, 2005). Clinical chemistry analyses were conducted on CHIR 99021 serum (ADVIA 1650, Bayer Healthcare Diagnostics). The following parameters were measured: alkaline phosphatase, aspartate transaminase (AST), alanine transaminase (ALT), creatine kinase, blood urea nitrogen, creatinine, bilirubin, albumin, total protein, serum iron, calcium, magnesium and glucose. CRP was analysed using a dendrimer-coupled cytidine diphosphocholine sandwich enzyme-linked immunosorbent assay

(ELISA) (Heegaard et al., 2009). Detection antibodies were from DAKO (Glostrup, Denmark) and pooled pig serum calibrated against a human CRP calibrator (DAKO A0073) was used as the standard. The detection limit was 67 ng mL−1 (human equivalents) and all samples were run in duplicate. IL-6 and IL-1β serum concentrations were determined by sandwich ELISAs from R&D Systems (Duoset DY686 and Duoset DY681, respectively; RG7422 ic50 Abingdon, UK). Samples were run in duplicate in a dilution of 1 : 2 with a detection limit of 125 pg mL−1 (IL-6) and 62.5 pg mL−1 (IL-1β), using R&D Systems calibrators as the standard. Tumour necrosis factor (TNF)-α serum concentrations were determined using a sandwich ELISA from R&D Systems (Quantikine PTA00). Samples were run in duplicate in a dilution of 1 : 2 with a detection limit of 46.8 pg mL−1, using R&D Systems calibrators as a standard. At inoculation,

most of the S. aureus-infected animals showed dyspnoea, which started about 1 min after the inoculation and lasted about 2 min. Two animals had apnoea and had to be ventilated mechanically by means of repeated pressure on

the thorax for about 2 min. The dyspnoea and apnoea were sometimes accompanied by repeated clonic seizures, each lasting approximately 5 s. After the respiration had become stable, diffuse erythema of the skin appeared in several of the pigs, but disappeared after GABA Receptor 10–15 min. Recovery from sedation was uneventful in all cases, and the animals were able to stand less than 1 h PI. Seven to eight hours PI, signs of clinical disease were observed in all the infected animals. They became lethargic and remained in lateral or sternal recumbency most of the time and stood up reluctantly on manipulation. The respiration was forced and the body temperature was elevated and remained high throughout the experiment. At 12 h PI, an acute abscess surrounded by a haemorrhagic rim was found in the lung of one S. aureus-infected animal (I-1). At 24 h, two of the infected animals (II-1 and II-3) had multiple haemorrhagic processes in the lungs. The third pig (II-2) had pulmonary oedema and hyperaemia as well as a single pulmonary abscess surrounded by a haemorrhagic rim. At 48 h, all infected animals had pulmonary processes, either in the form of petechiae or small abscesses.