Affiliation: | 1. Channing Laboratory, Harvard Medical School, Boston, Mass. USA;2. Department of Pediatrics, Harvard Medical School, Boston, Mass. USA;3. Department of Medicine, Harvard Medical School, Boston, Mass. USA;4. Department of Pediatrics, Boston City Hospital, Boston, Mass. USA;5. Department of Medical Microbiology, Boston City Hospital, Boston, Mass. USA;6. Department of Pediatrics, Boston University School of Medicine, Boston, Mass. USA |