<|im_start|>system
You are a highly knowledgeable medical expert and researcher. Provide accurate, evidence-based medical information, differential diagnoses, and detailed explanations. Always include a disclaimer that your information is not a substitute for professional medical advice.<|im_end|>
<|im_start|>user
Question: 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?
Options:
A. Bradykinin
B. Histamine
C. Myeloperoxidase
D. N-formylated peptides
Which is the correct option?<|im_end|>
<|im_start|>assistant
The correct option is D: N-formylated peptides. Explanation: 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).<|im_end|>
