Methylmercury distribution and production in the environment are reviewed. As for methylmercury distribution, the proportions of methylmercury to the total mercury in waters, soils, sediments and airs are mainly discussed. The origin of methylmercury in fish is also discussed. Methylation of inorganic mercury in the environment can be roughly divided into two groups ; one is biological and the other is chemical methylation. In this article, chemical methylations are discussed in detail. Effects of environmental factors, such as pH, redox potential and temperature, on the methylmercury production are also mentioned.

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By measuring concentrations of MT (metallothionein) and Zn in both malignant and non-malignant tissue of human liver, the following results were obtained. 1. MT concentration of non-malignant tissue in human liver was high and the data were 197, 538 and 552 μg/g. 2. The mean value of MT concentration in malignant tissue of human liver was 30.4 μg/g. 3. Between Zn concentration (x μg/g) and MT concentration (y μg/g) in the liver, a strong positive correlation (r=0.970) was observed. Its regression formula was y=-129+13.1x. The above results showed that MT concentration in human liver decreases by canceration.

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Long-term experiments were carried out, for up to 300 d after CdCl₂ injection, to investigate the mechanism of the testis injury induced by CdCl₂. The results are summarized as follows ; 1) Testis weight and lipoperoxide concentration were increased significantly at 3 d after CdCl₂ injection, and thereafter decreased steadily. The values at 300 d were very much lower than those of control group. 2) Although hemoglobin content in the testes treated with CdCl₂ was significantly higher at 3 d, presumably because of the intensive hemorrhage in situ, it decreased gradually and the value at 300 d after injection had returned almost to the control level. 3) In the testis at 3 d after CdCl₂ injection, edematous was found in the interstitial tissue numerous neutrophils had migrated into the seminiferous tubules and the tubules were contracted. These changes, however, disappeared as time elapsed after CdCl₂ injection. By 300 d, the seminiferous tubules were filled with materials which had a high concentration of Ca and P. The concentration of Ca in the interstitial tissues was also high. The enhancement of Ca deposition was observed in the testes of rats 3 d after CdCl₂ injection. 4) Although the activities of serum GOT and GPT were significantly higher at 3 d after CdCl₂ administration, they returned to the control level by 15 d after the injection and thereafter they showed normal values throughout the remainder of the observation periods. On the contrary, Al-P activity decreased significantly at 3 d after the injection. However, the enzyme activity returned to the control level at 90 d.

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The accumulation of metals in the several organs (hepato-pancreas, kidney, gills and spleen) of carp (Cyprinus carpio) was studied by two kinds of cadmium administration methods, namely, exposure to 5 mg Cd/l solution and intraperitoneal (i.p.) injection of 2 mg Cd/kg body wt. Cadmium concentrations in the kidneys accumulated by these two administration methods were highest among the organs, those in hepato-pancreas being next to the kidneys. Cadmium accumulation in hepato-pancreas and kidney was higher by the intraperitoneal injection than by the exposure. Zinc concentration was high in the spleen by the intraperitoneal injection, and that of copper was high in hepato-pancreas by the two administration methods. The cytosolic fractions obtained from carp hepato-pancreas, kidney, gills and spleen were further fractionated into high molecular fraction (HMF) and metallothionein (MT) fraction (MTF). The difference of concentrations of cadmium and zinc in the MTF and HMF by the two administration methods was studied. In the case of intraperitoneal injection, the cadmium concentration in the MTF was higher than that of the HMF in all organs. Compared with the control, the zinc concentration decreased in the MTF of hepatopancreas, but increased in that of gills by both administration methods. The induction of metallothionein in gills and spleen by the injection of cadmium was recognized, and two types of isometallothionein were separated (MT-I, MT-II). The metal composition in gills MT-I and spleen MT-I was mainly cadmium. The molar ration of cadmium, copper and zinc in gills MT-II was 48 : 2 : 1, and that of cadmium and zinc in spleen MT-II was 35.2 : 1.

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The sale of escolar (Lepidocybium flavobrunneum) and castor oil fish (Ruvettus pretiosus) is prohibited in Japan, because their muscles contain a large amount of wax and may cause a food poisoning when they are ingested much. Howover it is difficult to distinguish them from edible fishes when they are sliced. Therefore, we attempted to identify the species of these fishes by thin layer isoelectric focusing of sarcoplasmic proteins. The results showed that the electrophorograms of these proteins were species-specific, and therefore they were effectively utilized to distinguish these two fishes from other 26 edible fish species so far tested. In addition, seasoned slices of fishes were analyzed for sarcoplasmic proteins. The results obteined showed that the identification of each species was possible by thin layer isoelectric focusing of these sarcoplasmic proteins after desalting with gel filtration.

