<prompt> A 63-year-old man becomes febrile and begins expectorating large amounts of mucopurulent sputum. Sputum cultures are positive for Gram-positive diplococci. Which of the following mediators of inflammation provides potent chemotactic factors for the directed migration of inflammatory cells into the alveolar air spaces of this patient?BradykininHistamineMyeloperoxidaseN-formylated peptides  <response>: Chemotactic factors are substance that stimulalte cellular migration The most potent chemotactic factors for leukocytes at the site of injury are:- Complement proteins e.g., C5a Bacterial and mitochondrial products, paicularly low molecular weight N-formylated peptides Products of arachidonic acid metabolism especially LTB4 -Plasmin is a fibrinolytic enzyme generated by activated Hageman factor clotting factor XII. 