Sex steroid hormones and allergic diseases in children: a pilot birth cohort study in the Japan Environment and Children's Study cohort

BACKGROUND

Numerous studies suggest that sex steroids might play a role in sex disparity observed in allergic diseases in adults. However, whether sex hormones influence allergic diseases in children remains unclear. The aim of the present study was to examine the association of sex steroid hormones with allergic disease in Japanese children.

METHODS

The present cross-sectional study included 145 6-year-old children participating in a pilot birth cohort study in the Japan Environment and Children's Study. Data on allergic diseases were obtained from questionnaires, and serum levels of sex steroid hormones and allergen-specific IgE were measured. Logistic regression was performed to evaluate the association of sex hormones with allergic diseases.

RESULTS

After adjusted sex, amount of body fat at 6 years, parental history of allergic disease, and exposure to tobacco smoke, serum dehydroepiandrosterone sulfate level was significantly associated with reduced odds of any allergic disease (adjusted odds ratio, 0.58; 95% confidence interval, 0.36-0.93; P = 0.024) and serum follicle-stimulating hormone level was significantly associated with increased odds of any allergic disease (adjusted odds ratio, 2.04; 95% confidence interval, 1.01-4.11, P = 0.046). Dehydroepiandrosterone sulfate level showed a significant association with number of allergic diseases.

CONCLUSIONS

The current study findings suggest that sex hormones may play an important role in the development of allergic diseases in prepubertal children.

Sleep quality and temperament in association with autism spectrum disorder among infants in Japan

BACKGROUND

Sleep problems and irritable temperaments are common among infants with autism spectrum disorder (ASD). The prospective association between such sleep problems and irritable temperaments and ASDs needs to be determined for elucidating the mechanism and exploring the future intervention study. Thus, in this study, we investigated whether sleep quality and temperament in 1-month-old infants are associated with the onset of ASD in 3-year-old children. We also assessed its sex-stratified associations.

METHODS

We conducted a longitudinal study using data from 69,751 mothers and infants from a large-cohort study, the Japan Environment and Children's Study. We examined the prospective association between infant sleep quality and temperament at 1 month of age and ASD diagnosis by 3 years of age.

RESULTS

Here we show infants with longer daytime sleep have a higher risk of later ASD than those with shorter daytime sleep (risk ratio [RR]: 1.33, 95% confidence interval [CI]: 1.01-1.75). Infants who experienced intense crying have a higher risk of ASD than those who did not (RR: 1.31, 95% CI: 1.00-1.72). There is a difference in sex in the association between a bad mood and later ASD. In particular, female infants experiencing bad moods have a higher risk of ASD than others (RR: 3.59, 95% CI: 1.91-6.75).

CONCLUSIONS

The study findings provide important information for future intervention to reduce the risk of future ASD.

Prenatal metal levels and congenital anomalies of the kidney and urinary tract: The Japan Environment and Children's Study

BACKGROUND

Prenatal exposure to metal elements has been reported as a potential risk factor for congenital malformation. However, studies on the relationship with congenital anomalies of the kidney and urinary tract (CAKUT) are very scarce.

METHODS

Participants of a prospective cohort from the Japan Environment and Children's Study, conducted at 15 research centers, were recruited between January 2011 and March 2014. The exposure factors were concentrations of lead (Pb), cadmium (Cd), mercury (Hg), selenium (Se), and manganese (Mn) measured from maternal whole blood in the second or third trimester. The primary outcome was CAKUT diagnosed during the first three years of life, which was classified into isolated cases and complicated cases accompanied by extrarenal congenital defects. To conduct a nested case-control design within the cohort, we selected 351 isolated cases with 1404 matched controls, and 79 complicated cases with 316 matched controls.

RESULTS

A logistic regression model was used to examine the associations between individual metal concentrations and each subtype of CAKUT. A higher level of Se was associated with an increased risk of isolated CAKUT (adjusted odds ratio [95 % confidence interval]: 3.22 [1.33-7.77]). Meanwhile, higher levels of Pb and Mn were associated with a reduced risk of the complicated subtype (0.46 [0.24-0.90] and 0.33 [0.15-0.73], respectively). A Bayesian kernel machine regression model accounting for mixed effects of multiple metals further demonstrated that a higher level of Mn alone was significantly associated with a reduced occurrence of the complicated subtype.

CONCLUSIONS

Using a stringent statistical approach, the present study demonstrated that a higher Mn concentration in the maternal blood was associated with a lower risk of complicated CAKUT in offspring. Further cohort and experimental studies are needed to verify the clinical impact of this finding.

Association between maternal socioeconomic status and breastfeeding: Results from the Japan environment and children's study

Although breastfeeding has various benefits for mothers and children, there are several barriers to continuing breastfeeding practices. However, little is known about the relationship between breastfeeding in Japan and maternal socioeconomic circumstances. Based on data from the Japan Environment and Children's Study (n = 75,742), we evaluated maternal socioeconomic factors associated with breastfeeding 1 year after giving birth. Socioeconomic status (education, employment status, and household income), working hours, and breastfeeding were assessed using a self-administered questionnaire. After descriptive analysis, a logistic regression analysis was conducted with adjustments for age, educational level, employment status, and household income. Mothers with higher education and full-time homemakers were more likely to breastfeed one-year-old children. Mothers working long hours (both part-time and full-time) were less likely to breastfeed their one-year-old children. To improve breastfeeding among working mothers, it may be helpful to promote awareness of breastfeeding for every mother as well as to make the workplace environment conducive for working mothers to breastfeed.

Association between maternal fish consumption during pregnancy and preterm births: the Japan Environment and Children's Study

BACKGROUND

Fish are a rich source of essential nutrients that protect against preterm birth. However, as fish can absorb environmental pollutants, their consumption can also increase the risk of preterm birth. This study aimed to assess whether maternal fish consumption during pregnancy is associated with preterm birth in a nationwide large Japanese cohort that consumed relatively high amounts and many types of fish.

METHODS

This study included 81,428 mother-child pairs enrolled in a nationwide prospective Japanese birth cohort study. Fish consumption was assessed using a validated food frequency questionnaire. Multivariate logistic regression was used to investigate the association of total consumption of fish, fatty fish and lean fish, fish paste, and seafood and clams with preterm birth, adjusted for potential confounders.

RESULTS

There was no association between overall fish consumption and preterm births. However, the highest quintile of fish paste consumption was significantly associated with an increased risk of preterm birth (odds ratio [OR]: 1.11; 95% confidence interval [CI: 1.04, 1.17]). The consumption of baked fish paste at least three times per week was significantly associated with preterm birth (OR: 1.20; 95% CI: 1.03, 1.40). Consumption of other types of fish, except fish paste, was not significantly associated with preterm birth risk.

CONCLUSIONS

Fish paste consumption may increase the risk of preterm birth. Further studies are required to confirm this association.

