4-Hydroxyglutamate is a novel predictor of pre-eclampsia.

BACKGROUND: Pre-term pre-eclampsia is a major cause of maternal and perinatal morbidity and mortality worldwide. A multi-centre randomized-controlled trial has shown that first-trimester screening followed by treatment of high-risk women with aspirin reduces the risk of pre-term pre-eclampsia. However, the biomarkers currently employed in risk prediction are only weakly associated with the outcome. METHODS: We conducted a case-cohort study within the Pregnancy Outcome Prediction study to analyse untargeted maternal serum metabolomics in samples from 12, 20, 28 and 36 weeks of gestational age (wkGA) in women with pre-eclampsia delivering at term (n = 165) and pre-term (n = 29), plus a random sample of the cohort (n = 325). We used longitudinal linear mixed models to identify candidate metabolites at 20/28 wkGA that differed by term pre-eclampsia status. Candidates were validated using measurements at 36 wkGA in the same women. We then tested the association between the 12-, 20- and 28-wkGA measurements and pre-term pre-eclampsia. We externally validated the association using 24- to 28-wkGA samples from the Born in Bradford study (25 cases and 953 controls). RESULTS: We identified 100 metabolites that differed most at 20/28 wkGA in term pre-eclampsia. Thirty-three of these were validated (P < 0.0005) at 36 wkGA. 4-Hydroxyglutamate and C-glycosyltryptophan were independently predictive at 36 wkGA of term pre-eclampsia. 4-Hydroxyglutamate was also predictive (area under the receiver operating characteristic curve, 95% confidence interval) of pre-term pre-eclampsia at 12 (0.673, 0.558-0.787), 20 (0.731, 0.657-0.806) and 28 wkGA (0.733, 0.627-0.839). The predictive ability of 4-hydroxyglutamate at 12 wkGA was stronger than two existing protein biomarkers, namely PAPP-A (0.567, 0.439-0.695) and placenta growth factor (0.589, 0.463-0.714). Finally, 4-hydroxyglutamate at 24-28 wkGA was positively associated with pre-eclampsia (term or pre-term) among women from the Born in Bradford study. CONCLUSIONS: 4-hydroxyglutamate is a novel biochemical predictor of pre-eclampsia that provides better first-trimester prediction of pre-term disease than currently employed protein biomarkers.

The study of codeine-gluthetimide pharmacokinetic interaction in rats.

A high-performance liquid chromatographic (HPLC) assay with native fluorescence detection was developed for the simultaneous quantification of codeine and its two metabolites, morphine and morphine-3-glucuronide (M-3-G), in rat plasma. Solid-phase extraction was used to separate codeine and its metabolites from plasma constituents. Extraction efficiencies of codeine, morphine and M-3-G from rat plasma samples were 97, 92 and 93%, respectively. The chromatographic separation was performed using a reversed-phase C18 column and an elution gradient at ambient temperature. Using native fluorescence detection (excitation at 245 nm and emission at 345 nm), the detection limits of 50 ng/ml for morphine, 25 ng/ml for codeine and 20 ng/ml for M-3-G were obtained. The method had good precision, accuracy and linearity, and was applied to the study of glutethimide's influence on codeine metabolism in rat, following single doses of codeine-glutethimide association. The results confirmed the fact that glutethimide was responsible for a significant increase of morphine plasma levels and for their maintenance in time, concomitant with a significant decrease of M-3-G plasma levels, explained by the inhibition of morphine glucuronidation. In conclusion, glutethimide potentiates and prolongs the analgesic effect of codeine by a pharmacokinetic mechanism.

[Extraction of glutethimide and methyprylon from blood using thin layer chromatography]. / Wykrywanie glutetimidu i metyprylonu we krwi metoda chromatografii cienkowarstwowej.

Glutethimide and methyprylone were extracted from blood and plasma at pH ca. 4 (acetate buffer) thrice with chloroform, using 2.5 solvent volume ratio to that of aqueous phase. Phenobarbital was used as an internal standard in thin-layer chromatography experiments on silica gel--to obtain of comparable ratios of Rf values of glutethimide and/or methyprylone to that of phenobarbital. Suitable conditions of the separation of three substances were established using one of following mobile phases: benzene-dioxane-aq.ammonia (15:4:1), chloroform-acetone-aq.ammonia (25:25:1), chloroform-acetone-diaethylamine (5:4:1) and chloroform-diethyl ether-acetone (5:3:2); on 7.5 x 2.5 cm plates; development time (at 5 cm distance) was up to 10 minutes. The concentrations as small as 0.1 microg of examined substances in 1 cm3 of plasma may be identified on chromatograms using 20% Na2CO3 solution.

Lack of correlation between plasma 4-hydroxyglutethimide and severity of coma in acute glutethimide poisoning. A case report and brief review of the literature.

