Nnewi is the commercial nerve center and the most highly industrialized city east of the River Niger in Anambra State of Nigeria, West Africa. The industries specialize in manufacturing automobile batteries and accessories, electrical cables, agro-allied products and sundry items. One major problem in Nnewi is the lack or total absence of legal facilities authorized to dispose of industrial waste. We have investigated the impact of chemicals arising from industries on water and soil qualities in Nnewi. Higher levels of iron. copper, lead and manganese were found in the deep than in the top soil. Soil samples from battery manufacturing industries had the highest levels of manganese (3617ppm) and 664ppm of lead while soil samples from vegetable oil industry showed the highest level of lead (746ppm). The pH of the soil ranged from 3.5-6.4. River Ele had a higher level of lead (192.5ppm) at the source than in the middle and lower courses which had 25ppm each. The total hardness, salinity and biological oxygen demand of River Ele ranged from 14-35mg / l, 121.6-211.2mg / l and 1.9-2.7mg, respectively, from source to lower course. The highest level of volatile and non-volatile solids was 1.6 and 1.0mg, respectively. There was an absence of live or dead macro-organisms along the course of the river. Since there were elevated soil lead levels from most of the industrial sites which could have a public health impact, we recommend a control measure to reduce lead exposure to adjoining communities.

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The effects of zinc 2-mercaptobenzimidadolate (ZMBI), which contains ethylene thiourea (ETU) in its structure and is used as an accelerator and/or antioxidant in rubber manufacturing, on pregnant Wistar rats, were examined. Moreover, the effects were compared with those of ETU. ZMBI was administered orally to pregnant rats during the period of organogenesis (days 7-17 of gestation) at doses of 0, 5, 15, and 45mg/kg/day. The treatment resulted in reduced maternal thymus weight and increased thyroid gland weight at doses of ≥ 5mg/kg and ≥ 15mg/kg, respectively. Reduced fetal weight and visceral variations (kinked ureter and dilated renal pelvis) were seen at doses of ≥ 15mg/kg, and skeletal variation (rudimentary lumber ribs) was observed at 45mg/kg. Teratological effects were not observed at doses used in the present study. Thus, the no-observed-adverse-effect level (NOAEL) for maternal toxicity was considered to be less than 5mg/kg/day, and that for fetal toxicity was 5mg/kg/day. Effects of ZMBI at a dose of 73mg/kg/day (200μmol/kg/day) were compared with those of ETU at a dose of 41mg/kg/day (400μmol/kg/day). In this experiment these compounds were administered to dams during the gestational periods of days 7-10, 11-14, or 15-17. The ZMBI treatment on days 11-14 of gestation caused fetal dilated lateral ventricles and cleft plate in about 30% of the fetuses. Kinked ureter and dilated renal pelvis were also observed mainly in this group. The same visceral variations were also observed in the group treated with ETU on days 11-14 of gestation. Although cleft palate was detected in the fetuses of the dams treated with ZMBI on days 11-14 of gestation, ETU treatment on days 11-14 of gestation caused exencephaly, hydrocephaly/hydrace-phaly and club foot which were not observed in any group treated with ZMBI. Thus, in the present investigations, different spectra of malformations by the chemically related compounds, ZMBI and ETU, were observed.

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Mice were injected with an anticholinesterase, methanesulfonyl fluoride (MSF, 1.5mg/kg) or O, O-dimethyl O-(2, 2-dichlorovinyl) phosphate (DDVP, 10mg/kg) singly or repeatedly and examined for synaptic activities on the cerebral cholinergic system and behavior. MSF inhibited the activity of cerebral acetylcholinesterase (AChE) more slowly but more irreversibly than DDVP. Although a single injection of DDVP increased the concentrations of total, extraterminal, intraterminal and cytoplasmic acetylcholine (ACh) remarkably shortly after injection, MSF was still as effective at 24h as 3h after administration in increasing the concentrations of fractional ACh. Repeated injection of MSF for 3d showed a significant reduction in the activity of AChE one day after cessation with a slight recovery 5d later. Repeated administration of DDVP for 10days showed a less significant reduction in the activity of AChE one day after cessation with considerable recovery 14d later. Although a single injection of DDVP showed suppressive effects on locomotor activity, rectal temperature and rotarod performance in mice, the administration of MSF did not produce any significant effects, while DDVP suppressed locomotor activity and rectal temperature during and after the term of repeated injection. MSF showed a significant suppressive effect only at the 3rd day without causing any other changes during or after the term of repeated injection. In conclusion, MSF causes similar, but longer lasting effects on cholinergic mechanisms than DDVP and has fewer suppressive effects on behavioral parameters than DDVP.

