TLR4 and bacterial urinary tract infection: The results showed that UTI (1) improves neurological dysfunction after TBI, (2) alleviates brain damage in a mouse TBI model, (3) relieves neuroinflammation after TBI, decreases inflammatory brain damage, (4) prevents oxidative stress and apoptosis after TBI and alleviates neuronal death and (5) prevents the antiapoptosis and antioxidative stress effects of UTI that may be related to the TLR4/NF- kB/p65 signalling pathway (Fig. 6).