Liquid chromatography-tandem mass spectrometry (LC-MS-MS) is emerging as the tool of choice for rapid analysis and the detection of biologically active compounds in complex mixtures. We describe the development of a sensitive method for the simultaneous quantitation of 10 benzodiazepines in Calliphora vicina (Diptera: Calliphoridae) larvae and puparia. The use of larvae for toxicological analyses offers some technical advantages over putrefied tissue. Four sample pretreatment methods for isolating the benzodiazepines out of larvae were evaluated. A simple homogenization, followed by acetonitrile precipitation yielded the highest recoveries. Puparia were pulverized and extracted by ultrasonification in methanol. All extracts were subsequently analyzed using reversed-phase LC-MS-MS. Larvae and puparia calibrators containing benzodiazepines at concentrations ranging from 25 to 750 pg/mg and 50 to 500 pg/mg, respectively, were prepared and analyzed. The method was demonstrated to be linear over the ranges investigated. Limits of detection were from 1.88 to 5.13 pg/mg larva and from 6.28 to 19.03 pg/mg puparium. The developed method was applied to the determination of nordiazepam and its metabolite oxazepam in larvae and puparia of the Calliphora vicina fly that had been reared on artificial foodstuff (beef heart) spiked with 1 microg/g nordiazepam. The larvae were harvested at day 5 for analysis of drug content. The method was sufficiently sensitive to allow the detection of nordiazepam and oxazepam in a single larva or puparium.
Larvae of the Calliphora vicina (Diptera: Calliphoridae) were reared on artificial food spiked with different concentrations of nordiazepam. The dynamics of the accumulation and conversion of nordiazepam to its metabolite oxazepam in post-feeding larvae and empty puparia were studied. Analysis was performed using a previously developed liquid chromatography-tandem mass spectrometry (LC-MS/MS) method. This method enabled the detection and quantitation of nordiazepam and oxazepam in single larvae and puparia. Both drugs could be detected in post-feeding larvae and empty puparia. In addition, the influence of nordiazepam on the development and growth of post-feeding larvae was studied. However, no major differences were observed for these parameters between the larvae fed on food containing nordiazepam and the control group. To our knowledge, this is the first report describing the presence of nordiazepam and its metabolite, oxazepam, in single Calliphora vicina larvae and puparia.
BackgroundThere is a need for complete and accurate epidemiological studies for traumatic brain injury (TBI). Secondary use of administrative data can provide country-specific population data across the full spectrum of disease.AimThis study aims to provide a population-based overview of Belgian TBI hospital admissions as well as their health-related and employment outcomes.MethodsA combined administrative dataset with deterministic linkage at individual level was used to assess all TBI hospitalizations in Belgium during the year 2016. Discharge data were used for patient selection and description of injuries. Claims data represented the health services used by the patient and health-related follow-up beyond hospitalization. Finally, social security data gave insight in changes to employment situation.ResultsA total of 17,086 patients with TBI were identified, with falls as the predominant cause of injury. Diffuse intracranial injury was the most common type of TBI and 53% had injuries to other body regions as well. In-hospital mortality was 6%. The median length of hospital stay was 2 days, with 20% being admitted to intensive care and 28% undergoing surgery. After hospitalization, 23% had inpatient rehabilitation. Among adults in the labor force pre-injury, 72% of patients with mild TBI and 59% with moderate-to-severe TBI returned to work within 1 year post-injury.DiscussionAdministrative data are a valuable resource for population research. Some limitations need to be considered, however, which can in part be overcome by enrichment of administrative datasets with other data sources such as from trauma registries.
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