Glutethimide poisoning is characterised by coma, anticholinergic poisoning syndrome, hypotension, and other complications. Previous studies have shown that the severity of intoxication does not correlate with plasma glutethimide concentrations in individual patients. Glutethimide is partly converted to 4-hydroxyglutethimide, a metabolite which accumulates in the plasma of humans, and which has been thought to contribute to coma after plasma glutethimide concentrations have fallen. We followed plasma concentrations of glutethimide and 4-hydroxyglutethimide in a man who overdosed with glutethimide. Plasma 4-hydroxyglutethimide concentrations did not correlate with the degree of coma in our patient, and actually rose as the patient awakened. Other studies also indicate that 4-hydroxyglutethimide may not play an important role in glutethimide poisoning.

Deaths as a result of a combination of codeine and glutethimide.

Toxicological findings are described in 16 medical examiner cases directly related to the combination of codeine and glutethimide. The cases described represent a six-month period, July through December 1982, showing the epidemic rate of abuse of this drug combination, most prominent in the Newark, NJ area since the late 1970s. Concentrations of codeine and glutethimide, measured by gas liquid chromatography (GLC), in the blood averaged 0.62 and 4.07 mg/L, respectively. Similarly determined urine concentrations averaged 38.06 and 12.68 mg/L, respectively. Specific concentrations of each drug in most cases were in the high therapeutic range, suggesting a possible toxic synergistic effect.

Blood concentrations and clinical findings in nonfatal and fatal intoxications involving glutethimide and codeine.

Blood concentrations and clinical findings were evaluated in twenty-six nonfatal and twelve fatal intoxications involving the combination of glutethimide and codeine ("loads"). The mean glutethimide concentration was 10 +/- 5 mg/L for nonfatal cases (range 2-18 mg/L) and 13.9 +/- 6.6 mg/L for fatal cases (range 4.6-26.4 mg/L). The mean codeine concentration for fatal intoxications was 1.21 +/- 1.17 mg/L (range 0.13-4.32 mg/L). Codeine concentrations were not measured in cases of nonfatal intoxication. Nine nonfatal cases required hospitalization on a medical ward (mean length of stay 3 +/- 3 days). Depressed level of consciousness was the most common abnormal physical finding (24 cases); 18 patients were lethargic but arousable with nonpainful stimulation and 6 patients with serum glutethimide concentrations of 10 mg/L or greater were comatose. The level of consciousness showed statistically significant correlation with the glutethimide concentration (P less than 0.01). Twenty-four nonfatal intoxications involved at least one other drug in addition to glutethimide and codeine (salicylates in 12 and acetaminophen in 4), while only 7 fatal cases involved at least one additional drug (acetaminophen and diazepam in 3 each). The finding of glutethimide should prompt a search for codeine and vice versa, especially when the presence of either does not in and of itself explain the clinical condition of the patient.

Interpretation of blood glutethimide, meprobamate, and methyprylon concentrations in nonfatal and fatal intoxications involving a single drug.

We evaluated blood concentrations of three nonbarbiturate sedative-hypnotics in 19 nonfatal (NF) and five fatal (F) intoxications which were "pure" (i.e. which involved only one drug each): glutethimide, 4 (NF), 3 (F); meprobamate, 9 (NF), 1 (F); and methyprylon, 6 (NF), 1 (F). For each of the 24 cases, both a comprehensive toxicology panel (including blood and urine) and the clinical history established that only a single drug had been ingested. Blood drug concentrations showed statistically significant correlation with the level of consciousness for nonfatal meprobamate intoxication (p less than 0.01) and nonfatal methyprylon intoxication (p less than 0.05). Blood glutethimide concentrations did not show such correlation. Death was associated with a mean blood glutethimide concentration in excess of 4.0 mg/dL, a blood meprobamate concentration of 20.5 mg/dL, and a blood methyprylon concentration of 11.7 mg/dL. Interpretation of blood concentrations of these compounds is discussed, and physical findings and demographic data are presented.

Experience with activated carbon-bead haemoperfusion columns in the treatment of severe drug intoxication. A preliminary report.

Five patients who were severely poisoned with hypnotic drugs, paracetamol, or theophylline were treated by charcoal haemoperfusion. The device contained 160 g of activated carbon beads with a polyester coating. Four patients made a significant improvement; one subsequently died from a cerebral haemorrhage which had occurred prior to haemoperfusion. Platelet losses were minimal and no fibrinolysis was observed. No significant biochemical abnormality occurred as a result of haemoperfusion, although one patient, who presented with hypocalcaemia, required intravenous calcium throughout the procedure.

Gas-liquid chromatography of undervatized drugs after chromatographic extraction from blood.

We have developed an integrated method that overcomes the two main procedural difficulties of gas-liquid chromatography, namely, solvent-solvent extraction and chemical derivatization. Drugs are extracted from serum by column chromatography on granular diatomaceous earth (kieselguhr). Subsequent gas-liquid chromatography of underivatized samples can be performed on either of two liquid phases. A mixed liquid phase, used for quantitative gas-chromatographic assay on patients with a known therapeutic regimen, has enabled quantitation of 12 drugs in serum. Alternatively, a single liquid phase, used with the mixed liquid phase, permits the gas-chromatographic identification of unknown drugs on the basis of the characteristic pattern of the two relative retention times; by this approach more than 40 drugs have been identified in cases of suspected intoxication, both in serum and in gastric aspirate. Besides providing ease of performance and wide applicability, the proposed procedure offers a degree of precision and accuracy that compares favorably with established methods.

