Mechanistic insights into the specificity of human cytosolic sulfotransferase 2A1 (hSULT2A1) for hydroxylated polychlorinated biphenyls through the use of fluoro-tagged probes

Determining the relationships between the structures of substrates and inhibitors and their interactions with drug-metabolizing enzymes is of prime importance in predicting the toxic potential of new and legacy xenobiotics. Traditionally, quantitative structure activity relationship (QSAR) studies are performed with many distinct compounds. Based on the chemical properties of the tested compounds, complex relationships can be established so that models can be developed to predict toxicity of novel compounds. In this study, the use of fluorinated analogues as supplemental QSAR compounds was investigated. Substituting fluorine induces changes in electronic and steric properties of the substrate without substantially changing the chemical backbone of the substrate. In vitro assays were performed using purified human cytosolic sulfotransferase hSULT2A1 as a model enzyme. A mono-hydroxylated polychlorinated biphenyl (4-OH PCB 14) and its four possible mono-fluoro analogues were used as test compounds. Remarkable similarities were found between this approach and previously published QSAR studies for hSULT2A1. Both studies implicate the importance of dipole moment and dihedral angle as being important to PCB structure in respect to being substrates for hSULT2A1. We conclude that mono-fluorinated analogues of a target substrate can be a useful tool to study the structure activity relationships for enzyme specificity.     

First inter-laboratory comparison exercise for the determination of anticancer drugs in aqueous samples

The results of an inter-laboratory comparison exercise to determine cytostatic anticancer drug residues in surface water, hospital wastewater and wastewater treatment plant effluent are reported. To obtain a critical number of participants, an invitation was sent out to potential laboratories identified to have the necessary knowledge and instrumentation. Nine laboratories worldwide confirmed their participation in the exercise. The compounds selected (based on the extent of use and laboratories capabilities) included cyclophosphamide, ifosfamide, 5-fluorouracil, gemcitabine, etoposide, methotrexate and cisplatinum. Samples of spiked waste (hospital and wastewater treatment plant effluent) and surface water, and additional non-spiked hospital wastewater, were prepared by the organising laboratory (Jo?ef Stefan Institute) and sent out to each participant partner for analysis. All analytical methods included solid phase extraction (SPE) and the use of surrogate/internal standards for quantification. Chemical analysis was performed using either liquid or gas chromatography mass (MS) or tandem mass (MS/MS) spectrometry. Cisplatinum was determined using inductively coupled plasma mass spectrometry (ICP-MS). A required minimum contribution of five laboratories meant that only cyclophosphamide, ifosfamide, methotrexate and etoposide could be included in the statistical evaluation. z-score and Q test revealed 3 and 4 outliers using classical and robust approach, respectively. The smallest absolute differences between the spiked values and the measured values were observed in the surface water matrix. The highest within-laboratory repeatability was observed for methotrexate in all three matrices (CV?≤?12 %). Overall, inter-laboratory reproducibility was poor for all compounds and matrices (CV 27–143 %) with the only exception being methotrexate measured in the spiked hospital wastewater (CV?=?8 %). Random and total errors were identified by means of Youden plots.     

Enrichment of trace elements in the clay size fraction of mining soils

Reactive waste dumps with sulfide minerals promote acid mine drainage (AMD), which results in water and soil contamination by metals and metalloids. In these systems, contamination is regulated by many factors, such as mineralogical composition of soil and the presence of sorption sites on specific mineral phases. So, the present study dedicates itself to understanding the distribution of trace elements in different size fractions (<2-mm and <2-μm fractions) of mining soils and to evaluate the relationship between chemical and mineralogical composition. Cerdeirinha and Penedono, located in Portugal, were the waste dumps under study. The results revealed that the two waste dumps have high degree of contamination by metals and arsenic and that these elements are concentrated in the clay size fraction. Hence, the higher degree of contamination by toxic elements, especially arsenic in Penedono as well as the role of clay minerals, jarosite, and goethite in retaining trace elements has management implications. Such information must be carefully thought in the rehabilitation projects to be planned for both waste dumps.     

