Masana Ogata

Urinary excretion of hippuric acid and m- or p-methylhippuric acid in the urine of persons exposed to vapours of toluene and m- or p-xylene as a test of exposure

Ogata, M., Tomokuni, K., and Takatsuka, Y. (1970).Brit. J. industr. Med.,27, 43-50. Urinary excretion of hippuric acid and m- or p-methylhippuric acid in the urine of persons exposed to vapours of toluene and m- or p-xylene as a test of exposure. Twenty-three male volunteers were exposed in groups of four or five to toluene and m- and p-xylene vapour for periods of 3 hours or of 7 hours with one break of an hour. Urine was collected at hourly intervals for several hours, and thereafter all urine was collected until 18 hours after the end of the exposure period, and was analysed for hippuric and methylhippuric acids. It was shown that hippuric acid was excreted equivalent to 68% of the toluene absorbed, and m-methylhippuric acid equivalent to 72% of the m-xylene absorbed. Up to hydrocarbon concentrations of 200 ppm the total quantity of hippuric acids excerted was proportional to the total exposure (ppm × hours). In descending order of precision the following were also related to exposure: rate of excretion during the exposure period; concentrations of hippuric acid in urine corrected to constant urine density; and concentrations in urine uncorrected for density. The last could not be used to calculate exposure, but the others could be to give screening tests to show whether workmen could have been exposed to concentrations greater than the maximum allowable. The effects of exposure on blood pressure, pulse rate, flicker value, and reaction time were measured. There were some variations which suggested that the MAC of toluene should be set higher than 200 ppm.

Quantitation of urinary metabolites of toluene, xylene, styrene, ethylbenzene, benzene and phenol by automated high performance liquid chromatography.

SummaryAn automated high performance liquid chromatographic method (HPLC) for the direct determination of urinary concentrations of hippuric acid (HA), and o-, m- and p-methyl hippuric acids (MHAs), metabolites of toluene and o-, m-, and p-xylenes, and of urinary phenyl glyoxylic acid (PGA) and mandelic acid (MA), metabolites of styrene or ethylbenzene, is described. Methanol was added to urine, the mixture was centrifuged and the supernatant was injected into HPLC. A stainless-steel column packed with octadecyl silanized silicate was used and the mobile phase was a mixed solution of 5 mM potassium phosphate monobasic/acetonitrile (90/10). The method is simple and specific. Urine can be analyzed without solvent extraction. Analysis can be performed satisfactorily within 45 min for samples containing HA, MHAs, PGA and MA, and within 15 min for those containing HA, PGA and MA. Another automated HPLC method for the determination of urinary concentrations of phenylsulfate (PhS) and phenylglucuronide (PhG), metabolites of benzene and phenol, is also described. Urine was centrifuged and the supernatant was injected into HPLC. A column packed with octadecyl silicate and a mobile phase of 50 mM of potassium phosphate monobasic/acetonitrile (85/15) were used. The whole analyses and quantitative determination can be performed within 15 min for samples containing PhS and PhG in the workers urine with a simple mobile phase. The accuracy and precision in the present methods by the use of automated HPLC were satisfactory.

Quantitative determination in urine of hippuric acid and m- or p-methylhippuric acid, metabolites of toluene and m- or p-xylene

Ogata, M., Tomokuni, K., and Takatsuka, Y. (1969).Brit. J. industr. Med.,26, 330-334. Quantitative determination in urine of hippuric acid and m- or p-methylhippuric acid, metabolites of toluene and m- or p-xylene. Improved and more specific methods for the quantitative determination of hippuric and m- and p-methylhippuric acids in urine are described. The acids were extracted from urine with ether/ethanol, which was dried with silica gel, or with ethyl acetate. After removing the solvent by evaporation coloured azlactones were formed by reaction with p-dimethylaminobenzaldehyde in acetic anhydride (DAB, only usable after ether/ethanol extraction) or benzenesulphonyl chloride in pyridine, and the absorbances were measured. The sensitivities were about 4 μg./ml. of urine using DAB, and 20 μg./ml. of urine using benzenesulphonyl chloride reagent. Separation of hippuric and methylhippuric acids was achieved by paper and thin-layer chromatography before estimation. A spot test is also described.

Regional mapping of catalase and Wilms tumor--aniridia, genitourinary abnormalities, and mental retardation triad loci to the chromosome segment 11p1305----p1306.

SummaryGene dosage effects for catalase (CAT) were studied in two unrelated patients with an interstitial deletion involving 11p13 to determine precisely the sites of the genes for CAT and the Wilms tumor—aniridia, genitourinary abnormalities, and mental retardation triad (WAGR) in the 11p13 band. Case 1 had the aniridia-Wilms tumor association, and case 2 showed the AGR triad. The karyotypes identified by high resolution banding techniques were 46,XY,del(11)(pter→p13::p11.11→qter) for case 1 and 46,XY,t(2;17) (q23;q25), del(11) (pter→p13::p11.2 →qter) for case 2. In both cases, the distal breakpoints of the deleted chromosomes 11 appeared to have occurred on the middle portion of 11p13 (11p1305→p1306). The level of erythrocyte CAT activities in case 1 was reduced (47% of normal), while that in case 2 was normal. The results suggested not only that both the CAT and WAGR should be mapped to chromosome region 11p1305→p1306, but also that in this region the CAT locus is more distally placed than the WAGR locus. Because of the proximity of the two gene loci, assays of erythrocyte CAT may be useful to identify a submicroscopic deletion in some patients with sporadic aniridia and to predict a risk of developing Wilms tumor.

