Present state and future perspectives of using pluripotent stem cells in toxicology research

The use of novel drugs and chemicals requires reliable data on their potential toxic effects on humans. Current test systems are mainly based on animals or in vitro–cultured animal-derived cells and do not or not sufficiently mirror the situation in humans. Therefore, in vitro models based on human pluripotent stem cells (hPSCs) have become an attractive alternative. The article summarizes the characteristics of pluripotent stem cells, including embryonic carcinoma and embryonic germ cells, and discusses the potential of pluripotent stem cells for safety pharmacology and toxicology. Special attention is directed to the potential application of embryonic stem cells (ESCs) and induced pluripotent stem cells (iPSCs) for the assessment of developmental toxicology as well as cardio- and hepatotoxicology. With respect to embryotoxicology, recent achievements of the embryonic stem cell test (EST) are described and current limitations as well as prospects of embryotoxicity studies using pluripotent stem cells are discussed. Furthermore, recent efforts to establish hPSC-based cell models for testing cardio- and hepatotoxicity are presented. In this context, methods for differentiation and selection of cardiac and hepatic cells from hPSCs are summarized, requirements and implications with respect to the use of these cells in safety pharmacology and toxicology are presented, and future challenges and perspectives of using hPSCs are discussed

Harmful Elements in Estuarine and Coastal Systems

Estuaries and coastal zones are dynamic transitional systems which provide many economic and ecological benefits to humans, but also are an ideal habitat for other organisms as well. These areas are becoming contaminated by various anthropogenic activities due to a quick economic growth and urbanization. This chapter explores the sources, chemical speciation, sediment accumulation and removal mechanisms of the harmful elements in estuarine and coastal seawaters. It also describes the effects of toxic elements on aquatic flora and fauna. Finally, the toxic element pollution of the Venice Lagoon, a transitional water body located in the northeastern part of Italy, is discussed as a case study, by presenting the procedures adopted to measure the extent of the pollution, the impacts on organisms and the restoration activities

Annual geochemical mass balances in waters of the Firth of Clyde

A first-order mass balance of twelve minor and trace elements in the coastal sea area of the Firth of Clyde is presented for the period August 1989-July 1990. It is based on our own four sets of chemical data collected in the Clyde Estuary and Firth of Clyde over that period, complemented by independent information relating to water column hydrography, rainfall, wind speed, river discharge, as well as sewage sludge and dredged material disposed of at sea. Terrigenous inputs were measured or estimated as continuous functions of time. Mean exchange rates with the open shelf were calculated over four periods representative of 77 % of the one-year period considered here. All these fluxes were subsequently converted to monthly values to facilitate intercomparison. Sedimentation rates were estimated by difference. The trapping efficiency (%) of the system over the study period was 80 +/- 8 for Pb, 75 +/- 10 for Fe, 70 +/- 9 for Co, 68 +/- 12 for Mn, 50 +/- 14 for Zn, 34 +/- 31 for P, 33 +/- 20 for N, 33 +/- 25 for Cu, 26 +/- 30 for Ni, 20 +/- 46 for Si, 15 +/- 16 for Cd, 14 +/- 26 for organic C, and -14 +/- 13 for inorganic C. Most elements exhibited a close correspondence between their annual import and export fluxes across the marine boundary. The implication is that physical transport is the dominant process in the region adjoining the North Channel, i.e. the outermost part of the Firth of Clyde. By extension, the inner Firth and near-shore zone must act as a trap for metal-bearing particles. Such an understanding of the present-day state of the system with regard to trace metal and nutrient cycles would enable one to predict the response of the system to any scenario of modification of the metal/nutrient inputs only to the extent that the system responds linearly to input variability