Inhibition of cholinesterases by histamine 2 receptor antagonist drugs.

Many studies have demonstrated that histamine 2 receptor antagonists (H2RA) have in vitro anticholinesterase effects, but discrepancies about type and potency of this inhibitory effect exist among published results. Moreover, cholinesterase inhibition has not been shown in patients receiving H2RA. These discrepancies led us to study the in vitro antibutyryl- and in vitro antiacetylcholinesterase activities of ranitidine, cimetidine, nizatidine comparatively to pyridostigmines.

Toxicological screening of drugs by microbore high-performance liquid chromatography with photodiode-array detection and ultraviolet spectral library searches.

We use ultraviolet data, acquired with a photodiode-array detector coupled to a reversed-phase liquid-chromatographic system, to identify unknown drugs in plasma samples of acutely poisoned patients. Both retention time and spectra of the peaks obtained with a microbore Hypersil ODS column under gradient elution are compared with a library of approximately 350 compounds. We present our three-year experience with this system, which identifies drugs in less than 1 h, with a high degree of confidence.

Effects of an EDTA infusion on the urinary elimination of several elements in healthy subjects.

Ethylene diamine tetraacetate calcium disodium salt (EDTA Ca Na2), 1 g dissolved in 250 ml of 5% w/v glucose solution, was infused intravenously over 1 h into 10 healthy subjects (eight males and two females). Urines were collected over 24 h, the day before and on the day of the EDTA Ca Na2 infusion test. The elements Al, B, Ba, Cu, Fe, Mn, Si, Sr, Zn, Na, K, Ca, Mg, S and P were measured by inductively coupled plasma optical emission spectrometry.

Urinary elimination of molybdenum by healthy subjects as determined by inductively coupled plasma mass spectrometry.

The concentration of molybdenum was measured by inductively coupled plasma mass spectrometry (ICPMS) in the urines of two groups of healthy people living in two areas of France, Brest and Paris, about 500 km away. The concentration of Mo in the 24-hour urines of 10 healthy subjects from the Brest region was 25 +/- 10 micrograms/l, 38 +/- 20 micrograms/24 h and 21 +/- 9 micrograms/g creatinine. The concentration of Mo in the morning urines of 23 healthy men of the Paris region was 41 +/- 34 micrograms/l and 21 +/- 15 micrograms/g creatinine.