title: A comparative study of purified protein derivative (PPDs) and old tuberculin (OT) with special emphasis on weak tuberculin reaction elicited by PPDs.
mesh_terms: D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D000818:Animals; D001500:BCG Vaccine; D005260:Female; D006168:Guinea Pigs; D006801:Humans; D006968:Hypersensitivity, Delayed; D007223:Infant; D008297:Male; D008875:Middle Aged; D014373:Tuberculin; D014374:Tuberculin Test; D014397:Tuberculosis, Pulmonary / Q000175:diagnosis
chemical_list: D001500:BCG Vaccine; D014373:Tuberculin