Real-time quantitative RT-PCR detection of circulating tumor cells from breast cancer patients.

Circulating tumor cells (CTCs) were recognized as novel tumor biomarker for prognostic and predictive purposes in various cancers. Various detection technologies and devices have been developed to enumerate and characterize CTCs. Most of those approaches are based on the positive enrichment strategy and immunocytological techniques. However, the sensitivity of these approaches proved to be limited in metastatic tumors and the detection of early tumor cell dissemination was problematic. In the present study, we developed a novel CTC detection method by real-time RT-PCR technique in combination of negative enrichment strategy. The developed enrichment approach could recover more than 75% of spiked breast cancer cells from peripheral blood. The detection limit of duplex real-time RT-PCR assay using KRT19 and ERBB2 as targeted genes was consistently one breast tumor cell. Moreover, CTC detection by duplex real-time RT-PCR assay had higher detection sensitivity than that by immunostaining, especially in early breast cancer. In summary, the results of the present study indicated the potential clinical utilities of CTCs identification on breast cancer by duplex real-time RT-PCR in combination with negative enrichment.

Truncated abrin A chain expressed in Escherichia coli: a promising vaccine candidate.

Abrin toxin (AT) is a highly potent toxin, and is classified as one of the most important biological warfare and bioterrorism agents. There is currently no approved vaccine for AT. Therefore, the development of an effective vaccine is important in the prevention of intoxication by abrin. In this study, five vectors containing different gene of truncated abrin toxin A chain (tATA) fragments were constructed, and two of them (tATA1(1-126), tATA4(1-188)) were successfully expressed as a soluble form in E.coli strain. Both of the two tATA retained most of their immunogenicity with either low or no toxic effects as determined by both in vitro and in vivo assays. They were used to immunize BALB/c mice three times at an interval of three weeks apart. As a result, the tATA1 can elicite 80% protective efficacy against i.p. challenge of 5×LD50 of abrin, and the tATA4 provides a better protection, which can elicite 100% protective efficacy against intraperitoneal challenge of 40×LD50 of abrin. The superior fragment (tATA4(1-188)) should be considered as a promising vaccine candidate for further investigations.

Determination of antazoline hydrochloride in rat plasma and excreta by reversed-phase ion-pair chromatography and its application to pharmacokinetics.

A reversed-phase ion pair chromatography method with liquid-liquid extraction analytical method was developed and validated for the determination of antazoline hydrochloride in plasma and excreta of rat. The aim of our study was to characterize the preclinical pharmacokinetics and excretion profiles of antazoline hydrochloride in rats after intravenous injection at the dose of 10 mg/kg. Plasma and excreta samples were extracted with ethyl acetate, and phenacetin was used as the internal standard. The result showed that the method is suitable for the quantification of antazoline hydrochloride in plasma and excreta samples. Analysis of accuracy (90.89-112.33%), imprecision (<7.1%) and recovery (>82.5%) showed adequate values. After a single intravenous administration at 10 mg/kg to rats, plasma concentration profile showed a relative fast elimination proceeding with a terminal elimination half-life of 3.53 h. Approximately 61.8 and 14.2% of the administered dose were recovered in urine and bile after 72 and 24 h post-dosing respectively; 5.9% of the administered dose was recovered in feces after 72 h post-dosing. The above results show that the major elimination route is urinary excretion.