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The effects of ethylene glycol on reproduction of CD-1 mice were tested in a protocol which permitted continuous breeding during a specified interval. The dosage amounts of 0, 0.25, 0.5, or 1% ethylene glycol by continuous administration in drinking water for male and female mice were selected from the general toxic responses observed in a 14-day pilot study. After the first week of administration, begun at 11 weeks of age, the animals were housed one male and one female per cage for 14 weeks during which time any offspring were examined, sexed, weighted, and killed to allow continuous mating of the first generation. At the end of the 14-week cohabitation period, the males and females were separated and any litters delivered after that time were kept until weaning. Those second-generation animals were mated at about 70 days of age. Slight, but statistically significant, decreases were found in the numbers of litters per fertile pair and live pups per litter in the 1% dose group and live pup weight at the 1% dose groups compared to control F0 mice. Facial anomalies were noted in a number of offspring of high-dose-treated mice and an examination for skeletal defects demonstrated a pattern including reduction in the size of bones in the skull, fused ribs, and abnormally shaped sternebrae and vertebrae in the high-dose-treated, but not the untreated, mice. Neither the 0.25 nor 0.5% dose groups were significantly affected. No clinical signs of toxicity or significant adverse effects on body weight or water consumption were seen at the doses used, but two deaths occurred at the 0.5% quantity which may have been related to oxalate crystal deposition in the kidney.

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The ability of long-term exposures to inhaled ethylene oxide (EO) and propylene oxide (PO) to induce sister-chromatid exchanges (SCEs) and chromosome aberrations in peripheral lymphocytes of monkeys was investigated. Five groups of adult male cynomolgus monkeys were exposed at 0 (shared control), 50, or 100 ppm EO, and at 100 or 300 ppm PO (7 hr/day, 5 days/week) for 2 years. EO exposures at 50 and 100 ppm resulted in statistically significant increases in sister-chromatid exchange rates and in the incidence of chromosome aberrations in monkey lymphocytes. Both EO-exposed groups had increased numbers of SCEs/metaphase compared to controls, with the SCEs/metaphase of the EO 100 ppm group also significantly elevated versus the EO 50 ppm group. Variability of SCEs/metaphase within each monkey increased even more than the increase in total SCEs/metaphase group with increasing EO exposure. Chromatid-type aberrations were also significantly increased for both EO 50 and EO 100 ppm groups compared to controls. Statistically significant increases in the number of chromosome-type aberrations (excluding gaps) were found only in the EO 100 ppm group. Combined chromatid- and chromosome-type aberrations were increased in both EO 50 and EO 100 ppm groups. No group differences in the number of gaps were found. In lymphocytes from monkeys exposed at 100 and 300 ppm PO, there were no group differences compared to controls for any variable-chromatid or chromosome-type aberrations, gaps, or SCEs/metaphase. These results indicate that EO is a more potent clastogen than PO and demonstrate, for the first time, statistically significant effects of EO on both SCEs and chromosome aberrations in lymphocytes of nonhuman primates.

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The reproductive toxicity of ethylene glycol monoethyl ether (EGEE) was evaluated in the Fertility Assessment by Continuous Breeding protocol. Both male and female CD-1 mice were given 0, 0.5, 1.0 or 2% EGEE in the drinking water and were housed as breeding pairs continuously for 14 weeks. Significant adverse effects on fertility were seen at 1 and 2% but not at 0.5%. After the continuous breeding phase of this test was completed, treated males were housed with control females and treated females with control males and fertility and reproduction were compared to the corresponding pairs of control male and control female mice. Both males and females from the 1 and 2% groups were affected. Testicular atrophy, decreased sperm motility and increased abnormal sperm were noted in the treated males, but no specific anomalies were detected in the females.

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Benzo[a]pyrene between 50 and 125 mg/kg administered maternally caused a dose-related increase in sister-chromatid exchange in fetal hamster liver cells. There was no difference on days 11, 13 and 15 of gestation in the sensitivity of fetal liver to benzo[a]pyrene.

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A multiple bioassay approach was used to characterize and compare the genotoxicities of an Eastern U.S. (Kentucky) shale oil with the genotoxicities of Western U.S. shale oil, petroleum crude oil, and a coal-derived fuel oil. While the coal-derived oil was mutagenic in the Salmonella/microsome mutagenicity (Ames) assay, the shale oils had negligible to weak mutagenicity, and petroleum crude oil was not mutagenic. All the samples were also tested in the following mammalian test systems: an in vitro sister-chromatid exchange (SCE) assay in human lymphocytes and in vivo tests for induction of sperm abnormalities, micronuclei, and SCE in bone marrow of mice. Slight but statistically significant increases (P less than 0.001) in SCE in human lymphocytes were induced by all samples except petroleum crude oil. Neither sample induced a significant number of mutational events in either of the in vivo systems. In these preliminary studies no major differences in the genotoxicities of Eastern and Western shale oils were observed. The results were consistent with the following order of mutagenic potency: coal oil greater than Eastern and Western shale oil greater than petroleum crude oil.

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Gamma-irradiation induced high levels of nitrate reductase activity (NADH:nitrate oxidoreductase, EC 1.6.6.1) in callus of Haworthia mirabilis Haworth. Subcultures of gamma-irradiated tissues showed autonomous growth on minimal medium. We were able to mimic the effects of gamma-irradiation by inducing nitrate reductase activity in unirradiated callus with exogenous auxin and kinetin. These results revealed that induction of nitrate reductase activity by gamma-irradiation is mediated through in vitro activation of hormone synthesis in callus cells.

