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: ["Disease", "Chemical"].

Please return the output as a JSON object of the format: {"Chemical" : ["Naloxone", ...], "Disease" : ["Hypotensive", ...]}. 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:

Nerve growth factor and prostaglandins in the urine of female patients with overactive bladder. PURPOSE: NGF and PGs in the bladder can be affected by pathological changes in the bladder and these changes can be detected in urine. We investigated changes in urinary NGF and PGs in women with OAB. MATERIALS AND METHODS: The study groups included 65 women with OAB and 20 without bladder symptoms who served as controls. Evaluation included patient history, urinalysis, a voiding diary and urodynamic studies. Urine samples were collected. NGF, PGE2, PGF2alpha and PGI2 were measured using enzyme-linked immunosorbent assay and compared between the groups. In addition, correlations between urinary NGF and PG, and urodynamic parameters in patients with OAB were examined. RESULTS: Urinary NGF, PGE2 and PGF2alpha were significantly increased in patients with OAB compared with controls (p <0.05). However, urinary PGI2 was not different between controls and patients with OAB. In patients with OAB urinary PGE2 positively correlated with volume at first desire to void and maximum cystometric capacity (p <0.05). Urinary NGF, PGF2alpha and PGI2 did not correlate with urodynamic parameters in patients with OAB. CONCLUSIONS: NGF and PGs have important roles in the development of OAB symptoms in female patients. Urinary levels of these factors may be used as markers to evaluate OAB symptoms.
{"Chemical": ["PG", "PGs", "prostaglandins", "PGE2", "PGI2", "PGF2alpha"], "Disease": ["OAB", "overactive bladder"]}