Therapeutic monitoring of albendazole: a high-performance liquid chromatography method for determination of its active metabolite albendazole sulfoxide

A sensitive and specific reversed-phase high-performance liquid chromatography (HPLC) method is described for the quantitative determination of albendazole sulfoxide (ASOX); since albendazole sulfone (ASON) appears only in small amounts and albendazole (ABZ) normally does not appear in human plasma, only a qualitative determination of ASON and ABZ was made in human plasma. Plasma samples were extracted three times using ethylacetate and petroleum benzine; this yielded optically clear samples which after evaporation were dissolved in the HPLC solvent and injected onto an RP-C18 column, with ultraviolet detection at 290 nm. The detection limit of the main metabolite ASOX was 50 nM and that of ASON was 100 nM. The intraday coefficient of variation for ASOX was 3.3% at a concentration of 2.2 microM, and the interday coefficients of variation were 14.5, 7.3, and 9.1% at ASOX concentrations of 0.5, 2.5, and 5.0 microM, respectively. Calibration was linear in a concentration range of 0.05-12 microM for ASOX and 0.1-8 microM for ASON, respectively. Pharmacokinetic data of a patient with echinococcosis are presented

Albendazole kinetics in patients with echinococcosis: delayed absorption and impaired elimination in cholestasis

The pharmacokinetics of albendazole and its main metabolite, albendazole sulphoxide, have been examined after giving a single oral dose of 200 mg albendazole to 19 patients with either Echinococcus multilocularis or E. granulosus, 5 of whom had significant extrahepatic obstruction due to the underlying disease. The AUC of albendazole sulphoxide was increased in the latter patients (mean 122 mumols.h.l-1 compared to 17 mumols.h.l-1 in the non-obstructed group). Obstructed patients had delayed absorption, ka averaging 0.39 compared to 1.41 h-1 in non-obstructed patients. The corresponding elimination rate constant, ke was also prolonged, averaging 0.041 and 0.13 h-1 in the two groups, respectively. Four patients were restudied after complete or partial resolution of the cholestasis. The pharmacokinetic parameters in them had returned towards values comparable to those in the non-obstructed patients

Moths complement bumblebee pollination of red clover: A case for day-And-night insect surveillance

Recent decades have seen a surge in awareness about insect pollinator declines. Social bees receive the most attention, but most flower-visiting species are lesser known, non-bee insects. Nocturnal flower visitors, e.g. moths, are especially difficult to observe and largely ignored in pollination studies. Clearly, achieving balanced monitoring of all pollinator taxa represents a major scientific challenge. Here, we use time-lapse cameras for season-wide, day-And-night pollinator surveillance of Trifolium pratense (L.; red clover) in an alpine grassland. We reveal the first evidence to suggest that moths, mainly Noctua pronuba (L.; large yellow underwing), pollinate this important wildflower and forage crop, providing 34% of visits (bumblebees: 61%). This is a remarkable finding; moths have received no recognition throughout a century of T. pratense pollinator research. We conclude that despite a non-negligible frequency and duration of nocturnal flower visits, nocturnal pollinators of T. pratense have been systematically overlooked. We further show how the relationship between visitation and seed set may only become clear after accounting for moth visits. As such, population trends in moths, as well as bees, could profoundly affect T. pratense seed yield. Ultimately, camera surveillance gives fair representation to non-bee pollinators and lays a foundation for automated monitoring of species interactions in future.ISSN:1744-9561ISSN:1744-957