Masatoshi Kawai

Cerebral oxygenation responses during kangaroo care in low birth weight infants.

BackgroundKangaroo care (KC) has been widely using to improve the care of low birth weight infants. However, very little is known about cerebral hemodynamics responses in low birth weight infants during KC intervention. The objective of this study was to elucidate the response of cerebral hemodynamics during KC in low birth weight infants.MethodsNear infrared spectroscopy measured regional cerebral oxygenation (rSO2), heart rate (HR), respiration rate (RR) measured by electrocardiogram, and percentages of oxygen saturation (SpO2) measured by pulse oxymetry was monitored in 16 preterm infants (< 1600 g) in three sessions: before, during, and after KC. Using power spectral analysis, total power (TP), low-frequency (LF, 0.02–0.20 Hz) and high-frequency (HF, 0.20–0.50 Hz) bands, the ratio of LF/HF were calculated and normalized as %LF or %HF = LF or HF/TP × 100 (%).ResultsSignificant differences were not observed in the mean rSO2, HR, and SpO2 throughout sessions; however, the TP of these parameters was significantly decreased during KC and increased after KC (p < 0.001). The %LF of LrSO2 and RrSO2 was decreased during KC (p < 0.05) with decreased %HF in RrSO2 (p < 0.05). The %LF of HR was significantly increased during KC while %HF was decreased (p < 0.05). Mean and TP of RR was increased during KC (p < 0.01 respectively) with the increase of quiet sleep state (p < 0.05) and decreased after KC (p < 0.01). The %LF of RR was increased after KC (p < 0.05) with decreased %HF (p < 0.05); however, significant changes were not observed during KC.ConclusionKC intervention appears to have influence on cerebral hemodynamics as well as cardiorespiratory parameters. The results of rSO2 and HR might be associated with quiet sleep states. The results of this study may indicate the contribution of KC intervention to the activation of central nervous system and brain function. Further study is needed to determine the underlying physiology responsible for these differences.

Contribution of Parenting Factors to the Developmental Attainment of 9-Month-Old Infants: Results From the Japan Children's Study

Background Child development integrates several interdependent domains, but few studies have attempted to identify the common factors that contribute to these different domains of development in infancy. The aim of the present study was to identify the factors that contribute to several domains of developmental attainment in 9-month-old infants. Methods We used data from the Japan Children’s Study, a prospective cohort study underway in Japan since 2005. Mothers completed questionnaires about their children’s temperament, coparenting behaviors, maternal parenting stress, and parenting behavior. The Kinder infant development scale was used to evaluate child development outcomes. Results A total of 270 children were included in this analysis. After adjusting for the children’s birth weight, gestational age, temperament, and other family environmental variables, multiple logistic regression analyses showed that greater maternal cognitive stimulation was associated with the development of receptive language, expressive language, social relationships, and feeding. Results also suggest that early supportive coparenting helped to promote development in manipulation, receptive language, and social relationships. Maternal parenting stress was stable between the infant ages of 4 and 9 months and was negatively correlated with scores for coparenting and maternal stimulation, which suggests an indirect effect of maternal parenting stress on child outcomes. Conclusions Supportive coparenting and maternal cognitive stimulation were the most important contributors to most domains of child development. Our findings suggest that educational interventions targeting young families would help parents establish and maintain an environment of successful coparenting and cognitive stimulation as their children grow.

Emergence of physiological rhythmicity in term and preterm neonates in a neonatal intensive care unit

Background Biological rhythmicity, particularly circadian rhythmicity, is considered to be a key mechanism in the maintenance of physiological function. Very little is known, however, about biological rhythmicity pattern in preterm and term neonates in neonatal intensive care units (NICU). In this study, we investigated whether term and preterm neonates admitted to NICU exhibit biological rhythmicity during the neonatal period. Methods Twenty-four-hour continuous recording of four physiological variables (heart rate: HR recorded by electrocardiogram; pulse rate: PR recorded by pulse oxymetry; respiratory rate: RR; and oxygen saturation of pulse oxymetry: SpO2) was conducted on 187 neonates in NICU during 0–21 days of postnatal age (PNA). Rhythmicity was analyzed by spectral analysis (SPSS procedure Spectra). The Fisher test was performed to test the statistical significance of the cycles. The cycle with the largest peak of the periodogram intensities was determined as dominant cycle and confirmed by Fourier analysis. The amplitudes and amplitude indexes for each dominant cycle were calculated. Results Circadian cycles were observed among 23.8% neonates in HR, 20% in PR, 27.8% in RR and 16% in SpO2 in 0–3 days of PNA. Percentages of circadian cycles were the highest (40%) at <28 wks of gestational age (GA), decreasing with GA, and the lowest (14.3%) at >= 37 wks GA within 3 days of PNA in PR and were decreased in the later PNA. An increase of the amplitude with GA was observed in PR, and significant group differences were present in all periods. Amplitudes and amplitude indexes were positively correlated with postconceptional age (PCA) in PR (p < 0.001). Among clinical parameters, oxygen administration showed significant association (p < 0.05) with circadian rhythms of PR in the first 3 days of life. Conclusion Whereas circadian rhythmicity in neonates may result from maternal influence, the increase of amplitude indexes in PR with PCA may be related to physiological maturity. Further studies are needed to elucidate the effect of oxygenation on physiological rhythmicity in neonates.