Biodegradability of the anticancer drug etoposide and identification of the transformation products

Etoposide susceptibility to microbiological breakdown was studied in a batch biotransformation system, in the presence or absence of artificial wastewater containing nutrients, salts and activated sludge at two concentration levels. The primary focus of the present study was to study etoposide transformation products by ultra-high performance liquid chromatography coupled to high-resolution hybrid quadrupole-Orbitrap tandem mass spectrometry (MS/MS). Data-dependent experiments combining full-scan MS data with product ion spectra were acquired to identify the molecular ions of etoposide transformation products, to propose the molecular formulae and to elucidate their chemical structures. Due to the complexity of the matrix, visual inspection of the chromatograms showed no clear differences between the controls and the treated samples. Therefore, the software package MZmine was used to facilitate the identification of the transformation products and speed up the data analysis. In total, we propose five transformation products; among them, four are described as etoposide transformation products for the first time. Even though the chemical structures of these new compounds cannot be confirmed due to the lack of standards, their molecular formulae can be used to target them in monitoring studies.     

Utilizing international networks for accelerating research and learning in transformational sustainability science

A promising approach for addressing sustainability problems is to recognize the unique conditions of a particular place, such as problem features and solution capabilities, and adopt and adapt solutions developed at other places around the world. Therefore, research and teaching in international networks becomes critical, as it allows for accelerating learning by sharing problem understandings, successful solutions, and important contextual considerations. This article identifies eight distinct types of research and teaching collaborations in international networks that can support such accelerated learning. The four research types are, with increasing intensity of collaboration: (1) solution adoption; (2) solution consultation; (3) joint research on different problems; and (4) joint research on similar problems. The four teaching types are, with increasing intensity of collaboration: (1) adopted course; (2) course with visiting faculty; (3) joint course with traveling faculty; and (4) joint course with traveling students. The typology is illustrated by extending existing research and teaching projects on urban sustainability in the International Network of Programs in Sustainability, with partner universities from Europe, North America, Asia, and Africa. The article concludes with challenges and strategies for extending individual projects into collaborations in international networks.     

Conservation of animals traded for medicinal purposes in Brazil: Can products derived from plants or domestic animals replace products of wild animals?

Regional Environmental Change - The use and trade of animals in traditional medicine involves many different species, some of which are threatened with extinction. Thus, evaluating biological and...     

Automated data analysis to rapidly derive and communicate ecological insights from satellite-tag data: A case study of reintroduced red kites

Analysis of satellite-telemetry data mostly occurs long after it has been collected, due to the time and effort needed to collate and interpret such material. Delayed reporting reduces the usefulness of such data for nature conservation where timely information about animal movements is required. To counter this problem, we present a novel approach which combines automated analysis of satellite-telemetry data with rapid communication of insights derived from such data. A relatively simple algorithm (based on radial and angular velocity calculated from fixes) allowed instantaneous detection of excursions away from settlement areas and automated calculation of home ranges on the remaining data. Automating the detection of both excursions and home-range calculations enabled us to disseminate ecological insights from satellite-tag data instantaneously through a dedicated web portal. The automated analysis, interpretation, and communication of satellite-tag and other ecological data offer clear benefits to nature conservation research and practice.     

Limitations of recreational camera traps for wildlife management and conservation research: A practitioner’s perspective

The availability of affordable ‘recreational’ camera traps has dramatically increased over the last decade. We present survey results which show that many conservation practitioners use cheaper ‘recreational’ units for research rather than more expensive ‘professional’ equipment. We present our perspective of using two popular models of ‘recreational’ camera trap for ecological field-based studies. The models used (for >2 years) presented us with a range of practical problems at all stages of their use including deployment, operation, and data management, which collectively crippled data collection and limited opportunities for quantification of key issues arising. Our experiences demonstrate that prospective users need to have a sufficient understanding of the limitations camera trap technology poses, dimensions we communicate here. While the merits of different camera traps will be study specific, the performance of more expensive ‘professional’ models may prove more cost-effective in the long-term when using camera traps for research.