摘要:

AbstractThe effects of bacterial DNA excision repair on the mutagenic and lethal actions of 17 injectable anticancer drugs have been used to classify them into three levels of potential risk to medical personnel who are involved in their preparation and administration.

ISSN:0270-3211    

DOI:10.1002/tcm.1770050502

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe effects of different factors (temperature, light, enzymic activation) on the ability of selected mutagens and carcinogens to induce hereditary bleaching ofEuglena graciliswere investigated. In the resting medium, the elevation of incubation temperature from 25°C to 37°C increased significantly the effect of all compounds tested on the frequency of bleached mutants ofE. gracilis.The effect of light is not so unambiguous. While nitrosoguanidine (NG) exhibited practically the same bleaching activity both in the light and dark, the mutagenic effect of sodium azide (SA), nitrovin (NV), nitrosoethylurea (NEU), and benzo(a)pyrene (BP) was decreased in light. On the other hand, the light increased the bleaching activity of 5‐nitro‐2‐furylacrylic acid (NFAA) significantly. The activation mixture S9 increased bleaching effect of NFAA and BP, whereas other mutagens were partially (NG and SA) or completely (NV and NEU) inac

ISSN:0270-3211    

DOI:10.1002/tcm.1770050503

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractThe antihypertensive drug propyldazine (Atensil) was demonstrated to be muta‐ genic with auxotrophic mutants ofSalmonella typhimuriumandEscherichia coli. Addition of liver S9 mix (postmitochondrial supernatant fraction supplemented with an NADPH‐generating system) had little, if any, effect on the mutagenicity. The mutagenicity showed an unusual pattern of strain specificity. Increased fre‐ quencies of reversion were observed with all strains whose auxotrophy was caused by frame‐shift mutations: the number of revertant colonies per plate fromS. typhimurium TA98, TA1538, TA97, and TA1537 was increased up to 5‐, 9‐, 43‐, and 160‐fold, respectively, above background. Among the strains that became auxotrophic by substitution mutations,S typhimurium TA102, E. coliWP2, andE coliWP2uvrAyielded positive results (twofold above background).S. typhimuriumTA1535 and TA100 were not reverted by propyldazine.It should be noted that propyldazine, due to its low toxicity and good solubility, could be tested up to very high doses. Hence, although quite impressive mutagenic effects occurred, the mutagenic potency was moderate even in the most responsive strains, TA1537 and TA97 (about 0.3 and 1.0 revertants per nmole, respectively). With the limitation that the strain specificities were different, the mutagenic potency of propyldazine was in the same order of magnitude as that of hydralazine and dihydralazine, two related antihypertensive drugs which were already known to be mutagenic. In our hands, both compounds were mutagenic inS typhimuriumTA1535, TA100, TA1537, and TA98. These results differ from data in the literature in that we found clear but weak effects even with strains for which others have reported n

ISSN:0270-3211    

DOI:10.1002/tcm.1770050504

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractTwo methods of dissecting rat fetuses are compared: the generally well‐known freehand razor‐blade dissection method according to Wilson and an in situ sectioning method (ISM). For this purpose the substance EGYT 1978 was used, which induces—inter alia—cardiovascular anomalies. Thirty‐nine gravid rats were given either the test drug (EGYT 1978, 400 mg/kg body weight) or the vehicle orally from the 6th to the 15th day of gestation. The fetuses were assigned randomly to either dissection group. Both methods of examination revealed approximately the same number of anomalies per organ system. A comparison of the types of anomaly found showed, however, relevant differences in the nature of the changes revealed by the two methods. The in situ sectioning method was clearly superior to the freehand razor‐blade dissection method for the detection of discrete anomalies of the cardiovascular system. We therefore recommend the in situ sectioning method as the method of choice for examining small fetuses from teratological

ISSN:0270-3211    

DOI:10.1002/tcm.1770050505

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractA single oral dose of 75 mg/kg of all‐trans‐retinol or all‐trans‐retinylidene methyl nitrone, retinoids with potential cancer chemopreventive properties, on one of five successive days of embryogenesis resulted in a shift in the pattern of developmental anomalies in fetal mice. Treatment on days 7, 8, or 9 with retinol primarily induced malformations of the head whereas treatment on day 11 induced bilateral forelimb reduction defects. Treatment on day 8 with either retinoid produced the highest in utero death rate. Intubation of either retinoid on day 10 failed to induce a significant increase in the number of litters containing offspring with malformations, and the embryonic death rate declined to control values. The malformations induced by administration of either retinoid were similar, but retinol was always associated with a higher total percentage of malformed offspring. The similar teratogenic profile of these two retinoids may be related to their in vivo biotransformation to all‐trans‐re

ISSN:0270-3211    

DOI:10.1002/tcm.1770050506

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

摘要:

AbstractLung cancer risk in relation to airborne levels of hexavalent chromium was analyzed for chromium chemical production workers studied by Hayes, Lilienfeld, and Snell. Hayes et al [18] had observed statistically significant increases in lung cancer mortality among chromium chemical production workers hired during 1945–1959 and followed to mid‐1977. A dose‐response was observed by Hayes et al. in that long‐term workers had a higher lung cancer risk than short‐term workers. Concurrent exposure data for the study plant were abstracted from the records of a local health department. The usual air concentration of hexavalent chromium was estimated as 413 micrograms per cubic meter (μg/m3) during 1945–1949. Cumulative exposure estimates for individual workers could not be developed with available information. Instead, cumulative exposures in terms of μg/m3‐years were estimated for groups of short‐term workers and long‐term workers (cumulative exposure = usual exposure level in μg/m3× average length of exposure). For workers hired during 1945–1949, cumulative exposures were estimated as 670 and 3,647 μg/m3‐years for short‐term and long‐term workers, respectively. Like most estimates based on historical data, these exposure estimates are subject to uncertainty. Nevertheless, these results suggest a potential excess risk of death from lung cancer among U.S. workers exposed to the current permissible exposure limit (PEL) for hexavalent chromium of 52 μg/m3because such workers could accumulate exposures (μg/m3‐years) similar to those associated with excess risk in Hayes et al's cohort. Moreover, many current workers are estimated to be exposed to levels above the PEL. Further exploration of the dose‐response relationship for

ISSN:0270-3211    

DOI:10.1002/tcm.1770050507

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY

ISSN:0270-3211    

DOI:10.1002/tcm.1770050501

出版商:Wiley Subscription Services, Inc., A Wiley Company    

年代:1985

数据来源: WILEY