吡喹酮对日本血吸虫病肝组织中c-fos、c-jun mRNA和端粒酶逆转录酶表达的影响

为研究小鼠感染日本血吸虫时肝组织恶性变潜能以及吡喹酮对其的抑制作用，取120只小鼠随机分为4个组。第1、2组分别在感染日本血吸虫尾蚴6、12周时，以吡喹酮500mg·kg^-1·d^-1治疗2天；第3组为实验对照组，感染后不作任何治疗；第4组为正常对照组。应用HE染色、免疫组化染色及RT-PCR方法，观察和分析各组小鼠肝组织病理改变及产， c-fos和c-jun mRNA、端粒酶逆转录酶（TERT）的表达变化。结果表明病变早期予吡喹酮治疗后肝脏病理损伤减轻，肝组织中产，c-fos、c-jun mRNA以及端粒酶逆转录酶的表达均明显低于实验对照组（p〈0.01）但仍高于正常组（p〈0.01）；病变晚期予吡喹酮治疗后，与实验对照组比较，c-jun mRNA、端粒酶逆转录酶含量无显著差异（p〉0.05），仅c-fos mRNA表达降低（p〈0.05）。吡喹酮早期治疗组肝组织中上述3指标表达水平明显低于晚期治疗组。因此血吸虫病时肝硬化组织可存在恶性变潜能，早期吡喹酮治疗可显著降低肝组织这种恶性变潜能。     

Mechanical stretch promotes proliferation of rat bone marrow mesenchymal stem cells

Tissues and cells in the body are continuously exposed to a complex mechanical environment. Mechanical stimulations are critical to morphological, developmental and functional states of living cells, and the fashion of the mechanical stimulation applied to the cells is supposed to be extremely important for the induced cell response and function. In this study, we investigated whether mechanical stretch regulates and promotes proliferation of rat bone marrow mesenchymal stem cells (rMSCs) in vitro. rMSCs from rat bone marrow were isolated, purified and subjected to a cyclic equiaxial stretch treatment, and then MTT assay was adopted and expression of c-fos gene was measured by RT-PCR to access cell proliferation. The results demonstrated that OD values of rMSCs increased in a time-dependent and magnitude-dependent manner after exposure to 1 Hz stretch within 15–60 min and 2–8% strain. Expression of c-fos gene in rMSCs subjected to stretch treatment (1 Hz, 8% strain and 60 min) is significantly higher than that of unstimulated control cells. These results suggest that mechanical stretch plays an important role in regulating the cell growth and proliferation, and an appropriate mechanical stretch treatment could promote proliferating capacity of rMSCs.     

Effect of Endothelin, Angiotensin Ⅱ and ANP on Proliferation of Vascular Smooth Muscle Cells and Cardiomyocytes

By means of cell culture, ~3H-thymidine (~2H-TdR) incorporation and c-fos oncogene dot plotting technique, it was found that endothelin (ET) and angiotensin (ANG Ⅱ) could promote proliferation and DNA synthesis of cultured vascular smooth muscle cells (VSMCs) and myocardial cells, and stimulate expression of c-fos oncogene of VSMCs. However, atrial natriuretic peptide (ANP) antagonizes the above effects of ET and ANG Ⅱ.