title: Investigation of host defense mechanisms in the aged as determinants of nosocomial colonization and pneumonia.
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging; D003165:Complement System Proteins / Q000032:analysis; D003428:Cross Infection / Q000276:immunology*; D005260:Female; D006801:Humans; D007136:Immunoglobulins / Q000032:analysis; D008213:Lymphocyte Activation; D008297:Male; D008875:Middle Aged; D009504:Neutrophils / Q000276:immunology; D009895:Opsonin Proteins / Q000032:analysis; D010587:Phagocytosis; D011014:Pneumonia / Q000276:immunology*
chemical_list: D007136:Immunoglobulins; D009895:Opsonin Proteins; D003165:Complement System Proteins