Maternal Chronic Disease and Congenital Anomalies of the Kidney and Urinary Tract in Offspring: A Japanese Cohort Study

RATIONALE & OBJECTIVE

Several maternal chronic diseases have been reported as risk factors for congenital anomalies of the kidney and urinary tract (CAKUT) in offspring. However, these investigations used case-control designs, and cases with isolated genitourinary CAKUT were not distinguished from cases in which CAKUT were present with extrarenal congenital anomalies (complicated CAKUT). We examined the association of maternal diseases with isolated and complicated CAKUT in offspring using data from a prospective cohort study.

STUDY DESIGN

A nationwide prospective birth cohort study.

SETTING & PARTICIPANTS

100,239 children enrolled in the Japan Environment and Children's Study between January 2011 and March 2014 at 15 research centers. Physicians' diagnoses in mothers and children were collected from medical record transcripts and questionnaires.

EXPOSURES

Medical histories of maternal noncommunicable diseases, including obesity, hypertension, diabetes mellitus, kidney disease, hyperthyroidism, hypothyroidism, psychiatric disease, epilepsy, cancer, and autoimmune disease.

OUTCOMES

CAKUT diagnosed during the first 3 years of life, classified as isolated or complicated.

ANALYTICAL APPROACH

Multivariable Poisson regression with generalized estimating equations accounting for clustering by clinical center.

RESULTS

Among the 100,239 children, 560 (0.6%) had CAKUT, comprising 454 (81%) isolated and 106 (19%) complicated forms. The risk of isolated CAKUT was increased in children of mothers who experienced kidney disease (adjusted risk ratio [RR], 1.80 [95% CI, 1.12-2.91]) or cancer (RR, 2.11 [95% CI, 1.15-3.86]). Furthermore, the risk of complicated CAKUT was increased in children of mothers with diabetes mellitus (RR, 3.04 [95% CI, 1.64-5.61]).

LIMITATIONS

Lack of standardization or prespecification of clinical definitions, diagnostic criteria, measurements, and testing. Genetic testing was not performed.

CONCLUSIONS

Isolated CAKUTs and complicated CAKUTs were associated with different maternal diseases. The results may inform clinical management of pregnancy and highlight potential differences in the genesis of isolated and complicated forms of CAKUT.

The association between early formula and reduced risk of cow’s milk allergy during the first three year of life: a Japanese cohort study

Background

Our recent observational study showed that regular consumption of cow’s milk (CM) formula during early infancy (3–6 months old) was associated with a reduced risk of CM allergy (CMA) at 12 months old. However, the long-term association is unclear. The present study was aimed to examine how long this inverse association persists after 12 months old.

Methods

This study used the dataset of an ongoing nationwide prospective cohort, the Japan Environment and Children’s Study, in which participants were registered between January 2011 and March 2014. We analyzed 65,568 children followed-up until 36 months old. The exposure factors were the consumption statuses of formula milk from 0–3, 3–6, and 6–12 months old. The primary outcome was the prevalence of CMA at 6, 12, 18, 24 and 36 months old. CMA was defined as an allergic reaction and sensitization to CM protein in an individual with no or limited intake of this protein at the evaluation time, combined with physician-diagnosed food allergy. Multivariable regression models were used to estimate the association between the periods of formula consumption and the prevalence of CMA.

Results

The prevalence of CMA increased with a peak of 1.51% at 18 months old and then declined to 0.79% at 36 months old. Formula milk from 3–6 months old was associated with a reduced risk of CMA throughout the first 3 years of life, although the extent of the reduction was mitigated with age (adjusted relative risk: [95% confidence interval]: 0.19 [0.10–0.34] at 12 months old, 0.23 [0.16–0.33] at 18 months old, 0.41 [0.26–0.64] at 24 months old, and 0.47 [0.26–0.80] at 36 months old). The association between early formula and CMA were observed in both children with and without eczema, but more prominent and long-lasting in the former than the latter.

Conclusions

Regular exposure to CM protein during infancy was associated with a reduced prevalence of CMA during early childhood. At present, however, this observational study does not necessarily encourage formula feeding, and randomized controlled trials are warranted to confirm the findings and their significance.

Association of physical activity and sleep habits during pregnancy with autistic spectrum disorder in 3-year-old infants

Background:

We hypothesized that maternal lifestyle factors, such as physical activity and sleep habits, may be associated with autism spectrum disorder (ASD) in infants. This study aimed to investigate the association between maternal physical activity and sleep before and during pregnancy with infant ASD diagnosed by the age of 3 years.

Methods:

We used the data from the Japan Environment and Children’s Study between 2011 and 2014. The study included 103,060 pregnant women, among which, 69,969 women were analyzed. Participants were asked about their physical activity and sleep before and during pregnancy using questionnaires during pregnancy. Maternal physical activity was estimated using the international physical activity questionnaire. Based on the levels of physical activity before or during pregnancy, the participants were divided into five groups. Maternal sleep was analyzed based on sleep duration and bedtime. The outcome was diagnosis of ASD in 3-year-old infants.

Results:

In mothers with higher physical activity levels during pregnancy, the risk ratios (RR) for ASD in their 3-year-old infants were lower (RR = 0.61, 95% confidence interval (CI) = 0.42–0.90). In contrast, too short (<6 h) and too long (>10 h) sleep durations during pregnancy were associated with higher risk ratios for ASD than 7–8 h sleep duration (too short: RR = 1.87, 95% CI = 1.21–2.90; too long: RR = 1.56, 95% CI = 1.00–2.48). These associations were not observed before pregnancy.

Conclusion:

Maternal physical activity and sleep duration during pregnancy may be associated with ASD in infants.

Children with autism spectrum disorder (ASD) have difficulties with communication and can have problematic behavior. It is unclear whether lifestyle habits before and during pregnancy influence the chances of having a child with ASD. We investigated whether maternal physical activity and particular sleep habits before and during pregnancy increased the likelihood of 3-year-old infants having ASD. Mothers completed questionnaires asking about their physical activity, sleep habits, and any diagnosis of ASD in their child. The children of mothers with high levels of physical activity during pregnancy were less likely to have ASD. The children of mothers who had slept for less than 6 h or longer than 10 h a night were more likely to have ASD. Thus, improving sleep and increasing exercise during pregnancy might reduce the risk of ASD in their children.

Nakahara, Michikawa et al determined the physical activity and sleep habits of women before and during pregnancy and compared these with diagnoses of autism spectrum disorder in their offspring. Abnormal sleep and reduced physical activity during pregnancy were associated with a diagnosis of autism spectrum disorder.

Lack of catch-up in weight gain may intermediate between pregnancies with hyperemesis gravidarum and reduced fetal growth: the Japan Environment and Children’s Study

Background

Women with nausea and vomiting of pregnancy (NVP) have higher birth weight infants, while those with hyperemesis gravidarum, a severe manifestation of NVP, have lower birth weight infants. We aimed to investigate the associations between maternal weight loss (a consequence of hyperemesis gravidarum), NVP, and infant birth weight.

