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Gwendolyn A Mcmillin – One of the best experts on this subject based on the ideXlab platform.
cross reactivity of phentermine with an immunoassay designed to detect amphetamine in a meconium specimenClinical Chemistry, 2009Co-Authors: Stephanie J Marin, Gwendolyn A Mcmillin, Christine MooreAbstract:
Neonates exposed to drugs of abuse in utero can experience prenatal drug dependence leading to withdrawal symptoms and a number of other health problems (1). Early detection of exposure is critical to guide necessary treatment and improve outcomes for these children. Meconium begins to form in the digestive tract at 12–16 weeks gestation. Drugs and metabolites collect in meconium beginning at about 5 months gestation. Thus, meconium testing can identify exposure to drugs during the last 4 months of a full-term pregnancy (2).
Our laboratory uses ELISA reagents (Immunalysis) to detect drugs of abuse in meconium. Poor specificity of immunoassay reagents for Amphetamines is well characterized and as a result, specimens that test positive for Amphetamines by immunoassay are routinely tested by a second analytical method to prevent false-positive results. Our ELISA screen for meconium has separate detection antibodies for amphetamine and methamphetamine. The ELISA cutoff for these drugs is 20 ng/g. All positive screen results are confirmed by GC-MS.
We report the investigation of an unconfirmed positive amphetamine result. ELISA assay of the meconium specimen …
Arian Van Asten – One of the best experts on this subject based on the ideXlab platform.
novel selectivity based forensic toxicological validation of a paper spray mass spectrometry method for the quantitative determination of eight Amphetamines in whole bloodJournal of the American Society for Mass Spectrometry, 2017Co-Authors: Sebastiaan F Teunissen, Arian Van Asten, Patrick W Fedick, Bjorn J A Berendsen, Michel W F Nielen, Marcos N Eberlin, Graham R CooksAbstract:
Paper spray tandem mass spectrometry is used to identify and quantify eight individual Amphetamines in whole blood in 1.3 min. The method has been optimized and fully validated according to forensic toxicology guidelines, for the quantification of amphetamine, methamphetamine, 3,4-methylenedioxyamphetamine (MDA), 3,4-methylenedioxy-N-methylamphetamine (MDMA), 3,4-methylenedioxy-N-ethylamphetamine (MDEA), para-methoxyamphetamine (PMA), para-methoxymethamphetamine (PMMA), and 4-fluoroamphetamine (4-FA). Additionally, a new concept of intrinsic and application-based selectivity is discussed, featuring increased confidence in the power to discriminate the Amphetamines from other chemically similar compounds when applying an ambient mass spectrometric method without chromatographic separation. Accuracy was within ±15% and average precision was better than 15%, and better than 20% at the LLOQ. Detection limits between 15 and 50 ng/mL were obtained using only 12 μL of whole blood. Graphical abstract ᅟ.
Catherine Gebhard – One of the best experts on this subject based on the ideXlab platform.
Amphetamines induce tissue factor and impair tissue factor pathway inhibitor role of dopamine receptor type 4European Heart Journal, 2010Co-Authors: Catherine Gebhard, Alexander Breitenstein, Alexander Akhmedov, Giovanni G Camici, Thomas F Luscher, Felix C TannerAbstract:
Aims Amphetamine intake is associated with acute vascular syndromes. Since these events are caused by arterial thrombosis and this in turn is triggered by tissue factor (TF), this study examines whether Amphetamines regulate TF in human endothelial cells.
Methods and results Amphetamine (10−7–10−4 mol/L) enhanced thrombin- and tumour necrosis factor (TNF)-α-induced as well as basal TF expression ( P = 0.029, 0.0003, and 0.003 at maximal concentration), and TNF-α-induced plasminogen activator inhibitor (PAI)-1 expression ( P = 0.003), whereas tissue factor pathway inhibitor expression was impaired ( P = 0.008). Similarly, 3,4-methylenedioxymethamphetamine (10−7–10−4 mol/L) enhanced TF expression ( P = 0.046). These effects were paralleled by an increased TF activity ( P = 0.002); moreover, clotting time of human plasma was accelerated by supernatant from amphetamine-treated cells ( P = 0.03). Amphetamine enhanced TF mRNA expression via phosphorylation of the mitogen-activated protein kinases (MAPKs) extracellular signal-regulated kinase (ERK) and p38 ( P = 0.03 and 0.033), but not c-Jun NH2-terminal kinase (JNK; P = 0.81). The effect of amphetamine on TF expression was abrogated by the dopamine D4 receptor antagonists L-745,870 and L-750,667, but not D2 or D3 receptor antagonists; furthermore, L-745,870 blunted the amphetamine-induced activation of ERK and p38, but not JNK.
Conclusion Amphetamines induce endothelial TF expression via stimulation of dopamine D4 receptor and activation of the MAPKs p38 and ERK. These effects occur at clinically relevant amphetamine concentrations and may account for the increased incidence of acute vascular syndromes after amphetamine consumption.