Effect of recent cocaine use on the specificity of cardiac markers for diagnosis of acute myocardial infarction.

We evaluated whether recent cocaine use alters the specificity of CK-MB, myoglobin, and cardiac troponin I for acute myocardial infarction (AMI) in patients who are seen in the emergency department for chest pain. Patients <60 years old with potential myocardial ischemia underwent a standardized history and physical examination and routine CK-MB assays every 8 to 12 hours and had study serum obtained at presentation for CK-MB, myoglobin, and cardiac troponin I immunoassays, as well as benzoylecgonine, cocaine's main metabolite. We enrolled 97 patients, 19 (20%) of whom had recent used cocaine. Patients with and without cocaine use were similar with regards to sex, race, renal and muscular disease, diabetes, family history, and hypertension and rate of AMI (12% vs 11%, p = 1.0). In patients without MI, the mean myoglobin level was higher in cocaine users than noncocaine users (179 vs 74 ng/ml; Mann-Whitney p = 0.003), but the mean values were similar for CK-MB (2.2 vs 2.1 ng/ml; Mann-Whitney p = 0.58) and for cardiac troponin-I (0.02 vs 0.02 ng/ml; Mann-Whitney p = 0.87). The specificities of the markers in patients with and without cocaine use were as follows: cardiac troponin I, 94% vs 94%, (p = 1.0); CK-MB, 75% vs 88% (p = 0.24); and myoglobin, 50% vs 82%, (p = 0.02), respectively. Our data demonstrate that the specificity of myoglobin was altered by recent cocaine use. The specificity of CK-MB was affected less and the specificity of cardiac troponin I was not affected by recent cocaine use.

The distribution of ethanol in postmortem blood specimens.

Ethanol was determined by gas chromatography in a variety of tissues and body fluids secured at autopsy in 61 cases. The specimens tested included right and left heart blood, femoral blood, pericardial fluid, cerebrospinal fluid, vitreous humor, urine, stomach contents, and brain. Statistical analysis of the cases revealed no significant differences among the various blood sites tested. However, the variations in blood ethanol concentrations among the various sampling sites within each case were as follows: 40 cases showed differences of less than 25%; 16 cases revealed variability between 25% and 50%, 4 cases had differences exceeding 50%. In one case, satisfactory blood analyses could not be accomplished. The larger variances occurred especially in those instances in which stomach alcohol concentration was 0.50% or greater. In one case, the variability amongst the different blood sites exceeded 400% (femoral blood--0.043%, right atrium--0.070%, root of aorta--0.156%); the brain was 0.050%, and the stomach contents was 1.2%. For all 61 cases, variances in blood alcohol content among the different sampling sites in a single cadaver ranged from 1.8 to 428%.

Attempted murder with pancuronium.

A nurse was accused of attempting to murder her anesthesiologist husband on two occasions by administering to him a neuromuscular blocking agent. In both episodes, urine specimens were obtained from the victim shortly after the suspected assaults. The samples were initially tested fluorometrically using Rose Bengal dye as a pairing agent. Both were presumptively positive for pancuronium. Confirmation of these results was achieved by pairing the drug with potassium iodide, extracting the complex, and submitting the extract to thin-layer chromatography (TLC) cleanup, elution at the appropriate retardation factor (Rf), and, finally, gas chromatography/mass spectrometry (GC/MS) analysis in the selected-ion monitoring mode. The two quaternary amines of pancuronium appear to undergo pyrolytic N-demethylation in the injection port to yield an entity amenable to capillary column gas chromatography. The mass spectrum of the compound consists of a base peak of m/z 322, with additional fragments of 292, 323, 338, and 397 m/z, each of which was monitored. The confirmed positive findings were instrumental in adjudicating the case.

The production of amitriptyline from nortriptyline in formaldehyde-containing solutions.

The stability of nortriptyline in aqueous solutions containing various concentrations of formaldehyde was investigated. Amitriptyline, as a reaction product, was determined by gas chromatography/mass spectrometry (GC/MS) in these experiments. Factors that may contribute to this phenomenon, including pH, formaldehyde concentration, and incubation time were evaluated. At 40% (v/v) formaldehyde concentration and pH 4, there was a 68% decrease in nortriptyline concentration along with a concomitant formation of amitriptyline after 24 h. The N-methylated product was responsible for 48% of the total tricyclic drug present. The data also clearly indicate that the formation of amitriptyline is favored at elevated pH.