Methods

This study was a secondary analysis of a nationwide birth cohort in Japan. Singleton pregnancies delivered at 28–41 weeks of gestation were included in the analysis. Women were categorized based on their weight change in the 1^st trimester (as a proportion to their pre-pregnancy weight: >  + 3%, > 0 to + 3%, > -3 to 0%, > -5 to -3%, ≤ -5%) and severity of NVP (no nausea, only nausea, vomiting but able to eat, vomiting and unable to eat). The effects of weight change and severity of NVP on infant birth weight and small for gestational age (SGA) were assessed using regression models. We further examined how these effects could be modified by maternal weight gain up to the 2^nd trimester.

Results

Among 91,313 women, 5,196 (5.7%) lost ≥ 5% of their pre-pregnancy weight and 9,983 (10.9%) experienced vomiting and were unable to eat in the 1^st trimester. Women with weight loss ≥ 5% in the 1^st trimester had infants 66 (95% CI: 53, 78) g lighter and higher odds of SGA (aOR: 1.29; 95% CI: 1.14, 1.47) than women who gained > 3% during the same period. However, when adjusting for weight gain up to the 2^nd trimester, women with weight loss ≥ 5% in the 1^st trimester had infants 150 (95% CI: 135, 165) g heavier and lower odds of SGA (aOR: 0.39; 95% CI: 0.33, 0.46) than those who gained > 3% during the same period. In contrast, women with more severe NVP tended to have infants with larger birth weight and lower odds of SGA compared to women without NVP. These trends were strengthened when adjusting for weight gain up to the 2^nd trimester.

Conclusions

Our study suggests the possibility that reduced fetal growth in pregnancies with hyperemesis gravidarum may be caused by the lack of catch-up in gestational weight gain up to the 2^nd trimester.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12884-022-04542-0.

Association of maternal hemoglobin levels during pregnancy with sleep and developmental problems in 1‐year‐old infants: A cohort study

Background and Aims

Maternal hemoglobin concentration during pregnancy is reported to be associated with various perinatal outcomes and may also be associated with infant development. This study aims to investigate the association between maternal hemoglobin levels during early or mid‐pregnancy and sleep and developmental problems in 1‐year‐old infants.

Methods

We used the data of 66,935 pregnant women who were participants of the Japan Environment and Children's Study, a nationwide cohort study in Japan, between 2011 and 2014. Maternal hemoglobin level was examined at recruitment (mean gestational age, 15.3 weeks; SD, 2.85 weeks; range, 6–22 weeks). Information on infant sleep and development at the age of 1 year was acquired using a questionnaire. Infant development was evaluated using the Ages and Stages Questionnaire (ASQ).

Results

The mean (SD) maternal hemoglobin level was 12.0 (1.0) g/dl. Maternal hemoglobin levels were not associated with the majority of infant sleep and developmental outcomes. In the group with maternal hemoglobin <10.0 g/dl, the risk ratio (RR) for sleep at 22:00 or later was higher than that in the reference group with 11.0 g/dl ≤ hemoglobin < 14.0 g/dl (RR 1.12, 95% confidence interval = 1.00–1.25). In the analysis with maternal hemoglobin level as a continuous variable, both high and low hemoglobin levels were associated with a higher RR of a late bedtime. In addition, a low maternal hemoglobin level was associated with a higher RR for abnormal fine motor skills in the ASQ.

Conclusion

Our results suggest that a low level of maternal hemoglobin during pregnancy is associated with late bedtime and abnormal fine motor skills in 1‐year‐old infants. Conversely, a high level of maternal hemoglobin may also be associated with the infant's late bedtime.

Fluctuations of aeroallergen-specific immunoglobulins and children's allergic profiles: Japan Environment & Children's Study of a pilot cohort

BACKGROUND

Allergen-specific immunoglobulins have a crucial role in allergic diseases. Most wheeze episodes develop before school age, and allergic rhinitis later develops during early elementary school years. However, the clinical background and cytokine/chemokine profiles associated with changes in immunoglobulins during early school-age are poorly understood.

METHODS

This study used blood samples from children participating in the JECS Pilot Study. We examined nineteen kinds of aeroallergen-specific immunoglobulins (IgE, IgG1, IgG4, and IgA) levels in patients at age 6 and age 8. Fluctuations of Der f 1- and Cry j 1-specific immunoglobulins levels during the two periods were compared to assess the frequency of allergic statuses and clusters of cytokine/chemokine profiles.

RESULTS

The medians of aeroallergen-specific IgE levels did not fluctuate, and almost all IgG1 and IgG4 decreased. In IgA, four (e.g., Der f 1) increased, whereas the other four (e.g., Cry j 1) decreased. The ratio of the Der f 1-specific IgG1 level at age 8 to that at age 6 was higher in children with poor asthma control than in children with better asthma control. Moreover, the cytokine/chemokine cluster with relatively lower IL-33 and higher CXCL7/NAP2 was associated with lower Der f 1- and Cry j 1-specific IgG4 levels, but not IgE levels.

CONCLUSIONS

The cluster of cytokine/chemokine profiles characterized by lower IL-33 and higher CXCL7/NAP2 was associated with the maintenance of aeroallergen-specific IgG4 levels. This result provides a basis for considering the control of aeroallergen-specific immunoglobulins.

Female-dominant estrogen production in healthy children before adrenarche

OBJECTIVE

Ultra-sensitive hormone assays have detected slight sex differences in blood estradiol (E2) levels in young children before adrenarche. However, the origin of circulating E2 in these individuals remains unknown. This study aimed to clarify how E2 is produced in young girls before adrenarche.

DESIGN

This is a satellite project of the Japan Environment and Children's Study organized by the National Institute for Environmental Studies.

METHODS

We collected blood samples from healthy 6-year-old Japanese children (79 boys and 71 girls). Hormone measurements and data analysis were performed in the National Institute for Environmental Studies and the Medical Support Center of the Japan Environment and Children's Study, respectively.

RESULTS

E2 and follicle stimulating hormone (FSH) levels were significantly higher in girls than in boys, while dehydroepiandrosterone sulfate (DHEA-S) and testosterone levels were comparable between the two groups. Girls showed significantly higher E2/testosterone ratios than boys. In children of both sexes, a correlation was observed between E2 and testosterone levels and between testosterone and DHEA-S levels. Moreover, E2 levels were correlated with FSH levels only in girls.

CONCLUSIONS

The results indicate that in 6-year-old girls, circulating E2 is produced primarily in the ovary from adrenal steroids through FSH-induced aromatase upregulation. This study provides evidence that female-dominant E2 production starts several months or years before adrenarche. The biological significance of E2 biosynthesis in these young children needs to be clarified in future studies.

Measles antibody seropositivity among children with allergic diseases: A cross-sectional study in the Japan Environment & Children's Pilot Study

Background

The relationship between allergic individuals and their responsiveness to routine vaccines has rarely been investigated. This study examined whether the seroprevalence of measles antibody differed between children with and without allergic diseases in the general pediatric population.

Methods

The cross-sectional study was performed within a prospective general birth cohort (a pilot study of the Japan Environment & Children’s Pilot Study [JECS]) of children aged 8 years. The clinical history of allergic diseases, measles, and the concentration of measles immunoglobulin G titers in serum enzyme immunoassay were examined. Fisher’s exact tests were used to assess the relationships between the allergic characteristics of the children and their measles antibody positivity rates.