Cord blood CD4(+)CD25(+) regulatory T cells fail to inhibit cord blood NK cell functions due to insufficient production and expression of TGF-beta1.

Although CD4(+)CD25(+) Treg (Treg) cells are known to modulate NK cell functions, the modulation mechanism of these cells in cord blood has not been fully clarified. The purpose of this study was to clarify the mechanism whereby cord blood Treg cells modulate cord NK cells. By performing various cultures of purified NK cells with or without autologous Treg cells, diminished inhibitory effects of cord Treg cells towards cord NK cell functions, including activation, cytokine production, and cytotoxicity, were observed. We also observed lower secretion of sTGF-beta1 and lower expression of mTGF-beta1 by cord Treg cells than by adult Treg cells. These data revealed the capability of adult Treg cells to suppress rhIL-2-stimulated NK cell function by TGF-beta1, both membrane-bound and soluble types. The reduced inhibitory capabilities of cord Treg cells compared with adult Treg cells is thought to be due to insufficient expression of TGF-beta1.

Developmental trends in mother-infant interaction from 4-months to 42-months: using an observation technique.

Background It is clear that early social interaction follows from mother-infant interaction after pregnancy. Many researchers have illuminated this interaction in the first years of life. Most common mother-infant interaction is the attachment behavior of an infant. The Japan Children’s Study (JCS) development psychology group hypothesis is that the early mother-infant interaction will predict later social behaviors. But the method applied to evaluate this interaction mainly comes from the evaluation of the whole observation situation and is dependent upon the coder. We applied a new observational method that checked the on/off status of behavior and recorded sequentially. Methods Using a semi-structured observation setting as our method, we analyzed the developmental change of mother-infant interaction within a toy situation. Results The result indicated that mother-infant interaction with a toy altered at around 9-months and is salient to the usual developmental change of joint attention. Additionally cluster analysis suggested that the developmental pattern is divided into two clusters. This is the first report on a developmental pattern of joint attention. Conclusions These results indicated that the developmental trend of gaze direction and vocalization is one candidate of measure for evaluating the mother infant social interaction from the point of joint attention.

Mission in Sukusuku Cohort, Mie: Focusing on the Feasibility and Validity of Methods for Enrolling and Retaining Participants

Background We investigated the feasibility and validity of and systematized the methods used to enroll and retain participants requiring long-term interdisciplinary collaborations. We carried out this study in the Sukusuku cohort, Mie (SCM), as one of the regional research site of Japan Children’s Study (JCS). Methods A total of 467 families who were screened between December 1, 2004 and December 31, 2005, in the Mie-chuo Medical Center and 2 other hospitals; these families were deemed eligible for the study. Of these, a total of 185 families (39.6%) participated in the 4-month observation. Of these families, 5 dropped out at month 9 of the observation; 9, at month 18; 17, at month 30; and 5, at month 42. The retention rates at 9, 18, 30, and 42 months of observation were 97.3%, 92.4%, 83.2%, and 80.5%, respectively. Reinstatement to a previous job was the most common reason for dropouts. Results We observed that informative consultation notes during observation were beneficial for the retention of participants, and these notes also helped in improving communication between the study subjects and the evaluators during subsequent visits. Conclusions In this study, we did not perform the standard checks for child development alone but also investigated the motivating influence of research partnerships with participants. Further, these visits help maintain the motivation levels of the participants and encourage them to contribute for social causes. The results present integration models that can be applied in future relevant longitudinal cohort studies in Japan.