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Particulate matter was collected from the emissions of a diesel-powered engine and the organic components were extracted. The extract induced a dose-related increase in sister-chromatid exchanges in human lymphocytes with a potency of about one-fifth that of benzo[a]pyrene.

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The genotoxic activity of diesel exhaust emissions, particulate matter, and an organic extract of the particulate matter was evaluated in transplacentally exposed Syrian hamster fetal liver cells. The frequency of sister chromatid exchange (SCE) was determined on day 13 of gestation. The extract of diesel particulate matter caused a dose-dependent increase in the frequency of SCE with a doubling in the incidence above 320mg/kg. The diesel particulate matter and diesel exhaust emissions did not alter the frequency of SCE. The extract and particulate matter did cause a dose-dependent decrease in the mitotic activity of the fetal liver. The in utero SCE analysis was demonstrated to be a sensitive assay for determination of the genotoxic activity of a complex mixture in transplacentally exposed fetuses.

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The genotoxicity and airborne organic particles from forest fire smoke was compared to that from nonsmoky (ambient) urban air using the Salmonella reversion assay and the sister chromatid exchange (SCE) assay in cultured human lymphocytes. Salmonella strains TA98 and TA100 were used with and without the addition of Aroclor-induced rat liver homogenate (S9). Each sample induced dose-related increases in mutagenicity and SCE. However, on the basis of the volume of air sampled, the smoke-filled air induced 12 to 14 times more bacterial reversions in TA100 and 16-38 times more reversions in TA98 brain ambient air. Similarly, on a volume basis smoky air induced 43 times more SCE in human lymphocytes than did ambient air. The results indicate that the increased mutagenicity was due not only to the heavier particulate load of the air, but also to the increased specific mutagenicity of the particles.

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Irradiated Syrian hamster fetal cells (feeder layer) and rat-liver homogenate (S9 mix) were used to compare their capacity to metabolize 3 known promutagens/carcinogens; BaP, 3-MC and DMBA. DNA-damaging potential was determined by the induction of SCE in V79 target cells. The S9 mix (1/20th strength) was toxic to the target cells and reduced the mitotic index by half with an exposure time of 2.5 h. The feeder layer was not toxic to the target cells and, therefore, was included for the duration of the Expt. The test chemicals elicited a dose-response with both activating systems. At similar concentrations of the test chemicals, the cells grown on the feeder layer showed a greater number of SCEs as compared to those activated by the S9 mix.

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Hamster embryo brain cells exposed in vitro for 24 hrs. to benzo (a) pyrene and then subcultivated. undergo a morphological transformation. After several passages, transformed cells are capable in most cases of inducing tumors of a special type through intraocular or intracerebral grafting. Histological characterisation of these tumors suggests that they are of glial type. Untreated control brain cells subcultivated for one year, keep their normal characteristics and do not induce tumors when grafted in Hamster.

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Growth studies with Lemna minor revealed the additive and synergistic growth-inhibiting properties of the canaline-urea cycle amino acids. Simultaneous canavanine and canaline treatment caused an additive reduction in frond production. Ureidohomoserine interacted with canaline or canavanine to affect synergistically L. minor growth by enhancing individual canavanine or canaline toxicity and increasing the additive growth reduction caused by canavanine plus canaline. The ornithineurea cycle amino acids effectively counteracted both the additive and synergistic growth-inhibiting properties of the canaline-urea cycle compounds.

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Two normal diploid control cell lines and a heteroploid malignant transformed cell line from B(a)P treated hamster embryo cell cultures were established. The 14-month-old B(a)P transformed cell line grew 8-times faster than the 20-month-old control cell line. The control cell line showed normal diploid chromosome complement in 93% cells and heteroploidy in 7% cells while B(a)P treated line showed 83% heteroploid cells and only 17% diploid cells. This is the first report on the establishment of diploid hamster cell cultures grown for extended period.

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The aquatic microphyte, Lemna minor L., was utilized to assess the relative toxicity and general growth effects of canavanine, canaline, ureidohomoserine (UHS), and canavaninosuccinate (CSA). These amino acids are constituents of the canaline-urea cycle and structural analogues of the ornithine-urea cycle amino acids.Comparative growth studies with L. minor revealed that the canaline-urea cycle amino acids are potent antimetabolites. With the exception of CSA, they are extremely toxic at a concentration of 5 mum. Over a concentration range of 1 to 4 mum, canavanine is the most growth-inhibiting of the canaline-urea cycle amino acids. At or above 5 mum, canavanine and canaline possess comparable toxicity. UHS is less growth-inhibiting than canavanine or canaline, and CSA is the least toxic of the canaline-urea cycle intermediates.

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The effect of water-soluble extract of tobacco smoke condensate (TSC) from two commercially available cigarettes with dirrerent types of filters was studied on the cytology of root-tip cells of onion (Allium cepa). One of the cigarettes had a 2-cm cellulose acetate filter, and the other had a filter comprised of 1 cm of cellulose acetate and 2 cm of activated charcoal. TSC from these cigarettes induced mitotic abnormalities. To investigate whether these two commercial filters could retain cigarette smoke component (s) responsible for mitotic irregularities, the cigarettes were defiltered, and TSC was prepared and tested on the young roots of onion. Observations revealed that the cytological effect of TSC from defiltered cigarettes was not significantly different from the effect of TSC from cigarettes with filters. Thus, the filters utilized in these cigarettes do not retain compound(s) responsible for mitotic irregularities in the root-tip cells of onion. With increasing concentrations (0.01% ot 0.1%) of TSC from cigarettes with filters and defiltered, precent mitotic abnormalities increased. These abnormalities included scattering, stickiness, lagging, condensation, and breaking of chromosomes during metaphase. Bridging and lagging of chromosomes were observed during anaphase.

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