Objective To investigate the relationship between the expressions of P-gp, GST-π and C-erbB-2 and clinicopathologic characteristics as well as prognosis in breast cancer. Methods The expressions of P-gp， GST-π and C-erbB-2 were detected by immunohistochemistry in 48 cases of breast cancer, and histopathologic characteristics as well as 5-year survival rate of these cases were analyzed. Results There was no significant difference in the expressions of P-gp and GST-π with age, histologic grade, number of lymph node metastasis and TNM stage of breast cancer ( P ＞ 0.05). There was significant difference in expression of C-erbB-2 with histologic grade, number of lymph node metastasis and TNM stage of breast cancer （ P ＜ 0.05）. Positive rate of P-gp expression in breast cancer with positive C-erbB-2 expression was remarkably higher than that in breast cancer with negative C-erbB-2 expression ( P ＜ 0.05) . Positive rate of GST-π and C-erbB-2 expression in survivals within 5 years was remarkably lower than that in deaths within 5 years ( P ＜ 0.01). Conclusion P-gp participates primary drug-resistance mechanism of breast cancer. The possibility of primary drug-resistance is higher in breast cancer with positive C-erbB-2 expression. The expression of C-erbB-2 helps to evaluate prognosis and the result of treatment in breast cancer.
的报道楔形切开浆肌层的全阑尾切除术的临床应用体会。方法对72例根部肿胀增粗、坏疽穿孔合并盲肠壁增厚的急、慢性阑尾炎，从基底部楔形切开盲肠浆肌层，进行全阑尾切除术。结果该72例中无一例发生粪瘘、残端出血、残株炎及肠粘连等并发症。 结论合理应用从基底部楔形切开盲肠浆肌层的全阑尾切除术可有效预防根部肿胀增粗、坏疽穿孔的阑尾切除术后的粪瘘、残端出血、残株炎及肠粘连等并发症。
The stiffness of an ideal fracture internal fixation implant should have a time-varying performance, so that the fracture can generate reasonable mechanical stimulation at different healing stages, and biodegradable materials meet this performance. A topology optimization design method for composite structures of fracture internal fixation implants with time-varying stiffness is proposed, considering the time-dependent degradation process of materials. Using relative density and degradation residual rate to describe the distribution and degradation state of two materials with different degradation rates and elastic modulus, a coupled mathematical model of degradation simulation mechanical analysis was established. Biomaterial composite structures were designed based on variable density method to exhibit time-varying stiffness characteristics. Taking the bone plate used for the treatment of tibial fractures as an example, a composite structure bone plate with time-varying stiffness characteristics was designed using the proposed method. The optimization results showed that material 1 with high stiffness formed a columnar support structure, while material 2 with low stiffness was distributed at the degradation boundary and inside. Using a bone remodeling simulation model, the optimized bone plates were evaluated. After 11 months of remodeling, the average elastic modulus of callus using degradable time-varying stiffness plates, titanium alloy plates, and stainless steel plates were 8 634 MPa, 8 521 MPa, and 8 412 MPa, respectively, indicating that the use of degradable time-varying stiffness plates would result in better remodeling effects on the callus.
To address the conflict between the “fitness” and “feasibility” of body-fitted stents, this paper investigates the impact of various smoothing design strategies on the mechanical behaviour and apposition performance of stent. Based on the three-dimensional projection method, the projection region was fitted with the least squares method (fitting orders 1–6 corresponded to models 1–6, respectively) to achieve the effect of smoothing the body-fitted stent. The simulation included the crimping and expansion process of six groups of stents in stenotic vessels with different degrees of plaque calcification. Various metrics were analyzed, including bending stiffness, stent ruggedness, area residual stenosis rate, contact area fraction, and contact volume fraction. The study findings showed that the bending stiffness, stent ruggedness, area residual stenosis rate, contact area fraction and contact volume fraction increased with the fitting order's increase. Model 1 had the smallest contact area fraction and contact volume fraction, 77.63% and 83.49% respectively, in the incompletely calcified plaque environment. In the completely calcified plaque environment, these values were 72.86% and 82.21%, respectively. Additionally, it had the worst “fitness”. Models 5 and 6 had similar values for stent ruggedness, with 32.15% and 32.38%, respectively, which indicated the worst "feasibility" for fabrication and implantation. Models 2, 3, and 4 had similar area residual stenosis rates in both plaque environments. In conclusion, it is more reasonable to obtain the body-fitted stent by using 2nd to 4th order fitting with the least squares method to the projected region. Among them, the body-fitted stent obtained by the 2nd order fitting performs better in the completely calcified environment.
Stent migration is one of the common complications after tracheal stent implantation. The causes of stent migration include size mismatch between the stent and the trachea, physiological movement of the trachea, and so on. In order to solve the above problems, this study designed a non-uniform Poisson ratio tracheal stent by combining the size and structure of the trachea and the physiological movement of the trachea to improve the migration of the stent, meanwhile ensuring the support of the stent. In this study, the stent corresponding to cartilage was constructed with negative Poisson's ratio, and the stent corresponding to the circular connective tissue and muscular membrane was constructed with positive Poisson's ratio. And four kinds of non-uniform Poisson's ratio tracheal stents with different link lengths and negative Poisson's ratio were designed. Then, this paper numerically simulated the expansion and rebound process of the stent after implantation to observe the support of the stent, and further simulated the stretch movement of the trachea to calculate the diameter changes of the stent corresponding to different negative Poisson's ratio structures. The axial migration of the stent was recorded by applying different respiratory pressure to the wall of the tracheal wall to evaluate whether the stent has anti-migration effect. The research results show that the non-uniform Poisson ratio stent with connecting rod length of 3 mm has the largest diameter expansion in the negative Poisson ratio section when the trachea was stretched. Compared with the positive Poisson's ratio structure, the axial migration during vigorous breathing was reduced from 0.024 mm to 0.012 mm. The negative Poisson's ratio structure of the non-uniform Poisson's ratio stent designed in this study did not fail in the tracheal expansion effect. Compared with the traditional stent, the non-uniform Poisson's ratio tracheal stent has an anti-migration effect under the normal movement of the trachea while ensuring the support force of the stent.