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:

Effect of finasteride treatment on suburethral prostatic microvessel density in patients with hematuria related to benign prostate hyperplasia . INTRODUCTION In the present study we evaluated the effect of short-term finasteride treatment on microvessel density ( MVD ) which is an indicator of prostatic angiogenesis in patients with hematuria secondary to benign prostatic hyperplasia ( BPH ) . MATERIALS AND METHODS 30 patients who were candidates for BPH surgery were prospectively included in the study . All patients had history of gross hematuria and evaluated by ultrasonography and cystoscopy . The patients were randomized two groups before surgery . The treatment group consisted of 13 patients who were given 5 mg finasteride daily for 4 weeks before surgery . The control group consisted of 17 patients who did not receive finasteride before surgery . During surgery , resected suburethral and hyperplastic prostate specimens were sent for histopathologic MVD determination separately . RESULTS Mean MVD in the suburethral portion of prostate was significantly lower in patients treated with finasteride when compared with controls ( 9.08 +/- 5.6 and 13.94 +/- 5.90 , respectively , p < 0.05 ) . Mean MVD for the hyperplastic portion of prostate was similar for the finasteride and control groups ( 14.21 +/- 7.10 and 19.75 +/- 9.73 , respectively , p > 0.05 ) . CONCLUSION The potential role of finasteride on hematuria related to BPH may be the suppressive effect on MVD in the suburethral tissue of prostate .
{"Intervention": ["5 mg finasteride daily", "did not receive finasteride", "finasteride"], "Outcome": ["Mean MVD for the hyperplastic portion of prostate", "MVD", "Mean MVD in the suburethral portion of prostate was significantly lower"], "Participant": ["patients with hematuria related to benign prostate hyperplasia", "patients with hematuria secondary to benign prostatic hyperplasia ( BPH )", "candidates for BPH surgery", "history of gross hematuria and evaluated by ultrasonography and cystoscopy", "30 patients"]}