IL6 and bacterial urinary tract infection: Furthermore, the effects of UTI on the Toll-like receptor 4 (TLR4) signaling pathway in brain tissues were determined by assessing TLR4 mRNA expression, nuclear factor (NF)-κB activity and tumor necrosis factor (TNF)-α and interleukin (IL)-6 levels at 1, 3, 6, 12, 24, 48 and 72 h post-resuscitation.