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:

Enalapril ( 10 mg/day ) in systemic sclerosis . One year , double blind , randomised study ( ESS-1 ) : echocardiographic substudy -- three months follow-up . The ESS-1 study was designed to evaluate the long-term effects of the angiotensin converting enzyme inhibitor ( ACEI ) enalapril ( 10 mg per day ) on the cardio-pulmonary system in patients with scleroderma ( SSc ) . We estimated changes in heart diameters , systolic and diastolic left ventricle function and mean values of pulmonary artery pressure after 3 months treatment . The study group comprise 41 patients with SSc . 18 patients received placebo and 23 ones were given enalapril . After 3 months of treatment we did not observe statistically significant differences in heart diameters and left ventricle systolic function parameters between treated group and placebo . Enalapril therapy did not affect left ventricle diastolic function , nevertheless differences in MVA were almost of statistical significance . Echocardiographic signs of pulmonary hypertension were found in 4 patients .
{"Intervention": ["enalapril", "placebo", "Enalapril"], "Outcome": ["heart diameters", "heart diameters , systolic and diastolic left ventricle function and mean values of pulmonary artery pressure", "left ventricle diastolic function", "MVA", "pulmonary hypertension", "left ventricle systolic function parameters"], "Participant": ["41", "scleroderma ( SSc )"]}