Hiroyuki Ichiba

Trophic effect of multiple growth factors in amniotic fluid or human milk on cultured human fetal small intestinal cells

Objectives To evaluate the role of growth factors in amniotic fluid and in human milk on gastrointestinal adaptation of the fetus and very low-birth-weight infants, the effects of these fluids and multiple growth factors were investigated in a human fetal small intestinal cell line (FHs 74 Int). Methods After FHs 74 Int cells were incubated with amniotic fluid, human milk, or recombinant growth factors, growth-promoting activity was measured by [3H]-thymidine incorporation into cells. Results Incubating cells with amniotic fluid or human milk promoted growth dose dependently. Genistein almost completely inhibited growth-promoting activity in amniotic fluid P = 0.002), and growth was partially inhibited by antibodies against epidermal growth factor (EGF) (P = 0.047), insulin-like growth factor-1 (IGF-1, P = 0.047), or fibroblast growth factor (FGF, P = 0.014). This activity in human milk was inhibited almost completely by genistein (P h 0.0001) and partially inhibited by antibodies against EGF (P = 0.036), IGF-1 (P = 0.009), FGF (P = 0.004), hepatocyte growth factor (HGF, P = 0.001), or transforming growth factor-&agr; (TGF-&agr;, P = 0.001). Although recombinant EGF, IGF-1, FGF, HGF, and TGF-&agr; elicited a synergistic trophic response on cultured cells, the response was much less than with amniotic fluid or with human milk. Conclusion In aminiotic fluid and in human milk, EGF, IGF-1, FGF, HGF, and TGF-&agr; have a strong trophic effect on immature intestinal cells and may be involved in perinatal gastrointestinal adaptation.

Randomized controlled trial of magnesium sulfate infusion for severe birth asphyxia

Objective : To determine whether postnatal MgSO4 infusion (250 mg/kg per day) for 3 days is both safe and able to improve outcome in infants with severe birth asphyxia, as had been suggested by a small pilot study.

Aristaless -related homeobox gene disruption leads to abnormal distribution of GABAergic interneurons in human neocortex: evidence based on a case of X-linked lissencephaly with abnormal genitalia (XLAG)

X-linked lissencephaly with abnormal genitalia (XLAG) is a rare disorder caused by mutations in the aristaless-related homeobox (ARX) gene, located on Xp22.13. Arx-null mice show loss of tangential migration of GABAergic interneurons, presumably being related to caudal ganglionic eminence tangential migration. In the present study, we investigated a subpopulation of GABAergic interneurons in the brain of an infant with XLAG, who had a novel nonsense mutation of the ARX gene, compared with those of age-matched normal controls and Miller–Dieker syndrome. We performed immunocytochemistry for interneuron and migration markers. We found that glutamic acid decarboxylase (GAD)- and calretinin (CR)-containing cells were significantly reduced in the neocortex and located in the white matter and neocortical subventricular zone, while neuropeptide Y- or cholecystokinin-containing cells were normally distributed. Moreover, in the neocortical subventricular region, the GAD- and CR-containing cells expressed the radial migration marker Mash-1 as well as nestin. Our findings suggest that ARX protein controls not only the tangential migration of GABAergic interneurons from the ganglionic eminence, but also may serve to induce radial migration from the neocortical subventricular zone.

Measurement of Growth Promoting Activity in Human Milk Using a Fetal Small Intestinal Cell Line

To evaluate the effect of the growth promoting activity in human milk on intestinal cells, a bioassay method was established using a fetal intestinal cell line (FHS 74 Int, ATCC CCL 241), since the developing intestine is considered to be a target organ for the growth factors present in human milk. Human milk had a growth promoting activity on the cultured human fetal intestinal cells. The activity level was very high in colostrum and decreased gradually during lactation, while formula products had no activity. The epidermal growth factor (EGF) concentration in human milk was significantly correlated with the growth promoting activity measured by bioassay. Thus, EGF may be the main growth factor for the proliferation of intestinal cells. These results suggest that human milk may stimulate the proliferation of intestinal cells in newborn infants, especially in very-low-birth-weight infants, and accelerate the maturation of the intestinal portion of the digestive system.

Neurodevelopmental outcome of infants with birth asphyxia treated with magnesium sulfate

Background: A neuroprotective effect of MgSO4 has been shown in some animal models of perinatal hypoxic–ischemic brain damage. The aim of the present paper was to determine whether postnatal MgSO4 infusion (250 mg/kg per day i.v. for 3 days, in combination with dopamine) is safe in infants with severe birth asphyxia, and also observe effects on neurodevelopmental outcome at 18 months.

Connatal tuberculosis in an extremely low birth weight infant: case report and management of exposure to tuberculosis in a neonatal intensive care unit.

