Glutathione conjugation and subsequent mercapturic acid formation have long been considered as one of the major pathway of detoxication. In recent years, however, glutathione or its related conjugates of some halogenated alkanes and alkenes have been found to serve as bioactive nephrotoxicants. On the basis of the activation mechanism, those nephrotoxic sulfur-containing conjugates can be classified into three types : 1) direct-acting conjugates, 2) canjugates requiring metabolic activation, 3) others. Direct-acting toxins including S-(1, 2-dihaloethyl) glutathiones are strong alkylating agents. The β-halogen atom is displaced with a sulfur atom to result in the formation of highly reactive episulfonium ion, which is likely to react with the nucleophilic sites of bio-macromolecules. The second class of nephrotoxicants that require metabolic activation to express toxicity includes sulfur-containing conjugates of halogenated alkenes. In the diverse metabolic pathways, some metabolites such as sulfenic acids, thioacetaldehydes, and thiols are probably associated with the expression of toxicity. Among them, participation of the unstable thiols has been extensively studied. It is postulated that the penultimate intermediate thiols give rise to halothionoacyl halides and halothioketenes. Further studies on the whole metabolic pathway of sulfur containing conjugates as well as their toxicity will give light on how each pathway contributes to toxicity.

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Viral infection due to transfusion has been the root of various diseases, primarily hepatitis. The discovery and prompt removal of the causative virus have been very effective in the eradication of such disease. After the isolation of the HBV and the establishment of methods for testing it, screening of donated blood was enforced, and then the incidence of hepatitis B decreased dramatically. Before 1963, post transfusion hepatitis (PTH) incidence in Japan was approximately 50%. Prior to HBs Antigen screening by the Japan Red Cross Blood Center the incidence of PTH accounted for about 16%. At present, it accounts for only 0.5%. HBIG (hepatitis B immunoglobulin) and HB vaccine have been efficacious in the prophylaxis of infection after incidental exposure to infectious blood and in infants born from HBV carrier mathers. From 1980s, ATL (adult T cell leukemia) and AIDS (acquired immunodeficiency syndrome) have also become problematic diseases. In November of 1986, screening with anti-HTLV-I (human T cell Leukemia virus) antibody and anti-HIV (human immunodeficiency virus) antibody started at blood centers. However, as we did not know the existence of AIDS until 1981, we can not rule out the possibility that an unknown virus is yet present in the blood. Therefore, all blood and serum must be handled as if they are capable of transmitting infectious agents.

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Samples of water from two rivers in Osaka, one of which is considered to be unpolluted and the other moderately polluted by man made chemicals were shown to have different capabilities in the biodegradation of aniline. Microorganisms in the unpolluted Mino River water were not able to biodegrade aniline, whereas those in the moderately polluted Ina River water could do so. The microflora differed significantly in the two rivers. The MPN counts of the aniline degrading microorganisms of these two river waters also indicated less chance of aniline biodegradation in the Mino River. This would suggest that aniline degradation in river waters may reveal many facts on degree of adaptation to and alteration of natural populations under pollutant stress.

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A modified method for the determination of residual hydrogen peroxide (H₂O₂) in foods by oxygen electrode was developed. H₂O₂ content in the sample was calculated from the difference between H₂O₂ values obtained from the sample with and without catalase treatment. H₂O₂ was extracted from the sample by dipping with acidic extractant (sulfuric acid containing zinc sulfate and potassium bromate) in ice-water. The mixture of the extractant and the sample was adjusted to pH 6-8 with sodium hydroxide solution and phosphate buffer after the extraction. H₂O₂ content in the filtered extract was determined with oxygen electrode according to the Toyoda's method. The recoveries of H₂O₂ added to 14 kinds of commercial foods at levels of 1 and 5 μg/g were in the range of 62.3-102.9 and 89.8-100.2%, respectively. The recoveries from 8 kinds of foods by the modified method were higher than those by the Toyoda's method. H₂O₂ contents in 14 kinds of comercial foods were not detected except yogurt (2.49 μg/g). H₂O₂ contents obtained from 11 kinds of foods by the modified method were lower than those by the Toyoda's method. Residual H₂O₂ contents in 6 kinds of foods treated with H₂O₂ were determined. H₂O₂ contents obtained from the 2 kinds of foods by the modified method were higher than those by the Toyoda's method, and H₂O₂ contents obtained from 4 kinds of foods by the two methods were similar. These results suggested that the modified method is more suitable than the Toyoda's method for the determination of residual H₂O₂ in foods treated with H₂O₂.

