Tables for determining the statistical significance of mutation frequencies.
About: This article is published in Mutation Research.The article was published on 1970-05-01. It has received 918 citations till now. The article focuses on the topics: Mutation (genetic algorithm).
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TL;DR: Two alternative hypotheses are used to distinguish among the possibilities of a positive, inconclusive, or negative result in Drosophila mutagenicity tests.
Abstract: Two alternative hypotheses are used to distinguish among the possibilities of a positive, inconclusive, or negative result in Drosophila mutagenicity tests. In the null hypothesis one assumes that there is no difference in the mutation frequency between control and treated series. The alternative hypothesis postulates a priori that the treatment results in an increased mutation frequency that is m times the spontaneous frequency. To test against the hypotheses, the conditional binomial test according to Kastenbaum and Bowman or the chi 2 test for proportions may be applied. These 2 methods are in principle equivalent. An alternative method which is based on determining confidence limits of observed mutation frequencies also leads to the same conclusions. The practical calculations are formulated and an application is shown with a test example demonstrating the genotoxicity of the pyrrolizidine alkaloid 7-acetylintermedine in the somatic wing mosaic test. In the Appendix, the calculus for the 3 testing methods is explained with a numerical example.
492 citations
TL;DR: The essential oils obtained from the oregano plants Origanum vulgare subsp. hirtum, Coridothymus capitatus, and Satureja thymbra were examined by a combination of GC and GC−MS and found to be...
Abstract: The essential oils (EOs) obtained from the oregano plants Origanum vulgare subsp. hirtum, Coridothymus capitatus, and Satureja thymbra were examined by a combination of GC and GC−MS and found to be...
416 citations
TL;DR: The existing information appears to support the idea that pyrethroid insecticides have a weak (cypermethrin, deltamethrin and fenpropathrin) or nule (fenvalerate and permethrin) genotoxic activity in vitro.
Abstract: Five pyrethroid insecticides: cypermethrin, deltamethrin, fenpropathrin, fenvalerate and permethrin, were tested for their ability to induce micronuclei in both whole-blood (WB; three donors) and isolated human lymphocyte (IL, 2 donors) cultures, by using the cytokinesis-block method with 6 micrograms/ml cytochalasin B (Cyt-B). Fenvalerate and permethrin were tested with two different concentrations of Cyt-B (3 and 6 micrograms/ml). At the concentration ranges tested, all the five pyrethroids induced clear dose dependent cytotoxic effects, fenpropathrin being the most toxic. Nuclear division index (NDI) and the newly introduced index of cytotoxicity, the cytokinesis block proliferation index (CBPI), reflected the dose dependency more accurately than the percentage of binucleated cells did. CBPI is similar to NDI except that it estimates the average number of cell divisions that the cell population has gone through, and, therefore, classifies both trinucleate and tetranucleate cells into the same category. Cypermethrin and fenpropathrin slightly increased the number of MN and micronucleated cells in WB lymphocyte cultures from two out of the three donors. Deltamethrin produced a positive response only in WB cultures of one donor and in IL cultures of another donor. Permethrin gave mostly negative results, although it increased the MN frequency in WB cultures of one donor when 6 micrograms/ml Cyt-B was used. Fenvalerate did not significantly induce MN. With certain reservations to the purity and isomer composition of each pesticide, the existing information appears to support the idea that pyrethroid insecticides have a weak (cypermethrin, deltamethrin and fenpropathrin) or nule (fenvalerate and permethrin) genotoxic activity in vitro.
409 citations
TL;DR: Fifty chemicals were tested for mutagenic activity in post-meiotic and meiotic germ cells of male Drosophila melanogaster using the sex-linked recessive lethal (SLRL) assay and five of these, including 1,4-butanediol diglycidyl ether, 2,2-dimethyl vinyl chloride, hexamethylphosphoramide, isopropyl glycidyl Ether, and urethane induced reciprocal translocations.
Abstract: Fifty chemicals were tested for mutagenic activity in post-meiotic and meiotic germ cells of male Drosophila melanogaster using the sex-linked recessive lethal (SLRL) assay. As in the previous studies in this series, feeding was chosen as the first route of administration. If the compound failed to induce mutations by this route, injection exposure was used. One gaseous chemical (1,3-butadiene) was tested only by inhalation. Those chemicals that were mutagenic in the sex-linked recessive lethal assay were further tested for the ability to induce reciprocal translocations. Eleven of the 50 chemicals tested were mutagenic in the SLRL assay. These included bis(2-chloroethyl) ether, 1,4-butanediol diglycidyl ether, 1-chloro-2-propanol, dimethyl methylphosphonate, dimethyl morpholinophosphoramidate, dimethyloldihydroxyethylene urea, 2,2-dimethyl vinyl chloride, hexamethylphosphoramide, isatin-5-sulfonic acid (Na salt), isopropyl glycidyl ether, and urethane. Five of these, including 1,4-butanediol diglycidyl ether, 2,2-dimethyl vinyl chloride, hexamethylphosphoramide, isopropyl glycidyl ether, and urethane, also induced reciprocal translocations.
284 citations
TL;DR: 3-Nitrobenzanthrone (3-nitro-7H-benz[d,e]anthracen-7-one) was isolated from the organic extracts of both diesel exhaust and airborne particles and was identified as a new class of powerful direct mutagen as discussed by the authors.
Abstract: 3-Nitrobenzanthrone (3-nitro-7H-benz[d,e]anthracen-7-one) was isolated from the organic extracts of both diesel exhaust and airborne particles and was identified as a new class of powerful direct mutagen. Its mutagenicity by Ames Salmonella assay is very high (208 000 revertants/nmol in Salmonella typhimurium TA98 and 6 290 000 revertants/nmol in YG1024) and compares with that of 1,8-dinitropyrene, which is the direct mutagen of strongest activity (257 000 revertants/nmol in TA98 and 4 780 000 revertants/nmol in YG1024) so far reported in the literature. The new mutagen was also shown to induce micronuclei in mouse peripheral blood reticulocytes after intraperitoneal administration (micronucleated reticulocytes, 0.64% against 25 mg/kg dose after 48 h), suggesting its potential genotoxicity to mam malians. 3-Nitrobenzanthrone is most likely to be formed not only during the combustion process of fossil fuels but also from the atmospheric reaction between benzanthrone and lower oxides of nitrogen, since the ...
262 citations
References
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TL;DR: The Statistical Methods for Poisson Processes and Exponential Populations (SMPs) as discussed by the authors is a statistical method for poisson processes and exponential populations, which has been used in many applications.
Abstract: (1954). Statistical Methods for Poisson Processes and Exponential Populations. Journal of the American Statistical Association: Vol. 49, No. 266, pp. 254-266.
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