* Evaluation of in vitro and in vivo genotoxicity of single-walled carbon nanotubes.
- Single-walled carbon nanotubes (SWCNTs) have extensive potential industrial applications due to their unique physical and chemical properties; yet this also increases the chance of human and environment exposure to SWCNTs. Due to the current lack of hazardous effect information on SWNCTs, a standardized genotoxicity battery test was conducted to clarify the genetic toxicity potential of SWCNTs (diameter: 1-1.2 nm, length: ∼20 μm) according to Organization for Economic Cooperation and Development test guidelines 471 (bacterial reverse mutation test), 473 (in vitro chromosome aberration test), and 474 (in vivo micronuclei test) with a good laboratory practice system. The test results showed that the SWCNTs did not induce significant bacterial reverse mutations at 31.3-500 μg/plate in Salmonella typhimurium strains TA98, TA100, TA1535, and TA1537 or in Escherichia coli strain WP2uvrA, with and without a metabolic activation system. Furthermore, the in vitro chromosome aberration test showed no significant increase in structural or numerical chromosome aberration frequencies at SWCNT dose levels of 12.5-50 μg/ml in the presence and absence of metabolic activation. However, dose-dependent cell growth inhibition was found at all the SWCNT dose levels and statistically significant cytotoxic effects observed at certain concentrations in the presence and absence of metabolic activation. Finally, the SWCNTs did not evoke significant in vivo micronuclei frequencies in the polychromatic erythrocytes of an imprinting control region mice at 25-100 mg/kg. Thus, according to the results of the present study, the SWCNTs were not found to have a genotoxic effect on the in vitro and in vivo test systems.
=>意義深い, 重大な, 意味のある, 意味ありげな, 重要な
Overview of adj significant
The adj significant has 4 senses (first 4 from tagged texts)
1. (18) significant, important -- (important in effect or meaning; "a significant change in tax
laws"; "a significant change in the Constitution"; "a significant contribution"; "significant
details"; "statistically significant")
2. (9) significant, substantial -- (fairly large; "won by a substantial margin")
3. (3) significant -- (too closely correlated to be attributed to chance and therefore indicating a
systematic relation; "the interaction effect is significant at the .01 level"; "no significant
difference was found")
4. (2) meaning, pregnant, significant -- (rich in significance or implication; "a meaning look")
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PubMed database: last updated on 2020-02-18 (c)sirasawa 2019