Effect of topography on the risk of malaria infection in the Usambara Mountains, Tanzania.

We investigated whether the risk of infection with malaria parasites was related to topography in the Usambara Mountains, Tanzania. Clinical surveys were carried out in seven villages, situated at altitudes from 300 m to 1650 m. Each village was mapped and incorporated into a Digital Terrain Model. Univariate analysis showed that the risk of splenomegaly declined with increasing altitude and with decreasing potential for water to accumulate. Logistic regression showed that altitude alone could correctly predict 73% of households where an occupant had an enlarged spleen or not. The inclusion of land where water is likely to accumulate within 400 m of each household increased the accuracy of the overall model slightly to 76%, but significantly improved predictions between 1000 m and 1200 m, where malaria is unstable, and likely to be epidemic. This novel approach illustrates how topography could help identify local areas prone to epidemics in the African highlands.

Methods of in vitro toxicology.

In vitro methods are common and widely used for screening and ranking chemicals, and have also been taken into account sporadically for risk assessment purposes in the case of food additives. However, the range of food-associated compounds amenable to in vitro toxicology is considered much broader, comprising not only natural ingredients, including those from food preparation, but also compounds formed endogenously after exposure, permissible/authorised chemicals including additives, residues, supplements, chemicals from processing and packaging and contaminants. A major promise of in vitro systems is to obtain mechanism-derived information that is considered pivotal for adequate risk assessment. This paper critically reviews the entire process of risk assessment by in vitro toxicology, encompassing ongoing and future developments, with major emphasis on cytotoxicity, cellular responses, toxicokinetics, modelling, metabolism, cancer-related endpoints, developmental toxicity, prediction of allergenicity, and finally, development and application of biomarkers. It describes in depth the use of in vitro methods in strategies for characterising and predicting hazards to the human. Major weaknesses and strengths of these assay systems are addressed, together with some key issues concerning major research priorities to improve hazard identification and characterisation of food-associated chemicals.

Progress in applying the three Rs of Russell & Burch to the testing of biological products.

The Three Rs (Reduction, Refinement, Replacement) concept of Russell & Burch in relation to humane laboratory animal experimentation is introduced, and special aspects concerning the testing of biologicals are outlined. The role of ECVAM in promoting the Three Rs in the European Union, by organising workshops and task forces, supporting conferences, and financing and/or participating in alternative test development, pre-validation and validation, is reviewed. Finally, examples are given of biologicals-related issues which deserve attention or greater focus.

Implementation of three Rs alternatives in regulatory testing: possibilities and obstacles--the view of the validator.

After the establishment of the European Centre for the Validation of Alternative Methods (ECVAM) in 1993, the Scientific Advisory Committee (ESAC) decided at its first meeting that the implementation of the Three Rs in the production and quality control of biologicals should be one of ECVAMs priorities. In collaboration with experts, ECVAM has established guidelines on the pre-validation and validation of alternative toxicological methods, which are as applicable to alternative methods in the quality control of biologicals as they are to the testing of industrial chemicals. This paper explains the technical information which should be submitted to ECVAM to assess the readiness of a method for pre-validation, which is defined as a small-scale interlaboratory study to confirm that an optimised and transferable protocol is available. Where appropriate, a formal validation study is then conducted, to evaluate the scientific relevance and reliability of the test method.

The role of ECVAM in promoting the regulatory acceptance of alternative methods in the European Union. European Centre for the Validation of Alternative Methods.

The roles played by the European Centre for the Validation of Alternative Methods (ECVAM) and its advisory committee, the ECVAM Scientific Advisory Committee (ESAC), in the evolution of alternative methods are described. Particular emphasis is given to the process by which ECVAM and the ESAC assess the scientific validities of alternative methods, and, in appropriate cases, initiate the progression of scientifically validated methods toward regulatory acceptance.

Promotion of research on in vitro immunotoxicology.

ECVAM was established to play a leading role at the European level in the independent evaluation of the reliability and relevance of test methods and testing strategies for specific purposes through research on advanced methods and new test development and validation, so that chemicals and products of various kinds, including medicines, vaccines, medical devices, cosmetics, household products and agricultural products, can be manufactured, transported and used more economically and more safely, whilst the current relevance on animal test procedures is progressively reduced. Nowhere is this activity more necessary than in the field of immunotoxicology, where we know that chemicals and products of many kinds have the potential to stimulate, modulate or suppress the induction or expression of various types of immune responses. The problem is to effectively evaluate the potency of these effectors, and, since the available information is currently based on rather qualitative animal tests, to evaluate the true relevance of this knowledge and apply it intelligently in risk assessment processes which will protect human beings without unnecessarily limiting the development and use of materials which otherwise have economic, health and social benefits. The way forward must depend on the following: (a) a better understanding of immunotoxicological processes, based on a sounder understanding of the immune system itself (and of its network of control systems and interrelationships with other body systems); (b) The use of in vitro (not in vivo) systems based on human (not animal) cells and tissues; (c) integrated and tiered testing strategies, incorporating QSAR, as well as in vitro approaches; (d) taking advantage of the use of cells or factors from humans who have been exposed to potential immunotoxins, be this voluntarily, occupationally, environmentally or by accident; and (e) the recognition that virtually everything will effect one or more aspects of the immune system at some dose level and, in some circumstances, deciding when such effects are relevant, is the key to immunotoxicity testing. Some current ECVAM-sponsored work and activities at ECVAM are described.

Establishment of an in vitro reporter gene assay for developmental cardiac toxicity.

