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:

Lack of antihistamine properties of single dose cinnarizine in man . A simple way to study a histamine antagonist in man is to observe the effect it has on the magnitude of the skin reaction to intradermal histamine . The aim of the present study was to evaluate the antihistamine activity of single oral doses of 75 mg cinnarizine using 75 mg diphenhydramine as control , both being compared to placebo . The study was performed with two groups of 5 healthy subjects , each group receiving one of the active treatments or placebo randomly under blind conditions . All subjects received intradermal injections on the forearm of a 0.05 ml saline solution containing 5 micrograms of histamine before and at different times after drug intake . The histamine-induced wheal area was measured and , after drug administration , the percent decrease of the wheal area was calculated . Results showed that diphenhydramine produced a significant inhibition of the histamine-induced wheal size at 1.5 h which lasted up to 4 h after drug administration , reaching maximum inhibition at 2.5 h. After cinnarizine treatment no significant decrease of the histamine-induced wheal area was observed at any time .
{"Intervention": ["histamine .", "placebo .", "placebo", "saline solution", "diphenhydramine", "cinnarizine", "cinnarizine using", "diphenhydramine as control"], "Outcome": ["histamine-induced wheal size", "wheal area", "inhibition of the", "histamine-induced wheal area"], "Participant": ["man ."]}