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:

Preliminary efficacy assessment of intrathecal injection of an American formulation of adenosine in humans. BACKGROUND: Preclinical studies of intrathecal adenosine suggest it may be effective in the treatment of acute and chronic pain in humans, and preliminary studies in volunteers and patients with a Swedish formulation of adenosine suggests it may be effective in hypersensitivity states but not with acute noxious stimulation. The purpose of this study was to screen for efficacy of a different formulation of adenosine marketed in the US, using both acute noxious stimulation and capsaicin-evoked mechanical hypersensitivity. METHODS: Following Food and Drug Administration and institutional review board approval and written informed consent, 65 volunteers were studied in two trials: an open-label, dose-escalating trial with intrathecal adenosine doses of 0.25-2.0 mg and a double-blind, placebo-controlled trial of adenosine, 2 mg. Cerebrospinal fluid was obtained for pharmacokinetic analysis, and pain ratings in response to acute heat stimuli and areas of mechanical hyperalgesia and allodynia after intradermal capsaicin injection were determined. RESULTS: Adenosine produced no effect on pain report to acute noxious thermal or chemical stimulation but reduced mechanical hyperalgesia and allodynia from intradermal capsaicin injection for at least 24 h. In contrast, residence time of adenosine in cerebrospinal fluid was short (< 4 h). CONCLUSIONS: These results show selective inhibition by intrathecal adenosine of hypersensitivity, presumed to reflect central sensitization in humans after peripheral capsaicin injection. The long-lasting effect is consistent with that observed in preliminary reports of patients with chronic neuropathic pain and is not due to prolonged residence of adenosine in cerebrospinal fluid.
{"Chemical": ["adenosine", "Adenosine", "capsaicin"], "Disease": ["pain", "neuropathic pain", "acute and chronic pain", "hypersensitivity", "chronic pain", "allodynia", "mechanical hyperalgesia", "acute pain"]}