摘要:

AbstractThe volume of chemicals in everyday use that require ecotoxicity testing, the high‐costs of using whole animals for initial screenings of chemicals for their cyto‐ and genotoxicities, and the need for a ‚biological early warning signal”︁ to detect toxicants in aquatic environments have prompted the development of many microbial‐basedin vitroshort‐term bioassays. An area that has received relatively little study is the application of vertebrate cells, especially fish cells, for ecotoxicity testing of chemicals. From the few studies that are available it has been demonstrated that cultured, established fish cell lines can be used for (1) thein vitrocyto‐ and genotoxicity screening of known aquatic pollutants, (2) thein situmonitoring of natural waters and sediments for chemical cyto‐ and genotoxicants, and (c) elucidating structure‐activity relationships among chemicals, which can thereby serve as a biological adjunct to computer‐based mathematical predictions (QSARs) of chemical c

ISSN:0884-8181    

DOI:10.1002/tox.2540020202

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe SOS Chromotest is a bacterial assay for genotoxicity, based on the detection of damage to DNA as measured through the SOS DNA repair system. AnE. colistrain was derived by fusing the structurallacZgene with a promoter of one of the SOS genes, namely thesfiAgene. Auxiliary mutations increase the sensitivity of the Chromotest bacteria to genotoxic materials. In the SOS Chromotest, any damage to the DNA results in the activation of the SOS system, including thesfiAgene promoter. This, in turn, induces thede novotranscription and synthesis of the enzymeB. galactosidase. The enzyme is clearly and easily detected by a chromogenic reaction. We have miniaturized the SOS Chromotest and developed it into a self‐contained kit in the microtitration format. The kit contains all the components of the test, including dried bacteria and a dried liver S‐9 mix in a stable state, allowing on‐site operation. The whole test, including the revival of the bacteria, can be completed in 6–7 hours. In addition to being used as a genotoxics detection and monitoring system in chemical, cosmetics, food and pharmaceutical industries, the advantages of the rapid SOS Chromotest can be exploited in full for environmental and occupational health studies. In order to circumvent tedious concentrations of samples (e.g., urine, water), we have tried to further increase the sensitivity of the Chromotest by exposing the bacteria to relatively large volumes of unconcentrated samples. Employing this approach, we were able to demonstrate genotoxic activity in unconcentrated urine samples obtained from people exposed to environmental genotoxins. It appears, therefore, that the SOS Chromotest kit will allow an economically feasible and efficient monitoring of genotoxics in the envi

ISSN:0884-8181    

DOI:10.1002/tox.2540020203

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

年代:1987

数据来源: WILEY

摘要:

AbstractA new toxicity screening test, based on the inhibition of bacterial growth and luciferase activity by toxicants was developed. In the ATP‐TOX System, chemical toxicity was found to be time‐dependent and increased with increasing exposure time up to 5 hours. Three organisms were evaluated in this study:E. coliK‐12 PQ37,Pseudomonas fluorescensandSalmonella typhimurium. E. coliK‐12 PQ37 was found to be the most sensitive organism. It was also shown thatP. fluorescenswas more sensitive to toxicants when grown in minimal medium than in nutrient broth, suggesting that nutrients may have a protective effect on the bacterium. In comparative studies using selected toxic chemicals the ATP‐TOX System was found to be more sensitive than theSpirillum volutanstest and comparable to the Microtox test. Toxicant activity in sediment samples was found to be time dependent and increased with increasing exposure time in both ATP‐TOX (E. coli) System and Microtox. The ATP‐TOX System is complementary to the Microtox test as it also provides indications of low grade toxicant activity which is only manifested in actively growing cells over several life cycles. Thus, the ATP‐TOX System appears to be an ideal screening test for sediment toxicity. The data indicate that the ATP‐TOX System is sensitive, rapid, reproducible, economical and has great potential i

ISSN:0884-8181    

DOI:10.1002/tox.2540020204

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe question mark placed on a few herbicides because of their longer persistence in Black Cotton soil made this ecotoxicological assessment necessary. Since microbial responses can be used as an indicator of herbicide toxicity, soil respiration, dehydrogenase, and viable bacterial counts were used as the parameters to assess herbicide toxicity. Basalin, Lasso, and Tafazine are used in Black Cotton Soil of Southwest part of India. Soils treated with 1,5, and 25 ppm (w/w) and assessed 1, ε, 11, 16, and 21 days later, indicated a significant inhibitory effect on microbial activity measured in terms of these parameters. The improvement in soil quality started after 16–21 days in Basalin treated soil only. Further, there exists a correlation between soil respiration and number of bacterial colonies, and soil respiration and dehydrogenase activity. The study warrants a rigorous screening of all the recommended preemergence herbicides in Black Cotton soil of this fertile ar

