You will be shown an abstract from a biomedical research paper. Given this abstract, your task is to extract all unique entities of the following types: ["Outcome", "Participant", "Intervention"].

Please return the output as a JSON object of the format: {"Participant" : ["patients with COPD", ...], "Intervention" : ["Atenolol", ...], "Outcome" : ["blood pressure", ...]}. The keys should be entity types and values should be lists of extracted entities belonging to the corresponding type. If you cannot find entities belonging to a specific type, the value should be [].

Only output the JSON object and do not include any additional text.

Abstract:

Presentation of allergen in different food preparations affects the nature of the allergic reaction -- a case series . BACKGROUND Characterization of fatal and non-fatal reactions to food indicates that the majority of reactions are due to the ingestion of prepared foods rather than the non-processed allergen . In an ongoing study that used a double-blind placebo-controlled food challenge to investigate peanut allergy and clinical symptoms , the observed reaction severity in four of the first six subjects was greater than anticipated . We hypothesized that this was due to differences in the composition of the challenge vehicle . OBJECTIVE The aim was to investigate whether the severity of observed challenge reactions would be repeated on re-challenge with a lower fat challenge vehicle . METHODS Peanut-allergic subjects were re-challenged with a lower fat recipe after reacting more severely than was anticipated to an initial peanut challenge . Similar challenge vehicle recipes were used , the only difference being the lower fat content ( 22.9 % compared with 31.5 % ) . The peanut content of the two recipes was analysed using RAST inhibition studies and ELISA tests . RESULTS Three of four subjects reacted to much smaller doses of peanut protein on re-challenge ( mean dose equivalence - 23 times less peanut ) with the lower fat recipe . RAST inhibition showed that neither recipe altered epitope recognition . The higher fat recipe required twice as much peanut to cause 50 % inhibition . ELISA detected far lower levels of peanut in the higher fat recipe ( 220 000 parts per million ( p.p.m . ) ) than in the lower fat recipe ( 990 000 p.p.m. ) . CONCLUSION The fat content of a challenge vehicle has a profound effect on the reaction experienced after allergen ingestion . This is another factor to be considered in assessing the risk of certain foods to food-allergic consumers and adds another dimension to clinical , research and regulatory practice .
{"Intervention": ["lower fat recipe", "peanut", "lower fat challenge vehicle", "placebo-controlled"], "Outcome": ["doses of peanut protein on re-challenge", "epitope recognition", "RAST inhibition"], "Participant": ["allergic reaction", "Peanut-allergic", "food-allergic", "six"]}