Iwao Ijiri

Alcohol sensitivity related to polymorphism of alcohol-metabolizing enzymes in Japanese

Normal Japanese subjects were divided into two groups, i.e., one with both low and high Km isozymes of aldehyde dehydrogenase for acetaldehyde, and the other deficient in the low Km isozyme. After intake of 0.4 g/kg alcohol, the deficient subjects showed high level of blood acetaldehyde, facial flushing and the other dysphoric symptoms, including increase of pulse rate, decrease of diastolic blood pressure, changes of pulse wave in the fingertip, and elevation of the arterial pressure and blood flow rate in common carotid arteries as well as increase of plasma catecholamines level. In contrast, subjects with normal ALDH did not show these changes. From the observation of liver specimens obtained at autopsy, the frequency of deficient phenotype of ALDH in Japanese was presumed to be about 36%.

Urinary excretion of p-hydroxylated methamphetamine metabolites in man. I: A method for determination by high-performance liquid chromatography-electrochemistry

Abstractp-Hydroxymethamphetamine and p-hydroxyamphetamine in urine samples from methamphetamine addicts were analyzed by high-performance liquid chromatography-electrochemistry (HPLC-EC). The urine samples were hydrolyzed with equal volumes of 12 N HCl at 60 °C for 4 h and were then diluted with water and neutralized with NaOH solution. The neutralized urine was passed through a solid phase extraction column, Bond-Elut® C18, and after washing, the substances were eluted with acidified acetonitrile. The eluate was evaporated under a stream of nitrogen. The residue was dissolved in 0.1 N PCA and a small volume of the aliquots was injected into the HPLC. This procedure for determination quantitated both free and conjugated forms of the metabolites together. Thereby we could determine concentrations of the metabolites in minute urine samples; i.e., from 2.5 μl urine. The free form of the metabolites alone was analyzed by the same procedure except for hydrolysis of the conjugates.Concentrations of methamphetamine, p-hydroxymethamphetamine and p-hydroxyamphetamine in the urine samples of addicts collected at arbitrary times were determined by this procedure or by gas chromatography. It was found that there was no correlation between the concentration of methamphetamine and that of the metabolites. This investigation also revealed that various ratios between the concentrations generally were scattered over a wide range of percentages.

Rapid determination of p-hydroxylated methamphetamine metabolites by column liquid chromatography—electrochemistry

A method for electrochemical determination of p-hydroxymethamphetamine and p-hydroxyamphetamine in human urine was investigated by column liquid chromatography. A rapid and simple extraction of these substances from urine was performed using a solid-phase extraction column. The detection limit for quantitation was approximately 50 pg for the metabolites. The simplicity and sensitivity of this method allows for analysis of these metabolites in the fields of toxicology and forensic medicine.

The effect of heating on Y-chromosome detection

The effect of heating on Y-chromosome detection was investigated. Heat-treated blood was divided into four groups according to the hemolysis pattern obtained by the coil planet centrifuge system. A significant difference between the Y-positive nuclei of males and females was observed up to group III of the hemolysis pattern, and it was possible to determine the sex of the blood donor in spite of karyolysis and degeneration of blood components. However, sex determination of blood in group IV, indicating complete hemolysis, was impossible because of overlapping between male and female Y-chromosome counts. Practical application of this sex determination method was successful even with severely burned cadavers. However, it was suggested that putrefaction together with heat damage made the identification nearly impossible.

Simple and sensitive method for the determination of acetaldehyde in blood by gas chromatography

Acetaldehyde, an intermediate metabolite of ethanol, is suspected to be a mediator of a number of both the acute and chronic actions of ethanol. There has been considerable interest in assaying acetaldehyde in blood, and a number of sensitive and specific methods, apparently using similar head-space analysis, have recently been described [ l-41. However, the level of acetaldehyde in blood from normal healthy individuals given ethanol is extremely low. In fact, it is usually even below the detectable limit of the hydrogen flame ionization detector used in the head-space method. Various difficulties are also inherent in attempting to determine blood acetaldehyde levels, owing to acetaldehyde formation and disappearance when blood samples containing ethanol are treated in practice. Pentafluorobenzyloxylamine (PFBOA) , on the other hand, has been found to be an excellent derivatizing agent in the gas chromatographic (GC) determination of low-molecular-weight carbonyl compounds, such as aldehydes and ketones, in aqueous solution [ 5,6]. The derivatives are stable, very volatile and extremely sensitive to eletron-capture detection (ECD) . The present paper describes a reliable and sensitive GC-ECD method for assaying low levels of acetaldehyde in blood samples from its O-pentafluorobenzyloxime (0-PFBO) derivative.