Catálogo de publicaciones - libros

The viability of seeds growing around the nuclear power plant (NPP) can decrease up to 20–30 %. We consider the appearance of both multiple secondary cells and chromosomes with abnormalities. We used the ideas of adaptation to explain these phenomena. The aim was the statistical analysis of the appearances of cells and chromosomes with abnormalities in dependence on radiation factor around the NPP and seeds’ antioxidant status (AOS).

For the last 15 years, we have investigated low dose radiation genetic effects on human populations affected by the Chernobyl accident. Cytogenetic longitudinal investigations showed that amount of radiation markers for clean-up workers remained at the elevated level and had trend to grow up with the time. A dynamic profile of the amount of aberrations confirms that this group has symptoms of the genomic instability. State of the genomic instability correlates with accumulation of clastogenic factors, responsible for increased genomic instability in clean-up workers peripheral blood. As a model for clastogenic activity testing, we used human keratinocyte cell line with blocked 1st check point of cell cycle. Our results confirm that cytogenetic and molecular effects of irradiation can be fixed even 20 years after the Chernobyl accident.

Free-radical biology, which is central to the fields of radiation, aging and xenobiotics, has shifted from a paradigm highlighting damage to a paradigm emphasizing the role of free radicals in regulatory processes. A unified approach is possible since multiple stressors tend to activate a coordinated set of common mechanisms. These include antioxidant defenses, metal chelators, DNA repair systems, heat-shock proteins, xenobiotic efflux transporters, protein degradation systems, cell survival and apoptosis pathways and detoxification systems. Nearly all MAPK signal transduction pathways employ oxidative signaling, largely generated via membrane-bound NADPH oxidase systems. These regulate most cellular stress, growth and apoptotic responses. A new global perspective highlighting “Electroplasmic Cycles” incorporates numerous cellular aspects of control including free radicals, protein and histone modifications, nuclear–cytoplasmic transport, and ion channels. Aspects critical to multiple stressors include complex interactions related to apoptosis-necrosis, immunological responses (Toll-like receptors), bystander effects, chaperone proteins, and multiple xenobiotic efflux proteins. The synthesis suggests that a systems approach to multiple stressor impacts is required since understanding requires holistic appreciation of integrated regulatory circuitry.

The object of our research was to study interspecies and intervariety variability of pollutant (nitrates, heavy metals, radionuclides) accumulation in productive parts of vegetable crops, as well as the character of inheritance of nitrate and heavy metal accumulation in tomato fruits in the open ground. We investigated the genetical basis of cadmium, lead and nitrate accumulation using the diallel analysis method. Genotype variation between tomato varieties and hybrids in diallel crosses in cadmium (12.8–15.5-fold) and lead accumulation (7.5–14.1-fold) was established.

Abstract: The field of multiple stressors is highly complex. Agents can interact in an additive, antagonist or synergistic manner. The outcome following low dose multiple stressor exposure also is impacted by the context in which the stressors are received or perceived by the organism or tissue. Modern biology has given us very sensitive tools to access change following stressor interaction with biological systems at several levels of organization but the effect-harm-risk relationship remains difficult to resolve. This paper reviews some of the issues, using low dose ionizing radiation as a common stressor and chemicals known to act through similar mechanisms, as examples. Since multiple stressor exposure is the norm in the environment, it is essential to move away from single stressor based protection and to develop tools, including legal instruments, which will enable us to use responsebased risk assessment. The problem of radiation protection in the context of multiple stressors includes consideration of humans and non-humans as separate groups requiring separate assessment frameworks. This is because for humans, individual survival and prevention of cancer are paramount but for animals, it is considered sufficient to protect populations and cancer is not of concern. The need to revisit this position is discussed not only from the environmental perspective but because the importance of pollution as a cause of non-cancer disease is increasingly being recognized. Finally a way forward involving experimental assessment of biomarker performance coupled with modeling is discussed.

The purpose of this work was to study possible mechanisms of radiation-induced bystander effect proceeding from its modification using different radioprotective substances: melanin, melatonin and α -tocopherol. All substances were able to statistically significant decrease the damaging effect of bystander factor from irradiated cells on non-irradiated. The protective effect against bystander irradiation was much less than against direct irradiation. Melatonin showed the best protective effect against both direct and bystander irradiations, and vitamin E – the least. According to the results, bystander factor may have physical component and oxidative nature.

The rainbow trout () is one of the most extensively researched and characterised species of fish. In addition its low tolerance to poor water quality has established it as one of the most useful sentinel species for aquatic toxicology. The subject of proteomics offers a potentially powerful approach to ecotoxicology, particularly with respect to providing biomarkers of environmental contamination.

Environmental contamination by radionuclides and different chemical substances results in exposure of human and other beings to a complex of physical and chemical factors. Results of combined influence of diverse agents can be unpredictable, because observed effects can differ from the sum of effects of each one taken separately.We studied cytogenetic effects of sodium nitrite and nitrate in drosophila and mice. It was found that these substances didn’t possess mutagenic activity and sensibilized significantly (2–4 times) genetic effect of ionizing radiation. Genetic effects of herbicide zenkor were found to be completely different. Zenkor has mutagenic activity and irradiation of zenkor-treated mice results in decreasing aberration levels.

Risk associated to exposure to a single genotoxic agent can be assessed from the dose or concentration of the pollutant. For instance, radiation risk is estimated from physical dose (energy per mass unit), using radiation and tissue weighting factors and risk coefficients derived from epidemiology. However, for exposure to multiple stressor this approach is complicated, and deviations from simple additive models are common. Chromosomal aberrations in peripheral blood lymphocytes have long been considered a biomarker of cancer risk.

The “oxygen paradox” is that molecular oxygen is both essential for aerobic life but also can be toxic to cells largely because of the effects of oxygen-derived species collectively called “reactive oxygen species” (ROS) such as the hydroxyl radical. Cells have evolved elaborate defences against ROS but if these defences are decreased (as in ageing) or if the ROS challenge becomes too great (as in toxicity), a state of oxidative stress (OS) ensues. Proteins are the principal targets of ROS and redox proteomics uses proteomics tools to study redox-based effects on the cell’s protein complement. We have long used bivalve molluscs as sentinel organisms for study of pollution effects in estuaries, in particular looking at effects on stress-response proteins such as antioxidative enzymes, detoxification enzymes and heat shock proteins. Stress-response proteins are often affected by more than one stressor so these targets are likely to be of interest in other stress contexts. We are now applying redox proteomics approaches to study stress effects in bivalves. We detect carbonylation, glutathionylation, ubiquitination, effects on disulphide bridge patterns and changes in protein expression signatures in a range of electrophoresis formats. The effects are tissue- and treatment-specific. We find that many proteins targeted by OS are associated with either actin or protein disulphide isomerase. Many of the tools we use are species-independent and are appropriate for other stress scenarios.