Results

This study included 162 children. Any allergic disease was reported in 75 (46.3%). The measles antibody positivity rate was 94.7% among children with any allergic diseases and 92.0% among children without allergic diseases. Our results revealed no differences in measles antibody seropositivity between children with allergies and controls.

Conclusions

Children with allergies mount and maintain a comparable immune response to the measles vaccine.

Gestational weight gain growth charts adapted to Japanese pregnancies using a Bayesian approach in a longitudinal study: The Japan Environment and Children's Study

Background Tracking gestational weight gain (GWG) during pregnancy makes it possible to optimize pregnancy outcomes and GWG growth curves are well suitable for this purpose. The GWG guidelines for Japanese were revised in 2021. However, currently, there are no GWG growth curves to guide women on how to gain weight to meet these guidelines.Methods Using data on 96,631 live births from the Japan Environment and Children's Study (JECS), we created descriptive GWG percentile curves estimated the trajectory of GWG required to meet the GWG guidelines stratified by pre-pregnancy body mass index (BMI) For both analyses, Bayesian mixed models with restricted cubic splines adjusted for maternal characteristics were used.Results GWG curves substantially differed by pre-pregnancy BMI, and were higher among multiparas and those with lower maternal age and with no previous disease. We estimated that underweight, normal weight, overweight and obese women who gain 8.4 to 11.1 kg, 6.4 to 9.1 kg, 3.8 to 6.5 kg, and <1.9 kg at 30 weeks of gestation are on the trajectory to reach the new guidelines at 40 weeks of gestation.Conclusions We provide GWG percentiles curves for Japanese women as well as GWG trajectory curves to meet the new GWG recommendations. These results may help pregnant women monitor weight during their pregnancy.

Physical growth and neurodevelopment during the first year of life: a cohort study of the Japan Environment and Children's Study

BACKGROUND

The association between a slower physical growth and poorer neurodevelopment has been established in infants born preterm or small for gestational age. However, this association is inconsistent in term-born infants, and detailed investigations in infancy, when intervention is most beneficial for improving outcomes, are lacking. We therefore examined this association separately by sex during the first year of life in term-born infants.

METHODS

Using data collected until children reached 12 months old in an ongoing prospective cohort of the Japan Environment and Children's Study, we analyzed 44,264 boys and 42,541 girls with singleton term-birth. The exposure variables were conditional variables that disentangle linear growth from weight gain relative to linear growth, calculated from the length and weight at birth and 4, 7 and 10 months old. Neurodevelopmental delay was identified using the Japanese-translated version of Ages & Stages Questionnaires, third edition.

RESULTS

A reduced risk of neurodevelopmental delay at 6 months old was observed in children with a higher birth weight (adjusted relative risks [aRRs]: 0.91 and 0.93, 95 % confidence intervals [95 % CIs]: 0.87-0.96 and 0.88-0.98 in boys and girls, respectively) and increased linear growth between 0 and 4 months old (aRRs: 0.85 and 0.87, 95 % CIs: 0.82-0.88 and 0.83-0.91 in boys and girls, respectively). A reduced risk at 12 months was found in children with an increased linear growth between 0 and 4 months (aRRs: 0.92 and 0.90, 95 % CIs: 0.87-0.98 and 0.84-0.96 in boys and girls, respectively), boys with an increased relative weight gain between 0 and 4 months (aRR: 0.90, 95 % CI: 0.84-0.97), and girls with a higher birth weight (aRR: 0.89, 95 % CI: 0.83-0.96).

CONCLUSIONS

These results suggest that a slow physical growth by four months old may be a predictor of neurodevelopmental delay during infancy.

Breast feeding and infant development in a cohort with sibling pair analysis: the Japan Environment and Children's Study

OBJECTIVES

To investigate the association between breast feeding and infant development during the first year of life using sibling comparison.

DESIGN

Nationwide prospective birth cohort study with sibling pair analysis.

SETTING

15 regional centres that participated in the Japan Environment and Children's Study.

PARTICIPANTS

This study included 77 119 children (singleton, term birth and no malformation/severe diseases) whose mothers were registered between January 2011 and March 2014, including 3521 duos or trios of siblings.

PRIMARY OUTCOME MEASURES

The primary outcome was developmental delay at 6 and 12 months of age, assessed using the Japanese translation of the Ages and Stages Questionnaires, third edition. Multivariable regression analyses adjusted for confounders were performed to estimate the risk ratios of delay associated with any or exclusive breast feeding. Pairs of siblings discordant for statuses were selected, and conditional regression analyses were conducted with a matched cohort design.

RESULTS

Developmental delay was identified in 6162 (8.4%) and 10 442 (14.6%) children at 6 and 12 months of age, respectively. Any breast feeding continued until 6 months or 12 months old was associated with reduced developmental delay at 12 months of age (adjusted risk ratio (95% CI): 0.81 (0.77 to 0.85) and 0.81 (0.78 to 0.84), respectively). Furthermore, exclusive breast feeding until 3 months was associated with reduced developmental delay at 12 months of age (adjusted risk ratio, 0.86 (95% CI 0.83 to 0.90)). In sibling pair analysis, the association between any breast feeding until 12 months and reduced developmental delay at 12 months of age persisted (adjusted risk ratio, 0.64 (95% CI 0.43 to 0.93)).

CONCLUSIONS

The present study demonstrated the association of continuous breast feeding with reduced developmental delay at 1 year of age using sibling pair analysis, in which unmeasured confounding factors are still present but less included. This may provide an argument to promote breastfeeding continuation.

Maternal blood count parameters of chronic inflammation by gestational age and their associations with risk of preterm delivery in the Japan Environment and Children's Study

Neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and lymphocyte-to-monocyte ratio (LMR), are three reportedly predictive biomarkers that reflect subclinical chronic inflammatory burden. However, how these biomarkers change during pregnancy and its clinical utility among pregnant women have been rarely studied. Among 76,853 singleton pregnancies delivered at 28–41 weeks of gestation that were enrolled in the Japan Environment and Children’s Study, we observed the distribution of maternal NLR, PLR, and LMR values from week 0 to week 36 using spline curves, as well as their predictive values for preterm delivery with and without hypertensive disorders in pregnancy, placental abruption and intrauterine growth restriction (collectively termed ischemic placental disease due to their shared pathological and pathophysiological features) for measurements at 8–11 weeks, 12–17 weeks, and 18–21 weeks. NLR and PLR increased, whereas LMR decreased, with increasing gestation. High LMR and low NLR observed at 18–21 weeks, but not at earlier gestations, were associated with higher risk of preterm delivery with IPD (odds ratio 1.80 [95% CI 1.02, 3.19] per log[LMR]; odds ratio 0.49 [95% CI 0.29, 0.82] per log[NLR]). All parameters were not predictive of preterm delivery without IPD. We provide a robust reference curve for maternal blood count parameters NLR, PLR, and LMR by gestational week.

