Thickness of osteotomy affecting biomechanics of tibia cross-section in total knee arthroplasty / 医用生物力学

Objective To obtain different biomechanical conditions of the tibia section with different osteotomy thickness under different activity states,so as to provide theoretical basis for total knee arthroplasty (TKA) and patient activities after operation.Methods The three-dimensional models of lower limb were reconstructed and the proximal tibia was resect by 0 mm,5 mm,7 mm,9 mm,respectively,based on the principle of bone resection in TKA.The tibia models after osteotomy were assigned with the material properties,and the stress and strain of the tibia cross-section were then analyzed under the following activity states:standing,walking,running and climbing upstairs.Results The stress and displacement of the tibia cross-section increased with the increase of osteotomy thickness under the same activity state.The maximum stress and displacement of tibia cross-section with the same osteotomy thickness showed an increasing trend when the strength of activity increased.Conclusions For TKA in clinic,the stress and strain on tibia cross-section become larger with the thicker tibia osteotomy and the stronger postoperative activity.Excessive osteotomy in TKA and activity too intensively after TKA should be avoided,so as to reduce stress and strain of the tibia plateau and promote long-term life of the prosthesis.

Thickness of osteotomy affecting biomechanics of tibia cross-section in total knee arthroplasty / 医用生物力学

Objective To obtain different biomechanical conditions of the tibia section with different osteotomy thickness under different activity states,so as to provide theoretical basis for total knee arthroplasty (TKA) and patient activities after operation.Methods The three-dimensional models of lower limb were reconstructed and the proximal tibia was resect by 0 mm,5 mm,7 mm,9 mm,respectively,based on the principle of bone resection in TKA.The tibia models after osteotomy were assigned with the material properties,and the stress and strain of the tibia cross-section were then analyzed under the following activity states:standing,walking,running and climbing upstairs.Results The stress and displacement of the tibia cross-section increased with the increase of osteotomy thickness under the same activity state.The maximum stress and displacement of tibia cross-section with the same osteotomy thickness showed an increasing trend when the strength of activity increased.Conclusions For TKA in clinic,the stress and strain on tibia cross-section become larger with the thicker tibia osteotomy and the stronger postoperative activity.Excessive osteotomy in TKA and activity too intensively after TKA should be avoided,so as to reduce stress and strain of the tibia plateau and promote long-term life of the prosthesis.

Effects of thickness of osteotomy on biomechanics of tibia cross-section in total knee arthroplasty / 医用生物力学

Objective To obtain biomechanical conditions of the tibia section with different osteotomy thickness under different activity states, so as to provide theoretical basis for osteotomy thickness in total knee arthroplasty (TKA) and activities of patients after operation. Methods The three-dimensional models of the lower limb were reconstructed and the proximal tibia was resected by 0 mm,5 mm,7 mm,9 mm respectively based on the principle of bone resection in TKA. The tibia model after osteotomy were assigned the material properties and the stress and strain of the tibia cross-section were analyzed under the following activity states: standing, walking, running and going upstairs. Results The stress and displacement of the tibia cross-section increased with the increase in osteotomy thickness under the same activity state. The maximum stress and displacement of tibia cross-section increased in general with the same osteotomy thickness, when the strength of activity increased. Conclusions During TKA in clinic, the stress and strain on tibia cross-section became larger as the tibia osteotomy became thicker and the postoperative activity became stronger. Excessive osteotomy in TKA and high intensive activity after TKA should be avoided, so as to reduce stress and strain of the tibia plateau and promote long-term life of the prosthesis.

