In vitro neurotoxic esterase assay using leptophos oxon analogs as inhibitors.

In comparing neurotoxic esterase (NTE) inhibition properties of a series of phenylphosphonates, it was discovered that certain compounds including leptophos inhibited mipafox-insensitive phenylvalerate hydrolases. This leads to erroneous values for NTE inhibition which can be corrected by a differential assay: the total amount of mipafox-insensitive activity is determined with O-(2,6-dichlorophenyl)O-methyl phenylphosphonate and subtracted from the apparent NTE determined with the test compound before calculating pI50's.

On the molecular and submolecular structure of the semiquinone cations of alloxazines and isoalloxazines as revealed by electron-paramagnetic-resonance spectroscopy.

The thermodynamically stable and, therefore, analytically most important alloxazine and isoalloxazine radical cations have been studied in detail by electron paramagnetic resonance (EPR) spectroscopy. Isotopic and chemical substitutions have been made as in earlier studies with the less stable neutral and anionic species. The experimental spectra have been calculated with the aid of a more sophisticated computer-simulation program than previously used.

Biotransformation and porphyringogenic action of hexachlorobenzene and its metabolites in a primary liver cell culture.

Hexachlorobenzene (HCB) is metabolized in a primary culture of chick embryo liver cells and causes porphyrin accumulation within 24 h after administration. The HCB-metabolites, pentachlorothiophenol (PCThP), pentachlorobenzene (PeCB) and pentachlorophenol (PCP) identified in liver cell culture are already known from long-term experiments with rats. The pattern of accumulated porphyrins is comparable with the pathological porphyrin pattern observed in oral feeding studies with warm blooded laboratory animals.

Zero electrophoretic mobility of very low density lipoproteins in type III hyperlipidemic patients during treatment.

In some cases of type III hyperlipoproteinemia reduction of lipid levels by diet and/or drugs results in a complete loss of mobility of the VLDL fraction on paper electrophoresis.