Morbidity involving the hallucinogenic designer amines MDA and 2C-I.

A case is presented of a 39-year-old woman who suffered severe debilitation because of a hemorrhagic stroke in the context of substance abuse. The patient presented to the emergency room with rapidly diminishing mental status, hypertension, and vasoconstriction; her friends provided a history of ingestion of cocaine, 3,4-methylenedioxymethamphetamine (MDMA), and 2C-I, a novel designer amine. A multi-targeted LC-MS/MS method for sympathomimetic amines and related drugs in urine detected and quantified 2C-I and MDA, while ruling out MDMA.

Prevalence and prognostic significance of incidental cardiac troponin T elevation in ambulatory patients with stable coronary artery disease: data from the Heart and Soul study.

Background: The significance of troponin elevation and clinical utility of troponin testing in ambulatory patients with coronary artery disease (CAD) have not been examined. We sought to investigate the prevalence and prognostic value of cardiac troponin T (cTnT) elevation in a population with stable CAD.

Methods: We studied 987 patients with stable CAD enrolled in the Heart & Soul study who had plasma cTnT measurements before performing exercise treadmill testing.

Impact of systemic hypertension on the diagnostic performance of B-type natriuretic peptide in patients with acute dyspnea.

Hypertension may affect the diagnostic performance of B-type natriuretic peptide (BNP). The objective of the present study was to assess the impact of a history of hypertension or blood pressure elevation on admission on the diagnostic performance of BNP in the diagnosis of heart failure (HF) in patients with acute dyspnea. BNP levels were measured using a rapid point-of-care device in 1,586 patients with acute dyspnea.

Prevalence of smoking assessed biochemically in an urban public hospital: a rationale for routine cotinine screening.

Cotinine, a metabolite of nicotine, has been used to study tobacco smoke exposure in population studies, but the authors are unaware of its use to screen hospitalized patients. The authors measured serum cotinine levels in 948 patients admitted to an urban public hospital in San Francisco, California, between September 2005 and July 2006. On the basis of cotinine levels, they classified patients as active smokers (cotinine > or = 14 ng/mL), recent smokers or significantly exposed to secondhand smoke (SHS) (0.

N-terminal pro-B-type natriuretic peptide and inducible ischemia in the Heart and Soul Study.

Background: B-type natriuretic peptide (BNP) is predictive of inducible ischemia in patients with coronary heart disease (CHD). Whether N-terminal pro-B-type natriuretic peptide (NT-proBNP) has a comparable strength of association with ischemia is uncertain.

Hypothesis: Resting NT-proBNP levels are associated with inducible ischemia in patients with stable CHD.

Interpretation of high sensitivity cardiac troponin I results: reference to biological variability in patients who present to the emergency room with chest pain: case report series.

Background: The development of highly sensitive cardiac troponin (cTnI) assays has increased the number of true and false positive results for patients suspected of acute myocardial infarction (AMI). Cases are reported whereby the use of serial testing, the 99th percentile cutoff, and the application of biological variation of cTnI were used to help determine ischemic vs. non-ischemic causes of myocardial injury.

Clinical utility of an LC-MS/MS seizure panel for common drugs involved in drug-induced seizures.

Background: Approximately 6% of new-onset seizures are drug-related, but there is currently no reliable way to determine if a seizure is drug-induced. Liquid chromatography-tandem mass spectrometry (LC-MS/MS) is a powerful tool that allows simultaneous detection of numerous analytes of diverse chemical nature in patient samples. This allows a single analysis to incorporate many compounds relevant to a particular clinical presentation, such as suspected drug-induced seizures.

Short- and long-term biological variation in cardiac troponin I measured with a high-sensitivity assay: implications for clinical practice.

Background: The improved detection limit and precision in new-generation commercial assays for cardiac troponin I (cTnI) have lowered the 99th-percentile cutoff value, yielding higher frequencies of positive test results. Because serial testing is important in interpreting low concentrations, we evaluated the biological variation of cTnI in both the short (hours) and long (weeks) terms and determined reference change values (RCVs) and the index of individuality (II) for cTnI.

