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Clinical signs and haematological findings during the acute and convalescent phases of an infection with bovine respiratory syncytial virus (RSV) were studied under field conditions. The study was carried out in 139 cattle less than 16 months of age in 16 herds with serologically proven bovine RSV infections. Blood was collected for serological and haematological examination. Repeated clinical examinations were carried out until 35 days after appearance of disease. Signs of general disease such as reduced appetite and a body temperature of 40 degrees C or higher lasted less than three days in most cases. Signs of upper respiratory disease, such as coughing, nasal discharge and conjunctivitis were predominant and persisted in 10 to 30 per cent of the animals till the end of the observation period. Signs of lower respiratory disease such as abdominal breathing, bronchial and bronchovesicular sounds on auscultation and a high respiration rate were valuable in diagnosing the disease. These symptoms were present in about 50 per cent of the animals in the early stages of the disease. They lasted for about six days and disappeared in most animals after about 10 days. On haematological examination statistically significant blood changes were observed. A rise in zinc and iron between day 0 and day 10 and a reduction in copper content between day 10 and day 21 were found.

This is the report of a workshop organised by the European Centre for the Validation of Alternative Methods (ECVAM). ECVAM's main goal, as defined in 1993 by its Scientific Advisory Committee, is to promote the scientific and regulatory acceptance of alternative methods that are of importance to the biosciences and which replace, reduce or refine the use of laboratory animals. One of the first priorities set by ECVAM was the implementation of procedures that would enable it to become well informed about the state-of-the-art of non-animal test development and validation, and the potential for the possible incorporation of alternative tests into regulatory procedures. It was decided that this would be best achieved by the organization of ECVAM workshops on specific topics, at which small groups of invited experts would review the current status of various types of in vitro tests and their potential uses, and make recommendations about the best ways forward (Anonymous, 1994). The workshop on "The use of in vitro systems for evaluating Immunotoxicity" was held at ECVAM (Ispra), Italy, on 24th-26th November 2003. The participants represented academia, national organizations, international regulatory bodies and industry. The aim of the workshop was to review the state-of-the-art in the field of in vitro immunotoxicology, and to develop strategies towards the replacement of in vivo testing. At the end of this report are listed the recommendations that should be considered for prevalidation and validation of relevant and reliable procedures, that could replace the use of animals in chemical and cosmetics toxicity testing.

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