1 Department of Pediatrics, Graduate School of Medicine, Chiba University, Chiba, Japan; Department of Pediatrics, International University of Health and Welfare Narita Hospital, Narita, Japan. Electronic address: fumiyamaide@gmail.com.
2 Department of Pediatrics, Graduate School of Medicine, Chiba University, Chiba, Japan.
3 Department of Pediatrics, Graduate School of Medicine, Chiba University, Chiba, Japan; Center for Preventive Medical Sciences, Chiba University, Chiba, Japan.