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: ["HealthCareActivity", "InjuryOrPoisoning", "BodySubstance", "IntellectualProduct", "AnatomicalStructure", "SpatialConcept", "Chemical", "Bacterium", "MedicalDevice", "Organization", "BiomedicalOccupationOrDiscipline", "Finding", "BiologicFunction", "Virus", "ResearchActivity", "ClinicalAttribute", "PopulationGroup", "Eukaryote", "BodySystem", "Food", "ProfessionalOrOccupationalGroup"].

Please return the output as a JSON object of the format: {"Virus": ["HIV", ...], "Bacterium": ["MRSA", ...], "AnatomicalStructure": ["Lung", ...], "BodySystem": ["CNS", ...], "BodySubstance": ["Serum", ...], "Finding": ["Headache", ...], "InjuryOrPoisoning": ["Fracture", ...], "BiologicFunction": ["Death", ...], "HealthCareActivity": ["Biopsy", ...], "ResearchActivity": ["Clinical trial", ...], "MedicalDevice": ["Lenses", ...], "SpatialConcept": ["Camps", ...], "BiomedicalOccupationOrDiscipline": ["Forensic medicine", ...], "Organization": ["WHO", ...], "ProfessionalOrOccupationalGroup": ["Provider", ...], "PopulationGroup": ["Swimmers", ...], "Chemical": ["Gold", ...], "Food": ["Rice", ...], "IntellectualProduct": ["RPAM", ...], "ClinicalAttribute": ["Biomarker", ...], "Eukaryote": ["Dogs", ...]}. 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:

A rare cause of gastric obstruction: Lighters swallowing The majority of swallowed foreign bodies are thrown spontaneously without causing complications in the digestive system. Multiple number of foreign bodies may be swallowed by psychiatric patients which delay diagnosis and increase the complication rate. Long and hard objects cannot pass through the pylorus, and may cause obstruction, ulceration, bleeding and perforation. Endoscopy is used as an effective method in such cases. An exploratory laparatomy was performed after unsuccessful endoscopic foreign object removal in a 28-year-old schizophrenic patient with gastric outlet obstruction due to multiple cigarette lighter swallowing. Ten lighters were removed from the stomach through gastrotomy and one more lighter was removed from the descending colon by milking through the anus. The aim of this paper is to discuss encountered difficulties in psychiatric patients who underwent surgery due to intake of foreign bodies.
{"AnatomicalStructure": ["pylorus", "descending colon", "stomach", "anus"], "Bacterium": [], "BiologicFunction": ["swallowed", "obstruction", "ulceration", "gastric outlet obstruction", "bleeding", "complication", "gastric obstruction", "complications", "schizophrenic", "swallowing"], "BiomedicalOccupationOrDiscipline": [], "BodySubstance": [], "BodySystem": ["digestive system"], "Chemical": [], "ClinicalAttribute": [], "Eukaryote": [], "Finding": ["perforation", "difficulties", "swallowed foreign bodies"], "Food": [], "HealthCareActivity": ["exploratory laparatomy", "Endoscopy", "gastrotomy", "removal", "surgery", "milking"], "InjuryOrPoisoning": ["objects", "foreign bodies", "foreign object"], "IntellectualProduct": [], "MedicalDevice": [], "Organization": [], "PopulationGroup": [], "ProfessionalOrOccupationalGroup": [], "ResearchActivity": [], "SpatialConcept": ["endoscopic"], "Virus": []}