The stability of ethanol in human whole blood controls: an interlaboratory evaluation.

Sterile whole human blood control materials were commercially prepared in batches containing anticoagulants and preservatives and approximately 90, 150, and 230 mg/dL ethanol with and without 0.3% (w/v) sodium azide. Aliquots in sealed vials were stored by the manufacturer at 2-8 degrees C until shipped monthly to three academic toxicology laboratories that analyzed them in duplicate by gas chromatographic headspace methods at monthly intervals for one year.

Regulation of brain m calpain Ca2+ sensitivity by mixtures of membrane lipids: activation at intracellular Ca2+ level.

Combinations of certain phospholipids and gangliosides increase the specific activity of m calpain and can activate m calpain at 1 to 10 microM Ca2+ concentration. However, this level of calcium is still greater than the normal intracellular calcium level. We have used combinations of lipids to demonstrate the m calpain activity at the physiological Ca2+ level.

Analytical evaluation of methods for serum creatine kinase-MB. Electrophoresis, immunoinhibition and solid phase separation.

The purpose of this study was to evaluate immunoassay methods for the measurement of serum cardiac creatine kinase isoenzyme (CK-MB) with respect to sensitivity and specificity. The CK-MB electrophoretic assay (Helena Laboratories) was used as the reference. Two principles of immunoassay were included in the evaluation,--immunoinhibition and solid phase separation.

High-resolution proton nuclear magnetic resonance spectroscopy in the detection of low molecular weight volatiles.

Proton nuclear magnetic resonance spectroscopy (1H MRS) has been used to identify ethanol in vivo and to detect other exogenous low molecular weight volatiles in human serum. 1H MRS was used to detect and quantitate 15 human sera containing various concentrations and combinations of ethanol, isopropanol, acetone, and methanol as previously quantitated by headspace gas chromatography. The 1H MRS method was linear for each alcohol.

High-resolution proton nuclear magnetic resonance spectroscopy in the detection and quantitation of ethanol in human serum.

A precise, accurate, and nondestructive method for the detection and quantitation of serum ethanol in humans using proton (1H) nuclear magnetic resonance spectroscopy (MRS) was developed. The 1H MRS method was linear within the range of 30-1500 mg/L. The lowest detectable ethanol concentration was 15 mg/L, with 30 mg/L being the lowest level reproducibly quantitated.