Association between low MCV in early pregnancy and perinatal mental health in the Japan Environment and Children's Study and the possible effect of iron deficiency.

BACKGROUND: Postpartum anemia and iron deficiency are associated with postpartum depression. This study investigated the association between a low mean corpuscular volume (MCV) without anemia (which implies early-stage iron deficiency) in early pregnancy and perinatal mental health outcomes. METHODS: The fixed data from the Japan Environment and Children's Study (JECS), a Japanese nationwide birth cohort, were used. Perinatal mental health was assessed using the Kessler 6-item psychological distress scale (K6) in mid-pregnancy and the Edinburgh Postnatal Depression Scale (EPDS) at 1- and 6-months postpartum. RESULTS: Among the 3635 women with MCVs <85 fL in early pregnancy, the proportions of women with K6 scores ≥13 in mid-pregnancy and EPDS scores ≥9 at 1- and 6-months postpartum were 2.7 %, 12.8 %, and 9.9 %, respectively, compared with the 33,242 women with MCVs ≥85 fL at 1.9 %, 11.9 %, and 9.0 %, respectively. Multivariate logistic regression models showed that an MCV <85 in early pregnancy was associated with a K6 score ≥ 13 in mid-pregnancy and an EPDS score ≥ 9 at 1- and 6-months postpartum (adjusted odds ratio (95 % confidence interval): 1.48 (1.16-1.87), 1.14 (1.01-1.28), and 1.09 (0.95-1.24), respectively). LIMITATIONS: Low MCV values do not necessarily represent iron deficiency. Ferritin, currently the best indicator of iron deficiency, was not measured in the JECS. CONCLUSIONS: This study results suggest that a low MCV without anemia in early pregnancy is associated with a slightly increased risk of perinatal mental health deterioration.

The development of the hypothalamus-pituitary-adrenal axis during infancy may be affected by antenatal glucocorticoid therapy.

BACKGROUND: Developmental changes in the hypothalamus-pituitary-adrenal (HPA) axis during infancy have been reported in term infants, but those in preterm infants have yet to be elucidated. If developmental changes in the HPA axis of preterm infants are modulated by any factors, it may affect their future health. Few studies have examined the lasting consequences of antenatal glucocorticoids on the development of the HPA axis. METHODS: We measured pre- and post-palivizumab vaccination salivary cortisol values in two conforming periods of three-months intervals during infancy, and compared cortisol values and the response of cortisol secretion between groups with and without antenatal glucocorticoid (AG) therapy. RESULTS: Although the strength of the response of cortisol secretion to palivizumab fell age-dependently (until late infancy) in the Non-AG group, the opposite pattern was exhibited in the AG group. The changes of the delta cortisol values between the 2 groups were significant. CONCLUSIONS: This study suggests that the HPA axis of preterm infants whose mothers receive AG therapy may be upregulated during infancy, possibly leading to long lasting health problems.

Response to thyrotropin-releasing hormone stimulation tests in preterm infants with transient hypothyroxinemia of prematurity.

OBJECTIVE: Whether hormone supplementation is necessary for infants with transient hypothyroxinemia of prematurity (THOP) remains controversial, and further analysis of the hypothalamus-pituitary-thyroid axis of infants with THOP is necessary. STUDY DESIGN: Thyrotropin-releasing hormone (TRH) stimulation tests were performed at 2 weeks of age in 50 infants with a gestational age of 30 weeks or less, and the data were analyzed retrospectively. RESULT: Subjects were divided into three groups; group A consisted of euthyroid infants, group B consisted of infants with THOP and group C consisted of hypothyroid infants. The basal and peak thyroid-stimulating hormone level of group C in response to TRH stimulation tests was significantly higher than the others, but no differences were observed between groups A and B. CONCLUSION: The response of infants with THOP to the TRH stimulation test was not different from that of euthyroid infants, which suggested that their hypothalamic-pituitary-thyroid axis was appropriately regulated in infants with THOP.

Subcutaneous fat accumulation in early infancy is more strongly associated with motor development and delay than muscle growth.

AIM: Physical growth in neurologically healthy preterm infants affects motor development. This study investigated the separate relationships between muscle and fat in infancy and later motor development and physical growth. METHODS: Muscle thickness and subcutaneous fat thickness of the anterior thigh were measured using ultrasound images obtained from neurologically healthy preterm infants at birth, 3, 6, 12 and 18 months' corrected age. We also obtained the Pediatric Evaluation of Disability Inventory and Alberta Infant Motor Scale scores at 18 months' corrected age to assess motor ability and motor delay. RESULTS: Thirty preterm infants completed the study protocol. There was a significant positive correlation between motor ability and increments in subcutaneous fat thickness during the first 3 and 6 months' corrected age (r = 0.48 and 0.40, p < 0.05, respectively), but not between motor ability and muscle thickness growth in any of the periods. A secondary, logistic regression analysis showed that increments in subcutaneous fat thickness during the first 3 months were a protective factor for motor delay. CONCLUSION: Subcutaneous fat accumulation in early infancy is more strongly associated with motor development and delay than muscle growth.

Mitochondrial malate dehydrogenase of bovine cerebrum. Characterization and mechanisms of inhibition by silver ions.

Attempts were made to characterize mitochondrial malate dehydrogenase [L-malate: NAD+ oxidoreductase, EC 1.1.1.37] (M-MDH) purified from bovine cerebrum and to elucidate the mechanisms responsible for inhibition of the enzymic activity by Ag+. The molecular weights of the native enzyme and its subunits were 54,000-55,000 and 30,000-32,000, respectively. In general, the physiochemical and catalytic properties of bovine cerebral M-MDH was not very different from those of other corresponding mammalian enzymes. Incubation of the enzyme with Ag+ caused the loss of equivalent amounts of sulfhydryls with a parallel decrease of the enzymic activity. When the enzyme was exposed to 2-, 3.5-, and 5-fold molar excesses of Ag+, the enzymic activity showed an initial rapid fall and a subsequent slow restoration to a partially inactivated level (60-70, 45-50, and 15-20% of an untreated control, respectively), while the alpha-helical content of the enzyme fell exponentially with time. A 7-fold molar excess of Ag+ reduced both the enzymic activity and the alpha-helical content to a much greater degree and no restoration of the enzymic activity was observed. The Km values of Ag+-inactivated enzyme for NADH and oxaloacetate were the same as those of the native enzyme. The data suggest that Ag+ could inhibit enzymic activity both by reducing the structural regularity of the enzyme molecule and by attacking sulfhydryl groups necessary for the catalytic activity of bovine cerebral M-MDH.