title: Letter: Hepatitis-B surface antigen in cerebrospinal fluid.
mesh_terms: D000818:Animals; D001812:Blood-Brain Barrier; D002555:Cerebrospinal Fluid / Q000276:immunology*; D006509:Hepatitis B / Q000134:cerebrospinal fluid / Q000276:immunology*; D006511:Hepatitis B Antigens / Q000032:analysis*; D002679:Pan troglodytes / Q000276:immunology*
chemical_list: D006511:Hepatitis B Antigens