WBR0860

Author	[[PageAuthor::Rim Halaby, M.D. [1]]]
Exam Type	ExamType::USMLE Step 1
Main Category	MainCategory::Biochemistry, MainCategory::Pharmacology
Sub Category	SubCategory::General Principles
Prompt	[[Prompt::A 16 year old girl is brought to the emergency department by EMS after her father found her lying on the bathroom floor gasping for air. On admission, the patient is tachycardic and tachypneic with a temperature of 39.8˚C. ABGs show good oxygen saturation with significant respiratory alkalosis. After initial stabilization, the patient admits that she had taken 12 pills of aspirin a few hours back after she found out she was pregnant. What is the mechanism behind the associated fever in this patient?]]
Answer A	AnswerA::Direct inhibition of the electron transport chain
Answer A Explanation	AnswerAExp::Direct inhibition of the ETC occurs by disrupting electron transport. It is usually seen with agents like carbon monoxide and cyanide. Inhibition of the ETC does not lead to fever since energy production decreases.
Answer B	AnswerB::Inhibition of the mitochondrial ATP synthase
Answer B Explanation	AnswerBExp::Oligomycin is the typical agent that inhibits the mitochondrial ATP synthase. With inhibition of ATP synthase, fever is usually not present since the excess energy is not released as heat.
Answer C	AnswerC::Release and accumulation of pyrogenic cytokines
Answer C Explanation	AnswerCExp::Release of pyrogenic cytokines, especially IL-1 and IL-6, is responsible for the febrile reaction to infectious processes.
Answer D	AnswerD::Increase permeability of the inner mitochondrial membrane
Answer D Explanation	AnswerDExp::Salicylates like aspirin are uncoupling agents that increase the permeability of the inner mitochondrial membrane leading to loss of energy as heat and decrease in ATP production.
Answer E	AnswerE::Increase in proton gradient across electron transport chain
Answer E Explanation	AnswerEExp::An increase in proton gradient across electron transport chain can be seen with agents that inhibit ATP synthase. Inhibition of ATP synthase is usually not associated with fever.
Right Answer	RightAnswer::D
Explanation	[[Explanation:: Educational Objective: References: ]]
Approved	Approved::No
Keyword	WBRKeyword::Electron transport chain, WBRKeyword::oxidative phosphorylation, WBRKeyword::aspirin toxicity, WBRKeyword::salicylate toxicity, WBRKeyword::uncoupling agents
Linked Question	Linked::
Order in Linked Questions	LinkedOrder::