This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
[{'content': 'Which of the following markers has significant association with poor prognosis in traumatic brain injury? \nSelect and explain. \nA. S-100b Protein, B. b-Amyloid precursor protein, C. Increased CSF levels of three neurofilament H, D. Calpain-derived a-spectrin fragment', 'role': 'user'}, {'content': 'Answer: A \nExplanation: After moderate or severe traumatic brain injury, serum S-100b protein concentrations are significantly associated with unourable prognosis in the sho, mid, or long term. Optimal thresholds for discrimination remain unclear. Measuring the S-100b protein could be useful in evaluating the severity of traumatic brain injury and in the determination of long term prognosis in patients with moderate and severe injury. S-100b protein serum concentrations correlate significantly with unourable prognosis in patients with moderate or severe traumatic brain injury, as defined by moality, Glasgow outcome score <=3, or brain stem death, with or without concomitant traumatic injuries. Ref: Predictive value of S-100b protein for prognosis in patients with moderate and severe traumatic brain injury: systematic review and meta-analysis ; BMJ 2013;346:f1757.', 'role': 'assistant'}]