脂联素通过AMPK调节HepG2细胞中支链氨基酸的代谢

目的:探讨脂联素(APN)对HepG2细胞支链氨基酸(BCAA)分解代谢的影响及其作用机制。方法:将培养的HepG2细胞系随机分为对照组、APN组、APN+腺苷酸活化蛋白激酶(AMPK)抑制剂(Compound C,CpC)组(APN+CpC)组和AMPK激动剂(AICAR)组。用Western blot检测AMPK、P-AMPK、BCKD E1α(BCAA分解代谢过程中的关键酶,磷酸化时为失活状态)及P-BCKD E1α蛋白的表达,用ELISA方法检测培养HepG2细胞上清中BCAA的含量。结果:与对照组相比,APN组和AICAR组均可以显著上调细胞P-AMPK的水平(P0.05,P0.01),显著降低细胞p-BCKD E1α及上清中BCAA的水平(P0.05,P0.01)。与APN组比较,APN+CpC组,其细胞内PAMPK水平显著下降(P0.01),P-BCKD E1α及上清中BCAA的水平明显上升(分别为P0.05及P0.01)。结论:APN可显著促进HepG2细胞BCAA的分解代谢,其作用机制与AMPK磷酸化作用的上调相关。     

Surgical incision in complete video-assisted mitral valve replacement

Background Prosthetic mitral valve replacement is a common surgical treatment of mitral valve disease.Complete video-assisted mitral valve replacement represents the contemporary minimally invasive cardiac surgery in valve disease surgical therapy. In the field of minimally invasive cardiac surgery, the success of the operation is largely depending on surgical incision, it also reflects the surgeon's technique level. Method From February 2010 to February 2013, 80 cases of cardiac patients with mitral valve pathological changes in our department who had received surgical treatment of complete video-assisted mitral valve replacement were recruited, they were divided into two groups according to the surgical incision: midclavicular group(M group,n = 50) and parasternal group(P group, n = 30). The clinical data were recorded including: cardiopulmonary bypass time, aortic clamping time, volume of thoracic drainage after operation, ICU tracheal intubation time,postoperative days of hospital stay and time for observing the postoperative complications. The comparison between two groups was performed using t-test analysis. Result Both M Group and P Group had favorable surgical view, there were no emergency situation of redo median sternotomy during initial operative period or intraoperative death, no pericardial tamponade, no infection, and no other serious postoperative complications.Whereas, there were 2 cases of redo operation for stanch bleeding in M Group and 1 case of perivalvular leakage in P Group. Nevertheless, 3 months later, the result of reexamine showed that the perivalvular leakage had vanished. The clinical data was shown as follow(M Group vs. P Group): cardiopulmonary bypass time(90.2 ± 28.7 vs. 87.3 ± 24.5 min, P 0.05), aortic clamping time(65.2 ± 17.4 vs. 68.6 ± 21.9 min, P 0.05),1st day volume of thoracic drainage after operation 1(75.8 ± 35.6 vs. 53.2 ± 25.6 mL, P 0.05), ICU tracheal intubation time(9.6 ± 3.4 vs. 8.4 ± 4.5 hours, P 0.05), postoperative days of hospital stay(7.3 ± 2.2 vs. 6.9± 3.2 days, P 0.05). T-test analysis of the data of each groups showed that there were no significant statistically difference. Conclusions Appropriate surgical incisions guarantee a favorable surgical view and the success of the whole process during intraoperative period. In both midclavicular and parasternal approaches, the complete video-assisted mitral valve replacement is able to be accomplished safely and successfully. Due to the current development level of thoracoscopic instruments and equipment, the surgical incision and approach for video-assisted mitral valve replacement are diversified. As a result, diversified surgical incisions can be customized according to the variegated pathological changes of cardiac patients.     

