at protein using western blotting. Western blotting was employed to test protein expression of HES1. Results AD?AM12 shRNA significantly down-regulated the mRNA and protein expression levels of ADAM12. Compared with shRNA–C group, the relative expression levels of mRNA in shRNA-ADAM12 group and shRNA-NC group were 0.22 ± 0.03 and 0.98 ± 0.06 (F=425.37,P<0.01). The relative expression levels of protein in shRNA-ADAM12 group, shRNA-NC group and shRNA-C group were 28.72%±2.36%, 69.21%±3.92%and 69.04%±3.57%, respectively (F=145.42,P<0.01). Immunofluorescence staining showed that expression levels of ADAM12 and CD133 in cell spheres were significantly higher than those in normal cells. The number of spheres in three groups were 45.5±2.3、104.2±5.8 and 109.6±6.2, tumor sphere formation ability of shRNA-ADAM12 group was lower than that of shRNA-NC group and shRNA-C group (F=147.03,P<0.01). Compared with the shRNA-NC group and shRNA-C group, the protain expression of GFAP and Tuj1 were increased up to 166% and 146% (P<0.01) whereas the protein expression levels of CD133 and HES1 were down-regulated by 54% and 50% (P<0.01). Conclusion Knockdown of ADAM12 may suppress self-renewal ability of CD133 positive glioma cells by inhibiting the Notch pathway activity.

The effects of knockdown of S100A4 on invasion and migration of SNB19 glioma cells / 中国神经精神疾病杂志

Objective To investigate the effects of siRNA-mediated knockdown of S100A4 expression on the inva?sion and migration of SNB19 glioma cells. Methods The S100A4 expression was knockdowned using S100A4 siRNA in SNB19 glioma cells. Glioma cells were assigned into control group,siRNA-negative control treated group (siRNA-NC) and siRNA-S100A4 group. RT-PCR and western blot were used to detect the mRNA and protein expression of S100A4, respectively. The wound-healing assay and transwell invasion assay were used to determine the ability of migration and invasion of SNB19 glioma cells, respectively. The expression of matrix metalloproteinase 9 (MMP-9), matrix metallopro?teinase 2 (MMP-2) and E-cadherin proteins were evaluated by using western blot. Moreover, the morphology of lamellipo?dia of glioma cells were examined by using inverted phase-contrast microscopy. Results The mRNA and protein expres?sion levels of S100A4 was obviously down-regulated after transfection of S100A4 siRNA. Compared with control group, the mRNA expression levels of S100A4 in siRNA-NC group and siRNA-S100A4 group were 0.97±0.07 and 0.21±0.04,respectively(P<0.01). The protein expression levels of S100A4 in control, siRNA-NC and siRNA-S100A4 groups were 78.12%±2.63%, 77.16%±3.00%and 37.95%±2.71%, respectively(P<0.01). The migration and invasiveness capability were decreased up to 46% and 55% in the siRNA-S100A4 group compared with the control group(P<0.01). The pro?tein expression levels of MMP-9 and MMP-2 were inhibited up to 62% and 68%(P<0.01)whereas the expression of E-cadherin was increased up to 154%(P<0.01)in the siRNA-S100A4 group. The lamellipodia became smaller or unex?tended in siRNA-S100A4-treated SNB19 glioma cells. Conclusion S100A4 plays an important role in the invasion and migration of glioma cells, suggesting that S100A4 might be a potential candidate for anti-glioma strategy to prevent the invasion and migration of glioma cells.