IL1B and infection: IL-1β was also measured in the culture medium; however, it was undetectable until 24 h post-infection (9116 ± 3930 pg/g of tissue in the CHD and 6150 ± 4830 pg/g of tissue in the AMN, p < 0.05 vs. control values, which were considered as zero since they were below the detection limits of the assay).