Multiple central clinical studies on the needling method for regulating wei and strengthening brain for treatment of insomnia / 中国针灸

<p><b>OBJECTIVE</b>To observe the clinical therapeutic effect of the needling method for regulating wei and strengthening brain on insomnia.</p><p><b>METHODS</b>Two hundred cases of insomnia were randomly divided into a test group and a control group, 100 cases in each group. The test group were treated with the needling method for regulating wei and strengthening brain with Baihui (GV 20), Dazhui (GV 14), Shenmai (BL 62), Zhaohai (KI 6) and ear points Yuanzhong, Shenmen selected; and in the control group, Sishencong (EX-HN 1), Shenmen (HT 7) and Sanyinjiao (SP 6) were selected. Acupuncture was given once daily for 15 days. Pittsburgh sleep quality index (PSQI) was used for scoring before and after treatment.</p><p><b>RESULTS</b>The total effective rate was 89.0% in the test group and 65.0% in the control group with a very significant difference between the two groups (P<0.01); the difference of PSQI scores before and after was -9.15+/-5.68 in the test group and -5.64+/-5.73 in the control group, with a very significant difference before and after treatment in the two groups (P<0.01).</p><p><b>CONCLUSION</b>The therapeutic effect of the needling method for regulating wei and strengthening brain on insomnia is better than that of normal needling method.</p>

PTEN induces anoikis through its phosphatase activity in hepatocellular carcinoma cells / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To investigate the effect and mechanisms of tumor suppressor gene PTEN on the induction of anoikis of hepatocellular carcinoma SMMC-7721 cells.</p><p><b>METHODS</b>SMMC-7721 cells were transfected with GFP plasmids containing wild-type PTEN or phosphatase inactivating mutant PTEN (C124A-PTEN) in vitro; The PTEN expression and the phosphorylation levels of focal adhesion kinase (FAK) and protein kinase B (PKB/Akt) were detected by Western blotting; Flow cytometry assay and laser scanning confocal microscopy were used to analyze apoptosis in adherent and non-adherent cells.</p><p><b>RESULTS</b>Compared with the control, PTEN expression in the cells transfected with wild-type PTEN increased to 248%, while the phosphorylation level of FAK and Akt decreased 65.2% and 89.1%, respectively; and the anoikis percentage increased from 9.5% to 31.3%. In the cells transfected with C124A-PTEN, neither the phosphorylation of FAK and Akt nor the anoikis percentage had obviously changed, although the PTEN expression enhanced dramatically in comparison with the control.</p><p><b>CONCLUSION</b>Through its phosphatase activity, tumor suppressor gene PTEN can suppress the phosphorylation of FAK and Akt, and induce anoikis in hepatocellular carcinoma cells.</p>

PTEN induces apoptosis and up-regulates p53 expression in HepG2 cells / 中华肝脏病杂志

<p><b>OBJECTIVE</b>To investigate the effects of tumor suppressor gene PTEN on apoptosis and protein expression of p53 in HepG2 cells, as well as to explore its mechanisms.</p><p><b>METHODS</b>HepG2 cells were transfected with GFP plasmids containing wild-type PTEN or G129E-PTEN and C124A-PTEN in vitro. Both the expression of wild-type p53 and the phosphorylation of protein kinase B (PKB/Akt) and focal adhesion kinase (FAK) were detected by Western blotting. Flow cytometry and confocal microscopy were used to analyze apoptosis of the transfected cells.</p><p><b>RESULTS</b>Compared with the control, the expression of phosphorylated FAK and phosphoylated Akt were down-regulated in HepG2 cells transfected with wild-type PTEN (-65%, -93%) and G129E-PTEN (-65%, -35%), whereas the apoptosis percentage increased to (19.8+/-1.2)% and (9.2+/-0.6)%, and p53 expression was up-regulated by 120% and 50%, respectively. However, in the cells transfected with C124A-PTEN, neither the phosphorylation of FAK and Akt nor the apoptosis percentage and p53 expression had changed.</p><p><b>CONCLUSION</b>PTEN can dephosphrylate FAK through its protein phosphatase activity, and suppress phosphorylation of Akt mainly through its lipid phosphatase activity. Consequently, it can induce apoptosis of HepG2 cells and up-regulate p53 expression.</p>