Need for establishing integrated programs to monitor endocrine active compounds

Environmental monitoring programs on endocrine active compounds (EACs) have been used to document the level of exposure and to assess the possible association to the occurrence of developmental and reproductive disorders in wildlife. The establishment of causal links between exposure and effect data, however, was found to be difficult due to, for example, the presence of confounding factors or limited understanding of EAC mechanisms and interactions, but also because of conceptual and methodological limitations of current monitoring strategies. In order to provide plausibility of an EAC etiology for a developmental or reproductive alteration in a wildlife population, integrated monitoring programs are needed that will use a combination of complementary approaches: methods for a targeted search for suspected EACs in an environmental mixture, analysis of internal EAC doses instead of external EAC concentrations, utilization of mechanism-based end-points in bioanalytical and effect monitoring, investigation of the basic biology and physiology of wildlife sentinel species, laboratory replication of field effects, as well as consideration of epidemiological and weight-of-evidence criteria in the design and data evaluation of monitoring program

Морфологическая стратификация облаков электрическим полем атмосферы в периоды активного и спокойного солнца

Актуальность. В последнее десятилетие наблюдается стремительный рост регионального и глобального изменения климата в связи с хозяйственной деятельностью человека, которая в своих масштабах стала соизмерима с природными процессами. В качестве индикатора техногенной нагрузки может выступать электрическое поле атмосферы, так как техноэкономическая среда городов приводит к глобальным отклонениям и модификации естественных физических полей. Поэтому необходимость изучения влияния электрического поля атмосферы на распределение метеорологических параметров не вызывает сомнения, так как позволяет на качественном уровне проявить «тонкую» структуру стратификации атмосферы электрическим полем и ее изменение за счет антропогенного воздействия. Цель исследования: рассмотреть морфологическую стратификацию облачных образований электрическим полем атмосферы в период активного и спокойного солнца. Данный подход позволяет на качественном уровне прояснить механизм изменения процессов конденсации водяного пара (на примере облаков) сменой солнечной активности, как уменьшение количества возбужденных молекул за счет разной ионизации атмосферы, а также построить физическую теорию антропогенной нагрузки от промышленных предприятий на атмосферу и климат. Объект исследования: электрическое поле атмосферы, облака. Методика исследования построена на детальном статистическом анализе по данным самолетного зондирования в период международного геофизического года и международного геофизического сотрудничества 1958-1964 гг. Результаты исследования. Получены оценки радиационных сечений для молекул стандартной атмосферы и конденсированной фазы (облачные аэрозоли) в геометрическом приближении, которые показывают, что при характерном радиусе капель r-10[-3]см ионизация от конденсированной фазы соизмерима с фононовой ионизацией атмосферы. Приведена корреляционная зависимость средней водности облака и вертикального электрического поля. Анализ результатов показал, что среднегодовое распределение водности имеет высокую корреляцию со среднегодовым вертикальным распределением напряженности электрического поля для данного региона. Методами детального статистического анализа найдена взаимосвязь высоты образования облаков с электрическим полем атмосферы. Показано, что частота повторяемости нижней границы облаков совпадает с локальными точками равновесия плотности объемного заряда для этой же широты.Relevance of the research. In recent decade, regional and global climate has changed significantly due to human activities, which became comparable with natural processes. The electric field of atmosphere can serve as an indicator of anthropogenic impact, as the technical and economic environment of cities results in global deviations and modification of natural physical fields. Therefore, there is no doubt in the necessity to study the influence of the atmospheric electric field on distribution of meteorological parameters, since it allows us to reveal qualitatively the «thin» atmospheric stratification structure of the electric field and its change owing to anthropogenic impact. The aim of the research is to consider the morphological stratification of cloud formations by the atmospheric electric field in the period of the active and quiet sun. This approach allows us to clarify qualitatively the mechanism of change in water vapor condensation (on the example of clouds) by the solar activity change as the decrease in the number of excited molecules owing to different ionization of the atmosphere, as well as to build a physical theory of anthropogenic load from industrial plants on the atmosphere and climate. Research subject: the electric field of the atmosphere, clouds. Research technique: detailed statistical analysis of the data on an aircraft sounding during the International Geophysical Year and the International Geophysical Cooperation in 1958-1964. Results. The author has obtained the estimations of radiation cross-sections for the molecules of the standard atmosphere and the condensed phase (cloud aerosols) in geometric approximation. They show that when the characteristic radius is equal to r-10[-3] cm the ionization of the condensed phase is commensurate with the background ionization. The paper introduces the correlative relationship between average water content of clouds and vertical electric field. The analysis of the results demonstrates that the average annual distribution of water content is strongly correlated with the average vertical distribution of the electric field in this region. Using the methods of the detailed statistical analysis the author revealed the relationship between the height of cloud formation and the electric field of the atmosphere. It is shown that the repetition frequency of a cloud lower boundary demonstrates the high coincidence with local sites of neutrality of a bulk charge density for the same latitude

