Although it is believed that glioma is derived from brain tumor stem cells, the source and molecular signal pathways of these cells are stil unclear. In this study, we used stable doxycycline-inducible transgenic mouse brain tumor models (c-myc+/SV40Tag+/Tet-on+) to explore the malignant trans-formation potential of neural stem cells by observing the differences of neural stem cel s and brain tumor stem cells in the tumor models. Results showed that chromosome instability occurred in brain tumor stem cells. The numbers of cytolysosomes and autophagosomes in brain tumor stem cells and induced neural stem cel s were lower and the proliferative activity was obviously stronger than that in normal neural stem cells. Normal neural stem cells could differentiate into glial fibril ary acidic protein-positive and microtubule associated protein-2-positive cells, which were also negative for nestin. However, glial fibril ary acidic protein/nestin, microtubule associated protein-2/nestin, and glial fibril ary acidic protein/microtubule associated protein-2 double-positive cells were found in induced neural stem cells and brain tumor stem cel s. Results indicate that induced neural stem cells are similar to brain tumor stem cells, and are possibly the source of brain tumor stem cells.

注射用盐酸多西环素致严重过敏反应1例

病例:患者,男,28岁,2009年7月29日因"尿频、尿急、尿痛两天"来我市中心医院治疗.查体:体温36.5℃,心率76次/分,呼吸18次/分,血压110/80mmHg(1mmHg=0.133KPa).神志清,精神尚可,口唇无紫绀,无腰痛、腹痛、腹泻等症状.尿常规结果为支原体、衣原体阳性,诊断为泌尿系感染.于当日下午15点10分给予注射用盐酸多西环素(海南通用康力制药有限公司,批号:090502)0.2g加入到5%葡萄糖注射液5oomL中静脉滴注,每分钟40滴,至下午17点30分输注完毕.

Doxycycline抑制大肠癌LS174T细胞侵袭的体外实验研究

目的:观察多西环素(Doxycycline)在体外对LS174T侵袭能力的抑制作用,并尝试探讨该抑制作用的分子机制.方法:1)MTT法观察Doxycycline对LS174T细胞粘附力的影响;Transwell小室法检测不同浓度Doxycycline对细胞侵袭和运动能力的抑制作用;2)RT-PCR法检测不同浓度Doxycycline作用48h后,MMP2的mRNA表达情况,同时明胶酶谱法检测MMP2分泌.结果:1)Doxycycline能够以剂量依赖方式抑制大肠癌LS174T细胞的体外运动和侵袭能力,但不影响其粘附能力;2)Doxycycline能够抑制LS174T细胞MMP2的mRNA表达.结论:Doxycycline在体外能够有效地抑制大肠癌LS174T细胞的侵袭、转移,其中MMP2是抑制大肠癌细胞LS174T的一个有效靶点.

Doxycycline抑制人肝癌细胞系HepG2生长的实验研究

目的:观察多西环素(Doxycycline)对人肝细胞性肝癌细胞系HepG2生长抑制和凋亡的作用,并初步探讨其作用机制.方法:不同浓度的Doxycycline(5、10、20、30和50mg/L)对体外培养人肝癌细胞系HepG2进行不同的时间干预(24、48和72h),MTT法测定细胞生长抑制率,TUNEL法检测细胞凋亡率,免疫细胞化学检测Fas、 FasL及MMP-2蛋白表达的变化.结果:Doxycycline作用HepG2细胞48h和72h后,细胞生长被明显抑制,与无药对照组比较差异有统计学意义(P＜0.001),且呈时间、浓度依赖趋势.其细胞凋亡率较无药对照组也明显升高(P＜0.01);20mg/L Doxycycline作用于癌细胞48h后,实验组FasL蛋白阳性表达较无药对照组明显升高,MMP-2蛋白阳性表达较无药对照组明显降低,两组差异均有统计学意义(P＜0.01),而Fas蛋白表达则差异无统计学意义(P＞0.05).结论:Doxycycline对人肝癌细胞系HepG<,2>具有明显的生长抑制和促凋亡作用,其机制可能与下调MMP-2、上调FasL从而启动Fas/FasL膜受体途径有关.