Showing papers in "Toxicology in 1977"

TL;DR: All of the 2,4-D was absorbed from the gastrointestinal tract in man and cleared from the plasma and excreted from the body are first-order rate processes.

TL;DR: The metabolic disposition of different doses of [14C] safrole were studied in rat and man and 1'-Hydroxysafrole, a proximate carcinogen of safrole, and 3'-hydroxyisosafrole were detected as conjugates in the urine of the rat, but it was unable to demonstrate the presence of the latter metabolites in man.

TL;DR: The experiments support the theory that vinyl chloride metabolites react with adenosine moieties of nucleic acid under formation of 1-N(6)-etheno-adenosine and show that measurement of incorporation of radioactivity into nucleic acids after exposure of animals to radioactive vinyl chloride is not applicable.

TL;DR: Analysis of covariance is demonstrated to be superior to analysis of relative organ weights and an alternative method, that of analysis or organ weights using the current bodyweight as a covariate, is described.

TL;DR: When growth is markedly reduced in a toxicity experiment alterations of this kind in the organ weight: body weight ratios have to be expected as a physiological response of the organism to decreased feed intake.

TL;DR: Results support the concept that liver enlargement accompanied by induction of drug-metabolising enzymes represents an adaptive response and they provide a basis for the interpretation of pathological changes developing in the enlarged liver unaccompanied by drug- metabolising enzyme induction.

TL;DR: Investigations in the isolated rat tail artery suggest that the mechanism of lead action might be identified with a tissue calcium accumulation and with a lead-to-calcium competition.

TL;DR: Findings showing large differences between the results obtained from the two methods suggest that use of tissue preparations is likely to produce data more relevant to the toxicological assessment of esters.

TL;DR: Brain, kidney and myocardium showed a tendency to accumulate chromium irrespective of its valency state; the morphological changes were more marked in animals exposed to hexavalent chromium, but no definite co-relation could be observed between the concentration of the metal and the degree of histological changes in these organs.

TL;DR: In this paper, Cadmium in the form of CdCl2 was administered with the feed in concentrations of 0, 1, 3, 10 and 30 ppm over a period of 3 months to groups of 2 male and female beagle dogs each.

TL;DR: The relationship between an absence of sustained enzyme induction and the development of pathological changes in the enlarged liver is discussed.

TL;DR: Pharmacokinetic analysis shows that no significant cumulation of vinyl chloride or its major metabolites is to be expected on repeated administration of vinyl chlorides, which may be consistent with the theory that a reactive, shortly living, metabolite which occurs in low concentration only, may be responsible for the toxic effects of Vinyl chloride.

TL;DR: There is a need for further experimental, and possibly epidemiologic, studies on the consequences of styrene exposure, as well as for further investigations into the mechanisms leading to malformations in embryos.

TL;DR: Mass cultures of primary rat kidney cells were exposed briefly to aqueous solutions of 20 chemicals and their subsequent growth rate and mitotic activity measured to suggest the possession of growth inhibitory properties could give an indication of the carcinogenic activity of a chemical on a short-term basis.

TL;DR: It is concluded that most rats given paraquat by intraperitoneal injection die from acute lung damage characterised by a dramatic increase in the lung water content, and only a small proportion die many days later from lung fibrosis characterising by an increase in thymidine incorporation into DNA.

TL;DR: The validity of making extrapolations from animal dosimetry data to the human exposure situation is discussed and Cigarette dosage equivalents to which animals are subjected can be calculated on the basis of these comparisons.

TL;DR: Analysis of the Gut contents of rats killed at intervals after dosage with methyl cinnamate or cinnamic acid suggested that both ester and acid were rapidly absorbed; at no time was more than 5% of the dose detected in the lower part of the gut.

TL;DR: Sr-content in bone was increased at all dose levels having a constant level from 4 weeks onwards, thus indicating that a no effect level cannot be established, and if the increased Sr-concentration in the bone can be considered a non-Toxic effect, the non-toxic effect level appears to be 309 ppm.

TL;DR: Analysis ofesticular effects of cyclohexylamine hydrochloride in Wistar and Sprague-Dawley rats showed significant decreases in food consumption, body weight and body weight gain, but significant increases in the incidence of testicular lesions were found only in animals fed 6000 ppm CHA.

TL;DR: Comparison of the acute toxicity of CR with that of two other peripheral sensory irritant material, 1-chloroacetophenone (CN) and 2-chlorobenzyl-lidene malononitrile (CS), shows CR to be significantly less toxic than either of them.

TL;DR: The removal of injected compounds was slow between 3 and 6 h after the injection in the organ systems although lipid-soluble compounds tended to diminish in brain more rapidly than the total radioactivity.

TL;DR: Trans-1,2-dichloroethylene (t-DCE), an industrial solvent, proved to be moderately toxic when studied in small laboratory animals and failed to produce prenarcotic symptoms of narcosis (central nervous system (CNS) depression).

TL;DR: When methyl testosterone was administered orally to beagle dogs at dosage levels of 2, 4 and 6 mg/kg per day for 27 weeks, hepatotoxicity was induced and there was some evidence of recovery over a 13-week period.

TL;DR: On the basis of the biochemical parameters studied in the newborn rats, the “no-effect” level of lead administered in drinking water during lactation is around 1 ppm, which is rather similar to that found when lead was administered to the mother before and/or during pregnancy.

TL;DR: Plants collected in the dry season were more toxic than those collected during the wet season and Monofluoroacetate was detected in the plant material and is probably the toxic principle of D. barteri.

TL;DR: The toxic symptoms caused by N-methyl-N-formylhydrazine (MFH) were, however, only slightly inhibited by this vitamin; the convulsive, toxic, and lethal effects of four compounds were successfully prevented by administering PH before and/or after injection.

TL;DR: It is suggested that endosulfan may shorten the duration of pentobarbital-induced sleep, perhaps by induction of hepatic microsomal enzyme activity.

TL;DR: Investigations indicate that histological changes precede the appearance of hepatic nodules in Ponceau MX-treated rats suggesting that initially they are of a reactive nature, and once established the nodules continue to grow and may either develop fatty degeneration or become malignant.