Abstract A case of connatal tuberculosis in an extremely low birth weight infant is reported. The patient was a female with a birth weight of 973 g born in the 27th week of pregnancy. She developed respiratory distress and signs of infection immediately after birth, which did not respond to mechanical ventilation, antibiotics, and corticosteroid therapy. Connatal tuberculosis was confirmed at 48 days of age by isolation of Mycobacterium tuberculosis from the infants tracheal aspirate and the mothers menstrual discharge. The infant died of respiratory failure at 90 days of age. Mantoux tuberculin skin tests (TST) were performed on 99 infants, 144 medical staff members, and two family members. TST conversion occurred in three medical staff members, and preventive therapy with isoniazid was initiated. Eight exposed infants had normal chest X-rays and negative gastric aspirates for acid-fast bacilli and all received preventive isoniazid therapy. No case of tuberculosis developed during the 2-year follow-up period. Conclusion Connatal tuberculosis should be considered in neonatal respiratory infection resistant to antibiotics. Prevention of transmission of tuberculosis on the neonatal intensive care unit by chemoprophylaxis is important.

Three‐year follow up of term and near‐term infants treated with inhaled nitric oxide

Abstract Background : The present study describes the outcome at 3 years in term and near‐term infants treated with inhaled nitric oxide (iNO) for persistent pulmonary hypertension of the newborn (PPHN).

Bone mineral density of the lumbar spine in very-low-birth-weight infants : a longitudinal study

Abstract To examine osteopenia in very low birth weight (VLBW) infants we used repeated dual-energy X-ray absorptiometry in a prospective study of lumbar spinal bone mineral density (BMD) in Japanese VLBW infants (birthweight 426–1498 g; n = 61, group 1) aged 40 weeks postconception to 3 years of age. Control subjects were Japanese infants with birthweight 1500–1999 g (group 2), 2000–2499 g (group 3), or more than 2500 g (group 4). BMD in group 1 during the early period after birth was very low, increased rapidly for 1 year, and then gradually increased until 3 years of age (r =  0.931, P < 0.0001). BMD at the age of 40 weeks postconception was 0.085 ± 0.026, 0.132 ± 0.039, 0.178 ± 0.042, and 0.196 ± 0.046 g/cm2 in groups 1, 2, 3, and 4, respectively (P < 0.0001). However, at 1 and 2 years of age no differences were observed among the groups in BMD. Conclusion This study shows that lumbar spinal BMD in VLBW infants can normalize by the age of 2 years.

Amniotic Fluid Transforming Growth Factor-β1 and the Risk for the Development of Neonatal Bronchopulmonary Dysplasia

Chorioamnionitis (CAM) can initiate fetal lung injury resulting in neonatal bronchopulmonary dysplasia (BPD). While neonates with BPD have higher amniotic fluid concentrations of proinflammatory cytokines, overexpression of transforming growth factor (TGF)-β1 also appears important in the pathogenesis of BPD. The aim of this study was to investigate the relationship between TGF-β1 and CAM-induced fetal lung injury. Forty-four amniotic fluid samples were obtained at delivery of preterm infants (median gestation, 28 weeks; birth weight, 908 g). TGF-β1 and interleukin (IL)-6 concentrations in the amniotic fluid were measured with ELISA. Both TGF-β1 and IL-6 concentrations in the amniotic fluid increased with increasing histological severity of CAM (each p < 0.0001). The presence of both BPD and histological CAM was associated with significantly higher amniotic fluid TGF-β1 and IL-6 concentrations than the presence of BPD without histological CAM, or the absence of both (each p < 0.0001). Both concentrations also correlated with the duration of oxygen administration in the neonates (each p < 0.0001). Amniotic fluid TGF-β1 seems to be important in CAM-induced fetal lung injury progressing to neonatal BPD.

Mitogenic activity of tracheal effluents from premature infants with chronic lung disease

Lung injury alters the expression and release of growth factors that disrupt postnatal pulmonary development in newborns and causes chronic lung disease (CLD). The effect of these factors, released into the airways of newborns with CLD, on cell proliferation and collagen production was characterized in vitro. Human fetal lung fibroblast and alveolar-epithelial-like cell lines (FHs 738Lu and A549, respectively) were exposed to tracheal effluents from infants with CLD (mean gestation, 24.7 ± 0.9 wk; birth weight, 666 ± 85 g; postnatal age, 0 – 62 d). In both cell types, proliferation was assessed by measuring [3H]-thymidine uptake; in fibroblasts, collagen production was analyzed by measuring [3H]-proline incorporation. The activity of specific growth factors in effluents was determined using anti-growth factor antibodies and the growth factors themselves. Growth factors in tracheal effluents promoted proliferation in a dose-dependent manner and caused up to a 10.2- and 3.1-fold increase in thymidine uptake by fibroblasts and epithelial cells, respectively. Collagen production by fibroblasts increased dose dependently, peaking at 177% of baseline. Antibody against transforming growth factor beta-1 (TGF-β1) inhibited proliferation and the increase in collagen production by 31% (p = 0.01) and 14% (p = 0.045), respectively. Antibody against hepatocyte growth factor (HGF) inhibited proliferation of epithelial cells (25%, p = 0.039). The effects of exogenous TGF-β1 on fibroblasts and HGF on epithelial cells resembled those of tracheal effluents. Potent mitogenic and differentiating substances are released into the tracheal effluents of newborns with CLD. TGF-β1 may worsen CLD by inducing fibrosis whereas HGF may favor resolution by promoting epithelialization.