耐碳青霉烯类弗劳地枸橼酸杆菌耐药机制及治疗策略研究

目的 探索耐碳青霉烯类弗劳地枸橼酸杆菌耐药机制及治疗对策.方法 收集来自该院的17株耐碳青霉烯类弗劳地枸橼酸杆菌临床资料,采用PCR方法扩增碳青霉烯类耐药基因;采用琼脂稀释法和肉汤稀释棋盘法测磷霉素单药及联合用药最低抑菌浓度(MIC)值,计算部分抑菌浓度指数(ΣFICI).结果 8株菌产blaNDM-1,9株菌产blaIMP,blaKPC、blaoxA-48、blasPM均未检出;磷霉素联合亚胺培南协同作用和相加作用占75.oo％,其中协同作用高达56.25％,磷霉素联合头孢哌酮/舒巴坦钠协同作用和相加作用占50.oo％.结论 磷霉素联合亚胺培南或头孢哌酮/舒巴坦钠体外有较好的抗菌活性,亚胺培南联合磷霉素效果可能更好.     

DcR3基因对胰腺癌裸鼠移植瘤化疗敏感性的影响

目的探讨RNA 干扰沉默诱骗受体-3（DcR3）对人胰腺癌细胞裸鼠移植瘤化疗敏感性的影响及其可能机制。方法取对数生长期的AsPC-1 细胞1×106个/ml,接种于5 周龄裸鼠右后肢腹股沟,当皮下肿瘤直径为8 mm 左右,随机分为4 组（ n=10）：对照组、化疗组、阴性质粒+ 化疗组、DcR3 siRNA+ 化疗组。观察DcR3 siRNA联合化疗药物对人胰腺癌AsPC-1细胞裸鼠移植瘤的治疗效果。应用ELISA和Western blot检测DcR3 蛋白的变化;TUNEL 分析肿瘤细胞凋亡;Western blot 和RT-PCR 检测FasL、Caspase-8 和Caspase-3 等凋亡因子的表达。结果化疗组、阴性质粒+ 化疗及DcR3 siRNA+ 化疗组均可抑制移植瘤的生长,与对照组比较,3 组抑瘤率平均值分别为（35.87±4.58）%、（40.68±4.16）%和（90.25±2.53）%,4 组间差异有统计学意义（F =47.736,P =0.000）,DcR3 siRNA+ 化疗组抑瘤率较化疗组增加;对照组、化疗组、阴性质粒+ 化疗以及DcR3 siRNA+ 化疗组移植瘤重量平均值分别为（0.95±0.03）、（0.63±0.04）、（0.67±0.02）和（0.17±0.06）g,4 组间差异有统计学意义（F =85.531,P =0.000）,DcR3 siRNA+ 化疗组瘤重较化疗组减轻;对照组、化疗组、阴性质粒+化疗组、DcR3 siRNA+化疗组凋亡率平均值分别为（6.3±2.21）%、（14.8±2.65）%、（14.5±3.06）%和（54.6±3.23）%,4 组间差异有统计学意义（F =104.225,P =0.000）,DcR3 siRNA+ 化疗组凋亡率较化疗组增加;DcR3siRNA+化疗组的FasL、Caspase-8 和Caspase-3 蛋白表达较其他各组上升（P =0.000）。结论沉默DcR3 可激活FasL/Caspase 凋亡途径,促进细胞凋亡,增加胰腺癌细胞移植瘤对化疗的敏感性。     

Combination of tanshinone IIA and doxorubicin possesses synergism and attenuation effects on doxorubicin in the treatment of breast cancer

Doxorubicin (Dox) is a first‐line drug for breast cancer chemotherapy. However, with the prolongation of chemotherapy cycle, breast cancer cells are increasingly tempt to resist Dox, and meanwhile, high cumulative dose of Dox brings enhancing toxic side effects, and these effects may lead to chemotherapy failure. Hence, it is necessary to search an agent in combination medication with Dox, which can not only enhance the chemosensitivity of Dox but also reduce the toxic side effects. Tanshinone IIA (Tan IIA) is reported to have antitumor activity in addition to its cardiovascular protective effects. We employed human breast cancer MCF‐7 and MCF‐7/dox cells in order to assess whether Tan IIA might perform such function. Our in vitro studies showed that Tan IIA could enhance the sensitivity of breast cancer cells to Dox through inhibiting the PTEN/AKT pathway and downregulating the expression of efflux ABC transporters including P‐gp, BCRP, and MRP1. In addition, our in vivo studies showed Tan IIA enhanced the chemotherapeutic effect of Dox against breast cancer while reducing its toxic side effects including weight loss, myelosuppression, cardiotoxicity, and nephrotoxicity. Therefore, Tan IIA could be used as a novel agent combined with Dox in breast cancer therapy.     

