A roadmap for hazard monitoring and risk assessment of marine biotoxins on the basis of chemical and biological test systems.

Aquatic food accounts for over 40% of global animal food products, and the potential contamination with toxins of algal origin--marine biotoxins--poses a health threat for consumers. The gold standards to assess toxins in aquatic food have traditionally been in vivo methods, i.e., the mouse as well as the rat bioassay. Besides ethical concerns, there is also a need for more reliable test methods because of low inter-species comparability, high intra-species variability, the high number of false positive and negative results as well as questionable extrapolation of quantitative risk to humans. For this reason, a transatlantic group of experts in the field of marine biotoxins was convened from academia and regulatory safety authorities to discuss future approaches to marine biotoxin testing. In this report they provide a background on the toxin classes, on their chemical characterization, the epidemiology, on risk assessment and management, as well as on their assumed mode of action. Most importantly, physiological functional assays such as in vitro bioassays and also analytical techniques, e.g., liquid chromatography coupled mass spectrometry (LC-MS), as substitutes for the rodent bioassay are reviewed. This forms the basis for recommendations on methodologies for hazard monitoring and risk assessment, establishment of causality of intoxications in human cases, a roadmap for research and development of human-relevant functional assays, as well as new approaches for a consumer directed safety concept.

DHHC2 is a protein S-acyltransferase for Lck.

Lck is a non-receptor tyrosine kinase of the Src family that is essential for T cell activation. Dual N-terminal acylation of Lck with myristate (N-acylation) and palmitate (S-acylation) is essential for its membrane association and function. Reversible S-acylation of Lck is observed in vivo and may function as a control mechanism. Here we identify the DHHC family protein S-acyltransferase DHHC2 as an enzyme capable of palmitoylating of Lck in T cells. Reducing the DHHC2 level in Jurkat T cells using siRNA causes decreased Lck S-acylation and partial dislocation from membranes, and conversely overexpression of DHHC2 increases S-acylation of an Lck surrogate, LckN10-GFP. DHHC2 localizes primarily to the endoplasmic reticulum and Golgi apparatus suggesting that it is involved in S-acylation of newly-synthesized or recycling Lck involved in T cell signalling.

Harnessing opportunities in non-animal asthma research for a 21st-century science.

The incidence of asthma is on the increase and calls for research are growing, yet asthma is a disease that scientists are still trying to come to grips with. Asthma research has relied heavily on animal use; however, in light of increasingly robust in vitro and computational models and the need to more fully incorporate the 'Three Rs' principles of Replacement, Reduction and Refinement, is it time to reassess the asthma research paradigm? Progress in non-animal research techniques is reaching a level where commitment and integration are necessary. Many scientists believe that progress in this field rests on linking disciplines to make research directly translatable from the bench to the clinic; a '21st-century' scientific approach to address age-old questions.

Implementing scientifically-robust and humane shellfish toxicity testing: we're still waiting.

The response to a Parliamentary Question put to the then-Home Office Minister on 8 March 2006, was that "All protocols for the detection of toxins in shellfish intended for human consumption were assigned a substantial severity limit", and that "A total of 6,468 animals were used in the relevant procedures [for the testing of shellfish toxins in the UK] during 2004". The official European Union (EU) method for shellfish toxin testing is the Mouse Bioassay (MBA). The MBA is the primary method, although the Rat Bioassay (RBA) is permitted for some toxins. Six years later, following the completion of ten reports from the European Food Safety Authority (EFSA) stating that current reliance on the MBA is scientifically inappropriate, the regulatory climate for testing is almost unchanged, despite the availability of alternatives. The reliance on such a scientifically questionable method, and the welfare concerns for the animals used, highlight the extent of the clash between policy and science. The ongoing struggle to persuade the European Commission to formally adopt non-animal testing methods for all of the relevant toxins has been fruitless, and evidence remains that thousands of mice are used every year in lethal tests that could be replaced. There is an absolute requirement for advanced scientific methods to replace questionable methods which rely on outdated, inaccurate animal tests; in this case, marine biotoxin testing has surely been waiting in line for far too long.