Metal transformation assay

Ponti J, Munaro B, Fischbach M, Hoffmann S, Sabbioni E (2007) An optimised data analysis for the Balb/c 3T3 cell transformation assay and its application to metal compounds. Int J Immunopathol and Pharmacol 20(Suppl 2) 673-684... 

Finally, the Ames assay is not particularly useful for detecting carcinogenic metals and minerals. With the exception of chromate, the assay failed to give a positive reaction with either cadmium, nickel, or beryllium salts or asbestos. " Salts of cadmium, nickel chromium, and beryllium were positive, however, in an in vitro cell transformation assay. 

Keeckaeet GA, Leboeue A and Iseoet RJ (1996) Use of the Syrian hamster embryo cell transformation assay for determining the carcinogenic potential of heavy metal compounds. Fund Appl Toxicol 34 67-72. 

A useful in vitro transformation assay which may be particularly applicable for metals, is the the enhancement of hamster embryo cell transformation by simian adenovirus. Casto, et al (46) and DiPaolo et al ( ) reported that all metal salts (of a series of 38 tested) with known carcinogenic activity, increased the frequency of simian adenovirus SA-7 induced transformations. 

The assay system described in the present study should be useful in screening potential metal carcinogens for their ability to induce transformation. However, further work is required to demonstrate and validate that each of the various metals induce neoplastic transformation in tissue culture. A statistically significant number of transformed colonies induced by exposure of cells to each of the metal compounds must be cloned and derived into cell lines. The tumorigenic potency of these various cell lines must be tested in nude mice. 

The thermogravimetric analysis (TGA) provides information especially on the content of metallic catalyst particles in the sample. When performed in air, the carbon species will be oxidized to give volatile gaseous products way below 1000 C, whereas the metal portion is-in parts or completely-transformed into its oxides and remains in the crucible as such. Analyzing this residue thus allows for quite an accurate assay of the metal in a nanotube sample. It may be up to 30% (m/m) depending on the quality of the material under test. The portion of amorphous carbon, on the other hand, can only be insufficiently determined by TGA. 

By combining heteropolyanions (polyoxometalates POMs for convenience) and selected cations in acetonitrile, more than 150 combinations were assayed for their catalytic activity towards selective CEES oxidation to CEESO by dioxygen under ambient (room temperature and atmospheric pressure) conditions. The main criteria in choosing POMs were their ability to undergo reversible redox transformations and to catalyze homogeneous oxidations either by peroxides or other terminal oxidants. The cations chosen included redox-active transition metal ions or cations conventionally used as the counterions in POMs. In control experiments the chloride, nitrate or perchlorate salts of the same transition metal ions were also examined. The list of these catalytic systems and some selected results were recently published. ... 

The utility of 12 -halovinblastine, 12 -halovincristine and 1 T-halovinorelbine as substrates for recently developed transition metal based methodology was recognized and led to the preparation of novel analogues of the vinca alkaloids. The synthesis of key iodo intermediates and their transformation into final products along with the SAR based upon Hela and MCF-7 cell toxicity assays will be presented. 

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