Pharmacokinetic study of lappaconitine hydrobromide in mice by LC-MS.

A high sensitive and rapid method was developed for the analysis of lappaconitine in mouse plasma using liquid chromatography coupled to mass spectrometry (LC-MS). Detection was performed by positive ion electrospray ionization (ESI) in multiple reaction monitoring (MRM) mode, monitoring the transitions m/z 585 --> m/z 535 and m/z 356 --> m/z 192, for the quantification of lappaconitine and tetrahydropalmatine (internal standard, IS), respectively. The method was linear over the concentration range of 3.0-2000.0 ng x mL(-1). The lower limit of quantification was 3.0 ng x mL(-1). Intra- and inter-run precisions (RSD) were both less than 9.9% and accuracy (RE) within +/- 4.8%. After single intravenous injections of lappaconitine hydrobromide at 1.0, 2.0 and 4.0 mg x kg(-1), the elimination half-lives (t(1/2)) were 0.47, 0.48 and 0.49 h, and the areas under the curve (AUC(0-t)) were 55.5, 110.5 and 402.9 ng x h x mL(-1), separately. The pharmacokinetic profile of lappaconitine was linear at relatively lower dose levels (1.0-2.0 mg x kg(-1)). When the dose increased farther to 4.0 mg x kg(-1), the Vz and CL decreased, and the increase fold of the AUC was much larger than that of the dose.

[Monitoring "green tide" in the Yellow Sea and the East China Sea using multi-temporal and multi-source remote sensing images].

Landsat-TM (Theme Mapper) and EOS (Earth Observing System)-MODIS (MODerate resolution Imaging Spectrora-diometer) Terra/Aqua images were used to monitor the macro-algae (Ulva prolifera) bloom since 2007 at the Yellow Sea and the East China Sea. At the turbid waters of Northern Jiangsu Shoal, there is strong spectral mixing behavior, and satellite images with finer spatical resolution are more effective in detection of macro-algae patches. Macro-algae patches were detected by the Landsat images for the first time at the Sheyang estuary where is dominated by very turbid waters. The MODIS images showed that the macro-algae from the turbid waters near the Northern Jiangsu Shoal drifted southwardly in the early of May and affected the East China Sea waters; with the strengthening east-asian Summer Monsoon, macro-algae patches mainly drifted in a northward path which was mostly observed at the Yellow Sea. Macro-algae patches were also found to drift eastwardly towards the Korea Peninsular, which are supposed to be driven by the sea surface wind.