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Antiserum to carp (Cyprinus carpio) hepato-pancreatic MT-II was prepared by use of New Zealand white rabbit. Immunoglobulin G (IgG) was separated on a Protein A Sepharose CL-4B column, and labelled with horseradish peroxidase (HRP). The slices of hepato-pancreas and kidney from carps of the two groups, non-injected and Cd-injected, were prepared. Metallothionein in the slices reacted with the IgG by direct method. In the hepato-pancreas of carp injected with CdCl₂, the staining for metallothionein was observed in nucleus of hepatocytes, sinusoids, intracellular space and acinar cells in pancreas tissue, the nucleus and acinar cells being stained remarkably. In a non-injected carp, the acinar cells in pancreas tissue were stained slightly, suggesting the presence of metallothionein. This result indicated that (Cu, Zn)-metallothionein in hepato-pancreas from a non-injected carp was present mainly in the acinar cells in pancreas tissue. In the kidney slices prepared from non-injected and Cd-injected carps, the staining for metallothionein was observed in the eprithelium of neck segment, proximal convoluted segment II and distal convoluted segment, but was not found in the glomeruli. It was proved that (Cu, Zn)-metallothionein also exists in the kidney of a non-injected carp.

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Sensitive enzyme immunoassays for the determination of colistin and Bacillus Colistinus have been developed. Horseradish peroxidase was used as the labeling enzyme, and was conjugated with colistin or anti-Bacillus Colistinus IgG according to Nakane's method. Separation of bound and free fractions after immune reaction, was achieved by antibody or antigen solid phase method using Sepharose 4B or polystylene tubes. 3-(p-Hydroxyphenyl) propionic acid and hydrogen peroxide were used as substrates for the fluorometric assay of peroxidase activity. Satisfactory standard curves for colistin and Bacillus Colistinus were obtained in the range of 0.064 to 1000 ng/ml and 0.1 to 25 ng/ml, respectively. Enzyme immunoassay developed here could be applied to the determination of colistin in various tissues and Bacillus Colistinus in feed.

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Pyrethroid is widly used as one of home insecticidee in Japan. Its pollution level in the interior of a house was investigated. Allethrin, resmethrin, phthalthrin, permethrin and synergist S-421 were detected at a level of 0.01 to 7.6 ppm in all dust samples sucked into a vacuum cleanner. The degree of degradation of pyrethroid insecticides applied on the surface of glass cup was examined. Resmethrin, allethrin, phthalthrin and permethrin were decreased by 95%, 64%, 58% and 6% at a room temperature of 18-25°C after 7 days, respectively.

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From the results of HPLC-analysis of commercial cosmetic dyes, the existence of isomers of 1-xylylazo-2-naphthol (=XAN ; Japanese recommended name : Red No. 505) based on two methylgroups was suggested. Possible six isomers of XAN (2, 3-, 2, 4-, 2, 5-, 2, 6-, 3, 4-, and 3, 5-XAN) were synthesized and applied to reversed-phase HPLC by using a Zorbax ODS column. Six isomers except 3, 4- and 3, 5-XAN could be separated. Four commercial samples of Red No. 505 in Japan were applied to this method for the determination of isomeric constitutions. Two of them were constituted of only 2, 4-XAN and other two samples were mixtures of 2, 4-, 2, 5- and 2, 6-XAN. All the six isomers and four commercial samples of XAN did not show mutagenicity by testing with S. typhimurium TA 98 and TA 100.

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The sale of escolar (Lepidocybium flavobrunneum) and castor oil fish (Ruvettus pretiosus) is prohibited in Japan, because their muscles are rich in wax which may cause a food poisoning. The identification of these fishes was therefore investigated by wax analysis. The analytical procedure was as follows : lipids were extracted from fish meats, and the presence of wax in the lipids was examined by thin-layer chromatography (TLC). The compositions of these waxes were examined by gas chromatography with FID (FID-GC). In order to investigate the composition of higher alcohols included in the waxes, the lipids separated from fishes were saponified and the extracted unsaponifiable matters were subjected to FID-GC after acetylation. The results obtained from the analysis on 28 fish species showed that the lipids of john dory (Zeus faber) in addition to escolar and castor oil fish contained wax. The gas chromtogram of waxes showed that the molecular formular of waxes of escolar and castor oil fish were C₃₄H₆₆O₂, whereas that of john dory was C₄₀H₇₆O₂ as their main ingredient. Furthermore, it was shown that the alcohols of escolar and castor oil fish were of C 16 : 0, whereas that of john dory was of C 22 : 1 as their main ingredient. These results indicate that it is possible to distinguish sale-prohibited fishes from edible fishes by wax analysis, even if they are sliced.

