Methodology for the analysis of fenbendazole and its metabolites in plasma, urine, feces, and tissue homogenates

New methodology for the extraction and analysis of the anthelmintic fenbendazole and its metabolites from plasma, urine, liver homogenates, and feces from several animal species is presented. Quantitation of fenbendazole and its metabolites was conducted by high-pressure liquid chromatography using ultraviolet detection at 290 nm. The combined extraction and analysis procedures give excellent recoveries in all of the different biological matrices examined. High specificity, low limits of detection, and excellent linearity, accuracy, and inter- and intrasample variability were also obtained. The study of fenbendazole pharmacokinetics in vitro and in vivo should be greatly enhanced through the utilization of these methods.     

Quantifying the Effects of Green Crab Damage to Eelgrass Transplants

Mesocosm experiments were conducted in the summer of 1996 to quantify the effect of bioturbation by Carcinus maenas (the introduced European green crab) on survival of transplanted Zostera marina (eelgrass). The research grew out of a successful 2.52 ha eelgrass transplant project in the Great Bay Estuary of New Hampshire. At several subtidal sites, green crabs were found to damage transplanted eelgrass by cutting the shoots to the extent that some sites demonstrated poor survival. In three separate experiments, eight replicate mesocosm tanks were transplanted with 36 shoots of eelgrass, and different crab densities were introduced into the tanks. The number of shoots damaged by crabs was significantly higher in tanks with moderate (4.0 crabs/m²), high (7.0 crabs/m²), or very high (15.0 crabs/m²) crab densities than in tanks with low (1.0 crabs/m²) crab densities. Up to 39% of viable shoots were lost within one week of exposure to green crab activities. The mesocosm results demonstrated that green crabs were not directly attracted to eelgrass but that they significantly decreased transplant survival through their activity. Field densities of green crabs were found to exceed the density at which most damage occurred in the experiments, suggesting that this introduced species can be a major determinant of eelgrass transplant survival. The results underscore the major influence that biological components of transplant sites can have on transplant survival, and the need for their consideration in the site selection process.     

Effects of 2,4-Dichlorophenol, a Metabolite of a Genetically Engineered Bacterium, and 2,4-Dichlorophenoxyacetate on Some Microorganism-Mediated Ecological Processes in Soil

A genetically engineered microorganism, Pseudomonas putida PPO301(pRO103), and the plasmidless parent strain, PPO301, were added at approximately 10⁷ CFU/g of soil amended with 500 ppm of 2,4-dichlorophenoxyacetate (2,4-D) (500 μg/g). The degradation of 2,4-D and the accumulation of a single metabolite, identified by gas chromatography-mass spectrophotometry as 2,4-dichlorophenol (2,4-DCP), occurred only in soil inoculated with PPO301(pRO103), wherein 2,4-DCP accumulated to >70 ppm for 5 weeks and the concentration of 2,4-D was reduced to <100 ppm. Coincident with the accumulation of 2,4-DCP was a >400-fold decline in the numbers of fungal propagules and a marked reduction in the rate of CO₂ evolution, whereas 2,4-D did not depress either fungal propagules or respiration of the soil microbiota. 2,4-DCP did not appear to depress the numbers of total heterotrophic, sporeforming, or chitin-utilizing bacteria. In vitro and in situ assays conducted with 2,4-DCP and fungal isolates from the soil demonstrated that 2,4-DCP was toxic to fungal propagules at concentrations below those detected in the soil.     

Intensive Care Society's APACHE II study in Britain and Ireland--I: Variations in case mix of adult admissions to general intensive care units and impact on outcome.

OBJECTIVES--To describe the extent of variation in the case mix of adult admissions to general intensive care units in Britain and Ireland and investigate the impact of such variation on outcome. DESIGN--Prospective, cohort study of consecutive admissions to intensive care units. SETTING--26 general intensive care units in Britain and Ireland. SUBJECTS--9099 admissions to the intensive care units studied. MAIN OUTCOME MEASURE--Death or survival at discharge before and after adjustment of case mix (age, history of chronic conditions, surgical status, diagnosis, and severity of illness) according to the APACHE II method. RESULTS--Important differences in case mix were found, with large variations between the units. Hospital mortality was significantly associated with most of the case mix factors investigated. CONCLUSIONS--Comparing crude death rates in hospital between intensive care units may be misleading indicators of performance. The collection of data on case mix needs to be standardised and differences in case mix adjusted for when comparing outcome between different intensive care units.