A UHPLC-MS/MS method coupled with liquid-liquid extraction for the quantitation of phenacetin, omeprazole, metoprolol, midazolam and their metabolites in rat plasma and its application to the study of four CYP450 activities.

Drug-drug interactions (DDIs) are thought to be associated with the inhibition of cytochrome P450 activities. The cocktail method with analysis of the metabolism of two or more probe drugs is used to determine CYP450 activities. In this study, we established a UHPLC-MS/MS method for simultaneous quantitation of four CYP450 probe drugs (phenacetin, omeprazole, metoprolol and midazolam) and their metabolites (acetaminophen, 5'-hydroxy omeprazole, α-hydroxy metoprolol and 1'-hydroxy midazolam) in rat plasma. Sample preparation by plasma protein precipitation was combined with a liquid-liquid extraction method. The separation was carried out on a ZORBAX Eclipse Plus C18 Rapid Resolution High Definition column with a gradient elution, using water containing 0.1% formic acid (A) and acetonitrile (B) in a run time of only 3.0 min. Detection was conducted with a 6420 series triple-quadrupole tandem mass spectrometer, using ESI in positive ion mode with multiple reaction monitoring (MRM). The calibration curves were linear over the concentration range 10-5000 ng/mL for phenacetin, omeprazole, metoprolol and midazolam, and 1-500 ng/mL for their metabolites. Intra- and inter-day precisions were within 15%, and the accuracies were in the range of 87-112%. The method was successfully applied to the pharmacokinetic study of probe drugs/metabolites and DDIs with 3-n-butylphthalide (NBP) after administration of a single oral dose of phenacetin, omeprazole, metoprolol and midazolam in rats.

Predictors of short-term and long-term incontinence after robot-assisted radical prostatectomy.

Purpose To determine retrospectively the prognostic factors for urinary incontinence following robot-assisted radical prostatectomy (RARP). Methods Altogether, 180 patients with localized prostate cancer underwent RARP (same surgeon). Preoperative physical status, disease characteristics, laboratory findings, and surgical technique were recorded and the patients checked 1, 6, 12, and 24 months after RARP regarding their contribution to predicting post-prostatectomy urinary incontinence (PPI). Results Overall, 114 (63.3%) patients had PPI 1 month after RARP and 19 patients (16.0%) at 24 months. Univariate analysis showed that age was a significant factor for predicting PPI at 1 month. PPI predictors at 24 months were age, body mass index, preoperative serum albumin level, previous transurethral resection of the prostate, total operative time, and bladder neck sparing. Multivariate analysis indicated that age and total operative time were significant predictors. Conclusion Older age and longer operative time were highly relevant to short- and long-term PPI occurrence after RARP.

[Remote sensing analysis of ecological change caused by construction of the new island city: Pingtan Comprehensive Experimental Zone, Fujian Province].

Pingtan Island was officially established as the 'Pingtan Comprehensive Experimental Zone of Fujian' in 2010, and it led to a surge of construction in the island city. Based on the Landsat-5 images for 2007 and the latest Landsat-8 images for 2013, this paper studied the ecological status, the temporal trends of the ecological changes and the reasons for those changes in Pingtan Comprehensive Experimental Zone at its early stage of construction, by using the remote sensing of ecological index (RSEI). The results showed that as an ecologically fragile area, Pingtan Island had a moderate level of overall ecological status. In the early construction period (from 2007 to 2013), the ecological status of the island showed a downward trend, with a 14% drop of RSEI from 0.511 in 2007 down to 0.450 in 2013, and approximately 36.5% of the area of the island faced the degradation of ecological status, which mainly occurred in the central and southwestern parts of the island. The reason for the degradation was mainly due to the large-scale construction which further damaged the scarce vegetation on the island. Therefore, in order to curb the downward trend of the ecological quality of Pingtan Comprehensive Experimental Zone, some effective ecological protection measures must be developed and implemented during the construction.