Proliferative kidney disease (PKD) of rainbow trout: temperature- and time-related changes of Tetracapsuloides bryosalmonae DNA in the kidney

Proliferative kidney disease (PKD) of salmonids, caused by Tetracapsuloides bryosalmonae, can lead to high mortalities at elevated water temperature. We evaluated the hypothesis that this mortality is caused by increasing parasite intensity. T. bryosalmonae-infected rainbow trout (Oncorhynchus mykiss) were reared at different water temperatures and changes in parasite concentrations in the kidney were compared to cumulative mortalities. Results of parasite quantification by a newly developed real-time PCR agreed with the number of parasites detected by immunohistochemistry, except for very low or very high parasite loads because of heterogenous distribution of the parasites in the kidney. Two experiments were performed, where fish were exposed to temperatures of 12, 14, 16, 18 or 19°C after an initial exposure to an infectious environment at 12-16°C resulting in 100% prevalence of infected fish after 5 to 14 days of exposure. While mortalities differed significantly between all investigated water temperatures, significant differences in final parasite loads were only found between fish kept at 12°C and all other groups. Differences in parasite load between fish kept at 14°C to 19°C were not significant. These findings provide evidence that there is no direct link between parasite intensity and fish mortalit

The role of glutathione and sulfhydryl groups in cadmium uptake by cultures of the rainbow trout RTG-2 cell line

This is the final version. Available on open access from MDPI via the DOI in this record.Data Availability Statement: The data presented in this study are available on request from the corresponding author.The aim of this study is to investigate the role of cellular sulfhydryl and glutathione (GSH) status in cellular cadmium (Cd) accumulation using cultures of the rainbow trout cell line RTG-2. In a first set of experiments, the time course of Cd accumulation in RTG-2 cells exposed to a non-cytotoxic CdCl2 concentration (25 μM) was determined, as were the associated changes in the cellular sulfhydryl status. The cellular levels of total GSH, oxidized glutathione (GSSG), and cysteine were determined with fluorometric high-performance liquid chromatography (HPLC), and the intracellular Cd concentrations were determined with inductively coupled plasma mass spectrometry (ICP-MS). The Cd uptake during the first 24 h of exposure was linear before it approached a plateau at 48 h. The metal accumulation did not cause an alteration in cellular GSH, GSSG, or cysteine levels. In a second set of experiments, we examined whether the cellular sulfhydryl status modulates Cd accumulation. To this end, the following approaches were used: (a) untreated RTG-2 cells as controls, and (b) RTG-2 cells that were either depleted of GSH through pre-exposure to 1 mM L-buthionine-SR-sulfoximine (BSO), an inhibitor of glutathione synthesis, or the cellular sulfhydryl groups were blocked through treatment with 2.5 μM N-ethylmaleimide (NEM). Compared to the control cells, the cells depleted of intracellular GSH showed a 25% reduction in Cd accumulation. Likewise, the Cd accumulation was reduced by 25% in the RTG-2 cells with blocked sulfhydryl groups. However, the 25% decrease in cellular Cd accumulation in the sulfhydryl-manipulated cells was statistically not significantly different from the Cd accumulation in the control cells. The findings of this study suggest that the intracellular sulfhydryl and GSH status, in contrast to their importance for Cd toxicodynamics, is of limited importance for the toxicokinetics of Cd in fish cells.Deutsche Forschungsgemeinschaf

Interpretation of sexual secondary characteristics (SSCs) in regulatory testing for endocrine activity in fish.

