title: Letter: Poison pen?
mesh_terms: D003116:Color; D003300:Copper / Q000506:poisoning*; D005243:Feces; D006801:Humans; D007211:Indoles / Q000506:poisoning*; D007281:Ink / Q000009:adverse effects*; D008297:Male; D009942:Organometallic Compounds / Q000506:poisoning
chemical_list: D007211:Indoles; D009942:Organometallic Compounds; D003300:Copper