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:

Reversible cerebral lesions associated with tiazofurin usage: MR demonstration. Tiazofurin is an experimental chemotherapeutic agent currently undergoing clinical evaluation. We report our results with magnetic resonance (MR) in demonstrating reversible cerebral abnormalities concurrent with the use of this drug. The abnormalities on MR were correlated with findings on CT as well as with cerebral angiography. The utility of MR in the evaluation of patients receiving this new agent is illustrated.
{"Chemical": ["Tiazofurin", "tiazofurin"], "Disease": ["cerebral lesions", "cerebral abnormalities"]}