BACKGROUND: Heart rate (HR) and respiratory rate (RR) are key vital signs, yet few large studies have reported their normal values in toddlers. We thus assessed HR and RR in two-year-old Japanese children. Given that body size may influence vital signs, we first assessed the correlations of height and weight with HR and RR. We also examined associations of HR and RR with physical activity levels and residential region, as these factors have been linked to vital signs in adults. METHODS: This prospective cohort study included children from the Japan Environment and Children's Study. We measured their HR, RR, height, and weight at two years of age, and assessed their outdoor playtime from one to two years of age using a questionnaire. Participants without HR or RR data were excluded from the analysis. Descriptive statistics for HR and RR at two years of age were summarized. In addition, the correlation coefficient between the participants' height or weight and HR or RR were calculated. We investigated the association between the region or outdoor playtime and HR or RR using a one-way analysis of variance and multiple regression analyses. The covariates included medical history, mother's gestational hypertension, parents' height and weight, parents' smoking status, and parents' educational background. RESULTS: A total of 4,805 participants were included in the HR analysis, and 4,806 in the RR analysis. The mean HR and RR of were 109.2 ± 14.7 beats/min and 29.9 ± 6.1 breaths/min (mean ± standard deviation), respectively. No correlation was found between height or weight and HR or RR. The mean HR of participants who almost never spent time playing outdoors was 111.7 beats/min, whereas that of participants who spent ≥ 3 h/d playing outdoors was 108.2 beats/min (p = 0.038). The mean HR in Eastern Japan was 106.8 /min, whereas that in Western Japan was 112.7 beats/min (p < 0.001). CONCLUSION: We assessed the normal HR and RR in Japanese children aged two years, and these normal ranges did not correlate with height and weight. A longer duration of outdoor playtime was associated with a lower HR.

BACKGROUND: Lenz-Majewski syndrome (LMS) is a rare genetic disorder characterized by osteosclerosis, intellectual disability, characteristic facies, and distinct craniofacial, dental, cutaneous, and distal-limb anomalies. Mutations in the PTDSS1 gene, which encodes one of the phosphatidylserines (PS) synthase enzymes, PSS1, have been identified as causative in LMS patients. These mutations make PSS1 insensitive to feedback inhibition by PS levels. METHODS: Whole genome sequence (WGS) was performed on a patient with congenital cutis laxa and her parents. PS synthase activity was analyzed in PTDSS1 mutant cDNA clones to evaluate functional alterations. RESULTS: A 5-year-old girl presented with congenital skin wrinkles and was initially diagnosed with congenital cutis laxa. She had bilateral inner ear hypoplasia, bilateral low-frequency hearing loss, attention-deficit/hyperactivity disorder, and mild intellectual disability. Physical examination revealed protruding ears, frontal bossing, and dental malalignment. A de novo heterozygous missense variant in the PTDSS1 gene, c.284G>A (p. Arg95Gln) was identified by WGS. Functional analysis indicated increased PS synthase activity, supporting the pathogenicity of this variant. CONCLUSIONS: The patient's cutis laxa and facial features were consistent with LMS, though radiographic findings did not reveal the characteristic sclerosing bone dysplasia reported in previous cases. This observation suggests that LMS may have a broader phenotypic spectrum than previously recognized.

Next-generation sequencing (NGS) has become widely available and is routinely used in basic research and clinical practice. The reference genome sequence is an essential resource for NGS analysis, and several population-specific reference genomes have recently been constructed to provide a choice to deal with the vast genetic diversity of human samples. However, resources supporting population-specific references are insufficient, and it is burdensome to perform analysis using these reference genomes. Here, we constructed a set of resources to support NGS analysis using the Japanese reference genome, JG. We created resources for variant calling, variant-effect prediction, gene and repeat element annotations, read mappability, and RNA-seq analysis. We also provide a resource for reference coordinate conversion for further annotation enrichment. We then provide a variant calling protocol with JG. Our resources provide a guide to prepare sufficient resources for the use of population-specific reference genomes and can facilitate the migration of reference genomes.