[A simple gas chromatographic method for the determination of hypnotics in the serum (author's transl)]. / Eine einfache gaschromatographische Methode zur Bestimmung von Schlafmitteln im Serum.

In the extract of the serum, prepared as described by Külpmann (1979) (this J. 17, 89-96), other hypnotics, in addition to the barbiturates can be determined by gas chromatography; these are: carbromal, 2,2-diethylallylacetamide, ethinamate, glutethimide, methyprylone and pyrithyldione. Methaqualone can be detected qualitatively. The coefficient of variation for the precision in the series is dependent on the hypnotic investigated and ranges from 2.1 to 8.5%, the recovery from 76 to 92%; the detection limit is estimated to be 1.6 up to 4.6 mumol/l. The specificity was proved by comparison 1) of analyses of sera from poisoned patients or animals before and after the additional purification of the extract by thin-layer chromatography, 2) with the retention times of about 100 drugs under the gas chromatographic conditions that were used. The method allows the determination of 18 barbiturates and 7 non-barbiturates within one to two hours.

The removal of hypnotic drugs from human serum. A comparative investigation of the adsorptive properties of native and agarose-encapsulated resins and charcoal.

The adsorptive capacities of some ion-exchange resins and activated charcoal towards the hypnotic drugs, phenobarbital, glutethimide, carbromal, and methaqualone, have been investigated. Furthermore, the properties of some of these resins and charcoal, encapsulated in an agarose matrix in the form of beads, have been compared with those of the adsorbent phases in their native states. In general, the adsorptive capacities of charcoal were at least as good as, and frequently better than those of the resins. Amberlite XAD-type resins had a higher affinity than Dowex-type resins for all the drugs tested, except for phenobarbital, which was not adsorbed to a satisfactory extent onto Amberlite XAD-4. The encapsulation of adsorbent phases into agarose beads of diameter 5-10 mm results in a reduction of the adsorbtion of the drugs. Nonetheless, the remaining adsorptive capacity is sufficient for application in an extracorporeal detoxification system. Moreover, the overwhelming advantage of good haemocompatibility is provided by the agarose-encapsulated adsorbents.

Correlates of outcome following acute glutethimide overdosage.

Potential predictors of outcome following acute glutethimide overdosage were assessed in 63 patients hospitalized with this diagnosis at a large urban medical center between 1962 and 1975. Their mean age was 34 years (range, 15 to 84 years) and 62% were female. Assisted ventilation was required in 59% of cases, and 32% developed hypotension. Six patients died, including all three aged 60 years or older. Multiple regression analysis confirmed that age was the major identifiable determinant of survival, regardless of other factors. Among identifiable determinants of coma grade, glutethimide dose, glutethimide plasma concentration, and coingestion of barbiturates were the most important. An ingested dose of 10 g or more, or a plasma concentration exceeding 30 microgram/ml, was almost always associated with deep coma. However, a relatively small ingested dose or a low plasma level by no means ruled out development of serious intoxication, particularly in those patients who also ingested barbiturates. Thus elderly individuals are at high risk for fatal outcome following glutethimide overdosage and should receive priority for intensive care and monitoring. Glutethimide dose, plasma concentration, and history of coingestion of barbiturates are of value in predicting development of deep coma. These items of information should be obtained on admission whenever possible.

A selected ion monitoring method for glutethimide and six metabolites: application to blood and urine from humans intoxicated with glutethimide.

A method employing selected ion monitoring for the analysis of glutethimide and six of its metabolites has been developed. Hydroxylated metabolites analyzed as trifluoroacetates, included 4-hydroxyglutethimide, (1-hydroxyethyl)glutethimide and p-hydroxyglutethimide. The unchanged drug, 3-dehydroglutethimide, desethylglutethimide and the internal standard, [2H5]glutethimide, were chromatographed underivatized on OV-225. The assay was used to measure drug and metabolites in the plasma and urine of patients intoxicated with glutethimide. High levels (e.g. 20--35 microgram ml-1) of unconjugated 4-hydroxyglutethimide, an active metabolite, were found in all patients at a time when levels of unchanged drug were lower and declining. Other unconjugated and conjugated metabolites were found in relatively low concentrations in the plasma (i.e. less than 4 microgram ml-1). The major urinary metabolites were conjugates of 4-hydroxyglutethimide and (1-hydroxyethyl)glutethimide. The unchanged drug and other conjugated and unconjugated metabolites were found in lower amounts in the urine. Normal plasma half-lives of glutethimide and the relatively small amounts in urine of unchanged drug and unconjugated metabolites indicated that drug elimination was not markedly impaired in the intoxicated patients.