RESUMEN
OBJECTIVES: To determine the accuracy of the OnTrak rapid urine latex agglutination immunoassay (AIA) for testing pregnant ED patients for the cocaine metabolite benzoylecgonine (BE), and to determine the frequency of urine BE in pregnant ED patients and the association of test results with patient demographics. METHODS: A test performance evaluation was conducted using an inception cohort of pregnant patients at an urban teaching hospital ED. Patients with positive urine chorionic gonadotropin tests who had adequate remaining urine samples were studied. Patient demographics, ED diagnoses, and assay results were recorded without patient identifiers. Urine was tested using the rapid AIA. The first 150 samples were confirmed using a second immunoassay and gas chromatography with a nitrogen phosphorus detector. All positive samples also were confirmed with thin-layer chromatography, and quantification by gas chromatography-mass spectrometry. RESULTS: Twenty of 342 (5.9%, 95% CI 3.4-8.4%) pregnant patients had urine samples positive by AIA testing for BE. Confirmation testing demonstrated no false-positive or -negative AIA result. Positive test results were not associated with specific patient diagnoses or demographics. CONCLUSIONS: ED screening for cocaine use among pregnant patients can be accurately performed using the OnTrak AIA for BE. In the ED population screened, 5.9% of the pregnant women had urine samples positive for BE.
Asunto(s)
Cocaína/análogos & derivados , Detección de Abuso de Sustancias/métodos , Adulto , Cromatografía en Capa Delgada , Cocaína/orina , Estudios de Evaluación como Asunto , Femenino , Cromatografía de Gases y Espectrometría de Masas , Humanos , Pruebas de Fijación de Látex , Embarazo , Reproducibilidad de los ResultadosRESUMEN
Molecular mechanics techniques are used to derive structural parameters that allow carbon-13 nuclear magnetic resonance spectra of disaccharides to be modeled. On the basis of a collection of 40 disaccharide spectra, four linear models are derived that allow complete spectra to be simulated. On the basis of these 40 compounds, the average difference between simulated and observed chemical shifts is +/- 0.45 ppm. The majority of structural parameters used are based on interatomic distances computed from modeled three-dimensional atomic coordinates. Found particularly useful in modeling the disaccharide spectra are the effects of oxygen electron lone pairs and encodings of the structural environments of hydrogens alpha to the carbon whose chemical shift is being predicted. The computed models are examined, and their predictive ability is assessed. The potential application of the methodology to the structure elucidation of disaccharides is demonstrated.