A continuous-flow system was developed for evaluating the effects of insoluble and volatile organics on the developmental stages of fish. A closed test system, devoid of standing air space, was used to minimize volatility as a variable. Insoluble compounds were suspended in influent water by mechanical homogenization, without the use of carrier solvents. Tests were performed with aniline, chlorobenzene, and phenol. Water hardness was maintained at 50 and 200 mg/litre calcium carbonate, and exposure was continuous from fertilization through four to eight days after hatching for largemouth bass, channel catfish, goldfish, and rainbow trout. The results indicated that there was good reproducibility of exposure concentrations down to 1 µg/litte or less. For a calculated concentration of 1 µg/litre phenol, the actual test-water concentrations (mean ± standard error) for four replicates were 0.7 ± 0.2, 1.2 ± 0.3, 1.3 ± 0.3, and 1.5 ± 0.3. When phenol was administered in hard water, the LC1 and LC50 values determined at hatching were 0.2 and 80 µg/litre for trout, and 2.0 and 710 µg/litre for goldfish. Phenol was less toxic in soft water. Chlorobenzene at 0.09 mg/litre produced complete mortality of trout eggs. When bass eggs were exposed through four days after hatching, the LC50s for chlorobenzene ranged from 50 to 60 µg/litre. The aniline LC50 values calculated for catfish, goldfish, and bass eggs treated in soft water were 5.6, 10.2, and 47.3 mg/ litre, respectively. Because of the differential rates of larval mortality for the three species, the LC50 range narrowed considerably when the exposure time was increased beyond hatching. Water hardness exerted no appreciable effects on the toxicity of either chlorobenzene or aniline. All three organic compounds produced significant frequencies of teratic larvae.
Measurements of the backfat thickness over the last rib, 65 mm from the dorsal midline, were taken on 122 live pigs with five different ultasonic machines: Sonatest, Medata, Renco, Sonalyser and Ilis. These measurements were examined for their ability to predict the corresponding carcass introscope measurements. Each pig was measured with each machine 6 d before slaughter and carcass measurement. The RSDs for predicting introscope measurements were 2.35 mm (Sonatest), 2.43 mm (Sonalyser), 2.56 mm (Renco), 2.72 mm (Medata) and 2.90 mm (Ilis). The inclusion of liveweight in the prediction equation gave a small but significant improvement in the RSDs of all machines. The results suggest that none of the machines tested could predict backfat thickness satisfactorily for grading of pigs before slaughter.
1 The metabolism of the aldose reductase inhibitor, AL01567, was studied in man. The major biotransformation pathway was aromatic hydroxylation followed by glucuronide conjugation. 2 Hydroxylation occurred at several positions on the fluorene ring. The major metabolite was identified as the 7-hydroxy analogue of AL01567 and three minor metabolites were characterized as positional isomers of the 7-hydroxy metabolite. 3 Oxidative defluorination and metabolism on the hydantoin ring were also indicated as minor pathways. 4 The capacity of normal subjects to oxidize AL01567 was indicated by the urinary ratio of the parent drug to the 7-hydroxy metabolite after daily oral administration of 100 mg and 200 mg of AL01567. Most subjects having higher AL01567 plasma concentrations showed higher ratios.
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