Identification of lysophosphatidylcholine-chlorohydrin in human atherosclerotic lesions.

Lysophosphatidylcholine (LysoPtdCho) levels are elevated in sera in patients with atherosclerosis and in atherosclerotic tissue. Previous studies have shown that reactive chlorinating species attack plasmalogens in human coronary artery endothelial cells (HCAEC), forming lysoPtdCho and lysoPtdCho-chlorohydrin (lysoPtdCho-ClOH). The results herein demonstrate for the first time that lysoPtdCho-ClOH is elevated over 60-fold in human atherosclerotic lesions. In cultured HCAEC, 18:0 lysoPtdCho-ClOH led to a statistically significant increase in P-selectin cell-surface expression, but unlike 18:1 lysoPtdCho did not lead to cyclooxygenase-2 protein expression. These data show that 18:0 lysoPtdCho-ClOH is elevated in atherosclerotic tissue and may have unique pro-atherogenic properties compared to lysoPtdCho.

Modification of red cell membrane lipids by hypochlorous acid and haemolysis by preformed lipid chlorohydrins.

Hypochlorous acid (HOCl), a strong oxidant generated by the myeloperoxidase system of neutrophils and monocytes, has been implicated in inflammatory tissue damage by these cells. Reaction of HOCl with the double bonds of unsaturated lipids produces alpha, beta-chlorohydrin isomers. We have exposed red cell membranes to HOCl and used thin layer chromatography (TLC) of the extracted lipids and enzyme-linked immunosorbent assay (ELISA), using an antichlorohydrin monoclonal antibody, to show that fatty acyl chlorohydrins are formed. The ELISA was approximately 25 fold more sensitive than TLC, and chlorohydrins were detected when membranes from 10(6) cells were treated with > or = 0.16 nmoles HOCl. Lipid chlorohydrins are more polar and bulky than their parent lipids and as such could affect membrane stability and function. To determine the effect of incorporation of lipid chlorohydrins into cell membranes, preformed fatty acid and cholesterol chlorohydrins were incubated with red cells. Lysis was measured as release of haemoglobin and incorporation of lipids was determined by 14C scintillation counting. Addition of HOCl-treated oleic acid to red cells resulted in rapid lysis of a fraction of the cells in a concentration dependent manner. HOCl-treated cholesterol also caused a small amount of cell lysis that was predominantly due to chlorohydrin 3, one of the three major cholesterol chlorohydrin products. Chlorohydrin 3, which has a decreased planarity and polarity, was also primarily responsible for altering the critical micelle concentration of HOCl-treated cholesterol-containing liposomes.

Exposure to trichloroethylene II. Metabolites in blood and urine.

Fifteen men were exposed to trichloroethylene (TRI) in three different ways with regard to the concentration of TRI in the air as well as exercise on a bicycle ergometer. The total amount of TRI supplied and taken up by each person was measured. The concentrations of trichloroethanol (TCE) and trichloroacetic acid (TCA) were determined in blood and urine. In spite of large differences in uptake, there were only small differences in the concentration of TCA in blood during the day of exposure. There was a large scatter for the values of TCA in urine within each group. The concentration of TCE in arterial blood increased during exposure. Thereafter the concentrations were almost constant for 2 h and differed among the groups. These results can be interpreted as being due to balanced rates of the formation and elimination of TCE. The levels mentioned were related to the uptake of TRI. The same was found for the rate of excretion of TCE in urine when calculations were made from the morning sample obtained the day after exposure.

Methods for measuring trichloroethanol and trichloroacetic acid in blood and urine after exposure to trichloroethylene.

A description is given of procedures for the analysis of trichloroethanol, conjugated trichloroethanol, and trichloroacetic acid (TCA) in blood and urine. The determination of TCA is effected by measuring its decarboxylation product chloroform. The methods depend on extraction with isooctane and subsequent analysis by gas chromatography.

Analysis of chlormethiazole, ethchlorvynol and trichloroethanol in biological fluids by gas-liquid chromatography as an aid to the diagnosis of acute poisoning.

A simple method has been developed whereby chlormethiazole, ethchlorvynol and trichloroethanol can be simultaneously detected and measured in biological fluids. The procedure is based upon the rapid extraction of a small (50-microliter) sample volume with an equal volume of chloroform containing an internal standard, followed by the gas-liquid chromatographic analysis of this extract. Specimens of blood plasma or serum, urine and gastric contents can be used, and no interference from either endogenous or exogenous sources has been observed. The method is suitable for the measurement of the plasma concentrations of these compounds attained after overdosage.

Determination of trichloroethanol at therapeutic and overdose levels in blood and urine by electron capture gas chromatography.

A specific and sensitive gas chromatographic method for the determination of trichloroethanol, the active metabolite of chloral hydrate, in blood and urine is reported. A simple dilution of the sample with an ethanolic solution of internal standard followed by gas chromatography with electron capture detection is described. The method has been used to determine plasma levels after therapeutic dosing with chloral preparations.

[Biochemical and psychological examinations of trichloroenthylene exposed volunteers (author's transl)]. / Biochemische und psychologische Untersuchungen an Trichloräthylen-exponierten Probanden

Seven healthy volunteers were exposed to approximately 100 ppm (=520 mg/m3) trichloroethylene for six hours daily during a period of five consecutive days. A corresponding group was exposed a placebo in the same manner. -Biochemical and psychological examinations were accomplished in the beginning and the end of each day respectively the whole period. Thereby the intraindividual as well as the interindividual loads were taken to judge the health impairment. - For this purpose trichloroethylene, trichloroethanol and trichloracetic acid were determined in blood, as well as total trichloroethanol and trichloroacetic acid in urine. For the measurement of the biochemical parameters gaschromatography is considered the best method. The combination of the "intern standard" with the synchronous determination of the metabolites of trichloroethylene is described as a new treatment. These time-efficient and practicable procedures are the most important suppositions for "biological monitoring". Results are confirmed as far as known in literature as well as the course of trichloroethylene in blood is described for the first time. The modern methods of psychology applied to tests and standardized questionaires served to quantify the intellectual and psychological conditions of the solvent exposed volunteers and of their corresponding group. The group results were compared. Thereby no significative differences were visible. Altogother the results show that during the 5 days exposition to 100 ppm (=520 mg/m3) trichloroethylene no impairments of the examined persons' mental and psychological capacities could be determined in spite of the biochemically quantified incorporation of the solvent.