Association of maternal sleep before and during pregnancy with sleep and developmental problems in 1-year-old infants

This study investigated the association of maternal sleep before and during pregnancy with sleeping and developmental problems in 1-year-old infants. We used data from the Japan Environment and Children's Study, which registered 103,062 pregnancies between 2011 and 2014. Participants were asked about their sleep habits prior to and during pregnancy. Follow-up assessments were conducted to evaluate the sleep habits and developmental progress of their children at the age of 1 year. Development during infancy was evaluated using the Ages and Stages Questionnaire (ASQ). Maternal short sleep and late bedtime before and during pregnancy increased occurrence of offspring's sleeping disturbances. For example, infants whose mothers slept for less than 6 h prior to pregnancy tended to be awake for more than 1 h (risk ratio [RR] = 1.49, 95% confidence interval [CI] 1.34-1.66), sleep less than 8 h during the night (RR = 1.60, 95% CI 1.44-1.79), and fall asleep at 22:00 or later (RR = 1.33, 95% CI 1.26-1.40). Only subjective assessments of maternal sleep quality during pregnancy, such as very deep sleep and feeling very good when waking up, were inversely associated with abnormal ASQ scores in 1-year-old infants.

Influence of physical activity before and during pregnancy on infant's sleep and neurodevelopment at 1-year-old

The aim of this study was to investigate the association between maternal physical activity (PA) before and during pregnancy and sleep and developmental problems in 1-year-old infants. We used data from a nationwide cohort study in Japan that registered 103,062 pregnancies between 2011 and 2014. Participants were asked about their PA before and during pregnancy, and the sleep and development of their children at the age of 1 year. Maternal PA was estimated using the International Physical Activity Questionnaire and was expressed in METs per week. We defined scores below the cut-off points of the Ages and Stages Questionnaire (ASQ) as abnormal for infant development. Based on the levels of PA before or during pregnancy, the participants were divided into five groups. In mothers with higher PA levels, the risk ratio for bedtime after 22:00 or abnormal ASQ scores in their 1-years-old infants were lower. These associations were observed for PA before and during pregnancy. Higher levels of maternal PA, both before and during pregnancy, may reduce sleep and developmental problems in infants.

Comparison of Simultaneous Quantitative Analysis of Methylmercury and Inorganic Mercury in Cord Blood Using LC-ICP-MS and LC-CVAFS: The Pilot Study of the Japan Environment and Children's Study

Prenatal exposure to methylmercury (MeHg) affects child development after birth. However, many epidemiological studies have evaluated total mercury levels without analyzing speciation. Biomonitoring of MeHg and inorganic mercury (IHg) is essential to reveal each exposure level. In this study, we compared a high-throughput analysis for mercury speciation in blood using liquid chromatography-inductively coupled plasma-mass spectrometry (LC-ICP-MS) and liquid chromatography-cold vapor atomic fluorescence spectrometry (LC-CVAFS). The validated LC-ICP-MS method was applied to 101 maternal blood and 366 cord blood samples in the pilot study of the Japan Environment and Children’s Study (JECS). The accuracy of the LC-CVAFS method ranged 90–115% determined by reference material analysis. To evaluate the reliability of 366 cord blood samples, fifty cord blood samples were randomly selected and analyzed using LC-CVAFS. The median (5th–95th percentile) concentrations of MeHg and IHg were 5.4 (1.9–15) and 0.33 (0.12–0.86) ng/mL, respectively, in maternal blood, and 6.3 (2.5–15) and 0.21 (0.08–0.49) ng/mL, respectively, in cord blood. Inter-laboratory comparison showed a relatively good agreement between LC-ICP-MS and LC-CVAFS. The median cord blood:maternal blood ratios of MeHg and IHg were 1.3 and 0.5, respectively. By analyzing speciation, we could focus on the health effects of each chemical form.

Measurement of the Estradiol Concentration in Cerebrospinal Fluid from Infants and Its Correlation with Serum Estradiol and Exosomal MicroRNA-126-5p

Estradiol has an important role in the brain, such as in neuronal development and protection, but estradiol levels in the human brain have not been well investigated. In this study, we measured the estradiol concentration in the cerebrospinal fluid (CSF) of infants to reveal the relationships between the estradiol concentrations in the serum and the CSF and further determined exosomal microRNAs in serum. Estradiol in the CSF was strongly correlated with serum estradiol and moderately correlated with miR-126-5p in the serum exosomes. This report is the first to determine the estradiol concentration in CSF from infants and showed that the levels of miR-126-5p as well as serum estradiol can be candidates to predict brain estrogen status.

Possible association between early formula and reduced risk of cow's milk allergy: The Japan Environment and Children's Study

Background

Despite evidence for the protective effects of early regular exposure to peanut and egg proteins against allergies, the optimal timing of cow's milk (CM) protein exposure is unknown.

Objective

We aimed to determine when during the first year of life CM‐based formula consumption becomes associated with lower CM allergy (CMA) risk.

Methods

We used the data set of the Japan Environment and Children's Study (JECS), a nationwide birth cohort involving over 100 000 mother‐child pairs. CMA was defined as an allergic reaction to a CM product in an individual not consuming CM products at the time of evaluation, combined with physician‐diagnosed food allergy. For each exposure, we identified when formula milk was commenced, and its consumption status during 0‐3, 3‐6 and 6‐12 months old.

Results

The prevalence of CMA was 0.23% and 1.03% at 6 and 12 months old, respectively. Multivariable regression analyses revealed that introducing regular consumption of formula within the first 3 months of age was associated with lower risk of CMA at 12 months. Regular consumption at 3‐6 months was strongly associated with a reduction in 12‐month CMA (adjusted relative risks [95% confidence intervals]: 0.22 [0.12‐0.35]), whereas no association was observed at 0‐3 months (1.07 [0.90‐1.27]).

Conclusion and Clinical Relevance

Regular exposure to formula milk at age 3 months or older is associated with lower CMA at 12 months old, suggesting that the effect of very early CM exposure on CMA may disappear if the exposure is brief. At present, however, the results of this observational study should not be used for formula recommendation and randomized controlled trials are required to confirm this association.

Non-reassuring foetal status and sleep problems in 1-year-old infants in the Japan Environment and Children's Study: a cohort study

Abnormal autonomic function may cause false-positive non-reassuring foetal status (fpNRFS) and may also cause sleeping problems after birth. However, an association between fpNRFS and sleeping problems in infants has not been reported. We previously showed an association of NRFS with temperament, including bad mood and frequent crying for long durations in 1-month-old infants. In the present study, we aimed to assess this association in 1-year-old infants. A total of 62,612 single pregnant women were included in the analysis. fpNRFS was identified from medical records. Sleep problems, such as short sleep duration or crying at night, were investigated in 1-year-old infants using a questionnaire for mothers. We used a log-binominal regression model to explore the association of fpNRFS with each sleep problem and to estimate risk ratios (RRs). The number of fpNRFS cases was 2,071, with a frequency of 3.3%. We observed an association of fpNRFS with shorter sleep duration of less than 8 h a night (RR 1.30, 95% confidence intervals [CI] 1.10-1.54), crying at night (RR 1.19, 95% CI 1.03-1.39), and bedtime after 22:00 (RR 1.09, 95% CI 1.00-1.18). fpNRFS may be associated with sleep problems in 1-year-old infants.

