Seiji Kawasaki

Screening of organophosphorus pesticides using liquid chromatography-atmospheric pressure chemical ionization mass spectrometry

Screening and identification of organophosphorus pesticides in blood from patients suffering from acute agricultural chemical toxicity were established by a liquid chromatography-atmospheric pressure chemical ionization mass spectrometric method. To determine 21 pesticides, it was necessary to monitor both positive and negative ions. This method could easily screen for 21 organophosphorus pesticides in less than 30 min. By comparison with a gas chromatographic-mass spectrometric method, the chemicals indicated a similar extent of specificity and within equivalent detection limits, thus satisfying clinical requirements completely.

Simple, rapid and simultaneous measurement of eight different types of carbamate pesticides in serum using liquid chromatography—atmospheric pressure chemical ionization mass spectrometry

We have developed a method for simultaneous analysis of methylcarbamate pesticides in serum with an acute pesticide intoxication. This is performed by liquid chromatography-atmospheric pressure chemical ionization mass spectrometry. Rapid detection of eight types of methylcarbamate pesticide can be achieved with this method, it only requires an extremely simple pre-treatment of the sample. The specificity of this method is equal to that of gas chromatography-mass spectrometry, and it satisfies the clinical requirements for detection sensitivity and specificity. Although some problems with this analytical method remain to be solved, we consider it to be superior to any other analytical method previously reported.

Urinary excretion of 3,4-dimethylhippuric acid in workers exposed to 1,2,4-trimethylbenzene

SummaryThe urinary excretion of 3,4-dimethylhippuric acid (34DMHA), a 1,2,4-trimethylbenzene (124TMB) metabolite, was investigated in workers exposed to 124TMB vapor. The time-weighted average of exposure to 124TMB was determined with a diffusive sampler. For biological monitoring of exposure, urine samples were collected from individual workers and analyzed for metabolites by high-pressure liquid chromatography. The concentration of urinary 34DMHA had a positive correlation with the level of exposure to 124TMB (r = 0.72). The data suggest that 34DMHA is one of the useful indicators for biological monitoring of 124TMB exposure.

Stress maladjustment in the pathoetiology of ulcerative colitis.

BackgroundThe aims of this study were (1) to measure levels of cytokines and stress hormones in ulcerative colitis (UC) patients and determine whether there were any disturbances in the nervous, endocrine, or immune systems, and (2) to measure the ability of UC patients to cope with stress (using a sense of coherence, SOC, test) and their perceived self-efficacy, and to elucidate their response to a stress load.MethodsWe administered questionnaires to and took blood samples from 42 outpatients and eight inpatients whose UC was in remission, and 21 healthy volunteers. In addition, we evaluated blood samples from the inpatients and healthy volunteers following a mental calculation stress test.ResultsThe questionnaire results revealed that self-efficacy was significantly decreased in the patient groups. Levels of adrenocorticotropic hormone, β-endorphin and interleukin (IL)-6 were significantly higher in the outpatient than in the control group. IL-6 levels significantly increased following the mental calculation stress test in UC patients compared with in the volunteers.ConclusionsThese results indicate that UC patients (1) have hypersensitive nervous, endocrine, and immune systems, and (2) this hypersensitivity was augmented by the mental calculation stress test.

Normalization of Phospholipids Concentration of the Gastric Mucosa was Observed in Patients with Peptic Ulcer after Eradication of Helicobacter pylori

Background. Phospholipids concentration in the gastric mucosa decreased in patients with Helicobacter pylori infection. The aim of this study is to examine the effects of eradication of H. pylori on decreasing the phospholipids concentration in the gastric mucosa in patients with gastric or duodenal ulcer.