Methods: To assess short- and long-term variation, we collected blood from 12 healthy volunteers hourly for 4 h and from 17 healthy individuals once every other week for 8 weeks, measured cTnI with a high-sensitivity assay (detection limit, 0.

Interpretation of creatine kinase and aldolase for statin-induced myopathy: Reliance on serial testing based on biological variation.

Background: Statins are widely used drugs to reduce LDL cholesterol and risk for cardiovascular disease. Varying degrees of myopathies occur with statin use, ranging from mild myalgic symptoms alone to documented muscle damage and rhabdomyolysis. The activity of creatine kinase (CK) above a population-based reference range has been used to differentiate myalgias from documented myositic injury due to statins.

A hydrophilic-interaction chromatography tandem mass spectrometry method for quantitation of serum s-adenosylmethionine in patients infected with human immunodeficiency virus.

Background: s-Adenosylmethionine (SAM)1 has been suggested as a diagnostic test and surrogate marker for Pneumocystis jirovecii pneumonia (PCP) in HIV-positive patients. In this study, we report a robust hydrophilic-interaction liquid chromatography tandem mass spectrometry (LC-MS/MS) assay that can be used to quantitate serum SAM in clinical laboratories.

Methods: Proteins in serum samples were precipitated using trichloroacetic acid.

Cardiac troponin and outcome in acute heart failure.

Background: Cardiac troponin provides diagnostic and prognostic information in acute coronary syndromes, but its role in acute decompensated heart failure is unclear. The purpose of our study was to describe the association between elevated cardiac troponin levels and adverse events in hospitalized patients with acute decompensated heart failure.

Methods: We analyzed hospitalizations for acute decompensated heart failure between October 2001 and January 2004 that were recorded in the Acute Decompensated Heart Failure National Registry (ADHERE).

Diagnostic performance of a new automated heterophile antibody test in adults and children.

Epstein-Barr virus serologic profiles were obtained from 618 patients using an automated platform, including the new BioPlex heterophile assay. When compared with 2 IgM viral capsid antigen (VCA) assays and a predicate heterophile assay, the BioPlex heterophile assay was more likely to be associated with serologic patterns of acute infection.

Dosing algorithm for warfarin using CYP2C9 and VKORC1 genotyping from a multi-ethnic population: comparison with other equations.

Objectives: Polymorphism in the genes for cytochrome (CYP)2C9 and the vitamin K epoxide reductase complex subunit 1 (VKORC1) affect the pharmacokinetics and pharmacodynamics of warfarin. We developed and validated a warfarin-dosing algorithm for a multi-ethnic population that predicts the best dose for stable anticoagulation, and compared its performance against other regression equations.

Methods: We determined the allele and haplotype frequencies of genes for CYP2C9 and VKORC1 on 167 Caucasian, African-American, Asian and Hispanic patients on warfarin.

Use of genetic and nongenetic factors in warfarin dosing algorithms.

Despite the fact that warfarin has been used as an anticoagulant for many years, the safety profile for this drug has been poor. Inappropriate dosing continues to contribute to significant morbidity and mortality due to thrombotic disease and bleeding. Therefore, there is a need for the development, characterization and implementation of dosing algorithms using a patient's demographic information and genotype.

The clinical need for high-sensitivity cardiac troponin assays for acute coronary syndromes and the role for serial testing.

Background: Cardiac troponin is the biomarker of choice for the serologic diagnosis of acute coronary syndromes. International cardiology and laboratory medicine guidelines have suggested that the cutoff concentration be set at the 99th percentile of a healthy population, with an assay imprecision of 10% or less. Unfortunately, most commercial troponin assays do not have the sensitivity and precision to reliably detect troponin in sera of healthy subjects.