Quantification of the bombesin/gastrin releasing peptide antagonist RC-3095 by liquid chromatography-tandem mass spectrometry.

Bombesin (BN) and its mammalian equivalent, gastrin-releasing peptide (GRP), stimulate cell proliferation and are involved in the pathogenesis of several types of human cancer. BN/GRP and their receptors were shown to be critical for the growth of various human malignancies, such as small-cell lung, prostate, ovary, stomach and breast cancers in the human tumor xenograft model. In the present study, a fast, sensitive, robust method was developed for the determination and quantification of a BN/GRP receptor antagonist RC-3095 (D-Tpi-Gln-Trp-Ala-Val-Gly-His-Leupsi(CH2NH)Leu-NH2), in human plasma by liquid chromatography coupled with tandem mass spectrometry. RC-3095 was extracted from 0.2 ml human plasma by protein precipitation using cold acetonitrile (0.4 ml). The method has a chromatographic run of 10 min using a C(8) analytical column (150 mm x 4.6 mm i.d.) and the linear calibration curve over the range was linear from 20 to 10000 ng ml(-1) (r(2)>0.994). The between-run precision, based on the relative standard deviation replicate quality controls, was 5.7% (60 ng ml(-1)), 7.1% (600 ng ml(-1)) and 6.8% (8000 ng ml(-1)). The between-run accuracy was +/-0.0, 2.1 and 3.1% for the above-mentioned concentrations, respectively. The developed procedure allows the quantitative determination of peptide RC-3095 for pharmacokinetics studies in human plasma.

Is full-field digital mammography more accurate than screen-film mammography in overall population screening? A systematic review and meta-analysis.

OBJECTIVE: To compare the accuracy of screen-film mammography (SFM) and full-field digital mammography (FFDM) for population-based breast cancer screening. STUDY DESIGN AND SETTING: A quantitative systematic review was performed including randomized controlled trials and cohort studies. RESULTS: Ten studies (comprising 667,649 women, 82,573 of whom underwent SFM and FFDM) were included. The area under the summary receiver operating characteristic (SROC) curve was 0.92 (SE ± 0.06) for SFM and 0.91 (SE ± 0.11) for FFDM. The results in the random-effects model were 0.95 (95% CI, 0.72-1.24) and 0.52 (95% CI, 0.28-0.95) for SFM versus FFDM in all age and younger groups, respectively. CONCLUSION: FFDM is more accurate than SFM only in women less than 50 years old.