Associations of dog and cat ownership with wheezing and asthma in children: Pilot study of the Japan Environment and children's study

Objectives

No previous study has used repeated measures data to examine the associations of dog/cat ownership with wheezing and asthma prevalence among children. This prospective study used repeated measurers analysis to determine whether dog/cat ownership in childhood is an independent risk factor for wheezing and asthma, after adjustment for gestational, socio-economical, and demographical confounders confounders, in Japan.

Methods

We conducted a multicenter pilot study of the Japan Environment and Children's Study (JECS) during 2009–2010. Among 440 newborn infants enrolled, 410 (52.8% males) were evaluated for dog/cat ownership in the home and history of wheezing and asthma in five follow-up questionnaire surveys (until age 6 years). Dog/cat ownership during follow-up period was categorized into four groups: 7.6% were long-term dog/cat owners, 5.9% were toddler-age owners, 5.9% were preschool-age owners, and 80.7% were never owners.

Results

The prevalence of wheezing during follow-up period increased from 20.8% to 35.4% and the prevalence of asthma increased from 1.3% to 16.3%. A fitted logistic generalized estimating equation models including important confounders showed no significant associations of the interaction between dog and/or cat ownership and follow-up time with the risks of wheezing and asthma. However, the risks of wheezing and asthma were slightly lower for long-term and toddler-age dog/cat owners than for preschool-age and never owners.

Conclusions

The present findings suggest that dog and cat ownership from toddler-age does not increase the risks of wheezing and asthma compared with never owners among Japanese children.

Exploratory analysis of plasma cytokine/chemokine levels in 6-year-old children from a birth cohort study

This study aimed to reveal a new dimension of allergy profiles in the general population by using machine learning to explore complex relationships among various cytokines/chemokines and allergic diseases (asthma and atopic dermatitis; AD). We examined the symptoms related to asthma and AD and the plasma levels of 72 cytokines/chemokines obtained from a general population of 161 children at 6 years of age who participated in a pilot birth cohort study of the Japan Environment and Children's Study (JECS). The children whose signs and symptoms fulfilled the criteria of AD, which are mostly based on questionnaire including past symptoms, tended to have higher levels of the two chemokine ligands, CCL17 and CCL27, which are used for diagnosis of AD. On the other hand, another AD-related chemokine CCL22 level in plasma was higher only in children with visible flexural eczema, which is one of AD diagnostic criteria but was judged on the same day of blood examination unlike other criteria. Here, we also developed an innovative method of machine learning for elucidating the complex cytokine/chemokine milieu related to symptoms of allergic diseases by using clustering analysis based on the random forest dissimilarity measure that relies on artificial intelligence (AI) technique. To our surprise, the majority of children showing at least any asthma-related symptoms during the last month were divided by AI into the two clusters, either cluster-2 having elevated levels of IL-33 (related to eosinophil activation) or cluster-3 having elevated levels of CXCL7/NAP2 (related to neutrophil activation), among the total three clusters. Future studies will clarify better approach for allergic diseases by endotype classification.

A Single Amino Acid Substitution in the Intervening Region of 129K Protein of Cucumber Green Mottle Mosaic Virus Resulted in Attenuated Symptoms

Cucumber green mottle mosaic virus (CGMMV), a member of the genus Tobamovirus, is a major threat to economically important cucurbit crops worldwide. An attenuated strain (SH33b) derived from a severe strain (SH) of CGMMV caused a reduction in the viral RNA accumulation and the attenuation of symptoms, and it has been successfully used to protect muskmelon plants against severe strains in Japan. In this study, we compared GFP-induced silencing suppression by the 129K protein and the methyltransferase domain plus intervening region (MTIR) of the 129K protein between the SH and SH33b strains, respectively. As a result, silencing suppression activity (SSA) in the GFP-silenced plants was inhibited efficiently by the MTIR and 129K protein of SH strain, and it coincided with drastically reduced accumulation of GFP-specific small interfering RNAs (siRNAs) but not by that of SH33b strain. Furthermore, analyses of siRNA binding capability (SBC) by the MTIR of 129K protein and 129K protein using electrophoretic mobility shift assay revealed that SBC was found with the MTIR and 129K protein of SH but not with that of SH33b, suggesting that a single amino acid mutation (E to G) in the MTIR is responsible for impaired SSA and SBC of SH33b. These data suggest that a single amino acid substitution in the intervening region of 129K protein of CGMMV resulted in attenuated symptoms by affecting RNA silencing suppression.

Comprehensive analysis of coding variants highlights genetic complexity in developmental and epileptic encephalopathy

Although there are many known Mendelian genes linked to epileptic or developmental and epileptic encephalopathy (EE/DEE), its genetic architecture is not fully explained. Here, we address this incompleteness by analyzing exomes of 743 EE/DEE cases and 2366 controls. We observe that damaging ultra-rare variants (dURVs) unique to an individual are significantly overrepresented in EE/DEE, both in known EE/DEE genes and the other non-EE/DEE genes. Importantly, enrichment of dURVs in non-EE/DEE genes is significant, even in the subset of cases with diagnostic dURVs (P = 0.000215), suggesting oligogenic contribution of non-EE/DEE gene dURVs. Gene-based analysis identifies exome-wide significant (P = 2.04 × 10⁻⁶) enrichment of damaging de novo mutations in NF1, a gene primarily linked to neurofibromatosis, in infantile spasm. Together with accumulating evidence for roles of oligogenic or modifier variants in severe neurodevelopmental disorders, our results highlight genetic complexity in EE/DEE, and indicate that EE/DEE is not an aggregate of simple Mendelian disorders.

Many causative genes are known for epileptic or developmental and epileptic encephalopathies (EE/DEE) yet a genetic diagnosis cannot be made for many patients. Here, the authors analyse whole exome sequencing data from a Japanese case−control cohort to identify common, rare and ultra-rare coding variants associated with EE/DEE.

Recurrent autonomic and sensory neuropathy in a patient with anti-ganglionic acetylcholine receptor antibodies

We report a case of recurrent neuropathy with predominant autonomic and sensory involvement whose serum was positive for anti-ganglionic acetylcholine receptor (anti-gAChR) antibodies, a diagnostic marker of autoimmune autonomic ganglionopathy. An 11-year-old girl complained of numbness and limb pain after gastroenteritis. Although hyperalgesia and autonomic dysfunctions, such as orthostatic intolerance and gastrointestinal dysmotility subsequently developed, these symptoms faded after a few days. Similar sensory and autonomic impairments recurred three times within 12 months after the first episode. The sensory and autonomic symptoms were rapidly ameliorated by the administration of intravenous immunoglobulin (IVIg) at the second and third relapse; however, the symptoms persisted even after the administration of IVIg at the fourth relapse. The residual symptoms disappeared after methylprednisolone pulse therapy. The patient's serum was found to be positive for anti-gAChR antibodies at the second relapse, and was negative after methylprednisolone pulse therapy. Further studies are needed to clarify the efficacy of treatment and the nosological position in the spectrum of neuropathies that are associated with autonomic and sensory impairments.