This study aimed to investigate the impact of early group childcare on child development using data from the Japan Environment and Children's Study. This prospective cohort study enrolled participants between January 2011 and March 2014. The Ages and Stages Questionnaires (ASQ)-3 was used to obtain data regarding group childcare and other factors. The participants were divided into two groups: the early childcare group (exposed group) and the non-early childcare group (control group). The ASQ-3 scores in all five domains, i.e., communication, gross motor skills, fine motor skills, problem-solving, and personal-social skills, were compared. A total of 39,894 participants were included in this study. The exposed and control groups comprised 13,674 and 26,220 participants, respectively. The number of participants with the ASQ-3 values below the cut-off value did not differ significantly between the two groups in any of the five domains at six months of age. However, the number of participants with the ASQ-3 values below the cut-off values was significantly lower in the exposed group for all five domains at three years of age. The difference between the two groups, especially in terms of communication and personal-social skills, increased with age.

OBJECTIVE: The primary objective of this study was to investigate the parenting attitudes towards children with autism spectrum disorders in early childhood in Japan. DESIGN: This study was a cohort study. The participants were enrolled from January 2011 to March 2014. We obtained the prevalence of autism spectrum disorders at 3 years of age, parenting attitudes and other factors from questionnaires. We divided the participants into two groups, an autism spectrum disorders group and a non-autism spectrum disorders group, and compared the parenting attitudes. SETTING: This study used data from a Japanese birth cohort study: the Japan Environment and Children's Study, conducted across 15 regional centres in Japan. PARTICIPANTS: The full dataset of the Japan Environment and Children's Study comprised 104 059 records. We excluded 17 889 records because the answer for the autism spectrum disorders in the questionnaire was blank. As a result, we analysed the remaining 82 411 mother-child pairs. MAIN OUTCOME MEASURES: The primary outcome variable was parenting attitudes at 3.5 years of age, which was assessed using a questionnaire. We asked respondents 16 questions related to parenting attitudes, and they answered based on their behaviours. The independent variable was the prevalence of autism spectrum disorders at 3 years of age. RESULTS: Of the 82 411 participants, the children with autism spectrum disorders at 3 years of age were 372 (0.45%). In most questions about parenting attitudes, the autism spectrum disorders group had unfavourable responses. The difference was particularly noticeable when the parents taught their children social discipline. Unfavourable parenting attitudes were 16.6% in the autism spectrum disorders group and 0.8% in the non-autism spectrum disorders group in the question item with the largest difference between the two groups, a significant difference. CONCLUSIONS: Parents of children with autism spectrum disorders tended to have unfavourable attitudes, suggesting the importance of parental training.

BACKGROUND: The primary objective of this study was to examine risk factors for toddler's hypertension. METHODS: Subjects of this study were children and parents participating in a national birth cohort study in Japan, the Japan Environment and Children's Study. We measured the children's blood pressure (BP) at 2 and 4 years old. We obtained children's and parents' backgrounds from the questionnaire. We investigated the factors that affect BP elevation. RESULTS: Within 4988 participants, the mean systolic BP at 2 years old was 91.2 mmHg for boys and 90.0 mmHg for girls. The mean systolic BP at 4 years old was 93.8 mmHg for boys and 93.1 mmHg for girls. Parental smoking was associated with elevated values of BP at 2 and 4 years old. Obesity, gestational hypertension, and parental lower education were associated with elevated values of BP at 4 years old. Hypertensive group had a significantly higher obesity rate. The mother's lower education and parental smoking were involved in hypertensive groups. CONCLUSION: Parental smoking had a significant effect on BP even in early toddlers. We emphasize the importance of avoiding second-hand smoking from early infancy to prevent future lifestyle-related illnesses including hypertension. IMPACT: The mean systolic BP at 2 years old was 91.2 mmHg for boys and 90.0 mmHg for girls. The mean systolic BP at 4 years old was 93.8 mmHg for boys and 93.1 mmHg for girls. Obesity, parental smoking, and lower education were associated with hypertension at 4 years old. Parental smoking was associated with hypertension at 2 and 4 years old. We emphasize the importance of avoiding second-hand smoking from early infancy.

