Using the nucleolar biomarker and the micronucleus test on in vivo fish fin cells.

This study was aimed at developing the nucleolar biomarker and the micronucleus test on in vivo fish fin cells for assessing water cytotoxicity and genotoxicity. Both biomarkers can be used either jointly or separately on fins of the same fish during the experiment. For studying the nucleolar characteristics, small pieces of the fin edge were cut several times during 30-180 min of fish exposure. For micronucleus testing, the fin tissue regenerating after its cutting was investigated after 2-5 days of fish incubation. Effects of copper (0.1 and 2.5 mg/L), cadmium (0.005 and 1.0 mg/L) ions and chloral hydrate (400 and 800 mg/L) solutions were studied on cells of common carp (Cyprinus carpio L.), crucian carp (Carassius auratus gibelio Bloch.), and Mozambique tilapia (Tilapia (Sautherodon) mossambica) using a set of nucleolar characteristics (the number of nucleoli per cell, the size of a single nucleolus, and the percentage of cells with heteromorphic paired nucleoli) and the frequencies of cells with micronuclei and double nuclei. Substantial changes in parameters of nucleolar activity of fin cells were found to be caused by cadmium and copper impact. In comparison to blood cells, gill and fin cells were more sensitive as demonstrated by their nuclear damages after the chloral hydrate influence. Fin cells were useful to determine periodically cytotoxic and genotoxic effects of organic and inorganic substances in the same individual fish without any disruption of its physiological functions.

Use of a complex approach for assessment of metamizole sodium and acetylsalicylic acid toxicity, genotoxicity and cytotoxicity.

A complex approach based on the use of test organisms belonging to different systematic groups (plants, invertebrates and vertebrates), as well as the nucleolar biomarker and the micronucleus test on their cells, was applied to assess the toxicity, cytotoxicity and genotoxicity of two pharmaceutical substances (metamizole sodium and acetylsalicylic acid) applied at ic(50) concentrations for mammalian cells. The compound acetylsalicylic acid was evaluated at a concentration (1.6 x 10(3) mg l(-1)) that was non-toxic for bioassays based on fish (Carassius auratus gibelio) and hydra (Hydra attenuata) and acutely toxic for bioassays with ceriodaphnia (Ceriodaphnia affinis) and onion (Allium cepa). The metamizole sodium solution (6.25%) demonstrated acute toxicity for the whole set of test organisms. Both drugs, after their 30-360 min influence on the test organisms, first changed the nucleolar size in plant and animal cells (i.e. the transcriptional activity of ribosomal genes was affected most significantly). Moreover, the metamizole sodium solution caused nucleolar structural damage in 90% of hydra cells as early as after 30 min of exposure. The acetylsalicylic acid solution inhibited essentially the rate of cell division in the meristem of onion roots (the mitotic index decreased to 9.6 per thousand, as compared 51.7 per thousand for the control). The carp incubation and the onion germination in the acetylsalicylic acid solution showed a reproducible increase in the frequency of cells with micronuclei (2 and 5.5 times, respectively) and double nuclei (3 and 1.5 times, respectively). The approach described herein may be applied for obtaining rapid, cost-efficient and useful supplementary data on different types of toxicity for marketed drugs as well as for drugs under development.

A novel nucleolar biomarker in plant and animal cells for assessment of substance cytotoxicity.

The cytotoxicity of three substances (mercury(II), metolachlor, and 4-nitroquinoline-N-oxide) was assessed with a set of nucleolar parameters: the average number of nucleoli, the average volume of a single nucleolus, and the proportion of cells with heteromorphic-paired nucleoli (PNhet). Their toxic impact was studied on cells of animal and plant test organisms: onion (Allium cepa), lettuce (Lactuca sativa), and hydra (Hydra attenuata). In general, at concentrations near IC/LC(50) the three chemicals produced similar cytogenetic effects after 30-360 min of contact. For instance, in plant cells (Allium cepa and Lactuca sativa) the toxicants increased the percentage of cells with PNhet, decreased the volume of single nucleoli, and exerted no significant impact on the nucleolar number. In animal cells (Hydra attenuata), they reduced the size of nucleoli, produced no effect on the number of nucleoli, but decreased the share of cells with PNhet. Also, the chemicals affected the cells of the three test organisms to different degrees. Thus, the effectiveness of our approach of using nucleolar biomarker (use of the proposed set of parameters and time schedule of several determinations in the first hours of toxicant contact, etc.) as a means of assessing cytotoxicity was confirmed.

Quality of water types in Ukraine evaluated by WaterTox bioassays.

The quality of river, ground-, and tap water was analyzed using the basic set of WaterTox bioassays [Daphnia (Daphnia magna), Hydra (Hydra attenuata), and lettuce (Lactuca sativa)] as well as two additional bioassays, onion (Allium cepa) and microalga (Selenastrum gracile). Samples of these waters were also concentrated fivefold using a solid-phase procedure. The results of the Daphnia and Hydra bioassays showed that the winter and spring concentrated and nonconcentrated samples from the Dnieper and Desna rivers, the main water supply sources for Kiev, were nontoxic. In spring, after concentration, the two river samples brought about the same relative decrease in the lettuce root length (by 35%, p < 0.001), where the Desna River sample considerably reduced (by 79.1%, p < 0.001) the number of microalga cells. Samples of groundwater from countryside wells studied in autumn in several villages of the Kiev region were toxic mainly to Hydra (sublethal effects were found in 11%-78%) and lettuce (the root length decreased 15%-56%). Studies of tap water samples from two of the largest cities of Ukraine, Kiev and Kharkiv, were found to be nontoxic to both plants, lettuce and onion, but showed increased sublethal and lethal effects on both animals, Daphnia and Hydra, as well as a reduced number of microalgae. Different bioassays were sensitive to varying degrees to different water types. This reinforces the necessity of using sets of bioassays in toxicity evaluation. In general, all the tested water samples demonstrated some toxicity. These data suggest that drinking water quality in Ukraine needs improvement.

[Changes in the nucleolar characteristics in fish embryo cells under the action of low doses of radiation]. / Izmeneniia iadryshkovykh kharakteristik v zarodyshevykh kletkakh ryb pod vozdeistviem malykh doz radiatsii.

The nucleolus activity of fish embryo cells was stimulated by low-level radiation at a dose rate of 2-13 mGy/h. The size of nucleoli generally increased in embryos of Cyprinus carpio, whereas the number of nucleoli was greater in embryos of Carassius auratus gibelio. The higher the functional activity of nucleolus is, the more pronounced are changes in the characteristics. The size of single nucleolus at gastrulation is the most sensitive characteristic.

[The use of nucleolar characteristics in biotesting]. / Ispol'zovanie iadryshkovykh kharakteristik v biotestirovanii.

The utility of the use of quantitative nucleolus characteristics (number, size) for the assessment of the influence of threshold levels of different factors on plant and animal genomes was established. It is recommended to use the most sensitive and informative indices, in particular, for cells with a few nucleoli--the size of single nucleoli and per cent of heteromorphic paired nucleoli, and for cells with many nucleoli--their number.