This study is based on the unique potential of pluripotent embryonic stem (ES) cells to differentiate in vitro into embryoid bodies containing cell lineages representative of most cell types found in the mammalian fetus. However, the use of wild type ES cells as an in vitro assay for embryotoxicological studies is complicated by the simultaneous development of various cellular phenotypes. This prevents a quantitative assessment of drug effects on one specific cell type. Here we report the effects of 15 chemicals on cardiac differentiation as determined by various specific toxicological endpoints such as morphological inspection (contractile activity), quantitative mRNA analysis and cardiac-specific expression of green fluorescent protein (GFP), used as a quantitative reporter. The data from the different endpoints have been subjected to a statistical analysis, and a preliminary prediction model is proposed. The results demonstrate that genetically-engineered ES cells could provide a valuable tool for estimating the developmental cardiotoxic potential of compounds in vitro and form the basis for automated analysis in a high-throughput system.

The importance of the prediction model in the validation of alternative tests.

An overview is presented of the validation process adopted by the European Centre for the Validation of Alternative Methods, with particular emphasis on the central role of the prediction model (PM). The development of an adequate PM is considered to be just as important as the development of an adequate test system, since the validity of an alternative test can only be established when both components (the test system and the PM) have successfully undergone validation. It is argued, however, that alternative tests and their associated PMs do not necessarily need to undergo validation at the same time, and that retrospective validation may be appropriate when a test system is found to be reliable, but the case for its relevance remains to be demonstrated. For an alternative test to be considered "scientifically valid", it is necessary for three conditions to be fulfilled, referred to here as the criteria for scientific relevance, predictive relevance, and reliability. A minimal set of criteria for the acceptance of any PM is defined, but it should be noted that required levels of predictive ability need to be established on a case-by-case basis, taking into account the inherent variability of the alternative and in vivo test data. Finally, in view of the growing shift in emphasis from the use of stand-alone alternative tests to alternative testing strategies, the importance of making the PM an integral part of the testing strategy is discussed.

[Good cell culture practice (GCCP)--an initiative for standardization and quality control of in vitro studies. The establishment of an ECVAM Task Force on GCCP]. / Good Cell Culture Practice (GCCP)--eine Initiative zur Standardisierung und Qualitätssicherung von in vitro Arbeiten. Die Etablierung einer ECVAM Task Force on GCCP.

Cultured human and animal cells are increasingly used as the basis for simplified, direct test systems that have the potential to be more controllable and more reproducible than in vivo test systems. However, if a biological test system is simplified to fundamental levels then it is paramount that the essential components of such a reduced systems are closely defined and reproducible. Thus, minimal requirements for quality standards in cell and tissue culture have to be defined. It is the aim of this GCCP initiative to establish principles for standardisation, rationalisation, and international harmonisation of cell and tissue culture laboratory practices. Therefore, in analogy to Good Laboratory Practice (GLP), a Good Cell Culture Practice (GCCP) was initiated at the 3rd World Congress on Alternatives and Animal Use in the Life Sciences, Bologna, 29. August-2. September 1999. This "Bologna Statement on Good Cell Culture Practice" was presented, discussed, and refined in a Workshop, and a final version was approved at the closing ceremony of the Congress by the scientific audience. Based on the Bologna Statement, an ECVAM Task Force on GCCP was initiated, that is chaired by Thomas Hartung and Sandra Ceocke, in which experts in the field should elaborate minimal requirements for quality standards in cell culture. It is the intention of the GCCP Guidelines to encourage consensus among all concerned with the use of in vitro systems, in order to establish and maintain best laboratory practices, to promote effective quality control systems, to facilitate education and training, to support journal editors, and to help any authorities who need to interpret and apply conclusions based on in vitro data.

Ethical investment--what is it, and what are the implications for industry funding of research into alternatives?

This paper is intended to be a critical appraisal of ethical investment with respect to animal experimentation. It is aimed at a wide readership, ranging from scientists in the field and laypersons interested in laboratory animal welfare, potential investors, to senior management in industries directly or indirectly involved in animal testing.

ECVAM and the Promotion of International Co-operation in the Development, Validation and Acceptance of Replacement Alternative Test Methods.

The European Centre for the Validation of Alternative Methods (ECVAM) was established by the European Commission in 1991, to co-ordinate the validation of alternative methods at the European Union level, to establish a database on alternative methods, and to promote dialogue among all the interested parties, in order to secure the international recognition and acceptance of validated alternative test methods. All ECVAM activities, including workshops, task forces, in-house laboratory studies, and contracted external pre-validation and validation studies, involve international co-operation. Of particular importance has been the role played by ECVAM, notably in partnership with ZEBET, in establishing the principles of test development, validation and acceptance, defining the practical procedures necessary to optimise the progress of new tests toward acceptance, and in successfully validating the 3T3 NRU PT test for phototoxic potential. It is vital that international co-operation goes beyond mere discussion and leads to definite collaborative projects, which lead, in turn, to genuine achievements.

The Funding of Research on the Three Rs in the EU.

In a number of European countries, notably Germany, The Netherlands, Sweden and the UK, there has been a significant commitment to research designed to achieve one or more of the Three Rs. This work has been funded by industry, by government, and by the animal welfare movement. The cosmetic industry, ZEBET in Germany and the Dutch Platform in The Netherlands, and FRAME in the UK, deserve particular mention. The European Commission also plays a major role, in two main ways. Firstly, research is supported via DGXII, particularly through programmes such as BRIDGE, BIOTECH and BIOMED in the Third and Fourth Framework Programmes (1991-1998). In the Fifth Framework Programme (1999-2002), major support for international collaborative studies on the development of replacement alternative test methods will be provided as parts of programmes concerned with the Cell Factory (novel in vitro testing as alternatives to animal testing) and Environment and Health (improvement of predictive toxicity testing, with emphasis on in vitro test systems and alternative screening and testing protocols). The second kind of funding is by competitive contracts for specific studies required by various Services of the Commission, including, for example, pre-validation and validation studies conducted for ECVAM.