OBJECTIVE: To examine the relationship between timing of smoking cessation during pregnancy and anthropometric indices of newborns. METHODS: Mothers and neonates enrolled in the JECS (Japan Environment and Children's Study), a nationwide birth cohort study, were examined. Patients with full-term neonates were included in the analysis, and 73,025 mother-neonate pairs with complete data were identified. The mothers were classified into six groups according to smoking status during pregnancy (nonsmokers [Q1, n=44,198]; ex-smokers who quit before pregnancy [Q2, n=16,461]; ex-smokers who quit in the first trimester [Q3, n=8,948]; ex-smokers who quit in the second trimester [Q4, n=498]; ex-smokers who quit in the third trimester [Q5, n=651]; and smokers who smoked throughout pregnancy [Q6, n=2,269)]). Data on smoking were based on questionnaires administered in the first, second, or third trimester and 1 month after delivery. The primary outcomes were birth weight, height, and head circumference. RESULTS: Compared with nonsmokers (Q1), no adverse outcomes were observed for ex-smokers who quit before pregnancy (Q2). The mean adjusted weights of male and female neonates were 135 g and 125 g lower, respectively, in Q6 participants than in Q1 participants. Comparing Q1 and Q6 participants, height was 0.6 cm and 0.7 cm smaller for male and female neonates, respectively. Head circumference in neonates of Q6 participants was 0.3 cm and 0.3 cm smaller for male and female neonates, respectively, than that in Q1 participants. Across all three measures, smoking cessation in the first and second trimester reduced the differential in outcomes between nonsmokers and individuals who smoked throughout pregnancy. CONCLUSION: Smoking during pregnancy is associated with reduced newborn birth weight, height, and head circumference. Earlier smoking cessation during pregnancy reduces the adverse effects of smoking on fetal growth.

Although IL-12 is believed to contribute to protective immune responses, the role played by IL-23 (a member of the IL-12 family) in malaria is elusive. Here, we show that IL-23 is produced during infection with Plasmodium berghei NK65. Mice deficient in IL-23 (p19KO) had higher parasitemia and died earlier than wild-type (WT) controls. Interestingly, p19KO mice had lower numbers of IL-17-producing splenic cells than their WT counterparts. Furthermore, mice deficient in IL-17 (17KO) suffered higher parasitemia than the WT controls, indicating that IL-23-mediated protection is dependent on induction of IL-17 during infection. We found that macrophages were responsible for IL-17 production in response to IL-23. We observed a striking reduction in splenic macrophages in the p19KO and 17KO mice, both of which became highly susceptible to infection. Thus, IL-17 appears to be crucial for maintenance of splenic macrophages. Adoptive transfer of macrophages into macrophage-depleted mice confirmed that macrophage-derived IL-17 is required for macrophage accumulation and parasite eradication in the recipient mice. We also found that IL-17 induces CCL2/7, which recruit macrophages. Our findings reveal a novel protective mechanism whereby IL-23, IL-17, and macrophages reduce the severity of infection with blood-stage malaria parasites.

Recent studies show that some human malaria parasite species Plasmodium falciparum and P. vivax parasitize erythroblasts; however, the biological and clinical significance of this is unclear. To investigate further, we generated a rodent malaria parasite (P. yoelii 17XNL) expressing GFP-ovalbumin (OVA). Its infectivity to erythroblasts was confirmed, and parasitized erythroblasts were capable of initiating malaria infections. Experiments showed that MHC class I molecules were highly expressed on parasitized erythroblasts. As CD8(+) T cells recognize MHC class I and peptide complexes on target cells, and are involved in protection or pathology against malaria, we examined whether erythroblasts are targeted by CD8(+) T cells. Purified non-parasitized erythroblasts pulsed with OVA peptides were recognized by OVA-specific CD8(+) T cells. Crucially, parasitized erythroblasts isolated from GFP-OVA-, but not GFP- infected-mice, activated OT-I CD8(+) T cells, indicating that CD8(+) T cells recognize parasitized erythroblasts in an antigen-specific manner.