{"id":"438e0b3f-edf0-5685-a59f-ceb9040cd7c0","stable_key":"56f1d914-e7da-595a-af69-c217b2b47407:l-phenylalanine-tyrosine-brain-estimate","predicate":"transiently_changes","statement":"In ten PKU patients, 300 mg/kg/day tyrosine transiently raised calculated brain tyrosine influx from 27% to 90% of normal, but it remained below 70% for half the sampled period.","claim_class":"mechanistic","status":"source_derived_draft","evidence_grade":"ungraded","direction":"context_dependent","is_public":true,"mechanism_event_id":"f0355eb5-dc16-5055-8b18-0fe1fb7048df","mechanism_event_label":"A blood rise after supplementation need not provide steady predicted brain delivery.","subject":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"object":{"id":"b575543c-945d-5691-bc82-27227e3b8059","slug":"pku-calculated-tyrosine-brain-influx","display_name":"Calculated tyrosine brain influx in PKU","entity_type_key":"cellular_process"},"evidence_count":1,"mechanism_event":{"id":"f0355eb5-dc16-5055-8b18-0fe1fb7048df","stable_key":"56f1d914-e7da-595a-af69-c217b2b47407:l-phenylalanine-tyrosine-brain-estimate-event","event_type":"observed_relationship","label":"A blood rise after supplementation need not provide steady predicted brain delivery.","description":"In ten PKU patients, 300 mg/kg/day tyrosine transiently raised calculated brain tyrosine influx from 27% to 90% of normal, but it remained below 70% for half the sampled period.","status":"provisional","compartment":null,"participants":[{"entity":{"id":"bcfef85f-831d-5439-ba51-1aef4b090441","slug":"l-tyrosine","display_name":"L-Tyrosine","entity_type_key":"small_molecule"},"role":"subject","stoichiometry":null,"state_label":"","sequence_order":0,"notes":""},{"entity":{"id":"b575543c-945d-5691-bc82-27227e3b8059","slug":"pku-calculated-tyrosine-brain-influx","display_name":"Calculated tyrosine brain influx in PKU","entity_type_key":"cellular_process"},"role":"target","stoichiometry":null,"state_label":"","sequence_order":1,"notes":""},{"entity":{"id":"190407ad-0219-54b5-b05f-7c75f3895ca6","slug":"l-phenylalanine","display_name":"L-Phenylalanine","entity_type_key":"small_molecule"},"role":"context_participant","stoichiometry":null,"state_label":"","sequence_order":2,"notes":""}]},"contexts":[{"dimension":"availability_state","value_text":"biomarker_context","comparator":null,"unit":null,"notes":"Imported condition classification; unverified.","entity":null},{"dimension":"evidence_access","value_text":"Primary abstract","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"experimental_model","value_text":"Forty-eight-hour human study with tyrosine on day two and calculated transport estimates.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"limitations","value_text":"Brain influx was modeled, not directly measured; high phenylalanine and other competing amino acids remain part of the model.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"nutrient_topic","value_text":"L-Phenylalanine collection; species, compartment, exposure, co-substrates and manipulation remain explicit.","comparator":null,"unit":null,"notes":"","entity":{"slug":"l-phenylalanine","display_name":"L-Phenylalanine","entity_type_key":"small_molecule"}},{"dimension":"plain_language","value_text":"A blood rise after supplementation need not provide steady predicted brain delivery.","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"primary_references","value_text":"Tyrosine supplementation in phenylketonuria: diurnal blood tyrosine levels and presumptive brain influx of tyrosine and other large neutral amino acids. · 2001 · https://pubmed.ncbi.nlm.nih.gov/11562623/ · DOI 10.1067/mpd.2001.117576","comparator":null,"unit":null,"notes":"","entity":null},{"dimension":"trigger_kind","value_text":"biomarker_context","comparator":null,"unit":null,"notes":"Imported condition classification; 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