A 43-Year-Old Man Is Being Evaluated for Occasional Retrosternal Chest

question 169

Multiple Choice

A 43-year-old man is being evaluated for occasional retrosternal chest pressure that develops with moderate exertion and sometimes occurs when resting.  He does not use alcohol, tobacco, or illicit drugs.  The patient has an extensive family history of coronary artery disease.  His temperature is 36.7 C (98 F) , blood pressure is 124/72 mm Hg, pulse is 81/min, and respirations are 14/min.  Physical examination shows no abnormalities.  Coronary angiography shows mild luminal irregularities but no significant obstructive lesions.  Acetylcholine infusion during the procedure results in dilation of epicardial coronary vessels.  A reaction involving which of the following amino acids is most likely responsible for the observed dilation?

• A)Arginine
• B)Aspartate
• C)Glutamate
• D)Tryptophan
• E)Tyrosine

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Definitions:

Herfindahl Index

The Herfindahl Index is a measure of market concentration used to evaluate the level of competition within an industry, calculated as the sum of the squares of each firm's market share.

Four-Firm Concentration Ratio

An economic measure that assesses the concentration and competitive landscape of an industry by adding the market shares of the four largest firms.

Merged

The combining of two or more entities into one, through acquisitions or consolidations.

Herfindahl Index

An economic indicator used to assess the level of concentration and competition within an industry, calculated by summing the squares of the market shares of all firms in the market.