Interaction of Chromium with Nickel in the Induction of Sister Chromatid Exchanges, in Chinese Hamster Ovary Cells

Epidemiological studies report that populations exposed to complex mixtures show increased incidence rates of cancer. Therefore, chemical interaction is of major concern in the assessment of risk by regulatory agencies. In this study, treatment of CHO (Chinese Hamster Ovary) cells with nickel chloride (in 1.0 and 5.0 uM), or sodium chromate (0.5, 1.0, and 2.5 uM) induce sister chromatid exchanges (SCE) in a dose dependent fashion. Statistical analysis of the interaction factor, show that the combined treatments of nickel ( 1.0 and 0.5 uM) with chromium (0.5, 1.0 and 2.5 uM) interacted antagonistically for the induction of SCE. Previously, we reported that nickel with chromium, with UV light and with X-rays interacted antagonistically for the induction of SCE and MN (micronuclei) in human peripheral lymphocytes. These observations indicate that heavy metals, such as nickel and chromium, present in complex mixtures, may reduce the response, even in the presence of strong SCE or MN inducers, and may lead, therefore, to an underestimate of chemical exposure as assessed by these assays. Therefore, further studies are a necessity

Quantitative Trait Loci Associated with the "Shade Avoidance" Type Response in A. thaliana when Grown under Oscillating Daily Summer Temperatures

A poster discussing "shade avoidance" in A. thaliana plants