Aspirin to other NSAIDs but also suppresses the normal functioning of platelets. One common adverse effect is an upset stomach. More significant side effects include stomach ulcers, stomach bleeding, and worsening asthma. Bleeding risk is greater among those who are older, drink alcohol, take other NSAIDs, or are on other blood thinners. Aspirin is not recommended in the last part of pregnancy. It is not generally recommended in children with infections because of the risk of Reye syndrome. High doses may result in ringing in the ears. A precursor to aspirin found in leaves from the willow tree has been used
History of aspirin testing failures. Vane and Piper tested the biochemical cascade associated with anaphylactic shock (in extracts from guinea pig lungs, applied to tissue from rabbit aortas). They found that aspirin inhibited the release of an unidentified chemical generated by guinea pig lungs, a chemical that caused rabbit tissue to contract. By 1971, Vane identified the chemical (which they called "rabbit-aorta contracting substance," or RCS) as a prostaglandin. In a 23 June 1971 paper in the journal "Nature", Vane and Piper suggested that aspirin and similar drugs (the nonsteroidal anti-inflammatory drugs or NSAIDs) worked by blocking the production of prostaglandins. Later research