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Phenolic compounds are contained in effluents from various factories. Matsumoto reported the pollution of well waters by phenolic substances and proved the effluent source to be a coal gas plant. Underground permeation of phenolic substances from a dyestuffs factory into the wells beside the lower reaches of the Omuta river was also reported. Many substances such as medicines, nutritional substances and other natural biological substances contain compounds with phenolic groups, and the possibility of water pollution must be considered from effluents containing such substances. Water polluted by phenols shows high CODMn values. Therefore it is necessary to investigate the relationship between COD values and the chemical structure of phenolic compounds. A semimicro acidic or alkaline COD method was previously reported. In this report, the micro methods were adapted to determine the CODMn values of phenols.

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Effect of inorganic mercury administration on gel filtration (Sephadex G-200) patterns of endogenous selenium, most of which is supposedly incorporated into structural or functional proteins, in the rat plasma and soluble fractions of the liver and kidneys was investigated. High molecular weight complexes containing equimolar amount of ²⁰³Hg and ⁷⁵Se were observed in the plasma and soluble fraction of the liver, but not in the kidney, at 24 h after simultaneous administration of ²⁰³HgCl₂ and Na₂⁷⁵SeO₃ as in the cases of other animal species reported so far. However, an increase in the amount of endogenous selenium associated with these high molecular weight complexes in the plasma and liver was hardly observed at 24 h after HgCl₂ administration. These results suggest that inorganic mercury selectively interacts with co-administered selenium to form high-molecular weight complex, but not with the endogenous selenium.

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The effects of three classes of chlorinated pesticides, chloroethanes (DDT, etc.), cyclodienes (aldrin, etc.), and chlorophenols (PCP, etc.), on the activities of porcine pancreatic and Rhizopus delemar lipases were studied using water-soluble tripropionin as a substrate. The effects were examined by three different procedures : (I) preincubation of lipase with pesticide and initiation of the enzyme reaction by addition of substrate, (II) preincubation of substrate with pesticide and initiation of the enzyme reaction by addition of lipase, (III) addition of pesticide after initiation of the enzyme reaction. With porcine pancreatic lipase, chloroethanes and cyclodienes exhibited significant activation, increasing the V_max value and decreasing the K_m value, when procedure II was employed, but showed non-competitive inhibition when procedure I or III was employed. With Rhizopus delemar lipase, chloroethanes and cyclodienes exhibited significant activation, increasing only the V_max value in all three procedures. The activation of pancreatic lipase by chloroethanes was only temporary. Chlorophenols competitively inhibited both lipases in all three procedures.

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An enzymic method for determining simultaneously glucose, fructose, and sucrose in foods was developed. This method is based on the measurement of NADH formation by hexokinase (HK), glucose 6-phosphate dehydrogenase (G6PDH), and auxiliary enzymes. After measurement of glucose by HK and G6PDH, fructose is measured by the addition of glucosephosphate isomerase, and sucrose is successively measured by the aid of invertase. Results for sugar content in various foods obtained by the present method and gas chromatographic method were very similar. Precision (within-day and day-to-day) and analytical recovery of the present method were satisfactory. This method may offer advantages (simplicity, inexpensiveness, and applicability for multiple run) over gas chromatography and high-performance liquid chromatography in the routine assay of glucose, fructose, and sucrose in foods.

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A sensitive enzyme immunoassay for the determination of monensin has been developed. Horseradish poroxidase (HRP) used as a labeling enzyme was conjugated with monensin according to the mixed anhydride method. Bound and free fractions after immune reaction were separateb by double antibody solid phase using Sepharose 4B. Three assay methods, spectrophotometric, fluorophotometric and luminometric, for the measurement of HRP activity were compared. Spectrophotometric method using ABTS [2, 2'-azino-di-(3-ethyl-benzthiazoline-sulfate (6))] was suitable for routine assay method. Enzyme immunoassay developed here appears to be applicable to the determination of monensin in various tissues.

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In order to clarify daily variations of anionic and nonionic surfactants levels in the river waters, the atomic absorption spectrophotometric method reported previously was used. Water samples were taken from the two rivers close to Kobe Women's College of Pharmacy for about two months (1982. Oct.-Dec.). The results showed that there was a significant correlation between the levels of anionic and nonionic surfactants. The correlation coefficients between these two surfactants levels in the two rivers were 0.919 and 0.858 (p<0.01), respectively.

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