Inability of infants to push up in the prone position and subsequent development

BACKGROUND

During routine health screening, some infants cannot maintain the prone position with extended arm support at 6 months. Little is known, however, about the development of full-term infants with this developmental deviation. We investigated the developmental course of infants with this characteristic.

METHODS

We enrolled 2,020 full-term infants who had been recruited at a regional center for the Japan Environment and Children's Study. Their development was measured using the Ages and Stages Questionnaire, third edition, at 0.5, 1, 1.5, 2, 2.5, and 3 years. The children were grouped according to their ability to stay prone on extended arms at 6 months, and their development was compared.

RESULTS

A total of 1,625 infants could stay prone on extended arms and 179 could not. We excluded 212 infants who could stay prone on extended arms only sometimes, and four who did not have a questionnaire response. In the gross motor domain, significant difference in questionnaire scores was observed between the "could" and "could-not" groups at 6 months (Hedges' g, 1.83) and persisted until 3 years (Hedges' g, 0.33). Significant differences were also observed in the communication, fine motor, problem solving, and personal-social domains at 6 months (Hedges' g, 0.20-0.58) and persisted until 1, 2, 2, and 1.5 years, respectively (Hedges' g, 0.21-0.25).

CONCLUSIONS

Infants who cannot maintain the prone position on extended arms lag behind those who can, although the effect sizes become relatively small after 1.5 years of age. Early intervention may be considered if delay is problematic or persistent.

A recurrent homozygous NHLRC1 variant in siblings with Lafora disease

We report a case of two siblings with progressive myoclonus epilepsy whose parents were not consanguineous. Their clinical symptoms were typical of Lafora disease (LD), but skin biopsies revealed no Lafora bodies. Whole-exome sequencing identified a recurrent homozygous frameshift variant in the NHLRC1 gene in both siblings. The genetic analysis was useful for the diagnosis of LD, as neither consanguinity nor Lafora bodies were found.

[Tuberous sclerosis with infantile spasm and subependymal giant cell astrocytoma]

Tuberous sclerosis complex (TSC) is a genetic disease affecting many organ systems and showing different symptoms in each age group. We encountered a TSC patient with intractable epilepsy who had brain tumors suspected to be subependymal giant cell astrocytoma (SEGA). We used adrenocorticotropic hormone and ordinal antiepileptic drugs at first, but they showed limited effectiveness. After we tried several treatments for epilepsy, we started to use everolimus to prevent tumor growth. As a result, the development of the tumor stopped and the epileptic attack improved simultaneously. The frequency and duration of each epileptic spasm and seizure became milder, and the electroencephalogram findings also improved. The mental development had regressed when the epilepsy started, but it started to progress again after the epileptic attack disappeared. Everolimus may be used for treatment of intractable epilepsy with TSC in patients with a growing SEGA.

Genotype-phenotype correlations in alternating hemiplegia of childhood

OBJECTIVE

Clinical severity of alternating hemiplegia of childhood (AHC) is extremely variable. To investigate genotype-phenotype correlations in AHC, we analyzed the clinical information and ATP1A3 mutations in patients with AHC.

METHODS

Thirty-five Japanese patients who were clinically diagnosed with AHC participated in this study. ATP1A3 mutations were analyzed using Sanger sequencing. Detailed clinical information was collected from family members of patients with AHC and clinicians responsible for their care.

RESULTS

Gene analysis revealed 33 patients with de novo heterozygous missense mutations of ATP1A3: Glu815Lys in 12 cases (36%), Asp801Asn in 10 cases (30%), and other missense mutations in 11 cases. Clinical information was compared among the Glu815Lys, Asp801Asn, and other mutation groups. Statistical analysis revealed significant differences in the history of neonatal onset, gross motor level, status epilepticus, and respiratory paralysis in the Glu815Lys group compared with the other groups. In addition, 8 patients who did not receive flunarizine had severe motor deteriorations.

CONCLUSIONS

The Glu815Lys genotype appears to be associated with the most severe AHC phenotype. Although AHC is not generally seen as a progressive disorder, it should be considered a disorder that deteriorates abruptly or in a stepwise fashion, particularly in patients with the Glu815Lys mutation.

[ACTH therapy for two cases of epileptic spasms without hypsarrhythmia]

We present two patients with epileptic spasms without hypsarrhythmia (ESWoH) who were successfully treated with ACTH. One patient was an 18-month-old boy who had normal development for the first 16 months of his life. Thereafter, he experienced sudden flexion of the axial muscles, resulting in head nodings, or epileptic spasms (ES). EEG tracings showed generalized polyspikes that appeared frequently during sleep without associated hypsarrhythmia. We were thus able to diagnose him with ESWoH and treated him with ACTH, which resolved his seizures. Another patient was a 7-year-old boy. At 18 months of age, the patient began to sufferdil from sudden ES. Anti-epileptic drugs were administered individually and in combination but were proved ineffective. Like the first case, this child's EEG tracing showed generalized polyspikes during sleep without associated hypsarrhythmia. We diagnosed him with ESWoH and treated him with ACTH. His ES disappeared soon after the initiation of treatment. These two cases demonstrate the difficulty of treating ESWoH only with standard anti-epileptic drugs, we emphasize the importance of early treatment with ACTH.

[Effective cyclophosphamide pulse therapy for an young infant with severe dermatomyositis]

We herein report a 3 year-old boy, who showed proximal muscle weakness and pain at the age of one and a-half years. When he visited our hospital at the age of 1 year and 11 months, he could hardly move by himself. He also had difficulty in swallowing and suffered from multiple dermal ulcers. His blood test showed slightly elevated muscle enzyme activity, and magnetic resonance imaging suggested severe inflammation of the muscles. Radiological examination proved hypoperistalsis of the esophagus. With additional skin and muscle biopsies, we diagnosed him with juvenile dermatomyositis (JDM). Methyl-prednisolone pulse therapy was not effective enough, thus oral methotrexate, cyclosporine A and monthly cyclophosphamide pulse therapy were added. After the fourth cyclophosphamide pulse therapy, his muscular strength was restored, and the ulcers healed dramatically. Due to scarcity of severe cases, neither standardized classification nor grading system for severity in JDM has ever been established, which perplexes physicians in finding the best therapeutic strategy. Further investigation, experience and efforts are necessary to standardize an evaluating system and therapeutic strategy against JDM.