Secondary sexual characteristics (SSCs) are important features that have evolved in many fish species because of inter-individual competition for mates. SSCs are crucial not only for sexual selection, but also for other components of the reproductive process and parental care. Externally, they are especially clear in males (for instance, tubercles, fatpad, anal finnage, colouration) but are also externally present in the females (for instance, ovipositor). These characters are under hormonal control and as such there has been much interest in incorporating them as measures in fish test methods to assess the potential endocrine activity of chemicals. Here we describe the external SSCs in typical laboratory test species for endocrine testing - fathead minnow (Pimephales promelas), Japanese medaka (Oryzias latipes), zebrafish (Danio rerio) and the three-spined stickleback (Gasterosteus aculeatus L.). We also provide some examples and discuss the utility of SSC responses to the endocrine activity of chemicals in the field and the laboratory. This paper is not aimed to provide a comprehensive review of SSCs in fish but presents a view on the assessment of SSCs in regulatory testing. Due to the current regulatory importance of establishing an endocrine mode-of-action for chemicals, we also consider other, non-endocrine factors that may lead to SSC responses in fish. We conclude with recommendations for how the assessment of SSCs in fish could be usefully incorporated into the endocrine hazard and risk assessment of chemicals

Keeping an Eye on Wild Brown Trout (Salmo trutta) Populations: Correlation Between Temperature, Environmental Parameters, and Proliferative Kidney Disease.

Proliferative kidney disease (PKD) is an emerging disease of salmonids caused by the myxozoan parasite Tetracapsuloides bryosalmonae, which plays a major role in the decrease of wild brown trout (Salmo trutta) populations in Switzerland. Strong evidence demonstrated that water temperature modulates parasite infection. However, less knowledge exists on how seasonal water temperature fluctuations influence PKD manifestation under field conditions, how further environmental factors such as water quality may modulate the disease, and whether these factors coalesce with temperatures role possibly giving rise to cumulative effects on PKD. The aims of this study were to (1) determine the correlation between seasonal course of water temperature and PKD prevalence and intensity in wild brown trout populations, (2) assess if other factors such as water quality or ecomorphology correlate with the infection, and (3) quantitatively predict the implication of these factors on PKD prevalence with a statistical model. Young-of-the-year brown trout were sampled in 45 sites through the Canton of Vaud (Switzerland). For each site, longitudinal time series of water temperature, water quality (macroinvertebrate community index, presence of wastewater treatment plant effluent) and ecomorphological data were collected and correlated with PKD prevalence and intensity. 251 T. bryosalmonae-infected trout of 1,118 were found (overall prevalence 22.5%) at 19 of 45 study sites (42.2%). Relation between PKD infection and seasonal water temperature underlined that the mean water temperature for June and the number of days with mean temperature ≥15°C were the most significantly correlated parameters with parasite prevalence and intensity. The presence of a wastewater treatment plant effluent was significantly correlated with the prevalence and infection intensity. In contrast, macroinvertebrate diversity and river ecomorphology were shown to have little impact on disease parameters. Linear and logistic regressions highlighted quantitatively the prediction of PKD prevalence depending on environmental parameters at a given site and its possible increase due to rising temperatures. The model developed within this study could serve as a useful tool for identifying and predicting disease hot spots. These results support the importance of temperature for PKD in salmonids and provides evidence for a modulating influence of additional environmental stress factors