Angiotensin II inhibits uptake of transferrin-bound iron but not non-transferrin-bound iron by cultured astrocytes

The existence of all components of the renin–angiotensin system (RAS) and the iron metabolism system, and the recent findings on the functions of angiotensin II (ANGII) in peripheral iron metabolism imply that ANGII might play a role in iron homeostasis by regulating expression of iron transport proteins in the brain. Here, we investigated effects of ANGII on uptake and release of iron as well as expression of cell iron transport proteins in cultured astrocytes. We demonstrated that ANGII could significantly inhibit transferrin-bound iron (Tf-Fe) uptake and iron release as well as the expression of transferrin receptor 1 (TfR1) and the iron exporter ferroportin 1 (Fpn1) in cultured astrocytes. This indicated that the inhibitory role of ANGII on Tf-Fe uptake and iron release is mediated by its negative effect on the expression of TfR1 and Fpn1. We also provided evidence that ANGII had no effect on divalent metal transporter 1 (DMT1) expression as well as non-transferrin-bound iron (NTBI) uptake in the cells. Our findings showed that ANGII has a role to affect expression of iron transport proteins in astrocytes in vitro and also suggested that ANGII might have a physiological function in brain iron homeostasis.     

白色假丝酵母菌pACT1-GFP质粒的构建及表达

目的构建能够稳定表达绿色荧光蛋白（GFP）的白色假丝酵母菌菌株,以便对目的基因进行示踪。方法构建pACT1-GFP质粒,以白色假丝酵母菌CAI4菌株作为感受态进行转化培养后,分别观察绿色荧光蛋白在两相型下的表达情况。结果含有pACT1-GFP的白色假丝酵母菌菌株,99%在两相型下均有较高水平的荧光蛋白表达,且荧光强度没有明显差别。结论pACT1-GFP能够在白色假丝酵母菌体内稳定表达。     

弧形牵张成骨重建人体下颌骨颏部节段性缺损的三维有限元研究

目的:建立下颌骨颏部节段性缺损弧形牵张成骨的三维有限元模型,研究弧形牵张成骨重建下颌骨颏部节断性缺损过程中,不断变化方向的牵张力对新骨组织形成的影响。方法:建立颏部节段性缺损的三维有限元模型,并把简化后的弧形牵张器有限元模型置入截断后的下颌骨,模拟弧形牵张成骨,并测量在弧形牵张成骨过程中下颌骨整体位移及其von Mises应力分布。结果:在未考虑唇颊侧软组织作用的前提下,弧形牵张成骨形成的新骨向舌侧生长,重建的下颌骨弧度较原下颌骨弧度变小。von Mises应力主要集中于牵张器在下颌骨的固位处。结论:在弧形牵张成骨重建下颌骨缺损过程中,牵张力本身就促使新骨组织向舌侧生长,从而使重建的下颌骨弧度较正常时小。此项研究为临床上如何克服弧形牵张成骨所形成的下颌骨弧度较小的不足,提供了一定的理论依据。     

计算机辅助设计在单侧完全性唇腭裂婴儿术前矫治中的应用

目的:评价计算机辅助设计在单侧完全性唇腭裂患儿术前矫治中的应用价值。方法:对10例单侧完全性唇腭裂新生儿取模,通过三维激光扫描仪对模型进行扫描并实现三维重建,三维诊断设计软件模拟整个错位上颌骨各骨段的矫正过程,并输出用于矫治器加工的数字模型。快速激光成型技术恢复矫治过程的模型并制作一系列矫治器,临床应用于单侧完全性唇腭裂患儿的术前矫正治疗。结果:经过3～4个月的术前矫正,错位牙槽骨排列成较为规则的弧形;唇部裂隙宽度减小,鼻翼塌陷畸形得到改善,鼻小柱偏斜得到纠正。结论:计算机辅助设计的单侧完全性唇腭裂患儿术前矫治能实现精确、量化的矫治目标,同时减少复诊次数,是一种高效、简洁的术前矫治方法。