[The ketogenic diet as an effective treatment for Ohtahara syndrome]

We here report on a male infant with Ohtahara syndrome. Tonic spasms in series appeared in an one-month-old baby, with his EEG showing a typical suppression burst pattern. We attempted these therapies in the following order; high-dose pyridoxal phosphate; anti-epileptic drugs; sodium valproate, phenobarbital, clonazepam and clobazam in various doses and combination; ACTH; TRH; and gamma-globulin. These did not, however, prove effective enough. Then we tried the ketogenic diet and brought his seizures under control. Therefore, we recommend that doctors who treat Ohtahara syndrome consider using the ketogenic diet earlier in the treatment regimen if the patient does not seem to be responding to conventional drug therapies.

Down-regulated genes in mouse dental papillae and pulp

Important factors involved in odontogenesis in mouse dental papillae disappear between the pre- and post-natal stages of development. Therefore, we hypothesized that certain genes involved in odontogenesis in dental papillae were subject to pre-/post-natal down-regulation. Our goal was to identify, by microarray analysis, which genes were down-regulated. Dental papillae were isolated from embryonic 16-day-, 18-day- (E16, E18), and post-natal 3-day-old (P3) murine first mandibular molar germs and analyzed by microarray. The number of down-regulated genes was 2269 between E16 and E18, and 3130 between E18 and P3. Drastic down-regulation (fold change > 10.0) of Adamts4, Aldha1a2, and Lef1 was observed at both E16 and E18, and quantitative RT-PCR revealed a post-natal reduction in their expression (Adamts4, 1/3; Aldh1a2, 1/13; and Lef1, 1/37). These results suggest that down-regulation of these three genes is an important factor in normal odontogenesis in dental papillae.

Expression and function of laminin and integrins on adhesion/migration of primary culture cells derived from rat oral epithelium

BACKGROUND AND OBJECTIVE

It remains controversial whether or not the junctional epithelium cells that are directly attached to teeth migrate on the enamel surface, as those cells are able to adhere firmly to the enamel. The aim of this study was to investigate the expression patterns of laminin gamma(2), integrin beta(4) and integrin alpha(3), and to examine their potential function in cell migration.

MATERIAL AND METHODS

Oral epithelium cells obtained from Sprague-Dawley rats were established in primary culture. We employed a wound-healing assay to characterize the direction of cell extension at the start of cell migration, and observed different localizations of laminin and integrins using immunofluorescence. For functional analyses of integrins, we employed a phosphatidylinositol-3-kinase (PI3K) activator to promote integrin beta(4) function and used P1B5 to inhibit integrin alpha(3) function, and we analyzed the percentage of re-epithelialization as the migration function.

RESULTS

Marked accumulation of laminin gamma(2) was detected in the peripheral cytoplasm of cells adjacent to the wound area, as shown by the results of the migration assay. Integrin beta(4) was detected in the distal cell processes of actively migrating cells, while integrin alpha(3) was found in cell membranes of cells adjacent to the wound area. In the functional analyses, the percentage of re-epithelialization was significantly lower in the PI3K-activator group and in the P1B5-treated group (2.5% and 7.2%, respectively) than in the control group (39.0%) (p < 0.01).

CONCLUSION

The results suggest that laminin gamma(2) is secreted as a foothold for cell migration, that integrin beta(4) participates in cell adhesion and that integrin alpha(3) is involved in cell migration in the primary culture cells.

Blood levels of catecholamine metabolites and brain-derived neurotrophic factor in a case of Sydenham's chorea

We report a case of Sydenham's chorea with neuropsychiatric symptoms who was successfully treated with low-dose risperidone. We also longitudinally investigated serum BDNF levels and plasma levels of catecholamine metabolite in the patient. Serum BDNF levels were increased and plasma levels of HVA and MHPG were decreased according to the recovery from the active phase of the disease. These results suggest that dysfunctions of catecholaminergic neurons and neurotrophic factors might exist in Sydenham's chorea, and the decreasing catecholamine activities in response to risperidone might be associated with the improvement of the disease.

Effect of the dental adhesive, 4-META/MMA-TBB resin, on adhesion and keratinization of regenerating oral epithelium

BACKGROUND AND OBJECTIVE

The 4-META/MMA-TBB [4-(2-methacryloxyethyl)trimellitic anhydride/methyl methacrylate-tributylborane] resin is widely used as a dental adhesive. It has also been applied in the dressing of gingival wound surfaces following periodontal surgery. However, its effect on the regeneration and/or cell attachment of the oral epithelium remains to be clarified. To evaluate the effect of the resin applied as a wound dressing, we investigated expression of laminin 5, integrin beta(4) and cytokeratin 14 in regenerating oral epithelium treated with this resin following gingivectomy from the viewpoint of cell attachment and differentiation.

MATERIAL AND METHODS

The resin was applied to the entire wound surface in rats after gingival surgery, and regenerating epithelium was examined immediately and at 1, 3, 5, 7 and 14 days later. The resin was removed 2 weeks after application in some animals and tissue further examined at 1, 3, 5 and 7 days later.

RESULTS

Regenerating epithelium under the resin was not keratinized, but became keratinized immediately after removal of the resin. Laminin 5 and integrin beta(4) were immunolocalized in the basal lamina, the internal basal lamina, in marginal cells of the regenerating epithelium and at the resin-regenerating epithelium interface. Cytokeratin 14 localized in the regenerating epithelium underneath the resin, as well as in healthy and regenerated junctional epithelial cells.

CONCLUSION

These results suggest that this resin covers the wound surface and that the regenerating epithelium biologically adheres to the resin during the initial process of its regeneration.

Immunolocalization of laminin and integrin in regenerating junctional epithelium of mice after gingivectomy

BACKGROUND AND OBJECTIVE

The expression patterns of adhesive proteins and extracellular matrix proteins in regenerating gingival epithelium after gingivectomy are unknown. The aim of this study was to examine the expression of laminin 1, laminin gamma(2) (a specific component of laminin 5), integrin beta(4) and integrin alpha(3) in the regenerating gingival epithelium in order to understand the mechanism of wound healing during reconstitution of the sulcular environment.

MATERIAL AND METHODS

The palatal gingivae of the maxillary molars of Institute of Cancer Research mice were excised, and the regenerating tissues were examined 1, 3, 5, 7 and 14 days later. Fresh, non-fixed and non-decalcified frozen sections were prepared and stained using immunofluorescence.

RESULTS

At 1 day post-surgery, intense expression of laminin gamma(2), integrin beta(4) and integrin alpha(3) was distinct in the frontal margin of the regenerating oral epithelium. Laminin gamma(2) was diffusely detected on the root surface and in connective tissues beneath the regenerating oral epithelium at 3 and 5 days. At 7 days, laminin gamma(2) was intermittently recognizable in the internal basal lamina (IBL) close to tooth-facing cells, while laminin gamma(2), integrin beta(4) and integrin alpha(3) were observed in the IBL and in the external basal lamina (EBL) of the regenerating junctional epithelium at 14 days.

CONCLUSION

These results suggest that secretion of laminin 5 in the connective tissue may induce epithelial cell migration, and that binding of laminin 5 to integrin alpha(6)beta(4) and integrin alpha(3)beta(1) in the IBL may provoke cell adhesion and migration of cells facing the tooth on the enamel surface of the regenerating junctional epithelium.