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In order to clarify the mechanism of cadmium (Cd)-induced rat testicular cancer, cadmium (Cd) contents in the liver, kidney and testis and in hepatic, renal and testicular Leydig's cell nuclei after exposure to noncarcinogenic dose (3.87 μmol/kg, once, s.c.) or carcinogenic dose (30μmol/kg, once, s.c.) of CdCl₂ were asessed. Uptake and cytotoxicity of Cd and DNA damage by the metal in hepatocytes, Sertoli's cells and Leyding's cells were also assessed. Administration of carcinogenic dose of CdCl₂ to rats caused severe testicular damage as reflected by a remarkable rise in calcium content, discoloration and atrophy of the organ. In the rats given carcinogenic dose of CdCl₂, when Cd contents in the testis and testicular Leydig's cells nuclei were compared with those of the liver, kidney, hepatic and renal nuclei, in both whole tissue and the cellular nuclei the metal content was lower in the testis than in the liver and kidney. Leydig's cells were the most sensitive to Cd cytotoxicity although Cd uptake in this cell population was lesser than those in any other ones. Cd did not show any DNA damage in both testicular cell species. These results suggest that Cd induces testicular cancer by causing overall functional impairment of the organ or cytotoxicity to Leydig's cells, target cell population for Cd carcinogenecity.

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A screening method for 1, 4-benzodiazepines and their metabolites in the human urine was investigated by direct inlet-electron impact mass spectrometry (DI/EI). The 1, 4-benzodiazepines and their metabolites were extracted with ethylether from the urine. The extract was evaporated to dryness and the dried residue was dissolved in 0.2 N hydrochloric acid. The solution was neutralized with 2 N sodium hydroxide solution and applied to the Sep-pak C₁₈ cartridge with dichloromethane-methanol (9 : 1) as eluent. The eluate was evaporated to dryness, dissolved in methanol. Methanol solution was analyzed by mass chromatography (MC) with selected specific fragment ion in DI/EI of the 1, 4-benzodiazepines and their metabolites. The 1, 4-benzodiazepines and their metabolites less than 20 ng were well-detected by DI/EI/MC.

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Activities of alkaline phosphatate (ALP), leucine aminopeptidase (LAP) and γ-glutamyl transpeptidase (γ-GTP), which were all present at high concentration in the proximal tubules, were determined for the serum and homogenate from kidney and liver of mice to assess nephropathy induced after oral administration of thiabendazole (TBZ), which was suspended in olive oil or in 3% gum arabic to female mice at a dosage of 350, 700 and 1300 mg/kg/d for 5 or 10 d. Kidney tissue preparations were also examined by microscopy. The specific activities of both ALP and LAP in the liver increased after the repetitive administration of TBZ. Specific activities of ALP, LAP and γ-GTP in the kidney increased at a dose level of 350 mg/kg/d for 10 d, but they decreased at a dose level of either 700 and 1300 mg/kg/d for 10 d, or 1300 mg/kg/d for 5 d. Marked changes in kidney tissues were observed microscopically at a dose level of 1300 mg/kg/d. The brush border disappeared and the tubular lumen was dilated. These results indicate an induction of nephropathy by TBZ which is accompanied by changes in the proximal tubules of mice.

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The analytical method combined with chemical treatment (ion exchange, solvent extraction, coprecipitation) and measurement of β radiation by a low back ground counter has been adopted in "Standard Method of Analysis for Hygienic Chemists" as the analytical method of ¹³¹I in milk. However, it was difficult to apply this method to the analysis of some kinds of milk on the market, because some colloidal phenomena appeared at the coprecipitation step. As a result of detection by use of thin layer chromatography and mass spectrometry, it is guessed that this is caused by materials possessing surface active action, such as fatty acids which constitute milk fat (e.g., palmitic acid, stearic acid etc.), and surface active agents added to dairy products. Therefore, after the removal with ether of these surfactants before the coprecipitation step, the measurement of radioactivities of ¹³¹I can be carried out without trouble.