Infant Responses to Maternal Still Face at 9 Months Predict Social Abilities at 18 Months

Background This study investigated developmental change and stability in infant responses to the still-face (SF) situation, as well as predictive validity at age 18 months, focusing on autonomy and responsiveness. Methods A total of 231 children (117 boys and 114 girls) and their Japanese mothers were observed in a face-to-face SF situation at two infant ages (4 and 9 months), as well as a caregiver-child teaching interaction at age 18 months. Each infant’s facial expression, gaze direction, and vocalization were coded according to the SF paradigm, including the Natural Interaction (NI) and SF phases. Each child’s Autonomy and Responsiveness to the Caregiver at age 18 months were both evaluated by means of the Interaction Rating Scale. Results The results indicated that negative facial expression and vocalization in the SF phases at age 9 months predicted the Autonomy rating at age 18 months, while positive facial expression and gaze toward the caregiver in the NI at age 9 months predicted the Responsiveness to Caregiver rating at age 18 months. Conclusions The results are discussed in the context of developmental continuity and change in the children’s social cognition and voluntary movements.

Behavioral characteristics of children with high functioning pervasive developmental disorders during a game.

Background To evaluate children’s sociability through their behavior, we compared the motion features of children with high functioning pervasive developmental disorders (HFPDD) and typical development (TD) during a game. We selected ‘Jenga’ as the game because this is an interactive game played by two people. Methods We observed the behavior of 7 children with HFPDD and 10 children with TD. An optical motion capture system was used to follow the movement of 3-dimensional position markers attached to caps worn by the players. Results The range of head motion of the children with HFPDD was narrower than that of the control group, especially in the X-axis direction (perpendicular to the line connecting the two players). In each game, we calculated the range of motion in the X-axis of each child and divided that figure by the matched adult player’s range. The average ratios of children with HFPDD and TD were 0.64 and 0.89 (number of games are 61 and 18), and the difference of these two ratios is significant (P < 0.001). Conclusions This ratio has sensitivity to identify HFPDD children and could be useful in their child care.

Mission in Sukusuku cohort, Mie: a study focusing on the characteristics of participants and the mental health of the mothers raising children

Background We carried out Sukusuku cohort, Mie (SCM), a long term cohort study of child development and investigated the feasibility and validity of this study. Then we focused on the characteristics of the enrolled families and verified the representativeness of the participants in SCM. Methods The characteristics of 185 families recruited from 3 hospitals were analyzed, and we verified the representativeness of these subjects. We also analyzed the factors that may influence the mental health of the mothers who are raising children. Results There were no significant differences between the subjects from the 3 hospitals in terms of the age distribution, academic background, occupation, and annual income of the participating families. At 42 months, the average developmental quotients for postural and motor, cognitive and adaptive, and speech and social development in the 140 infants were 98.6, 100.6, and 99.9, respectively. The overall developmental quotient for infants was 100.3 ± 13.2; this score was within the standard range (55–132). The path-analysis model revealed that family function was an important factor influencing the mental health of mothers. Conclusions The participant characteristics were thought to be generally representative, and we showed the validity and representativeness of the participants in this cohort study. The mental health analysis of mothers suggested that relieving mothers from child-rearing stress and maintaining family function were important for the maintenance and improvement of maternal mental health.

CEREBRAL OXYGENATION RESPONSES DURING SKIN-TO-SKIN CARE IN LOW BIRTH WEIGHT INFANTS

INTRODUCTION: Kangaroo care (KC) has been thought of as an important intervention for improving the care of low birth weight infants; however, the physiological effect of KC is still controversial. OBJECTIVE: The aim of this study was to investigate physiological responses during KC. METHODS: Sixteen low birth weight (<1600 g) infants with gestational ages of 24 to 32 weeks were studied. Heart rate (HR), respiration rate, pulse oxygen saturation (SPo2), and regional cerebral oxygenation (rSo2) were obtained in 3 periods continuously: before, during, and after KC. Spectral analysis was performed. Total amplitude, the power of low-frequency (LF; 0.06–0.10 Hz) band, high-frequency (HF, 0.15–0.40 Hz) band, and the ratio of LF/HF were calculated. Three groups were compared by analysis of variance. RESULTS: Significant differences were not observed during KC in terms of mean HR, SPo2, and rSo2. By amplitude, these parameters were significantly decreased during KC (P < .001) and increased after KC (P < .001). The power of LF or HF was either significantly decreased during KC in HR, SPo2, and rSo2 (P < .05); however, the ratio of LF/HF was increased during KC in HR, whereas the ratio was decreased in rSo2 (P < .05). CONCLUSIONS: These results suggest that KC influences the stability of rSo2 as well as HR and SPo2. Discrete results in the LF/HF ratio of rSo2 may indicate that KC has different effects on rSo2 associated with cerebral function.