Quantitative determination of urinary hippuric acid and m- or p-methylhippuric acid as indices of toluene and m- or p-xylene exposure by high performance liquid chromatography.

SummaryA high performance liquid chromatographic method for the determination of hippuric and m-(p-)methylhippuric acids in urine, metabolites of toluene and m-(p-)xylene, is described. A stainless-steel column packed with octadecyl silanized silica gel was used and the mobile phase was a mixed solution of methanol/water/acetic acid (20/80/0.2). The method is simple and specific. Urine can be analyzed directly, without solvent extraction or pretreatment. The method has a lower detection limit of 0.2 μg on column. All the analysis and quantitative determination can be performed within about 30 min. for samples containing m-(p-)methylhippuric acid.

Metabolism of trichloroethylene

Abstract Trichloroethylene was metabolized to chloral hydrate, trichloroethanol and trichloroacetic acid in vitro . The three metabolites in the incubation mixture were determined by gas-liquid chromatography using an electron capture detector. The kinetics of the individual steps of the metabolism of trichloroethylene were investigated in rat liver subcellular fractions or recombined fractions. The general features of trichloroethylene metabolism in vitro were demonstrated by the conversion of trichloroethyleme to the three metabolites (6 per cent total yield) by the 700 g supernatant fraction of rat liver in 2 hr. Oxidation of trichloroethylene to chloral hydrate occurred only in the microsomal fraction of rat liver, as previously reported by Byington and Leibman [5]. (This step was rate-limiting and was stimulated by both phenobarbital and 3-methylcholanthrene pretreatment.) Reduction of chloral hydrate to trichloroethanol occurred in the cytosol of rat liver. This activity was separated into at least three fractions by a DEAE cellulose column—one of them was NADH-dependent and the others were NADPH-dependent.) The formation of trichloroacetic acid from chloral hydrate required cytosol or mitochondria with NAD.

Partition coefficients as a measure of bioconcentration potential of crude oil compounds in fish and shellfish.

This paper deals with the correlation between the partition coefficient and the concentration factor of alkyl benzenes in crude oil for gold fish and also the correlation between the partition coefficients and concentration factor of alkyl dibenzothiophene for shellfish reared in oil suspension and that caught in the sea.

Cooperative effect of sulfite and vanadium compounds on lipid peroxidation

Abstract The cooperative mechanism of the action of sulfite and metal compounds on lipid peroxidation was investigated in vitro. Results obtained were as follows: (1) Lipid peroxidation of rat lung extracts, liver microsomes, and mitochondria was induced by sulfite, depending on its concentration. Peroxidation was accelerated remarkably by metal compounds such as iron or vanadium. (2) The increased lipid peroxidation by sulfite and vanadium was inhibited effectively by free radical scavengers such as hydroquinone, α-tocopherol, or superoxide dismutase. (3) Similar effect of these radical scavengers was seen in lipid peroxidation induced by superoxide anion radical. (4) In the presence of sulfite and vanadium, a significant lysis of human erythrocytes was caused, suggesting an additive action of the effect of these substances.

High performance liquid chromatographic procedure for quantitative determination of urinary phenyl-glyoxylic, mandelic, and hippuric acids as indices of styrene exposure

SummaryA method is described for the quantitative determination of phenyl-glyoxylic, mandelic, and hippuric acids in urine are all metabolites of styrene monomer. After o-methylhippuric acid was added to urine as an internal standard, these three acids and o-methylhippuric acid were extracted with a mixture of ethyl ether and methanol (9/1, by vol.).After 1.0 ml of extract was transferred to a test tube and dried, 0.25 ml of methanol was added. An aliquot of this solution was injected into a high performance liquid chromatography equipped with column packed with octadecylsilicate. Phenylglyoxylic acid was estimated from the peak height at wave length 254 nm. Mandelic, hippuric and o-methylhippuric acids were estimated from their peak height at 225 nm.For a micro-determination of urinary mandelic acid, phenacyl esterification of mandelic acid could be performed by combination with phenacyl bromide and thriethylamine. This was then analyzed at 254 nm using the column packed with silica gel.

Identification of substances in petroleum causing objectionable odour in fish

Abstract In order to identify substances causing an offensive-odour in fish from the sea facing petroleum and petrochemical industries, analyses have been made on sea water, industrial wastes, fish and eels kept in the sea or industrial waste for a certain period, by means of gas chromatography, i.r., u.v. absorption and mass spectrometry. Observations revealed toluene as a possible main cause of the odour. Finally, by analysing the meat extract of fish kept in sea water containing toluene which had the same smell as that of the offensive-smelling fish from near the oil refineries, it has been confirmed that toluene imparts the offensive-odour to fish near Mizushima. By gas chromatographic analysis of eels kept alive experimentally in sea water containing oil and their components, it has been proved that aromatic hydrocarbons (benzene and o -, m - and p -xylene) other than toluene and some aliphatic hydrocarbons are also probable substances that impart an offensive-odour to fish. Gasoline rich in olefine imparts offensive-odour to fish more than gasoline rich in paraffin or naphthene.