Screening for barbiturates in vitreous humor by the EMIT-st serum enzyme immunoassay

In 16 medical examiner's cases, which were found to be barbiturate-positive by thin-layer chromatographic screening of the liver, blood barbiturate concentrations were determined by gas chromatography. The corresponding vitreous humor samples were screened by the enzyme multiplied immunoassay technique, the EMIT-st serum barbiturate assay. By using the recommended dilution for detecting serum barbiturates, it was possible to detect barbiturates in vitreous humor at a toxic concentration. By using one fourth the amount of diluent, the barbiturates could be detected also at a therapeutic concentration. The EMIT-st assay proved to be useful in the screening for barbiturates in vitreous humor, a material that is readily available in forensic toxicology.     

Peak blood-ethanol concentration and the time of its occurrence after rapid drinking on an empty stomach

Healthy men, 20 to 60 years old, drank a moderate dose of ethanol in the morning after an overnight fast. They consumed either neat whisky in amounts corresponding to 0.34, 0.51, 0.68, 0.85, or 1.02 g of ethanol per kilogram of body weight or 0.80 g/kg ethanol solvent diluted with orange juice. The peak blood-ethanol concentration (BEC) increased with the dose administered, but the time required to reach the peak was not markedly influenced over the range of doses studied. At a dose of 0.68 g/kg, the peak BEC ranged from 52 to 136 mg/dL (N = 83), and slow absorption (a late-occurring peak) produced a lower peak BEC. The peak BEC was reached between 0 and 45 min for 77% of the subjects (N = 152) and between 0 and 75 min for 97% of them. The time of peaking in venous blood occurred, on average, 10 min later than in capillary (fingertip) blood although the peak BEC was not appreciably different; the mean venous BEC was 97.0 mg/dL (range, 76 to 112 mg/dL), and the mean capillary BEC was 99.6 mg/dL (range, 75 to 123 mg/dL). When subjects drank 0.80 g/kg ethanol diluted with orange juice over 30 min, the average BEC increment between the end of drinking and the peak was 33 mg/dL (range, 0 to 58 mg/dL). The rate of absorption of ethanol was 1.78 mg/dL/min (range, 0.52 to 4.8 mg/dL/min), and the peak BEC occurred within 60 min after the end of drinking in 92% of the trials. The largest BEC increment (mean, 21 mg/dL; range, 0 to 44 mg/dL) was seen during the first 15 min after the drinking period.     

Detection of deception with fMRI: Are we there yet?

A decade of spectacular progress in functional magnetic resonance imaging (fMRI) technology and systems neuroscience research has so far yielded few changes in our daily lives. The dearth of clinical applications of this prolific and academically promising research tool began raising the eyebrows of the public and the research funding agencies. This may be one of the reasons for the enthusiasm and interest paid to the growing body of literature suggesting that blood oxygenation level‐dependent (BOLD) fMRI of the brain could be sensitive to the differences between lie and truth. The word ‘differences’ is critical here since it refers to the often‐ignored core concept of BOLD fMRI: it is only sensitive to differences between two brain states. Thus, available studies report using fMRI to discriminate between lie and truth or some other comparative state rather than to positively identify deception. This nuance is an example of the extent to which applied neuroscience research does not lend itself to the type of over‐simplification that has plagued the interpretation of fMRI‐based lie detection by the popular press and the increasingly vocal academic critics. As an early contributor to the modest stream of data on fMRI‐based lie detection, I was asked by Dr Aldert Vrij to write a piece in favour of fMRI‐based lie detection, to be contrasted with a piece by Dr Sean Spence presenting an opposite point of view ( Spence, 2008 ). This seemingly straightforward task presented two hurdles: having to respond to the popular as well as scientific view of what lie detection with fMRI is and present a wholly positive view of evolving experimental data.