title: Letter: Tryptophan and hepatic encephalopathy.
mesh_terms: D000596:Amino Acids / Q000378:metabolism; D001693:Biological Transport, Active; D001921:Brain / Q000378:metabolism*; D006501:Hepatic Encephalopathy / Q000378:metabolism*; D006801:Humans; D014364:Tryptophan / Q000378:metabolism*
chemical_list: D000596:Amino Acids; D014364:Tryptophan