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A 54kDa protein, which is induced by treatment with 3, 3', 4, 4', 5-pentachlorobiphenyl, 3-methylcholanthrene and butylated hydroxytoluene, was purified from rat liver by conventional methods involving DEAE-Sephacel column chromatography and processing using a Rotofor Cell^TM. This method does not require a denaturation or solubilization step and yields a single protein on SDS-PAGE. The molecular mass of the purified protein was 54.7kDa. We also characterized the 54kDa protein by immunoblot analysis and measured the binding ratio of selenium. The purified 54kDa protein was stained with antiserum which had been previously obtained, and the molecular ratio of selenium to the 54kDa protein was 0.014. Glutathione peroxidase (GPx) is a typical selenoprotein which has a selenocysteine amino acid sequence. We measured the binding ratio of selenium with commercial GPx as a positive control and obtained a value of 1.214. The binding ratio of selenium to 54kDa protein was much lower than that of GPx, and this led us to believe that there is no selenocysteine in the 54kDa protein. In this report, we have developed a convenient purification procedure and measured the purification factors and binding ratio of selenium associated with a 54kDa protein in rat liver which is homologous with a selenium-binding protein in the mouse.

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Chickens are sensitive to organophosphorus-induced delayed neuropathy (OPIDN), while Japanese quail are less sensitive. Birds were treated with an organophosphate (OP), diisopropylfluorophosphate (DFP) or fenthion, and were examined for the activity of neuropathy target esterase (NTE) in their brains and spinal cords 24h later, or for clinical signs of OPIDN for 3 weeks. Some birds were treated with OP and then with phenylmethylsulfonyl fluoride (PMSF), a promoter of OPIDN, and some Japanese quail were treated repeatedly with each OP for one week. The activity of NTE in the brains and spinal cords of hens and quail treated with DFP alone was strongly inhibited. Hens showed characteristic hindlimb paralysis, but quail did not . Birds treated with fenthion alone showed neither reduced NTE activity nor clinical signs. PMSF markedly inhibited NTE activity in both types of birds. Hens treated with DFP plus PMSF developed stronger clinical signs than those treated with DFP alone, while fenthion plus PMSF caused no signs. Quail treated with either OP plus PMSF had no signs. Quail treated repeatedly with DFP but not with fenthion had slight clinical signs. Thus, the inhibition of NTE activity was not linked to the onset of OPIDN.

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The in vitro metabolism of p, p'-DDT (p, p'-dichlorodiphenyltrichloroethane), an important environmental pollutant, was examined in fish, focusing on reductive dechlorination. When p, p'-DDT was incubated with hepatopancreas microsomes or the blood of goldfish, Carassius auratus, in the presence of both a reduced pyridine nucleotide and FMN, a dechlorinated metabolite, p, p'-DDD (p, p'-dichlorodiphenyldichloroethane) was formed under anaerobic conditions. These reductase activities were inhibited by carbon monoxide. Although the microsomes or blood was boiled, the dechlorinating activity was not abolished. Hemoglobin and hematin exhibited the reductase activity toward p, p'-DDT with NADH and FMN. The activity of hematin was also exhibited with FMNH₂. The reductive dechlorination appears to proceed nonenzymatically by the reduced flavin, catalyzed by the heme group of hemoproteins.

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For the selective quantification of metallothionein (MT)-III, MT samples from mouse brain were converted to Hg-MT, then chromatographed using a double (connected-in-tandem) FPLC-gel permeation column system. The chromatogram showed two peaks with a slight overlap. Hg-MT-III was eluted prior to Hg-MT-I and II, probably due to a slightly higher molecular weight. The amount of each isomer was determined from an analysis of the Hg content in each fraction. The present procedure revealed that MT-III in the mouse brain was comparable in quantity to MT-I and II. Thus, MT-III in mouse brain could be selectively quantified at a sub-picomol level.

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A rapid searching method of active components in a tablet sample such as benzodiazepines and 3, 4-methylenedioxyamphetamines by micro FT-IR was investigated. The drug was eluted with quite a small volume of dichloromethane and/or benzene from a small piece of tablet sample (generally several hundred μg) to a potassium bromide disk. A portion of the eluate on the disk where the concentration of the drug would be high was measured by micro FT-IR. The obtained spectrum was compared with 480 searchable library data to identify the drug. When the drug contents of a tablet was more than 0.5%, this method was applicable for the tablet sample. Satisfactory results were obtained within about 10min.

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In water environment, it is important to elucidate a correlation between the content of pesticides detected in waste water from golf links and mutagenicity. We investigated seasonal changes of the mutagenicity and measured the content of pesticides in water samples obtained from golf link reservoirs, such as two stations of Uji River basin and three stations of Kizu River basin during one year from spring in 1995 to winter in 1996. The mutagenicity was assayed with Salmonella typhimurium strains TA98 and TA100 in the presence and absence of S9mix. In the water samples obtained from the reservoirs and rivers no seasonal changes were detected. However, indirect frameshift-type or base pair substitution-type mutagens were found. The magnitude of the mutagenicity of water obtained from golf link reservoirs was presumed to be almost the same as that from the rivers. No correlation was shown between the mutagenicity and the contents of pesticides detected. Moreover, concerning water from golf link reservoirs the mutagenicity seemed not to be related with the values used as an index of the quality of water such as COD etc..

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