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The intraperitoneal administration of 2-isopropylnaphthalene (2-IPN) (3000 mg/kg) to rats resulted in an increase of phospholipids and phosphatidylcholine in the pulmonary lavage fluid. The fatty acid composition of the phosphatidylcholine in the fluid of rats so treated, however, was unchanged from that of untreated animals. Prior treatment of rats with piperonyl butoxide, a known cytochrome P-450 inhibitor, resulted in an inhibition of the above increase of phospholipids and phosphatidylcholine. In contrast, prior treatment with diethyl maleate, which induced depletion of reduced glutathione (GSH) in the tissue, enhanced the effect of 2-IPN on phospholipid and phosphatidylcholine contents in the pulmonary lavage fluid. To confirm the possible participation of GSH, pulmonary nonprotein-SH (NP-SH) was determined. Treatment with 2-IPN resulted in a decrease of NP-SH, and the administration of 2-IPN to rats pretreated with diethyl maleate caused a significant decrease of NP-SH compared to 2-IPN given without pretreatment. From these results, it is suggested that reactive metabolites such as 2-IPN-epoxides are produced, leading to an increase in secretion of pulmonary surfactant from alveolar Type II cells.

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An apparatus for micro-determination of mercury by cold vapor atomic absorption by utilizing double-beam spectrophotometer was constructed. D₂ lamp was displaced with mercury lamp and a gas flow cell (10 cm length, 2.5 cm i.d.) was placed in the cell room. Inorganic or organic mercury in the prepared solution was reduced by added stannous chloride and vaporized mercury was trapped once with a bundle of gold wires. Next time, the bundle in a quartz tube was heated and released mercury vapor was flowed through the absorption cell at a speed of 1.0 l/min. Atomic absorption by the vapor was recorded and mercury content was calculated. Calibration curves of inorganic and organic mercury, directly or after heating treatment, were agreed very well. Methylmercury chloride was separated well (82%) by direct distillation method, then total mercury, organic and inorganic mercury could be determined with these methods by using very small amount of samples.

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Hexafluoroisopropyl ester-trifluoroacetate (HFIP-TFA) derivatives or methyl estertrifluoroacetate (Me-TFA) derivatives of 18 bile acids and non-derivatized or trifluoroacetate (TFA) derivatives of 4 neutral steroids containing cholesterol and its metabolites were analyzed by capillary GC. Non-polar or slightly polar columns were effective for the analysis of HFIP-TFA derivatives of bile acids. Non-polar columns were useful for the analysis of Me-TFA derivatives of bile acids. TFA derivatives of 4 neutral steroids were completely separated and analyzed by non-polar columns. Furthermore, HFIP-TFA derivatives of 18 bile acids and TFA derivatives of 4 neutral steroids were analyzed by capillary GC/MS with electron impact (EI) or chemical ionization (CI). Molecular ions ([M]⁺ or [MH]⁺) did not occasionally appear, but the specific fragment ions ([M-CF₃COOH]⁺ or [MH-CF₃COOH]⁺ and so on) were observed. Intensities of the specific fragment ions were tabulated.

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The concentrations of dust, benzo [α] pyrene (B [α] P) and nitrogen dioxide (NO₂) were determined in the air inside and outside of private houses in Nagoya City. Thirty-eight private houses were investigated in summer and winter during 1985-88. The mean indoor dust, B [α] P and NO₂ concentrations were 0.05±0.05 mg/m³, 2.03±2.11 ng/m³ and 18±9 ppb in summer, and 0.09±0.05 mg/m³, 3.59±4.68ng/m³ and 38±24 ppb in winter, respectively. A significant correlation was obtained between indoor and outdoor B [a] P concentrations both in summer and winter, but the indoor B [a] P concentration was higher in the houses with oil stoves (reflex type) than in those without oil stoves (reflex type). The combustion between old and brand-new oil stoves was examined experimentally.

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pH values and microbial colony forming unit (CFU) of JP 11 purified waters (8 samples) were studied. pH values of 8 samples tested were between 5.64 to 5.98. No bacteria were detected from 2 test samples for 3 months. A few bacteria were detected in another samples at immediately after preparation, and after 1 month microbial CFU in 3 sample increased remarkedly. The microbial CFU in these samples were 6.7×10³-1.2×10⁵ CFU/ml. Most bacteria isolated were gram negative rod after 1-3 month, and these were identified as Shigella sp. by using api 20NE system. Slight correlation between the increase of microbial CFU and the contents of total organic carbon (TOC) were found.

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