双琼脂MTT法测定肿瘤的药物敏感性

目的：采用将集落法和ＭＴＴ法结合发展而成的双琼脂ＭＴＴ法以克服ＭＴＴ法中存在下沉细胞干扰测定的缺点。方法;对人肿瘤细胞及正常细胞株在双琼脂ＭＴＴ法和ＭＴＴ法光密度,抗癌药抑制率进行比较及临床实体瘤用两种方法的抗癌药抑制率进行比较。结果：正常细胞在双琼脂ＭＴＴ法中生长不良,用该两种方法测定临床２０例食道癌对抗癌药抑制率,比较显示双琼脂ＭＴＴ法的抑制率大于ＭＴＴ法。结论：双琼脂ＭＴＴ法提高了药敏结果的     

Anticancer chemosensitivity profile of freshly separated human pancreatic cancer cells assessed by DNA synthesis inhibition assay

The chemosensitivity of 49 freshly separated human pancreatic cancers to seven kinds of anticancer agents were assessed by a DNA synthesis (³H-thymidine incorporation) inhibition assay. DNA synthesis is higher in involved lymph nodes (n=7), malignant effusion (n=15), liver metastasis (n=7), primary cancer (n=15), and skin metastasis (n=5). Chemosensitivity assay demonstrates that etoposide, 4-epirubicin, carboquone, and 5-fluorouracil are more effective than cisplatin, mitomycin-C, and Adriamycin. In general, metastatic lesions of pancreatic cancer tend to show higher chemosensitivity than primary lesions. Pathological analysis demonstrates that small primary pancreatic cancers tend to be more responsive than large primary cancers, and primary pancreatic cancers with no regional lymph node involvement also tend to be more responsive than those with nodal involvement. No significant differences are seen in terms of tumor spread, vascular involvement, sex of patient, and histological type. When chemosensitivity assay is not available, the results of the present study may be beneficial to choose the regimens. © 1994 Wiley-Liss, Inc.     

Loss of 1p, 19q,and 10q heterozygosity prospectively predicts prognosis of oligodendroglial tumors—towards individualized tumor treatment?

The purpose of this study was to determine whether chromosome 10q loss is a predictor of tumor aggressiveness and poor clinical outcome in patients with oligodendroglial tumors alone or together with loss of heterozygosity (LOH) on chromosomes 1p and 19q. A microsatellite analysis was performed on sections from 130 patients with grade II and grade III oligodendroglial tumors to assess the allelic status of chromosomes 1p, 19q, and 10q, plus detailed clinical and radiological information was taken prospectively. Median age at diagnosis was 45.5 years. Seventy-eight patients had disease progression after initial therapy; median progression-free survival (PFS) was 27.5 months. Age <47 years, postoperative Karnofsky performance score >65, no contrast enhancement on MRI, grade II, and complete removal on surgery were significantly correlated with a better PFS. Median overall survival (OS) was 40.5 months. Pure oligodendroglioma and temozolomide chemotherapy were correlated with better OS. 10q LOH was correlated with anaplastic grade and 1p19q LOH correlated with pure oligodendroglioma. There was a significant association between LOH status and the tumors'' response to chemotherapy: 92.3% with 1p19q LOH, 83.3% without allelic losses, 50% with 1p19q10q LOH, and 14.5% with 10q LOH. Patients with 10q LOH alone had PFS of 6 months and a 3-year survival rate of 1%, when compared with 36 months and 85%, respectively, in patients with 1p19q LOH but without 10q LOH. 1p loss was correlated with better PFS (P < .005) and OS (P = .0007), whereas 10q loss was correlated with decreased PFS (P < .0001) and OS (P < .0001). 10q LOH predicted a survival disadvantage in patients with oligodendroglial tumors irrespective of 1p/19q LOH status.     

胃肠道肿瘤细胞周期素A的表达及其与化疗药物敏感性的关系

目的探讨胃肠道肿瘤细胞细胞周期素A（Cyclin A）的表达及其与肿瘤化疗敏感性之间的相关性。方法用流式细胞术双参数标记法对45例临床胃肠道肿瘤标本Cyclin A的表达进行检测，同时用四甲基偶氮唑盐显色法（MTT法）检测该肿瘤标本对几种常用化疗药物单药和联合用药方案的敏感程度。结果Cyclin A阳性表达的肿瘤细胞中对5-氟尿嘧啶（5-FU）、顺铂（DDP）、5-FU＋丝裂霉素（MMC）敏感的标本比例分别为76.9%、73.1%和84.6%；Cyclin A阴性表达的肿瘤细胞中相应的比例分别为15.8%、15.8%和10.5%，Cyclin A的表达与5-FU、DDP、5-FU＋MMC的药物敏感性之间具有相关性（均P〈0.01）。Cyclin A的表达与泰素（Taxol）、替尼泊苷（VM-26）、MMC、5-FU＋Taxol、5-FU＋DDP药物敏感性未发现有相关性（均P〉0.05）。结论Cyclin A的表达与某些肿瘤术后化疗方案的敏感程度显著相关，检测该指标对术后化疗药物和联合化疗方案选择可起到一定指导作用。     

RNAi沉默中期因子基因表达对结肠癌细胞凋亡和化疗敏感性的影响

目的观察中期因子(midkine,MK)基因小干扰RNA(small interfering RNA,si RNA)对结肠癌细胞增殖、凋亡和化疗药物敏感性的影响。方法设计合成MKsi RNA,转染结肠癌SW620细胞。细胞分5组:空白对照组,脂质体对照组和3.125nmol/L、6.25nmol/L、12.5nmol/L的si RNA干预组。于不同时间收获细胞。分别以实时定量PCR和Western blot检测各组细胞MK的mRNA及蛋白表达,分别通过caspase-3和TUNEL检测结肠癌细胞凋亡,以MTT法检测100μg/L伊立替康(CPT-11)对各组肿瘤细胞的生长抑制率。结果si RNA可有效抑制SW620结肠癌细胞MKmRNA和蛋白表达水平。结肠癌细胞caspase-3活性增高,呈浓度和时间依赖性;TUNEL结果显示,凋亡细胞明显增多,呈时间和浓度依赖性。MTT结果显示:CPT-11对各组细胞均有抑制作用,以12.5nmol/L的最为明显,而各对照组细胞无明显差异。结论MKsi RNA可诱导结肠癌细胞凋亡和增加化疗药物的敏感性。