ISSN:0884-8181    

DOI:10.1002/tox.2540020205

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

年代:1987

数据来源: WILEY

摘要:

AbstractLead is a significant environmental pollutant in Portugal, mainly as a consequence of its use as an antidetonant in gasoline. Due to the vast annual gas consumption, evidence of lead emission has been found in the air, soil, plants, and water. Concentrations of lead in Lisbon waste waters average 0.15 mg/L, with occasional levels reaching 1.5 mg/L. The biodegradability of these waste waters is affected by lead. To understand the interaction between lead toxicity and protein concentrations, a study was initiated using selected strains ofProteus mirabilisandKlebsiella pneumoniaeand synthetic effluents. The toxicity of lead to bacteria was noted by an increase in the cell's metabolic activity, and a greater induction of ATP and RNA contents. However, bacterial replication was evidently uninhibited by the lead content in the test medium. While high peptone content in the growth medium caused an increase in the cell's biosynthesis, increased lead concentrations in the growth medium resulted in a substantial loss of metabolic product. This complex interaction was apparently responsible for lead's toxicity to bacteria.

ISSN:0884-8181    

DOI:10.1002/tox.2540020206

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

年代:1987

数据来源: WILEY

摘要:

AbstractWe present and evaluate a new bacterial test suitable for the detection of toxicants in water, chemicals, pharmaceuticals, foodstuff, food additives and cosmetics. It is a simple, rapid (1–1.5 hours), colorimetric assay which does not require special equipment, and can easily be carried out under field conditions.The assay is based on the ability of toxicants to inhibit thede novosynthesis of an inducible enzyme, e.g., β‐galactosidase, by a rough mutant ofE. coli, which is highly sensitive to a wide spectrum of toxic substances, such as pesticides, mycotoxins and heavy metals. The test is performed under stress conditions for the bacterium, since under such conditions better sensitivity for low concentrations of analytes is obtained. In the assay, serial dilutions of the sample are mixed with the stressed bacteria and a cocktail containing the specific inducer for the chromogenic enzyme and essential factors, required for the recovery of the bacteria from their‐stressed condition. The ability of cells to synthesize β‐galactosidase under these conditions depends on their ability to recover from the stress. Toxic materials interfere and/or inhibit the recovery process and with it the synthesis of β‐galactosidase. The amount of thede novosynthesized enzyme is determined by a colorimetric reaction.We have developed a commercial kit based on the assay. The kit is field oriented and easy to operate. The kit contains the bacteria in a lyophilized form and all the reagents have been stabilized so that the kit may be stored under normal refrigeration for a long pe

ISSN:0884-8181    

DOI:10.1002/tox.2540020207

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

年代:1987

数据来源: WILEY

摘要:

AbstractTen widely used pharmaceutical agents for which mutagenicity or carcinogenicity data are still lacking were tested in parallel with three methods: Ames' bacterial mutagenicity test (TA1535, TA1537, TA98, and TA100 Salmonella strains), micronucleus (mice BDF1), and sperm morphology abnormality (mice) tests. The groups and generic names of the tested products, all produced by Pharmachim (Bulgaria), were as follows: Psychopharmaca (Loxapinsuccinate, Medazepam hydrochloride, Nomifensinmaleate, Viloxazine hydrochloride), Vasodilatators (Nitroprussid Na, Isosorbid mononitrate, Isosorbid dinitrate), Spasmolytica (Trimetoquinol), Antirheumatica (Diclofenac Na), and the antimycotic agent Lavendotricin. In all tests, negative results were obtained. To avoid false negative results, several suggestions are made.

ISSN:0884-8181    

DOI:10.1002/tox.2540020208

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

年代:1987

数据来源: WILEY

摘要:

AbstractThe effects of 2,4‐Dichlorophenoxyacetic acid on the growth rate, chemical composition,14C‐2,4‐dichlorophenoxyacetic acid and45Ca2+uptake byRhizobiumsp. M 4 able to nodulateArachis hypogaeawere determined. Cellular growth was diminished by the presence of 10−3M 2,4‐dichlorophenoxyacetic acid in the medium. Alterations in cellular chemical composition, in14C‐2,4‐dichlorophenoxyacetic acid and in45Ca2+upta

ISSN:0884-8181    

DOI:10.1002/tox.2540020209

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

年代:1987

数据来源: WILEY

ISSN:0884-8181    

DOI:10.1002/tox.2540020210

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

年代:1987

数据来源: WILEY

ISSN:0884-8181    

DOI:10.1002/tox.2540020211

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

年代:1987

数据来源: WILEY