Correlations on radioimmunoassay, fluorescence polarization immunoassay, and enzyme immunoassay of cannabis metabolites with gas chromatography/mass spectrometry analysis of 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid in urine specimens.

Results obtained from three commercial immunoassay kits, Abuscreen, TDx, and EMIT, commonly used for the initial test of urine cannabinoids (and metabolites) were correlated with the 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (9-THC-COOH) concentration as determined by GC/MS. Correlation coefficients obtained based on 26 (out of 1359 total sample population) highly relevant samples, are 0.601 and 0.438 for Abuscreen and TDx. Correlation coefficients obtained from a parallel study on a different set of 47 (out of 5070 total sample population) highly relevant specimens are 0.658 and 0.575 for Abuscreen and Emit. The immunoassay concentration levels, that correspond to the commonly used 15 ng/ml GC/MS cutoff value for 9-THC-COOH, as calculated from the regression equations are 82 ng/ml and 75 ng/ml for TDx and EMIT and 120 ng/ml and 72 ng/ml for Abuscreen manufactured at two different time periods. The difference of these calculated corresponding concentrations provides quantitative evidence of the reagent specificity differences.     

Factors associated with breath test refusals in drunken driving arrests.

OBJECTIVE: Jurisdictions with per se breath alcohol legislation rely heavily on breath test evidence in prosecuting drunk driving cases. Depending on other legal considerations, where subjects refuse the breath test, prosecution may be more difficult. The objective was to identify factors significantly associated with the risk of test refusal. This knowledge would be relevant for improving the compliance rate. METHOD: A retrospective observational study evaluated drunken driving arrest records (n = 38,687) within Washington State during 2003 where breath tests were requested under implied consent legislation. The association was determined between the risk of test refusal and several categorical variables including: arresting agency, gender, race, age, accident involvement, repeat offense, pre-arrest breath test, driver's license and all possible two-way interactions. The association was quantified by odds ratios (OR) and 95% confidence intervals (CI) using a logistic regression model. RESULTS: The overall refusal rate was 19.7%. The single main effect variable associated with the greatest reduction in risk of refusal was the performance of a pre-arrest breath test (OR = 0.31, 95% CI 0.30-0.33). No single main effect variables showed significant association with an increased risk of refusal. Several two-way interactions, however, were significant. Other possible predictor variables, not included in the analysis, are also discussed. CONCLUSIONS: An arrested subject's decision to refuse the breath test is clearly a multivariate issue. Knowledge of these results should help in developing a jurisdictionally specific breath test compliance model by identifying the legal, demographic and procedural factors contributing most significantly to breath test refusal rates.     

Hair analysis for cocaine: Factors in laboratory contamination studies and their relevance to proficiency sample preparation and hair testing practices

Hair samples were contaminated by rubbing with cocaine (COC) followed by sweat application, multiple shampoo treatments and storage. The samples were then washed with isopropanol for 15 min, followed by sequential aqueous washes totaling 3.5 h. The amount of drug in the last wash was used to calculate a wash criterion to determine whether samples were positive due to use or contamination. Analyses of cocaine and metabolites were done by LC/MS/MS. These procedures were applied to samples produced by a U.S. government-sponsored cooperative study, in which this laboratory participated, and to samples in a parallel in-house study. All contaminated samples in both studies were correctly identified as contaminated by cutoff, benzoylecgonine (BE) presence, BE ratio, and/or the wash criterion. A method for determining hair porosity was applied to samples in both studies, and porosity characteristics of hair are discussed as they relate to experimental and real-world contamination of hair, preparation of proficiency survey samples, and analysis of unknown hair samples.     

Understanding management: Henry Mintzberg on the activities of managers

The Nature of Managerial Work, 2^nd edition. By Henry Mintzberg . Engle‐wood Cliffs, N.J.: Prentice‐Hall.     

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